A Novel in vitro Assay to Measure Stochastic Reactivation of HIV-1 from Resting CD4+ T Cells: Implications for Measuring the Size of the Latent Reservoir in Infected Patients

HIV-1;latency;cure;assays;Cellular & Molecular Medicine

Hosmane, NinaBlankson, Joel N. ;

Johns Hopkins University

关键词: HIV-1;    latency;    cure;    assays;    Cellular & Molecular Medicine;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/59381/HOSMANE-DISSERTATION-2016.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Human Immunodeficiency Virus-1 (HIV-1) is an enveloped retrovirus that preferentially infects activated CD4+ T helper lymphocytes. After completion of reverse transcription, HIV-1 cDNA integrates into the host genome. Latency arises when HIV-1 infects an activated CD4+ T cell as the cell is returning back to a resting memory state. Critical host cell transcription factors, NFκB and NFAT, are also required for HIV-1 transcription, but are inactive in resting T cells. This results in a stably integrated but transcriptionally silent form of the viral genome in a long-lived memory CD4+ T cell. Activation of a latently infected resting memory CD4+ T cell can give rise to replication-competent virus. Longitudinal analyses of latently infected cells purified from infected patients suppressed on ART (combination antiretroviral therapy) demonstrated that this infected cell population has a long half-life of 44 months and requires life-long ART to eliminate all infected cells. Therefore, the stability of the latent reservoir is the major barrier to curing HIV-1 infection. While there have been major efforts in the field to discover therapeutic strategies to reverse latency in order to reduce or eliminate the reservoir, there is a lack of an assay that can accurately quantify the true size of the latent reservoir. Without a reliable measure, eradication clinical trials will not be able to determine whether or not there has been a true reduction in the frequency of latently infected cells harboring replication-competent virus. Here, I describe the advantages and disadvantages of current assays used in the field to measure the size of the latent reservoir. In addition, my thesis research involved developing a novel in vitro assay that provides a more accurate measure of the size of the latent reservoir of replication-competent virus. This work has revealed that latently infected cells, including clonally expanded cells, release replication-competent virus in a stochastic manner after multiple rounds of maximal T cell activation. My work highlights the need to develop additional assays that accurately measure the size of the latent reservoir and suggests the need to address reservoir elimination strategies that include targeting clonally expanded latently infected cells harboring replication-competent viruses.