bluuebunny/crossref_metadata_2025 huggingface dataset:
Human cytomegalovirus‐specific cytotoxic T lymphocytes: requirements for in vitro generation and specificity
Authors: Borysiewicz Leszek K. , Morris Susanna , Page Jamie D. , Patrick Sissons J. G.
Published: February 2007

The nature of any virus‐specific T cells involved in controlling human cytomegalovirus (HCMV) infection in normal subjects harboring latent virus is unknown. As an approach to this problem, peripheral blood mononuclear cells (PBM) from normal seropositive subjects were cocultured with HCMV and responding T cells expanded in interleukin 2 (IL2)‐dependent culture, determining in particular whether HCMV‐specific cytotoxic T cells (Tc) were generated. Coculture of PBM with free HCMV resulted in the generation of short‐term T cell lines of predominantly helper phenotype (Leu 3a+), expressing no cytotoxicity. However, when PBM were cocultured on HCMV‐infected fibroblasts (autologous to the donor in these experiments) predominantly Leu 2a+ lines were generated, which lysed HCMV‐infected cells. The cytotoxicity of these short‐term IL2‐dependent lines was HCMV‐specific and human HLA‐restricted; HCMV‐infected target cells expressing only early viral antigens were lysed. It is concluded that HCMV‐specific Tc precursors are present in peripheral blood of latently infected individuals without preceding overt infection and that effector Tc may be capable of lysing infected cells prior to viral replication.
Standard sera in solid‐phase immunoassays
Authors: Mäkelä Olli , Péterfy Ferenc
Published: February 2007

Solid‐phase immunoassay‐derived antibody titers are often converted to weight unit concentrations with the aid of standard sera containing known antibody concentrations. Systematic studies justifying this procedure have not yet been published. We therefore investigated the magnitude of errors associated with this conversion. Antibody concentrations of thirteen sera or ascites fluids were determined by quantitative precipitation or equlibrium dialysis, and one was then used as a “standard antibody” for the others in solid‐phase radioimmunoassay (SP‐RIA) or enzyme‐linked immunosorbent (ELISA) assays.

Antibody concentrations determined by the conventional solid‐phase assay (the “standard serum” has the same specificity as the “sample”) had up to fourfold errors. These errors could be reduced by basing the conversion on the combination of two standard sera instead of one.

The possibility was studied of whether the conversion to weight units could be done with the aid of a standard serum directed to a different antigen than the sample antibody. Errors associated with the use of such a heterologous standard were not significantly greater than those found using the conventional conversion. A combination of two reference sera again reduced the errors. The use of such heterologous standard(s), however, requires checking the binding capacity of the antigen coats.
One out of five peripheral blood B lymphocytes is activated to high‐rate Ig production by human alloreactive T cell clones
Authors: Lanzavecchia Antonio
Published: February 2007

Human alloreactive helper T cell clones were isolated from a secondary mixed lymphocyte reaction by limiting dilution in the presence of irradiated stimulator cells and T cell growth factor (interleukin 2). When cultured with B cells and macrophages possessing the relevant alloantigens, the T cell clones proliferated and induced a strong B cell activation with production of high immunoglobulin levels. Limiting dilution of the B cells from the peripheral blood showed that about one in 5–10 can be activated to produce IgG, one in 10 IgM, one in 20–40 IgA and one in 2000–5000 IgE. Following stimulation by the relevant alloantigen, the clones were able to help also B cells that lacked the alloantigen, indicating that a direct T‐B cell interaction is not required.

This method is particularly interesting because it is suitable for the clonal analysis of a B cell subset that is triggered in the absence of antigen by an unrestricted T cell help.
Molecular nature of the W3/25 and MRC OX‐8 marker antigens for rat T lymphocytes: comparisons with mouse and human antigens
Authors: Thomas Matthew L. , Green Jon R.
Published: February 2007

The mouse monoclonal antibodies W3/25 and MRC OX‐8 have been used to distinguish rat T lymphocyte subpopulations. In the peripheral T lymphocyte population, W3/25 antibody recognizes an antigen on the Thelper (Th) subset, while MRC OX‐8 antibody recognizes an antigen on the Tsuppressor/cytotoxic (Ts/c) subset. To determine the nature of these antigens, rat thymocytes were either metabolically labeled with [35S]L‐methionine or surface‐labeled at sialic acid residues by periodate oxidation followed by [3H]NaBH4 reduction. Thymocytes were solubilized with nonionic detergent, the antigens immunoprecipitated and the molecular weights determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis. Using metabolically labeled cells, W3/25 antibody immunoprecipitated an antigen that electrophoresed under reducing conditions as a broad band between 48000–53000 Mr. Unreduced samples migrated between 46000–50000 Mr. Surface‐labeled W3/25 antigen, electrophoresed under reducing conditions, separated into two bands of 44000 and 52000 Mr. Metabolically labeled MRC OX‐8 antigen was identified as a protein of at least two chains of 39000 and 34000 Mr. There was also a fainter band at approximately 67000 Mr. Unreduced samples indicated a more complex structure with bands at 70000, 110000 and 165000 Mr. Surface‐labeled MRC OX‐8 antigen was of similar nature. These data, when considered with functional and tissue distribution data, suggest that W3/25 antigen is equivalent to T4 in man and MRC OX‐8 antigen is equivalent to T8 in man, and Lyt‐2 in mouse.
The specificity of H‐2‐restricted cytotoxic T lymphocytes directed to AKR/Gross leukemia virus‐induced tumors II. Altered gp70 display and production of noninfectious virus particles by an insusceptible variant tumor
Authors: Green William R. , Brown Melissa A.
Published: February 2007

Derived from the susceptible AKR.H‐2bSL1 tumor cell line, a variant tumor subclone, cl.18‐5, was selectively insusceptible to H‐2‐restricted anti‐AKR/Gross virus cytotoxic T lymphocytes (CTL) due to its failure to be recognized. In this study, the expression of virus‐related products by variant cl.18‐5 cells was compared to that of AKR.H‐2bSL1 cells and a susceptible clone, as an approach towards defining the virus‐associated antigens recognized by anti‐AKR/Gross virus CTL.

