Defective mononuclear cell antibody-dependent cellular cytotoxicity (ADCC) in patients with leukocyte adhesion deficiency emphasizing on different CD11/CD18 requirement of Fc gamma RI versus Fc gamma RII in ADCC.
The defective antibody-dependent cellular cytotoxicity (ADCC) of mononuclear cells (MNC) from patients with leukocyte adhesion deficiency (LAD), beta 2 integrins (CD11a-c/CD18) deficiency was shown. LAD patients completely failed to generate MNC-ADCC against sheep red blood cells (SRBC) sensitized with murine (m) IgG2b, but had diminished but significant cytolysis against mIgG2a-SRBC, suggesting that the CD11/CD18 requirement of Fc gamma RI is different from that of Fc gamma RII in MNC-ADCC. Blocking experiments with monoclonal antibodies (mAb) against individual subunits of CD11/CD18 revealed that anti-CD18 mAb almost completely inhibited mIgG2b-mediated ADCC by normal monocytes, but only partially inhibited mIgG2a-mediated ADCC. These data may confirm the evidence that Fc gamma RII-mediated ADCC absolutely requires CD11/CD18 but Fc gamma RI-mediated ADCC does not. Among subunits of CD11/CD18, appeared to be most involved in lysis of sensitized SRBC.
Majima
T
T
Department of Pediatrics, College of General Education, Tohoku University, Sendai, Japan.
Ohashi
Y
Y
Nagatomi
R
R
Iizuka
A
A
Konno
T
T
D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D015703:Antigens, CD / Q000502:physiology*; D018845:CD11 Antigens; D018821:CD18 Antigens; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007153:Immunologic Deficiency Syndromes / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D017452:Receptors, IgG / Q000502:physiology*
D015703:Antigens, CD; D018845:CD11 Antigens; D018821:CD18 Antigens; D007074:Immunoglobulin G; D017452:Receptors, IgG