Human dendritic cells express a 95 kDa activation/differentiation antigen defined by CMRF-56

Tissue Antigens. 1999 Apr;53(4 Pt 1):320-34. doi: 10.1034/j.1399-0039.1999.530402.x.


Despite the unique functions of dendritic cells (DC), only two cell surface antigens (CMRF-44 and CD83) with relatively restricted expression on human DC have been described to date. We describe a third mAb, CMRF-56, which recognizes another DC early activation/differentiation antigen with limited expression on other haemopoietic cell populations. Circulating blood leukocytes did not express the CMRF-56 antigen and, following either in vitro culture or activation of PBMC populations, CMRF-56 antigen expression was detected only on DC and a subpopulation of CD19+ lymphocytes. Circulating blood DC were CMRF-56 but induced expression within 6 h of in vitro culture. This, together with the finding that tonsil and synovial fluid DC upregulate the antigen following short-term in vitro culture, confirmed that CMRF-56 recognizes an early activation antigen on DC. Isolated Langerhan's cells, dermal DC, migratory dermal DC and monocyte derived DC (GM-CSF/IL-4/TNFalpha) also express the CMIRF-56 antigen. Antigen modulation studies demonstrated that the amount of cell surface bound CMRF-56 and CMRF-44 (but not CD83) mAb was dramatically reduced by short-term incubation at 37 degrees C. This effect was not due to internalization and the reduction in CMRF-56 binding was a reversible, temperature-dependent process. In contrast, the decrease in CMRF-44 binding was irreversible, suggesting that following ligation the CMRF-44 antigen undergoes an irreversible conformational change or shedding at 37 degrees C. Western blotting confirmed that CMRF-56 recognizes a previously undescribed 95 kDa activation antigen whose cellular distribution and expression kinetics overlaps with, but is clearly distinguishable from, that of the CD83 and CMRF-44 antigens. CMRF-56 therefore provides a useful additional marker for studies on human DC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, Differentiation / immunology*
  • Antigens, Surface / immunology*
  • Cell Line
  • Dendritic Cells / immunology*
  • Flow Cytometry
  • Humans
  • Immunoglobulins / immunology
  • Membrane Glycoproteins / immunology
  • Organ Specificity


  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, Differentiation
  • Antigens, Surface
  • CD83 antigen
  • CMRF-56 antigen
  • Immunoglobulins
  • Membrane Glycoproteins