REGULATION OF IMMUNITY TO MALARIA - VALUABLE LESSONS LEARNED FROM MURINE MODELS

A major advance in immunology has been the establishment of a framewor k for analysing how certain immune responses dominate following exposu re to a particular pathogen or antigen. CD4(+) T helper (Th) cells can be separated into two major subsets which mediate qualitatively disti nct cell-mediated (Th1) and humoral (Th2) immune responses. Immunity t o most pathogens can be broadly categorized into a predominant protect ive response of either type. A characteristic of murine malarias is th at primary infections with asexual erythrocytic parasites (the pathoge nic stage of the malaria life cycle) generate a host protective immune response with a broad spectrum of Th1- and Th2-type CD4(+) T-cell inv olvement and so can be examined as models of the interaction of Th1 an d Th2 cells during an immune response to an infectious agent. Andrew T aylor-Robinson here describes recent events in the dissection of the m echanisms responsible for tile generation of protective immunity to Pl asmodium chabaudi chabaudi and other experimental malarias in mice.