Degradation of the immunogenic peptide gp100(280-288) by the monocyte-like U937 cell line.

Abstract

The possible degradation of the tumor antigen epitope gp100(280-288) (YLEPGPVTA) in the presence of the monocyte-like line U937, and the effect of degradation on the in vitro-measured immune recognition, were investigated by chromatographic techniques and immunological assays. Results indicate a rapid hydrolysis of the substrate in the presence of the model cells, which is consistent with the hypothesis that degradation of gp100(280-288) is caused by the activity of U937-expressed enzymes, specifically amino- and carboxypeptidases. On the other hand, these results do not support the involvement of other enzymes known to be expressed by U937 cells. From a functional point of view, these data indicate that the degradation of gp100(280-288) severely hampered recognition by specific CTL clones. The results obtained may provide a model for epitope degradation by the antigen-presenting cells found in defined anatomical compartments and may, at least in part, account for the low activity of peptide-based antineoplastic vaccines, as well as for the transience of the effects of subcutaneously administered peptides in general.

• Authors: Federica Albo, Antonella Cavazza, Bruno Giardina, Silvio Lippa, Mario Marini, L Giorgio Roda, Giulio Spagnoli
• Journal: Peptides (Peptides) Vol. 24 Issue 3 Pg. 371-8 (Mar 2003) ISSN: 0196-9781 [Print] United States
• PMID: 12732334 (Publication Type: Journal Article)

Chemical References

• Amino Acids
• Antigens, Neoplasm
• Peptide Fragments

Topics

• Amino Acids (metabolism)
• Antigens, Neoplasm (chemistry, immunology, metabolism)
• Humans
• Hydrolysis
• Kinetics
• Melanoma (chemistry, immunology)
• Monocytes (metabolism)
• Peptide Fragments (chemistry, immunology, metabolism)
• T-Lymphocytes, Cytotoxic (immunology)
• U937 Cells