High avidity myeloid leukemia-associated antigen-specific CD8+ T cells preferentially reside in the bone marrow.
The activity of allogeneic CD8(+) T cells specific for leukemia-associated antigens (LAAs) is thought to mediate, at least in part, the curative effects of hematopoietic stem cell transplantation (HSCT) in myeloid malignancies. However, the identity and nature of clinically relevant LAA-specific CD8(+) T-cell populations have proven difficult to define. Here, we used a combination of coreceptor-mutated peptide-major histocompatibility complex class I (pMHCI) tetramers and polychromatic flow cytometry to examine the avidity profiles, phenotypic characteristics, and anatomical distribution of HLA A*0201-restricted CD8(+) T-cell populations specific for LAAs that are over-expressed in myeloid leukemias. Remarkably, LAA-specific CD8(+) T-cell populations, regardless of fine specificity, were confined almost exclusively to the bone marrow; in contrast, CD8(+) T-cell populations specific for the HLA A*0201-restricted cytomegalovirus (CMV) pp65(495-503) epitope were phenotypically distinct and evenly distributed between bone marrow and peripheral blood. Furthermore, bone marrow-resident LAA-specific CD8(+) T cells frequently engaged cognate antigen with high avidity; notably, this was the case in all tested bone marrow samples derived from patients who achieved clinical remission after HSCT. These data suggest that concomitant examination of bone marrow specimens in patients with myeloid leukemias might yield more definitive information in the search for immunologic prognosticators of clinical outcome.
Melenhorst
J Joseph
JJ
Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA. melenhoj@nhlbi.nih.gov
Scheinberg
Phillip
P
Chattopadhyay
Pratip K
PK
Gostick
Emma
E
Ladell
Kristin
K
Roederer
Mario
M
Hensel
Nancy F
NF
Douek
Daniel C
DC
Barrett
A John
AJ
Price
David A
DA
D000293:Adolescent; D000328:Adult; D001854:Bone Marrow Cells / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015234:HLA-A Antigens / Q000276:immunology; D015789:HLA-A2 Antigen; D006801:Humans; D007951:Leukemia, Myeloid / Q000276:immunology*; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology*; D008875:Middle Aged; D010641:Phenotype
D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D008562:Membrane Glycoproteins; C028388:thymus-leukemia antigens