CD34 immunoreactivity and interstitial cells of Cajal in the human and mouse gastrointestinal tract

Cell Tissue Res. 2000 Nov;302(2):145-53. doi: 10.1007/s004410000264.


Immunoreactivity for the tyrosine kinase receptor Kit (Kit-ir) is an established marker for the interstitial cells of Cajal (ICC) of the gut. Recently, the presence of CD34 immunoreactivity (CD34-ir) has been reported in Kit-ir ICC around the myenteric plexus in human small intestine. Conversely, we observed that CD34-ir labeled Kit-negative fibroblast-like cells, closely adjacent to, but distinct from, the Kit-ir ICC. The existence of cells expressing both CD34-ir and Kit-ir remains controversial. CD34-ir and Kit-ir were studied by high-resolution confocal microscopy on cryostat sections of human and murine gut as well as murine whole-mounts, using specific antibodies raised to human and murine CD34, respectively. CD34-ir labeled numerous cells in all parts of the gut, in man and in mouse. CD34-ir was consistently observed in Kit-negative cells, distinct from the closely adjacent Kit-ir ICC. Thin processes of both cell types intermingled extensively, often at the limit of resolution for light microscopy. CD34-ir was also observed in Kit-negative mesenchymal cells in the submucosa, in capillaries and in mesothelial cells. CD34-ir is not a marker for Kit-ir ICC in the human and murine gut. No CD34-ir, Kit-ir-expressing cells were encountered. Conversely, CD34-ir cells, closely adjacent to, but distinct from, Kit-ir ICC were consistently identified. The intimate relationship between these cells may offer an alternative explanation for reports of CD34 and Kit co-localization. The ontogeny and function of CD34-ir cells in the gut, as well as the origin of gastrointestinal stromal tumors, remain unclear.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD34 / immunology
  • Antigens, CD34 / metabolism*
  • Colon / anatomy & histology
  • Colon / cytology*
  • Colon / metabolism
  • Enteric Nervous System / cytology
  • Enteric Nervous System / metabolism
  • Fluorescent Antibody Technique
  • Gastric Mucosa / metabolism
  • Humans
  • Intestine, Small / cytology*
  • Intestine, Small / innervation
  • Intestine, Small / metabolism
  • Mice
  • Muscle, Smooth / cytology
  • Muscle, Smooth / innervation
  • Muscle, Smooth / metabolism
  • Proto-Oncogene Proteins c-kit / immunology
  • Proto-Oncogene Proteins c-kit / metabolism*
  • Stomach / anatomy & histology
  • Stomach / cytology*


  • Antigens, CD34
  • Proto-Oncogene Proteins c-kit