HIV-infected Donors Research Articles

Impact of glycan depletion, glycan debranching and increased glycan charge on HIV-1 neutralization sensitivity and immunogenicity.

Broadly neutralizing antibodies (bNAbs) isolated from HIV-1 infected donors are vaccine paradigms. These bNAbs recognize envelope glycoprotein trimers that carry 75-90 oligomannose and complex-type glycans. Although bNAbs and their precursors must navigate past glycans, they usually also make some glycan contacts. Glycan-modified vaccines may therefore be useful to initiate and guide bNAb development. Here, we describe two ways to modify Env glycans for possible vaccine use: 1) using a cocktail of glycosidases (termed "NGAF3" (Neuraminidase, β-Galactosidase, N-Acetylglucosaminidase, endoglycosidase F3 (endo F3)) to deplete complex glycans to try to minimize bNAb-glycan clashes and 2) co-expressing β-1,4-galactosyltransferase 1 (B4G) and β-galactoside α-2,6 sialyltransferase 1 (ST6) during Env biosynthesis, creating bNAb-preferred glycan structures. Mass spectrometry revealed that NGAF3 removed glycan heads at 3/7 sites occupied by complex glycans. B4G overexpression resulted in hybrid glycan development whenever complex glycans were closely spaced. The glycan at position 611 in of Env's gp41 transmembrane subunit was uniquely isolated from the effects of both endo F3 and B4G. B4G and ST6 co-expression increased hybrid and sialylated glycan abundance, reducing glycan complexity. In rabbit vaccinations, B4G+ST6 virus-like particles (VLPs) induced less frequent, weaker titer NAbs, implying that ST6-mediated increased Env charge dampens vaccine antibodies. In some cases, vaccine sera preferentially neutralized B4G+ST6-modified pseudovirus. HIV-1+ donor plasma NAbs were generally more effective against B4G+ST6 modified pseudovirus, suggesting a preference for less complex and/or α-2,6 sialylated Env trimers. Collectively, our data suggest that B4G and ST6 Env modifications are best suited for intermediate or late vaccine shots.

Clinical course, management and outcomes of COVID-19 in HIV-infected renal transplant recipients: A case series.

HIV-infected kidney transplant recipients with COVID-19 are at increased risk of acute illness and death owing to their underlying comorbidities and chronic immunosuppression. To describe the incidence, clinical presentation and course of COVID-19, vaccination status, and SARS-CoV-2 antibody positivity rate among HIV-infected-to-HIV-infected kidney transplant recipients in South Africa (SA). This retrospective study reports on rates of SARS-CoV-2 infection, COVID-19 and mortality among SA HIV-infected kidney transplant recipients who received organs from HIV-infected donors (HIV positive to HIV positive), before and after vaccination. Patient demographics, clinical presentation, course, management and disease outcomes were analysed. Antibody serology tests were performed between May and September 2022. Among 39 HIV-positive-to-HIV-positive transplant recipients, 11 cases of COVID-19 were diagnosed from March 2020 to September 2022. Six patients (55%) required hospitalisation, of whom 3 were admitted to a high-care unit or intensive care unit. Two patients required mechanical ventilation, and 2 received acute dialysis. One patient was declined access to intensive care. Four patients (10%) died of COVID-19 pneumonia. All the COVID-19-positive patients had at least one comorbidity. Vaccination data were available for 24 patients, of whom 5 had refused SARS-CoV-2 vaccination. SARS-CoV-2 antibody data were available for 20 patients; 4 vaccinated patients had a negative nucleocapsid protein antibody test and a positive spike protein antibody test, suggesting vaccination-acquired immunity. The remaining 16 patients demonstrated immunity that was probably due to COVID infection, and of these, 14 were also vaccinated. Of the 11 COVID-19 cases, only 1 was observed after vaccination. In our case series, ~10% of the HIV-positive-to-HIV-positive transplant recipients died of COVID-19 pneumonia. This mortality rate appears higher than figures reported in other transplant cohorts. However, it is likely that the actual number of cases of SARS-CoV-2 infection was much higher, as the study only included polymerase chain reaction-confirmed cases. It remains unclear whether HIV infection, transplant or the combination of the two drives poorer outcomes, and larger studies adjusting for important demographic and biological factors may isolate these effects.

1480. Detection of Multiple HIV Strains in an HIV-positive Transplant Recipient from an Acutely HIV Infected Donor.

Abstract Background The HIV Organ Policy Equity (HOPE) Act allows persons living with human immunodeficiency virus (HIV) infection to accept HIV-positive donor organs. Risk of superinfection or viral recombination resulting from the transmission of a genetically distinct donor HIV-1 strain may be a concern. It is unknown if transplantation from acutely infected donors pose additional risk. Analysis of viral quasispecies from donor and recipient samples provides an opportunity to evaluate the transplanted kidney as a viral reservoir and explore the potential for viral superinfection or recombination in the recipient. Methods A 63-year-old HIV-positive recipient with focal segmental glomerulosclerosis and suppressed viral load (< 20 copies/mL) on antiretroviral therapy (ART) with dolutegravir and lamivudine, received a kidney from an acutely infected deceased HIV-positive donor (Table 1). Single genome amplification of the HIV-1 env gene was performed with viral RNA extracted from recipient urine and plasma and viral DNA from donor kidney cells, recipient PBMC and renal cells. We constructed phylogenetic trees assessed recombination probabilities. Results A new, genetically distinct env sequence was amplified from the recipient’s urine 30 hours post-transplant suggesting transfer of donor virus to recipient. Donor virus became undetectable on subsequent visits while recipient was maintained on ART. Notably, a third virus was detected 1.5 months post-transplant in urine-derived renal tubular epithelial cells and 5 months post-transplant in urine which was genetically distinct from previously detected donor and recipient strains (Figure 1). This third strain did not have genetic features suggestive of recombination. Our findings suggest potential superinfection in the donor or recipient. Figure 1. Phylogenetic Analysis of HIV Quasispecies Isolated from an HIV-Positive Kidney Transplant Recipient, Showing Three Distinct Viral Lineages* Conclusion We documented presence of three unrelated HIV strains within a transplanted recipient and within different viral reservoirs. Donor and recipient recombination did not occur. In acutely infected donors, when the transfer of virus within the kidney occurs, ongoing virologic suppression can be achieved if appropriate ART is maintained. Additional long-term monitoring of viral populations in the recipient is important to fully assess any clinical and virologic implications of this finding. Disclosures All Authors: No reported disclosures

Implications of highly suppressive treatment HIV infection.

Treatment of HIV infection has modified the initially fatal infection into a typically chronic disease requiring lifelong treatment. However, there is no complete normalization of immune activation, signs of inflammation and prothrombotic state in treated patients. This condition is the result of many factors, but the main cause is thought to be the residual production of HIV-1 RNA and viral proteins by infected cells in cellular reservoirs. Persistence of immune activation/inflammation/prothrombotic state leads to the pathophysiology of "sterile inflammation" and so-called non-AIDS diseases, which manifest one to two decades earlier in those infected. Despite all the pitfalls and unwanted secondary manifestations of antiretroviral drugs, the treatment of HIV infection has managed to reverse the trajectory of a fatal pandemic and has made it possible to approach therapeutic modalities that were absolutely unimaginable just a few years ago. Solid organ transplantation is now a completely legitimate therapeutic method for patients living with HIV, and highly suppressive treatment even allows transplantation from an HIV-infected donor. The text below presents a brief overview of the basic pitfalls, but also of the successes, of the current highly suppressive treatment of HIV infection.

Elevated Galectin-9 across the human brain correlates with HIV neuropathology and detrimental cognitive states.

HIV persistence and neuroinflammation are known to contribute to HIV-associated neuropathology. However, the multifaceted pathways driving impairment remain poorly understood. Galectin-glycan interactions have emerged as significant contributors to neuroinflammatory processes and may play a role in neuroHIV. Here, we quantified Galectin-9 (Gal-9), a pleiotropic immunomodulatory protein, in post-mortem brain tissue across multiple regions from HIV-infected and HIV-uninfected donors to determine causal associations with HIV brain injury. We demonstrate that the staining intensity, total staining area, and cell-associated frequency of Gal-9 were elevated, principally in the frontal lobe and basal ganglia. Higher frontal lobe Gal-9 levels correlated with lower pre-mortem neuropsychological performance test scores in areas of attention and motor skills. Our results suggest that Gal-9 activity across the brain plays a role in neuroHIV pathogenesis and constitutes a promising disease-modifying target.

Toll-like receptor agonists enhance HIV-specific T cell response mediated by plasmacytoid dendritic cells in diverse HIV-1 disease progression phenotypes

Plasmacytoid dendritic cells (pDCs) sense viral and bacterial products through Toll-like receptor (TLR)-7 and-9 and translate this sensing into Interferon-α (IFN-α) production and T-cell activation. The understanding of the mechanisms involved in pDCs stimulation may contribute to HIV-cure immunotherapeutic strategies. The objective of the present study was to characterize the immunomodulatory effects of TLR agonist stimulations in several HIV-1 disease progression phenotypes and in non HIV-1 infected donors. pDCs, CD4 and CD8 T-cells were isolated from 450ml of whole blood from non HIV-1 infected donors, immune responders (IR), immune non responders (INR), viremic (VIR) and elite controller (EC) participants. pDCs were stimulated overnight with AT-2, CpG-A, CpG-C and GS-9620 or no stimuli. After that, pDCs were co-cultured with autologous CD4 or CD8 T-cells and with/without HIV-1 (Gag peptide pool) or SEB (Staphylococcal Enterotoxin B). Cytokine array, gene expression and deep immunophenotyping were assayed. pDCs showed an increase of activation markers levels, interferon related genes, HIV-1 restriction factors and cytokines levels after TLR stimulation in the different HIV-disease progression phenotypes. This pDC activation was prominent with CpG-C and GS-9620 and induced an increase of HIV-specific T-cell response even in VIR and INR comparable with EC. This HIV-1 specific T-cell response was associated with the upregulation of HIV-1 restriction factors and IFN-α production by pDC. These results shed light on the mechanisms associated with TLR-specific pDCs stimulation associated with the induction of a T-cell mediated antiviral response which is essential for HIV-1 eradication strategies. This work was supported by Gilead fellowship program, the Instituto de Salud Carlos III (Fondo Europeo de Desarrollo Regional, FEDER, "a way to make Europe") and the Red Temática de Investigación Cooperativa en SIDA and by the Spanish National Research Council (CSIC).

HIV-1 prehairpin intermediate inhibitors show efficacy independent of neutralization tier

HIV-1 strains are categorized into one of three neutralization tiers based on the relative ease by which they are neutralized by plasma from HIV-1-infected donors not on antiretroviral therapy; tier-1 strains are particularly sensitive to neutralization while tier-2 and tier-3 strains are increasingly difficult to neutralize. Most broadly neutralizing antibodies (bnAbs) previously described target the native prefusion conformation of HIV-1 Envelope (Env), but the relevance of the tiered categories for inhibitors targeting another Env conformation, the prehairpin intermediate, is not well understood. Here, we show that two inhibitors targeting distinct highly conserved regions of the prehairpin intermediate have strikingly consistent neutralization potencies (within ~100-fold for a given inhibitor) against strains in all three neutralization tiers of HIV-1; in contrast, best-in-class bnAbs targeting diverse Env epitopes vary by more than 10,000-fold in potency against these strains. Our results indicate that antisera-based HIV-1 neutralization tiers are not relevant for inhibitors targeting the prehairpin intermediate and highlight the potential for therapies and vaccine efforts targeting this conformation.

Modeling the Risk of HIV Transfusion Transmission.

