Immunological communications最新文献

One hundred thirty-two patients were separated into clinically defined groups of definite, probable and possible multiple sclerosis (MS), the spinal cord variant of MS (SCV), and non MS neurologic disease. HLA antigens A3 and B7 occurred at increased frequencies in definite and probably MS patients when compared with neurologic controls and healthy adults. CSF elevations of either kappa/lambda ratio, IgG/total protein ratio, or IgG were seen in 65% of the definite, probable and SCV groups. Patients with HLA A3 and B7 antigens had a higher than predicted incidence of elevated kappa/lambda ratio, suggesting that there may be immunogenetic control mechanisms which influence this CSF parameter. Neither HLA antigens nor CSF protein abnormalities correlated with the age of onset, progression, or degree of disability of disease, thus limiting their prognostic usefulness.

Antibodies raised in rabbits against pig kidney DOPA decarboxylase show immunological cross-reactivity towards extracts from monkey, beef, rat and rabbit kidney. The influence of the immuno-reaction on the enzymatic activity has been investigated.

A Modified Microcomplement Fixation Test (MMFT), useful for detecting and quantifying soluble immune complexes (ICs) and their components in chromatographic separations, is described. This method is based on the addition of excess specific antibody to the ICs against any of their components in order to increase the ICs' anticomplementarity. The concentration of ICs is expressed as the sample dilution which fixes 50% of the added Complement. The MMFT was applied to profiles of ICs obtained in vivo and in vitro. MMFT allows great sensitivity, good reproductibility and the detection of noncomplement fixing ICs without any interference of free antigen (Ag) or free antibody (Ab).

The oxidative response of murine spleen cells to secondary exposure to antigen was determined by luminol (5-amino-2,3-dihydro-1,4-pthalazinedione) amplified chemiluminescence, CL. BALB/cj and CBA/J mice were immunized with saline or an antigen solution of saline, luminol, and bovine serum albumin. Spleen cells were obtained from mice two and four days after immunization, and the CL response to in vitro antigenic exposure was measured for 35 minutes. At two days post-immunization, there was no difference in the CL of control and antigen-primed cells. By day four, the antigen-primed CL response differed significantly in both magnitude and time course from the primary antigen-stimulated response of the controls. This early development of differential CL response to antigenic challenge suggests a role for oxidative metabolic activity in the expression of the anamnestic immune response.

The development of a quantitative spreading assay of macrophage activation is described. The assay involved incubation of macrophages on glass coverslips for 1 hour and assessment of cell size using a microscope attached to a microcomputer-assisted digitising system which allowed the diameter of 200 cells to be assessed within 10 minutes. Mouse peritoneal macrophages were used in the development of the assay. Internal consistency of the assay was shown by minimal inter-observer, intra-observer and inter-animal variation. Validation of the assay as a measure of macrophage activation was confirmed by the use of in vivo and in vitro activating agents. Once validated the assay was used to detect activation in alveolar macrophages from rats exposed to airborne asbestos. The macrophage spreading assay described here is quick, reliable, consistent and easy to perform and has a potentially wide application in studies of macrophage function and dysfunction.

Human peripheral blood B-cells can be stimulated with PWM and antigen to produce specific antibody in vitro. This stimulation depends on the presence of T-cells and antigen. T cells, however, can be replaced by a soluble factor derived from a 48-hr culture of T-cells with either PWM and/or antigen. The helper factor, in the absence of antigen, acts as a polyclonal activator causing minimal proliferation of B-cells. When antigen is present, production of specific antibody is not dependent on the source of helper factor. Removal of monocytes abolished synthesis of both Ig and specific antibody although antigen and/or helper factor were present. While production of total IgG required autologous monocytes, the origin of the helper factor was not crucial. Production of specific antibody required that both monocytes and helper factor be derived from the same donor; therefore it seems that cooperation of B-, T-cells and monocytes for production of specific antibody is probably Ia restricted. In contrast, for production of polyclonal Ig (in the absence of antigen), cooperation of B-cells and monocytes with T-cells is not.

We examined dynamics of expression of the human T-suppressor specific antigen, T8, following interaction of peripheral lymphocytes with wheat germ agglutinin (WGA). Cells were incubated at 37 degrees C with or without WGA (15 micrograms/ml) for 18 hrs, washed sequentially with N-acetylglucosamine (to remove bound WGA) and plain medium, then analyzed by flow cytometry for binding of lectins and monoclonal antibodies OKT8(T-suppressor specific) and OKT3 (pan-T specific). WGA pretreatment induced an overall 65% reduction in WGA binding and concomitant 30% reduction in percentage of T8+ cells. Furthermore, residual T8+ cells showed 50% reduction in T8 expression. Taking into account reductions in both percentages of T8+ cells and also antigen densities, WGA reduced T8 expression by greater than 60% overall. By contrast, binding of OKT3 and the lectins, concanavalin A (con A) and Ricinus communis agglutinin (RCA-I), was unaffected by WGA. The decreased T8 expression could not be explained by residual cell bound WGA and was fully reversible within 48 hours of removal of cells from WGA-containing medium. Therefore, WGA caused downregulation of T8 antigen expression. The effect of WGA was time- and concentration-dependent. Downregulation did not occur at 4 degrees C nor in the presence of azide, thereby demonstrating a requirement for cellular metabolism. The data suggest that WGA may bind to the T8 antigen, and they provide the possibility that similar downregulation of T8 by WGA may underlie certain of the in vitro immunoregulatory effects of this lectin.

Circulating immune complexes were detected by the immunoelectrophoretic method in 18 of 29 (62 per cent) of patients with systemic scleroderma. The presence of immune complexes did not correlate with that of antinuclear antibodies to dsDNA, DNP, RNP, and Sm. The mean levels of immunoglobulins G, A, and M as well as of C3 were significantly higher in patients with systemic scleroderma than in blood donors.

We have observed that CT6 cell line, a murine interleukin 2 (IL 2)-dependent T cell line, was highly responsive to phorbol myristate acetate (PMA) and to a lesser extent but significantly responsive to lipopolysaccharide (LPS) in the short-term proliferation assay. In contrast, two other murine IL 2-dependent cell lines, CTLL-2 and NK clone 7, were totally unresponsive to these stimulants. Even when CT6 was recloned by a limiting dilution, no unresponsive clone to PMA was obtained, whereas several clones unresponsive to LPS were obtained. PMA, unlike to IL 2, could not support a long-term culture of CT6. There are no differences between CT6 and CTLL-2 except that the former possessed asialo GM1 while the latter lacked it. Though it is unknown whether this difference is involved in the mechanism of the response of CT6 to PMA or LPS, these data give caution to us against the use of CT6 for the determination of IL 2 activity contaminated with PMA and LPS.