Improved induced innate immune response after cART initiation in people with HIV.

Introduction: Impairment of the innate immune function may contribute to the increased risk of bacterial and viral infections in people with HIV (PWH). In this study we aimed to investigate the induced innate immune responses in PWH prior to and after initiation of combinational antiretroviral therapy (cART). Furthermore, we aimed to investigate if the induced innate immune responses before initiation of cART were associated with CD4+ T-cell recovery one year after initiating cART. Material and method: The induced innate immune response was assessed by the TruCulture® whole blood technique in 32 PWH before cART initiation and after 1, 6 and 12 months. To mimic bacterial and viral infections we used a panel of three stimuli (lipopolysaccharide (LPS), resiquimod (R848), and polyinosinic:polycytidylic acid (Poly I:C)) to stimulate the extracellular Toll-like receptor (TLR) 4 and the intracellular TLR7/8 and TLR3, respectively. The following cytokine responses were analyzed by Luminex 200: Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1b, IL-6, IL-8, IL-10, IL-12p40, IL17A, Interferon (IFN)-α, and IFN-γ. Results: At baseline PWH with nadir CD4+ T-cell count <350 cell/µL had lower levels of LPS-, R848-, and Poly I:C-induced IL-6 and IFN-γ, LPS- and R848-induced TNF-α and IL-12, LPS induced IL-1b, and R848-induced IL-10 than PWH with nadir CD4+ T-cell count >350 cells/µL. The majority (>50%) had induced cytokine concentrations below the reference intervals at baseline which was most pronounced for the LPS- and Poly I:C-induced responses. The induced responses in the whole population improved after 12 months of cART, and more PWH had induced cytokine concentrations within the reference intervals after 12 months. However, the majority of PWH still had LPS-induced INF-α, INF-γ and Poly I:C-induced TNF-α and IL-6 below the reference interval. The induced innate immune responses before cART initiation were not associated with the CD4+ T-cell recovery after 12 months of cART. Conclusion: The innate immune response was impaired in PWH, with a more pronounced impairment in PWH with low nadir CD4+ T-cell count. Initiation of cART improved the innate immune response, but compared to the reference intervals, some impairment remained in PWH without viral replication.

Combination anti-HIV antibodies provide sustained virological suppression.

Antiretroviral therapy is highly effective in suppressing human immunodeficiency virus (HIV)1. However, eradication of the virus in individuals with HIV has not been possible to date2. Given that HIV suppression requires life-long antiretroviral therapy, predominantly on a daily basis, there is a need to develop clinically effective alternatives that use long-acting antiviral agents to inhibit viral replication3. Here we report the results of a two-component clinical trial involving the passive transfer of two HIV-specific broadly neutralizing monoclonal antibodies, 3BNC117 and 10-1074. The first component was a randomized, double-blind, placebo-controlled trial that enrolled participants who initiated antiretroviral therapy during the acute/early phase of HIV infection. The second component was an open-label single-arm trial that enrolled individuals with viraemic control who were naive to antiretroviral therapy. Up to 8 infusions of 3BNC117 and 10-1074, administered over a period of 24 weeks, were well tolerated without any serious adverse events related to the infusions. Compared with the placebo, the combination broadly neutralizing monoclonal antibodies maintained complete suppression of plasma viraemia (for up to 43 weeks) after analytical treatment interruption, provided that no antibody-resistant HIV was detected at the baseline in the study participants. Similarly, potent HIV suppression was seen in the antiretroviral-therapy-naive study participants with viraemia carrying sensitive virus at the baseline. Our data demonstrate that combination therapy with broadly neutralizing monoclonal antibodies can provide long-term virological suppression without antiretroviral therapy in individuals with HIV, and our experience offers guidance for future clinical trials involving next-generation antibodies with long half-lives.

The PD1 inhibitory pathway and mature dendritic cells contribute to abacavir hypersensitivity in human leukocyte antigen transgenic PD1 knockout mice.

