Adoptive transfer of cytomegalovirus-specific CTL to stem cell transplant patients after selection by HLA–peptide tetramers

Abstract

Stem cell transplantation is used widely in the management of a range of diseases of the hemopoietic system. Patients are immunosuppressed profoundly in the early posttransplant period, and reactivation of cytomegalovirus (CMV) remains a significant cause of morbidity and mortality. Adoptive transfer of donor-derived CMV-specific CD8+ T cell clones has been shown to reduce the rate of viral reactivation; however, the complexity of this approach severely limits its clinical application. We have purified CMV-specific CD8+ T cells from the blood of stem cell transplant donors using staining with HLA–peptide tetramers followed by selection with magnetic beads. CMV-specific CD8+ cells were infused directly into nine patients within 4 h of selection. Median cell dosage was 8.6 × 103/kg with a purity of 98% of all T cells. CMV-specific CD8+ T cells became detectable in all patients within 10 d of infusion, and TCR clonotype analysis showed persistence of infused cells in two patients studied. CMV viremia was reduced in every case and eight patients cleared the infection, including one patient who had a prolonged history of CMV infection that was refractory to antiviral therapy. This novel approach to adoptive transfer has considerable potential for antigen-specific T cell therapy.

Depletion of naive T cells using clinical grade magnetic CD45RA beads: a new approach for GVHD prophylaxis

“…11 The use of CD45RA À memory T cells in adoptive immunotherapy could also circumvent the technically much more complex and pathogen-restricted ex vivo selection of pathogen-specific donor T cells by HLA-peptide multimers or cytokine secretion assays. 12,13 The absolute numbers of pathogen-reactive IFN-g spot-forming cells were overall not increased in CD45RA -memory T cells compared with original LPs. Potential reasons for this observation are the depletion-induced variation in CD4/CD8 ratio as well as the removal of late effector T cells.…”

Vaccine properties of a novel marker gene-free recombinant modified vaccinia Ankara expressing immunodominant CMV antigens pp65 and IE1

“…Procedures which depend on CMV lysate for T cell expansion are unlikely to be applicable to the clinic, since the reproducibility of the antigenic mixture is in question, as well as its composition that includes disrupted CMV virions. Other techniques that rely on purification of CMV-specific T cells using HLA tetramers, or through the combination of stimulating peptides and bi-specific capture antibodies are not designed to amplify T cells [14,21]. Consequently, they require more incubation time and larger volumes of blood, because they capture existing T cells, but do not stimulate T cell proliferation that is the hallmark of MVA.…”

“…Similar to healthy adults, CMV tegument protein pp65 and CMV IE1 are frequently recognized by human CD4 + and CD8 + T cells in HCT and SOT recipients and CMI against them may be linked to protection against viremia. [18][19][20][21][22][23][24][25].…”

Concise Review: Expanding Roles for Hematopoietic Cellular Therapy and the Blood Transfusion Services

“…It is now possible to identify and select out CMV-specific T-lymphocytes from healthy donor blood by immunomagnetic techniques. These concentrated CMV specific cells are then reinfused into the patient, with a dramatic increase in CMV-specific lymphocytes, and importantly, resolution of the viraemia [31]. Similar techniques have been adopted to treat Ebstein-Barr virus (EBV)-and adenovirusassociated viraemia in both the post-bone marrow transplants and solid organ transplant setting [32,33].…”