Hepatic cellular immune responses in mice with cure and non-cure phenotype to Leishmania infantum infection:: importance of CD8+ T cells and TGF-β production

The objective of this study was to analyse hepatic cellular immune response of mice with cure and non-cure phenotypes to Leishmania infantum infection. During infection establishment, elevated TGF-beta levels and absence of a Th1 response may have contributed to parasite multiplication and to similar hepatic parasitic loads. Later in infection, an increase in the number and activation levels of CD8(+) cells was observed simultaneously with parasite elimination, but only significant in cure strain. During this recovering phase, non-cure animals showed low Th2 cytokine levels, while TGF-beta production was higher than in cure mice. These results point out to a role for CD8(+) T cells in liver acquired immune response and to TGF-beta regulation of cure and non-cure phenotype to L. infantum infection. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.