摘要:

AbstractCultures of normal diploid fibroblasts and of a human osteosarcoma cell line (MG‐63) are shown to be able to produce a factor which promotes the growth of B cell hybridomas (hybridoma growth factor, HGF). The induction is stimulated by treatment of the cells with interleukin 1 (IL 1) (α or β) or polyriboinosinic‐polyribocytidylic acid [poly(rI) · poly(rC)]. Combined treatment with cycloheximide and actinomycin D also stimulates production and enhances production induced by IL 1 or poly(rI) · poly(rC). Extremely small doses of IL 1 (0.1 units/ml) are active as inducer of HGF. Also, under optimal conditions the yield of HGF can attain as much as 104units/ml. Tumor necrosis factor (TNF‐α), which otherwise shares various properties with IL 1, is a weak inducer of HGF.Although there is a superficial resemblance between induction of HGF and that of interferon‐β, the two activities are serologically distinct and conditions for their induction are quite different. In fact, conditions for induction of HGF are indistinguishable from those described for the induction of the mRNA of the so‐called 26‐kDa protein (also known as interferon‐β2). Finally, the HGF derived from IL 1‐ or poly(rI) ‐ poly(rC)‐treated fibroblasts is serologically not distinguishable from that produced by mitogen‐stimulated

ISSN:0014-2980    

DOI:10.1002/eji.1830170102

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractVariable region nucleotide sequences and respective translated amino acid sequences for three heavy chains (DB3, 11/32 and 10/8) and two light chains (DB3 and 11/32) of monoclonal mouse IgG1anti‐progesterone antibodies have been determined by primer extension mRNA sequencing. The three VHregions exhibit the same rarely observed VHIX gene family and have>88% homology between them. Two associated light chain sequences are 95% homologous and belong to the VxI group. The N‐terminal twenty two amino acids of the x light chain of the third antibody 10/8 have been determined by automated protein sequencing and are identical to those of 11/32. Thus, these three monoclonal anti‐progesterones derived from separate fusions all use VHIX‐Vx1 gene combi

ISSN:0014-2980    

DOI:10.1002/eji.1830170103

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractCD2 (the sheep erythrocyte receptor) is a surface antigen of human T lymphocytes. A role for CD2 in T cell function has been implicated from the observation that antibodies against CD2 are capable of transmitting both positive and negative signals for cell growth. Biochemically, the molecule has been identified as a broad band on sodium dodecyl sulfate (SDS)‐polyacrylamide gels of about 50–58 kDa. This communication demonstrates that CD2 contains N‐linked carbohydrate as endo‐β‐N‐acetylglucosaminidase F digestion reduced its apparent mol. mass to a compact band of 40 kDa. CD2 was purified from the T leukemia cell line J6 by immunoaffinity chromatography and preparative SDS‐polyacrylamide gel electrophoresis (PAGE). Four bands of 52, 54, 56 and 58 kDa could be distinguished in the immunoaffinity‐purified protein which formed a broad zone on SDS‐PAGE extending from about 45 to 58 kDa. Preparative SDS‐PAGE yielded a product suitable for determining the N‐terminal amino acid sequence. Assignments were made for the first 26 (excluding the 23rd) residues and the sequence identifi

ISSN:0014-2980    

DOI:10.1002/eji.1830170104

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractA modified splenic fragment assay was used to assess the role of antigen‐specific helper T cells in B cell isotype expression. Limiting numbers of carrier‐specific helper T cells from lines or clones were injected along with a source of B cells into lethally irradiated unprimed recipients. The incidence of lodging of the T cell lines in recipient spleens at 18 h was determined by autoradiography to be 1.5 to 4.3% of the injected cells. These T cells were necessary and sufficient for the generation of T‐dependent B cell responses within splenic fragments culturedin vitrowith specific antigen. A comparison of isotypic responses from splenic and Peyer's patch B cells generated with the same T cell population revealed that a high proportion of the response from Peyer's patch B cells consisted of IgA antibody exclusively (46–57%) while the percentage of such responses from splenic B cells was much lower (7–10%). Thus, the isotype pattern of the response reflected the B cell source. Experiments in which cloned hemocyanin‐specific T cells provided help to T‐depleted spleen cells within splenic fragments from athymic recipients indicated that a single specificity of helper T cell is both necessary and sufficient to support the generation of antibody responses consisting of multiple isotypes. Isotype‐specific T cells do not appear to be required

