title: Scrub typhus vaccine candidate Kp r56 induces humoral and cellular immune responses in cynomolgus monkeys.
abstract: A truncated recombinant 56-kDa outer membrane protein of the Karp strain of Orientia tsutsugamushi (Kp r56) was evaluated in cynomolgus monkeys (Macaca fascicularis) for immunogenicity and safety as a vaccine candidate for the prevention of scrub typhus. This recombinant antigen induced strong humoral and cellular immune responses in two monkeys and was found to be well tolerated. Antigen-specific immunoglobulin M (IgM) and IgG were produced to almost maximal levels within 1 week of a single immunization. Peripheral blood mononuclear cells from vaccinated animals showed an induction of antigen-specific proliferation and gamma interferon production. The Kp r56 was not as efficient as infection with live organisms in preventing reinfection but was able to reduce the inflammation produced at the site of challenge. This report describes the results of the first systematic study of the immunogenicity of a recombinant scrub typhus vaccine candidate in a nonhuman primate model.
authors.affiliation: Rickettsial Diseases Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
authors.forename: Suchismita
authors.initials: S
authors.lastname: Chattopadhyay
authors.forename: Ju
authors.initials: J
authors.lastname: Jiang
authors.forename: Teik-Chye
authors.initials: TC
authors.lastname: Chan
authors.forename: T Scott
authors.initials: TS
authors.lastname: Manetz
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Chao
authors.forename: Wei-Mei
authors.initials: WM
authors.lastname: Ching
authors.forename: Allen L
authors.initials: AL
authors.lastname: Richards
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood; D000917:Antibody Formation / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology*; D049109:Cell Proliferation; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008252:Macaca fascicularis; D012285:Orientia tsutsugamushi / Q000276:immunology; D012612:Scrub Typhus / Q000276:immunology / Q000517:prevention & control*; D013997:Time Factors
chemical_list: D000906:Antibodies; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D007371:Interferon-gamma