EFFECT OF ANTIBODIES ON CHEMILUMINESCENCE AND ON KILLING OF STREPTOCOCCUS-SOBRINUS BY POLYMORPHONUCLEAR LEUKOCYTES

The effect of a polyclonal antiserum and OMVU10, a monoclonal antibody reactive with Antigen B of Streptococcus sobrinus, on the interaction of polymor-phonuclear leukocytes with S. sobrinus was studied, using chemiluminescence and bacterial killing assays. Increased stimulation of neutrophils as measured in the chemiluminescence assays was establi shed when S. sobrinus was preincubated with polyclonal antiserum or wh en polyclonal antiserum was added to the reaction mixture. Higher coun ts were measured in comparison to preimmune serum. After 90 min, 52% o f S, sobrinus preincubated with polyclonal antiserum was killed. Killi ng was also increased when polyclonal antiserum was added to the react ion mixture in comparison to the controls. No killing was found when b acteria were preincubated with OMVU10 or when OMVU10 was added to the reaction mixture in comparison to Clone 24, a control antibody.