Cytomegalovirus Replication in Semen Is Associated with Higher Levels of Proviral HIV DNA and CD4 ⁺ T Cell Activation during Antiretroviral Treatment

Abstract

Asymptomatic cytomegalovirus (CMV) replication occurs frequently in the genital tract in untreated HIV-infected men and is associated with increased immune activation and HIV disease progression. To determine the connections between CMV-associated immune activation and the size of the viral reservoir, we evaluated the interactions between (i) asymptomatic seminal CMV replication, (ii) levels of T cell activation and proliferation in blood, and (iii) the size and transcriptional activity of the HIV DNA reservoir in blood from 53 HIV-infected men on long-term antiretroviral therapy (ART) with suppressed HIV RNA in blood plasma. We found that asymptomatic CMV shedding in semen was associated with significantly higher levels of proliferating and activated CD4 ؉ T cells in blood (P < 0.01). Subjects with detectable CMV in semen had approximately five times higher average levels of HIV DNA in blood CD4؉ T cells than subjects with no CMV. There was also a trend for CMV shedders to have increased cellular (multiply spliced) HIV RNA transcription (P ‫؍‬ 0.068) compared to participants without CMV, but it is unclear if this transcription pattern is associated with residual HIV replication. In multivariate analysis, the presence of seminal plasma CMV (P ‫؍‬ 0.04), detectable 2-long terminal repeat (2-LTR), and lower nadir CD4 ؉ (P < 0.01) were independent predictors of higher levels of proviral HIV DNA in blood. Interventions aimed at reducing seminal CMV and associated immune activation may be important for HIV curative strategies. Future studies of anti-CMV therapeutics will help to establish causality and determine the mechanisms underlying these described associations. IMPORTANCEAlmost all individuals infected with HIV are also infected with cytomegalovirus (CMV), and the replication dynamics of the two viruses likely influence each other. This study investigated interactions between asymptomatic CMV replication within the male genital tract, levels of inflammation in blood, and the size of the HIV DNA reservoir in 53 HIV-infected men on long-term antiretroviral therapy (ART) with suppressed HIV RNA in blood plasma. In support of our primary hypothesis, shedding of CMV DNA in semen was associated with increased activation and proliferation of T cells in blood and also significantly higher levels of HIV DNA in blood cells. These results suggest that CMV reactivation might play a role in the maintenance of the HIV DNA reservoir during suppressive ART and that it could be a target of pharmacologic intervention in future studies.

Replication of Human Herpesviruses Is Associated with Higher HIV DNA Levels during Antiretroviral Therapy Started at Early Phases of HIV Infection

“…Cycling conditions for this PCR were 10 min at 95°C, 60 cycles consisting of a 30-s denaturation at 94°C followed by a 60°C extension for 60 s, and a final 10 min at 98°C. Copy numbers were calculated as the means of replicate PCR measurements and normalized to total RNA as determined by A 260 /A 280 absorptivity ratio using a NanoDrop 2000 spectrophotometer (Thermo Scientific) (10).…”

“…ϩ T cells (10,14). This cross-sectional study had a number of limitations which may have confounded the analysis, including the lack of longitudinal data and missing information about timing of HIV infection, ART history, and dynamics of viral suppression.…”

“…Further, chronic inflammation and immune activation modulate both HIV replication and T-cell proliferation and contribute to the maintenance of the HIV DNA reservoir even during ART (5)(6)(7). Similar to the case with HIV, asymptomatic replication of human herpesviruses (HHV) also mediates immune activation (8)(9)(10). This can be important since subclinical bursts of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivation are common among HIV-infected individuals, even those with high CD4 ϩ T-cell counts and those receiving effective ART (11).…”

Asymptomatic CMV Replication During Early Human Immunodeficiency Virus (HIV) Infection Is Associated With Lower CD4/CD8 Ratio During HIV Treatment

“…HIV-infected individuals who are seronegative for CMV show better immune recovery following ART initiation than do HIV-infected persons coinfected with CMV [15]. In persons with HIV and CMV coinfection, the presence of detectable CMV replication is associated with increased activation, proliferation, and exhaustion of T cells [16,17], but the effect of subclinical CMV replication on CD4/CD8 dynamics after early initiation of ART is unknown. Similarly to CMV, Epstein-Barr virus (EBV) is another herpesvirus that establishes lifelong infection, has almost universal prevalence among HIV-infected people, and has recurrent reactivation; EBV coinfection has not been associated with lower CD4/CD8 ratio.…”

The Association of Human Cytomegalovirus with Biomarkers of Inflammation and Immune Activation in HIV-1-Infected Women

“…25 Several studies in HIV-1-infected men have used semen specimens to establish an association between CMV shedding and both HIV-1 shedding and increased levels of HIV-1 proviral DNA. [26][27][28][29][30] Others have reported detectable levels of CMV DNA in CVL, saliva, and peripheral blood mononuclear cells (PBMCs). 25,31,32 However, immunological markers of CMV infection in blood specimens have shown significant associations with biomarkers of inflammation and non-AIDSdefining events.…”