- Human immunodeficiency virus contains an epitope immunoreactive with thymosin alpha 1 and the 30-amino acid synthetic p17 group-specific antigen peptide HGP-30. Naylor, P.H., Naylor, C.W., Badamchian, M., Wada, S., Goldstein, A.L., Wang, S.S., Sun, D.K., Thornton, A.H., Sarin, P.S. Proc. Natl. Acad. Sci. U.S.A. (1987)