CCR5 and cytomegalovirus infection: [26, 30–34] This inflammation at the maternal-fetal interface may induce immune activation and alter cytokine production, increasing viral load, and upregulating the expression of CCR5 T-cell receptors as well as CCR5 HIV co-receptors on Hofbauer cells (macrophages) in the placenta, which contribute towards increased HIV tropism and infectivity.[46, 53] It has been suggested that many of these factors are especially important in understanding the role CMV infection plays as a risk factor for HIV MTCT, particularly at the placental interface.