The plasticity zone (PZ) of Helicobacter pylori is a genomic region harbouring genes that can be exchanged between strains, contributing to the genetic diversity of this bacterium. The presence or absence of genes reflects the adaptation and coevolution of a pathogen within its host. Among the genes present in PZ, jhp0940, jhp0945, jhp0947 and jhp0949 have gained attention due to their association with gastroduodenal disease, and the prevalence of the latter three among H. pylori isolates from different geographical regions has allowed this association to be understood. With respect to jhp0940, also known as ctkA (cellular translocation kinase A), various results have been obtained regarding its prevalence. However, the presence of jhp0940 in isolates from children seems to be higher than that in isolates from adults, and the product of this gene can induce TNF-α, IL-6 and IL-8 via translocation of NF-κB into macrophages. While little is known about the functions of jhp0945, jhp0947 and jhp0949, their presence in H. pylori strains induces IL-8 and IL-12 expression at higher levels than that in strains lacking these genes. In this chapter, we aim to show a general overview of the prevalence, association with gastroduodenal disease, and currently known function of the H. pylori genes jhp0940, jhp0945, jhp0947 and jhp0949, which are located in PZ.
Part of the book: Helicobacter Pylori