Possible roles of sulfur-containing amino acids in a chemoautotrophic bacterium-mollusc symbiosis.

Invertebrate hosts of chemoautotrophic symbionts face the unique challenge of supplying their symbionts with hydrogen sulfide while avoiding its toxic effects. The sulfur-containing free amino acids taurine and thiotaurine may function in sulfide detoxification by serving as sulfur storage compounds or as transport compounds between symbiont and host. After sulfide exposure, both taurine and thiotaurine levels increased in the gill tissues of the symbiotic coastal bivalve Solemya velum.

Defective production of IL-18 and IL-12 by cord blood mononuclear cells influences the T helper-1 interferon gamma response to group B Streptococci.

Human neonates are uniquely susceptible to group B streptococcal (GBS) infections. We have shown that neonatal mixed mononuclear cells have a deficiency in the production of the T helper-1 (Th-1) cytokine, interferon gamma (IFN-gamma), and that incubation of neonatal neutrophils with recombinant IFN-gamma corrects these neutrophil defects. IL-12 and the more recently described IL-18 are also Th-1 type cytokines that are able to induce the production of IFN-gamma in the presence of bacteria and bacterial products.