IP-10 is critical for effector T cell trafficking and host survival in Toxoplasma gondii infection

The generation of an adaptive immune response against intracellular pathoge ns requires the recruitment of effector T cells to sites of infection. Here we show that the chemokine IP-10, a specific chemoattractant for activated T cells, controls this process in mice naturally infected with Toxoplasma gondii. Neutralization of IP-10 in infected mice inhibited the massive infl ux of T cells into tissues and impaired antigen-specific T cell effector fu nctions. This resulted in >1000-fold increase in tissue parasite burden and a marked increase in mortality compared to control antibody-treated mice. These observations suggest that IP-10 may play a broader role in the locali zation and function of effector T cells at sites of Th1 inflammation.