Fc gamma RII/CD32-negative human Langerhans cells may be responsible for the immunostimulatory activity of freshly isolated epidermal cells.
Cultured murine and human epidermal Langerhans cells (LC) undergo a phenotypical and functional maturation process. In fact, they loose Fc gamma RII and Birbeck granules, increase HLA-DR expression, and become potent accessory cells for allogeneic MLR. However, resident/freshly isolated human epidermal LC represent a phenotypically heterogeneous cell population. Indeed, a subset of CD1a+ LC lacks Birbeck granules, is Fc gamma RII/CD32-, and strongly expresses HLA-DR and the RFD1 antigen that is considered to be specific for interdigitating cells. In the present study the functional capacity of this Fc gamma RII/CD32- CD1a+ LC subset was investigated in MLR assays by comparing the stimulatory activity of freshly isolated crude epidermal cells (EC) with that of freshly isolated EC depleted in CD1a+ or in Fc gamma RII+ cells. Thereby, we observed that crude EC stimulated allogeneic PBMC while the removal of CD1a+ cells abrogated this stimulation. However, crude EC depleted in Fc gamma RII/CD32+ cells still exhibited a stimulatory capacity that was at least equal to that of crude EC. Taken together, these data suggest that among resident human epidermal LC there exists a subset of phenotypically and functionally more differentiated cells that may be solely responsible for the stimulatory capacity of freshly isolated crude EC.
Schmitt
D A
DA
Laboratoire d'Histocompatibilité, Centre Régional de Transfusion Sanguine de Strasbourg, France.
Bieber
T
T
Cazenave
J P
JP
Hanau
D
D
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology*; D018949:Antigens, CD1; D000943:Antigens, Differentiation / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007801:Langerhans Cells / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D011961:Receptors, Fc / Q000276:immunology; D017452:Receptors, IgG; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018949:Antigens, CD1; D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG