Visualizing CTL activity for different CD8( ) effector T cells supports the idea that lower TCR/epitope avidity may be advantageous for target cell killing

Abstract

Time-lapse video microscopy allows analysis of the interaction between individual CTLs and adherent peptide-pulsed targets, from contact, to lymphocyte detachment, APC rounding, phosphatidylserine exposure and finally loss of plasma membrane integrity characteristic of end-stage apoptosis. Using in vitro-stimulated effectors specific for the ovalbumin K(b)OVA(257) (OT-I) and influenza A virus D(b)NP(366) and D(b)PA(224) epitopes, no significant correlation was found between the duration of CTL contact and the time to phosphatidylserine exposure or loss of membrane integrity. Furthermore, there were minimal indications that transgenic T cells specific for the K(b)OVA(257) epitope (TCR) divers..