Intervention Mechanism of Biejiajian Wan on Primary Liver Cancer by Regulating lncRNA SNHG5/miRNA-26a-5p/GSK-3β Signal Axis / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Biejiajian Wan in the intervention of primary liver cancer based on long non-coding RNA SNHG5 （lncRNA SNHG5）/micro RNA-26a-5p （miRNA-26a-5p）/glycogen synthase kinase-3β （GSK-3β） signal axis. MethodDouble luciferase reporting assay was used to verify the targeted interaction between lncRNA SNHG5 and miRNA-26a-5p， miRNA-26a-5p， and GSK-3β in HepG2 cells. Nude-mouse transplanted tumor model of human HepG2 were established and randomly divided into model group， Biejiajian Wan low-dose group （0.5 g·kg-1）， medium-dose group （1.0 g·kg-1）， and high-dose group （2.0 g·kg-1）， and sorafenib group （100 mg·kg-1）， with 10 mice in each group. The mice were given intragastric administration of normal saline or drug for 28 days， and the tumor volume was measured at different time. Hematoxylin-eosin （HE） staining was used to observe the histological changes of tumors. The nucleic acid levels of lncRNA SNHG5， miRNA-26a-5p， GSK-3β， and β-catenin mPNA in tumor tissue were detected by real-time quantitative polymerase chain reaction （Real-time PCR）. The protein expression levels of GSK-3β and β-catenin in tumor tissue were detected by western blot. ResultCompared with the SNHG5-WT （wild type） + miRNA NC （negative control） group， the relative luciferase activities of the SNHG5-WT + miRNA-26a-5p mimic group were decreased （P<0.05）. Compared with the GSK-3β-WT + miRNA NC group， the relative luciferase activity of the GSK-3β-WT + miRNA-26a-5p mimic group was decreased （P<0.05）. Compared with the model group， the tumor volume of Biejiajian Wan low-dose， medium-dose， and high-dose groups was significantly decreased （P<0.05， P<0.01）. Compared with the model group， the cells in the tumor tissue of nude mice in each dose group of Biejiajian Wan were sparsely arranged with necrocytosis， which showed concentration-dependent changes. Compared with the model group， the expression levels of lncRNA SNHG5， GSK-3β， and β-catenin were decreased （P<0.05， P<0.01）， while the expression of miRNA-26a-5p was increased in each dose group of Biejiajian Wan （P<0.05， P<0.01）. Compared with the model group， the protein expression levels of GSK-3β and β-catenin were decreased in each dose group of Biejiajian Wan （P<0.05， P<0.01）. ConclusionBiejiajian Wan may affect the necrosis of liver cancer cells through lncRNA SNHG5/miRNA-26a-5p/GSK-3β signal axis and thus play an anti-tumor role. This research will provide more theoretical basis for the clinical application of Biejiajian Wan.

[Effects of different peanut-cotton intercropping modes on physiological characteristics and yield of peanut in late growth stage]. / 不同花生棉花间作模式对花生生育后期生理特性及产量的影响.

Using peanut cultivar Huayu 25 and cotton cultivar Liaomian 19 as experimental material, we examined the effects of different intercropping patterns on physiological characteristics of peanut in later growth stage, yield and economic benefit, based on an experiment with five treatments, including intercropping modes of 4 rows peanut and 4 rows cotton (H4M4), 6 rows peanut and 4 rows cotton (H6M4), 4 rows peanut and 4 rows cotton (H4M2), sole peanut (DH) and sole cotton (DM). The results showed that intercropping mode increased the length of main stem and branches of peanut, but decreased green leaves number of main steam, leaf area index, and total dry matter accumulation. Among the intercropping modes, chlorophyll content, chlorophyll fluorescence parameters, root vigor, nitrate reductase activity under H6M4 and H4M2 were significantly higher than that under H4M4, as well as higher superoxide dismutase, peroxidase, catalase activity and decreased malondialdehyde content. Intercropping significantly reduced peanut and cotton yields, but enhanced the gross economic output value. The yield reduction of H6M4 was the lowest and the economic output was the highest among all the intercropping modes. In addition, the land equivalent ratio of H6M4 was greater than 1, indicating the obvious advantage of intercropping. Our results indicated that appropriate reduction of the ratio of cotton under the peanut-cotton intercropping systems could strengthen root vigor and increased nitrate reductase activity, promote nutrient absorption capacity, reduce senescence, and increase the economic output.

