A Possible Sterilizing Cure of HIV-1 Infection Without Stem Cell Transplantation.

BACKGROUND: A sterilizing cure of HIV-1 infection has been reported in 2 persons living with HIV-1 who underwent allogeneic hematopoietic stem cell transplantations from donors who were homozygous for the CCR5Δ32 gene polymorphism. However, this has been considered elusive during natural infection. OBJECTIVE: To evaluate persistent HIV-1 reservoir cells in an elite controller with undetectable HIV-1 viremia for more than 8 years in the absence of antiretroviral therapy. DESIGN: Detailed investigation of virologic and immunologic characteristics. SETTING: Tertiary care centers in Buenos Aires, Argentina, and Boston, Massachusetts. PATIENT: A patient with HIV-1 infection and durable drug-free suppression of HIV-1 replication. MEASUREMENTS: Analysis of genome-intact and replication-competent HIV-1 using near-full-length individual proviral sequencing and viral outgrowth assays, respectively; analysis of HIV-1 plasma RNA by ultrasensitive HIV-1 viral load testing. RESULTS: No genome-intact HIV-1 proviruses were detected in analysis of a total of 1.188 billion peripheral blood mononuclear cells and 503 million mononuclear cells from placental tissues. Seven defective proviruses, some of them derived from clonally expanded cells, were detected. A viral outgrowth assay failed to retrieve replication-competent HIV-1 from 150 million resting CD4+ T cells. No HIV-1 RNA was detected in 4.5 mL of plasma. LIMITATIONS: Absence of evidence for intact HIV-1 proviruses in large numbers of cells is not evidence of absence of intact HIV-1 proviruses. A sterilizing cure of HIV-1 can never be empirically proved. CONCLUSION: Genome-intact and replication-competent HIV-1 were not detected in an elite controller despite analysis of massive numbers of cells from blood and tissues, suggesting that this patient may have naturally achieved a sterilizing cure of HIV-1 infection. These observations raise the possibility that a sterilizing cure may be an extremely rare but possible outcome of HIV-1 infection. PRIMARY FUNDING SOURCE: National Institutes of Health and Bill & Melinda Gates Foundation.

7-oxo-DHEA enhances impaired M. tuberculosis-specific T cell responses during HIV-TB coinfection.

BACKGROUND: Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), affecting approximately one third of the world's population. Development of an adequate immune response will determine disease progression or progress to chronic infection. Risk of developing TB among human immunodeficiency virus (HIV)-coinfected patients (HIV-TB) is 20-30 times higher than those without HIV infection, and a synergistic interplay between these two pathogens accelerates the decline in immunological functions. TB treatment in HIV-TB coinfected persons is challenging and it has a prolonged duration, mainly due to the immune system failure to provide an adequate support for the therapy. Therefore, we aimed to study the role of the hormone 7-oxo-dehydroepiandrosterone (7-OD) as a modulator of anti-tuberculosis immune responses in the context of HIV-TB coinfection. METHODS: A cross-sectional study was conducted among HIV-TB patients and healthy donors (HD). We characterized the ex vivo phenotype of CD4 + T cells and also evaluated in vitro antigen-specific responses by Mtb stimulation of peripheral blood mononuclear cells (PBMCs) in the presence or absence of 7-OD. We assessed lymphoproliferative activity, cytokine production and master transcription factor profiles. RESULTS: Our results show that HIV-TB patients were not able to generate successful anti-tubercular responses in vitro compared to HD, as reduced IFN-γ/IL-10 and IFN-γ/IL-17A ratios were observed. Interestingly, treatment with 7-OD enhanced Th1 responses by increasing Mtb-induced proliferation and the production of IFN-γ and TNF-α over IL-10 levels. Additionally, in vitro Mtb stimulation augmented the frequency of cells with a regulatory phenotype, while 7-OD reduced the proportion of these subsets and induced an increase in CD4 + T-bet+ (Th1) subpopulation, which is associated with clinical data linked to an improved disease outcome. CONCLUSIONS: We conclude that 7-OD modifies the cytokine balance and the phenotype of CD4 + T cells towards a more favorable profile for mycobacteria control. These results provide new data to delineate novel treatment approaches as co-adjuvant for the treatment of TB.

Env-Specific IgA from Viremic HIV-Infected Subjects Compromises Antibody-Dependent Cellular Cytotoxicity.

UNLABELLED: Elucidating the factors that modulate HIV-specific antibody-dependent cellular cytotoxicity (ADCC) will help in understanding its role in HIV immunity. The aim of this study was to determine whether IgA could modify the magnitude of ADCC in HIV infection, abrogating its protective role. Plasma samples from 20 HIV-positive (HIV(+)) subjects enrolled during primary HIV infection (PHI), 10 chronically infected subjects (chronic), and 7 elite controllers (EC) were used. ADCC was determined by using a fluorometric ADCC assay, before and after removal of plasma IgA. Data were analyzed by using nonparametric statistics. ADCC was documented in 80% of PHI enrollment samples and in 100% of PHI 12-month, chronic, and EC samples; it peaked after acute infection, reached a plateau in chronic infection, and decreased after initiation of antiretroviral treatment (ART). Significant associations between ADCC and disease progression were found only after removal of plasma IgA from 12-month PHI samples: the magnitude of ADCC not only increased after IgA removal but also correlated with CD4(+) T-cell preservation. This work provides evidence that gp120-specific IgA was capable of modifying ADCC responses during natural HIV infection for the first time and adds to similar evidence provided in other settings. Furthermore, it underscores the complexity of the ADCC phenomenon and will help in an understanding of its underlying mechanisms. IMPORTANCE: Although the induction of ADCC-mediating antibodies in HIV-infected subjects has been extensively documented, the association of these antibodies with protection from disease progression is poorly understood. Here, we demonstrate that plasma IgA is a factor capable of modifying the magnitude of IgG-mediated ADCC in HIV infection, mitigating its beneficial effect. These results help in understanding why previous studies failed to demonstrate correlations between ADCC and disease progression, and they also contribute to the notion that an HIV vaccine should stimulate the production of ADCC-mediating IgG antibodies but not IgA.

HIV-TB coinfection impairs CD8(+) T-cell differentiation and function while dehydroepiandrosterone improves cytotoxic antitubercular immune responses.

Tuberculosis (TB) is the leading cause of death among HIV-positive patients. The decreasing frequencies of terminal effector (TTE ) CD8(+) T cells may increase reactivation risk in persons latently infected with Mycobacterium tuberculosis (Mtb). We have previously shown that dehydroepiandrosterone (DHEA) increases the protective antitubercular immune responses in HIV-TB patients. Here, we aimed to study Mtb-specific cytotoxicity, IFN-γ secretion, memory status of CD8(+) T cells, and their modulation by DHEA during HIV-TB coinfection. CD8(+) T cells from HIV-TB patients showed a more differentiated phenotype with diminished naïve and higher effector memory and TTE T-cell frequencies compared to healthy donors both in total and Mtb-specific CD8(+) T cells. Notably, CD8(+) T cells from HIV-TB patients displayed higher Terminal Effector (TTE ) CD45RA(dim) proportions with lower CD45RA expression levels, suggesting a not fully differentiated phenotype. Also, PD-1 expression levels on CD8(+) T cells from HIV-TB patients increased although restricted to the CD27(+) population. Interestingly, DHEA plasma levels positively correlated with TTE in CD8(+) T cells and in vitro DHEA treatment enhanced Mtb-specific cytotoxic responses and terminal differentiation in CD8(+) T cells from HIV-TB patients. Our data suggest that HIV-TB coinfection promotes a deficient CD8(+) T-cell differentiation, whereas DHEA may contribute to improving antitubercular immunity by enhancing CD8(+) T-cell functions during HIV-TB coinfection.

Early Gag immunodominance of the HIV-specific T-cell response during acute/early infection is associated with higher CD8+ T-cell antiviral activity and correlates with preservation of the CD4+ T-cell compartment.

The important role of the CD8(+) T-cell response on HIV control is well established. Moreover, the acute phase of infection represents a proper scenario to delineate the antiviral cellular functions that best correlate with control. Here, multiple functional aspects (specificity, ex vivo viral inhibitory activity [VIA] and polyfunctionality) of the HIV-specific CD8(+) T-cell subset arising early after infection, and their association with disease progression markers, were examined. Blood samples from 44 subjects recruited within 6 months from infection (primary HIV infection [PHI] group), 16 chronically infected subjects, 11 elite controllers (EC), and 10 healthy donors were obtained. Results indicated that, although Nef dominated the anti-HIV response during acute/early infection, a higher proportion of early anti-Gag T cells correlated with delayed progression. Polyfunctional HIV-specific CD8(+) T cells were detected at early time points but did not associate with virus control. Conversely, higher CD4(+) T-cell set points were observed in PHI subjects with higher HIV-specific CD8(+) T-cell VIA at baseline. Importantly, VIA levels correlated with the magnitude of the anti-Gag cellular response. The advantage of Gag-specific cells may result from their enhanced ability to mediate lysis of infected cells (evidenced by a higher capacity to degranulate and to mediate VIA) and to simultaneously produce IFN-γ. Finally, Gag immunodominance was associated with elevated plasma levels of interleukin 2 (IL-2) and macrophage inflammatory protein 1ß (MIP-1ß). All together, this study underscores the importance of CD8(+) T-cell specificity in the improved control of disease progression, which was related to the capacity of Gag-specific cells to mediate both lytic and nonlytic antiviral mechanisms at early time points postinfection.

