摘要:

AbstractThe xid gene in mice controls a recessive defect resulting in the absence of a late maturing subset of B cells. Whereas the responsiveness pattern of these mice has been clearly defined in terms of their ability or inability to make antibodies to certain classes of thymus‐independent antigens, there are conflicting reports in regard to affinity maturation of the antibody response to thymus‐dependent antigens. To resolve this controversial issue, the two major isotypes of the IgG response, namely IgG1and IgG2awere examined with a highly sensitive radioimmunoassay that measures both the magnitude and affinity of the anti‐2,4‐dinitrophenyl antibody of each isotype in individual serum samples. It was found that the xid gene reduced the amount but not affinity of the IgG1antibody produced, whereas it impaired the whole IgG2aresponses severely. In fact, mice carrying the defective gene were unable to mount a secondary IgG2aresponse, measured either quantitatively or qualitatively in terms of increased affinity. To test the possibility that Lyb3, an isogenic B celltriggering receptor lacking in xid‐mutant mice, plays a direct role in the maturation of the immune response, the antibody profile in normal mice immunized either with antigen alone or in combination with anti‐Lyb3 antiserum has been compared. It was found that triggering of the Lyb3 receptor substantially elevated and accelerated the primary IgG2aresponse, whereas it had little effect on the I

ISSN:0014-2980    

DOI:10.1002/eji.1830110502

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractThe distribution of receptors for theHelix pomatialectin on mouse lymphoid cells and other tissues was investigated. Using a sensitive resetting assay combined with immunofluorescence, lectin receptors were found on the membrane of approximately 90% of peripheral T lymphocytes, 75% of thymocytes, 30% of bone marrow cells, 20% of nude spleen cells, 15–50% of peritoneal exudate macrophages, and a subpopulation of peritoneal exudate mast cells. The Thy‐1‐positive nude spleen cells were predominantlyHelixlectin receptor‐negative. Approximately 5% of B lymphocytes were weakly positive, and neutrophils were negative. Receptors were present also on a subpopulation of cells of a fibroblast cell line and in acetone powder from the liver and, at a lower level, from the kidney and brain. Membrane receptors on all cell types were partially detectable without neuraminidase treatment of the cells. Two methods of fractionatingHelixlextin‐positive cells were employed, which gave significantly different results. By rosetting and depletion using density fractionation, T cell mitogen responses were abolished, while B cell mitogen responses, T cell cytotoxicity, and natural killer cytotoxicity were only slightly affected, if at all.Helixlectinagarose column fractionation seemed more sensitive, in that essentially all natural killer cells bound to the column, as well as a considerable number of B lymphocytes. Cytotoxic T cells were heterogeneous: roughly half were not bound, but the remainder were bound a

ISSN:0014-2980    

DOI:10.1002/eji.1830110503

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractThis study was undertaken to investigate the nature of the immunogenic moiety recognized by the human T cell which proliferates in response to tetanus toxoid (TT) antigen.Immunosorbent‐purified anti‐TT IgG antibodies failed, even when added in great excess, to inhibit T cell proliferation in response to TT. Urea‐denatured (UD) TT antigen containing less than 1% native TT, as assessed by its reactivity with antibodies raised against native TT, triggered proliferation in T cells to an extent equal to that seen with native TT. The proliferative response to UDTT was seen only in T cells obtained from donors immune to TT and was inhibited by antisera to DRw antigens of the cell donor. T cells responding to TT and to UDTT essentially overlapped because exposure to 5′‐bromo‐2‐deoxyuridine and light of T cells prestimulated with TT or UDTT abolished the specific response to both forms of the TT antigen but not to phytohemagglutinin or toManillaantigen. It is concluded that proliferating human T cells recognize determinants which differ from those that elicit an antibody response and which may arise as a result of antigen processing by macrophages. The implications of these present results on the nature of the human T cell receptor for antigen

ISSN:0014-2980    

DOI:10.1002/eji.1830110504

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractA broad spectrum of agents known to block various steps in the lipid peroxidation process were tested for their ability to protect mouse spleen cells and thereby enhance their activities,in vitro, in either the primary antibody response or the lipopolysac‐charide‐stimulated proliferation response. Each agent (superoxide dismutase, butylated hydroxyanisole/butylated hydroxytoluene/n‐propyl gallate, lucigenin, and α‐tocopherol) was able to enhance the cellular response in both assay systems. The degree of enhancement of these immune functions was in proportion to the efficacy of each agent in blocking the overall process in lipid peroxidation. Previous work in this laboratory has shown that the enhancement of the primary antibody response by 2‐mercaptoethanol (2‐ME) is mediated by the enhanced availability of reduced glutathione in the culture medium. Suboptimal doses of each lipid antioxidant agent were able to enhance the antibody response in an additive manner with a suboptimal dose of 2‐ME up to a maximum response equal to that achieved with an optimal dose of 2‐ME alone. These data support the hypothesis that the enhancement of cellular responses in the presence of 2‐ME is mediated by the lipid antioxidant activity of r

ISSN:0014-2980    

DOI:10.1002/eji.1830110505

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractTo investigate the histocompatibility requirements for the macrophage‐T cell interaction in the secondary antibody response, splenic T cells from antigen (carrier)‐primed F1hybrid mice were restimulatedin vitrowith carrier‐pulsed F1, parental or allogeneic macrophages. Surviving T cells were cocultured with hapten‐primed F1or parental “B cells” and restimulated with the appropriate hapten‐carrier conjugate. The IgG antibody‐forming cell response was then measured using a plaque assay.Mapping of the genetic restriction was performed by use of different strain combinations. T helper cells could be restimulated in the presence of macrophages only provided they shared the I‐A subregion of the major histocompatibility complex with the F1T cells. T cells from F1hybrids restimulated with parental or I‐A‐identical macrophages were shown to only cooperate with parental B cells of the same I‐A haplotype as the macrophages used for restimulation. The defect was at the level of the macrophage, as addition of macrophages of the I‐A haplotype used for the restimulation culture reconstituted the ability of F1helper cells to cooperate with the

ISSN:0014-2980    

DOI:10.1002/eji.1830110506

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractCompetitive antigen binding experiments were performed with purified T and B cells of C3H.SW (H‐2b) mice. As antigen, (T, G)‐A–L [poly‐L(Tyr, Glu)‐poly‐DL‐Ala–poly‐L Lys] was used, both in an Ia‐containing form, released by adherent cells (IAC, Puri and Lonai,Eur. J. Immunol.1980.10:273), and in regular solution. It was found that regular (T, G)‐A–L did not compete with the binding of125I‐labeled‐IAC‐(T, G)‐A–L even at a 104‐fold excess, whereas IAC‐(T, G)‐A–L inhibited binding at 10‐fold excess. The specificity of (T, G)‐A–L binding to high‐responder T and B cells was compared by using related branched synthetic copolymers as competitors. B cells cross‐reacted with (T, G)‐A–L, (H, G)‐A–L, (Phe, G)‐A–L, (G)‐A–L and (T, G)‐Pro–L. In contrast, antigen‐binding C3H.SW T cells cross‐reacted only with (T, G)‐A–L and (Phe, G)‐A–L, to both of which they are Ir gene‐controlled high responders. Evidence for the Ir gene control of IAC‐binding T cells was obtained by showing that high × low‐responder F1hybrid T cells preferentially bind IAC‐(T, G)‐A–L processed by processor cells deriving from the high‐responder parental strain. These data are interpreted to suggest that T cells have high affinity for antigen plus self Ia complexes, whereas they have a much lower, if any, affinity for free antigen. It also follows from the results that the structure of the complex

ISSN:0014-2980    

DOI:10.1002/eji.1830110507

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractThe Simian virus 40‐transformed rabbit spleen cell TRSC‐1 synthesizes intracellular whole IgG molecules of the a1b4 allotype. Two hypoxanthine‐guanine phosphoryl transferase‐deficient mutants were derived from this line. One of these, TRSC‐1‐8, was used in somatic cell fusion experiments together with gangliocytes from a rabbit immunized against β‐galactosidase.Out of nineteen hybrid clones surviving in selective medium, only one, L17, was shown to produce free γ chains which express the a2 allotype of the donor rabbit rather than the a1 marker of the parents TRSC‐1‐8 line. The inability to restore IgG secretion in hybrids suggests that dominant regulatory controls are exerted by the TRSC‐1 genome on Ig production. This supports the notion that the TRSC‐1 line originated from a splenocyte that had not reached the final plasmocyte differentiation stage at the time

ISSN:0014-2980    

DOI:10.1002/eji.1830110508

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractIn order to study whether allotype linkage of idiotype expression is related to the total absence of structural gene(s) or to regulatory mechanisms acting on its phenotype expression, the M460 clone expression was followed in B cells from various inbred and recombinant strains of mice cultured at low density in the presence of lipopolysaccharide. Under these conditions, all cultures were found to contain anti‐trinitrophenyl (TNP) antibody plaque‐forming cells, some of which were inhibitable by anti‐M460 immunoglobulins.In the course of these studies, it also became apparent that, even in the absence of T cells, B lymphocytes are able to exert regulatory functions. Experiments carried out using anti‐M460 hybrid cells F6 (51), and affinity‐purified anti‐(anti‐M460) antibodies revealed that clonotype regulation by B cells is mediated by idiotype‐auto‐anti‐id

ISSN:0014-2980    

DOI:10.1002/eji.1830110509

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractThe antibody response to the synthetic polypeptide, poly(LTyr, LGlu)‐poly(DLAla)–poly(LLys), [(T, G)‐A–L], injected entrapped in liposomes which served as adjuvant, has been analyzed. The liposomes used were composed of phosphatidylcholine, cholesterol, dicetylphosphate and DL α‐tocopherol (molar ratios as 4:3:0.1:0.5) and therefore, were negatively charged. Since the (T, G)‐A–L is also negatively charged, no free complexes were formed. The (T, G)‐A–L was found to be entrapped inside the enclosed volume of the liposomes, and no (T, G)‐A–L antigenic determinants could be detected on the liposomal membranes. Injection of high‐responder C3H.SW (H‐2b) mice with (T, G)‐A–L‐bearing liposomes demonstrated that the i.p. and the i.v. routes of immunization were efficient in eliciting (T, G)‐A–L‐specific antibodies, whereas the i.d. injection led to poor antibody responses. The latter route of immunization is the most effective when (T, G)‐A–L is injected in complete Freund's adjuvant (CFA). When low doses (0.1 and 1 μg) of (T, G)‐A–L were used for immunization, the liposomes were better adjuvants than CFA. The effectiveness of the liposomes as immunological adjuvants was also shown in their ability to induce high‐potential, primed memory cells. The pattern of low (H‐2k, a) and high (H‐2b) responsiveness to (T, G)‐A–L was retained following immunization with (T, G)‐A–L entrapped in liposomes, as tested in two pairs of congenic strains. (T, G)‐A–L‐specific antibodies induced by injection with 1μ antigen entrapped in liposomes bear the (T, G)‐A–L site‐related idiotypic markers of C3H.SW (Igh‐1a) mice in a significantly higher frequency than the homologous idiotypes, namely the antibodies elicited in this strain against (T, G)‐A–L in CFA. Thus, liposomes may serve as adjuvants for the pro

ISSN:0014-2980    

DOI:10.1002/eji.1830110510

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY

摘要:

AbstractMurine splenic lymphocytes exhibit a requirement for helper T cells for the induction of a cytolytic T lymphocyte response to suboptimal doses of allogeneic cells, membranes from allogeneic cells, or purified H‐2 antigen in liposomes. The conditions where a requirement for help is apparent are the same conditions where a dependence on splenic adherent cells (SAC) has been demonstrated (Weinberger, O. et al.,Proc. Natl. Acad. Sci. USA1980.77:6091). Help can be provided in the form of primed, radioresistant, Ly‐1+spleen or lymph node cells or helper factor (interleukin 2, IL‐2). A factor generated from phytohemagglutinin‐stimulated human lymphocytes, when added to culture in the presence of antigen, bypassed the requirement for Ia+SAC and helper cells. IL‐2 reconstituted the response to H‐2Kkin liposomes in cultures depleted of SAC, strongly suggesting that the helper cell must see antigen re‐expressed by an antigen‐presenting cell, whereas the prekiller does not. IL‐2 could be generated by culturing Ly‐1+murine spleen cells with

ISSN:0014-2980    

DOI:10.1002/eji.1830110511

出版商:WILEY‐VCH Verlag GmbH    

年代:1981

数据来源: WILEY