Search for Klebsiella cell wall components cross-reactive with lymphocytes of B27+ AS+ individuals.

It has been suggested that some Klebsiella sp may cross-react with a cell surface determinant on the lymphocytes of B27+AS+ individuals. Studies were undertaken to identify culture filtrates capable of rendering the lymphocytes of B27-positive healthy controls susceptible to lysis by the anti-Klebsiella antiserum. Polyacrylamide gel electrophoresis of cell wall material of Klebsiella K43 prepared by sonication, high-speed centrifugation, and nonidet solubilization, demonstrated the presence of four major protein bands. When antisera raised in rabbits to each of these were tested for their cytotoxic effect on the lymphocytes of B27+AS+ individuals, an antiserum to one component only, of 40-52 K daltons molecular weight, reproduced the activity of the whole serum. Studies on the K43 filtrate indicated that the 'modifying' factor appeared to reside in a 25-50 K dalton component. Immunoelectrophoresis against anti-K43 serum demonstrated overlapping bands in the culture filtrate and the 40-52 K dalton cell wall fraction and these appeared to be identical on immunodiffusion. Antibody to the cell wall component removed both the 'modifying' activity and the appropriate protein band from the filtrate. The results suggest that a 40-52 K dalton component of the Klebsiella K43 cell wall is cross-reactive with a determinant on the lymphocytes of B27+AS+ individuals and is similar to or identical with a modifying factor in K43 culture filtrate which renders the lymphocytes of B27-positive healthy controls susceptible to lysis by anti-Klebsiella antiserum.