Activation of the respiratory burst by Pneumocystis carinii: Efficiency of different antibody isotypes, complement, lung surfactant protein D, and mannan-binding lectin
Abstract:Laursen AL, Obel N, Holmskov U, Jensenius JC, Aliouat EM, Andersen PA. Activation of the respiratory burst by Pneumocystis carinii. Efficiency of different antibody isotypes, complement, lung surfactant protein D, and mannan-binding lectin. APMIS 2003;111:405–15.
The effect of opsonization of Pneumocystis carinii with different antibody classes, complement, mannan-binding lectin (MBL), and lung surfactant protein D (SP-D) on respiratory burst activation was studied. Antibodies were obtained by affinity chromatography, complement from a hypogammaglobulinaemic patient, and phagocytic cells from blood donors. Respiratory burst activation was measured by chemiluminescence (CL). With freshly isolated neutrophils the combination of antibodies and complement but not antibody alone, had opsonizing properties. With neutrophils cultured for 20 h, however, IgG increased the CL response. In macrophages P. carinii opsonized with IgG alone induced a CL response proportional to the antibody titre used. With IgA an effect, albeit lower, was also seen, whereas IgM alone was inefficient. The combined effect of antibodies and complement increased the response significantly for all three antibody classes, IgG and complement giving the largest response. Binding of MBL to P. carinii and Candida albicans was demonstrated; however, only the former stimulated activation of the respiratory burst. SP-D did not bind to either microorganism and had no effect on the respiratory burst. It is concluded that IgG, IgA and complement are important opsonizing factors in infections involving P. carinii. The relative importance varies with the type of phagocytic cell studied.
Document Type: Research Article
Affiliations: 1: Department of Infectious Diseases, Skejby Hospital, University of Aarhus, Brendstrupgaardssvej 100, Aarhus, Denmark 2: Department of Immunology and Microbiology, Institute of Medical Biology, University of Southern Denmark, Odense, Denmark 3: Department of Medical Microbiology, University of Aarhus, Bartolinbygningen, Aarhus, Denmark 4: Department of Parasitology, Faculty of Pharmacy and Department of Microbiology of Ecosystems, Institut Pasteur de Lille, Lille, France
Publication date: March 1, 2003