CD Markers
CD49d

Author: Nat Pernick, M.D. (see Authors page)

Revised: 7 December 2016, last major update December 2010

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: CD49

Related:   CD49aCD49bCD49c


General
  • Receptor for fibronectin, thrombospondin and VCAM1/CD106
  • Also called very late antigen (VLA) alpha 4 chain (VLA4), ITGA4
  • Relevant to tumor progression and metastasis
  • Increased expression during relapse in multiple sclerosis (J Neuroimmunol 2005;166:189); treatment with alpha4 integrin antagonist natalizumab led to fewer inflammatory brain lesions and fewer relapses in patients with relapsing MS (N Engl J Med 2003;348:15), although it is also associated with PML (Neurol Res 2006;28:299)
  • References: OMIM #192975
Pathophysiology
  • Combines with CD29 to form alpha4 beta1 integrin
  • Has role in cell-cell interactions, cell adhesion to the extracellular matrix
  • Integrins alpha4beta1 and alpha4beta7 are receptors for fibronectin
  • Integrin alpha4beta1 is also a receptor for VCAM1/CD106, MAdCAM1 and thrombospondin
  • Avidity (binding strength) of cells expressing alpha4beta1 integrin can be rapidly changed by chemokines and chemoattractants
  • Integrin anchorage to cytoskeleton enhances the mechanical stability of its adhesive bonds under strain and promotes its ability to mediate leukocyte adhesion under physiological shear stress conditions (J Cell Biol 2005;171:1073)
  • Promotes (a) lymphocyte migration into tissue by strengthening lymphocyte adhesion to endothelial cells, (b) rolling of T cells in vascular lumen on VCAM-1 of endothelium, (c) homing of T cell subsets to Peyer's patches, (d) differentiation of hematopoietic precursor cells by adhesion to bone marrow stromal cells
Uses by Pathologists
Positive Staining - Normal
  • Macrophages, T and B cells, eosinophils, basophils, NK cells, dendritic cells, Langerhans cells, myeloid cells, erythrocyte precursors and thymocytes
  • Also basal epidermal layer
Positive Staining - Disease
  • Found in suprabasal skin during wound healing and psoriasis
  • Melanoma, ALL and AML
Negative Staining
  • Erythrocytes, platelets and neutrophils