Viral kinetics in untreated versus treated acute HIV infection in prospective cohort studies in Thailand

Nef defect attenuates HIV viremia and immune dysregulation in the bone marrow-liver-thymus-spleen (BLTS) humanized mouse model

In vitro studies have shown that deletion of nef and deleterious mutation in the Nef dimerization interface attenuates HIV replication and associated pathogenesis. Humanized rodents with human immune cells and lymphoid tissues are robust in vivo models for investigating the interactions between HIV and the human immune system. Here, we demonstrate that nef deletion impairs HIV replication and HIV-induced immune dysregulation in the blood and human secondary lymphoid tissue (human spleen) in bone marrow-liver-thymus-spleen (BLTS) humanized mice. Furthermore, we also show that nef defects (via deleterious mutations in the dimerization interface) impair HIV replication and HIV-induced immune dysregulation in the blood and human spleen in BLTS-humanized mice. We demonstrate that the reduced replication of nef-deleted and nef-defective HIV is associated with robust antiviral innate immune response, and T helper 1 response. Our results support the proposition that Nef may be a therapeutic target for adjuvants in HIV cure strategies.

A remarkable genetic shift in a transmitted/founder virus broadens antibody responses against HIV-1

A productive HIV-1 infection in humans is often established by transmission and propagation of a single transmitted/founder (T/F) virus, which then evolves into a complex mixture of variants during the lifetime of infection. An effective HIV-1 vaccine should elicit broad immune responses in order to block the entry of diverse T/F viruses. Currently, no such vaccine exists. An in-depth study of escape variants emerging under host immune pressure during very early stages of infection might provide insights into such a HIV-1 vaccine design. Here, in a rare longitudinal study involving HIV-1 infected individuals just days after infection in the absence of antiretroviral therapy, we discovered a remarkable genetic shift that resulted in near complete disappearance of the original T/F virus and appearance of a variant with H173Y mutation in the variable V2 domain of the HIV-1 envelope protein. This coincided with the disappearance of the first wave of strictly H173-specific antibodies and emergence of a second wave of Y173-specific antibodies with increased breadth. Structural analyses indicated conformational dynamism of the envelope protein which likely allowed selection of escape variants with a conformational switch in the V2 domain from an α-helix (H173) to a β-strand (Y173) and induction of broadly reactive antibody responses. This differential breadth due to a single mutational change was also recapitulated in a mouse model. Rationally designed combinatorial libraries containing 54 conformational variants of V2 domain around position 173 further demonstrated increased breadth of antibody responses elicited to diverse HIV-1 envelope proteins. These results offer new insights into designing broadly effective HIV-1 vaccines.

Impact of very early antiretroviral therapy during acute HIV infection on long-term immunovirological outcomes

OBJECTIVES

We aimed to determine if starting antiretroviral therapy (ART) in the first 30 days after acquiring HIV infection has an impact on immunovirological response.

METHODS

Observational, ambispective study including 147 patients with confirmed acute HIV infection (January/1995-August/2022). ART was defined as very early (≤30 days after the estimated date of infection), early (31-180 days), and late (>180 days). We compared time to viral suppression (viral load [VL] <50 copies/ml) and immune recovery (IR) (CD4+/CD8+ ratio ≥1) according to the timing and type of ART using survival analysis.

RESULTS

ART was started in 140 (95.2%) patients. ART was very early in 24 (17.1%), early in 77 (55.0%), and late in 39 (27.9%) cases. Integrase strand transfer inhibitor (INSTI)-based regimens were the most used in both the overall population (65%) and the very early ART group (23/24, 95.8%). Median HIV VL and CD4+/CD8+ ratio pre-ART were higher in the very early ART group (P <0.05). Patients in the very early and early ART groups and treated with INSTI-based regimens achieved IR earlier (P <0.05). Factors associated with faster IR were the CD4+/CD8+ ratio pre-ART (hazard ratio: 9.3, 95% CI: 3.1-27.8, P <0.001) and INSTI-based regimens (hazard ratio: 2.4, 95% CI: 1.3-4.2, P = 0.003).

CONCLUSIONS

The strongest predictors of IR in patients who start ART during AHI are the CD4+/CD8+ ratio pre-ART and INSTI-based ART regimens.