Despite the type specificity of the CTL, cl.18‐5 displayed normal levels of the group‐specific antigen (gag) encoded proteins p30, p15, p12 and p10, and the gag‐associated Gross cell surface antigen. These results were confirmed by fluorescence‐activated cell sorter analysis employing monoclonal antibodies specific for either AKR p12 or the cell surface glycosylated form of AKR ecotropic gag product. In contrast, cl.18‐5 was variably less sensitive than AKR.H‐2bSL1 to the action of complement and xenogeneic antisera directed against the envelope (env) product gp70. In addition, a panel of five monoclonal antibodies to gp70, which detect distinct endogenous ecotropic viral determinants, lysed AKR.H‐2bSL1, but not cl.18‐5 cells. However, absorption experiments indicated that cl.18‐5 did express near normal levels of these specificities, suggesting an alteration in the orientation or topographical distribution of these determinants.

Consistent with an inappropriate display of env products, cl.18‐5 was found to be deficient in the production of infectious ecotropic leukemia virus. The particulate fraction of the cell‐free supernatant of cl.18‐5 contained normal levels of reverse transcriptase activity, indicating that noninfectious viral particles were being produced. Collectively, these results point to an association between recognition by anti‐AKR/Gross virus CTL and the expression of ecotropic gp70 required for infectivity of virus.
Allocytotoxic T cell clones: both Leu 2+3− and Leu 2−3+ T cells recognize class I histocompatibility antigens
Authors: Flomenberg Neal , Naito Kazuyuki , Duffy Ellen , Knowles Robert W. , Evans Robert L. , Dupont Bo
Published: February 2007

T cell clones were selected which were cytotoxic for human class I major histocompatibility target antigens. Specificity was based on target cell panel studies and inhibition by monoclonal antibodies to class I determinants. Eight clones were Leu 2+3−. The cytotoxicity of these clones was inhibited by antibody to the Leu 2 antigen. Two clones expressed the Leu 2−3+ phenotype and were not inhibited by anti‐Leu 2a or anti‐Leu 3a antibodies. These studies indicate that class I‐specific cytotoxic T cells are distributed in both T cell subsets, though predominantly in the Leu 2+3− group. In addition, these studies suggest that the Leu 3 molecule may not function in identical fashion in Leu 3+ cytotoxic T cells, which recognize class I target antigens, as in those which recognize class II targets.
Selection and continuous growth of antigen‐specific human T cells by antigen‐treated monocytes
Authors: Barak Vivian , Fuks Zvi , Galilli Naomi , Treves Abraham J.
Published: February 2007

Antigen‐specific human T lymphocytes were selected by adsorption of peripheral blood mononuclear cells on monolayers of antigen‐treated autologous monocytes. The enriched cell populations were propagated in interleukin 2‐containing medium for 60–80 days. Their activity was tested by a proliferative response against the sensitizing antigen in the presence of irradiated autologous lymphocytes. Continuous cultures of enriched T cells responded specifically to three different protein antigens. The specific reactivity induced in vitro against at least one of the antigens was probably a primary response. In addition, the selected cultures were found to be enriched for OKT4‐positive cells, in contrast to cultures of nonselected T cells which were enriched for OKT8‐positive cells. These properties of the selected T lymphocyte populations were obtained following only one exposure to the sensitizing antigen, which was concomitant with adsorbance on monocytes and without cloning of the reactive cells. We suggest that specific adsorbance of lymphocytes on antigen‐treated monocytes may result in a T cell population which combines both properties of antigen specificity and enrichment for the helper proliferative subset of T cells.
Activation of human T lymphocytes I. Requirements for mitogen‐induced proliferation of antigen‐specific T lymphocyte clones
Authors: Fleischer Bernhard
Published: February 2007

In a model system for accessory cell (AC)‐dependent mitogen‐induced T cell proliferation the response of several human antigen‐specific, HLA‐restricted helper T lymphocyte clones (HTLC) to mitogens was studied. It was found that the HTLC themselves did not or only weakly respond to various mitogens or to oxidation by galactose oxidase, but that the response could be strongly increased if certain tumor cell lines were added to the assay as AC. Pretreatment with lectins or oxidation of either HTLC or AC was effective in stimulating the proliferation of the T cells in this system. Reduction of the aldehydes formed during oxidation completely abolished the stimulatory activity of oxidized B lymphoblastoid cell line. This shows that crosslinking of T cell and AC is required to induce proliferation.

