Correction of antigen‐specific T cell defects in aged murine gut‐associated lymphoid tissues an immune intervention by combined adoptive transfer of an antigen‐specific immunoregulatory CD4 T cell subset and interleukin 2 administration

摘要

AbstractGut‐associated lymphoid tissues (GALT) from aged mice enterically immunized withMycobacterium paratuberculosisprotoplasmic antigen show hyperreactive humoral immune responses; this hyperresponsiveness can be corrected to a considerable extent, but not entirely, by systemic administration of interleukin 2 (IL 2) alone. The aim of the present study was to determine further whether the hyperreactivity in the antigen‐specific humoral immune responses in aged GALT could be fully restored by adoptive transfer ofin vitroexpanded antigen‐specific IL 2‐dependent helper (CD4+VV−) T cells from GALT in conjunction with recombinant IL 2 administration. The results show that the age‐associated hyperresponsiveness in gut mucosal antigen‐specific humoral immune responses can be entirely corrected by adoptive transfer with the antigen‐specific GALT T helper cells together within vivoIL 2 adminstration. The mechanism of this restoration involves reversal of the decline in antigen‐specific CD8+suppressor T cell funct