Hematopoietic progenitor kinase 1 is a negative regulator of dendritic cell activation.
Hematopoietic progenitor kinase 1 (HPK1) is a hematopoietic cell-restricted member of the Ste20 kinases that acts as a negative regulator of T cell functions through the AP-1, NFAT, and NFkappaB pathways. Using HPK1-deficient (HPK1(-/-)) mice, we report in this study a novel role for HPK1 in dendritic cells (DCs). Specifically, we observed that matured HPK1(-/-) bone marrow-derived DCs (BMDCs) are superior to their wild-type (WT) counterpart in stimulating T cell proliferation in vivo and in vitro. Several characteristics of HPK1(-/-) BMDCs may account for this enhanced activity: Matured HPK1(-/-) BMDCs express higher levels of costimulatory molecules CD80, CD86, and I-A(b) as well as produce more proinflammatory cytokines IL-12, IL-1beta, TNF-alpha, and IL-6 than their WT littermates. The role of HPK1 as a proapoptotic molecule was assessed post activation with LPS, and results indicated that HPK1(-/-) BMDCs are significantly resistant to LPS-induced apoptosis. Our results led us to investigate the role of HPK1(-/-) BMDCs in tumor immunotherapy. Using a s.c. murine model of Lewis Lung Carcinoma, we found that HPK1(-/-) BMDCs eliminate established s.c. Lewis Lung Carcinoma more efficiently than their WT counterpart. Our data reveal a novel role for HPK1 as a negative regulator of DC functions, identifying its potential as a molecular target for DC-based immunotherapy against cancers.
Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, NY 10016, USA.
Saba
S
Alzabin
Nina
N
Bhardwaj
Friedemann
F
Kiefer
Sansana
S
Sawasdikosol
Steven
S
Burakoff
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D017209:Apoptosis / Q000276:immunology; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D018827:Carcinoma, Lewis Lung / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D008213:Lymphocyte Activation / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D016207:Cytokines; C102102:hematopoietic progenitor kinase 1; D017346:Protein Serine-Threonine Kinases