Activation of murine polymorphonuclear neutrophils for fungicidal activity with supernatants from antigen-stimulated immune spleen cell cultures

Abstract

An in vitro model of in vivo immunological activation of murine polymorphonuclear neutrophils (PMN) was developed. Culture supernatants of spleen cells from Blastomyces dermatitidis-immunized mice stimulated with B. dermatitidis antigens in vitro were studied. Incubation of the supernatants with thioglycolate-elicited PMN enabled the cells to significantly reduce (31 +/- 6%) B. dermatitidis inoculum CFU. Optimum production of active supernatants occurred after 4 to 6 days of stimulation in vitro and required 200 micrograms of nonviable B. dermatitidis cells per ml. Generation of activity by immune spleen cells was shown to be antigen specific in that stimulation with a heterologous antigen or stimulation of nonimmune spleen cells with B. dermatitidis antigen did not produce active supernatants. The activity in supernatants was dose dependent, nondialyzable (molecular weight greater than or equal to 14,000), and relatively heat labile (80 degrees C, 30 min). Activation of PMN by supernatants for fungicidal activity against B. dermatitidis required only a short incubation period (1 h) followed by a 2-h coculture (challenge) period. Stimulation of normal spleen cells with concanavalin A also resulted in the production of supernatants capable of activating PMN for significant fungicidal activity (31.1 +/- 8.5%). These findings demonstrate for the first time a link between soluble factors produced by antigen stimulation of sensitized lymphoid cells and activation of PMN for enhanced microbicidal activity. Such a process defines an additional immune defense mechanism whereby the immune host may clear specific microorganisms.

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

“…Evidence has accumulated that indicates that polymorphonuclear neutrophils (PMN) are functionally a heterogenous population (24,25). Furthermore, the metabolic activity of PMN has been reported to be enhanced during gram-negative bacterial infections (12,18), elicitation in immune mice with antigen (5), or treatment in vitro with supernatants from either mitogen (4,7,11) or antigen-stimulated lymphocyte cultures (4). Enhancement of PMN metabolic activity associated with gram-negative bacterial infections was measured by increased reduction of nitro-blue tetrazolium (12,18) or by chemiluminescence (CL) (2) upon interaction with opsonized zymosan.…”

Exoenzyme S from Pseudomonas aeruginosa induces apoptosis in T lymphocytes

“…T cells are important regulators of the innate, as well as cognate, immune response. T cells produce lymphokines capable of activating macrophages, natural killer cells, and polymorphonuclear cells for efficient killing of infectious agents [34,35]. T lymphocytes are also important in pulmonary immune responses, which is the target organ for many Pseudomonas infections.…”

“…Because cognate immunity, specifically T cells, has been demonstrated to influence both innate and specific effector functions [3][4][5], attention has more recently focused on the contribution of T cells as critical orchestrators of lung defense. Perhaps as a consequence of their importance in coordinating the immune response in the pulmonary compartment, T cells are often targeted by infectious agents to produce a disproportionately heightened and undirected inflammatory response [6,7].…”

Granulocyte colony-stimulating factor potentiates anti-Candida albicans growth inhibitory activity of polymorphonuclear cells

“…Recently, PMN activation by lymphokines has been reported by a number of investigators. For example, Brummer and Stevens reported that treatment with lymphokine-rich culture supernatants induced fungicidal activity of PMNs [17]. Cross et al reported that a human cell line could release a PMN-activating factor which enhanced PMN migration and oxygen production [18].…”