Based on recent genome-wide association studies, abacavir-induced hypersensitivity is highly associated with human leukocyte antigen (HLA)-B*57:01 allele. However, the underlying mechanism of this occurrence is unclear. To investigate the underlying mechanism, we developed HLA-B*57:01 transgenic mice and found that application of abacavir could cause CD8 T cell activation with elevation in PD1 expression; however, severe skin hypersensitivity was not observed. To eliminate the immunosuppressive effect of PD1, HLA-B*57:01 transgenic/PD1 knockout (01Tg/PD1) mice were generated by mating HLA-B*57:01 transgenic mice and PD1 knockout mice. Thereafter, 01Tg/PD1 mice were treated with abacavir. Similar to the above results, severe skin hypersensitivity was not observed. Therefore, we treated 01Tg/PD1 mice with an anti-CD4 antibody to deplete CD4 T cells, followed by abacavir topically and orally. Severe abacavir-induced skin hypersensitivity was observed in 01Tg/PD1 mice after depletion of CD4 T cells, in addition to significant CD8 T cell activation and dendritic cell maturation. Taken together, we succeeded in reproducing severe skin hypersensitivity in a mouse model. And we found that through the combined depletion of PD1 and CD4 T cells, CD8 T cells could be activated and could proceed to clonal proliferation, which is promoted by mature dendritic cells, thereby eventually inducing severe skin hypersensitivity.

[Importance of HLA in Determining Individual Differences in the Onset of Adverse Drug Reactions].

Individuals vary in their susceptibility to adverse reactions to medications, some of which can be potentially life-threatening. Idiosyncratic drug toxicity (IDT) has been shown to be strongly associated to specific polymorphisms in genes encoding human leukocyte antigens (HLAs) by recent genome-wide association studies. However, the pathogenic mechanisms governing such reactions remain unclarified, at least in part because of a lack of suitable experimental animal models to assess IDT. This review describes our work on the specific allele/drug combination of HLA-B*57:01 and abacavir, an antiretroviral drug targeting the human immunodeficiency virus. As abacavir is known to trigger an HLA-dependent immune response, we engineered a transgenic mouse model-HLA-Tg-by partially substituting the mouse HLA sequence for the corresponding human sequence. Local abacavir exposure was found to trigger a significant immune response in an HLA-dependent manner, and oral administration induced liver injury partially via concurrent activation of the innate immune system. Additionally, we developed a technique for evaluating structural alterations in HLA complexes resulting from drug exposure based on phage display to ensure specificity. Further scrutiny of the mechanism(s) underlying drug-induced immune reactions using the HLA-Tg model, as well as enhanced methods for predicting adverse event incidence, are anticipated to help resolve issues surrounding HLA-associated drug hypersensitivity.

Kinetics of Abacavir-Induced Remodelling of the Major Histocompatibility Complex Class I Peptide Repertoire.

Abacavir hypersensitivity syndrome can occur in individuals expressing the HLA-B*57:01 major histocompatibility complex class I allotype when utilising the drug abacavir as a part of their anti-retroviral regimen. The drug is known to bind within the HLA-B*57:01 antigen binding cleft, leading to the selection of novel self-peptide ligands, thus provoking life-threatening immune responses. However, the sub-cellular location of abacavir binding and the mechanics of altered peptide selection are not well understood. Here, we probed the impact of abacavir on the assembly of HLA-B*57:01 peptide complexes. We show that whilst abacavir had minimal impact on the maturation or average stability of HLA-B*57:01 molecules, abacavir was able to differentially enhance the formation, selectively decrease the dissociation, and alter tapasin loading dependency of certain HLA-B*57:01-peptide complexes. Our data reveals a spectrum of abacavir mediated effects on the immunopeptidome which reconciles the heterogeneous functional T cell data reported in the literature.

Autoantibodies Among HIV-1 Infected Individuals and the Effect of Anti-Retroviral Therapy (ART) on It.

BACKGROUND: Antiretroviral therapy (ART) has led to a decline in autoimmune diseases but lacks studies on its effect on autoantibodies. METHODS: It is a cross-sectional study with archived samples from 100 paired HIV-1 infected ART naïve and experienced individuals and 100 prospectively collected matched blood-donor controls. Antinuclear antibody, IgG anticardiolipin antibody, IgM and IgG ß2 glycoprotein-1 antibodies, and total IgG levels were detected. Results are expressed as mean with standard deviation (SD), median, percentage positivity, and a p<0.05 is considered significant. The study was approved by the Institutional Review Board. RESULTS: The median viral load of the treatment naïve samples was 4.34 Log copies/mL, while all were virally suppressed post ART with a median duration of treatment for 12 months (range: 3-36 months). The percentage of antinuclear antibody positivity was 5% among ART naïve and controls, with a decrease of 2% post ART (p= 0.441). The positivity for anti-cardiolipin antibody was 15% among ART naïve while none of the ART experienced or controls were positive (p<0.05). IgM ß2 glycoprotein-1 were 4%, 1% and 3% among ART naïve, treated and controls, respectively (p<0.05). IgG ß2 glycoprotein-1 was 2% among ART naïve while none of the treated and controls were positive (p<0.05). The mean total IgG level among ART naïve, experienced, and controls were 21.82 (SD 6.67), 16.91 (SD 3.38), 13.70 (SD 2.24) grams/Litre, respectively (p<0.05). CONCLUSION: ART has a significant effect on IgG anti-cardiolipin antibody and total IgG but only a marginal effect on ANA, IgM, and IgG ß2 glycoprotein-1 antibodies.

The V2 loop of HIV gp120 delivers costimulatory signals to CD4+ T cells through Integrin α4ß7 and promotes cellular activation and infection.

Acute HIV infection is characterized by rapid viral seeding of immunologic inductive sites in the gut followed by the severe depletion of gut CD4+ T cells. Trafficking of α4ß7-expressing lymphocytes to the gut is mediated by MAdCAM, the natural ligand of α4ß7 that is expressed on gut endothelial cells. MAdCAM signaling through α4ß7 costimulates CD4+ T cells and promotes HIV replication. Similar to MAdCAM, the V2 domain of the gp120 HIV envelope protein binds to α4ß7 In this study, we report that gp120 V2 shares with MAdCAM the capacity to signal through α4ß7 resulting in CD4+ T cell activation and proliferation. As with MAdCAM-mediated costimulation, cellular activation induced by gp120 V2 is inhibited by anti-α4ß7 monoclonal antibodies (mAbs). It is also inhibited by anti-V2 domain antibodies including nonneutralizing mAbs that recognize an epitope in V2 that has been linked to reduced risk of acquisition in the RV144 vaccine trial. The capacity of the V2 domain of gp120 to mediate signaling through α4ß7 likely impacts early events in HIV infection. The capacity of nonneutralizing V2 antibodies to block this activity reveals a previously unrecognized mechanism whereby such antibodies might impact HIV transmission and pathogenesis.

Monoclonal antibodies with subnanomolar affinity to tenofovir for monitoring adherence to antiretroviral therapies: from hapten synthesis to prototype development.

Approximately 32 million people have died of HIV infection since the beginning of the outbreak, and 38 million are currently infected. Among strategies adopted by the Joint United Nations Programme on HIV/AIDS to end the AIDS global epidemic, the treatment, diagnosis, and viral suppression of the infected subjects are considered crucial for HIV prevention and transmission. Although several antiretroviral (ARV) drugs are successfully used to manage HIV infection, their efficacy strictly relies on perfect adherence to the therapy, which is seldom achieved. Patient supervision, especially in HIV-endemic, low-resource settings, requires rapid, easy-to-use, and affordable analytical tools, such as the enzyme-linked immunosorbent assay (ELISA) and especially the lateral flow immunoassay (LFIA). In this work, high-affinity monoclonal antibodies were generated to develop ELISA and LFIA prototypes for monitoring tenofovir (TFV), an ARV drug present in several HIV treatments. TFV was functionalized by inserting a carboxylated C5-linker at the phosphonic group of the molecule, and the synthetic derivative was conjugated to proteins for mice immunization. Through a rigorous screening strategy of hybridoma supernatants, a panel of monoclonal antibodies strongly binding to TFV was obtained. Following antibody characterization for affinity and selectivity by competitive ELISA, a LFIA prototype was developed and tentatively applied to determine TFV in simulated urine. The point-of-care test showed ultra-high detectability (the visual limit of detection was 2.5 nM, 1.4 ng mL-1), excellent selectivity, and limited proneness to matrix interference, thus potentially making this rapid method a valuable tool for the on-site assessment of patient adherence to ARV therapy.

Aging and HIV infection: focus on cardiovascular disease risk.

Effective antiretroviral therapy has extended life expectancy for individuals with HIV. Estimates from 2015 indicate that 47% of persons with HIV in the US were older than 50 years of age and 16% were older than 65 years. These older patients are at increased risk of age-related diseases and conditions. Further, there is substantial evidence that patients with HIV infection accumulate age-related conditions earlier than do those in the general population. There is risk for increased comorbidities and polypharmacy in the aging HIV-infected population. Specific measures for assessing and reducing the risk of cardiovascular disease and other age-related conditions in the aging HIV population are needed. This article summarizes a presentation by Judith A. Aberg, MD, at the International Antiviral Society-USA (IAS-USA) annual continuing education program held in Chicago, Illinois, in May 2019.

New genetic predictors for abacavir tolerance in HLA-B*57:01 positive individuals.

Abacavir hypersensitivity syndrome (ABC HSS) is strongly associated with carriage of human leukocyte antigen (HLA)-B*57:01, which has a 100% negative predictive value for the development of ABC HSS. However, 45% of individuals who carry HLA-B*57:01 can tolerate ABC. We investigated immune and non-immune related genes in ABC HSS (n = 95) and ABC tolerant (n = 43) HLA-B*57:01 + patients to determine other factors required for the development of ABC HSS. Assignment of phenotype showed that ABC HSS subjects were significantly less likely than tolerants to carry only ERAP1 hypoactive trimming allotypes (p = 0.02). An altered self-peptide repertoire model by which abacavir activates T cells is in keeping with observation that endoplasmic reticulum aminopeptidase 1 (ERAP1) allotypes that favour efficient peptide trimming are more common in ABC HSS patients compared to patients who tolerate ABC. Independently, non-specific immune activation via soluble cluster of differentiation antigen 14 (sCD14) may also influence susceptibility to ABC HSS.

Adherence, virological outcome, and drug resistance in Chinese HIV patients receiving first-line antiretroviral therapy from 2011 to 2015.

Stavudine (D4T), zidovudine (AZT), and tenofovir (TDF) along with lamivudine (3TC) are the most widely used HIV treatment regimens in China. China's National Free Antiretroviral Treatment Programme (NFATP) has replaced D4T with AZT or TDF in the standard first-line regimens since 2010. Few studies have evaluated the adherence, virological outcome, and drug resistance in HIV patients receiving first-line antiretroviral therapy (ART) from 2011 to 2015 due to changes in ART regimen.From 2011 to 2015, 2787 HIV patients were examined, with 364, 1453, and 970 patients having initiated D4T-, AZT-, and TDF-based first-line ART regimens, respectively. The Cochran-Armitage test was used to examine the trends in clinical and virological outcomes during 2011 to 2015. Logistic regression was used to examine the effects of different regimens after 9 to 24 months of ART.From 2011 to 2014-2015, adverse drug reactions decreased from 18.9% to 6.7%, missed doses decreased from 9.9% to 4.6%, virological failure decreased from 16.2% to 6.4%, and drug resistance rates also significantly decreased from 5.4% to 1.1%. These successes were strongly associated with the standardized use of TDF- or AZT-based regimens in place of the D4T-based regimen. Poor adherence decreased from 11.3% in patients who initiated D4T-based regimens to 4.9% in those who initiated TDF-based regimens, adverse drug reactions decreased from 32.4% to 6.7%, virological failure reduced from 18.7% to 8.6%, and drug resistance reduced from 5.8% to 2.9%. Compared with patients who initiated AZT-based regimens, patients who initiated TDF-based regiments showed significant reductions in adherence issues, adverse drug reactions, virological outcomes, and drug resistance. Significant differences were also observed between those who initiated D4T- and AZT-based regimens.The good control of HIV replication and drug resistance was attributed to the success of China's NFATP from 2011 to 2015. This study provided real world evidence for further scaling up ART and minimizing the emergence of drug resistance in the "Three 90" era.

