Abstract 1983: Cancer exosomes immunosuppressive activity in the absence of contaminating soluble factors is multifactorial
Year: 2019
Type: conference-abstract
Abstract: Cancer derived exosomes, along with soluble factors such as growth factors, cytokines and chemokines have been identified as integral immunosuppressive pathways employed by cancer cells. Using melanoma cell lines as a model for generating human melanoma exosomes (HMEX), we studied the soluble factors associated with exosome purification methods. A Luminex 13-plex T cell activation kit was used to detect the presence of soluble factors in exosome isolates. We have demonstrated that combining Ultrafiltration and Size Exclusion Chromatography (REIUS method) can yield up to 58-fold more exosomes than ultracentrifugation (UC) with greatly reduced concentrations of contaminating soluble factors (IL-8: 4.6 pg/ml by REIUS versus 489 pg/ml by UC | IL-10: 1,052 pg/ml by REIUS versus 34,500 pg/ml by UC). A novel exosome-based Compact Surface Plasmon Resonance Biosensor demonstrated that REIUS-isolated exosomes abundantly express PD-L1 on their surface compared to UC-purified exosomes. These HMEX significantly inhibited a cloned NY-ESO tumor antigen-specific patient derived T cell function when co-cultured with a NY-ESO positive melanoma cell line for 4 h (IFN-γ positive T cell population: 78.5 ± 0.03 % versus 49.05 ± 0.07 %). Blocking with anti-PDL1 or anti-IL-10 failed to restore T cell function (IFN-γ production), while both anti-PD-L1 and anti-IL-10 antibodies partially reverse this suppression, thereby identifying IL-10 and PD-L1 as a novel collaborating inhibitory pathway. Taken together, we report that different exosome isolation methods impact the nature of the exosomes and contaminating soluble factors and should be chosen with caution. In addition, our data suggests a novel role for tumor-derived exosomes in the IL-10 and PD1-PDL1 axis crosstalk that impacts functional activity of T cells.Citation Format: Shin La Shu, Junko Matsuzaki, Cheryl Allen, Yunchen Yang, Edward Hurley, Kunle Odunsi, Yun Wu, Marc S. Ernstoff. Cancer exosomes immunosuppressive activity in the absence of contaminating soluble factors is multifactorial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1983.
Source: Tumor Biology
Authors: Shin La Shu, Junko Matsuzaki, Cheryl Allen, Yunchen Yang, Edward Hurley, Kunle Odunsi, Yun Wu, Marc S. Ernstoff
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,500
OpenAlex ID: W4244089985