title: Polymeric glycoconjugates protect and activate macrophages to promote killing of Bacillus cereus spores during phagocytosis.
abstract: Diseases caused by Bacillus spores might be attenuated if macrophages were able to kill the spores on exposure. Glycoconjugate-bearing polymers, which have been shown to bind to Bacillus spores, were tested for modulation of phagocytosis of B. cereus spores. Without glycoconjugate activation, murine macrophages were ineffective at killing Bacillus spores during phagocytosis. In the presence of glycoconjugates, however, the macrophages efficiently killed the organisms. The glycoconjugates were shown to have a protective influence, sparing macrophages from spore-induced cell death. Very low concentrations of the glycoconjugates prevented macrophage cell death, as shown by lactate dehydrogenase (LDH) release and trypan blue assays. Increased levels of inducible nitric oxide (NO) production by the macrophages in the presence of glycoconjugates suggested that the glycoconjugates provide an activation signal to the macrophages. These results suggest that glycoconjugates promote the killing of Bacillus spores by blocking spore-induced macrophage cell death, while increasing their activation level. Polymeric glycoconjugates may suggest novel approaches to improve existing vaccines as well as prevent and treat infections incurred through either B. cereus or B. anthracis spores.
authors.affiliation: Department of Biology, University of Arkansas at Little Rock, Little Rock, AR 72204, USA. omtarasenko@ualr.edu
authors.forename: Olga
authors.initials: O
authors.lastname: Tarasenko
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Burton
authors.forename: Lee
authors.initials: L
authors.lastname: Soderberg
authors.forename: Pierre
authors.initials: P
authors.lastname: Alusta
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000166:cytology* / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006001:Glycoconjugates / Q000737:chemistry / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000096:biosynthesis; D010587:Phagocytosis / Q000187:drug effects*; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000166:cytology* / Q000187:drug effects
chemical_list: D006001:Glycoconjugates; D011108:Polymers; D009569:Nitric Oxide