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A major barrier to curing HIV-1 is the long-lived latent reservoir that supports re-emergence of HIV-1 upon treatment interruption. Targeting this reservoir will require mechanistic insights into the establishment and maintenance of HIV-1 latency. Whether T cell signaling at the time of HIV-1 infection influences productive replication or latency is not fully understood. We used a panel of chimeric antigen receptors (CARs) with different ligand binding affinities to induce a range of signaling strengths to model differential T cell receptor signaling at the time of HIV-1 infection. Stimulation of T cell lines or primary CD4+ T cells expressing chimeric antigen receptors supported HIV-1 infection regardless of affinity for ligand; however, only signaling by the highest affinity receptor facilitated HIV-1 expression. Activation of chimeric antigen receptors that had intermediate and low binding affinities did not support provirus transcription, suggesting that a minimal signal is required for optimal HIV-1 expression. In addition, strong signaling at the time of infection produced a latent population that was readily inducible, whereas latent cells generated in response to weaker signals were not easily reversed. Chromatin immunoprecipitation showed HIV-1 transcription was limited by transcriptional elongation and that robust signaling decreased the presence of negative elongation factor, a pausing factor, by more than 80%. These studies demonstrate that T cell signaling influences HIV-1 infection and the establishment of different subsets of latently infected cells, which may have implications for targeting the HIV-1 reservoir. [ABSTRACT FROM AUTHOR]

Despite advances in antiretroviral therapy, HIV-1 infection remains incurable in patients and continues to present a significant public health burden worldwide. While a number of factors contribute to persistent HIV-1 infection in patients, the presence of a stable, long-lived reservoir of latent provirus represents a significant hurdle in realizing an effective cure. One potential strategy to eliminate HIV-1 reservoirs in patients is reactivation of latent provirus with latency reversing agents in combination with antiretroviral therapy, a strategy termed “shock and kill”. This strategy has shown limited clinical effectiveness thus far, potentially due to limitations of the few therapeutics currently available. We have identified a novel class of benzazole compounds effective at inducing HIV-1 expression in several cellular models. These compounds do not act via histone deacetylase inhibition or T cell activation, and show specificity in activating HIV-1 in vitro. Initial exploration of structure-activity relationships and pharmaceutical properties indicates that these compounds represent a potential scaffold for development of more potent HIV-1 latency reversing agents. [ABSTRACT FROM AUTHOR]

Background: HIV-infected individuals may be at increased risk of poor physical function. Chronic inflammation has been associated with decreased physical function in the elderly and may also influence physical function in HIV-infected individuals. Methods: This cross-sectional study assessed physical function in 65 HIV-infected women aged 40 and older on stable antiretroviral treatment using the Short Physical Performance Battery (SPPB): a standardized test of balance, walking speed, and lower- extremity strength developed for elderly populations. The relationship between low SPPB score, selected demographic and medical characteristics, and high inflammatory biomarker profile was analyzed using Fisher's exact test and Wilcoxon rank sum test. Results: The median age of subjects was 49 years (interquartile range [IQR] 45-55), and the median CD4 T-cell count was 675 cells/mm3 (IQR 436-828). Thirteen subjects (20%) had a low SPPB score. Subjects with a low SPPB score were more likely to be cigarette smokers ( p=0.03), had more medical comorbidities ( p=0.01), and had higher levels of interleukin-6 (IL-6) ( p<0.05). They also tended to be older (median age 55 vs. 48, p=0.06), more likely to have diabetes ( p=0.07), and have higher levels of soluble tumor necrosis factor-1 ( p=0.09). Conclusions: Twenty percent of women aged 40 and older with well-treated HIV had poor physical-function performance, which was associated with the high burden of comorbidities in this population and with increased IL-6. However, it is unclear from this cross-sectional study whether increased inflammation was related to poor physical function or to other factors, such as age and medical comorbidities. [ABSTRACT FROM AUTHOR]

Periodontal infections contribute to HIV-associated co-morbidities in the oral cavity and provide a model to interrogate the dysregulation of macrophage function, inflammatory disease progression, and HIV replication during co-infections. We investigated the effect of Porphyromonas gingivalis on the establishment of HIV infection in monocyte-derived macrophages. HIV replication in macrophages was significantly repressed in the presence of P. gingivalis . This diminished viral replication was due partly to a decrease in the expression of integrated HIV provirus. HIV repression depended upon signaling through TLR4 as knock-down of TLR4 with siRNA rescued HIV expression. Importantly, HIV expression was reactivated upon removal of P. gingivalis. Our observations suggest that exposure of macrophages to Gram-negative bacteria influence the establishment and maintenance of HIV persistence in macrophages through a TLR4-dependent mechanism. [ABSTRACT FROM AUTHOR]