When several established cell lines were tested for their capacity to function as AC in this system, profound differences in AC activity were detected. The inability of cells with poor AC activity to stimulate the HTLC was not due to trivial reasons, such as requirements for different mitogen concentrations, a decreased binding of mitogens or suppressive effects. Furthermore, AC activity was not dependent on the presence of Ia antigens on the AC. These findings are discussed with regard to the mechanism of mitogen‐induced T cell activation.
Chromosome assignment of monoclonal antibody‐defined determinants on human leukemic cells
Authors: Katz Fay , Povey Susan , Parkar Mohamed , Schneider Claudio , Sutherland Robert , Stanley Karina , Solomon Ellen , Greaves Melvyn
Published: February 2007

Hybrids formed between human acute lymphoblastic leukemia (ALL) cells and mouse myeloma have been used to determine the chromosomal location of genes required for the expression of several monoclonal antibody (mAb)‐defined cell surface antigens on ALL cells. Cloned hybrids were tested for antibody binding, immunoprecipitation of the relevant protein, chromosome isoenzyme markers and karyotype. Two antigens of those studied could be definitively mapped, OKT10/p45 to chromosome 4 and BA‐2/p24 to chromosome 12. mAb BA‐2 reacts with the same protein as another mAb designated 609‐29 (anti‐teratocarcinoma). Reactivity with the latter mAb has been previously shown to segregate with chromosome 12.
Fine specificity of the immune response to oxazolones III. Antibodies but not contact sensitivity specific for 2‐furyloxazolone are controlled by an Igh‐V gene in the mouse
Authors: Mäkelä Olli , Matoso‐Ferreira Antonio , Kaartinen Matti
Published: February 2007

Early IgM and IgG antibodies of CBA and C3H mice (Igh allotype j) against furyloxazolone (furyl Ox) were found to be heteroclitic, they had a 4–6 times higher affinity for styryloxazolone (styryl Ox) than for furyloxazolone. Anti‐furyl Ox antibodies of six other strains (Igh allotypes a, b, c, e, f or g) had approximately 100 times higher affinity for furyl Ox than for styryl Ox. The heteroclitic fine‐specificity was inherited as an Igh allotype‐linked trait.

Furyl Ox‐specific contact sensitivity was induced by painting, and its specificity was studied with a recently developed method (Ferreira et al., J. Immunol. 1981. 127: 2366). Small strain differences in specificity were detected. They were not inherited as an Igh allotype‐linked trait.
Marginal zone B cells express CR1 and CR2 receptors
Authors: Gray David , McConnell Ian , Kumararatne Dinakantha S. , Maclennan Ian C. M. , Humphrey John H. , Bazin Hervé
Published: February 2007

Opsonized yeast is known to bind strongly to the marginal zones in frozen sections of rat spleen (Kumararatne, D. S. et al., Eur. J. Immunol. 1981. 11: 858). This study reports an analysis of the cells involved in this binding. Sheep red cells coated respectively with C3b, C3bi or C3d were used as indicator cells. These showed homogeneous binding of both C3b and C3bi to marginal zones and germinal centers. C3d‐coated red cells bound in a uniform speckled pattern to marginal zones. They also bound to germinal centers and the small lymphocyte zones of the follicles. Selective depletion experiments were undertaken to show that binding to marginal zones was a property of the IgM+ and IgD− B cells characteristic of this area. Binding to germinal centers was attributable to follicular dendritic cells. The C3d receptors in follicles were shown to be on IgM+ and IgD+ small B lymphocytes.
Monoclonal autoantibodies to histones from autoimmune NZB/NZW F1 mice
Authors: Laskov Reuven , Muller Sylviane , Hochberg Malka , Giloh Haim , van Regenmortel Marc H. V. , Eilat Dan
Published: February 2007

Fusion of spleen cells from autoimmune NZB/NZW female mice with drug‐resistant myeloma cells (clones NSI/1, X63‐Ag8.653 and NSO/1) produced hybrid clones which secreted antibodies to various nuclear components. Roughly 50% of the anti‐nuclear hybridomas produced antibodies reacting with DNA, 20% with RNA and 30% reacted with other nuclear antigens. Two hybridomas of the latter group were cloned and studied in detail. They secreted antibodies which produced bright fluorescence staining of nuclei and metaphase chromosomes. The specificity of the antibodies was determined by testing them in an enzyme‐linked immunosorbent assay and a radioimmunoassay against individual acid‐ and salt‐extracted histones, against histones mixed two and three at a time and against histone complexes isolated as such from chromatin. One of the monoclonal antibodies was specific for histone H2B and reacted with the histone free in solution or when present as a H2A‐H2B complex. The second monoclonal antibody recognized a specific conformation in the H3‐H4 complex that was present only when the complex was obtained from chromatin by salt extraction. The same conformation, however, could be induced by adding histone H2B to a mixture of acid‐extracted H3 and H4.

Our findings show that the autoimmune syndrome in NZB/NZW mice resembles human systemic lupus erythematosus not only in the incidence of antibodies to DNA and RNA, but also in the production of autoantibodies to histones.
The expressed lysozyme‐specific B cell repertoire I. Heterogeneity in the monoclonal anti‐hen egg white lysozyme specificity repertoire, and its difference from the in situ repertoire
Authors: Metzger Dennis W. , Ch'ng Lean‐Kuan , Miller Alexander , Sercarz Eli E.
Published: February 2007

A panel of closely and distantly related lysozymes and lysozyme‐peptide fragments were utilized in assessing the specificity repertoire of murine anti‐hen egg white lysozyme hybridomas. The 44 monoclonal antibodies could be divided into a minimum of 18 fine specificity groups in tests using the lysozyme panel. Two hybridoma products were specific for epitopes containing amino acids 68 and 121, respectively; and another was specific for an epitope including amino acids 113–114. Several hybridomas demonstrated unique heteroclitic binding, for example, to bob‐white lysozyme (BEL), but not other closely related lysozymes, suggesting lysine at position 68 in BEL as an important residue of recognition. Radioimmunoassays using lysozyme peptides bound to plastic plates specified the regional specificity of 6 additional antibodies of the 44. A comparison of the specificities of monoclonal antibodies with antibody produced in vivo showed some major differences suggesting that those cells proceeding on to antibody formation in the regulatory milieu of the whole animal are a selected subpopulation.
Activation and proliferation signals in mouse B cells I. A comparison of the capacity of anti‐Ig antibodies or phorbol myristic acetate to activate B cells from CBA/N or normal mice into G1
Authors: Hawrylowicz Catherine M. , Keeler Keith D. , Klaus Gerry G. B.
Published: February 2007

