CD4 and B-cell chronic lymphocytic leukemia: Splenocytes were isolated from either untreated naïve mice or from CLL- or PBSL-treated mice day 8 p.i. and cultured in vitro with immunodominant peptides from either WNV NS3 protein or NS4B protein, which stimulate WNV-specific CD4 T cells or CD8 T cells, respectively (Fig 4A and 4B).