Enrichment of gut-derived Fusobacterium is associated with suboptimal immune recovery in HIV-infected individuals.

We explored the gut microbiota profile among HIV-infected individuals with diverse immune recovery profiles following long-term suppressive ART and investigated the relationship between the altered bacteria with markers of immune dysfunction. The microbiota profile of rectal swabs from 26 HIV-infected individuals and 20 HIV-uninfected controls were examined. Patients were classified as suboptimal responders, sIR (n = 10, CD4 T-cell <350 cells/ul) and optimal responders, oIR (n = 16, CD4 T-cell >500 cells/ul) after a minimum of 2 years on suppressive ART. Canonical correlation analysis(CCA) and multiple regression modelling were used to explore the association between fecal bacterial taxa abundance and immunological profiles in optimal and suboptimal responders. We found Fusobacterium was significantly enriched among the HIV-infected and the sIR group. CCA results showed that Fusobacterium abundance was negatively correlated with CD4 T-cell counts, but positively correlated with CD4 T-cell activation and CD4 Tregs. Multiple linear regression analysis adjusted for age, baseline CD4 T-cell count, antibiotic exposure and MSM status indicated that higher Fusobacterium relative abundance was independently associated with poorer CD4 T-cell recovery following ART. Enrichment of Fusobacterium was associated with reduced immune recovery and persistent immune dysfunction following ART. Modulating the abundance of this bacterial taxa in the gut may be a viable intervention to improve immune reconstitution in our setting.

Combination therapy with anti-HIV-1 antibodies maintains viral suppression.

Individuals infected with HIV-1 require lifelong antiretroviral therapy, because interruption of treatment leads to rapid rebound viraemia. Here we report on a phase 1b clinical trial in which a combination of 3BNC117 and 10-1074, two potent monoclonal anti-HIV-1 broadly neutralizing antibodies that target independent sites on the HIV-1 envelope spike, was administered during analytical treatment interruption. Participants received three infusions of 30 mg kg-1 of each antibody at 0, 3 and 6 weeks. Infusions of the two antibodies were generally well-tolerated. The nine enrolled individuals with antibody-sensitive latent viral reservoirs maintained suppression for between 15 and more than 30 weeks (median of 21 weeks), and none developed viruses that were resistant to both antibodies. We conclude that the combination of the anti-HIV-1 monoclonal antibodies 3BNC117 and 10-1074 can maintain long-term suppression in the absence of antiretroviral therapy in individuals with antibody-sensitive viral reservoirs.

A competitive lateral flow assay for the detection of tenofovir.

Proper management of an HIV infection requires that a patient be at least 80-95% adherent to a prescribed drug regimen to avoid poor health outcomes and the development of drug-resistant HIV strains. Clinicians generally monitor adherence habits indirectly through patient self-reporting, pill counting, and electronic drug monitoring. While direct measurement of patient samples like urine for monitoring drug levels is possible, it requires specialized equipment and training that is not readily available in resource-limited settings where the need is greatest. In this work we report the development of an antibody that binds to tenofovir (TFV), a key small molecule drug for both the treatment and prevention of HIV, and a competitive lateral flow assay that uses that antibody to monitor urine samples for the presence of the drug. TFV was conjugated to an immunogenic protein and injected into rabbits to raise polyclonal antibodies sensitive to the drug. The antibodies were verified for TFV-sensitivity by immunoprecipitation and HPLC. A gold nanoparticle-based competitive assay was developed to detect the presence of TFV in urine samples with a sensitivity of 1 µg mL-1. This TFV assay could be deployed as a point-of-care device for adherence monitoring in resource-limited settings as a low-cost, accurate, and speedy alternative to current methods to better inform changes in treatment.

Hypersensitivity to antiretroviral drugs.

Summary: Background. Antiretroviral therapy (ART) may be responsible for hypersensitivity reactions varying in severity, clinical manifestations and frequency. Case report. We report the case of a 47-year-old woman with HIV infection who developed a delayed mucocutaneous reaction after treatment with ART. Hypersensitivty reaction (HR) to emtricitabine and tenofovir was considered probable based on positive patch tests (PT) and hypersensitivity reaction to nevirapine was confirmed by drug provocation test. Discussion. The diagnosis of HR to ART remains a diagnostic challenge, partly due to unknown mechanism and the absence of validated diagnostic tools. Patch testing may represent a useful method for confirming hypersensitivity. Further investigation in this area is required, so that successful management strategies can be offered, preventing loss of potent and viable antiretroviral agents.

Increased frequencies of Th17 cells and IL17a-producing regulatory T-cells preceding the immunodiscordant response to antiretroviral treatment.

BACKGROUND: Despite the fact that antiretroviral therapy (cART) suppresses HIV-viremia, an adequate CD4 T-cell recovery is not always achieved (immunodiscordant response to cART). IL17a-producing CD4 T-cells (Th17) constitutes an important subset involved in the preservation of mucosal surfaces integrity, which depletion has been associated with disease progression in HIV-infection. However, whether Th17 frequency at cART initiation is associated with a poor CD4 T-cell recovery has not been yet explored. Our aim was to explore whether the Th17 cells and other IL17a-producing T-cell subsets at cART initiation were associated with a subsequent immunodiscordant response to cART. METHODS: We selected pre-cART samples of antiretroviral-naïve subjects with and without a low CD4 recovery after cART (LR-subjects and HR-subjects, respectively). Peripheral blood mononuclear cells (PBMCs) were stimulated with PMA/ionomycine, and the production of several cytokines including IL17a was analyzed by flow cytometry. RESULTS: A trend to higher Th17 (p = 0.05) and increased frequencies of IL17a-producing Treg (p = 0.011) was found in LR-subjects before cART onset. Despite increased frequencies of both Treg and Th17 in LR-subject at cART initiation, no alteration of Treg/Th17 ratio was observed. While polifunctional profile of CD4 T-cells was not different, frequencies of CD4 T-cells producing cytokine-combinations including IL17a were increased in LR-subjects. CONCLUSION: Increased frequencies of Th17, IL17a-producing Treg and CD4 T-cells producing specific IL17a-containing combinations of cytokines, precede the immunodiscordant response to cART, suggesting a potential contribution of these subsets in such anomalous response to cART.

TSG101: Tumor Susceptibility Gene 101 (tsg101) Product-Role in Therapy Against HIV/AIDS.

HIV infection presents a major community health hazard, partially because the HIV virus is capable of evading antiretroviral therapies. Most anti-HIV drugs were intended to target virus-encoded mechanisms; however, some host-encoded molecules comparatively execute a vital role in the life cycle of virus. Thus, these might be considered as target sites for antiviral agents. TSG101 is important among these antiviral therapies because, as a cytoplasmic molecule, it facilitates viral budding and release. In this review, HIV-infected cells have TSG101 on their surface and thus can be used in antibody-based therapies. The development of a monoclonal antibody CB8-2 lessens the assembly of viruses from infected cells. This mechanism represents the potential use of TSG101-directed antibodies to fight against AIDS.

A 2-4-Amino Acid Deletion in the V5 Region of HIV-1 Env gp120 Confers Viral Resistance to the Broadly Neutralizing Human Monoclonal Antibody, VRC01.

The envelope glycoprotein (Env) gp120 of human immunodeficiency virus type 1 (HIV-1) plays a critical role in viral entry into host cells. The broadly neutralizing human monoclonal antibody VRC01, which recognizes the CD4 binding site on gp120, neutralizes more than 90% of HIV-1 isolates. However, some of the CRF01_AE viruses prevalent in Southeast Asia are resistant to VRC01-mediated neutralization. We previously reported that 3 amino acid residues at positions 185, 186, and 197 of gp120 played an important role in the VRC01 resistance of CRF01_AE Env (AE-Env) clones isolated from HIV-infected Thai individuals. However, the VRC01 susceptibility of AE-Env clones was not fully explained by mutations at these 3 residues. In the present study, we examined other factors involved in the acquisition of viral VRC01 resistance. Neutralization tests using lentiviral vectors expressing a series of mutant AE-Env clones revealed that the deletion of 2-4 amino acid residues on the loop structure in the V5 region of gp120 conferred VRC01 resistance to several AE-Env clones. Our results provide novel insights into the mechanisms underlying viral VRC01 resistance.