Utilização de extrato de levedura contendo β-glucana no melanoma B16F10 em camundongos C57BL/6

Abstract

INTRODUCTION: Melanoma is one of the most aggressive types of tumors, and strategies to modulate the immune response have been explored as adjuvant therapies. β-glucan, a polysaccharide derived from Saccharomyces cerevisiae, is known for its immunomodulatory properties; however, its impact on experimental melanoma has not yet been fully elucidated. OBJECTIVE: To evaluate the effects of treatment with β-glucan (extract S.c) in the B16F10 melanoma model on the splenic immune response and its influence on tumor development. METHODS: C57BL/6 mice were treated with 1 mg of β-glucan (extract S.c) intraperitoneally (i.p.) daily after tumor onset (7 days post-inoculation) and evaluated at different stages of tumor progression. Flow cytometry was performed to characterize splenic cell populations and cytokines, along with histopathological analyses for structural assessment of the spleen. Hematological analysis was conducted to evaluate peripheral blood. RESULTS: β glucan treatment increased spleen size and the absolute number of splenocytes, including macrophages, dendritic cells, NK cells, and NKT cells. It also enhanced MHCII expression by DCs and promoted the formation of Germinal Centers, indicating immune activation in the spleen. Additionally, it led to an increase in circulating monocytes and lymphocytes, improved survival, and reduced tumor growth. Treated animals also preserved the splenic white pulp region and showed larger T cell areas (periarteriolar lymphoid sheath) in the spleen at 18 days post-inoculation, whereas untreated mice exhibited tumor cell infiltration in the spleen by day 24. Treated animals further exhibited higher absolute numbers of CD4+ and CD8+ T cells producing IFN-γ and TNF-α, especially after anti-CD3 stimulation. CONCLUSIONS: Treatment with β glucan (extract S.c) demonstrates immunomodulatory potential by increasing both splenic and systemic cellular frequencies and contributes to the control of experimental melanoma.