Highly divergent patterns of genetic diversity and evolution in proviral quasispecies from HIV controllers.

BACKGROUND: Ongoing intra-host HIV-1 evolution has been shown in individuals that naturally suppress the viremia to low levels (HIV controllers) by the analysis of the RNA in plasma compartment. Detection of evolution at the DNA proviral compartment in HIV controllers, however, has been more challenging and the precise correlation between the systemic viral suppression level and rate of reservoir's reseeding in those individuals is not fully understood. In this sense, we examined the proviral DNA quasispecies by single genome amplification of the env gene in a cohort of 23 HIV controllers from Brazil, divided in three groups, according to the level of systemic viral suppression: (1) elite controllers with persistent undetectable viral load (PEC, n = 6); (2) elite controllers with occasional episodes of transient (51-400 copies/mL) viremia (EEC, n = 7); and (3) viremic controllers with persistent low-level (80-2000 copies/mL) viremia (VC, n = 10). RESULTS: The HIV-1 diversity of the PBMC-associated proviral quasispecies in EC was significantly (P < 0.01) lower than in VC, but not significantly different between PEC and EEC groups. We detected a considerable variation in the average pairwise nucleotide distance and proportion of unique sequences in the HIV-1 proviral quasispecies of PEC and EEC. Some PEC and EEC displayed highly homogenous proviral populations with large clusters of identical sequences, while others exhibited relatively diverse proviral populations with a high proportion of unique sequences comparable to VC subjects. The long-term (10-15 years) follow-up of the HIV-1 proviral populations revealed a complete evolutionary stasis in one PEC and measurable divergence rates in one EEC [3.1 (1.2-5.6) × 10-3 substitutions/site/year and one VC [2.9 (0.7-5.1) × 10-3 substitutions/site/year]. CONCLUSIONS: There is no simple relationship between systemic viral suppression and intra-host proviral diversity or rate of reservoir's reseeding in chronically infected HIV controllers. Our results demonstrate that very divergent patterns of intra-host viral diversity and divergence could be detected in the setting of natural suppression of HIV-1 replication and that ongoing evolution and reseeding of the PBMC proviral reservoir occurs in some elite controllers.

Recent HIV infection and annualized HIV incidence rates among sexual and gender minorities in Brazil and Peru (ImPrEP seroincidence study): a cross-sectional, multicenter study.

Background: HIV incidence estimation is critical for monitoring the HIV epidemic dynamics and the effectiveness of public health prevention interventions. We aimed to identify sexual and gender minorities (SGM) with recent HIV infections, factors associated with recent HIV infection, and to estimate annualised HIV incidence rates. Methods: Cross-sectional multicentre study in HIV testing services in Brazil and Peru (15 cities). Inclusion criteria: 18+ years, SGM assigned male at birth, not using pre-/post-exposure prophylaxis. We identified recent HIV infection using the Maxim HIV-1 LAg-Avidity EIA assay as part of a recent infection testing algorithm (RITA). Annualized HIV incidence was calculated using the UNAIDS/WHO incidence estimator tool. Multivariable logistic regression models were used to estimate factors associated with recent HIV infection. Trial registration: NCT05674682. Findings: From 31-Jan-2021 to 29-May-2022, 6899 individuals participated [Brazil: 4586 (66.5%); Peru: 2313 (33.5%)]; 5946 (86.2%) cisgender men, 751 (10.9%) transgender women and 202 (2.9%) non-binary/gender diverse. Median age was 27 (IQR: 23-34) years. HIV prevalence was 11.4% (N = 784/6899); 137 (2.0%) SGM were identified with recent HIV infection. The overall annualized HIV incidence rate was 3.88% (95% CI: 2.86-4.87); Brazil: 2.62% (95% CI: 1.78-3.43); Peru: 6.69% (95% CI: 4.62-8.69). Participants aged 18-24 years had higher odds of recent HIV infection compared to those aged 30+ years in both countries. Interpretation: Our results highlight the significant burden of HIV epidemic among SGM in large urban centres of Brazil and Peru. Public health policies and interventions to increase access to effective HIV prevention methods such as PrEP are urgently needed in Latin America. Funding: Unitaid, WHO (Switzerland), Ministry of Health from Brazil and Peru.

