Presence and kinetics of sensitized cells in different tissue compartments

The question was studied as to whether lymph nodes (LN), spleen (SP) and bone marrow (BM) contain different amounts of sensitized cells at various times after one or repeated immunizations. The following model was used: C57 mice were injected i.p. once, twice or three times with C3H cells. Between 3 and 20 days after the last immunization, LN, SP and BM cell suspensions were tested in vivo for their local cutaneous lymphocyte transfer reactivity in C3H mice and in vitro for their lymphocytotoxicity (partially after preincubation with anti-theta serum). In both test systems similar observations were made: after one sensitization, reactive cells were demonstrated first in the LN and then in the SP, but only during the next few days; BM cell reactivity appeared later. In the first few days after two sensitizations SP cells reacted strongly whereas LN and BM cells reacted weakly; later BM cell reactivity increased while the others decreased. After three sensitizations reactivity of the SP cells predominated during the entire period of observations; the BM cells showed less, the LN cells no reactivity. These findings suggest dependance of T cell-mediated reactivity on (1) the origin of the cells from LN, SP or BM, (2) the time of the harvesting from these tissues, and (3) the degree of sensitization.