B lymphocytes from the CBA/N mouse do not synthesize DNA when cultured with anti‐Ig antibodies. However, these cells like normal B cells, do manifest increased Ia antigen expression and RNA synthesis (i.e. enter G1) when stimulated by anti‐Ig, even at doses which are nonmitogenic for normal B cells. Pretreatment of both normal and CBA/N B cells with anti‐Ig also primes them to give an enhanced proliferative reponse to lipopolysaccharide (LPS). The tumor promoter phorbol myristic acetate (PMA) also enhances RNA synthesis and Ia antigen expression in B cells from both normal and CBA/N mice. However, PMA only primes CBA/N B cells to respond to LPS: pretreatment of normal B cells with PMA causes a modest suppression of LPS‐induced, and a marked suppression of anti‐Ig induced, DNA synthesis.

These results therefore confirm and extend earlier data showing that there are distinct activating (G0 to G1) vs. proliferative (G1 to S) signals discernible in B cells. They also suggest that the activation mechanism of CBA/N B cells is subtly different from that of any known subpopulation of normal B cells.
Mechanism of activation of the classical pathway of complement by monoclonal IgE (DES). Restricted regulation of C4b by C4b‐binding protein
Authors: Saint‐Remy Jean‐Marie R.
Published: February 2007

A human monoclonal IgE from patient DES, IgE (DES), has been shown to activate the classical pathway of complement. The mechanism of this activation has been investigated and can be summarized as follows: (a) IgE (DES) is able to bind and activate C1 in a dose‐dependent fashion. This activation increases with the size of the aggregates used, but the affinity of C1 for IgE (DES) is weaker than for IgG. (b) A classical pathway C3 convertase can be assembled on IgE (DES) using purified C1, C4 and C2. The formation decay of this convertase is similar to that formed on IgG with an half‐life of 9 min at 37 °C. (c) The extrinsic regulation of the C3 convertase by C4bp is restricted on IgE (DES) as compared to IgG. This restriction is shown on both the formation and the decay of the convertase. The mechanism of activation of the classical pathway of complement by IgE (DES) thus present some similarities with the assembly of the C3 convertase by the alternative pathway.
Isolation of follicular dendritic cells from human tonsils and adenoids. II. Immunocytochemical characterization
Authors: Heinen Ernst , Lilet‐Leclercq Chantal , Mason David Y. , Stein Harald , Boniver Jacques , Radoux Daniel , Kinet‐Denoël Cécile , Simar Léon J.
Published: February 2007

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the generation of B cell memory. In the present report the isolation of FDC from human tonsils and adenoids is described. These isolated cells have an unusual spherical arrangement and enclose lymphocytes within extensions of their membranes. Their ultrastructural features are similar to those observed in situ. The reactivity of isolated FDC with a number of monoclonal antibodies was analyzed by immunofluorescence and by immunostaining (at the electron microscopic level) with colloidal gold. In keeping with the results of previous investigations on tissue sections IgM, IgG and IgA (but not IgD) can be detected on the surface of isolated FDC, as can C3b receptors and the FDC‐associated antigen detected by monoclonal antibody R4/23. The immunoglobulins associated with FDC are mostly embedded in an electron‐dense material. The majority of the lymphoid cells enclosed within the membrane extensions of FDC are of B cell type. These results suggest that isolated FDC may be suitable for further in vitro investigation of their role in the humoral immune response.
Cyclosporin A inhibits the delayed‐type hypersensitivity reaction: impaired production of early pro‐inflammatory mediator(s)
Authors: Shidani Babak , Milon Genevieve , Marchal Gilles , Truffa‐Bachi Paolo
Published: February 2007

The effect of cyclosporin A (CsA) on the delayed‐type hypersensitivity (DTH) elicited in mice by sheep red blood cells was investigated. Evidence is presented that a single injection of CsA adversely affects the inflammatory reaction. Sensitized T lymphocytes initiate the DTH reaction by their recruiting activity on phagocytic cells which infiltrate the cutaneous site of antigen deposition. CsA administration has no adverse effect on the recruitment of phagocytic cells at the site of the inflammatory reaction. The present studies show that CsA acts on specific T cells: (a) in adoptive transfer, T‐DTH‐mediating cells cannot elicit a response in mice treated with CsA 8 h before; (b) when collected 8 h after a single injection of CsA, T‐DTH‐mediating lymphocytes are no longer able to adoptively transfer the reaction. This conclusion is strengthened by in vitro studies: (a) the frequency of T‐DTH‐mediating lymphocytes is 50‐fold decreased after a short in vitro incubation with CsA; (b) in vitro production by concanavalin A‐activated lymphocytes of chemotactic pro‐inflammatory mediator(s) is abolished in presence of CsA.
Partial characterization of the putative rat interleukin 2 receptor
Authors: Osawa Hisao , Diamantstein Tibor
Published: February 2007

T lymphoblasts of rat origin were (a) surface labeled with 125I and (b) internally labeled with 3H‐marked sugars. Cell lysates were purified by immunoabsorption using the putative anti‐rat interleukin 2 (IL 2) receptor monoclonal antibody ART18. The purified material was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis. Two specific membrane components were detected: a 50‐kDa major and a 36‐kDa minor component in reducing and a 45‐kDA major and a 72‐kDa minor component in nonreducing conditions, respectively. Both components were found to be susceptible to trypsinization and to neuraminidase treatment. 3H‐labeled sugars were incorporated into the major component. The results indicate that the rat IL 2 receptor is either a 50‐kDa glycoprotein or a 36‐kDa molecule, or that both components are part of the receptor molecule.
Immunodominant protein epitopes II. The primary antibody response to hen egg white lysozyme requires and focuses upon a unique N‐terminal epitope
Authors: Wicker Linda S. , Benjamin Christopher D. , Miller Alexander , Sercarz Eli E.
Published: February 2007

