IL17A and infection: H. pylori VacA (from strain CCUG17874) was previously shown to interfere with the synthesis and presentation of nascent HLA class II molecules (Molinari et al., 1998), as well as the interaction between B7-H2 and CD28 on CD4+ T cell to trigger immune activation marked by early IL-17 production to control infection (Lina et al., 2014).