Inhibition of phosphatidylserine recognition heightens the immunogenicity of irradiated lymphoma cells in vivo.
Strategies to enhance the immunogenicity of tumors are urgently needed. Although vaccination with irradiated dying lymphoma cells recruits a tumor-specific immune response, its efficiency as immunogen is poor. Annexin V (AxV) binds with high affinity to phosphatidylserine on the surface of apoptotic and necrotic cells and thereby impairs their uptake by macrophages. Here, we report that AxV preferentially targets irradiated lymphoma cells to CD8+ dendritic cells for in vivo clearance, elicits the release of proinflammatory cytokines and dramatically enhances the protection elicited against the tumor. The response was endowed with both memory, because protected animals rejected living lymphoma cells after 72 d, and specificity, because vaccinated animals failed to reject unrelated neoplasms. Finally, AxV-coupled irradiated cells induced the regression of growing tumors. These data indicate that endogenous adjuvants that bind to dying tumor cells can be exploited to target tumors for immune rejection.
Bondanza
Attilio
A
Clinical Immunology Unit, Cancer Immunotherapy and Gene Therapy Program, H. San Raffaele Institute, DIBIT 3A1, via Olgettina 58, 20132 Milano, Italy.
Zimmermann
Valérie S
VS
Rovere-Querini
Patrizia
P
Turnay
Javier
J
Dumitriu
Ingrid E
IE
Stach
Christian M
CM
Voll
Reinhard E
RE
Gaipl
Udo S
US
Bertling
Wolf
W
Pöschl
Ernst
E
Kalden
Joachim R
JR
Manfredi
Angelo A
AA
Herrmann
Martin
M
D000818:Animals; D017304:Annexin A5 / Q000276:immunology* / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D007114:Immunization; D008223:Lymphoma / Q000276:immunology* / Q000628:therapy*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010587:Phagocytosis / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
D017304:Annexin A5; C498708:Ptdsr protein, mouse; D011956:Receptors, Cell Surface; C408123:phosphatidylserine receptor