T-cell clones in immunoparasitology

Cell-mediated immunity (CMI) is important in many parasitic infections. Stimulation by parasite-specific antigens can induce clonal expansion of parasite-specific T-cells which may act by direct cytotoxic action or by indirect effects on other cells such as natural killer cells or antibody-producing B-cells (Box 1). In many cases however, the precise effector functions and the identity of antigens that elicit protective responses in parasitic infections are poorly defined. Analysis of proliferative and cytotoxic activities of subcloned cultures of T-cells stimulated with parasite antigens can provide some clues about the importance of CMI, but, as this review shows, much more precise information can be obtained by analysis of the response of cloned T-cell cultures.