Current opinion in HIV and AIDS最新文献

Purpose of review: The intricate interplay between HIV and the host microbiota has emerged as a significant area of investigation with therapeutic potential. Despite numerous studies on this complex interaction in adults, vertically acquired infections, which have distinct immunological and virological characteristics, remain relatively understudied.

Recent findings: Disturbances, including prolonged exposure to HIV and antiretroviral therapy, significantly impact the gut microbiome, though isolating these effects from other influencing factors is challenging. Children and adolescents living with HIV exhibit reduced microbiome diversity and potential imbalances between beneficial and pathogenic taxa. However, most available data focus on microbiome composition rather than function. The observed variations in specific microbial phyla are intriguing, but their health effects are unknown. Although modulating the microbiota may be theoretically easier during childhood, few interventional trials have included children.

Summary: Therapeutic interventions aimed at modulating the gut microbiome in children with HIV have shown limited impact, and their ability to induce long-term microbiome changes remains uncertain. A more functional, longitudinal approach, along with an ecological perspective, is needed to understand the complex interplay between the microbiome and the host. This will help clarify the relevance of microbiota alterations and their potential implications for clinical outcomes, such as inflammation and immune reconstitution in pediatric HIV.

Purpose of review: To review novel experimental approaches for studying host:microbe interactions and their role in intestinal and systemic inflammation in people living with HIV (PLWH).

Recent findings: Inflammation in PLWH is impacted by interactions between the microbiome, the intestinal epithelium, and immune cells. This complex interplay is not fully understood and requires a variety of analytical techniques to study. Using a multiomic systems biology approach provides hypothesis generating data on host:microbe interactions that can be used to guide further investigation. The direct interactions between host cells and microbes can be elucidated using peripheral blood mononuclear cells (PBMCs), lamina propria mononuclear cells (LPMC's) or human intestinal organoids (HIO). Additionally, the broader relationship between the host and the microbiome can be explored using animal models such as nonhuman primates and germ-free and double humanized mice.

Summary: To explore complex host:microbe relationships, hypotheses are generated and investigations are guided by multiomic data, while causal components are identified using in-vitro and in-vivo assays.

Purpose of review: The penile microbiome has been linked to local inflammation and increased risk for sexually transmitted infections, including HIV. This review explores recent studies of this emerging area of HIV research.

Recent findings: The male urogenital tract supports multiple distinct niches, where their associated microbiome are shaped by abiotic (e.g., oxygen, moisture) and biotic (e.g., host immunity) environmental factors and host behaviors, particularly sexual activity. In addition, male circumcision is a significant drivers of male genital microbiome in both children and adults. Recent sexual partner studies provide new insight into the exchange of genital bacteria and concurrent local immune changes that may impact HIV risk.

Summary: The male genital microbiome is shaped by the local microenvironment and host behaviors including sexual activity. Improving our understanding of the connection between the male genital microbiome, local inflammation, and HIV susceptibility, as well as how pro-inflammatory genital bacteria are transmitted between sexual partners may inform new strategies to prevent HIV transmission.

Purpose of review: Dysbiosis may be a key driver of systemic inflammation, which increases the risk of non-AIDS events in people living with HIV (PLWH). Modulation of the microbiome to reverse this dysbiosis may be a novel approach to decrease inflammation and therefore morbidity and mortality in PLWH.

Recent findings: Fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, postbiotics, and dietary modifications have the potential to modulate the microbiome. These interventions have been well tolerated in clinical trials to date. However, these interventions have not resulted in consistent or lasting changes to the microbiome or consistent changes in biomarkers of intestinal permeability, microbial translocation, inflammation, immune activation, or CD4 + T cell counts. Sustained engraftment may require prebiotics and/or dietary modifications added to either probiotics or FMT.

Summary: Adequately powered randomized controlled trials are needed to elucidate whether microbiome modulation can be achieved and impact systemic inflammation in PLWH.

Purpose of review: To unravel the current knowledge and possible link between the gut microbiome and HIV-1 virological control in elite controllers (EC), who can suppress viral replication in the absence of antiretroviral therapy. In addition, to discuss the limitations of current research and propose future research directions.

Recent findings: EC possess a different gut bacterial microbiota profile in composition and functionality from that of treatment-naive HIV-1 viremic progressors (VP). Specifically, EC have a richer bacterial microbiota as compared to VP, which closely resembles the microbiota in HIV-1 negative healthy controls (HC). Differentially abundant bacteria are found between EC and VP or HC, though results vary among the few existing studies. These data imply that the gut microbiome could contribute to the natural suppression of HIV-1 infection.

Summary: An association between the gut microbiome and HIV-1 virological control is evidenced by recent studies. Yet, there are substantial knowledge gaps, and the underlying mechanism of how the microbiome influences the EC phenotype is far from clarified. Future research should consider diverse microbial communities, the complex microbe-host interactions, as well as yet-unidentified causal links between microbiome alterations and HIV-1 disease progression.

Purpose of review: Among women, having a nonoptimal, highly diverse vaginal microbiome dominated by bacteria other than optimal Lactobacillus species such as L. crispatus or L. jensenii predicts HIV transmission. Reducing HIV acquisition among women requires a better understanding of the mechanisms through which the vaginal microbiome impacts HIV transmission dynamics and how to more effectively treat and intervene. Technological advancements are improving the ability of researchers to fully characterize interacting host-bacteria mechanisms. Consequently, the purpose of this review was to summarize the most innovative research on the vaginal microbiome and its role in HIV transmission in the past year.

Recent findings: Studies combining multiomics, experimental, and translational approaches highlight the associations of a nonoptimal microbiome with maladaptive alterations in immune cell functioning, vaginal metabolites, host cell transcription, mucosal immunity, and epithelial barrier integrity. While there are multiple mechanisms proposed to increase HIV acquisition risk, there are virtually zero acceptable and effective treatments to improve the vaginal microbiome and immunity.

Summary: Women-centered solutions to modify the vaginal microbiome and bacterial metabolites should continue to be explored as a mechanism to reduce HIV acquisition.

Purpose of review: To report recent evidence on associations between human microbiome, particularly airway and gut, and pulmonary comorbidities in people with HIV (PWH). Furthermore, we explore how changes in the microbiome may contribute to pulmonary immune dysregulation and higher rates of pulmonary comorbidities among PWH. Finally, we propose future directions in the field.

Recent findings: Increased risk of pulmonary comorbidities and rapid lung function decline have been reported in even well treated PWH. Altered microbiota profiles have been reported in PWH with pulmonary comorbidities and rapid lung function decline as compared to those without. The most consistent data have been the association between HIV-related pulmonary comorbidities, lung and oral microbiota dysbiosis, which has been also associated with distinct respiratory mucosal inflammatory profiles and short-term mortality. However, a possible causal link remains to be elucidated.

Summary: Associations between the lung and oral microbiome, HIV-associated pulmonary comorbidities and rapid lung function decline have been reported in recent studies. Yet the underlying mechanism underpinning the observed associations is largely unknown and substantial knowledge gaps remain. Future research is warranted to unveil the role and mechanism of human microbiome from different anatomical compartments in relation to pulmonary comorbidities in PWH.

Purpose of review: The primate microbiome consists of bacteria, eukaryotes, and viruses that dynamically shape and respond to host health and disease. Understanding how the symbiotic relationship between the host and microbiome responds to HIV has implications for therapeutic design.

Recent findings: Advances in microbiome identification technologies have expanded our ability to identify constituents of the microbiome and to infer their functional capacity. The dual use of these technologies and animal models has allowed interrogation into the role of the microbiome in lentiviral acquisition, vaccine efficacy, and the response to antiretrovirals. Lessons learned from such studies are now being harnessed to design microbiome-based interventions.

Summary: Previous studies considering the role of the microbiome in people living with HIV largely described viral acquisition as an intrusion on the host:microbiome interface. Re-framing this view to consider HIV as a novel, albeit unwelcome, component of the microbiome may better inform the research and development of pre and postexposure prophylaxes.

Purpose of review: Although current treatment could eradicate vertical transmission, in 2022, 130 000 infants acquired HIV globally. HIV suppression with antiretroviral therapy (ART) transforms survival for people living with HIV (PLWH), and prevents transmission, including vertical. International guidelines recommend lifelong ART for PLWH, consequently perinatal HIV acquisition reflects implementation gaps in the HIV care cascade. We summarize these gaps, exploring potential novel approaches and therapeutic innovations towards eliminating vertical HIV transmission.

Recent findings: Multifactorial challenges continue to underpin gaps in the HIV care cascade, including accessibility, availability and sustainability of HIV testing, prevention and treatment, alongside stigma, gender-based violence and poverty. Long-acting ART may be important in preventing perinatal HIV acquisition, with early data demonstrating tolerability and efficacy of injectable ART throughout pregnancy, both as HIV treatment and prevention. Carefully selected long-acting broadly neutralizing antibodies (bNAbs) matching circulating, exposing viral envelope sequences have demonstrated safety, clinical trials are ongoing to demonstrate efficacy.

Summary: Emerging clinical studies should prioritize pregnant/lactating people and infants to ensure such therapies are well tolerated and efficacious. Alongside therapeutic innovation, programmatic strategies must address social and economic challenges, ensuring sustainable HIV treatment/prevention programmes and facilitating global elimination of blood-borne viruses.