Title

Cancer Immunotherapy By Antisense Suppression Of Ii Protein In Mhc- Class-Ii-Positive Tumor Cells

Keywords

Antisense; Ii protein; Immunotherapy; MHC class II

Abstract

This study was aimed at creating a more effective tumor cell vaccine by suppressing Ii protein in the presence of MHC class II molecules within a cancer cell. Absence of the Ii protein, which normally blocks the antigenic- peptide-binding site of MHC class II molecules at synthesis in the endoplasmic reticulum, presumably increases the range of cancer-related epitopes presented to CD4+ helper T cells. Effective suppression of Ii protein was achieved with an antisense, phosphorothioate oligonucleotide, which was selected on the basis of (1) the RNase H activation assay, (2) an assay for Ii protein suppression, and (3) a test for potency with respect to the extent of base sequence ('sequence walking'). The SaI murine sarcoma, which is MHC-class-I+ and MHC-class-II-, Ii-protein-, upon transfection with genes for either interferon γ or the MHC class II transactivator, came to express MHC class II molecules and Ii protein. In each line of transfected tumor cells, the antisense oligonucleotide profoundly suppressed Ii protein in 35%-55% cells, without affecting expression of MHC class II molecules. Inoculation of mice with such Ii-protein-suppressed tumor vaccine cells, after either formaldehyde fixation or X-irradiation, led to much greater protection against challenge with the parental SaI sarcoma than did inoculation with untreated cells. This approach to cancer cell vaccination can be applied in a wide range of human tumors.

Publication Date

1-1-1999

Publication Title

Cancer Immunology Immunotherapy

Volume

48

Issue

9

Number of Pages

499-506

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1007/s002620050598

Socpus ID

0032694226 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0032694226

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