Blood donations are routinely screened for HIV to prevent an infectious unit from being released to the blood supply. Despite improvements to blood screening assays, donations from infected donors remain undetectable during the window period (WP), when the virus has not yet replicated above the lower limit of detection (LOD) of a screening assay. To aid in the quantitative risk assessments of WP donations, a dose-response model describing the probability of transfusion-transmission of HIV over a range of viral RNA copies was developed. An exponential model was chosen based on data fit and parsimony. A data set from a HIV challenge study using a nonhuman primate model and another data set from reported human blood transfusions associated with HIV infected donors were separately fit to the model to generate parameter estimates. A Bayesian framework using No-U-Turn Sampling (NUTS) and Monte Carlo simulations was performed to generate posterior distributions quantifying uncertainty in parameter estimation and model predictions. The parameters of the exponential model for both nonhuman primate and human data were estimated with a mean (95% credible intervals) of 2.70 × 10 -2 (7.74 × 10 -3 , 6.06 × 10 -2 ) and 7.56 × 10 -4 (3.68 × 10 -4 , 1.31 × 10 -3 ), respectively. The predicted ID 50 for the animal and human models was 26 (12, 90) and 918 (529, 1886) RNA copies transfused, respectively. This dose-response model can be used in a quantitative framework to estimate the probability of transfusion-transmission of HIV through WP donations. These models can be especially informative when assessing risk from blood components with low viral load.

Characterization of a VRC01-like antibody lineage with immature VL from an HIV-1 infected Chinese donor

Because of the broadly neutralizing activity, VRC01-class antibodies are attractive templates for HIV-1 vaccine development and suitable candidates for HIV-1 therapy. Although we previously revealed that glycans in gp120 may have a role in the uneven evolution of the VH and the VL of a VRC01-class antibody, DRVIA7, which was isolated from an elite neutralizer, it is unknown whether the immature VH or VL of VRC01-class antibodies are also present in the non-neutralizer. We identified a CD4bs-directed antibody – 263A9 – with low neutralizing activity from a donor whose plasma had a moderate neutralizing spectrum in this study. The 263A9 antibody, in particular, was a VRC01-like antibody whose VH and VL were derived from IGHV1–2 * 04 and IGKV1–33 * 01, respectively, and both had significant SHM rates. Surprisingly, we discovered that the VL of 263A9 hindered the neutralizing activity of the antibody, and that replacing its LCDR1 and LCDR3 with VRC01 increased the neutralizing breadth of the chimeric antibodies. Following that, an antibodyomics research revealed that the VL of 263A9 lineage was remote from VRC01-class antibodies. We also looked at the envelope sequence characteristics of donor CBJC263 and discovered that N276 in the D loop and N460/N463 glycans in the V5 region of gp120 potentially interact with VL of 263A9 at the structural level. This study will provide valuable information for immunogen screening and vaccine development for eliciting VRC01-class antibodies. Data availability statementThe original data presented in the study are included in the article or Supplementary materials. Further inquiries can be directed to the corresponding author. HIV Env sequences in the manuscript had been deposited into the GenBank with the accession numbers from OL466822 to OL466859.

Cross-reactivity of glycan-reactive HIV-1 broadly neutralizing antibodies with parasite glycans.

The HIV-1 Envelope glycoprotein (Env) is the sole target for broadly neutralizing antibodies (bnAbs). Env is heavily glycosylated with host-derived N-glycans, and many bnAbs bind to, or are dependent upon, Env glycans for neutralization. Although glycan-binding bnAbs are frequently detected in HIV-infected individuals, attempts to elicit them have been unsuccessful because of the poor immunogenicity of Env N-glycans. Here, we report cross-reactivity of glycan-binding bnAbs with self- and non-self N-glycans and glycoprotein antigens from different life-stages of Schistosoma mansoni. Using the IAVI Protocol C HIV infection cohort, we examine the relationship between S.mansoni seropositivity and development of bnAbs targeting glycan-dependent epitopes. We show that the unmutated common ancestor of the N332/V3-specific bnAb lineage PCDN76, isolated from an HIV-infected donor with S.mansoni seropositivity, binds to S.mansoni cercariae while lacking reactivity to gp120. Overall, these results present a strategy for elicitation of glycan-reactive bnAbs which could be exploited in HIV-1 vaccine development.

Metavirome composition of Brazilian blood donors positive for the routinely tested blood-borne infections

Viral metagenomics is widely applied to characterize emerging viral pathogens but it can also reveal the virome composition in health and disease. The evaluation of the virome in healthy blood donors can provide important knowledge on possible transfusion threats. Currently, there is still a paucity of information regarding the virome of blood donors who test positive for routinely tested blood-borne infections. Such analysis may reveal co-infections which in turn appear to be crucial for transfusion medicine and for patient management. The aim of this study was to evaluate the metavirome in blood donors who tested positive for routinely tested blood-borne infections, the information for which is important for transfusion medicine and blood donor management. For this purpose, we analyzed 18 blood donations obtained from HIV and HBV-infected blood donors from the Brazilian Amazon (Amapa state) and 11 HIV, HBV, HCV, syphilis and Chagas disease - positive blood donations obtained from blood donors sampled in South Brazil (Rio Grande do Sul state). We additionally included a control group of 20 blood donors obtained from Southeast Brazil (State of São Paulo). Samples were assembled in pools and sequenced by the Illumina NovaSeq 6000 platform. To link a given virus with geographic region or type of blood donor, we performed supervised machine learning classification (fingerprint analysis). The virome of both locations was predominantly composed of commensal viruses. However, in HBV-infected blood donors from the Brazilian Amazon, the Human Pegivirus-1 (HPgV-1) reads were prevailing, while in HIV-infected donors from the same location, the torque teno virus (TTV) reads expressive abundance. In blood donors from South Brazil, the most abundant reads were classified as Human endogenous retrovirus K (HERV-K). Putative emerging viruses like the Human gemykibivirus-2 (HuGkV-2) were exclusively identified in samples from the Brazilian Amazon. The fingerprint analysis demonstrated that the HERV-K, TTV-7, 13, and 15 were statistically important for the infected blood donors, while TTV-5, 12 and 20 were linked to geographic localization. Our study revealed differences in the viral composition among blood donors who tested positive for routinely tested blood-borne infections from two different Brazilian regions and indicated the presence of putative emerging viruses in samples obtained from the Amazon. Together our results show that the presence of specific commensal viruses may be related donor infection status but additional investigations including larger study groups and samples from other Brazilian regions are needed to confirm this hypothesis.

Identification and Characterization of Antigen-Specific CD8+ T Cells Using Surface-Trapped TNF-α and Single-Cell Sequencing.

CD8+ T cells are key mediators of antiviral and antitumor immunity. The isolation and study of Ag-specific CD8+ T cells, as well as mapping of their MHC restriction, has practical importance to the study of disease and the development of therapeutics. Unfortunately, most experimental approaches are cumbersome, owing to the highly variable and donor-specific nature of MHC-bound peptide/TCR interactions. Here we present a novel system for rapid identification and characterization of Ag-specific CD8+ T cells, particularly well suited for samples with limited primary cells. Cells are stimulated ex vivo with Ag of interest, followed by live cell sorting based on surface-trapped TNF-α. We take advantage of major advances in single-cell sequencing to generate full-length sequence data from the paired TCR α- and β-chains from these Ag-specific cells. The paired TCR chains are cloned into retroviral vectors and used to transduce donor CD8+ T cells. These TCR transductants provide a virtually unlimited experimental reagent, which can be used for further characterization, such as minimal epitope mapping or identification of MHC restriction, without depleting primary cells. We validated this system using CMV-specific CD8+ T cells from rhesus macaques, characterizing an immunodominant Mamu-A1*002:01-restricted epitope. We further demonstrated the utility of this system by mapping a novel HLA-A*68:02-restricted HIV Gag epitope from an HIV-infected donor. Collectively, these data validate a new strategy to rapidly identify novel Ags and characterize Ag-specific CD8+ T cells, with applications ranging from the study of infectious disease to immunotherapeutics and precision medicine.

