The B10.Q͞J strain of mice was serendipitously discovered to be highly susceptible to infection by the intracellular protozoan parasite, Toxoplasma gondii but markedly resistant to induction of autoimmune arthritis. We have previously shown that the B10.
Pertactin (PRN) is an autotransporter protein produced by all members of the Bordetella bronchiseptica cluster, which includes B. pertussis, B. parapertussis, and B. bronchiseptica. It is a primary component of acellular pertussis vaccines, and anti-PRN antibody titers correlate with protection. In vitro studies have suggested that PRN functions as an adhesin and that an RGD motif located in the center of the passenger domain is important for this function. Two regions of PRN that contain sequence repeats (region 1 [R1] and R2) show polymorphisms among strains and have been implicated in vaccine-driven evolution. We investigated the role of PRN in pathogenesis using B. bronchiseptica and natural-host animal models. A ⌬prn mutant did not differ from wild-type B. bronchiseptica in its ability to adhere to epithelial and macrophage-like cells in vitro or to establish respiratory infection in rats but was cleared much faster than wild-type bacteria in a mouse lung inflammation model. Unlike wild-type B. bronchiseptica, the ⌬prn mutant was unable to cause a lethal infection in SCID-Bg mice, but, like wild-type bacteria, it was lethal for neutropenic mice. These results suggest that PRN plays a critical role in allowing Bordetella to resist neutrophil-mediated clearance. Mutants producing PRN proteins in which the RGD motif was replaced with RGE or in which R1 and R2 were deleted were indistinguishable from wild-type bacteria in all assays, suggesting that these sequences do not contribute to PRN function.Bordetella pertussis and Bordetella bronchiseptica cause respiratory infections in mammals. These two closely related bacterial subspecies display a high level of biochemical and genomic similarity and produce a similar set of virulence factors that are regulated at the transcriptional level by a highly conserved two-component signaling system called BvgAS (8,46,50,65). However, they differ in symptomatic manifestations and host ranges: B. pertussis infects only humans and causes the acute disease whooping cough, while B. bronchiseptica has been isolated from nearly all mammals and typically causes chronic asymptomatic infections (41, 52). Nevertheless, some crucial factors are functionally interchangeable, such as filamentous hemagglutinin (FHA) (30) and the BvgAS signaling system (40), suggesting that studying B. bronchiseptica can reveal insights into the function of B. pertussis factors and vice versa. B. bronchiseptica and its natural-host animal models are therefore valuable tools for exploring molecular mechanisms of Bordetella pathogenesis.Pertactin (PRN) is a putative Bordetella virulence factor belonging to the autotransporter (AT) family. It was discovered as a surface-localized immunogen of B. bronchiseptica in 1985 (49) and was found to have highly conserved homologs in B. pertussis and B. parapertussis shortly thereafter (5, 38). Many subsequent studies focused on the immunogenic and protective properties of PRN, leading to its inclusion in acellular pertussis vaccines (34, 48), and efficacy trials have...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.