title: In vitro assessment of halobacterial gas vesicles as a Chlamydia vaccine display and delivery system.
abstract: Chlamydia trachomatis is the leading cause of bacterial sexually transmitted disease worldwide and while antibiotic treatment is effective in eliminating the pathogen, up to 70% of all infections are asymptomatic. Despite sustained efforts over the past 2 decades, an effective chlamydial vaccine remains elusive, due in large part to the lack of an effective delivery system. We explored the use of gas vesicles derived from Halobacterium salinarium as a potential display and delivery vehicle for chlamydial antigens of vaccine interest. Various size gene fragments coding for the major outer membrane protein (MOMP), outer membrane complex B (OmcB) and polymorphic outer membrane protein D (PompD) were integrated into and expressed as part of the gas vesicle protein C (gvpC) on the surface of these stable structures. The presence of the recombinant proteins was confirmed by Western blots probed using anti-gvpC and anti-Chlamydia antibodies as well as sera from Chlamydia-positive patients. Tissue culture evaluation revealed stability and a time-dependent degradation of recombinant gas vesicles (r-Gv) in human and animal cell lines. In vitro assessment using human foreskin fibroblasts (HFF) confirmed Toll-like receptor (TLR) 4 and 5 engagement by wild type and r-Gv, leading to MyD88 activation, TNF-α, IL-6 and IL-12 production. The data suggest that r-GV could be an effective, naturally adjuvanting, time-release antigen delivery system for immunologically relevant Chlamydia vaccine antigens which are readily recognized by human immune sera.
authors: Department of Microbiology, University of Massachusetts, Amherst, MA 01003, United States.
authors: Tawanna S
authors: TS
authors: Childs
authors: Wilmore C
authors: WC
authors: Webley
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D002692:Chlamydia trachomatis / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D022162:Cytoplasmic Vesicles / Q000235:genetics / Q000276:immunology*; D004269:DNA, Bacterial / Q000235:genetics; D006217:Halobacterium / Q000235:genetics / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000276:immunology; D011506:Proteins / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000276:immunology; D051198:Toll-Like Receptor 5 / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D007106:Immune Sera; D015850:Interleukin-6; D053594:Myeloid Differentiation Factor 88; C436968:OmcB protein, bacteria; D011506:Proteins; D011994:Recombinant Proteins; D051197:Toll-Like Receptor 4; D051198:Toll-Like Receptor 5; D014409:Tumor Necrosis Factor-alpha; C038524:gas vesicle protein; D018664:Interleukin-12