Humoral and cellular immune response of BALB/c mice to repeated infestations with Ixodes ricinus nymphs.

The capacity of female BALB/c mice to mount an immune response and effective resistance to repeated infestations with I. ricinus nymphs was studied. An anamnestic antibody response and transient in vitro responsiveness of spleen lymphocytes to tick antigens were demonstrated in repeatedly infested mice. On the other hand, the response to concanavalin A--a T-cell mitogen, was suppressed at the same time. In the presented experiment, BALB/c mice did not manifest tick resistance after three successive infestations (with a reinfestation period of 2 weeks). The possibility of an infestation-dependent modulation of immune response in BALB/c mice is discussed.