摘要:

The biological importance of the presence of class II transplantation antigens on highly differentiated epithelial cells such as keratinocytes in certain conditions, is still unknown. We have therefore investigated the antigen‐presenting capacity of separated human epidermal cells obtained from tuberculin‐reactive skin 6 days after intradermal injection of purified protein derivative (PPD). Earlier studies have shown a high percentage of HLA‐DR‐expressing keratinocyles at this time. Peripheral adherent blood cells were used as control stimulator cells a d highly purified peripheral blood T lymphocytes as responder cells. The T‐cell proliferation in response to PPD in the presence of autologous epidermal cells from normal and tuberculinreactive skin was measured by [3H]thymidine incorporation on day 6. The latter cell population, 76‐86% of which consisted of HLA‐DR‐expressing cells as judged by immunocytochemistry, induced a greater T‐cell response to PPD than do normal epidermal cells. This discrepancy in the T‐cell proliferation could not be explained by a difference in ihe numbers of anti‐Leu 6 or anti‐HLA‐DQ‐reactive Langerhans cells. The present data indicate that epidermal cell suspensions containing HLA‐DR‐expressing keratinocytes induce a greater T‐cell response to P

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02227.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The kinetics of Ca2+uptake into lectin‐induced secondary lymphocytes was studied during reactivation to DNA synthesis with concanavalin A (Con A) or interleukin 2 (IL‐2). IL‐2 did not cause any significant uptake of Ca2+into the lymphocytes, while Con A induced an accumulation of Ca2+into the lymphocytes which reached a maximum 1 to 2h after the addition of the lectin. The time during which Ca2+uptake occurred corresponded to the time of dependence on extracellular Ca2+for lectin‐induced DNA synthesis. The increased rate of Ca2+accumulation and the shortened Ca2+dependence period of secondary lymphocytes as compared with primary lymphocytes could explain the ability of secondary lymphocytes to display an accelerated response, in terms of DNA synthesis, to re

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02228.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Although antigen‐presenting cells (APC) appear to be able to process minor histocompatibility antigens (MIHA) expressed on allogeneic cells and present them in association with intrinsic H‐2 of the APC in vivo, this does not occur in vitro. This could be due to fundamentally different mechanisms of antigen handling by APC in vitro, or it could represent compromised APC function. In order to distinguish these possibilities, we designed a system in which BALB/c spleen cells are transferred into an MIHA‐disparate irradiated host and allowed to reside for 2‐3 days; the spleen cells of the repopuiated host are removed and used as stimulator cells for the CTL response of primed BALB/c responder cells to DBA/2 MIHA. These cells are referred to as in vivo‐pulsed APC (IVP‐APC). Donor BALB/c cells are able to pick up DBA/2 MIHA after a passage in DBA/2 hosts and efficiently present MIHA to primed CTL precursors to generate DBA/2‐specific CTL. The donor cell type able lo pick up and present MIHA is present in spleen bul not thymus or bone marrow, is Thy‐1.2 negative, Ia+, and nylon wooladherent. Its stimulatory capacily is as efficient on a per cell basis as that of DBA/2 spleen cells. The generation of IVP‐APC requires repopulation of the irradiated host, which must express MIHA foreign to the BALB/c donor cells. When we attempled to generate IVP‐APC in H‐2 incompatible hosts, we found that, although the IVP‐APC could present H‐2 antigens, they were unable to present MIHA in association with intrinsic APC H‐2 antigens. Use of intra‐H‐2 recombinant strains as host mice indicated that compatibility of donor and host at the KI region of H‐2 was essential for the generation of IVP‐APC able to present apparently unprocessed MIHA to primed BALB/c responder cells. Thus, we were unable to reproduce the antigenprocessing function of APC encountering antigen in situ using an adoptive transfer method of pulsing APC with MIHA in vivo. In addition, we suggest that our results may impose constraints on the formulation of models to account for the as

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02229.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Eighty‐seven seropositive subjects with HIV (human immunodeficiency virus) infection together with 20 normal controls with no history of any illness were investigated for the presence of circulating immune complexes (CIC) by the conglutinin binding assay (KgBA) and further studied for isotype characterization of CIC. Six out of 87 patients showing very high values for immune complexes (CIC) were studied for the presence of free antigen. In 3 out of 6 (1, IVcl; 1, III; I, IVa) we could detect by ultracentrifugation analysis the presence of specific HIV (p15) anti‐HIV (anti‐p15) and gp41‐anti‐gp41 CIC. Evidence in favour of this finding is supported by: (1) the presence of specific CIC (p15‐anti‐p15 or gp41‐anti‐gp41) seen only at pH 7.2; (2) the apparent presence of free antigen and specific HIV antibodies were only at pH 4.0. The relevance of this finding lies in the attempt to explain the occurrence of false seronegativity seen occasionally in symptomatic patients. Thus, the presence of CIC might perhaps interfere in the routine assay (i.e. ELISA) making the diagnosis difficult. All these considerations will have to be taken into account in the future handlin

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02230.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Starting from unimmunized BALB/c splenocytes, B‐cell clones were obtained by lipopolysaccharide (LPS) stimulation, and the frequencies of their anti‐TNP, anti‐BALB/c actin, and anti‐BALB/c tubulin secretion were determined. The culture conditions were then chosen so as to have one anti‐TNP precursor per positive well. Out of the 41 wells containing one anti‐TNP antibody‐secreting cell, nine (22%) also reacted either with actin or with tubulin and five (12%) with both actin and tubulin. Using horse red blood cells to which trinitrophenyl (TNP) had been coupled, spleen cell rosettes were prepared, enriched, micromanipulated, and cultured individually. Of the 500 micromanipulated and cultured TNP antigen‐binding cells, 28 were found to secrete antibodies directed against TNP. Eight of these 28 clones (28%) also reacted with either actin or tubulin, and five (17%) reacted with both actin and tubulin. The frequency of these multispecific clones is of the same order of magnitude as that obtained with the limiting dilution experiments. The results show that unimmunized BALB/c mouse spleen contains precursor cells that secrete natural multispecific

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02231.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

A B cell line derived from a human nodular lymphocytic lymphoma (Brill‐Symmers) was shown to be dependent on the presence of a low molecular weight B cell growth factor (BCGF) for its growth in vitro. The caryotype was normal and no contamination with Epstein‐Barr virus (EBV) could be detected. These cells did not respond to recombinant gamma interferon or to recombinant human interleukin 2 (IL‐2), although they displayed a weak density of IL‐2 receptor sites. They were both responsive to and dependent on BCGF for their multiplication in vitro. Furthermore, the putative receptor for this growth factor (CD23) was detected on these cells and the BCGF‐dependent proliferation could be blocked by a monoclonal anti‐CD23 antibody. A tumour‐derived cell line like this provides an interesting model for studying the mechanisms regulating B cell growth and the early events leading to the process of B cell im

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02232.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Chronic inflammatory synovitis is characterized by both lymphocytic infiltrates and persistent polymorph exudates. Activated polymorphs release reactive oxygen species (ROS) during inflammation, but the contribution that these make to the lymphocyte abnormalities associated with RA has been little studied. We therefore investigated the cytotoxic effects of the reactive oxygen speices on human peripheral blood mononuclear cells (PBMC). PBMC were exposed to RPMI 1640 medium previously irradiated for up lo 60 min. Consistent dose‐dependent killing was observed at 24 h. Antioxidant studies indicated that H2O2was the effective species. Catalase, which specifically degrades H2O2, gave almost total protection against cell death, while superoxide dismutase (SOD), thiourea, and mannitol were largely ineffective. Addition of exogenous H2O2caused an identical pattern of cell death to that observed with irradiated medium. PBMC cultures supplemented with desferrioxamine (a ferric iron chelator) also gave significant protection, suggesting that H2O2mediated its effects via OH* radicals, Analysis of lymphocyte subpopulalions showed that ROS caused a selective depletion, depending on the level of H2O2present. Low levels induced a speciftc loss of CD8+cells, while higher concentrations caused significant loss of CD4+T cells as well. slg+B cells were unaffected at either concentration. This selective lymphotoxic effect of ROS may be of considerable importance in the pathogenesis of autoimmune inflammatory diseas

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02233.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The ontogeny patterns of IgD in saliva were studied prospectively in 27 healthy full‐term infants. The concentrations and the proportion of samples with detectable levels of IgD were higher near birth. After 6 months of age IgD was rarely detected in saliva. There was an inverse assoeiation between the detection of IgD and IgA in saliva. There were no correlations between IgD and IgG or albumin. These observations support the theory that IgD synthesis and secretion at mucosal sites reflects a ‘physiological’ deficiency in IgA synt

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02234.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The Kva IgG2(k) myeloma protein showed a complete resistance to papain in the presence of cysteine at neutral pH, and a higher resistance to trypsin and α‐chymotrypsin digestion than other IgG2 proteins. On the other hand, the Kva molecule was cleaved by pepsin at low pH to give the expected F(ab′)2 fragment. When the cleavage conditions were altered, it was possible to obtain Fab, Fc, and Fc′ fragments from this molecule as well. The Fab/c fragment and FacbFc′ complex were also obtained, which have not previously been reported from human IgG2 molecules. Incubation at elevated temperatures (45‐50°C) and/or lower pH resulted mainly in enzymatic attack on the C terminal side of the hinge. It was necessary to destroy the hinge by reduction or to expose the Kva molecule at 70°C or at lower pH (2.5) prior to digestion to facilitate enzyme digestion on the NH2terminal side of the hinge. These results indicate that the hinge region of the Kva molecule has an unusually compact structure, which makes it extremely resistant t

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02235.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Ninety‐nine sera from patients with different rheumatic diseases (systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, and mixed and unidifferentiated connective tissue disease) were applied to a newly developed isoelectric focusing (IEF) immunoblot system for the demonstration of antinuclear antibodies. Nucleoproteins were separated according to their isoelectric points (pI) and immobilized onto nitrocellulose, and binding of serum antibodies was determined by an alkaline phosphatase labelled second antibody. 89.8% of all sera positive in indirect immunofluorescence assays with Hep 2 as substrate showed positive reactivity in IEF immunoblot. Furthermore, 88% of patients' sera negative on Hep 2 cells gave a positive reaction in IEF immunoblot. The predominant antibody banding pattern observed showed parallel bands in the acidic as well as the neutral pH ranges. Antibody specificities found in the IEF immunoblot system turned out to be patient‐specific, but no marker antibody for a discrete disease entity was obtained. Even when monoclonal antibodies or WHO standard sera were applied to nuclear antigen they exhibited heterogeneity in their binding pattern. Bands with the same pI were observed using sera from patients with different rheumatic disease entities. Immunodeletion experiments suggest the recognition of identical antigenic proteins by the different patients' s

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1987.tb02236.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY