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.
Laboratoire d'Histocompatibilité, Centre Régional de Transfusion Sanguine de Strasbourg, France.
D A
DA
Schmitt
T
T
Bieber
J P
JP
Cazenave
D
D
Hanau
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