Immunostimulating effect of culture filtrates of Yersinia enterocolitica

Application of sterile culturing supernatant of Yersinia (Y.) enterocolitica (tested serovars were 03 and 08) caused significantly accelerated transplant rejection in mice of various inbreeding strains. Action correlated with dosage (r = -0.92). C57B16 mice were tested for their pregnancy rates in response to the same filtrate (serovar 03), with 5.5 live births per mating being recorded from 47 control matings but only 4.4 from 45 experimental matings (alpha less than 0.0025). The mean gestation period of experimental animals was extended by five percent over that of simultaneous controls (alpha = 0.25). Particular reference is made in this paper to Vesikari et al. (1987) who found Y. enterocolitica to function as interleukin-1 inductor via lipopolysaccharide. The active substance tested in this context, however, proved to be thermolabile, with 30 minutes of heating to 56 degrees C eliminating the action tested before. Y. enterocolitica infections were frequently found to coincide with rheumatoid arthritis, and evidence has been produced to the unspecific stimulating effect of Y. enterocolitica culture filtrates (testing being applied to serovar 03, biovar 4 and serovar 08, biovar 2). It is against the background of these aspects that chronic and other infections by Y. enterocolitica are considered to be of substantive relevance to the etiopathogenesis of autoimmune diseases, above all rheumatoid arthritis.