Potential contribution of Helicobacter pylori proteins in the pathogenesis of type 1 gastric neuroendocrine tumor and urticaria. In silico approach

Abstract

BackgroundHelicobacter pylorihas been linked to several diseases such as chronic urticaria, gastritis, and type 1 gastric neuroendocrine tumors (type 1 gNET). Although these diseases seem to have different mechanisms, their relationship withH.pylorisuggests a common inflammatory pathway.ObjectiveTo identify potential cross-reactive antigens betweenH.pyloriand humans involved in chronic urticaria and type 1 gNET.MethodsAlignment was carried out among human proteins associated with urticaria (9 proteins), type 1 gNET (32 proteins), andH.pyloriproteome. We performed pairwise alignment among the human andH.pyloriantigens with PSI-BLAST. Modeling based on homology was done with the Swiss model server and epitope prediction with the Ellipro server. Epitopes were located on a 3D model using PYMOL software.ResultsThe highest conserved sequence was found between the human HSP 60 antigen and theH.pylorichaperonin GroEL with an identity of 54% and a cover of 92%, followed by the alpha and gamma enolases and twoH.pyloriphosphopyruvate hydratase, both with an identity and cover of 48% and 96%, respectively. The H/K ATPase (Chain A) showed high identity with twoH.pyloriproteins (35.21% with both P-type ATPase), but with low cover (only 6%). We observed eight linear and three discontinuous epitopes for human HSP 60 and three lineal and one discontinuous epitope for both alpha-enolase and gamma enolase, high conserved withH.pylorisequences.ConclusionSome type 1 gNET antigens shared potential cross-reactive epitopes withH.pyloriproteins, suggesting that molecular mimicry could be a mechanism that explains the relationship between the infection and this disease. Studies evaluating the functional impact of this relationship are needed.