title: Comparison of macrophage scavenger receptor-A knockout mice with wild type ones in the immune response against repeated infestation with Haemaphysalis longicornis.
abstract: Using macrophage scavenger receptor-A knockout (SRKO) mice, we examined the role of macrophage class A scavenger receptors (MRS-A) on the immune response and acquisition of host resistance against repeated infestation with Haemaphysalis longicornis. Except for one batch of nymphs that infested one of the SRKO (SR-/-) mice and showed no appreciable reduction in body weight, all the other groups of nymphs manifested significant decrease in body weight. Both SR-/- and wild type (SR+/+) mice showed a sustained increase in anti-tick antibody titers, but SR+/+ mice showed significantly higher titers. The IFN-gamma assayed in SR-/- mouse immune sera was substantially less compared with that in SR+/+ mice. Immune sera from SR-/- and SR+/+ mice recognized the 51 and 44 kDa, and 44 kDa proteins, respectively, of the salivary gland antigen. The difference in the level of anti-tick resistance manifested by both groups of mice may be influenced by less efficient trapping and processing of tick antigens by macrophages in mice lacking for the macrophage scavenger receptors, and consequently affected the cascade of Th1 and Th2 responses. We have thus obtained valuable data that strongly infer the role of MSR-A in enhancing host defense against repeated infestation with H. longicornis.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kabamoto
authors.forename: Negi A
authors.initials: NA
authors.lastname: Bhagat
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Myungjo
authors.initials: M
authors.lastname: You
authors.forename: Tsugihiko
authors.initials: T
authors.lastname: Kamio
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Tsuji
authors.forename: Florencia G
authors.initials: FG
authors.lastname: Claveria
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nagasawa
authors.forename: Ikuo
authors.initials: I
authors.lastname: Igarashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Toyoda
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007371:Interferon-gamma / Q000097:blood; D051379:Mice; D018345:Mice, Knockout; D011971:Receptors, Immunologic / Q000276:immunology*; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D013984:Tick Infestations / Q000276:immunology*; D013987:Ticks / Q000254:growth & development*
chemical_list: C495140:Msr1 protein, mouse; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D007371:Interferon-gamma