Regenerative potential of neonatal tendon cells is regulated by intrinsic resistance to inflammation and supportive T cell-secreted factors

Proliferation and migration potential were also properties intrinsic to neonatal tendon cells. While adult tendon cells were more sensitive to secreted T cell factors, neonatal T cell factors generally supported regenerative properties in adult tendon cells. Using RNA sequencing, we further identified a role for JAK/STAT signaling specific to treatment with adult T cell supernatants; using a small molecule inhibitor of JAK/STAT, we confirmed that suppression of adult tendon cell migration by adult T cell factors can be rescued by JAK/STAT inhibition.

Altogether, these data show that regenerative tendon healing in neonates is due to both intrinsic neonatal tendon cell resistance to T cell-mediated inflammation as well as a more favorable immunological environment induced by neonatal CD4+ T cells.