Targeted in-vitro-stimulation reveals highly proliferative multi-virus-specific human central memory T cells as candidates for prophylactic T cell therapy

PLoS One. 2019 Sep 30;14(9):e0223258. doi: 10.1371/journal.pone.0223258. eCollection 2019.

Abstract

Adoptive T cell therapy (ACT) has become a treatment option for viral reactivations in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT). Animal models have shown that pathogen-specific central memory T cells (TCM) are protective even at low numbers and show long-term survival, extensive proliferation and high plasticity after adoptive transfer. Concomitantly, our own recent clinical data demonstrate that minimal doses of purified (not in-vitro- expanded) human CMV epitope-specific T cells can be sufficient to clear viremia. However, it remains to be determined if human virus-specific TCM show the same promising features for ACT as their murine counterparts. Using a peptide specific proliferation assay (PSPA) we studied the human Adenovirus- (AdV), Cytomegalovirus- (CMV) and Epstein-Barr virus- (EBV) specific TCM repertoires and determined their functional and proliferative capacities in vitro. TCM products were generated from buffy coats, as well as from non-mobilized and mobilized apheresis products either by flow cytometry-based cell sorting or magnetic cell enrichment using reversible Fab-Streptamers. Adjusted to virus serology and human leukocyte antigen (HLA)-typing, donor samples were analyzed with MHC multimer- and intracellular cytokine staining (ICS) before and after PSPA. TCM cultures showed strong proliferation of a plethora of functional virus-specific T cells. Using PSPA, we could unveil tiniest virus epitope-specific TCM populations, which had remained undetectable in conventional ex-vivo-staining. Furthermore, we could confirm these characteristics for mobilized apheresis- and GMP-grade Fab-Streptamer-purified TCM products. Consequently, we conclude that TCM bare high potential for prophylactic low-dose ACT. In addition, use of Fab-Streptamer-purified TCM allows circumventing regulatory restrictions typically found in conventional ACT product generation. These GMP-compatible TCM can now be used as a broad-spectrum antiviral T cell prophylaxis in alloHSCT patients and PSPA is going to be an indispensable tool for advanced TCM characterization during concomitant immune monitoring.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Adenoviridae / immunology*
  • Adoptive Transfer
  • Biological Assay
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / virology
  • Cell Proliferation
  • Cytomegalovirus / genetics
  • Cytomegalovirus / immunology*
  • Epitopes / genetics
  • Epitopes / immunology*
  • Female
  • Gene Expression
  • Healthy Volunteers
  • Herpesvirus 4, Human / genetics
  • Herpesvirus 4, Human / immunology*
  • Histocompatibility Testing
  • Humans
  • Immunologic Memory*
  • Immunomagnetic Separation / methods
  • Immunophenotyping
  • Lymphocyte Activation
  • Male
  • Peptides / genetics
  • Peptides / immunology
  • Primary Cell Culture

Substances

  • Epitopes
  • Peptides

Grants and funding

This work was supported by the German Center for Infection Research (DZIF, TTU 07.801 and 07.902) (B.F., F.S.,K.M.D., D.H.B., M.N.), and the Deutsche Forschungsgemeinschaft (DFG) through collaborative center TR36- A10 (M.N. and D.H.B.). C.S. is an employee of Juno Therapeutics GmbH, CellGene. Juno Therapeutics GmbH, CellGene provided support in the form of salaries for authors [CS], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of CS is articulated in the ‘author contributions’ section.