ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00970.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Media conditioned by clones of normal helper T cells exposed to appropriate antigenpresenting cells contain growth‐promoting activity for B‐cell blasts induced either by lipopolysaccharide or on direct interaction with competent helper cells. This B‐cell growth factor (TH‐BGApet) is recovered on sodium dodecyl sulphate polyacrylamide gel electrophoresis corresponding to mol. wt of 15,000–20,000 displays no mitogenicity for small, non‐induced B lymphocytes and is completely devoid of the ability to activate immunoglobulin secretion in proliferating B cells. These results are ascribed to the activity derived from normal T cells, with the same characteristics as BSF‐pl previously obtained from lymphomas and hybridomas. Since hybridization of these T helper cells results in the constitutive production of BSF‐pl in the absence of macrophages, these experiments demonstrate that BSF‐pl is a norm

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00971.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The function of B‐L (Ia‐equivalent)‐positive (B‐L+) and ‐negative (B‐L‐) chicken peripheral blood lymphocytes (PBL) was studied in vitro and in vivo. The PBL were first stained in direct immunofluorescence tests with a fluorescein isothiocyanate‐labelled anti‐B‐L alloantiserum and then separated by means of a fluorescence‐activated cell sorter. In agreement with our previous findings, B‐L‐cells showed functional properties of T lymphocytes, responding to concanavalin A and phytohaemagglutinin‐P in vitro and inducing a graft‐versus‐host (GVH) reaction when injected into allogeneic embryos. Sorted B‐L+gave no responses in any of these assays. Neither B‐L+nor B‐L‐cells, when tested alone, responded significantly to pokeweed mitogen, but mixtures of the two restored the responsiveness to that of the original unsorted suspension. Of the B‐L+PBL, 10% were T cells, which may account for the lo

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00972.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Immune complexes were isolated by ultracentrifugation in sucrose gradients (20‐65% (w/w)). The centrifugation procedure was demonstrated 10 be isopycnic. The banding density of the complexes was influenced by the chemical nature and molecular size of the antigen and by the antigen to antibody ratio. The method was applied for preparative isolation of immune complexes from patients with systemic lupus erythematosus. rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and uncomplicated psoriasi

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00973.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

E‐rosette‐negative lymphocytes (TE‐), which express monoclonal T‐cell markers (OKT3+) were found in higher frequencies in humnn cord blood (CB) (30% by phenotype and 11.7% by sequential rosette isolation) than in adult peripheral blood lymphocytes (13% by phenotype and 3.7% by isolation). TE‐cells had very low levels of 5′‐nucleotidase. a lymphocyte maturational marker low in thymocytes. Like other CB T cells. TE‐cells possessed marked suppressor capability. Irradiated TE‐cells from two cord blood samples demonstrated helper activity tor Ig production hy adult B cells. In six cord blood samples, however, irradiated TE‐cells lacked helper activity. When incubated with thymosin, these TE‐cells became E‐and differentiated into inducer‐helper T cells. These observations confirm previous assumptions that CB T cells are not fully differentiated. Furthermore. T cells from different CB samples may be at various stages of ontogeny. We have also shown that thymosin fraction 5 is able to confer a new

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00974.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

We have examined to what extent human fibronectin associated with agarose beads with a 5‐ to 10‐μm diameter mediates binding and uptake of the heads by mouse macrophages and human monocytes. Native agarose beads preincubated with125I‐fibronectin were neither associated with nor taken up by mouse macrophages after 30 min of incubation under serum‐free conditions. When fibronectin was cross‐linked to cyanogen bromide‐activated agarose heads or incubated with gelatinized heads, this resulted in a significant increase in particle binding by macrophages and monocytes as compared with gelatinized beads, whereas the fraction of cells with ingested particles remained unaltered. Native agarose heads activated by cyanogen bromide and treated with ethanolamine were to a greater extent associated with and taken up by phagocytes than fibronectin‐ or gelatin‐coated heads. Our results indicate thai fibronectin acts as an adhesive glycoprotein and not as an opsonin. Since agarose beads are activators of the alternative pathway of complement, and fibronectin is reported to bind to factor C3, we speculate that cell‐derived C3b is bound to the beads and fibroneetin‐coaled beads arc ingested by the phagocytes via complement C3b re

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00975.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Previous studies have shown that cyclosporin A (CyA) prevents the elaboration of the lymphokine leucocyte migration inhibitory factor (LIF). Since LIF production is interleukin 1 (IL‐1)‐dependent, we carried out experiments using partially and highly purified IL‐1 preparations to study the effect of CyA. We found that (a) IL‐1 was consistently depleted during a 1‐h incubation with human blood T lymphocytes but not with B lymphocytes or erythrocytes; (b) the depletion could not be ascribed to pinocytosis, cell functions requiring active metabolism, or enzyme‐mediated destruction of IL‐1; (c) CyA, but not biologically inactive cyelosporin, antagonized the apparent absorption of IL‐1; (d) T cells pre‐exposed to CyA were rendered incapable of removing the monokine; and (e) CyA was capable of displacing IL‐1 once absorbed by T cells. Because the putative binding of IL‐1 showed salurability. reversibility (with CyA as a probe), and tissue specificity consistent with a known target for the monokine, we propose that IL‐1 interacts with a receptor‐like structure on T cells. Finally, we found that insulin interfered with the function of CyA at the very early macrophage‐T‐cell co‐operative stage, even

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00976.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Amyloid fibrils were isolated from the renal papillae and glomeruli of cows with spontaneous AA amyloidosis. The fibrils were solubilized by treatment with guanidine hydrochloride (Gu HCl) and subjected to gel filtration on Sephacryl S‐200. Two other fractions were obtained beside the void volume and the AA fractions. Reaggregation studies were performed by dialysing the fractions, separately or in combinations, against Gu‐HCl‐free solutions. Protein AA alone (about 10 kd) appeared not to precipitate. The olher fractions alone and the combinations of fractions tested formed precipitates. The precipitates containing all fractions (including prolein AA) or protein AA plus a fraction containing a 14‐ and a 23‐kd protein revealed congophilic green birefringent fibrillar material. Dialysis against acidic and calcium‐containing solutions gave the best results. Amyloid fibril‐like material was visible on electron microscopic examination. The amino acid composition of the 19 + 23‐kd material appeared to be slightly different from protein A A and evidently unlike SAP. On imniunolluorescence‐absorbance studies the 19 + 23‐kd material appeared evidently unlike protein A A and SAP. From these findings it is concluded that for spontaneous formation of A A amyloid fibrils other non‐AA p

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00977.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The heterologous interaction between β2‐microglobulin (β2m) and rat major histocompatibility complex (MHC) (RT1) antigens was measured in a two‐step binding assay consisting of binding of radiolabelled β2‐m to RT1 antigens and immunoprecipitation of β2m‐RT1 antigen complexes with RT1 antisera. The effects of varying the concentrations of the three reactants involved were studied. The molecular events taking place in the two steps were analysed by gel chromatography. The β2m‐RT1 antigen complex had the apparent size of albumin and reacted completely with specific alloantisera. RT1 antigens prepared from Wistar/Furth (RT1u) and Brown Norway (RT1n), respectively, both effectively bound heterologous β2m. The times for association and dissociation, respectively, at 37°C, were of the same order, but dissociation was slightly slower. Association was markedly temperature‐dependent and was considerably slower at low temperatures. All these processes were slower for RT1uthan for RT1uantigens. The association constant for the interaction between RT1uantigens and125I‐human β2m was estimated by Scatchard analysis to be about 109M‐1. Contribution to the heterologous interaction by products from various rat MHC subloci (A, B, and C) was investigated by the introduction of sublocus‐specific antisera in step 2. The reaction apparently involved neither class 2 antigens (sublocus B) nor the presumed rat Qa homologue (sublocus C). Classical class 1 antigens (suhlocus A) clearly contributed to the binding. However, a monoclonal antibody against products from rat MHC class 1 genes only precipitated less than half of the RTI antigen‐complexed β2m. Thus, at least two RT1uclass 1 alloantigen molecules seem to participate in the reaction. This, in turn, indicates that the rat genome may contain multiple class 1 genes, an is the case for mos

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00978.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

β2‐microglobulin (β2m) was found to interact with many group A streptococcal strains. The interaction appeared to require multipoint attachment, since monomeric β2m in solution showed no binding, whereas both β2m monomers bound to liposomes, and β2m in aggregates showed affinity for the bacteria. Aggregated HLA antigens (‐A, ‐B and ‐C) and aggregated β2m exhibited the same binding patterns when tested in binding experiments with various group A streplococcal strains. Furthermore, β2m aggregates in excess completely blocked the binding of aggregated HLA antigens, thereby demonstrating that β2m is able to interact with streptococcal surface structures also when it is part of the HLA antigen complex. M protein‐positive group A streptococcal strains bound significantly more β2m than M protein‐negative variants of these strains. Purified M 12 protein partly inhibited the binding of radiolabelled β2‐m aggregates to whole streptococci, and in gel filtration and affinity chromatography experiments, the M 12 protein interacted with β2m. These various data suggest that the interaction between β2m and group A streptococci could be mediated by M protein. Lipoteichoic acid (LTA) is a constituent of the streptococcal cell wall that has been reported to form complexes with M protein at the bacterial cell surface. However, LTA did not influence the interaction between β2m and streptococci, suggesting that the binding of β2m to streptococcal M protein represents a pure protein‐protein interaction. In vivo such an interaction could be established between infecting streptococci and host cells. Among 45 strains of different M types large differences in β2m binding were recorded, whereas among 60 strains of the classical nephritogenic M types 12 and 49, all were highly β2m‐reactive, which points towards a role for

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00979.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY