Evidence for Possible Biological Advantages of the Newly Emerging HIV-1 Circulating Recombinant Form from Malaysia - CRF33_01B in Comparison to its Progenitors _ CRF01_AE and Subtype B

• Main Authors: Lau, Katherine A., Wang, Bin, Miranda-Saksena, Monica, Boadle, Ross, Kamarulzaman, Adeeba, Ng, Kee Peng, Saksena, Nitin K.
• Format: Article
• Published: Bentham Science Publishers 2010
• Subjects: R Medicine
• Online Access: http://eprints.um.edu.my/4568/; https://doi.org/10.2174/157016210791111151

In Malaysia, co-circulation of CRF01_AE and subtype B has resulted in the emergence of the second generation derivative; CRF33_01B in approximately 20% of its HIV-1 infected individuals. Our objective was to identify possible biological advantages that CRF33_01B possesses over its progenitors. Biological and molecular comparisons of CRF33_01B against its parental subtypes clearly show that CRF33_01B replicated better in activated whole peripheral blood mononuclear cells (PBMCs) and CD4+ T-lymphocytes, but not monocyte-derived macrophages (MDMs). Also, its acquired fitness was greater than CRF01_AE but not subtype B. Moreover, CRF33_01B has higher rate of apoptotic cell death and syncytia induction compared to subtype B. These adaptive and survival abilities could have been acquired by CRF33_01B due to the incorporation of subtype B fragments into the gag-RT region of its full-length genome. Our studies confirm the previously held belief that HIV-1 strains may harbor enhanced biological fitness upon recombination. We therefore estimate a possible gradual replacement of the current predominance of CRF01_AE, as well as wider dissemination of CRF33_01B, together with the identification of other new CRF01_AE/B inter-subtype recombinants in Malaysia.