Impact of HIV-1 Subtypes on AIDS Progression in a Brazilian Cohort

Functional variability of Nef in antagonizing SERINC5 during acute to chronic HIV-1 infection

OBJECTIVE

The ability of HIV-1 Nef to counteract the host restriction factor SERINC5 and enhance virion infectivity has been well established. However, the impact of long-term within-host Nef evolution on this antagonistic capability remains unclear.

DESIGN

Analysis of longitudinal activity of Nef in antagonizing SERINC5.

METHODS

We investigated the downregulation activity of Nef against SERINC5 at different stages of infection by analyzing the cognate transmitted/founder, set point, and/or chronic Nef isolates from a cohort of 19 people with either subtype B or C HIV-1.

RESULTS

The Nef isolates from different stages exhibited varying abilities to antagonize SERINC5. Long-term evolution resulted in mutations accumulated in Nef and a decline of Nef-mediated SERINC5 downregulation function in subtype B, but not in subtype C viruses, leading to a rapid reduction in viral load from peak viremia. Furthermore, we identified four polymorphisms of both subtype B and C Nef that are associated with variations in the SERINC5 antagonistic function and viral infectivity. HIV-1 NL4-3 variants encoding Nef E63G, A83G, R105K, or D108E mutants exhibited reduced replication capacity through a SERINC5-dependent mechanism. However, among different subjects, only a small part of naturally occurring mutations at these sites were selected by host T-cell responses, suggesting a limited impact of host T-cell responses on influencing Nef's ability to antagonize SERINC5.

CONCLUSION

These results highlight the potential contribution of functional variation in Nef to differences in HIV-1 pathogenesis and provide significant implications for understanding the evolutionary interaction between Nef and SERINC5 in vivo .

Dynamics and features of transmission clusters of HIV-1 subtypes in the state of São Paulo, Brazil

Background

Molecular epidemiology techniques allow us to track the HIV-1 transmission dynamics. Herein, we combined genetic, clinical and epidemiological data collected during routine clinical treatment to evaluate the dynamics and characteristics of transmission clusters of the most prevalent HIV-1 subtypes in the state of São Paulo, Brazil.

Methods

This was a cross-sectional study conducted with 2,518 persons living with HIV (PLWH) from 53 cities in São Paulo state between Jan 2004 to Feb 2015. The phylogenetic tree of protease/reverse transcriptase (PR/RT) regions was reconstructed by PhyML and ClusterPicker used to infer the transmission clusters based on Shimodaira-Hasegawa (SH) greater than 90% (phylogenetic support) and genetic distance less than 6%.

Results

Of a total of 2,518 sequences, 2,260 were pure subtypes at the PR/RT region, being B (88%), F1 (8.1%), and C (4%). About 21.2% were naïve with a transmitted drug resistance (TDR) rate of 11.8%. A total of 414 (18.3%) of the sequences clustered. These clusters were less evident in subtype B (17.7%) and F1 (15.1%) than in subtype C (40.2%). Clustered sequences were from PLWH at least 5 years younger than non-clustered among subtypes B (p < 0.001) and C (p = 0.037). Men who have sex with men (MSM) predominated the cluster in subtype B (51%), C (85.7%), and F1 (63.6%; p < 0.05). The TDR rate in clustered patients was 15.4, 13.6, and 3.1% for subtypes B, F1, and C, respectively. Most of the infections in subtypes B (80%), C (64%), and F1 (59%) occurred within the state of São Paulo. The metropolitan area of São Paulo presented a high level of endogenous clustering for subtypes B and C. The São Paulo city had 46% endogenous clusters of subtype C.

Conclusion

Our findings showed that MSM, antiretroviral therapy in Treatment-Naive (ART-naïve) patients, and HIV1-C, played an important role in the HIV epidemic in the São Paulo state. Further studies in transmission clusters are needed to guide the prevention intervention.

