TCR Transgenic Mice: A Valuable Tool for Studying Viral Immunopathogenesis Mechanisms
1）However, due to large T cell receptor (TCR) diversity (1 × 10的13方), complete and precise analyses of viral antigen-specific T-cell responses are almost impossible.
2）Diverse TCR Tg mice expressing TCRs specific for viral antigens of LCMV, influenza virus, RSV, WNV, HBV, TMEV, HSV, and MCMV have been generated to contribute to understanding mechanisms of viral immunopathogenesis (Table 1).
Lymphocytic Choriomeningitis (LCMV)
a single-stranded RNA genome
mice are its natural host研儒，給小鼠轉(zhuǎn)入識(shí)別LCMV的TCR
Since LCMV is a non-cytolytic virus, it is possible to accurately measure the cytotoxic activity by the host anti-viral immune response
T cell–DC coculture（PMID: [23023500]）
Na?ve CD4+ T cells (25×103 cells) labeled with 5 μM carboxy-fluorescein diacetate succinimidyl ester (CFSE; Molecular Probes) were cultured with 0.5×103 DC and indicated concentration of toxic shock syndrome toxin 1 (TSST-1, Toxin Technology).
miRNA quantification：using a mirVana? qRT-PCR miRNA detection kit (Applied Biosystems).Briefly, 25 ng of RNA from isolated T cells was reverse-transcribed in 10 μl at 37°C for 30 min using a miRNA- or U6-specific oligonucleotide.
腹腔注射（Intraperitoneal Injections，IP）
i.v.尾靜脈注射
by plaque assay on Vero cells.
activated CD62L– CD44+ CD8 T cells
檢測T細(xì)胞器官：肝臟，脾臟岔乔，淋巴結(jié)
T細(xì)胞活性標(biāo)志：interferon gamma (IFNγ)-, tumor necrosis factor alpha (TNFα)- or interleukin 2 (IL-2)-producing
檢測病毒滴度的地方：腎洼专，脾臟
CD4 T細(xì)胞通常是作為是免疫系統(tǒng)中的“輔助”角色军掂，它們大多數(shù)情況并不能直接中和感染嫡意，而是引導(dǎo)并觸發(fā)機(jī)體對(duì)感染源的免疫應(yīng)答秆撮，類似于免疫系統(tǒng)的“哨兵”他宛。在CD啟動(dòng)免疫應(yīng)答后船侧，后再由CD8T細(xì)胞來扮演“行刑官”的角色，清除感染源（包括被HIV感染的CD4細(xì)胞）厅各。
In antiviral T cell responses, CD8 T cells differentiate into memory precursor and short-lived effector T cells that can be distinguished based on variable expression of CD127 (IL-7Rα) and KLRG1 (Joshi et al., 2007; Sarkar et al., 2008).
T細(xì)胞的發(fā)育镜撩、分化和成熟
胸腺是T細(xì)胞分化、發(fā)育的主要場所队塘，胸腺微環(huán)境是誘導(dǎo)并調(diào)控該過程的關(guān)鍵因素[4]袁梗。早期的胸腺細(xì)胞表面為不表達(dá)CD4卫旱、CD8分子的雙陰性細(xì)胞（DN），DN細(xì)胞在向深皮質(zhì)遷移的過程中围段，逐漸發(fā)生T細(xì)胞受體（TCR）α顾翼、β基因重排和表達(dá)，雙陰性細(xì)胞免于凋亡奈泪，并發(fā)育為CD4+适贸、CD8+ 雙陽性細(xì)胞（DP）。DP細(xì)胞α鏈基因發(fā)生重排涝桅，開始表達(dá)有功能性的TCR拜姿，CD3表達(dá)水平逐漸上升。TCR可以與自身肽-主要組織相容性復(fù)合體(MHC)分子進(jìn)行識(shí)別和結(jié)合冯遂。隨后DP細(xì)胞經(jīng)歷陽性選擇：DP細(xì)胞與胸腺基質(zhì)細(xì)胞表面的MHC若不能結(jié)合或結(jié)合力過高蕊肥，則發(fā)生凋亡；若結(jié)合力適當(dāng)蛤肌，則存活并轉(zhuǎn)變?yōu)閱侮栃约?xì)胞（SP）壁却。SP細(xì)胞分為兩類，能與MHCⅠ類分子結(jié)合的分化為CD4-CD8+ 細(xì)胞裸准，與MHCⅡ類分子結(jié)合的分化為CD4+CD8- 細(xì)胞展东，經(jīng)過這一過程，兩類SP細(xì)胞分別獲得對(duì)MHC限制性（MHC restriction）識(shí)別能力炒俱。隨后T細(xì)胞移至胸腺皮質(zhì)與髓質(zhì)的交界處進(jìn)行陰性選擇盐肃；單陽性細(xì)胞若能與局部樹突狀細(xì)胞（DC）或巨噬細(xì)胞表面的自身MHC分子復(fù)合物高親和力結(jié)合，即被誘導(dǎo)凋亡或失能;反之权悟，則繼續(xù)分化砸王、發(fā)育，成為僅能識(shí)別非己抗原的T細(xì)胞峦阁。
細(xì)胞免疫應(yīng)答是一個(gè)連續(xù)的過程谦铃，可分為三個(gè)階段：①T細(xì)胞特異性識(shí)別抗原階段；②T細(xì)胞活化拇派、增殖和分化階段荷辕；③效應(yīng)性T細(xì)胞的產(chǎn)生及效應(yīng)階段。在免疫應(yīng)答過程中件豌，還有部分活化T細(xì)胞分化為記憶T細(xì)胞（memory T cell）[
