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Abstract Background Elucidating mechanisms that promote HIV-1 transfer between CD4+ T-lymphocytes and their subsequent loss is of importance to HIV-1 pathogenesis. We recently reported that whey acidic protein, ps20, promotes cell-free HIV-1 spread through ICAM-1 modulation. Since ICAM-1 is pivotal in cell conjugation and intercellular HIV-1 transfer, this study examines ps20 effects on HIV-1 spread between T lymphocytes. Results We demonstrate intrinsic ps20 variability in primary CD4+ T-lymphocyte clonal populations and a significant positive correlation between endogenous ps20 levels and virus transfer involving fusion resulting in a spreading infection that could be reversed by the addition of reverse transcriptase inhibitors. Blocking anti-ps20 antibody or siRNA mediated ps20 knockdown, significantly reduced virus transfer. Conversely, virus transfer was promoted by ectopic ps20 expression or by exogenous addition of recombinant ps20. A higher frequency of virological synapse formation was evident in cocultures of HIV-1 infected donor T-cells with ps20high v ps20low/intermediate targets. Blocking ps20 inhibited T-lymphocyte conjugate formation and ICAM-1 expression, and was as potent as ICAM-1 in inhibiting HIV-1 transfer. Conclusions Therefore ps20 is a novel marker of CD4+ T-cells rendered vulnerable to HIV-1 infection by regulating the fundamental biologic process of intercellular conjugate formation and consequently of potential importance in HIV-1 pathogenesis.

Abstract This review summarizes recent advances and current gaps in understanding of innate immunity to human immunodeficiency virus (HIV) infection, and identifies key scientific priorities to enable application of this knowledge to the development of novel prevention strategies (vaccines and microbicides). It builds on productive discussion and new data arising out of a workshop on innate immunity against HIV held at the European Commission in Brussels, together with recent observations from the literature. Increasing evidence suggests that innate responses are key determinants of the outcome of HIV infection, influencing critical events in the earliest stages of infection including the efficiency of mucosal HIV transmission, establishment of initial foci of infection and local virus replication/spread as well as virus dissemination, the ensuing acute burst of viral replication, and the persisting viral load established. They also impact on the subsequent level of ongoing viral replication and rate of disease progression. Modulation of innate immunity thus has the potential to constitute a powerful effector strategy to complement traditional approaches to HIV prophylaxis and therapy. Importantly, there is increasing evidence to suggest that many arms of the innate response play both protective and pathogenic roles in HIV infection. Consequently, understanding the contributions made by components of the host innate response to HIV acquisition/spread versus control is a critical pre-requisite for the employment of innate immunity in vaccine or microbicide design, so that appropriate responses can be targeted for up- or down-modulation. There is also an important need to understand the mechanisms via which innate responses are triggered and mediate their activity, and to define the structure-function relationships of individual innate factors, so that they can be selectively exploited or inhibited. Finally, strategies for achieving modulation of innate functions need to be developed and subjected to rigorous testing to ensure that they achieve the desired level of protection without stimulation of immunopathological effects. Priority areas are identified where there are opportunities to accelerate the translation of recent gains in understanding of innate immunity into the design of improved or novel vaccine and microbicide strategies against HIV infection.

Abstract Detailed characterisation of immune responses induced by COVID-19 vaccines rolled out in India: COVISHIELDTM (CS) and COVAXIN® (CO) in a pre-exposed population is only recently being discovered. We addressed this issue in subjects who received their primary series of vaccination between November 2021 and January 2022. Both vaccines are capable of strongly boosting Wuhan Spike-specific neutralising antibody, polyfunctional Th1 cytokine producing CD4+ T-cells and single IFN-γ + CD8+ T-cells. Consistent with inherent differences in vaccine platform, the vector-based CS vaccine-induced immunity was of greater magnitude, breadth, targeting Delta and Omicron variants compared to the whole-virion inactivated vaccine CO, with CS vaccinees showing persistent CD8+ T-cells responses until 3 months post primary vaccination. This study provides detailed evidence on the magnitude and quality of CS and CO vaccine induced responses in subjects with pre-existing SARS-CoV-2 immunity in India, thereby mitigating vaccine hesitancy arguments in such a population, which remains a global health challenge.

