The Synthetic Peptide GA-Hecate and Its Analogs Inhibit Multiple Steps of the Chikungunya Virus Infection Cycle In Vitro.

Chikungunya virus (CHIKV) belongs to the Alphavirus genus and is responsible for significant outbreaks worldwide. Currently, there is no approved antiviral therapy against CHIKV. Bioactive peptides have great potential for new drug development. Here, we evaluated the antiviral activity of the synthetic peptide GA-Hecate and its analogs PSSct1905 and PSSct1910 against CHIKV infection. Initial screening showed that all three peptides inhibited the CHIKV replication cycle in baby hamster kidney fibroblast cells (BHK-21) and human hepatocarcinoma epithelial cells (Huh-7). GA-Hecate and its analog PSSct1905 were the most active, demonstrating suppression of viral infection by more than 91%. The analog PSSct1905 exhibited a protective effect in cells against CHIKV infection. We also observed that the analogs PSSct1905 and PSSct1910 affected CHIKV entry into both cell lines, inhibiting viral attachment and internalization. Finally, all tested compounds presented antiviral activity on the post-entry steps of CHIKV infection in all cells evaluated. In conclusion, this study highlights the potential of the peptide GA-Hecate and its analogs as novel anti-CHIKV compounds targeting different stages of the viral replication cycle, warranting the development of GA-Hecate-based compounds with broad antiviral activity.

Synthesis of copaiba (Copaifera officinalis) oil nanoemulsion and the potential against Zika virus: An in vitro study.

Zika virus (ZIKV) has spread all over the world since its major outbreak in 2015. This infection has been recognized as a major global health issue due to the neurological complications related to ZIKV infection, such as Guillain-Barré Syndrome and Zika virus Congenital Syndrome. Currently, there are no vaccines or specific treatments for ZIKV infection, which makes the development of specific therapies for its treatment very important. Several studies have been developed to analyze the potential of compounds against ZIKV, with the aim of finding new promising treatments. Herein, we evaluate the ability of a copaiba (Copaifera officinalis) oil nanoemulsion (CNE) to inhibit ZIKV. First, the highest non-cytotoxic concentration of 180 µg/mL was chosen since this concentration maintains 80% cell viability up to 96h after treatment with CNE in VERO cells resulted from MTT assay. The intracellular uptake assay was performed, and confirmed the internalization of the nanoemulsion in cells at all times analyzed. VERO cells were infected with ZIKV and simultaneously treated with CNE and the nanoformulation without oil (ENE) at the highest non-toxic concentration. The results evaluated by plaque assay revealed a viral inhibition of 80% for CNE and 70% for ENE. A dose-dependence assay revealed that the CNE treatment demonstrated a dose-dependent response in the viral RNA levels, whereas all ENE tested concentrations exhibited a similar degree of reduction. Taken together, our results suggest CNE as a promising nano-sized platform to be further studied for antiviral treatments.

The Dimeric Peptide (KKYRYHLKPF)2K Shows Broad-Spectrum Antiviral Activity by Inhibiting Different Steps of Chikungunya and Zika Virus Infection.

Chikungunya virus (CHIKV) and Zika virus (ZIKV) are important disease-causing agents worldwide. Currently, there are no antiviral drugs or vaccines approved to treat these viruses. However, peptides have shown great potential for new drug development. A recent study described (p-BthTX-I)2K [(KKYRYHLKPF)2K], a peptide derived from the Bothropstoxin-I toxin in the venom of the Bothrops jararacussu snake, showed antiviral activity against SARS-CoV-2. In this study, we assessed the activity of this peptide against CHIKV and ZIKV and its antiviral action in the different stages of the viral replication cycle in vitro. We observed that (p-BthTX-I)2K impaired CHIKV infection by interfering with the early steps of the viral replication cycle, reducing CHIKV entry into BHK-21 cells specifically by reducing both the attachment and internalization steps. (p-BthTX-I)2K also inhibited the ZIKV replicative cycle in Vero cells. The peptide protected the cells against ZIKV infection and decreased the levels of the viral RNA and the NS3 protein of this virus at viral post-entry steps. In conclusion, this study highlights the potential of the (p-BthTX-I)2K peptide to be a novel broad-spectrum antiviral candidate that targets different steps of the replication cycle of both CHIKV and ZIKV.

Condyloma acuminata: An evaluation of the immune response at cellular and molecular levels.

Condyloma acuminata (CA) is a benign proliferative disease mainly affecting in non-keratinized epithelia. Most cases of CA are caused by low-risk human papillomavirus (HPV), mainly HPV 6 and 11. The aim of the current study was to highlight the candidate genes and pathways associated with immune alterations in individuals who did not spontaneously eliminate the virus and, thus, develop genital warts. Paraffin-embedded condyloma samples (n = 56) were analyzed by immunohistochemistry using antibodies against CD1a, FOXP3, CD3, CD4, CD8, and IFN-γ. The immunomarkers were chosen based on the evaluation of the innate and adaptive immune pathways using qPCR analysis of 92 immune-related genes, applying a TaqMan Array Immune Response assay in HPV 6 or HPV 11 positive samples (n = 27). Gene expression analysis revealed 31 differentially expressed genes in CA lesions. Gene expression validation revealed upregulation of GZMB, IFNG, IL12B, and IL8 and downregulation of NFATC4 and IL7 in CA samples. Immunohistochemical analysis showed increased FOXP3, IFN-γ, CD1a, and CD4 expression in CA than in the control tissue samples. In contrast, CD3 and CD8 expression was decreased in CA lesion samples. Increased levels of pro-inflammatory cytokines in HPV-positive patients compared with HPV-negative patients seem to reflect the elevated immunogenicity of HPV-positive CA lesions. Host defense against HPV begins during the early stages of the innate immune response and is followed by activation of T lymphocytes, which are mainly represented by CD4+ and regulatory T cells. The low CD8+ T cell count in CA may contribute to this recurrent behavior. Additional studies are needed to elucidate the mechanism of host defense against HPV infection in CA.

Early infection of Zika virus in the male reproductive system of AG129 mice: molecular and immunohistochemical evaluation.

Sexual transmission of Zika virus (ZIKV), an important arbovirus, and the virus persistence in semen raise several questions about how and where it circulates in the male reproductive system (MRS). Several studies reported detection of the virus in testes, epididymis, and prostate at 5 days post-infection (dpi) or more in animal models. In the present study, we investigated the interactions of ZIKV with mouse MRS using the AG129 strain, a ZIKV permissive immunodeficient mouse strain, at two dpi. Viral RNA was detected in blood, testes, epididymis, and prostatic complexes (prostate and seminal vesicles). Immunohistochemical (IHC) analyses, based on the envelope protein, showed an early infection in organs of MRS since ZIKV positive antigens were detected in cells within or surrounding blood vessels, Sertoli, and germ cells in testes and epithelial cells in epididymis and prostate. Positive antigens for NS5 protein, the virus RNA-dependent RNA polymerase, were also detected by IHC in these organs and circulating leukocytes, suggesting that the virus replicates in these sites as early as 2 days post-infection. Analysis of the early stages of ZIKV infection in MRS may improve the current knowledge about this issue and contribute to the development of therapies directed to the infection at this site.

Telocytes contribute to aging-related modifications in the prostate.

Telocytes are interstitial cells present in the stroma of several organs, including the prostate. There is evidence that these cells are present during prostate alveologenesis, in which these cells play a relevant role, but there is no information about the presence of and possible changes in telocytes during prostate aging. Throughout aging, the prostate undergoes several spontaneous changes in the stroma that are pro-pathogenic. Our study used histochemistry, 3D reconstructions, ultrastructure and immunofluorescence to compare the adult prostate with the senile prostate of the Mongolian gerbil, in order to investigate possible changes in telocytes with senescence and a possible role for these cells in the age-associated alterations. It was found that the layers of perialveolar smooth muscle become thinner as the prostatic alveoli become more dilated during aging, and that telocytes form a network that involves smooth muscle cells, which could possibly indicate a role for telocytes in maintaining the integrity of perialveolar smooth muscles. On the other hand, with senescence, VEGF+ telocytes are seen in stroma possibly contributing to angiogenesis, together with TNFR1+ telocytes, which are associated with a pro-inflammatory microenvironment in the prostate. Together, these data indicate that telocytes are important both in understanding the aging-related changes that are seen in the prostate and also in the search for new therapeutic targets for pathologies whose frequency increases with age.

Natural Products Isolated from Oriental Medicinal Herbs Inactivate Zika Virus.

Zika virus (ZIKV) has been associated with serious health conditions, and an intense search to discover different ways to prevent and treat ZIKV infection is underway. Berberine and emodin possess several pharmacological properties and have been shown to be particularly effective against the entry and replication of several viruses. We show that emodin and berberine trigger a virucidal effect on ZIKV. When the virus was exposed to 160 µM of berberine, a reduction of 77.6% in the infectivity was observed; when emodin was used (40 µM), this reduction was approximately 83.3%. Dynamic light scattering data showed that both compounds significantly reduce the hydrodynamic radius of virus particle in solution. We report here that berberine and emodin, two natural compounds, have strong virucidal effect in Zika virus.