弓形虫复合粘膜疫苗滴鼻免疫小鼠诱导的Peyer's patches持续性细胞免疫应答

目的以可溶性速殖子抗原（soluble tachyzoite antigen，STAg）和霍乱毒素（choleratoxin，CT）佐剂制备的弓形虫复合粘膜疫苗滴鼻免疫小鼠，观察肠粘膜诱导部位Peyer’s patches（PP）的细胞免疫应答及持续时间，探讨其免疫机制。方法BALB／c小鼠96只，随机分为实验组和对照组，实验组以STAg（20μg／只）为抗原，CT（1／μg／只）为佐剂滴鼻免疫，对照组PBS滴鼻。滴鼻2次（间隔2周）后，每组6只小鼠分别于第1、2、3、4、6、8、10、12周处死。计数PP个数，制备PP淋巴细胞悬液，计数并涂片；免疫细胞化学法检测CD4^＋、CD8^＋T细胞亚群。结果实验期间两组小鼠PP数目均无明显变化；实验组免疫后PP淋巴细胞数量明显增生，第2周达高峰，第1、2、3周显著高于对照组（P〈0.05），其中以CD4^＋T细胞增生为主，第1周～第8周高于对照组（P〈0.01），CD8^＋T细胞第1周～第4周显著增高（P〈0.01），CD4^＋／CD8^＋比值无显著变化（P〉0．05）。结论弓形虫复合粘膜疫苗滴鼻免疫BALB／c小鼠可有效诱导肠PP部位持续性的免疫应答，从而激活肠粘膜效应部位淋巴细胞的抗弓形虫感染作用。

The Influence of HIF-1α Expression on Apoptosis and Number of T Lymphocyte in Peyer’s Patches after Burn with Delayed Fluid Resuscitation in Rats at Plateau

Objective: To research the expression of hypoxia inducible factor-1 alpha (HIF-1 alpha) on the apoptosis and number of T lymphocyte in Peyer’s patches after severe burn on plateau in rats. Methods: Wistar rats (n = 130) were subjected to deep thickness burn injury (30% TBSA, III degree), at two different altitudes. 60 of them were given delayed fluid resuscitation (DFR, n = 30 at each altitude) 6 h after burn at different altitude;60 of them were carried out immediate fluid resuscitation (IFR, n = 30 at each altitude);10 rats were subjected to 37°C warm water as sham burn (SG, n = 10). The Peyer’s patches were harvested from the ileum of rats at different time point after burn respectively. The expression of HIF-1 alpha, CD3(+) and the apoptosis and number of T lymphocyte in Peyer’s patches were detected by tissue microarray technology and immunohistochemistry. Results: The apoptosis was higher in DFR group than that in IFR group. The increase in HIF-1 alpha expression was observed mainly on cell nucleus in T lymphocytes. The expression levels of HIF-1 alpha in Peyer’s patches were much higher in DFR group and IFR group than those in SG, and they were higher at high altitude (3848 metres) than those at lower altitude (1517 metres), and also higher in DFR group compared with IFR group (all P < 0.05). The expression levels of CD3+ in Peyer’s patches were much lower in DFR group and IFR group than those in sham group, and the lowest value appeared at 12 hours after burn (all P < 0.05). Conclusion: High expression of HIF-1 alpha may induce the apoptosis of T lymphocytes in Peyer’s patches after severe burn with delayed fluid resuscitation in rats at plateau.

