T cell immune discriminants of HIV reservoir size in a pediatric cohort of perinatally infected individuals.

The size of the latent HIV reservoir is associated with the timing of therapeutic interventions and overall health of the immune system. Here, we demonstrate that T cell phenotypic signatures associate with viral reservoir size in a cohort of HIV vertically infected children and young adults under durable viral control, and who initiated anti-retroviral therapy (ART) <2 years old. Flow cytometry was used to measure expression of immune activation (IA), immune checkpoint (ICP) markers, and intracellular cytokine production after stimulation with GAG peptides in CD4 and CD8 T cells from cross-sectional peripheral blood samples. We also evaluated the expression of 96 genes in sort-purified total CD4 and CD8 T cells along with HIV-specific CD4 and CD8 T cells using a multiplexed RT-PCR approach. As a measure of HIV reservoir, total HIV-DNA quantification by real-time PCR was performed. Poisson regression modeling for predicting reservoir size using phenotypic markers revealed a signature that featured frequencies of PD-1+CD4 T cells, TIGIT+CD4 T cells and HIV-specific (CD40L+) CD4 T cells as important predictors and it also shows that time of ART initiation strongly affects their association with HIV-DNA. Further, gene expression analysis showed that the frequencies of PD-1+CD4 T cells associated with a CD4 T cell molecular profile skewed toward an exhausted Th1 profile. Our data provide a link between immune checkpoint molecules and HIV persistence in a pediatric cohort as has been demonstrated in adults. Frequencies of PD-1+ and TIGIT+CD4 T cells along with the frequency of HIV-specific CD4 T cells could be associated with the mechanism of viral persistence and may provide insight into potential targets for therapeutic intervention.

Caregivers' psychosocial assessment for identifying HIV-infected infants at risk of poor treatment adherence: an exploratory study in southern Mozambique.

Psychosocial support (PSS) to caregivers of HIV-infected infants on antiretroviral treatment (ART) is crucial to ensure ART adherence and sustained long-term viral suppression in children. A specific approach including tools to monitor and understand adherence behavior and risk factors that prevent optimal treatment compliance are urgently needed. This qualitative exploratory study, conducted in southern Mozambique, monitored the infants' viral response trajectories during 18 months follow-up, as a measure of adherence, reviewed the caregiver's PSS session notes and the answers to a study questionnaire, to analyze whether the standard PSS checklist applied to infants' caregivers can identify barriers influencing their adherence. Only 9 of 31 infants had sustained virologic response. Reported factors affecting adherence were: difficulties in drugs administration, shared responsibility to administer treatment; disclosure of child's HIV status to family members but lack of engagement; mother's ART interruption and poor viral response. In conclusion, we found that the standard PSS approach alone, applied to caregivers, was lacking focus on many relevant matters that were identified by the study questionnaire. A comprehensive patient-centered PSS package of care, including an adherence risk factor monitoring tool, tailored to caregivers and their children must be developed.

Immune correlates of cardiovascular co-morbidity in HIV infected participants from South India.

