title: Successful isolation and expansion of CMV-reactive T cells from G-CSF mobilized donors that retain a strong cytotoxic effector function.
abstract: Cytomegalovirus (CMV) infections post-haematopoietic stem cell transplantation (HSCT) can be effectively controlled through the adoptive transfer of donor-derived CMV-specific T cells (CMV-T). Current strategies involve a second leukapheresis collection from the original donor to manufacture CMV-T, which is often not possible in the unrelated donor setting. To overcome these limitations we have investigated the use of a small aliquot of the original granulocyte-colony stimulating factor (G-CSF) mobilized HSCT graft to manufacture CMV-T. We explored the T cell response to CMVpp65 peptide stimulation in G-CSF mobilized peripheral blood mononuclear cells (PBMC) and subsequently examined isolation of CMV-T based on the activation markers CD154 and CD25. CD25(+)  enriched CMV-T from G-CSF mobilized PBMC contained a higher proportion of FoxP3 expression than non-mobilized PBMC and showed superior suppression of T cell proliferation. Expanded CMV-T enriched through CD154 were CD4(+)  and CD8(+) , demonstrated a high specificity for CMV, secreted cytotoxic effector molecules and lysed CMVpp65 peptide-loaded phytohaemagglutinin-stimulated blasts. These data provide the first known evidence that CMV-T can be effectively manufactured from G-CSF mobilized PBMC and that they share the same characteristics as CMV-T isolated in an identical manner from conventional non-mobilized PBMC. This provides a novel strategy for adoptive immunotherapy that abrogates the need for successive donation.
authors.affiliation: Department of Haematology, University College, London Medical School, University College London, London, UK.
authors.forename: Edward R
authors.initials: ER
authors.lastname: Samuel
authors.forename: Katy
authors.initials: K
authors.lastname: Newton
authors.forename: Stephen
authors.initials: S
authors.lastname: Mackinnon
authors.forename: Mark W
authors.initials: MW
authors.lastname: Lowdell
mesh_terms: D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005434:Flow Cytometry; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006801:Humans; D016219:Immunotherapy, Adoptive; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D010750:Phosphoproteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000494:pharmacology
chemical_list: D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D016179:Granulocyte Colony-Stimulating Factor