Functional Fv fragment of an antibody specific for CD28: Fv-mediated co-stimulation of T cells.
The most predominant co-stimulation pathway, which is critical for T cell activation and proliferation, is the CD28-B7 pathway. The anti-CD28 monoclonal antibody (mAb) also provides a co-stimulatory signal to T cells. In order to construct a functional Fv fragment (complex of VH and VL domains) of anti-CD28 antibody using a bacterial expression system, cDNA encoding the variable regions of immunoglobulin from 15E8 hybridoma cells was cloned and expressed in Escherichia coli. The Fv fragment was obtained as a soluble protein from the periplasmic fraction and showed a binding pattern similar to parental IgG. The Fv fragment induced proliferation of peripheral blood mononuclear cells in the presence of anti-CD3 or anti-CD2 mAb and enhanced anti-tumor activity of anti-MUC1x(anti)-CD3 bispecific antibody when tested with lymphokine-activated killer cells with T cell phenotype. Thus, the anti-CD28 Fv fragment will be promising not only for the study of co-stimulation, but also for cancer immunotherapy.
Takemura
S
S
Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Asano
R
R
Tsumoto
K
K
Arai
T
T
Sakurai
N
N
Kodama
H
H
Yoshida
H
H
Katayose
Y
Y
Suzuki
M
M
Matsuno
S
S
Kudo
T
T
Kumagai
I
I
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D018106:CD28 Antigens / Q000276:immunology*; D002455:Cell Division; D003001:Cloning, Molecular; D003602:Cytotoxicity, Immunologic; D004274:DNA, Recombinant / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D006825:Hybridomas; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology*; D007167:Immunotherapy; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018106:CD28 Antigens; D004274:DNA, Recombinant; D007128:Immunoglobulin Fragments; C055966:immunoglobulin Fv