BACKGROUND: Understanding the immune correlates of cardiovascular disease (CVD) risk in HIV infection is an important area of investigation in the current era of aging with HIV infection. Less is known about CVD risk and HIV infection in developing nations where additional risk factors may be playing a role in the CVD development. In this study, we assessed the effects of systemic inflammation, microbial translocation (MT), T cell immune activation (IA), and nadir CD4 counts on cardiac function and arterial stiffness as markers of subclinical atherosclerosis in HIV-infected individuals. METHODS: People with HIV (PWH) who were ART naïve (n = 102) or virally suppressed on ART (n = 172) were stratified on nadir CD4 counts and compared to HIV-uninfected controls (n = 64). Determination was made of cardiac function via radial pulse wave and carotid intima thickness (C-IMT) measurements. Plasma biomarkers of inflammation and MT by ELISA or multiplex assays, and immune activation (IA) of T cells based HLA-DR and CD38 expression were investigated by flow cytometry. T-test, Mann-Whitney U test, and Spearman correlation were used to analyze study parameters. RESULTS: Reduction in cardiac function with lower cardiac ejection time (p < 0.001), stroke volume (p < 0.001), cardiac output (p = 0.007), higher arterial stiffness (p < 0.05) were identified in ART-naïve participants, compared to PWH on ART (p < 0.05). No significant difference in C-IMT values were noted. Higher inflammatory and MT markers were found in the ART-naïve group compared to treated group who were comparable to uninfected participants, except for having higher TNF-α (p < 0.001) and sCD14 (p < 0.001). Immune activation of CD4 and CD8 T-cells was greater in ART-naïve participants compared to ART-treated and uninfected controls (p < 0.05). Lower nadir CD4 counts, higher inflammation, and higher MT predicted poor cardiac measures in the ART-naïve with nadir CD4 < 200cells/mm3 manifesting the highest arterial stiffness, and lowest cardiac function, whereas ART-treated, even with nadir < 200 cells/mm3 were similar to uninfected in these measures. CONCLUSIONS: In HIV-infected individuals, initiation of ART even at nadir of < 200 cells/mm3 may prevent or reverse cardiovascular disease outcomes that are easily measurable in low income countries.

Dysfunctional peripheral T follicular helper cells dominate in people with impaired influenza vaccine responses: Results from the FLORAH study.

Antigen-primed cluster of differentiation (CD) 4+ T follicular helper (Tfh) cells interact with B cells in the germinal centers (GCs) of lymph nodes to generate vaccine-induced antibody (Ab) responses. In the circulation, peripheral Tfh (pTfh) cells, a subset of memory CD4 T cells, serve as surrogates for GC Tfh because of several functional and phenotypic similarities between them. We investigated features of H1N1 influenza antigen-specific pTfh (Ag.pTfh) in virologically controlled HIV+ volunteers on antiretroviral therapy (ART) and healthy control (HC) participants selected from a seasonal influenza vaccine responsiveness study. Selection of the participants was made based on age, defined as young (18-40 y) and old (>60 y) and on their classification as a vaccine responder (VR) or vaccine nonresponder (VNR). VRs demonstrated expansion of CD40L+ and CD69+ Ag.pTfh, with induction of intracellular interleukin 21 (IL-21) and inducible costimulator (ICOS) post vaccination; these responses were strongest in young HC VRs and were less prominent in HIV+ individuals of all ages. Ag.pTfh in VNRs exhibited dramatically different characteristics from VRs, displaying an altered phenotype and a cytokine profile dominated by cytokines IL-2, tumor necrosis factor alpha (TNF-α), or IL-17 but lacking in IL-21. In coculture experiments, sorted pTfh did not support the B cell IgG production in VNRs and were predominantly an inflammatory T helper 1 (Th1)/T helper 17 (Th17) phenotype with lower ICOS and higher programmed cell death protein 1 (PD1) expression. Induction of IL-21 and ICOS on Ag.pTfh cells are negatively affected by both aging and HIV infection. Our findings demonstrate that dysfunctional Ag.pTfh cells with an altered IL-21/IL-2 axis contribute to inadequate vaccine responses. Approaches for targeting inflammation or expanding functional Tfh may improve vaccine responses in healthy aging and those aging with HIV infection.

Impact of Early Antiretroviral Therapy Initiation on HIV-Specific CD4 and CD8 T Cell Function in Perinatally Infected Children.

