Inhibition of CD40 expression and CD40‐mediated dendritic cell function by tumor‐derived IL‐10

• Published in: International journal of cancer Vol. 101; no. 1; pp. 61 - 68
• Main Authors: Shurin, Michael R., Yurkovetsky, Zoya R., Tourkova, Irina L., Balkir, Levent, Shurin, Galina V.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.09.2002; Wiley-Liss
• Subjects: Animals; Biological and medical sciences; CD40; CD40 Antigens - metabolism; CD40 Ligand - pharmacology; Cell Differentiation; dendritic cell; Dendritic Cells - cytology; Dendritic Cells - drug effects; Dendritic Cells - metabolism; dendropoiesis; Down-Regulation - drug effects; Flow Cytometry; Gene Expression Regulation, Neoplastic - drug effects; Host-tumor relations. Immunology. Biological markers; IL‐10; immunosuppression; Interleukin-10 - pharmacology; Interleukin-12 - biosynthesis; Male; Medical sciences; Membrane Proteins - pharmacology; Mice; Mice, Inbred C57BL; Tumor Cells, Cultured; Tumors; Adenocarcinoma; Dendritic cell; Cytokine; Rodentia; Accessory cell; Malignant tumor; Cell differentiation; Costimulatory molecule; Colonic disease; Vertebrata; Immunosuppression; Mammalia; Mouse; Hematopoiesis; Animal; Interleukin 10; Established cell line; Digestive diseases; Intestinal disease; Colon; Biological receptor
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.10576

As CD40 plays a key role in both antitumor immunity and DC maturation, we have studied the regulation of its expression during DC hematopoiesis (dendropoiesis) in vitro and in vivo in the tumor microenvironment. Using MC38 colon adenocarcinoma tumor models, we have demonstrated that DCs generated in vitro from bone marrow precursors obtained from tumor‐bearers have significantly lower expression of CD40 molecules compared to DCs generated from tumor‐free mice. Furthermore, CD40 expression on DCs isolated from the spleens of tumor‐bearing mice was also significantly reduced, suggesting that tumor‐derived factors inhibit CD40 expression on DCs during dendropoiesis both in vitro and in vivo. Interestingly, CD40 ligation on DCs generated from tumor‐bearers did not result in inducible expression of IL‐12 protein or IL‐12 p40 mRNA. However, Staphylococcus aureus–induced IL‐12 production by DCs was not altered in tumor‐bearers, confirming that inhibition of IL‐12 production by DCs generated in vitro from tumor‐bearing mice was due to reduced expression of CD40 on DCs. We have also shown that MC38 tumor cells produce IL‐10 and that exogenous IL‐10 causes downregulation of CD40 expression on DCs. In addition, endogenous IL‐10 produced by colon carcinoma cells inhibited CD40‐dependent IL‐12 production by DCs since tumor‐induced inhibition of IL‐12 production was abrogated by neutralizing anti‐IL‐10 antibody. Finally, systemic administration of FLT3L and/or CD40L reversed CD40 and IL‐12 (p40) deficiency of DCs in tumor‐bearing mice in vivo. These findings thus demonstrate that tumor‐derived factors, including IL‐10, inhibit CD40 expression on DCs and DC precursors and suppress their maturation and function. © 2002 Wiley‐Liss, Inc.