Figure 3. Model of immune interactions during placental malaria and human immunodeficiency virus type 1 (HIV-1) co-infection and their putative impact on mother-to-child transmission of HIV-1.

Figure 3

Model of immune interactions during placental malaria and human immunodeficiency virus type 1 (HIV-1) co-infection and their putative impact on mother-to-child transmission of HIV-1. Infection of the placenta with Plasmodium falciparum activates the immune system and results in up-regulation of placental proinflammatory cytokines, especially tumor necrosis factor-alpha (TNF-α), which in turn could increase HIV-1 replication. Placental malaria also results in the increased infiltration of mononuclear cells in the inter-villous spaces of the placenta (IVBMC) and increased expression of CC chemokine receptor 5 (CCR5) on placental macrophages and fetal Hofbauer cells. These changes may further increase the placental HIV-1 viral load. With a healthy immune status, tightly regulated proinflammatory response, and CC-chemokine responses to malaria (which block HIV-1 entry through the CCR5 receptor) may successfully control malaria parasite densities and favor protection against mother-to-child transmission (MTCT) by controlling viral load and promoting other as yet undefined protective factors. Conversely, these putative protective factors may be overwhelmed in women with high-density malaria infections and/or HIV-related immunosuppression associated with high placental HIV-1 viral load and sub-optimal immune response to malaria. This could result in a local environment that favors MTCT of HIV-1.

From: The Burden of Co-Infection with Human Immunodeficiency Virus Type 1 and Malaria in Pregnant Women in Sub-Saharan Africa

Cover of The Intolerable Burden of Malaria II: What's New, What's Needed
The Intolerable Burden of Malaria II: What's New, What's Needed: Supplement to Volume 71(2) of the American Journal of Tropical Medicine and Hygiene.
Breman JG, Alilio MS, Mills A, editors.
Copyright © 2004, American Society of Tropical Medicine and Hygiene.

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