Significance of initiating antiretroviral therapy in the early stage of HIV infection

A growing number of guidelines now recommend that human immunodeficiency virus (HIV) infected patients should be given early antiretroviral therapy (ART), especially in acute HIV infection. ART during early infection can limit viral reservoirs and improve immune cell function. From a societal prospect, early-infected individuals who achieve a state of viral suppression through ART can reduce the chance of HIV transmission and reduce the acquired immunodeficiency syndrome (AIDS)-related disease burden. However, there are many problems in the early diagnosis and treatment of HIV infection, including personal and social factors, which hinder the implementation and development of early treatment. It is recommended that initiating ART in the early stage of HIV infection, combined with other treatment strategies, so as to achieve functional cure.

Concordance of immunological events between intrarectal and intravenous SHIVAD8-EO infection when assessed by Fiebig-equivalent staging

Primary HIV-1 infection can be classified into six Fiebig stages based on virological and serological laboratory testing, whereas simian-HIV (SHIV) infection in nonhuman primates (NHPs) is defined in time post-infection, making it difficult to extrapolate NHP experiments to the clinics. We identified and extensively characterized the Fiebig-equivalent stages in NHPs challenged intrarectally or intravenously with SHIVAD8-EO. During the first month post-challenge, intrarectally challenged monkeys were up to 1 week delayed in progression through stages. However, regardless of the challenge route, stages I-II predominated before, and stages V-VI predominated after, peak viremia. Decrease in lymph node (LN) CD4+ T cell frequency and rise in CD8+ T cells occurred at stage V. LN virus-specific CD8+ T cell responses, dominated by degranulation and TNF, were first detected at stage V and increased at stage VI. A similar late elevation in follicular CXCR5+ CD8+ T cells occurred, consistent with higher plasma CXCL13 levels at these stages. LN SHIVAD8-EO RNA+ cells were present at stage II, but appeared to decline at stage VI when virions accumulated in follicles. Fiebig-equivalent staging of SHIVAD8-EO infection revealed concordance of immunological events between intrarectal and intravenous infection despite different infection progressions, and can inform comparisons of NHP studies with clinical data.

Abrupt and altered cell-type specific DNA methylation profiles in blood during acute HIV infection persists despite prompt initiation of ART

HIV-1 disrupts the host epigenetic landscape with consequences for disease pathogenesis, viral persistence, and HIV-associated comorbidities. Here, we examined how soon after infection HIV-associated epigenetic changes may occur in blood and whether early initiation of antiretroviral therapy (ART) impacts epigenetic modifications. We profiled longitudinal genome-wide DNA methylation in monocytes and CD4⁺ T lymphocytes from 22 participants in the RV254/SEARCH010 acute HIV infection (AHI) cohort that diagnoses infection within weeks after estimated exposure and immediately initiates ART. We identified monocytes harbored 22,697 differentially methylated CpGs associated with AHI compared to 294 in CD4⁺ T lymphocytes. ART minimally restored less than 1% of these changes in monocytes and had no effect upon T cells. Monocyte DNA methylation patterns associated with viral load, CD4 count, CD4/CD8 ratio, and longitudinal clinical phenotypes. Our findings suggest HIV-1 rapidly embeds an epigenetic memory not mitigated by ART and support determining epigenetic signatures in precision HIV medicine.

Trial Registration:NCT00782808 and NCT00796146.

The epigenetic marker, DNA methylation, plays a key role regulating the immune system during host-pathogen interactions. Using cell-type specific DNA methylation profiling, we explored whether epigenetic changes occurred soon after HIV infection and following early treatment with anti-HIV drugs. Acute infection was associated with early DNA methylation changes in purified monocytes and CD4⁺ T cells isolated from blood. In monocytes, rapid anti-HIV treatment minimally restored DNA methylation changes associated with infection and unexpectedly had no impact in CD4⁺ T cells. DNA methylation patterns before treatment informed long term clinical outcomes including CD4⁺ T cell counts and favorable clinical phenotypes. These findings identify candidates for consideration in epigenome editing approaches in HIV prevention, treatment, and cure strategies.