T cell receptor-targeted immunotherapeutics drive selective in vivo HIV- and CMV-specific T cell expansion in humanized mice.

To delineate the in vivo role of different costimulatory signals in activating and expanding highly functional virus-specific cytotoxic CD8+ T cells, we designed synTacs, infusible biologics that recapitulate antigen-specific T cell activation signals delivered by antigen-presenting cells. We constructed synTacs consisting of dimeric Fc-domain scaffolds linking CD28- or 4-1BB-specific ligands to HLA-A2 MHC molecules covalently tethered to HIV- or CMV-derived peptides. Treatment of HIV-infected donor PBMCs with synTacs bearing HIV- or CMV-derived peptides induced vigorous and selective ex vivo expansion of highly functional HIV- and/or CMV-specific CD8+ T cells, respectively, with potent antiviral activities. Intravenous injection of HIV- or CMV-specific synTacs into immunodeficient mice intrasplenically engrafted with donor PBMCs markedly and selectively expanded HIV-specific (32-fold) or CMV-specific (46-fold) human CD8+ T cells populating their spleens. Notably, these expanded HIV- or CMV-specific CD8+ T cells directed potent in vivo suppression of HIV or CMV infections in the humanized mice, providing strong rationale for consideration of synTac-based approaches as a therapeutic strategy to cure HIV and treat CMV and other viral infections. The synTac platform flexibility supports facile delineation of in vivo effects of different costimulatory signals on patient-derived virus-specific CD8+ T cells, enabling optimization of individualized therapies, including HIV cure strategies.

Hsa-miR-31 Governs T-Cell Homeostasis in HIV Protection via IFN-γ-Stat1-T-Bet Axis.

It remains poorly defined whether any human miRNAs play protective roles during HIV infection. Here, focusing on a unique cohort of HIV-infected former blood donors, we identified miR-31 (hsa-miR-31) by comparative miRNA profiling as the only miRNA inversely correlating with disease progression. We further validated this association in two prospective cohort studies. Despite conservation during evolution, hsa-miR-31, unlike its mouse counterpart (mmu-miR-31), was downregulated in human T cell upon activation. Our ex vivo studies showed that inhibiting miR-31 in naïve CD4+ T cells promoted a transcriptional profile with activation signature. Consistent with this skewing effect, miR-31 inhibition led to remarkably increased susceptibility to HIV infection. The suppressive nature of miR-31 in CD4+ T cell activation was pinpointed to its ability to decrease T-bet, the key molecule governing IFN-γ production and activation of CD4+ T cells, by directly targeting the upstream STAT1 transcriptional factor for downregulation, thus blunting Th1 response. Our results implicated miR-31 as a useful biomarker for tracking HIV disease progression and, by demonstrating its importance in tuning the activation of CD4+ T cells, suggested that miR-31 may play critical roles in other physiological contexts where the CD4+ T cell homeostasis needs to be deliberately controlled.

HIV primary drug resistance and associated HIV risk factors among HIV positive blood donors in Brazil from 2007 to 2017.

Acquisition of HIV primary drug resistant (PDR) infection can lead to poor virologic and clinical outcomes in individuals and hampers public health efforts in epidemic control. Monitoring PDR in HIV-positive blood donors can be used to inform nationwide trends in the spread of drug-resistant HIV strains. We conducted a cross-sectional study using genetic sequence analysis to assess HIV pol sequences, PDR, and risk factors for infection using audio computer-assisted structured interviews in four large blood centers in Brazil from 2007 to 2017. Of 716 HIV-positive blood donors, 504 (70.4%) were successfully sequenced. HIV clade B (73.2%) was the most prevalent subtype, followed by a mix of non-B (21.2%) sub-types. A twofold increase (from 4% to 8%) in recombinants prevalence was observed during the study period. Sixty-four (12.7%) presented PDR. Overall, HIV PDR prevalence remained stable during the study period. Drug resistance mutations for non-nucleoside reverse transcriptase inhibitors were found in 39 (7.7%) donors, while for nucleoside reverse transcriptase inhibitors were found in 26 (5.1%), and for protease inhibitors in 24 (4.8%) of HIV-infected donors. We did not find statistically significant differences in demographics, behavioural risk factors, or HIV genotypes when comparing volunteers with and without PDR. The HIV PDR rate among donors remained stable during the study period. HIV-positive blood donors can be an informative population to monitor primary HIV resistance and ultimately may help to increase the knowledge and awareness of HIV risk factors and PDR.

False Negative Tuberculin Skin Test (TST) Response in Asymptomatic HIV-1 Infected Blood Donors with Subclinical Iron Overload Developing High Incidence of Pulmonary Tuberculosis on Follow Up

Tuberculin skin testing (TST) response as a predictive tool for development of pulmonary tuberculosis (PT) in Human Immunodeficiency Virus type-1 (HIV-1) infected subjects, is likely to be more valuable at early stage of illness in order to adapt timely management strategy. Earlier reports on HIV-1 infected blood donors with history of oral iron intake and biochemical evidence of iron overload documented development of high incidence of PT on follow up.

The African natural product knipholone anthrone and its analogue anthralin (dithranol) enhance HIV-1 latency reversal

A sterilizing or functional cure for HIV is currently precluded by resting CD4+ T cells that harbor latent but replication-competent provirus. The "shock-and-kill" pharmacological ap-proach aims to reactivate provirus expression in the presence of antiretroviral therapy and target virus-expressing cells for elimination. However, no latency reversal agent (LRA) to date effectively clears viral reservoirs in humans, suggesting a need for new LRAs and LRA combinations. Here, we screened 216 compounds from the pan-African Natural Product Library and identified knipholone anthrone (KA) and its basic building block anthralin (dithranol) as novel LRAs that reverse viral latency at low micromolar concentrations in multiple cell lines. Neither agent's activity depends on protein kinase C; nor do they inhibit class I/II histone deacetylases. However, they are differentially modulated by oxidative stress and metal ions and induce distinct patterns of global gene expression from established LRAs. When applied in combination, both KA and anthralin synergize with LRAs representing multiple functional classes. Finally, KA induces both HIV RNA and protein in primary cells from HIV-infected donors. Taken together, we describe two novel LRAs that enhance the activities of multiple "shock-and-kill" agents, which in turn may inform ongoing LRA combination therapy efforts.

Brief Report: Willingness to Accept HIV-Infected and Increased Infectious Risk Donor Organs Among Transplant Candidates Living With HIV.

HIV-infected (HIV+) donor to HIV+ recipient (HIV D+/R+) transplantation might improve access to transplantation for people living with HIV. However, it remains unknown whether transplant candidates living with HIV will accept the currently unknown risks of HIV D+/R+ transplantation. We surveyed transplant candidates living with HIV from 9 US transplant centers regarding willingness to accept HIV+ donor organs. Among 116 participants, the median age was 55 years, 68% were men, and 78% were African American. Most were willing to accept HIV+ living donor organs (87%), HIV+ deceased donor organs (84%), and increased infectious risk donor organs (70%). Some (30%) were concerned about HIV superinfection; even among these respondents, 71% were willing to accept an HIV D+ organ. Respondents from centers that had already performed a transplant under an HIV D+/R+ transplantation research protocol were more willing to accept HIV+ deceased donor organs (89% vs. 71%, P = 0.04). Respondents who chose not to enroll in an HIV D+/R+ transplantation research protocol were less likely to believe that HIV D+/R+ transplantation was safe (45% vs. 77%, P = 0.02), and that HIV D+ organs would work similar to HIV D- organs (55% vs. 77%, P = 0.04), but more likely to believe they would receive an infection other than HIV from an HIV D+ organ (64% vs. 13%, P < 0.01). Willingness to accept HIV D+ organs among transplant candidates living with HIV does not seem to be a major barrier to HIV D+/R+ transplantation and may increase with growing HIV D+/R+ transplantation experience.

Changes in gastrointestinal microbial communities influence HIV-specific CD8+ T-cell responsiveness to immune checkpoint blockade.

The aim of this study was to examine the relationship between gut microbial communities in HIV-infected individuals on suppressive antiretroviral therapy (cART), and the peripheral HIV-Gag-specific CD8 T-cell responses before and after ex-vivo immune checkpoint blockade (ICB). Thirty-four HIV-seropositive, 10 HIV-seronegative and 12 HIV-seropositive receiving faecal microbiota transplant (FMT) participants were included. Gut microbial communities, peripheral and gut associated negative checkpoint receptors (NCRs) and peripheral effector functions were assessed. Bacterial 16s rRNA sequencing for gut microbiome study and flow-based assays for peripheral and gut NCR and their cognate ligand expression, including peripheral HIV-Gag-specific CD8 T-cell responses before and after ex-vivo anti-PD-L1 and anti-TIGIT ICB were performed. Fusobacteria abundance was significantly higher in HIV-infected donors compared to uninfected controls. In HIV-infected participants receiving Fusobacteria-free FMT, Fusobacteria persisted up to 24 weeks in stool post FMT. PD-1 TIGIT and their ligands were expanded in mucosal vs. peripheral T cells and dendritic cells, respectively. PD-L1 and TIGIT blockade significantly increased the magnitude of peripheral anti-HIV-Gag-specific CD8 T-cell responses. Higher gut Fusobacteria abundance was associated with lower magnitude of peripheral IFN-γ+ HIV-Gag-specific CD8 T-cell responses following ICB. The gut colonization of Fusobacteria in HIV infection is persistent and may influence anti-HIV T-cell immunity to PD-1 or TIGIT blockade. Strategies modulating Fusobacteria colonization may elicit a favourable mucosal immune landscape to enhance the efficacy of ICB for HIV cure.

The replication-competent HIV reservoir is detectable in circulating monocytes and is increased in ART-suppressed chronic HIV-infected individuals with cognitive impairment

Abstract Background Measuring replication-competent HIV (rcHIV) in monocytes (MO) in the setting of antiretroviral therapy (ART)-suppression, remains a topic of intense interest, particularly due to the continued presence of cognitive (cog.) decline, as well as in our pursuit for an HIV cure. Methods PBMCs from ART-suppressed chronic HIV-infected donors, whom had available cog. performance scores, were cell sorted using flow cytometry to obtain ultra pure MO and CD4 T cells confirmed by subsequent flow analyses. Using a novel modified TZM-bl co-culture assay, frequencies of cells producing rcHIV (IUPM) were calculated. Total p24 associated with rcHIV produced by MO or CD4 T cells was quantified using a relative light unit to rcHIV-associated p24 standard curve. The infectious potential (IP) was calculated as a ratio of total rcHIV-associated p24 and IUPM. Non-parametric tests assessed group comparisons. Results All HIV-infected donors in cog. impaired (n=7) and cog. normal (n=9) groups were male, on ART &amp;gt; 3 months, and virally-suppressed. IUPMs in MO were detectable in 11 of 16 donors (median IUPM=1.32). IUPMs in CD4 T cells were detectable in 13 of 16 donors (median IUPM=7.22) and were higher as compared to MO (p=0.004). Median IP was slightly higher in MO as compared to CD4 T cells (0.443 vs. 0.104, p=0.271). Cog. impaired donors had higher IUPMs in MO as compared to cog. normal donors (4.43 vs. 0.31, p=0.015). IP between cog. groups were similar for both cellular compartments. Conclusions Despite ART-suppression, circulating MO are capable of producing rcHIV and may contribute to cog. impairment, as well as pose a challenge for HIV remission efforts. Monitoring and targeting HIV persistence in MO during ART-suppression are warranted.