The contained self-reactive peripheral T cell repertoire: size, diversity and cellular composition. Mus musculus

To further characterize the self-reactive T cell population and determine if there are sub-compartments within the naïve T cell pool that are more likely to respond in the absence of Treg cell-mediated control, we focused on CD5. CD5 is a membrane protein that is associated with the TCR and its expression is correlated with higher signaling intensity, presumably due to higher TCR self-MHC/peptide affinity, during positive selection. FACS was used to purify three distinct populations of naïve CD4+ T cells from the bottom, middle and top 10 percent based on CD5 expression; CD5low, CD5int and CD5high. Overall design: Naïve (CD44low/int CD62Lhigh) CD4+ CD5low, CD5int and CD5high T cell populations were FACS purified from spleens from three female (Fe) and three male (Ma) mice, to account for possible gender differences. RNA was extracted using the RNEasy Plus Micro Kit (Qiagen).