bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of alloantigen‐primed lymphocytes in vitro Quantitative analysis of the relative frequency of reactive lymphocytes in primed populations which respond to allogeneic stimulating cells
Authors: Corley R. B.
Published: February 2007

Populations of lymphocytes primed to alloantigens in vitro are stimulated by allogeneic cells which are unrelated to the specific stimulator cells used for priming. The number of lymphocytes in the primed population which responded to unrelated stimulators could be estimated in relation to the number of primed lymphocytes responding to the specific stimulator. This was done by measuring the responses of decreasing numbers of primed lymphocytes to various stimulator cell populations. Similar estimates were obtained on several occasions using the same combination of lymphocytes which were primed and retested at different times.

There was a close correlation between the estimated frequency of lymphocytes in a primed population which responded to unrelated stimulators and the number of responder lymphocytes required to obtain a measurable response. Stimulators which activated a high frequency of primed cells required fewer responder lymphocytes than those which activated lower frequencies of primed cells. The specific stimulator was capable of initiating a response using fewer responder lymphocytes than were most unrelated stimulator cells. This confirms that primed populations are predominantly enriched for lymphocytes responding to the specific stimulator.

At least some lymphocytes in a primed population responded to both the specific stimulator and unrelated stimulator cells. This was demonstrated in two types of experiments. In the first, it was possible to enrich lymphocytes in a primed population which responded to unrelated stimulator cells without depleting lymphocytes which also responded to the specific stimulator. In the second, primed lymphocytes from donor A, which showed strong reactivity to stimulators from donor D after priming with B stimulator cells, also showed significant reactivity to B stimulators after priming with D cells. These results strongly suggest that primed populations contain several subpopulations (clones) of lymphocytes whose specificities differ as exhibited by their responsiveness to unrelated stimulator cells.
Estimation by radioimmunoassay of VH determinants (Aa1) associated with rabbit T lymphocytes
Authors: Jensenius J. C. , Williams A. F. , Mole L. E.
Published: February 2007

A radioimmunoassay with specificity for the al allotype determinant of rabbit immunoglobulin (Ig) heavy chains was used for the quantitation of VH in detergent extracts of lymph node cells from a1a1/b4b4 rabbits. B cell‐derived Ig in the same extracts was estimated with a radioimmunoassay specific for L‐chain. About 2 × 105 molecules/cell was found by both assays when assuming a molecular weight of 1.5 × 105 dalton. Extracts prepared from lymphocytes depleted of B cells (surface Ig+ cells) were also found to contain corresponding amounts of a1 and L‐chain, with values varying from about 103 to 104 molecules/cell. The estimates were not influenced by the presence of inhibitors of proteolytic enzymes. Supernatants, obtained after keeping the lymphocytes in culture for 16 h, were analyzed by the same methods. Again, matching amounts of a1 and L‐chain were found in supernatants from nonfractionated as well as from B cell‐depleted populations.

The results obtained indicate that T cells do not carry or produce an excess of a1 compared to L‐chain, as would have been expected if the T cell antigen receptor carried the same variable region as the Ig heavy chain while being otherwise composed of nonimmunoglobulin‐like structures.
Peptide mapping of the λ‐like chains of the BASILEA rabbits
Authors: Jaton J.‐C. , Kelus A. S.
Published: February 2007

The recently established mutant strain of rabbits, named BASILEA, lacks the K polypeptide L‐chain which is replaced by a λ‐like type (bas). This is evident from the amino acid composition and peptide maps of the bas L‐chain when compared to the L‐chains of the rabbits suppressed for the expression of the b locus allotypes.
Decidual extracts suppress antibody response in vitro
Authors: Globerson Amiela , Bauminger S. , Abel L. , Peleg S.
Published: February 2007

Extracts of decidual tissue produced in pseudopregnant rats were found to suppress in vitro antibody response to α‐2,4‐d initrophenyl‐polylysine. The peak levels of both the total antibody response and the 2‐m ercaptoethanol‐resistant fraction were reduced. Extracts prepared in a similar manner from uteri of normal untreated or pseudopregnant rats did not exert such an effect.
Spontaneous, augmentable cell‐mediated cytotoxicity with limited target cell specificity in human blood
Authors: Saksela Eero , Lmir Turgut , Mäkelä O.
Published: February 2007

Nonadherent and nonphagocytic lymphoid cells from human peripheral blood became strongly cytotoxic against 51Cr‐labeled chicken red blood cells and cells from an established human myeloma cell line when subjected to repeated cycles of washing in phosphate buffered saline or treated with trypsin or lecithinase. Prior to augmentation the effector cells pass nylon wool columns that remove practically all surface IgG‐positive cells, but after augmentation they are retained in such columns. Augmentation docs not make them phagocytic or adherent to plastic surfaces. Incubation at 37°C of augmented cells prior to addition on the target cells restores the original nonaggressive state. Morphologically the cells making contact with the target cells are small or intermediate‐sized mononuclear cells.
Separation and properties of EA‐rosette‐forming lymphocytes in humans
Authors: Van Oers M.H.J. , Zeijlemaker W.P. , Schellekens P. T. H. A.
Published: February 2007

Human peripheral blood lymphocytes were separated into subpopulations enriched or depleted with respect to B lymphocytes (Ig‐bearing cells), T lymphocytes, (cells forming rosettes with sheep erythrocytes: E‐RFC) and Fc receptor‐bearing lymphocytes (EA‐RFC).

From the distributions and recoveries of the various cell types it could be concluded that there was very little overlap between Ig‐bearing lymphocytes and EA‐RFC. The latter cells partly belonged to “null” (non‐T, non‐B) cells; it was however demonstrated that 30 % of the EA‐RFC were T cells (E‐RFC).

The lytic capacity in antibody‐dependent lymphocytotoxicity (ADL) was shown to correspond with the proportions of EA‐RFC in the various fractions. Non‐T cells showed enhanced ADL activity when compared to the unseparated cells. Purified T cell populations also displayed ADL activity. Since the latter could not be due to contaminating non‐T cells, this activity was ascribed to Fc receptor‐bearing T lymphocytes.
Surface immunoglobulins of lipopolysaccharide‐stimulated spleen cells The behaviour of IgM, IgD and IgG
Authors: Bourgois A. , Kitajima K. , Hunter I.R. , Askonas Brigitte A.
Published: February 2007

The nature of Ig receptors carried by lipopolysaccharide (LPS)‐stimulated mouse spleen B cells was analyzed by surface iodination, direct antiserum precipitation and polyacrylamide gel electrophoresis. LPS activation led to a rapid decrease of surface IgD to 20 % and 80 % of the original level on days three and five of culture, respectively. Efficiency of iodination of cells doubled after culture but the proportional radioactivity in IgM remained constant.

We could definitively identify γ‐chains on the surface of cells, but only in small amounts (1 % of total surface Ig) and this expression of IgG remained constant during 5 days of culture.
Control of immunity in parental and F1, hybrid mouse strains to a spontaneously arising parental tumor I. Correlation between in vitro and in vivo anti‐tumor reactivity in responsive and unresponsive animals
Authors: Levy R.B. , Waksal S.D. , Shearer Gene M.
Published: February 2007

This study has investigated the in vivo and in vitro cellular immunity of the AKR/J, (AKR/J × C57BL/6)F1, and (AKR/J × DBA/2)F1 mouse strains to a spontaneously arising AKR/J tumor. The study concludes that: 1) there is an excellent correlation between the growth of the tumor in vivo, and the ability of spleen cells from the respective strains to generate both primary and secondary cell‐mediated cytotoxic responses in vitro; and 2) one F1 host can be considered a responder against this tumor, whereas the other F1 strain studied appears to be genetically nonresponsive. Possible mechanisms relating to the observed patterns of response are discussed.
Hapten‐bearing cell in carrier‐determined tolerance
Authors: Aldo‐Benson Marlene , Borel Y.
Published: February 2007

The relationship between tolerance to the 2,4‐dinitrophenyl (DNP) hapten and cells bearing this hapten on their surface, was investigated using autoradiography. Animals injected with nontolerogenic conjugates of DNP‐ε‐lysine‐IgG, DNP‐azo‐IgG, and DNP‐mustard‐IgG (J. Immunol. 1975. 115: 1409) did not have splenic lymphocytes bearing DNP on their surface 5 days after their last injection, while those injected with tolerogenic conjugates of DNP‐ε‐lysine‐IgG did have splenic hapten‐bearing cells. Control studies showed that I25I‐labeled anti‐DNP used to reveal hapten‐bearing cells did react with the nontolerogenic conjugates on the cell surface. There was no difference in the numbers of hapten‐bearing cells in animals receiving either 100 μg or 1000 μg of tolerogenic DNP‐IgG 5 days after the injection. Animals injected with 1000μg of tolerogen remained tolerant for 6 months. These tolerant animals still had hapten‐bearing cells in their spleens 6 weeks after injection. In contrast, animals which had lost tolerance 3 months after 200 μg of tolerogen injection did not have hapten‐bearing cells.

These experiments confirm that the hapten DNP remains on the surface of hapten‐binding cells in tolerance only. It is unlikely that the carrier alone, either nonspecifically or specifically via Fc binding, accounts for the presence of the tolerogen on lymphoid cells because it would be observed with nontolerogenic as well as tolerogenic DNP‐IgG conjugates. A direct relationship between tolerance and hapten‐bearing cells exists. The significance of this correlation to the mechanism of tolerance is discussed.
Regulation of the immune response II. Repressor T cells in cyclophosphamide‐induced tolerant mice
Authors: Ramshav I.A. , Bretscher P.A. , Parish C.R.
Published: February 2007

Specific antibody unresponsiveness was induced in adult CBA/H mice by the injection of cyclophosphamide 24 h after immunization with a large dose of horse red blood cells (HRBC). Four lines of experimental evidence indicated that this unresponsive state was maintained by active T cell repression. First, the cellular basis of the unresponsive state was in the T cell rather than the B cell population. Second, when normal spleen cells were transferred into the unresponsive animals, they were unable to break the unresponsive state. Third, the induction of unresponsiveness was antagonized by anti‐lymphocyte serum. Finally, T cells from unresponsive mice specifically repressed the anti‐HRBC antibody response of normal spleen cells when these were mixed together and injected into irradiated recipients.

