摘要:

AbstractThe proposition that the development of Peyer's patches (PP) is influenced by anti‐genic stimulation has been examined in sheep. Terminal lengths of ileum containing about half of the ileocecal PP were isolated from the intestinal tracts of fetal lambs during the last month before birth. Antigen was injected into some of these segments and the subsequent development of the PP studied before and after birth.The injection of either killedB. abortus, ferritin or maternal colostrum into the lumens of the isolated ileal segments did not cause premature growth of the PP follicles, nor did it effect the content of lymphoblasts in them. In contrast, the injection of these antigens into the isolated segments caused the development of germinal centers and plasma cells in the regional mesenteric lymph nodes. Plasma cells also appeared in the lamina propria along the intestinal tract in response to these antigens. These results provided experimental evidence that lymphopoiesis in the follicles of the PP of fetal lambs is not dependent on antigen. The PP in ileal segments that were not injected with antigen and had no contact with antigen subsequently grew at the normal rate before and for the first 2 weeks after birth; after this the growth of the follicles became significantly slower than normal. The follicles in these isolated ileal segments had almost completely disappeared by 3–4 months of age, whereas the follicles in the normal functional ileum did not undergo involution until around 15 months of age. The premature involution in the PP in the isolated segments was prevented by reconnecting the segment to the functional intestinal tract before 3 months of

ISSN:0014-2980    

DOI:10.1002/eji.1830140102

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe magnitude of the output of lymphocytes from Peyer's patches (PP), the morphology of the lymphocytes and their route of exit from PP has been examined in sheep. An extracorporeal perfusion system was used to selectively label a 3–4 m length of the terminal ileum of lambs at 6–10 weeks of age (the mesenteric lymph nodes had previously been excised from most lambs). This part of the intestine contains about 80% of the total PP tissue in a lamb and most of the lymphoid cells in the perfused tissue were within the PP. During a 10 min labeling period, fluorescein isothiocyanate (FITC) was added to the perfusate to label all the cells in the perfused tissues and [3H]thymidine ([3H] dThd) was added at the same time to label only those cells in the S‐phase of the cell cycle. The unincorporated label was then washed from the perfused tissues, the normal blood circulation was reestablished and the lamb allowed to recover from anesthesia. It was established that the labeling was restricted to the perfused tissue and therefore that any labeled cells subsequently found elsewhere in the animal must have emigrated from the terminal ileum. During the 24 h after perfusion 1.4 × 109−3.9 × 109lymphoid cells (i.e.FITC labeled) left the perfused tissues via the lymph; 12–19% of these cells were either in the process of dividing or less than 24 h old (i.e.[3H] dThd labeled). The majority of the labeled cells probably came from the PP and most were classified as small lymphocytes although the [3H] dThd labeled population included a high proportion of large lymphocyte and lymphoblasts especially during the early hours after the perfusion. The labeled lymphocytes entered the blood in substantial numbers which increased linearly with time so that by 24 h about 7% of the lymphocytes in the blood were fluorescent. The numbers of newly produced cells began to increase rapidly in the blood only during the 12 h to 24 h period. The number of labeled cells in the blood was reduced by about 95% when the lymph from the perfused tissues was drained from the lamb during the experiment. This result provides clear evidence that the vast majority of all of the cells that leave the PP do so via the lymph and not vi

ISSN:0014-2980    

DOI:10.1002/eji.1830140103

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractAllogeneic irradiation bone marrow chimeras C57BL/10 (H‐2b) →B10.BR (H‐2k) and B10.BR (H‐2k)→C57BL/10 (H‐2b) were raised under specific pathogen‐free (SPF) conditions; they survived very well and were healthy under SPF for 3–4 months and subsequently, under conventional housing conditions, for 1 to 8 months. Their immune response against third‐party alloantigens was comparable with that of controls. Anti‐vaccinia virus responses were very low when compared with syngeneic control chimeras or unmanipulated control animals; if anti‐vaccinia virus cytotoxic T cell reactivity was measurable, it was specific for the bone marrow donor, rather than the recipient thymic H‐2 type. In contrast, the anti‐LCMV (lymphocytic‐choriomeningitis virus) response was excellent and comparable to that in controls for B10.BR (H‐2k)→C57BL/10 (H‐2b) chimeras, but was completely absent for C57BL/10 (H‐2b)→B10.BR (H‐2k) chimeras. LCMV‐specific cytotoxic effector T cells from B10.BR→C57BL/10 chimeras were restricted entirely to recipient H‐2b. In contrast to the asymmetric cytotoxic T cell response, both types of chimeras developed good primary footpad swelling reactions after local infection, which arose somewhat slower with LCMV than in control of chimeras. The capacity to control infection byListeria monocytogeneswas excellent for all controls and B10.BR→C57BL/10 chimeras but apparently absent in C57BL/10→B10.BR chimeras.Differentiation of T cell restriction specificity for thymic H‐2 is apparently most efficient, but it remains unclear whether the observed asymmetry reflects exaggerated immune response regulation in H‐2‐incompatible stem cell‐thymus chimeras or differential cross

ISSN:0014-2980    

DOI:10.1002/eji.1830140104

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractStimulation of peripheral blood lymphocyte (PBL) cultures from tetanus toxoid (TT)‐immunized donor with Epstein‐Barr virus (EBV) yielded cells with much higher frequencies of hybrid formation (36 × 10−7) compared to unstimulated PBL or cells cultured with pokeweed mitogen or TT antigen. The proportion of hybridomas (approximately 1%) producing anti‐TT antibody was similar in EBV‐ and TT‐stimulated cultures. A marked increase in immunoglobulin secretion was observed after hybridization and preselection of EBV subcultures for high anti‐TT production prior to fusion resulted in a fivefold increase in TT‐specific hybridomas (p<0.001). Most (20/21) specific hybrids produced IgM anti‐TT, whereas one (1/21) produced IgG anti‐TT, possibly due to the immature stage of differentiation in EBV‐stimulated parental cells. The ability to choose an antigen, immunize a human subject and expand the rare antigen‐specific B cells from PBL,in vitro, with EBV, prior to fusion, should yield an increasing spectrum of human monoclonal antibodies for diagnostic, ther

ISSN:0014-2980    

DOI:10.1002/eji.1830140105

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe I‐A subregion mutant B6.C‐H‐2bm12(bm12) and the C57BL/6 parent were used to examine the role of the Ia‐1 gene product as a restriction element in the antibody response to sheep red blood cells (SRBC). Using anin vitroculture system, it was shown that cooperation between histocompatible T cells, B cells and macrophages was required to generate a secondary IgM response to SRBC. The alteration in the Ia‐1 gene in bm12 altered the ability of bm12 T cells to collaborate with C57BL/6 B cells, but not with C57BL/6 macrophages. Similarly, C57BL/6 T cells could not collaborate with bm12 B cells. The mutation in bm12 did not affect the ability of T cells to interact with C57BL/6 macrophages, eitherin vitroorin vivo, or of bm12 macrophages to interact with C57BL/6 T cells. Thus in this system, the Ia‐1 gene product restricts T‐B cell interaction but not T cell‐macroph

ISSN:0014-2980    

DOI:10.1002/eji.1830140106

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractA limiting dilution culture system based on stimulation with concanavalin A (Con A) has been used to study the quantitative distribution of helper and of cytotoxic precursor cells in Lyt‐2‐defined subpopulations of murine T cells. Virtually all of the selected Lyt‐2+and Lyt‐2−T cells grow and expand to large clonal colonies within an 8–9‐day culture period. Our data show that upon stimulation with Con A, 90% of the Lyt‐2−T cells were capable to produce interleukin 2 (IL2) activity. In addition, IL2 activity is produced by 8–10% of Lyt‐2+T cells. However, at the clonal level, the average of the IL 2 activity produced by Lyt‐2+T cells is about 8‐fold less as compared to Lyt‐2−T cells. Precursors of cytotoxic T cells were almost exclusively found in the Lyt‐2+population, of which about 70% displayed lytic activity in a lectin‐dependent cytolysis test. For the vast majority of clones analyzed the capacity to produce IL 2 activity and the capacity to express lytic activity, was found to be mutually exclusive. A minority of clones (<3%) was found to simultaneously produce IL2 activity and to express cytotoxicity. These latter cells are therefore c

ISSN:0014-2980    

DOI:10.1002/eji.1830140107

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractIt has recently been shown that the classical 24–48‐h component of delayed‐type hypersensitivity (DTH) in mice is preceded by an early 2‐h component. This early component of DTH resembles IgE‐dependent hypersensitivity reactions, but is mediated by an antigen‐specific T cell factor that activates cutaneous mast cells (MC). In the current study of cutaneous hypersensitivity reactions, evidence is presented that serotonin and histamine are released from the granules of MC in IgE‐dependent responses, but that T cell activation of MC induces preferential release of serotonin. In T cell‐dependent reactions, it was found that serotonin was released under experimental conditions in which MC granules were depleted of serotonin, but catabolism of serotonin in the cytosol was prevented. This suggests that T cells induce differential release of serotonin from nongranule storage sites in MC, such as transport vesicles in the cytoplasm. Morphological observations of MC in IgE‐dependent compared to T cell‐dependent cutaneous reactions were consistent with this hypothesis. Exocytosis of granules characterized IgE activation and was not found in MC that were activated by T cells, which instead showed mild degranulation accompanied by numerous cy

ISSN:0014-2980    

DOI:10.1002/eji.1830140108

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractOpsonized yeast is known to bind strongly to the marginal zones in frozen sections of rat spleen (Kumararatne, D. S. et al.,Eur. J. Immunol.1981.11:858). This study reports an analysis of the cells involved in this binding. Sheep red cells coated respectively with C3b, C3bi or C3d were used as indicator cells. These showed homogeneous binding of both C3b and C3bi to marginal zones and germinal centers. C3d‐coated red cells bound in a uniform speckled pattern to marginal zones. They also bound to germinal centers and the small lymphocyte zones of the follicles. Selective depletion experiments were undertaken to show that binding to marginal zones was a property of the IgM+and IgD−B cells characteristic of this area. Binding to germinal centers was attributable to follicular dendritic cells. The C3d receptors in follicles were shown to be on IgM+and IgD+small B lymphocy

ISSN:0014-2980    

DOI:10.1002/eji.1830140109

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractInterferon‐γ (IFN‐γ), tested in the form of the product of a cloned murine IFN‐γ gene, was found to increase the expression of H‐2 antigens on cultured cell lines of a wide variety of cell types including factor‐dependent hemopoietic cells, pre‐B and B cells, macrophages, T cells, mast cells and cell lines of epithelial, fibroblastic and neuronal origin. However, IFN‐γ induced Ia antigens on only B cells, macrophages and T‐dependent mast cells or persisting cells. On the basis of these results, we suggest that a major function of IFN‐γ is to potentiate immune responses by enhancing the expression of H‐2 and Ia antigens on

ISSN:0014-2980    

DOI:10.1002/eji.1830140110

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractDuring the acute cytolytic T lymphocyte (CTL) response of mice to infection with the murine cytomegalovirus two independent populations of activated interleukin‐receptive CTL precursors can be demonstrated. One population is specific for cell membrane‐incorporated viral structural antigens, whereas the second population detects an antigen, whose appearance is correlated with the synthesis of viral immediate early proteins. Since this new type of antigen is only defined by lymphocyte recognition, it is referred to as the lymphocyte‐detected immediate early antigen (LYDIEA). Expression of immediate early antigen precedes the production of viral progeny and, therefore, it is possible that LYDIEA‐specific CTL could serve as indicator cells for the very first activities of the viral genome, even during nonproductive in

ISSN:0014-2980    

DOI:10.1002/eji.1830140111

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY