Candida Albicans Activated Splenocytes Promote Strong Immune Responses in a Murine Model of Breast Cancer

The potential of Candida albicans to modulate antigen-presenting cells maturation has been documented in past studies. Dendritic cells are critical modulators in the orchestration of adaptive immune responses alongside myeloid subtypes, which play an important role in the presentation of antigens to T cells. The aim of this study was to evaluate the efficacy of splenocytes activated with the extract of heated 4T1 cells and the yeast form of C. albicans against breast cancer growth in vivo‏.

4T1 cells were subcutaneously injected into the left flanks of female BALB/c mice (n=40). At a time when palpable tumors had developed, experimental groups were immunized twice at one-week interim with either activated splenocytes with the extract of heated 4T1 or the killed preparation of yeast form of C. albicans or a combination of the two-One week after the second injection, one-half of animals (n=20) were euthanized to investigate the immune response profile.

Administration of activated splenocytes with the combination protocol caused a favorable survival curve and slower rates of tumor development compared to other tumor-bearing mice. Moreover, combination therapy significantly increased the secretion of IFN-γ, respiratory burst and nitric oxide production and conversely diminished the secretion of IL-4, IL-10 and TGF-β in the splenocyte population.

Since the murine 4T1 cell line is similar to the final stage of human breast carcinoma, we postulate that activated splenocytes with the extract of heated 4T1 cells and yeast form of C. albicans can reduce tumor development in tumor-bearing mice.