Recombinant Forms of HIV-1 in the Last Decade of the Epidemic in the Russian Federation

Currently, HIV-1 displays a substantial level of genetic diversity on a global scale, partly attributed to its recombinant variants. This study seeks to identify and analyze HIV-1 recombinants in Russia during the last decade of the epidemic. A comprehensive examination was conducted, encompassing 3178 partial pol sequences. Subtyping was achieved through various programs including COMET, the Stanford Database, REGA, jpHMM, RIP, and RDP4 for recombination analysis. The study also involved phylogenetic analysis to trace the origins of the identified recombinants. Primary resistance (PrimDR) prevalence and Drug Resistance Mutations (DRMs) were assessed. The study uncovered an overall proportion of recombinants at 8.7%, with a statistically significant increase in their frequency observed over time (p < 0.001). The Northwestern (18.5%) and Siberian (15.0%) Federal Districts exhibited a high prevalence of recombinants, while the Volga (1.9%) and Ural (2.8%) Federal Districts had a lower prevalence. Among HIV-1 recombinants, a PrimDR prevalence of 11.4% was identified. Notably, significant differences in DRMs were observed, with a higher prevalence of M184V in sub-subtype A6 (p = 0.018) and K103N in CRF63_02A6 (p = 0.002). These findings underscore the increasing HIV-1 genetic diversity and highlight a substantial prevalence of PrimDR among its recombinant forms, emphasizing the necessity for ongoing systematic monitoring.

HIV-1 subtypes maintain distinctive physicochemical signatures in Nef domains associated with immunoregulation

BACKGROUND

HIV subtype is associated with varied rates of disease progression. The HIV accessory protein, Nef, continues to be present during antiretroviral therapy (ART) where it has numerous immunoregulatory effects. In this study, we analyzed Nef sequences from HIV subtypes A1, B, C, and D using a machine learning approach that integrates functional amino acid information to identify if unique physicochemical features are associated with Nef functional/structural domains in a subtype-specific manner.

METHODS

2253 sequences representing subtypes A1, B, C, and D were aligned and domains with known functional properties were scored based on amino acid physicochemical properties. Following feature generation, we used statistical pruning and evolved neural networks (ENNs) to determine if we could successfully classify subtypes. Next, we used ENNs to identify the top five key Nef physicochemical features applied to specific immunoregulatory domains that differentiated subtypes. A signature pattern analysis was performed to the assess amino acid diversity in sub-domains that differentiated each subtype.

RESULTS

In validation studies, ENNs successfully differentiated each subtype at A1 (87.2%), subtype B (89.5%), subtype C (91.7%), and subtype D (85.1%). Our feature-based domain scoring, followed by t-tests, and a similar ENN identified subtype-specific domain-associated features. Subtype A1 was associated with alterations in Nef CD4 binding domain; subtype B was associated with alterations with the AP-2 Binding domain; subtype C was associated with alterations in a structural Alpha Helix domain; and, subtype D was associated with alterations in a Beta-Sheet domain.

CONCLUSIONS

Recent studies have focused on HIV Nef as a driver of immunoregulatory disease in those HIV infected and on ART. Nef acts through a complex mixture of interactions that are directly linked to the key features of the subtype-specific domains we identified with the ENN. The study supports the hypothesis that varied Nef subtypes contribute to subtype-specific disease progression.

Infection with HIV-1 subtype D adversely affects the live expectancy independently of antiretroviral drug use

INTRODUCTION

HIV-1 subtypes have been associated with less favourable clinical profiles, differences in disease progression and higher risk of neurocognitive deficit. In this study we aimed to analyse the long term survival disparities between patients infected with the most common HIV-1 variants observed in Poland.

METHODS

For the study data from 518 Caucasian non-immigrant patients of Polish origin infected with divergent HIV subtypes and variants [subtype A (n = 35, 6.8%), subtype B (n = 386, 74.5%), subtype C (n = 13, 2.5%), subtype D (n = 58, 11.19%) or other non-A,B,C,D (n = 26, 5.01%)variants] were analysed. Subtyping was performed using the partial pol (reverse transcriptase and protease) sequencing. HIV variant was coupled with clinical, virologic and survival data censored at 20 years of observation. Overall survival and on antiretroviral treatment survival was analysed using Kaplan-Meyer as well as unadjusted and multivariate Cox proportional hazards models.

