Clinical grade expansion of CD45RA, CD45RO, and CD62L-positive T-cell lines from HLA-compatible donors: high cytotoxic potential against AML and ALL cells.
OBJECTIVE
Identification of a clinical grade method for the ex vivo generation of donor-derived T cells cytotoxic against both myeloid and lymphoblastic cells still remains elusive. We investigated rapid generation and expansion of donor derived-allogeneic T-cell lines cytotoxic against patient leukemic cells.


METHODS
Acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) blasts were cultured 5 days in Stem Span, granulocyte macrophage colony-stimulating factor, interleukin-4, and calcium ionophore. All B-precursor ALL (N22) and AML (N13), but not T-cell ALL (N3), differentiated into mature leukemia-derived antigen-presenting cells (LD-APC). All but one LD-APC generated cytotoxic T lymphocyte (CTL) from adult human leukocyte antigen (HLA)-identical (N8) or unrelated donors (N2).


RESULTS
Upon in vitro culture, donor-derived CTL acquired a memory T phenotype, showing concomitant high CD45RA, CD45RO, CD62L expression. CD8(+) cells, but not CD4(+) cells, were granzyme, perforine, and interferon-gamma-positive. Pooled CD4(+) and CD8(+) cells were cytotoxic against leukemic blasts (32%, 30:1 E:T ratio), but not against autologous or patient-derived phytohemagglutinin blasts. LD-APC from five ALL patients were used to generate CTL from cord blood. A mixed population of CD4(+) and CD8(+) cells was documented in 54% of wells. T cells acquired classical effector memory phenotype and showed a higher cytotoxicity against leukemia blasts (47%, 1:1 E:T ratio). Adult and cord blood CTL showed a skewing from a complete T-cell receptor repertoire to an oligo-clonal/clonal pattern.


CONCLUSIONS
Availability of these cells should allow clinical trials for salvage treatment of leukemia patients relapsing after allogeneic stem cell transplantation.
Laboratorio di Terapia Cellulare e Genica G. Lanzani, Ematologia, Ospedali Riuniti di Bergamo, Italy. abarbui@osepadaliriuniti.bergamo.it
Anna M
AM
Barbui
Gianmaria
G
Borleri
Elena
E
Conti
Alice
A
Ciocca
Anna
A
Salvi
Caterina
C
Micò
Martino
M
Introna
Alessandro
A
Rambaldi
D000293:Adolescent; D000328:Adult; D000368:Aged; D017951:Antigen Presentation / Q000187:drug effects / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002460:Cell Line; D002675:Child, Preschool; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D016219:Immunotherapy, Adoptive / Q000379:methods; D007223:Infant; D015847:Interleukin-4 / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D019041:L-Selectin / Q000276:immunology*; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000276:immunology* / Q000628:therapy; D015470:Leukemia, Myeloid, Acute / Q000276:immunology* / Q000628:therapy; D017493:Leukocyte Common Antigens / Q000276:immunology*; D019520:Living Donors; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D033581:Stem Cell Transplantation / Q000379:methods; D014184:Transplantation, Homologous
D006680:HLA Antigens; D007476:Ionophores; D019041:L-Selectin; D015847:Interleukin-4; D016173:Macrophage Colony-Stimulating Factor; D017493:Leukocyte Common Antigens