RT Journal Article
SR Electronic
T1 The Anti-MUC1 Monoclonal Antibody BCP8 Can Be Used to Isolate and Identify Putative Major Histocompatibility Complex Class I Associated Amino Acid Sequences
JF Cancer Research
JO Cancer Res
FD American Association for Cancer Research
SP 5151
OP 5156
VO 58
IS 22
A1 Agrawal, Babita
A1 Reddish, Mark A.
A1 Christian, Brenda
A1 VanHeele, Anneke
A1 Tang, Leon
A1 Koganty, R. Rao
A1 Longenecker, B. Michael
YR 1998
UL http://cancerres.aacrjournals.org/content/58/22/5151.abstract
AB MHC class I molecules were isolated from the MUC1-positive human breast adenocarcinoma cell line MCF-7 by immunoaffinity using the panreactive anti-class I monoclonal antibody (MAb) W6/32. Acid-eluted peptides from the class I molecules were separated twice by high-performance liquid chromatography and tested for reactivity with the MAb BCP8, which reacts with the minimal MUC1 core peptide sequence PDTRPA. A peak with strong and specific BCP8 reactivity was found in fractions eluting at 16.5–17.5 min. The protocol used for the MUC1+ pancreatic adenocarcinoma cell line CAPAN-1 (HLA.A2) was to perform sequential affinity purifications of class I molecules using MAb W6/32, followed by affinity purification of HLA.A2 molecules by the HLA.A2.1-specific MAb, MA2.1, and high-performance liquid chromatography fractionation of the acid-eluted material. A single peak with MAb BCP8 reactivity was noted at 18–19 min. The protocol for the MUC1+ breast adenocarcinoma cell line SKBr-3 (HLA.A11,B40), which used A11- and B40-specific MAbs, also resulted in the detection of BCP8-specific peaks at ∼18–19 min. A preliminary mass spectral analysis of BCP8 affinity-purified class I associated material surprisingly revealed the presence of two 3-mer MUC1 amino acid sequences and one 6-mer sequence. A synthetic 9-mer MUC1 peptide, TSAPDTRPA, containing the isolated fragments was found to cause strong class I up-regulation in T2 cells as well as to serve as an epitope for CTL generated in a primary in vitro immune response. These studies suggest that MUC1-derived peptides are processed and presented in the context of MHC class I molecules on the surface of tumor cells and support the use of MAb BCP8 to further define MHC class I associated MUC1 motifs. ©1998 American Association for Cancer Research.