The ability of primed rabbit blood lymphocytes to respond in vitro to the homologous streptococcal group antigen depends on its presence in culture in the form of vaccine or cell walls thereof. These lymphocytes can also be stimulated in vitro by streptococcal vaccines with chemically related group antigens. The basis for this cross-stimulation apparently resides in shared rhamnose moieties. Activation of these lymphocytes was not achieved by vaccines from unrelated bacteria. There is also the suggestion that rabbits of different genetic origin differentiate between cross-stimulating antigens, probably at the level of antigenic determinants. The data support the view that recognition and response pattern of the immune system rely heavily on a network of antigens.

No abstract

Activation of primed rabbit PBL by homologous antigen in the early proliferative phase (on days 3–5) mainly involves lymphocytes which neither secrete specific antibody nor contain immunoglobulin in their cell membrane. This stimulation is antigen-specific, and evidence is given that the major proportion of these cells are T lymphocytes. The B cells forming Av-CHO-specific PFC were studied by autoradiography on days 6 and 12 of culture. Since incorporation of radioactive thymidine was found in the majority of PFC, these cells are also in proliferation.

No abstract

No abstract