Extended Data Fig. 9: Naive and central memory T cells are the major telomere acquiring cells from APCs.
(a) Analysis of telomere transfer by flow FISH flow cytometry upon conjugation of APCs live-labelled with TelC PNA telomere probes and total primary human CD3+ T cells for 24 hours. Each dot is an individual donor from n = 4 independent biological experiments. Control, APCs loaded with antigen pool and stimulated with T cells but without telomere labelling throughout experiments (no APC telomere). No antigen (pool) control is also shown confirming antigen dependency. (b) Naïve and central memory T cells are the major APC telomere acquiring cells. Purified primary human CD4+ T cell populations (CD28+ CD45RA+ naïve purity 98.7%; CD28+ CD45RA− central memory (CM) purity 95%; CD28− CD45RA− senescent effector memory (EM) 97.5%; senescent CD28− CD45RA+ EMRA purity 94%) were treated as in (a) and telomere transferred was measured by flow FISH with TelC probe. Pooled results from n = 3 (CM and EM) and n = 4 (naïve and EMRA) independent individual donors. Note that since primary human CD4+ T cells first lose expression of CD27 followed by that of CD28, CD28− CD4+ T cells are highly differentiated cells, many of which are considered senescent8,31,32,33,34,42. The opposite regulation occurs in primary human CD8 T cells, where the CD27- population is considered highly differentiated/senescent since the cells first expression of CD28 followed by that of CD279,32. The reason for this is not known. Statistical Tests are provided in the Supplementary Table 1. Error bars indicate S.E.M.
