γ-干擾素

干擾素-γ（Interferon gamma、Interferon-γ、IFNG、IFNγ）是水溶性二聚體的細胞因子^[2]。是II型干擾素的唯一成員^[3]曾被稱為巨噬細胞活化因子。

干擾素-γ
γ-干擾素晶體結構線狀表示[1]
有效結構 PDB 直系同源檢索：PDBe, RCSB PDB查詢代碼列表 1EKU​, 1FG9​, 1FYH​, 1HIG​, 3BES​
標識
代號	IFNG; IFG; IFI
擴展標識	遺傳學：147570 鼠基因：107656 同源基因：55526 GeneCards: IFNG Gene
基因本體論描述 分子功能 · cytokine activity · interferon-gamma receptor binding 細胞成分 · extracellular region · extracellular space · external side of plasma membrane 生物過程 · protein import into nucleus, translocation · negative regulation of transcription from RNA polymerase II promoter · neutrophil apoptotic process · regulation of the force of heart contraction · positive regulation of mesenchymal cell proliferation · adaptive immune response · CD8-positive, alpha-beta T cell differentiation involved in immune response · negative regulation of mesenchymal to epithelial transition involved in metanephros morphogenesis · apoptotic process · cellular component movement · humoral immune response · cell cycle arrest · cell surface receptor signaling pathway · response to virus · cytokine-mediated signaling pathway · antigen processing and presentation · neutrophil chemotaxis · endoplasmic reticulum unfolded protein response · negative regulation of myelination · positive regulation of synaptic transmission, cholinergic · negative regulation of interleukin-17 production · positive regulation of interleukin-12 production · positive regulation of interleukin-23 production · positive regulation of tumor necrosis factor production · positive regulation of peptidyl-serine phosphorylation of STAT protein · positive regulation of smooth muscle cell apoptotic process · positive regulation of T cell proliferation · response to drug · positive regulation of tyrosine phosphorylation of Stat1 protein · defense response to bacterium · defense response to protozoan · negative regulation of growth of symbiont in host · positive regulation of chemokine biosynthetic process · positive regulation of interleukin-12 biosynthetic process · positive regulation of MHC class II biosynthetic process · positive regulation of interleukin-6 biosynthetic process · positive regulation of nitric oxide biosynthetic process · positive regulation of neuron differentiation · positive regulation of osteoclast differentiation · positive regulation of cell adhesion · positive regulation of transcription from RNA polymerase II promoter · positive regulation of isotype switching to IgG isotypes · negative regulation of smooth muscle cell proliferation · positive regulation of interleukin-1 beta secretion · regulation of insulin secretion · positive regulation of membrane protein ectodomain proteolysis · defense response to virus · positive regulation of killing of cells of other organism · interferon-gamma-mediated signaling pathway · regulation of interferon-gamma-mediated signaling pathway · positive regulation of fructose 1,6-bisphosphate 1-phosphatase activity · positive regulation of fructose 1,6-bisphosphate metabolic process · positive regulation of vitamin D biosynthetic process · positive regulation of calcidiol 1-monooxygenase activity · cellular response to lipopolysaccharide · cellular response to interleukin-18 · negative regulation of metanephric nephron tubule epithelial cell differentiation · positive regulation of tumor necrosis factor (ligand) superfamily member 11 production Sources: Amigo / QuickGO
RNA表達模式
更多表達數據
直系同源體
物種	人類	小鼠
Entrez	3458	15978
Ensembl	ENSG00000111537	ENSMUSG00000055170
UniProt	P01579	P01580
mRNA序列	NM_000619	NM_008337
蛋白序列	NP_000610	NP_032363
基因位置	Chr 12: 68.55 – 68.55 Mb	Chr 10: 118.44 – 118.45 Mb
PubMed查詢	[1]	[2]
閱 論 編

IFN-γ
Crystal structure of a biologically active single chain mutant of human interferon gamma
鑑定
標誌	?
Pfam	PF00714（舊版）
Pfam宗系	CL0053（舊版）
InterPro（英語：InterPro）	IPR002069
SCOP（英語：Structural Classification of Proteins）	1rfb / SUPFAM
現有可用的蛋白結構： Pfam 結構（舊版） / ECOD PDB RCSB PDB; PDBe; PDBj PDBsum（英語：PDBsum） 結構概要

Γ-干擾素

臨床資料
商品名（英語：Drug nomenclature）	Actimmune
AHFS/Drugs.com	Monograph
MedlinePlus	a601152
ATC碼	L03AB03 (WHO)
識別資訊
IUPAC命名法 Human interferon gamma-1b
CAS號	82115-62-6  Y 98059-61-1
DrugBank	DB00033 N
ChemSpider	NA Y
ChEMBL	ChEMBL1201564 N
化學資訊
化學式	C761H1206N214O225S6
摩爾質量	17145.6 g/mol

結構

干擾素-γ的單體是由六個α螺旋組成一個核心^[4]和在C端區延伸展開的片斷序列。

生物活性的二聚體是由兩個反平行相互鎖定的單體形成。

生物活性

所有的細胞都可以產生干擾素-α（英語：Interferon alfa）和干擾素-β， 而干擾素-γ只由自然殺傷細胞（NK細胞）和活化的T細胞產生。I型干擾素對酸穩定，而干擾素-γ則遇酸變性。

干擾素-γ具有抗病毒、免疫調節及抗腫瘤特性^[5]。干擾素-γ可以與干擾素伽瑪受體（英語：Interferon-gamma receptor）(IFNGR)結合，進而調節JAK-STAT通路。干擾素-γ激活抗原提呈細胞，通過上調轉錄因子T-bet而促進I型輔助T細胞(Th1細胞)的分化。

干擾素-γ是I型輔助T細胞(Th1細胞)的標誌性的細胞因子。II型輔助T細胞(Th2細胞)釋放白血球介素-4（IL-4）和白血球介素-13（IL-13）。自然殺傷細胞和CD8⁺T細胞也產生干擾素-γ。干擾素-γ通過迅速降解RANK-RANKL信號通路的TRAF6而抑制破骨細胞形成。

治療用途

干擾素可以用來治療傳染病，但也能促成自體免疫。在接受干擾素伽瑪治療的病人中，多達19%的病人會有自體免疫.

干擾素IFNγ用於豬生殖與呼吸道綜合症PRRSV的治療上，有試驗發現干擾素IFNγ能活化先天免疫細胞，進而達到抑制病毒數量的效果。^[6]

A型流感的治療上，也有小鼠試驗表現出當缺失干擾素後，流感感染小鼠死亡率大幅提升且體內病毒數量維持高濃度水平；相較之下，體內有干擾素存在的小鼠，流感病毒數量隨著干擾素的生成而逐漸下降。^[7]