| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
,
,
* Department of Molecular Biosciences,
Institute of Immunology, and
Centre for Immune Regulation, University of Oslo, Oslo, Norway; and
Department of Vaccines, National Institute of Public Health, Oslo, Norway
Targeting of T cell epitopes to APC enhances T cell responses. We used an APC-specific Ab (anti-IgD) and substituted either of 18 loops connecting β strands in human IgG constant H (CH) domains with a characterized T cell peptide epitope. All Ab-epitope fusion molecules were secreted from producing cells except IgG-loop 2(BC)CH1, and comparing levels, a hierarchy appeared with fusions involving CH2
CH1>CH3. Within each domain, fusion at loop 6(FG) showed best secretion, while low secretion correlated with the substitution of native loops that contain conserved amino acids buried within the folded molecule. Comparing the APC-specific rAb molecules for their ability to induce T cell activation in vitro, the six mutants with epitope in CH2 were the most effective, with loop 4CH2 ranking on top. The CH1 mutants were more resistant to processing, and the loop 6CH1 mutant only induced detectable activation. The efficiency of the CH3 mutants varied, with loop 6CH3 being the least effective and equal to loop 6 CH1. Considering both rAb secretion level and T cell activation efficiency, a total of eight loops may carry T cell epitopes to APC for processing and presentation to T cells, namely, all in CH2 in addition to loop 6 in CH1 and CH3. Comparing loop 4CH2 with loop 6CH1 mutants after injection of Ab in BALB/c mice, the former was by far the most efficient and induced specific T cell activation at concentrations at least 100-fold lower than loop 6CH1.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This work was funded by the Norwegian Cancer Society (to M.F. and I.B.R.) and the Research Council of Norway (to E.L., T.F., and G.B.).
2 Current address: BioInn, 2317 Hamar, Norway.
3 Address correspondence and reprint requests to Dr. Inger Sandlie, Department of Molecular Biosciences, University of Oslo, PO Box 1041 Blindern, NO-0316 Oslo, Norway. E-mail address: inger.sandlie{at}imbv.uio.no
4 Abbreviations used in this paper: CH, constant region of Ig H chain; RT, room temperature; AEP, asparaginyl endopeptidase; wt, wild type.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
