With the aim to identify HP epitopes responsible for host immune-response modulation and infection progression, we applied a discovery-driven approach, called Interactome-sequencing, that couples “phage display” and deep sequencing and is based on the screening of DNA phage libraries. specifically generated from the pathogen’s genome, with sera antibodies from patients with different outcomes HP-related.. Defining the Helicobacter pylori disease specific antigenic repertoire

The analysis of the interaction between H. pylori and the host in vivo is a necessary and extremely informative way to elucidate the molecular mechanisms involved in persistency/latency of the bacterium as well as in the progression of the infection. An important source of information is represented by circulating antibodies, whom repertoire defines a “disease signature” thus having an important diagnostic power. The diagnosis of HP induced Gastric Cancer (GC), MALT lymphoma (MALT) and Autoimmune Gastritis (AG) is not easy because patients do not show symptoms of illness in early onset stages, at the same time they progress rapidly. The possibility of doing an early diagnosis would be extremely beneficial since a late diagnosis results in a delay in active therapy undergoing and reduces the survival rate of patients. With the aim to identify HP epitopes responsible for host immune-response modulation and infection progression, we applied a discovery-driven approach, called Interactome-sequencing, that couples “phage display” and deep sequencing and is based on the screening of DNA phage libraries. specifically generated from the pathogen’s genome, with sera antibodies from patients with different outcomes HP-related. Two genomic phage display libraries from the WT 26695 and the pathogenic B128 HP strains have been constructed, filtered for ORF by using a ORF selection vector developed by our group (Di Niro et al., 2005; Soluri et al., 2018) and screened with antibodies from patients affected by GC, MALT, and AG as well as from HP+ healthy subjects, and putative HP antigens/epitopes were selected. The results obtained show that selection significantly reduced the library diversity. Furthermore comparison of individual ranks for each condition allowed us to highlight the pattern of putative antigens specific for the different pathological outcomes or common for all of them. Finally, one of the HP CagY protein domains, resulting among those mostly enriched after selection, has been validated through an antibody-capture ELISA assay on a wide number of sera. We thus demonstrated that this specific HP CagY domain can be considered a good marker of HP infection progression. Overall, we have defined HP Interactome and produced a panel of putative specific antigens/epitopes for three different HP infection pathological outcomes that could be validated in the next future.