Enhanced oxidative burst in immunologically activated but not elicited polymorphonuclear leukocytes correlates with fungicidal activity

Abstract

Polymorphonuclear neutrophils (PMN) induced locally in immune mice by intraperitoneal injection of antigen exhibit enhanced fungicidal activity compared with PMN elicited with thioglycolate. The mechanism of the differences in these PMN populations was studied. Sublethal infection was used to produce immunity to Blastomyces dermatitidis. A correlation was sought between the ability of PMN to kill, or not kill, B. dermatitidis and the production of the oxidative burst, as measured by luminol-enhanced chemiluminescence (CL). Although elicited PMN cocultured with Candida albicans produced a burst of CL and were candidacidal, killing did not occur when PMN were cocultured with B. dermatitidis. Lack of killing ofB. dermatitidis by elicited PMN correlated with lack of stimulation of a brisk oxidative burst. In contrast to elicited PMN, PMN induced by B. dermatitidis antigen responded to this fungus with a burst of CL and a significant reduction of inoculum CFU (80%). Furthermore, these PMN when cocultured with C. albicans produced an enhanced burst of CL, and killing was enhanced compared with that by elicited PMN, e.g., 86 versus 58%. The CL burst and killing of B. dermatitidis by antigen-induced PMN was abrogated in the presence of catalase, implying a critical role for hydrogen peroxide. Partial but significant depression of CL and killing in the presence of dimethyl sulfoxide, a hydroxyl radical scavenger, identified hydroxyl radical, or its metabolites, as a toxic product(s) responsible for a significant fraction of fungicidal activity. These results indicate that the metabolic activity and microbicidal activity of PMN can be altered (enhanced) at the site of an immunological reaction and thus could constitute an important factor in resistance.

Transcriptomic Analysis of Vulvovaginal Candidiasis Identifies a Role for the NLRP3 Inflammasome

“…2 ). These results are consistent with those of previous studies that have demonstrated that VVC results in robust infiltration of PMNs, their associated oxidative burst ( 40 ), and the secretion of Th17 cytokines, including IL-22, IL17A, IL-17F, and IL-6, into the lavage fluid ( 17 , 34 , 41 – 44 ).…”

Fungicidal mechanisms of activated macrophages: evidence for nonoxidative mechanisms for killing of Blastomyces dermatitidis

“…This conclusion was indicated by the meager luminol-enhanced CL responses and the inability of catalase, azide, or DMSO to inhibit killing. Although the H202-MPO-halide system is effective in killing B. dermatitidis (6,17), resident peritoneal macrophages are noted for their paucity of MPO (14), and this fact probably accounts for our findings. We speculate that activated macrophages could kill B. dermatitidis by an enhanced ability to discharge (degranulate) lysosomal contents (e.g., cationic proteins [16]) into the B. dermatitidis-macrophage interface.…”

Blastomycosis

“…24,25 Although granulocytes have been shown in vitro to phagocytize B. dermatitidis, intracellular killing of organisms is poor but may be enhanced by lymphokines derived from immunologically stimulated T-lymphocytes. 26,27 These in vitro findings provide a link between cell-165 mediated immunity and polymorphonuclear leukocyte function, which were both implicated by the pathologic response noted.…”