Prion Protein Binds to Aldolase A Produced by Bovine Intestinal M Cells

Microfold (M) cells are a kind of intestinal epithelial cell in the follicle-associated epithelium (FAE) of Peyer’s patches. They can transport antigens and microorganisms to lymphoid tissues. Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disorder in cattle. It is linked to variant Creutzfeldt-Jakob disease in humans. Although it is thought that M cells transport the BSE agent, the exact mechanism by which it crosses the intestinal barrier is not clear. We have bovine intestinal epithelial cell line (BIE cells), which can differentiate into the M cell type in vitro after stimulation, and which is able to transport the BSE agent. We show here that M cells are able to incorporate large numbers of PrP coated magnetic particles into intracellular vesicles, which we collected. The results of 2-DE show a specific protein associated with the PrP-coated particles, compared with non-coated particles. This protein was identified as aldolase A, a glycolytic pathway enzyme, using LC-MS/MS analysis. Aldolase A was synthesized and secreted by BIE cells, and increased during M cell differentiation. In the villi of the bovine intestine, aldolase A was detected on the surface of the epithelium and in the mucus droplet of goblet cells. In the FAE of bovine jejunal and ileal Peyer’s patches, aldolase A was localized on the surface and the apical part of the M cells. The binding of rbPrP to aldolase A was clearly detected and inhibited by pre-treatment of anti-aldolase A antibody. Aldolase A was co-stained with incorporated PrPSc in M-BIE cells. These results suggest that bovine M cells and goblet cells synthesize aldolase A, and that aldolase A may have the ability to bind PrP and associate with PrP in cellular vesicles. Therefore, aldolase A-positive M cells may play a key role in the invasion of BSE into the body.

Interaction between enteric epithelial cells and Peyer's patch lymphocytes in response to Shigella lipopolysaccharide: Effect on nitric oxide and IL-6 release

AIM： TO investigate the effect of interaction between enteric epithelial cells and lymphocytes of Peyer＇s patch on the release of nitric oxide （NO） and IL-6 in response to Shigella lipopolysaccharide （LPS）. METHODS： Human colonic epithelial cells （Caco-2） were mixed cocultured with lymphocytes of Peyer＇s patch from wild-type （C57 mice） and inducible NO synthase knockout mice, and challenged with Shigella F2a-12 LPS. Release of NO and raiL-6 was measured by Griess colorimetric assay and enzyme-linked immunosorbent assay （ELISA）, respectively. RESULTS： In the absence of LPS challenge, NO was detected in the culture medium of Caco-2 epithelial cells but not in lymphocytes of Peyer＇s patch, and the NO release was further up-regulated in both cocultures with lymphocytes from either the wild-type or iNOS knockout mice, with a significantly higher level observed in the coculture with iNOS knockout lymphocytes. After Shigella F2a-12 LPS challenge for 24-h, NO production was significantly increased in both Caco-2 alone and the coculture with lymphocytes of Peyer＇s patch from the wild-type mice but not from iNOS knockout mice. LPS was found to stimulate the release of mIL-6 from lymphocytes, which was suppressed by coculture with Caco-2 epithelial cells. The LPS-induced mIL-6 production in lymphocytes from iNOS knockout mice was significantly greater than that from the wild-type mice. CONCLUSION： Lymphocytes of Peyer＇s patch maintain a constitutive basal level of NO production from the enteric epithelial cell Caco-2. LPS-induced mIL-6 release from lymphocytes of Peyer＇s patch is suppressed by the cocultured epithelial cells. While no changes are detectable in NO production in lymphocytes from both wild-type and iNOS knockout mice before and after LPS challenge, NO from lymphocytes appears to play an inhibitory role in epithelial NO release and their own mIL-6 release in response to LPS.

四君子汤复方总多糖对肠黏膜Peyer's结细胞凋亡的影响

目的探讨四君子汤复方总多糖对小鼠肠黏膜Peyer's结细胞凋亡的影响。方法取NIH小鼠随机分为正常组、模型组、四君子汤复方总多糖(SJZPS)组和四君子汤去蛋白多糖(SJZFP)组,肉眼计数Peyer's结细胞个数和面积,流式细胞(FCM)定量分析法(Annexin V联合PI)测定Peyer's结细胞的凋亡率,免疫组化法测定Peyer's结细胞BCL-2蛋白的表达。结果模型组Peyer's结个数和面积均小于正常组,与模型组比较,SJZPS组和SJZFP组Peyer's结个数和面积,均具有非常显著性差异(P<0.01);模型组Peyer's结细胞凋亡率大于正常组,与模型组比较,SJZPS组和SJZFP组Peyer's结细胞凋亡率具有非常显著性差异(P<0.01);模型组Peyer's结BCL-2蛋白表达低于正常组,与模型组比较,SJZPS组和SJZFP组Peyer's结BCL-2蛋白表达具有非常显著性差异(P<0.01)。结论SJZPS和SJZFP均可抵抗肠黏膜Peyer's结细胞的凋亡,具有肠道黏膜免疫调节作用。

