炎症与免疫研究进展 中科院感染免疫重点实验室 唐 宏

炎症的病理特征与进程 炎症的局部临床特征是红、热、肿、痛和组织/器官功能衰竭 炎症通常可按其病程分为急性炎症和慢性炎症 红热: 炎症局部血管扩张、血流加快所致。 肿胀: 局部炎症性充血、血液成分渗出引起。 疼痛: 渗出物压迫和炎症介质直接作用于神经末梢而引起疼痛。 功能衰竭：基于炎症的部位、性质和严重程度将引起不同的功能障碍，如肺炎影响气血交换从而引起缺氧和呼吸困难/窘迫等。 炎症通常可按其病程分为急性炎症和慢性炎症 急性炎症：启动急骤，持续几天至一个月。有害刺激一旦去除，炎症也就随之消失。以血浆渗出和中性粒细胞浸润为主要特征。 慢性炎症：持续数月至数年，以淋巴细胞和单核-巨噬细胞浸润以及微/小血管和结缔组织增生为主要病理学特征。

炎症的细胞反应 1、吞噬细胞是启动炎症反应的重要效应细胞，包括巨噬细胞和中性粒细胞。吞噬细胞通过其表面表达的多种受体 (甘露糖受体，葡聚糖受体，Toll样受体等)，迅速识别并摄入外源微生物，形成吞噬体，继而与溶酶体结合形成吞噬溶酶体，微生物通过氧依赖或氧非依赖途径被杀伤。被激活的吞噬细胞同时分泌大量的促炎症因子和趋化因子（IL-1，TNF，IL-6和KC/CXCL8等)，发挥多种非特异性效应，包括致炎，致热，趋化炎症细胞，激活免疫细胞，抑制病毒复制，胞毒作用等。 中性粒细胞存在于外周血，寿命短，数量多； 巨噬细胞是从血液中的单核细胞分化而来分布于不同组织中，寿命长，形体大，富含细胞器。 2、NK细胞也是参与炎症反应的重要细胞，在多种细胞因子刺激下，杀伤感染细胞内的微生物并产生细胞因子，进一步促进炎症细胞发挥作用而产生级联放大效应。 3、此外，DC 、γδT 、B1、肥大细胞、NKT 、上皮细胞等在一定范围内参与炎症反应。

炎症是所有具有血管系统的个体，其组织与细胞 对损伤性因子/因素所产生的反应

PAMP vs DAMP

Adaptive immune system prevents overreactive innate immunity in the initial phase of infections Dong et al, Nat Med (2007)

Acute infection in immunocompromised mice results in stronger innate immune responses Hepatitis virus induced lethality in nude mice A 20 40 60 80 100 2 4 6 8 10 12 14 Balb/c Nude Days after injection % survival Balb/c Nude P=0.02 P=0.06 2000 4000 6000 8000 Day 2 Day 4 ALT (U/L) Balb/c Nude P=0.7 P=0.05 1000 2000 3000 4000 Day 2 Day 4 AST (U/L) B C TNF-  20 40 60 80 100 Balb/c Nude pg/ml IFN-  50 100 150 200 250 Balb/c Nude pg/ml MCP-1  100 200 300 400 500 600 Balb/c Nude pg/ml IL-6  20 40 60 80 Balb/c Nude pg/ml Balb/c Nude 2 3 4 5 6 Day 2 Day 4 Log PFU/gm Liver

The susceptibility to TLR stimulation is independent of infectious agents TNF- Balb/c Nude  300 600 900 1200 1500 pg/ml IFN-  300 600 900 1200 1500 2h 6h pg/ml   BALB/c Nude 30 60 90 120 150 2 h 6 h 15 45 MCP-1 (ng/ml) IL-6 (ng/ml) Hours after Poly I:C injection 20 40 60 80 100 12 24 36 48 Wt Nude % Survival D C  2 h 6 h 50 100 150  2 h 6 h 5 10 15 BL6 Rag-/- ng/ml Hours after Poly I:C injection 20 40 60 80 100 12 24 36 48 Wt Rag-/- % Survival  2 h 6 h 1 2 3  2 h 6 h 25 50 75 100 125 BL6 Rag-/- ng/ml

Conventional T cells are necessary and sufficient to suppress the early inflammatory responses to pIC IFN- 1 2 ng/ml TNF- 4 6 8 Control Transfer F 2h 6h 2h 6h E TNF- 2 h 6 h 5 10 15 Control -CD4/8 ng/ml  IFN- 200 400 600 800 pg/ml Balb/C Rag1-/-

(TCR engagement-independent, but MHC-dependent) T cells tempering the innate cytokine surge is cell-cell contact dependent (TCR engagement-independent, but MHC-dependent) NT NT+T 200 400 600 800 Transwell + Poly I-C pg/ml  TNF- IFN- 25 50 75 100 125 B D C  TNF- NT Pan-T OTII CD4 OTI CD8 100 200 300 + NT + Poly I-C pg/ml  IFN- 500 1000 pg/ml MHC Class II KO NT 50 100 150 IFN- (pg/ml) (CD4T/NT ratio) 0 0 0.3 1.0 + Poly I:C 0 0 0.3 1.0 Wild NT 250 500 750 1000 1250 IFN- (pg/ml) + Poly I:C

Both naïve and Treg cells efficiently suppress the inflammatory cytokine storm TNF- 100 200 pg/ml NT PanT Non Treg Treg Poly I:C - - + - - - - - + - - - - - + - + + + + + + + + +  NT+GFP-T F TNF- NT NT+T 100 200 Poly I:C pg/ml  IFN- 50 150 IFN- 50 100 150 - - + - - - - - + - - - - - + - + + + + + + + + +  100 200 pg/ml (CD4 T/NT ratio) +Poly I:C 0 0 0.3 1.0 0.3 1.0 IL10-/- T Wild T

NK cells play essential roles in pIC-induced sudden death of Rag-1 KO mice. 20 40 60 80 100 12 24 36 48 Rag-/- NK-depleted Hours after Poly I:C injection % Survival  TNF- 2 h 6 h 1 2 3 4 Rag-/- NK-/- Rag-/- ng/ml IFN- 2 h 6 h 0.0 0.5 1.0 

T cells primarily inhibit APCs to block NK activation CD11b TNF- CD11c NK1.1 IFN- NT+ Poly I:C + Pan-T cell 11.33 3.74 28.08 5.76 0.52 5.34 IFN- 10 20 pg/ml  TNF- 250  200  150 pg/ml 100 50 CD11b+: + + + + - - NK : - - + + + + T cell: - + - + - +

T CELLS MAINTAIN THE HOMEOSTASIS OF INNATE INFLAMMATION Trends Immunol （2009）

Neonates are susceptible to higher proinflammatory responses Adult ** 2 4 6 8 TNF- (ng/ml) ** 60 120 180 240 MCP-1 (ng/ml) Neonate Adult ** 100 200 300 400 IL-6 (ng/ml) Neonate Adult pIC B ** 0.4 0.8 1.2 TNF- (ng/ml) Neonate Adult ** 2 4 6 8 10 MCP-1 (ng/ml) Neonate Adult ** 5 10 15 20 IL-6 (ng/ml) Neonate Adult LPS ** 200 400 600 800 1000 Adult Neonate TNF- (pg/ml) ** 1 2 3 IL-6 (ng/ml) Adult Neonate MHV

Neonatal splenocytes produced more inflammatory cytokines than adults Neonatal mice (Day 1) Adult mice 1x106 or 2x10 6 Splenocytes + LPS +poly I:C +MHV-A59 Culture for 20h Detect TNF in supernatants 8 6 ** 6 ** ** 4 ** ** TNF- (ng/ml) 4 IL-6 (ng/ml) ** ** 2 2 ** ** ** ** ** Adult Adult Neonate Neonate Adult Neonate Adult Neonate Adult Neonate Adult Neonate Adult Neonate Adult Neonate Untreated Poly(I:C) MHV-A59 LPS Untreated Poly(I:C) MHV-A59 LPS

T cells counts reversely correlate with the levels of inflammatory cytokines LPS pIC MHV 20 40 60 80 100 120 1 2 3 4 5 6 7 8 Survival Rate (%) day 1 day 7 2 wk 10 wk 20 40 60 80 100 120 12 24 36 48 72 Hours Post Injection Survival (%) Day 1 Adult Day 7 20 40 60 80 100 120 2 4 6 8 Days After Infection Survival (%) Neonate 6x10^3pfu/g Neonate 2x10^3pfu/g Adult 6x10^3pfu/g Adult 2x10^3pfu/g Days 100 200 300 IL-6 (ng/ml) day 1 day 7 2 wk 10wk ** B 2 4 day 1 day 7 2 wk 10wk TNF- (ng/ml) ** 50 100 150 200 day 1 day 7 2 wk 10wk MCP-1 (ng/ml) ** T cell(%) <1 5-7 7-10 40-45

Adoptive transfer of T cells renders efficient control of inflammation in neonates B 5 10 15 20 Control Anti-CD4/8 TNF- (ng/ml) ** 30 45 IL-6 (ng/ml) * C 4 8 12 Control Transfer TNF- (ng/ml) 5 10 MCP-1 (ng/ml) 2.5 5.0 IL-6 (ng/ml) * **

Adult or neonatal T cells are functionally the same 1x106 neonatal non-T cells Culture for 20h 2x106 neonatal T cells 2x106 adult T cells or + LPS detection of TNF/IL6 in supernatants B ** 100 200 300 TNF- (pg/ml) Neonatal NT - + LPS Neonatal T Adult T 1 2 3 IL-6 (ng/ml)

TNF is the mortality factor of neonatal death 12 24 36 48 60 72 25 50 75 100 Wild TNFRI/II KO TNFRI KO time (h) % survival Hours after poly(I:C) injection 20 40 60 80 100 12 24 36 48 Control Ig Anti-IFN- Ab Percent survival Zhao J et al, PNAS, 2008

T CELLS MAINTAIN THE HOMEOSTASIS OF INNATE INFLAMMATION TNF effect T memory IL1β，IL18 PNAS (2008) Trends Immunol （2009）

T cells are part of the innate immunity and negatively regulate the early innate inflammatory response Adaptive immunity

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