PHA- and Con A-induced chemiluminescence of human blood mononuclear cells and granulocytes in luminol or lucigenin.

Phytohemagglutinin (PHA) and concanavalin A (Con A) can evoke a chemiluminescence (CL) response both in granulocytes and blood mononuclear cells. We have used two parallel systems to compare the quantity and quality of oxygen radicals produced during activation. While the luminol-enhanced CL response is linked to the myeloperoxidase-H2O2-chloride system, the lucigenin-dependent light production measures only the superoxide radical. PHA produced higher CL response in the presence of luminol than with lucigenin. Con A showed high CL response only in the lucigenin-enhanced system. The results suggest that while Con A induces mostly superoxide production, the membrane stimulus evoked by PHA produces light through the myeloperoxidase-H2O2-halide system. Granulocytes are less sensitive to PHA than the blood mononuclear cells. The sensitivity of the responses to several scavengers and enzymes support the differential production of oxygen radicals following activation via these two lectins.