肠内免疫营养对烫伤大鼠Peyer’s结淋巴细胞的影响

目的观察不同肠内营养物对大鼠烫伤后Peyer’s结T淋巴细胞亚群的影响。方法选取Wistar大鼠104只,随机分为饲料组(Chow组,n=32)、标准肠内营养组(EN组,n=32)、肠内免疫营养组(EIN组,n=32)和对照组(n=8)。除对照组外,其余3组均造成30%TBSAⅢ度烫伤模型,伤后早期Chow组、EN组、EIN组分别给予常规饲料、标准肠内营养制剂(能全力)和肠内免疫营养制剂(士强),于伤后第1、4、7、10天用流式细胞仪检测观察Peyer’s结淋巴细胞总数及其T淋巴细胞亚群(CD3+、CD4+、CD8+)的变化。对照组大鼠制成假烫模型,其标本检测数据作为其它3组制模前数据。结果制模后各时点Chow组和EN组Peyer’s结淋巴细胞总数均显著减少(P<0.01或P<0.05),而EIN组仅在制模后第1、4天显著减少(P<0.01或P<0.05),EIN组在制模后第7、10天均明显高于EN组(均P<0.05)。制模后第1、4天Chow组Peyer’s结CD3+细胞和CD4+细胞数均显著减少(P<0.05),而EN组和EIN组变化不明显;3组在伤后各时点CD8+细胞数均无显著变化(均P>0.05)。结论烧伤后早期肠内免疫营养支持能快速有效地促进Peyer’s结淋巴细胞增殖,有利于肠道免疫屏障的恢复。

Self-assembled aggregations in Coptidis Rhizoma decoction dynamically regulate intestinal tissue permeability through Peyer's patch-associated immunity

Objective:To investigate the dynamic regulation of self-assembled aggregations(SAA)in Coptidis Rhizoma decoction on the permeability of intestinal tissue and the mechanism underlying.Methods:The effects of SAA on berberine(Ber)absorption were respectively analyzed in an in situ intestinal perfusion model and in an Ussing Chamber jejunum model with or without Peyer’s patches(PPs).The expression levels of ZO-1,Occludin and Claudin-1 were detected by immunofluorescence to evaluate the tight junction(TJ)between intestinal epithelium cells.The expression levels of T-box-containing protein expressed in T cells,signal transducers and activators of tranion-6,retinoic acid receptor-related orphan receptor ct and forkhead box P3 in PPs were detected by the reverse transcription-polymerase chain reaction and the secretions of interferon-c(IFN-c),interleukin-4(IL-4),interleukin-17(IL-17)and transforming growth factor-b(TGF-b)in PPs were evaluated by immunohistochemistry,to reflect the differentiation of T lymphocyte in PPs to helper T(Th)cell 1,Th2,Th17 and regulatory T(Treg)cell.To confirm the correlation between SAA in Coptidis Rhizoma decoction,PPs-associated immunity and intestinal epithelium permeability,SAA were administrated on an Ussing Chamber jejunum model with immunosuppressed PPs and evaluated its influences on intestinal tissue permeability and TJ proteins expression.Results:SAA in Coptidis Rhizoma decoction could dose-dependently promote Ber absorption in jejunum segment,with the participation of PPs.The dose-dependent and dynamical regulations of SAA on permeability of intestinal tissue and TJ proteins expression level between intestinal epithelium cells occurred along with the dynamically changed T lymphocyte differentiation and immune effectors secretion in PPs.The administration of SAA on immunosuppressed PPs exhibited dose-dependent PPs activation,inducing dynamic promotion on intestinal tissue permeability and inhibition on TJ proteins expression.Conclusion:SAA can improve the Ber absorption in small intestine,through the PPs-associated immunity induced dynamic regulation on intestinal tissue permeability and TJ proteins expression.These findings might enlighten the research of traditional Chinese medicine decoction.

芪黄煎剂对大鼠胃切除后Peyer结淋巴细胞的影响

目的探讨芪黄煎剂对大鼠胃切除后Peyer结淋巴细胞的影响。方法将90只大鼠随机分为假手术组、模型组、芪黄煎剂组,每组30只。假手术组大鼠仅给予腹部正中切开后缝合,不行胃切除,手术后自由饮水进食,不给予肠内营养和芪黄煎剂;模型组大鼠行胃切除手术后给予肠内营养制剂能全素;芪黄煎剂组大鼠行胃切除手术后给予能全素和芪黄煎剂。疗程1周。疗程结束后,处死大鼠,分离出Peyer结及其内淋巴细胞,采用流式细胞仪检测αβT细胞抗原受体-白细胞分化抗原3阳性(αβT cell antigen receptor-cluster of differentia-tion 3 positive,αβTCR-CD3+)T细胞,白细胞分化抗原4阳性(cluster of differentiation 4 positive,CD4+)、白细胞分化抗原8阳性(cluster of differentiation 8 positive,CD8+)T细胞;免疫组织化学法检测免疫球蛋白A阳性(immunoglobulin A positive,IgA+)B细胞。结果模型复制后1周,与假手术组比较,模型组Peyer结中αβTCR-CD3+、CD4+T细胞构成比和IgA+B细胞数显著降低(P<0.05,或P<0.01),模型组和芪黄煎剂组CD8+T细胞构成比无显著变化;与模型组比较,芪黄煎剂组Peyer结中αβTCR-CD3+、CD4+T细胞构成比和IgA+B细胞数显著上升(P<0.05,或P<0.01)。结论芪黄煎剂能刺激Peyer结中T细胞的成熟、分化和增殖,并进一步促进Peyer结中B细胞的增殖和活化,有利于胃切除手术应激后肠道免疫屏障功能的调节和恢复。

地塞米松对脓毒血症鼠Peyer小结Tfh细胞的影响

目的:测定脓毒血症鼠Peyer小结内滤泡辅助性T细胞(T follicular helper,Tfh)的变化,分析地塞米松(dexamethasone,Dex)对脓毒血症Tfh细胞的可能作用。方法:昆明小鼠诱导脓毒血症模型,模型诱导成功后随机分2组,脓毒血症组(SE组,n=12)、脓毒血症+Dex处理组(DE组,n=12)。另设对照组(NC组,n=12)。测定血清白介素-6(interleukin-6,IL-6)、降钙素原(procalcitonin,PCT)、中性粒细胞明胶酶相关载脂蛋白(neutrophil gelatinase-associated lipocalin,NGAL)水平。Peyer小结Ⅰ型1-磷酸鞘氨醇(Sphingosine 1-Phosphate 1,S1P1)、CXC趋化因子配体13(CXC chemokine ligand 13,CXCL13)免疫组化染色。Western blot分别检测Peyer小结IL-21、程序性死亡分子-1(programmed death 1,PD-1)、胞嘧啶脱氨酶(enzyme activation-induced cytidine deaminase,AID)蛋白的表达。流式细胞仪测定3组Peyer小结Tfh细胞占T淋巴细胞的百分率。结果:与NC组相比,SE组血清IL-6(19.7±5.20 vs 10.7±3.60 ng·L^(-1))、PCT(1.56±0.92 vs 0.31±0.09μg·L^(-1))、NGAL(0.44±0.11 vs 0.35±0.09 mg·L^(-1))升高(P<0.05或0.01),Peyer小结S1P1(0.22±0.06 vs 0.14±0.04)、CXCL13(0.25±0.07 vs 0.15±0.04)的表达增加(P<0.01),IL-21(0.60±0.08 vs 0.35±0.08)、PD-1(0.30±0.04 vs 0.20±0.05)、AID(0.23±0.05 vs 0.18±0.03)蛋白的表达亦升高(P<0.05或0.01),Tfh细胞占T淋巴细胞(8.30±2.00 vs 5.69 vs 1.64%)的百分率升高(P<0.01)。Dex治疗可降低SE鼠血清IL-6(19.7±5.20 vs 12.8±3.40 ng·L^(-1))、PCT(1.56±0.92 vs 0.71±0.44μg·L^(-1))水平(P<0.05或0.01),降低Peyer小结S1P1(0.22±0.06 vs 0.17±0.05)、CXCL13(0.25±0.07 vs 0.19±0.06)的表达(P<0.05或0.01),下调Peyer小结IL-21(0.60±0.08 vs 0.48±0.09)、PD-1(0.30±0.04 vs 0.26±0.06)、AID(0.23±0.05 vs0.19±0.04)蛋白的表达(P<0.05),降低Tfh细胞占T淋巴细胞(8.30±2.00 vs 6.56±1.59%)的百分率(P<0.05)。结论:Peyer小结Tfh细胞可能参与脓毒血症的发病机制,Dex抑制Peyer小结Tfh的活化,对Peyer小结微环境起保护作用。