Early initiation of antiretroviral therapy (ART) in vertically HIV-infected children limits the size of the virus reservoir, but whether the time of treatment initiation (TI) can durably impact host immune responses associated with HIV infection is still unknown. This study was conducted in PBMC of 20 HIV-infected virally suppressed children on ART (mean age 9.4 y), classified as early treated (ET; age at ART initiation ≤0.5 y, n = 14) or late treated (LT; age at ART initiation 1-10 y, n = 6). Frequencies and functions of Ag-specific CD4 (CD40L+) and CD8 (CD69+) T cells were evaluated by intracellular IL-2, IFN-γ, and TNF-α production with IL-21 in CD4 or CD107a, granzyme B and perforin in CD8 T cells following stimulation with HIV gp140 protein (ENV) or GAG peptides by multiparameter flow cytometry. ET showed a higher proportion of cytokine-producing ENV- and GAG-specific CD4 and CD8 T cells compared with LT. In particular, ET were enriched in polyfunctional T cells. RNA sequencing analysis showed upregulation of immune activation pathways in LT compared with ET. Our results suggest that timing of TI in HIV-infected children has a long-term and measurable impact on the quality of the HIV-specific T cell immune responses and transcriptional profiles of PBMC, reinforcing the importance of early TI.

Impaired peripheral blood T-follicular helper cell function in HIV-infected nonresponders to the 2009 H1N1/09 vaccine.

The generation of Ab-secreting plasma cells depends critically on CD4 T-follicular helper (TFH) cells during the germinal center reaction. Germinal center TFH cells share functional properties with circulating CXCR5(+) CD4 T cells, referred to herein as peripheral TFH (pTFH) cells. Because deficient Ab production and CD4 T-cell loss are recognized features of HIV infection, in the present study, we investigated pTFH cells in 25 HIV-infected patients on antiretroviral therapy. pTFH frequency was equivalent in patients and healthy controls (HCs), and these cells displayed a central memory phenotype. Sixteen patients and 8 HCs in this group were given a single dose of H1N1/09 influenza vaccine during the 2009 H1N1 influenza outbreak. In the vaccine responders (n = 8) and HCs, pTFH cells underwent expansion with increased IL-21 and CXCL13 secretion in H1N1-stimulated PBMC culture supernatants at week 4 (T2). These changes were not seen in vaccine nonresponders (n = 8). In coculture experiments, sorted pTFH cells supported HIN1-stimulated IgG production by autologous B cells only in vaccine responders. At T2, frequencies of pTFH were correlated with memory B cells, serum H1N1 Ab titers, and Ag-induced IL-21 secretion. Characterization of pTFH cells may provide additional insight into cellular determinants of vaccine-induced Ab response, which may have relevance for vaccine design.

Soluble Plasma Proteins of Tumor Necrosis Factor and Immunoglobulin Superfamilies Reveal New Insights into Immune Regulation in People with HIV and Opioid Use Disorder.

People with HIV (PWH) frequently suffer from Opioid (OP) Use Disorder (OUD). In an investigation of the impact of OUD on underlying immune dysfunction in PWH, we previously reported that OP use exacerbates inflammation in virally controlled PWH followed in the Infectious Diseases Elimination Act (IDEA) Syringe Services Program (SSP). Unexpectedly, Flu vaccination-induced antibody responses in groups with OUD were superior to PWH without OUD. Here, we investigated the profile of 48 plasma biomarkers comprised of TNF and Ig superfamily (SF) molecules known to impact interactions between T and B cells in 209 participants divided into four groups: (1) HIV+OP+, (2) HIV-OP+, (3) HIV+OP-, and (4) HIV-OP-. The differential expression of the top eight molecules ranked by median values in individual Groups 1-3 in comparison to Group 4 was highly significant. Both OP+ groups 1 and 2 had higher co-stimulatory TNF SF molecules, including 4-1BB, OX-40, CD40, CD30, and 4-1BBL, which were found to positively correlate with Flu Ab titers. In contrast, HIV+OP- exhibited a profile dominant in Ig SF molecules, including PDL-2, CTLA-4, and Perforin, with PDL-2 showing a negative correlation with Flu vaccine titers. These findings are relevant to vaccine development in the fields of HIV and OUD.

Accelerated CD8+ T cell maturation in infants with perinatal HIV infection.

In perinatal HIV infection, early antiretroviral therapy (ART) initiation is recommended but questions remain regarding infant immune responses to HIV and its impact on immune development. Using single cell transcriptional and phenotypic analysis we evaluated the T cell compartment at pre-ART initiation of infants with perinatally acquired HIV from Maputo, Mozambique (Towards AIDS Remission Approaches cohort). CD8+ T cell maturation subsets exhibited altered distribution in HIV exposed infected (HEI) infants relative to HIV exposed uninfected infants with reduced naive, increased effectors, higher frequencies of activated T cells, and lower frequencies of cells with markers of self-renewal. Additionally, a cluster of CD8+ T cells identified in HEI displayed gene profiles consistent with cytotoxic T lymphocytes and showed evidence for hyper expansion. Longitudinal phenotypic analysis revealed accelerated maturation of CD8+ T cells was maintained in HEI despite viral control. The results point to an HIV-directed immune response that is likely to influence reservoir establishment.

Upregulation of IL-21 receptor on B cells and IL-21 secretion distinguishes novel 2009 H1N1 vaccine responders from nonresponders among HIV-infected persons on combination antiretroviral therapy.

Mechanisms underlying failure of novel 2009 H1N1 influenza vaccine-induced Ab responses in HIV-infected persons are poorly understood. This study prospectively evaluated 16 HIV-infected patients on combination antiretroviral therapy and eight healthy controls (HC) who received a single 15 µg dose of nonadjuvanted novel 2009 H1N1 influenza vaccine during the 2009 H1N1 epidemic. Peripheral blood was collected at baseline (T0) and at 7 d (T1) and 28 d (T2) postvaccination for evaluation of immune responses. Prevaccination hemagglutination inhibition Ab titer was <1:20 in all except one study participant. At T2, all HC and 8 out of 16 patients (50%) developed a vaccine-induced Ab titer of ≥ 1:40. Vaccine responder (R) and vaccine nonresponder patients were comparable at T0 in age, CD4 counts, virus load, and B cell immunophenotypic characteristics. At T2, HC and R patients developed an expansion of phenotypic and functional memory B cells and ex vivo H1N1-stimulated IgG Ab-secreting cells in an ELISPOT assay. The memory B cell response was preceded by a significant expansion of plasmablasts and spontaneous H1N1-specific Ab-secreting cells at T1. At T2, HC and R patients also exhibited significant increases in serum IL-21 levels and in the frequency and mean fluorescence intensity of IL-21R-expressing B cells, which correlated with serum H1N1 Ab titers. Vaccine nonresponder patients failed to develop the above-described vaccine-induced immunologic responses. The novel association of novel 2009 H1N1 vaccine-induced Ab responses with IL-21/IL-21R upregulation and with development of memory B cells and plasmablasts has implications for future research in vaccine design.

Longitudinal analysis of innate immune system in infants with perinatal HIV infection until 18 months of age.

With the advent of antiretroviral therapy (ART), perinatal HIV infection is declining globally but prevalence in Sub-Saharan Africa is still greater than other nations. The relationship of HIV replication in early infancy and the developing immune system is not well understood. In this study, we investigated cellular components of the innate immune system including Natural Killer (NK) cells, monocytes, and Dendritic Cells (DC) in a cohort of HIV exposed infected (HEI) and age-matched HIV exposed uninfected (HEU) infants from Mozambique. Study entry was at the first visit after delivery at age 1-2 months for HIV diagnosis and initiation of ART. Phenotypic analysis by multi-parameter flow cytometry revealed an expansion of total NK cells and the dysfunctional, CD56-CD16+, NK cell subset; increased activation in monocytes and DC; and higher levels of inflammatory homing receptor CCR5 on circulating DC subsets in the HEI infants. NKG2A, an inhibitory receptor for NK cytolytic function, was reduced in HEI compared to HEU and positively correlated with pre-ART viral load (VL) while expression of CCR2, the inflammatory homing receptor, on NK was negatively correlated with VL. Other subsets exhibited positive correlations with VL including the frequency of intermediate monocytes amongst total monocytes. Longitudinal analysis of VL indicated suboptimal ART adherence in HEI. Regardless of level of viral suppression achieved, the frequencies of specific innate immune subsets in HEI were normalized to HEU by 18m. These data support the notion that in early life, NK cells play a role in virus control and should be explored for functional attributes that are effective against HIV at this time during development. Overall, our study provides high resolution overview of the innate immune system during perinatal HIV infection.

IL-21-IgFc immunotherapy alters transcriptional landscape of lymph node cells leading to enhanced flu vaccine response in aging and SIV infection.

Aging people living with HIV (PWH) frequently manifest impaired antibody (Ab) responses to seasonal flu vaccination which has been attributed to ongoing inflammation and immune activation. We have recently reported a similar scenario in old simian immunodeficiency virus (SIV) infected rhesus macaques (RM) with controlled viremia and have been able to compensate for this deficiency by immunotherapy with interleukin (IL)-21-IgFc. To understand the underlying mechanisms of IL-21-induced immunomodulation leading to enhanced flu vaccine response in aging and SIV, we have investigated draining lymph node (LN) cells of IL-21-treated and -untreated animals at postvaccination. We observed IL-21-induced proliferation of flu-specific LN memory CD4 T cells, expansion of B cells expressing IL-21 receptor (IL-21R), and modest expansion of T follicular helper cells (Tfh) co-expressing T-cell immunoreceptor with Ig and ITIM domains (TIGIT) and DNAX accessory molecule (DNAM-1). Transcriptional analysis of LN cells of IL-21-treated animals revealed significant inhibition of germinal center (GC) Tfh and B-cell interferon signaling pathways along with enhanced B-cell development and antigen presentation pathways. We conclude that IL-21 treatment at the time of flu vaccination in aging SIV-infected animals modulates the inductive LN GC activity, to reverse SIV-associated LN Tfh and B-cell dysfunction. IL-21 is a potential candidate molecule for immunotherapy to enhance flu vaccine responses in aging PWH who have deficient antibody responses.

B-cell immunity and vaccine induced antibody protection reveal the inefficacy of current vaccination schedule in infants with perinatal HIV-infection in Mozambique, Africa.

BACKGROUND: Despite antiretroviral treatment (ART), immune dysfunction persists in children with perinatal HIV infection (HEI). Here we investigated the impact of HIV status on maternal antibody (Ab) passage, long-term vaccine induced immunity and B-cell maturation. METHODS: 46 HIV Exposed Uninfected (HEU), 43 HEI, and 15 HIV unexposed uninfected (HUU) infants were vaccinated with 3 doses of DTaP-HepB-Hib-PCV10-OP at 2, 3, and 4 months at Matola Provincial Hospital, Maputo, Mozambique. Tetanus toxoid specific (TT) IgG, HIV Ab and B-cell phenotype characteristics were evaluated at entry, pre-ART, 5, 10, and 18 months in this longitudinal cohort study. FINDINGS: Baseline (maternal) plasma TT Ab levels were significantly lower in HEI compared to both HEU and HUU and a faster decay of TT Ab was observed in HEI compared to HEU with significantly lower TT Ab levels at 10 and 18 months of age. TT unprotected (UP) (≤0.1 IU/mL) HEI showed higher HIV-RNA at entry and higher longitudinal HIV viremia (Area Under the Curve) compared to TT protected (P) HEI. A distinct HIV-Ab profile was found at entry in HEI compared to HEU. B-cell phenotype showed a B-cell perturbation in HEI vs HEU infants at entry (mean age 40.8 days) with lower transitional CD10+CD19+ B-cells and IgD+CD27- naive B-cells and an overall higher frequency of IgD-CD27- double negative B-cell subsets in HEI. INTERPRETATION: B-cell perturbation, presenting with higher double negative IgD-CD27- B-cells was observed in neonatal age and may play a major role in the B-cell exhaustion in HEI. The ability to maintain TT protective Ab titers over time is impaired in HEI with uncontrolled viral replication and the current vaccination schedule is insufficient to provide long-term protection against tetanus. FUNDING: This work was supported by: NIH grant to SP (5R01AI127347-05); Children's Hospital Bambino Gesú (Ricerca corrente 2019) to NC, and Associazione Volontari Bambino Gesù to PP.

HIV-1 reservoir evolution in infants infected with clade C from Mozambique.

BACKGROUND: The persistence of HIV-1-infected cells during antiretroviral therapy is well documented but may be modulated by early initiation of antiretroviral therapy in infants. METHODS: Here, we longitudinally analyzed the proviral landscape in nine infants with vertical HIV-1 infection from Mozambique over a median period of 24 months, using single-genome, near full-length, next-generation proviral sequencing. RESULTS: We observed a rapid decline in the frequency of intact proviruses, leading to a disproportional under-representation of intact HIV-1 sequences within the total number of HIV-1 DNA sequences after 12-24 months of therapy. In addition, proviral integration site profiling in one infant demonstrated clonal expansion of infected cells harboring intact proviruses and indicated that viral rebound was associated with an integration site profile dominated by intact proviruses integrated into genic and accessible chromatin locations. CONCLUSION: Together, these results permit rare insight into the evolution of the HIV-1 reservoir in infants infected with HIV-1 and suggest that the rapid decline of intact proviruses, relative to defective proviruses, may be attributed to a higher vulnerability of genome-intact proviruses to antiviral immunity. Technologies to analyze combinations of intact proviral sequences and corresponding integration sites permit a high-resolution analysis of HIV-1 reservoir cells after early antiretroviral treatment initiation in infants.

Opioids exacerbate inflammation in people with well-controlled HIV.

Introduction: People with HIV (PWH) are known to have underlying inflammation and immune activation despite virologic control. Substance use including opioid dependence is common in this population and is associated with increased morbidity and reduced lifespan. The primary objective of the present study termed opioid immunity study (OPIS), was to investigate the impact of chronic opioids in PWH. Methods: The study recruited people with and without HIV who had opioid use disorder (OUD). Study participants (n=221) were categorized into four groups: HIV+OP+, n=34; HIV-OP+, n=66; HIV+OP-, n=55 and HIV-OP-, n=62 as controls. PWH were virally suppressed on ART and those with OUD were followed in a syringe exchange program with confirmation of OP use by urine drug screening. A composite cytokine score was developed for 20 plasma cytokines that are linked to inflammation. Cellular markers of immune activation (IA), exhaustion, and senescence were determined in CD4 and CD8 T cells. Regression models were constructed to examine the relationships of HIV status and opioid use, controlling for other confounding factors. Results: HIV+OP+ participants exhibited highest inflammatory cytokines and cellular IA, followed by HIV-OP+ for inflammation and HIV+OP- for IA. Inflammation was found to be driven more by opioid use than HIV positivity while IA was driven more by HIV than opioid use. In people with OUD, expression of CD38 on CD28-CD57+ senescent-like T cells was elevated and correlated positively with inflammation. Discussion: Given the association of inflammation with a multitude of adverse health outcomes, our findings merit further investigations to understand the mechanistic pathways involved.

Innate immune defects correlate with failure of antibody responses to H1N1/09 vaccine in HIV-infected patients.

BACKGROUND: Mechanisms underlying the failure of influenza vaccine-induced antibody responses in HIV-infected persons are poorly understood. OBJECTIVE: To investigate innate immune factors regulating B-cell function in HIV-infected persons and to correlate them with serologic responses to H1N1/09 vaccine. METHODS: We evaluated immunologic characteristics of 17 HIV-infected patients and 8 healthy controls (HCs) at 0, 7, and 28 days (designated T0, T1, and T2) following a single 15-µg dose of nonadjuvanted H1N1/09 influenza vaccine by using flow cytometry, ELISpot, and ELISA. All HCs and 9 patients (53%) seroconverted with >1:40 hemagglutination inhibition antibody titer at T2. RESULTS: In vaccine responders and HCs, serum levels of BAFF (B cell-activating factor) and APRIL (a proliferation-inducing ligand) increased from T0 to T2 in conjunction with increases in frequencies of memory B cells. Concurrently, receptors for these factors showed changes, with increases in expression of TACI (transmembrane activator and calcium modulator and cyclophilin ligand interactor) and decreases in BAFF receptor in memory B cells. IL-2 secreting cells and IgG antibody-secreting cells increased at T2 in vaccine responders and HCs in ex vivo H1N1 antigen-stimulated cultures. These immunologic responses were not evident at T1 and were deficient in vaccine nonresponder patients at T2. At T0, vaccine nonresponders had lower frequencies of BAFF receptor and TACI-expressing memory B cells than did responders. CONCLUSION: Impaired memory B-cell responses, deficiencies in serum BAFF and APRIL, and alterations in their receptors on B cells were associated with failure of H1N1/09 influenza vaccine responses among virologically controlled HIV-infected patients.

Distinct Molecular Signatures of Aging in Healthy and HIV-Infected Individuals.

BACKGROUND: Virally suppressed chronic HIV-infected individuals on antiretroviral therapy experience similar immune impairments as HIV-uninfected elderly. However, they manifest symptoms of premature immune aging such as suboptimal responses to vaccination at a younger age. Mechanisms underlying premature immune aging are unclear. SETTING: The study site was University of Miami Miller School of Medicine. METHODS: In this study, we aimed to identify molecular signatures of aging in HIV-infected (HIV) individuals compared with age-matched healthy control (HC) participants. Transcriptomic profiles of peripheral blood mononuclear cells collected cross-sectionally from study participants were evaluated using RNA sequencing, and genes and pathways associated with age and HIV status were identified and compared between study groups. Generalized linear modeling was used to identify transcriptional signatures associated with age. RESULTS: Despite that fewer differentially expressed genes between young (<40 yrs) and old (>59 yrs) were observed in the HIV group, metabolic and innate immune activation pathways were associated with increasing age in both HIV and HC. Age was also associated with pathways involved with T-cell immune activation in HC and with interferon signaling pathways in HIV. We observed signs of precocious immune aging at the transcriptional level in HIV and defined a transcriptional perturbation associated with innate immunity and glucose metabolism induced by aging in both HC and HIV. CONCLUSION: In this study, we identified distinct molecular signatures predictive of age in HIV versus HC, which suggest precocious immune aging in HIV. Overall, our results highlight the molecular pathways of immune aging in both HC and HIV that may be targeted for additional mechanistic insights or in a therapeutic setting.

Viral Response among Early Treated HIV Perinatally Infected Infants: Description of a Cohort in Southern Mozambique.

Early initiation of antiretroviral therapy and adherence to achieve viral load suppression (VLS) are crucial for reducing morbidity and mortality of perinatally HIV-infected infants. In this descriptive cohort study of 39 HIV perinatally infected infants, who started treatment at one month of life in Mozambique, we aimed to describe the viral response over 2 years of follow up. VLS ≤ 400 copies/mL, sustained VLS and viral rebound were described using a Kaplan-Meier estimator. Antiretroviral drug transmitted resistance was assessed for a sub-group of non-VLS infants. In total, 61% of infants reached VLS, and 50% had a rebound. Cumulative probability of VLS was 36%, 51%, and 69% at 6, 12 and 24 months of treatment, respectively. The median duration of VLS was 7.4 months (IQR 12.6) and the cumulative probability of rebound at 6 months was 30%. Two infants had resistance biomarkers to drugs included in their treatment regimen. Our findings point to a low rate of VLS and high rate of viral rebound. More frequent viral response monitoring is advisable to identify infants with rebound and offer timely adherence support. It is urgent to tailor the psychosocial support model of care to this specific age group and offer differentiated service delivery to mother-baby pairs.

Association of Flu specific and SARS-CoV-2 specific CD4 T cell responses in SARS-CoV-2 infected asymptomatic heath care workers.

Influenza vaccination is widely advocated to avoid infection with influenza virus, a serious respiratory pathogen, and this was greatly emphasized during the raging COVID-19 epidemic. We conducted a study for baseline Flu specific immunity in a group of health care workers with documented past SARs-CoV-2 infection (designated COVID+) with mild or no symptoms and compared them with a control group that had not been infected with SARS CoV-2 (COVID-). Concurrently, we examined flu and SARS-CoV-2 specific T cell responses using the AIM (activation induced molecules) assay by flow cytometry. All COVID+ and 40% COVID- participants exhibited AIM responses to SARS-CoV-2 peptides, but only COVID+ were positive for SARs-CoV-2 antibody. Influenza HIN1 antigen specific CD4 T cells were found in 92% COVID+ and 76% COVID- participants and exhibited a strong direct correlation with SARS-CoV-2 specific CD4 T cells. This observation suggests that influenza specific T cell immunity may impact immune responses to SARS-CoV-2.

Immunological age prediction in HIV-infected, ART-treated individuals.

Anti-retroviral therapy (ART) improves life expectancy in people living with HIV (PWH), but it remains unclear how chronic HIV infection affects normal aging of the immune system. Plasma cell-free protein expression and immune phenotypes were assessed in blood from ART treated PWH (19-77yrs, n = 106) and age-matched, HIV-negative controls (HC, n = 103). Using univariate spearman correlation, we identified 277 and 491 age-associated parameters out of a total 1,357 in HC and PWH, respectively. PWH exhibited shared and distinct age-associated immune profiles compared to HC highlighting the effect of HIV infection on immunological aging. Our analysis resulted in an 8-parameter, plasma-detectable inflammatory index that correlated with chronological age of all study participants but was higher overall in PWH. Additionally, predictive modeling for age in HC participants and age-associated parameters generated a 25-parameter signature, IMAP-25, with 70% and 53% accuracy in HC and PWH, respectively. Applying the IMAP-25 signature to immunological data from PWH revealed accelerated aging in PWH by 5.6 yrs. Overall, our results demonstrate that immune signatures, easily monitored in human blood samples, can be used as an indicator of one's 'immunological age' during ART-treated HIV infection and can be applied to other disease states that affect the immune system.

Age Associated Microbiome and Microbial Metabolites Modulation and Its Association With Systemic Inflammation in a Rhesus Macaque Model.

Aging is associated with declining immunity and inflammation as well as alterations in the gut microbiome with a decrease of beneficial microbes and increase in pathogenic ones. The aim of this study was to investigate the age associated gut microbiome in relation to immunologic and metabolic profile in a non-human primate (NHP) model. 12 geriatric (age 19-24 years) and 4 young adult (age 3-4 years) Rhesus macaques were included in this study. Immune cell subsets were characterized in peripheral blood mononuclear cells (PBMC) by flow cytometry and plasma cytokines levels were determined by bead based multiplex cytokine analysis. Stool samples were collected by ileal loop and investigated for microbiome analysis by shotgun metagenomics. Serum, gut microbial lysate, and microbe-free fecal extract were subjected to metabolomic analysis by mass-spectrometry. Our results showed that the gut microbiome in geriatric animals had higher abundance of Archaeal and Proteobacterial species and lower Firmicutes than the young adults. Highly abundant microbes in the geriatric animals showed a direct association with plasma biomarkers of inflammation and immune activation such as neopterin, CRP, TNF, IL-2, IL-6, IL-8 and IFN-γ. Significant enrichment of metabolites that contribute to inflammatory and cytotoxic pathways was observed in serum and feces of geriatric animals compared to the young adults. We conclude that aging NHP undergo immunosenescence and age associated alterations in the gut microbiome that has a distinct metabolic profile. Aging NHP can serve as a model for investigating the relationship of the gut microbiome to particular age-associated comorbidities and for strategies aimed at modulating the microbiome.