Use of B cell-bound HLA-A2 class I monomers to generate high-avidity, allo-restricted CTLs against the leukemia-associated protein Wilms tumor antigen.
Recent studies have detected Wilms tumor antigen (WT1)-specific cytotoxic T lymphocytes (CTLs) in patients with acute myelogenous leukemia (AML) and chronic myelogenous leukemia (CML) and demonstrated that most of these CTLs were low avidity. Although HLA-mismatched donors can mount high-avidity CTLs against HLA-A2-presented peptides of WT1, a dominant anti-alloimmune response usually obscures detection of peptide-specific CTLs. Here we explored the feasibility of using recombinant HLA-A2 monomers containing single peptide epitopes as immunogens to generate peptide-specific CTLs from allogeneic donors. We demonstrate that the coating of HLA-A2(-) B lymphocytes with A2/peptide monomers provides a strong stimulus for autologous peptide-specific CTLs. After 3 to 5 rounds of stimulation a population of CD8(+) T cells binding A2/peptide tetramers is easily detectable by fluorescence-activated cell sorting analysis. Furthermore, sorted A2/WT1 tetramer-positive CTLs display strong cytotoxic activity against leukemia cells expressing WT1 endogenously but not against WT1(-) human tumor cells. Thus, HLA/peptide monomers may be useful to isolate peptide-specific donor lymphocytes for treatment of patients with leukemia after HLA-mismatched transplantation.
Alexis Biotechnology Ltd., London, England, UK.
Philip
P
Savage
Liquan
L
Gao
Kevin
K
Vento
Pam
P
Cowburn
Stephen
S
Man
Neil
N
Steven
Graham
G
Ogg
Andrew
A
McMichael
Agamemnon
A
Epenetos
Els
E
Goulmy
Hans J
HJ
Stauss
D000915:Antibody Affinity / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D012016:Reference Values; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D025721:WT1 Proteins / Q000276:immunology*
D015789:HLA-A2 Antigen; D025721:WT1 Proteins