Peyer结介导的小肠黏膜免疫及其物种间差异的研究进展

肠道不仅是消化吸收营养物质并进行新陈代谢的消化器官,也是抵抗病原体入侵的免疫器官,在机体免疫功能中扮演重要角色。Peyer结位于肠相关淋巴组织的诱导部位,是小肠黏膜免疫的重要组织,是产生IgA的主要来源。本文阐述了Peyer结的组织学特征,重点归纳了Peyer结主要的免疫细胞类型及其参与的黏膜免疫过程,并对人及主要模式动物Peyer结的研究现状进行综述,以期为后续深入研究Peyer结介导的黏膜免疫提供基础资料。

Rig-I^-/- mice develop colitis associated with downregulation of Gαi2

RIG-I （retinoid acid-inducible gene-I）, a putative RNA helicase with a cytoplasmic caspase-recrultment domain （CARD）, was identified as a pattem-recognition receptor （PRR） that mediates antiviral immunity by inducing type I interferon production. To further study the biological function of RIG-I, we generated Rig-I^-/- mice through homologous recombination, taking a different strategy to the previously reported strategy. Our Rig-I^-/- mice are viable and fertile. Histological analysis shows that Rig-I^-/ mice develop a colitis-like phenotype and increased susceptibility to dextran sulfate sodium-induced colitis. Accordingly, the size and number of Peyer＇s patches dramatically decreased in mutant mice. The peripheral T-cell subsets in mutant mice are characterized by an increase in effector T cells and a decrease in naive T cells, indicating an important role for Rig-I in the regulation ofT-cell activation. It was further found that Rig-I deficiency leads to the downregulation of G protein αi2 subunit （Gαi2） in various tissues, including T and B lymphocytes. By contrast, upregulation of Rig-I in NB4 cells that are treated with ATRA is accompanied by elevated Gαi2 expression. Moreover, Gαi2 promoter activity is increased in co-transfected NIH3T3 cells in a Rig-I dose-dependent manner. All these findings suggest that Rig-I has crucial roles in the regulation of Gαi2 expression and T-cell activation. The development of colitis may be, at least in part, associated with downregulation of Gαi2 and disturbed T-cell homeostasis.

Effects of huoxiangzhengqi liquid on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea

AIM： To explore effects of huoxiangzhengqi liquid （HXZQ） on enteric mucosal immune responses in mice with Bacillus dysenteriae and Salmonella typhimurium induced diarrhea （BSD）. METHODS： BSD was induced in Balb/c mice by oral administration with Bacillus dysenteriae and Salmonella typhimurium. HXZQ was administrated from the day of diarrhea induction at dosages of 5.21 g/kg and 0.52 g/kg, respectively. The onset of diarrhea and lasting time were recorded. Peyer＇s patches and peripheral lymphocytes were prepared for flow cytometry, and levels of TNF-α in peripheral blood and enteric tissue homogenates were determined with ELISA. Student＇s t test was employed for statistics. RESULTS： Mice in BSD group started showing continuous diarrhea on the day of induction until the fourth day when they were sacrificed. Diarrhea in the mice of HXZQ high and low dose groups lasted for 36 and 54 h, respectively. There were more CD4^＋ and CD8^＋ cells in peripheral blood, fewer CD4^＋ cells in Peyer＇s patches in BSD mice compared to normal mice. Fewer CD4^＋ and CD8^＋ cells was shown in the mice in HXZQ high group compared to BSD mice. In Peyer＇s patch, there were more CD8^＋ cells in mice in HXZQ high and low dose groups and more CD4^＋ in mice in HXZQ high group. Higher levels of TNF-α in peripheral blood and intestinal tissue homogenates in BSD group were observed. Mice in HXZQ high group showed decreased levels of TNF-α in peripheral blood and enteric tissue homogenates. CONCLUSION： The immune regulation of CD4^＋ and CD8^＋ cells in Peyer＇s patch and suppression of TNF-α levels in enteric homogenates may partially explain the effect of HXZQ on improvement of BSD.

