EVALUATION OF THE IMMUNOMODULATORY ACTIVITY INDUCED BY THE CELL WALL OF SACCHAROMYCES CEREVISIAE AND ITS MICRONIZED VARIANTS.

Rosario

Congreso; 7ma Edición de la Reunión Internacional de Ciencias Farmacéutica (RICIFA); 2023

The use of antibiotics in livestock as growth promoters and disease preventatives has been identified as a potential cause of antimicrobial resistance in human pathogens. This issue has driven the search for alternatives to antibiotics, with immunomodulatory substances being one of the promising options.The main objective of this study was to evaluate the immunomodulatory activity of the Saccharomyces cerevisiae cell wall (CW) and its micronized variants (CW with a size close to 10 µm-CWM) and micronized coated (CWM + Acryl-EZE®), both in in vitro and in vivo assays. Additionally, efforts were made to identify potential bacterial contaminants in the sample and analyze the role of receptors of innate immunity as TLR4 and TLR2 on the immunomodulatory property.In the in vitro assays, female wild type (WT) C57BL/6 and TLR4-deficient mice (Tlr4-/-) were used. Spleen cells were extracted from both groups and incubated for 48 hours at 37°C with different stimuli. Subsequently, cytokine production was measured using ELISA assays, and cell viability was assessed.In the in vivo assays, female WT C57BL/6 and TLR2-deficient mice (Tlr2-/-) were employed. Mice were intraperitoneally injected with the different stimuli. At 6 hours post-injection, submandibular blood (for serum collection) was collected, and peritoneal lavage was performed. Peritoneal lavage cells were reserved for immunostaining and flow cytometry analysis. The cell supernatant and serum were used for cytokines determination.In the in vitro assays, it was observed that CW induced a higher production of IL-6 and IFN-γ compared to multiparticulate systems (CWM and CWM + Acryl-EZE®). TNF-α and IL-12p40/p70 was not detected in any of the groups. Furthermore, it was demonstrated that CW did not contain bacterial contaminants, as it stimulated cytokine release in both WT and Tlr4-/- mouse cells.In the in vivo assays, after the administration of CW, CWM, or CWM + Acryl-EZE®, a reduction in the population of macrophages and an increase in the presence of neutrophils and Ly6C+ monocytes were observed. This effect could be associated with the ability of β-glucans (present in CW) to recruit and activate leukocytes via dectin-1. In Tlr2-/- mice, a decrease in recruited monocytes was observed compared to WT mice.In summary, this study highlighted the potential of CW and its multiparticulate systems as immunomodulatory agents due to their immunoactivating effect. Although CWM and CWM + Acryl-EZE® systems did not show immunostimulatory capacity in vitro, they maintained their effect in in vivo assays. The results emphasized the importance of considering factors such as the route of administration and biological environments when evaluating the immunomodulatory property of these substances, and suggested their potential application as alternatives to antibiotics in the livestock industry.