Macrophage heterogeneity and Ir-gene control as factors involved in the immune response of guinea pigs to infection with Leishmania enrietti

Abstract

Macrophages from strains 2/N, 13/N, and (2 × 13)F 1, guinea pigs have been fractionated by velocity sedimentation and the various subpopulations used as target cells for infection by Leishmania enrietti. The data presented show: (i) that the ability of infected macrophages to support the subsequent growth and replication of the parasite varies according to the cell subpopulation examined, (ii) that different subpopulations differ in their capacity to promote lymphocyte proliferation from lymph node cells of a guinea pig which have recovered from a primary lesion, (iii) that lymphocyte proliferation depends upon presentation of leishmanial antigens in the context of products of the original I-region-coded genes present during the initial ( in vivo) infection and, (iv) that in immune animals, changes occur in terms of the ability of the macrophages to promote lymphocyte proliferation, but not apparently in terms of their ability to support parasite growth in vitro.