B-cell expansion in the presence of the novel 293-CD40L-sCD40L cell line allows the generation of large numbers of efficient xenoantigen-free APC.
BACKGROUND
CD40-activated B lymphocytes have been used successfully as potent APC for the induction of T-cell responses. However, the 3T3-CD40L cell line, regularly used for engagement of CD40 on the B-cell surface, is a potential source of xenoantigens. This may affect the specificity of T cells stimulated with CD40-activated B cells, especially when generation of T-cell lines specific for endogenously processed Ag is desired.


METHODS
To develop a system that allows efficient expansion of B cells in the absence of sources of xenoantigens, we created a human 293-CD40L-sCD40L cell line that produces soluble CD40L and expresses CD40L on the cell surface. B cells from patients with hematologic malignancies were expanded on the 293-CD40L-sCD40L cells and used for stimulation of either naive or in vivo primed donor T cells in three HLA-identical patient-donor combinations.


RESULTS
The 293-CD40L-sCD40L cell line was able to stimulate B-cell growth with an efficiency superior to that of the commonly used 3T3-CD40L cell line. In all cases T-cell lines and, subsequently, T-cell clones were generated that showed reactivity against patient and not donor B cells, suggesting their specificity for minor histocompatibility antigens (mHAg).


CONCLUSIONS
B cells activated with GMP grade 293-CD40L-sCD40L can be used in a variety of applications. In particular, they may be suitable for ex vivo stimulation of T cells prior to donor lymphocyte infusion (DLI), which may enhance its graft versus leukemia (GvL) effect.
Ivanov
R
R
Jordan Laboratory for Hemato-Oncology, Department of Hematology, University Medical Center Utrecht, The Netherlands.
Aarts
T
T
Hagenbeek
A
A
Hol
S
S
Ebeling
S
S
D016475:3T3 Cells / Q000276:immunology; D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology* / Q000276:immunology; D015478:Antigens, Heterophile / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D019013:CD40 Antigens / Q000276:immunology; D023201:CD40 Ligand / Q000096:biosynthesis* / Q000276:immunology; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D049109:Cell Proliferation; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007938:Leukemia / Q000276:immunology / Q000628:therapy; D008213:Lymphocyte Activation / Q000276:immunology*; D017710:Lymphocyte Transfusion / Q000379:methods; D051379:Mice; D015778:Minor Histocompatibility Antigens / Q000276:immunology; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology
D015478:Antigens, Heterophile; D019013:CD40 Antigens; D006680:HLA Antigens; D015778:Minor Histocompatibility Antigens; D023201:CD40 Ligand