RANKL-RANK interaction in immune regulatory systems

The interaction between the receptor activator of NF-κB ligand(RANKL)and its receptor RANK plays a critical role in the development and function of diverse tissues.This review summarizes the studies regarding the functions of RANKL signaling in immune regulatory systems.Previous in vitro and in vivo studies have indicated that the RANKL signal promotes the survival of dendritic cells(DCs),thereby activating the immune response.In addition,RANKL signaling to DCs in the body surface barriers controls self-tolerance and oral-tolerance through regulatory T cell functions.In addition to regulating DC functions,the RANKL and RANK interaction is critical for the development and organization of several lymphoid organs.The RANKL signal initiates the formation of clusters of lymphoid tissue inducer cells,which is crucial for lymph node organogenesis.Moreover,the RANKL-RANK interaction controls the differentiation of M cells,specialized epithelial cells in mucosal tissues,that take up and transcytose antigen particles to control the immune response to pathogens or commensal bacterium.The development of epithelial cells localized in the thymic medulla(m TECs)is also regulated by the RANKL-RANK signal.Given that the unique property ofm TECs to express a wide variety of tissue-specific selfantigens is critical for the elimination of self-antigen reactive T cells in the thymus,the RANKL-RANK interaction contributes to the suppression of autoimmunity.Future studies on the roles of the RANKL-RANK system in immune regulatory functions would be informative for the development and application of inhibitors of RANKL signaling for disease treatment.

Abdominal lymphadenopathy:An atypical presentation of enteric fever

This is a case report of a patient who presented to the Aga Khan University Hospital with generalized abdominal lymphadenopathy and high-grade fever.Due to ambiguous clinical findings,which were suggestive of either abdominal tuberculosis,or a lymphoma,the patient was started on empirical anti-tuberculous treatment due to the endemicity of tuberculosis in this region.The blood culture reports,however,were reported to grow colonies of Salmonella paratyphi A;thus the diagnosis of the patient was changed to enteric fever,and the patient improved on the subsequently started therapy of ceftriaxone 2000 mg bid.To the best of our knowledge,this is the first reported case of a patient suffering from enteric fever whose primary clinical findings were abdominal lymphadenopathy and fever.

Selected Aspects of Camel Immune System and Immune Responses

The camel economy is of considerable importance for arid countries. In the last decade, studies about camel immune system and immune responses have recorded increasing interest. However, drawing a comprehensive picture of the camel immune system remains far from reached. A major part of this review is to cover the studies of the primary and secondary immune organs and the markers of the camel immune cells and certain lymphoid tissues. At the same time, immune responses to different diseases and the nature of effective immunity were included, with an emphasis on the most important zoonotic diseases in camels such as MERS CoV;brucellosis. New findings on the diversity mechanisms of camel immunoglobulin genes were addressed. However, detail of the mechanism of MHC-restricted cellular immunity and the mechanism of B lymphocyte activation in camels await further attention. Interestingly, the gross and the histological structure of the lymphoid tissues of the camel’s thymus, tonsils, and peyer’s patches have indicated significant differences from other animals in terms of structure and function. The most peculiar CD expression, such as LPAM-I, MAdCAM-1 and CX3CR1, in certain camel cells and tissues refers to possible extraordinary mechanisms of immune hemostasis in camel in comparison to other ruminants. The widely applied immunodiagnostic techniques to control camel diseases and to assist in improving the camel resistance were considered. Extensive studies of the camel immune system were greatly hampered by lack of specific reagents to camel markers and low funds in the field of camel immunology.

大黄酸对免疫球蛋白A肾病的改善作用及机制研究

目的基于信号转导与转录激活因子3(STAT3)信号通路,研究大黄酸改善免疫球蛋白A肾病(IgAN)模型大鼠的作用及机制。方法将大鼠随机分为正常对照组、IgAN模型组和大黄酸治疗组(100 mg/kg),每组10只。IgAN模型组和大黄酸治疗组采用牛血清白蛋白+脂多糖+四氯化碳联合法复制IgAN模型。造模第7周开始,大黄酸治疗组大鼠灌胃相应药物,正常对照组和模型组大鼠灌胃等量生理盐水,连续4周。末次给药后,检测大鼠尿红细胞数、24 h尿蛋白(24 h-UTP)以及血清中免疫球蛋白A(IgA)、小肠黏液中分泌型IgA(sIgA)的水平;观察大鼠肾皮质和小肠黏膜Peyer结的病理形态学变化以及肾皮质中IgA沉积情况;检测大鼠小肠黏膜Peyer结中白细胞介素17(IL-17)、IL-6和转化生长因子β(TGF-β)的表达水平;检测Peyer结中STAT3和维甲酸受体相关孤儿受体γt(RORγt)mRNA的表达水平;检测Peyer结中磷酸化STAT3(p-STAT3)和RORγt蛋白的表达水平。结果与正常对照组比较,IgAN模型组大鼠尿红细胞数、24 h-UTP以及血清中IgA、小肠黏液中sIgA水平均显著升高(P<0.01);肾皮质中肾小体增大,肾小囊扩张,球内系膜增生、纤维化明显;小肠黏膜Peyer结体积和生发中心增大;肾皮质中IgA沉积明显;小肠黏膜Peyer结中IL-17、IL-6、TGF-β、STAT3 mRNA、RORγt mRNA以及p-STAT3、RORγt蛋白的表达水平均显著升高(P<0.01)。与IgAN模型组比较,大黄酸治疗组大鼠上述指标水平均显著降低(P<0.01),肾皮质病理损伤有所改善,小肠黏膜Peyer结体积和生发中心减小,肾皮质中IgA沉积减弱。结论大黄酸对IgAN模型大鼠具有较好的改善作用,其作用机制可能与抑制STAT3信号通路活性、调控小肠黏膜Peyer结内的免疫功能有关。

Lanthanum chloride or citrate is absorbed mainly via M cells in gastrointestinal tracts with lanthanum phosphates as the transformed species

In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements（REEs） in gastrointestinal（GI） tract, using La Cl3 and La Cit as representative compounds. Artificial gastric and intestinal fluids were used to simulate the environment of the digestive tract in vivo. The inductively coupled plasma mass spectrometry（ICP-MS） result showed that more than 99.9% of La Cl3 and La Cit formed precipitation in artificial intestinal fluid, with the average size distribution of 200 nm（2-h incubation） increasing to 600 nm（24-h incubation） determined by dynamic light scattering（DLS）, indicating the aggregation of the particles. The Fourier transform infrared spectroscopy（FTIR） analysis demonstrated that the constituents of these particles were mainly in the form of lanthanum phosphates. To explore the transport mechanism of REEs in GI tract, the mice Peyer＇s patches（PPs） and intestinal epithelium were separated to evaluate the content of lanthanum by ICP-MS following oral administration with 2 or 100 mg/kg/day of La Cit for 7 d. The results showed that the amount of lanthanum phosphate particles absorbed by PPs was significantly greater than that of intestinal epithelium, indicating that lanthanum particles might be phagocytosed mainly by M cells located in the follicle-associated epithelium（FAE） overlying PPs. Furthermore, Caco-2 cell monoculture and Caco-2/Raji B cell coculture models were established to simulate intestinal epithelial cells and FAE, respectively. The result showed that the transport of lanthanum in Caco-2/Raji B coculture model was significantly higher than that in Caco-2 monoculture model（about 60 times higher）, and the level of lanthanum in the basal compartment of Caco-2 monoculture model was very low, supporting that M cells were the main route for lanthanum phosphate particles to be transported and absorbed. Taken together, these data suggested that La Cl3 and La Cit in GI tract were absorbed mainly via M cells with lanthanum phosphates as transformed species. The obtained results would provide the theoretical basis for the rational application of REEs in agriculture and medicine.

小鼠肠上皮内淋巴细胞在粘膜免疫应答中的形态学研究

采用免疫组织化学和电镜方法，观察了ＢＡＬＢ／ｃ小鼠灌服伤寒杆菌后回肠及集合淋巴小结圆顶区肠上皮内淋巴细胞（ｉｎｔｒａｅｐｉｔｈｅｌｉａｌｌｙｍｐｈｏｃｙｔｅ，ＩＥＬ）的形态和分布特征，以探讨ＩＥＬ在抗原诱导下的粘膜免疫应答中的作用。经免疫组织化学方法证实灌服伤寒杆菌后回肠及集合淋巴小结圆顶区肠上皮内含Ｂ和Ｔ两种淋巴细胞，以Ｂ淋巴细胞为主；电镜下可见上皮内淋巴细胞主要由小和中等淋巴细胞组成，且后者有两种形态。一种细胞器较少，与上皮微绒毛之间有紧密接触。另一种细胞器丰富，内质网呈扩张状态。同时观察到ＩＥＬ有的位于上皮细胞内，有的位于相邻的上皮细胞间隙内。本研究提示，小肠上皮不仅为粘膜免疫效应部位，而且也是免疫诱导部位。提示伤寒杆菌能诱导淋巴细胞向小肠上皮和圆顶区上皮迁移，且圆顶区上皮比小肠上皮更易接受抗原刺激。

清胰汤Ⅱ号冲剂对急性胰腺炎小鼠的保护作用及机制

目的:探讨清胰汤Ⅱ号冲剂(QYT)对急性胰腺炎(acute pancreatitis,AP)小鼠的保护作用及机制。方法:成年C57BL/6小鼠24只,雌雄各半,随机均分为3组。AP组和AP+QYT组首先经腹腔注射雨蛙肽(50μg/kg)及脂多糖(10 mg/kg)复制重症AP模型,AP组小鼠给予饮用水灌胃,AP+QYT组给予QYT灌胃;正常对照组小鼠给予等量生理盐水注射及饮用水灌胃。于末次注药后3 h麻醉处死动物。检测和分析胰腺组织的病理改变、肠道细菌总数和分类、Peyer’s结T淋巴细胞亚群的变化、血浆淀粉酶、白细胞介素6(IL-6)、单核细胞趋化蛋白1(MCP-1)水平以及胰腺和肺脏组织髓过氧化物酶(MPO)活性等。结果:与对照组相比,AP小鼠的胰腺组织病理学评分、肠道细菌数量、血浆淀粉酶活性、IL-6及MCP-1水平、胰和肺组织的MPO活性都有明显升高(P<0.05);QYT可在一定程度上逆转AP时相关指标的变化(P<0.05)。小肠Peyer’s结数量在各组无明显差异,但AP组的CD3+T淋巴细胞百分比较对照组明显降低(P<0.05),而且,AP组和AP+QYT组,尤其是后者CD4+T淋巴细胞百分比和CD4+/CD8+比值较对照组明显升高(P<0.05)。结论:清胰汤II号冲剂对雨蛙肽和脂多糖诱导的小鼠急性胰腺炎具有明显的拮抗作用,其机制可能与其抑制炎症反应、促进肠内细菌的清除和调节肠道T淋巴细胞功能有关。

不同发育时期大鼠肠道黏膜形态与树突状细胞发育活化的研究

目的探讨不同发育时期SD大鼠肠道黏膜形态发育及树突状细胞发育与活化的关系。方法25只SD大鼠随机分为五组,分别在3、5、7、9、11周应用图像分析检测技术及流式细胞技术检测幼鼠肠黏膜绒毛与肠集合淋巴结发育状况及肠树突状细胞发育及活化指标。结果不同发育时期肠绒毛长度、绒毛宽度、绒毛面积、隐窝深度及绒毛长度/隐窝深度差异均有统计学意义(P<0.05);不同发育时期小肠集合淋巴结面积增加差异有统计学意义(P<0.05);随着周龄的增加,肠道OX62^+总树突状细胞增加,OX62^+/CD4^-/OX41^-亚型树突状细胞减少,同时,OX62^+/CD4^+/OX41^+亚型树突状细胞增加,变化均有统计学意义(P<0.05)。结论随着周龄的增长,SD大鼠小肠绒毛-隐窝轴增殖分化,肠道树突状细胞逐渐发育与成熟,且两者的发育成熟状况基本同步。SD大鼠肠黏膜形态及黏膜免疫细胞早在断乳期就逐渐成熟,在7～9周时发育幅度最大,并在11周时逐渐达到成熟状态。断乳早期,食物改变会影响SD大鼠肠道黏膜形态发育及树突状细胞发育活化。