RETRACTED ARTICLE: Immunoinformatic mapping of conserved regions of the human adenovirus hexon protein

Abstract

Human Adenoviruses (HAdVs) are important infectious agents associated with high incidence and morbidity and mortality in immunocompromised patients, such as those undergoing allogeneic hematopoietic progenitor cell transplantation (allo-TCPH). HAdVs belong to the family Adenoviridae, genus Mastadenovirus, and are further classified into seven species (A–G) and 103 genotypes, characterized so far. The HAdV capsid consists mainly of the hexon protein, which has four highly conserved regions (CR1—4) and known for their immunogenic potential, being one of the main targets of the T and B cell-mediated anti-HAdV immune response of the present study was to perform the mapping of potentially immunogenic epitopes, located in the HAdV hexon CRs and to evaluate the HAdV infection in patients undergoing allo-TCPH. To this end, predictions of T and B cell epitopes and IFN-γ induction were performed, considering 101 HAdV genotypes with sequences available in databases. The most conserved and best-classified epitopes were then selected by the prediction programs to perform the molecular docking analysis with HLA alleles of the study population, consisting of nine adult patients undergoing allo-TCPH. It was also carried out the HAdV research by TaqMan real-time polymerase chain reaction (qPCR) in the patient's serum samples. As a result, regions containing overlapping T and B cell epitopes were obtained and, based on immunoinformatics analysis (prediction and molecular docking), two peptides with high conservation and immunogenic potential were designed. Nine patients were positive for HAdV by qPCR TaqMan, with the average viral load found in the serum samples of the study population being 6.71 × 1011 CG / mL. The genomic sequencing of the positive samples returned sequences that showed 100% similarity with sequences of the hexad protein of HAdV C, deposited in a database. The present study allowed the mapping of the main immunogenic regions located in the HAdV hexon CRs, as well as the construction of two peptides that will be used in future studies to assess the immune response of patients undergoing allo-TCPH, participants in the present study.