Dendritic cells are important antigen presenting cells (APCs) that play a key role in the immune system. These powerful APCs can modulate responses against viral infection and they represent a crucial set of immune cells in HIV infection.
Dendritic cells influence several factors in HIV infection including viral transmission, the targeting of infected cells and presentation of the HIV antigens.
Through cytokine and interferon secretion, dendritic cells can also influence the activation and proliferation of T cells and therefore contribute to the disrupted immune responses that are observed in chronic HIV.
Dendritic cells are present in the mucosal lining of tissues and are therefore one of the first cell types to come into contact with HIV that is sexually transmitted.
HIV binds to various receptors displayed on the dendritic cell. One of the most well studied examples is a lectin receptor called DC-SIGN which occurs on subset 1 of the myeloid dendritic cells. DC-SIGN is capable of binding to the viral envelope glycoprotein (gp)120 in type 1 HIV.
The dendritic cell binds to HIV and moves to the lymph node where it contributes to the development of the infection by transferring the virus to CD4+ T helper cells. In this way, the infected dendritic cells provide an HIV reservoir for the spread of the infection.
This infection of the dendritic cells is considered a potential mechanism by which HIV manages to persist in the body despite highly active antiretroviral therapy.