The early antibody-forming response to Salmonella antigens. A study of morphology and kinetics in vivo and in vitro

Abstract

This paper describes a new method for the morphological study of individual antibody-forming cells (AFC) on cell smears of the quality of normal haematological preparations.

The early AFC response to polymerized flagellin of S. adelaide was studied in vivo using C57BL mice, which have very low background levels of AFC and in vitro using dispersed spleen cell cultures from CBA mice. AFC, arising as a result of in vivo or in vitro stimulation were found to comprise a heterogeneous population, including basophilic mononuclear cells, lymphocytes of most sizes, immature blast cells and occasional plasma cells. The earliest AFC detected comprised a high percentage (28 per cent in vivo, 31 per cent in vitro) of small lymphocyte-like cells. Studies of the incorporation of [³H]thymidine showed that most AFC arose by proliferation but that a proportion of AFC, the small lymphocyte-like cells, arose by differentiation of precursor cells not involving cell division.

The effects of antigen concentration on the kinetics of AFC were investigated in vitro. Subtolerogenic antigen doses caused a delayed and decreased AFC response.