Lipid compartments and lipid metabolism as therapeutic targets against coronavirus.

Lipids perform a series of cellular functions, establishing cell and organelles' boundaries, organizing signaling platforms, and creating compartments where specific reactions occur. Moreover, lipids store energy and act as secondary messengers whose distribution is tightly regulated. Disruption of lipid metabolism is associated with many diseases, including those caused by viruses. In this scenario, lipids can favor virus replication and are not solely used as pathogens' energy source. In contrast, cells can counteract viruses using lipids as weapons. In this review, we discuss the available data on how coronaviruses profit from cellular lipid compartments and why targeting lipid metabolism may be a powerful strategy to fight these cellular parasites. We also provide a formidable collection of data on the pharmacological approaches targeting lipid metabolism to impair and treat coronavirus infection.

Microbiome analysis of Brazilian women cervix reveals specific bacterial abundance correlation to RIG-like receptor gene expression.

The relationship among microbiome, immunity and cervical cancer has been targeted by several studies, yet many questions remain unanswered. We characterized herein the virome and bacteriome from cervical samples and correlated these findings with innate immunity gene expression in a Brazilian convenience sample of HPV-infected (HPV+) and uninfected (HPV-) women. For this purpose, innate immune gene expression data were correlated to metagenomic information. Correlation analysis showed that interferon (IFN) is able to differentially modulate pattern recognition receptors (PRRs) expression based on HPV status. Virome analysis indicated that HPV infection correlates to the presence of Anellovirus (AV) and seven complete HPV genomes were assembled. Bacteriome results unveiled that vaginal community state types (CST) distribution was independent of HPV or AV status, although bacterial phyla distribution differed between groups. Furthermore, TLR3 and IFNαR2 levels were higher in the Lactobacillus no iners-dominated mucosa and we detected correlations among RIG-like receptors (RLR) associated genes and abundance of specific anaerobic bacteria. Collectively, our data show an intriguing connection between HPV and AV infections that could foster cervical cancer development. Besides that, TLR3 and IFNαR2 seem to create a protective milieu in healthy cervical mucosa (L. no iners-dominated), and RLRs, known to recognize viral RNA, were correlated to anaerobic bacteria suggesting that they might be related to dysbiosis.

The Endolysosomal System: The Acid Test for SARS-CoV-2.

This review aims to describe and discuss the different functions of the endolysosomal system, from homeostasis to its vital role during viral infections. We will initially describe endolysosomal system's main functions, presenting recent data on how its compartments are essential for host defense to explore later how SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) and other coronaviruses subvert these organelles for their benefit. It is clear that to succeed, pathogens' evolution favored the establishment of ways to avoid, escape, or manipulate lysosomal function. The unavoidable coexistence with such an unfriendly milieu imposed on viruses the establishment of a vast array of strategies to make the most out of the invaded cell's machinery to produce new viruses and maneuvers to escape the host's defense system.

Differential Expression of Human MicroRNAs During Dengue Virus Infection in THP-1 Monocytes.

Dengue virus (DENV) is the most widespread arbovirus, responsible for a wide range of clinical manifestations, varying from self-limited illness to severe hemorrhagic fever. Dengue severity is associated with host intense proinflammatory response and monocytes have been considered one of the key cell types involved in the early steps of DENV infection and immunopathogenesis. To better understand cellular mechanisms involved in monocyte infection by DENV, we analyzed the expression levels of 754 human microRNAs in DENV-infected THP-1 cells, a human monocytic cell line. Eleven human microRNAs showed differential expression after DENV infection and gene ontology and enrichment analysis revealed biological processes potentially affected by these molecules. Five downregulated microRNAs were significantly linked to cellular response to stress, four to cell death/apoptosis, two to innate immune responses and one upregulated to vesicle mediated, TGF-ß signaling, phosphatidylinositol mediated signaling, lipid metabolism process and blood coagulation.

HPV Induces Changes in Innate Immune and Adhesion Molecule Markers in Cervical Mucosa With Potential Impact on HIV Infection.

While most HPV infections are asymptomatic and clear spontaneously, persistent infection with high-risk HPVs is associated with cervical cancer and with increased risk of HIV acquisition. Although several hypotheses have been proposed to explain this phenomenon, none has been confirmed. Our aim was to investigate the expression of host factors involved in the susceptibility to HIV infection among HPV-infected women. Cervical samples were collected to characterize the expression levels of HIV susceptibility markers in the mucosa of HPV-infected compared with HPV-uninfected women. No differences in the frequency of CCR5+, integrin α4ß7+, activated and memory CD4+ T-cell were detected between the groups. We additionally evaluated the expression levels of genes involved in innate immune responses and in cell adhesion. HPV infected patients expressed higher levels of TLR9 and lower levels of pattern recognition receptors that recognize RNA (TLR3, TLR7, and MDA5/IFIH1). We also detected an impaired IFN pathway, with an increased Type I IFN and a decreased IFNα2 receptor expression. HPV+ samples displayed reduced expression of genes for adherens and tight junctions. Taken together, these results suggest that although HPV infection does not result in the recruitment/activation of susceptible CD4+ T-cell in the female genital tract, it leads to changes in the innate antiviral immune responses and in cell adhesion that are likely to favor HIV infection.

Detection of sexually transmitted infections at a Brazilian gynecology center: high prevalence of co-infections / Detecção de infecções sexualmente transmissíveis em uma unidade ginecológica brasileira: alta prevalência de coinfecções

ABSTRACT Introduction: Sexually transmitted infections (STI) remain a major public health problem and surveillance is crucial for prevention and control strategies. Objective: Our aim was to assess the prevalence of STI in a reference center for gynecology in Rio de Janeiro, Brazil. Materials and methods: It is a cross-sectional study conducted between August 2016 and June 2017. Whole blood and cervical cells were collected from 62 women and tested for human papillomavirus (HPV), human immunodeficiency virus (HIV), syphilis, chlamydia, gonorrhea and herpes simples virus 1 and 2 (HSV-1/2). Cervical lesions were diagnosed by cytopathology and in some patients by colposcopy (79%). Other STI were evaluated during clinical examination. Results: Cervical lesions were detected by cytopathology examinations in 46.8% of patients; those with a history of four sexual partners were at higher risk of developing them. There was moderate agreement between the cytopathology e colposcopy results (Kappa = 0.69). The prevalence of HSV (96.7%), syphilis (6.4%) and HIV (3.2%) were higher than that described in the literature, while the prevalence of chlamydia (6.4%) and gonorrhea (1.6%) were similar. HPV was detected in 53.2% of women, 32.3% of which were infected by HPV 16. In the context of co-infections, 38 women (61.3%) presented more than one STI. Conclusion: Since most of the women analyzed were affected by more than one STI, our results suggest that routine screening for these infections at health centers would help in early detection, treatment and prevention of these infections. These measures would also impact on patients' cervical cancer control.

RESUMO Introdução: As infecções sexualmente transmissíveis (ISTs) ainda são um importante problema de saúde pública, e a vigilância é essencial para sua prevenção e seu controle. Objetivo: Avaliar a prevalência das ISTs em uma unidade de referência ginecológica no Rio de Janeiro, Brasil. Materiais e métodos: Trata-se de um estudo transversal realizado entre agosto de 2016 e junho de 2017. Foram coletados sangue total e células cervicais de 62 mulheres e realizados testes para detecção de papiloma vírus humano (HPV), vírus da imunodeficiência humana (HIV), sífilis, clamídia, gonorreia e vírus do herpes simples 1 e 2 (HSV-1/2). As lesões cervicais foram diagnosticadas por citopatologia, e em algumas pacientes, por colposcopia (79%). Outras ISTs foram avaliadas durante o exame clínico. Resultados: Foram encontradas lesões cervicais pelo exame citopatológico em 46,8% das pacientes; aquelas com história de quatro parceiros sexuais tiveram mais risco de desenvolvê-las. Houve concordância moderada entre os resultados da citopatologia e colposcopia (Kappa = 0,69). A prevalência de HSV (96,7%), sífilis (6,4%) e HIV (3,2%) foi maior que a descrita na literatura, enquanto a prevalência de clamídia (6,4%) e gonorreia (1,6%) foi similar. O HPV foi detectado em 53,2% das mulheres, sendo 32,3% delas infectadas pelo HPV 16. No contexto das coinfecções, 38 mulheres (61,3%) tinham mais de uma IST. Conclusão: Visto que a maioria das mulheres analisadas era acometida por mais de uma IST, nossos resultados sugerem que uma triagem rotineira dessas infecções nas unidades de saúde poderia auxiliar na detecção precoce, bem como no tratamento e na prevenção. Essas medidas também impactariam no controle do câncer cervical das pacientes.

T-cell regulator RNF125/TRAC-1 belongs to a novel family of ubiquitin ligases with zinc fingers and a ubiquitin-binding domain.

The recently identified RNF125 [RING (really interesting new gene) finger protein 125], or TRAC-1 (T-cell RING protein in activation 1), is unique among ubiquitin ligases in being a positive regulator of T-cell activation. In addition, TRAC-1 has been shown to down-modulate HIV replication and to inhibit pathogen-induced cytokine production. However, apart from the presence of an N-terminal C3HC4 (Cys(3)-His-Cys(4)) RING domain, the TRAC-1 protein remains uncharacterized. In the present paper, we report novel interactions and modifications for TRAC-1, and elucidate its domain organization. Specifically, we determine that TRAC-1 associates with membranes and is excluded from the nucleus through myristoylation. Our data are further consistent with a crucial role for the C-terminus in TRAC-1 function. In this region, novel domains were recognized through the identification of three closely related proteins: RNF114, RNF138 and RNF166. TRAC-1 and its relatives were found to contain, apart from the RING domain, a C2HC (Cys(2)-His-Cys)- and two C2H2 (Cys(2)-His(2))-type zinc fingers, as well as a UIM (ubiquitin-interacting motif). The UIM of TRAC-1 binds Lys(48)-linked polyubiquitin chains and is, together with the RING domain, required for auto-ubiquitination. As a consequence of auto-ubiquitination, the half-life of TRAC-1 is shorter than 30 min. The identification of these novel modifications, interactions, domains and relatives significantly widens the contexts for investigating TRAC-1 activity and regulation.

Molecular aspects of Schistosoma mansoni female maturation

Incubation of total protein extracts of Schistosoma mansoni with 3H 17-beta-estradiol and 20-hydroxyecdysone, revealed steroid binding proteins in both, male and female worms. The interaction of nuclear proteins with restriction fragments of the gender and stage-specific gene F-10 was investigated using the "Band-Shift" technique. Distinct male and female nuclear proteins bound to the fragments of this gene. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the estrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females, a band profile similar to that obtained with male worm protein extracts. When Tamoxifen was injected into schistosome infected mice, the eggs produced by females presented an abnormal morphology, compatible with non-viable eggs. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.