CXCR3 and CXCR5 are highly expressed in HIV-1-specific CD8 central memory T cells from infected patients.

New ways of characterizing CD8+ memory T cell responses in chronic infections are based on the measurement of chemokine receptor expression (CXCR3, CXCR5, and CX3CR1). We applied these novel phenotyping strategies to chronic HIV infection by comparing healthy donors (HDs), HIV-infected patients receiving antiretroviral therapy (ART), and spontaneous HIV controllers (HICs). In all groups, the memory cells exhibited high proportion of CXCR3+ cells. Proportions of CXCR5+ and CX3CR1+ cells were preferentially observed among central memory cells (Tcm) and effector memory cells (Tem) respectively. Chronic controlled HIV infection impacted the chemokine receptor profile of both HIV-specific and nonspecific CD8+ T cells. In total CD8+ T cells, the proportions of CXCR3- CXCR5- CX3CR1- Tcm and Tem were lower in HIV-infected patients than in HDs with subtle differences between ART and HICs. Such phenotyping strategy also revealed differences in exhaustion and senescence phenotypes, the CXCR3+ CXCR5+ CX3CR1- being more exhausted and senescent than the CXCR3+ CXCR5- CX3CR1- Tcm fraction. Among HIV-specific CD8+ T cells, the vast majority of Tcm cells were CXCR3+ and CXCR5+ cells in contrast with their nonspecific counterparts. In conclusion, the addition of migration markers contributes to better characterize Tcm/Tem compartment.

Early SIV and HIV infection promotes the LILRB2/MHC-I inhibitory axis in cDCs.

Classical dendritic cells (cDCs) play a pivotal role in the early events that tip the immune response toward persistence or viral control. In vitro studies indicate that HIV infection induces the dysregulation of cDCs through binding of the LILRB2 inhibitory receptor to its MHC-I ligands and the strength of this interaction was proposed to drive disease progression. However, the dynamics of the LILRB2/MHC-I inhibitory axis in cDCs during early immune responses against HIV are yet unknown. Here, we show that early HIV-1 infection induces a strong and simultaneous increase of LILRB2 and MHC-I expression on the surface of blood cDCs. We further characterized the early dynamics of LILRB2 and MHC-I expression by showing that SIVmac251 infection of macaques promotes coordinated up-regulation of LILRB2 and MHC-I on cDCs and monocytes/macrophages, from blood and lymph nodes. Orientation towards the LILRB2/MHC-I inhibitory axis starts from the first days of infection and is transiently induced in the entire cDC population in acute phase. Analysis of the factors involved indicates that HIV-1 replication, TLR7/8 triggering, and treatment by IL-10 or type I IFNs increase LILRB2 expression. Finally, enhancement of the LILRB2/MHC-I inhibitory axis is specific to HIV-1 and SIVmac251 infections, as expression of LILRB2 on cDCs decreased in naturally controlled chikungunya virus infection of macaques. Altogether, our data reveal a unique up-regulation of LILRB2 and its MHC-I ligands on cDCs in the early phase of SIV/HIV infection, which may account for immune dysregulation at a critical stage of the anti-viral response.

Long-term Therapeutic Impact of the Timing of Antiretroviral Therapy in Patients Diagnosed With Primary Human Immunodeficiency Virus Type 1 Infection.

Background: We aimed to determine the consequences of delayed human immunodeficiency virus type 1 (HIV-1) infection diagnosis by comparing long-term outcomes depending on the time of combination antiretroviral therapy (cART) initiation in patients diagnosed during primary HIV infection (PHI). Methods: We selected patients from the French National Agency for Research on AIDS and Viral Hepatitis (ANRS) PRIMO cohort, treated for ≥36 months, with sustained HIV RNA <50 copies/mL: 77 treated within 1 month following PHI diagnosis (immediate ART) and 73 treated >12 months after infection (deferred ART). We measured inflammatory biomarkers from PHI through the last visit on cART, and CD4+ and CD8+ T-cell activation and plasma ultrasensitive HIV RNA at the last visit. Inflammation/activation levels were compared with those of uninfected controls. We modeled CD4+ count, CD4:CD8 ratio, and HIV DNA dynamics on cART. Results: The decrease of HIV DNA levels was more marked in the immediate than deferred ART group, leading to a sustained mean difference of -0.6 log10 copies/106 peripheral blood mononuclear cells. Immediate ART led to improved CD4+ T-cell counts and CD4:CD8 ratios over the first 4 years of cART. At the last visit (median, 82 months), there was no difference between groups in CD4+ counts, CD4:CD8 ratio, ultrasensitive HIV RNA, or inflammation/activation marker levels. Long-term suppressive cART failed to normalize inflammation levels, which were not associated with immunovirological markers. Conclusions: Antiretroviral therapy initiated during PHI promotes long-term reduction of HIV reservoir size. In patients with sustained virologic suppression, inflammation may be driven by non-HIV-related factors.

Elevated Basal Pre-infection CXCL10 in Plasma and in the Small Intestine after Infection Are Associated with More Rapid HIV/SIV Disease Onset.

Elevated blood CXCL10/IP-10 levels during primary HIV-1 infection (PHI) were described as an independent marker of rapid disease onset, more robust than peak viremia or CD4 cell nadir. IP-10 enhances the recruitment of CXCR3+ cells, which include major HIV-target cells, raising the question if it promotes the establishment of viral reservoirs. We analyzed data from four cohorts of HIV+ patients, allowing us to study IP-10 levels before infection (Amsterdam cohort), as well as during controlled and uncontrolled viremia (ANRS cohorts). We also addressed IP-10 expression levels with regards to lymphoid tissues (LT) and blood viral reservoirs in patients and non-human primates. Pre-existing elevated IP-10 levels but not sCD63 associated with rapid CD4 T-cell loss upon HIV-1 infection. During PHI, IP-10 levels and to a lesser level IL-18 correlated with cell-associated HIV DNA, while 26 other inflammatory soluble markers did not. IP-10 levels tended to differ between HIV controllers with detectable and undetectable viremia. IP-10 was increased in SIV-exposed aviremic macaques with detectable SIV DNA in tissues. IP-10 mRNA was produced at higher levels in the small intestine than in colon or rectum. Jejunal IP-10+ cells corresponded to numerous small and round CD68neg cells as well as to macrophages. Blood IP-10 response negatively correlated with RORC (Th17 marker) gene expression in the small intestine. CXCR3 expression was higher on memory CD4+ T cells than any other immune cells. CD4 T cells from chronically infected animals expressed extremely high levels of intra-cellular CXCR3 suggesting internalization after ligand recognition. Elevated systemic IP-10 levels before infection associated with rapid disease progression. Systemic IP-10 during PHI correlated with HIV DNA. IP-10 production was regionalized in the intestine during early SIV infection and CD68+ and CD68neg haematopoietic cells in the small intestine appeared to be the major source of IP-10.

Long-Term Spontaneous Control of HIV-1 Is Related to Low Frequency of Infected Cells and Inefficient Viral Reactivation.

UNLABELLED: HIV establishes reservoirs of infected cells that persist despite effective antiretroviral therapy (ART). In most patients, the virus begins to replicate soon after treatment interruption. However, a low frequency of infected cells at the time of treatment interruption has been associated with delayed viral rebound. Likewise, individuals who control the infection spontaneously, so-called HIV-1 controllers (HICs), carry particularly low levels of infected cells. It is unclear, however, whether and how this small number of infected cells contributes to durable viral control. Here we compared 38 HICs with 12 patients on effective combined antiretroviral therapy (cART) and found that the low frequency of infected cells in the former subjects was associated both with less efficient viral reactivation in resting CD4(+) T cells and with less efficient virion production ex vivo We also found that a potent HIV-specific CD8(+) T cell response was present only in those HICs whose CD4(+) T cells produced virus ex vivo Long-term spontaneous control of HIV infection in HICs thus appears to be sustained on the basis of the inefficient reactivation of viruses from a limited number of infected cells and the capacity of HICs to activate a potent HIV-specific CD8(+) T cell response to counteract efficient viral reactivation events. IMPORTANCE: There is a strong scientific interest in developing strategies to eradicate the HIV-1 reservoir. Very rare HIV-1-infected patients are able to spontaneously control viremia for long periods of time (HIV-1 controllers [HICs]) and are put forward as a model of HIV-1 remission. Here, we show that the low viral reservoirs found in HICs are a critical part of the mechanisms underlying viral control and result in a lower probability of HIV-1 reactivation events, resulting in limited HIV-1 release and spread. We found that those HICs in whom viral reactivation and spread from CD4(+) T cells in vitro were the most difficult were those with diminished CD8(+) T cell responses. These results suggest that, in some settings, low HIV-1 reservoirs decisively contribute to at least the temporary control of infection without antiretroviral therapy. We believe that this work provides information of relevance in the context of the search for HIV-1 remission.

High Soluble CD14 Levels at Primary HIV-1 Infection Predict More Rapid Disease Progression.

The soluble CD14 (sCD14) level was found associated with mortality during the chronic phase of human immunodeficiency virus (HIV) infection. Here we assessed its prognostic value in 138 patients with primary HIV infection. Higher sCD14 levels were associated with death, from myocardial infarction, but this was based on 3 deaths only. Among 68 untreated patients, those with higher sCD14 levels had more rapid spontaneous CD4 cell decline during the first 18 months following primary infection. This association persisted after adjustment for age, the CD4 cell count, and HIV viral load at diagnosis.

High eomesodermin expression among CD57+ CD8+ T cells identifies a CD8+ T cell subset associated with viral control during chronic human immunodeficiency virus infection.

During HIV infection, increased CD57 expression among CD8(+) T cells has been associated with immune senescence and defective immune responses. Interestingly, CD57-expressing CD8(+) T cells exhibit a dual profile, being simultaneously highly cytotoxic (terminally differentiated effectors) and poorly proliferative (replicative senescent). Recent publications point toward a positive role of CD57-expressing CD8(+) T cell subsets, presumably due to their high cytolytic activity. We further investigated the phenotype of CD57-expressing CD8(+) T cells in healthy donors and during HIV infection combining CD57 expression to Eomesodermin (EOMES), a T box transcription factor which determines, coordinately with T-bet, effector and memory CD8(+) T cell differentiation. We defined in healthy donors two functionally distinct CD57-expressing CD8(+) T cell subsets exhibiting different levels of EOMES expression: EOMES(hi) CD57(+) and EOMES(int) CD57(+) CD8(+) T cells. EOMES(hi) CD57(+) cells exhibited low cytotoxic activity but preserved proliferative capacity and interleukin 7 (IL-7) receptor expression, whereas EOMES(int) CD57(+) cells exhibited obvious cytotoxic functions and a more terminally differentiated phenotype. We next performed a similar analysis in different contexts of HIV infection: primary infected patients, long-term viremic patients, aviremic patients treated with antiretroviral therapy, and HIV controllers; we demonstrated a higher percentage of CD57-expressing cells in all HIV-infected patients regardless of virological status. When heterogeneity in EOMES expression among CD57 cells was taken into account, we detected significantly higher proportions of EOMES(hi) CD57(+) cells among HIV-specific and nonspecific CD8(+) T cells from HIV controllers than in aviremic antiretroviral-treated patients and viremic patients. Importantly, such a peculiar non-terminally differentiated EOMES(hi) CD57(+) phenotypic profile was associated with viral control. Importance: This study demonstrates that functional heterogeneity exists among CD57-expressing CD8 T cells, which include both terminally differentiated, highly cytotoxic EOMES(int) CD57(+) CD8(+) T cells and less differentiated EOMES(hi) CD57(+) CD8 T cells, which do not exhibit immediate cytotoxic functions but present high proliferative capacity. Interestingly, HIV controllers present a high proportion of EOMES(hi) CD57 cells among CD57-expressing HIV-specific CD8 T cells compared to both long-term viremic and aviremic antiretroviral therapy (ART)-treated patients, suggesting a beneficial role for this cell subset in viral control.

Both HLA-B*57 and plasma HIV RNA levels contribute to the HIV-specific CD8+ T cell response in HIV controllers.

CD8(+) T cell responses are thought to play an important role during HIV infection, particularly in HIV controllers (HIC) in whom viral replication is spontaneously controlled without any treatment. We have demonstrated that CD8(+) T cells from these subjects are able to suppress viral replication in vitro. In parallel, HIV-specific CD8(+) responses were shown to be strong and of high quality, with proliferative abilities and cytotoxic capacities, in HIC. The HLA-B*57 allele, which is associated with a better clinical outcome in HIV infection, is overrepresented in HIC. However, we showed that these patients constitute a heterogeneous group that includes subjects who present weak suppression of viral replication in vitro and HIV-specific responses. We performed an extensive study of 101 HIC (49 HLA-B*57(+) and 52 HLA-B*57(-)) to determine the impact of HLA-B*57 on the HIV-specific CD8(+) response. The HLA-B*57-restricted response displayed better qualitative features, such as higher functional avidity, higher proliferation capacity, and a higher level of cytokine production, than responses not restricted by HLA-B*57. However, the highest frequencies of HIV-specific CD8(+) T cells were observed only in a subset of HLA-B*57(+) subjects. They were tightly associated with the ability to suppress viral replication in vitro. In contrast, the subset of HLA-B*57(+) subjects with a weak ability to suppress viral replication had significantly lower ultrasensitive viral loads than all the other groups of controllers. In conclusion, both HLA-B*57 and the amount of ultrasensitive viral load seem to play a role in HIV-specific CD8(+) T cell responses in HIC.

Post-treatment HIV-1 controllers with a long-term virological remission after the interruption of early initiated antiretroviral therapy ANRS VISCONTI Study.

Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs); instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naïve T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.

Pressure from TRIM5α contributes to control of HIV-1 replication by individuals expressing protective HLA-B alleles.

The expression of certain HLA class I alleles, including HLA-B*27 and HLA-B*57, is associated with better control of human immunodeficiency virus type 1 (HIV-1) infection, but the mechanisms responsible are not fully understood. We sought evidence that pressure from the human restriction factor TRIM5α (hTRIM5α) could contribute to viral control. The hTRIM5α sensitivity of viruses from both HLA-B*57-positive (HLA-B*57(+)) and HLA-B*27(+) patients who spontaneously controlled viral replication, but not viruses from viremic patients expressing these alleles, was significantly greater than that of viruses from patients not expressing these protective HLA-B alleles. Overall, a significant negative correlation between hTRIM5α sensitivity and viral load was observed. In HLA-B*57(+) patients, the T242N mutation in the HLA-B*57-restricted TW10 CD8(+) T lymphocyte (CTL) epitope was strongly associated with hTRIM5α sensitivity. In HLA-B*27(+) controllers, hTRIM5α sensitivity was associated with a significant reduction in emergence of key CTL mutations. In several patients, viral evolution to avoid hTRIM5α sensitivity was observed but could be associated with reduced viral replicative capacity. Thus, in individuals expressing protective HLA-B alleles, the combined pressures exerted by CTL, hTRIM5α, and capsid structural constraints can prevent viral escape both by impeding the selection of necessary resistance/compensatory mutations and forcing the selection of escape mutations that increase hTRIM5α sensitivity or impair viral replicative capacity.

Early and long-lasting alteration of effector CD45RA(-)Foxp3(high) regulatory T-cell homeostasis during HIV infection.

Regulatory T-cell (Treg) quantification in human immunodeficiency virus (HIV) infection remains ill defined because of the lack of reliable specific markers to identify human Tregs and the diversity of clinical stages of HIV infection. Using a recently described Treg identification strategy based on CD45RA and Foxp3 expression, we performed an extensive quantification of total, naive (CD45RA(+)Foxp3(low)), and effector (CD45RA(-)Foxp3(high)) Tregs in different contexts of HIV infection: primary HIV infection, long-term viremic patients, aviremic patients treated with highly active antiretroviral therapy, and HIV controllers. We showed that although total Treg percentages were mildly affected by HIV infection, Treg absolute numbers were significantly reduced in all groups studied. We demonstrated that although naive Treg numbers were essentially preserved, effector Tregs were consistently affected during HIV infection. Finally, we demonstrated that effector but not total or naive Treg numbers were negatively correlated with the magnitude of HIV-specific CD8 T-cell responses.

More rapid blood interferon α2 decline in fatal versus surviving COVID-19 patients.

Background: The clinical outcome of COVID-19 pneumonia is highly variable. Few biological predictive factors have been identified. Genetic and immunological studies suggest that type 1 interferons (IFN) are essential to control SARS-CoV-2 infection. Objective: To study the link between change in blood IFN-α2 level and plasma SARS-Cov2 viral load over time and subsequent death in patients with severe and critical COVID-19. Methods: One hundred and forty patients from the CORIMUNO-19 cohort hospitalized with severe or critical COVID-19 pneumonia, all requiring oxygen or ventilation, were prospectively studied. Blood IFN-α2 was evaluated using the Single Molecule Array technology. Anti-IFN-α2 auto-Abs were determined with a reporter luciferase activity. Plasma SARS-Cov2 viral load was measured using droplet digital PCR targeting the Nucleocapsid gene of the SARS-CoV-2 positive-strand RNA genome. Results: Although the percentage of plasmacytoid dendritic cells was low, the blood IFN-α2 level was higher in patients than in healthy controls and was correlated to SARS-CoV-2 plasma viral load at entry. Neutralizing anti-IFN-α2 auto-antibodies were detected in 5% of patients, associated with a lower baseline level of blood IFN-α2. A longitudinal analysis found that a more rapid decline of blood IFN-α2 was observed in fatal versus surviving patients: mortality HR=3.15 (95% CI 1.14-8.66) in rapid versus slow decliners. Likewise, a high level of plasma SARS-CoV-2 RNA was associated with death risk in patients with severe COVID-19. Conclusion: These findings could suggest an interest in evaluating type 1 IFN treatment in patients with severe COVID-19 and type 1 IFN decline, eventually combined with anti-inflammatory drugs. Clinical trial registration: https://clinicaltrials.gov, identifiers NCT04324073, NCT04331808, NCT04341584.

Identification of a particular HIV-specific CD8+ T-cell subset with a CD27+ CD45RO-/RA+ phenotype and memory characteristics after initiation of HAART during acute primary HIV infection.

CD8(+) T cells play an important role in controlling viral infections. Defective CD8(+) T-cell responses during HIV infection could contribute to viral persistence. Early initiation of highly active antiretroviral therapy during acute primary HIV infection helps to preserve HIV-specific immune responses. Here, we describe a particular CD27(+) CD45RO(-)/RA(+) HIV-specific CD8(+) T cell in participants treated early during the primary infection. These cells, which were present at a very low frequency during primary HIV infection, increased markedly after early treatment, whereas their frequency remained unchanged in untreated participants and in participants treated later. These nonnaive antigen-experienced cells are in a resting state and have characteristics of long-lived memory cells. They also possess direct effector capabilities, such as cytokine production, and are able to proliferate and to acquire cytotoxic functions on reactivation. Our results suggest that these HIV-specific CD27(+) CD45RO(-)/RA(+) CD8(+) T cells, observed when early viral replication is inhibited, form a pool of resting cells with memory characteristics.

Antiretroviral therapy for HIV controllers: Reasons for initiation and outcomes in the French ANRS-CO21 CODEX cohort.

BACKGROUND: Less than 1% of Human Immunodeficiency Virus (HIV)-infected individuals are able to achieve spontaneous viral control without requiring antiretroviral therapy (ART). Whether these HIV controllers (HIC) are at risk of HIV-associated comorbidities and could benefit from ART is debated, but recent studies reported decreased T-cell activation upon ART initiation. We report the frequency of ART initiation, reasons to treat, treatment outcome on immunovirological parameters, and rate of side-effects and treatment discontinuation in the French cohort of HIC. METHODS: Participants included in the French multicenter Agence Nationale de Recherche sur le SIDA et les Hépatites (ANRS) Cohorte des extremes (CODEX) cohort of HIC between July 6, 2007 and January 3, 2018 were prospectively followed. ART initiation, indication, discontinuation, non-Acquired ImmunoDeficiency Syndrome (AIDS)-defining events, side-effects, and immunovirological parameters were recorded. Undetectable HIC (u-HIC) were defined as participants with strictly undetectable viral loads based on routinely used assays throughout the follow-up and blipper HIC (b-HIC) as participants with possible detectable viral loads above the detection threshold during follow-up. FINDINGS: Among 302 HIC followed for a median of 14.8 years [10.3-20.2], 90 (30%) received ART (7 u-HIC and 83 b-HIC). The main reasons for ART initiation were decreased CD4 T-cell counts (n = 36, 40%), loss of virological control (n = 13, 14%), and non-AIDS-defining events (n = 12, 13%). Sixteen (18%) participants experienced 17 grade 1-2 adverse events. In b-HIC, ART slightly increased the CD4/CD8 ratio (median +0.19, p < 0.0001) and decreased the frequency of circulating CD38+ HLA-DR.+ CD4 and CD8 lymphocytes (median -0.75%, p = 0.003, and -2%, p < 0.0001, respectively), but these changes were not observed for treated u-HIC. Thirteen (14%) participants discontinued ART (5 (38%) because of side-effects, and 10 remained HIC after treatment cessation (median follow-up: 305 days [235-728]). INTERPRETATION: Only 30% of participants in this large cohort of HIC required ART during a median follow-up of 14.8 years. These results show that HIC status is very stable and vouch for a patient-centered treatment decision based on the individual benefit/risk balance.

Persistence of monocyte activation under treatment in people followed since acute HIV-1 infection relative to participants at high or low risk of HIV infection.

BACKGROUND: Interpretation of the increase in certain inflammatory markers in virally suppressed HIV-infected individuals must rely on an appropriate uninfected control group well characterized for non-HIV-related factors that contribute to chronic inflammation, e.g. smoking, alcohol consumption, or being overweight. We compared the inflammatory profiles of HIV-infected participants under long-term antiretroviral therapy (ART) with those of two HIV-uninfected groups with contrasting health behaviours. METHODS: We studied 150 HIV-infected participants (42 women, 108 men) under long-term ART (median, 6 years) followed in the ANRS PRIMO cohort since acute/early HIV-1 infection (AHI) diagnosis. Sex and age-matched controls were sampled from i) the ANRS IPERGAY pre-exposure prophylaxis trial among men at high risk for HIV infection and with high frequencies of non-HIV factors of inflammation ii) the ANRS COHVAC cohort of volunteers in vaccine trials with a low-risk profile for HIV infection. We measured the plasma levels of ten inflammatory markers. FINDINGS: After adjusting for smoking, alcohol use and body mass index, both HIV-infected men and women had higher levels of sCD14, sCD163, sTNFRII and I-FABP than their high-risk IPERGAY and low-risk COHVAC counterparts. Hierarchical clustering showed a subset of 15 PRIMO participants to have an inflammatory profile similar to that of most HIV-negative participants. These participants already had favourable markers at AHI diagnosis. INTERPRETATION: Long-term ART, even when initiated at a low level of immunodeficiency, fails to normalize monocyte/macrophage activation and gut epithelial dysfunction. Persistent inflammation under treatment may be related to an increased inflammatory profile since AHI. FUNDING: ANRS and Paris-Saclay University.

A Pilot Study of the Humoral Response Against the AntiSense Protein (ASP) in HIV-1-Infected Patients.

The existence of an antisense Open Reading Frame (ORF) that encodes a putative AntiSense Protein (ASP) on the proviral genome of Human Immunodeficiency Virus type 1 (HIV-1) was a source of debate for 30 years. During the last years, some progresses have been made to characterize the cellular immune response against ASP in HIV-1 seropositive patients. However, no tools were available for the detection of antibodies to ASP in the plasma of HIV-1-infected patients during the natural course of the infection. The aim of our study was to develop a Luciferase Immuno-Precipitation System (LIPS) to monitor the quantitative detection of ASP-specific antibodies in the plasma of HIV-1-infected patients [antiretroviral therapy (ART) naive-patients, patients under ART and HIV-1 controllers], patients who discontinued antiretroviral drugs (ARV). We further used this approach to delineate the epitopes of ASP targeted by antibodies. Antibodies directed against ASP were detected in 3 out of 19 patients who discontinued ARV (15%) and in 1 out of 10 ART-naive patients (10%), but were neither detected in HIV-1 infected patients under ART nor in HIV-1 controllers. Individual variations in levels of ASP-specific antibodies were detected overtime. Both the conserved prolin-rich motif and the core 60-189 region of ASP were found to be essential for antibody recognition in the four patients tested positive for anti-ASP antibodies, who were all untreated at the time of sampling. Moreover, for two of these patients, increased levels of ASP-specific antibodies were observed concomitantly to viremia declines. Overall, our method may represent a useful tool to detect a humoral response to ASP in HIV-1-infected patients, which allowed us to confirm the expression of ASP during the course of HIV-1 infection. Further studies will be needed to fully characterize the humoral response to ASP in HIV-1-infected patients.

The proportion of CD57+ cells among effector CD8+ T cells is lower in HIV controllers compared with antiretroviral therapy-treated patients.

BACKGROUND: HIV infection has often been linked to faster immune ageing. We sought to determine whether or not treatment-naive spontaneous HIV-1 controllers (HICs) and ART-exposed patients differ with regard to the expression of cell senescence markers. METHODS: Eighty-eight chronically infected HICs and ART-exposed patients (median time since infection: 15 years) with an undetectable plasma HIV RNA load (at least for the previous 2 years) were included. We used flow cytometry to measure immunosenescence markers (KLRG-1 and CD57) expression in fresh blood samples collected from patients and healthy donors. RESULTS: For the CD8 T-cell population as a whole, the ART-exposed but not the HIC patients exhibited a much higher proportion of KLRG-1 and CD57 CD8 T cells than healthy blood donors. For the CD8 T-cell subsets, HICs had a lower proportion of CD57 effector CD8 T cells than ART patients or healthy blood donors, whereas the proportions of KLRG-1 effector were similar. A similar trend was observed for terminal effectors. No impact of age, sex or standard parameters of infection (CD4 percentage, protective HLA allele, viral blips) was observed. The difference in the proportion of CD57 cells between HICs and ART was observed more specifically in long-term infected patients (>20 years). However, whenever considering the CD57 effector memory and effector subsets, the cytotoxic granule content was greater in HICs than in ART. CONCLUSION: The proportion of CD57 effector CD8 T cells is lower in HICs than in ART-exposed patients. This profile may be beneficial by ensuring limited senescence associated with consistent cytotoxic potential.

Mass Cytometry Analysis Reveals Complex Cell-State Modifications of Blood Myeloid Cells During HIV Infection.

Dendritic cells (DC), which are involved in orchestrating early immune responses against pathogens, are dysregulated in their function by HIV infection. This dysregulation likely contributes to tip the balance toward viral persistence. Different DC subpopulations, including classical (cDCs) and plasmacytoid (pDCs) dendritic cells, are subjected to concomitant inflammatory and immunoregulatory events during HIV infection, which hampers the precise characterization of their regulation through classical approaches. Here, we carried out mass cytometry analysis of blood samples from early HIV-infected patients that were longitudinally collected before and after 1 year of effective combination antiretroviral therapy (cART). Blood samples from HIV controller patients who naturally control the infection were also included. Our data revealed that plasma HIV RNA level was positively associated with a loss of cDC and pDC subpopulations that display high expression of LILR immunomodulatory receptors. Conversely, specific monocyte populations co-expressing high levels of HLA-I, 3 immunomodulatory receptors, CD64, LILRA2, and LILRB4, and the restriction factor CD317 (also known as BST2/Tetherin), were more abundant in early HIV-infection. Finally, our analysis revealed that the blood of HIV controller patients contained in a higher abundance a particular subtype of CD1c+ cDCs, characterized by elevated co-expression of CD32b inhibitory receptor and HLA-DR antigen-presentation molecules. Overall, this study unravels the modifications induced in DC and monocyte subpopulations in different HIV+ conditions, and provides a better comprehension of the immune regulation/dysregulation mechanisms induced during this viral infection.

Dynamics in HIV-DNA levels over time in HIV controllers.

INTRODUCTION: HIV controllers (HIC) maintain viraemia at low levels without antiretroviral treatment and have small HIV reservoirs. Nevertheless, they are heterogeneous regarding their risk of infection progression. The study of reservoirs can help elucidate this control. This study aimed to explore the factors implicated in the pathogenesis of HIV infection that are potentially associated with HIV reservoirs and their dynamics in HIC. METHODS: Individuals living with HIV included in the ANRS-CODEX cohort with at least two HIV-DNA measurements between 2009 and 2016 were selected. The total HIV-DNA levels had been quantified prospectively from blood samples. Mixed-effect linear models estimated the HIV-DNA dynamics over time. RESULTS: The median (interquartile range (IQR)) HIV-DNA level was 1.5 (1.3 to 1.9) log copies/million peripheral blood mononuclear cells at inclusion (n = 202 individuals). These low levels showed heterogeneity among HIC. Lower levels were then associated with the protective HLA-B*27/B*57 alleles and/or lower HIV-RNA level at inclusion, negative hepatitis C virus serology, lower HIV-suppressive capacity of specific CD8 T cells and lower levels of immune activation and inflammation. Interestingly, mathematical modelling of the dynamics of HIV-DNA over time (840 measurements) showed that the number of infected cells decreased in 46% of HIC (follow-up: 47.6 months) and increased in 54% of HIC. A multivariate analysis indicated that HLA-B*27/B*57 alleles, a low level of HIV-RNA and a low level of HIV-DNA at inclusion were markers independently associated with this decrease. CONCLUSIONS: These results offer new insights into the mechanisms of long-term control in HIC. In half of HIC, the decrease in HIV-DNA level could be linked to tighter viral control and progressive loss of infected cells. These findings allow the identification of HIC with a low risk of progression who may not need treatment.

Metabolic plasticity of HIV-specific CD8+ T cells is associated with enhanced antiviral potential and natural control of HIV-1 infection.

Spontaneous control of human immunodeficiency virus (HIV) is generally associated with an enhanced capacity of CD8+ T cells to eliminate infected CD4+ T cells, but the molecular characteristics of these highly functional CD8+ T cells are largely unknown. In the present study, using single-cell analysis, it was shown that HIV-specific, central memory CD8+ T cells from spontaneous HIV controllers (HICs) and antiretrovirally treated non-controllers have opposing transcriptomic profiles. Genes linked to effector functions and survival are upregulated in cells from HICs. In contrast, genes associated with activation, exhaustion and glycolysis are upregulated in cells from non-controllers. It was shown that HIV-specific CD8+ T cells from non-controllers are largely glucose dependent, whereas those from HICs have more diverse metabolic resources that enhance both their survival potential and their capacity to develop anti-HIV effector functions. The functional efficiency of the HIV-specific CD8+ T cell response in HICs is thus engraved in their memory population and related to their metabolic programme. Metabolic reprogramming in vitro through interleukin-15 treatment abrogated the glucose dependency and enhanced the antiviral potency of HIV-specific CD8+ T cells from non-controllers.