Different localisation of cystatin C in immature and mature dendritic cells

Background. Limited antigen degradation by proteolytic enzymes and their control by protease inhibitors represent a crucial step in generating antigenic peptides inside the endocytic pathway of antigen-presenting cells such as dendritic cells. Methods. Human dendritic cells were used as a cell model in which quantitative immunogold electron microscopy was applied in order to study endogenous protease inhibitor cystatin C. Ultrathin cryosections were prepared from immature and mature dendritic cells and labelled with specific antibody. Under the transmission electron microscope gold particles, bound to specific probe (antibody), pointed the exact localization of labelled inhibitor. Results. Quantification of immunogold labelling and further statistical analysis by chi-squared test emphasized the differences in cystatin C content in different cell compartments. Conclusions. Statistically significant differences in intracellular distribution of cystatin C have been determined between immature and mature dendritic cell population. (author)