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Abstract
Identification of HIV-1C gag and nef specific elispot based T-lymphocytes responses in infected Indian individuals
Vajpayee M.1, Mendiratta S.1, Kaushik S.1
Objectives: T cell immune responses to Gag have been most frequently linked to control of viremia whereas CTL responses to Nef have direct relationship with viral load. It is important to characterize these responses with the aim of identifying protective correlates of immunity for successful implementation of an immunotherapeutic strategy to control HIV-1 infection in Indian population.
Methods: We performed a comprehensive analysis of the T cell immune responses directed at HIV-1 subtype C Gag and Nef proteins in 30 ART-naïve; chronic HIV-1 infected Indian individuals using IFN-g ELISpot assay for HIV-1 Gag and Nef at both matrix and single peptide level.
Results: Gag and Nef antigens were responded respectively by 73.3% and 90% of the study population. A mean of 2.73 epitopes were recognized for Nef in contrast to 2.03 for Gag. Increasing values for HIV-1C Gag specific T- cell responses were correlated with decreasing values of plasma viral load(r=-0.752,p value=.019). In contrast higher Nef specific responses were correlated with higher plasma viral load(r=.029,p value =0.945) The mean frequency of Nef specific responses (1064 SFC/106PBMC) correlated with the number of epitopes recognized (R = 0.83, P = 0.00) Similarly mean magnitude of responses for Gag antigen (699 SFC/106 cells) correlates significantly with the breadth (R = 0.70, P = 0.00). The conserved immunodominant region of Nef protein (Nef 73-95:QVPLRPMTYKAAFDLSFFLKEKG) and (Nef 129-143: PGPGVRYPLTFGWCF) were identified by 69.5% and 26% of the studied population whereas (Gag 17-31,p17; EKIRLRPGGKKHYML), (Gag 260-274,p24;DIYKRWIILGLNKIV) & ( Gag 348-362 ;TACQGVGGPSHKARV) were identified by 13% each.
Conclusions: Immunodominant regions, particularly directed to Gag and Nef, and Correlation among Viral load, Magnitude and Breadth of response merit further consideration, for vaccine design. All the identified immunodominant regions are also correlated with HIV Immunology database (Los Alamos) indicating the importance of Gag and Nef-specific responses in multi-clade vaccine approach.
4th IAS Conference on HIV Pathogenesis, Treatment and Prevention
Abstract no.
CDA009
Suggested Citation
"VajpayeeM., et al.
Identification of HIV-1C gag and nef specific elispot based T-lymphocytes responses in infected Indian individuals.
:
4th IAS Conference on HIV Pathogenesis, Treatment and Prevention:
Abstract no.
CDA009"
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