Next-Generation Sequencing in a Direct Model of HIV Infection Reveals Important Parallels to and Differences from In Vivo Reservoir Dynamics.

Next-generation sequencing (NGS) represents a powerful tool to unravel the genetic make-up of the HIV reservoir, but limited data exist on its use in vitro Moreover, most NGS studies do not separate integrated from unintegrated DNA, even though selection pressures on these two forms should be distinct. We reasoned we could use NGS to compare the infection of resting and activated CD4 T cells in vitro to address how the metabolic state affects reservoir formation and dynamics. To address these questions, we obtained HIV sequences 2, 4, and 8 days after NL4-3 infection of metabolically activated and quiescent CD4 T cells (cultured with 2 ng/ml interleukin-7). We compared the composition of integrated and total HIV DNA by isolating integrated HIV DNA using pulsed-field electrophoresis before performing sequencing. After a single-round infection, the majority of integrated HIV DNA was intact in both resting and activated T cells. The decay of integrated intact proviruses was rapid and similar in both quiescent and activated T cells. Defective forms accumulated relative to intact ones analogously to what is observed in vivo Massively deleted viral sequences formed more frequently in resting cells, likely due to lower deoxynucleoside triphosphate (dNTP) levels and the presence of multiple restriction factors. To our surprise, the majority of these deleted sequences did not integrate into the human genome. The use of NGS to study reservoir dynamics in vitro provides a model that recapitulates important aspects of reservoir dynamics. Moreover, separating integrated from unintegrated HIV DNA is important in some clinical settings to properly study selection pressures.IMPORTANCE The major implication of our work is that the decay of intact proviruses in vitro is extremely rapid, perhaps as a result of enhanced expression. Gaining a better understanding of why intact proviruses decay faster in vitro might help the field identify strategies to purge the reservoir in vivo When used wisely, in vitro models are a powerful tool to study the selective pressures shaping the viral landscape. Our finding that massively deleted sequences rarely succeed in integrating has several ramifications. It demonstrates that the total HIV DNA can differ substantially in character from the integrated HIV DNA under certain circumstances. The presence of unintegrated HIV DNA has the potential to obscure selection pressures and confound the interpretation of clinical studies, especially in the case of trials involving treatment interruptions.

HIV Protease-Generated Casp8p41, When Bound and Inactivated by Bcl2, Is Degraded by the Proteasome.

HIV protease is known to cause cell death, which is dependent upon cleavage of procaspase 8. HIV protease cleavage of procaspase 8 generates Casp8p41, which directly binds Bak with nanomolar affinity, causing Bak activation and consequent cell death. Casp8p41 can also bind Bcl2 with nanomolar affinity, in which case cell death is averted. Central memory CD4 T cells express high levels of Bcl2, possibly explaining why those cells do not die when they reactivate HIV. Here, we determine that the Casp8p41-Bcl2 complex is polyubiquitinated and degraded by the proteasome. Ixazomib, a proteasome inhibitor in clinical use, blocks this pathway, increasing the abundance of Casp8p41 and causing more cells to die in a Casp8p41-dependent manner.IMPORTANCE The Casp8p41 pathway of cell death is unique to HIV-infected cells yet is blocked by Bcl2. Once bound by Bcl2, Casp8p41 is polyubiquitinated and degraded by the proteasome. Proteasome inhibition blocks degradation of Casp8p41, increasing Casp8p41 levels and causing more HIV-infected cells to die.

HIV-associated psoriasis: Epidemiology, pathogenesis, and management.

People living with HIV (PLWH) are affected by a higher incidence skin disorders, which are often associated with high morbidity and mortality. In particular, psoriasis affects PLWH severely and for a longer time than the general population. Human immunodeficiency virus (HIV) infection is characterized by a progressive decrease in CD4+ T-cell count, and it could seem paradoxical that psoriasis exacerbations are more frequent in this subset of patients than the general population, even though it is commonly observed at any stage of infection. For a long time, there have been limited therapeutic choices for PLWH affected by psoriasis. The introduction of the combined antiretroviral therapy dramatically changed the natural course of both HIV and psoriasis in PLWH, leading to an improvement of quality and duration of life. However, the clinical severity of psoriasis in PLWH often requires the use of immunosuppressant drugs. Knowledge about their safety and efficacy are limited to case-reports, small case-series and studies, therefore their use has not yet entered the routine. Further studies are needed to determine if immunosuppressive drugs can be safely and effectively used in PLWH affected by psoriasis and other autoimmune disorders.

Measuring integrated HIV DNA ex vivo and in vitro provides insights about how reservoirs are formed and maintained.

The identification of the most appropriate marker to measure reservoir size has been a great challenge for the HIV field. Quantitative viral outgrowth assay (QVOA), the reference standard to quantify the amount of replication-competent virus, has several limitations, as it is laborious, expensive, and unable to robustly reactivate every single integrated provirus. PCR-based assays have been developed as an easier, cheaper and less error-prone alternative to QVOA, but also have limitations. Historically, measuring integrated HIV DNA has provided insights about how reservoirs are formed and maintained. In the 1990s, measuring integrated HIV DNA was instrumental in understanding that a subset of resting CD4 T cells containing integrated HIV DNA were the major source of replication-competent virus. Follow-up studies have further characterized the phenotype of these cells containing integrated HIV DNA, as well as shown the correlation between the integration levels and clinical parameters, such as duration of infection, CD4 count and viral load. Integrated HIV DNA correlates with total HIV measures and with QVOA. The integration assay has several limitations. First, it largely overestimates the reservoir size, as both defective and replication-competent proviruses are detected. Since defective proviruses are the majority in patients on ART, it follows that the number of proviruses capable of reactivating and releasing new virions is significantly smaller than the number of integrated proviruses. Second, in patients on ART clonal expansion could theoretically lead to the preferential amplification of proviruses close to an Alu sequence though longitudinal studies have not captured this effect. Proviral sequencing combined with integration measures is probably the best estimate of reservoir size, but it is expensive, time-consuming and requires considerable bioinformatics expertise. All these reasons limit its use on a large scale. Herein, we review the utility of measuring HIV integration and suggest combining it with sequencing and total HIV measurements can provide insights that underlie reservoir maintenance.

Monitoring Integration over Time Supports a Role for Cytotoxic T Lymphocytes and Ongoing Replication as Determinants of Reservoir Size.

The dynamics of HIV reservoir accumulation off antiretroviral therapy (ART) is underexplored. Levels of integrated HIV DNA in peripheral blood mononuclear cells (PBMCs) were longitudinally monitored before and after antiviral therapy. HIV integration increased over time in both elite controllers (ECs; n = 8) and noncontrollers (NCs; n = 6) before ART, whereas integration remained stable in patients on ART (n = 4). The median annual fold change was higher in NCs than in ECs and negatively correlated with CD4/CD8 T-cell ratio. Cytotoxic T lymphocyte (CTL) function as assessed by infected CD4 T-cell elimination (ICE) and granzyme B activity did not significantly change over time in ECs, suggesting that the gradual increase in integrated HIV DNA observed in ECs was not a result of progressive loss of immune-mediated control. Also, acutely infected (n = 7) but not chronically infected (n = 6) patients exhibited a significant drop in integrated HIV DNA 12 months after ART initiation. In conclusion, in the absence of ART, integrated HIV accumulates over time both in NCs and in ECs, at variable individual rates. Starting ART early in infection leads to a greater drop in integrated HIV DNA than does initiating treatment after years of infection. The increase in integrated HIV DNA over time suggests that early treatment may be of benefit in limiting HIV reservoirs. IMPORTANCE: The establishment of a latent reservoir represents a barrier to cure among HIV-infected individuals. The dynamics of HIV reservoir accumulation over time in patients before antiviral therapy is underexplored, in large part because it is difficult to accurately and reproducibly measure the size of HIV reservoir in this setting. In our study, we compared the dynamics of integrated HIV DNA over time in ECs and NCs before and after ART was initiated. We found that integrated HIV DNA levels progressively increase over time in the absence of ART, but with a higher, albeit variable, rate in NCs compared to ECs. In addition, integrated HIV DNA declines more dramatically when ART is initiated in acute rather than chronic HIV infection, suggesting important differences between acute and chronic infection. Our study highlights the role of HIV replication and CTL control in reservoir accumulation in sanctuary sites and why ART appears to be more effective in acute infection.

Heel quantitative ultrasound in HIV-infected patients: a cross-sectional study.

PURPOSE: HIV infection has been associated with increased risk of osteoporosis and fragility fractures. Dual-energy X-ray absorptiometry (DXA) is the reference standard to assess bone mineral density (BMD); however, it is not easily accessible in several settings. Heel Quantitative ultrasound (QUS) is a radiation-free, easy-to-perform technique, which may help reducing the need for DXA. METHODS: In this cross-sectional study, we used heel QUS (Hologic Sahara(®)) to assess bone status in a cohort of HIV-infected patients. A QUS stiffness index (QUI) threshold >83 was used to identify patients with a low likelihood of osteoporosis. Moreover, we compared QUS results with those of 36 sex- and age-matched HIV-negative controls. RESULTS: 244 HIV-positive patients were enrolled. Median heel QUI value was 83 (73-96) vs. 93 (IQR 84-104) in the control group (p = 0.04). 110 patients (45 %) had a QUI value ≤83. Risk factors for low QUI values were age (OR 1.04 per year, 95 % CI 1.01-1.07, p = 0.004), current use of protease inhibitors (OR 1.85, CI 1.03-3.35, p = 0.039), current use of tenofovir (OR 2.28, CI 1.22-4.27, p = 0.009) and the number of risk factors for secondary osteoporosis (OR 1.46, CI 1.09-1.95, p = 0.01). Of note, QUI values were significantly correlated with FRAX score (r = -0.22, p = 0.004). According to EACS guidelines, 45 % of patients had risk factors for osteoporosis which make them eligible for DXA. By using QUS, we may avoid DXA in around half of them. CONCLUSIONS: As HIV-positive patients are living longer, the prevalence of osteoporosis is expected to increase over time. Appropriate screening, prevention and treatment are crucial to preserve bone health in this population. The use of screening techniques, such as heel QUS, may help reducing the need for DXA. Further studies are needed to define the diagnostic accuracy of this promising technique in the setting of HIV.

Duration of antimicrobial therapy in community acquired pneumonia: less is more.

Community acquired pneumonia (CAP) represents the most common cause of infection-related morbidity and mortality worldwide. Appropriate treatment of CAP is challenging and sometimes limited by the availability to obtain rapid and timely identification of the etiologic agent in order to initiate or deescalate the correct antimicrobial therapy. As a consequence, prescribers frequently select empiric antimicrobial therapy using clinical judgment, local patterns of antimicrobial resistance, and, sometimes, individual patient expectations. These issues may contribute to prolonged courses of inappropriate therapy. In this review, we discuss the evidence and recommendations from international guidelines for the management of CAP and the clinical trials that specifically addressed duration of antimicrobial therapy for CAP in adults. In randomized controlled trials comparing the clinical efficacy of a short-course antimicrobial regimen versus an extended-course regimen, no differences in terms of clinical success, bacterial eradication, adverse events, and mortality were observed. The use of biomarkers, such as procalcitonin, to guide the initiation and duration of antimicrobial therapy may reduce total antibiotic exposure and treatment duration, healthcare costs, and the risk of developing antimicrobial resistance. In clinical practice, antimicrobial stewardship interventions may improve the management of CAP and may help in reducing treatment duration. Sometimes "less is more" in CAP.

Pharmacological approaches to promote cell death of latent HIV reservoirs.

PURPOSE OF REVIEW: HIV requires lifelong antiviral treatment due to the persistence of a reservoir of latently infected cells. Multiple strategies have been pursued to promote the death of infected cells. RECENT FINDINGS: Several groups have focused on multipronged approaches to induce apoptosis of infected cells. One approach is to combine latency reversal agents with proapoptotic compounds and cytotoxic T cells to first reactivate and then clear infected cells. Other strategies include using natural killer cells or chimeric antigen receptor cells to decrease the size of the reservoir.A novel strategy is to promote cell death by pyroptosis. This mechanism relies on the activation of the caspase recruitment domain-containing protein 8 (CARD8) inflammasome by the HIV protease and can be potentiated by nonnucleoside reverse transcriptase inhibitors. SUMMARY: The achievement of a clinically significant reduction in the size of the reservoir will likely require a combination strategy since none of the approaches pursued so far has been successful on its own in clinical trials. This discrepancy between promising in vitro findings and modest in vivo results highlights the hurdles of identifying a universally effective strategy given the wide heterogeneity of the HIV reservoirs in terms of tissue location, capability to undergo latency reversal and susceptibility to cell death.

Interferon-γ and interleukin-17 production from PPD-stimulated PBMCss of patients with pulmonary tuberculosis.

PURPOSE: The purpose of this study was to evaluate Interferon (IFN)-γ and Interleukin(IL)-17 profiles in patients with different clinical presentations of pulmonary tuberculosis (TB) and to compare them with those of tuberculin-negative and tuberculin-reactive healthy controls METHODS: Peripheral blood mononuclear cells (PBMCss), isolated from patients (n=52) and controls (n=30), were stimulated ex vivo with purified protein derivative (PPD) and IFN-γ and IL-17 levels in the supernatant were measured. RESULTS: At baseline, PBMCss from patients with TB released a significantly lower amount of IL-17 (p=0.043) than PBMCss from healthy controls, whereas IFN-γ levels were similar in the two groups. After PPD stimulation, a significant rise in IL-17 levels was found only among healthy controls (p=0.02). This rise in IL-17 levels was similar between tuberculin-reactive and tuberculin-negative subjects. After PPD stimulation, patients with infiltrative TB secreted higher levels of IL-17 and IFN-γ than those affected with chronic, miliary and cavitary TB (p < 0.01). IFN-γ production from patients with infiltrative TB was even higher than for healthy controls (p < 0.01). PBMCss from tuberculin-reactive patients released higher levels of IFN-γ than tuberculin-negative subjects after PPD stimulation (p < 0.01). CONCLUSION: Ex vivo PPD stimulation of PBMCs from patients with pulmonary TB does not significantly stimulate IL-17 release; however, higher IL-17 and IFN-γ levels are found in patients with infiltrative disease, in comparison with those affected with miliary, cavitary and chronic TB.

Localized and systemic bacterial infections in necrotizing pancreatitis submitted to surgical necrosectomy or percutaneous drainage of necrotic secretions.

BACKGROUND: Infectious complications are observed in 40-70% of all patients with severe acute pancreatitis. Infections are associated with a significant increase in mortality rates. METHODS: We evaluated the prevalence and characteristics of pancreatic and systemic infections in 46 patients with necrotizing pancreatitis submitted to surgical procedures during their hospital stay as well as the impact of such infectious complications on patient clinical outcome. Samples for microbiological cultures were taken at hospital admission from blood and bile and 2 days after invasive procedure from blood, drainage fluid, bile and necrotic tissues. RESULTS: 74% patients with necrotizing pancreatitis had a localized or systemic infection. At admission, 15% of subjects had positive blood cultures whereas 13% had evidence of bacterial growth from bile cultures. Two days after the invasive procedures for removal of necrotic materials and fluids, blood cultures became positive in 30% of patients in spite of antibiotic prophylaxis and bile cultures resulted positive in 22% of cases. Furthermore, bacterial growth from drainage fluids was found in 30% and from homogenized necrotic material in 44% of cases. As refers to bacterial isolates, all patients had a monomicrobial infection. Carbapenems were the drugs with the best sensitivity profile. CONCLUSIONS: Infectious complications significantly increase mortality in patients with necrotizing pancreatitis. In addition, subjects with systemic infections developed more complications and demonstrated a higher mortality rate in comparison with those having a localized infection. In our study, the sensitivity pattern of the isolated microorganisms suggests to consider carbapenems as the best option for empirical treatment in patients with necrotizing pancreatitis who develop a clear-cut evidence of systemic or localized bacterial infection.

Machine Learning Bolsters Evidence That D1, Nef, and Tat Influence HIV Reservoir Dynamics.

Background: The primary hurdle to curing HIV is due to the establishment of a reservoir early in infection. In an effort to find new treatment strategies, we and others have focused on understanding the selection pressures exerted on the reservoir by studying how proviral sequences change over time. Methods: To gain insights into the dynamics of the HIV reservoir we analyzed longitudinal near full-length sequences from 7 people living with HIV between 1 and 20 years following the initiation of antiretroviral treatment. We used this data to employ Bayesian mixed effects models to characterize the decay of the reservoir using single-phase and multiphasic decay models based on near full-length sequencing. In addition, we developed a machine-learning approach utilizing logistic regression to identify elements within the HIV genome most associated with proviral decay and persistence. By systematically analyzing proviruses that are deleted for a specific element, we gain insights into their role in reservoir contraction and expansion. Results: Our analyses indicate that biphasic decay models of intact reservoir dynamics were better than single-phase models with a stronger statistical fit. Based on the biphasic decay pattern of the intact reservoir, we estimated the half-lives of the first and second phases of decay to be 18.2 (17.3 to 19.2, 95%CI) and 433 (227 to 6400, 95%CI) months, respectively.In contrast, the dynamics of defective proviruses differed favoring neither model definitively, with an estimated half-life of 87.3 (78.1 to 98.8, 95% CI) months during the first phase of the biphasic model. Machine-learning analysis of HIV genomes at the nucleotide level revealed that the presence of the splice donor site D1 was the principal genomic element associated with contraction. This role of D1 was then validated in an in vitro system. Using the same approach, we additionally found supporting evidence that HIV nef may confer a protective advantage for latently infected T cells while tat was associated with clonal expansion. Conclusions: The nature of intact reservoir decay suggests that the long-lived HIV reservoir contains at least 2 distinct compartments. The first compartment decays faster than the second compartment. Our machine-learning analysis of HIV proviral sequences reveals specific genomic elements are associated with contraction while others are associated with persistence and expansion. Together, these opposing forces shape the reservoir over time.

HIV RNA suppression and immune restoration: can we do better?

HAART has significantly changed the natural history of HIV infection: patients receiving antiretrovirals are usually able to control viremia, even though not all virological responders adequately recover their CD4+ count. The reasons for poor immune restoration are only partially known and they include genetic, demographic and immunologic factors. A crucial element affecting immune recovery is immune activation, related to residual viremia; indeed, a suboptimal virological control (i.e., low levels of plasma HIV RNA) has been related with higher levels of chronic inflammation and all-cause mortality. The sources of residual viremia are not yet completely known, even though the most important one is represented by latently infected cells. Several methods, including 2-LTR HIV DNA and unspliced HIV RNA measurement, have been developed to estimate residual viremia and predict the outcome of antiretroviral therapy. Considering that poor immunologic responders are exposed to a higher risk of both AIDS-related and non-AIDS-related diseases, there is a need of new therapeutic strategies, including immunomodulators and drugs targeting the latent viral reservoirs, in order to face residual viremia but also to "drive" the host immunologic responses.

Rapid manufacturing of non-activated potent CAR T cells.

Chimaeric antigen receptor (CAR) T cells can generate durable clinical responses in B-cell haematologic malignancies. The manufacturing of these T cells typically involves their activation, followed by viral transduction and expansion ex vivo for at least 6 days. However, the activation and expansion of CAR T cells leads to their progressive differentiation and the associated loss of anti-leukaemic activity. Here we show that functional CAR T cells can be generated within 24 hours from T cells derived from peripheral blood without the need for T-cell activation or ex vivo expansion, and that the efficiency of viral transduction in this process is substantially influenced by the formulation of the medium and the surface area-to-volume ratio of the culture vessel. In mouse xenograft models of human leukaemias, the rapidly generated non-activated CAR T cells exhibited higher anti-leukaemic in vivo activity per cell than the corresponding activated CAR T cells produced using the standard protocol. The rapid manufacturing of CAR T cells may reduce production costs and broaden their applicability.

Naive infection predicts reservoir diversity and is a formidable hurdle to HIV eradication.

Historically, naive cells have been considered inconsequential to HIV persistence. Here, we compared the contributions of naive and memory cells to the reservoirs of individuals with a spectrum of reservoir sizes and variable immunological control. We performed proviral sequencing of approximately 6000 proviruses from cellular subsets of 5 elite controllers (ECs) off antiretroviral therapy (ART) and 5 chronic progressors (CPs) on ART. The levels of naive infection were barely detectable in ECs and approximately 300-fold lower compared with those in CPs. Moreover, the ratio of infected naive to memory cells was significantly lower in ECs. Overall, the naive infection level increased as reservoir size increased, such that naive cells were a major contributor to the intact reservoir of CPs, whose reservoirs were generally very diverse. In contrast, the reservoirs of ECs were dominated by proviral clones. Critically, the fraction of proviral clones increased with cell differentiation, with naive infection predicting reservoir diversity. Longitudinal sequencing revealed that the reservoir of ECs was less dynamic compared with that of CPs. Naive cells play a critical role in HIV persistence. Their infection level predicts reservoir size and diversity. Moreover, the diminishing diversity of the reservoir as cellular subsets mature suggests that naive T cells repopulate the memory compartment and that direct infection of naive T cells occurs in vivo.

Persistence of an intact HIV reservoir in phenotypically naive T cells.

Despite the efficacy of antiretroviral therapy (ART), HIV persists in a latent form and remains a hurdle to eradication. CD4+ T lymphocytes harbor the majority of the HIV reservoir, but the role of individual subsets remains unclear. CD4+ T cells were sorted into central, transitional, effector memory, and naive T cells. We measured HIV DNA and performed proviral sequencing of more than 1900 proviruses in 2 subjects at 2 and 9 years after ART initiation to estimate the contribution of each subset to the reservoir. Although our study was limited to 2 subjects, we obtained comparable findings with publicly available sequences. While the HIV integration levels were lower in naive compared with memory T cells, naive cells were a major contributor to the intact proviral reservoir. Notably, proviral sequences isolated from naive cells appeared to be unique, while those retrieved from effector memory cells were mainly clonal. The number of clones increased as cells differentiated from a naive to an effector memory phenotype, suggesting naive cells repopulate the effector memory reservoir as previously shown for central memory cells. Naive T cells contribute substantially to the intact HIV reservoir and represent a significant hurdle for HIV eradication.

Investigational drugs in HIV: Pros and cons of entry and fusion inhibitors (Review).

Despite the profound changes and improvements reached in the field of HIV treatment, tolerability and adherence to highly active antiretroviral therapy remains a challenge. Furthermore, multi-experienced patients could take advantage of drugs with different mechanisms of action to combat the spread of resistance to actual therapy. For these reasons identification of new HIV drugs is crucial. Among all the molecules that at present are under investigation, entry and fusion inhibitors pose an interesting class owing to their peculiar characteristics, including prevention of entry of the virus into the human cells. In this study, we reviewed articles, clinical trials, and conference communications about all the drugs under investigation belonging to the class of entry and fusion inhibitors that are at least in phase I clinical trials.

Circulating angiopoietin-like protein 2 levels are associated with decreased renal function in HIV+ subjects on cART: A potential marker of kidney disease.

Chronic kidney disease (CKD) is an important cause of morbidity and mortality in HIV-infected individuals, even in the antiretroviral therapy (ART) era. Inflammatory cytokines and adipokines have been suggested to play a role in the development of CKD. The aim of the present study was to examine the circulating levels of a novel proinflammatory cytokine, angiopoietin-like protein 2 (ANGPTL2), in a cohort of 72 HIV-positive subjects on ART. HIV-positive patients were on cART for at least one year. Urine and blood samples were collected. Various factors were analyzed including body mass index (BMI), smoking, and presence/treatment for comorbidities such as diabetes. The estimated glomerular filtration rate was calculated by using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Plasma samples obtained were stored and used to measure sCD14 and ANGPTL2 levels. Data were presented as mean (± standard deviation) or median (interquartile range) for continuous variables. Categorical variables were expressed as number (%). Variables were compared using Student's t-test, Mann-Whitney test, or χ2 test. The results showed an independent negative association between plasma ANGPTL2 and CKD-EPI values. Further prospective studies on larger cohorts are needed to evaluate the pathogenetic role of ANGPTL2 as well as its use as a diagnostic marker of renal dysfunction.

Longitudinal HIV sequencing reveals reservoir expression leading to decay which is obscured by clonal expansion.

After initiating antiretroviral therapy (ART), a rapid decline in HIV viral load is followed by a long period of undetectable viremia. Viral outgrowth assay suggests the reservoir continues to decline slowly. Here, we use full-length sequencing to longitudinally study the proviral landscape of four subjects on ART to investigate the selective pressures influencing the dynamics of the treatment-resistant HIV reservoir. We find intact and defective proviruses that contain genetic elements favoring efficient protein expression decrease over time. Moreover, proviruses that lack these genetic elements, yet contain strong donor splice sequences, increase relatively to other defective proviruses, especially among clones. Our work suggests that HIV expression occurs to a significant extent during ART and results in HIV clearance, but this is obscured by the expansion of proviral clones. Paradoxically, clonal expansion may also be enhanced by HIV expression that leads to splicing between HIV donor splice sites and downstream human exons.

Head and neck squamous cell carcinoma and its correlation with human papillomavirus in people living with HIV: a systematic review.

Over the last 20 years we assisted to an increase in the mean age of People Living with HIV and their comorbidities. Especially, there was an increase in Human Papillomavirus-related head and neck squamous cell carcinomas. Despite their increasing incidence in HIV-positive people, mechanisms that lead to their development and progression are only partially understood. The aim of this review is to identify key data and factors about HPV-related head and neck squamous cell carcinoma in HIV-seropositive patients. Systematic search and review of the relevant literature-peer-reviewed and grey-was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. We included in our review only the 35 full-text articles we considered the most substantial. It is mandatory to improve our knowledge about the interactions existing between HPV and HIV, and about their actions on oral mucosa immune system.