The antibody response to a defined protein antigen, hen egg white lysozyme (HEL) has been investigated using an aminopeptidase‐treated HEL molecule, des‐1,2,3‐HEL (AP‐HEL). Surprisingly, removal of these three N‐terminal residues eliminates an epitope which is a dominant B cell determinant recognized in the primary antibody response to HEL. Thus, the initial antibody response focuses on a very small region of the molecule. Even more striking is the observation that removal of this epitope markedly reduces the immunogenicity of HEL. Therefore, the epitope is not only the focus of the primary antibody response, but is essential for the initiation of the response. This report demonstrates that a selective mechanism must be activated during the response to this protein antigen. Of the multitude of B cell determinants present on HEL, only a limited number are focused upon by the immune system.
Anti‐immunoglobulin antibodies IV. Cross‐reaction of anti‐idiotypic antibodies specific for rabbit and murine anti‐a1 allotype antibodies with Fc fragment of human immunoglobulins
Authors: Bona Constantin A. , Goldberg Burt , Metzger Dennis , Urbain Jacques , Kunkel Henry G.
Published: February 2007

Anti‐idiotype (Id) antibodies against anti‐a1 rabbit allotype antibodies were produced in rabbits and mice by immunization with polyclonal rabbit anti‐a1 allotype or with a monoclonal murine anti‐a1 allotype antibody, respectively. These antibodies recognize an interspecies cross‐reactive idiotope on anti‐a1 allotype antibodies. However, these anti‐Id antibodies also react with various subclasses of human IgG. In multiple systems, it was shown that these anti‐Id antibodies interact with the Fc fragment of human IgG and, therefore, exhibit a rheumatoid factor‐like activity. These results support the hypothesis that γ‐globulin may not be the only stimulus to clones producing rheumatoid factors and that perhaps other antibodies, especially anti‐Id antibodies, also bind γ‐globulin secondarily.
Autoimmunity following viral infection: demonstration of monoclonal antibodies against normal tissue following infection of mice with reovirus and demonstration of shared antigenicity between virus and lymphocytes
Authors: Tardieu Marc , Powers M. Linda , Hafler David A. , Hauser Stephen L. , Weiner Howard L.
Published: February 2007

Splenic lymphocytes from adult C57BL/6 mice infected with purified reovirus type 1 or 3 particles were fused with NS1 myeloma cells. Approximately 300 clones were obtained from each fusion (type 1 or type 3) and the supernatants from these clones were screened by radioimmunoassay for their ability to bind virus, T lymphocytes, brain, liver, lung tissues and isolated oligodendrocytes and ependymal cells. Approximately 10% of clones (33 and 26 clones, respectively) were positive for each fusion. For reovirus type 1: 21% of positive clones bound only virus, 64% bound one of the normal tissues but not virus, and 15% bound both virus and one or more of the normal tissues. For reovirus type 3: 19% of positive clones bound only virus, 73% bound normal tissue only, and 8% bound both virus and normal tissue. Only 3 positive clones were obtained from uninfected control animals. These experiments demonstrate that (a) during the course of an immune response to a virus, autoantibodies are generated which react with a large variety of normal tissues and that (b) there are shared antigenic structures between viral determinants and normal tissue that can be identified by monoclonal antibodies. Although these results suggest two mechanisms by which an autoimmune response may develop following viral infection, the biological significance of these autoreactive monoclonal antibodies remains to be elucidated.
Immune response against the T‐independent antigen α(1→3)dextran II. Occurrence of Bγ memory cells in the course of immunization with the native polysaccharide is T cell dependent
Authors: Schuler Walter , Schuler Amelie , Kölsch Eckehart
Published: February 2007

The immune response of BALB/c mice against the bacterial antigen dextran B1355S [α(1 → 3)dextran] (Dex), a class 2 T cell‐independent antigen, is largely restricted to IgM class antibody production. However, despite the fact that Dex fails to give rise to enhanced IgG responses upon repeated immunization, the development of Dex‐specific Bγ memory cells, i.e. resting B cells committed to the production of specific IgG antibodies, is observed upon immunization with Dex. These Bγ memory cells, albeit not activated to IgG production in situ, can be activated upon adoptive transfer into irradiated congenic BALB.Ighb mice. This mouse strain is a nonresponder strain to Dex. The expression of adoptively transferred Dex‐specific Bγ memory cells is T cell‐independent as T cell depletion of spleen prior to cell transfer into BALB.Ighb recipients does not abolish the IgG response. Dex‐primed athymic BALB/c nude mice, in contrast to euthymic mice, give a pronounced primary IgG response but do not develop Dex‐specific Bγ memory cells. Yet, they do so when reconstituted with syngenic T cells prior to immunization. This indicates that the formation of Dex‐specific Bγ memory cells requires the presence of functional T cells. The pronounced primary IgG anti‐Dex response of nude mice is greatly impaired by T cell reconstitution. Thus, with regard to T cell dependence, there is an inverse relationship between the formation of Bγ memory cells and the capacity to produce IgG anti‐Dex. Dex‐specific Bγ memory cells from BALB/c mice are expressed in congenic BALB.Ighb recipients (nonresponder to Dex) but not when transferred into identically treated syngenic hosts. This also applies to memory cells from Dex‐primed female (CBA/N × BALB/c)F1 [NBF1] or from (BALB/c × CBA/N)F1 hybrids. Dex‐specific Bγ memory cells from these donors are demonstrable upon adoptive transfer into BALB.Ighb mice, but they are not expressed when transferred into syngenic recipients, including male NBF1 hybrids. NBF1 males, albeit possessing the VH‐Dex+ allele, do not mount humoral responses to Dex, a deficiency which is ascribed to an X chromosome‐linked B cell defect. The apparent absence of Dex‐specific antibodies in NBF1 males provides an opportunity to examine whether Bγ memory cell expression is inhibited in syngenic recipients by anti‐Dex or autologous anti‐idiotype antibodies. The observed nonpermissiveness of NBF1 males for transferred Bγ memory cells excludes this possibility but rather suggests a cellular suppressor mechanism acting upon Dex‐specific Bγ cells.

