A. Husebekk et al., Selection and expansion of T cells from untreated patients with CLL: source of cells for immune reconstitution?, CYTOTHERAPY, 2(3), 2000, pp. 187-193
Citations number
24
Categorie Soggetti
Hematology,"Medical Research Diagnosis & Treatment
Background Lymphocyte-derived malignancies can be treated with combinations
of drugs that efficiently eradicate normal and malignant lymphocytes. Lack
of T lymphocytes after treatment of B lymphocyte CLL (B-CLL) makes the pat
ients susceptible to serious infections and may limit the benefit of the th
erapy. The aim of the study was to purify and culture-expand normal T lymph
ocytes from B-CLL patients prior to therapy. These cells could be frozen an
d given to the patients in the period post-chemotherapy.
Methods T lymphocyte were isolated from the mononuclear cell apheresis prod
ucts from five patients with previously untreated B-CLL. The apheresis prod
ucts were red-cell depleted by density gradient centrifugation. B-lymphocyt
e purging was performed by incubating with MAbs to four different B-cell ep
itopes, followed by magnetic-bead depletion. One round of negative selectio
n removed >90% of the B lymphocytes. The T-lymphocyte enriched cell suspens
ion was cultured for 10/11 days in the presence of IL-2 and the anti-T cell
receptor Ab OKT3. In addition, in some cultures anti-CD22 ricin immunotoxi
n was added.
Results T cells from CLL patients expanded 4.7-21-fold over a 10/11 days cu
lture interval. After culture, CLL cells could no longer be identified by f
low cytometric evaluation. The cultured T lymphocytes were predominately CD
8+, and were capable of lysing autologous CLL cells through a fas-dependent
mechanism.
Discussion Selection and expansion of T lymphocytes by this method may repr
esent a strategy for enhancing immunity in the lymphocytic period following
CLL treatment.