RESULTS

Significantly higher mortality was observed among subtype D (28.8%) infected subjects compared to subtype B (11.7%, p = 0.0004). Increased risk of death among subtype D cases remained significant when cART treated individuals were analysed, with on-treatment mortality of 26.9% for subtype D (p = 0.006) compared to 10.73% in subtype B infected cases. Kaplan-Meyer survival estimates differed significantly across all investigated HIV-1 variant groups when overall 20 year mortality was analysed (log rank p = 0.029), being non-significant for the cART treated group. In multivariate model of overall 20 year survival, adjusted for age at diagnosis, gender, HCV and AIDS status, lymphocyte CD4 count, transmission route and HIV viral load, only age and subtype D were independently associated with higher likelihood of death [HR: 1.08 (95%CI: 1.03-1.14, p = 0.002) and HR: 7.91 (95%CI:2.33-26.86), p < 0.001, respectively]. In the on-treatment (cART) multivariate model of 20 year survival adjusted for the same parameters only subtype D remained as the independent factor associated with higher mortality risk [HR: 4.24 (95%CI:1.31-13.7), p = 0.02].

CONCLUSIONS

Subtype D has an independent deleterious effect of survival, even in the setting of antiretroviral treatment. Observed effect indicated higher clinical vigilance for patients infected with this subtype even after long time of stable antiretroviral treatment.

Differential Vpu-Mediated CD4 and Tetherin Downregulation Functions among Major HIV-1 Group M Subtypes

Downregulation of BST-2/tetherin and CD4 by HIV-1 viral protein U (Vpu) promotes viral egress and allows infected cells to evade host immunity. Little is known however about the natural variability in these Vpu functions among the genetically diverse viral subtypes that contribute to the HIV-1 pandemic. We collected Vpu isolates from 332 treatment-naive individuals living with chronic HIV-1 infection in Uganda, Rwanda, South Africa, and Canada. Together, these Vpu isolates represent four major HIV-1 group M subtypes (A [n = 63], B [n = 84], C [n = 94], and D [n = 59]) plus intersubtype recombinants and uncommon strains (n = 32). The ability of each Vpu clone to downregulate endogenous CD4 and tetherin was quantified using flow cytometry following transfection into an immortalized T-cell line and compared to that of a reference Vpu clone derived from HIV-1 subtype B NL4.3. Overall, the median CD4 downregulation function of natural Vpu isolates was similar to that of NL4.3 (1.01 [interquartile range {IQR}, 0.86 to 1.18]), while the median tetherin downregulation function was moderately lower than that of NL4.3 (0.90 [0.79 to 0.97]). Both Vpu functions varied significantly among HIV-1 subtypes (Kruskal-Wallis P < 0.0001). Specifically, subtype C clones exhibited the lowest CD4 and tetherin downregulation activities, while subtype D and B clones were most functional for both activities. We also identified Vpu polymorphisms associated with CD4 or tetherin downregulation function and validated six of these using site-directed mutagenesis. Our results highlight the marked extent to which Vpu function varies among global HIV-1 strains, raising the possibility that natural variation in this accessory protein may contribute to viral pathogenesis and/or spread.IMPORTANCE The HIV-1 accessory protein Vpu enhances viral spread by downregulating CD4 and BST-2/tetherin on the surface of infected cells. Natural variability in these Vpu functions may contribute to HIV-1 pathogenesis, but this has not been investigated among the diverse viral subtypes that contribute to the HIV-1 pandemic. In this study, we found that Vpu function differs significantly among HIV-1 subtypes A, B, C, and D. On average, subtype C clones displayed the lowest ability to downregulate both CD4 and tetherin, while subtype B and D clones were more functional. We also identified Vpu polymorphisms that associate with functional differences among HIV-1 isolates and subtypes. Our study suggests that genetic diversity in Vpu may play an important role in the differential pathogenesis and/or spread of HIV-1.