From our results we conclude that the T cell‐independent terminal differentiation of Dex‐specific Bγ cells into IgG‐secreting plasma cells is blocked in euthymic BALB/c mice by a T cell‐mediated suppressor mechanism. This suppression allows the accumulation of Dex‐specific Bγ memory cells.
Characterization of human granular lymphocyte subpopulations expressing HNK‐1 (Leu‐7) and Leu‐11 antigens in the blood and lymphoid tissues from fetuses, neonates and adults
Authors: Abo Toru , Miller Charles A. , Balch Charles M.
Published: February 2007

Three subpopulations of human granular lymphocytes from blood and lymphoid tissues were characterized using combinations of the monoclonal antibodies (mAb) HNK‐1 (Leu‐7), Leu‐11 and VEP13. Each subpopulation was confirmed to possess natural killer (NK) cell functional capability, but a different level of cytotoxic efficiency (HNK‐1+Leu‐11− HNK‐1+Leu‐11+ < HNK‐1+Leu‐11+). In adult from 23 healthy donors, the subpopulations with HNK‐1+Leu‐11−, HNK‐1+Leu‐11+ and HNK‐1+Leu‐11+ phenotypes comprised 4.7 ± 3.0, 8.0 ± 6.4 and 3.9 ± 3.5% of mono‐nuclear cells, respectively. Despite their distinct surface marker phenotypes and NK functional ability, all 3 subpopulations exhibited granular lymphocyte morphology. One of these subpopulations, HNK‐1+Leu‐11−, also expressed the pan‐T cell antigen Leu‐4. Different patterns were observed in fetal bone marrow and cord blood, where the vast majority of HNK‐1+ cells lacked the Leu‐11 antigen (HNK‐1+ Leu‐11− cells). The HNK‐1 antigen was not expressed on granulocytes and their precursors, whereas both Leu‐11 and VEP13 antigens were expressed on these myeloid cells from fetal bone marrow and cord blood as well as adult bone marrow and spleen. Cell lines of granular lymphocytes cultured in the presence of interleukin 2 all possessed the HNK‐1+Leu‐4+ phenotype and NK functional capability but lacked the Leu‐11 and VEP13 antigens on their surface after 15 days of culture. Although granular lymphocytes expressing the Fc receptors reacting with the mAb Leu‐11 and VEP13, are the most functionally active NK cells, the HNK‐1+ subpopulation lacking the Leu‐11 and VEP13 antigens appears to be an important population (possibly an immature form of granular lymphocytes) for delineating the cell lineage(s) and differentiation of human granular lymphocytes. Although none of the currently available mAb react both inclusively and exclusively with human granular lymphocytes, the combination usage of these antibodies permits a more precise and comprehensive analysis of these subsets.
Cellular expression of idiotopes defined by monoclonal antibodies
Authors: Bast Bert J. E. G. , Cooper Max D. , Kearney John F.
Published: February 2007

Monoclonal anti‐idiotype (Id) antibodies with specificities for determinants related to the antigen‐binding sites of 3 BALB/c myeloma proteins, MOPC‐460, HOPC‐8 and J558, were used to study Id expression on murine lymphocytes. The monoclonal antibodies were shown to react only with Id structures associated with immunoglobulin on B cells. None of these 3 Id nor a VH Id, detected by a monoclonal antibody made against HOPC‐8 heavy chain, were found on T cells. These Id were detected on splenic B cells in neonatal mice; the frequencies in normal, nude and germ‐free mice were similar: MOPC‐460 Id+: 1.05 ± 1.7/104 spleen cells, HOPC‐8 Id+: 1.45 ± 1.2/104 and J558: 0.35 ± 0.6/104. Almost all Id+ cells bore surface IgM, a few expressed surface IgG. MOPC‐460 Id+ IgG+ cells were mainly γ2a+ or γ2b+, whereas J558 and HOPC‐8 Id+ IgG+ cells were γ3+.
In vivo regulation of the cytolytic T cell response to hapten‐altered self: suppressor T cells induced in the regional lymph nodes by exposure to syngeneic spleen cells
Authors: Wong Henry L. , Battisto Jack R.
Published: February 2007

During the course of examining the in vivo development of the cytotoxic T lymphocyte (CTL) response to hapten‐modified self antigens in mice, we have observed that it can be abrogated through prior exposure of the host's regional lymph nodes (LN) to normal syngeneic spleen cells (NSC). Suppression appeared to be antigen nonspecific and was best seen when animals were injected in the footpads with NSC at least 72 h before sensitization for CTL. The ability to prevent the development of the CTL response was restricted primarily to syngeneic splenic T and B cells since syngeneic thymocytes stimulated only partial suppression and syngeneic LN cells, as well as hapten‐coupled syngeneic spleen cells, did not at all. Suppression appeared to be a local phenomenon in that the NSC induced transferrable suppressor T cells to appear in the popliteal LN draining the footpads but not in spleens. In addition, animals splenectomized prior to injections of NSC showed abrogated CTL responses equivalent to sham‐splenectomized animals indicating that the spleen does not contribute to the mechanism of suppression. Finally, when only one footpad was injected with NSC, suppression was seen in the draining popliteal node and not in the contralateral node. Taken together, the evidence suggests that the source of the suppression and the suppressor T cells may be attributed to an in vivo syngeneic mixed lymphocyte reaction occurring between responder cells of the draining LN and injected stimulator spleen cells.
In vivo blockage of B cell maturation by splenic T cells of total lymphoid irradiated mice
Authors: Zan‐Bar Israel
Published: February 2007

The effect of fractionated total lymphoid irradiation (TLI) on the induction of cells blocking in vivo B cell maturation was examined. (BALB/c × C57BL/6)F1 mice received 200 rds lymphoid irradiation daily for 8 days. One month after termination of the irradiation splenic T cells of TLI‐treated mice were transferred, together with normal bone marrow cells, to lethally irradiated hosts. In addition, splenic cells or splenic B cells of TLI mice were transferred to irradiated hosts. Two months later, we checked the reconstituted mice for their ability to produce in vivo anti‐trinitrophenyl (TNP)‐Ficoll antibodies and their capacity to respond in vitro to dextran sulfate and lipopolysaccharide. In parallel, stained spleen cells were analyzed on the fluorescence‐activated cell sorter using monoclonal anti‐μ, anti‐λ and anti‐B220 surface marker antibodies.

The results indicate that splenic T cells originating from TLI‐treated mice cause maturation arrest of normal and TLI‐treated B cells, since normal bone marrow cells injected together with those cells have immature phenotypic and functional features. In addition, neither splenic cells nor splenic B cells of TLI‐treated mice can mature upon transfer to normal irradiated hosts. The B cells are IgM+, IgD−; they respond with a high proliferation rate to dextran sulfate and low proliferation rate to lipopolysaccharide, and poorly to TNP‐Ficoll challenge.
Suppression of the cytotoxic T cell response to minor alloantigens in vivo II. Fine specificity of suppressor T cells and lack of restriction by immunoglobulin heavy chain‐linked gene products
Authors: Gascoigne Nicholas R. J.
Published: February 2007

While it has been widely reported that some subsets of suppressor T cells are restricted by products of immunoglobulin heavy chain genes (particularly the variable region genes), we have been unable to find evidence for such interactions in the suppression of the primary in vivo cytotoxic T cell response to minor alloantigens. We have also examined the repertoire of the suppressor T cells active in this system and find that they recognize a different set of antigens from cytotoxic T cells, out of the same available pool of minor antigens.
Unusually restricted anti‐isotype human immune response to OKT3 monoclonal antibody
Authors: Baudrihaye Marc‐Francois , Chatenoud Lucienne , Kreis Henry , Goldstein Gideon , Bach Jean‐Francois
Published: February 2007

The unusual anti‐mouse immunoglobulin (Ig) sensitization of a renal allograft recipient who was treated prophylactically with the anti‐T cell monoclonal antibody OKT3 (IgG2a) is reported. Whereas in most patients, the injection of OKT3 (5 mg/day, i.v. for 13 days) induces the rapid appearance of neutralizing anti‐OKT3 antibodies, the patient reported here did not show the signs of conventional anti‐OKT3 sensitization. High levels of circulating OKT3 persisted and no OKT3+ lymphocytes reappeared during the whole treatment period. Moreover, no IgG or IgM anti‐OKT3 antibodies were detected at any time, using a specific enzyme‐linked immunosorbent assay. However, an atypical anti‐isotype response was evidenced in this subject whose Ig were shown by indirect fluorescence to bind to normal T cells coated with OKT3 or with other anti‐T cell murine monoclonal antibodies carrying the IgG2a isotype (no reactivity was observed with IgG1 or IgG2b molecules). The patient's Ig did not bind to normal T cells coated with F(ab')2 fragments of OKT3 and did not inhibit the binding of OKT3 to its target antigen indicating that they reacted with the Fc fragment of the OKT3 molecule. Additionally, and probably explained by this unusual anti‐OKT3 response, the patient's Ig were shown to inhibit the phytohemagglutinin‐induced proliferation of normal lymphocytes, to bind under selected in vitro conditions to normal T cells and lastly to enhance the antigenic modulation induced in vitro by OKT3 on its membrane receptor.
Antigen‐specific proliferative human T cell clones with specificity for diphtheria toxoid: genetic and molecular restriction by class II antigens
Authors: Triebel Frédéric , Missenard‐Leblond Véronique , Autran Brigitte , Couty Marie‐Claude , Charron Dominique , Debré Patrice
Published: February 2007

Human T lymphocyte clones (TLC) specific for diphtheria toxoid (DT) were isolated from a DR6/7 individual by cloning in soft agar in vivo sensitized T lymphocytes. We report here the isolation and characterization of 3 of these clones by studying: (a) the kinetic of activation, (b) the surface phenotypes, (c) the fine specificity for one of the 2 DT chains and (d) the genetic restriction of the proliferative response by the haplotype DR7.

