In-vivo and in-vitro interference of antibiotics with antigen-specific antibody responses: effect of josamycin.

The effects of josamycin on the antigen-specific primary antibody responses of human peripheral blood cells have been studied by the method of haemolytic colonies in soft agar. The tests were performed before and after the oral administration of 1 g of josamycin or by adding the drug directly to cultures of cells from untreated donors. The results demonstrate that josamycin, added in vitro or administered in vivo significantly depresses the primary antibody responses. The mechanism by which josamycin exerts its activity on antibody production has been partially elucidated. The immunodepression depends on the stimulation of hydrogen peroxide production by monocytes and requires the actual presence of josamycin during the immune response. The stimulation of the respiratory burst of the phagocytic cell is a common feature of macrolide antibiotics and suggests the need for more extensive clinical and preclinical trials on antibacterial antibiotics that alter the human immune responses.