IN-VITRO PRODUCTION OF INTERLEUKIN-4 AND INTERFERON-GAMMA BY LYMPH-NODE CELLS FROM BALB C MICE INFESTED WITH NYMPHAL IXODES-RICINUS TICKS/

In this study we compared the ability of lymphocytes taken from axilla ry and brachial lymph nodes of BALB/c mice that had been infested once three times with 15 nymphal Ixodes ricinus ticks, to produce interleu kin-4 (IL-4) and interferon-gamma (IFN-gamma) after in vitro stimulati on with concanavalin A (Con A). They released high levels of IL-4 and low levels of IFN-gamma. An increase of IFN-gamma between the first an d the third tick infestation was observed. Salivary gland extracts fro m female I. ricinus ticks induced specific in vitro proliferation of l ymphocytes from infested mice. IL-4 production was correlated with the salivary gland extracts' ability to stimulate tick-specific lymphocyt e proliferation. Its levels remained high from the first to the third infestation. IFN-gamma production was not necessarily associated with tick salivary gland antigen stimulation. In BALB/c mice, anti-tick imm une response induction is regional and the contribution of other simil ar secondary lymphoid organs is negligible. Only cells from the lymph nodes which drained the tick-fixation site proliferated in vitro in th e presence of tick antigens, and when stimulated with Con A produced I L-4 and IFN-gamma.