Mohamed El-Far, Montreal

Centre hospitalier de l'Université de Montréal (CHUM) | CHUM · -

Background Chronic inflammation persists in some people living with HIV (PLWH), even during antiretroviral therapy (ART) and is associated with premature aging. The gp120 subunit of the HIV-1 envelope glycoprotein can shed from viral and cellular membranes and can be detected in plasma and tissues, showing immunomodulatory properties even in the ab...

Chronic inflammation is associated with higher risk of cardiovascular disease (CVD) in people living with HIV (PLWH). We have previously shown that interleukin-32 (IL-32), a multi-isoform proinflammatory cytokine, is chronically upregulated in PLWH and is linked with CVD. However, the mechanistic role of the different IL-32 isoforms in CVD are yet...

Studies have shown an increased risk of coronary artery disease (CAD) in the human immunodeficiency virus (HIV) population. Epicardial fat (EF) quality may be linked to this increased risk. In our study, we evaluated the associations between EF density, a qualitative characteristic of fat, and inflammatory markers, cardiovascular risk factors, HIV-...

Chronic inflammation persists in people living with HIV (PLHIV) despite antiretrovial therapy (ART) and is involved in their premature development of cardiovascular diseases (CVD) such as atherosclerosis. We have previously reported that an excess of “B-cell activating factor” (BAFF), an important molecule for the selection and activation of first-...

We report that PWH diagnosed with coronary artery atherosclerotic plaques display higher levels of HIV DNA compared to those without atherosclerotic plaques. In a multivariable prediction model that included 27 traditional and HIV-related risk factors, measures of HIV DNA were among the most important predictors of atherosclerotic plaque formation.

Chronic inflammation persists in people living with HIV (PLHIV) despite antiretrovial therapy (ART), and is involved in their premature development of cardiovascular diseases (CVD) such as atherosclerosis. We have previously reported that an excess of "B-cell activating factor" (BAFF), an important molecule for the selection and activation of first...

HIV elite controllers (ECs) are characterized by the spontaneous control of viral replication, and by metabolic and autophagic profiles which favor anti-HIV CD4 and CD8 T-cell responses. Extracellular acyl coenzyme A binding protein (ACBP) acts as a feedback inhibitor of autophagy. Herein, we assessed the circulating ACBP levels in ECs, compared to...

The crosstalk between intestinal epithelial cells (IEC) and Th17-polarized CD4⁺ T-cells is critical for mucosal homeostasis, with HIV-1 causing significant alterations in people living with HIV (PLWH) despite antiretroviral therapy (ART). In a model of IEC and T-cell co-cultures we investigated the effects of IL-17A, the Th17 hallmark cytokine, on...

Background: Persistent inflammation in HIV infection is associated with elevated cardiovascular disease risk, even with viral suppression. Identification of novel surrogate biomarkers can enhance cardiovascular disease risk stratification and suggest novel therapies. We investigated the potential of IL-32, a proinflammatory multi-isoform cytokine,...

Objectives: Untreated HIV infection was previously associated with IL-32 overexpression in gut epithelial cells (IEC). Here, we explored IL-32 isoform expression in the colon of people living with HIV (PLWH) receiving antiretroviral therapy (ART) and IL-32 triggers/modulators in IEC. Design: Sigmoid colon biopsies (SCB) and blood were collected...

Persistent immune activation and inflammation in people living with HIV (PLWH) are associated with immunosenescence, premature aging and increased risk of non-AIDS comorbidities, with the underlying mechanisms not fully understood. In this study, we show that downregulation of the T-cell immunoglobulin receptor CD96 on CD8 ⁺ T cells from PLWH is as...

Background: People living with HIV (PLWH) have a higher risk of myocardial infarction. Coronary atherosclerotic plaque CT characterization helps to predict cardiovascular risk. Purpose: To measure CT characteristics of coronary plaque in PLWH without known cardiovascular disease and healthy volunteers without HIV. Materials and Methods: In this pro...

Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) are still at higher risk for cardiovascular diseases (CVDs) that are mediated by chronic inflammation. Identification of novel inflammatory mediators with the inherent potential to be used as CVD biomarkers and also as therapeutic targets is critically needed for bet...

Background: Despite the success of antiretroviral therapy (ART) to control viral replication, people living with HIV (PLWH) have high levels of chronic systemic inflammation and immune dysregulation which drives accelerated comorbidities including coronary artery disease (CAD). Regulatory T-cells (Tregs) and ectonucleotidases CD39/CD73 are known t...

Elite controllers (ECs) are people living with HIV who spontaneously control viral replication without antiretroviral therapy. We observed that elevated anti-CMV IgG levels correlated with annual CD4 T-cell count decay in ECs independently of age, sex and HLA type. Elevated anti-CMV titers may favor disease progression in ECs.

Background: Human IL-32 is a polyfunctional cytokine that was initially reported to inhibit HIV-1 infection. However, recent data suggest that IL-32 may enhance HIV-1 replication by activating the HIV-1 primary targets, CD4 T-cells. Indeed, IL-32 is expressed in multiple isoforms, some of which are proinflammatory, whereas others are anti-inflamma...

Background: HIV-1 transmitted/founder viruses (TF) are selected during the acute phase of infection from a multitude of virions present during transmission. They possess the capacity to establish infection and viral dissemination in a new host. Deciphering the discrete genetic determinant of infectivity in their envelope may provide clues for vacc...

The identification of transmission clusters (TCs) of HIV-1 using phylogenetic analyses can provide insights into viral transmission network and help improve prevention strategies. We compared the use of partial HIV-1 envelope fragment of 1,070 bp with its loop 3 (108 bp) to determine its utility in inferring HIV-1 transmission clustering. Serum sam...

HIV persists in latently infected CD4⁺ T cells during antiretroviral therapy (ART). Immune checkpoint molecules, including PD-1, are preferentially expressed at the surface of persistently infected cells. However, whether PD-1 plays a functional role in HIV latency and reservoir persistence remains unknown. Using CD4⁺ T cells from HIV-infected indi...

Elite controllers (ECs) are a rare subset of HIV-1 slow progressors characterized by prolonged viremia suppression. HLA alleles B27 and B57 promote the cytotoxic T lymphocyte (CTL)-mediated depletion of infected cells in ECs, leading to the emergence of escape mutations in the viral capsid (CA). Whether those mutations modulate CA detection by inna...

CA N-terminal amino acid sequences from clinical isolates. (PDF)

CA polymorphisms and associated functions in published reports. (PDF)

Oligodeoxynucleotide (ODN) primers used for Gag amplification and cloning. (PDF)

ODN primers used for Real-Time qPCR. (PDF)

References for supplementary tables. (PDF)

TRIM5α and Mx2 knockdown validation. (a) mRNA levels were determined by RT-qPCR and normalized on GAPDH mRNA levels. Shown are mean mRNA levels calculated by RT-qPCR performed in duplicates on total RNA extracted from IFN-β-treated Jurkat cells, and normalized to the shLuc control. (b) Same analysis in THP-1 cells. (PDF)

CRISPR/Cas9-mediated editing of TRIM5α in human cell lines. (a) Cas9 was targeted to exon 1 of the TRIM5 gene (green) by two selected gRNAs, whose binding sites are schematized with scissors. Arrowheads indicate the positions of the binding sites for the ODNs used in the PCR-Surveyor assay. (b) Surveyor assay. Briefly, PCR products amplified from 2...

ODN primers used to construct vectors for the expression of gRNAs and shRNAs. (PDF)

Patient characteristics. (a) CD4+ T cell counts, (b) viremia, at the time-points used in this study and according to their HLA type. B27 or B57 are grouped together. (c) Evolution of CD4, CD8 and virus counts for EC9. The black arrow indicates the time-point used in this study. The red line shows initiation and continuation of antiretroviral therap...

HLA status and presence of mutations known to modulate restriction by Mx2 and TRIM5α. (a) Bar graph of the contingency table of mutations at the G116 position (Mx2) in individuals bearing B27/B57 or other alleles (Chi-square test; p = 0.0169). (b) Bar graphs showing the presence or the absence of mutations previously shown to be associated with TRI...

Productively infected cells in microscopy experiments. (a) Microscopy images corresponding to Fig 6A with the GFP field included. (b) Frequency of infected (GFP+) cells quantified by analyzing ≥100 cells from ≥ 10 pictures and plotted according to TRIM5α expression and viral infection. The Kruskal-Wallis test and the Dunn's Multiple Comparison Test...

Hypothetical model. Following entry, viruses from a B27/B57+ subject escape Mx2 restriction but are recognized by TRIM5α. TRIM5α disrupts the proper uncoating process and may trigger pro-inflammatory signals through Ubc13- and TAK1-dependent signaling. In THP-1 cells, this leads to activation of NF-κB and AP-1 and production of type I IFN productio...

Sensitivity of NRC10GFP and NL43GFP to restriction by Mx2 and TRIM5α. Jurkat cells knocked down for Mx2 or TRIM5α or both were infected with increasing amounts of the two HIV-1vectors. Infectivity was measured by FACS as the % of GFP+ cells 48 h post-infection. (PDF)

Effect of inhibitors on HIV-1 vector infectivity. THP-1 cells were pre-treated or not with (a) BX795 (iTBK1), (b) BAY11-7085 (iNF-κB) or (c) SP600125 (iAP-1) for 1 h, infected with DsRed-expressing chimeric vectors (“virus 1”), and 48 h later infected with NRC1GFP (“virus 2”). Infectivity of DsRed-virus 1 was assessed by flow cytometry 48 h later....

Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing public health prevention efforts. To identify recent HIV-1 infections, we evaluated and compared the performance of 4 sequence-based diversity measures including percent diversity, percent complexity, Shannon entropy and number of haplotypes targeting 13 ge...

Sequence-based diversity measures expressed as the median/IQR and calculated from NGS of 7 segments representing 4 selected HIV-1 env GP120 conserved subdomains. (PDF)

Viral sequences data qualifiers. (XLSX)

Sequence based diversity measures calculation methods. (PDF)

Sequence-based diversity measures expressed as the median/IQR and calculated from NGS of 5 segments representing 5 selected HIV-1 env GP120 variable loops and 1 segment for a part of the gp41ectodomain. (PDF)

Sequence-based diversity measures expressed as the mean with student t-test results comparing recent versus chronic HIV infected sequences by 13 env segments. (PDF)

Purpose of review: Although the HIV-infected population is living longer and getting older under current treatment regimens, significant challenges arise for health management as the infection is associated with various premature aging phenotypes, particularly increased incidence of cardiovascular diseases (CVDs). Here we review the current unders...

The innate and adaptive immune systems fail to control HCV infection in the majority of infected individuals. HCV is an ssRNA virus, which suggests a role for Toll-like receptors (TLRs) 7 and 8 in initiating the anti-viral response. Here we demonstrate that HCV genomic RNA harbours specific sequences that initiate an anti-HCV immune response throug...

Early HIV-1 infection is characterized by enhanced tryptophan catabolism, which contributes to immune suppression and disease progression. However, mechanism by which kynurenine, a tryptophan-related metabolite, induces immune suppression remains poorly understood. Herein, we showed that the increased production of kynurenine correlates with defect...

HIV-infected slow progressors (SP) represent a heterogeneous group of subjects who spontaneously control HIV infection without treatment for several years while showing moderate signs of disease progression. Under conditions that remain poorly understood, a subgroup of these subjects experience failure of spontaneous immunological and virological c...

Background: The HIV-1 infection is characterized by profound CD4(+) T cell destruction and a marked Th17 dysfunction at the mucosal level. Viral suppressive antiretroviral therapy restores Th1 but not Th17 cells. Although several key HIV dependency factors (HDF) were identified in the past years via genome-wide siRNA screens in cell lines, molecul...

HIV-1 infection results in long-lasting activation of the immune system including elevated production of pro-inflammatory cytokine/chemokines, and bacterial product release from gut into blood and tissue compartments, which are not fully restored by antiretroviral therapies. HIV-1 has also developed numerous strategies via viral regulatory proteins...

Background: Tryptophan (Trp) catabolism into kynurenine (Kyn) contributes to immune dysfunction in chronic human immunodeficiency virus (HIV) infection. To better define the relationship between Trp catabolism, inflammation, gut mucosal dysfunction, and the role of early antiretroviral therapy (ART), we prospectively assessed patients early after...

Here, we evaluated the in vitro anti-HIV-1 activity of the experimental CCR5 inhibitor VCH-286 as a single agent or in combination with various classes of HIV-1 inhibitors. Although VCH-286 used alone had highly inhibitory activity, paired combinations with different drug classes led to synergistic or additive interactions. However, combinations wi...

Background Coexpression of CD160 and PD-1 on HIV-specific CD8+ T-cells defines a highly exhausted T-cell subset. CD160 binds to Herpes Virus Entry Mediator (HVEM) and blocking this interaction with HVEM antibodies reverses T-cell exhaustion. As HVEM binds both inhibitory and activatory receptors, our aim in the current study was to assess the impac...

CD86 and CD80, the ligands for the co-stimulatory molecules CD28 and CTLA-4, are members of the Ig superfamily. Their structure includes Ig variable-like (IgV) domains, Ig constant-like (IgC) domains and intracellular domains. Although crystallographic studies have clearly identified the IgV domain to be responsible for receptor interactions, earli...

HIV-1 Nef protein down-regulates several cell surface receptors through its interference with the cell sorting and trafficking machinery. Here we demonstrate for the first time the ability of Nef to down-regulate cell surface expression of the negative immune modulator CTLA-4. Down-regulation of CTLA-4 required the Nef motifs DD175, EE155 and LL165...

We compared the relative efficacies against simian immunodeficiency virus (SIV) challenge of three vaccine regimens that elicited similar frequencies of SIV-specific CD4+ and CD8+ T-cell responses but differed in the level of antibody responses to the gp120 envelope protein. All macaques were primed with DNA plasmids expressing SIV gag, pol, env, a...

Chronic viral infections lead to persistent CD8 T cell activation and functional exhaustion. Expression of programmed cell death-1 (PD-1) has been associated to CD8 T cell dysfunction in HIV infection. Herein we report that another negative regulator of T cell activation, CD160, was also upregulated on HIV-specific CD8 T lymphocytes mostly during t...

A natural densovirus (DNV) of a serious phytophagous pest, Helicoverpa armigera, was isolated. The genome of HaDNV contained 6,039 nucleotides (nt) and included inverted terminal repeats (ITRs) of 545 nt with terminal Y-shaped hairpins of 126 nt. Its DNA sequence and ambisense organization with four typical open reading frames (ORFs) demonstrated t...

Background / Purpose: In spite of advances in the treatment of HIV infection, HAART does not eradicate HIV because a small pool of latently infected memory CD4+ T cells persist in virally suppressed subjects. Characterization of the phenotype of these cells is a prerequisite to the design of novel targeted strategies aimed at eliminating them.Rec...

Bombyx mori densovirus 1 (BmDNV-1), a major pathogen of silkworms, causes significant losses to the silk industry. The structure of the recombinant BmDNV-1 virus-like particle has been determined at 3.1-Å resolution using X-ray crystallography. It is the first near-atomic-resolution structure of a virus-like particle within the genus Iteravirus. Th...

HIV type 1 infection is associated with a rapid depletion of Th17 cells from the GALT. The chemokine receptor CCR6 is a marker for Th17 lineage polarization and HIV permissiveness in memory CD4(+) T cells. CCR6(+) T cells have the potential to migrate into the GALT via the gut-homing integrin α(4)β(7), a newly identified HIV-gp120 binding receptor....

16‐17 July 2010, International AIDS Society’s Workshop “Towards a Cure”: HIV Reservoirs and Strategies to Control Them, Vienna, Austria

Viral replication and microbial translocation from the gut to the blood during HIV infection lead to hyperimmune activation, which contributes to the decline in CD4+ T cell numbers during HIV infection. Programmed death-1 (PD-1) and interleukin-10 (IL-10) are both upregulated during HIV infection. Blocking interactions between PD-1 and programmed d...