摘要:

AbstractMost human nucleated cells and cell lines possess C3 step regulators, decayaccelerating factor (DAF; CD55) and membrane cofactor protein (MCP; CD46) and an inhibitor of membrane attack complex (MAC) formation (p18; CD59). Unless DAF and MCP were simultaneously blocked by their antibodies, Mg2+‐EGTA‐human serum treatment did not induce C3 deposition on most nucleated cells. Furthermore,<20% lysis occurred even after the block of all the three factors. In contrast, three myeloid cell lines, U‐937, HL‐60 and p39, were found to exhibit unusual C3 deposition or cytolysis. U‐937 possessed DAF and MCP but lacked p18, and about 50% was lysed by treatment with anti‐DAF and anti‐MCP followed by Mg2+‐EGTA‐serum, which caused C3, C5 and C8 deposition. Anti‐DAF evoked similar but less complement (C) deposition and cytolysis while anti‐MCP alone did not, although it enhanced the anti‐DAF‐mediated C deposition and cytolysis. Thus, once the C3 step is overcome, U‐937 is attacked by the late components leading to cytolysis because of the absence of p18. On the other hand, HL60 allowed the deposition of C3 by blocking of either DAF or MCP followed by the Mg2+‐EGTA‐serum treatment. C5, C8 and C9 were subsequently deposited but resulted in no lysis. Lysis of 60% was attained by the additional blocking of p18. Thus, HL60 is poorly protected by C3 and C9 step regulation. Strikingly, extensive C3 deposition occurs on p39 without any antibody treatment, suggestive of the presence of unique alternative pathway activators. However, little cytolysis was induced on p39 even by blocking of all three inhibitors with antibodies. These results suggest that in activation of the alternative pathway on myeloid cells, C3 step is controlled by the inhibitors and alternative pathway activators, and C‐mediated cytolysis is blocked by p18 and additional regulatory mechanisms or factors which assist in protection of nucleated host cells from MAC attack. Susceptibility to homologous C of these cell lines, therefore, reflects relatively low potency

ISSN:0014-2980    

DOI:10.1002/eji.1830210802

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractHuman CD8+lymphocyte subpopulations were analyzed for their expression of CD8 α and CD8 β subunits. Investigations with uncloned peripheral blood lymphocytes as well as cloned human natural killer and T cell subpopulations demonstrate that CD3−natural killer cells, T cell receptor γ/δ, and CD4+CD8+T cell clones express exclusively CD8 α gene products. Structural analysis of CD8 molecules demonstrates that CD8 α+/β−T lymphocytes surface express 75‐kDa CD8 α/α homodimers whereas CD8 α/β lymphocytes express concomittantly two CD8 isoforms of different molecular masses (67 kDa and 75 kDa, respectively). Peptide mapping of these latter two isoforms suggests that CD8 is expressed as α/α homodimers and α/β heterodimers on CD8 α/β+cells. Importantly, we found that the two CD8 isoforms behave functionally different. Thus, in contrast to CD8 α/β+/CD8 α/α+T lymphocytes, cytolytic activity of CD8α/β−/CD8 α/α+T cell clones was not inhibited by anti‐CD8 monoclonal antibodies and the latter were not induced to prolifera

ISSN:0014-2980    

DOI:10.1002/eji.1830210803

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe protective effects of two different monoclonal antibodies (mAb) raised against theSchistosoma mansoni28‐kDa glutathione S‐transferase (Sm 28 GST) were investigated. Two mAb of the same isotype (IgM) have been selected according to the blocking effect on Sm 28 GSTenzymatic activity (S13) or the lack of blockade (H12). When passively transfered into Fischer rats, both S13 and H12 significantly reduced the worm burden. In BALB/c mice clear effects on female worm fecundity and egg viability were observed when the S13 mAb was transfered; these effects included significantly reduced loads of intestinal eggs, reduced egg hatching rates and an increased proportion of non‐living eggs. No effect on egg production and egg hatching was observed in H12‐treated mice. In addition, worm pairs recovered from S13‐but not H12‐treated mice laid significantly fewer eggsin vitro, and normal worm pairs incubatedin vitrowith the S13 mAb produced significantly fewer eggs than those incubated with H12 mAb. The impairment of egg hatching ability was also reproducedin vitroby the S13 mAb. These data suggest the existence of two different effector mechanisms induced by immunization with Sm 28 GST. The effect on the schistosome worm burden appears to be independent of GST activity whereas the effect onS. mansonifemale fecundity and egg viability seems to be significantly linked to the inactivation of the enz

