Selection of autologous CD4+ T-cells for adoptive T-cell substitution in patients with CD23+ B-cell CLL.
BACKGROUND
B-cell CLL (B-CLL) is accompanied by a progressive decrease in cellular immune functions, and treatment-related immunosuppression can further aggravate T-cell immunodeficiency. To reduce the risks of T-cell depletion, it seems feasible to collect autologous CD4+ cells at an early disease stage and subsequently reinfuse them during periods of profound T-cell depletion.


METHODS
We describe a two-step cell-selection method to obtain highly enriched CD4+ T-cells from leukapheresis compounds of patients with CD23+ B-CLL. The double selection procedure was performed using the CellPro Ceperate device, and consisted of CD4+ selection followed by CD23 purging to further remove contaminating CD23+ B-cells from the CD4+ cell fraction. The results of eight runs performed with leukapheresis material obtained from eight patients with CD23+ B-CLL at different disease stages are presented.


RESULTS
The CD4/CD23 double cell-selection procedure resulted in the purification of > 90% CD4+ cells. Median recovery of CD4+ T lymphocytes after selection was 46%, and was negatively affected by the initial tumor cell load. The final T-cell fraction still contained lymphocytes of the B-CLL clone, as determined by FACS and PCR. The cell-processing procedure had no impact on T-cell function, as assessed by the in vitro production of the cytokine interferon-gamma. Moreover, the selected CD4+ cells retained their capacity to co-stimulate mitogen-induced B-cell IgG production in vitro.


CONCLUSIONS
The described CD4 selection/CD23 depletion strategy is a suitable approach to obtaining high numbers of functional active autologous CD4+ T cells for adoptive T-cell transfer in patients with CD23+ BCLL.
Dettke
M
M
AKH Wien, Department for Blood Group Serology and Transfusion Medicine, University of Vienna, Austria.
Berger
R
R
Jurko
S
S
Mitterbauer
G
G
Schwarzmeier
J D
JD
Höcker
P
P
D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000637:transplantation; D002469:Cell Separation / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology / Q000628:therapy*; D008875:Middle Aged; D010865:Pilot Projects; D017455:Receptors, IgE / Q000276:immunology / Q000378:metabolism; D014182:Transplantation, Autologous
D007074:Immunoglobulin G; D017455:Receptors, IgE; D007371:Interferon-gamma