Interferon-gamma-mediated antiviral immunity against orthopoxvirus infection is provided by gamma delta T cells. - Agrati C; Castilletti C; De Santis R; Cimini E; Bordi L; Malkovsky M; Poccia F; Capobianchi MR; Abate G; Eslick J; Newman FK; Frey SE; et al. (Journal of Infectious Diseases, 2006)