Table 1.

Summary of previous works suggesting the presence of senescent T cells in MS and AD patients.

DISEASE	EVIDENCES OF T CELL SENESCENCE	REFERENCES
Multiple sclerosis	- Accelerated thymic involution in RRMS and PPMS patients	Reviewed in Haegert DG, Mult Scler Int 2011 (20)
	- Increased percentage of circulating IFN-γ-producing CD4+CD28- T cells in a subset of RRMS patients	Reviewed in Broux et al., Trends Mol Med. 2012 (21)
	- CX3CL1-mediated infiltration of potentially cytotoxic CD4+CD28- T cells in MS brain	Broux et al., J Autoimmun. 2012 (22)
	- Presence of chronically activated, effector memory-like CD8+ T cells with putative cytotoxic activity in white matter lesions of progressive MS patients	van Nierop et al., Acta Neuropathol 2017 (23)
	- Reduced thymic output of naïve T cells and increased percentage of circulating memory-like T cells in paediatric MS patients	Balint et al., Neurology 2013 (24)
Alzheimer disease	- Association of telomere shortening in T cells with mild cognitive impairment and dementia in Down syndrome patients	Jenkins et al., Neurobiol Aging. 2006 (25); Jenkins et al., Neurobiol Aging. 2010 (26)
	- Positive correlation of shorter telomere length in T cells with disease severity, plasma TNF-α levels, lower CD28 expression by CD8+ T cells, and increased sensitivity to apoptosis in T cells in AD patients	Panossian et al., Neurobiol Aging. 2003 (27)
	- Decreased percentage of naïve CD4+ T cells and increased percentage of terminally differentiated memory CD4+ T cells expressing KLRG1 in AD patients	Pellicanò et al., J Neuroimmunol. 2012 (28)