Spleen cell transfer studies were done in BALB/c strain mice in an attempt to define the role of θ-antigen-bearing lymphoid cells in immune responses to SE. Incubation with alloantiserum to θ-C3H and rabbit C' virtually completely abolished the ability of the cells to transfer both primary and secondary (IgM and IgG) responses to 650 R irradiated recipients. Normal thymus cells partially reconstituted the ability of such treated cells to transfer the primary but not the secondary response. The results are interpreted as showing immunological memory for SE in the θ-bearing thymus-derived cells.
Incubation of the spleen cells with alloantiserum to the PC.1 antigen present on antibody-forming cells did not significantly affect the ability to transfer either primary or secondary response.