Young but not older adults exhibit an expansion of CD45RA+CCR7+CD95+ T follicular helper cells in response to tetanus vaccine

The differentiation courses of the Tfh cells: a new perspective on autoimmune disease pathogenesis and treatment

“…After vaccination, cTfh cells was low in frequency despite an effector memory phenotype in older adults, while CCR7 + CD45RA + cTfh cells were transiently increased in the blood of younger adults. Upon antigen reencounter, CCR7 + CD45RA + cTfh cells showed higher levels of CD95, CD40L, CXCR3, and Bcl-6 [ 117 ]. After COVID-19 infection, older adults had higher levels of pro-inflammatory cytokines, more circulating plasmablasts, and a lower proportion of cTfh cells with antibodies, demonstrating that poor prognosis in older adults is associated with a pro-inflammatory state in vivo and an inability to generate appropriate antiviral response [ 118 ].…”