Self-DNA Sensing Fuels HIV-1-Associated Inflammation

Nonnegligible Contribution of Nonlymphoid Tissue to Viral Reservoir During the Short-Term Early cART in SIVmac239-Infected Chinese Rhesus Macaques

HIV/AIDS cannot be cured because of the persistence of the viral reservoir. Because of the complexity of the cellular composition and structure of the human organs, HIV reservoirs of anatomical site are also complex. Recently, although a variety of molecules have been reported to be involved in the establishment and maintenance of the viral reservoirs, or as marker of latent cells, the research mainly focuses on blood and lymph nodes. Now, the characteristics of the viral reservoir in tissue are not yet fully understood. In this study, various tissues were collected from SIVmac239-infected monkeys, and the level of total SIV DNA, SIV 2-LTR DNA, and cell-associated virus RNA in them were compared with character of the anatomical viral reservoir under early treatment. The results showed that short-term combination antiretroviral therapy (cART) starting from 3 days after infection could significantly inhibit viremia and reduce the size of the anatomical viral reservoir, but it could not eradicate de novo infections and ongoing replication of virus. Moreover, the effects of early cART on the level of total SIV DNA, SIV 2-LTR DNA, and cell-associated virus RNA in different tissues were different, which changed the size distribution of viral reservoir in anatomical site. Finally, the contribution of nonlymphoid tissues, especially liver and lung, to the viral reservoir increased after treatment, while the contribution of intestinal lymphoid to the viral reservoir significantly reduced. These results suggested that early treatment effectively decreased the size of viral reservoir, and that the effects of cART on the tissue viral reservoir varied greatly by tissue type. The results implied that persistent existence of virus in nonlymphoid tissues after short-term treatment suggested that the role of nonlymphoid tissues cannot be ignored in development strategies for AIDS therapy.

Self-DNA driven inflammation in COVID-19 and after mRNA-based vaccination: lessons for non-COVID-19 pathologies

The coronavirus disease 2019 (COVID-19) pandemic triggered an unprecedented concentration of economic and research efforts to generate knowledge at unequalled speed on deregulated interferon type I signalling and nuclear factor kappa light chain enhancer in B-cells (NF-κB)-driven interleukin (IL)-1β, IL-6, IL-18 secretion causing cytokine storms. The translation of the knowledge on how the resulting systemic inflammation can lead to life-threatening complications into novel treatments and vaccine technologies is underway. Nevertheless, previously existing knowledge on the role of cytoplasmatic or circulating self-DNA as a pro-inflammatory damage-associated molecular pattern (DAMP) was largely ignored. Pathologies reported 'de novo' for patients infected with Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 to be outcomes of self-DNA-driven inflammation in fact had been linked earlier to self-DNA in different contexts, e.g., the infection with Human Immunodeficiency Virus (HIV)-1, sterile inflammation, and autoimmune diseases. I highlight particularly how synergies with other DAMPs can render immunogenic properties to normally non-immunogenic extracellular self-DNA, and I discuss the shared features of the gp41 unit of the HIV-1 envelope protein and the SARS-CoV 2 Spike protein that enable HIV-1 and SARS-CoV-2 to interact with cell or nuclear membranes, trigger syncytia formation, inflict damage to their host's DNA, and trigger inflammation - likely for their own benefit. These similarities motivate speculations that similar mechanisms to those driven by gp41 can explain how inflammatory self-DNA contributes to some of most frequent adverse events after vaccination with the BNT162b2 mRNA (Pfizer/BioNTech) or the mRNA-1273 (Moderna) vaccine, i.e., myocarditis, herpes zoster, rheumatoid arthritis, autoimmune nephritis or hepatitis, new-onset systemic lupus erythematosus, and flare-ups of psoriasis or lupus. The hope is to motivate a wider application of the lessons learned from the experiences with COVID-19 and the new mRNA vaccines to combat future non-COVID-19 diseases.

