AP-1γ2 is an adaptor protein 1 variant required for endosome-to-Golgi trafficking of the mannose-6-P receptor (CI-MPR) and ATP7B copper transporter.

Selective retrograde transport from endosomes back to the trans-Golgi network (TGN) is important for maintaining protein homeostasis, recycling receptors, and returning molecules that were transported to the wrong compartments. Two important transmembrane proteins directed to this pathway are the Cation-Independent Mannose-6-phosphate receptor (CI-MPR) and the ATP7B copper transporter. Among CI-MPR functions is the delivery of acid hydrolases to lysosomes, while ATP7B facilitates the transport of cytosolic copper ions into organelles or the extracellular space. Precise subcellular localization of CI-MPR and ATP7B is essential for the proper functioning of these proteins. This study shows that both CI-MPR and ATP7B interact with a variant of the clathrin adaptor 1 (AP-1) complex that contains a specific isoform of the γ-adaptin subunit called γ2. Through synchronized anterograde trafficking and cell-surface uptake assays, we demonstrated that AP-1γ2 is dispensable for ATP7B and CI-MPR exit from the TGN while being critically required for ATP7B and CI-MPR retrieval from endosomes to the TGN. Moreover, AP-1γ2 depletion leads to the retention of endocytosed CI-MPR in endosomes enriched in retromer complex subunits. These data underscore the importance of AP-1γ2 as a key component in the sorting and trafficking machinery of CI-MPR and ATP7B, highlighting its essential role in the transport of proteins from endosomes.

Prediction of MAYV peptide antigens for immunodiagnostic tests by immunoinformatics and molecular dynamics simulations.

The Mayaro virus is endemic to South America, and the possible involvement of Aedes spp. mosquitoes in its transmission is a risk factor for outbreaks of greater proportions. The virus causes a potentially disabling illness known as Mayaro fever, which is similar to that caused by the chikungunya virus. The cocirculation of both viruses, with their clinical and structural similarities, and the absence of prophylactic and therapeutic measures highlight the need for studies that seek to understand the Mayaro virus. Using approaches in silico, we identified an antigenic and specific epitope (p_MAYV4) in domain A of the E2 glycoprotein of the Mayaro virus. This epitope was theoretically predicted to be stable and exposed on the surface of the protein, where it showed key properties that enable its interaction with neutralizing antibodies. These characteristics make it an interesting target for the development of immunodiagnostic platforms. Molecular dynamics simulation-based structural analysis showed that the PHE95 residue in the E1 fusion loop region is conserved among Alphavirus family members. PHE95 interacts with the hydrophobic residues of the E2 glycoprotein to form a cage-shaped structure that is critical to assemble and stabilize the E1/E2 heterodimer. These results provide important insights useful for the advancement of diagnostic platforms and the study of therapeutic alternatives.

Molecular and serological surveys of canine distemper virus: A meta-analysis of cross-sectional studies.

BACKGROUND: Canine morbillivirus (canine distemper virus, CDV) persists as a serious threat to the health of domestic dogs and wildlife. Although studies have been conducted on the frequency and risk factors associated with CDV infection, there are no comprehensive data on the current epidemiological magnitude in the domestic dog population at regional and national levels. Therefore, we conducted a cross-sectional study and included our results in a meta-analysis to summarize and combine available data on the frequency and potential risk factors associated with CDV infection. METHODS: For the cross-sectional study, biological samples from dogs suspected to have canine distemper (CD) were collected and screened for viral RNA. Briefly, the PRISMA protocol was used for the meta-analysis, and data analyses were performed using STATA IC 13.1 software. RESULTS: CDV RNA was detected in 34% (48/141) of dogs suspected to have CD. Following our meta-analysis, 53 studies were selected for a total of 11,527 dogs. Overall, the pooled frequency of CDV positivity based on molecular and serological results were 33% (95% CI: 23-43) and 46% (95% CI: 36-57), respectively. The pooled subgroup analyses of clinical signs, types of biological samples, diagnostic methods and dog lifestyle had a wide range of CDV positivity (range 8-75%). Free-ranging dogs (OR: 1.44, 95% CI: 1.05-1.97), dogs >24 months old (OR: 1.83, 95% CI: 1.1-3) and unvaccinated dogs (OR: 2.92, 95% CI: 1.26-6.77) were found to be positively associated with CDV infection. In contrast, dogs <12 months old (OR: 0.36, 95% CI: 0.20-0.64) and dogs with a complete anti-CDV vaccination (OR: 0.18, 95% CI: 0.05-0.59) had a negative association. CONCLUSION: Considering the high frequency of CDV positivity associated with almost all the variables analyzed in dogs, it is necessary to immediately and continuously plan mitigation strategies to reduce the CDV prevalence, especially in determined endemic localities.

Molecular technique for detection and identification of Helicobacter pylori in clinical specimens: a comparison with the classical diagnostic method / Técnica molecular para detecção e identificação de Helicobacter pylori em espécimes clínicas: comparação com o método clássico de diagnóstico

ABSTRACT Introduction: Helicobacter pylori is a bacterium found in human epithelial cells of the gastrointestinal tract. Its infection is related to different diseases, such as chronic gastritis, peptic ulcers, gastric lymphoma and adenocarcinoma. The infection by H. pylori is present in more than a half of the world population. Objectives: To detect H. pylori and to compare the diagnostic methods of the rapid urease test (RUT) and polymerase chain reaction (PCR). Materials and methods: The study was conducted between April and July, 2015. For such, three biopsies were collected from each patient. Two were used for PCR and one for RUT. Results: A total of 85 samples were collected from patients undergoing endoscopy, with 56 (65.88%) females and 29 (34.11%) males. From the total samples subjected to RUT, 15 (17.64%) were positive and 70 (82.35%), negative. In PCR for detection of gene 16S ribosomal ribonucleic acid (rRNA) of H. pylori, 66 (77.64%) presented positive results and 19 (22.35%), negative results. For the analysis of the presence of UreA gene in all samples, positive results were found in 70 (82.35%), and negative in 15 (17.64%). According to the results, RUT and the molecular test presented statistical difference. Conclusion: PCR is a useful method in the laboratorial routine to detect the presence of H. pylori in the stomach tissue, due to high sensitivity and specificity, but it requires a more careful analysis and standardization.

RESUMO Introdução: Helicobacter pylori é uma bactéria encontrada nas células epiteliais do trato gastrointestinal humano. Sua infecção relaciona-se com diferentes patologias, como gastrite crônica, úlcera péptica, linfoma gástrico e adenocarcinoma. A infecção por Helicobacter pylori está presente em mais da metade da população mundial. Objetivos: Detectar a presença de H. pylori e comparar os métodos diagnósticos do teste rápido de urease (TRU) e reação em cadeia da polimerase (PCR). Materiais e métodos: No estudo, realizado entre abril e julho de 2015, três biópsias foram coletadas de cada paciente. Duas foram usadas para realizar PCR e uma, para TRU. Resultados: Oitenta e cinco amostras foram coletadas dos pacientes por meio de endoscopia, sendo 56 (65,88%) mulheres e 29 (34,11%) homens. Do total dos indivíduos sujeitos ao TRU, 15 (17,64%) foram positivos e 70 (82,35%), negativos. Na PCR, na detecção do gene 16S ácido ribonucleico ribossômico (rRNA) de H. pylori, 66 (77,64%) apresentaram resultados positivos e 19 (22,35%), negativos. Para a análise da presença do gene UreA em todas as amostras, resultados positivos foram encontrados em 70 (82,35%) e negativos em 15 (17,64%). De acordo com os resultados, o TRU e o teste molecular apresentaram diferenças estatísticas. Conclusão: A PCR é um método útil na rotina laboratorial para detectar H. pylori em tecido de estômago devido à sua alta sensibilidade e especificidade, mas é necessária maior atenção na análise e na padronização.