Characterisation of functional biotinylated TNF-alpha targeted to the membrane of apoptotic melanoma cells.
The physiologic clearance of apoptotic cells prevents inflammation at the site of cell death and limits the immunogenicity of tumors. In this study we report the functional characterisation of biotinylated tumor necrosis factor-alpha (TNF-alpha) after anchorage to apoptotic melanoma cells via a biotin-avidin-biotin bridge. Flow cytometric and morphological analysis showed that biotinylated TNF-alpha efficiently bound to apoptotic membrane blebs of dying cells. Membrane-bound TNF-alpha (12 fg/cell) killed sensitive WEHI164 cells 250-fold more effectively than equivalent amounts of the soluble cytokine. Furthermore, macrophages engulfing apoptotic cells with membrane-bound TNF-alpha secreted significantly higher amounts of soluble TNF-alpha and lower amounts of interleukin-10 (IL-10). Therefore the bridging of TNF-alpha potentiates its biological function and influences the outcome of the phagocytic clearance of apoptotic tumor cells.
Cancer Immunotherapy and Gene Therapy Programme, H San Raffaele Scientific Institute, via Olgettina 58, 20132, Milan, Italy.
Valérie S
VS
Zimmermann
Attilio
A
Bondanza
Patrizia
P
Rovere-Querini
Barbara
B
Colombo
Angelina
A
Sacchi
Umberto
U
Fascio
Angelo
A
Corti
Angelo A
AA
Manfredi
D000818:Animals; D017209:Apoptosis; D019921:Biotinylation; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D016503:Drug Delivery Systems; D005434:Flow Cytometry; D008264:Macrophages / Q000276:immunology; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D051379:Mice; D010587:Phagocytosis; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000737:chemistry / Q000627:therapeutic use*
D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha