title: Sialoadhesin-deficient mice exhibit subtle changes in B- and T-cell populations and reduced immunoglobulin M levels.
abstract: Sialoadhesin (Sn, also called Siglec-1 or CD169) is a transmembrane receptor and the prototypic member of the Siglec family of sialic acid binding immunoglobulin-like lectins. It is expressed on specialized subsets of resident macrophages in hematopoietic and lymphoid tissues and on inflammatory macrophages. In order to investigate its function, we generated Sn-deficient mice and confirmed that these mice are true nulls by fluorescence-activated cell sorter analysis and immunohistochemistry. Mice deficient in Sn were viable and fertile and showed no developmental abnormalities. Analysis of cell populations revealed no differences in bone marrow, peritoneal cavity, and thymus, but there was a small increase in CD8 T cells and a decrease in B220-positive cells in spleens and lymph nodes of Sn-deficient mice. Furthermore, in spleen there was a slight decrease in follicular B cells with an increase in numbers of marginal zone B cells. B- and T-cell maturation as well as responses to stimulation with thioglycolate were only slightly affected by Sn deficiency. Immunoglobulin titers in Sn-deficient mice were significantly decreased for immunoglobulin M (IgM) but similar for IgG subclasses. These results suggest a role for sialoadhesin in regulating cells of the immune system rather than in influencing steady-state hematopoiesis.
authors.affiliation: The Wellcome Trust Biocentre, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Oetke
authors.forename: Mary C
authors.initials: MC
authors.lastname: Vinson
authors.forename: Claire
authors.initials: C
authors.lastname: Jones
authors.forename: Paul R
authors.initials: PR
authors.lastname: Crocker
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology; D004247:DNA / Q000235:genetics; D005260:Female; D015870:Gene Expression; D018390:Gene Targeting; D006410:Hematopoiesis / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008562:Membrane Glycoproteins / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010529:Peritoneal Cavity / Q000166:cytology; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000172:deficiency* / Q000235:genetics; D063267:Sialic Acid Binding Ig-like Lectin 1; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D013864:Thioglycolates / Q000633:toxicity
chemical_list: D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D063267:Sialic Acid Binding Ig-like Lectin 1; C571167:Siglec1 protein, mouse; D013864:Thioglycolates; D004247:DNA