Abstract
Phenotypic and functional analyses of tumor-infiltrating lymphocytes (TILs) used in clinical trials revealed that cells other than CTLs can have antitumor efficacy. This observation led us to search for mechanisms for tumor recognition by lymphocytes that utilize alternatives to surface structures of tumor cells, for example, MHC antigen complexes; the latter are generally believed to be the immunogenic platforms for CTLs. Therefore, as a possible source of immunostimulatory activity, we compared the ability of plasma membrane components of tumor cell lines with first secreted tumor cell components and then intracellular tumor components to act as mitogenic sources for human TIL lines. Surprisingly, the latter was found to be most potent, particularly Oncoimmunin-L, which is a 45-kDa protein with sequence similarity to members of the serpin family of proteins. This protein, which has at least a 31% sequence identity to human leukocyte elastase inhibitor and stimulates [3H]-thymidine incorporation into the DNA of human TILs, may be found in the cytosol of many tumor cells. Taken together with our earlier work in which a 36-kDa protein, also of tumor cytosolic origin, was shown to induce differentiation of myeloid cells, we propose soluble factors derived from tumor cells as a pathophysiological source of tumor immunogenicity. Moreover, detailed biochemical and biophysical characterization of tumor cell-immunocyte interactions will define the tumor immunoenvironment.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.