ISSN:0014-2980    

DOI:10.1002/eji.1830170105

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe capacity of the B cell immunoglobulin receptor to recognize complexes of Sendai viral and H‐2bantigens was investigated by studying the antibody response to injections of syngeneic Sendai virus‐coated (SV+) spleen cells in C57BL/6 (B6) mice. Almost all mice produced alloreactive anti‐H‐2 lymphocytotoxic antibodies. In contrast, such antibodies were found very exceptionally in mice injected with normal (SV−) cells or with Sendai virus (SV) only. The reaction pattern of the cytotoxic antibodies induced was variable and ranged from almost anti‐private to widely cross‐reactive serotypes. The results of reactions on H‐2‐congenic, ‐recombinant and ‐mutant mouse strains, and of capping and immunoprecipitation experiments showed that the cytotoxic antibodies were directed against H‐2 class I molecules. The anti‐H‐2 antibodies exhibited enhanced binding for SV+target cells, but absorption experiments showed that this was not the result of cross‐reactions with cell surface Sendai viral determinants or with a molecular complex of H‐2 plus SV. This conclusion was supported by the observation that syngeneic SV+cells were not the predominant targets for the induced lymphocytotoxic antibodies. Our results do not support the existence of MHC‐restricted antiviral antibodies, but show the induction of anti‐class I H‐2 alloantibodies by injections with syngeneic SV‐coated cells. We present a model for regular induction of anti‐H‐2 anti

ISSN:0014-2980    

DOI:10.1002/eji.1830170106

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractConsiderable numbers of large granular lymphocytes (LGL) were isolated from rat liver by a simple method consisting of sinusoidal lavage at elevated (50 cm water column) perfusion pressure. This method gave a yield comparable with the enzymatic dissociation method commonly used for the isolation of nonparenchymal liver cells, but was shorter in time and had the advantage of avoiding the potentially harmful effects of the dissociating enzymes. The isolated LGL were highly cytotoxic against YAC‐1 lymphoma cells and this cytolytic activity was blocked by treatment of the effector cells with an antibody against natural killer cells (anti‐asialo GM1). We characterized the hepatic LGL as nonphagocytic, nonadherent, peroxidase‐negative and acid phosphatase‐positive cells which could be enriched in the low‐density fraction of a Percoll gradient. At the light microscopic level, they showed characteristic azurophilic granules which corresponded to strongly osmiophilic granules with a specific morphology in electron microscopy. It is concluded that these LGL are identical to the “pit cells” which were formerly described by electron microscopyin situas normal components of the liver sinusoids and which are easily recognized by their fine structure. It is also proposed that the liver may represent one of the major natural

ISSN:0014-2980    

DOI:10.1002/eji.1830170107

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractFollowing T cell‐depleted bone marrow transplantation, helper T cell numbers remain depressed for some months. Nonetheless, functional B cells can be adoptively transferred to the recipients of such grafts, where they continue to secrete antibody. We now show that immunoglobulin production by these transferred B cells is induced by activated large granular lymphocytes (LGL) which circulate in the recipients in substantial numbers during the immediate post‐transplant period. The LGL are CD3 negative and therefore provide help in an antigen‐unlinked manner. Helper effects for autologous (donor) B cells are augmented by the addition of anti‐LFA‐2 (anti‐CD2) which appears to act by blocking recruitment of LGL inhibitory to developing B cells. In contrast antibody to the β chain of LFA‐1, which effectively reduces natural killer activity of LGL, does not influence their helper function. The peripheral blood LGL fraction thus contains both helper and cytotoxic activity, which can be distinguished by appropriate monoclo