Inflammasomes as mediators of inflammation in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) infection is a chronic disease without a known cure. The advent of effective antiretroviral therapy (ART) has enabled people with HIV (PWH) to have significantly prolonged life expectancies. As a result, morbidity and mortality associated with HIV-1 infection have declined considerably. However, these individuals experience chronic systemic inflammation whose multifaceted etiology is associated with other numerous comorbidities. Inflammasomes are vital mediators that contribute to inflammatory signaling in HIV-1 infection. Here, we provide an overview of the inflammatory pathway that underlies HIV-1 infection, explicitly highlighting the role of the NLRP3 inflammasome. We also delineate the current literature on inflammasomes and the therapeutic targeting strategies aimed at the NLRP3 inflammasome to moderate HIV-1 infection-associated inflammation. Here we describe the NLRP3 inflammasome as a key pathway in developing novel therapeutic targets to block HIV-1 replication and HIV-1-associated inflammatory signaling. Controlling the inflammatory pathways is critical in alleviating the morbidities and mortality associated with chronic HIV-1 infection in PWH.

Efficacy and safety of traditional Chinese herbal medicine combined with HAART in the treatment of HIV/AIDS: A protocol for systematic review and meta-analysis

BACKGROUND

Acquired immunodeficiency syndrome (AIDS) is one of the infectious diseases pandemic in the word. Traditional Chinese herbal medicine, as an alternative and complementary therapy of highly active antiretroviral therapy (HAART), has been put into the treatment of human immunodeficiency virus (HIV)/AIDS over 30 years due to its good therapeutic effects and high safety, while there is a lack of evidence-based medicine support. The purpose of this study is to explore the efficacy and safety of traditional Chinese herbal medicine combined with HAART for HIV/AIDS patients.

METHODS

We will search all randomized controlled trials of Chinese herbal medicine combined with HAART in the treatment of HIV/AIDS from electronic databases including PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, WanFang, China Science and Technology Journal Database and Chinese Biomedical Literature Database from inception to December 31, 2021. Literature screening will be conducted through EndNote software, and data extraction will be processed according to inclusion and exclusion criteria by two independent researchers. We will use Review Manager 5.4 and Stata 16 software for data analysis and publication bias test.

RESULTS

This systematic review and meta-analysis will provide a high-quality evidence for the efficacy and safety of traditional Chinese herbal medicine combined with HAART in the treatment of HIV/AIDS.

CONCLUSION

The conclusion of this review will provide an objective assessment to evaluate whether Chinese herbal medicine integrated with HAART has the effect of improving the efficiency and depressing the toxicity.

REGISTRATION NUMBER

INPLASY2021110082.

Diabetes induces macrophage dysfunction through cytoplasmic dsDNA/AIM2 associated pyroptosis

Diabetes is emerging as a severe global health problem that threatens health and increases socioeconomic burden. Periodontal impairment is one of its well-recognized complications. The destruction of the periodontal defense barrier makes it easier for periodontal pathogens to invade in, triggering a greater inflammatory response, and causing secondary impairment. Macrophages are the major immune cells in periodontium, forming the frontier line of local innate immune barrier. Here, we explored the periodontal impairments and functional changes of macrophages under the diabetic and aging conditions. Besides, we further explored the molecular mechanism of how hyperglycemia and aging contribute to this pathogenesis. To test this, we used young and aged mice to build diabetic mice, and metformin treatment was applied to a group of them. We demonstrated that under hyperglycemia conditions, macrophage functions, such as inflammatory cytokines secretion, phagocytosis, chemotaxis, and immune response, were disturbed. Simultaneously, this condition elevated the local senescent cell burden and induced secretion of senescence-associated secretory phenotype. Meanwhile, we found that expressions of Gasdermin D (GSDMD) and caspase-1 were up-regulated in diabetic conditions, suggesting that the local senescent burden and systemic proinflammatory state during diabetes were accompanied by the initiation of pyroptosis. Furthermore, we found that the changes in aged condition were similar to those in diabetes, suggesting a hyperglycemia-induced pre-aging state. In addition, we show that metformin treatment alleviated and remarkably reversed these functional abnormalities. Our data demonstrated that diabetes initiated macrophage pyroptosis, which further triggered macrophage function impairments and gingival destructions. This pathogenesis could be reversed by metformin.

Post-translational modification control of viral DNA sensors and innate immune signaling

The vertebrate innate immune system confers host cells with mechanisms to protect against both evolutionarily ancient pathogens and newly emerging pathogenic strains. Innate immunity relies on the host cell's ability to distinguish between self and pathogen-derived molecules. To achieve this, the innate immune system uses germline encoded receptors called pattern recognition receptors (PRRs), which recognize various molecular signatures, including nucleic acids, proteins, lipids, glycans and glycolipids. Among these molecules, the recognition of pathogenic, mislocalized, or damaged DNA by cellular protein receptors, commonly called DNA sensors, represents a major surveillance pathway for initiating immune signaling. The ability of cells to temporally regulate DNA sensor activation and subsequent signal termination is critical for effective immune signaling. These same mechanisms are also co-opted by pathogens to promote their replication. Therefore, there is significant interest in understanding DNA sensor regulatory networks during microbial infections and autoimmune disease. One emerging aspect of DNA sensor regulation is through post-translational modifications (PTMs), including phosphorylation, acetylation, ubiquitination, ADP-ribosylation, SUMOylation, methylation, deamidation, glutamylation. In this chapter, we discuss how PTMs have been shown to positively or negatively impact DNA sensor functions via diverse mechanisms, including direct regulation of enzymatic activity, protein-protein and protein-DNA interactions, protein translocations and protein turnover. In addition, we highlight the ability of virus-induced PTMs to promote immune evasion. We also discuss the recent evidence linking PTMs on DNA sensors with human diseases and more broadly, highlight promising directions for future research on PTM-mediated regulation of DNA sensor-dependent immune signaling.

Blue Monday: Co-occurring Stimulant Use and HIV Persistence Predict Dysregulated Catecholamine Synthesis

BACKGROUND

This longitudinal study examined whether co-occurring stimulant use and HIV disease processes predicted greater risk for depression via dysregulated metabolism of amino acid precursors for neurotransmitters.

METHODS

In total, 110 sexual minority men (ie, gay, bisexual, and other men who have sex with men) living with HIV who had biologically confirmed recent methamphetamine use were enrolled in a randomized controlled trial. The kynurenine/tryptophan (K/T) and phenylalanine/tyrosine (P/T) ratios were measured over 15 months to index dysregulated metabolism of amino acid precursors for serotonin and catecholamines. Markers of gut-immune dysregulation such as lipopolysaccharide binding protein and soluble CD14 (sCD14), HIV persistence in immune cells (ie, proviral HIV DNA), and stimulant use were examined as predictors. These bio-behavioral measures, including the K/T and P/T ratios, were also examined as predictors of greater risk for depression over 15 months.

RESULTS

Higher time-varying sCD14 levels (β = 0.13; P = 0.04) and time-varying detectable viral loads (β = 0.71; P < 0.001) were independent predictors of a higher K/T ratio. Time-varying reactive urine toxicology results for stimulants (β = 0.53; P < 0.001) and greater proviral HIV DNA at baseline (β = 0.34; P < 0.001) independently predicted an increased P/T ratio. Greater time-varying, self-reported methamphetamine use uniquely predicted higher odds of screening positive for depression (Adjusted Odds Ratio = 1.08; 95% confidence interval: 1.01 to 1.17).

CONCLUSIONS

Ongoing stimulant use and HIV persistence independently predict dysregulated metabolism of amino acid precursors for catecholamines, but this did not explain amplified risk for depression.

Generation and Release of Mitochondrial-Derived Vesicles in Health, Aging and Disease

Mitochondria are intracellular organelles involved in a myriad of activities. To safeguard their vital functions, mitochondrial quality control (MQC) systems are in place to support organelle plasticity as well as physical and functional connections with other cellular compartments. In particular, mitochondrial interactions with the endosomal compartment support the shuttle of ions and metabolites across organelles, while those with lysosomes ensure the recycling of obsolete materials. The extrusion of mitochondrial components via the generation and release of mitochondrial-derived vesicles (MDVs) has recently been described. MDV trafficking is now included among MQC pathways, possibly operating via mitochondrial-lysosomal contacts. Since mitochondrial dysfunction is acknowledged as a hallmark of aging and a major pathogenic factor of multiple age-associated conditions, the analysis of MDVs and, more generally, of extracellular vesicles (EVs) is recognized as a valuable research tool. The dissection of EV trafficking may help unravel new pathophysiological pathways of aging and diseases as well as novel biomarkers to be used in research and clinical settings. Here, we discuss (1) MQC pathways with a focus on mitophagy and MDV generation; (2) changes of MQC pathways during aging and their contribution to inflamm-aging and progeroid conditions; and (3) the relevance of MQC failure to several disorders, including neurodegenerative conditions (i.e., Parkinson's disease, Alzheimer's disease) and cardiovascular disease.

Older Adults with Physical Frailty and Sarcopenia Show Increased Levels of Circulating Small Extracellular Vesicles with a Specific Mitochondrial Signature

Mitochondrial dysfunction and systemic inflammation are major factors in the development of sarcopenia, but the molecular determinants linking the two mechanisms are only partially understood. The study of extracellular vesicle (EV) trafficking may provide insights into this relationship. Circulating small EVs (sEVs) from serum of 11 older adults with physical frailty and sarcopenia (PF&S) and 10 controls were purified and characterized. Protein levels of three tetraspanins (CD9, CD63, and CD81) and selected mitochondrial markers, including adenosine triphosphate 5A (ATP5A), mitochondrial cytochrome C oxidase subunit I (MTCOI), nicotinamide adenine dinucleotide reduced form (NADH):ubiquinone oxidoreductase subunit B8 (NDUFB8), NADH:ubiquinone oxidoreductase subunit S3 (NDUFS3), succinate dehydrogenase complex iron sulfur subunit B (SDHB), and ubiquinol-cytochrome C reductase core protein 2 (UQCRC2) were quantified by Western immunoblotting. Participants with PF&S showed higher levels of circulating sEVs relative to controls. Protein levels of CD9 and CD63 were lower in the sEV fraction of PF&S older adults, while CD81 was unvaried between groups. In addition, circulating sEVs from PF&S participants had lower amounts of ATP5A, NDUFS3, and SDHB. No signal was detected for MTCOI, NDUFB8, or UQCRC2 in either participant group. Our findings indicate that, in spite of increased sEV secretion, lower amounts of mitochondrial components are discarded through EV in older adults with PF&S. In-depth analysis of EV trafficking might open new venues for biomarker discovery and treatment development for PF&S.

Inter-Organelle Membrane Contact Sites and Mitochondrial Quality Control during Aging: A Geroscience View

Mitochondrial dysfunction and failing mitochondrial quality control (MQC) are major determinants of aging. Far from being standalone organelles, mitochondria are intricately related with cellular other compartments, including lysosomes. The intimate relationship between mitochondria and lysosomes is reflected by the fact that lysosomal degradation of dysfunctional mitochondria is the final step of mitophagy. Inter-organelle membrane contact sites also allow bidirectional communication between mitochondria and lysosomes as part of nondegradative pathways. This interaction establishes a functional unit that regulates metabolic signaling, mitochondrial dynamics, and, hence, MQC. Contacts of mitochondria with the endoplasmic reticulum (ER) have also been described. ER-mitochondrial interactions are relevant to Ca²⁺ homeostasis, transfer of phospholipid precursors to mitochondria, and integration of apoptotic signaling. Many proteins involved in mitochondrial contact sites with other organelles also participate to degradative MQC pathways. Hence, a comprehensive assessment of mitochondrial dysfunction during aging requires a thorough evaluation of degradative and nondegradative inter-organelle pathways. Here, we present a geroscience overview on (1) degradative MQC pathways, (2) nondegradative processes involving inter-organelle tethering, (3) age-related changes in inter-organelle degradative and nondegradative pathways, and (4) relevance of MQC failure to inflammaging and age-related conditions, with a focus on Parkinson’s disease as a prototypical geroscience condition.