摘要:

AbstractPrevious studies performed in our laboratory have revealed that an ordered, sequential, tricellular interaction is obligatory for the antigen‐driven induction of a specific effector memory T cell. Thus, it was found that antigen‐pulsed peritoneal macrophages signal, in spleen cells, the generation of antigen‐specific initiator lymphocytes. These lymphocytes, following injection to syngeneic recipients, recruit, in the draining lymph nodes, “virgin” antigen‐reactive T lymphocytes. Although the nature of the first and last cell in the interacting sequence was well characterized, the identity of the intermediary initiator splenic cell was obscure. Studies were carried out to characterize the nature of the splenic initiator cells. It was found that spleen cells from nu/nu, adult thymectomized and neonatal thymectomized, or spleen cells from normal donors which had been subjected to cytolysis using anti‐Thy‐1.2 antibodies in the presence of complement, did generate, following interaction with keyhole limpet hemocyanin (KLH)‐fed macrophages, specific initiator cells. Carrageenan impairment of spleen macrophages did not affect the generation of initiator cells, nor did the depletion of dendritic cells from the spleen. On the other hand highly enriched B cell, but not highly enriched T cell populations, when seeded on KLH‐pulsed macrophages, generated antigen‐specific initiators, which,in vivo, recruited antigen‐reactive T cells. It thus appeared that B lymphocytes can function as intermediary obligatory antigen‐presenting cells and actively transfer immunogenic signals from peritoneal antigen‐presenting cells to T lymphocytes. These findings may therefore suggest that antigen‐specific B cells do not function solely as antibody‐producing cells, but, once activated by macrophages, may control the induction and differentiation of some antigen‐reactive T cell subsets. Thus, one can view the B cell as an important regulatory cell of both cellular and humoral immune functions. The significance of this observation with regard to Ir gene control at the le

ISSN:0014-2980    

DOI:10.1002/eji.1830130202

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractVHfragments were prepared from several mouse IgM molecules by cyanylation. In all cases VHfragments were purified to homogeneity by using Ig light chain affinity columns. Several different anti‐VHantisera were prepared in rabbits and the specificities of these antibodies were studied. Two patterns of cross‐reactivities were observed: (a) some anti‐VHantibodies reacted only with closely related VHmolecules,e.g., anti‐VHHPC52 anti bodies reacted only with VHof phosphorylcholine‐binding myeloma or hybridoma protesin, and concrodantly, stained about 4% of mouse spleen B cells; (b) on the other hand, antisera‐like anti‐VH104E and 8916 antibodies were very cross‐reactive. Binding assays showed that both of these anti‐VHantibodies reacted with 50–60% of mouse immunoglobulins, and thus the pool of these antibodies reacted with about 95% of mouse VHregions. Concordantly, anti‐VH104E antibodies stained in the fluorescence‐activated cell sorter (FACS) analysis more than 50% of mouse spleen B cells.Cross‐reactive anti‐VHantibodies (“anti‐framework”) did not stain T cells nor did they immunoprecipitate VH‐like molecule

ISSN:0014-2980    

DOI:10.1002/eji.1830130203

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe complement protein C1q, isolated from bullfrog (Rana catesbeiana) serum, was found by electron microscopy to resemble human C1q; peripheral globular units, probably six in number, are connected by thin strands to a hollow stem‐like central structure. The dimensions of frog and human C1q were also found to be very similar. These results are consistent with earlier observations that frog and human C1q are similar, although not identical, in overall size, subunit structure, amino acid composition, and functional properties. Evidently this protein, which binds to antigen‐antibody complexes and to C1r and C1s, thereby forming a physical link between the immune and complement systems, has been highly conserved in evolut

ISSN:0014-2980    

DOI:10.1002/eji.1830130204

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractA series of HLA‐DR‐reactive mouse anti‐human B cell or anti‐Ia monoclonal antibodies (mAb) have been used to explore the serological complexity of human class II antigens at the determinant level, using two techniques: (a) cross antibody‐binding competitor assays using125I‐labeled and ‐unlabeled mAb were performed to study the topological organization of the corresponding determinants to determine epitopic clusters recognized by this collection of mAb and (b) differential reactivity of mAb to detergent‐solobilized solid‐phase‐immobilized HLA‐DR molecules to determine epitopes expressed on identical DR isotypes. The fifteen mAb could be classified according to the first technique as falling into three different epitopic clusters. Using the second technique, we were able to define at least two independent molecular subsets, one co‐expressing two of the three epitopic clusters and the second expressing only the third one. We could not formally identify molecular subsets expressing only one of the first two clusters, using the second technique.The precise serological mapping of the determinants recognized by various anticlass II mAb should prove very useful if such mAb were to be introduced in anticlass II‐specific T cell clone blocking experiments. We anticipate that some of them should facilitate the correlation at the clonal level between the T cell repertoire and the epitopes or molecular subsets defined by these mAb. However, within mAb belonging apparently to a same cluster, some could mediate dif

ISSN:0014-2980    

DOI:10.1002/eji.1830130205

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractIa antigens were localized in cryostat sections of rat intestine and other tissues by an indirect immunoperoxidase technique using monoclonal antibodies that recognize the rat antigens homologous to the gene products of the I‐A and I‐E subregions of the mouse major histocompatibility complex (MHC). Two categories of Ia+cells were characterized, namely epithelial cells and bone marrow‐derived cells with dendritic morphology. In the small intestine Ia antigen was present in the distal 2/3 of the absorptive epithelium but absent from the bases of the villi, the crypts and the epithelium covering the Peyer's patches. The distribution in nude rats was similar, indicating that T lymphocytes are not obligatory for its expression. In ontogeny Ia antigen was absent in the epithelium of neonatal gut, appearing at about 4 weeks of age and reaching adult levels at about 6 weeks. Different rat strains showed large differences in the amount of Ia antigen expressed by villus epithelium and the traits for the level of expression were shown to map outside the MHC. The levels of expression of Ia antigen in the proximal tubules of the kidney followed that of the gut epithelium in the different strains and in both tissues was mostly intracellular. Studies with chimeras showed that the Ia antigen in epithelial cells was not acquired from bone marrow‐derived cells.The second category of cell studied had a characteristic dendritic morphology and was present in large numbers in the lamina propria of the villi and in the crypts. In the Peyer's patches these cells were present both in the subepithelial dome region and within the epithelium itself. These Ia+dendritic cells were present in nude rat jejunum and appeared in normal fetal gut by 18 days gestation and were also shown to migrate into antigen‐free grafts of fetal gut. This suggests that they do not require stimulation from antigens, bacterial products or T lymphocytes in order to localize in the gut or to express Ia antigen. Studies with other cell surface markers suggest that the Ia+cells with dendritic morphology represent a range of cell types, some with similarities to macrophages and others to nonphagocytic dendri

ISSN:0014-2980    

DOI:10.1002/eji.1830130206

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractA nucleic acid probe specific for heavy chains bearing the cross‐reactive idiotype (Id) associated with the anti‐p‐azophenylarsonate response of strain A mice has been prepared. Analysis of arsonate‐binding Id+hybridoma cell lines has revealed that all of them contain the same germ‐line VHgene rearranged to the JH2 segment. An Id+hybridoma which is unable to bind arsonate utilized the same VHgene, but it has apparently rearranged to the JH4 segment. Id−cell lines contain other rearranged VHgenes. Analysis of DNA of strain A mice revealed that there is apparently only one germ line gene that can give rise to Id+heavy chains. Since the Id is expressed as a large collection (>50) of related but nonidentical heavy chain sequences, we conclude that their diversity is the result of a somatic mutation process. Analysis of a single hybridoma cell line (45–59) reveals that somatic mutation can operate on an Id‐encoding gene and result in an antigen‐binding molecule that has lost all of its Id determinants. Further analysis of the genome of strain A mice has revealed the presence of germ‐line genes differing from the Id‐encoding gene by at least 8 base pairs. These genes, however, apparently do not contribute to the anti

ISSN:0014-2980    

DOI:10.1002/eji.1830130207

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractSpontaneous cytolytic activity of shark peripheral blood leukocytes is observed only during periods of decreased environmental temperature (<23°C). The effector cell is adherent to glass and is phagocytic. Leukocytes tested during warmer periods (26–31°C) exhibit no spontaneous activity; however, glass‐adherent cells isolated from those fish are cytotoxicin vitro, indicating that the effector cell is present at all temperatures. During warmer temperatures, nonadherent cells added to adherent cells were shown to inhibit spontaneous cytotoxicity. This inhibition requires viable cells in contact with the spontaneous cytotoxic population. Thus decreased environmental temperature correlated with spontaneous cytotoxicity, and appears to affect a regulatory cell that is glass nonadherent. In addition, the cytotoxic effector cell is more active at 23°C than 30°Cin vitro. These data show that by the time of emergence of the nurse shark, a temperature‐dependent mechanism had evolved for cellular regulation of at least one immune function, spontaneous cyt

ISSN:0014-2980    

DOI:10.1002/eji.1830130208

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractPeyer's patch (PP) cells transferred into sublethally irradiated recipients generated substantial IgM, IgG and IgA anti‐sheep red blood cell (SRBC) plaque‐forming cell (PFC) responses in the recipient spleen. If donor mice were given SRBC orally for 4–5 weeks prior to transfer, the adoptively transferred PP IgG and IgA responses were considerably suppressed, although the IgM responses were often unaffected. Co‐injection of PP cells from antigen‐fed mice with PP cells from normal mice resulted in marked suppression of the normal PP IgG and IgA response. However, treatment of PP cells from antigen‐fed mice with anti‐Thy‐1.2 plus complement prior to cotransfer completely abrogated suppression of the IgG PFC response and partially abrogated the suppressed IgA response. B cells from the PP of antigen‐fed mice, when transferred into SRBC‐primed irradiated recipients (to provide T cell help) generated 2–3 times more IgG and IgA PFC than comparable numbers of B cells from the PP of normal mice. Thus antigen feeding generates suppressor T cells in PP which can mask the expression of B cell priming to orally

ISSN:0014-2980    

DOI:10.1002/eji.1830130209

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe purpose of this work was to study the interrelationship of proliferation and secretion of plasminogen activator (PA) and interferon (IFN) by murine macrophages. For induction of macrophage proliferation and secretion of PA, concanavalin A (Con A) was used. Secretion of IFN was induced by polyinosinic polycytidylic acid complex. The glucocorticoid dexamethasone acetate (DA) (10−6− 109M) inhibited Con A‐stimulated secretion of PA and synthesis of DNA as evaluated by incorporation of [3H]thymidine. DA did not inhibit IFN induction. Preincubating macrophages with DA for 45 h reduced basal proliferation and secretion of PA but did not reduce responsiveness to Con A. Also retinoic acid, a modulator of carcinogenesis was used in inhibition studies because of its known antagonistic effects on lymphocyte mitogenesis. In macrophages a biphasic effect of retinoic acid (1 × 10−5− 5 × 10−5M) was found: (a) inhibition of DNA synthesis and secretion of PA during the first 45 h of incubation, and (b) enhancement of DNA synthesis (but not PA secretion) after 72 h. Secretion of IFN was not affected. It is suggested that secretion of PA but not IFN is linked to cell cycle traverse o

ISSN:0014-2980    

DOI:10.1002/eji.1830130210

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractIn the present report the characteristics of nonepithelial phagocytic cells of the murine thymic reticulum are described. Primary cultures were established from thymic fragments. Nonadherent cel s with hairy membranes proliferated on the surface of established primary monolayers. These cells were recovered and replated in secondary cultures were they appeared as large adherent cells with dendritic shape. At the electron microscopic level, phagocytic cells of the thymic reticulum in culture (P‐TR‐C) appear as clear vacuolated cells with an indented nucleus and few lysosomes; this morphological aspect makes them different from the common macrophage, despite their phagocytic capacity. P‐TR‐C are positive for nonspecific esterase, acid phosphatase which is found in the few lysosomes present, 5′‐nucleotidase and α‐D‐mannosidase, but negative for peroxidase. A high proportion of α‐mannosidase‐positive cells is inconsistent with the common macrophage, but in common with other cells with dendritic shape such as Langerhans cells. They are Thy‐1−, Ig−and nearly half of them are IA+. P‐TR‐C can be defined as the stimulator cells for syngeneic stimulation; they are able to induce the proliferation of lymphocytes enriched in mature syngeneic medullary thymocytes, but not in immature cortical ones. Characteristics of P‐TR‐C make them very similar to the interdigitating cells described in the peripheral lymph

ISSN:0014-2980    

DOI:10.1002/eji.1830130211

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY