Immunological communications最新文献

A one step solid phase radioimmunoassay is used as a simple and reproducible method of detection and quantitation of IgG produced by human PBL after stimulation with PWM. Modifications of culture conditions are necessary to make culture supernatants suitable for this assay. Pulsing with PWM must be performed in serum-supplemented culture medium for 4-5 days. After thorough washing, medium is then replaced with serum-free medium. Under these conditions, synthesis and secretion of IgG continues for at least 9 days. The amount of IgG produced by 10(6) normal adult PBL as detected in this system is 0.77 +/- 0.47 micrograms. No close correlation between cell proliferation and IgG synthesis was observed.

The kinetics of the temperature-mediated immunomodulation of the humoral antibody response to an erythrocyte antigen was remarkably different in two species of a marine teleost, the winter flounder (Pseudopleuronectes americanus) and the summer flounder (Paralichthys dentatus). These two species were caught in the same area, maintained under the same conditions and injected with the same antigen (horse red blood cells). Experiments were performed at 8, 12 and 17 degrees C during the same time of the year. Summer flounder showed only a delay in the appearance of circulating antibody at lower temperatures while winter flounder showed both a delay and a marked suppression at lower temperatures. Antibody titers remained high for over three months in summer flounder while in winter flounder antibody levels began decreasing after one month.

In the present experiment we attempted to confirm the specific stimulation of substance P (SP) on human T lymphocyte proliferation as reported by Payan et al. and to observe its effect on human B lymphocyte proliferation. As a result, no definite mitogenic effect of SP (10(-11) to 10(-7) M) was found on both human T and B cells, no significant influence of SP on the blastogenic response of T cells to Con A or PHA stimulation in a wide range of concentrations and no effect on proliferative response of B cells to Staphylococcus aureus Cowen strain I stimulation were shown. Payan's conclusion was based on percentage increase of 3H-TdR incorporation. But as the background cpm is generally very low, even 100 per cent increase would only indicate a very small cpm increase, so in this situation percentage increase might give false phenomenon, and only cpm could tell whether the effect was strong or weak. Thus, we believe that is the reason for our disagreement with Payan's conclusion.

Rabbits immunized with purified Sm and RNP small nuclear ribonucleoproteins (snRNPs) produced precipitating and hemagglutinating antibodies against these antigens. These antibodies had immunological specificity identical to the naturally occurring SLE anti-Sm/RNP antibodies as demonstrated by immunoprecipitation results and studies involving the characterization of immunoaffinity purified antigens isolated from the rabbit immune and SLE anti-Sm/RNP IgG affinity columns.

Treatment in vitro of nude mouse spleen prothymocytes with relatively low concentrations (1-50 micrograms/ml) of trypsin induce the Thy 1- to Thy 1+ conversion. The effect of trypsin was inhibited by prior heating or by addition of soybean trypsin inhibitor. The maximal effect achieved by trypsin treatment, approximately 25% conversion of spleen cells from layer B of an albumin gradient into theta-positive cells, was equivalent to that obtained with thymic hormone preparation (TP-1) at 10 ng/ml. Maximal conversion required 120 min incubation with TP-1 or trypsin. We conclude that both trypsin and TP-1 act by perturbation of a membrane receptor which can send a signal initiating the differentiation process.

Cells producing specific antibodies against the hapten penicilloyl (Pen) are demonstrated in tissue sections of the spleen, using peroxidase immunocytochemistry. Horseradish peroxidase-human serum albumin-penicilloyl (HRP-HSA-Pen) conjugate, prepared by coupling Pen to HRP-HSA conjugate, was used for detection of anti-Pen producing cells in the spleen after intravenous injection of bovine gamma globulin-penicilloyl (BGG-Pen) conjugate. HRP-HSA conjugate was used as a control to exclude the possibility that positive cells contained antibody against a common determinant in both HSA and BGG. The method may be applied for the detection of cells producing antibodies against other haptens as well.

The carbohydrate moieties exposed on enterobacteria before and after antibody binding have been tested with fluorescent lectins. Salmonella typhimurium 395 MS (S-type) and its Rd-mutant MR10 were coated with hyperimmune anti-MS and anti-MR 10 IgG, respectively. MR 10 bacteria and Escherichia coli O86 bacteria were coated with human colostral secretory IgA (SIgA). There was a conspicuous binding of some of the lectins to untreated bacteria not always closely related to the sugar composition of the outer membrane lipopolysaccharide (LPS) or other known sugar residues. Antibody IgG and SIgA binding modified the affinity for the lectins. The binding of some lectins was reduced, presumably by masking the bacterial sugars. Antibody IgG binding to S. typhimurium MS and R 10 enhanced the affinity for RCA-I (Gal) and to a smaller extent for WGA (GlcNAc) which may be explained by exposure of IgG oligosaccharide. Antibody SIgA binding to S. typhimurium R 10 and E. coli O86 enhanced the affinity for the above lectins to a larger extent as well as for Con A (Man, Glc). The corresponding sugars N-acetylglucosamine, mannose and glucose are present in the carbohydrate chain of the secretory component as well as in IgA indicating that when SIgA antibody binds its sugar components are exposed.

Infectious mononucleosis sera gave positive results in enzymoimmunoassay with glutaraldehyde-treated human erythrocytes. This unexpected reaction appeared to be caused by the interaction of Paul-Bunnell (P-B) antibodies with a partial P-B antigen that apparently appears on human red blood cells in a hidden form and becomes exposed by the treatment with glutaraldehyde.

Thymidine uptake into the acid soluble cell fraction of human tonsillar lymphocytes was studied in vitro. Uptake was linear for 15-20 minutes at low concentrations (less than 1.2 microM) of thymidine. The plot of uptake versus time could be extrapolated to the origin. Value for KM (0.5-0.6 microM) and values for Vmax were determined. In the presence of a lymphokine which inhibited thymidine incorporation into DNA the uptake of thymidine into the acid soluble cell fraction was also inhibited. The decreased uptake could be characterized by an increase in the apparent KM, without the alteration of Vmax. Lymphokines which inhibit thymidine incorporation may influence and regulate in vivo the entry of the exogenous thymidine into the cells.