Multiple sclerosis patients have peripheral blood CD45RO+ B cells and increased intestinal permeability

Increased intestinal permeability and the CD45RO isoform expression of the leukocyte common antigen on peripheral blood CD20+ B cells are found in Crohn's disease. Others have observed that multiple sclerosis (MS) patients may have an increased risk of coacquisition of Crohn's disease. The aim of this study was to identify an association between these diseases using peripheral blood CD45 isoform expression and intestinal permeability in MS. Lactulose/mannitol permeability and peripheral blood CD20+ B cell CD45RO expression were defined in healthy controls, MS patients, and patients coincidentally affected by MS and Crohn's or MS and ulcerative colitis (UC). Five of 20 MS patients had increased intestinal permeability, a finding not previously reported. High levels of CD45RO were found on circulating CD20+ B cells from patients with MS. This has not been reported previously in MS and is found in very few other conditions. Eight patients with coincident MS and Crohn's disease or MS and UC were studied. Coincident MS and UC patients expressed CD45RO on CD20+ B cells, a finding not identified in UC patients alone. A subgroup of MS patients has increased intestinal permeability. These patients express CD45RO CD20+ B cells, also found in Crohn's disease.     

Peripheral decrease and pulmonary homing of CD4+CD45RO+ helper memory T cells in cystic fibrosis

Interstitial lung disease, although of prognostic impact for patients with cystic fibrosis (CF), remains difficult to assess without histopathologic investigations. As changes of peripheral blood lymphocyte subsets (LS) may accompany severe systemic lymphocyte immune responses, we compared peripheral LS of 44 patients with CF, 23 non-CF patients with recurrent pulmonary infections and 83 healthy controls (flow cytometry; CD3, CD19, CD16, CD56, CD4, CD8, CD11b, CD45RA, CD45RO, HLA-DR and CD25 antigens). Additional immunohistochemistry was performed on lung tissue of four CF patients aged 0.5, 12, 17 and 20 years, respectively. Patients with CF showed low absolute counts of CD4+CD45RO+ memory helperT cells, CD16+CD56+ NK cells, CD8+ and interleukin-2 receptor-positive T cells in peripheral blood (P < 0.001). Similar changes were registered in the non-CF patients with pulmonary infections, indicating that those were not specific for CF. Immunohistochemistry showed activation of bronchus-associated lymphoid tissue with interstitial accumulation of CD4+CD45 RO+ T cells in the three older patients. Patients with CF show marked changes of peripheral blood LS which are presumably not CF-specific and may mirror homing to lung tissue in the course of interstitial lung disease. Further research should evaluate its usefulness in monitoring progression of lung disease in CF.     

Effect of long-term infection with nef-defective attenuated HIV type 1 on CD4+ and CD8+ T lymphocytes: increased CD45RO+CD4+ T lymphocytes and limited activation of CD8+ T lymphocytes

Members of the Sydney Blood Bank Cohort (SBBC) have been infected with an attenuated strain of HIV-1 with a natural nef/LTR mutation and have maintained relatively stable CD4+ T lymphocyte counts for 14-18 years. Flow cytometric analysis was used to examine the phenotype of CD4+ and CD8+ T lymphocytes in these subjects, including the immunologically important naive (CD45RA+CD62L+), primed (CD45RO+), and activated (CD38+HLA-DR+ and CD28-) subsets. The median values were compared between the SBBC and control groups, comprising age-, sex-, and transfusion-matched HIV-1-uninfected subjects; transfusion-acquired HIV-1-positive LTNPs; and sexually acquired HIV-1-positive LTNPs. Members of the SBBC not only had normal levels of naive CD4+ and CD8+ T lymphocytes, but had primed CD45RO+ CD4+ T lymphocytes at or above normal levels. Furthermore, these primed cells expressed markers suggesting recent exposure to specific antigen. SBBC members exhibited variable activation of CD8+ T lymphocytes. In particular, SBBC members with undetectable plasma HIV-1 RNA had normal levels of activated CD8+ T lymphocytes. Therefore, the result of long-term infection with natural nef/LTR mutant HIV-1 in these subjects suggests a decreased cytopathic effect of attenuated HIV-1 on susceptible activated CD4+ T lymphocyte subsets in vivo, and minimal activation of CD8+ T lymphocytes.     

Preferential attachment of HIV particles to activated and CD45RO+CD4+ T cells.

We have studied the binding of biotinylated HIV particles to various cell lines and peripheral blood mononuclear cells (PBMCs). Viruses were harvested from cultures of cell surface-biotinylated cells productively infected with HIV-IIIB. Labeled HIV particles bound to and infected CD4(+) cell lines and PBMCs. The interaction between gp120 and CD4 contributed in part to HIV binding to CD4(+) cells. However, HIV binding was for the most part independent of CD4 expression and sensitive to polyanion inhibition. Polyanion-sensitive interactions involved heparan sulfate in cell lines but not in primary T cells. Interestingly, HIV binding to primary cells was heterogeneous and targeted discrete subsets of CD4(+) and CD4(-) cells. The CD4(+) T cell subset that displayed high HIV-binding capacity contained mostly CD4(+)CD45RO(+) cells, whereas the subset showing undetectable HIV binding contained higher proportions of CD4(+)CD45RO(-) cells. Consistently, purified CD4(+)CD45RO(-) cells or purified CD4(+) T cells with low virus-binding capacity showed lower HIV entry and delayed HIV replication when compared with purified CD4(+)CD45RO(+) or purified CD4(+) T cells with high virus-binding capacity, respectively. Our data suggest that the binding of HIV to cell surface-expressed CD4 might be inefficient in a subset of CD4(+) T cells and that increased binding of HIV to activated and CD4(+)CD45RO(+) cells may contribute to the higher susceptibility of these cells to HIV infection.     

CD25+CD4+ T cells contribute to the control of memory CD8+ T cells

Previously we demonstrated that IL-15 and IL-2 control the number of memory CD8+ T cells in mice. IL-15 induces, and IL-2 suppresses the division of these cells. Here we show that CD25+CD4+ regulatory T cells play an important role in the IL-2-mediated control of memory phenotype CD8+ T cell number. In animals, the numbers of CD25+CD4+ T cells were inversely correlated with the numbers of memory phenotype CD8+ T cells with age. Treatment with anti-IL-2 caused CD25+CD4+ T cells to disappear and, concurrently, increased the numbers of memory phenotype CD8+ T cells. This increase in the numbers of CD8+ memory phenotype T cells was not manifest in animals lacking CD4+ cells. Importantly, adoptive transfer of CD25+CD4+ T cells significantly reduced division of memory phenotype CD8+ T cells. Thus, we conclude that CD25+CD4+ T cells are involved in the IL-2-mediated inhibition of memory CD8+ T cell division and that IL-2 controls memory phenotype CD8+ T cell numbers at least in part through maintenance of the CD25+CD4+ T cell population.     

CD147 (Basigin/Emmprin) identifies FoxP3+CD45RO+CTLA4+-activated human regulatory T cells

Human CD4(+)FoxP3(+) T cells are functionally and phenotypically heterogeneous providing plasticity to immune activation and regulation. To better understand the functional dynamics within this subset, we first used a combined strategy of subcellular fractionation and proteomics to describe differences at the protein level between highly purified human CD4(+)CD25(+) and CD4(+)CD25(-) T-cell populations. This identified a set of membrane proteins highly expressed on the cell surface of human regulatory T cells (Tregs), including CD71, CD95, CD147, and CD148. CD147 (Basigin or Emmprin) divided CD4(+)CD25(+) cells into distinct subsets. Furthermore, CD147, CD25, FoxP3, and in particular CTLA-4 expression correlated. Phenotypical and functional analyses suggested that CD147 marks the switch between resting (CD45RA(+)) and activated (CD45RO(+)) subsets within the FoxP3(+) T-cell population. Sorting of regulatory T cells into CD147(-) and CD147(+) populations demonstrated that CD147 identifies an activated and highly suppressive CD45RO(+) Treg subset. When analyzing CD4(+) T cells for their cytokine producing potential, CD147 levels grouped the FoxP3(+) subset into 3 categories with different ability to produce IL-2, TNF-α, IFN-γ, and IL-17. Together, this suggests that CD147 is a direct marker for activated Tregs within the CD4(+)FoxP3(+) subset and may provide means to manipulate cells important for immune homeostasis.     

Fas/Fas ligand expression and characteristics of primed CD45RO+ T cells in the inflamed mucosa of ulcerative colitis

BACKGROUND: Chronic immune activation in the colon is characteristic of ulcerative colitis (UC). Fas/Fas ligand (FasL) system is a mechanism responsible for activation-induced cell death (AICD), which maintains homeostasis within the immune system. Thus, Fas/FasL expression on activated colonic T cells of UC patients, as well as the susceptibility of such T cells to AICD was investigated in order to determine the role of activated colonic T cells in the long lasting inflammation in UC. METHODS: Fas, FasL, and CD45RO expression on peripheral blood and colonic T cells of UC patients were assayed by flow cytometry. Apoptosis of colonic T cells induced by anti Fas antibody was assessed using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay. RESULTS: The majority of colonic T cells expressed both CD45RO and Fas in the colonic mucosa, a situation that was quite different from that in the peripheral blood. The number of CD45RO+CD8+ and Fas+CD8+ T cells was significantly lower in UC patients than the controls, unlike the number of Fas+CD4+ T cells. In contrast, the number of both CD45RO+CD4+ and CD45RO+CD8+ T cells in UC mucosa expressing FasL was significantly higher than in the controls. While Fas mediated apoptosis of CD45RO+CD8+ T cells was higher in UC patients than the controls, the number of apoptotic CD45RO+CD4+ T cells from UC mucosa was not. CONCLUSIONS: In UC patients, CD45RO+CD4+ T cells are less sensitive to apoptotic signals mediated by Fas. These phenomena may contribute to the pathogenesis of UC.     

Low percentages of regulatory T cells in common variable immunodeficiency (CVID) patients with autoimmune diseases and its association with increased numbers of CD4+CD45RO+ T and CD21low B cells

BackgroundCommon variable immunodeficiency (CVID) is a heterogeneous group of primary antibody deficiencies defined by marked reductions in serum IgG, IgA and/or IgM levels and recurrent bacterial infections. Some patients are associated with defects in T cells and regulatory T cells (Tregs), resulting in recurrent viral infections and early-onset autoimmune disease.MethodsWe analyzed whether there is an association between Tregs cells (CD4+CD25+CD127^low and CD4+CD25+FoxP3+); memory T cells (CD4+CD45RO+); memory B cells (CD19+CD27-IgD-); and CD21^low B cells (CD19+CD38^lowCD21^low); as well as autoimmune manifestations in 36 patients with CVID (25 women and 11 men, mean age 24 years), all by flow cytometry.ResultsFourteen patients presented with autoimmune diseases (AI) (39%), including 11 with autoimmune thrombocytopenia (ITP) (31%); two with vitiligo (6%); one with systemic lupus erythematosus (LES) (3%); and one with multiple sclerosis (MS) (3%). CVID patients with AI had a reduced proportion of Tregs (both CD4+CD25+CD127^low and FoxP3+ cells) compared with healthy controls. CVID patients with AI had expanded CD21^low B cell populations compared with patients who did not have AI. A correlation between increased CD4+CD45RO T cell populations and reduced Tregs was also observed.ConclusionsOur results showed that 39% of patients with CVID had AI and reduced Tregs populations. Research in this area might provide noteworthy data to better understand immune dysfunction and dysregulation related to CVID.     

Intestinal double-positive CD4+CD8+ T cells of neonatal rhesus macaques are proliferating, activated memory cells and primary targets for SIVMAC251 infection

Peripheral blood and thymic double-positive (DP) CD4(+)CD8(+) T cells from neonates have been described earlier, but the function and immunophenotypic characteristics of other tissue-derived DP T cells are not clearly understood. Here, we demonstrate the functional and immunophenotypic characteristics of DP cells in 6 different tissues, including thymus from normal neonatal rhesus macaques (Macaca mulatta) between 0 and 21 days of age. In general, intestinal DP T cells of neonates have higher percentages of memory markers (CD28(+)CD95(+)CD45RA(low)CD62L(low)) and proliferation compared with single-positive (SP) CD4(+) and CD8(+) T cells. In addition, percentages of DP T cells increase and CD62L expression decreases as animals mature, suggesting that DP cells mature and proliferate with maturity and/or antigen exposure. Consistent with this, intestinal DP T cells in neonates express higher levels of CCR5 and are the primary targets in simian immunodeficiency virus (SIV) infection. Finally, DP T cells produce higher levels of cytokine in response to mitogen stimulation compared with SP CD4(+) or CD8(+) T cells. Collectively, these findings demonstrate that intestinal DP T cells of neonates are proliferating, activated memory cells and are likely involved in regulating immune responses, in contrast to immature DP T cells in the thymus.     

