The antibacterial lectin RegIIIgamma promotes the spatial segregation of microbiota and host in the intestine.

The mammalian intestine is home to ~100 trillion bacteria that perform important metabolic functions for their hosts. The proximity of vast numbers of bacteria to host intestinal tissues raises the question of how symbiotic host-bacterial relationships are maintained without eliciting potentially harmful immune responses. Here, we show that RegIIIγ, a secreted antibacterial lectin, is essential for maintaining a ~50-micrometer zone that physically separates the microbiota from the small intestinal epithelial surface.

B cell development in GALT: role of bacterial superantigen-like molecules.

Intestinal bacteria drive the formation of lymphoid tissues, and in rabbit, bacteria also promote development of the preimmune Ab repertoire and positive selection of B cells in GALT. Previous studies indicated that Bacillus subtilis promotes B cell follicle formation in GALT, and we investigated the mechanism by which B. subtilis stimulates B cells.

Roles of the Bacillus anthracis spore protein ExsK in exosporium maturation and germination.

The Bacillus anthracis spore is the causative agent of the disease anthrax. The outermost structure of the B. anthracis spore, the exosporium, is a shell composed of approximately 20 proteins.

Identification of severe acute respiratory syndrome coronavirus replicase products and characterization of papain-like protease activity.

Gene 1 of the coronavirus associated with severe acute respiratory syndrome (SARS) encodes replicase polyproteins that are predicted to be processed into 16 nonstructural proteins (nsps 1 to 16) by two viral proteases, a papain-like protease (PLpro) and a 3C-like protease (3CLpro). Here, we identify SARS coronavirus amino-terminal replicase products nsp1, nsp2, and nsp3 and describe trans-cleavage assays that characterize the protease activity required to generate these products. We generated polyclonal antisera to glutathione S-transferase-replicase fusion proteins and used the antisera to detect replicase intermediates and products in pulse-chase experiments.