The migration of blood-borne lymphocytes into rat popliteal lymph nodes stimulated with xenogeneic red blood cells.

The recruitment of radiolabelled blood-borne lymphocytes into rat popliteal lymph nodes (PLN) was investigated following the injection of varying doses of chicken (CRBC) or sheep red blood cells (SRBC) into the hind foot pad. Within the dose range tested (10(5)-10(8) RBC) an increase in the dose of injected antigen resulted in elevated levels of lymphocyte recruitment into the draining popliteal lymph node. The kinetics of lymphocyte recruitment with the same dose of CRBC or SRBC was similar even though these red cells differ in size and are antigenically non-cross-reactive. While little is known of the mechanisms which control the rate of entry of blood-borne lymphocytes into antigen-stimulated lymph nodes, the extent of lymphocyte recruitment was shown to be directly related to the quantity of antigen injected.