Eva Riveira-Munoz

IrsiCaixa Institute for AIDS Research | IRSICAIXA · Retrovirology

Animal models have been instrumental in elucidating the pathogenesis of SARS-CoV-2 infection and testing COVID-19 vaccines and therapeutics. Wild-type (WT) mice are not susceptible to many SARS-CoV-2 variants, therefore transgenic K18-hACE2 mice have emerged as a standard model system. However, this model is characterized by severe disease, particu...

The lung is prone to infections from respiratory viruses such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). A challenge in combating these infections is the difficulty in targeting antiviral activity directly at the lung mucosal tract. Boosting the capability of the respiratory mucosa to trigger a potent immune response at the on...

Safe and effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are crucial to fight against the coronavirus disease 2019 pandemic. Most vaccines are based on a mutated version of the Spike glycoprotein [K986P/V987P (S-2P)] with improved stability, yield and immunogenicity. However, S-2P is still produced at low levels. Her...

Age is associated with reduced efficacy of vaccines and linked to higher risk of severe COVID-19. Here we determined the impact of ageing on the efficacy of a SARS-CoV-2 vaccine based on a stabilised Spike glycoprotein (S-29) that had previously shown high efficacy in young animals. Thirteen to 18-month-old golden Syrian hamsters (GSH) and 22–23-mo...

Most COVID-19 vaccines are based on the SARS-CoV-2 Spike glycoprotein (S) or their subunits. However, S shows some structural instability that limits its immunogenicity and production, hampering the development of recombinant S-based vaccines. The introduction of the K986P and V987P (S-2P) mutations increases the production and immunogenicity of th...

Purpose The lack of validated surrogate biomarkers is still an unmet clinical need in the management of early breast cancer cases that do not achieve complete pathological response after neoadjuvant chemotherapy (NACT). Here, we describe and validate the use of SAMHD1 expression as a prognostic biomarker in residual disease in vivo and in vitro ....

Most COVID-19 vaccines are based on the SARS-CoV-2 Spike glycoprotein (S) or their subunits. However, the S shows some structural instability that limits its immunogenicity and production, hampering the development of recombinant S-based vaccines. The introduction of the K986P and V987P (S-2P) mutations increases the production of the recombinant S...

The oral cavity is particularly susceptible to viral infections that are self-recovering in most cases. However, complications may appear in severe cases and/or immunocompromised subjects. Cetylpyridinium chloride (CPC)-containing mouthwashes are able to decrease the infectivity of the SARS-CoV-2 virus by disrupting the integrity of the viral envel...

Background and Aims In diabetic patients, hyperglycemia has been associated with a hypoxic state that contributes to an increased rate of morbidity due to Acute Kidney Failure (AKI). For this reason, we are interested in studying the molecular mechanisms involved in the development of AKI to contribute to the search for effective therapies that can...

e13063 Background: Treatment for estrogen receptor-positive (ER+)/HER2-negative advanced breast cancer (ABC) has undergone a revolution with the approval of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). Biomarkers of treatment resistance are limited, though growing evidence points towards antitumor immune response as a key factor. We aimed to i...

Safe and effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been crucial to fight against the coronavirus disease 2019 pandemic. Most vaccines are based on a mutated version of the Spike glycoprotein [K986P/V987P (S-2P)] with improved stability, yield and immunogenicity. However, S-2P is still produced at low level...

Most individuals acutely infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibit mild symptoms. However, 10 to 20% of those infected develop long-term symptoms, referred to as post-coronavirus disease 2019 (COVID-19) condition (PCC). One hypothesis is that PCC might be exacerbated by viral persistence in tissue sanctuarie...

Purpose SAMHD1 is a deoxynucleotide triphosphate (dNTP) triphosphohydrolase which has been proposed as a putative prognostic factor in haematological cancers and certain solid tumours, although with controversial data. Here, we evaluate SAMHD1 function in ovarian cancer, both in vitro and in ovarian cancer patients. Methods SAMHD1 expression was d...

The implementation and access to combined antiretroviral treatment (cART) have dramatically improved the quality of life of people living with HIV (PLWH). However, some comorbidities, such as neurological disorders associated with HIV infection still represent a serious clinical challenge. Soluble factors in plasma that are associated with control...

In the present study we report the functional and structural characterization of 17T2, a new highly potent pan-neutralizing SARS-CoV-2 human monoclonal antibody (mAb) isolated from a convalescent COVID-19 individual infected during the first wave of the COVID-19 pandemic. 17T2 is a class 1 VH1-58/κ3-20 antibody, derived from a receptor binding doma...

HIV latent infection may be associated with disrupted viral RNA sensing, interferon (IFN) signaling, and/or IFN stimulating genes (ISG) activation. Here, we evaluated the use of compounds selectively targeting at the inhibitor of nuclear factor-κB (IκB) kinase (IKK) complex subunits and related kinases (TBK1) as a novel pathway to reverse HIV-1 lat...

We describe a case of a patient who experienced recurrent COVID-19 pneumonia over a period of 123 days. Neither remdesivir nor convalescent plasma were temporally associated with viral clearance or increased plasma neutralization capacity. Antibody levels remained low until day 151 and cellular immunity increased overtime with no viral evolution.

The persistence of latent HIV reservoirs allows for viral rebound upon antiretroviral therapy interruption, hindering effective HIV-1 cure. Emerging evidence suggests that modulation of innate immune stimulation could impact viral latency and contribute to the clearing of HIV reservoir. Here, the latency reactivation capacity of a subclass of selec...

The SARS-CoV-2 antigen-detecting rapid diagnostic test (Ag-RDTs) is an easy-to-use diagnostic tool to identify the contagious individuals and reduce the new infections. However, to be effective, Ag-RDTs require the detection of distinct variants of concern (VOC) with high analytical sensitivity. Here, we found that the VOC diverge at the nucleocaps...

The emerging SARS-CoV-2 variants of concern (VOCs) may display enhanced transmissibility, more severity and/or immune evasion; however, the pathogenesis of these new VOCs in experimental SARS-CoV-2 models or the potential infection of other animal species is not completely understood. Here we infected K18-hACE2 transgenic mice with B.1, B.1.351/Bet...

Background Evidence on the determinants of the magnitude of humoral responses and neutralizing titers in individuals with mild COVID-19 is scarce. Methods In this cohort study of mild COVID-19 patients, we assessed viral load (VL) by RT-qPCR at two/three time points during acute infection, and anti-SARS-CoV-2 antibodies by ELISA and plasma neutral...

Current diagnostics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection heavily rely on reverse transcription-polymerase chain reaction (RT-PCR) or on rapid antigen detection tests. The former suffers from long time-to-result and high cost while the latter from poor sensitivity. Therefore, it is crucial to develop rapid, sensi...

SAMHD1 is a deoxynucleotide triphosphate (dNTP) triphosphohydrolase with important roles in the control of cell proliferation and apoptosis, either through the regulation of intracellular dNTPs levels or the modulation of the DNA damage response. However, SAMHD1′s role in cancer evolution is still unknown. We performed the first in-depth study of S...

Angiotensin converting enzyme 2 (ACE2) is a host ectopeptidase and the receptor for the SARS-CoV-2 virus, albeit virus-ACE2 interaction goes far beyond viral entry into target cells. Controversial data exists linking viral infection to changes in ACE2 expression and function, which might influence the subsequent induction of an inflammatory respons...

SARS-CoV-2 variants display enhanced transmissibility and/or immune evasion and can be generated in humans or animals, like minks, thus generating new reservoirs. The continuous surveillance of animal susceptibility to new variants is necessary to predict pandemic evolution. In this study we demonstrate that, compared to the B.1 SARS-CoV-2 variant,...

Introduction SAMHD1 is a triphosphohydrolase that catalyzes the degradation of deoxynucleoside triphosphates (dNTP), and its function is tightly linked to cell cycle progression and proliferation. SAMHD1 has been also related to the replication stress response, preventing chronic inflammation. Here, we explore the potential rol of SAMHD1 expression...

Background SARS-CoV-2 reinfections have been reported; however, most cases are milder than the primary infection. We report the first case of a life-threatening critical presentation of a SARS-CoV-2 reinfection. Case presentation A 62-year male from Palamós (Spain) suffered a first mild COVID-19 episode in March 2020, confirmed by 2 independent SA...

There is an urgent need to elucidate the molecular mechanisms underlying the transmissibility and pathogenesis of SARS-CoV-2. ACE2 is a host ectopeptidase with well-described anti-inflammatory and tissue protective functions and the receptor for the virus. Understanding SARS-CoV-2-ACE2 interaction and the expression of antiviral host genes in early...

We designed and synthesized 21 new indolylarylsulfones (IAS) as new HIV-1 NNRTIs. Among these, IAS 12 exhibited a remarkable antiviral activity against single and double mutants (K103N EC50: <0.7 nM; Y181C EC50: <0.7 nM; Y188L EC50: 21.3 nM; K103N-Y181C EC50: 6.2 nM), resulting equally or more active than previuosly reported IAS 6 and some approved...

Background Current strategies for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are limited to non-pharmacological interventions. Hydroxychloroquine (HCQ) has been proposed as a postexposure therapy to prevent Coronavirus disease 2019 (Covid-19) but definitive evidence is lacking. Methods We conducted an open-la...

Background: No therapeutics have yet been proven effective for the treatment of mild-illness caused by SARS-CoV-2. We aimed to determine whether early treatment with hydroxychloroquine (HCQ) would be more efficacious than no-treatment for outpatients with mild Covid-19. Methods: We conducted a multicenter, open label, randomized controlled trial...

HIV-1 infection requires life-long treatment and with 2.1 million new infections/year, faces the challenge of an increased rate of transmitted drug-resistant mutations. Therefore, a constant and timely effort is needed to identify new HIV-1 inhibitors active against drug-resistant variants. The ribonuclease H (RNase H) activity of HIV-1 reverse tra...

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Nucleos(t)ide analogues are commonly used in the treatment of infectious disease and cancer. SAMHD1 is a deoxyribonucleotide (dNTP) triphosphohydrolase which is involved in the regulation of the intracellular dNTP pool, whose function has been linked to viral restriction, cancer development, and autoimmune disorders. Here, we evaluate SAMHD1 functi...

Viral infection induces innate intracellular antiviral defenses, aimed at restricting virus replication and spread. Therefore, understanding the role and function of innate immune modulators can help to establish novel strategies for viral control. Here, we explore the role of ADAR1 as a regulator of the HIV, HCV, and HPV infections, both in vitro...

Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) is a dNTP triphosphohydrolase involved in the regulation of the intracellular dNTP pool, linked to viral restriction, cancer development and autoimmune disorders. SAMHD1 function is regulated by phosphorylation through a mechanism controlled by cyclin-dependent kin...

Introduction: SAMHD1 is a triphosphohydrolase that catalyzes the degradation of deoxynucleoside triphosphates (dNTP). SAMHD1 expression and function are coordinated during the cell cycle and tightly linked to cell cycle progression and proliferation. SAMHD1 affects nucleotide and antimetabolite drug susceptibility and has been identified as a bioma...

Introduction Cyclin-dependent kinase (CDK) 4/6 inhibitors represent a new paradigm in the treatment of hormone receptor (HR) positive and HER-2 negative metastatic breast cancer (MBC). However, despite their evident clinical benefit, the cellular and molecular mechanisms underlying treatment efficacy and drug failure are still largely unknown. CDK4...

Infection by human papillomavirus (HPV) alters the microenvironment of keratinocytes as a mechanism to evade the immune system. A-to-I editing by ADAR1 has been reported to regulate innate immunity in response to viral infections. Here, we evaluated the role of ADAR1 in HPV infection in vitro and in vivo. Innate immune activation was characterized...

Midostaurin is a multi-kinase inhibitor with antineoplastic activity. We assessed the capacity of midostaurin to affect early and late steps of HIV-1 infection and to reactivate HIV-1 latently infected cells, alone or in combination with histone deacetylase inhibitors (HDACi)known to act as latency-reversing agents (LRA). Acute HIV-1 infection was...

Conformational restriction applied to dihydrobenzylpyrimidin-4-(3H)-ones (DABOs) by the intoduction of a methyl group at the α-benzylic position is known to massively improve the anti-HIV-1 activity of these compounds. Here, we report the effects of methoxy substitution at the α-benzylic position in S-, NH-, and N,N-DABOs carrying 2,6-difluoro, 2-c...

CD32 has been shown to be preferentially expressed in latently HIV-1-infected cells in an in vitro model of quiescent CD4 T cells. Here we show that stimulation of CD4+ T cells with IL-2, IL-7, PHA, and anti-CD3/CD28 antibodies induces T-cell proliferation, co-expression of CD32 and the activation of the markers HLA-DR and CD69. HIV-1 infection inc...

The persistence of HIV despite suppressive antiretroviral therapy is a major roadblock to HIV eradication. Current strategies focused on inducing the expression of latent HIV fail to clear the persistent reservoir, prompting the development of new approaches for killing HIV+ cells. Recently, acitretin has been proposed as a pharmacological innate c...

ADAR1-dependent A-to-I editing has recently been recognized as a key process for marking dsRNA as self, therefore, preventing innate immune activation and affecting the development and resolution of immune-mediated diseases and infections. Here, we have determined the role of ADAR1 as a regulator of innate immune activation and modifier of viral su...

We designed and synthesized a series of chiral indolyarylsulfones (IASs) as new HIV-1 NNRTIs. The new IASs 8-37 showed potent inhibition of the HIV-1 WT NL4-3 strain and of the mutant K103N, Y181C, Y188L and K103N-Y181C HIV-1 strains. Six racemic mixtures, 8, 23-25, 31 and 33, were separated at semipreparative level into their pure enantiomers. The...

The ability of some viruses to establish latently infected chronic reservoirs that escape to immune control becomes a major roadblock that impedes the cure of these infections. Therefore, new alternatives are needed to pursuit the eradication of viral persistent infections. Gene silencing technologies are in constant evolution and provide an outsta...

SAMHD1 is a triphosphohydrolase that restricts HIV-1 by limiting the intracellular dNTP pool required for reverse transcription. Although SAMHD1 is expressed and active/unphosphorylated in most cell lines, its restriction activity is thought to be relevant only in non-cycling cells. However, an in depth evaluation of SAMHD1 function and relevance i...

Author Macrophages are a heterogeneous population of immune cells that provide crucial innate immune defense against pathogens, including HIV-1. The molecular biology of HIV-1 infection in macrophages is influenced by the presence of the host cell restriction factor SAMHD1, which is regulated by phosphorylation by cyclin dependent kinases, the cat...

Cyclin D2 restricts HIV-1 replication and proviral DNA formation in GM-CSF macrophages. (A) SAMHD1 expression levels after knockdown of CCND2 and CCND3 expression by siRNA. Relative mRNA expression of SAMHD1 in M-CSF (white bars) and GM-CSF (black bars) macrophages. SAMHD1 mRNA was measured by quantitative PCR and normalized to GAPDH expression. Da...

Mouse peritoneal macrophages resemble GM-CSF expression profile. (A) Comparative gene expression of cell cycle-related genes and SAMHD1 in mouse peritoneal macrophages and human M-CSF and GM-CSF macrophages. mRNA levels of CCND2, CCND3, CDK2, CDK4, SAMHD1 and the CDK inhibitors p21 (CDKN1A) and p27 (CDKN1B) were quantified by real time PCR. Relativ...

Phenotypic characterization of M-CSF and GM-CSF macrophages. (A) Summary of cell surface antigens expression. Markers of macrophage differentiation, HIV-1 receptor and coreceptors and cell activation and proliferation markers were evaluated by flow cytometry. The table shows mean ± SD of at least 3 different donors. nd, not detected. (B) Intracellu...

GM-CSF macrophages cultured with human serum (HS) or fetal bovine serum (FBS) show lower proliferation rates, higher expression of cyclin D2 and are less susceptible to HIV-1 infection compared to M-CSF. (A) Evaluation of cell proliferation by Ki67 staining. Histograms of a representative donor showing Ki67 staining in M-CSF and GM-CSF derived macr...

Knockdown of cyclin D2 does not affect macrophage function. (A) Cytokine expression in GM-CSF siRNA-treated macrophages. Cytokine mRNA expression was measured using a TaqMan Human Cytokine Network array and expression of each gene was normalized to GAPDH. Data is normalized to Mock-transfected macrophages. Mean ± SD of 2 different donors performed...

HIV-1 infection is thought to impair type I interferon (IFN-I) production in macrophages, a cell type that is also relatively resistant to HIV-1 cytotoxic effects. Here, we show that monocyte differentiation into macrophages by M-CSF led to cell proliferation and susceptibility to HIV-1 infection that induced cell cycle arrest and increased cell de...

Objectives: Sterile α motif and histidine-aspartate domain-containing protein 1 (SAMHD1) has been shown to restrict retroviruses and DNA viruses by decreasing the pool of intracellular deoxynucleotides. In turn, SAMHD1 is controlled by cyclin-dependent kinases (CDK) that regulate the cell cycle and cell proliferation. Here, we explore the effect o...

Cyclins control the activation of cyclin-dependent kinases (CDK), which in turn, control the cell cycle and cell division. Intracellular availability of deoxynucleotides (dNTP) plays a fundamental role in cell cycle progression. SAM domain and HD domain-containing protein 1 (SAMHD1) degrades nucleotide triphosphates and controls the size of the dNT...

We synthesized new indolylarylsulfone (IAS) derivatives carrying a heterocyclic tail at the indole-2-carboxamide nitrogen as potential anti-HIV/AIDS agents. Several new IASs yielded EC50 values <1.0 nM against HIV-1 WT and mutant strains in MT-4 cells. The (R)-11 enantiomer proved to be exceptionally potent against the whole viral panel; in the rev...

HIV-1 exploits multiple host proteins during infection. siRNA-based screenings have identified new proteins implicated in different pathways of the viral cycle that participate in a broad range of cellular functions. The Human Mediator Complex (MED) is composed by 28 elements and represents a fundamental component of the transcription machinery, in...

Objectives: SAMHD1 and the CDKN1A (p21) cyclin-dependent kinase inhibitor have been postulated to mediate HIV-1 restriction in CD4+ cells. We have shown that p21 affects HIV replication through its effect on SAMHD1. Thus, we aimed at evaluating the expression of SAMHD1 and p21 in different HIV+ phenotypic groups. Patients and methods: We evaluat...

Background: Sterile α motif and HD domain-containing protein-1 (SAMHD1) inhibits HIV-1 reverse transcription by decreasing the pool of intracellular deoxynucleotides. SAMHD1 is controlled by cyclin-dependent kinase (CDK)-mediated phosphorylation. However, the exact mechanism of SAMHD1 regulation in primary cells is unclear. We explore the effect o...

Genome editing using zinc finger nucleases (ZFNs) has been successfully applied to disrupt CCR5 or CXCR4 host factors and inhibit viral entry and infection. Gene therapy using ZFNs to modify the PSIP1 gene, which encodes the lens epithelium-derived growth factor (LEDGF) protein, might restrain an early step of the viral replication cycle at the int...

SAMHD1 is a dNTP triphophohydrolase recently been recognized as an antiviral factor that acts by depleting dNTP availability for viral reverse transcriptase. SAMHD1 restriction is counteracted by the HIV-2 accessory protein Vpx, which targets SAMHD1 for proteosomal degradation, resulting in an increased availability of dNTPs and consequently enhanc...