Antigen-initiated B lymphocyte differentiation. IV. The adherence properties of antibody-forming cell progenitors from primed and unprimed mice.

Distinct sub-populations of B lymphocytes may be fractionated by passage through glass-bead columns, due to a temperature-independent adherence of certain cells. The relative adherence properties of AFC-progenitors from spleens of primed or unprimed CBA mice were compared with an adoptive immune assay employing as antigen the hapten NIP on the carrier polymerized flagellin, under conditions where T lymphocytes did not limit the response. The AFC-progenitors for an anti-NIP IgM response from unprimed mice, whether conventional, germ-free, or athymic were more adherent than the majority of cells in the spleen. The AFC-progenitors for an IgG response from hapten-primed mice were less adherent that the majority of spleen cells. The results indicate that there are sub-classes of AFC-progenitors, differing in surface properties and probably corresponding to differences between the "antigen-inexperienced" and the "memory" B cell populations.