Evolution and Diversity of Immune Responses during Acute HIV Infection

Understanding the earliest immune responses following HIV infection is critical to inform future vaccines and therapeutics. Here, we review recent prospective human studies in at-risk populations that have provided insight into immune responses during acute infection, including additional relevant data from non-human primate (NHP) studies. We discuss the timing, nature, and function of the diverse immune responses induced, the onset of immune dysfunction, and the effects of early anti-retroviral therapy administration. Treatment at onset of viremia mitigates peripheral T and B cell dysfunction, limits seroconversion, and enhances cellular antiviral immunity despite persistence of infection in lymphoid tissues. We highlight pertinent areas for future investigation, and how application of high-throughput technologies, alongside targeted NHP studies, may elucidate immune response features to target in novel preventions and cures.

The Hitchhiker Guide to CD4+ T-Cell Depletion in Lentiviral Infection. A Critical Review of the Dynamics of the CD4+ T Cells in SIV and HIV Infection

CD4⁺ T-cell depletion is pathognomonic for AIDS in both HIV and simian immunodeficiency virus (SIV) infections. It occurs early, is massive at mucosal sites, and is not entirely reverted by antiretroviral therapy (ART), particularly if initiated when T-cell functions are compromised. HIV/SIV infect and kill activated CCR5-expressing memory and effector CD4⁺ T-cells from the intestinal lamina propria. Acute CD4⁺ T-cell depletion is substantial in progressive, nonprogressive and controlled infections. Clinical outcome is predicted by the mucosal CD4⁺ T-cell recovery during chronic infection, with no recovery occurring in rapid progressors, and partial, transient recovery, the degree of which depends on the virus control, in normal and long-term progressors. The nonprogressive infection of African nonhuman primate SIV hosts is characterized by partial mucosal CD4⁺ T-cell restoration, despite high viral replication. Complete, albeit very slow, recovery of mucosal CD4+ T-cells occurs in controllers. Early ART does not prevent acute mucosal CD4⁺ T-cell depletion, yet it greatly improves their restoration, sometimes to preinfection levels. Comparative studies of the different models of SIV infection support a critical role of immune activation/inflammation (IA/INFL), in addition to viral replication, in CD4⁺ T-cell depletion, with immune restoration occurring only when these parameters are kept at bay. CD4⁺ T-cell depletion is persistent, and the recovery is very slow, even when both the virus and IA/INFL are completely controlled. Nevertheless, partial mucosal CD4⁺ T-cell recovery is sufficient for a healthy life in natural hosts. Cell death and loss of CD4⁺ T-cell subsets critical for gut health contribute to mucosal inflammation and enteropathy, which weaken the mucosal barrier, leading to microbial translocation, a major driver of IA/INFL. In turn, IA/INFL trigger CD4⁺ T-cells to become either viral targets or apoptotic, fueling their loss. CD4⁺ T-cell depletion also drives opportunistic infections, cancers, and comorbidities. It is thus critical to preserve CD4⁺ T cells (through early ART) during HIV/SIV infection. Even in early-treated subjects, residual IA/INFL can persist, preventing/delaying CD4⁺ T-cell restoration. New therapeutic strategies limiting mucosal pathology, microbial translocation and IA/INFL, to improve CD4⁺ T-cell recovery and the overall HIV prognosis are needed, and SIV models are extensively used to this goal.

Tyrosine Kinase Inhibition: a New Perspective in the Fight against HIV

PURPOSE OF REVIEW

HIV-1 infection is incurable due to the existence of latent reservoirs that persist in the face of cART. In this review, we describe the existence of multiple HIV-1 reservoirs, the mechanisms that support their persistence, and the potential use of tyrosine kinase inhibitors (TKIs) to block several pathogenic processes secondary to HIV-1 infection.

RECENT FINDINGS

Dasatinib interferes in vitro with HIV-1 persistence by two independent mechanisms. First, dasatinib blocks infection and potential expansion of the latent reservoir by interfering with the inactivating phosphorylation of SAMHD1. Secondly, dasatinib inhibits the homeostatic proliferation induced by γc-cytokines. Since homeostatic proliferation is thought to be the main mechanism behind the maintenance of the latent reservoir, we propose that blocking this process will gradually reduce the size of the reservoir. TKIs together with cART will interfere with HIV-1 latent reservoir persistence, favoring the prospect for viral eradication.