Human Umbilical Cord Mesenchymal Stem Cells to Treat Neuromyelitis Optica Spectrum Disorder (hUC-MSC-NMOSD): A Study Protocol for a Prospective, Multicenter, Randomized, Placebo-Controlled Clinical Trial.

Background: Neuromyelitis Optica spectrum disorder (NMOSD) is severe relapsing and disabling autoimmune disease of the central nervous system. Its optimal first-line treatment to reduce relapse rate and ameliorate neurological disability remains unclear. We will conduct a prospective, multicenter, randomized, placebo-controlled clinical trial to study the safety and effectiveness of human umbilical cord mesenchymal stem cells (hUC-MSCs) in treating NMOSD. Methods: The trial is planned to recruit 430 AQP4-IgG seropositive NMOSD patients. It consists of three consecutive stages. The first stage will be carried out in the leading center only and aims to evaluate the safety of hUC-MSCs. Patients will be treated with three different doses of hUC-MSCs: 1, 2, or 5 × 106 MSC/kg·weight for the low-, medium-, and high-dose group, respectively. The second and third stages will be carried out in six centers. The second stage aims to find the optimal dosage. Patients will be 1:1:1:1 randomized into the low-, medium-, high-dose group and the controlled group. The third stage aims to evaluate the effectiveness. Patients will be 1:1 randomized into the optimal dose and the controlled group. The primary endpoint is the first recurrent time and secondary endpoints are the recurrent times, EDSS scores, MRI lesion numbers, OSIS scores, Hauser walking index, and SF-36 scores. Endpoint events and side effects will be evaluated every 3 months for 2 years. Discussion: Although hUC-MSC has shown promising treatment effects of NMOSD in preclinical studies, there is still a lack of well-designed clinical trials to evaluate the safety and effectiveness of hUC-MSC among NMOSD patients. As far as we know, this trial will be the first one to systematically demonstrate the clinical safety and efficacy of hUC-MSC in treating NMOSD and might be able to determine the optimal dose of hUC-MSC for NMOSD patients. Trial registration: The study was registered with the Chinese Clinical Trial Registry (CHICTR.org.cn) on 2 March 2016 (registration No. ChiCTR-INR-16008037), and the revised trial protocol (Protocol version 1.2.1) was released on 16 March 2020.

Narrative evidence-based medicine:a strategy for evaluation of clinical efficacy of Chinese medicine / 中国中药杂志

Rich experience of clinical diagnosis and treatment has been accumulated in the developmental history of Chinese medicine, and the efficacy has been increasingly accepted by the public. However, the evaluation of clinical efficacy is currently based more on scientific evidence instead of merely the changes of patient symptoms. In Chinese medicine, the changes of major disease indicators, patient symptoms, and pathogenesis are the major criteria for the evaluation of clinical efficacy. The lack of well-accepted and uniform criteria and the uncertainty of subjective evaluation limit the development of clinical Chinese medicine. Evidence-based medicine combines clinical skills with the current best evidence. Narrative medicine, utilizing people's narratives in clinical practice, emphasizes patient feelings, willingness, and value orientation. The introduction of both evidence-based medicine and narrative medicine into the evaluation of clinical efficacy refers to the construction of the clinical efficacy evaluation system in a paradigm of participatory diagnosis and treatment. It can fully reflect the characteristics of Chinese medicine, respect the values of patients, and achieve universal clinical evidence. Therefore, it helps to improve the diagnosis and treatment, the relationship between doctors and patients, patients' life quality and decision-making awareness, and finally the new evaluation model of clinical efficacy of Chinese medicine.

Comparative study of oncologic efficacy of cephalomedial to lateral dissection versus medial to lateral dissection in laparoscopic total mesorectal excision for rectal cancer: An RCT study.

BACKGROUND AND OBJECTIVES: We compared the 3-year overall survival between cephalomedial-to-lateral approach proctectomy (CEMP) and medial-to-lateral approach proctectomy (MAP) in patients undergoing laparoscopic total mesorectal excision for rectal cancer. The advantages of CEMP and the clinical value of No. 253 lymph nodes resection have not been objectively analyzed in literature. METHODS: This was a prospective, two-arm, multicenter, single-blinded, randomized trial. The primary endpoint was 3-year overall survival, and secondary endpoints included safety, feasibility, oncological radicality (including number of No. 253 lymph nodes harvested), short-term outcome, 3-year disease-free survival, rate of postoperative complications, mortality, and rate of recurrence. RESULTS: From May 2016 to July 2020, 506 patients were enrolled-256 in the CEMP group and 250 in the MAP group. Comparison of overall survival and disease-free survival showed that there was treatment benefit in the CEMP group (28.22 ± 12.12 vs. 27.44 ± 13.06, p = 0.485; 27.24 ± 12.01 vs. 26.42 ± 12.81; p = 0.457). More No. 253 lymph nodes were harvested in the CEMP group, and cases with positive No. 253 lymph nodes had worse prognosis in stage III. Surgical safety was equal for both approaches. CONCLUSIONS: Dissection of No. 253 lymph nodes may be important to improve clinical prognosis, but further studies with larger samples are needed to confirm this finding.

Citrus fruit intake and lung cancer risk: A meta-analysis of observational studies.

OBJECTIVE: To explore the hypothesis that Citrus intake may reduce the risk of lung cancer. DESIGN: Meta-analyses of Dichotomy and dose-response relationship. DATA SOURCES: We searched online literature databases including PubMed, Embase, and Cochrane Library to screen relevant articles available up to 27 July 2020. Search terms included (i) Citrus, Fruit, Diet, Dietary; (ii) cancer, neoplasm, tumor (iii)lung; (iv)case-control, cohort, prospective. STUDY SELECTION: The selection of studies and the meta-analysis were carried out by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The following inclusion criteria were chosen: (i) epidemiological studies with case-control or cohort design; (ii) human participants; (iii) studies investigated the relationship between Citrus fruit intake and lung cancer risk; (iv) if data were duplicated in more than two studies, we brought the most recent or all-sided study into this analysis. We collected all full-text articles that met the inclusion criteria. We applied the following exclusion criteria to the full-text articles, including possible articles listed by manual search: (i) there was no represented odds ratio (OR) or relative risk (RR) estimate and its corresponding 95 % confidence interval (95 % CI) (or data to calculate them) for the highest versus lowest levels of Citrus fruit consumption (ii) reviews, systematic reviews and meta-analyses; (iii) there was no data of Citrus fruit intake at the individual level. DATA EXTRACTION: Two reviewers independently performed the extraction of data from eligible studies. STATISTICAL METHODS: Adjusted odds ratios (ORs) and 95 % CIs were combined and weighted by the method of "Dersimonian and Laird" to produce pooled ORs using a random-effects model. Moreover, we utilized the method reported by "Longnecker and Greenland" to evaluate linear trends and 95 % CIs by the ORs' natural logs and corresponding CIs from categories of Citrus intake. Finally, we evaluated the risk of publication bias and selection bias by inspecting for asymmetry in the pre-specified funnel plots of the study OR against the standard error of the OR's logarithm and by "Egger's test". RESULTS: We included twenty-one studies in the final review. Pooled analyses suggested that those with the highest Citrus fruit intake compared to the lowest intake had a 9% reduction in lung cancer risk [OR 0.91 (95 % CI 0.84-0.98)]. We found a nonlinear association between Citrus intake and lung cancer risk in the dose-response analysis (p = 0.0054) and that the risk reached the minimum (OR = 0.91) around 60 g/d. However, no obvious dose-response association was observed with intakes above 80 g/d. CONCLUSION: We found that Citrus fruit intake was negatively associated with the risk of lung cancer. Besides, there was a nonlinear dose-response relationship between Citrus intake and lung cancer risk within a certain range.

[Clinical study of digital clear aligner treatment of 33 adult periodontal disease patients with malocclusion].

PURPOSE: The purpose of this study was to investigate the periodontal status in adult periodontal disease patients with malocclusion treated with digital clear aligners. METHODS: Thirty-three patients with periodontal disease who needed orthodontic treatment were selected. The patients were randomly divided into 2 groups, digital clear aligners group (experimental group, 16 patients) and fixed appliances group (control group, 17 patients). Bleeding index (BI), probing depth(PD), plaque index(PLI) and gingival index(GI) were recorded at baseline and 1, 3, 6 and 9 months during orthodontic treatment. SPSS 17.0 software package was used to analyze and compare the data of periodontal status between two groups. RESULTS: 1, 3, 6, and 9 months after orthodontic treatment, clinical parameters of the control group were significantly higher than baseline(P<0.05). The same measurements of the experimental group showed no significant differences at 1, 3, 6, and 9 months of treatment (P>0.05). After 1, 3, 6, and 9 months of treatment, the clinical parameters of BI, PLI and GI in the experimental group were significantly lower than the control group(P<0.05); PD in the experimental group was smaller than the control group, but there was no significant difference(P>0.05). CONCLUSIONS: Compared with conventional fixed appliance, clear aligner of digitalization can more effectively maintain periodontal heath in adult periodontal disease patients with malocclusion.

Effects of PKM2 on global metabolic changes and prognosis in hepatocellular carcinoma: from gene expression to drug discovery.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor that threatens global human health. High PKM2 expression is widely reported in multiple cancers, especially in HCC. This study aimed to explore the effects of PKM2 on global gene expression, metabolic damages, patient prognosis, and multiple transcriptional regulation relationships, as well as to identify several key metabolic genes and screen some small-molecule drugs. METHODS: Transcriptome and clinical HCC data were downloaded from the NIH-GDC repository. Information regarding the metabolic genes and subsystems was collected from the Recon 2 human metabolic model. Drug-protein interaction data were obtained from the DrugBank and UniProt databases. We defined patients with PKM2 expression levels ≥11.25 as the high-PKM2 group, and those with low PKM2 expression (< 11.25) were defined as the low-PKM2 group. RESULTS: The results showed that the global metabolic gene expression levels were obviously divided into the high- or low-PKM2 groups. In addition, a greater number of affected metabolic subsystems were observed in the high-PKM2 group. Furthermore, we identified 98 PKM2-correlated deregulated metabolic genes that were associated with poor overall patient survival. Together, these findings suggest more comprehensive influences of PKM2 on HCC. In addition, we screened several small-molecule drugs that target these metabolic enzymes, some of which have been used in antitumor clinical studies. CONCLUSIONS: HCC patients with high PKM2 expression showed more severe metabolic damage, transcriptional regulation imbalance and poor prognosis than low-PKM2 individuals. We believe that our study provides valuable information for pathology research and drug development for HCC.

Staphylococcal enterotoxins in the etiopathogenesis of mucosal autoimmunity within the gastrointestinal tract.

The staphylococcal enterotoxins (SEs) are the products of Staphylococcus aureus and are recognized as the causative agents of classical food poisoning in humans following the consumption of contaminated food. While illness evoked by ingestion of the SE or its producer organism in tainted food are often self-limited, our current understanding regarding the evolution of S. aureus provokes the utmost concern. The organism and its associated toxins, has been implicated in a wide variety of disease states including infections of the skin, heart, sinuses, inflammatory gastrointestinal disease, toxic shock, and Sudden Infant Death Syndrome. The intricate relationship between the various subsets of immunocompetent T cells and accessory cells and the ingested material found within the gastrointestinal tract present daunting challenges to the maintenance of immunologic homeostasis. Dysregulation of the intricate balances within this environment has the potential for extreme consequences within the host, some of which are long-lived. The focus of this review is to evaluate the relevance of staphylococcal enterotoxin in the context of mucosal immunity, and the underlying mechanisms that contribute to the pathogenesis of gastrointestinal autoimmune disease.

Prognostic implications for high expression of MiR-25 in lung adenocarcinomas of female non-smokers.

