EXCEED THE SPACE PROVIDED. Human immunodeficiency virus (HIV) infection ranks in the top five causes of death globally and presents a major threat to public health. By using antiretroviral drug combination (Highly Active Antiretroviral Therapy), HAART has been effective in dramatically reducing HIV-related mortality and morbidity. However, nearly half of HIV-infected patients still fail HAART. Although genetic analyses of viral genomes from these patients show multiple-drug resistance mutations in vrial pol gene, the molecular mechanisms for the emergence of drug-resistance are not yet known. Therefore, it is important to define the mechanisms for multiple-drug resistance in order to more efficiently control HIV infection. Here, we propose to study the role of viral recombination in the generation of multiple-drug resistance during HAART. We have established a prospective clinical cohort and developed methods to analyze recombinant viral genomes within an infected individual.
Specific aims of this proposal are: (i) We will genetically characterize the baseline viral population and determine their predictive values for treatment failure by sequencing multiple clones from each patient before HAART treatment. (ii) To determine the role of recombination in generation of multiple-drug resistance, we will compare the drug-resistant viral population with the baseline viral population and identify recombinant genomes and recombinant index increase of the viral population from the patients who fail HAART. Viral populations before and after each treatment failure in the consecutive HAART regimes will be obtained. (iii) We will analyze the dynamic viral population changes and determine the repeated drug-resistance mechanisms and fitness of drug-resistance viruses during the salvage treatment regimens. (iv) We will experimentally determine the multiple-drug resistance mechanism and recombination rate in vitro by co-infecting single-drug resistance viruses into single cells in a single round infection system. Understanding the viral population changes, drug-resistance mechanisms and viral fitness during HAART will allow for the development of more effective antiretroviral agents, better treatment regimens and accurate prediction of treatment efficacy. Knowledge learned from this study can be broadly applicable to viral escape from immune surveillance and other selective forces. PERFORMANCE SITE ========================================Section End===========================================
