HIV-1 DNA levels in peripheral blood mononuclear cells and cannabis use are associated with intermittent HIV shedding in semen of men who have sex with men on successful antiretroviral regimens.

BACKGROUND: Few data exist on the efficacy of combined antiretroviral therapy (cART) in semen of human immunodeficiency virus type 1 (HIV-1) infected men who have sex with men (MSM) with sustained control of HIV replication in blood. METHODS: HIV-1 infected MSM on successful cART for >6 months were enrolled. HIV-RNA was quantified in seminal plasma (spVL) and in blood plasma (bpVL) from 2 paired samples collected 4 weeks apart. Relationship between spVL and bpVL (measured by an ultrasensitive assay, LOQ 10 copies/mL), total peripheral blood mononuclear cells (PBMC)-associated HIV-DNA, sexually transmitted infections (STIs), and self-reported socio-behavioral characteristics was assessed using GEE logistic regression. RESULTS: In total, 157 patients were included. Median time with bpVL <50 copies/mL was 3.3 years. spVL was detectable in 23/304 samples (prevalence 7.6%). Median spVL was 145 cp/mL (100-1475). spVL was detectable on the first, on the second, and on both samples in 5, 14, and 2 men, respectively. In sum, 33 individuals (21%) had STIs (asymptomatic in 24/33). Residual bpVL was undetectable by ultrasensitive assay in 225/300 samples (75%). After multivariable adjustments, PBMC-associated HIV-DNA (OR 2.6[1.2; 6.0], for HIV-DNA > 2.5 log10 cp/10(6) PBMC, P = .02), and cannabis use during sexual intercourse (OR 2.8[1.2; 6.7], P = .02) were the only factors associated significantly with spVL. CONCLUSION: We show that HIV-RNA can be detected intermittently in semen of HIV-1 infected MSM despite successful cART. The size of blood HIV-1 reservoir predicted spVL detection. Our results indicated also that the possible effect of cannabis should be taken into account when developing prevention interventions targeted toward HIV-infected MSM on successful cART.

Caspase-8 sumoylation is associated with nuclear localization.

The cysteine protease caspase-8 plays a pivotal role in the initiation of different apoptotic pathways and controls the maturation and differentiation of various cell types including neurons, fibroblasts and lymphocytes. Specific substrates of caspase-8 are present in both the cytoplasm and the nucleus, which may determine the ultimate biological effect of caspase-8. However, the mechanisms regulating the cellular localization of caspase-8 are still unknown. We show here that, in contrast to other caspases such as caspase-9 and -3, caspase-8 can be sumoylated at lysine 156. This sumoylation (i) is associated with the nuclear localization of caspase-8 and (ii) did not impair caspase-8 activation.