title: CD4+ CD25+ FOXP3+ regulatory T cells increase de novo in kidney transplant patients after immunodepletion with Campath-1H.
abstract: Campath-1H (Alemtuzumab) is an effective immunodepletion agent used in renal transplantation. To evaluate its influence on T lymphocytes during repletion, we analyzed peripheral blood from Campath-1H-treated renal allograft recipients for the presence of FOXP3(+) regulatory T (Treg) cells. Flow cytometry demonstrated that CD4(+)CD25(+)FOXP3(+) lymphocytes increased significantly within the CD4(+) T-cell population, skewing Treg/Teff (T effector) ratios for up to several years. In contrast, Treg levels in patients treated with anti-CD25 (Basiliximab) and maintained on CsA demonstrated a sustained decrease. The increase in Tregs in Campath-1H treated patients developed independent of maintenance immunosuppression. Importantly, the increase in Tregs was not fully explained by their homeostatic proliferation, increased thymic output, or Treg sparing, suggesting de novo generation/expansion. Consistent with this, in vitro stimulation of PBMCs with Campath-1H, with or without anti-CD3, activation led to an increase in CD4(+)CD25(+)FOXP3(+) cells that had suppressive capabilities. Together, these data suggest that Campath-1H promotes an increase in peripheral Tregs and may act as an intrinsic generator of Tregs in vivo.
authors.affiliation: University of Wisconsin-Madison, Department of Surgery, Division of Solid Organ Transplantation, Madison, WI, USA. bloom@surgery.wisc.edu
authors.forename: D D
authors.initials: DD
authors.lastname: Bloom
authors.forename: Z
authors.initials: Z
authors.lastname: Chang
authors.forename: J H
authors.initials: JH
authors.lastname: Fechner
authors.forename: W
authors.initials: W
authors.lastname: Dar
authors.forename: S P
authors.initials: SP
authors.lastname: Polster
authors.forename: J
authors.initials: J
authors.lastname: Pascual
authors.forename: L A
authors.initials: LA
authors.lastname: Turka
authors.forename: S J
authors.initials: SJ
authors.lastname: Knechtle
mesh_terms: D000293:Adolescent; D000328:Adult; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000276:immunology* / Q000627:therapeutic use*; D000077552:Basiliximab; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D016030:Kidney Transplantation / Q000276:immunology*; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D008875:Middle Aged; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use; D020123:Sirolimus / Q000627:therapeutic use; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D053645:Interleukin-2 Receptor alpha Subunit; D011993:Recombinant Fusion Proteins; D000074323:Alemtuzumab; D000077552:Basiliximab; D020123:Sirolimus