|
|
||||||||


Departments of
*
Molecular Genetics and Biochemistry, and
Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261; and
Department of Pathology, Allegheny General Hospital, Pittsburgh, PA 15212
We examined the functional and molecular parameters involved in
direct TCR recognition of a tumor-specific peptide epitope on the tumor
Ag MUC1. This peptide epitope is tandemly repeated and recognized on
the native molecule rather than processed and bound to the MHC. Even
though the TCR was not MHC restricted, intercellular interactions found
to facilitate this recognition included intercellular adhesion
molecule-1/LFA-1, LFA-3/CD2, and class I/CD8. Intracellular parameters
of MHC-unrestricted CTL activation were examined to compare the
recognition of the MUC1 epitope presented on synthetic microspheres,
with the recognition of the native epitope in the context of other
molecules on the target cells. The epitope on microspheres induced a
transient influx of Ca2+ that was not accompanied by
detectable tyrosine phosphorylation of the
-associated protein
ZAP-70, whereas recognition of MUC1 epitopes on tumor cells caused a
sustained Ca2+ influx and ZAP-70 phosphorylation. The
transient influx of Ca2+ was not sufficient to cause
translocation of the nuclear factor of activated T cells (NF-AT) into
the nucleus or CTL proliferation. In contrast, recognition of the MUC1
epitope on tumor cells resulted in full activation of the CTL, nuclear
translocation of NF-AT, and proliferation. MHC-unrestricted TCR
triggering, therefore, involves similar intercellular and intracellular
events that participate in the conventional, MHC-restricted Ag
recognition. Direct recognition of the MUC1 peptide epitope by the TCR
in the absence of presentation by the MHC induces a partial signal that
is completed by further interactions of other receptor/ligand pairs on
the surface of the CTL and their target cells.
This article has been cited by other articles:
![]() |
Q. J. Wang, K.-i. Hanada, and J. C. Yang Characterization of a Novel Nonclassical T Cell Clone with Broad Reactivity against Human Renal Cell Carcinomas J. Immunol., September 15, 2008; 181(6): 3769 - 3776. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. J. Finn Immunological Weapons Acquired Early in Life Win Battles with Cancer Late in Life J. Immunol., August 1, 2008; 181(3): 1589 - 1592. [Full Text] [PDF] |
||||
![]() |
Q. Shen, J. J. Rahn, J. Zhang, N. Gunasekera, X. Sun, A. R.E. Shaw, M. J. Hendzel, P. Hoffman, A. Bernier, and J. C. Hugh MUC1 Initiates Src-CrkL-Rac1/Cdc42-Mediated Actin Cytoskeletal Protrusive Motility after Ligating Intercellular Adhesion Molecule-1 Mol. Cancer Res., April 1, 2008; 6(4): 555 - 567. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. M. Alajez, J. Schmielau, M. D. Alter, M. Cascio, and O. J. Finn Therapeutic potential of a tumor-specific, MHC-unrestricted T-cell receptor expressed on effector cells of the innate and the adaptive immune system through bone marrow transduction and immune reconstitution Blood, June 15, 2005; 105(12): 4583 - 4589. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. J. Wajchman, C. W. Pierce, V. A. Varma, M. M. Issa, J. Petros, and K. E. Dombrowski Ex Vivo Expansion of CD8+CD56+ and CD8+CD56- Natural Killer T Cells Specific for MUC1 Mucin Cancer Res., February 1, 2004; 64(3): 1171 - 1180. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Hiltbold, A. M. Vlad, P. Ciborowski, S. C. Watkins, and O. J. Finn The Mechanism of Unresponsiveness to Circulating Tumor Antigen MUC1 Is a Block in Intracellular Sorting and Processing by Dendritic Cells J. Immunol., October 1, 2000; 165(7): 3730 - 3741. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Komatsu, L. Yee, and K. L. Carraway Overexpression of Sialomucin Complex, a Rat Homologue of MUC4, Inhibits Tumor Killing by Lymphokine-activated Killer Cells Cancer Res., May 1, 1999; 59(9): 2229 - 2236. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |