• Autoimmunity;
  • male accessory glands;
  • circulating and bound antibodies;
  • immunoglobulins secreting cells;
  • rats

ABSTRACT: A correlation between spleen B-cell antibody production against MAG antigens and the presence of different antibodies in circulation or antibodies bound to target glands was attempted.

The number of 7S and 19S Ig-secreting cells (ISC) found in the spleen and the number of ISC generated after in vitro stimulation of the cells with MAG antigens were evaluated by using the hemolytic plaque assay. Low numbers of 7S and 19S ISC-less than 0.01% of spleen cells—were generated in response to MAG immunization, and no significative increase was observed after in vitro culture of spleen cells with MAG antigens, suggesting that secretory activity of the B-cells can not be improved when liberated from humoral homeostatic mechanisms.

The humoral response of MAG-immunized rats, investigated by complement fixation and immunodiffusion assays, has proved negative, and in only two out of 17 rats a weak haemagglutinating activity was observed. Attempts to detect antibodies bound to cellular MAG antigens by immunofluorescence have shown a weak fluorescence in the epithelial cells of the prostate gland in only two rats. In both cases a concomitant tissue damage was observed, but in nine out of 11 cases with histological alterations no fluorescence was observed in the target glands.

The medium value of rosette-forming cells (RFC) found in the spleen of MAG-immunized rats did not significantly differ from the value of the HSA-treated control group, although both groups differ in their specific humoral response.

Contrary to the depressed humoral response, the MAG-immunized rats showed in all cases a cellular immune mechanism by at least one of the tests in study and in 70.5% of the cases the simultaneous presence of various factors has been demonstrated. In 11 cases the cell-mediated immune response was accompanied by seminal vesicle and/or prostatic lesions with a microscopic aspect close to that of delayed hypersensitivity reactions. These observations suggest that the characteristic lesions of experimental autoimmune vesiculoprostatitis (EAVP) are unlikely to be initiated by antibodies directed against MAG antigens. The mechanism affecting the impaired antibody response is discussed.