The pathogenesis of Leishmania/HIV co-infection: cellular and immunological mechanisms.
The intracellular protozoan parasites of the genus Leishmania have been recognized as opportunistic pathogens in immunosuppressed individuals, including those infected with human immunodeficiency virus type-1 (HIV-1). Leishmaniasis and AIDS overlap in several sub-tropical and tropical regions around the world, including the Mediterranean area. In 1994, 3%-7% of HIV-1-infected individuals in southern Europe developed visceral leishmaniasis. In humans, interestingly, both HIV-1 and Leishmania interact with, invade, and multiply within cells of myeloid or lymphoid origin. The combined modulation of Leishmania - and HIV-1-related pathogenesis in the co-infected cases is therefore probably a realistic goal. In the light of the recent demonstration that L. donovani can up-regulate HIV-1 replication, both in monocytoid and lymphoid cells in vitro and in co-infected individuals, it is clear from the epidemiological data available that Leishmania can probably act as a powerful co-factor in the pathogenesis of HIV-1 infection. In those who are co-infected, complex mechanisms involving cytokine secretion and cellular-signalling events play pivotal roles in the Leishmania-mediated activation and pathogenesis of HIV-1. An overview of the recent findings concerning this Leishmania/HIV-1 interaction is presented here.
Olivier
M
M
Faculty of Medicine, McGill University, Lyman Duff Medical Building, 3775 University Street, Montreal, Québec, H3A 2B4, Canada.
Badaró
R
R
Medrano
F J
FJ
Moreno
J
J
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology*; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D015897:Comorbidity; D016207:Cytokines / Q000276:immunology; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D007896:Leishmaniasis / Q000276:immunology*; D015398:Signal Transduction; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014779:Virus Replication / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines