Cell wall preparation consisting of group A carbohydrate and peptidoglycan moieties from Streptococcus pyogenes activates murine B lymphocytes

Mutanolysin-induced lysis of actinomyces pyogenes determined by aggregometry

The lytic activity of mutanolysin from Streptomyces globisporus on 42 cultures of Actinomyces pyogenes could be effectively analyzed in an aggregometer. It was expressed as increase of transmittance at 546 nm after 20 min and 2 h at 37 degrees C. The A. pyogenes cultures revealed no uniform lysis pattern. Most of the cultures were lyzed within 20 to 40 min at 37 degrees C, others were lyzed only moderately or weakly within 2 h of incubation. The lytic activity was optimal at low (0.01 mol/l) molarity of the lysis buffer between pH 5.7 and 7 and could be inhibited by HgCl2.A. pyogenes was not lyzed by lysostaphin or lysozyme.

Systemic uptake and intestinal inflammatory effects of luminal bacterial cell wall polymers in rats with acute colonic injury

The systemic uptake and local intestinal inflammatory potential of luminal bacterial cell wall polymers in rats with normal and acutely inflamed colons were measured. Rats were injected intracecally with either 125I-labeled group A streptococcal peptidoglycan-polysaccharide complexes or equal amounts of Na125I, after either nonspecific colonic injury with 4% acetic acid or injection with buffer. The colons of rats injected with peptidoglycan-polysaccharide had higher inflammatory scores than Na125I-injected rats, a greater incidence of mucosal ulceration and transmural inflammation after acetic acid injury, and an increased frequency of focal accumulations of inflammatory cells in the lamina propria and submucosa after buffer injection. Radioactivity in the liver, spleen, and mesenteric lymph nodes was higher in the colon-injured rats that received peptidoglycan-polysaccharide 48 h before tissue collection than in the noninjured rats (P less than 0.002). Group A streptococcal polysaccharide antigen concentration within the liver, spleen, and mesenteric lymph nodes, measured by enzyme-linked immunosorbent assay, was significantly higher in the colon-injured rats that received cell wall polymers than in noninjured rats. These results indicate that luminal bacterial cell wall polymers with well-described inflammatory and immunoregulatory potential can cross injured colonic epithelia and are capable of initiating and potentiating intestinal inflammation.

Polyclonal activation of murine B lymphocytes in vitro by Salmonella typhimurium porins

Porins were prepared from the outer membrane of Salmonella typhimurium and consisted of three polypeptides with similar molecular ratios around 40 kDa, and isoelectric points around 4.7. They constituted potent polyclonal activators for murine B lymphocytes. The compounds were mitogenic towards splenic lymphocytes of lipopolysaccharide responder Balb/c, non-responder (C3H/HeJ), and athymic (Balb/c nu/nu) mouse inbred strains, as measured by 3H-thymidine incorporation into DNA. Furthermore, porin-activated B cells differentiated into immunoglobulin-secreting cells, as was measured by an ELISA test. The porins will be valuable in elucidating the molecular mechanism of lymphocyte activation in bacterial infections.

Effective murolytic solubilization of streptococcal-group-specific antigen

Streptococcal-group-specific antigens were solubilized with a murolytic enzyme contained in the culture supernatant of Streptomyces globisporus. This facilitated the effective serogrouping of streptococci from humans and animals.