title: Identification of Liver Epithelial Cell-derived Ig Expression in μ chain-deficient mice.
abstract: Growing evidence indicates that B cells are not the only source of immunoglobulin (Ig). To investigate this discovery further, we used μMT mice, which have a disruption of the first transmembrane exon of the μ heavy chain and do not express the membrane form of IgM. These mice lack mature B cells and thus serve as a good model to explore Ig expression by liver epithelial cells. We found that Ig heavy chains (μ, δ, γ and α) and light chains (κ and λ) were expressed in sorted liver epithelial cells of μMT mice. Surprisingly, each heavy chain class showed its respective variable region sequence characteristics in their variable region, instead of sharing the same VDJ usage, which suggests that class switching does not occur in liver epithelial cells. Moreover, the γ and α chains, but not the μ and δ chains, showed mutations in the variable region, thus indicating that different classes of Ig have different activities. Our findings support the concept that non-B cells, liver epithelial cells here, can produce different classes of Ig.
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
authors.forename: Wenwei
authors.initials: W
authors.lastname: Shao
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Medical Immunology, Ministry of Health, Beijing, 100191, China.
authors.forename: Enyang
authors.initials: E
authors.lastname: Liu
authors.affiliation: Key Laboratory of Medical Immunology, Ministry of Health, Beijing, 100191, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
authors.forename: Junfan
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Gong
authors.affiliation: Department of Immunology, Institute of Biophysics Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Qin
authors.affiliation: Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.|Key Laboratory of Medical Immunology, Ministry of Health, Beijing, 100191, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D004847:Epithelial Cells / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000235:genetics / Q000378:metabolism; D007143:Immunoglobulin Heavy Chains / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D007132:Immunoglobulin Isotypes / Q000097:blood / Q000235:genetics / Q000378:metabolism; D007147:Immunoglobulin Light Chains / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D007148:Immunoglobulin mu-Chains / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D017403:In Situ Hybridization; D008099:Liver / Q000166:cytology*; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007132:Immunoglobulin Isotypes; D007147:Immunoglobulin Light Chains; D007148:Immunoglobulin mu-Chains