Transcription profiling of rhesus macaque model infected with H. pylori induces an antimicrobial host response in rhesus macaques in a Cag pathogenicity island-dependent manner

ABSTRACT: We used the rhesus macaque model to study the effects of the cag pathogenicity island (cag PAI) on the H. pylori host-pathogen interaction. Specific pathogen free (SPF) monkeys with no prior exposure to H. pylori were experimentally challenged with wild type (WT) H. pylori strain J166 (N=4) or its cag PAI isogenic knockout (KO, N=4). Animals underwent endoscopy before and 1, 4, 8, and 13 wks after challenge. Gastric biopsies were collected for quantitative culture, histopathology, and host gene expression. Quantitative cultures showed that all experimentally challenged animals were infected with WT H. pylori or its isogenic cag PAI KO. Histopathology demonstrated that inflammation and expansion of the lamina propria were attenuated in animals infected with KO compared to WT. Microarray analysis was performed on challenged animals before and 1 and 13 wks after challenge, and on unchallenged control animals (N=4). Of the 119 up-regulated genes in the WT-infected animals, several encode innate antimicrobial; effector proteins, including elafin, siderocalin, DMBT, DUOX2, and several novel paralogues of human defensin-2. Quantitative RT-PCR analysis showed that high level induction of each of these genes was dependent upon the presence of the cag PAI. Immunohistochemistry confirmed increased defensin epithelial cell staining in animals challenged with WT H. pylori compared to either KO-challenged or uninfected control animals. We propose that one function of the cag PAI is to induce an antimicrobial host response that serves to increase the competitive advantage of H. pylori in the gastric niche. Experiment Overall Design: Twelve male and female rhesus macaques (Macaca mulatta) housed at the California National Primate Research Center (CNPRC) were hand raised by nursery staff to obtain Specific Pathogen (Helicobacter pylori) Free (SPF) experimental animals. At six months of age the animals were documented to be uninfected with H. pylori by serology, histology, and cultures of gastric biopsies using methods reported previously (Solnick et al., 1999). Two experimental groups of four SPF animals were challenged with either wild type (WT) H. pylori J166 or an isogenic PAI knockout (KO). A third group of four SPF animals served as uninoculated controls. Monkeys were housed indoors in separate cages throughout the duration of the experiment. All experiments were approved by the Research Advisory Committee of the CNPRC and the Institutional Animal Care and Use Committee at the University of California.Antrum and corpus stomach biopsies from rhesus macaques infected with wild type Helicobacter pylori J166, isogenic cag-PAI knockout strain, or mock infected were pooled. Biopsies were taken prior to bacterial inoculation and at 1 and 13 weeks post infection. Control biopsies were taken according to the same time line. Four animals were used for each experimental condition.

ORGANISM(S): Macaca mulatta

SUBMITTER: Michael Hornsby 

PROVIDER: E-GEOD-8749 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress