Modulation of T-cell receptor (TCR) signaling is essential for the regulati
on of T-cell responses to infectious agents. Recently, many laboratories ha
ve suggested that TCR triggering might be compartmentalized in plasma membr
ane microdomains called rafts. Results on the role of lipid rafts as signal
ing units in TCR triggering suggest that rafts might be used by T cells to
fine-tune their immune responsiveness.