ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03198.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Because of similarities between the human and monkey immune systems, we considered the monkey a suitable model for studies on the catabolism of various molecular forms of IgA, for which little information is available. The residualizing label dilactilol‐[125I]tyramine was coupled to monkey(Macaca fuscata)IgA and IgG, as well as to human monomeric and polymeric myeloma IgA1 and IgA2 proteins. When labelled proteins were injected intravenously into monkeys, the non‐metabolizable radioiodinated tracer accumulated at the cellular site of protein degradation, allowing identification of the catabolic sites. To determine the uptake or injected proteins by various tissues, monkeys were sacrificed 6‐7 days after injection of labelled proteins, when blood‐associated radioactivity was ≥ 10% of the injected dose, as measured by plasma clearance. When monkey or human monomeric IgA. as well as human polymeric IgA, irrespective of subclass, was administered to monkeys, the liver showed the greatest tissue uptake relative to total dose injected and to organ weight, and the highest acid soluble radioactivity (degraded protein). Although both hepatocytes and non‐parenchymal liver cells were involved in IgA uptake, the hepatocytes were more active. Therefore, it appears that the liver is the major site of uptake and catabolism of IgA in monkeys and possibl

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03199.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We have examined the frequencies of Tγδ cells in blood, synovial fluids, and synovial membranes of patients with rheumatoid arthritis (RA) and in blood from age‐matched controls Immunocyto‐chemical and immunohistochemical techniques were used with monoclonal antibodies BB3 and A13 to define a major and minor blood subset of Tγδ cells respectively. Together, these antibodies identify the majority (if not all) of the peripheral blood Tγδ cells.Significantly lower levels of Tγδ cells were found in the blood of RA patients compared with controls, whilst higher but not significant numbers were found in the synovial fluids or paired samples Scattered Tγδ cells were found only in some synovial membranes with A distribution similar to the Tγδ cells Analysis of the two different Tγδ ‐cell subsets indicated a ratio of BB3 to A13 of about 5:1 in control and RA blood. However, this ratio was less than 1:1 in the RA synovial fluids and membranes. The migratory nature of the A13+cells could account for their predominance in these sites the possible pathological significance of these cells in the rheumatoid synovial fluid and synovial mem

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03200.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We show that thymic epithelial cells grown under serum‐free conditions in a chemically defined culture medium can act as veto cells in vitro. The veto activity of thymic epithelial cells results in inactivation of specific alloreactive cytotoxic T‐cell precursors at the clonal level. It is concluded that the epithelial stromal cells of the thymus, by acting as veto cells, may he responsible for the negative intrathymic selection of self‐reactive thymocytes leading to elimination of the vast majority of immature thymic lympho

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03201.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We have examined the effects of recombinant human IL‐1α and IL‐1β on expression of the gene for the class II major histocompatibility antigen, HLA‐DR, and the class I MHC antigen, HLA‐B7. induced by natural or recombinant human IFN–γ in several human cell types. Recombinant hIL‐1α and hIL‐1β antagonized the class II MHC‐inducing effect of IFN‐γ in human monocytes and normal skin fibroblasts, and in chondrosarcoma and astrocytoma cell lines. In the presence of IL‐1α or IL‐1β, the induction by IFN‐γ of HLA‐DR mRNA. and the expression of the corresponding antigen on the cell surface, were reduced when analysed by dot‐blot hybridization and flow cytometry respectively. Nuclear transcription assays showed that IFN‐γ augmented expression of the HLA‐DR gene and that IL‐1α inhibited this effect. IL‐I‐mediated inhibition was not observed with IFN‐γ‐induced expression of MHC class I mRNA (HLA‐B7). Both IL‐α and IL‐β induced production of IL‐6 mRNA and of PGE; in these cell types. However, recombinant IL‐6 or PGE2did not inhibit IFN‐γ‐induced HLA‐DR mRNA expression. Dexamethasone did not inhibit HLA‐DR expression in the cells studied but eliminated the inhibitory effect of IL‐1 on such expression. The observations suggest that MHC gene expression is influenced by the cytokine network in a complex manner which is different for class I and II ge

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03202.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The splenic mononuclear cells (MNC) of rabbits 7‐14 and 30‐48 days following primary intravenous immunization with sheep erythrocytes generated large numbers of antibody‐secreting or plaque‐forming cells (PFC) in secondary immune responses induced in vitro, whereas the splenic MNC obtained from rabbits 18‐30 days following primary intravenous immunization generated poor secondary immune responses (few PFC) in vitro. However, these latter splenic MNC depleted of T cells consistently generated many PFC in the secondary immune response in vitro. Furthermore, the splenic MNC of rabbits thymectomized prior to day 3 following primary intravenous immunization also generated good secondary immune responses in vitro, irrespective of the time of killing post‐immunization, whereas the splenic MNC of rabbits thymectomized after day 7 following primary immunization generated poor secondary immune responses in vitro. These results indicate that the depressed ability of the splenic MNC, obtained from rabbits killed between days 18 and 30 post‐primary immunization, to generate significant secondary immune responses in vitro is due to suppressor T cells. The suppressor cells are referred to as immune spleen suppressor cells or ISSC. It was demonstrated that the suppression by the ISSC is antigen‐specific and that the ISSC secrete an antigen‐specific suppressor factor referred to as immune spleen suppressor factor or ISSF. It is concluded that the ISSC are generated in the thymus within a few days following primary immunization, that they migrate to and infiltrate the spleen between days 3 and 7 following primary immunization, and that they suppress or down‐regulate further antibody synthesis via the secreti

