An update on cytokines in the pathogenesis of insulin-dependent diabetes mellitus

Correlation studies between cytokines expressed in islets and autoimmune diabetes development in NOD mice and BB rats have demonstrated that β-cell destructive insulitis is associated with increased expression of proinflammatory cytokines (IL-1, TNFα, and IFNα) and type 1 cytokines (IFNγ, TNFβ, IL-2 and IL-12), whereas non-destructive (benign) insulitis is associated with increased expression of type 2 cytokines (IL-4 and IL-10) and the type 3 cytokine (TGFβ). Cytokines (IL-1, TNFα, TNFβ and IFNγ) may be directly cytotoxic to β-cells by inducing nitric oxide and oxygen free radicals in the β-cells. In addition, cytokines may sensitize β-cells to T-cell-mediated cytotoxicity in vivo by upregulating MHC class I expression on the β-cells (an action of IFNγ), and inducing Fas (CD95) expression on β-cells (actions of IL-1, and possibly TNFα and IFNγ). Transgenic expression of cytokines in β-cells of non-diabetes-prone mice and NOD mice has suggested pathogenic roles for IFNα, IFNγ, IL-2 and IL-10 in insulin-dependent diabetes mellitus (IDDM) development, and protective roles for IL-4, IL-6 and TNFα. Systemic administrations of a wide variety of cytokines can prevent IDDM development in NOD mice and/or BB rats; however, a given cytokine may retard or accelerate IDDM development, depending on the dose and frequency of administration, and the age and the diabetes-prone animal model studied (NOD mouse or BB rat). Islet-reactive CD4⁺ T-cell lines and clones that adoptively transfer IDDM into young NOD mice have a Th1 phenotype (IFNγ-producing), but other islet-specific Th1 clones that produce TGFβ can adoptively transfer protection against IDDM in NOD mice. NOD mice with targeted deletions of IL-12 and IFNγ genes still develop IDDM, albeit delayed and slightly less often. In contrast, post-natal deletions of IL-12 and IFNγ, also IL-1, TNFα, IL-2, and IL-6—by systemic administrations of neutralizing antibodies, soluble receptors and receptor antagonists, and receptor-targeted cytotoxic drugs—significantly decrease IDDM incidence in NOD mice and/or BB rats. These cytokine deletion studies have provided the best evidence for pathologic roles for proinflammatory cytokines (IL-1, TNFα, and IL-6) and type 1 cytokines (IFNγ, IL-2 and IL-12) in IDDM development. © 1998 John Wiley & Sons, Ltd.     

日本血吸虫感染可诱导共刺激分子（ICOS）转基因小鼠的免疫应答及其病理反应

目的 观察ICOS转基因小鼠感染日本血吸虫后的免疫应答及其免疫病理反应。 方法 收集ICOS转基因小鼠及对照组野生型小鼠分别感染30条日本血吸虫尾蚴后4～8周的血清及脾淋巴细胞培养上清，用ELISA双抗体夹心法检测血清抗体IgG、IgG1、IgG2a的水平和培养上清中的Th1细胞因子γ干扰素（IFN-γ），Th2细胞因子白细胞介素-4（IL-4）水平。取小鼠感染后6、8周肝脏，常规石蜡连续切片，HE染色，在光镜观察单个虫卵肉芽肿病变。 结果 转基因小鼠IFN-γ的表达水平无显著变化，而6、8周时转基因小鼠的IL?鄄4水平呈显著上调表达，分别为（20.8±1.6）pg/ml和（25.3±3.4）pg/ml（P<0.01）。转基因小鼠血清IgG、IgG1表达水平也均高于对照组。在转基因小鼠，反映Th1/Th2免疫平衡的Th2分化指数和IgG1/IgG2a比值也明显呈Th2优势应答，分别为2.20±0.68和5.59±0.31。感染6、8周转基因小鼠肝虫卵肉芽肿反应比对照组更为显著。转基因小鼠肝虫卵肉芽肿体积显著大于同期对照组的肉芽肿，增大率分别为24.48%和26.37%（P<0.01）。 结论 ICOS转基因小鼠感染日本血吸虫后表现出Th2优势应答的免疫学特征，表明ICOS在血吸虫病免疫病理中具有重要作用。     

广州管圆线虫感染小鼠血清细胞因子及IgG亚类的动态观察

目的观察小鼠感染广州管圆线虫后机体免疫的动态变化。方法分别采集感染前、感染后第1、3、7、18d的小鼠血清,用ELISA方法检测血清中细胞因子IL-2、IL-4以及特异性免疫球蛋白G（IgG）亚类水平。结果广州管圆线虫感染的小鼠血清中IL-2的水平较感染前呈逐渐下降趋势,IL-4的水平与感染前小鼠相比先下降后呈升高趋势。抗体IgG1的水平与感染前小鼠相比明显升高,IgG2a的水平与感染前小鼠相比未见明显变化。结论小鼠Th1型免疫应答较弱,Th2型免疫应答增强。表明小鼠感染广州管圆线虫后机体细胞免疫较弱,体液免疫较强。     

Th1和Th2型细胞因子对小鼠感染血吸虫的免疫保护性研究

目的 探讨Th1和Th2类细胞因子对小鼠感染血吸虫的免疫保护作用. 方法 C57BL/6小鼠48只,抽签法随机均分为4组,白细胞介素（interleukin,IL）-4组,给予IL-4 （200 ng）; IL-12组,给予IL-12 （200 ng）;胸腺基质淋巴生成素（thymic stromal lymphopoietin,TSLP）组,给予TSLP（200 ng）;生理盐水组,给予生理盐水（200μl）.4组均为腹腔注射,每周3次,持续注射8周.给药后2周,各组小鼠经皮攻击感染日本血吸虫尾蚴（40±2）条/鼠,感染后第3、6周剖杀,计算各组小鼠虫荷数、肝脏卵荷数.芯片检测各组小鼠感染前和感染后不同时间点血清中IL-5、IL-10、γ-干扰素（interferon-γ,IFN-γ）及肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）的动态变化.观察小鼠肝、脾的病理变化. 结果 细胞因子注射的第8周,IL-4组的Th2类细因子IL-5、IL-10依次为161.97、65.47 μg/ml; TSLP组的IL-5、IL-10依次为132.72、77.18 μg/ml; IL-12组的IL-5、IL-10依次为87.15、12.29 μg/ml;生理盐水组的IL-5、IL-10依次为188.92、167.52 μg/ml.IL-4和TSLP组Th2类细胞因子水平均高于IL-12组,但低于生理盐水组.IL-12组IFN-γ、TNF-α依次为165.7、23.64 μg/ml,水平高于其它各组.感染后3周IL-4、IL-12、TSLP、生理盐水组虫荷数依次为（9.50±4.51）、（12.83±2.32）、（6.75±2.87）、（9.80±3.03）条;感染后6周上述各组虫荷数依次为（18.83±5.91）、（24.80±9.42）、（21.67±3.67）、（17.67±6.74）条,每克肝组织虫卵数依次为（58 286.98±25 351.60）、（80 460.18±35 542.66）、（54 579.56±16 399.21）、（41 094.92±25 598.27）.与生理盐水组相比,各实验组虫荷数与每克肝组织虫卵数差异均无统计学意义.感染后第3周,IL-4、IL-12、TSLP、生理盐水组脾指数依次为（0.010±0.002）、（0.011±0.002）、（0.009±0.001）、（0.007 ±0.001）,各实验组与生理盐水组相比,差异均有统计学意义（t=3.158、5.076、6.204,P＜0.05）.感染后第6?     

泡球蚴感染BALB/c小鼠IgG亚类和细胞因子的动态观察

目的　观察小鼠感染泡球蚴后其体液免疫的动态变化。　方法　BALB/c小鼠感染泡球蚴后,分别于2、4、8、12、16、20及25wk(IgG含量达高峰)取脾脏制备淋巴细胞悬液体外培养,分别以多房棘球蚴抗原(EmAg)、伴刀豆球蛋白A(ConA)刺激诱生可溶性白细胞介素2受体(IL2R)、肿瘤坏死因子α(TNFα)及白细胞介素1(IL1);以植物凝集素(PHA)刺激诱生干扰素γ(IFNγ)。检测培养上清中IL2R、TNFα、IL1及IFNγ含量。各组均设RPMI1640培养液平行对照。检测血清中一氧化氮(NO)及特异性免疫球蛋白G(IgG)亚类水平。　结果　小鼠感染泡球蚴16wk后NO水平明显升高,IgG、IgG1和IgG3水平升高,IgG2a及IgG2b呈低水平。感染后的前12wk,脾淋巴细胞以分泌IL2R和TNFα为主,12wk后以IFNγ为主、16wk后以IL1为主。　结论　小鼠感染泡球蚴后的前8wk呈Th1反应。感染后期Th2反应逐渐增强     

Relative expression and correlation of tumor necrosis factor-α, interferon-γ, and interleukin-17 in the rheumatoid synovium

Although tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-17 (IL-17) play important roles in RA, their relative expression and possible correlation in synovial tissues are not well understood. In this study, mRNA expression levels of IFN-γ, IL-17, and TNF-α were investigated in individual patients with RA and the correlations between pairs of these three pro-inflammatory cytokines were analyzed. Synovial tissues were obtained during arthroplasties from 24 joints of 24 RA patients. After harvesting synovial tissues, total RNA was isolated then quantitative real-time polymerase chain reaction (qRT-PCR) for IFN-γ, IL-17, and TNF-α was performed. Correlation of expression levels between them was also analyzed. Expression levels of TNF-α, IFN-γ, and IL-17 in patients receiving TNF inhibitors (TNFi) and those treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) alone were also compared between groups. Based on relative expression levels of the three pro-inflammatory cytokines, patients were classified into three major types; an IFN-γ plus TNF-α-dominant type, an IL-17-dominant type, and the other type. TNF-α expression levels were correlated with IFN-γ. In addition, there was a negative correlation between TNF-α and IL-17, and IFN-γ and IL-17. Median relative expression levels of TNF-α have no significant difference between the TNFi and the csDMARDs groups. In the rheumatoid synovial tissues, expression levels of TNF-α were modulated in parallel with IFN-γ, and TNF-α and IL-17, or IFN-γ and IL-17 did not co-express at high levels. This characteristic expression pattern of the three pro-inflammatory cytokines may be clinically useful information in the current cytokine-targeted treatment with biological DMARDs for RA.     

糖皮质激素对Th1／Th2平衡的影响

最近10年积累的证据显示,糖皮质激素可抑制抗原提呈细胞和Th1细胞表达自细胞介素（IL）-12、干扰素（IFN）-γ、IFN-α和肿瘤坏死因子（TNF）-α,而上调Th2细胞表达IL-4、IL-10和IL-13。通过以上机制,使用糖皮质激素会选择性抑制Th1介导的细胞免疫,并向Th2介导的体液免疫偏移,而不是对Th1和Th2均产生抑制。在免疫反应和炎症反应过程中,应激系统激活,糖皮质激素水平升高,诱导向Th2偏移,从而使机体免于Th1／促炎细胞因子和激活的巨噬细胞产生的其他产物的损伤。尽管如此,引起糖皮质激素水平较大变化的情况,如急性或慢性应激、剧烈运动、妊娠、产褥期等,均可通过调节Th1／Th2细胞平衡而引起感染和自身免疫、变态反应性疾病或改变其敏感性。     

Cytokine mRNA expression in skin in response to ectoparasite infection

Cellular infiltration and local cytokine mRNA levels were examined during the first 48 h of infection of skin by larvae of the sheep blowfly Lucilia cuprina. At the cellular level the response involved a dramatic influx of leucocytes (CD45⁺ cells). Among these infiltrating cells were large numbers of granulocytes, including neutrophils and eosinophils, as well as macrophage-like cells and lymphocytes. Many of the lymphocytes expressed cell surface markers characteristic of T cells including CD4, CD8 and the γδ TCR. The numbers of each of these cell types increased progressively as infection continued so that by 48 h the lesions were densely populated. Expression of mRNA for IL-6 could be detected by Northern blot analysis while mRNA for other inflammatory cytokines including IL-1α, IL-1β, IL-8 and TNFα was detected using the polymerase chain reaction. Coincident with the influx of granulocytes and other cells there was an increase in the level of mRNA for the cytokines IL-lα, IL-1β, IL-6 and IL-8. In the skin of the sheep there appeared to be constitutive expression of message for the cytokines IL-1β, IL-6 and TNFα, with the level of the latter not found to increase during the 48 h of infection examined. In situ hybridization was used to determine the location of IL-6 and TNFα mRNA within resting and infected skin. During infection, fibroblasts, macrophage-like cells and endothelium appeared to produce high levels of IL-6 mRNA. Expression of the T cell dependent cytokines IL-2 and IFN-γ but not IL-4, increased in expression as time progressed and the population of infiltrating cells, including T cells, expanded.     

Immunotherapy of airborne tuberculosis in mice via the lung-specific delivery of cytokines

The immunotherapeutic potential of interleukin-2 (IL-2), tumour necrosis factor alpha (TNFα) and interferon gamma (IFN-γ) administered by aerosol was examined on mice infected with Mycobacterium tuberculosis by the aerogenic route. Infection of balb/c mice with 10(4) colony forming units (cfu) of M tuberculosis led to death of all mice at day 35 post infection after progressive microbial growth in the lungs. Aerosolization of IL-2 (100 μg per mouse) did not promote an increase in resistance to tuberculosis, as seen by growth of M tuberculosis in the lungs. Administration of IFN-γ or TNFα (100 μg) by the aerosol route led to a significant reduction in microbial growth in the lungs and a 100% survival of infected mice at day 60. Similarly, aerosolization of TNFα and IFN-γ combined led to a very high degree of tuberculostatic activity in the lungs of infected animals, but not superior to that seen with either cytokine alone. Administration of similar amounts of cytokines by repeated intraperitoneal infusions led to a very marginal improvement in mouse resistance. These results suggest that localized cytokine administration may be beneficial in the treatment of lung diseases.     

Crucial role of interleukin-10/interleukin-12 balance in the regulation of the type 2 T helper cytokine response in reactive arthritis

Objective. To investigate whether a predominant type 1 T helper (Thl) or Th2 cytokine pattern is present in the joints of patients with reactive arthritis (ReA), and whether the cytokine pattern can be modulated by cytokines or anticytokines. Methods. Eleven patients with ReA following infection with either Chlamydia trachomatis, Yersinia enterocolitica, or Salmonella enteritidis were investigated for the presence of Th1/Th2 cytokines in the joints. Release of the bacteria-specific cytokines interferon-γ (IFNγ), tumor necrosis factor α (TNFα), interleukin-10 (IL-10), and IL-4 was measured in synovial fluid mononuclear cells (SFMC) using enzyme-linked immunosorbent assay and polymerase chain reaction. In the synovial membrane, secretion of IFNγ and IL-4 was determined by immunohistologic analysis. Cytokine regulation was studied by adding cytokines and anticytokines to the cultures. Results. Upon stimulation with specific bacteria, SFMC secreted low amounts of IFNγ and TNFα, but high amounts of IL-10. IL-10 was responsible for the suppression of IFNγ and TNFα, as judged by the effect of adding either anti-IL-10 antibodies or exogenous IL-10 to these cultures. The addition of neutralizing anti-IL-12 to the cultures completely abolished the effects of anti-IL-10, suggesting that inhibition of the Th1-like cytokines by IL-10 is mediated through suppression of IL-12 synthesis. Exogenous IL-12 clearly enhanced IFNγ and TNFα secretion. In the synovial membrane, a higher number of cells were positive for the Th2 cytokine IL-4, compared with the amount of IFNγ-secreting cells. Conclusion. These data indicate that a Th2 cytokine pattern predominates in the joints of patients with ReA. Since Thl cytokines are necessary for the elimination of ReA-associated bacteria, Th2 cytokines might contribute to bacterial persistence in the joint. Therefore, the IL-10/IL-12 balance appears to be crucial for regulation of the cytokine pattern in the joints of patients with ReA.     

p38γ and p38δ kinases regulate the Toll-like receptor 4 (TLR4)-induced cytokine production by controlling ERK1/2 protein kinase pathway activation

On the basis mainly of pharmacological experiments, the p38α MAP kinase isoform has been established as an important regulator of immune and inflammatory responses. However, the role of the related p38γ and p38δ kinases has remained unclear. Here, we show that deletion of p38γ and p38δ impaired the innate immune response to lipopolysaccharide (LPS), a Toll-like receptor 4 (TLR4) ligand, by blocking the extracellular signal-regulated kinase 1/2 (ERK1/2) activation in macrophages and dendritic cells. p38γ and p38δ were necessary to maintain steady-state levels of tumor progression locus 2 (TPL2), the MKK kinase that mediates ERK1/2 activation after TLR4 stimulation. TNFα, IL-1β, and IL-10 production were reduced in LPS-stimulated macrophages from p38γ/δ-null mice, whereas IL-12 and IFNβ production increased, in accordance with the known effects of TPL2/ERK1/2 signaling on the induction of these cytokines. Furthermore, p38γ/δ-deficient mice were less sensitive than controls to LPS-induced septic shock, showing lower TNFα and IL-1β levels after challenge. Together, our results establish p38γ and p38δ as key components in innate immune responses.     

Coadministration of protoxin Cry1Ac from Bacillus thuringiensis with metacestode extract confers protective immunity to murine cysticercosis

The Bacillus thuringiensis Cry1Ac protoxin (pCry1Ac) is a promising mucosal immunogen and adjuvant that induces protective immunity against Naegleria fowleri and malaria infection models. We determined whether pCry1Ac acted as a protective adjuvant against infection with Taenia crassiceps. BALB/C mice were thrice i.p. immunized with (i) pCry1Ac, (ii) metacestode extract, (iii) extract + pCry1Ac or (iv) vehicle, challenged with metacestodes on day 26 and then sacrificed 35 days later. Cysticerci in the peritoneal cavity were counted, while the serum antibody response and cytokines were analysed after immunization and during infection. Only immunization with pCry1Ac plus extract conferred a significant protection (up to 47%). This group presented fluctuating antibody peaks during infection and the highest IgG1 and IgM titres. Immunization with extract alone elicited high IgG1 and the highest IgG2a responses after 25 days of infection, while nonimmunized mice presented a poor, mixed‐Th1/Th2 response during infection. Sharp peaks of TNFα and IFN‐γ occurred immediately after the first immunization with extract, especially in the presence of pCry1Ac, but not after the challenge, while in the control and pCry1Ac‐alone groups, cytokines were only detected after the challenge. The data support the protective‐adjuvant effect of co‐administration of pCry1Ac in cysticercosis.     

Interleukin-1, Interleukin-2, Interleukin-4, Interleukin-6, Tumor Necrosis Factor α, and Interferon-γ Levels in Sera from Patients With Scleroderma

Objective. To determine whether interleukin-lα (IL-1α), IL-1β, IL-2, IL-4, interferon-γ (IFNγ), IL-6, and tumor necrosis factor α (TNFα) are detected more frequently in sera from scleroderma patients than in sera from controls. Methods. Serum concentrations of these cytokines were measured in 78 scleroderma patients and 73 controls, using enzyme-linked immunosorbent assay, radioimmunoassay, and bioassay techniques. Results. IL-2, IL-4, and IL-6 were each detected more frequently in sera from scleroderma patients than in sera from controls. TNFα and IL-1α were found with equal frequency in patient and control sera. IL-1β and IFNγ were not detected in any sera. Conclusion. IL-2, IL-4, and IL-6 may be among the cytokines that contribute to the disease process in scleroderma patients. To our knowledge, this is the first report of elevated serum IL-4 levels in human disease.     

慢性乙型肝炎、乙肝肝硬化、乙肝肝癌患者Th1/Th2型细胞因子水平变化研究

目的分析慢性乙型肝炎(CHB)、乙肝肝硬化(LC)、乙肝肝癌(HCC)患者血清中Th1/Th2型细胞因子水平变化,为慢性乙型肝炎至肝癌的发生发展过程中的免疫变化研究提供线索,并为患者的临床治疗研究提供免疫学指标。方法选取2010年2月-2011年11月于首都医科大学附属北京佑安医院就诊的40例CHB患者、40例LC患者、53例HCC患者,用Luminex技术检测血清中Th1类细胞因子[白细胞介素(interleukin,IL)-12、干扰素(interferon,IFN)-γ和肿瘤坏死因子(tumor necrosis factor,TNF)-α]水平及Th2类细胞因子(IL-4、IL-6和IL-10)水平,并将25例健康志愿者作为正常对照组进行比较。结果除TNF-α外,CHB组、LC组和HCC组Th1类IL-12、IFN-γ和Th2类IL-4、IL-6、IL-10细胞因子水平均低于正常对照组;CHB组中大部分Th1类和Th2类细胞因子都高于LC组和HCC组;HCC组中TNF-α细胞因子水平要高于CHB组、LC组。结论 CHB、LC和HCC患者体内Th1/Th2细胞因子分泌水平受到抑制,Th1/Th2平衡发生漂移,对HBV病毒的清除作用受到抑制。TNF-α在肝癌发生过程中发挥着重要作用。     

A shift in the balance of inhibitory and activating Fcγ receptors on monocytes toward the inhibitory Fcγ receptor IIb is associated with prevention of monocyte activation in rheumatoid arthritis

Objective

To assess surface expression of the inhibitory receptor for IgG (Fcγ receptor IIb [FcγRIIb]) in relation to activating FcγR on monocyte/macrophages from patients with rheumatoid arthritis (RA) and healthy controls and to study the influence of proinflammatory and antiinflammatory cytokines on the balance of inhibitory and activating FcγR.

Methods

Using a combination of genotyping and phenotyping, surface expression of FcγRIIb on monocytes from healthy control subjects and RA patients was demonstrated. Expression of FcγR on CD14+ monocytes was assessed by flow cytometry. Regulation of inhibitory and activating FcγR on monocytes by proinflammatory (interferon‐γ [IFNγ], tumor necrosis factor α [TNFα]) and antiinflammatory (interleukin‐4 [IL‐4], IL‐10) cytokines was studied. A functional change in cytokine‐modulated monocytes was assessed in secondary cultures by their ability to produce TNFα upon FcγR crosslinking by IgG.

Results

Monocytes from healthy controls and RA patients expressed FcγRIIb at similar levels, in contrast to the higher levels of activating FcγRI and FcγRIIa in RA patients. The regulation of FcγR expression was comparable for patients and controls. IFNγ selectively up‐regulated FcγRI. TNFα down‐regulated expression of FcγRIIb and the activating FcγR, whereas IL‐10 up‐regulated expression of monocytic FcγRIIb and all activating FcγR. Increased or sustained levels of activating over inhibitory FcγR induced by IFNγ, TNFα, and IL‐10 alone were associated with enhanced IgG‐triggered TNFα production. In contrast, IL‐4 and, more specifically, IL‐4 plus IL‐10 altered the FcγR balance in favor of FcγRIIb and completely prevented IgG‐triggered TNFα production.

Conclusion

The altered balance of FcγR in favor of activating receptors in RA may contribute to increased activation of monocyte/macrophages. A change in the FcγR balance toward the inhibitory FcγRIIb may offer a novel treatment strategy for preventing the pleiotropic activity of FcγR‐triggered macrophages.

     

Antibody and Th1/Th2-type responses in BALB/c mice inoculated with live or dead Echinococcus granulosus protoscoleces

The aims of this study were to investigate whether a Th1- or a Th2-type response is stimulated in the first stages of experimental infection with Echinococcus granulosus, and to determine whether live or dead protoscoleces equally contribute to such Th1/Th2-type polarization. Live parasites stimulated the production of IL-10, IL-4 and IL-5 as early as week 1 postinoculation. The levels of IL-10 and IL-4 decreased towards week 4 p.i. and that of IFN gamma increased. The production of specific antibodies was characterized by high levels of systemic IgG1 and local IgM and IgG3 (measured in peritoneal lavages). In contrast, dead parasites induced elevated levels of IL-4, IFN gamma, IL-10 and IL-5 on week 1 postinoculation followed by a decrease of IFN gamma and an increase of IL-4. Low levels of specific antibodies were stimulated by dead parasites both systemically and in the peritoneal cavity. These results show that E. granulosus infection induced an early Th2-type response and that live parasites stimulated stronger antibody responses than dead parasites. In addition, they strongly suggest that both phenomena were modulated by live protoscoleces.     

Paradoxical effects of constitutive human IL-32{gamma} in transgenic mice during experimental colitis

Inflammatory cytokines mediate inflammatory bowel diseases (IBDs) and cytokine blocking therapies often ameliorate the disease severity. IL-32 affects inflammation by increasing the production of IL-1, TNFα, and several chemokines. Here, we investigated the role of IL-32 in intestinal inflammation by generating a transgenic (TG) mouse expressing human IL-32γ (IL-32γ TG). Although IL-32γ TG mice are healthy, constitutive serum and colonic tissue levels of TNFα are elevated. Compared with wild-type (WT) mice, IL-32γ TG mice exhibited a modestly exacerbated acute inflammation early following the initiation of dextran sodium sulfate (DSS)-induced colitis. However, after 6 d, there was less colonic inflammation, reduced tissue loss, and improved survival rate compared with WT mice. Associated with attenuated tissue damage, colonic levels of TNFα and IL-6 were significantly reduced in the IL-32γ TG mice whereas IL-10 was elevated. Cultured colon explants from IL-32γ TG mice secreted higher levels of IL-10 compared with WT mice and lower levels of TNFα and IL-6. Constitutive levels of IL-32γ itself in colonic tissues were significantly lower following DSS colitis. Although the highest level of serum IL-32γ occurred on day 3 of colitis, IL-32 was below constitutive levels on day 9. The ability of IL-32γ to increase constitutive IL-10 likely reduces TNFα, IL-6, and IL-32 itself accounting for less inflammation. In humans with ulcerative colitis (UC), serum IL-32 is elevated and colonic biopsies contain IL-32 in inflamed tissues but not in uninvolved tissues. Thus IL-32γ emerges as an example of how innate inflammation worsens as well as protects intestinal integrity.     

Age- and disease-related innate immunity of human leukocytes ex vivo

Two mechanisms of innate immunity, i.e. resistance to viral infection and the production of cytokines by leukocytes, were compared in blood isolated from four groups of donors: healthy young (19-35 years old), healthy elderly (over 60), elderly Alzheimer's disease (AD) patients, and elderly patients with alimentary tract cancer (CA).Peripheral blood leukocytes (PBLs) were isolated by gradient centrifugation in Gradisol G. The degree of resistance was calculated from the kinetics of vesicular stomatitis virus (VSV) replication in the PBLs. Cytokine (TNFα, IFNα, IFNγ, IL-12, and IL-10) levels were determined by ELISA.The antiviral resistance of the PBLs varied, but a difference was observed only between the young and elderly groups and not between the healthy elderly controls and those with AD or cancer. Differences observed in all the groups concerned the ability and intensity of cytokine production. The most impressive results were obtained for spontaneous TNF and IFNα release. While TNF was released spontaneously by the PBLs of the elderly CA patients and the young healthy group, it was usually undetected in the AD and only sometimes in the healthy elderly group. Leukocytes isolated from the elderly groups responded to VSV infection with more intense IFNα and IFNγ production than the younger group.     

Calorie restriction modulates Th-1 and Th-2 cytokine-induced immunoglobulin secretion in young and old C57BL/6 cultured submandibular glands

Immunoglobulin production by the salivary gland plays an important role in oral and upper respiratory tract immunity. Age and/or disease may compromise salivary gland function. In order to gain insight into the role of calorie restriction (CR) on immunoglobulin (Ig) production, we determined the effect of ad libitum (AL) feeding and CR in young (3 months) and old (18-24 months) C57BL/6 mouse submandibular glands (SM). The SM tissues were fragmented and cultured in the absence (control) or presence of either Th-1 cytokines, such as interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), or Th-2 cytokines, e.g. IL-4 and IL-5, for seven days. Culture supernatants were then analyzed for immunoglobulin A (IgA), IgM, and IgG2a levels by ELISA. Aging increased basal (control) IgA and IgM production by 3.1-and 3.7-fold, respectively, in AL mice. CR prevented the age-dependent rise of both IgA and IgM, maintaining levels equal to those of young AL mice. Interestingly, age resulted in a decrease of Th-1 cytokine-induced IgA and IgM, and increased IgG2a secretion in AL mice, while Th-2 cytokines did not appear to have an age effect. In general, CR suppressed Ig production induced by both Th-1 and Th-2 cytokines in young mice. In contrast, CR in old mice resulted in enhanced IgA and IgM production to levels similar to those in their young counterparts, while IgG2a was predominantly suppressed by Th-1 and not Th-2 cytokines. The data presented herein show, for the first time, the ability of CR to offset age-induced changes in submandibular gland Ig production, which may play a role in maintaining mucosal immune function, including proper oral health.