Tissue Culture Studies on Bacterial Allergy in Experimental Brucellosis

Tissue culture methods have been used to investigate infectious allergy in experimental brucellosis. A study was made of the effect of whole cell Brucella antigen on cultures of spleen from normal and Brucella-infected guinea pigs. The degree of toxicity was based upon the inhibition of migration of wandering cells and upon the morphologic appearance of stained sections of tissue cultures at different periods of incubation. A suspension of heat-killed Br. suis was more toxic for splenic cells from guinea pigs infected with Br. suis than for normal splenic cells. Macrophages were more sensitive than leucocytes to the toxic action of the antigen. The degenerative changes observed in Brucella-sensitive cells exposed to the antigen were similar to the degeneration previously observed in cultures of tuberculin-sensitive cells in the presence of tuberculin. The specific toxicity of the whole Brucella antigen, however, was more marked than that of tuberculin. Preliminary experiments indicate that serum and plasma containing specific antibodies obtained from Brucella-infected guinea pigs reduce the toxic effect of the antigen in cultures of both normal and Brucella-sensitive cells. The protective action of the homologous antiserum was greater for Brucella-sensitive cells than for normal cells.