HAX1 deficiency: impact on lymphopoiesis and B-cell development

Eur J Immunol. 2010 Nov;40(11):3161-72. doi: 10.1002/eji.200940221. Epub 2010 Sep 24.


HAX1 was originally described as HS1-associated protein with a suggested function in receptor-mediated apoptotic and proliferative responses of lymphoid cells. Recent publications refer to a complex and multifunctional role of this protein. To investigate the in vivo function of HAX1 (HS1-associated protein X1) in B cells, we generated a Hax1-deficient mouse strain. Targeted deletion of Hax1 resulted in premature death around the age of 12 wk accompanied by a severe reduction of lymphocytes in spleen, thymus and bone marrow. In the bone marrow, all B-cell populations were lost comparably. In the spleen, B220(+) cells were reduced by almost 70%. However, as investigated by adoptive transfer experiments, this impairment is not exclusively B-cell intrinsic and we hypothesize that a HAX1-deficient environment cannot sufficiently provide the essential factors for proper lymphocyte development, trafficking and survival. Hax1(-/-) B cells show a significantly reduced expression of CXCR4, which might have an influence on the observed defects in B-cell development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • Bone Marrow / immunology
  • Bone Marrow / metabolism
  • Cell Movement / genetics
  • Cell Movement / immunology*
  • Cell Survival / genetics
  • Cell Survival / immunology
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / immunology
  • Intracellular Signaling Peptides and Proteins
  • Leukocyte Common Antigens / genetics
  • Leukocyte Common Antigens / immunology
  • Leukocyte Common Antigens / metabolism
  • Lymphopoiesis / genetics
  • Lymphopoiesis / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Proteins / genetics
  • Proteins / immunology*
  • Proteins / metabolism
  • Receptors, CXCR4 / biosynthesis
  • Receptors, CXCR4 / genetics
  • Receptors, CXCR4 / immunology
  • Spleen / immunology
  • Spleen / metabolism
  • Thymus Gland / immunology
  • Thymus Gland / metabolism


  • CXCR4 protein, mouse
  • Hs1bp1 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Proteins
  • Receptors, CXCR4
  • Leukocyte Common Antigens