Plasmatic Levels of IL-18, IP-10, and Activated CD8+ T Cells Are Potential Biomarkers to Identify HIV-1 Elite Controllers With a True Functional Cure Profile.

Elite controllers (ECs) are rare individuals able to naturally control HIV-1 replication below the detection limit of viral load (VL) commercial assays. It is unclear, however, whether ECs might be considered a natural model of a functional cure because some studies have noted CD4+ T cell depletion and disease progression associated with abnormally high levels of immune activation and/or inflammation in this group. Here, we propose the use of immunological parameters to identify HIV-1 ECs that could represent the best model of a functional cure. We compared plasma levels of six inflammatory biomarkers (IP-10, IL-18, sCD163, sCD14, CRP, and IL-6) and percentages of activated CD8+ T cells (CD38+HLA-DR+) between 15 ECs [8 with persistent undetectable viremia (persistent elite controllers) and 7 with occasional viral blips (ebbing elite controllers)], 13 viremic controllers (VCs-plasma VL between 51 and 2,000 RNA copies/mL), and 18 HIV-1 infected patients in combined antiretroviral therapy, with suppressed viremia, and 18 HIV-uninfected controls (HIV-neg). The two groups of ECs presented inflammation and activation profiles similar to HIV-neg individuals, and there was no evidence of CD4+ T cell decline over time. VCs, by contrast, had higher levels of IL-18, IP-10, and CRP and a lower CD4/CD8 ratio than that of HIV-neg (P < 0.05). Plasma levels of IL-18 and IP-10 correlated positively with CD8+ T cell activation and negatively with both CD4/CD8 and CD4% in HIV-1 controllers. These results suggest that most ECs, defined using stringent criteria in relation to the cutoff level of viremia (≤50 copies/mL) and a minimum follow-up time of >5 years, show no evidence of persistent inflammation or immune activation. This study further suggests that plasmatic levels of IL-18/IP-10 combined with the frequency of CD8+CD38+HLA-DR+ T cells can be important biomarkers to identify models of a functional cure among HIV-1 ECs.

Increasing genetic distance to HIV-1 subtype B and F1 consensus sequences in the Brazilian epidemic: a challenge for vaccine strategies based on central immunogens?

It has been postulated that the non-synonymous divergence (distance to the subtype consensus sequence) observed in several HIV-1 subtype populations during 1990s attained the maximum limit that is compatible with viral fitness or survival, at least in the V3 env gene domain. To test this hypothesis, 145 subtype B and 64 subtype F env V3 sequences isolated from Brazilian HIV-1 positive patients between 1989 and 2004 were analyzed. HIV-1 env V3 sequences were grouped by year of collection and the mean intra-subtype diversity and divergence were examined at synonymous, non-synonymous, and amino acid level. The analyses clearly show that the mean intra-subtype divergence constantly increases in both subtype populations in the last 15 years, and more importantly, this trend was not only driven by a significant increase of the synonymous distance but also by a significant increase of the non-synonymous and amino acid distances between Brazilian circulating viruses and subtype consensus sequences. These results clearly disagree with the notion that the non-synonymous distance to the HIV-1 subtype consensus observed at population level had already attained the maximum limit, and suggest that the likelihood for success of vaccines based on "central" immunogens, as those based on any other empirically selected viral sequence, could be continuously diminishing over time.

Demographic history of HIV-1 subtypes B and F in Brazil.

The reconstruction of the epidemic history of several HIV populations, by using methods that infer the population history from sampled gene sequence data, has revealed important subtype-specific and regional-specific differences in patterns of epidemic growth. Here, we employ Bayesian coalescent-based methods to compare the population history of the HIV-1 subtype B and F1 epidemics in Brazil from non-contemporary env and pol gene sequences. Our results suggest that after the introduction of the subtypes B and F1 into Brazilian population, around mid to late 1960s and late 1970s, respectively, these subtypes experienced an initial period of exponential growth with similar epidemic growth rates ( approximately 0.5-0.6year(-1)). Later, the spreading rate of both subtypes seems to have slowed-down since mid to late 1980s. This demographic pattern is very similar to that reported for the subtype B epidemics in high-income countries where HIV was initially transmitted through homosexual intercourse and injecting drug use, as in Brazil; suggesting that the characteristics of transmission networks may be a key determinant of the HIV epidemic growth pattern. It is important to note that most of the subtype B and F1 sequences used in this study come from the Southeast region that has been the most affected by the AIDS epidemic in Brazil, being responsible for around 63% of all AIDS cases reported since the early eighties; but may not represent the demographic trend of the HIV-1 epidemic in other Brazilian regions.

HIV-1, HBV, HCV, HTLV, HPV-16/18, and Treponema pallidum infections in a sample of Brazilian men who have sex with men.

BACKGROUND: Men who have sex with men (MSM) are more vulnerable to blood-borne infections and/or sexually-transmitted infections (STI). This study was conducted to estimate the prevalences of mono and co-infections of HIV-1 and other blood-borne/STIs in a sample of MSM in Campinas, Brazil. METHODS: Responding Driven Sampling (RDS) was used for recruitment of MSM. Serum samples collected from 558 MSM were analyzed for the presence of serological markers for HIV-1, HBV, HCV, HTLV, HPV-16/18, and T. pallidum infections. RESULTS: The highest prevalences of infection in serum samples were found for HPV-16 and 18 (31.9% and 20.3%, respectively). Approximately 8% of the study population showed infection with HIV-1, and within that group, 27.5% had recently become infected with HIV-1. HBV infection and syphilis were detected in 11.4% and 10% of the study population, respectively, and the rates of HTLV and HCV infection were 1.5% and 1%, respectively. With the exception of HTLV, all other studied infections were usually found as co-infections rather then mono-infections. The rates of co-infection for HCV, HPV-18, and HIV-1 were the highest among the studied infections (100%, 83%, and 85%, respectively). Interestingly, HTLV infection was usually found as a mono-infection in the study group, whereas HCV was found only as a co-infection. CONCLUSIONS: The present findings highlight the need to educate the MSM population concerning their risk for STIs infections and methods of prevention. Campaigns to encourage vaccination against HBV and HPV could decrease the rates of these infections in MSM.

Anti-human immunodeficiency virus-1 antibody titers in injection drug users compared to sexually infected individuals.

Sera from infected injection drug users (IDU) have shown to have antibodies against synthetic human immunodeficiency virus-1 (HIV-1) envelope peptides more frequently. In this study, reactivity of 48 IDU plasma were compared to 60 plasmas obtained from sexually infected individuals (S). The overall reactivity of plasma from IDU compared to S was higher, and the reactivity titers were much higher for IDU plasma than S. IDU plasma also showed a broader antibody response. The higher reactivity titers were observed mainly for the gp41 immunodominant epitope and V3 peptides corresponding to the consensus sequences of HIV-1 subtypes/variants prevalent in Brazil (B, F, C) indicating the specificity in the higher immune response of IDU.

Anti-human immunodeficiency virus-1 antibody titers in injection drug users compared to sexually infected individuals

Sera from infected injection drug users (IDU) have shown to have antibodies against synthetic human immunodeficiency virus-1 (HIV-1) envelope peptides more frequently. In this study, reactivity of 48 IDU plasma were compared to 60 plasmas obtained from sexually infected individuals (S). The overall reactivity of plasma from IDU compared to S was higher, and the reactivity titers were much higher for IDU plasma than S. IDU plasma also showed a broader antibody response. The higher reactivity titers were observed mainly for the gp41 immunodominant epitope and V3 peptides corresponding to the consensus sequences of HIV-1 subtypes/variants prevalent in Brazil (B, F, C) indicating the specificity in the higher immune response of IDU