IFN-alpha enhances poly-IC responses in human keratinocytes by inducing expression of cytosolic innate RNA receptors: relevance for psoriasis.

Keratinocytes play a key role in innate immune responses of the skin to bacterial and viral pathogens. Viral double-stranded RNA and its synthetic analogue polyriboinosinic-polyribocytidylic acid (poly-IC) are recognized via multiple pathways involving the receptors Toll-like receptor 3 (TLR3), protein kinase R (PKR), and the recently described cytosolic RNA helicases retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5). We show that preincubation of human keratinocytes with IFN-alpha enhances the proinflammatory responses to poly-IC.

Isopentenyl pyrophosphate-reactive Vgamma9Vdelta 2 T helper 1-like cells are the major gammadelta T cell subset recovered from lesions of patients with genital herpes.

Herpes simplex virus (HSV)-specific T cells are essential to control and resolve genital herpes (GH). To investigate the potential involvement of gamma delta T cells in GH, T cells were recovered and expanded, by mitogenic stimulation, to T cell lines from the genital lesions of 17 patients with GH and 5 control subjects who had other diseases. Relatively high numbers of gamma delta T cells--predominantly, V gamma 9V delta 2 T cells--were detected only in the T cell lines of the patients with GH.