A KINETIC STUDY OF ANTIBODY PRODUCING CELLS IN SPLEEN OF MICE IMMUNIZED INTRAVENOUSLY WITH SHEEP ERYTHROCYTES

Abstract

The number of antibody producing cells, i.e. rosette forming cells (RFC) was studied in the spleen of mice injected intravenously with a full immunizing dose of sheep RBC. The spleen of a non-immunized mouse contains a background of about 70,000 RFC (normal RFC), which do not appear to be the "target cells" for antigens of sheep RBC. The spleen of a mouse may contain about 4000 "target cells" which initiate the immune response to sheep RBC. In the primary response, the rise of RFC is exponential for about 96 hr. with a doubling time of 13 hr. involving 7-8 consecutive doubling periods. The peak value of RFC is 1.6 x 106 spleen. In the secondary response, the doubling time of RFC is 6-7 hr. The exponential rise lasts 72 hr. and includes 9-11 doubling periods leading to a peak of 3.5 X 106 RFC/spleen. Adjuvant in the primary response leaves the doubling time of RFC unaltered but prolongs the exponential rise until the 120th hr. leading to a peak of 6.3 X 10[degree] RFC/spleen after 10 doubling periods. The effects of priming and adjuvant are not fully additive.