ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01197.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The development of non‐specific immunosuppression during the infection of different strains of mice with three mycobacterial species was evaluated by studying the immune response to a heterologous antigen (sheep red blood cells) and comparing it with the induction of non‐specific resistance to aListeria monocytogeneschallenge. It was shown that early (at 15 days) immunosuppression developed inMycobacterium avium‐susceptible mouse strains infected with a high inoculum dose [2.5 ± 106colony forming units (CFU)] of virulentM. aviumbut not in resistant mice infected with a similar inoculum nor in susceptible mice infected by a smaller inoculum dose (2.5 ± 106CFU). In the latter case it developed only during the second month of infection and was of smaller magnitude. An inoculum ofM. aviumof attenuated virulence did not induce immunosuppression.M. lepraemuriuminduced a late immunosuppression, which occurred when extensive bacterial proliferation had already taken place. The non‐pathogenicM. bovisBCG induced immunosuppression in C57BL/6 mice. The results do not establish a correlation between the development of generalized immunosuppression and susceptibility to infection. It could be seen that the early immunosuppression was observed in those situations where there was extensive macrophage activation as shown by the development of non‐specific resistance to a listeria challenge. The late immunosuppression was observed when bacterial proliferation wa

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01198.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The complement‐fixing properties of human IgA antibodies bound lo specific antigen, or coated directly on plastic surfaces, were examined in comparison with those of IgG antibodies. Use was made of antigen‐binding (anti‐staphylococcal α‐toxin) IgA and IgG monoclonal antibodies and normal polyclonal IgA and IgG, purified>99.9% by avoidance of denaturing processes. Complement‐fixation ELISA was used, with a high density of biotin‐conjugated staphylococcal α‐toxin bound to avidin‐coated plates for the efficient capture of antibodies, and conditions were adjusted for the assessment of classical and alternative pathways of complement activation. Although IgA coated directly on plastic surfaces activated the alternative complement pathway in a dose‐dependent manner, IgA antibodies bound to antigen failed to fix complement by either classical or alternative pathways. In contrast, IgG antibodies, either bound to antigen or coated directly on plastic, activated complement mainly by the classical pathway. It was concluded that the complexation of IgA antibodies with antigen is insufficient to elicit complement actuation: rather a degree of denaturation seems to play a part in the expression of alternative complement pathway‐activat

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01199.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The restriction fragment length polymorphism of the human tumour necrosis factor (TNFα) region was investigated by means of 20 different restriction enzymes and a human TNFα cDNA probe. Only one of the enzymes,NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5.5 kb, which behaved as alleles. In a panel of 108 random, healthy, unrelated Danes, the phenotype frequencies of the 10.5 and 5.5 kb bands were 0.94 and 0.53 and the gene frequencies were 0.71 and 0.29, respectively. The test for Hardy‐Weinberg equilibrium showed no significant deviation from the expected values. The 5.5 kb band was strongly positively associated with HLA‐DR3, HLA‐B8, and HLA‐A1. In 22 patients with primary biliary cirrhosis a significantly (correctedP= 0.024) decreased frequency of the 10.5 kb fragment was found. Additional studies are in progress to substantiate this as

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01200.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The T‐cell antigen receptor is composed of two variable chains (α and β, termed TcR) which confer ligand specificity, and four constant chains (γ, δ,ɛ, and ζ, collectively termed CD3) whose functions are not Cully understood. To explore the role of the individual CD3 components, the human T‐cell tumour line Jurkat was chemically mutagenized followed by negative selection with F101.01 (a monoclonal antibody against the TcR‐CD3 complex), and cloning. Growing clones were analysed for TcR‐CD3 expression by immunofluorescence. One clone, J79, was found to express greatly diminished levels of TcR‐CD3. This clone produced all the TcR‐CD3 components except the CD3‐ζ, as demonstrated by metabolic labelling and immunoprecipitation followed by one‐ and two‐dimensional sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. These data indicate that the CD3‐ζ determines the normal intracellular fate of the TcR‐CD3 complex, and that the CD3‐ζ is necessary for the intracellular transport and expression at the c

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01201.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Recent data suggest that vitamin D3may be capable of immunoregulation after it is converted to an active metabolite, 1,25‐dihydroxyvitamin D3(1,25(OH)2D3). The effect of vitamin D3and 1,25(OH)2D3on human natural killer (NK) cells and their activation by interferon (IFN) and interleukin 2(IL‐2) was investigated. Vitamin D3and 1,25(OH)2D3inhibited NK cytotoxicity in a dose‐dependent manner. Pretreatment of non‐adherent (NA) cells at 37°C for 18 h with the vitamins also led to inhibition of NK activity. Both the inhibition of NK lysis and pretreatment of NA cells were dependent on the concentrations of fetal calf serum (FCS) in the medium. The inhibition of NK activity was less effective in the presence of 10% FCS than with 1% FCS. Vitamin D3inhibited both IFN and IL‐2 activation of NK activity. However, increasing doses of IL‐2 were able in abrogate the inhibition caused by vitamin D3. Vitamin D3was able to inhibit NK activity of phytohaemagglutinin and IL‐2‐activaled cells, and also inhibit the proliferation and lymphokine‐activated killer activity induced by IL‐2. NA cells pretreated with vitamin D3did not respond well to IL‐2. NA cells pretreated with tow doses of IL‐2 were sensitive to inhibition by vitamin D3while those pretreated with high doses of IL‐2 were not. The data presented suggest that vitamin D3and 1,25(OH)2D3inhibit NK activity and LA

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01202.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The present study was undertaken in order to test the hypothesis that homologous erythrocytes (E) coated in vivo with C3d could modulate the immunoglobulin (Ig) synthesis of human peripheral blood mononuclear cells (PBMC), stimulated with pokeweed mitogen (PWM) in vitro. E from healthy individuals were found to enhance markedly the Ig synthesis of PBMC cultures stimulated with suboptimal doses (0.01 μg/ml) of PWM. E coated in vivo with increasing amounts of C3d (1.4–6.3 times the amounts on normal E), obtained from patients with systemic lupus erythematosus, failed to induce any significant increase in Ig synthesis of PBMC cultures stimulated with suboptimal PWM doses, compared with cultures co‐stimulated in parallel with normal E. In contrast, an increase in IgM and IgG synthesis was observed in about 50% of PBMC cultures from different donors when stimulated with PWM in the presence of L‐ touted with Ohm vivo (from a patient with congenital factor I deficiency), compared with the Ig synthesis in cultures co‐stimulated in parallel with normal E. In contrast to the inability of C3d‐coated E to modulate B‐cell proliferation, the monoclonal anti‐CR2 antibody OKB7 was found to be mitogenic for unstimulated peri

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01203.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A semi‐quantitative immunoblotting method was developed to screen for scrum auto‐antibodies against tumour necrosis factor α (TNFα). Forty nitrocellulose strips containing identical amounts of human recombinant TNFα (rTNFα) were prepared for each set‐up, and the anti‐TNFα antibody immunoreactivities were scored according to the density of the resulting colour reaction. A significant number of sera from apparently healthy donors contained detectable auto‐antibodies to TNFα (40%), while the strongest reaction was observed in 8%. A higher prevalence of anti‐TNFα antibodies was found in ten from patients with Gram‐negative bacterial septicaemia (66%), cystic fibrosis with chronicPseudomonas aeruginosalung infection (72%), and various rheumatic diseases (61%). The antibodies in sera from these patients belonged primarily to the IgG and IgM classes, the latter exhibiting the strongest response. Longitudinally collected serum samples from patients in septic endotoxin shock revealed that the anti‐TNFα antibodies were induced initially during septicaemia, reaching maximum reactivities within the first week and returning to tow or undetecta

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01204.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The ability of 17 monoclonal antibodies (MoAb) antibodies measles virus haemagglutinin (MV‐H) to bind to 10 selected MV‐H‐specific synthetic peptides was tested in an enzyme immunoassay (EIA). Three peptides representing residues 126–135 (close to the NH2terminus). 309–318 (middle), and 587–596 (C‐terminal) reacted with MoAb designated 48, 129, and 18, respectively. Binding of MoAb 129 to purified virus was abolished after pre‐incubation with the peptide 309–318. Similarly. MoAb 48 did not bind to the virus after absorption with the peptide 126–135. Longer peptides of 19 residues from the regions reacting with the MoAb were also synthesized and tested in EIA. None of the MoAb recognized these longer peptides when the latter were bound as free peptides on solid phase. However, MoAb 129 binding to purified virus was blocked equally well by peptides 304–322 and 309–318. In contrast, peptide 121–139 absorbed the reactivity of the MoAb 48 much more weakly than the shorter peptide 126–135, suggesting that the conformation of the longer peptide in solution is different. To analyse affinities in the antigen antibody reactions, the plates were washed with buffers of varying pH after absorption of the MoAb to MV or peptides. The MoAb 129 bound both to MV and peptide 309–318 with equal affinity, but MoAb 48 and 18 bound to the peptides 126–135 and 587–596 with lower affinity than to the virus. This study indicates that regions corresponding to amino acids 126–135, 309–318, and 587–596

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01205.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Activation of protein kinase C (PKC) has been implicated in the regulation of many biological processes including the regulation of T and B lymphocyte responses. A direct means of studying activation of this kinase is to analyse specific phosphorylation events of cellular substrates, in the present report we describe a fractionation method that allows quantitative analysis of phosphorylation of two distinct PKC substrates using normal human T cells and T‐cell tumour lines. This method, which selectively visualizes PKC‐dependent phosphorylation of both an 80‐and a 19‐kDa substrate, involves three simple fractionation steps and allows a large number of samples to be analysed simultaneously. Since specific antibodies to these cellular substrates are not commonly available, the present method provides an alternative approach which makes it feasible to UK phosphorylation of the 19‐ and 80‐kDa proteins as a sensitive marker for PKC activation. Finally, in a cellular system where PKC‐mediated phosphorylation of these substrates can be studied without prior purification, the present method results in greatly improved resolution of these phosphory

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1989.tb01206.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY