摘要:

AbstractMurine lymphoid cells which were stimulated in liquid culture containing thymus culture fluid (Thy‐CF) and seeded in a soft agar culture system, proliferated and developed into B cell colonies. Two types of colonies were formed: large colonies within the upper layer and small flat colonies on the surface of the upper layer.Thy‐CF prepared from cells of normal hydrocortisone‐treated mice had a higher cloning potential than Thy‐CF prepared from untreated mice. At concentrations of Thy‐CF in culture medium greater than 35%, Thy‐CF prepared from normal mice had an inhibitory effect on colony formation.Cells of nude mice were also able to form B cell colonies if thymocytes of normal mice were mixed with lymphoid cells in the culture medium. Thymocytes elaborate a B lymphocyte colony‐stimulating factor which, with the help of T cells, triggers a B cell population into colony formation and immunoglobul

ISSN:0014-2980    

DOI:10.1002/eji.1830081002

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractTwo strains of H‐2bmutant mice, H‐2baand H‐2bf, in which the mutational event took place at H‐2K, make anti‐H‐Y cytotoxic T cell responses which are H‐2‐restricted, Db‐associated and indistinguishable in target cell specificity from those of H‐2bmice. Thus, alteration of the H‐2K molecule affects neither the Ir gene controlling the response, nor the associative antigen. On the other hand, one H‐2Dbmutant strain, H‐2bo, although it makes a good anti‐H‐Y cytotoxic response, shows target cell specificity restricted to its own Dboantigen(s), and neither H‐2b, H‐2baor H‐2bfanti‐H‐Y cytotoxic cells kill H‐2bomale target cells. Thus, the alteration of the H‐2Dbmolecule does not affect the Ir gene of H‐2bmice, bu

ISSN:0014-2980    

DOI:10.1002/eji.1830081003

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThe BALB/c secondary response against the β‐galactosidase (β‐gal) enzyme ofE. Coliwas analyzed at the precursor cell level by using the splenic focus technique. Our results indicate that in immunized mice, one out of 18000 B cells is able to recognize β‐gal. Among the families of anti‐β‐gal monoclonal antibodies, a subset of specific antibodies was detected which is capable of protecting the enzyme from heat denaturation. The frequency of clones making protecting antibodies is 1 out of 90000 and appears to be fairly constant among different individual mice. Further, the degree of heterogeneity of protecting antibodies analyzed in one individual is very high (250‐fold difference in affinity) but comparable to other secondary repertoires.Specific frequencies are compared with previous findings relative to secondary responses against artificial haptens. It is suggested that a different type of recognition exists between protein determinants and artificial haptens. In addition, the relatively high proportion of clones making antibodies of the protecting type suggests that only a small proportion of antigenic sites on the β‐gal is actually able to stimulate

ISSN:0014-2980    

DOI:10.1002/eji.1830081004

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractPhytohemagglutinin (PHA)‐stimulated human lymphocytes release soluble products which are mitogenic for other lymphocytes, so‐called mitogenic factors (MF). MF is highly mitogenic for peripheral T lymphocytes separated by rosetting with sheep red blood cells (SRBC), while being very poorly mitogenic for unseparated human peripheral lymphocytes. This lack of correlation between the magnitude of the responses and the number of T cells in these cell preparations was investigated.aPeripheral T cells enriched by passage through nylon wool columns donotrespond to MF.bUnfractionated lymphoid preparations are strongly activated by MF once they have been exposed to SRBC, even without further enrichment for rosetteforming cells.cRed cells from species other than sheep, which do not form rosettes with human T cells, are not capable of inducing responsiveness to MF.dLymphocytes exposed to PHA for 24 h become highly responsive to MF.We conclude from these results that rosetting of human T cells with SRBC has functional consequences and alters the reactivity of T cells to MF. Furthermore, these factors are not directly mitogenic for resting, unmodified T cells but rather to cells which have already been activated or modified in some

ISSN:0014-2980    

DOI:10.1002/eji.1830081005

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractSpleen cells from old mice responded less well to phytohemagglutinin (PHA), lipopolysaccharide (LPS), lipid A and allogeneic cells than those from young mice. The defect in each case resided with the nonadherent responding lymphocyte population rather than adherent accessary cells (macrophages). This conclusion was reached by showing that macrophages from old mice functioned normally in each of their known roles in lymphocyte responsesin vitro; namely, presentation of antigen or mitogen to responding lymphocytes, support of lymphocyte responses and regulation of responses to mitogens and antigens. Normal presentation function was demonstrated by the comparable ability of peritoneal exudate cells from old and young mice to furnish the macrophage requirement for PHA responsivenessin vitro.This conclusion was confirmed by the finding that old, nonadherent cells reconstituted with macrophages from young mice, responded to PHA like unfrationated old cells. Old macrophages were also shown to be normal in their ability to provide the 2‐mercaptoethanol (2ME) replaceable support function to young lymphocytesin vitro.Furthermore, replacement of macrophage supportive activity with 2ME did not rejuvenate the response of old cells to PHA, LPS, lipid A or alloantigens. Finally, no evidence of adherent cell suppression of responses of old cells could be obtained by two different approaches. First, although depletion of adherent cells increased, to a similar degree, the responses ofbothold and young cells to allogeneic stimulation, this procedure did not reduce the difference in responsiveness between them. That is, the decreased response of old cells in a mixed lymphocyte culture (MLC) could not be explained by excessive adherent cell suppression. Second, no evidence for suppression could be obtained in co‐cultures of old and young cells responding to PHA, LPS or allogeneic cells. Taken together, these results suggest that macrophage function, in contrast to lymphocyte function, does not decline with age. It is suggested that this difference may result from the different half‐lives of macrophages and lymphocytes in the intact animal.In contrast to the above results, old spleen cells acting as stimulators in an MLC were not always less effective than young cells. Furthermore, any difference that did exist between young and old cells was largely ablated by depletion of adherent cells. This result suggests that adherent cells from old mice may determine the ability of old cells to stimulate allogeneic lymphocytes in an MLC. It is not known whether this adherent cell is a macrophage or some other adherent (perhaps regulatory)

ISSN:0014-2980    

DOI:10.1002/eji.1830081006

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractHuman peripheral blood lymphocytes have been sensitizedin vitroto influenza virus antigen. After an induction period of 4–14 days, cytotoxic cells which lyse autologous influenza virus‐infected lymphoid cells could be demonstrated. The cytotoxic cell is a T lymphocyte which shows specificity for sensitizing influenza virus type A or B. It cannot distinguish between major subtypes of influenza A virus. The use of virus‐infected normal lymphoid cells as target cells overcame the difficulties of nonspecific killing encountered with some transformed

ISSN:0014-2980    

DOI:10.1002/eji.1830081007

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractEvidence is presented for the unique sensitivity of memory cells bearing surface immunoglobulin G1(IgG1) to functional elimination with anti‐immunoglobulin (anti‐Ig) sera and complement (C). Treatment of cells for adoptive transfer with C and anti‐γ1, anti‐K, or anti‐Ig significantly reduces the number of plaque‐forming cells (PFC) of only the IgG1isotype found in adoptive recipients. An increase in PFC of other isotypes accompanies the decrease in IgG1PFC; there is no net change in the total PFC response. The depletion of IgG1PFC requires treatment of transferred cells with both specific antisera and C; antisera directed against other isotypes show no significant effects. The maintenance of the magnitude of PFC response, compensation,

ISSN:0014-2980    

DOI:10.1002/eji.1830081008

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractLectin‐resistant mutants with specific defects in glycosylation have been selected from the mouse lymphoma cell line, BW5147 (Thy‐1+). The quantitative expression of cell surface glycoproteins on the mutant cells has been studied. The results show that some glycosylation defects that confer resistance to the cytotoxic effects of concanavalin A block the expression of Thy‐1 glycoprotein on the cell surface. However, some changes in the oligosaccharides of Thy‐1 glycoprotein generated by glycosylation defects found in PHARmutant cells and restricted to the termini of complex‐type oligosaccharides have no effect on the ability of Thy‐1 to reach the cell surface. No glycosylation defects were found that interfered with the expression of either gp 69,71 or H‐2 on the surface of the mutant cells. It is concluded that aberrant biosynthesis of Thy‐1 oligosaccharides can interfere with its expression on the cell surface, but that specific changes in oligosaccharide structure are necessary to block transport to the cell surface and integration into the

ISSN:0014-2980    

DOI:10.1002/eji.1830081009

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractUsing a wide range of experimental conditions, several kinds of T lymphocyte responses in spleen cell populations from trypanosome‐infected mice were studied. Lymphocyte stimulation after culture with the mitogen concanavalin A or with histoincompatible cells differing at H‐2 or minor lymphocyte‐stimulating loci was reduced or abolished in spleen cells from infected mice when compared with responses of spleen cells from uninfected controls. In addition, cytotoxic lymphocytes were not generated in mixed lymphocyte cultures which contained spleen cells from infected animals. Allogeneic skin grafting experiments performed with normal and infected mice showed that a decreased T lymphocyte response also occursin vivo.The depressed immune responses were not simply due to low numbers of T lymphocytes in spleens of infected animals, but reflected a generalized immune depression which was not antigen‐s

ISSN:0014-2980    

DOI:10.1002/eji.1830081010

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThymic tissue of C57BL/6 mice and DA rats was cultured. After 6–8 weeks, cultures were analyzed for their capacity to absorb anti‐Thy‐1 serum, and for the expression of Thy‐1 on the surface of different cell types by means of the indirect peroxidase labeling method. Three main cell types were identified: epithelium‐like cells, fibrocyte‐like cells and macrophages, but no lymphocytes were found. The presence of Thy‐1 on cultured nonlymphocytic thymus‐derived cells was demonstrated by their ability to absorb the cytotoxic activity of the appropriate anti‐Thy‐1 sera. Electron microscopical analyses of labeling experiments revealed that Thy‐1 was predominantly expressed on epithelium‐like cells with preference for their cell protrusions.The possible role of Thy‐1 expression, both on thymocytes and thymus epithelium for cellular

ISSN:0014-2980    

DOI:10.1002/eji.1830081011

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY