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Zika virus (ZIKV) has the ability to cross placental and brain barriers, causing congenital malformations in neonates and neurological disorders in adults. However, the pathogenic mechanisms of ZIKV-induced neurological complications in adults and congenital malformations are still not fully understood. Gas6 is a soluble TAM receptor ligand able to promote flavivirus internalization and downregulation of immune responses. Here we demonstrate that there is a correlation between ZIKV neurological complications with higher Gas6 levels and the downregulation of genes associated with anti-viral response, as type I IFN due to Socs1 upregulation. Also, Gas6 gamma-carboxylation is essential for ZIKV invasion and replication in monocytes, the main source of this protein, which was inhibited by warfarin. Conversely, Gas6 facilitates ZIKV replication in adult immunocompetent mice and enabled susceptibility to transplacental infection. Our data indicate that ZIKV promotes the upregulation of its ligand Gas6, which contributes to viral infectivity and drives the development of severe adverse outcomes during ZIKV infection.

We documented 4 cases of severe acute respiratory syndrome coronavirus 2 reinfection by non-variant of concern strains among healthcare workers in Campinas, Brazil. We isolated infectious particles from nasopharyngeal secretions during both infection episodes. Improved and continued protection measures are necessary to mitigate the risk for reinfection among healthcare workers.

Zika virus (ZIKV) is an emerging arbovirus associated with foetal malformations and neurological complications. The infection is usually associated with mild symptoms. The comparison between the allelic frequency of polymorphic genes in symptomatic infected individuals in the population can clarify the pathogenic mechanisms of ZIKV. During ZIKV infection, cytokines are produced and natural killer (NK) cells are recruited, whose activation depends on signaling pathways activated by specific receptors, such as killer cell immunoglobulin-like receptors (KIR). These molecules interact with human leukocyte antigen (HLA) class I ligands and are encoded by polymorphic genes.This study aimed to evaluate the frequency of allelic variants of the genes encoding the KIR receptors and their HLA class I ligands in 139 symptomatic ZIKV-patients and 170 controls negative for the virus, and to evaluate the role of these variants for ZIKV susceptibility.KIR and HLA class I genes were genotyped using the polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) technique.No significant differences in the frequency distribution of KIRs and KIR-HLA in patients compared to controls were observed.KIR and its HLA ligands might play a minor role in ZIKV infection in the south and southeast Brazilian individuals.

SARS-CoV-2 is an emerging virus from the Coronaviridae family and is responsible for the ongoing COVID-19 pandemic. In this work, we explored the previously reported SARS-CoV-2 structural membrane protein (M) interaction with human Proliferating Cell Nuclear Antigen (PCNA). The M protein is responsible for maintaining virion shape, and PCNA is a marker of DNA damage which is essential for DNA replication and repair. We validated the M PCNA interaction through immunoprecipitation, immunofluorescence co-localization, and a PLA assay. In cells infected with SARS-CoV-2 or transfected with M protein, using immunofluorescence and cell fractioning, we documented a reallocation of PCNA from the nucleus to the cytoplasm and the increase of PCNA and γH2AX (another DNA damage marker) expression. We also observed an increase of PCNA and γH2AX expression in the lung of a COVID-19 patient by immunohistochemistry. In addition, the inhibition of PCNA translocation by PCNA I1 and Verdinexor led to a reduction of plaque formation in an in vitro assay. We, therefore, propose that the transport of PCNA to the cytoplasm and its association with M could be a virus strategy to manipulate cell functions and may be considered a target for COVID-19 therapy.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is mainly transmitted by airborne droplets generated by infected individuals. Since this and many other pathogens are able to remain viable on inert surfaces for extended periods of time, contaminated surfaces play an important role in SARS-CoV-2 fomite transmission. Cosmetic products are destined to be applied on infection-sensitive sites, such as the lips and eyelids. Therefore, special biosafety precautions should be incorporated into the routine procedures of beauty parlors and shops. Indeed, innovative cosmetics companies are currently searching for disinfection protocols that ensure the customers’ safety in makeup testing. Here, we propose an ultraviolet germicidal irradiation (UVGI) strategy that can be used to reduce the odds of COVID-19 fomite transmission by makeup testers. It is well-known that UVGI effectively inactivates pathogens on flat surfaces and clear fluids. However, ultraviolet-C (UVC) radiation at 254 nm penetrates poorly in turbid and porous materials, such as makeup and lipstick formulations. Thus, we investigated the virucidal effect of UVGI against SARS-CoV-2 deposited on such substrates and compared their performance to that of flat polystyrene surfaces, used as controls. Concentrated infectious SARS-CoV-2 inoculum (106 PFU/mL) deposited on lipstick and makeup powder was completely inactivated (>5log10 reduction) following UVC exposures at 1,260 mJ/cm2, while flat plastic surfaces required 10 times less exposure (126 mJ/cm2) to reach the same microbicidal performance. We conclude that UVGI comprises an effective disinfection strategy to promote biosafety for cosmetics testers. However, appropriate UVC dosimetry must be implemented to overcome inefficiencies caused by the optical properties of turbid materials in lipsticks and makeup powders.

The COVID-19 disease caued by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has two characteristics that distinguish it from other viral infections. It affects more severely people with pre-existing comorbidities and viral load peaks prior to the onset of the symptoms. Investigating factors that could contribute to these characteristics, we found increased mTOR signaling and suppressed genes related to autophagy, lysosome, and vesicle fusion in Vero E6 cells infected with SARS-CoV-2. Transcriptomic data mining of bronchoalveolar epithelial cells from severe COVID-19 patients revealed that COVID-19 severity is associated with increased expression of genes related to mTOR signaling and decreased expression of genes related to autophagy, lysosome function, and vesicle fusion. SARS-CoV-2 infection in Vero E6 cells also resulted in virus retention inside the cells and trafficking of virus-bearing vesicles between neighboring cells. Our findings support a scenario where SARS-CoV-2 benefits from compromised autophagic flux and inhibited exocytosis in individuals with chronic hyperactivation of mTOR signaling, which might relate to undetectable proliferation and evasion of the immune system.

Background Mutations accrued by SARS-CoV-2 lineage P.1—first detected in Brazil in early January, 2021—include amino acid changes in the receptor-binding domain of the viral spike protein that also are reported in other variants of concern, including B.1.1.7 and B.1.351. We aimed to investigate whether isolates of wild-type P.1 lineage SARS-CoV-2 can escape from neutralising antibodies generated by a polyclonal immune response. Methods We did an immunological study to assess the neutralising effects of antibodies on lineage P.1 and lineage B isolates of SARS-CoV-2, using plasma samples from patients previously infected with or vaccinated against SARS-CoV-2. Two specimens (P.1/28 and P.1/30) containing SARS-CoV-2 lineage P.1 (as confirmed by viral genome sequencing) were obtained from nasopharyngeal and bronchoalveolar lavage samples collected from patients in Manaus, Brazil, and compared against an isolate of SARS-CoV-2 lineage B (SARS.CoV2/SP02.2020) recovered from a patient in Brazil in February, 2020. Isolates were incubated with plasma samples from 21 blood donors who had previously had COVID-19 and from a total of 53 recipients of the chemically inactivated SARS-CoV-2 vaccine CoronaVac: 18 individuals after receipt of a single dose and an additional 20 individuals (38 in total) after receipt of two doses (collected 17–38 days after the most recent dose); and 15 individuals who received two doses during the phase 3 trial of the vaccine (collected 134–230 days after the second dose). Antibody neutralisation of P.1/28, P.1/30, and B isolates by plasma samples were compared in terms of median virus neutralisation titre (VNT50, defined as the reciprocal value of the sample dilution that showed 50% protection against cytopathic effects). Findings In terms of VNT50, plasma from individuals previously infected with SARS-CoV-2 had an 8·6 times lower neutralising capacity against the P.1 isolates (median VNT50 30 [IQR Interpretation SARS-CoV-2 lineage P.1 might escape neutralisation by antibodies generated in response to polyclonal stimulation against previously circulating variants of SARS-CoV-2. Continuous genomic surveillance of SARS-CoV-2 combined with antibody neutralisation assays could help to guide national immunisation programmes. Funding São Paulo Research Foundation, Brazilian Ministry of Science, Technology and Innovation and Funding Authority for Studies, Medical Research Council, National Council for Scientific and Technological Development, National Institutes of Health. Translation For the Portuguese translation of the abstract see Supplementary Materials section.

Microbiota-derived molecules called short-chain fatty acids (SCFAs) play a key role in the maintenance of the intestinal barrier and regulation of immune response during infectious conditions. Recent reports indicate that SARS-CoV-2 infection changes microbiota and SCFAs production. However, the relevance of this effect is unknown. In this study, we used human intestinal biopsies and intestinal epithelial cells to investigate the impact of SCFAs in the infection by SARS-CoV-2. SCFAs did not change the entry or replication of SARS-CoV-2 in intestinal cells. These metabolites had no effect on intestinal cells’ permeability and presented only minor effects on the production of anti-viral and inflammatory mediators. Together our findings indicate that the changes in microbiota composition of patients with COVID-19 and, particularly, of SCFAs do not interfere with the SARS-CoV-2 infection in the intestine.

Background: Some studies have determined that the SARS-CoV-2 B.1.1.7 variant of concern (VOC) has been associated with increased transmissibility, hospitalization, and mortality. This study aimed to explore the factors associated with B.1.1.7 VOC infection in the context of vaccination with adenovirus-vectored and inactivated vaccines. Methods: We analyzed epidemiological, clinical, and laboratory data from simultaneous COVID-19 outbreaks in a convent (Outbreak A) and in a long-term care facility (Outbreak B) in individuals vaccinated with a single dose of ChAdOx1 or two doses of the CoronaVac vaccine, respectively. First, we identified the viral lineages associated with these outbreaks by genome sequencing. Then, we assessed the relationship of viral load, specific immunoglobulin antibody levels, neutralization antibodies, case characteristics (age, vaccine type, and presence or absence of symptoms), and associations with risk of developing COVID-19. Findings: On March 2021, we detected SARS-CoV-2 RNA in nasopharyngeal samples from 14 of 22 of the ChAdOx1 vaccine recipients (Outbreak A, n=26), and 22 of 42 of the CoronaVac-vaccinated individuals (Outbreak B, n=52) for breakthrough infection rates for ChAdOx1 of 63·6% and 52·4% for CoronaVac. Vaccinated individuals from Outbreak A received a single dose at least 23 days before the outbreak, and the Outbreak B was involved virus detection 5 to 27 days after a second dose. In these outbreaks, the median ages were 73 and 77 years old, respectively. The median viral loads were 3·4×101 and 2·3×103 RNA copies per mL in Outbreaks A and B, respectively. In total for both outbreaks, 12 people had mild-COVID-19 while 26 were asymptomatic, but one case involving a person from Outbreak B was fatal. Based on analysis of SARS-CoV-2 genome sequences, we determined that outbreaks A and B were caused by two independent clusters of the B.1.1.7 VOC. Interestingly, the serum of PCR-positive symptomatic SARS-CoV-2-infected individuals had ~1·8 to 3·4-fold more neutralizing capacity against B.1.1.7 compared to the serum of asymptomatic, SARS-CoV-2-infected individuals, indicating that the levels of neutralizing antibodies induced by ChAdOx1 and CoronaVac were not correlated with protection against symptomatic infection. Interpretation: These data suggest that the B.1.1.7 variant can escape from the immune response elicited by immunization with a single dose of an adenovirus-vectored vaccine or two doses of an inactivated vaccine. However, partial immunization with ChAdOx1 and the complete series of CoronaVac seemed to provide protection against severe COVID-19 and death in the large majority of individuals. Continued and rapid immunization combined with nonpharmaceutical interventions (e.g., masking and physical distancing), are necessary to break the SARS-CoV-2 transmission until herd immunity improves. Funding Information: Sao Paulo Research Foundation, Brazilian Ministry of Science, Technology and Innovation and Funding Authority for Studies, Coordination for the Improvement of Higher Education Personnel, Wellcome Trust, Medical Research Council, National Institutes of Health, and Brazilian National Council for Scientific and Technological Development. Declaration of Interests: All other authors declare no competing interests. Ethics Approval Statement: All procedures followed the ethical standards of the responsible committee on human experimentation and were approved by the ethics committees from the University of Campinas, Brazil (Approval number: CAEE 31170720.3.0000.5404).

Background: A new SARS-CoV-2 lineage, named P.1 (20J/501Y.V3), has recently been detected in Brazil. Mutations accrued by the P.1 lineage include amino acid changes in the receptor-binding domain of the spike protein that also are reported in variants of concern in the United Kingdom (B.1.1.7) and South Africa (B.1.325). Methods: We isolated two P.1-containing specimens from nasopharyngeal and bronchoalveolar lavage samples of patients of Manaus, Brazil. We measured neutralization of the P.1 virus after incubation with the plasma of 19 COVID-19 convalescent blood donors and recipients of the chemically-inactivated CoronaVac vaccine and compared these results to neutralization of a SARS-CoV-2 B-lineage previously circulating in Brazil. Findings: The immune plasma of COVID-19 convalescent blood donors had 6-fold less neutralizing capacity against the P.1 than against the B-lineage. Moreover, five months after booster immunization with CoronaVac, plasma from vaccinated individuals failed to efficiently neutralize P.1 lineage isolates. Interpretation: These data indicate that the P.1 lineage may escape from neutralizing antibodies generated in response to polyclonal stimulation against previously circulating variants of SARS-CoV-2. Funding: Sao Paulo Research Foundation, MCTI/FINEP, Medical Research Council, National Council for Scientific and Technological Development, National Institutes of Health. Conflict of Interest: M.S.D. is a consultant for Inbios, Vir Biotechnology, NGMBiopharmaceuticals, and Carnival Corporation, and on the Scientific Advisory Boards of Moderna and Immunome. The Diamond laboratory has received funding support in sponsored research agreements from Moderna, Vir Biotechnology, and Emergent BioSolutions. Ethical Approval: All procedures followed the ethical standards of the responsible committee on humanexperimentation and approved by the ethics committees from the University of Campinas, Brazil (Approval number CONEP 4.021.484 for plasma collection of blood donors, CAEE32078620.4.0000.5404 and 30227920.9.0000.5404 for the sampling of vaccinated and viral genome sequencing, respectively). All patient data were anonymized before study inclusion.Informed consent was obtained from all subjects for being included in the study.

Made available in DSpace on 2021-06-25T10:23:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de Goiás National Institute of General Medical Sciences Although the widespread epidemic of Zika virus (ZIKV) and its neurological complications are well-known there are still no approved drugs available to treat this arboviral disease or vaccine to prevent the infection. Flavonoids from Pterogyne nitens have already demonstrated anti-flavivirus activity, although their target is unknown. In this study, we virtually screened an in-house database of 150 natural and semi-synthetic compounds against ZIKV NS2B-NS3 protease (NS2B-NS3p) using docking-based virtual screening, as part of the OpenZika project. As a result, we prioritized three flavonoids from P. nitens, quercetin, rutin and pedalitin, for experimental evaluation. We also used machine learning models, built with Assay Central® software, for predicting the activity and toxicity of these flavonoids. Biophysical and enzymatic assays generally agreed with the in silico predictions, confirming that the flavonoids inhibited ZIKV protease. The most promising hit, pedalitin, inhibited ZIKV NS2B-NS3p with an IC50 of 5 μM. In cell-based assays, pedalitin displayed significant activity at 250 and 500 µM, with slight toxicity in Vero cells. The results presented here demonstrate the potential of pedalitin as a candidate for hit-to-lead (H2L) optimization studies towards the discovery of antiviral drug candidates to treat ZIKV infections. Laboratory of Antibiotics and Chemotherapeutics (LAQ) Institute of Biosciences Humanities and Exact Sciences São Paulo State University (Unesp) Laboratory of Molecular Modeling and Drug Design (LabMol) Faculdade de Farmácia Universidade Federal de Goiás Institute of Physics of São Carlos University of São Paulo Brazilian Biosciences National Laboratory (LNBio) Brazilian Center for Research in Energy and Materials (CNPEM) Laboratory of Emerging Viruses (LEVE) Department of Genetics Evolution Microbiology and Immunology Institute of Biology University of Campinas (UNICAMP) Collaborations Pharmaceuticals Inc. Laboratory of Antibiotics and Chemotherapeutics (LAQ) Institute of Biosciences Humanities and Exact Sciences São Paulo State University (Unesp) CAPES: 130767/2016-01 CNPq: 150759/2017-7 FAPESP: 2013/07600-3 FAPESP: 2014/18330-0 FAPESP: 2016/00194-8 Fundação de Amparo à Pesquisa do Estado de Goiás: 20171026700006 FAPESP: 2018/03917-6 FAPESP: 2018/15083-2 Fundação de Amparo à Pesquisa do Estado de Goiás: 300508/2017-4 CNPq: 306251/2016-7 CNPq: 309957/2019-2 CNPq: 429322/2018-6 CNPq: 471129/2013-5 National Institute of General Medical Sciences: R43AT010585-01S1

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as coronavirus disease-2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality1,2. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here we show that SARS-CoV-2 infects human CD4+T helper cells, but not CD8+T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.

Made available in DSpace on 2020-12-12T02:25:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundo de Apoio ao Ensino, à Pesquisa e Extensão, Universidade Estadual de Campinas Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) COVID-19 can result in severe lung injury. It remained to be determined why diabetic individuals with uncontrolled glucose levels are more prone to develop the severe form of COVID-19. The molecular mechanism underlying SARS-CoV-2 infection and what determines the onset of the cytokine storm found in severe COVID-19 patients are unknown. Monocytes and macrophages are the most enriched immune cell types in the lungs of COVID-19 patients and appear to have a central role in the pathogenicity of the disease. These cells adapt their metabolism upon infection and become highly glycolytic, which facilitates SARS-CoV-2 replication. The infection triggers mitochondrial ROS production, which induces stabilization of hypoxia-inducible factor-1α (HIF-1α) and consequently promotes glycolysis. HIF-1α-induced changes in monocyte metabolism by SARS-CoV-2 infection directly inhibit T cell response and reduce epithelial cell survival. Targeting HIF-1ɑ may have great therapeutic potential for the development of novel drugs to treat COVID-19. Diabetic people with uncontrolled blood glucose levels have a greater risk to develop severe COVID-19 disease. Codo et al. show that elevated glucose levels and glycolysis promote SARS-CoV-2 (CoV-2) replication and cytokine production in monocytes through a mitochondrial ROS/hypoxia-inducible factor-1α dependent pathway, resulting in T cell dysfunction and epithelial cell death. Laboratory of Immunometabolism Department of Genetics Evolution Microbiology and Immunology Institute of Biology University of Campinas Department of Genetics Evolution Microbiology and Immunology Institute of Biology University of Campinas Department of Biochemistry and Tissue Biology Institute of Biology University of Campinas Department of Genetics at Ribeirao Preto Medical School University of Sao Paulo, Ribeirao Preto Department of Clinical and Toxicological analyses School of Pharmaceutical Sciences University of São Paulo Brazilian Biosciences National Laboratory (LNBio), Campinas Department of Animal Biology Institute of Biology University of Campinas, Campinas Department of Internal Medicine School of Medical Sciences University of Campinas, Campinas Department of Clinical Medicine School of Medical Sciences University of Campinas, Campinas Hematology and Hemotherapy Center University of Campinas, Campinas Obesity and Comorbidities Research Center (OCRC) University of Campinas Experimental Medicine Research Cluster (EMRC) University of Campinas Department of Structural and Functional Biology Institute of Biosciences São Paulo State University (UNESP), Botucatu D'Or Institute for Research and Education (IDOR) Instituto Nacional de Biomarcadores em Neuropsiquiatria Conselho Nacional de Desenvolvimento Científico e Tecnológico Department of Structural and Functional Biology Institute of Biosciences São Paulo State University (UNESP), Botucatu FAPESP: 20/04579-7 FAPESP: 2015/15626-8 FAPESP: 2016/18031-8 FAPESP: 2016/23328-0 FAPESP: 2017/01184-9 FAPESP: 2018/22505-0 FAPESP: 2019/00098-7 FAPESP: 2019/06372-3 FAPESP: 2020/04522-5 FAPESP: 2020/04558-0 FAPESP: 2020/04583-4 FAPESP: 2020/04746-0 FAPESP: 2020/04919-2 Fundo de Apoio ao Ensino, à Pesquisa e Extensão, Universidade Estadual de Campinas: 2274/20

To investigate the role of TYRO3, AXL and TIM1 receptors in the Zika virus (ZIKV) cycle, we determined their mRNA expression in different placental sites of ZIKV infected tissue during pregnancy. Unexpectedly, the ZIKV infection was not related with mRNA upregulation of these receptors or changes in expression of type I and III interferons in different placental sites. Instead, a decrease of TYRO3 mRNA expression was observed in positive sites of ZIKV positive placentas in comparison to negative sites. The basis of this downregulation can help to understand how ZIKV persists in placental tissue during pregnancy.

A SARS-CoV-2 B.1.1.7 variant of concern (VOC) has been associated with increased transmissibility, hospitalization, and mortality. This study aimed to explore the factors associated with B.1.1.7 VOC infection in the context of vaccination. On March 2021, we detected SARS-CoV-2 RNA in nasopharyngeal samples from 14 of 22 individuals vaccinated with a single-dose of ChAdOx1 (outbreak A, n = 26), and 22 of 42 of individuals with two doses of the CoronaVac vaccine (outbreak B, n = 52) for breakthrough infection rates for ChAdOx1 of 63.6% and 52.4% for CoronaVac. The outbreaks were caused by two independent clusters of the B.1.1.7 VOC. The serum of PCR-positive symptomatic SARS-CoV-2-infected individuals had ~1.8–3.4-fold more neutralizing capacity against B.1.1.7 compared to the serum of asymptomatic individuals. These data based on exploratory analysis suggest that the B.1.1.7 variant can infect individuals partially immunized with a single dose of an adenovirus-vectored vaccine or fully immunized with two doses of an inactivated vaccine, although the vaccines were able to reduce the risk of severe disease and death caused by this VOC, even in the elderly.

Oropouche orthobunyavirus (OROV) is an emerging arbovirus with a high potential of dissemination in America. Little is known about the role of peripheral blood mononuclear cells (PBMC) response during OROV infection in humans. Thus, to evaluate human leukocytes susceptibility, permissiveness and immune response during OROV infection, we applied RNA hybridization, qRT-PCR and cell-based assays to quantify viral antigens, genome, antigenome and gene expression in different cells. First, we observed OROV replication in human leukocytes lineages as THP-1 monocytes, Jeko-1 B cells and Jurkat T cells. Interestingly, cell viability and viral particle detection are maintained in these cells, even after successive passages. PBMCs from healthy donors were susceptible but the infection was not productive, since neither antigenome nor infectious particle was found in the supernatant of infected PBMCs. In fact, only viral antigens and small quantities of OROV genome were detected at 24 hpi in lymphocytes, monocytes and CD11c+ cells. Finally, activation of the Interferon (IFN) response was essential to restrict OROV replication in human PBMCs. Increased expression of type I/III IFNs, ISGs and inflammatory cytokines was detected in the first 24 hpi and viral replication was re-established after blocking IFNAR or treating cells with glucocorticoid. Thus, in short, our results show OROV is able to infect and remain in low titers in human T cells, monocytes, DCs and B cells as a consequence of an effective IFN response after infection, indicating the possibility of leukocytes serving as a trojan horse in specific microenvironments during immunosuppression.