CD4+CD25+ T细胞在溃疡性结肠炎中的表达及其临床意义

目的 研究溃疡性结肠炎(UC)患者外周血CD 4CD 25调节性T细胞比例的变化,探讨其在UC病理机制中的意义.方法 选择UC患者33例,对照组20例.用流式细胞仪检测外周血CD 4CD 25T细胞阳性率.用RT-PCR检测外周单个核细胞(PBMC)中Foxp3 mRNA的表达.用酶联免疫吸附试验检测血清中IL-10和TGF-β的浓度.结果 UC患者CD 4CD 25T细胞占CD 4T细胞的比例明显低于对照组(P＜0.01),并且与疾病的活动指数及血沉水平均呈显著负相关(R值分别为-0.660和-0.572,P值均＜0.01).UC患者Foxp3 mRNA的表达也明显低于对照组(P＜0.01).两组患者血清IL-10和TGF-β的浓度比较无明显差异(P＞0.05).结论 UC患者外周血CD 4CD 25 调节性T细胞明显降低,与疾病活动性相关,提示这类细胞可能在UC的病理机制中发挥作用.Foxp3表达降低可能是导致CD 4CD 25 T细胞发育障碍的重要因素.     

CD4+CD8+ human small intestinal T cells are decreased in coeliac patients, with CD8 expression downregulated on intra-epithelial T cells in the active disease

BACKGROUND/OBJECTIVE: The intestinal lesion of coeliac disease is thought to be initiated and exacerbated by dysregulation of local T-lymphocyte sub-populations. This study examines changes in intestinal T cells from coeliac patients, with a particular focus on CD4CD8 T cells, immunoregulatory cells normally found in relatively high proportions in the small intestine. METHODS: Cells were obtained from duodenal biopsies from active and treated coeliac patients using chelating and reducing agents (epithelial layer) followed by collagenase treatment (lamina propria). Cell yield and viability were assessed and flow cytometric analysis was used to examine CD4CD8 T cells and to quantify CD8 expression. RESULTS: Surprisingly, total T-cell yields in the epithelial layer did not increase in active coeliac disease although enterocyte counts decreased significantly, giving an appearance of infiltration. In active coeliac patients, CD4CD8 T cell percentages were significantly decreased in both the epithelial layer and lamina propria. Levels of CD8 expression by CD4CD8 T cells in the epithelial layer were decreased significantly in patients with active coeliac disease. CD4CD8 T cell proportions did not return to normal in treated coeliac patients whose villous architecture had responded to gluten withdrawal. CONCLUSIONS: No increase of intra-epithelial lymphocytes in the coeliac lesion may require us to reconsider the definition of coeliac disease as an inflammatory condition. Low CD4CD8 populations in treated as well as untreated coeliac patients indicate that these T cells are inherently absent in individuals genetically predisposed to coeliac disease.     

肺结核患者外周血CD_4~+、CD_8~+T细胞Blimp-1表达下降

目的研究活动性肺结核患者外周血单个核细胞(PBMCs)Blimp-1的表达及临床意义。方法采集31例活动期肺结核患者和45位健康对照组外周血,纯化PBMCs,用结核分枝杆菌ESAT-6和CFP-10混合性抗原肽库刺激,通过细胞表面标记和细胞内细胞因子染色技术,采用流式技术检测CD+4、CD+8T细胞Blimp-1的表达。结果与对照组比较,肺结核患者PBMCs中的CD+4、CD+8T细胞亚群分布出现显著性下降,且肺结核患者CD+4T细胞中Blimp-1的表达比例(%)下降(肺结核组89.5%(83.8%,95.7%),对照组94.5%(89.8%,98.7%),P0.05),且CD+4、CD+8T细胞中Blimp-1的表达量(平均荧光强度)也显著性下降(CD+4T细胞:肺结核组9.28(7.5,18.9),对照组15.4(11,25.4),P0.05);CD+8T细胞:肺结核组9.01(6.08,14.7),对照组14.2(9.53,23.1),P0.05)。结论活动期肺结核CD+4、CD+8T细胞群内Blimp-1的表达下降可能会使效应性和调节性T细胞的分化出现异常。Blimp-1可能参与结核病的疾病进程,这为研究结核病的诊断和治疗提供了线索。     

CD4+CD45RBhigh T细胞转入SCID鼠诱导的结肠炎模型

炎症性肠病的病因未明,因此此疾病的动物模型的制备比较困难.现有的多种制模方法都不能完全模拟人的炎症性肠病.我们介绍一种比较新的免疫方法诱导的结肠炎动物模型,即用CD4 CD45RBhighT细胞转入SCID鼠诱导产生结肠炎.以下就此模型的制备方法、原理、特点、与IBD的相似处、用途、优缺点作一综述.     

CTLA4-Ig对老年支气管哮喘病人CD4+ CD45 RO+ T细胞功能的影响

目的研究老年支气管哮喘病人周围血CD4 CD45RO T细胞表达IL-4及IL-13的情况及CTLA4-Ig对其影响。方法用ELISA方法测定老年支气管哮喘病人CD4 CD45RO T细胞产生IL-4和IL-13的水平及CTLA4-Ig对其影响。结果老年支气管哮喘病人CD4 CD45RO T细胞分泌IL-4、IL-13增多,IL-13增多较IL-4更为明显(P<0.01),CTLA4-Ig可有效抑制老年哮喘病人CD4 CD45RO T细胞分泌IL-4和IL-13(P<0.01)。结论CD4 CD45RO T细胞产生的IL-4和IL-13在老年哮喘发病中起重要作用,CTLA4-Ig可有效抑制IL-4和IL-13的分泌。     

CTLA4-Ⅰg对老年支气管哮喘病人CD4^＋CD45RO^＋T细胞功能的影响

目的 研究老年支气管哮喘病人周围血CD4^＋CD45RO^＋T细胞表达IL4及IL-13的情况及CTLA4-Ⅰg对其影响。方法 用ELISA方法测定老年支气管哮喘病人CD4^＋CD45RO^＋T细胞产生IL-4和IL-13的水平及CTLA4-Ⅰg对其影响。结果 老年支气管哮喘病人CD4^＋CD45RO^＋T细胞分泌IL4、IL-13增多，IL-13增多较IL-4更为明显（P〈0．01），CTLA4-Ⅰg可有效抑制老年哮喘病人CD4^＋CD45RO^＋T细胞分泌IL-4和IL-13（P〈0．01）。结论 CD4^＋CD45RO^＋T细胞产生的IL-4和IL-13在老年哮喘发病中起重要作用，CTLA4-Ⅰg可有效抑制IL-4和IL-13的分泌。     

Loss of EBNA1-specific memory CD4+ and CD8+ T cells in HIV-infected patients progressing to AIDS-related non-Hodgkin lymphoma

We previously observed a loss of Epstein-Barr virus (EBV)-specific CD8+ T cells in subjects progressing to EBV-related non-Hodgkin lymphoma (NHL), correlating with loss of CD4+ T cells. The aim of the present study was to determine the role of EBV-specific CD4+ T cells in the development of NHL during chronic HIV infection. To this end, CD4+ and CD8+ memory T cells, capable of both proliferation and subsequent interferon gamma (IFNgamma) production, directed against a latent (Epstein-Barr virus nuclear antigen 1 [EBNA1]) and a lytic (BamH fragment Z left frame 1 [BZLF1]) EBV antigen were studied longitudinally in 9 progressors to NHL, 4 progressors to non-EBV-related AIDS, and 4 slow progressors to AIDS. In all 3 groups we observed a decline of EBV-specific memory CD4+ and CD8+ T-cell responses during HIV infection. However, whereas latent antigen EBNA1-specific CD4+ T cells were lost well before diagnosis in all subjects who developed an AIDS-related NHL (and EBNA1-specific CD8+ T cells were significantly lower compared with the other groups), these cells were better preserved in progressors to non-EBV-related disease and slow progressors. Loss of EBNA1-specific T-cell immunity thus might be important for progression to NHL. Interestingly, BZLF1-specific T cells were not lost in all progressors to NHL, suggesting a different function of these cells in the surveillance of EBV-infected B cells.     

Percentage of CD3+CD4-CD8-gammadeltaTCR- T cells is increased HIV disease.

HIV patients given highly active antiretroviral therapy (HAART) experience a rapid rise in alphabetaT cell numbers, but changes in gammadeltaT cell populations have not been described. Here we investigate the effects of immune reconstitution and immune restoration diseases (IRDs) on expression of a pan-gammadeltaT cell receptor (TCR) marker on double-negative (CD3(+)CD4(-)CD8(-)) T cells and T cells expressing CD4 or CD8. IRDs are inflammatory disorders associated with preexisting infections in patients who have achieved immune reconstitution after HAART. Proportions of CD3(+)CD4(-)CD8(-) T cells and total gammadeltaT cells were not affected by CD4(+) T cell counts, HAART, or a history of IRD, but levels of CD4(-)CD8(-)gammadeltaTCR(-) T cells were higher in patients with <15% CD4(+) T cells.