A simple and efficient method for the monitoring of antigen-specific T cell responses using peptide pool arrays in a modified ELISpot assay

In this study, we describe a simple and efficient method for both the monit oring of antigen-specific CD4 and CD8 T cell responses as well as the ident ification of novel CD4 and CD8 T cell epitopes using a modified ELISpot ass ay and pools of 20mer peptides. We have demonstrated that pools containing as many as 64 20mer peptides may be used to screen for CD4 and CD8 T cell r esponses to HPV 16 L1. E1, and E7 in mice. Using arrays of pools of overlap ping 20mer peptides, we have identified novel CD4 and CD8 epitopes in both HPV16L1 and HPV16E1 which are presented in Balb/c mice. We have Further sho wn that the use of 20mer peptides is equivalent to using minimal 9mer epito pes for the stimulation of CD8 T cell responses in our assay. While our exp eriments are conducted in mice, the use of peptide pool arrays allows for t he identification of epitope-specific responses using far fewer cells than is required for testing a panel of overlapping peptides individually, makin g this strategy particularly useful in clinical settings where immune cells may be limiting. (C) 2001 Published by Elsevier Science B.V.