title: Leucine-rich repeat containing 8A (LRRC8A)-dependent volume-regulated anion channel activity is dispensable for T-cell development and function.
abstract: BACKGROUND
  Leucine-rich repeat containing 8A (LRRC8A) is an ubiquitously expressed transmembrane protein with 17 leucine-rich repeats (LRRs) at its C-terminal end and is an essential component of the volume-regulated anion channel (VRAC), which controls cellular volume. A heterozygous mutation in LRRC8A that truncates the 2 terminal LRRs was reported in a patient with agammaglobulinemia and absent B cells and was demonstrated to exert a dominant negative effect on T- and B-cell development in mice. Lrrc8a-/-mice have severely defective T-cell development and function. It is not known whether the T- and B-cell defects caused by LRRC8A deficiency are caused by loss of VRAC activity.
  
  
  OBJECTIVE
  We sought to determine whether VRAC activity is required for normal T-cell development and function.
  
  
  METHODS
  VRAC activity was examined by using patch-clamp analysis. Flow cytometry was used to examine T-cell development. T-cell proliferation, cytokine secretion, and antibody titers were measured by using standard techniques.
  
  
  RESULTS
  We demonstrate that the spontaneous mouse mutant ébouriffé (ebo/ebo) harbors a homozygous 2-bp frameshift mutation in Lrrc8a that truncates the 15 terminal LRRs of LRRC8A. The Lrrc8aebomutation does not affect protein expression but drastically diminishes VRAC activity in T cells. ebo/ebo mice share features with Lrrc8a-/-mice that include curly hair, infertility, reduced longevity, and kidney abnormalities. However, in contrast to Lrrc8a-/-mice, ebo/ebo mice have normal T-cell development and function and intact antibody response to T-dependent antigen.
  
  
  CONCLUSIONS
  LRRC8A-dependent VRAC activity is dispensable for T-cell development and function.
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Platt
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Janet
authors.initials: J
authors.lastname: Chou
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Mass.
authors.forename: Patrick
authors.initials: P
authors.lastname: Houlihan
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Yousef R
authors.initials: YR
authors.lastname: Badran
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Lalit
authors.initials: L
authors.lastname: Kumar
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Wayne
authors.initials: W
authors.lastname: Bainter
authors.affiliation: Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
authors.forename: P Luigi
authors.initials: PL
authors.lastname: Poliani
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Perez
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex.
authors.forename: Sharon Y R
authors.initials: SYR
authors.lastname: Dent
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Mass; Howard Hughes Medical Institute, Chevy Chase, Md.
authors.forename: David E
authors.initials: DE
authors.lastname: Clapham
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex.
authors.forename: Fernando
authors.initials: F
authors.lastname: Benavides
authors.affiliation: Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass. Electronic address: raif.geha@childrens.harvard.edu.
authors.forename: Raif S
authors.initials: RS
authors.lastname: Geha
mesh_terms: D000361:Agammaglobulinemia / Q000235:genetics*; D000818:Animals; D027321:Anion Transport Proteins / Q000378:metabolism*; D000906:Antibodies / Q000097:blood; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D048429:Cell Size; D002478:Cells, Cultured; D006801:Humans; D017136:Ion Transport / Q000235:genetics; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D017384:Sequence Deletion / Q000235:genetics; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D027321:Anion Transport Proteins; D000906:Antibodies; C000589080:LRRC8A protein, mouse; D008565:Membrane Proteins
keywords: Leucine-rich repeat containing 8A; thymocyte development; volume-regulated anion channel