bluuebunny/crossref_metadata_2025 huggingface dataset:
Indomethacin‐sensitive suppressor cells regulate the cell‐mediated cytotoxic response to SV 40‐induced tumor‐associated antigens in mice
Authors: Glaser Moshe
Published: February 2007

Specific secondary cytotoxic reactivity (as measured by 51Cr‐release assay) against SV 40‐induced tumor‐associated antigens was generated in vitro in spleen cells of tumor‐free (BALB/c × C57 BL/6)F1 (CBF1) mice immunized against a syngeneic SV 40‐induced tumor of BALB/c origin (mKSA), following in vitro sensitization for 5 days with the relevant antigens in mixed lymphocyte‐tumor cell cultures. In contrast, spleen cells of CBF1 mice bearing the SV 40‐induced tumor demonstrated suppressed specific secondary cytotoxic reactivity following incubation with the corresponding antigens. Spleens from tumor‐bearing mice contained 4 times the number of mononuclear cells and 3 times the percentage of macrophages, as compared to spleens of normal mice. The percentage of B cells was also elevated in spleens of tumor‐bearing mice. There was a slight reduction in the percentage of T cells. The cytotoxic reactivity of spleen cells of tumor‐bearing mice was restored following removal of macrophages by either rayon adherence columns or iron and magnet, or incubation on plastic petri dishes. No such effect was seen with spleen cells of tumor‐free or normal mice. Spleen cells of tumor‐bearing mice inhibited the in vitro generation of secondary cytotoxic reactivity of spleen cells of tumor‐free mice, sensitized in vitro with SV 40‐induced tumor cells by mixing experiments. The suppressor cells were found to be macrophages by the 3 techniques for removal of macrophages described above. The addition of indomethacin (1–10 μg/ml), a noncompetitive irreversible prostaglandin synthesis inhibitor, to cultures of responding spleen cells from tumor‐bearing mice and stimulating SV 40‐induced tumor cells resulted in marked augmentation of spleen cells responsiveness. With higher indomethacin concentrations (100 μg/ml), no enhancement was seen. The augmenting effect was noted only when indomethacin was present during the initial 24 h of the 5‐day culture. Indomethacin at 1–10 μg/ml had no effect on cytotoxic reactivity of spleen cells of tumor‐free mice, whereas at higher concentrations (100 μg/ml) it had a strong suppressive effect. Preincubation of spleen cells of tumor‐bearing mice with indomethacin for 3 days abrogated their ability to suppress the generation of secondary cytotoxic reactivity of spleen cells of tumor‐free mice. It is hypothesized that indomethacin‐sensitive suppressor macrophages regulate the immune responsiveness in tumor‐bearing mice.
Functional Thy‐1+ cells in cultures of spleen cells from nu/nu mice
Authors: Dennert Gunther , Hyman Robert
Published: February 2007

Thy‐1+ lymphocytes, detectable by quantitative serum absorption, arise in cultures of spleen cells from congenitally athymic (nu/nu) mice supplemented with supernatants from cultures of normal spleen cells stimulated with the T cell mitogen concanavalin A. Pretreatment of nu/nu spleen cells with appropriate anti‐Thy‐1 alloantibody and complement prior to culture reduces their capacity to generate Thy‐1+ cells by about 90%. This shows that the majority of cells proliferating in these cultures are descendants of Thy‐1+ cells which can be detected in the original nu/nu spleens. Experiments aimed at exploring the function of these Thy‐1+ cells after culture in conditioned medium revealed that within one or two days after culture initiation, strong cooperative activity for a humoral response to xenogeneic erythrocytes can be detected. In mixtures of bone marrow‐derived lymphocytes from various mouse strains with cultured nu/nu spleen cells, it was observed that T‐B cooperation is not H‐2‐restricted. Attempts at inducing T cell‐mediated cytotoxicity to alloantigens in such cultures of nu/nu spleen cells were unsuccessful. In contrast, nonspecific cytotoxicity which was attributed to natural killer cells was regularly observed and could be maintained in these cultures over extended periods.
A theoretical analysis of the phenotypic expression of immune response genes
Authors: Grossman Zvi , Cohen Irun R.
Published: February 2007

This study presents a theoretical analysis of the phenotypic expression of the products of immune response (Ir) genes linked to the major histocompatibility complex. Recent evidence indicates that animals with “low”‐responder Ir genotypes can be induced to express adequate immune responses by minor variations in the manner or site of immunization. Hence, it is unlikely that Ir genes code for defective structural products in low‐responder animals. A quantitative model is presented of the behavior of Ir genes based on two principal elements: (a) clones of lymphocytes compete for prominence through processes of growth, differentiation and feedback suppression, and (b) Ir gene products influence the affinities of lymphocyte clones for antigenic determinants, without coding for the lymphocyte receptors for antigen. The theoretical analysis of this model leads to the conclusion that small differences in affinity on the level of single cells can be amplified through differential population growth and competition between clones of cells to produce a final response that appears “all‐or‐none” on a population level. Therefore, high or low responsiveness based on Ir genes can be explained by small shifts in the strength of interaction parameters. These small shifts can result from variation in H‐2 alleles, the mode of immunization, or the array of determinants on the immunogen; factors that were observed experimentally. These shifts in interaction parameters account for the observed flexibility of phenotypic expression of Ir genes. The model explains a number of immunological observations by a few basic facts or assumptions, and avoids the problem of postulating the existence of defects to account for low responsiveness. It aims at clarifying the relationship between systemic, macroscopic observations and the underlying cellular parameters. The translation of cellular characteristics into patterns of behavior manifested by populations of cells may not necessarily result in an averaging out of the characteristics, but could also accentuate them.
Antigen‐induced feedback suppression: antigen‐specific initiator T cells fail to recruit new antigen‐reactive cells in immunized mice
Authors: Tzehoval Esther , Segal Shraga , Feldman Michael
Published: February 2007

Experiments were carried out to investigate the control exerted by memory cells on the activation of virgin antigen‐reactive T cells. Spleen cells from normal mice, educated on human gamma‐globulin (HGG)‐fed macrophages, then injected into the footpads of syngeneic recipients, recruited antigen‐specific reactive lymphocytes in normal mice, but failed to do so in HGG‐tolerant or HGG‐immunized recipients. This inhibition of recruitment was antigen‐specific, since keyhole limpet hemocyanin (KLH) initiator lymphocytes did recruit KLH‐reactive cells in HGG‐immunized recipients. Spleen cells from immunized animals, unlike those from tolerant ones, were capable of supporting the generation in culture of HGG‐initiator lymphocytes. Hence, the suppression we observed in immunized mice cannot be simply attributed to conventional Ly 23 suppressor T cells. To analyze the mechanism of the observed suppression, we tested the capacity of initiator cells educated on macrophages fed simultaneously with KLH and HGG to recruit antigen‐reactive lymphocytes in normal as compared to immunized recipients. Such initiator lymphocytes recruited, in normal animals, both and HGG‐ and anti KLH‐reactive cells. Yet, in HGG‐immunized mice, initiator cells educated under similar conditions failed to recruit not only anti HGG‐reactive cells but also anti KLH‐reactive lymphocytes. This suggested that in HGG‐immunized recipients, stimulated by HGG initiators (or by HGG antigen), HGG memory cells may lead to the generation of a factor (or factors) which may then nonspecifically suppress the recruitment and maturation of virgin antigen‐reactive cells to unrelated antigens. This assumption is further strengthened by our findings which revealed that in the presence of HGG, spleen cells originating in HGG‐immunized mice exert a weaker mixed lymphocyte culture reaction to alloantigens. Thus, it appears that an antigen may induce, in the presence of specific activated memory cells, the generation of factors which may suppress antigen‐induced proliferation of certain T cell subsets. These results may contribute to our understanding of the possible homeostatic role played by memory T cells in feedback regulatory circuits existing among T cell subsets during immune processes. The possible role of such mechanisms in high‐ and low‐zone tolerance is discussed.
Mitogenic effects of partially purified interleukin 2 on thymocyte subpopulations and spleen T cells of the mouse
Authors: Bödeker Berthold G. D. , van Eijk Ronald V. W. , Mühlradt Peter F.
Published: February 2007

Partially purified interleukin 2 (IL‐2) promotes proliferation of mouse spleen T, but not B cells, and of peanut‐agglutinin‐negative (PNA−), and cortisone‐resistant “mature” thymocytes, but not of PNA+ “immature” thymocytes. Within the cortisone‐resistant thymocyte population, IL‐2‐responsive cells were found in the blast cell fraction. Proliferation was measured by [3H] thymidine incorporation and subsequent increase in viable cells. The mitogenic effect of IL‐2 could not be inhibited by 50 mM methyl‐α‐D‐mannoside which excludes contaminating concanavalin A (Con A) as a cause of mitogenicity. The relative increase in viable cells in IL‐2 vs. control cultures was abrogated by 1.5 mM hydroxyurea. A possible effect of IL‐2 on cell survival is thus ruled out. IL‐2, when acting as comitogen with Con A, affected only PNA− and cortisone‐resistant thymocytes. These cells also showed high intrinsic IL‐2 release when stimulated with Con A such that a comitogenic effect of externally added IL‐2 was only seen at low cell concentrations. PNA+ thymocytes could neither be induced to release IL‐2 nor did these cells become Con A‐responsive under the influence of IL‐2, thereby excluding an IL‐2‐mediated maturation.
Individual‐specific (idiotypic) T‐B cell interactions regulating the production of anti‐2,4,6‐trinitrophenyl antibody. II. Development of idiotype‐specific helper and suppressor T cells within mice making an immune response
Authors: Gorczynski Reginald M. , Khomasurya Barbara , Kennedy Marion , Macrae Susannah , Cunningham Alastair J.
Published: February 2007

The previous report demonstrated that serum and cells from CBA mice immunized with trinitrophenyl (TNP), when injected into normal, syngeneic “recipient” mice, induce the formation of apparently idiotype‐specific suppressor cells and serum factors, and that such regulatory elements develop within the serum of the TNP‐immunized animals themselves. In this report, it is indicated that regulator cells develop also within the spleens of TNP‐keyhole limpet hemocyanin‐immunized animals, and may in part be responsible for our earlier observation that T cells from TNP‐immune CBA mice stimulate optimal antibody production in culture when paired with B cells from the same individual animal. While some evidence for individual‐specific T helper cells was obtained, the poorer response of mismatched T and B cells could be attributed in part to Ly‐2.2‐bearing suppressor T cells. Overall, the results support the view that idiotype‐related regulation is not confined to dominant‐idiotype models but is also involved in heterogeneous anti‐hapten antibody responses.
Flow microfluorometric analysis of alloantigen expression during T cell development
Authors: Potter Terry A. , Hogarth P. Mark , McKenzie Ian F. C.
Published: February 2007

The fluorescence‐activated cell sorter (FACS) was used to examine the expression of several alloantigens on T cells: Thy‐1, Lyt‐1.1, Lyt‐2.1, Ly‐5, Ly‐6 and Ly‐7. Antibodies secreted by monoclonal cell lines were used to characterize the Thy‐1.2, Lyt‐1.1 and Lyt‐2.1 antigenic determinants, whereas Ly‐5.1, Ly‐6.2 and Ly‐7.2 determinants were identified with alloantisera raised by conventional hyperimmunization. Using indirect immunofluorescence with fluorescein isothiocyanate‐conjugated reagents, the profiles obtained with the FACS demonstrated that: (a) the expression of Thy‐1 is greater on normal thymocytes than on cortisone‐resistant thymocytes (CRT), lymph node and spleen cells; (b) in contrast to Thy‐1, the expression of Ly‐1 on normal thymocytes is less than on CRT, lymph node and spleen cells; (c) about 90% of normal thymocytes but < 50% of CRT, spleen and lymph node T cells are Lyt‐2+ and (d) although weakly expressed on normal thymocytes, the amount of Ly‐6 and Ly‐7 present on peripheral T cells was considerably increased. The significance of these findings and the potential for further analysis of T cell developmental pathways is discussed.
Biochemical comparison of HLA‐DR molecules derived from autologous human T and B lymphoblasts
Authors: Altevogt Peter , Fohlman Jan , Kurnick James T. , Peterson Per , Wigzell Hans
Published: February 2007

Earlier findings that human activated T blasts display HLA‐DR determinants have been confirmed. After phytohemagglutinin activation, Percoll gradient‐purified blast cells were cultured for two weeks in mitogen‐derived supernatants from human lymphocyte cultures. Using purified T blasts and internal labeling procedures, it was established that T blasts actively produced HLA‐DR‐like chains, as assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Further, HLA‐DR chains obtained from Epstein‐Barr virus‐transformed B cells and from T blasts of the same donor were compared. Two‐dimensional gel electrophoretic comparisons indicated a striking homology between 29 kD and 35 kD chains, obtained from the two different cell types. Peptide map analysis and preliminary amino acid sequence comparisons further supported this similarity. A more complete analysis would, however, be required to prove actual identity. The fact that human T blasts produce and display HLA‐DR molecules very similar, if not identical, to those present on B cells must then be incorporated into models discussing major histocompatibility complex‐restricted collaborations involving HLA‐DR molecules.
Trypanosome‐induced suppression of anti‐parasite responses during experimental African trypanosomiasis
Authors: Sacks David L. , Askonas Brigitte A.
Published: February 2007

The effect of Trypanosoma brucei infections on parasite‐specific antibody responses was examined by immunization of infected mice with radio‐attenuated trypanosomes of a noncross‐reacting clone. Antibody liters (total Ig) against variant surface antigen were determined by indirect immunofluorescence. The suppression resulting from acute infection was virtually complete, and is associated with the failure to control the first relapse variant of the acute clone. The suppression resulting from chronic infection was much less severe, and subsequently variant populations of the chronic clone are successfully controlled. Antibody collected 10 days after each of the first 3 peaks of parasitemia during chronic infection was titrated on the homologous parasite preparations isolated from each wave in individual mice. As the infection progressed, both IgG and IgM antibody responses to each successive wave declined. However, the decline of IgG antibody was more rapid than IgM, so that by the third parasite wave the mice were responding with predominantly, if not exclusively, low levels of IgM antibody. We conclude that the severity of trypanosome‐induced suppression of the anti‐parasite response and IgM response in particular, determines the course of infection by trypanosomes varying in virulence.
Identification and characterization of immature thymocytes responsive to T cell growth factor
Authors: Dráber Petr , Kisielow Pawel
Published: February 2007

The surface antigenic phenotype of peanut lectin agglutinin (PNA)‐separated, high‐density (“immature”) thymocytes which are the target for the T cell growth factor (TCGF) enabling this otherwise unresponsive cell population to mount a strong proliferative response to concanavalin A (Con A) has been studied. The results obtained indicate that (a) the major population of cells bearing the typical phenotype of immature thymocytes, i.e. low content of H‐2, high content of Thy‐1, TL, Lyt‐1 and Lyt‐2 antigens, is unable to respond to Con A in the presence of TCGF, and (b) that the responsive population constitutes a minor fraction (about 15%) of PNA+, high‐density thymocytes with surface antigenic phenotypes similar to those of mature T cells, i.e. high content of H‐2, low content of Thy‐1 and differentiated expression of Lyt antigens. Such a unique combination of properties and the presence of TL antigen on some members of the responding population suggest that it contains cells at intermediate stage(s) of differentiation between immature thymocytes and T cells.
Role of glycosylation in the H‐2‐restricted cytolysis of virus‐infected cells
Authors: Black Paul L. , Vitetta Ellen S. , Forman James , Kang Chil‐yong , May Richard D. , Uhr Jonathan W.
Published: February 2007

The role of the oligosaccharide portions of cell surface glycoproteins in the susceptibility of virus‐infected cells to H‐2‐restricted cytolysis was investigated by using the antibiotic tunicamycin (TM). TM inhibits the addition of sugars to the polypeptides of glycoproteins. TM treatment of P 815 cells before and during infection with vesicular stomatitis virus (VSV) inhibited glycosylation of proteins and reduced by about 50% the lysis of infected P 815 cells by VSV‐immune, H‐2‐identical killer cells. In contrast, TM treatment had a modest inhibitory effect on cytolysis of P 815 cells by alloimmune effector cells. TM treatment did not inhibit the surface expression of either H‐2 or VSV glycoprotein. Thus, glycosylation of H‐2 and/or viral glycoprotein is a prerequisite for the lysis of infected cells by H‐2‐identical, VSV‐immune cytotoxic cells.
Immunosuppressor cells from newborn mouse spleen are macrophages differentiating in vitro from monoblastic precursors
Authors: Piguet Pierre‐François , Irle Claude , Vassalli Pierre
Published: February 2007

Newborn mouse spleen, whose cells strongly suppress the in vitro humoral response of adult spleen cells, is essentially a hematopoietic organ. It contains a large percentage of proliferating cells, among which about 50% are erythroblasts (identified by their spectrin content) and about 15% are cells of the myelocytic and monocytic lineage. Lymphoid cells are a minority, with about 20% B and only 1‐2% T lymphocytes. After 4 days, a culture of newborn spleen cells contains 5‐10 times more macrophages than that of an adult spleen. Most of these macrophage precursors from the newborn spleen are proliferating cells, partially glass‐ or plastic‐adherent, which differentiate in culture into activated macrophages producing large amounts of plas‐minogen activator. It is this macrophage excess which is responsible for the immunosuppressive effect of newborn spleen cells in culture, as indicated by (a) the effect of silica particles added to the cultures, which both relieve the suppression and prevent the accumulation of macrophages and (b) the suppression of the humoral response of adult spleen cells when they are cultured on the adherent cells from a newborn but not from an adult spleen.

The suppressive effect of macrophages seems to result, at least in part, from the production of prostaglandin, since it can be relieved by indomethacin or aspirin. Suppression is not related to arginine depletion of the medium or to production of an excess of plasminogen activator. T lymphocytes from newborn spleen or lymph nodes have no suppressive capability.
The selective effect of tunicamycin on the secretion of IgM and IgG produced by the same cells
Authors: Blatt Cila , Haimovich Joseph
Published: February 2007

Cells of the hybridoma cell line X 63/38 C‐13 secreting both IgM and IgG have been used in studies on the importance of the carbohydrate moieties of the Ig molecules for their secretion. It has been found that the secretion of the IgM produced in the presence of the glycosylation inhibitor tunicamycin was strongly inhibited, while the secretion of the IgG produced by the same cells was only slightly affected.
Multiple B cell stimulation by individual antigen‐specific T lymphocytes
Authors: Pierce Susan K. , Klinman Norman R.
Published: February 2007

Recently, an experimental system has been described which allows for the isolation and antigenic stimulation of individual antigen‐specific helper T lymphocytes in collaboration with a nonlimiting number of primary B lymphocytes. In the studies presented in this report, this system has been employed to determine whether an individual T lymphocyte has the potential to interact with more than a single B lymphocyte, when the B cells are of different antigenic specificities. The results of these studies indicate that an individual influenza virus PR 8‐specific T lymphocyte has the ability to promote antibody responses of both trinitrophenyl (TNP)‐ and PR 8‐specific B lymphocytes in response to the in vitro antigen TNP‐PR 8. Similar results were obtained when T cells specific for the hapten TNP were used in collaboration with TNP‐ and PR 8‐specific B cells. These results demonstrate that an individual T lymphocyte has the potential to collaborate with more than one B lymphocyte, and that these B cells may differ in their antibody receptor for antigen. These results do not rule out a role for idiotype or allotype‐specific T cells in antibody responses but, rather, strongly argue that antigen‐specific T cells are able to independently initiate primary B cell responses of B cells with distinct antibody receptors. In addition, under these conditions, hapten‐specific helper T cells can be readily demonstrated and may facilitate the response of B cells specific for the same or different determinants.
Immunodepression in trypanosome‐infected mice VI. Comparison of immune responses of different lymphoid organs
Authors: Kar Santosh K. , Roelants Georges E. , Mayor‐Withey Kathleen S. , Pearson Terry W.
Published: February 2007

Mitogen stimulation of cells from various lymphoid organs of C3H/He mice chronically infected with an isolate of Trypanosoma congolense was studied at different time intervals after infection, using concanavalin A (Con A) and lipopolysaccharide (LPS). At the same time, changes in the percentages of T, B and null lymphocytes in these organs were determined by immunofluorescence staining. The responses of T and B lymphocytes in the spleen were totally depressed, and the cellular composition was drastically altered by day 14 after infection. Unlike the spleen, the lymph nodes showed minor changes in their T and B lymphocyte responses and cell composition during the course of the infection, except the B cell response and composition which were altered late in the infection. The thymus and bone marrow did not show any appreciable changes in their mitogen responses and cell composition throughout the infection. The peripheral blood lymphocytes showed reduced B cell responses. Spleen cells from chronically infected mice suppressed lymphocyte stimulation induced in normal spleen and lymph node cell populations by Con A, LPS and allogeneic stimulator cells. Lymph node cells from the same group of mice did not exhibit any such suppressor activity.

In the experimental system used here, the spleen is the primary site of immune depression, and other lymphoid organs such as the lymph nodes and thymus are very little affected.
Activation of the alternative complement pathway by normal and transformed cells in homologous and heterologous sera
Authors: McConnell Ian , Gorman Neil T. , Raniwalla Joher , Powell Patrick
Published: February 2007

A variety of both normal and viral transformed or infected cells have been tested for their ability to activate the alternative pathway of complement in either homologous or heterologous sera. Normal cell lines fail to produce alternative pathway activation in homologous sera but readily activate the alternative pathway in heterologous sera. In contrast, human cells, persistently infected with measles virus or chicken cells transformed with oncogenic avian viruses, produce a marked activation in homologous sera. It is suggested that in certain circumstances, the alternative pathway of complement can discriminate between normal and abnormal “self” cells or foreign cell surfaces.
Syngeneic thyroglobulin is immunogenic in good responder mice
Authors: Elrehewy M. , Kong Yi‐chi M. , Giraldo Alvaro A. , Rose Noel R.
Published: February 2007

Mouse thyroglobulin (MTg) or thyroid extract (TE) was given repeatedly to good responder C3H/Anf (H‐2k) and poor responder BALB/c (H‐2d) mice in the absence of adjuvant. Anti‐MTg antibodies reached high levels in good responder mice given high doses of thyroid antigen. To eliminate stimulation by alloantigenic determinants and reduce the chance of denaturation, TE from syngeneic mice was prepared freshly each week and injected into good and poor responder strains. Again, significant antibody titers were observed in good responder mice. The antibody was specific for MTg since (a) it was not inhibited by extracts of other organs and (b) it reacted strongly with the closely related rat Tg and weakly with Tg from other species. Histology revealed mononuclear cell infiltration of the thyroid of good responder, but not of poor responder mice, regardless of the strain used to provide the thyroid antigen. The data demonstrate the presence of both T and B cell populations reactive with this self antigen and their stimulation by repeated high doses of antigen, without the aid of adjuvant, to override the regulatory controls that normally prevent autoimmune responses.
Cytotoxic T lymphocytes generated across an I‐Ab mutant difference are directed against a molecule bearing Ia antigens
Authors: de Waal Leo P. , Melief Cornelis J. M. , Melvold Roger W.
Published: February 2007

The recently discovered B6.C‐H‐2bm12 (bm12) histocompatibility mutant bears a mutation of the I‐A subregion of the H‐2b haplotype. We have studied cytotoxic T lymphocytes (CTL) generated in secondary mixed lymphocyte culture (MLC) between the bm12 mutant and the strain of origin C57BL/6 (B6). In both directions, strong CTL responses were generated against lipopolysaccharide‐stimulated, but not against concanavalin A‐stimulated target cells.

Studies of the specificity of the bm12 anti‐B6 CTL response, using target cells from a panel of H‐2 recombinants, showed that the CTL were directed against specificities of the I‐Ab subregion.

This conclusion was confirmed by the observation that the bm12 anti‐B6 CTL could be specifically blocked by anti‐Iab, but not by anti‐Kb antisera. EL4 tumor cells, which express Kb and Db but not Iab antigens, were not lysed by these CTL. The combined data confirm that bm12 is an I‐A subregion mutant and indicate that the I‐A subregion antigens, recognized by antibody and those recognized by CTL, are probably present on the same molecule.

The CTL effector cells generated in secondary MLC across the I‐Ab mutant difference had the surface phenotype Lyt 1−2+.
Regulation of experimental allergic encephalomyelitis III. Demonstration of effector cells in tolerant rats
Authors: Holda James H. , Swanborg Robert H.
Published: February 2007

Effector cells, which transfer experimental allergic encephalomyelitis (EAE), can be demonstrated in the spleens of Lewis rats which have been rendered tolerant to myelin basic protein (BP). Transfer of EAE was achieved following in vitro culture of tolerant donor spleen cells with antigen. The donor animals were, themselves, protected against EAE induced by active challenge with BP in complete Freund's adjuvant, although BP‐activated effector spleen cells could partially override this protection. The finding that effector cells are present in unresponsive animals supports the hypothesis that immunologic self tolerance is actively regulated by suppressor mechanisms.
Genetic control of the immune response to the L‐Glu60‐L‐Ala30‐L‐Tyr10 (GAT) terpolymer V. Three types of idiotypic specificities on BALB/c anti‐GAT antibodies
Authors: Sommé Gerard , Leclercq Lise , Petit Christine , Thèze Jacques
Published: February 2007

Three types of idiotypic specificities compose the major idiotype of anti‐poly (L‐Glu60‐L‐Ala30‐L‐Tyr10) (GAT) antibodies from BALB/c mice (idiotype termed GAT‐715). Assays have been designed to analyze and study the distribution of these specificities. The highly conserved idiotypic specificity (h.c.GAT) has been assayed by the binding of serum 715‐7A4 to radiolabeled rat anti‐GAT antibodies. Guinea pig and mouse anti‐GAT antisera all express the same h.c.GAT specificity. The public specificity (p.GAT) has been shown to be present in an identical form in all anti‐GAT antisera from all strains of mice studied. The assay used for p.GAT was the binding of serum 715‐7A4 to C57BL/6 anti‐GAT antibodies that express only p.GAT. Finally, the strain‐restricted specificity s.r.GAT has also been investigated by radioimmunoassay; this specificity is expressed only by strains BALB/c, BALB/b, BUB/J, DBA/2, DBA/1 and ATL. This expression is independent of known allotypic markers. However, the expression of the s.r.GAT specificity of BALB/c mice follows the genetic distribution of VH genes of BALB/c origin indicating that s.r.GAT can be considered as a genetic marker of some VH gene(s) involved in the specific immune response to the GAT terpolymer.
Biochemical characterization of avian T lymphocytespecific antigens
Authors: Pink J. Richard L. , Fedecka‐Bruner B. , Coltey M. , Péault B. M. , Le Douarin N. M.
Published: February 2007

Sera from rabbits injected with quail thymocytes were absorbed on quail bursal and liver cells. The absorbed sera reacted with avian T but not B lymphocytes in an immunofluorescence assay. Material precipitated by the anti‐T antisera from lysates of radioiodinated chicken or quail thymocytes was analyzed by one‐ and two‐dimensional electrophoresis. Of two anti‐T cell antisera studied in detail, one reacted mainly with a protein of an apparent molecular weight of 45000–55000, and the other with a protein of an apparent molecular weight 65000–70000. These proteins may be homologues of previously described mammalian T lymphocyte‐specific antigens.
Thirteen hybridomas secreting hapten‐specific immunoglobulin E from mice with Iga or Igb heavy chain haplotype
Authors: Rudolph Andreas K. , Burrows Peter D. , Wabl Matthias R.
Published: February 2007

Thirteen hybridomas producing 2,4,6‐trinitrophenyl‐(TNP)‐specific mouse IgE of Iga or Igb haplotype are described. They are freely available. Monoclonal IgE, as well as polyclonal serum IgE, is shown to bind to concanavalin A.
Influence of IgG and IgM receptor triggering on human natural killer cell cytotoxicity measured on the level of the single effector cell
Authors: Merrill Jean E. , Ullberg Måns , Jondal Mikael
Published: February 2007

By using an agarose single cell cytotoxicity assay, in combination with rosetting with IgG‐ or IgM‐coated ox red blood cells for detection of Fc receptors for IgG (FcγR) or IgM (FcμR), it was found that 60% of natural killer (NK) cells are FcγR+ and 17% FcμR+. This system was further used to investigate the consequence of FcμR and FcγR triggering on NK killing as measured on the single effector cell level. It was found that stimulation of the FcγR, but not the FcμR, resulted in substantial NK inhibition. In order for NK cells to be inhibited by IgG‐coated ox red blood cells, they must first be exposed to the IgG‐containing complex prior to conjugation with the target. While exposure of the FcμR to immune complexes can block up to 57% of NK activity, the particulate immune complexes do not interfere with binding of effector cells to targets. Modulation of Fcγ R by capping at 37°C does not interfere with the NK inhibition for up to 3 h, though after 20 h, when FcγR+ cells are almost completely modulated, NK activity has fully returned. Although to a lesser extent, the soluble immune complex human transferrin‐anti‐transferrin also reduces NK cell activity when activating effector cell FcγR prior to target cell binding. Also, pretreatment of target cells with high concentrations of specific antibody toward membrane antigens can block NK activity while not inhibiting target cell binding as evidenced by anti‐IgM IgG binding to Daudi cells. The regulatory influence of the FcγR on the NK system is discussed in terms of other functions associated with this receptor and in terms of its possible biological significance.
The effect of second signals on the induction of B cell tolerance: failure of helper T cells to block tolerance induction
Authors: Cambier John C. , Corley Ronald B.
Published: February 2007

The effect of carrier‐primed helper T (Th) cells and T cell‐replacing factors on the induction of hapten‐specific tolerance in B cells from adult mice has been tested. The 2,4,6‐trinitrophenyl conjugate of human γ‐globulin (TNP17HGG) was used as tolerogen in an in vitro tolerance induction system. Tolerance was assessed by the subsequent induction of plaque‐forming cell responses using TNP‐Brucella abortus and trinitrophenylated sheep red blood cells (TNP‐SRBC) plus SRBC‐primed Th cells as T‐independent (TI) and T‐dependent (TD) forms of TNP, respectively. B cells that respond to the different forms of TNP appear to be distinct B cell subpopulations. TNP17HGG induced TNP‐specific tolerance in B cells responsive to TI and TD forms of the antigen, although more tolerogen was required to induce unresponsiveness in the TD antigen‐reactive B cells. The presence of antigen nonspecific T cell‐replacing factors during tolerance induction had no effect on the induction of unresponsiveness in either TI or TD antigen‐responsive B cells, although these factors were able to support primary anti‐TNP responses in T‐depleted B cell populations to subtolerogenic doses of TNP‐HGG. Populations of irradiated lymphocytes enriched for HGG‐specific Th cells also had no effect on tolerogenesis in TI or TD antigen‐responsive B cells, although priming of TD antigen‐responsive B cells occurred at subtolerogenic doses of tolerogen. The inability of these Th cells to modulate B cell unresponsiveness was not due to their inability to exert helper function at higher concentrations of HGG. Thus, in this system, tolerance susceptibility is an intrinsic property of B lymphocytes, i.e. immunogenicity vs. tolerogenicity of signals is not determined by a “second signal” provided by Th cells.
Concanavalin A‐induced resistance to Listeria monocytogenes and activation of macrophages: defect in mice treated with 89Sr
Authors: Masuda Aoi , Bennett Michael
Published: February 2007

89Sr‐treated mice injected with concanavalin A (Con A) 24 h prior to infection with Listeria monocytogenes (LM) could not enhance the clearance of LM from the spleen. Adoptive transfer of normal syngeneic spleen cells together with Con A rendered these animals more resistant. Spleen cells of 89Sr‐treated or age‐matched control mice were stimulated with Con A for 24 h, and supernatant fluids were assessed for macrophage‐activating factor (MAF), i.e. the ability to activate resident peritoneal macrophages to kill LM intracellularly in vitro. A defective MAF production by spleen cells was observed in 89Sr‐treated, 2 week‐old, and athymic nude mice. Also, treatment of spleen cells with anti‐Thy‐1.2 antiserum plus complement inhibited MAF production. Synergism between spleen cells from 89Sr‐treated and nude mice did not occur. The cells required for MAF production were relatively resistant to gamma irradiation. Nylon wool filtration did not modify the ability of spleen cells to make MAF. 89Sr‐treated mice possess macrophages responsive to MAF derived from normal spleen cells. The data suggest that the failure of 89Sr‐treated mice to develop an anti‐LM response observed in this system could be due to a defective capacity to produce protective humoral factors and/or cells in response to Con A.
Two structurally distinct and independently regulated idiotypic families associated with the A/J response to azophenylarsonate
Authors: Marshak‐Rothstein Ann , Margolies Michael N. , Benedetto James D. , Gefter Malcolm L.
Published: February 2007

At least two distinct subpopulations of A/J anti‐azophenylarsonate (Ars) antibodies can be defined on the basis of serological cross‐reactivity and sequence homology of heavy and light chains. The most frequently occurring idiotype family, IdCR, was initially identified by a rabbit antiserum and is present only in A/J mice. Examination of several randomly selected hybridoma proteins which failed to express IdCR‐associated determinants revealed a second set of closely related molecules. The second idiotype family, Id36–60, is recognized by a rabbit antiserum prepared against the hybridoma protein 36–60. It is present in practically all A/J and BALB/c, but not B10.A Ars immune sera. On average, A/J immune sera contain approximately one‐fifth as much Id36–60 as IdCR.

A/J mice can be suppressed for subsequent expression of either idiotype by neonatal injection of anti‐IdCR or anti‐Id36–60 antisera. Suppression of IdCR does not affect the production of Id36–60 and vice versa. Together, these idiotype systems provide two independent markers for monitoring network regulation of the anti‐Ars antibody response in A/J mice.
Genetic control of the expression of immunoglobulin isotypes in the responses of mice to sheep red blood cells
Authors: Haber Jerome , Winn Henry J.
Published: February 2007

Studies have been carried out on the genetic control of the expression of individual Ig classes in the responses of A/J (A) and C57BL/6J (B6) mice to sheep red blood cells (SRBC). An isotopic anti‐immunoglobulin test employing Ig class‐specific reagents was used to measure levels of IgM, IgA, IgG1 IgG2a, IgG2b and IgG3 anti‐SRBC antibodies in sera of hyperimmunized mice. Compared with B6 mice, A mice are low IgM and IgA responders but high responders with respect to all IgG subclasses. In (B6 × A)F1 mice low responsiveness was dominant for all Ig classes indicating that IgM and IgA responses are controlled by genes different from those which control IgG subclass responses. Analysis of the responses of [(B6 × A)F1 × A] and [(B10. A × A)F1 × A] backcross mice indicates multigenic control of IgG subclass responses. Expression of IgG2a and IgG3 responses appear to be regulated largely by single genes whose action is modified by genes at other loci; control of IgG1 and IgG2b is, clearly, polygenic with no evidence for major control by any single gene. The magnitude of all IgG subclass responses appears to be regulated by a gene(s) associated with or linked to the IgCH locus. Analysis of the responses of H‐2‐congenic mice shows that major histocompatibility genes do not have a strong influence on the patterns of IgM and IgG responses in A or B6 mice. The overall results indicate that while there is some common control of all IgG classes, there is also separate polygenic control of individual Ig classes.
Non‐H‐2‐associated genetic regulation of cytotoxic responses to hapten‐modified syngeneic cells Effect on the magnitude of secondary response and helper T cell generation after in vivo priming
Authors: Fujiwara Hiromi , Shearer Gene M.
Published: February 2007

The present study investigates the role of non‐H‐2 genes in controlling generation of the H‐2‐restricted, T cell‐mediated cytotoxic response against trinitrophenyl (TNP)‐modified syngeneic cells (TNP‐self). Spleen cells from C3H/He (H‐2k) or B10.BR (H‐2k) normal mice or from mice primed to TNP in vivo by skin painting with trinitro‐chlorobenzene were used (a) for in vitro sensitization to TNP‐self and (b) as a source of radioresistant helper cells for augmenting the TNP‐self cytotoxic T lymphocyte (CTL) response generated by normal syngeneic spleen cells. Although spleen cells from unprimed mice from these two strains exhibited a comparable CTL response in a primary culture, a strong difference was observed in a secondary CTL response after in vivo priming. CTL activities generated in the secondary culture were much stronger in C3H/He than in B10.BR strains. This difference in the magnitude of secondary CTL responses was paralleled by generation of strong and weak helper cell activity in C3H/He and B10.BR, respectively. No detectable difference was observed between the two H‐2k strains in the lysability of target cells and ability of stimulating cells to activate the primed unirradiated cells and radioresistant helper cells. This genetic difference detected in the H‐2k haplotype was also demonstrated in the H‐2b haplotype, by using C3H.SW and C57BL/10 mice which bear non‐H‐2 background genes corresponding to C3H/He and B10.BR mice, respectively. These results indicate the existence of a control mechanism influenced by non‐H‐2 genes, in addition to the established H‐2‐linked gene control.
Role of β1H for the binding of C3b‐coated particles to human lymphoid and phagocytic cells
Authors: Schmitt Manfred , Mussel Hans‐Hermann , Hammann Klaus P. , Scheiner Otto , Dierich Manfred P.
Published: February 2007

Coating of EAC14oxy23b with highly purified human serum β1H globulin (β1H) led to acceleration of rosette formation with human peripheral blood lymphocytes (PBL), tonsil lymphocytes, B lymphoblastoid (Raji) cells, granulocytes and monocytes. This reaction was discernible from C3bi‐dependent rosette formation. Enhancement of rosette formation of C3b cells by β1H was most effective at limiting amounts of C3 per EAC14oxy23b. The β1H effect was not due to trace contamination with C3b inactivator. β1H‐dependent rosette formation with the various lymphoid and phagocytic cells could be suppressed by the F(ab′)2 fragment of anti‐β1H suggesting β1H‐mediated binding of β1H‐coated particles to complement receptor‐positive (CR+) cells.

In turn, binding of fluid‐phase β1H to lymphoid and phagocytic cells could be demonstrated by fluorescence and by 14C‐labeled β1H. In addition, the functional status of these cells with respect to their receptor reactivity was altered.

Treatment of normal lymphocytes (PBL, tonsil lymphocytes) and of granulocytes with β1H improved their rosette formation with both EAC14oxy23b and EAC14oxy23b‐β1H. The reaction of monocytes was hardly affected. The β1H effect on Raji cells resulted in reduced rosette formation with EAC14oxy23b‐β1H, while binding of EAC14oxy23b remained unchanged.

These results suggest the presence of sites on CR+ cells, to which soluble and particlebound β1H can bind, leading to alteration of the functional status of the cells. In all likelihood, EAC14oxy23bi can attach to the β1H‐binding sites on CR+ cells.
Decline, in aging mice, of the anti‐2, 4, 6‐trinitrophenyl (TNP) cytotoxic T cell response attributable to loss of Lyt‐2−, interleukin 2‐producing helper cell function
Authors: Miller Richard A. , Stutman Osias
Published: February 2007

The in vitro generation of cytotoxic T lymphocytes (CTL) specific for 2, 4, 6‐trinitrophenyl (TNP)‐modified syngeneic spleen cells is found to be almost invariably depressed in apparently healthy 18‐month‐old mice of the long‐lived (BALB/c × C57BL/6)F1 hybrid strain. Studies of CTL production from Lyt‐2+ thymus cells have suggested that pre‐killer cells may require, for maturation into effectors, the presence of a soluble helper factor, interleukin 2 (IL2), produced by Lyt‐2− cells which are themselves devoid of pre‐CTL activity. We have therefore developed a petri‐dish adherence technique for separating spleen cells into Lyt‐2+ and Lyt‐2− populations in order to test for helper and pre‐killer activity independently. Pre‐CTL function is measured by stimulating Lyt‐2+ cells in the presence of exogenous IL2. Helper cell activity is tested by adding Lyt‐2− cells to “indicator” populations of Lyt‐2+ pre‐CTL. Estimation of IL2 levels in medium conditioned by unfractionated, TNP‐self‐stimulated splenocytes provides a second measurement of helper cell function.

Mice 18 months of age, when compared to 4 month‐old controls, are found to retain nearly all of their pre‐CTL activity, but to have lost sufficient helper cell activity to account for the decline in unseparated spleen cell cultures. Older mice also produce lower IL2 levels.
Variation of interferon induction at the bone marrow level. Studies on interferon induction in relation to natural cell‐mediated cytotoxic mechanisms
Authors: Örn Anders , Gidlund Magnus , Wigzell Hans , Gresser Ion
Published: February 2007

The effects of interferon inducers on different cytolytic mechanisms were studied in the high leukemia mouse strain AKR. A clear depression in baseline cytolytic potential and interferon‐mediated stimulation of natural killer cell activities was demonstrated. This depression was most pronounced after 8 weeks of age. In contrast, antibody‐dependent, cell‐mediated cytotoxicity against IgG‐coated chicken red blood cells was always normal. Bone marrow chimeras between CBA and AKR mice were produced to investigate the influence of bone marrow vs. host‐mediated factors in these two strains with regard to interferon induction and cytolytic functions. Bone marrow genotype was found to be the dominating factor with regard to both parameters. Mice reconstituted with AKR bone marrow were deficient both in interferon production using tilorone and Newcastle disease virus as inducers, and at the level of natural killer cells responding to exogenously administered interferon. The possible relationship between these findings and the development of lymphomas in AKR mice is discussed.
Surface antigens of human melanoma cells defined by monoclonal antibodies. I. Biochemical characterization of two antigens found on cell lines and fresh tumors of diverse tissue origin
Authors: Johnson Judith P. , Demmer‐Dieckmann Maria , Meo Tommaso , Hadam Martin R. , Riethmüller Gert
Published: February 2007

Monoclonal antibodies were produced against melanoma cell lines derived from patients presently disease free. Based on tissue distribution of binding, the antibodies obtained could be used to classify melanoma surface antigens into groupings similar to those obtained from studies of autologous and xenogeneic antibodies. Three antibodies (21.43, 15.75 and 15.95) reacted with the immunizing tumor but not with peripheral blood lymphocytes or a lymphoblastoid cell line derived from the tumor donor. When tested on a broader cell panel, antibody 21.43 reacted only with melanoma lines, while antibodies 15.75 and 15.95 reacted with carcinoma cell lines as well as with the majority of melanoma cell lines. Antibody 15.95 precipitated a 49000 dalton glycoprotein from both melanoma and carcinoma cells. Antibody 15.75 precipitated a 74 000 dalton glycoprotein from the surface of melanoma and carcinoma cell lines which is also found on freshly isolated tumor cells from melanoma and carcinoma metastases in vivo.
The strain A anti‐p‐azophenylarsonate major crossreactive idiotypic family includes members with no reactivity toward p‐azophenylarsonate
Authors: Wysocki Lawrence J. , Sato Vicki L.
Published: February 2007

The sera of unimmunized A/J mice contain low but detectable levels of immunoglobulin, bearing previously described cross‐reactive idiotypic (CRI) determinants diagnostic of the strain A anti‐p‐azophenylarsonate (Ars) response. Such molecules from nonimmune sera cannot be adsorbed onto affinity columns coupled to a high density with Ars. After extensive immunization with Ars‐coupled proteins, Ars‐nonbinding CRI is found at the same low level, even though substantial Ars‐binding CRI appears. On the other hand, immunization with a monoclonal rat anti‐CRI, which was originally raised against Ars‐binding CRI, elicits high concentrations of Ars‐binding as well as Ars‐nonbinding CRI immunoglobulin. Three hybridoma proteins produced from an A/J mouse immunized with the rat anti‐CRI react with all tested anti‐idiotypic sera from three species of animals, but show no reactivity toward Ars in several different assays. One hybridoma protein from the same fusion demonstrates Ars‐binding capacity.