Quantitation of Blood Lymphocytes Secreting Antibodies to Pneumococcal Polysaccharides after in Vivo Antigenic Stimulation

摘要

An indirect plaque‐forming cell assay detecting B cells secreting IgM, IgG and IgA antibodies against pneumococcal polysaccharides (PPS) is described. The numbers of anti‐PPS‐secreting cells (SC) and Ig‐SC in the blood of normal persons immunized with a polyvalent PPS vaccine were quantitated. Anti‐PPS‐SC were recorded from the fourth to the twelfth post‐vaccination day, and the maximum number was found between days 6 and 9. Quantitatively IgA anti‐PPS‐SC outnumbered the IgM and IgG anti‐PPS‐SC. Concomitant with the increase in the numbers of antibody‐SC an increase in polyclonally activated IgM‐,IgG‐ and IgA‐SC was recorded.The specific anti‐PPS‐antibody‐SC constituted 20–80 of the total numbers of Ig‐SC from th