<PAGE>   1

                                                                   EXHIBIT 10.22


                               LICENSE AGREEMENT


THIS LICENSE AGREEMENT (together with the attached Exhibits, the ("Agreement")
is made as of July 8 (the "Effective Date") by and between Genetics Institute,
Inc., a Delaware corporation with a business address at 87 Cambridge Park Drive,
Cambridge, Massachusetts 02140 ("GI") and Xcyte Therapies, Inc., a Delaware
corporation with a business address at 2203 Airport Way South, Suite 300,
Seattle, Washington 98134 ("Xcyte").

1.      BACKGROUND.

        1.1     GI. GI has acquired and/or licensed the rights to certain
                patents, as set forth in Exhibit D to this Agreement (the
                "Patents"), pursuant to agreements between GI and third parties
                (defined below as the "Licensors").

        1.2     XCYTE. Xcyte desires to license and/or sublicense the Patents
                from GI, to make, use and sell Products (defined below) in the
                Field (defined below). GI is Willing, for the consideration and
                on the terms set forth herein, to license and/or sublicense the
                Patents to Xcyte for such purposes.

        1.3     AGREEMENT. In consideration of the mutual covenants and promises
                contained in this Agreement and other good and valuable
                consideration, the Parties agree as follows:

2.      DEFINITIONS. As used in this Agreement, the following terms shall have
        the meanings set forth below.

        2.1     "AFFILIATE" means any corporation, company, partnership, joint
                venture and/or firm which controls, is controlled by or is under
                common control with a Party. For purposes of this Section 2.1,
                "control" means (a) in the case of corporate entities, direct or
                indirect ownership of at least fifty percent (50%) of the stock
                or shares entitled to vote for the election of directors; and
                (b) in the case of non-corporate entities, direct or indirect
                ownership of at least fifty percent (50%) of the equity interest
                with the power to direct the management and policies of such
                noncorporate entities.

        2.2     "COMBINATION PRODUCT" means any Product sold in combination with
                one or more other products which are not Products.



        2.3     "CONFIDENTIAL INFORMATION" shall mean(i) any proprietary or
                confidential information or material in tangible form disclosed
                hereunder that is marked as "Confidential" at the time it is
                delivered to the receiving party, or (ii) proprietary or
                confidential information disclosed orally hereunder which is
                identified as confidential or proprietary when disclosed and
                such disclosure of confidential information is confirmed in
                writing within thirty (30) days by the disclosing party.


*Certain information on this page has been omitted and filed
 separately with the Commission. Confidential treatment has
 been requested with respect to the omitted portions.
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                "Confidential Information" does not include information which
                (a) was known to the receiving Party at the time it was
                disclosed, other than by previous disclosure by the disclosing
                Party, as evidenced by written records at the time of
                disclosure; (b) is at the time of disclosure or later becomes
                publicly known under circumstances involving no breach of this
                Agreement; (c) is lawfully and in good faith made available to
                the receiving Party by a third party who did not derive it from
                the disclosing Party and who imposes no obligation of confidence
                on the receiving Party; or (d) is developed by the receiving
                Party independent of any disclosure by the disclosing Party.

        2.4     "DISTRIBUTOR" means a third party which is not a Xcyte Affiliate
                or Sublicensee and which is a distributor, wholesaler or other
                entity purchasing Products from Xcyte or its Affiliate or
                Sublicensee for resale.

        2.5     "FIELD" means ex vivo activation or expansion of human T-cells
                (including T-cells modified through gene transfer (except as
                indicated below) or otherwise) for treatment and/or prevention
                of infectious diseases (including, without limitation, AIDS),
                cancer and immunodeficiency states. [*]

        2.6     "IMPROVEMENTS" means any invention or discovery whether or not
                patentable which is used commercially by Xcyte during the term
                of this Agreement and which directly relates to the methods of
                preparing T-cells claimed in the Patents, and is within the
                scope thereof. It is understood and agreed that any ligand
                (including, without limitation, any antibody or antibody
                derivative) identified or used by Xcyte or its designees for the
                practice of the methods claimed in the Patents shall not be an
                Improvement.

        2.7     "LICENSE AGREEMENTS" means the 1995 Acquisition Agreement
                between GI and Repligen Corporation, together with the following
                agreements, pursuant to which GI licensed the Patents which are
                sublicensed to Xcyte under this Agreement:

                (a)     "NAVY AGREEMENT" means the December 10, 1996 License
                        Agreement between GI and the Navy, a copy of which is
                        attached as EXHIBIT A to this Agreement.

                (b)     "MICHIGAN AGREEMENT" means the May 28, 1992 License
                        Agreement between GI and Michigan, a copy of which is
                        attached as EXHIBIT B to this Agreement

                (c)     "DFCI AGREEMENT" means the July 20, 1993 License
                        Agreement between DFCI and Repligen, a copy of which is
                        attached as EXHIBIT C to this Agreement.

        2.8     "LICENSORS" means the United States of America, represented by
                the Secretary of the Navy (the "Navy"), the University of
                Michigan ("Michigan") and the Dana Farber Cancer Institute
                ("DFCI").


*Certain information on this page has been omitted and filed
 separately with the Commission. Confidential treatment has
 been requested with respect to the omitted portions.

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        2.9     "NET SALES" means the aggregate United States dollar equivalent
                of gross revenues derived by or payable to Xcyte, its Affiliates
                and Sublicensees from or on account of the sale or distribution
                of Products (including Combination Products) and Services to
                third parties, less (a) reasonable credits or allowances, if
                any, actually granted on account of price adjustments, rebates,
                discounts, recalls, rejection or return of items previously
                sold, (b) excises, sales taxes, value added taxes, consumption
                taxes, duties or other taxes imposed upon and paid with respect
                to such sales or Services (excluding income or franchise taxes
                of any kind) and (c) separately itemized insurance, packaging
                and transportation costs incurred in shipping Products
                (including Combination Products) to such third parties. No
                deduction shall be made for any item of cost incurred by Xcyte,
                its Affiliates or Sublicensees in preparing, manufacturing,
                shipping or selling Products (including Combination Products)
                except as permitted pursuant to clauses (a), (b) and (c) of the
                foregoing sentence. Net Sales shall not include any transfer
                between Xcyte and any of its Affiliates or Sublicensees for
                resale.

                If Xcyte or an Affiliate or Sublicensee sells Products
                (including Combination Products) to a Distributor, Net Sales
                shall be calculated from the gross revenues received by Xcyte
                and/or its Affiliate or Sublicensee from the sale of Products to
                the Distributor.

                In the event that Xcyte or any of its Affiliates or Sublicensees
                shall make any transfer of Products (including Combination
                Products) to third parties for other than monetary value, such
                transfer shall be considered a sale hereunder for accounting and
                royalty purposes. Net Sales for any such transfers shall be
                determined on a country-by-country basis and shall be the
                average price of "arms length" sales by Xcyte, its Affiliates or
                Sublicensees in such country during the royalty reporting period
                in which such transfer occurs or, if no such "arms length" sales
                occurred in such country during such period, during the last
                period in which such "arms length" sales occurred. If no "arms
                length" sales have occurred in a particular country, Net Sales
                for any such transfer in such country shall be the average price
                of arms length" sales in all countries in the Territory.

                Notwithstanding the foregoing, no transfer of Products
                (including Combination Products) for testing, pre-clinical,
                clinical or developmental purposes or as samples shall be
                considered a sale hereunder.

                In the event a Product or Combination Product is sold to
                end-users together with a Service, in calculating Net Sales the
                payment received by Xcyte for such Service component shall be
                included in Net Sales, subject to Section 5.2(b); provided, any
                payment received by Xcyte for any service which is not a Service
                shall not be included in Net Sales.

        2.10    "PARTY" means GI or Xcyte; "Parties" means GI and Xcyte.




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        2.11    "PATENTS" means the patents and patent applications listed in
                EXHIBIT D attached to this Agreement and shall include any
                foreign counterparts of the patents and patent applications
                listed in EXHIBIT D (which for all purposes of this Agreement
                shall be deemed to include certificates of invention anti
                applications for certificates of invention and priority rights),
                together with any reissues extensions or other governmental acts
                which effectively extend the period of exclusivity by the patent
                holder, substitutions, confirmations, registrations,
                revalidations, additions, continuations, continuations-in-pan,
                or divisions of or to any of the foregoing, to the extent GI
                owns or controls such rights, or has acquired or licensed such
                rights under the License Agreements.

        2.12    "PRODUCT" means any product developed by or on behalf of Xcyte,
                the manufacture, use or sale of which is covered by a Valid
                Claim of the Patents in the country of manufacture, use or sale.

        2.13    "SERVICE" means any service provided by Xcyte in connection with
                a Product in the Field. By way of illustration and without
                limitation, services would include apheresis conducted in
                connection with the use of a Product or services relating to
                cell testing or cell characterization or quality assurance or
                quality control of Products.

        2.14    "SUBLICENSEE" means a third party, including any Xcyte
                Affiliate, to which Xcyte has granted a further sublicense to
                make, use, import, offer for sale and/or sell the Products.

        2.15    "TECHNOLOGY" means the technology described in the Patents
                related to the manufacture, use or sale of the Products in the
                Field.

        2.16    "TERRITORY" means, with respect to each Patent, the area of the
                world in which GI has the rights to practice under such Patent,
                as set forth in applicable License Agreement under which GI
                obtained rights to such Patent.

        2.17    "VALID CLAIM" means (a) a claim of an unexpired patent which
                shall not have been withdrawn, canceled or disclaimed, nor held
                invalid or unenforceable by a court of competent jurisdiction in
                an. unappealed or unappealable decision or (b) a claim of a
                patent application which is either: (i) the subject of a pending
                patent interference proceeding or (ii) supported by the
                disclosure of such application or any prior filed patent
                application for a cumulative period not exceeding seven (7)
                years from the earliest date of such supporting disclosure for
                such claim in any such patent application.

3.      LICENSE FROM GI TO XCYTE.

        3.1     GRANT. Subject to the fulfillment of the terms and conditions of
                this Agreement, including, without limitation, the conditions of
                sublicense set forth in Section 3.4, below, GI grants to Xcyte
                exclusive, royalty-bearing licenses and/or sublicenses





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                under the Patents, restricted to the Field, to make and have
                made, to use, to offer for sale, to sell and have sold, to
                import and have imported, and to export and have exported, the
                Products in the Territory.

        3.2     TERM. The licenses and/or sublicenses granted in Section 3.1,
                above, shall run to the end of the enforceable term of the
                Patents or License Agreements under which such license and/or
                sublicense is granted.

        3.3     FURTHER SUBLICENSES. Xcyte shall have the right to grant further
                sublicenses under the foregoing license and/or sublicense,
                provided the Sublicensees agree to comply with all terms and
                conditions of this Agreement. Notwithstanding any such further
                sublicenses, Xcyte shall remain primarily liable for all of such
                Affiliates' and Sublicensees' duties and obligations contained
                in this Agreement.

        3.4     CONDITIONS OF SUBLICENSE. With respect to the applicable Patents
                or the applicable claim or claims of such Patents, the
                sublicenses granted to Xcyte under this Agreement are subject to
                the following conditions imposed on GI, as licensee, and Xcyte,
                as sublicensee, by the applicable Licensors:

                (a)     APPROVAL OF LICENSORS. Each such sublicense shall be
                        subject to the prior written approval of the applicable
                        Licensor to the extent required by the License
                        Agreements.

                (b)     LICENSORS' RETAINED RIGHTS. Each sublicense is subject
                        to any and all rights retained by the applicable
                        Licensor.

                (c)     CONSISTENT WITH TERMS OF LICENSE AGREEMENTS. Each
                        sublicense is granted pursuant to the terms of the
                        applicable License Agreement. No provision of this
                        Agreement shall be in derogation of or diminish any
                        rights of each Licensor in the applicable License
                        Agreement. Each sublicense under this Agreement may be
                        modified or terminated in whole or in part upon the
                        modification or termination in whole or in part of the
                        applicable License Agreement; provided, GI shall not
                        terminate or enter into any modification of any of the
                        License Agreements if such modification or termination
                        would affect the rights of Xcyte under this Agreement,
                        without the prior written consent of Xcyte, and shall
                        notify Xcyte within ten (10) business days if GI
                        receives any notice from any Licensor that (i) such
                        Licensor believes that GI is in default or breach of the
                        relevant License Agreement, or (ii) such Licensor
                        intends to terminate the relevant License Agreement, or
                        (iii) such Licensor intends to modify GI's rights under
                        the applicable License Agreement (e.g., by converting
                        GI's exclusive rights under such License Agreement to
                        non-exclusive rights). Should any sublicense granted by
                        Xcyte under this Agreement not comply with the
                        requirements of any License Agreement, such sublicense
                        of rights under this Agreement may be void. If either
                        Party becomes aware of any potential inconsistency of a
                        sublicense granted by Xcyte with this





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                        Agreement, it shall promptly notify the other Party,
                        providing a detailed explanation of the potential
                        inconsistency.

                (d)     GI TO FURNISH COPY. Within thirty (30) days of the
                        Effective Date, and within thirty (30) days of any
                        modification of this Agreement, GI may be obligated to
                        furnish to each Licensor a true and complete copy of
                        this Agreement and any modification hereof.

4.      PRODUCT DEVELOPMENT.

        4.1     DILIGENCE OBLIGATIONS. Xcyte shall exercise commercially
                reasonable and diligent efforts, in its scientific and business
                judgement, to develop at least one Product itself or through
                sublicensees. Each year during the term of the Agreement until
                the first commercial sale of a Product, Xcyte, itself or through
                a sublicensee, shall expend no less than five hundred thousand
                dollars ($500,000) annually on research and development
                activities directly relaxing to Product development. During the
                term of this Agreement, within sixty (60) days of each
                anniversary of the Effective Date, Xcyte shall issue to GI a
                progress report detailing Xcyte's progress in developing
                Products.

        4.2     CONVERSION OF LICENSE AND/OR SUBLICENSE. In the event that Xcyte
                fails to satisfy the requirements set forth in Section 4.1,
                above, GI shall have the right, in its sole discretion, upon
                written notice to Xcyte, to convert the licenses and/or
                sublicenses granted to Xcyte under this Agreement from exclusive
                to non-exclusive; provided Xcyte has not cured such failure
                within sixty (60) days following written notice from GI of any
                such failure. In the event that GI converts such licenses and/or
                sublicense to non-exclusive, GI shall be entitled to grant
                additional licenses and/or sublicenses under the Patents to not
                more than two (2) unrelated third parties. If GI exercises its
                conversion right under this Section 4.2, thereafter the royalty
                obligation due to GI pursuant to Section 5.2 below shall be
                reduced by [*] but in no event shall be less than [*] of Net
                Sales of Product or Combination Product.

5.      CONSIDERATION.

        5.1     LICENSE FEE. In partial consideration for the license granted
                herein, on the Effective Date Xcyte shall pay to GI a license
                fee in the form of 145,875 shares of Xcyte preferred stock,
                subject to the terms and conditions of the Stock Purchase
                Agreement attached hereto as Exhibit E, and shall pay a total of
                fifty three thousand four hundred eighty-seven U.S. dollars and
                fifty cents ($53,487.50) to the Licensors as provided in the
                Letter Agreement of even date herewith between GI, Xcyte and the
                Licensors. In addition, upon the first to occur of(i) notice
                from GI to Xcyte of the issuance of the first Valid Claim within
                the Patents, (ii) the first grant of a sublicense by Xcyte to a
                third party pursuant to Section 3.3, or (iii) the third
                anniversary of the Effective Date, GI shall have the right to
                purchase 194,500 additional shares of Xcyte stock, subject to
                the terms and conditions of the Stock Warrant Agreement attached
                hereto as Exhibit F.

        5.2     ROYALTY PAYMENTS.


*Certain information on this page has been omitted and filed
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                (a)     With respect to the sales of each Product, Xcyte shall
                        pay GI a royalty of [*] of Net Sales of Products sold by
                        Xcyte, its Affiliates and Sublicensees without any
                        Services.

                (b)     With respect to the sales of each Product, Xcyte shall
                        pay GI a royalty of [*] of Net Sales of Products by
                        Xcyte, its Affiliates and Sublicensees sold together
                        with one or more Services.

                (c)     With respect to the sales of each Combination Product,
                        Xcyte shall pay GI a royalty of such Combination
                        Product, as follows:

                        (i)     [*] of Net Sales of each Combination Product
                                sold by Xcyte, its Affiliates and Sublicensees,
                                if such Combination Product is sold without any
                                Services, and

                        (ii)    [*] of Net Sales of each Combination Product
                                sold by Xcyte, its Affiliates and Sublicensees,
                                if such Combination Product is sold together
                                with one or more Services;

                        provided, in each case, in determining Net Sales of
                        Combination Products, Net Sales shall first be
                        calculated in accordance with the definition of Net
                        Sales and then multiplied by a fraction, the numerator
                        of which is the current Net Selling Price of Product and
                        the denominator of which is the current Net Selling
                        Price of the Combination Product. If there is no Net
                        Selling Price of Product, then the numerator shall be
                        the fair market value of the Product for the quantity
                        contained in the Combination Product and of the same
                        class, purity and potency, as negotiated in good faith
                        by the parties, or, failing such agreement, as is
                        determined by an appraisal to be conducted by an
                        independent third party mutually agreed to by Xcyte and
                        GI, which determination shall be binding. However, in no
                        event shall the royalty be less than [*] of Net Sales of
                        each Combination Product.

                (d)     In addition to the royalties payable under this Section
                        5.2, Xcyte shall pay to GI a portion of all
                        compensation, including license fees, advances and other
                        payments of compensation (however characterized), which
                        are owed to Xcyte pursuant to further sublicensing of
                        the rights granted to Xcyte hereunder, as follows:

<TABLE>
<CAPTION>
                                 Sublicense Date                     % of Compensation
                                 ---------------                     -----------------
                        <S>                                          <C>
                        Within 24 months of Effective Date                   [*]

                        After 24 months after Effective Date                 [*]
</TABLE>


*Certain information on this page has been omitted and filed
 separately with the Commission. Confidential treatment has
 been requested with respect to the omitted portions.

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                        Notwithstanding the above, it is understood and agreed
                        that Xcyte shall not be obligated to pay to GI any
                        portion of any amounts received from any Sublicensee as
                        payments for research and development activities to be
                        conducted by Xcyte on behalf of such Sublicensee, or
                        amounts received from a Sublicensee for equity, or the
                        license or sublicense of any intellectual property other
                        than the Patents, or products other than the Products,
                        or reimbursement for patent or other expenses.

                (e)     Xcyte and its Affiliates and Sublicensees shall be
                        responsible for any payments due to third parties under
                        licenses or similar agreements entered by Xcyte or its
                        Affiliates or Sublicensees necessary for the
                        manufacture, use or sale of Products. Xcyte may offset
                        one-half of any such payments made by Xcyte or its
                        Affiliates or Sublicensees to third parties against
                        royalties due GI pursuant to Section 5.2(a), (b) and (c)
                        above; provided, GI shall have the right to receive the
                        greater of (i) [*] the amounts due pursuant to Sections
                        5.2(a), (b) and (c) above, or (ii) [*] of Net Sales of
                        Product or Combination Product.

                (f)     Payments due under this Section 5.2 shall be payable on
                        a country-by-country and Product-by-Product basis and
                        shall be payable until (i) with respect to Patents owned
                        by GI, the expiration of the last-to-expire Valid Claim,
                        and (ii) with respect to Patents subject to the License
                        Agreements, the expiration of the applicable license
                        term, as set forth in Section 3.2.

                (g)     Regardless of any credits or offsets available to Xcyte
                        under Section 5.2(e) of this Agreement commencing on the
                        first anniversary of the Launch of the first Product in
                        any country, in no year shall Xcyte pay to GI less than
                        the greater of (i) [*] of the royalties due pursuant to
                        Sections 5.2(a), (b) or (c) in any year with regard to
                        any Product or (ii) [*] of Net Sales of Product or
                        Combination Product. Any credits or offsets not
                        creditable against royalties in the year such credit or
                        offset is earned may be carried forward until fully
                        applied.

        5.3     REPORTS AND PAYMENT. Xcyte shall deliver to GI, within sixty
                (60) days after the end of each calendar quarter, a written
                report showing its computation of royalties due under this
                Agreement upon Net Sales by Xcyte, its Affiliates and
                Sublicensees during such calendar quarter. All Net Sales shall
                be segmented in each such report according to sales by Xcyte,
                each Affiliate and each Sublicensee, as well as on a
                country-by-country basis, including the rates of exchange used
                to convert such royalties to United States Dollars from the
                currency in which such sales were made. Subject to the
                provisions of Sections 5.4 and 5.5 of this Agreement,
                simultaneously with the delivery of each such report, Xcyte
                shall tender payment in United States Dollars of all royalties
                shown to be due therein.


*Certain information on this page has been omitted and filed
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 been requested with respect to the omitted portions.

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                For purposes hereof, the rates of exchange to be used for
                converting royalties hereunder to United States Dollars shall be
                the closing price published for the purchase of United States
                Dollars in the East Coast Edition of the Wall Street Journal for
                the last business day of the calendar quarter for which payment
                is due.

        5.4     FOREIGN ROYALTIES. Where royalties are due hereunder for sales
                of Products in a country where, by reason of currency
                regulations or taxes of any kind, it is impossible or illegal
                for Xcyte, any Affiliate or Sublicensee to transfer royalty
                payments to GI for Net Sales in that country, such royalties
                shall be deposited in whatever currency is allowable by the
                person or entity not able to make the transfer for the benefit
                or credit of GI in an accredited bank in that country that is
                reasonably acceptable to GI.

        5.5     TAXES. Any and all income or similar taxes imposed or levied on
                account of the receipt of royalties payable under this Agreement
                which are required to be withheld by Xcyte shall be paid by
                Xcyte, its Affiliates or Sublicensees on behalf of GI and shall
                be paid to the proper taxing authority. Proof of payment shall
                be secured and sent to GI by Xcyte, its Affiliates or
                Sublicensees as evidence of such payment in such form as
                required by the tax authorities having jurisdiction over Xcyte,
                its Affiliates or Sublicensees. Such taxes shall be deducted
                from the royalty that would otherwise be remittable by Xcyte,
                its Affiliates or Sublicensees.

        5.6     RECORDS. Xcyte shall keep, and shall require all Affiliates and
                Sublicensees to keep, for a period of at least two (2) years,
                full, true and accurate books of accounts and other records
                containing all information and data which may be necessary to
                ascertain and verify the royalties payable hereunder. During the
                term of this Agreement and for a period of two (2) years
                following its termination, GI shall have the right from time to
                time (not to exceed once during each calendar year) to inspect
                in confidence, or have an agent, accountant or other
                representative inspect in confidence, such books, records and
                supporting data.

6.      REPRESENTATION, WARRANTY AND INDEMNITY.

        6.1     REPRESENTATION AND WARRANTY OF GI. GI represents and warrants to
                Xcyte that, subject to the terms and conditions of this
                Agreement and the License Agreements, (i) it has an interest
                licensable or sublicensable to Xcyte in the Patents; (ii) it has
                full right, power and authority to grant the licenses and /
                sublicense granted by it under this Agreement; (iii) GI has not
                previously granted, and will not grant during the term of this
                Agreement, any right, license or interest in and to the Patents,
                or any portion thereof, inconsistent with the license granted to
                Xcyte herein; (iv) as of the Effective Date, there are no
                actions, suits, investigations, claims or proceedings pending or
                threatened in any way relating to the Patents except as set
                forth on Schedule 6.1 to this Agreement; and (v) during



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                the term of this Agreement, GI shall use its reasonable efforts
                not to breach any of the License Agreements.

        6.2     REPRESENTATION AND WARRANTY OF XCYTE. Xcyte represents and
                warrants to GI that, subject to the terms and conditions of this
                Agreement and the License Agreements, during the term of this
                Agreement, Xcyte shall use its reasonable efforts not to breach
                any of the License Agreements.

        6.3     INDEMNITY OF GI BY XCYTE. Xcyte shall defend, indemnify and hold
                GI (and its agents, directors, officers and employees) harmless,
                at Xcyte's cost and expense, from and against any and all
                losses, costs, liabilities, damages, fees and expenses,
                including reasonable attorneys' fees and expenses (collectively,
                "Liabilities") arising out of or in connection with the
                manufacture, promotion, sale or other disposition of the
                Products by Xcyte, its Affiliates and Sublicensees, and any
                actual or alleged injury, damage, death or other consequence
                occurring to any third person as a result, directly or
                indirectly, of the possession, consumption or use of the
                Products sold by Xcyte or its Affiliates or Sublicensees,
                regardless of the form in which any such claim is made.

        6.4     EFFECT OF REPRESENTATIONS AND WARRANTIES. It is understood that
                if the representations and warranties made by a party under this
                Article 6 are not true and accurate, the party making such
                representations and warranties shall indemnify and hold the
                other party harmless from and against any Liabilities incurred
                as a result.

        6.5     EXCLUSION. IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER
                PARTY, OR ANY OF ITS OFFICERS, DIRECTORS, SHAREHOLDERS,
                EMPLOYEES OR AGENTS, OR ANY OTHER PERSON OR ENTITY, FOR ANY
                INCIDENTAL, CONSEQUENTIAL, OR OTHER SPECIAL DAMAGES, INCLUDING
                WITHOUT LIMITATION, LOST PROFITS OR OPPORTUNITIES INCURRED BY
                SUCH PARTY, OR ANY OTHER PERSON OR ENTITY, ARISING OUT OF OR
                RELATING TO THIS AGREEMENT, THE LICENSES AND RIGHTS GRANTED
                HEREIN, THE PRODUCT, PATENTS OR IMPROVEMENTS, OR ACTUAL OR
                ALLEGED NEGLIGENCE, STRICT LIABILITY, BREACH OF REPRESENTATIONS
                OR WARRANTIES, OR ANY OTHER CAUSE OF ACTION.

        6.6     PROCEDURE. A party entitled to indemnification hereunder agrees
                to give prompt written notice to the indemnifying party after
                the receipt by such party of any written notice of the
                commencement of any action, suit, proceeding or investigation or
                threat thereof made in writing for which such party will claim
                indemnification pursuant to this Agreement. Unless, in the
                reasonable judgment of the indemnified party, a conflict of
                interest may exist between the indemnified party and the
                indemnifying party with respect to a claim, the indemnifying
                party may assume the defense of such claim with counsel
                reasonably satisfactory to the



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                indemnified party. if the indemnifying party is not entitled to,
                or elects not to, assume the defense of a claim, it will not be
                obligated to pay the fees and expenses of more than one counsel
                with respect to such claim. The indemnifying party will not be
                subject to any liability for any settlement made without its
                consent, which consent shall not be unreasonably withheld or
                delayed.

7.      INTELLECTUAL PROPERTY.

        7.1     IMPROVEMENTS. Xcyte shall own the entire right, title and
                interest in and to all Improvements.

        7.2     OPTION; RIGHT OF FIRST REFUSAL. Xcyte grants to GI an option to
                execute an exclusive, worldwide, royalty-bearing
                commercialization license, with the right to grant sublicenses,
                to the Improvements, to commercialize products based on or
                incorporating Improvements outside the Field, on terms to be
                negotiated by the parties in good faith.

                GI may exercise its option by written notice to Xcyte within
                three (3) months of notice by Xcyte to GI of such Improvement
                and receipt by GI of sufficient technical information to
                evaluate such Improvement. If GI exercise its option, the
                parties will negotiate in good faith to reach agreement on a
                commercialization license for up to 120 days. If GI does not
                exercise its option, or the parties do not reach agreement
                within 120 days, Xcyte may commercialize such Improvement
                outside the Field, itself or license such Improvement to a third
                party, without obligation to GI. Before entering into any
                transaction with a third party on terms which, taken as a whole,
                are materially more favorable than those offered to GI in
                writing to license such Improvement, Xcyte will inform GI and
                shall allow GI sixty (60) days in which to elect whether to
                license such Improvement under all the terms of the proposed
                transaction with the third party. Nothing in this Section 7.2
                shall imply the grant of any license under the Patents to Xcyte
                outside the Field.

        7.3     PATENT MAINTENANCE. GI shall have the right to seek or continue
                to seek or maintain patent protection on the Patents in any
                country. GI shall obtain the advice of Xcyte concerning the
                countries in which to seek or maintain patent protection, and
                the nature and text of such patents and prosecutions matters
                related thereto prior to the filing thereof and provide Xcyte a
                reasonable opportunity to review and comment on all proposed
                submissions to any patent office before submittal, and provided
                further that GI shall keep Xcyte reasonably informed as to the
                status of such patent applications by promptly providing Xcyte
                copies of all communications relating to such patent
                applications that are received from any patent office. Xcyte
                shall reimburse GI for any reasonable expenses incurred by GI
                during the term of this Agreement in preparing, filing,
                prosecuting and maintaining any Patents containing claims
                relating to the Field. If GI elects not to seek or continue to
                seek or maintain patent protection on any patent



                                      -11-
<PAGE>   12

                application or patent within the Patents in any country, Xcyte
                shall have the right, at its expense, to file, procure and
                maintain in such countries such Patents. If Xcyte elects not to
                continue to make payments to seek or continue to seek or
                maintain patent protection on any patent application or patent
                within the Patents in any country, it may notify GI, and its
                obligation to make such payments shall cease and its license
                with regard to such patent application or patent shall
                terminate. Xcyte shall have the right, at Xcyte cost and
                expense, to audit all expenses relating to the preparing,
                filing, prosecuting and maintaining of the Patents.

        7.4     PATENT INFRINGEMENT.

                (a)     Each Party shall promptly report in writing to the other
                        Party during the term of this Agreement any known
                        infringement or suspected infringement of any of the
                        Patents, and promptly shall provide the other Party with
                        all available evidence supporting said infringement,
                        suspected infringement, or unauthorized use or
                        misappropriation.

                (b)     Except as provided in Section 7.4(c) below, Xcyte shall
                        have the right to initiate an infringement or other
                        appropriate suit anywhere in the Territory against any
                        third party who at any time has infringed, or is
                        suspected of infringing, any of the Patents in the
                        Field. Xcyte shall give GI sufficient advance notice of
                        its intent to file said suit and the reasons therefor,
                        and shall provide GI with an opportunity to make
                        suggestions and comments regarding such suit. Xcyte
                        shall keep GI promptly informed, and shall from time to
                        time consult with GI regarding the status of any such
                        suit and shall provide GI with copies of all documents
                        filed in, and all written communications relating to,
                        such suit. Xcyte shall have the sole and exclusive right
                        to select counsel for any such suit and shall, except as
                        provided below, pay all expenses of the suit, including
                        without limitation attorneys' fees and court costs. GI,
                        in its sole discretion, may elect, within sixty (60)
                        days after the commencement of such litigation, to
                        contribute to the costs incurred by Xcyte in connection
                        with such litigation and, if it so elects, any damages,
                        royalties, settlement fees or other consideration
                        received by Xcyte or any of its Affiliates for
                        infringement as a result of such litigation shall be
                        shared by Xcyte and GI pro rata based on their
                        respective sharing of the costs of such litigation. In
                        the event that Gl elects not to contribute to the costs
                        of such litigation, Xcyte and/or its Sublicensees shall
                        be entitled to retain any damages, royalties, settlement
                        fees or other consideration for infringement resulting
                        therefrom. If necessary, GI shall join as a party to the
                        suit but shall be under no obligation to participate
                        except to the extent that such participation is required
                        as the result of being a named party to the suit. GI
                        shall offer reasonable assistance to Xcyte in connection
                        therewith at no charge to Xcyte except for reimbursement
                        of reasonable out-of-pocket expenses,



                                      -12-
<PAGE>   13

                        incurred in rendering such assistance. GI shall have the
                        right to participate and be represented in any such suit
                        by its own counsel at its own expense.

                (c)     In the event that Xcyte elects not to initiate an
                        infringement or other appropriate suit pursuant to
                        Section 7.4(b) above, Xcyte shall promptly advise GI of
                        its intent not to initiate such suit, and GI shall have
                        the right, at the expense of GI, of initiating an
                        infringement or other appropriate suit against any third
                        party who at any time has infringed, or is suspected of
                        infringing, any of the Patents in the Field. GI shall
                        have the sole and exclusive right to select counsel for
                        any such suit and shall, except as provided below, pay
                        all expenses of the suit including without limitation
                        attorneys' fees and court costs. Xcyte, in its sole
                        discretion, may elect, within sixty (60) days after the
                        commencement of such litigation, to contribute to the
                        costs incurred by GI in connection with such litigation
                        and, if it so elects, any damages, royalties, settlement
                        fee or other consideration received by GI or any of its
                        Affiliates for infringement as a result of such
                        litigation shall be shared by GI and Xcyte pro rata
                        based on their respective sharing of the costs of such
                        litigation. In the event that Xcyte elects not to
                        contribute to the costs of such litigation, GI and/or
                        its Affiliates shall be entitled to retain any damages,
                        royalties, settlement fees or other consideration for
                        infringement resulting therefrom. If necessary, Xcyte
                        shall join as a party to the suit but shall be under no
                        obligation to participate except to the extent that such
                        participation is required as a result of being a named
                        party to the suit. At GI's request, Xcyte shall offer
                        reasonable assistance to GI in connection therewith at
                        no charge to GI except for reimbursement of reasonable
                        out-of-pocket expenses incurred in rendering such
                        assistance. Xcyte shall have the right to participate
                        and be represented in any such suit by its own counsel
                        at its own expense.

        7.5     CLAIMED INFRINGEMENT.

                (a)     In the event that a third party at any time provides
                        written notice of a claim to, or brings an action, suit,
                        or proceeding against, either Party or any of their
                        respective Affiliates or Sublicensees, claiming
                        infringement of its patent rights or unauthorized use or
                        misappropriation of its know-how, based upon an
                        assertion or claim arising out of the development, use,
                        manufacture, distribution, or sale of Products, such
                        Party shall promptly notify the other Party of the claim
                        or the commencement of such action, suit, or proceeding,
                        enclosing a copy of the claim and/or all papers served.
                        Each Party agrees to make available to the other Party
                        its advice and counsel regarding the technical merits of
                        any such claim at no cost to the other Party.

                (b)     THE FOREGOING STATES THE ENTIRE RESPONSIBILITY OF THE
                        PARTIES IN THE CASE OF ANY CLAIMED INFRINGEMENT OR



                                      -13-
<PAGE>   14

                        VIOLATION OF ANY THIRD PARTY'S RIGHTS OR UNAUTHORIZED
                        USE OR MISAPPROPRIATION OF ANY THIRD PARTY'S KNOW-HOW.

8.      CONFIDENTIAL INFORMATION.

        8.1     NONDISCLOSURE OF CONFIDENTIAL INFORMATION. Each Party shall not
                directly or indirectly publish, disseminate or otherwise
                disclose, deliver or make available to any person outside its
                organization any of the other Party's Confidential information.
                Each Party may disclose the other Party's Confidential
                Information to persons within its organization and to its
                Affiliates and Sublicensees who/which have a need to receive
                such Confidential Information in order to further the purposes
                of this Agreement and who/which are bound to protect the
                confidentiality of such Confidential Information, as set forth
                in Section 8.4 below. Each Party may disclose the other Party's
                Confidential Information to a governmental authority or by order
                of a court of competent jurisdiction, provided that such
                disclosure is subject to all applicable governmental or judicial
                protection available for like material and reasonable advance
                notice is given to the other Party.

        8.2     USE OF CONFIDENTIAL INFORMATION. Each Party shall use the other
                Party's Confidential Information solely for the purposes
                contemplated in this Agreement or for such other purposes as may
                be agreed upon by the Parties in writing.

        8.3     PHYSICAL PROTECTION OF CONFIDENTIAL INFORMATION. The Parties
                shall exercise commercially reasonable precautions to physically
                protect the integrity and confidentiality of the other Party's
                Confidential Information.

        8.4     AGREEMENTS WITH PERSONNEL AND THIRD PARTIES. The Parties have or
                shall obtain agreements with all personnel and third parties who
                will have access to the other Party's Confidential Information
                which impose comparable confidentiality obligations as are set
                forth in this Agreement on such personnel and third parties.

9.      TERM AND TERMINATION.

        9.1     TERM. Unless sooner terminated in accordance with the provisions
                of this Section 9, this Agreement shall continue in force on a
                country-by-country and Product-by-Product basis for the period
                set forth in Section 3.2.

        9.2     TERMINATION FOR BREACH. Each Party shall be entitled to
                terminate this Agreement by written notice to the other party in
                the event that the other party shall be in default of any of its
                material obligations hereunder, and shall fail to remedy any
                such default within sixty (60) days after notice thereof by the
                non-breaching party. Any such notice shall specifically state
                that the non-breaching party intends to terminate this Agreement
                in the event that the breaching party shall fail to remedy the
                default.



                                      -14-
<PAGE>   15

        9.3     PERMISSIVE TERMINATION. Xcyte may terminate this Agreement with
                thirty (30) days notice to GI.

        9.4     EFFECT OF TERMINATION.

                (a)     ACCRUED OBLIGATIONS. Termination of this Agreement for
                        any reason shall not release any Party hereto from any
                        liability which, at the time of such termination, has
                        already accrued to the other Party or which is
                        attributable to such termination, nor shall it preclude
                        either Party from pursuing all rights and remedies it
                        may have hereunder or at law or in equity with respect
                        to any breach of this Agreement.

                (b)     RETURN OF CONFIDENTIAL INFORMATION. Subject to any
                        license granted pursuant to Section 7.2, upon any
                        termination of this Agreement each Party shall return to
                        the other Party all Confidential Information received
                        from the other Party (except one copy of which may be
                        retained for archival purposes), and neither Party shall
                        use any such Confidential Information of the other Party
                        for any purpose.

                (c)     STOCK ON HAND. In the event this Agreement is terminated
                        for any reason, Xcyte, its Affiliates and its
                        Sublicensees shall have the right for six (6) months
                        following the date of termination to sell or otherwise
                        dispose of the stock of any Licensed Product subject to
                        this Agreement then on hand, subject to the right of GI
                        to receive payment thereon as provided in Section 5.

        9.5     SURVIVAL OF OBLIGATIONS. Notwithstanding any termination of this
                Agreement, the obligations of the Parties under Sections 5.3,
                5.6, 6,7.1, 8,9.4, 9.5 and 10 shall survive and continue to be
                enforceable.

10.     MISCELLANEOUS.

        10.1    PUBLICITY. Neither Party shall originate any publicity, news
                release or other public announcement, written or oral, relating
                to this Agreement or the existence of an arrangement between the
                Parties, without the prior written approval of the other Party,
                which approval shall not be unreasonably withheld, except as
                otherwise required by law. It is expressly understood that
                nothing in this Section 10.1 shall prevent a Party from making a
                disclosure in connection with any required filings with the
                Securities and Exchange Commission or in connection with the
                offering of securities or any financing.

        10.2    EXPORT CONTROL. The Parties acknowledge that the export of
                technical data, materials, or products is subject to the
                exporting Party receiving the necessary export licenses and that
                the Parties cannot be responsible for any delays attributable to
                export controls which are beyond the reasonable control of
                either Party. The Parties agree that regardless of any
                disclosure made by the Party



                                      -15-
<PAGE>   16

                receiving an export of an ultimate destination of any technical
                data, materials, or products, the receiving Party will not
                reexport either directly or indirectly, any technical data,
                material, or products without first obtaining the applicable
                validated or general license from the United States Department
                of Commerce, United States Food and Drug Administration, and/or
                any other agency or department of the United States Government,
                as required. The receiving Party shall provide the exporting
                Party with any information, materials, certifications, or other
                documents which may be reasonably required in connection with
                such exports under the Export Administration Act of 1979, as
                amended, its rules and regulations, the Federal Food, Drug and
                Cosmetic Act, and other applicable export laws.

        10.3    NO IMPLIED LICENSES. Only the licenses granted pursuant to the
                express terms of this Agreement shall be of any legal force and
                effect. No license tights shall be created by implication or
                estoppel.

        10.4    NO AGENCY. Nothing herein shall be deemed to constitute either
                Party as the agent or representative of the other Party, or both
                Parties as joint venturers or partners for any purpose. Each
                Party shall be an independent contractor, not an employee or
                partner of the other Party, and the manner in which each Party
                renders its services under this Agreement shall be within its
                sole discretion. Neither Party shall be responsible for the acts
                or omissions of the other Party, and neither Party will have
                authority to speak for, represent or obligate the other Party in
                any way without prior written authority from the other Party.

        10.5    NOTICE. All notices required under this Agreement to be given by
                one Party to the other shall be in writing and shall be given by
                addressing the same to the other at the address or facsimile
                number set forth below, or at such other address or facsimile
                number as either may specify in writing to the other. All
                notices shall become effective when deposited in the United
                States Mail with proper postage for first class registered or
                certified mail prepaid, return receipt requested, or when
                delivered personally, or, if promptly confirmed by mail as
                provided above, when dispatched by facsimile.


                GI:      Genetics Institute, Inc.
                         87 Cambridge Park Drive
                         Cambridge, Massachusetts 02140
                         Telecopier (617) 876-5851
                         Attn: Legal Department

                Xcyte:   Xcyte Therapies, Inc.
                         2203 Airport Way South
                         Suite 300
                         Seattle, Washington 98134
                         Telecopier (206) 328-7316



                                      -16-
<PAGE>   17

                Attn:    President and CEO

        10.6    ASSIGNMENT. This Agreement, and the rights and obligations
                hereunder, may not be assigned or transferred, in whole or in
                part, by either Party without the prior written consent of the
                other Party, except that neither Party shall require the other
                Party's consent to assign this Agreement to any Affiliate, or to
                any entity acquiring such Party or substantially all of the
                assets of such Party as to which this Agreement relates whether
                by sale, operation of law or otherwise, or to any successor
                entity of such Party as the result of a merger or consolidation.

        10.7    ENTIRE AGREEMENT. This Agreement constitutes the entire
                agreement of the Parties with regard to its subject matter, and
                supersedes all previous written or oral representations,
                agreements and understandings between the Parties.

        10.8    NO MODIFICATION. This Agreement may be changed only by a writing
                signed by the Parties.

        10.9    HEADINGS. The headings contained in this Agreement are for
                convenience of reference only and shall not be considered in
                construing this Agreement.

        10.10   WAIVER. The waiver by either Party of a breach or a default of
                any provision of this Agreement by the other Party shall not be
                construed as a waiver of any succeeding breach of the same or
                any other provision, nor shall any delay or omission on the part
                of either Party to exercise or avail itself of any right, power
                or privilege that it has or may have hereunder operate as a
                waiver of any right, power, or privilege by such Party.

        10.11   SEVERABILITY. In the event that any one or more of the
                provisions contained in this Agreement shall, for any reason, be
                held to be invalid, illegal or unenforceable in any respect,
                such invalidity, illegality or unenforceability shall not affect
                any other provisions of this Agreement, and all other provisions
                shall remain in full force and effect. If any of the provisions
                of this Agreement is held to be excessively broad or invalid,
                illegal or unenforceable in any jurisdiction, it shall be
                reformed and construed by limiting and reducing it so as to be
                enforceable to the maximum extent permitted by law in
                conformance with its original intent. In the event that after
                such reformation, a Party's rights or obligations are materially
                changed, then such Party may terminate this Agreement.

        10.12   FORCE MAJEURE. Any delays in or failures of performance by
                either party under this Agreement shall not be considered a
                breach of this Agreement if and to the extent caused by
                occurrences beyond the reasonable control of the party affected,
                including but not limited to: acts of God, acts, regulations or
                laws of any government; strikes or other concerted acts of
                workers; fires; earthquakes; floods; explosions; riots; wars;
                rebellion; and sabotage. Any time for performance imposed
                hereunder shall be extended by the actual time of delay caused
                by any such occurrence.



                                      -17-
<PAGE>   18

        10.13   LIMITATION OF LIABILITY. NEITHER. PARTY SHALL BE LIABLE TO THE
                OTHER FOR ANY SPECIAL, CONSEQUENTIAL, INCIDENTAL OR INDIRECT
                DAMAGES ARISING OUT OF THIS AGREEMENT, HOWEVER CAUSED, UNDER ANY
                THEORY OF LIABILITY.

        10.14   SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon and
                inure to the benefit of the Parties hereto and their successors
                and permitted assigns.

        10.15   COUNTERPARTS. This Agreement may be executed in any number of
                counterparts, each of which shall be deemed an original but all
                of which together shall constitute one and the same instrument.

        10.16   APPLICABLE LAW. This Agreement shall in all events and for all
                purposes be governed by, and construed in accordance with, the
                law of The Commonwealth of Massachusetts without regard to any
                choice of law principle that would dictate the application of
                the law of another jurisdiction.

        10.17   HSR. Xcyte represents and warrants that neither Xcyte nor any
                ultimate parent entity of Xcyte has $10 million in sales or
                total assets and therefore does not meet the size of person test
                under Title II of the Hart-Scott-Rodino Antitrust Improvements
                Act of 1976 and the regulations promulgated thereunder.



                                      -18-
<PAGE>   19

        IN WITNESS WHEREOF, duly-authorized representatives of the Parties have
signed this Agreement as a document under seal as of the Effective Date.



GENETICS INSTITUTE, INC.

By /s/ Egon E. Berg
   -------------------------------
Print Name
           -----------------------
Title
      ----------------------------

XCYTE THERAPIES, INC.

By /s/ Ronald Jay Berenson
   -------------------------------
Print Name Ronald Jay Berenson
           -----------------------
Title President & CEO
      ----------------------------



                                      -19-