Pretreatment HIV-1 Resistance in Argentina: Results from the Second Surveillance Study Following World Health Organization Guidelines (2019).

More than 62,000 individuals are currently on antiretroviral treatment within the public health system in Argentina. In 2019, more than 50% of people on ART received non-nucleoside reverse transcriptase inhibitors (NNRTIs). In this context, the second nationwide HIV-1 pretreatment drug resistance surveillance study was carried out between April and December 2019 to assess the prevalence of HIV-1 drug resistance in Argentina using the World Health Organization guidelines. This was a nationwide cross-sectional study enrolling consecutive 18-year-old and older individuals starting ARVs at 19 ART-dispensing centers. This allowed us to estimate a point prevalence rate of resistance-associated mutations (RAMs) with a confidence interval (CI) of 5% (for the total population and for those without antiretroviral exposure). Four-hundred forty-seven individuals were included in the study. The prevalence of mutations associated with resistance was detected in 27.7% (95% CI 25.6-34.9%) of the population. For NNRTI, it was 19.6% (95% CI 16.3-24.5%), for integrase strand transfer inhibitor (INSTI) 6.1% (95% CI 6.1-11.9%), for nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) 3% (95% CI 1.9-5.9%), and for protease inhibitors 1.5% (95% CI 0.7-3.6%). Naive individuals had variants of resistance to NRTIs in 16.8% (95% CI 12.8-21.4) and 5.7% (95% CI 2.9-15.9) to INSTI. For experienced individuals, the prevalence of variants associated with resistance was 30.38% (95% CI 20.8-42.2) for NRTIs and 7.7% (95% CI 2.9-15.9) for INSTI. This study shows an increase in the frequency of nonpolymorphic RAMs associated with resistance to NNRTI. This study generates the framework of evidence that supports the use of schemes based on high genetic barrier integrase inhibitors as the first line of treatment and the need for the use of resistance test before prescribing schemes based on NNRTI. We report for the first time the presence of a natural polymorphism associated with the most prevalent recombinant viral form in Argentina and the presence of a mutation linked to first-line integrase inhibitors such as raltegravir.

Humoral and T Cell Response to SARS-CoV-2 Vaccination in Patients With Rheumatoid Arthritis.

OBJECTIVE: The objective of this study was to assess the SARS-CoV-2-specific humoral and T cell response after a two-dose regimen of SARS-CoV-2 vaccine in patients with rheumatoid arthritis (RA). METHODS: In this observational study, patients with RA who are ≥18 years of age and vaccinated for SARS-CoV-2 according to the Argentine National Health Ministry's vaccination strategy were included. Anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies (ELISA-COVIDAR test), neutralizing activity (cytotoxicity in VERO cells), and specific T cell response (IFN-γ ELISpot Assay) were assessed after the first and second dose. RESULTS: A total of 120 patients with RA were included. Mostly, homologous regimens were used, including Gam-COVID-Vac (27.5%), ChAdOx1 (24.2%), and BBIBP-CorV (22.5%). The most frequent combination was Gam-COVID-Vac/mRNA-1273 (21.7%). After the second dose, 81.7% presented with anti-SARS-CoV-2 antibodies, 70.0% presented with neutralizing activity, and 65.3% presented with specific T cell response. The use of BBIBP-CorV and treatment with abatacept (ABA) and rituximab (RTX) were associated with undetectable antibodies and no neutralizing activity after two doses. BBIBP-CorV was also associated with the absence of T cell response. The total incidence of adverse events was 357.1 events per 1,000 doses, significantly lower with BBIBP-CorV (166.7 events per 1,000 doses, P < 0.02). CONCLUSION: In this RA cohort vaccinated with homologous and heterologous regimens against COVID-19, 2 out of 10 patients did not develop anti-SARS-CoV-2 IgG, 70% presented with neutralizing activity, and 65% presented with specific T cell response. The use of BBIBP-CorV was associated with deficient humoral and cellular response, whereas treatment with ABA and RTX resulted in an impaired anti-SARS-CoV-2 IgG formation and neutralizing activity.

Increased risk of false-positive HIV ELISA results after COVID-19.

OBJECTIVE: From the first-generation options available in 1985, tests to detect HIV-1 specific antibodies have increased its sensitivity and specificity. HIV-1 and SARS-CoV-2 surface glycoproteins present a certain degree of homology and shared epitope motifs, which results of relevance as both pandemics coexist. Here, we aimed to evaluate the rate of false-positive HIV serology results among individuals with COVID-19 diagnosis and in vaccinated individuals. DESIGN: A retrospective analysis of the samples stored at the Infectious Disease Biobank in Argentina from donors with previous COVID-19 diagnosis or anti-SARS-CoV-2 vaccination. METHODS: Plasma samples were analyzed using Genscreen Ultra HIV Ag-Ab. In those with a positive result, the following assays were also performed: ELISA lateral flow Determine Early Detect; RecomLine HIV-1 & HIV-2 IgG and Abbott m2000 RealTime PCR for HIV-1 viral load quantification. In all samples, the presence of anti-SARS-CoV-2 IgG antibodies was evaluated by ELISA using the COVIDAR kit. Statistical analysis was done using Pearson's and Fisher's exact chi-squared test; Mann-Whitney and Kruskal-Wallis tests. RESULTS: Globally, the false-positive HIV ELISA rate was 1.3% [95% confidence interval (95% CI) 0.66-2.22; χ2  = 4.68, P  = 0.03, when compared with the expected 0.4% false-positive rate]. It increased to 1.4% (95% CI 0.70-2.24, χ2  = 5.16, P  = 0.02) when only samples from individuals with previous COVID-19 diagnosis, and to 1.8% (95% CI 0.91-3.06, χ2  = 7.99, P  = 0.005) when only individuals with detectable IgG SARS-CoV-2 antibodies were considered. CONCLUSION: This higher occurrence of HIV false-positive results among individuals with detectable antibodies against Spike SARS-CoV-2 protein should be dispersed among virology testing settings, health providers, and authorities.

Markers of Natural Killer Cell Exhaustion in HIV/HCV Coinfection and Their Dynamics After HCV Clearance Mediated by Direct-Acting Antivirals.

Background: Liver fibrosis is a leading cause of morbimortality in people with HIV/hepatitis C virus (HCV). Natural killer (NK) cells are linked with amelioration of liver fibrosis; however, NK cells from individuals coinfected with HIV/HCV with cirrhosis display impaired functionality and high PD-1 expression. Here, we aimed to study PD-1, TIGIT, and Tim3 as potential exhaustion markers in NK cells from persons coinfected with HIV/HCV with mild and advanced liver fibrosis. We also evaluated the role of PD-1 expression on NK cells after HCV clearance by direct-acting antivirals (DAAs). Methods: Peripheral blood mononuclear cells were isolated from individuals coinfected with HIV/HCV (N = 54; METAVIR F0/F1, n = 27; F4, evaluated by transient elastography, n = 27). In 26 participants, samples were collected before, at the end of, and 12 months after successful DAA treatment. The frequency, immunophenotype (PD-1, TIGIT, and Tim3 expression), and degranulation capacity (CD107a assay) of NK cells were determined by flow cytometry. Results: Unlike PD-1, Tim3 and TIGIT were comparably expressed between persons with mild and advanced fibrosis. Degranulation capacity was diminished in NK/TIGIT+ cells in both fibrosis stages, while NK/PD-1+ cells showed a lower CD107a expression in cirrhotic cases. Twelve months after DAA treatment, those with advanced fibrosis showed an improved NK cell frequency and reduced NK/PD-1+ cell frequency but no changes in CD107a expression. In individuals with mild fibrosis, neither PD-1 nor NK cell frequency was modified, although the percentage of NK/CD107a+ cells was improved at 12 months posttreatment. Conclusions: Although DAA improved exhaustion and frequency of NK cells in cirrhotic cases, functionality was reverted only in mild liver fibrosis, remarking the importance of an early DAA treatment.

Serological response to SARS-CoV-2 vaccines in patients with multiple sclerosis in Argentina.

INTRODUCTION: The objective was to assess the immunogenicity and effectiveness of vaccines against SARSCoV-2 in multiple sclerosis (MS) patients included in the Argentinean MS registry. METHODS: A prospective cohort study between May and December 2021. The primary outcome was immunogenicity and effectiveness of vaccines during a three-month follow-up. Immunogenicity was evaluated based on detection of total antibodies (Ab) against spike protein and neutralizing Ab in serum 4 weeks after the second vaccine dose. A positive COVID-19 case was defined according to Argentinean Ministry of Health. RESULTS: 94 patients were included, mean age: 41.7 ± 12.1 years. Eighty (85.1%) had relapsing remitting multiple sclerosis (RRMS); 30 (31.9%) were under fingolimod treatment. The Sputnik V vaccine was the first dose in 33 (35.1%), and AstraZeneca in 61 (64.9%). In 60 (63.8%), the vaccine elicited a specific humoral response. Immunological response according to the vaccination schemes showed no qualitative differences (p = 0.45). Stratified analysis according to the MS treatment showed that a significantly smaller number of subjects developed antibodies against spike antigen among those that were on ocrelizumab compared to other groups (p = 0.001), while a reduced number of patients under ocrelizumab where evaluated (n = 7). This was also observed for neutralizing antibodies in the ocrelizumab group (p < 0.001). During the three-month follow-up, two individuals were diagnosed with COVID-19. CONCLUSION: We found that MS patients that received Sputnik V or AstraZeneca vaccines for SARS-CoV-2 developed a serological response with no differences between the vaccines used.

Introducción: El objetivo fue evaluar la inmunogenicidad y efectividad de las vacunas contra el SARS-CoV-2 en pacientes con esclerosis múltiple (EM) incluidos en el registro argentino de EM (RelevarEM, NCT03375177). Métodos: Estudio de cohorte prospectivo entre mayo y diciembre 2021. Se evaluó la inmunogenicidad (detección de anticuerpos totales (Ab) contra proteína espiga y anticuerpos neutralizantes en suero) y eficacia (nueva infección por COVID-19) durante seguimiento de tres meses. El momento de detección de anticuerpos fue 4 semanas después de segunda dosis de vacuna. Un caso positivo de COVID-19 se definió de acuerdo con la definición del Ministerio de Salud. Resultados: Se incluyeron 94 pacientes, edad media de 41.7 ± 12.1 años. Ochenta (85.1%) tenían EM remitente-recurrente; 30 (31.9%) en tratamiento con fingolimod. La vacuna Sputnik V fue usada en 33 (35.1%), mientras que AstraZeneca se administró en 61 (64.9%). En 60 pacientes (63.8 %), la vacuna provocó respuesta humoral específica. La respuesta inmunológica según esquemas de vacunación (Sputnik V, Astra Zeneca o esquemas heterólogos) no mostró diferencias cualitativas (p = 0.45). El análisis estratificado según tratamiento recibido para la EM mostró que número significativamente menor de sujetos desarrolló anticuerpos contra el antígeno espiga en los pacientes que recibieron ocrelizumab (p = 0.001), aunque con un número reducido de pacientes evaluados bajo este tratamiento (n = 7). Esto también se observó para anticuerpos neutralizantes en el grupo bajo ocrelizumab (p < 0.001). Durante el seguimiento de tres meses, dos personas fueron diagnosticadas con COVID-19. Conclusión: Encontramos que los pacientes con EM que recibieron vacunas Sputnik V o AstraZeneca para el SARS-CoV-2 desarrollaron respuesta serológica sin diferencias entre las vacunas utilizadas.

Persistent symptoms after COVID-19 in children and adolescents from Argentina.

OBJECTIVES: Although long COVID-19 is widely recognized in adults, less information is available about this condition in children, especially in developing countries. Here, we studied the long-term symptoms of SARS-CoV-2 infection beyond 3 months and the associated risk factors in a pediatric population. METHODS: This observational study included 639 Argentinian children and adolescents with previously confirmed COVID-19 from June 2020-June 2021 and 577 children without previous COVID-19. Parents completed a survey about symptoms that their child had for >3 months after the diagnosis of SARS-CoV-2 infection. RESULTS: At least one persistent symptom was observed more frequently in children with previous COVID-19 than in the non-COVID-19 group (34% vs 13%, P <0.0001). SARS-CoV-2 infection increased the risk of headache, dizziness, loss of taste, dyspnea, cough, fatigue, muscle pain, and loss of weight by three- to seven-fold. The loss of smell was only reported in infected children. After controlling for the other variables, older age, symptomatic COVID-19, and comorbidities were independent predictors of long-term symptoms. CONCLUSIONS: One-third of children experienced persistent symptoms after COVID-19. Older age, symptomatic infection, and comorbidities were shown to be risk factors for long COVID-19. Pediatric long COVID-19 is a new condition that requires further investigation.

A clustering phenomenon among HCV-1a strains among patients coinfected with HIV from Buenos Aires, Argentina.

The human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes which lead to high coinfection rates. Among HIV-infected individuals such rates reached 21% in Argentina, being HCV-1a the most predominant subtype. In this work, 25 HCV subtype 1a (HCV-1a) strains from Argentinean patients coinfected with HIV were studied based on E2 and NS5A sequences. Phylogenetic analyses indicated that 12 strains were highly related to each other, constituting a highly supported (posterior probability = 0.95) monophyletic group that we called "M." The remaining HCV strains (group dispersed or "D") were interspersed along the phylogenetic trees. When comparing both groups of HCV-1a, 10 amino acid differences were located in functional domains of E2 and NS5A proteins that appeared to affect eventually the peptides binding to MHC-I molecules thus favoring immune escape and contributing to the divergence of HCV genotypes. Bayesian coalescent analyses for HCV-1a cluster M isolates indicated that the time to the most recent common ancestor (tMRCA) overlaps with the age estimated recently for the HIV-BF epidemic in Argentina. Furthermore, the genomic characterization based on pol gene analysis from HIV viremic patients showed that most HIV isolates from patients coinfected with HCV-1a cluster M were BF recombinants with identical recombination patterns. In conclusion, these results suggest the presence of an HCV-1a monophyletic cluster with a potential HIV co-transmission by phylogenetic analyses.

Macrophage Migration Inhibitory Factor (MIF) Promotes Increased Proportions of the Highly Permissive Th17-like Cell Profile during HIV Infection.

In this study, we evaluate the role of the MIF/CD74 axis in the functionality of CD4+ T lymphocytes (CD4TL) during HIV infection. MDMs from healthy donors were infected with a R5-tropic or Transmitted/Founder (T/F) HIV strain. At day 11 post-MDM infection, allogeneic co-cultures with uninfected CD4TLs plus MIF stimulus were performed. Cytokine production was evaluated by ELISA. MIF plasma levels of people with HIV (PWH) were evaluated by ELISA. The phenotype and infection rate of CD4TLs from PWH were analyzed after MIF stimulus. Intracellular cytokines and transcription factors were evaluated by flow cytometry. Data were analyzed by parametric or non-parametric methods. The MIF stimulation of HIV-infected MDMs induced an increased expression of IL-6, IL-1ß and IL-8. In CD4TL/MDM co-cultures, the MIF treatment increased IL-17A/RORγt-expressing CD4TLs. Higher concentrations of IL-17A in supernatants were also observed. These results were recapitulated using transmitted/founder (T/F) HIV-1 strains. The MIF treatment appeared to affect memory CD4TLs more than naïve CD4TLs. MIF blocking showed a negative impact on IL17A+CD4TL proportions. Higher MIF concentrations in PWH-derived plasma were correlated with higher IL-17A+CD4TL percentages. Finally, MIF stimulation in PWH-derived PBMCs led to an increase in Th17-like population. MIF may contribute to viral pathogenesis by generating a microenvironment enriched in activating mediators and Th17-like CD4TLs, which are known to be highly susceptible to HIV-1 infection and relevant to viral persistence. These observations establish a basis for considering MIF as a possible therapeutic target.

A Dynamic Interplay of Circulating Extracellular Vesicles and Galectin-1 Reprograms Viral Latency during HIV-1 Infection.

Combined Antiretroviral therapy (cART) suppresses HIV replication but fails to eradicate the virus, which persists in a small pool of long-lived latently infected cells. Immune activation and residual inflammation during cART are considered to contribute to viral persistence. Galectins, a family of ß-galactoside-binding proteins, play central roles in host-pathogen interactions and inflammatory responses. Depending on their structure, glycan binding specificities and/or formation of distinct multivalent signaling complexes, different members of this family can complement, synergize, or oppose the function of others. Here, we identify a regulatory circuit, mediated by galectin-1 (Gal-1)-glycan interactions, that promotes reversal of HIV-1 latency in infected T cells. We found elevated levels of circulating Gal-1 in plasma from HIV-1-infected individuals, which correlated both with inflammatory markers and the transcriptional activity of the reservoir, as determined by unspliced-RNA (US-RNA) copy number. Proinflammatory extracellular vesicles (EVs) isolated from the plasma of HIV-infected individuals induced Gal-1 secretion by macrophages. Extracellularly, Gal-1 interacted with latently infected resting primary CD4+ T cells and J-LAT cells in a glycan-dependent manner and reversed HIV latency via activation of the nuclear factor κB (NF-κB). Furthermore, CD4+ T cells isolated from HIV-infected individuals showed increased HIV-1 transcriptional activity when exposed to Gal-1. Thus, by modulating reservoir dynamics, EV-driven Gal-1 secretion by macrophages links inflammation with HIV-1 persistence in cART-treated individuals. IMPORTANCE Antiretroviral therapy has led to a dramatic reduction in HIV-related morbidity and mortality. However, cART does not eradicate the virus, which persists in resting CD4+ T cells as the main viral reservoir, consequently requiring lifelong treatment. A major question is how the functional status of the immune system during antiretroviral therapy determines the activity and size of the viral reservoir. In this study, we identified a central role for galectin-1 (Gal-1), a glycan-binding protein released in response to extracellular vesicles (EVs), in modulating the activity of HIV reservoir, thus shaping chronic immune activation in HIV-infected patients. Our work unveils a central role of Gal-1 in linking chronic immune activation and reservoir dynamics, highlighting new therapeutic opportunities in HIV infection.

Immune Response to SARS-CoV-2 Third Vaccine in Patients With Rheumatoid Arthritis Who Had No Seroconversion After Primary 2-Dose Regimen With Inactivated or Vector-Based Vaccines.

OBJECTIVE: The aim of this study was to assess the immune response after a third dose of SARS-CoV-2 vaccine in patients with rheumatoid arthritis (RA) with undetectable antibody titers after the primary regimen of 2 doses. METHODS: Patients with RA with no seroconversion after 2 doses of SARS-CoV-2 vaccine and who received a third dose of either an mRNA or vector-based vaccine were included. Anti-SARS-CoV-2 IgG antibodies, neutralizing activity, and T cell responses were assessed after the third dose. RESULTS: A total of 21 nonresponder patients were included. At the time of vaccination, 29% were receiving glucocorticoids and 85% biologic disease-modifying antirheumatic drugs (including 6 taking abatacept [ABA] and 4 taking rituximab [RTX]). The majority (95%) received the BNT162b2 vaccine and only one of them received the ChAdOx1 nCoV-19 vaccine. After the third dose, 91% of the patients presented detectable anti-SARS-CoV-2 IgG and 76% showed neutralizing activity. Compared to other treatments, ABA and RTX were associated with the absence of neutralizing activity in 4 out of 5 (80%) patients and lower titers of neutralizing antibodies (median 3, IQR 0-20 vs 8, IQR 4-128; P = 0.20). Specific T cell response was detected in 41% of all patients after the second dose, increasing to 71% after the third dose. The use of ABA was associated with a lower frequency of T cell response (33% vs 87%, P = 0.03). CONCLUSION: In this RA cohort, 91% of patients who failed to seroconvert after 2 doses of SARS-CoV-2 vaccine presented detectable anti-SARS-CoV-2 IgG after a third dose. The use of ABA was associated with a lower frequency of specific T cell response.

Antibody response against SARS-CoV-2 variants of concern in children infected with pre-Omicron variants: An observational cohort study.

BACKGROUND: Despite that pediatric COVID-19 is usually asymptomatic or mild, SARS-CoV-2 infection typically results in the development of an antibody response. Contradictory observations have been reported when the antibody response of children and adults were compared in terms of strength, specificity and perdurability. METHODS: This observational study includes three cohorts infected with SARS-CoV-2 between March 2020-July 2021: unvaccinated infected children (n=115), unvaccinated infected adults (n=62), and vaccinated infected children (n=76). Plasma anti-spike IgG antibodies and neutralising activity against Wuhan, Delta and Omicron variants after 7-17 months post-infection were analysed. FINDINGS: More than 95% of unvaccinated infected children and adults remained seropositive when evaluated at 382-491 and 386-420 days after infection, respectively. Anti-spike IgG titers and plasma neutralising activity against Wuhan, Delta and Omicron variants were higher in children compared to adults. No differences were found when unvaccinated infected children were stratified by age, gender or presence/absence of symptoms in the acute phase of SARS-CoV-2 infection, but a slight decrease in the antibody response was observed in those with comorbidities. Vaccination of previously infected children with two doses of the inactivated BBIBP-CorV or the mRNA vaccines, BNT162b2 and/or mRNA-1273, further increased anti-spike IgG titers and neutralising activity against Wuhan, Delta and Omicron variants. INTERPRETATION: Unvaccinated infected children mount a more potent and sustained antibody response compared with adults, which is significantly increased after vaccination. Further studies including not only the analysis of the immune response but also the effectiveness to prevent reinfections by the different Omicron lineages are required to optimise vaccination strategy in children. FUNDING: National Agency for Scientific and Technological Promotion from Argentina (PICTO-COVID-SECUELAS-00007 and PMO-BID-PICT2018-2548).

Longitudinal Study after Sputnik V Vaccination Shows Durable SARS-CoV-2 Neutralizing Antibodies and Reduced Viral Variant Escape to Neutralization over Time.

Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC; Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI; Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples (N = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.

Dynamics of SARS-CoV-2-specific antibodies among COVID19 biobank donors in Argentina.

Biobanks are instrumental for accelerating research. Early in SARS-CoV-2 pandemic, the Argentinean Biobank of Infectious Diseases (BBEI) initiated the COVID19 collection and started its characterization. Blood samples from subjects with confirmed SARS-CoV-2 infection either admitted to health institutions or outpatients, were enrolled. Highly exposed seronegative individuals, were also enrolled. Longitudinal samples were obtained in a subset of donors, including persons who donated plasma for therapeutic purposes (plasma donors). SARS-CoV-2-specific IgM and IgG levels, IgG titers and IgG viral neutralization capacity were determined. Out of 825 donors, 57.1% were females and median age was 41 years (IQR 32-53 years). Donors were segregated as acute or convalescent donors, and mild versus moderate/severe disease donors. Seventy-eight percent showed seroconversion to SARS-CoV-2 specific antibodies. Specific IgM and IgG showed comparable positivity rates in acute donors. IgM detectability rate declined in convalescent donors while IgG detectability remained elevated in early (74,8%) and late (83%) convalescent donors. Among donors with follow-up samples, IgG levels seemed to decline more rapidly in plasma donors. IgG levels were higher with age, disease severity, number of symptoms, and more durable in moderate/severe disease donors. Levels and titers of anti-spike/RBD IgG strongly correlated with neutralization activity against WT virus. The BBEI-COVID19 collection serves a dual role in this SARS-CoV-2 global crisis. First, it feeds researchers and developers transferring samples and data to fuel research projects. Second, it generates highly needed local data to understand and frame the regional dynamics of the infection.

Pre-cART Immune Parameters in People Living With HIV Might Help Predict CD8+ T-Cell Characteristics, Inflammation Levels, and Reservoir Composition After Effective cART.

BACKGROUND: Combined antiretroviral treatment (cART) for HIV infection is highly effective in controlling viral replication. However, it cannot achieve a sterilizing cure. Several strategies have been proposed to achieve a functional cure, some of them based on immune-mediated clearing of persistently infected cells. Here, we aimed at identifying factors related to CD8TC and CD4TC quality before cART initiation that associate with the persistence of CD8TC antiviral response after cART, inflammation levels, and the size of the viral reservoir. METHODS: Samples from 25 persons living with HIV were obtained before and after (15 months) cART initiation. Phenotype and functionality of bulk and HIV-specific T cells were assayed by flow cytometry ex vivo or after expansion in pre-cART or post-cART samples, respectively. Cell-Associated (CA) HIV DNA (total and integrated) and RNA (unspliced [US] and multiple spliced [MS]) were quantitated by real-time PCR on post-cART samples. Post-cART plasma levels of CXCL10 (IP-10), soluble CD14 (sCD14) and soluble CD163 (sCD163) were measured by ELISA. RESULTS: Pre-cART phenotype of CD8TCs and magnitude and phenotype of HIV-specific response correlated with the phenotype and functionality of CD8TCs post-cART. Moreover, the phenotype of the CD8TCs pre-cART correlated with markers of HIV persistence and inflammation post-cART. Finally, exhaustion and differentiation of CD4TCs pre-cART were associated with the composition of the HIV reservoir post-cART and the level of inflammation. CONCLUSIONS: Overall, this work provides data to help understand and identify parameters that could be used as markers in the development of immune-based functional HIV cure strategies.

Immune variations throughout the course of tuberculosis treatment and its relationship with adrenal hormone changes in HIV-1 patients co-infected with Mycobacterium tuberculosis.

HIV infection is a major risk factor predisposing for Mycobacterium tuberculosis infection and progression to active tuberculosis (TB). As host immune response defines the course of infection, we aimed to identify immuno-endocrine changes over six-months of anti-TB chemotherapy in HIV+ people. Plasma levels of cortisol, DHEA and DHEA-S, percentages of CD4+ regulatory T cell subsets and number of IFN-γ-secreting cells were determined. Several cytokines, chemokines and C-reactive protein levels were measured. Results were correlated with clinical parameters as predictors of infection resolution and compared to similar data from HIV+ individuals, HIV-infected persons with latent TB infection and healthy donors. Throughout the course of anti-TB/HIV treatment, DHEA and DHEA-S plasma levels raised while cortisol diminished, which correlated to predictive factors of infection resolution. Furthermore, the balance between cortisol and DHEA, together with clinical assessment, may be considered as an indicator of clinical outcome after anti-TB treatment in HIV+ individuals. Clinical improvement was associated with reduced frequency of unconventional Tregs, increment in IFN-γ-secreting cells, diminution of systemic inflammation and changes of circulating cytokines and chemokines. This study suggests that the combined anti-HIV/TB therapies result in partial restoration of both, immune function and adrenal hormone plasma levels.