Optimization of human T-cell expansion ex vivo using magnetic beads conjugated with anti-CD3 and Anti-CD28 antibodies.
T-cell receptor engagement and accompanying costimulatory signals control the level of activation and functional potential of individual T cells. The authors previously developed a novel technology in which human T cells are activated and expanded in culture ex vivo using anti-CD3 and anti-CD28 monoclonal antibodies covalently linked to superparamagnetic beads (Xcyte Dynabeads). In this study the addition of N-acetyl L-cysteine (NAC) to the cultures markedly increased the expansion of T cells from human peripheral blood mononuclear cells without diminishing cell function. NAC increased the rate of T-cell division, reduced apoptosis, and increased the percentage of antigen-specific memory T cells in the cultures. The effect of varying the ratio of beads to T cells (1:10-10:1) at culture initiation was also evaluated. Polyclonal T cells were expanded at all bead-to-T cell ratios tested (range 1:10-10:1). While high bead-to-T cell ratios (5:1 and 10:1) deleted, low ratios (1:10 and 1:5) preserved memory T cells directed against cytomegalovirus, Epstein-Barr virus, and influenza virus antigens. Adding more anti-CD3/anti-CD28 beads during the culture led to further expansion of T cells. Experiments also revealed that reducing the amount of anti-CD3 antibodies relative to the amount of anti-CD28 antibodies on the beads favored the proliferation of antigen-specific T cells. In summary, these data indicate that T cell-stimulating effects of anti-CD3/anti-CD28 beads can be further manipulated to control the expansion of antigen-specific memory T cells and can be used to rapidly expand antigen-specific T cells ex vivo for potential clinical applications.
Xcyte Therapies, Inc., Seattle, Washington 98104, USA.
Dale
D
Kalamasz
S A
SA
Long
Ruth
R
Taniguchi
Jane H
JH
Buckner
Ronald J
RJ
Berenson
Mark
M
Bonyhadi
D000111:Acetylcysteine / Q000494:pharmacology; D018106:CD28 Antigens / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology*; D018929:Cell Culture Techniques / Q000379:methods*; D005434:Flow Cytometry; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D008280:Magnetics; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000276:immunology
D018106:CD28 Antigens; D017252:CD3 Complex; D000111:Acetylcysteine