摘要:

AbstractThe idiotypic cross‐reactivity of mouse and human monoclonal immunoglobulins with binding activity for phosphorylcholine (PC) was investigated, using an idiotypic antibody elicited against the PC‐binding human IgMFR. The isolated FR heavy chain proved to be a better inhibitor for the reaction of IgMFRwith anti‐FR than the FR light chain, but the intact protein was necessary for full idiotypic expression. PC was an inhibitor only at concentrations greater than 10−3M indicating that the idiotypic antibody was not combining site‐directed. Among the murine PC‐binding IgA myeloma proteins, MOPC 167 was found to be the best inhibitor, but its inhibitory capacity was about 4 orders of magnitude lower than that of the homologous IgMFR. McPC 603 was an even weaker inhibitor, while TEPC 15 effected no better inhibition than human monoclonal immunoglobulins without PC‐binding activity. MOPC 167 has a most similar binding specificity to IgMFRas indicated by the high affinity for choline of these two proteins. TEPC 15 and McPC 603, on the other hand, exhibit a much lower affinity for choline. In addition to their similarity in specificity, proteins FR and MOPC 167 show important structural similarities within parts of their heavy and light chain variable domains. The data provide some evidence for the existence of idiotypic cross‐reactivity between the two specie

ISSN:0014-2980    

DOI:10.1002/eji.1830090602

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA fraction of la‐like glycoproteins was prepared from rat thymocytes by lentil lectin affinity chromatography and gel filtration in deoxycholate. Spleen cells from mice immunized with this preparation were fused with myeloma cells to produce antibody‐secreting hybrid cell lines. Antibody from four lines called MRC OX, 3, 4, 5, 6 reacted with the la‐like glycoproteins, and MRC OX 3 antibody recognized an antigenie determinant polymorphic in the rat. All four antibodies also bound to mouse spleen cells and all detected polymorphisms. Studies on recombinant mouse strains suggest that the determinants are coded by the I‐A subregion of the H‐2 complex. MRC OX 3 correlates with Ia specificity 9, while MRC OX 4, 5, 6 correlate with specificity 17 or 18. MRC OX 4 monoclonal antibody was used for affinity chromatography to purify Ia glycoproteins from rat spleen. The rat Ia glycoprotein complex was composed of two noncovalently linked polypeptide chains of apparent mol. wt. (unreduced) 30 000 and 24 000 as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The purified Ia glycoprotein partially inhibited the binding to thoracic duct lymphocytes of an alloantiserum which detects Ia antigens linked to the major histocompatibility complex. The monoclonal anti‐la antibodies bound to the majority of peripheral B lymphocytes and 18% of thymocytes, but did not significantly bind to peripheral T lymphocytes. There were on average 150000 molecules of Ia glycoprotein per la‐positive B lymphocyte, and 45 000 molecules per la‐positive thymocyte.From the same fusion, another cell line was prepared called MRC OX 2 which secretes monoclonal antibody to a previously undefined thymus glycoprotein of apparent mol. wt. 60000. Preliminary studies showed that the antigen was expressed on all thymocytes and on peripheral B lymphocytes in smaller amounts. It was also present in brain, but not liver or ki

ISSN:0014-2980    

DOI:10.1002/eji.1830090603

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThe blastogenic response of human lymphocytesin vitroto hyperoptimal concentrations of concanavalin A (Con A) has been studied by means of volume spectroscopy (measuring cellular and nuclear volume), flow cytofluorometry (measuring cellular DNA content) and incorporation of [3H]thymidine ([3H]dThd). The optimal Con A dose with respect to [3H]dThd incorporation was about 30 u, g/ml. In cultures given hyperoptimal doses,e.g.100 μg/ml, [3H]dThd incorporation was strongly inhibited, whereas the number of cells entering S‐phase and significantly increasing their cellular and nuclear volume was considerably larger than with 30 μg/ml. With 200 μg/ml Con A, which induced negligible [3H]dThd incorporation, the percentage of responding cells was even larger. Hence, doses of Con A, which were hyperoptimal with regard to [3H]dThd incorporation, induced blastogenic response, including DNA synthesis, in a larger percentage of the cells than did the optimal dose. However, in cultures with hyperoptimal Con A doses, the progression of the cell cycle stagnated mainly during S‐ and G2‐phase and few cells completed mitosis. Thus, the blocking effect of hyperoptimal doses was not confined to any particular point of the cell cycle. The reduced [3H]dThd incorporation, seen with hyperoptimal doses, is attributed partly to a failure of this assay under such co

ISSN:0014-2980    

DOI:10.1002/eji.1830090604

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractOld (15–20 month) male (NZB × NZW)F1(B/W) mice have severely impaired spleen cell reactivity to phytohemagglutinin (PHA), a mitogen which stimulates mainly T lymphocytes. Spleen cells from old mice markedly suppressed the PHA response of splenocytes from young (3–4 month) B/W males. Similar suppressor activity was not present in the spleens of old mice of four nonautoimmune strains.The suppressor activity of old B/W spleen cells was mediated by a nonphagocytic, radioresistant, mononuclear leukocyte. Although this cell was eluted in the “T lymphocyte” fraction of nylon wool columns, it was not sensitive to treatment with anti‐Thy‐1 antiserum and complement. Suppressor activity was lost after 18 h incubation at 37 °C in tissue culture medium. Supernatants of these overnight cultures had no suppressive effect on fresh young B/W spleen cells.Old B/W spleen cells suppressed PHA reactivity more than concanavalin A or lipopolysaccharide reactivity. Kinetic studies demonstrated an increasing suppression with time over 72 h of culture. This study demonstrates that the severely impaired PHA reactivity of old B/W mice is mediated, at least in part, by activ

ISSN:0014-2980    

DOI:10.1002/eji.1830090605

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractHuman leukocyte interferon increased the expression of HLA‐A, B antigens and β2‐microglobulin on two lines of human lymphoblastoid cells and on peripheral blood lymphocytes. No effect was observed on the expression of HLA‐DR an

ISSN:0014-2980    

DOI:10.1002/eji.1830090606

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThe specificity was established for the anti‐thymocyte autoantibody which appeared in BALB/c mice (BAA) during immunization to the P 1798 lymphoma. The results indicate that BAA is specific for the Thy‐1 alloantigen of murine T cells. By immunoprecipitation of125I‐labeled A/J thymocyte surface antigens from freeze‐thaw lysates and electrophoretic resolution of the immunoprecipitates on sodium dodecyl sulfate polyacrylamide gels, the BAA and congenic anti‐Thy‐1.1 or 1.2 were shown to be specific for determinants on the same antigens. Specificity of BAA for Thy‐1.2 was shown also by quantitative absorption studies. Coating P 1798 lymphoma cells with either BAA or anti‐Thy‐1.2 reduced the absorptive capacity of these cells for the same or the reciprocal antiserum. Coating P 1798 with an antiserum to P 1798 which was indifferent to the Thy‐1.2 alloantigen did not diminish the absorptive capacity of these cells for either BAA or anti‐Thy‐1.2. These studies have provided firm evidence that BAA is specific for determinants o

ISSN:0014-2980    

DOI:10.1002/eji.1830090607

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractPrimed spleen cells respond well to metabolically inactivated stimulator cells while normal spleen cells do not. This observation has been interpreted as showing that cytotoxic T cell precursors are different from unprimed precursors in their antigen recognition requirements for induction. A different model is proposed here which accounts for these observations as due to enhanced helper cell levels in primed populations. Experiments are described in this study which test several predictions of this model. These experiments show that in the presence ofin vitroprimed helper T cells, normal cells are able to respond efficiently to glutaraldehyde‐fixed stimulator cells. The helper effect is antigen‐specific. Since unprimed spleen cells can be efficiently induced by metabolically active stimulators (γ‐irradiated cells) and can respond to glutaraldehyde‐fixed antigen (metabolically inactive cells) only in the presence of specific helper cells, it seems reasonable to propose that helper cell signals are enhanced by a nonantigenic property of γ‐irradiated stimulator cells requiring metabolic activity. It is also clear that glutaraldehyde‐fixed cells are anti‐ genically intact as helper cells, primed to antigens on γ‐irradiated stimulator cells, efficiently and specifically help a response to fixed stimulators. Conversely, helper cells primedin vitroto glutaraldehyde‐fixed stimulators recognize antigen on γ‐irradiated stimulator cells. The level of help generated in response to glutaraldehyde‐ fixed stimulator cells is at least 10‐fold higher in primed cells than in normal cells. In addition, primed spleen cells can be inducedin vitroto yield helper function by both fixed or unfixed stimulator cells. Normal helper cell precursors are induced at least 100‐fold more efficiently by γ‐irradiated as compared to glutaraldehyde‐fixed stimulator cells. This work supports the idea that a major effect of priming, which allows primed cells to respond to metabolically inactive stimulators, is to enhance levels of helpe

ISSN:0014-2980    

DOI:10.1002/eji.1830090608

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA spontaneous assembly variant, B 50, has been isolated from the MPC‐11 mouse myeloma cell line. This variant synthesizes fewer light chains per cell than the parent resulting in the production of a slight molar excess of heavy chains. These changes are associated with a delay and change in the pathway of assembly and a delay in secretion. Spontaneous revertants of B 50 have been obtained, all of which synthesize normal amounts of light chains and assemble and secrete the immunoglobulin molecule through the same pathways and with the same kinetics as the parental cells. A comparison of the tryptic‐chymotryptic peptides of the parental, variant and revertant heavy and light chains did not reveal any differences. These studies indicate that variants in mouse myeloma cells can arise with defects in the quantitative expression of the immunoglobulin gene and suggest that the presence of excess light chains facilitates the assembly and secretion of some immunoglobulin molecu

ISSN:0014-2980    

DOI:10.1002/eji.1830090609

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractPrevious studies have established that T cell‐mediated cytolysis can be reversibly inhibited by the hexose analogue 2‐deoxy‐D‐glucose (2‐DG) by a mechanism which is apparently unrelated to energy depletion. The possibility that the inhibitory effect of 2‐DG on cytolysis was linked to its known inhibitory effect on glycoprotein synthesis was therefore investigated. In contrast to the results obtained with 2‐DG, no inhibition of cytolysis was observed in the presence of tunicamycin, a potent and specific inhibitor of lipid carrier‐dependent protein glycosylation. Furthermore, populations of cytolytic cells which had been pretreated with doses of tunicamycin sufficient to block the incorporation of mannose (or 2‐DG) into glycoproteins were still fully susceptible to inhibition by 2‐DG. Other known inhibitors of viral protein glycosylation, such as glucosamine and galactosamine, inhibited cytolysis only weakly under conditions where 2‐DG was highly effective. Kinetic studies revealed that the inhibitory effect of 2‐DG on cytolysis could be reversed within minutes by the addition of exogenous glucose. Furthermore, suggestive evidence was obtained that inhibition of cytolysis by 2‐DG was linked to a parallel inhibition of effector: target cell binding. Taken together, these results strongly suggest that the inhibitory effect of 2‐DG on cytolysis can be dissociated from its effect on protein glycosylation. An alternative mechanism of

ISSN:0014-2980    

DOI:10.1002/eji.1830090610

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA reverse hemolytic plaque assay utilizing protein A‐coated sheep red cells and a specific rabbit anti‐rat IgE preparation has been adapted for the enumeration of rat IgE‐secreting cells derived from the IR‐162 rat plasmacytoma and from rats infected withNippostrongylus brasiliensis.Under optimal conditions, approximately 10–15% of the viable plasmacytoma cells were scored as plaque‐forming cells. In rats infected with 5000Nippostrongylus brasiliensislarvae, a maximum of 2 × 106IgE‐secreting cells were found in the mesenteric lymph nodes, and no IgE plaque‐forming cells in their spleens. The kinetics of the mesenteric lymph node plaque‐forming cell responses closely coincided with total serum IgE levels, with maximum responses occurring 15–16 days after infection. There was a high degree of correlation between the mesenteric lymph node IgE plaque‐forming cell responses and total serum IgE levels of individual rats. It was concluded that the IgE‐secreting cells in the mesenteric lymph nodes contributed, in a large way, to the elevated levels of IgE found in the c

ISSN:0014-2980    

DOI:10.1002/eji.1830090611

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY