Dendritic cell precursors are permissive to dengue virus and human immunodeficiency virus infection

CD14⁺ interstitial cells reside beneath the epidermis of skin and mucosal tissue and may therefore play an important role in viral infections and the shaping of an antiviral immune response. However, in contrast to dendritic cells (DC) or blood monocytes, these antigen-presenting cells (APC) have not been well studied. We have previously described long-lived CD14 ⁺ cells generated from CD34⁺hematopoietic progenitors, which may represent model cells for interstitial CD14⁺ APC. Here, we show that these cells carry DC-SIGN and differentiate into immature DC in the presence of granulocyte-macrophage colony-stimulating factor. We have compared the CD14⁺ cells and the DC derived from these cells with respect to dengue virus and human immunodeficiency virus type 1 (HIV-1) infection. Both cell types are permissive to dengue virus infection, but the CD14⁺ cells secrete the anti-inflammatory cytokine interleukin 10 and no tumor necrosis factor alpha. Regarding HIV, the CD14⁺ cells are permissive to HIV-1, release higher p24 levels than the derived DC, and more efficiently activate HIV Pol-specific CD8⁺ memory T cells. The CD14⁺ DC precursors infected with either virus retain their DC differentiation potential. The results suggest that interstitial CD14⁺ APC may contribute to HIV-1 and dengue virus infection and the shaping of an antiviral immune response.