In vitro lymphoproliferative response and cytokine production in mice with experimental disseminated candidiasis

Abstract

Objectives: Systemic candidiasis is an infection of Candida albicans (C. albicans) causing disseminated disease and sepsis, invariably when host defenses are compromised. We investigated the histopathological changes as well as the lymphoproliferative responses and cytokine production of splenic cells after stimulation with Concanavalin A (Con A) and Pokeweed mitogen (PWM) in mice with disseminated candidiasis.

Materials and methods: Lymphoproliferative responses were stimulated in vitro with Con A (1 µg/ml) and PWM (1 µg/ml) mitogens in Roswell Park Memorial Institute (RPMI) 1640 media, and the production of interferon (IFN)-γ and interleukin-4 (IL-4) in the supernatants was measured by enzyme-linked immunosorbent assay (ELISA).

Results: The results revealed that C. albicans organisms multiplied to a greater extent in the kidneys than in the liver and spleen of infected mice. The most predominant forms of C. albicans in different parts of the kidneys were yeast mixed with hyphal forms. Infected mice had a significantly increased proliferative response when splenocytes were stimulated with PWM (2.0±0.16) and Con A (1.9±0.19) (P<0.05). PWM and Con A-stimulated production of IFN-γ significantly tended to be higher in infected mice (PWM: 68.4±14.0 pg/ml; Con A: 53.7±17.3 pg/ml) when compared to controls (P<0.05). Stimulation with PWM and Con A showed no differences in IL-4 production between infected mice and controls.

Conclusion: These findings demonstrated a significant increase in both cell proliferation and IFN-γ secretion in supernatants of PWM and Con A- stimulated splenocyte cultures obtained from mice with disseminated candidiasis.

Keywords: Candida albicans; Cytokine production; Lymphocyte proliferation; Mice; Mitogens; Systemic candidiasis.

Figure 1

Mean weight of different mice groups at day 7 - d1, d2 and d3: days 1, 2 and 3, respectively

Figure 2

The presence of candidal yeast cells and pseudohyphae in parenchymal tissue of kidneys (GMS)

Figure 3

Proliferative response of mononuclear cells from infected and control mice under different stimuli

Figure 4

IFN-γ production by stimulated mononuclear cells in culture

Figure 5

IL-4 production by stimulated mononuclear cells in culture