Novel Transmitted/Founder Simian-Human Immunodeficiency Viruses for Human Immunodeficiency Virus Latency and Cure Research

A robust simian-human immunodeficiency virus (SHIV)-macaque model of latency is critical to investigate eradicative and suppressive strategies that target HIV-1 Env. To this end, we previously reported a novel strategy for constructing SHIVs that bear primary or transmitted/founder (TF) Envs with modifications at Env residue 375 that enable efficient replication in Indian rhesus macaques (RM). Such TF SHIVs, however, have not been examined for their suitability for HIV-1 latency and cure research. Here, we evaluate two promising TF SHIVs, SHIV.D.191859 and SHIV.C.CH848, which encode TF subtype D and C HIV-1 Envs, respectively, for their viral kinetics and persistence during suppressive combination antiretroviral therapy (cART) and treatment interruption in RM. Our results suggest that the viral kinetics of these SHIVs in RM during acute, early, and chronic infection, and upon cART initiation, maintenance and discontinuation, mirror those of HIV-1 infection. We demonstrate consistent early peak and set point viremia, rapid declines in viremia to undetectable plasma titers following cART initiation, infection of long-lived cellular subsets and establishment of viral latency, and viral rebound with return to pretreatment set point viremia following treatment interruption. The viral dynamics and reservoir biology of SHIV.D.191859, and to a lesser extent SHIV.C.CH848, during chronic infection, cART administration, and upon treatment interruption suggest that these TF SHIVs are promising reagents for a SHIV model of HIV-1 latency and cure.IMPORTANCE Simian-human immunodeficiency viruses (SHIVs) have been successfully used for over 2 decades to study virus-host interactions, transmission, and pathogenesis in rhesus macaques. The majority of Env trimers of most previously studied SHIVs, however, do not recapitulate key properties of transmitted/founder (TF) or primary HIV-1 isolates, such as CCR5 tropism, tier 2 neutralization resistance, and native trimer conformation. Here, we test two recently generated TF SHIVs, SHIV.D.191859 and SHIV.C.CH848, which were designed to address these issues as components of a nonhuman primate model of HIV-1 latency. We conclude that the TF SHIV-macaque model reflects several hallmarks of HIV and SIV infection and latency. Results suggest that this model has broad applications for evaluating eradicative and suppressive strategies against the HIV reservoir, including Env-specific interventions, therapeutic vaccines, and engineered T cells.

Feasibility and safety of research sigmoid colon biopsy in a cohort of Thai men who have sex with men with acute HIV-1

BACKGROUND

The gut-associated lymphoid tissue (GALT) is a major reservoir of HIV-1 established early in acute HIV-1 infection (AHI). Sampling tissue from GALT can provide information about viral reservoirs and immune responses but may be complicated during AHI for reasons such as high viral replication, CD4 T cell depletion and immune activation. Risk of adverse events (AEs) associated with research sigmoid colon biopsies was assessed in participants with AHI in Bangkok, Thailand.

METHODS

Between 2009 and 2016, 170 biopsies collected from the sigmoid colon were performed during AHI and at follow-up visits (median 24 weeks post AHI diagnosis). Adverse event incidence was evaluated, as well as the associations of procedure timing, repetition and clinical parameters with AE risk. Negative binomial regression models were used to calculate incidence rate ratios and 95% confidence intervals.

RESULTS

Among 103 participants (median age of 27 years, 97.1% male, 96.1% men who have sex with men), 87 sigmoidoscopies were completed during AHI and 83 at a follow-up visit. Approximately 30 biopsies were obtained per procedure for assessment of colonic viral load and HIV-1 reservoir, immunohistochemistry or phenotypic assays. All 11 AEs were grade 1 (6.5%) and included abdominal discomfort (n = 5, 2.9%), mild rectal bleeding (n = 5, 2.9%) and difficulty passing stool (n = 1, 0.6%). Biopsy-related AE risk was not significantly associated with age, HIV-1 RNA, CD4 T cell count, or number and time of biopsy.

CONCLUSIONS

Complications of sigmoidoscopy with biopsy in participants with AHI were infrequent and mild. Longitudinal sampling of the sigmoid colon to evaluate the gut-associated HIV-1 reservoir can be safely performed as part of research studies.

