(116bi) Principal Component Analysis of the Differentiation of Dendritic Cells

Immunity against invading pathogens is a complex mechanism initiated by dendritic cells (DC). As DCs migrate from the bone marrow to lymph nodes, they acquire certain functional abilities at different developmental stages, which are distinguished by changes in expression of proteins on the cell surface. The objective of this study is to quantify and model mathematically the dynamic changes in surface protein expression during DC differentiation from immature DC precursors.

I have extracted and cultured bone-marrow derived dendritic cells (BMDC) from mice and used multi-color flow cytometry to measure the expression of surface proteins as BMDC differentiated into activated DC over eight days.

Currently, we are using the R/Bioconductor program to identify dynamic patterns in protein expression during DC differentiation. Data extracted from the flow cytometry files was plotted as histograms that portray multiple cell populations. We intend to identify key expression patterns in this data using principal component analysis, and later model mathematically the correspondence of these patterns to the developmental stages of DC. We hope to eventually verify our model by observing differentiating immature cells exposed to a pathogen. Ultimately, this equation may be used to reverse-engineer the differentiation of DC precursors to elicit a desired immune response.