I have been deriving human T cell clones against synthetic peptides by
stimulating naive PBMC and following standard methodology such as
limiting dilution cloning, etc. I have generated several CD4+ lines,
which is what I am after, but some clones have a CD4+CD8+/- phenotype,
and I don't understand what's going on here.
By FACS analysis these cells are 100% CD4 positive and their CD8
expression ranges from zero to high in a near-continuum. There might
be two clonal populations here, one CD4 SP and one CD4+CD8+ DP, but I
dont think so. Nevertheless, is there a significance to generating a
CD4+CD8+ DP cell line from naive peripheral blood, in that I associate
DP cells with immature thymocytes and not with mature peripheral T
cells?
Also, if the CD8+ heterogeneity represents differential CD8 expression
by a clonal population (and not two different T cell clones in one
well), what does this represent?
David N. Levy
University of Alabama at Birmingham
Birmingham, AL 35294-0007
levy at uab.edu
