Differential signaling through the Ig‐α and Ig‐β components of the B cell antigen receptor

European Journal of Immunology - Tập 23 Số 4 - Trang 911-916 - 1993
Kwang‐Myong Kim1,2, Gottfried Alber1,3, Peter Weiser1, Michael Reth1
1Max-Planck Institut für Immunbiologie, Freiburg
2Recipient of a fellowship from the Alexander von Humboldt Foundation.
3Recipient of a “Habilitation stipend” fellowship from the Deutsche Forschungsgemeinschaft.

Tóm tắt

Abstract

The B cell antigen receptor is a complex containing the antigen‐binding immunoglobulin molecules and the Ig‐α/Ig‐β heterodimer which presumably connects the B cell antigen receptor to intracellular signaling components. To analyze the functional properties of the cytoplasmic parts of the B cell antigen receptor, we used the K46 B lymphoma line (IgG2a, χ) to express chimeric molecules composed of the extracellular and transmembrane part of the CD8α molecule and the cytoplasmic sequence of either the Ig‐α (CD8α/Ig‐α), the Ig‐β (CD8α/Ig‐β) protein or the membrane‐bound γ2a heavy chain (CD8α/γ2a). From these three types of chimeric molecules only CD8α/Ig‐α and CD8α/Ig‐β, but not CD8α/γ2a, could transduce signals, thus providing the first evidence that the cytoplasmic tail of Ig‐α and Ig‐β have a signaling capacity. After cross‐linking with anti‐CD8α antibodies, both molecules induced a similar increase in intracellular free calcium ion and in MAP kinase phosphorylation. Protein tyrosine kinases, however, were strongly activated via the CD8α/Ig‐α and only marginally via the CD8α/Ig‐β molecule. This suggests that the Ig‐α and Ig‐β proteins have distinct roles during signal transduction through the B cell antigen receptor.

Từ khóa


Tài liệu tham khảo

10.1126/science.2404338

10.1126/science.1702903

10.1002/j.1460-2075.1990.tb07381.x

10.1038/345810a0

10.1073/pnas.88.8.3436

10.1073/pnas.88.4.1311

10.4049/jimmunol.149.5.1548

10.1002/j.1460-2075.1988.tb03219.x

10.1002/j.1460-2075.1988.tb03220.x

10.1038/343760a0

10.1002/eji.1830201239

10.1038/352777a0

Campbell K. S., 1990, J. Immunol., 147, 1575, 10.4049/jimmunol.147.5.1575

10.1073/pnas.88.9.3982

10.1146/annurev.iy.10.040192.000525

10.1016/0167-5699(91)90053-V

10.1002/j.1460-2075.1987.tb02739.x

10.1084/jem.167.2.652

10.1083/jcb.109.1.73

Kim K.‐J., 1979, J. Immunol., 122, 549, 10.4049/jimmunol.122.2.549

10.1073/pnas.85.18.6890

10.1016/0092-8674(89)90100-1

10.1016/0092-8674(92)90085-Q

Justement L. B., 1990, J. Immunol., 144, 3272, 10.4049/jimmunol.144.9.3272

10.1111/j.1600-065X.1993.tb00840.x

10.1146/annurev.iy.08.040190.001035

10.1146/annurev.ge.25.120191.002415

10.1016/0092-8674(91)90314-O

10.1016/0092-8674(91)90327-U

10.1073/pnas.88.20.8905

10.1084/jem.176.1.139

10.1038/338383b0

10.1016/0092-8674(92)90208-T

10.1126/science.1532456

Yu L. M., 1992, J. Immunol., 148, 633, 10.4049/jimmunol.148.2.633

Ha H., 1992, J. Immunol., 148, 1526, 10.4049/jimmunol.148.5.1526

10.1007/BF00215058

10.1002/eji.1830220641

10.1126/science.1439759

10.1073/pnas.89.12.5660

10.4049/jimmunol.148.10.3021

10.1016/0006-291X(92)90496-8

10.1073/pnas.88.7.2745

10.1126/science.1382311

10.1016/0092-8674(92)90075-N

10.1016/0092-8674(92)90076-O

10.1016/0092-8674(92)90361-F