However, although the mice were unresponsive to HRBC at the humoral level, via active T cell repression, they simultaneously expressed high levels of delayed‐type hypersensitivity (DTH) to HRBC. In contrast, we have reported recently (Eur. J. Immunol. 1976. 6: 674) that T cells from mice expressing humoral immunity to HRBC can specifically suppress the development of DTH to HRBC. On the basis of these two sets of observations, it is suggested that the frequently observed inverse relationship between humoral and cell‐mediated immunity is mediated by different types of inhibitory T cells. The role of T cell help in the induction of these different types of immunity is also discussed.
Mouse immunoglobulin receptors on lymphocytes: identification of IgM and IgD molecules by tryptic cleavage and a postulated role for cell surface IgD
Authors: Bourgois A. , Abney Erika R. , Parkhouse R.M.E.
Published: February 2007

The two mouse immunoglobulin receptors on lymphocytes (IgM and IgD‐like) were individually digested by trypsin. Their tryptic susceptibility, and the products released, were similar to those of their human counterparts. Evidence for a structural homology between human IgD and its presumed mouse counterpart has been provided by the remarkably similar profile of fragments resulting from digestion. More definitive homology awaits sequence determination. The extreme susceptibility of surface IgD to proteolysis contrasted with the resistance of surface IgM. We therefore propose that the major role of IgD is to release a fragment (Fabδ) following exposure to antigen and then elicit a regulatory anti‐idiotype response which acts through recognition of the protease‐resistant IgM idiotype remaining on the cell surface.
Experimental allergic neuritis induced by a basic neuritogenic protein (P1 L) of human peripheral nerve origin
Authors: Abramsky O. , Teitelbaum Dvora , Arnon Ruth
Published: February 2007

Experimental allergic neuritis (EAN) in the peripheral nervous system, without involvement of the central nervous system, was produced in laboratory animals by the injection of a basic neuritogenic protein, P1L, purified from human peripheral nerves. The animals manifested a positive skin test with P1L, and their lymphocytes were found to be transformed in vitro in the presence of this protein several days before the appearance of the clinical signs. Passive transfer of the disease was performed with lymph node cells from donor guinea pigs immunized with P1L protein. EAN, the experimental model for the human disease Guillain‐Barré syndrome, was shown to be a transient disease and could be suppressed by the administration of hydrocortisone.
Cell surface components of carcinogen‐induced lymphoid tumors in SJL/J mice
Authors: Haimovich J. , Bergman Y. , Linker‐Israeli Mariana , Haran‐Ghera N.
Published: February 2007

Preleukemic cells could be detected in the bone marrow cell population of SJL/J mice within several days after induction of leukemia by repeated feedings with a chemical carcinogen 7,12‐dimethylbenz[a]anthracene (DMBA). Bone marrow cells collected 7,30 or 60 days following carcinogenic treatment, developed lymphoid tumors upon transplantation into syngeneic irradiated recipients. The incidence of these tumors varied between 40–45 % when the bone marrow cells were collected and transferred 7–30 days after feeding with DMBA, and raised to an incidence of 80 % when transferred 60 days after carcinogen administration (compared to 50 % incidence in the DMBA‐treated bone marrow donors). A survey of several cell surface components on the lymphoid tumor cells, obtained after transplantation of preleukemic cells, indicated that most of the tumor lines bore both the Thy‐1.2 antigen (weak) and the Fc receptor, whereas the rest were positive only for the Fc receptor. None of these tumor cell lines would yield a significant amount of cell‐bound immunoglobulin.
Spontaneous release of Fc receptor‐like material from human lymphoblastoid cell lines
Authors: Molenaar J.L. , Van Galen M. , Hannema A.J. , Zeijlemaker W. , Pondman K.W.
Published: February 2007

In the culture medium of some human lymphoblastoid cell lines material is released with the following properties: (a) hemagglutination reaction of IgG‐sensitized erythrocytes; (b) enhancement of precipitation of DNA‐anti‐DNA complexes; (c) inhibition of binding of Clq to immune complexes; (d) inhibition of immune complex binding to lymphocytes; (e) inhibition of antibody‐dependent lymphocytotoxicity The material is not identical with Clq or rheumatoid factor, it is heat resistant (30 min at 56 °C); the molecular weight is about 100 000 daltons and it is capable of inhibiting antibody production in vitro

It is suggested that this material consists of Fc receptors spontaneously shed from lymphocyte membranes.
The importance of the serologically detectable histocompatibility antigens in the induction and effector step of cell‐mediated lysis
Authors: Dennert G. , Hyman R.
Published: February 2007

The induction and effector steps of T cell‐mediated cytotoxicity (CMC) have been studied using a mouse tumor cell line and its variant, which is deficient in serologically defined (SD) H‐2 antigens. In allogeneic mice the SD+ cell line induces CMC, while the SD− cell line does not. However, both cell lines can be lysed by xenogeneic rat lymphocytes. Antiserum specific for rat T cells was used to demonstrate that CMC of both targets is partially due to T cells. In allogeneic or syngeneic mouse systems the SD− cells coupled with the 2,4,6‐trinitrophenyl (TNP) residue can neither induce CMC nor serve as targets for CMC, while TNP‐coupled SD+ cells can serve both as immunogen and as targets. Thus allogeneic or syngeneic mouse T cells do not interact with the TNP group on targets lacking H‐2 SD antigens. However, mouse T killer cells sensitized to TNP‐coupled cells may lyse TNP‐coupled targets carrying different H‐2 haplotypes. These experiments show that the induction and effector steps of CMC executed by mouse T cells, using TNP‐coupled cells as immunogen or targets, need not necessarily demonstrate restriction with regard to a certain genetically defined H‐2 haplotype. The presence of cell surface H‐2 SD antigens is, however, absolutely necessary for the induction and effector steps of CMC by mouse T cells. Using cold target inhibition assays, it was not possible to demonstrate recognition of the TNP moiety on TNP‐coupled SD+ cells.
The immune response to allogeneic rat platelets; Ag‐B antigens in matrix form lacking la
Authors: Welsh K. I. , Burgos H. , Batchelor J. R.
Published: February 2007

Allogeneic rat platelets fail to induce either primary antibody or cell‐mediated immune responses despite repeated injections. Platelets bear Ag‐B epitopes which are capable of being recognized by antigen‐reactive T and B cells since primed rats develop secondary responses after challenge with allogeneic platelets. The secondary responses induced decrease rather than increase on repeated injection of platelets. Repeated injection of allogeneic platelets into nonprimed rats leads to a state of specific, partial non‐reactivity; recipients given such treatment show marked depression of cytotoxic antibody responses, but normal cellular immunity after challenge with viable lymphoid cells taken from the platelet‐donor strain. Injection of normal rats with allogeneic platelets mixed with 3rd party, viable lymphoid cells, does not provoke an anti‐platelet Ag‐B antibody response.
Restoration of the T lymphoid system of nude mice: different regeneration of neonatal and adult thymuses
Authors: Loor F. , Hägg Lena‐Britt
Published: February 2007

When a neonatal thymus and an adult (reticuloepithelial) thymus from normal mice are simultaneously grafted to individual adult nude mice, the host‐derived T cell precursors regenerate the neonatal thymus more efficiently than the adult (reticuloepithelial) thymus. Thus, this is a direct cause for the poor restoration of the T lymphoid system of nude mice by adult and/or reticuloepithelial thymus grafts.
Genetic selection of mice for quantitative responsiveness of lymphocytes to phytohemagglutinin
Authors: Stiffel C. , Liacopoulos‐Briot Monique , Decreusefond C. , Lambert Francine
Published: February 2007

A two‐way selection was performed in mice according to the quantitative in vitro response of lymph node lymphocytes to the mitogenic activity of phytohemagglutinin (PHA).

The foundation population was composed of outbred mice produced by reciprocal mating of equal numbers of mice from four different colonies. The selective breeding was carried out by mating of mice at each generation giving the best or the lowest response, respectively.

The progressive interline separation produced by 6 generations of selective breeding demonstrates that responsiveness to PHA is submitted to polygenic regulation. The heritability of the character investigated is 0.28 ± 0.08.

The interline separation is also found with another T mitogen, concanavalin A (Con A). In spleen cells PHA and Con A produce a similar interline difference.

In contrast, the purified protein derivative of tuberculin (PPD) stimulated both lines equally, and E. coli lipopolysaccharide gave only a slightly higher response in high line. This finding implies that our selection based upon response to PHA did not influence B cell function.
Continuously proliferating allospecific T cells, lifespan and antigen receptors
Authors: Dennert G. , Raschke W.
Published: February 2007

Allospecific mouse T cells derived from one‐way mixed lymphocyte cultures after 19 months in tissue culture still require allogeneic stimulation for their proliferation. If injected into normal or immunodeficient mice these cells do not form tumors. After proliferation over long time periods or after extensive expansion these T cells tend to lose their cytotoxic activity which cannot be reconstituted by addition of cells from active cultures of a different specificity. Accordingly, the specificity of the cytotoxic and proliferative response was investigated. The cytotoxic activity appears to be specific for the H‐2 SD antigens, while the proliferative response and also the activation of cytotoxicity in resting cultures is only triggered by lymphocyte activating determinants (LAD) coded either inside or outside the H‐2 region.

The receptors for LAD on these allospecific T cells appear to be clonally distributed. This finding comes from the observation that old and therefore highly selected lines only react to some LAD while younger ones react to many others as well. A search for immunoglobulin on these functional and antigen‐specific thymus‐derived lymphocytes (T cells) was performed using surface radioiodination, immunoprecipitation and polyacrylamide gel electrophoresis combined with autoradiography. Using various antisera no or very little immunoglobulin molecules were found on these T cells. The small amount of immunoglobulin was attributed to a contamination of allogeneic spleen cells used to stimulate the T killer cells.
Linear density gradient separation of human lymphocyte subsets
Authors: Zier Karen S. , Huber C. H. , Braunsteiner H.
Published: February 2007

Linear density gradients were used to separate either unsensitized human peripheral blood lymphocytes or cells sensitized in mixed leukocyte culture (MLC), at different time points in the immune response. Testing of cells from the various density fractions for their ability to respond in MLC and cell‐mediated lympholysis (CML) revealed that (a) activity between individual fractions differed, as well as activity between individual fractions and a suspension of unfractionated cells, (b) although precursor cells of MLC and CML were maximally enriched in closely associated light density regions, their respective distribution profiles were strikingly different, and (c) the density of cells responding in MLC and CML differed depending upon the point of the immune response at which the cells were separated. Whereas effector cells were of light density relative to the precursor cells, putative memory cells for CML exhibited a high density.
In vitro secondary mixed leukocyte reaction (MLR)
Authors: Fathman C. G. , Nabholz M.
Published: February 2007

T cells from strain A primed in vitro to (C57BL/6 × A/J)F1 [(B6 × A)F1 ] cells, respond better to restimulation by (B6 × A)F1 than by B6 or a 1:1 mixture of A and B6 cells. The increase in the response to F1 cells is specific and due to MLR determinants present on (B6 × A)F1 cells but not on either of the parental cell types. (B6 × A)F1 cells express more than one F1‐specific MLR determinant, and this expression is dependent upon products of alleles of at least two loci within the major histocompatibility complex (MHC). Responsiveness to these F1‐MLR determinants is apparently controlled by more than one locus within the MHC.
Transfer of idiotype suppression and idiotypes by leukocytes from ascitic fluids
Authors: Ju S. ‐T. , Sato S. , Nisonoff A.
Published: February 2007

A procedure is described for producing ascites containing both high concentrations of antibodies and immunologically active leukocytes. In mice that were immunologically suppressed with respect to a cross‐reactive idiotype, the ascitic cells were found to be very active in adoptively transferring the suppressed state to mildly irradiated, syngeneic recipients and simultaneously transferring the capacity to produce the “private” idiotype characteristic of the donor's anti‐ p‐azophenylarsonate antibodies. The participation of both T and B cells is therefore suggested. As few as 2 × 106 cells were sufficient for suppression and for inducing the production of the private idiotype in the recipient, in concentrations comparable to that of the donor mouse. A single donor can thus be used to colonize many recipients with the private idiotype, without sacrifice of the donor. The method should be useful in structural studies of antibodies of a given specificity with different idiotypes, and for investigations of the mechanism of idiotype suppression, as well as other studies in cellular immunology.
The relative distribution of foci forming antibodies to two different haptens in repopulated mouse spleens
Authors: Sullman Susan F. , Feinstein A.
Published: February 2007

The distribution has been studied of the foci of antibody‐secreting cells in the spleens of mice responding to two different haptens, 4‐hydroxy‐5‐iodo‐3‐nitro‐phenacetyl (NIP) and 2,4‐dinitrophenyl (DNP) on identical or different carriers, using a sensitive focus assay technique.

Mice were irradiated and repopulated with an excess of spleen cells from donor mice primed with the two haptens and a limiting number of cells primed to one carrier. The recipient mice were then challenged with both haptens, each conjugated to a different sample of the identical carrier. The incidence of monospecific foci occurring in different areas of the spleen was 21 % for each hapten, and the coincidence of foci directed to the different haptens occurring in the same area of the spleen was about 31%. This distribution was not significantly different from that seen in experiments when a further population of cells primed to a second carrier was also injected, followed by challenge with the two haptens conjugated to the different carriers. Experiments in which small fragments of the spleens were cultured confirmed, in the single carrier system, the presence of regions in which antibody to one hapten only was secreted, and of other regions in which antibodies to both NIP and DNP were secreted.

These results support the hypothesis that cooperation is an extremely local and selective phenomenon, such that in our system one effective T cell is able to help only one B cell precursor to develop into a clone of antibody‐secreting cells.
Specificity of T and B lymphocytes for myeloma protein 315
Authors: Jørgensen T. , Hannestad K.
Published: February 2007

The antibody response of BALB/c mice directed against the idiotype of the BALB/c myeloma protein MOPC 315 (M315) is T cell‐dependent. The specificity of helper T cells for M31 5 was investigated. Helper cells were primed with M31 5, M315 affinity‐labeled with Nα‐bromoacetyl‐Nε‐2,4‐dinitrophenyl‐L‐lysine, M315 L‐chain and H‐chain the M315 Fv fragment, myeloma protein MOPC 460 and monoclonal human kappa and lambda chains. The primed cells were transferred together with (4‐hydroxy‐5‐iodo‐3‐nitrophenyl(acetyl)) (NIP)‐primed B cells to 500 R‐irradiated recipient syngeneic BALB/c mice which were challenged with NIPsM315. The anti‐NIP antibody responses were augmented by helpers primed with all derivatives and subunits of M315. This effect disappeared almost completely when the helper cells were treated with anti‐Thy‐1,2 and C prior to transfer. Priming with M460 induced weak and inconsistent helper effects, which opens the possibility that some of the helper cells may recognize nonidiotypic determinants on M315. The strong and consistent helper effect induced by free M315 L‐chain (L‐31 5)‐primed cells was not due to dissociation of NIP‐L‐315 from intact NIP5 M315 used for challenge, because L‐315‐primed T cells also augmented the antibody response against the idiotype of M315 which is only expressed on associated (H+L) chain pairs. In contrast, BALB/c antibodies elicited by free L‐315 were specific for a determinant which was present on free L‐chains but which was not or only minimally accessible on the complete M315. The data indicate that the helper cells recognize determinants which are separate from the ligand binding site of M315 and which are accessible on both the complete M315 7 S subunit and its isolated chains. In contrast, B cells stimulated by free L‐315 recognize determinants which are hidden on associated (H+L) chains. Moreover, the associated (VL+VH) domains of M31 5 Fv fragment, which lacks C domains are immunogenic for T helper cells.
Embryonic bursa development in vitro
Authors: Ritter Mary A. , Lebacq Anne‐Marie
Published: February 2007

An in vitro culture system for embryonic chicken bursa is described, in which development, as measured by follicle formation (site of B lymphocyte development), position of large basophilic cells (stem cells), and presence of lymphocytes and cells containing cytoplasmic immunoglobulin (B cells), was comparable to that of the bursa in vivo. Using this system, preliminary studies on B lymphocyte differentiation were made. These support the view that bursa1 lymphocytes develop from precursors that migrate through the surrounding mesenchyme and into the follicles, but indicate that at least some of these cells may be “pre‐B cells” rather than pluripotent stem cells.
Humoral response to Salmonella typhimurium antigens in normal and thymectomized urodele amphibian Pleurodeles waltlii Michah.
Authors: Charlemagne J. , Tournefier A.
Published: February 2007

Normal and thymectomized 16‐month‐old Pleurodeles were immunized with Salmonella typhimurium H (flagellar) and 0 (somatic) antigens. Thymectomies were performed on 10‐week‐old stage 52 larvae, and the efficiency of thymectomy was determined 10 months later by allogenic skin grafting.

Each animal received, as a single intraperitoneal injection of 0.2 ml, 1.5 × 109 bacteria emulsified in Freund's complete adjuvant. Agglutinating antibodies were checked every 3 weeks, from 3 weeks after immunization t o the 18th week.

The antibody titers of H antigen‐immunized Pleurodeles increased during the first 6 weeks and reached a maximum by the 9th week in controls and the 12th week in thymectomized animals. The peak titers remained constant until the 18th week. Nine weeks after H immunization, mean agglutinating anti‐H titers are statistically higher in controls than in thymectomized Pleurodeles.

The antibody titers of 0 antigen‐immunized Pleurodeles increased exponentially during the first 12 weeks and remained constant until the 18th week. No significant differences were found between controls and thymectomized animals.

These results show that in Pleurodeles early thymectomy which is highly efficient in hypersensitivity reaction abrogation, has only a slight effect on the antibody synthesis against the flagellar H antigen of Salmonella which is in mammals a partially thymus‐dependent antigen.

In the absence of IgG‐equivalent synthesis in urodeles and the probably correlative lack of immunization against the classical soluble thymus‐dependent antigens, the question o f the participation of T cells in specific antibody synthesis remains open in these species.
Genetic control of two different types of antibody responses to oxazolone
Authors: Andó I. , Fachet J.
Published: February 2007

The genetic control of antibody responses induced by contact sensitization with oxazolone and immunization with an oxazolone‐mouse serum albumin conjugate was studied in inbred, H‐2‐congenic and nude mice.

Both types of antibody responses are T cell‐dependent and regulated by immune response genes mapping at the I‐B subregion of the H‐2 complex. The relative magnitude of antibody responses induced by the two methods of immunization is governed by a gene or genes mapping at the I‐B subregion of the H‐2 complex. Presentation of antigen by these two methods gives H‐2‐dependent distributions of high and low responsiveness which are exactly opposite. Non‐H‐2 genes affect the overall level of antibody response but not the relative magnitude of the responses.
Study of two different subpopulations of anti‐acetylcholine receptor antibodies in a rabbit with experimental autoimmune myasthenia gravis
Authors: Zurn Anne D. , Fulpius B.W.
Published: February 2007

Two different subpopulations of anti‐acetylcholine receptor antibodies were studied during the evolution of experimental autoimmune myasthenia in one rabbit immunized with Torpedo acetylcholine receptor. The results show that the subpopulation of antibodies directed against the toxin‐binding site of the receptor might play a role in the appearance of the paralysis observed in this particular case.
The ontogeny of B lymphocytes IV. Induction signals mediating phenotypic conversion of PC.1− to PC.1+B cells
Authors: Hämmerling U. , Chin Ann F.
Published: February 2007

The present study presents evidence that spleen and lymph node cell populations contain a distinct subpopulation of B lymphocytes amounting to < 1 % of the total, which are committed and poised to the expression of the PC. 1 alloantigen, and which can be triggered in vitro to express PC.1. The pheno‐type of the PC.l‐inducible cells has been determined as Ig+ Ia+ complement receptor (CR)+ PC.l− which characteristically is associated with mature lymphocytes. Since the PC.l alloantigen identifies plasmacytes, the induction experiments imply that the latter cells are in principle descendents of CR+ B lymphocytes.

The induction signal mediating PC.l− to PC.1+ conversion is different from that mediating early pro‐B cell induction. Inducing agents of PC.l−←PC.1 + include carbamylcholine, thymopoietin, prostaglandin F2α and 8‐bromo cyclic GMP, all of which have previously been shown to inhibit early pro‐B cell induction. Conversely, most agents inducing phenotype conversion in early pro‐B cells (e.g. lipopolysaccharide, tumor‐necrotizing serum, isoproterenol, prostaglandin E1 and dibutyryl cyclic AMP) are strong inhibitors of PC. 1 induction. The results suggest that inducible B lymphocytes are under dual control of agents imparting opposing signals to them, but that the mode in which they respond is reversed when they have matured to the CR+ state. Since PC. 1 expression coincides largely with differentiation to antibody‐forming cells, the reversal of responses to regulatory signals may be of significance as a safeguard against spurious activation of B lymphocytes.
The role of the Fc receptor (FcR) of thymus‐derived lymphocytes II. Presence of FcR on suppressor cells and direct involvement in suppression
Authors: Fridman W.H. , Fradelizi D. , Guimezanes A. , Plater Christine , Leclerc J.C.
Published: February 2007

Alloantigen‐activated T cells (ATC) were prepared by injecting C3H/He thymocytes into host‐irradiated BALB/c mice. ATC were taken from the spleen of the recipients at day 5 and tested for their activity on “In vitro” primary antibody production to sheep red blood cells (SRBC) induced in splenic C3H/He lymphocytes. ATC added 24 h after antigen were found to be suppressive. Separation of ATC by velocity sedimentation, according to cell size showed that suppressor cells were found in each population, medium and large lymphocytes, however, being more active. Separation of ATC, according to the presence of Fc receptor (FcR) at their membrane was achieved by velocity sedimentation after rosetting with IgG‐sensitized SRBC (EA). Suppressor cells were then found in FcR+ and not in FcR− fractions, the degree of suppression being parallel to the ratio of FcR+ cells. At both extremes, pure populations of FcR+ cells were highly suppressive, while populations of ATC, completely devoid of FcR+ cells, were inactive. Since FcR is a very labile molecule at the T cell surface and shed within 3 h at 37°C, but not at 4°C, ATC were pre‐incubated at each temperature and added 24 h after antigen to the spleen cell cultures. In these cases, ATC having released their FcR, were much less suppressive than control ATC, and in previous work we have shown that the suppressive activity was found in the cell supernatant associated with an FcR‐like molecule (immunoglobulin‐binding factor). The data therefore allow the conclusion that FcR may be a marker of nonantigen‐specific suppressor T cells and seems to be involved itself in the suppression phenomenon.
Idiotype suppression by maternal influence
Authors: Weiler Ivan Jeanne , Weiler E. , Sprenger Renate , Cosenza H.
Published: February 2007

In BALB/c mice, antibodies to the α‐(1–3) glucosidic linkage of some dex‐trans (Dex) carry the idiotype of the BALB/c myeloma protein J558. Both specific antibody and idiotype are inherited in a dominant fashion, linked to the immunoglobulin (Ig) (heavy chain) allotype Igla of BALB/c mice (Eur. J. Immunol. 1975.5: 775). In F1 hybrid mice from the parent strains SJL and BALB/c, we were able to suppress the expression of anti‐Dex antibodies by immunizing prospective SJL mothers to the J558 idiotype. The state of suppression in the progeny was ascertained by immunization with Dex, and tests for the following were carried out: (a) antibodies specific for Dex; (b) inhibition of such antibodies (if present) by anti‐idiotypic serum to protein J558; (c) presence of the J558 idiotype; and (d) concentration of λ1 chains (which are associated with the 558 idiotype) in the serum.

SJL mothers, once immunized, conferred suppression upon several successive litters, spanning a period of 4–5 months. Suppression in F1 progeny animals lasted for 16 weeks or more. Spleen cells from suppressed F1 mice which had neither been treated with Dex nor with J558 protein, were able to confer suppression to further F1 newborn mice.
T cells which proliferate in response to concanavalin A include cells which proliferate in mixed leukocyte reactions
Authors: Watanabe T. , Fathman C.G. , Coutinho A.
Published: February 2007

Selection in long‐term culture of alloreactive T cells, by successive in vitro restimulation with semi‐allogeneic cells, results in primed responder cell populations which maintain full proliferative reactivity to allogeneic cells as well as to the T cell mitogens concanavalin A (Con A) and phytohemagglutinin (PHA) but are depleted of cells which can effect target cell destruction in either a specific or nonspecific manner.

Con A‐induced T cell blasts (selected by velocity sedimentation) can revert to small resting lymphocytes in the presence of inert “filler” cells. Con A blasts which have reverted, readily proliferate in response to Con A or allogeneic stimulator cells but are largely depleted of effector killer cells and PHA‐re‐sponsive cells.
Mechanism of lymphocyte activation: the binding of phytohemagglutinin to the lymphocyte surface
Authors: Perlés Brigitte , Flanagan M.T. , Auger Judy , Crumpton M.J.
Published: February 2007

The dynamics of phytohemagglutinin (PHA)‐lymphocyte interaction was studied using 125I‐labeled PHA (leucoagglutinin) and pig mesenteric lymph node lymphocytes that had been depleted of erythrocytes, dead cells, adherent cells and immunoglobulin‐bearing cells. Evidence was obtained that PHA stimulated the majority of the lymphocytes to transform. Binding of PHA at 37°C was fairly rapid (rate constant for association: 2.6 x 105 M−1 sec−1), saturable, reversible and specifically inhibited by N‐acetylgalactosamine (Kdiss: 3 x 10−4 M) and unlabeled PHA. A Scatchard plot was curvilinear and gave evidence for 3.6 x 105 binding sites per cell comprising 8.7 % of high affinity sites (Kdiss: 3.7 x 10−9 M) and 91.3 % of lower affinity (Kdiss: 1.4 x 10−7 M). About 20 % of the sites were occupied under culture conditions giving maximal transformation. Alternative explanations for the curvilinear plot included negative cooperative interactions and/or increase in affinity through multivalent interaction. Negative cooperativity was supported by the demonstration that free PHA promoted the dissociation of bound PHA. Binding was not affected by metabolic inhibitors, and binding to purified lymphocyte plasma membrane resembled that to whole cells. These results suggested that PHA binding to whole lymphocytes was not grossly influenced by “capping”, endocytosis and shedding.
Enhancing effect of low dose cyclophosphamide treatment on the in vitro antibody response
Authors: Duclos HéLène , Galanaud P. , Devinsky O. , Maillot Marie‐Christine , Dormont J.
Published: February 2007

We have studied the effect of cyclophosphamide (CY) administration on the subsequent in vitro antibody response in the mouse. Treatment with a low dose (20 mg/kg) of CY four days before culture results in an increased IgM response to the T‐independent antigen trinitrophenylated polyacrylamide (TNP‐PAA), without affecting the background response of unstimulated cultures. This suggests that CY treatment eliminates a short‐lived suppressor cell, involved in the regulation of the in vitro B cell response. In contrast, the same regimen decreases the ability of nude mouse spleen cells to respond to TNP‐PAA, showing that the target of CY‐enhancing effect is a mature T cell. The increased response observed in conventional mice should be the result of a balance between the direct suppressive effect of CY on B cells and the elimination of a suppressor T cell, the latter phenomenon being of predominant significance in our conditions. The target of CY‐enhancing effect is nonadherent to plastic, but adherent to Sephadx G‐10 columns.
Structure of mouse Fc receptor
Authors: Burgois A. , Abney Erika R. , Parkhouse R.M.E.
Published: February 2007

A variety of mouse cell types were externally labeled with radioactive iodine and solubilized in detergent. A single chain radioactive molecule of mol. wt. 120 000 was precipitated from lysates of surface‐labeled lymphocytes, macrophages and fibroblasts by complexes between pneumococcal type 3 poly‐saccharide and its homologous rabbit antibody in the IgG form, but not as F(ab'Iz or Facb. The same results were obtained using an alternative precipitating system, namely ovalbumin and IgG and F(ab'Iz forms of rabbit antiovalbumin. The 120 000 mol. wt. compound could not be detected on a thymoma cell line (5 178) previously known to lack the Fc receptor. On the basis of these criteria the material was therefore identified as mouse Fc receptor.Although very susceptible t o proteolysis, the fragments resulting from digestion remain associated by disulfide bonds in such a way as t o still bind to the anti‐body‐antigen precipitate. The proteolytic fragmentation products (mol. wts. 75 000,45 000,20 000 and 10 000) only become apparent upon chemical reduction, but the ease with which the molecule is degraded explains the wide variation in mol. wts. reported for the Fc receptor, and is perhaps a clue to explain the biological role of the molecule.
Organ culture studies of nude mouse thymus
Authors: Jordan R. K. , Owen J.J.T. , Raff M.C.
Published: February 2007

There is evidence that peripheral lymphoid organs of nude mice, born from homozygous matings, contain a small proportion of θ‐positive lymphocytes indicating that nude mice may not be totally devoid of T cell function. It has been suggested that such lymphocytes may develop within the dysplastic nude thymus itself. While this suggestion receives no support from morphological studies, it has been claimed that on explantation to organ culture the developing nude thymus becomes lymphoid.

In this present study we confirm the presence of θ‐positive lymphocytes in peripheral lymphoid tissues of homozygous nude mice born of nude parents. However, when we have organ‐cultured nude thymus, explanted from homozygous nudeembryos at days 13, 14, 16 and 18 of gestation, we have found no histologica sign of lymphopoiesis nor have we detected any θ‐positive cells in such cultured material. On the contrary, the nude thymus in vitro develops into the polycystic structure characteristic of the adult nude thymus.

We conclude that the small number of θ‐positive cells present in the periphery result from extrathymic differentiation.
T lymphocyte tissue culture lines produced by cell hybridization
Authors: Hämmerling G.J.
Published: February 2007

This study describes the generation of permanent T cell tissue culture lines by cell fusion techniques. The AKR strain‐derived T cell tumor BW 5147 was hybridized in the presence of polyethylene glycol with various T cell populations isolated from antigen‐sensitized mice. Surface analysis of resulting hybrid cell lines showed expression of both Thy‐1.2 and H‐2 antigens which are characteristic for the lymphocyte used for fusion. In contrast, in hybrids derived from spleen cells neither expression of Ig nor of B cell‐typicyl Ia determinants was found suggesting either preferential hybridization of BW 5147 cells with T lymphocytes or extinction of B cell markers in hybrid cells. These hybrid lines which may display the immunological properties of the T cell population chosen are presently investigated for their antigen reactivity.
Identification of the effector cells in human blood displaying spontaneous cytotoxicity to chicken erythrocytes
Authors: Saksela E. , Häyry P. , Anderrson L. C.
Published: February 2007

By combining velocity and linear density fractionations as well as target cell rosetting techniques we have isolated and morphologically identified the human effector cell type responsible for spontaneous, trypsin‐augmentable cytotoxicity against chicken red cells and human myeloma cell line targets. This cell is a large lymphoid cell with strong α‐naphthyl esterase activity concentrated in a limited area in the cytoplasm usually at the indentation site of a slightly reniform nucleus. Cells with this morphology also formed plaques on chicken erythrocyte monolayers. The cell is nonphagocytic and nonadherent, it carries Fc receptors but no complement receptors on its surface, and shows a weak affinity t o sheep red blood cells (SRBC). The frequency of these cells based on morphological analysis is 3 × 104‐ 6 × 104/ml in normal human blood. This cell shows similarities (surface Ig‐, Fc+, C3‐) with the human natural killer (NK) cells lytic to hematopoetic target cell lines but differs in that the cytotoxicity is augmentable by trypsin and the affinity to SRBC is lower. Therefore, we postulate that these two killer populations represent different subpopulations of human NK cells.
Suppressor T cells in low zone tolerance II. Characterization of suppressor T and amplifier cells by physical and serological methods
Authors: Heuer J. , Stumpf R. , Kölsch E. , Shen F.W. , Hämmerling G.J.
Published: February 2007

Suppressor cells involved in low zone tolerance to bacteriophage fd have been characterized by serological and physical methods. Suppressor T cells are peripheral T2 cells which are Ly‐1‐, Ly‐2+ and Ia+. They are of high electrophoretic mobility, sediment 5 mm/h at 1 × g in a linear Ficoll 70 gradient, but are not restricted to a distinct band in a discontinuous bovine serum albumin gradient. Adherent phagocytic cells of low electrophoretic mobility can act as amplifier cells with a much shorter half‐life than suppressor T cells.