title: Delivery of a Chlamydial Adhesin N-PmpC Subunit Vaccine to the Ocular Mucosa Using Particulate Carriers.
abstract: Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), remains the world's leading preventable infectious cause of blindness. Recent attempts to develop effective vaccines rely on modified chlamydial antigen delivery platforms. As the mechanisms engaged in the pathology of the disease are not fully understood, designing a subunit vaccine specific to chlamydial antigens could improve safety for human use. We propose the delivery of chlamydia-specific antigens to the ocular mucosa using particulate carriers, bacterial ghosts (BGs). We therefore characterized humoral and cellular immune responses after conjunctival and subcutaneous immunization with a N-terminal portion (amino acid 1-893) of the chlamydial polymorphic membrane protein C (PmpC) of Ct serovar B, expressed in probiotic Escherichia coli Nissle 1917 bacterial ghosts (EcN BGs) in BALB/c mice. Three immunizations were performed at two-week intervals, and the immune responses were evaluated two weeks after the final immunization in mice. In a guinea pig model of ocular infection animals were immunized in the same manner as the mice, and protection against challenge was assessed two weeks after the last immunization. N-PmpC was successfully expressed within BGs and delivery to the ocular mucosa was well tolerated without signs of inflammation. N-PmpC-specific mucosal IgA levels in tears yielded significantly increased levels in the group immunized via the conjunctiva compared with the subcutaneously immunized mice. Immunization with N-PmpC EcN BGs via both immunization routes prompted the establishment of an N-PmpC-specific IFNγ immune response. Immunization via the conjunctiva resulted in a decrease in intensity of the transitional inflammatory reaction in conjunctiva of challenged guinea pigs compared with subcutaneously and non-immunized animals. The delivery of the chlamydial subunit vaccine to the ocular mucosa using a particulate carrier, such as BGs, induced both humoral and cellular immune responses. Further investigations are needed to improve the immunization scheme and dosage.
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Inic-Kanada
authors.affiliation: Department of Research and Development, Institute of Virology, Vaccines and Sera-TORLAK, Belgrade, Serbia.
authors.forename: Marijana
authors.initials: M
authors.lastname: Stojanovic
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Simone
authors.initials: S
authors.lastname: Schlacher
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Stein
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Sandra
authors.initials: S
authors.lastname: Belij-Rammerstorfer
authors.affiliation: Department of Research and Development, Institute of Virology, Vaccines and Sera-TORLAK, Belgrade, Serbia.
authors.forename: Emilija
authors.initials: E
authors.lastname: Marinkovic
authors.affiliation: Department of Research and Development, Institute of Virology, Vaccines and Sera-TORLAK, Belgrade, Serbia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Lukic
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Montanaro
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Nadine
authors.initials: N
authors.lastname: Schuerer
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Nora
authors.initials: N
authors.lastname: Bintner
authors.affiliation: Department of Research and Development, Institute of Virology, Vaccines and Sera-TORLAK, Belgrade, Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Kovacevic-Jovanovic
authors.affiliation: Department of Research and Development, Institute of Virology, Vaccines and Sera-TORLAK, Belgrade, Serbia.
authors.forename: Ognjen
authors.initials: O
authors.lastname: Krnjaja
authors.affiliation: BIRD-C GmbH&CoKG, Vienna, Austria.
authors.forename: Ulrike Beate
authors.initials: UB
authors.lastname: Mayr
authors.affiliation: BIRD-C GmbH&CoKG, Vienna, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Lubitz
authors.affiliation: OCUVAC-Center of Ocular Inflammation and Infection, Laura Bassi Centers of Expertise, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Talin
authors.initials: T
authors.lastname: Barisani-Asenbauer
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology*; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D002692:Chlamydia trachomatis / Q000276:immunology*; D003228:Conjunctiva / Q000276:immunology; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry*; D000939:Epitopes; D004926:Escherichia coli / Q000378:metabolism; D005123:Eye / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D005260:Female; D006168:Guinea Pigs; D007114:Immunization; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000097:blood; D007279:Injections, Subcutaneous; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008807:Mice, Inbred BALB C; D009092:Mucous Membrane / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D052638:Particulate Matter / Q000737:chemistry*; D011994:Recombinant Proteins / Q000378:metabolism; D013154:Spleen / Q000473:pathology; D013666:Tears / Q000378:metabolism; D014141:Trachoma / Q000276:immunology / Q000382:microbiology / Q000473:pathology / Q000517:prevention & control; D022223:Vaccines, Subunit / Q000276:immunology*
chemical_list: D018829:Adhesins, Bacterial; D004337:Drug Carriers; D000939:Epitopes; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D052638:Particulate Matter; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D015847:Interleukin-4; D007371:Interferon-gamma