CD4 and gastritis: In support of this, we previously showed that patients infected with cagPAI+ H pylori strains had higher levels of IL10 mRNA and increased infiltration of CD4+CD25hi cells in their gastric mucosa.9 These data may appear to be in conflict with the evidence that PUD is more common among individuals infected with cagPAI+ strains.1 Kido et al37 have suggested that the cagT4SS has a dual role in H pylori infection, acting to both promote and suppress gastritis.