Application of the chemiluminescence systems to evaluate the role of Fcγ and complement receptors in stimulating the oxidative burst in neutrophils

Abstract

We have established a luminol- and a lucigenin-dependent CL methods to investigate the role of the receptors for Fc portion of IgG (FcγR) and/or complement receptors (CR) in mediating the oxidative burst in neutrophils from systemic lupus erythematosus (SLE) patients compared with healthy controls. In the luminol-CL system, all the reactive oxygen species (ROS) are responsible for light production, whereas in the lucigenin-CL system, only the first ROS generated, converts the lucigenin into an unstable intermediate molecule, which also emits light. First, neutrophils from healthy controls and SLE patients were stimulated with different IC opsonized or not with complement from normal human serum (NHS) or SLE serum, in presence of 10 −4 M luminol. This method was able to differentiate the role of the FcγR, CR and FcγR/CR co-operation in mediating the oxidative burst, as well as show that the oxidative burst mediated by these receptors was reduced in neutrophils from SLE patients. Second, neutrophils from healthy controls and SLE patients were stimulated with different IC, opsonized or not with NHS, in presence of 10 −3 M lucigenin. In this case, the lucigenin-CL system was also able to differentiate the role of FcγR and FcγR/CR co-operation, as well as show differences among healthy controls and two different groups of SLE patients according to their clinical manifestations. In conclusion, we have established two sensitive CL systems to study the role of FcγR and/or CR in stimulating the oxidative burst of neutrophils, which can be applied in monitoring the involvement of these receptors in the immunopathogenesis of SLE.