Tetanus toxoid provides efficient T-cell help for the induction of HA-1(H) cytotoxic T cells.
BACKGROUND
In vitro generation and expansion of leukemia-reactive T cells may improve the efficacy and specificity of cellular immunotherapy against hematologic malignancies in the context of allogeneic stem cell transplantation. Since the expression of minor histocompatibility antigen HA-1(H) is limited to hematopoietic cells, ex vivo generated HA-1(H)-specific CD8+ cytotoxic T lymphocytes (CTLs) can be used for adoptive immunotherapy.


METHODS
Numerous studies have shown that primary CTL induction from naïve precursors requires professional antigen-presenting cells. Here, the feasibility of ex vivo induction of HA-1(H)-specific CD8+ CTLs is demonstrated from unfractionated peripheral blood mononuclear cells (PBMNCs) from healthy blood donors when CD4+ T-cell help is provided during primary stimulation. As a stimulus for the induction of T-cell help, tetanus toxoid (TT) was used.


RESULTS
After the second restimulation cycle, approximately 1 percent of CD8+ T cells stained positively with the HLA-A*0201/HA-1(H) pentamer. Positive T cells were further expanded more than 1000-fold by antigen-independent stimulation with anti-CD3/CD28 monoclonal antibodies. HA-1(H)-induced T cells showed the classical phenotype for CD8+ memory effector cells: the phenotype changed from a mixed CD45RA/RO phenotype to an activated phenotype characterized by high expression of CD45RO and no expression of CCR7. The generated T cells revealed a very potent CTL response, even at low E:T ratios.


CONCLUSIONS
This study demonstrates that TT provides a very potent and cost-effective tool for the in vitro induction of antigen-specific CTLs from precursor PBMNCs that can easily be adapted to GMP conditions for translational purposes.
Eiz-Vesper
Britta
B
Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany.
Horn
Peter A
PA
Daubert
Claudia
C
Khattab
Barbara
B
Blasczyk
Rainer
R
D017951:Antigen Presentation / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D008213:Lymphocyte Activation / Q000187:drug effects*; D015778:Minor Histocompatibility Antigens / Q000032:analysis / Q000276:immunology*; D009842:Oligopeptides / Q000032:analysis / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013745:Tetanus Toxoid / Q000276:immunology / Q000494:pharmacology*
C110615:HA-1 antigen; D015778:Minor Histocompatibility Antigens; D009842:Oligopeptides; D013745:Tetanus Toxoid