RESUMO
In the present study, we sought to develop materials applicable to personal and collective protection equipment to mitigate SARS-CoV-2. For this purpose, AgNPs were synthesized and stabilized into electrospinning nanofiber matrices (NMs) consisting of poly(vinyl alcohol) (PVA), chitosan (CHT), and poly-ε-caprolactone (PCL). Uniaxial nanofibers of PVA and PVA/CHT were developed, as well as coaxial nanofibers of PCL[PVA/CHT], in which the PCL works as a shell and the blend as a core. A crucial aspect of the present study is the in situ synthesis of AgNPs using PVA as a reducing and stabilizing agent. This process presents few steps, no additional toxic reducing agents, and avoids the postloading of drugs or the posttreatment of NM use. In general, the in situ synthesized AgNPs had an average size of 11.6 nm, and the incorporated nanofibers had a diameter in the range of 300 nm, with high uniformity and low polydispersity. The NM's spectroscopic, thermal, and mechanical properties were appropriate for the intended application. Uniaxial (PVA/AgNPs and PVA/CHT/AgNPs) and coaxial (PCL[PVA/CHT/AgNPs]) NMs presented virucidal activity (log's reduction ≥ 5) against mouse hepatitis virus (MHV-3) genus Betacoronavirus strains. In addition to that, the NMs did not present cytotoxicity against fibroblast cells (L929 ATCC® CCL-1TM lineage).
RESUMO
Mice infected with mouse hepatitis virus A59 (MHV-A59) develop hepatitis and autoantibodies (autoAb) to liver and kidney fumarylacetoacetate hydrolase (FAH), a fact closely related to the release of alarmins such as uric acid and/or high-mobility group box protein 1 (HMGB1). We studied the effect of neutralizing monoclonal antibodies (MAb) against IL-17A in our model of mouse MHV-A59-infection. MAb anti-IL-17F and anti-IFNγ were used to complement the study. Results showed that transaminase levels markedly decreased in MHV-A59-infected mice treated with MAb anti-IL-17A whereas plasmatic Ig concentration sharply increased. Conversely, MAb anti-IL-17F enhanced transaminase liberation and did not affect Ig levels. Serum IFNγ was detected in mice infected with MHV-A59 and its concentration increased after MAb anti-IL-17A administration. Besides, MAb anti-IFNγ greatly augmented transaminase plasmatic levels. IL-17A neutralization did not affect MHV-A59-induction of HMGB1 liberation and slightly augmented plasmatic uric acid concentration. However, mice treated with the MAb failed to produce autoAb to FAH. The above results suggest a reciprocal regulation of Th1 and Th17 cells acting on the different MHV-A59 effects. In addition, it is proposed that IL-17A is involved in alarmins adjuvant effects leading to autoAb expression.
Assuntos
Interleucina-17/metabolismo , Vírus da Hepatite Murina/patogenicidade , Animais , Autoanticorpos/imunologia , Diferenciação Celular/fisiologia , Feminino , Hidrolases/metabolismo , Rim/metabolismo , Fígado/metabolismo , Camundongos , Vírus da Hepatite Murina/imunologia , Vírus da Hepatite Murina/metabolismoRESUMO
Mice infected with mouse hepatitis virus A59 (MHV-A59) develop autoantibodies (autoAb) to liver and kidney fumarylacetoacetate hydrolase (FAH) with a concomitant enhancement of transaminases and release of alarmins such as uric acid and high-mobility group box protein 1 (HMGB1). Tryptophan catabolism is an endogenous mechanism that restricts excessive immune responses, thereby preventing immunopathology. Since indoleamine-2,3-dioxygenase (IDO) is the key and rate-limiting enzyme of tryptophan catabolism, the aim of this work was to explore whether specific inhibition of IDO by Levo-1-methyl tryptophan (MT) could affect MHV actions. Results showed that MT strongly enhanced the hypergammaglobulinemia induced by the virus, as well as anti-MHV Ab and uric acid release. Moreover, infected mice treated with MT did express anti-FAH autoAb and high levels of serum HMGB1. Survival of MHV-infected animals treated with MT was severely reduced compared with that of MHV-infected mice or controls only treated with MT. Furthermore, histological liver examination indicated that MT induced fibrosis in MHV-infected animals, whereas MT itself increased uric acid levels without shortening the animal life Thus, under our experimental conditions, results indicated an exacerbated response to MHV infection when IDO was blocked by MT.
Assuntos
Infecções por Coronavirus , Hepatite Viral Animal , Hipergamaglobulinemia , Vírus da Hepatite Murina , Triptofano/análogos & derivados , Alanina Transaminase/sangue , Animais , Anticorpos Antivirais/sangue , Aspartato Aminotransferases/sangue , Autoanticorpos/imunologia , Linhagem Celular , Infecções por Coronavirus/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Feminino , Proteína HMGB1/sangue , Hepatite Viral Animal/sangue , Hepatite Viral Animal/imunologia , Hepatite Viral Animal/patologia , Hidrolases/imunologia , Hipergamaglobulinemia/sangue , Hipergamaglobulinemia/imunologia , Hipergamaglobulinemia/patologia , Imunoglobulinas/sangue , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Rim/imunologia , Fígado/imunologia , Fígado/patologia , Camundongos Endogâmicos BALB C , Vírus da Hepatite Murina/imunologia , Triptofano/farmacologia , Ácido Úrico/sangueRESUMO
A reverse transcriptase polymerase chain reaction (RT-PCR) to detect mouse hepatitis virus (MHV) in hepatic tissue was developed. To circumvent possible failures in RT-PCR amplifications, a second round of PCR with internal primers was used to confirm the specificity and increase the sensitivity of the test. Using this method specific amplification of MHV sequences was observed in 18 out of 20 mouse colonies examined.
Desenvolveu-se a técnica de transcrição reversa - reação em cadeia pela polimerase para detectar o vírus da hepatite do camundongo em tecido hepático. Para se eliminar possíveis falhas na reação de amplificação RT-PCR usou-se um segundo ciclo de amplificação com primers internos para confirmar a especificidade e aumentar a sensibilidade do teste. Após a optimização do protocolo, descreve-se a detecção da amplificação específica da seqüência-alvo em camundongos de 18 das 20 colônias examinadas.