ISSN:0014-2980    

DOI:10.1002/eji.1830170108

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractBrown‐Norway (BN) rats injected with HgCl2have been previously shown to develop a variety of autoimmune abnormalities. The susceptibility of BN rats is genetically controlled, and Lewis rats bearing a different RT1 haplotype are resistant. It will be shown in the present study that the number of MRC OX‐8+(suppressor/cytotoxic) cells increases in the spleen and lymph nodes of Lewis rats injected with HgCl2. The responsiveness to T cell mitogens and to alloantigens is concomitantly inhibited. Spleen cells from Lewis rats injected with HgCl2fail to induce a local graft‐vs.‐host reaction. Data presented show that MRC OX‐8+cells are involved in the immunosuppression in Lewis rats treated with HgCl2. Furthermore, lymph node cells and MRC OX‐8+cells from these rats are able to inhibit the normal mixed lymphocyte reaction indicating that suppression is active. Thus, HgCl2is able to trigger immune dysregulation leading either to autoimmunity or to immunosuppression depending upon the genetic background of the rat st

ISSN:0014-2980    

DOI:10.1002/eji.1830170109

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractIt has previously been shown that some anti‐T11 monoclonal antibodies, when used in combination, can activate the human T cell line Jurkat to produce interleukin 2. In this study, we investigate the mechanism by which perturbation of different epitopes of T11 molecules induces activation in Jurkat cells. We show that this activation is initiated by a T11‐mediated increase in the concentration of free cytoplasmic calcium ions ([Ca2+]i). The initial increment in [Ca2+]ican occur when extracellular Ca2+is depleted by EGTA, indicating that Ca2+from intracellular stores is mobilized. As an early response to extracellular signals provokes a rapid breakdown of a class of lipid known collectively as the phosphoinositides, we measured the levels of phosphatidyl‐inositol bisphosphate (PIP2) which is hydrolyzed to generate inositol triphosphates (IP3), the putative mobilizer of Ca2+from internal stores and 1,2‐diacylglycerol (DAG), the physiological activator of protein kinase C. Monoclonal antibodies directed either against different epitopes of T11 molecules or the T3‐Ti antigen receptor complex provoke a rapid breakdown of PIP2, the parental product from which IP3and DAG derive. In addition antibodies to either the T11 molecules or T3‐Ti antigen receptor complex induce marked elevations in IP3, other inositol phosphate compounds and DAG. Taken together, these data indicate that, during T cell activation, due to the perturbation of T11 molecules or T3‐Ti antigen receptor complex, membrane phosphoinositides are specifically hydrolyzed. This hydrolysis of phosphoinositides generates two putative second messengers such as IP3and DAG, which mobilizes Ca2+from intracellular stores and stimulates protein phosphorylation,

ISSN:0014-2980    

DOI:10.1002/eji.1830170110

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe effect of homozygosity at HLA loci on natural killer (NK) cell activity has been examined. Lymphocytes obtained from heterozygous and homozygous individuals were incubated with51Cr‐labeled, NK‐sensitive K562 cells at different effector/target ratios, and lytic activity was determined. Homozygous cells, obtained from individuals who are known HLA homozygotes (homozygous typing cells) and from selected families, had low NK activity compared to those heterozygous donors. This low cytotoxic activity had no correlation with sex, but did correlate with homozygosity at the HLA‐A, B and/or DR loci. A significantly lower number of cells, which bind to anti‐Leu 7 antibody, was found in homozygous donors. However, this reduced number of Leu 7+cells could only partially account for the decrease in NK activity. These studies suggest that in some individuals homozygosity at HLA may be linked to genes that control NK a

ISSN:0014-2980    

DOI:10.1002/eji.1830170111

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY