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Protective Immunity in Transplant Recipients
Author(s) -
Mulupuri Prasad,
Gourley Tania,
Popkowski Adam,
Mehta Aneesh,
Begley Beth,
Breeden Cynthia,
Larsen Christian,
Ahmed Rafi
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.532
Subject(s) - immunology , cd8 , immune system , immunity , t cell , cytotoxic t cell , antigen , biology , cd28 , transplantation , medicine , in vitro , biochemistry
To better understand the effect of chronic immunosuppressive therapies on protective immunity in transplant recipients, analysis of T cell subsets including antigen‐specific memory cells was performed at the time and various times after transplantation (3, 6, 9 and 12 months). A group of transplant recipients showed a maintenance or elevation in CMV‐specific T cells, despite being on a Tacrolimus immuno‐suppression. This elevation in CMV‐specific T cells is possibly due to exposure or due to reactivation of virus. CMV‐specific CD8 T cells from a transplant recipient showed functional exhaustion (as measured by lack of TNFa and IL‐2 production). We also studied patients undergoing T‐cell depletion with anti‐thymocyte globulin (ATG), to understand the dynamics and characteristics of repopulating T cells. Overall, T cells were homogeneously depleted by ATG. However, repopulation of CD8 T cells were variable (3–12 months) and were of an effector memory phenotype (CD45RA‐ CCR7‐). CMV and EBV specific T‐cells were reduced at 3 months after ATG induction. At later time points there was an elevation in CMV‐specific T cells, possibly due to loss of protective immunity and virus reactivation. These results suggest that patients on active immuno‐suppression can mount antigen‐specific immune responses and future experiments will be aimed at determining phenotype and functional quality of these cells.