Figure 3. Current model of HIV-1 infection in mast cell progenitors (prMC) and the creation of a stable reservoir of infected tissue mast cells.
Circulating mast cell progenitors can become infected with CCR5-tropic HIV-1 or, following interactions with IgE, CXCR4-tropic HIV-1 as well. The progenitor mast cells then mature into tissue mast cells that are resistant to new HIV-1 infection. These mast cells may harbor latent HIV-1 that can later be reactivated, or they may be able to continuously produce HIV-1 due to the virus's reduced cytotoxicity in this cell type. In either case, a viral reservoir in tissue mast cells is created and can contribute to viral persistence.