Quantification of T Cell Polarization.

Primary CD4+ T cells and P2 cells infected with VSV-G-pseudotyped HIV-1 encoding Gag-YFP were cultured for two days, fixed, immunostained for cellular proteins, and examined by fluorescence microscopy. Gag-YFP-positive and -negative cells were categorized based on cell morphology, and cells in each category were counted. Cells with circularity below 0.8 (see Materials and Methods) were categorized as polarized cells.