ISSN:0014-2980    

DOI:10.1002/eji.1830210804

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractWe established one transgenic mouse line which developed pre‐B leukemic lymphomas by introducing ret cDNA driven by the SV40 promoter and the mouse immunoglobulin (Ig) enhancer. Lymphomas developed not only in the lymph nodes and the spleen but also in the thymus between the ages of 7 and 21 weeks. Analyses of cell surface phenotypes and Ig gene rearrangement revealed that these tumors were surface IgM−B220+pre‐B lymphomas. The rearrangement pattern of the Ig heavy chain locus indicated that the tumor cells were mono‐ or oligoclonal. Northern blot analysis showed that the ret transgene was expressed at a high level not only in the tumors but also in the prelymphomatous lymphoid tissues. We found that the expression of N‐myc was dramatically down‐regulated in the tumor cells, while the expression of c‐myc was rather stable. Further experiments demonstrated that ret gene product did not directly down‐regulate the expression of N‐myc in transformed pre‐B cell lines byin vitrotransfection assay. From these results, we conclude that under the control of Ig enhancer, the ret transgene affected B lymphocytes at the early maturation stage as a prerequisite for transformation, preferentially generating a unique maturation stage of pre‐B lymphomas whose N‐myc expression was develop

ISSN:0014-2980    

DOI:10.1002/eji.1830210805

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractIn previous reports, we demonstrated that adoptively transferred T cells homed to the tumor site (among other sites) and that amplification of immune responses occurredin situleading to the generation of cytotoxic CD8+tumor‐infiltrating lymphocytes (TIL) and macrophages. The present report extends these findings and shows that following adoptive immunotherapy (AIT) of mice bearing the immunogenic transplanted methylcholanthrene‐induced rhabdomyosarcoma (MCA/76‐9) there was a differential expansion of CD4+and CD8+TIL, the numbers peaking on days 6 and 8, respectively. At this time, CD8+TIL accounted for the majority of Thy‐1+cells. Northern analyses of RNA extracted from positively selected (by panning) Thy‐1+, CD8+and CD4+TIL isolated 8 days after AIT indicated the following: in five separate experiments, CD4+cells expressed three‐ to sixfold more interleukin (IL)2 mRNA and six‐ to eightfold more IL6 mRNA than CD8+cells, while CD8+TIL expressed three‐ to sixfold more IL 2 receptor (IL 2R) mRNA and four‐to sixfold more interferon‐γ mRNA than CD4+cells. TIL cultured in 10% fetal bovine serum failed to release IL2 over a 24‐h period, whereas both IL6 and interferon‐γ activities were demonstrable. The level of IL2R mRNA expression was reflected by a vigorous proliferative response of CD8+TIL to exogenous recombinant IL2 and only a low response by CD4+cells suggesting that most of the CD4+TIL were in the resting stage. This was confirmed when it was shown that the incubation of panned CD4+TIL with IL2 supplemented with irradiated spleen cells and “spent” 76‐9 tumor culture supernatant (as a source of antigen) induced expansion of TIL resulting in a population consisting of>90% CD4+TIL. The overall data suggest that the relatively deactivated state of the CD4+TIL at this particular time reflects the status of the rejection process in terms of the absence or low concentration of stimu

ISSN:0014-2980    

DOI:10.1002/eji.1830210806

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractTwo large regions of the human immunoglobulinxlocus, the so‐called O regions, have been characterized on cosmid and phage λ clones. The two regions are very similar but not identical duplicates belonging to the Cxproximal (p) and the distal (d) copies of thexlocus. The Op and Od regions comprise contigs of 90 and 120 kb, respectively, and contain 20 Vxgenes and pseudogenes which have been sequenced. Three pairs of Vxgenes were found to be practically identical in the duplicates while allotypic differences, at least for two of the genes, are considerable. The similarities between the duplicate genes may be related to the fact that the two copies of thexlocus are arranged in a palindrome‐like fashion with the 5′ sides of the O regions pointing towards each other (CxJxB Lp Ap Op‐Od Ad Ld). This may have contributed to equalizing the sequences. Beyond Op and Od no further Vxgenes were found within about 80 kb. Instead, repetitive DNA sequences have been localized there, the structures of which suggest that they may have been involved in the evolution of the Vxgene‐containing regions. The Vxpseudogene containing W regions, that had been transposed in evolution from the short to the long arm of chromosome 2 by a pericentric inversion, may have been derived from the O regions according to structural homologies between defined sections of the O and

ISSN:0014-2980    

DOI:10.1002/eji.1830210807

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractBy comparing the restriction patterns of the DNA from 23 unrelated individuals 16 polymorphisms were defined which allowed us to differentiate between the duplicated copies Op, Ap, Lp and Od, Ad, Ld of thexlocus (p for the Cxproximal, d for the distal copy). Some of these duplication‐differentiating polymorphisms or DDP revealed also allelic differences between individuals; they are therefore restriction fragment length polymorphism (RFLP) markers at the same time. Three RFLP in the single copy B‐Jx‐Cxregion were included into the study. Three basic haplotypes were derived from the combined genotype data, haplotypes N, G and 11. The latter haplotype in which the whole distal copy of thexlocus is missing was found three times among the 46 haploid genomes studied. The genotypes of the family members of an individual who is homozygous for haplotype 11 are consistent with Mendelian inheritance. Haplotypes N and G are distinguished from each other by eight RFLP markers. Six additional haplotypes, which were found in one or several individuals each, can be derived from the basic haplotypes N and G by hypothetical recombination and/or mutation e

ISSN:0014-2980    

DOI:10.1002/eji.1830210808

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractMost monoclonal human rheumatoid factors (RF) and some RF from rheumatoid patient's synovia are restricted in their light chains, using predominantly thexIIIb subfamily. Very few sequence differences are found between these light chains. Light chains with similar variable region framework sequences are also found in some mouse monoclonal RF derived from mice stimulated with lipopolysaccharide or secondarily immunized with protein antigens.There are two likely explanations for this restriction in framework sequences between the two species: (a) the sequences are important for the immunoregulation of RF production or (b) the sequences are concerned with the antibody binding specificity of the RF. We have examined overlapping octapeptides from thexIIIb light chain variable region and show that some framework peptides have the ability to bind aggregated IgG. Replacement of amino acids within the peak binding peptide have indicated the critical amino acids necessary for binding.

ISSN:0014-2980    

DOI:10.1002/eji.1830210809

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractDecay‐accelerating factor (DAF) is a membrane protein that inhibits C3 convertase activity of autologous complement at the cell surface. We found that DAF+cells and DAF−(DAFlow, if any) cells are clearly separated from each other among CD8‐brightly positive (CD8bright) cells. Using three‐color fluorescence flow cytometry, we found that whereas the CD8brightDAF−population express HLA‐DR (class II major histocompatibility complex antigens, and an activated T cell marker), the CD8brightDAF+population does not. Therefore, among the CD8brightT cells, DAF and HLA‐DR are mutually exclusive. In addition, the CD8brightDAF+population proliferates in the presence of recombinant interleu‐kin 2 (rIL2) while the CD8brightDAF−population does not. After a 4‐day cultivation of peripheral blood lymphocytes in the presence of rIL2, expression of HLA‐DR increased in the CD8brightDAF−population and expression of IL 2Rp55 (α chain, the receptor for IL2, and a marker of T cell activation) occurred in the CD8brightDAF+population. Furthermore, C3 deposition occurred in the CD8brightHLA‐DR+population which lacks DAF when lymphocytes, that had been cultured for 3 days in the presence of rIL2, were incubated with fresh autologous serum. This result suggests that the absence of DAF on CD8brightHLA‐DR+T cells might play a role in permitting complement reaction on the cellsin vivoand may be related to the reg

ISSN:0014-2980    

DOI:10.1002/eji.1830210810

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractPre‐thymic stem cells which arise extrinsically to the thymus differentiate into mature T cells after colonizing the fetal thymus, but the origin of the stem cells during mammalian embryogenesis remains unknown. More than one potential site has been proposed, including the liver, the omentum and the embryonic yolk sac (YS). Since the murine YS appears earliest in gestation and is the first site of hematopoiesis, our studies focus on the mouse YS as the early major source of pre‐thymic stem cells. Previous studies showed that freshly obtained YS cells expressing no known major T cell marker can develop into Thy‐1+cellsin vitroeither transiently or stably. However, the critical steps leading to functional maturation of T cells involve the rearrangement and expression of the T cell receptor (TcR) genes. We report here that YS cells grown in short‐term cell culture show no detectable rearrangement or transcription at the TcRγ gene locus, although the TcRγ gene ofin vitrotransformed YS cells rearranges in the absence of the thymus. However, after seeding lymphocyte‐depleted thymusesin vitro, YS cells can differentiate into various subsets of cells appearing in the thymus, including CD3/TcR α/β‐ and γ/δ‐bearing cells. TcR Vγ3 which is expressed mainly on early fetal thymocytes and on Thy‐1+dendritic cells can be detected on YS‐derived cells. TcR Vβ8‐expressing cells which appear later in thymic ontogeny are also detected. The kinetics for reconstituting the thymus varies among YS cells of different ages (day 10 to 13 gestation). These results indicate that a single wave of early mouse YS cells can undergo the molecular and cellular changes associated with T cell differentiation and acquire mature T cell characteristics in the absence of continuous inflow of other stem cells. The thymus acts in an inductive/regulatory ro

ISSN:0014-2980    

DOI:10.1002/eji.1830210811

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY