摘要:

AbstractSoluble immune complexes of guinea pig IgG2anti‐DNP (2,4‐dinitrophenyl) antibodies and DNP19BSA (bovine serum albumin) were prepared at a variety of antibody‐to‐antigen ratios. The mean sizes of the complexes were determined by gel filtration, and equilibrium binding of the complexes to homologous peritoneal macrophages was measured at 4°C. Scatchard plots of the binding data were linear indicating that the complexes were binding to a uniform population of functionally independent membrane receptors.The avidity constants for complex binding to macrophages increased from 15.4 × 107M−1for complexes containing an average of two antibody molecules to 59.0 × 107M−1for complexes containing an average of four, compared with an association constant for monomeric IgG2of 0.21 × 107M−1. Calculation of the molar‐free energy changes accompanying monomer and immune complex binding revealed not only that the intrinsic binding activity of mononer was sufficient to account for the complex binding activities by simple cooperation of linked antibodies, but also that the cross‐ linking of antibodies with antigen imposed a strain on the antibody‐receptor interaction, resulting in complex binding energies that were lower than the values expected from a simple cooperative mechanism.Complex inhibition by monomeric IgG2of unrelated antibody specificity was studied, and it was observed that high concentrations of monomer led to an increase in macrophage discrimination between complexes of different size. The relevance of this finding to thein vivoclearance of circulating

ISSN:0014-2980    

DOI:10.1002/eji.1830100502

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractRadioassays have been developed to measure, as separate events, the ingestion and degradation of macrophage‐bound guinea pig IgG anti‐DNP (2,4‐dinitrophenyl)‐ DNP‐BSA (bovine serum albumin) complexes of defined size and subclass. Complex ingestion was observed to be temperature‐dependent and was effectively blocked only by a combination of inhibitors of respiration and glycolysis indicating that the process is under the same metabolic control as fluid phase pinocytosis. On the other hand, the half‐life of membrane‐bound complexes at 37 °C (t1/2= 5.6 ± 1.7 min) was considerably shorter than the value expected from membrane turnover studies (t1/2= 22.4 min) suggesting that complexes are selectively cleared from the cell surface. The rate of ingestion at 20°C was independent of complex size and of the IgG subclass used in complex formation, but was affected byin vivostimulation of the macrophages before assay.Complex digestion was shown to be highly temperature‐dependent and, at 37 °C, proceeded at a rate (t1/2= 1.5‐5 h) which was 20‐60‐fold slower than the rate of ingestion indicating that the latter is unlikely to influence digestion kinetics. On the other hand, the selective action of 2‐deoxyglucose in blocking digestion, but not ingestion, suggests that pinosome‐lysosome fusion may play a part in determining the overall catabolic rate. A 2 to 3‐fold difference in digestion rates was observed between the proteins employed as antibody (guinea pig IgG1or IgG2) and as antigen (DNP‐BSA). This finding suggests that the intrinsic susceptibility of ingested proteins to enzymatic hydrolysis may be the prime determinant of digestion rate. As with ingestion, no discrimination was observed in the degradation of complexes of different size or IgG antibody subclass.The observations in this and the preceding study (Eur. J. Immunol. 1980.10: 317) indicate that complex size is important in determining the level of uptake by phagocytes but not subsequen

ISSN:0014-2980    

DOI:10.1002/eji.1830100503

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractMixed responder populations, consisting of selected Lyt‐2,3+cells and unselected T cells from two congenic mouse strains differing in their Lyt‐2,3 alleles, were used to study the role of Lyt‐1,2,3+cells in the generation of cytotoxic effector cellsin vitro. The fact that, under these conditions, all primary alloreactive and H‐2‐restricted killer cells are generated from the unselected T cell population and not from the selected Lyt‐2,3+subset is demonstrated. Isolated, unsensitized Lyt‐2,3+cells are able to produce primary alloreactive cytotoxic T lymphocytes (CTL) when incubated with alloantigen alone, but appear to be suppressed in the presence of Lyt‐1,2,3+cells. In contrast, mixtures of Lyt‐2,3+cells selected from C 57 BLI6 T cells previously primed to alloantigenin vitro, and unselected T cells from the Lyt‐2,3‐congenic partner after exposure to the same antigen give rise to cytotoxic effector cells which derive mainly from the primed Lyt‐2,3+cell pool and not from the unselected T cell population. Both populations were able to generate CTL when sensitized separately with the alloantigen. The data suggest that Lyt‐1,2,3+cells contain all primary precursors for both H‐2‐restricted and alloreactive killer cells, as well as lymphocytes suppressing the formation of cytotoxic effector cells from unsensitized Lyt‐2,3+cells. The Lyt‐ 2,3+cell pool most likely contains the secondary CTL precursors. In addition, the same antigen‐primed Lyt‐2,3+pool contains suppressor cells which inhibit the formation of primary CTL from Lyt‐1,2,3+cells. The data are discussed with respect t

ISSN:0014-2980    

DOI:10.1002/eji.1830100504

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe role of adherent phagocytic cells in anin vitrosecondary cytotoxic response against Simian virus 40 (SV40)‐induced tumor‐associated antigens was investigated. Spleen cells (responder cells), from mice primed with syngeneic SV40‐transformed cells, extensively depleted of macrophages by filtration through a Sephadex G–10 column followed by iron carbonyl treatment, had a markedly decreased capacity to generatein vitrosecondary cytotoxic reactivity against syngeneic SV 40‐transformed cells when cultured with the relevant stimulator cells. The secondary response was restored by the addition of adherent peritoneal cells from normal mice syngeneic to those immunized with the antigen. Within a certain dose range, small numbers of peritoneal cells completely reconstituted the response, whereas large numbers inhibited the reactivity. The restored cultures maintained specific cytotoxic reactivity against SV40‐induced tumor‐associated antigens which was mediated by effector T cells as shown by sensitivity to anti‐Thy‐1.2 antiserum and complement. These results suggested a requirement for adherent phagocytic cells (accessory cells) inin vitrogeneration of a secondary, cytotoxic response to tumor‐

ISSN:0014-2980    

DOI:10.1002/eji.1830100505

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractA messenger RNA fraction from the C 3 H mouse myeloma 5563 was used to direct the synthesis of heavy (γ2J) and light (χ) chain precursors. The synthetic products were radiolabeled by inclusion of [3H] or [35S] amino acids in a wheat‐germ cell‐free translation system. Precursor peptides for both H and L chains were indicated by comparison by polyacrylamide gel analysis of apparent molecular weights of chains synthesizedin vitro vs. in vivo. The nonglycosylated H chain synthesizedin vivoin the presence of tunicamycin was used for comparison. This approach should be generally applicable for the demonstration of precursor forms of N‐glycosylated polypeptides. Following immunoprecipitation and preparative polyacrylamide gel electrophoresis, the isolated chains were subjected to automated Edman degradation. The amino acid sequence data obtained for these precursors were significantly different from those reported for BALB/c immunoglobulins. The 5563 H chain precursor bears little homology to the previously reported H chain precursor from MOPC 315 (IgA) (Jilka, J. A. and Pestka, S.,Proc. Nat. Acad. Sci. USA1977.74: 5692). The 5563 H chain can be assigned to a heretofore undescribed H chain variable region subgroup on the basis of partial sequence data. The amino terminal sequence of the 5563 L chain precursor has maximum homology (25‐55%) to the sequence of the precursor peptide of MOPC4

ISSN:0014-2980    

DOI:10.1002/eji.1830100506

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractModulation of receptors for IgG (FcγR) on human lymphocytes was induced by the interaction with erythrocyte‐IgG antibody (EAG) complexes followed by incubation at 37°C. The re‐expression of FcγR could be achieved by two independent processes, (a) Active synthesis, susceptible to inhibition by puromycin or cycloheximide was shown to peak 4 to 6 h after removal of EAGcomplexes; it required addition of at least 2% fetal calf serum. (b) Insertion of soluble FcγR into the membrane of modulated lymphocytes was shown to occur within 20 min of contact between cells and FcγR‐containing supernatants; it was not altered by protein synthesis inhibitors. FcγR‐like material, spontaneously released by unstimulated peripheral blood lymphocytes or by polymorphonuclear cells, was taken up by modulated lymphocytes. This soluble material was fully absorbed on polymerized human IgG; it was non‐ dialyzable, thermolabile (56 °C, 30 min) and partially destroyed by freezing and thawing; it was recovered as two broad peaks from chromatography on polyacrylamide gel; it was shown to bind to both T and non‐T FcγR‐bearing lymphocytes capable of forming EAGrosettes before modulation; and it could be inserted into allogeneic lymphocytes. These results demonstrate that the FcγR structure bears two active sites, one binding to the Fcγ and the other to the surface of EAGrosette‐forming cells. Rapid release of soluble FcγR from the cells and their possible insertion into the membrane may have important implications with respect to the biological functions assoc

ISSN:0014-2980    

DOI:10.1002/eji.1830100507

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractWe have identified membrane glycoproteins which carry T cell‐specific antigens on human T lymphocytes and thymocytes. Purified cells were surface‐labeled with NaB3H4after treatment with neuraminidase and galactose oxidase. Immunoprecipitations were performed with rabbit anti‐human T cell‐specific antibodies using co precipitation with protein A‐containing staphylococci strain Cowan I. The labeled membrane glycoproteins and the precipitates were subjected to polyacrylamide slab gel electrophoresis and visualized by fluorography.The antibodies specifically precipitated 4 proteins called GP200, GP180, GP165 and GP160 (mol. wts. = 200000, 180000, 165000 and 160000) from surface‐labeled T lymphocytes and low‐density (medullary) thymocytes. The GP200 and GP180 were not labeled on high‐density (cortical) thymocytes. A protein with a mol. wt. of 45000 was precipitated from thymocytes. Another glycoprotein on T lymphocytes and thymocytes with a mol. wt. similar to that of mouse and rat Thy‐1 or Θ antigen (mol. wt. 25000) reacted w

ISSN:0014-2980    

DOI:10.1002/eji.1830100508

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe tumor‐associated cell surface antigens (TAA) gp71 and AgI cocap H‐2, but are not associated with H‐2 following solubilization of membranes with detergent. We have attempted to solubilize intact TAAIH‐2 complexes from surface‐labeled L cells using decreasing concentrations of the nonionic detergent Nonidet‐P40 (NP40). Associations between gp71 and H‐2 and between AgI and H‐2 in solution were detected using sequential immunoprecipitation. gp7UH‐2 and AgI/H‐2 complexes were solubilized at the lowest detergent concentration used, 0.01% NP40. No co‐ precipitation of these antigen pairs was seen at any higher NP 40 concentration tested. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that precipitation of antigens solublized in 0.01% NP40 leads to co precipitation of a small number of other protein peaks and does not appear to involve wholesale inclusion of labeled membrane proteins. These results, together with previous observations of cocapping between TAA and H‐2 antigens, suggest that the molecules are associated with one another in the membrane. Detergent solubilization of membranes with all but the most gentle conditions leads to disrup

ISSN:0014-2980    

DOI:10.1002/eji.1830100509

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractSusceptibility to HgCl2‐induced glomerulonephritis was transferred to resistant Lewis (LEW) rats, irradiated and reconstituted with (LEW × BN)F1, hybrid immunocompetent cells. This glomerulonephritis was similar to that observed in Brown‐Norway (BN) rats with a first stage characterized by anti‐glomerular basement membrane antibodies and a second stage with immune complex‐type deposits in the glomerular tufts and in the small renal

ISSN:0014-2980    

DOI:10.1002/eji.1830100510

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractLeukocytes from C57BL/6 mice immunized against DBA/2 strain antigens by intraperitoneal injection of mastocytoma P 815 cells produced, when stimulated in the mixed leukocyte reaction assay with DBAI2 spleen cells, an earlier and more intense secretion of immune interferon than leukocytes from untreated mice. This secondary‐type interferon response was independent of cell proliferation. The memory phenomenon was induced by long‐lived, recirculating lymphocytes found in spleen, lymph nodes and thoracic duct, but not in the thymus. Memory cells could be recruited into inflammatory sites. They were shown to be specific for H‐2 alloantigens, although some cross‐reactivity with stimulating cells bearing unrelated H‐2 antigens was observed. The possible anti‐tumor, antiviral and immunoregulatory roles of this memory phenomenon, and its significance in transplantation immunity ar

ISSN:0014-2980    

DOI:10.1002/eji.1830100511

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY