Scientific Publications by FDA Staff

AIDS Res Hum Retroviruses 2007 Aug;23(8):1008-19

Identification of a Novel Circulating Recombinant Form (CRF) 36_cpx in Cameroon That Combines Two CRFs (01_AE and 02_AG) with Ancestral Lineages of Subtypes A and G.

Powell RL, Zhao J, Konings FA, Tang S, Nanfack A, Burda S, Urbanski MM, Saa DR, Hewlett I, Nyambi PN

Nyambi PN (reprint author), NYU, VA Med Ctr, Dept Pathol, Sch Med, 423 E 23rd St,Room 18124N, New York, NY 10010 USA NYU, VA Med Ctr, Dept Pathol, Sch Med, New York, NY 10010 USA NYU, Sch Med, Dept Microbiol, New York, NY 10010 USA US FDA, Mol Virol Lab, Div Emerging & Transfus Transmitted Dis, Bethesda, MD 20892 USA Lab Sante Hyg Mobile, Yaounde, Cameroon Minist Publ Hlth, Yaounde, Cameroon Vet Affairs New York Harbor Healthcare Syst, New York, NY USA

An array of CRFs have been identified in Cameroon, the most notable being CRF02_AG. HIV-1 in the East Province of Cameroon is particularly diverse: in a recent study, we found a high proportion of unique recombinant forms (URFs). Herein we describe the analysis of the full-length sequences of two of these URFs, which, after preliminary analysis of gag, pol, and env fragments, appeared to be a novel CRF. This novel strain, CRF36_cpx, contains fragments that can be assigned to the CRF01_AE, CRF02_AG, and subtype A and G radiations. Forty percent of the genome can be classified as CRF02_AG, including regions in gag, pol, env, and the accessory genes. Twenty-seven percent is CRF01_AE, comprising the majority of gag, the beginning of env, and the end of env into the 3' LTR. Twenty percent of the genome can be assigned to subtype A, with segments in pol and env. The remaining 13% of the sequence is classifiable as subtype G, in pol and vpu. The subtype A and G lineages formed by the CRF36_cpx sequences are unique and appear ancestral in nature. CRF36_cpx is both the first to combine more than one CRF and the first to include fragments of CRF02_AG. The ancestral sequences present in CRF36_cpx represent a link to extinct strains, and, potentially, insight into the evolution of HIV-1.