title: Biochemical and functional analysis of mice deficient in expression of the CD45-associated phosphoprotein LPAP.
abstract: The role of the CD45-associated phosphoprotein (LPAP / CD45-AP) during an immune response remains unclear. To understand better the function of LPAP we generated LPAP-deficient mice by disrupting exon 2 of the LPAP gene. LPAP-null mice were healthy and did not show gross abnormalities compared to their wild-type littermates. However, immunofluorescence analysis of T and B lymphocytes revealed a reduced expression of CD45, which did not affect a particular subpopulation. In contrast to a recent report (Matsuda et al., J. Exp. Med. 1998. 187: 1863 - 1870) we neither observed significant alterations of the assembly of the CD45 / lck-complex nor of polyclonal T-cell responses. However, lymphnodes from LPAP-null mice showed increased cellularity, which could indicate that expression of LPAP might be required to prevent expansion of lymphocytes in particular lymphatic organs rather than potentiating immune responses.
authors.affiliation: Immunomodulation Laboratory of the Institute for Immunology University of Heidelberg, Heidelberg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Ding
authors.forename: E
authors.initials: E
authors.lastname: Bruyns
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.forename: D
authors.initials: D
authors.lastname: Magada
authors.forename: M
authors.initials: M
authors.lastname: Paskind
authors.forename: L
authors.initials: L
authors.lastname: Rodman
authors.forename: T
authors.initials: T
authors.lastname: Seshadri
authors.forename: D
authors.initials: D
authors.lastname: Alexander
authors.forename: T
authors.initials: T
authors.lastname: Giese
authors.forename: B
authors.initials: B
authors.lastname: Schraven
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000276:immunology*; D047908:Intracellular Signaling Peptides and Proteins; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D010750:Phosphoproteins / Q000235:genetics* / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; C513303:Ptprcap protein, mouse; D017493:Leukocyte Common Antigens