Yeast (Saccharomyces cerevisiae) Polarizes Both M-CSF- and GM-CSF-Differentiated Macrophages Toward an M1-Like Phenotype

Abstract

Macrophages are a heterogeneous and plastic cell population with two main phenotypes: pro-inflammatory classically activated macrophages (M1) and anti-inflammatory alternatively activated macrophages (M2). Saccharomyces cerevisiae is a promising vehicle for the delivery of vaccines. It is well established that S. cerevisiae is taken up by professional phagocytic cells. However, the response of human macrophages to S. cerevisiae is ill-defined. In this study, we characterized the interaction between S. cerevisiae and M1- or M2-like macrophages. M1-like macrophages had a higher yeast uptake capacity than M2-like macrophages, but both cell types internalized opsonized yeast to the same extent. The M1 surface markers HLAII and CD86 were upregulated after yeast uptake in M1- and M2-like macrophages. Moreover, mRNA expression levels of pro-inflammatory cytokines, such as TNF-α, IL-12, and IL-6, increased, whereas the expression of anti-inflammatory mediators did not change. These results demonstrate that S. cerevisiae can target both M1 and M2 macrophages, paralleled by skewing toward an M1 phenotype. Thus, the use of yeast-based delivery systems might be a promising approach for the treatment of pathologic conditions that would benefit from the presence of M1-polarized macrophages, such as cancer.

Targeted delivery of functionalized PLGA nanoparticles to macrophages by complexation with the yeast Saccharomyces cerevisiae

“…Although not fully statistically significant ( p = .07) for M1, in either case, opsonized yeast cells showed a higher uptake rate than untreated yeast cells. This observation is in accordance with our previous data on the uptake of non‐opsonized yeast cells by primary human macrophages (Seif et al, ). Accordingly, opsonized yeast was used for all further experiments.…”

“…PBMC were washed in PBS and monocytes were separated by positive selection using magnetic anti‐CD14 microbeads (Miltenyi Biotec). For macrophage differentiation, monocytes were cultured at a density of 1.5 × 10 7 cells per 175 cm 2 flask in RPMI‐1640 medium supplemented as above and 20 ng/ml human recombinant macrophage colony‐stimulating factor (M‐CSF; Miltenyi Biotec) for 5 days, as described previously (Seif, Philippi, Breinig, Kiemer, & Hoppstädter, ). Macrophages were maintained at 37°C in a humidified atmosphere of 5% CO 2 , and the medium was changed every second day.…”

“…Yeast cells have been repeatedly proven to be a remarkably efficient delivery vehicle for targeting a whole bunch of cargos to phagocytic cells in general and macrophages in particular (Bazan, Geginat, Breinig, Schmitt, & Breinig, ; Seif, Hoppstädter, Breinig, & Kiemer, ; Seif, Philippi, Breinig, Kiemer, & Hoppstadter, ; Stubbs et al, ; Walch, Breinig, Schmitt, & Breinig, ). Among the different yeast genera, the well‐characterized baker's yeast Saccharomyces cerevisiae possesses the GRAS status facilitating a possible application as a carrier system, thereby providing the advantages of a single cell organism including easy handling and genetic modification.…”

Immuno-silent polymer capsules encapsulating nanoparticles for bioimaging applications

“…22,23 Upon activation with LPS/IFN-γ for 24 h DC demonstrated typical signs of maturation by increase in HLA-DR, CD80, CD40, CD86 and gain of CD83 (Figure S2a,b). [30][31][32][33][34] Resting DC and MO are very sensitive to a wide range of signals that indicate the presence of potential pathogens or damaged tissues. Therefore, novel imaging reagents would ideally not result in activation of resting APC.…”

“…CD83 and CD40 were absent on immature and mature M2 but whilst absent on immature M1 they were expressed by mature M1 (Figure S3a,b). 30,34 Mature M1 macrophages produced high levels on IL-12 and low IL-10 while mature M2 macrophages preferentially secreted IL-10 whereas IL-12 levels were low. M1 macrophages incubated with polymer capsules encapsulating nanoparticles expressed similar levels of IL-12 and IL-10 after LPS activation compared to control (only cells) indicating that they are not altering the immune response of cells (Figures 5a and c).…”