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03203.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Non‐fermenting mycoplasma species deplete culture media for arginine through arginase activity linked to their arginine deiminase pathway, resulting in proliferation arrest and cell death in mycoplasma‐contaminated cell cultures. The presence of only 2‐3 Mycoplasma (M.) arginini‐contaminated T cells in a one‐way allogeneic mixed‐lymphocyte culture (MLC) significantly inhibits development of cytotoxic T‐cell activity. Likewise, strong degrees of inhibition are observed after addition of nanogram doses ofM. argininiextracts (MAE) to MLC or cell proliferation cultures.M. arginini‐inducedcell inhibition can be reversed by addition of excess arginine to the culture medium. Antisera raised against non‐fermenting, but not against fermenting, mycoplasma species block the inhibitory effect of MAE. SDS‐PAGE separation of MAE disclosed a broad band at 60 kDa which contained arginase activity when assayed in MLC and cell proliferation culture. SDS PAGE followed by western blotting and reaction with antisera raised against non‐fermenting mycoplasma species demonstrated a band at 43 kDa common for

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03204.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The effect of purified‐ recombinant human interleukin 4 (IL‐4) on proliferation and IgM secretion of normal and malignant human B cells was studied. IL‐4 was found to co‐stimulate the proliferation of splenic B cells in the presence of anti‐Ig coupled to polyacrylamide beads (anti‐Ig beads) for a period of 4 days In contrast. IL‐4 had little co‐stimulatory effect on the proliferative response of splenic B cells to the more potent mitogenStaphylococcus aureusCowan strain I (SAC) Moreover, IL‐4 inhibited interleukin: 2(IL‐2) induced proliferation of cells co‐stimulated with SAC Mitogen‐induced pre‐activation of B cells in the presence of IL‐4 resulted in a reduction in subsequent IL‐2‐induced IgM secretion without significantly affecting proliferation Human B‐cell tumours were also cultured over a 2‐3 day period in the presence of anti‐Ig beads plus IL‐2. or IL‐4orboth IL‐2 and IL‐4. IL‐4 inhibited IL‐2‐induced proliferation in all cases of B‐cell chronic lymphocytic leukaemia (B‐CLL)and the majority of cases of low‐grade lymphoma (LGL)and hairy cell leukaemia (HCL). These findings suggest that IL‐4 has stimulatory actions on resting B cells, most evident in the presence of submaximal co‐mitogenic signals, and inhibitory actions on a

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03205.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The immunomodulatory drug isoprinosine has been found to delay the occurrence of opportunistic infections in HIV‐infected individuals. To elucidate the mechanism of action, eight HIV‐positive, healthy patients were treated with isoprinosine, 3 g/day for 28 days; six patients received no treatment but were examined in parallel, and two patients were withdrawn. All patients had blood collected just before the start as well as on days 14 and 28 of isoprinosine treatment.Isoprinosine significantly enhanced the lymphoproliferative response after stimulation with phytohaemagglutinin (PHA) and purified derivative of tuberculin (PPD), while isoprinosine had no effect on the following immune parameters: the expression of surface markers on blood mononuclear cells including CD2, CD3, CD4, CD8, CD14, CD19, CD20, CD25, leu‐8, and HLA‐DR. Furthermore isoprinosine did not influence the ability of interleukin 2 (IL‐2) to stimulate the proliferation of lymphocytes or the natural killer (NK) cell activity either unstimulated or stimulated in vitro with alpha interferon (IFN‐α), IL‐2. or indomethacin. Neither did isoprinosine affect the in vitro production of (IL‐1) α orβ, IL‐2, IL‐6. or tumour

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03206.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Using the anti‐TcRγ/δ‐1 monoclonal antibody and flow cytometry, we examined the number of Tγδ cells in paired samples of peripheral blood and synovial fluid or tissue from 24 children with juvenile rheumatoid arthritis (JRA). five adult patients with JRA, and 14 patients with rheumatoid arthritis (RA). No significant difference was found in the synovial compartment Tγδ values compared with the blood in JRA, adult JRA, or RA patients. Nor was any significant difference found in the peripheral blood or synovial compartment Tγδ values in any of the three patient groups compared with the peripheral blood of normal controls. However, seven of the children with JRA had very high Tγδ values in the synovial compartment while none of the normal children had high Tγδ values in the blood (P= 0.02. Fisher's exact test). This may indicate a possible separate JRA patient group with high Tγδ levels in the synovial compartment. In six JRA patients further analysed for Tγδ subpopulations, a significant predominance of Vδ1+cells was found in the synovial compartment compared with the corresponding peripheral blood samples (P<0 05. Wilcoxon's signed test) and with peripheral blood of child controls (P<0 05, Mann Whitney U test). In these six patients, the Tγδ ‐cell expression of the very early activation antigen CD69 were significantly higher (P<0 05. Wilcoxon's signed test) in the synovial compartment compared with the peripheral blood. Synovial Tγδ cells expressing HLA‐DR and interleukin 2 receptors could also be detected, in contrast to the peripheral blood in which no Tγδ cells expressing these antigens could be found. These data suggest that the synovial Tγδ

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1990.tb03207.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY