title: Characterization and expression of MHC class II alpha and II beta genes in mangrove red snapper (Lutjanus argentimaculatus).
abstract: The major histocompatibility complex (MHC) class II plays a key role in adaptive immunity by presenting foreign peptides to CD4(+) T cells and by triggering the adaptive immune response. While the structure and function of MHC class II have been well characterized in mammalian, limited research has been done on fishes. In this study, we characterized the gene structure and expression of MHC class II α (Lunar-DAA) and II β (Lunar-DAB) of mangrove red snapper (Lutjanus argentimaculatus). Both genes shared, respectively, a high similarity and typical features with other vertebrate MHC class II α and II β. The phylogenetic analysis of the deduced peptides revealed that both Lunar-DAA and Lunar-DAB were located in the teleost subclass. Western blotting analyses indicated that both MHC class II α and II β were expressed ubiquitously in immune-related cells, tissues and organs, and that MHC class II α and II β chains existed mainly as heterodimers. While it was highly expressed in gills, thymus, head kidney (HK), spleen, head kidney macrophage and spleen leucocytes, MHC class II β chain was expressed with a low abundance in skin, intestine, stomach and heart. The highest expression of MHC class II β in thymus confirmed the conclusion that thymus is one of the primary lymphoid organs in fishes. The detection of MHC class II αβ dimers in HK macrophages and spleen leucocytes indicated that HK macrophages and spleen leucocytes play a critical role in the adaptive immunity in fishes. All these results provide valuable information for understanding the structure of MHC class II α and II β and their function in immune responses.
authors.affiliation: School of Life Science, Tsinghua University, Beijing 100084, PR China; Shenzhen Public Platform of Screening & Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China.
authors.forename: Tianyan
authors.initials: T
authors.lastname: Wang
authors.affiliation: School of Life Science, Tsinghua University, Beijing 100084, PR China; Shenzhen Public Platform of Screening & Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China.
authors.forename: Shangjin
authors.initials: S
authors.lastname: Tan
authors.affiliation: School of Life Science, Tsinghua University, Beijing 100084, PR China; Shenzhen Public Platform of Screening & Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China. Electronic address: caizh@sz.tsinghua.edu.cn.
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Cai
mesh_terms: D056704:Adaptive Immunity; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D015870:Gene Expression; D015723:Gene Library; D005880:Gills / Q000276:immunology / Q000378:metabolism; D006031:Glycosylation; D060226:Head Kidney / Q000276:immunology / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000145:classification / Q000235:genetics / Q000276:immunology*; D007962:Leukocytes / Q000166:cytology / Q000276:immunology; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D008969:Molecular Sequence Data; D010473:Perciformes / Q000145:classification / Q000235:genetics / Q000276:immunology*; D010802:Phylogeny; D020033:Protein Isoforms / Q000145:classification / Q000235:genetics / Q000276:immunology; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000145:classification / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology / Q000378:metabolism
chemical_list: D000949:Histocompatibility Antigens Class II; D020033:Protein Isoforms; D011994:Recombinant Proteins
keywords: Adaptive immunity; Characterization; Cloning; Expression; MHC class II; N-glycosylation