Decreased Seroreactivity in Individuals Initiating Antiretroviral Therapy during Acute HIV Infection

Antiretroviral therapy (ART) during acute HIV infection (AHI) interrupts viral dynamics and may delay the emergence of serological markers targeted by current HIV screening and confirmatory assays, thus creating challenges for correctly classifying HIV infection status. The performance of three HIV antigen/antibody combination (HIV Ag/Ab Combo) assays (the Bio-Rad GS, Abbott Architect, and Bio-Rad BioPlex 2200 assays) was evaluated with samples collected from RV254/South East Asia Research Collaboration in HIV 010 (RV254/SEARCH010) study (Bangkok, Thailand) participants at weeks 12 and 24 following the initiation of ART at Fiebig stage I (FI) (n = 23), FII (n = 39), or FIII/IV (n = 22). Supplemental, confirmatory testing was performed by the Geenius HIV 1/2 and HIV-1 Western blot assays (Bio-Rad). Samples from 30 untreated, HIV-1-infected individuals demonstrated robust HIV Ag/Ab Combo assay reactivity with well-developed HIV-1 Western blotting profiles by 24 weeks after infection. In contrast, 52.2% of samples from individuals initiating ART at FI, 7.7% of samples from individuals initiating ART at FII, and 4.5% of samples from individuals initiating ART at FIII/IV were nonreactive by the HIV Ag/Ab Combo assays, with 36.4 to 39.1% of samples having low signal-to-cutoff (S/CO) results by the Architect and BioPlex assays (S/CO < 10). Seroreversion from a reactive to a nonreactive status was observed in 10 individuals initiating ART at FII and 3 individuals initiating ART at FIII/IV. The Geenius and HIV-1 Western blot assay results were negative or indeterminate for 73.9% and 69.6% of individuals, respectively, treated at FI; 50.0% and 26.3% of individuals, respectively, treated at FII; and 54.5% and 40.9% of individuals, respectively, treated at FIII/IV. Virologic suppression of HIV-1 by ART during AHI impedes seroconversion to biomarkers of infection, limiting the utility of HIV Ag/Ab Combo and supplemental, confirmatory assays for infection status determination.

Predictors of faster virological suppression in early treated infants with perinatal HIV from Europe and Thailand

Supplemental Digital Content is available in the text

Objective:

To identify predictors of faster time to virological suppression among infants starting combination antiretroviral therapy (cART) early in infancy.

Design:

Cohort study of infants from Europe and Thailand included in studies participating in the European Pregnancy and Paediatric HIV Cohort Collaboration.

Methods:

Infants with perinatal HIV starting cART aged less than 6 months with at least 1 viral load measurement within 15 months of cART initiation were included. Multivariable interval-censored flexible parametric proportional hazards models were used to assess predictors of faster virological suppression, with timing of suppression assumed to lie in the interval between last viral load at least 400 and first viral load less than 400 copies/ml.

Results:

Of 420 infants, 59% were female and 56% from Central/Western Europe, 26% United Kingdom/Ireland, 15% Eastern Europe and 3% Thailand; 46 and 54% started a boosted protease inhibitor-based or nonnucleoside reverse transcriptase inhibitor-based regimen, respectively. At cART initiation, the median age, CD4⁺% and viral load were 2.9 [interquartile range (IQR): 1.4–4.1] months, 34 (IQR: 24–45)% and 5.5 (IQR: 4.5–6.0) log₁₀ copies/ml, respectively. Overall, an estimated 89% (95% confidence interval: 86–92%) achieved virological suppression within 12 months of cART start. In multivariable analysis, younger age [adjusted hazard ratio (aHR): 0.84 per month older; P < 0.001], higher CD4⁺% (aHR: 1.11 per 10% higher; P = 0.010) and lower log₁₀ viral load (aHR: 0.85 per log₁₀ higher; P < 0.001) at cART initiation independently predicted faster virological suppression.

Conclusion:

We observed a significant independent effect of age at cART initiation, even within a narrow 6 months window from birth. These findings support the earliest feasible cART initiation in infants and suggest that early therapy influences key virological and immunological parameters that could have important consequences for long-term health.

Liver damage in patients living with HIV on antiretroviral treatment with normal baseline liver function and without HBV/HCV infection: an 11-year retrospective cohort study in Guangxi, China

OBJECTIVE

To characterise the association between duration of exposure to antiretroviral treatment (ART) and liver damage in HIV patients with an initially normal baseline liver function and without hepatitis B virus (HBV)/hepatitis C virus (HCV) infection.

METHODS

A retrospective cohort study was conducted in HIV-infected individuals with normal liver function parameters at ART initiation and without HBV/HCV infection, from 14 April 2004 to 13 April 2015 in Guigang city, Guangxi, China. The association between duration of ART and liver damage (grade II-IV liver enzyme elevation [LEE] and/or total bilirubin elevation [TBE]), was analysed. Cox regression was used to examine the factors related to liver damage.

RESULTS

Of 2119 eligible patients, 12.41% (263/2119) developed liver damage (grade II-IV LEE/TBE) and contributed 4.11/100 person-years crude incidence rate. The highest liver damage incidence was observed in patients with 6-12 months' ART (15.16/100 person-years). The incidence decreased to 5.56/100 person-years in patients with 12-18 months' ART and 3.13/100 person years in patients with 18-24 months' ART, and then maintained at a relatively low and stable level in patients with 2 years' ART or longer (average of 3.65/100 person-years). Cox regression analysis revealed that current WHO disease stage II, III or IV (compared with stage I) were the risk factors for liver damage, while baseline disease stage II, III (compared with stage I) and current regimen 3TC+AZT+NVP were the protective factors for liver damage.

CONCLUSIONS

Liver damage always exists among HIV-infected patients on ART with normal baseline liver function and without HBV/HCV infection. Nevertheless, cumulative ART duration does not increase the risk of liver damage. ART could tend to be long-term, however, monitoring and management of liver damage among patients on ART are also important in clinical therapy.

Effectiveness and safety of dual therapy with rilpivirine and boosted darunavir in treatment-experienced patients with advanced HIV infection: a preliminary 24 week analysis (RIDAR study)

Background

The objective was to analyze the effectiveness and safety of dual therapy with rilpivirine plus boosted-darunavir (RPV + bDRV) in real-life patients.

Methods

Observational, retrospective, multi-center study in HIV+ patients who had received RPV + bDRV for 24 weeks to optimize/simplify their previous antiretroviral treatment. We determined the percentage of patients without virologic failure (2 consecutive viral loads > 50 copies/mL) at 24 weeks of treatment.

Results

The study included 161 patients from 15 hospitals with median age of 49 years; 29.3% had previous AIDS stage and median CD4+ lymphocyte nadir of 170 cells/uL. They had been diagnosed with HIV for a median of 17 years and had received 14 years of ART, with five previous treatment combinations, and 36.6% had a history of virological failure. The reasons for the switch were simplification/optimization (49.7%), toxicity/intolerance (17.4%), or inadequate effectiveness of previous ART (10.6%).

Baseline VL of 50–1000 copies/mL was recorded in 25.5% of the patients. In the“intention-to-treat” analysis at 24 weeks, 87.6% of 161 patients continued the study treatment without virologic failure criteria.

In the “on treatment” analysis (excluding patients who discontinued treatment with dual therapy for any reason other than virologic failure) the efficacy was 94.6% (141/149 patients).

Conclusions

Dual therapy with RPV + DRVb proved to be effective and safe in patients with advanced HIV infection, long exposure to ART, low CD4 nadir, previous virologic failure, and/or history of ineffective ART.

The early bird gets the worm: benefits and future directions with early antiretroviral therapy initiation in primary HIV infection

Primary HIV infection is defined as the first few weeks after infection where plasma viremia is rapidly increasing. Early diagnosis of primary HIV infection enhances the tendency of behavioral changes in newly infected individuals to prevent secondary HIV transmission. Early antiretroviral therapy (ART) benefits individuals by reducing plasma viral load, gut damage, microbial translocation and subsequent systemic immune activation. Early ART leads to the establishment of low HIV reservoir size that may contribute to HIV eradication research. However, substantial diagnostic and logistical barriers remain as a burden to rapid diagnosis and early treatment initiation. In this review, we critically evaluate the effects of early ART and summarize hurdles that must be addressed to implement rapid treatment initiation for newly infected individuals.