Immunotherapy and cytokines

Pharmacologic Interventions to Immunologic and Immune-Mediated Conditions in Horses

Immunomodulators can stimulate, suppress, or regulate one or many aspects of the immune response. Use of a variety of immunostimulants, immunosuppressors, and anti-inflammatory drugs are described in horses, but the evidence supporting their efficacy is variable. Corticosteroids and nonsteroidal anti-inflammatory drugs are the best characterized immunomodulators in horses, but further study is needed to fully define their ideal dosing protocols and indications and to characterize the efficacy of other immunomodulators in equine medicine.

[2-hydroxy-methyl-1(N-phtaloyltryptophyl) aziridine stimulates in vitro human lymphocyte proliferation and interleukin secretion]

AIM OF THIS WORK: Aziridines have been shown to possess marked immunotropic activity. In this study, the in vitro effects of a new aziridine, 2-hydroxy-methyl-1-(N-phtaloyltryptophyl) aziridine, were determined on the proliferative responses of human lymphocytes stimulated by mitogens and on interleukin (IL-2, IL-6) secretion.

MATERIAL AND METHODS

Peripheral blood lymphocytes were isolated using differential centrifugation on a density gradient of Ficoll-Paque. They were cultured with or without mitogens (Concanavalin A and lipopolysaccharide), and with different concentrations of the aziridine. Proliferation was monitored by direct cell counts and confirmed by MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. After different incubations, IL-2 and IL-6 were determined by using commercially available Elisa kits.

RESULTS

The aziridine tested significantly stimulated the resting and mitogen T and B lymphocyte proliferation at concentrations between 1 microM and 1 mM, in a dose-dependent manner. It also increased IL-2 and IL-6 secretion.

CONCLUSION

2-hydroxy-methyl-1-(N-phtaloyltryptophyl) aziridine displayed immunomodulatory properties and is potentially immunostimulant. It could be used to provide non-specific cell-mediated immune responses.

Immunomodulation in horses

Nonspecific immunomodulators are substances that induce non-antigen-specific enhancement of the body's native or acquired defense mechanisms. Immunomodulant preparations are most often used for treatment of chronic, viral, or bacterial infection with evidence of secondary immunosuppression. The proposed mechanism of action of these products is macrophage activation and subsequent release of cytokines that enhance humoral and cell-mediated immunity. In equine medicine, nonspecific immunostimulant products are used for prevention and treatment of infectious respiratory disease and treatment of sarcoid skin tumors.