title: Infectious dose and repeated infections are key factors influencing immune response characteristics in guinea pig ocular chlamydial infection.
abstract: The aim of this study was to determine whether infectious dose of Chlamydia caviae after repeated infections influences the immunological responses and subsequent clearance of pathogen at the ocular surface of guinea pigs. Animals were infected three times via the conjunctiva at six- and twelve-week intervals by applying either 1 × 10(4) or 1 × 10(6) inclusion-forming units (IFUs) of C. caviae. Ocular pathology, infection course, C. caviae-specific serum IgG levels and their capacity to bind and neutralize infection ex vivo were assessed. Animals infected with 1 × 10(4) IFUs had completely diminished ocular infection and pathology after the 2nd infection with increased levels of C. caviae-specific serum IgG and their effective capacity to bind and neutralize C. caviae. Only partial protection was observed in animals infected with 1 × 10(6) IFUs after the 2nd and 3rd infections. Our findings show that full protection was observed in animals repeatedly infected with the lower dose. The lower dose appeared not to compromise the host immune system, thereby enabling fast clearance of the pathogen and the establishment of competent neutralizing antibodies.
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: 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: 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: 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: 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: Nora
authors.initials: N
authors.lastname: Bintner
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: Schürer
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: Ehsan
authors.initials: E
authors.lastname: Ghasemian
authors.affiliation: Institute of Environmental Health, Center for Public Health, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Kundi
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. Electronic address: talin.barisani@meduniwien.ac.at.
authors.forename: Talin
authors.initials: T
authors.lastname: Barisani-Asenbauer
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D057134:Antibodies, Neutralizing / Q000097:blood; D002689:Chlamydia / Q000276:immunology* / Q000472:pathogenicity*; D002690:Chlamydia Infections / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology / Q000517:prevention & control; D004195:Disease Models, Animal; D015817:Eye Infections / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology / Q000517:prevention & control; D006168:Guinea Pigs; D007074:Immunoglobulin G / Q000097:blood
chemical_list: D000907:Antibodies, Bacterial; D057134:Antibodies, Neutralizing; D007074:Immunoglobulin G
keywords: Chlamydia caviae; Guinea pig ocular animal model; Infectious dose; Trachoma