Retrovirology BioMed Central Open Access Oral presentation HIV-2 gene product-specific T cell responses and viraemia control Aleksandra Leligdowicz*1,2, Louis-Marie Yindom1, Assan Jaye1, Tao Dong2, Abraham Alabi1, Ramu Sarge-N'jie1, Harr Njai1, Andrew McMichael2, Hilton Whittle1 and Sarah Rowland-Jones1,2 Address: 1Medical Research Council Laboratories, Fajara, The Gambia and 2Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, Oxford, UK * Corresponding author from 2006 International Meeting of The Institute of Human Virology Baltimore, USA. 17–21 November, 2006 Published: 21 December 2006 Retrovirology 2006, 3(Suppl 1):S35 doi:10.1186/1742-4690-3-S1-S35 <supplement> <title> <p>2006 International Meeting of The Institute of Human Virology</p> </title> <note>Meeting abstracts. A single PDF containing all abstracts in this Supplement is available <a href=" http://www.biomedcentral.com/content/files/pdf/1742-4690-3-S1-full.pdf ">here</a></note> <url>http://www.biomedcentral.com/content/pdf/1742-4690-3-S1-info.pdf</url></supplement> © 2006 Leligdowicz et al; licensee BioMed Central Ltd. Background Conclusion HIV-2 infection is characterized by an attenuated disease course in most patients, which may reflect viraemia control by an efficient immune response. However, there is little information on the breadth, magnitude, or specificity of cellular immune responses to the proteome and their relationship to viral control. There is a strong relationship between HIV-2 VL and IFNg responses. VL ≤ 100 correlates with targeting Gag, with the 6 most frequently recognized peptides originating from a highly conserved region spanning 149 aa, suggesting that immune responses to this region play a role in HIV-2 viraemia control. Methods 105 freshly separated PBMCs from 64 members of a welldescribed community-based HIV-2 cohort (Caio, Guinea Bissau) were used in ex vivo IFNg ELISpot assays. 424 peptides spanning the HIV-2 proteome were divided into 3 × 24 pools in a 3-dimensional matrix (16–20 peptides/ pool, 2 μg/ml per peptide). Results All HIV-2 gene products induced IFNg responses, with Gag being targeted most frequently (89% of patients). The total proteome response inversely correlated with HIV-2 VL (p < 0.01) and this relationsAhip was due to targeting Gag (p < 0.01). Patients with VL ≤ 100 (N = 31) had a greater median gag-specific response (1120 vs 385 SFU, p < 0.01) than patients with VL ≥ 100 (N = 33). Responses to a single Gag peptide (recognized by >30% of patients) correlated with low VL (p = 0.05). Page 1 of 1 (page number not for citation purposes)