Characterization of HIV-1 genetic diversity and antiretroviral resistance in the state of Maranhão, Northeast Brazil

The HIV-1 epidemic in Brazil has been growing in northeast and north regions, particularly an increase in AIDS cases among the younger male population has been observed. This study aims to characterize the HIV-1 genetic diversity and to evaluate its antiretroviral resistance profile among individuals presenting virological failure in the state of Maranhão—Brazil. HIV-1 pol gene sequences from 633 patients on antiretroviral therapy were obtained from the Department of Surveillance, Prevention and Control of Sexually Transmitted Infections, HIV/AIDS and Viral Hepatitis of the Brazilian Ministry of Health. Phylogenetic and recombination analyses were performed to characterize viral genetic diversity. The presence of antiretroviral resistance mutations was assessed using the HIV Drug Resistance Database online platform of Stanford University. A predominance of subtype B (84.5%) was observed, followed by recombinant BF (9.5%), where more than half of the sequences were dispersed in 3 clusters. Antiretroviral resistance was detected in 74.1% of the sequences, and it was significantly higher for nucleoside analogue reverse-transcriptase inhibitors (NRTIs) than for non-nucleoside analogue reverse-transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). Inference of putative transmissions clusters identified 11 clusters with 22 query sequences (22/633, 3.5%). Thus, we conclude that continuous monitoring of the molecular epidemiology of HIV-1 is essential for prevention strategies, epidemic control, and treatment adequacy.

Molecular Epidemiology of HIV-1 Infected Migrants Followed up in Portugal: Trends between 2001-2017

Migration is associated with HIV-1 vulnerability. Objectives: To identify long-term trends in HIV-1 molecular epidemiology and antiretroviral drug resistance (ARV) among migrants followed up in Portugal Methods: 5177 patients were included between 2001 and 2017. Rega, Scuel, Comet, and jPHMM algorithms were used for subtyping. Transmitted drug resistance (TDR) and Acquired drug resistance (ADR) were defined as the presence of surveillance drug resistance mutations (SDRMs) and as mutations of the IAS-USA 2015 algorithm, respectively. Statistical analyses were performed. Results: HIV-1 subtypes infecting migrants were consistent with the ones prevailing in their countries of origin. Over time, overall TDR significantly increased and specifically for Non-nucleoside reverse transcriptase inhibitor (NNRTIs) and Nucleoside reverse transcriptase inhibitor (NRTIs). TDR was higher in patients from Mozambique. Country of origin Mozambique and subtype B were independently associated with TDR. Overall, ADR significantly decreased over time and specifically for NRTIs and Protease Inhibitors (PIs). Age, subtype B, and viral load were independently associated with ADR. Conclusions: HIV-1 molecular epidemiology in migrants suggests high levels of connectivity with their country of origin. The increasing levels of TDR in migrants could indicate an increase also in their countries of origin, where more efficient surveillance should occur.

Understanding the mechanisms driving the spread of subtype C HIV-1

Human immunodeficiency virus type 1 (HIV-1) subtype C (C-HIV) is the most prevalent form of HIV-1 globally, accounting for approximately 50% of infections worldwide. C-HIV is the predominant and near-exclusive subtype in the low resource regions of India and Southern Africa. Given the vast diversity of HIV-1 subtypes, it is curious as to why C-HIV constitutes such a large proportion of global infections. This enriched prevalence may be due to phenotypic differences between C-HIV isolates and other viral strains that permit enhanced transmission efficiency or, pathogenicity, or might due to the socio-demographics of the regions where C-HIV is endemic. Here, we compare the mechanisms of C-HIV pathogenesis to less prominent HIV-1 subtypes, including viral genetic and phenotypic characteristics, and host genetic variability, to understand whether evolutionary factors drove C-HIV to predominance.

Depression and Coping Are Associated with Failure of Adherence to Antiretroviral Therapy Among People Living with HIV/AIDS

Sustained adherence to antiretroviral therapy (ART) is critical in the prevention of drug resistance, disease progression, and death. We aimed to assess the level of ART adherence among 112 people living with HIV/AIDS (PLWHA) and to determine associated factors with that. The socioeconomic aspects were evaluated by medical records; the adherence, depression, and coping by specific questionnaires. Although most patients have undetectable viral load (79%) and CD4⁺ T count >500 cells/mm³ (65%), two-third (66%) of them exhibited a lower adherence, which was directly associated with some signs of depression (p = .006) presented by 65% of them. Some risk factors to presence of depression were female gender (p = .008) and low income (p = .013). In addition, most participants who reported tobacco (33%) and alcohol (29%) consumption had a low or intermediate adherence score. Among the coping strategies, self-control (p = .029), social support (p = .006), problem solving (p = .013), and positive reappraisal (p = .049) led to an improvement in adherence.

Reduction of inflammation and T cell activation after 6 months of cART initiation during acute, but not in early chronic HIV-1 infection

Objectives

To investigate the impact of early combined antiretroviral therapy (cART) on inflammation biomarkers and immune activation during acute and early chronic HIV-1 infection.

Methods

We included 12 acute (AHI), 11 early chronic (EcHI), and 18 late chronic HIV-1-infected (LcHI) individuals who were treated with cART and 18 HIV-1-uninfected (HIV-neg) individuals. Plasmatic levels of inflammation biomarkers, CD8⁺CD38⁺HLA-DR⁺ T cell frequencies, CD4 T cell counts, CD4/CD8 ratio, total HIV-1 DNA and plasmatic viral load were evaluated. Mann–Whitney test, Pearson and Spearman correlation, and linear regression models were used for statistical analyses.

Results

IP-10, IL-18, and sCD163 were significantly elevated at pre-ART in the AHI and EcHI groups, showing a significant reduction after 6 months of cART in the AHI group, achieving similar levels to the HIV-neg group. For the EcHI group, the IP-10 and sCD163 levels were also significantly reduced on M6-ART; however, IP-10 levels remained higher than in the HIV-neg group, and no significant reduction of IL-18 levels was observed. The CD8⁺ T cell activation levels were elevated in the AHI and EcHI groups at pre-ART and showed a significant reduction on M6-ART, but they were similar to levels seen for HIV-neg only after 12 months of cART. At pre-ART, IP-10 levels but not IL-18 levels were positively correlated with HIV-1 viral load in the AHI group.

Conclusions

Early initiation of cART in HIV infection can reduce systemic inflammation, but the earlier normalization of the inflammation markers was only observed when cART was initiated in the acute phase of infection. A slower dynamic of reduction was observed for CD8⁺ T cell activation.

Electronic supplementary material

The online version of this article (10.1186/s12977-018-0458-6) contains supplementary material, which is available to authorized users.

Potential overestimation of HIV-1 sub-subtype F1 circulation in Rio de Janeiro, Brazil

In Brazil, detection of the HIV-1 sub-subtype F1 has decreased with a simultaneous increase in detection of the recombinant FB and FC forms. In previous HIV-1 env molecular epidemiology studies in Rio de Janeiro, 11.4% of the detected sequences were of the F1 sub-subtype. With the goal of re-estimating the prevalence of the HIV-1 F1 sub-subtype, we performed extended analyses of these samples by examining five genomic regions, resulting in 3.3% being confirmed as F1. Moreover, genomic analysis of 11 of the 21 samples identified as F1 confirmed that nine were F1 and two were BF1. Considering the number of samples assayed, the prevalence of F1 was quite low, which supports the use of different genomic regions for the assessment of HIV-1 classification in countries where several subtypes and recombinant forms co-circulate.

High Prevalence of Non-B HIV-1 Subtypes in Overseas Sailors and Prostitutes in Korea

There have been no studies related to groups at the highest risk for HIV-1 infection in Korea before 1993. In this study, for the first time, we report the distribution of HIV subtypes in overseas sailors (OSs) and prostitutes who worked in brothels near U.S. military bases in Korea. We retrospectively determined the sequences of nef in 131 patients using reverse transcription polymerase chain reaction (RT-PCR). These patients composed of 102 OSs, 14 OS spouses, and 15 prostitutes. Phylogenetic analysis was performed using 128 Korean OSs, OS spouses, and prostitutes. The distribution of non-B subtypes (n = 105) was as follows: 39, CRF02_AG; 15, CRF01_AE; 7, A1; 7, A2; 6, D; 2, CRF06_cpx; 3, C; 6, G; 11, untypable; and 1 each for CRF09_cpx, CRF12_BF, CRF50_A1D, A3, AFG, H, F1, F2, and A. Of the 116 OSs and OS spouses, 101 (87%), 11 (9%), and 4 (3%) subjects had non-B, Western B, and Korean subclade B (KSB) HIV-1s, respectively. Among the 15 prostitutes, 10 had Western B (67%), 4 non-B (27%), and 1 KSB (7%) HIV-1s. All 14 couples, each comprising of an OS and his spouse, had the same subtype. KSB (5%) was detected in OSs and prostitutes in 1990 and 1994, respectively. Of the 131 patients analyzed in this study, 105 (80%), 21 (16%), and 5 (4%) were infected with the non-B, Western B, and KSB subtypes of HIV, respectively. In future, these data may provide an important foundation for analysis of HIV-1 subtypes in Korea.

Characterization of HIV-1 Near Full-Length Proviral Genome Quasispecies from Patients with Undetectable Viral Load Undergoing First-Line HAART Therapy

Increased access to highly active antiretroviral therapy (HAART) by human immunodeficiency virus postive (HIV⁺) individuals has become a reality worldwide. In Brazil, HAART currently reaches over half of HIV-infected subjects. In the context of a remarkable HIV-1 genetic variability, highly related variants, called quasispecies, are generated. HIV quasispecies generated during infection can influence virus persistence and pathogenicity, representing a challenge to treatment. However, the clinical relevance of minority quasispecies is still uncertain. In this study, we have determined the archived proviral sequences, viral subtype and drug resistance mutations from a cohort of HIV⁺ patients with undetectable viral load undergoing HAART as first-line therapy using next-generation sequencing for near full-length virus genome (NFLG) assembly. HIV-1 consensus sequences representing NFLG were obtained for eleven patients, while for another twelve varying genome coverage rates were obtained. Phylogenetic analysis showed the predominance of subtype B (83%; 19/23). Considering the minority variants, 18 patients carried archived virus harboring at least one mutation conferring antiretroviral resistance; for six patients, the mutations correlated with the current ARVs used. These data highlight the importance of monitoring HIV minority drug resistant variants and their clinical impact, to guide future regimen switches and improve HIV treatment success.

HIV-1 Genetic Diversity in Northeastern Brazil: High Prevalence of Non-B Subtypes

The Northeastern Brazilian region has experienced a constant increase in the number of newly reported AIDS cases over the last decade, but the genetic diversity of HIV-1 strains currently disseminated in this region remains poorly explored. HIV-1 pol sequences were obtained from 140 patients followed at outpatient clinics from four Northeastern Brazilian states (Alagoas, Bahia, Ceará, and Piauí) between 2014 and 2015. Subtype B was the most prevalent HIV-1 clade (72%) detected in the Northeastern region, followed by subtypes F1 (6%), C (5%), and D (1%). The remaining strains (16%) displayed a recombinant structure and were classified as follows: BF1 (11%), BC (4%), BCF1 (1%), and CRF02_AG like (1%). The 20 HIV-1 BF1 and BC recombinant sequences detected were distributed among 11 lineages classified as follows: CRF28/29_BF like (n = 5), CRF39_BF like (n = 1), URF_BF (n = 9), and URF_BC (n = 5). Non-B subtypes were detected in all Northeastern Brazilian states, but with variable prevalence, ranging from 16% in Ceará to 55% in Alagoas. Phylogenetic analyses support that subtype D and CRF02_AG strains detected in the Northeastern region resulted from the expansion of autochthonous transmission networks, rather than from exogenous introductions from other countries. These results reveal that HIV-1 epidemic spreading in the Northeastern Brazilian region comprised by multiple subtypes and recombinant strains and the molecular epidemiologic pattern in this Brazilian region is much more complex than originally estimated.