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MHC Class II (HLA-DRB and DQB) Allele Frequencies in Botswana: Association with HIV-1 Infection Thumbi Ndung'u*, Simani Gaseitsiwe, Enoch Sepako, Florence Doualla-Bell, Trevor Peter, Soyeon Kim, Ibou Thior, Vladimir A. Novitsky, and Max Essex Botswana-Harvard Partnership for HIV Research and Education, Private Bag BO320, Gaborone, Botswana Background: Southern Africa is facing an unprecedented public health crisis due to the high prevalence of the human immunodeficiency virus type 1 (HIV-1). Vaccine development and testing efforts are underway; mainly based on elicitation of HIV-specific T cells. To understand the role of human leukocyte antigens (HLA) class II alleles in HIV pathogenesis and to facilitate HLA-based HIV-1 vaccine design, we studied the frequencies of HLA class II alleles within the southern African country of Botswana. Methods and Results: Common HLA class II alleles were identified within the Botswana population through the molecular genotyping of DRB and DQB1 loci. The DRB1 allele groups DRB1*01, DRB1*02/15, DRB1*03, DRB1*11, and DRB1*13 were encountered at frequencies above 20%. Within the DQB1 locus, DQB1*06 (47.7.0%) was the most common allele group, followed by DQB1*03 (39.2%) and DQB1*04 (25.8%). We found that DRB1*01 was more common in HIV-negative than in HIV-positive individuals and that those who expressed DRB1*08 had lower median viral loads. Conclusion: We demonstrate that the frequencies of certain HLA class II alleles in this Batswana population differ substantially from North American populations including African Americans. Common allele groups within Botswana cover a large percentage of the population in other African populations and could be targeted in regional vaccine designs. KEYWORDS: MHC class II, HIV-1, HIV-1 vaccine, Botswana |