Immunohistochemistry of H. felis-infected mice

Gastric tissue samples from WT and Myd88^−/− control and H. felis-infected mice were incubated with specific antibodies overnight (Supplementary Table 2) after antigen retrieval in a pressure cooker using 0.01 M sodium citrate. These antibodies have been previously validated by our group and others^{36 (link)–38 (link)}. After incubation with HRP-conjugated secondary antibodies, sections were developed using SignalStain DAB substrate (Cell Signaling) following manufacturer’s instructions. A secondary antibody only control was included to ensure that the secondary antibody did not unspecifically bind to certain cellular compartments. Samples were counterstained with hematoxylin (Morphisto). For automated image acquisition, Olympus Virtual Slide System VS120 (Olympus) was used. Stainings were visually quantified in a blinded manner. Five random high power field (HPF) areas per sample were scored blinded.