title: SOCS1 restricts dendritic cells' ability to break self tolerance and induce antitumor immunity by regulating IL-12 production and signaling.
abstract: DC-based tumor vaccine research has largely focused on enhancing DC maturation/costimulation and antigen presentation in order to break tolerance against self tumor-associated antigens. DC immunization can activate autoreactive T cells but rarely causes autoimmune pathologies, indicating that self tolerance at the host level is still maintained in the vaccinated hosts. This study in mice reveals a novel regulatory mechanism for the control of self tolerance at the host level by DCs through the restriction of positive cytokine feedback loops by cytokine signaling inhibitor SOCS1. The study further finds the requirement of persistent antigen presentation by DCs for inducing pathological autoimmune responses against normal tissues and tumor, which can be achieved by silencing SOCS1 to unleash the unbridled signaling of IL-12 and the downstream cytokine cascade. However, the use of higher-affinity self peptides, enhancement of DC maturation, and persistent stimulation with cytokines or TLR agonists fail to break tolerance and induce pathological antitumor immunity. Thus, this study indicates the necessity of inhibiting SOCS1, an antigen presentation attenuator, to break self tolerance and induce effective antitumor responses.
authors.affiliation: Center for Cell and Gene Therapy, Department of Immunology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Evel-Kabler
authors.forename: Xiao-Tong
authors.initials: XT
authors.lastname: Song
authors.forename: Melissa
authors.initials: M
authors.lastname: Aldrich
authors.forename: Xue F
authors.initials: XF
authors.lastname: Huang
authors.forename: Si-Yi
authors.initials: SY
authors.lastname: Chen
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000502:physiology*; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005786:Gene Expression Regulation; D018664:Interleukin-12 / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D008546:Melanoma, Experimental / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012097:Repressor Proteins / Q000502:physiology*; D017634:Self Tolerance / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D012097:Repressor Proteins; C491590:Socs1 protein, mouse; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D018664:Interleukin-12