Research Paper Volume 4, Issue 9 pp 606—619
Aging induced decline in T-lymphopoiesis is primarily dependent on status of progenitor niches in the bone marrow and thymus
Figure 4. In vitro competition between aged and young LPCs accumulated by grafted fetal thymic lobes in vivo under old or young mouse kidney capsules.
(A) Schematic workflow of the comprehensive competitive culture assay showing the recruitment of old and young natural thymus-seeding cells in vivo to the in vitro competitive co-culture on OP9-DL1 monolayer stromal cells. (B) A representative result of % T-lineage cells derived from old (CD45.2+) and young (CD45.1+) thymus-seeding LPCs after competitive co-culture on OP9-DL1 stromal cell monolayer. (C) A summary of % T-lineage cells derived from old (CD45.2+) and young (CD45.1+) thymus-seeding LPCs after competitive co-culture on OP9-DL1 stromal cells. (D) A representative flow cytometry dot-plot shows CD4 vs. CD8 profile of T-lineage cells from the grafted fetal thymic lobes 7 days after KCT (left panels); purification of DN cells after negative-selection with beads (middle panels); and CD4 vs. CD8 profile of T-lineage cells after competitive co-culture on OP9-DL1 stromal cells (right panels). (E) A summary of % CD4+CD8+ (DP) cells derived from old (CD45.2+) and young (CD45.1+) thymus-seeding LPCs after competitive co-culture on OP9-DL1 stromal cells. Data in C and E panels show mean ± SEM, n = competitive co-culture wells; total host animal number is 5 young and 5 old WT mice. The experiment was conducted 5 times (i.e. 5 FTOC, 5 sorts, and 5 cultures).