Moreover, blocking studies of the proliferative response to DT by various immunochemically characterized anti‐HLA‐DR monoclonal antibodies indicate that, on the DR7 molecule, more than one Ia determinant may participate in the clonal DT proliferative response. By using human TLC of a defined specificity and well‐characterized anti‐DR monoclonal antibodies, such studies may help to define the functional repertoire of Ia molecules in man.
The E receptor regulates interferon‐gamma production: four‐receptor model for human lymphocyte activation
Authors: Wilkinson Miles , Morris Alan
Published: February 2007

The E receptor (binds sheep erythrocytes) is found on virtually all human T cells. Here we show that a monoclonal antibody 9.6, which recognizes and binds the E receptor, inhibited interferon‐γ production by human peripheral blood mononuclear leukocytes induced with the mitogens phytohemagglutinin, concanavalin A, Staphylococcal enterotoxin A and the monoclonal antibody OKT3. Metabolic activation (RNA and DNA synthesis) in human peripheral blood mononuclear leukocytes in response to mitogens was also sharply inhibited by 9.6. This inhibitory effect occurred early during the induction phase since 9.6 had much diminished inhibitory effects when added 15‐24 h after induction; peak IFN‐γ production and DNA synthesis occurred 3‐4 days post induction. An early event inhibited by 9.6 appeared to be interleukin 2 (IL2) receptor formation since: (a) the ability of mitogen‐stimulated peripheral blood mononuclear leukocytes to absorb IL2 was inhibited by 9.6, and (b) lines of T lymphocytes which already expressed IL2 receptors were largely resistant to the inhibitory effects of 9.6 on IFN‐γ production and DNA synthesis. The tumor promoters 12‐O‐tetradecanoyl phorbol‐13‐acetate and teleocidin largely reversed the inhibition by 9.6 of IFN‐γ production and metabolic activation induced by mitogens. A model for the control of IFN‐γ induction involving four receptors, those for mitogens, tumor promoter, IL2 and erythrocyte, is proposed.
Monoclonal antibodies to polymorphic epitopes on Ia antigens: three independent groups of determinants expressed on DRw6 homozygous cells
Authors: Johnson Judith P. , Wank Rudolf
Published: February 2007

Murine monoclonal antibodies directed against polymorphic epitopes on HLA‐linked antigens were readily obtained following a single immunization with DRw6‐homozygous cells. Five antibodies directed against class II antigens were isolated. Two precipitated DC‐like molecules and 3 DR‐like molecules from the immunizing lymphoblastoid cell line. Analysis of association with HLA‐DR antigens in a panel of 60 individuals revealed 2 antibodies directed against the DC1 specificity (S1, R1) and one against the MT2 specificity (R3). Antibodies S2 and S3 showed significant association with DRw6 (χ2 = 30.27) and DRw6 and w8 (χ2 = 18.86), respectively. An analysis of 29 haplotypes indicated that epitopes defined by these monoclonal antibodies appear to identify polymorphic determinants on three independent gene products which can be encoded by a single HLA haplotype.
A Mott cell hybridoma
Authors: Weiss Siegfried , Burrows Peter D. , Meyer Jutta , Wabl Matthias R.
Published: February 2007

A hybridoma is described that exhibits all the characteristic features of Mott cells. It has spherules (Russell bodies) in the cytoplasm made up of dilated rough endoplasmatic reticulum and containing condensed immunoglobulin (λ1 light chains). Some of the cells appear to be very fragile, and free spherules are often found on cell smears. Cells with the Mott cell characteristics are still able to divide, but they do not secrete immunoglobulin. Hybridomas of this kind should be useful for determining the place of the Mott cell within the scheme of B cell differentiation.
Sympathetic innervation of fetal mouse thymus
Authors: Singh Upendra
Published: February 2007

This study was carried out to investigate the presence of sympathetic nerve fibers in the developing thymus. Thymic rudiments from 13 days of gestation up to birth and adult thymuses were examined by histofluorescence microscopy to detect the presence of these nerve fibers during ontogeny. Sympathetic nerve fibers were first visible around day 17 of gestation and increased in density and distribution by the time of birth and in the adult thymus. The appearance of immunoreactive cells about the same time as the presence of nerve fibers in the thymic rudiments has been discussed in light of a regulatory role for the sympathetic neuronal input on the maturation of thymocytes during ontogeny.
Phorbol 12,13‐dibutyrate enhances lateral redistribution of membrane glycoproteins in human blood lymphocytes
Authors: Patarroyo Manuel , Gahmberg Carl G.
Published: February 2007

Nanomolar concentrations of 4β‐phorbol 12,13‐dibutyrate markedly enhanced the redistribution of concanavalin A receptors, the common leukocyte antigen and the Lyt‐3 antigen in human blood lymphocytes, as measured by cap formation. The effect on the lateral mobility of these cell surface molecules was dose dependent and occurred within a few minutes of treatment. 12‐O‐Tetradecanoyl phorbol 13‐acetate, another tumor promoter, was similarly active. 4α‐Phorbol 12,13‐didecanoate, which does not have tumor‐promoting activity, did not enhance cap formation. The effect of various drugs and treatments indicated that the phorbol ester‐enhanced cap formation was energy and temperature dependent and required functional microfilaments. Retinoic acid, an antitumor‐promoting agent, was inhibitory and trifluoperazine, an inhibitor of calmodulin‐dependent processes, had a minor inhibitory effect. Protein secretion and synthesis, extracellular Ca2+/Mg2+ and functional microtubules did not seem to be involved. The enhanced capping was inhibited by the alkylating agents tosyl phenylalanyl chloromethyl ketone and tosyl lysyl chloromethyl ketone but not by other protease inhibitors. The effect of various amino acid derivatives suggested the participation of an esterase. A comparative study of dose response, kinetics and sensitivity to drugs indicated a direct correlation between the phorbol 12,13‐dibutyrate‐enhanced redistribution of membrane glycoconjugates and the phorbol ester‐induced binding (adhesion) between human blood lymphocytes, a phenomenon previously described.