Vaccines that confer protection through induction of adaptive T-cell immunity rely on understanding T-cell epitope (TCE) evolution induced by immune escape. This is poorly understood in tuberculosis (TB), an ancient, chronic disease, where CD4 T-cell immunity is of recognized importance. We probed 905 functionally validated, curated human CD4 T cell epitopes in 79 Mycobacterium tuberculosis (Mtb) whole genomes from India. This screen resulted in identifying 64 mutated epitopes in these strains initially using a computational pipeline and subsequently verified by single nucleotide polymorphism (SNP) analysis. SNP based phylogeny revealed the 79 Mtb strains to cluster to East African Indian (EAI), Central Asian Strain (CAS), and Beijing (BEI) lineages. Eighty-nine percent of the mutated T-cell epitopes (mTCEs) identified in the 79 Mtb strains from India has not previously been reported. These mTCEs were encoded by genes with high nucleotide diversity scores including seven mTCEs encoded by six antigens in the top 10% of rapidly divergent Mtb genes encoded by these strains. Using a T cell functional assay readout, we demonstrate 62% of mTCEs tested to significantly alter CD4 T-cell IFNγ and/or IL2 secretion with associated changes in predicted HLA-DR binding affinity: the gain of function mutations displayed higher predicted HLA-DR binding affinity and conversely mutations resulting in loss of function displayed lower predicted HLA-DR binding affinity. Most mutated antigens belonged to the cell wall/cell processes, and, intermediary metabolism and respiration families though all known Mtb proteins encoded mutations. Analysis of the mTCEs in an SNP database of 5,310 global Mtb strains identified 82% mTCEs to be significantly more prevalent in Mtb strains isolated from India, including 36 mTCEs identified exclusively in strains from India. These epitopes had a significantly higher predicted binding affinity to HLA-DR alleles that were highly prevalent in India compared to HLA-DR alleles rare in India, highlighting HLA-DR maybe an important driver of these mutations. This first evidence of region-specific TCE mutations potentially employed by Mtb to escape host immunity has important implications for TB vaccine design.

This proof-of-concept study tested if prior BCG revaccination can qualitatively and quantitively enhance antibody and T-cell responses induced by Oxford/AstraZeneca ChAdOx1nCoV-19 or COVISHIELD™, an efficacious and the most widely distributed vaccine in India. We compared COVISHIELD™ induced longitudinal immune responses in 21 BCG re-vaccinees (BCG-RV) and 13 BCG-non-revaccinees (BCG-NRV), all of whom were BCG vaccinated at birth; latent tuberculosis negative and SARS-CoV-2 seronegative prior to COVISHIELD™ vaccination. Compared to BCG-NRV, BCG-RV displayed significantly higher and persistent spike-specific neutralizing (n) Ab titers and polyfunctional CD4+ and CD8+ T-cells for eight months post COVISHIELD™ booster, including distinct CD4+IFN-γ+ and CD4+IFN-γ- effector memory (EM) subsets co-expressing IL-2, TNF-α and activation induced markers (AIM) CD154/CD137 as well as CD8+IFN-γ+ EM,TEMRA (T cell EM expressing RA) subset combinations co-expressing TNF-α and AIM CD137/CD69. Additionally, elevated nAb and T-cell responses to the Delta mutant in BCG-RV highlighted greater immune response breadth. Mechanistically, these BCG adjuvant effects were associated with elevated markers of trained immunity, including higher IL-1β and TNF-α expression in CD14+HLA-DR+monocytes and changes in chromatin accessibility highlighting BCG-induced epigenetic changes. This study provides first in-depth analysis of both antibody and memory T-cell responses induced by COVISHIELD™ in SARS-CoV-2 seronegative young adults in India with strong evidence of a BCG-induced booster effect and therefore a rational basis to validate BCG, a low-cost and globally available vaccine, as an adjuvant to enhance heterologous adaptive immune responses to current and emerging COVID-19 vaccines.

A fundamental challenge in human immunodeficiency virus (HIV) eradication is to understand how the virus establishes latency, maintains stable cellular reservoirs, and promotes rebound upon interruption of antiretroviral therapy (ART). Here, we discovered an unexpected role of the ubiquitous gasotransmitter hydrogen sulfide (H2S) in HIV latency and reactivation. We show that reactivation of HIV is associated with downregulation of the key H2S producing enzyme cystathionine-γ-lyase (CTH) and reduction in endogenous H2S. Genetic silencing of CTH disrupts redox homeostasis, impairs mitochondrial function, and remodels the transcriptome of latent cells to trigger HIV reactivation. Chemical complementation of CTH activity using a slow-releasing H2S donor, GYY4137, suppressed HIV reactivation and diminished virus replication. Mechanistically, GYY4137 blocked HIV reactivation by inducing the Keap1-Nrf2 pathway, inhibiting NF-κB, and recruiting the epigenetic silencer, YY1, to the HIV promoter. In latently infected CD4+ T cells from ART-suppressed human subjects, GYY4137 in combination with ART prevented viral rebound and improved mitochondrial bioenergetics. Moreover, prolonged exposure to GYY4137 exhibited no adverse influence on proviral content or CD4+ T cell subsets, indicating that diminished viral rebound is due to a loss of transcription rather than a selective loss of infected cells. In summary, this work provides mechanistic insight into H2S-mediated suppression of viral rebound and suggests exploration of H2S donors to maintain HIV in a latent form.

Neonate responses to pathogen-associated molecular patterns (PAMPS) differ from adults; such understanding is poor in Indian neonates, despite recognized significant infectious risk. Immune profiling analysis was undertaken of 10 secreted mediators contextualized with cellular source induced by six PAMPs in umbilical cord (CB; n = 21) and adult-blood (PBMC; n = 14) from a tertiary care hospital in South India. Differential cytokine expression analysis (minimum log2-fold difference; adj P-value < 0.05) identified bacterial PAMPs induced higher concentrations of IL-1β, IL-10, TNF-α in adults versus IL-8, GM-CSF, IFN-γ, and IL-2 in CB. CB responded to poly I:C and SARS-CoV-2 lysate with a dominant IL-8 response, whereas in PBMC, CXCL-10 dominated poly I:C, but not SARS-CoV-2, responses, highlighting potential IL-8 importance, in the absence of Type I Interferons, in antiviral CB immunity. Candida albicans was the only PAMP to uniformly induce higher secretion of effectors in CB. The predominant source of IL-8/IL-6/TNF-α/IL-1β in both CB and PBMC was polyfunctional monocytes and IFN-γ/IL-2/IL-17 from innate lymphocytes. Correlation matrix analyses revealed IL-8 to be the most differentially regulated, correlating positively in CB versus negatively in PBMC with IL-6, GM-CSF, IFN-γ, IL-2, consistent with more negatively regulated cytokine modules in adults, potentially linked to higher anti-inflammatory IL-10. Cord and adult blood from India respond robustly to PAMPs with unique effector combinations. These data provide a strong foundation to monitor, explore, mechanisms that regulate such immunity during the life course, an area of significant global health importance given infection-related infant mortality incidence. Immune profiling analysis was conducted on umbilical cord blood (CB; n=21) and adult peripheral blood mononuclear cells (PBMC; n=14) from India. Six pathogen-associated molecular patterns (PAMPs) were used to stimulate immune responses. Differential secreted cytokine expression analysis, relative to no stimulation control, as measured by a multiplex ELISA, revealed PAMP-specific distinct effectors patterns. The predominant cellular source of IL-8/IL-6/TNF-a/IL-1ß in both CB and PBMC, as determined by intracellular cytokine staining, was polyfunctional monocytes and IFN-? /IL-2/IL-17/IL-10 from innate lymphocytes. Graphical Abstract [ABSTRACT FROM AUTHOR]

Galectin-9 (Gal-9) and osteopontin (OPN) play immunomodulatory roles in tuberculosis and HIV infections. Evaluation of their levels as well as their interplay with different pro-inflammatory cytokines is critical to understand their role in immunopathogenesis of HIV/tuberculosis co-infection considering the complexity of the disease. Plasma levels of these proteins were measured by ELISAs in HIV-negative individuals with pulmonary (n = 21), extrapulmonary (n = 33), and latent tuberculosis (n = 22) and in HIV infected patients with pulmonary (n = 14), latent tuberculosis (n = 17), and without tuberculosis (n = 41). Levels of pro-inflammatory cytokines were estimated by Luminex assay. Receiver operated characteristic curve analysis was performed to evaluate discriminatory roles of these proteins. Spearman’s correlation analysis was performed with the markers of HIV and tuberculosis disease progression to evaluate their immunopathogenic roles. Gal-9 and OPN levels were higher in HIV uninfected patients with active tuberculosis than with latent tuberculosis. Gal-9 but not OPN levels were higher in HIV infected patients with active tuberculosis than with latent tuberculosis. Area under curve for Galectin-9 was >0.9 in HIV/tuberculosis co-infection and extrapulmonary tuberculosis. OPN and IL-6 levels were higher in patients with severe chest X-ray grade indicating its association with severity of the disease and positively correlated with each other. Stronger positive and negative correlations of Gal-9 levels, respectively, with viral loads and CD4 cell counts in HIV infected patients were observed than OPN levels indicating their association with HIV disease progression. Thus, significantly elevated Gal-9 levels were reported for the first time in HIV/tuberculosis co-infection and extrapulmonary tuberculosis in our study than single infections with HIV and tuberculosis. The study indicated a need for further evaluation of monitoring role of Gal-9 for detection of developing tuberculosis in HIV infected individuals. The findings also indicated differential roles of Gal-9 and OPN in the pathogenesis of tuberculosis and HIV infections.

Detailed characterisation of immune responses induced by COVID-19 vaccines rolled out in India: COVISHIELDTM (CS) and COVAXIN® (CO) in a pre-exposed population is only recently being discovered. We addressed this issue in subjects who received their primary series of vaccination between November 2021 and January 2022. Both vaccines are capable of strongly boosting Wuhan Spike-specific neutralising antibody, polyfunctional Th1 cytokine producing CD4+ T-cells and single IFN-γ + CD8+ T-cells. Consistent with inherent differences in vaccine platform, the vector-based CS vaccine-induced immunity was of greater magnitude, breadth, targeting Delta and Omicron variants compared to the whole-virion inactivated vaccine CO, with CS vaccinees showing persistent CD8+ T-cells responses until 3 months post primary vaccination. This study provides detailed evidence on the magnitude and quality of CS and CO vaccine induced responses in subjects with pre-existing SARS-CoV-2 immunity in India, thereby mitigating vaccine hesitancy arguments in such a population, which remains a global health challenge. [ABSTRACT FROM AUTHOR]

Background and objectives: The purpose of this study is to determine whether diabetes individuals who have a variation in the MnSOD gene are more likely to experience cardiovascular problems. This is accomplished by determining the prevalence of MnSOD gene polymorphism in type 2 diabetic patients who either have or do not have cardiovascular disease, as well as in healthy control subjects. To determine whether or not this MnSOD polymorphism results in decreased SOD activity. Method: To conduct this case-control investigation, ethical approval was obtained. This investigation was conducted between February 2023 to May 2023 at Government Medical College Sircilla, Telangana, India. Seventy patients with diabetes that had been ongoing for more than five years were included in the investigation after receiving informed consent. The diagnosis is based on the clinical history, fasting plasma glucose levels, and electrocardiogram (ECG) findings. Result: The genotype and allele frequency of the SOD2 gene are displayed for those with type 2 diabetes, those without the disease, and healthy controls. More people with diabetes and cardiovascular disease (n = 25; 71.42%) have the TT genotype than people with diabetes and no cardiovascular disease (n = 15; 42.85%) or controls (n = 10; 28.5%). There is a significant (P = 0.006) difference in the frequency of the TT genotype among diabetic CVD cases. Genetics and SOD activity interacted. The SOD activity was lower in people with the TT genotype. SOD activity ranges from 86U/L in TT to 187U/L in CC, with CT falling in the middle at 145U/L. It's 0.000. The SOD activity was lower in people with the TT genotype. Conclusion: This study compared diabetics with and without cardiovascular disease for SOD2 gene (T>C) substitution polymorphism. 35 diabetics with and without cardiovascular disease were compared. T2DM patients with cardiovascular disease had a higher SOD2 TT genotype rate than those without CVD and controls. TT genotype differs significantly amongst diabetics with and without cardiovascular disease. Diabetes patients with cardiovascular disease had reduced serum SOD activity, which may contribute to cardiovascular illness. The TT genotype was associated with cardiovascular disease due to its low serum superoxide dismutase (SOD) activity. After controlling for variables, the TT genotype predicts cardiovascular disease complications. [ABSTRACT FROM AUTHOR]