摘要:

AbstractMice injected subcutaneous with 1 × 108sheep red blood cells (SRBC) developed high levels of delayed‐type hypersensitivity (DTH) to SRBC 4–8 days after injection. Such DTH was suppressed when 100 μg lip polysaccharide (LPS) was injected intravenously 1–2 days before or at the time of SRBC injection. This suppression of DTH was transferable by spleen, lymph node, thymus and bone marrow cells to sensitize or normal syngeneic recipients, but could not be transferred by serum. Suppressor cells were not induced by LPS alone or SRBC alone, and they were antigen‐specific since DTH to chicken red blood cells was not affected. The suppressor cells appeared in the spleen in optimum number 3–4 days after induction. They were theta‐negative and Ig‐positive as judged by antiserum plus complement treatment and by Ig rosette separation. Attempts to obtain soluble suppressor factor from the suppressor cells by sanitation orin vitroincubation were unsuccessful. Mitomycin C treatment of the suppressor cells completely abolished the suppressor activity. Thus, LPS, in conjunction with antigen, appears to induce a population of specific suppressor B cells which are capable of regulating

ISSN:0014-2980    

DOI:10.1002/eji.1830090202

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThis study deals with the requirements for target cell recognition by influenza A virus‐ specific cytotoxic T lymphocytes (CTL). H‐2‐identical cells were incubated with infectious or UV light‐inactivated influenza A virus expressing either cleaved or uncleaved hemagglutinin (HA). Thereafter, the treated cells were tested in a 4‐h51lCr assay for susceptibility to CTL‐mediated cytolysis.Regardless whether the influenza virus was infectious, virions expressing cleaved HA were efficient in target cell formation. In contrast, cells incubated with either active or UV‐inactivated virions expressing uncleaved HA were not lysed by virus‐ specific CTL. Yet, after mere trypsin‐mediated cleavage of the HA of cell‐absorbed viroins, strong cytolysis could be observed. On the other hand, solubilization of the envelope lipid bilayer by ethyiether abolished the capacity of the remaining HA to induce target cell formation. The results clearly suggest that mere adsorption of virions to the membrane of cells, which is performed by virus with uncleaved HA, is insufficient for target cell formation. For this, both cleaved HA and an intact envelope appear to be crucial. We conclude that fusion of the virion into the cell membrane is essential for ta

ISSN:0014-2980    

DOI:10.1002/eji.1830090203

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA null lymphocyte subpopulation was isolated from human peripheral blood using a combination of Ficoll density gradient centrifugation, chromatographic separation of immunoglobulin‐bearing cells on Sephadex G‐200‐anti‐human F(ab'), columns and E rosette sedimentation. Null cell recovery averaged 5% of total peripheral mononuclear cells with greater than 90% purity by surface marker analysis. The purified null subpopulation was markedly enriched for antibody‐dependent cellular cytotoxicity (ADCC) and natural killing (NK) activity, while the Ig+′ and E' populations were virtually inactive. In the NK assay, the number of recovered lytic units in the null subpopulation was greatly increased over the total lytic units in unf ractionated cell populations, while enrichment in ADCC lytic units was strictly dependent on the concentration of null cells in effector populations. The null cell mediators of both ADCC and NK activity were shown to lack the Ia‐like surface antigen, p 23, 30. The results suggest that both ADCC and NK are mediated by the same population of null cells comprising less than 5% of peripheral lymphocytes and which lack the Ia‐like antigen p 23, 30, as well as mature T and B cell surface markers. The marked enrichment of NK activity in purified null populations suggests that E+T cells may regulate NK by this subpo

ISSN:0014-2980    

DOI:10.1002/eji.1830090204

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractPeritoneal exudate lymphocytes (PEL) from immune guinea pigs adhere to macrophages carrying the relevant antigen and are thereby stimulated to proliferate in culture. The resultant PEL represent a population highly enriched with regard to their capacity to specifically rebind to antigen‐pulsed macrophages. We have studied the mechanisms underlying specific binding of lymphocytes to macrophages by examining the effects of physical and chemical modifications of the two cell types. Specific binding was inhibited by fixation of cells, metabolic inhibitors, low temperatures, cytochalasin B and divalent cation depletion. After specific binding has taken place, cation depletion, but not cytochalasin B or low temperatures, disrupts binding. These observations indicate that specific binding occurs by a series of discrete events that can be operationally distinguishe

ISSN:0014-2980    

DOI:10.1002/eji.1830090205

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractSix hundred and twelve mouse plasmacytomas were screened for hapten binding by using eleven different bacteriophage‐hapten conjugates (phage T4 conjugated with haptens NP, NIP, DIP, DNP, BOC‐ABA‐Tyr, ABA‐NP, ABA‐MIP, ABS‐HOP, PAB‐HOP, penicillin G, cloxacillin). Fifteen ascites fluids (2.4%) inactivated at least one of the phage conjugates at a high dilution indicating binding. The specificity of these reactions was studied by titrating one ascites fluid with phage conjugates carrying unrelated haptens, and by inhibiting the phage inactivation with free haptens. Of the 15 myeloma proteins, 10 had high titers (at least 30 times higher than the ascites fluid background) with the NIP‐cap phage or the NP‐cap phage or both. Four had high titers with the DNP‐cap phage and one with the ABA‐MIP phage. Thirteen of the 15 myeloma proteins were IgA, one

ISSN:0014-2980    

DOI:10.1002/eji.1830090206

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA molecule with an apparent molecular weight of 21000 daltons was found to be a predominating differentiation antigen of peripheral rat T lymphocytes. This antigen is also expressed on the cell surface of thymus lymphocytes though partially in masked form. The observation that these determinants could be unmasked by neuraminidase treatmentin vitrosuggests that enzymatic processes may play an important role in antigenic transformation along the differentiation pathway of T axis lymphocytes. Since this structure was found to be displayed also by peritoneal exudate macro‐ phages, it is referred to as T lymphocyte‐macrophage antigen. The finding that an identical antigen could be identified in the mouse suggests its more common biological significa

ISSN:0014-2980    

DOI:10.1002/eji.1830090207

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractStrains CBA (M523) ( = M523) and CBA differ by a mutation which has been mapped genetically into the K region of the H‐2 complex. Similarly, strains B 10.D2 (M504) ( = MS04) and B10.D2 differ in a mutation which occurred in the D region. The data presented in this study show that mixed lymphocyte culture in M523 anti‐ CBA and M504 anti‐B 10.D2 strain combinations leads to the release of membrane fragments from the stimulating cells and binding of these fragments by blast cells. The fragments always carry H‐2K (in the M523 anti‐CBA combination) or H‐2D (in the M504 anti‐B 10.D2 combination) antigens present in the stimulating and absent in the responding cells (antigens H‐2.60 and H‐2.40, respectively). Although Ia antigens may occasionally be present on the CBA membrane fragments, these antigens do not participate in the M523 anti‐CBA MLR stimulation. The data thus demonstrate that serologically detectable H‐2K and H‐2D antigens can induce a MLR and that a mutation can change properties of H‐2K or H‐2D molecules so that the alteration is detectable by both serological means and l

ISSN:0014-2980    

DOI:10.1002/eji.1830090208

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThe Thy‐1, Tla and Ig phenotype of peanut agglutinin (PNA)‐binding cells was characterized in various strains of mice. In the thymus, PNA was found to bind principally but not exclusively to the Thy‐1+Tla+Ig−steroid‐sensitive cortical thymocytes. Thy‐1+Tla−Tg−steroid‐resistant cells are not labeled with PNA. In other lymphoid organs, PNA bound to a minority of T or null cells but generally not to B cells.During ontogeny, PNA+and PNA−T lineage cells appear simultaneously in the liver at day 10 of gestation, in the thymus at day 11 and in the spleen at day 18. No evidence was found for a maturation from PNA+to PNA−cells. Prethymocytes present in nude mice were also divided into a PNA+and PNA−population.The findings possibly support the proposition that cortical and medullary thymocytes develop independently. Moreover, they suggest that both populations might arise from distinct precursors and give rise to distinct functi

ISSN:0014-2980    

DOI:10.1002/eji.1830090209

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractIntraveneous hyperimmunization of selectively bred rabbits with streptococcal group A‐variant vaccines elicits antibody responses of restricted heterogeneity at high antibody levels. In these antisera, IgG with dissociation constants KD= 10−6M constitutes 90% and IgG with KD= 10−9M accounts for only 10% of the group A‐variant polysaccharide‐specific antibodies. The low affinity antibody fraction represents the dominant clonotypes. Preparative isoelectric focusing in granulated (Ultrodex G‐75) gels was used to successfully purify single‐band material belonging to dominant spectrotypes. Affinity studies with these antibody fractions with the highest reported degree of purity yielded KD= 10−6M values, thus confirming that clonal dominance is exclusively associated with low‐affinity antibodies. Since it is known from previous work (M. Cramer and D. G. Braun,Scand. J. Immunol.1975.4: 63) and from the rabbit antisera used here that clonal dominance of this sort is long‐lived, this work fails to support the argument of immune maturation. The data more logically relate to antibodies that emerge with different subspecificities ‐ recognized in the antigen as a function of time in immunization procedures — rather than to an inherent proper

ISSN:0014-2980    

DOI:10.1002/eji.1830090210

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThe mitogenic activity ofMycoplasma pulmonishas been demonstrated to reside in the membrane of this microorganism. Studies aimed at the identification of the membraneous mitogenic factor have revealed that membrane proteins are essential components of this mitogenic manifestation. In addition, it has been shown that the microorganism's outer surface membrane proteins are responsible for mitogenic activity. It has been shown, however, that isolated membrane lipids are not mitogenic for rat lymphocytes and are not required for the membrane's mitogenic potential.

ISSN:0014-2980    

DOI:10.1002/eji.1830090211

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY