title: Impaired CD19 expression and signaling, enhanced antibody response to type II T independent antigen and reduction of B-1 cells in CD81-deficient mice.
abstract: The tetraspanin CD81 is ubiquitously expressed and associated with CD19 on B lymphocytes and with CD4 and CD8 on T lymphocytes. Analysis of mice with disrupted CD81 gene reveals normal T cells but a distinct abnormality in B cells consisting of decreased expression of CD19 and severe reduction in peritoneal B-1 cells. CD81-deficient B cells responded normally to surface IgM crosslinking, but had severely impaired calcium influx following CD19 engagement. CD81-deficient mice had increased serum IgM and IgA and an exaggerated antibody response to the type II T independent antigen TNP-Ficoll. These results suggest that CD81 is important for CD19 signaling and B cell function.
authors.affiliation: Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: E N
authors.initials: EN
authors.lastname: Tsitsikov
authors.forename: J C
authors.initials: JC
authors.lastname: Gutierrez-Ramos
authors.forename: R S
authors.initials: RS
authors.lastname: Geha
mesh_terms: D000818:Animals; D000917:Antibody Formation; D015703:Antigens, CD / Q000235:genetics*; D018941:Antigens, CD19 / Q000235:genetics / Q000378:metabolism*; D000955:Antigens, T-Independent / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D007070:Immunoglobulin A / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008212:Lymphocyte Depletion; D008565:Membrane Proteins; D051379:Mice; D015398:Signal Transduction; D060225:Tetraspanin 28
chemical_list: D015703:Antigens, CD; D018941:Antigens, CD19; D000955:Antigens, T-Independent; C554799:Cd81 protein, mouse; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D008565:Membrane Proteins; D060225:Tetraspanin 28