BACKGROUND: Adenocarcinoma (ADC) is the most common histological type of lung cancer and its proportion is rising, especially in Asian non-smoking women. Recent studies suggest miR-25 may have diverse effects on the pathogenesis of different types of cancer. However, the role of miR-25 in lung cancer is still unknown. The aim of this study was to investigate the potential clinical value of miR-25 in non-smoking women with lung ADC. PATIENTS AND METHODS: Quantitative RT-PCR was performed to evaluate the expression of miR-25 in 100 lung ADC tumor tissues and matched plasma samples and Pearson correlation tests were used to analyze the relationship between values. Associations of miR-25 expression with clinicopathological features were determined using the Student's t-test. To determine prognostic value, overall survival (OS) was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazard model. RESULTS: Expression of miR-25 in tissue was found to be associated with lymph node metastasis (P=0.021) and disease stage (P=0.012). Moreover, high miR-25 expression was also associated with poorer overall survival of women with lung ADC (P=0.008). CONCLUSION: Tissue miR-25 expression may be associated with tumor progression and have prognostic implications in female lung ADC patients.

Meta-Analysis of the Association between Mir-196a-2 Polymorphism and Cancer Susceptibility.

OBJECTIVE: MicroRNA plays a vital role in gene expression, and microRNA dysregulation is involved in carcinogenesis. The miR-196a-2 polymorphism rs11614913 is reportedly associated with cancer susceptibility. This meta-analysis was performed to assess the overall association of miR-196a-2 with cancer risk. METHODS: A total of 27 independent case-control studies involving 10,435 cases and 12,075 controls were analyzed for the rs11614913 polymorphism. RESULTS: A significant association was found between rs11614913 polymorphism and cancer risk in four genetic models (CT vs. TT, OR=1.15, 95%CI=1.05-1.27; CC vs. TT, OR=1.23, 95%CI=1.08-1.39; Dominant model, OR=1.17, 95%CI=1.06-1.30; Additive model, OR=1.08, 95%CI=1.01-1.14). In the subgroup analysis of different tumor types, the C allele was associated with increased risk of lung, breast, and colorectal cancer, but not with liver, gastric, or esophageal cancer. In the subgroup analysis by ethnicity, a significantly increased risk of cancer was found among Asians in all genetic models, but no associations were found in the Caucasian subgroup. CONCLUSIONS: The meta-analysis demonstrated that the miR-196a-2 polymorphism is associated with cancer susceptibility, especially lung cancer, colorectal cancer, and breast cancer among Asian populations.

[Analysis of variation trends of thyroid cancer treated in Tianjin Cancer Hospital form 1954 to 2009].

OBJECTIVE: To investigate and analyze the variation trends in the pathological composition of thyroid cancer patients treated in Tianjin Cancer Hospital from 1954 to 2009. METHODS: To retrospectively analyze the incidence and clinical features of different pathological types of thyroid cancers in 4342 patients between different time periods from 1954 to 2009. RESULTS: In the four main pathological types of thyroid cancers, the component ratio of papillary thyroid cancer in every period was 68.1%, 78.3%, 81.3%, 82.1%, 85.8%, respectively, while the morbidity of patients with papillary thyroid carcinoma concurrent with Hashimoto's thyroiditis was increased, so was the proportion of tumors in diameter < or = 2 cm. The proportion of follicular thyroid carcinoma and anaplastic thyroid carcinoma was decreasing accordingly; however, the proportion of medullary thyroid carcinoma did not change significantly. CONCLUSIONS: The pathological classification of the thyroid carcinoma patients has significant changes in the 4342 cases treated in our Hospital from 1954 to 2009. The proportion of papillary carcinoma is increased, while that of follicular carcinoma and anaplastic carcinoma is decreased. The reasons might attribute to the improved level of consultations and iodized diet or other factors.

TGF-beta can leave you breathless.

Transforming growth factor-beta (TGF-beta), a ubiquitous and multifunctional cytokine, is central to the evolution and modulation of host defense. Early on, TGF-beta was recognized for its chemotactic and pro-inflammatory properties, but then identification of its powerful suppressive activities focused attention on dissecting its mechanisms of immune inhibition. Just as quickly as TGF-beta-mediated regulation of a population of CD4(+)CD25(+)Foxp3(+) regulatory T cells became the rage, a surprising finding that TGF-beta was the impetus behind a subset of pro-inflammatory T helper (Th)17 cells brought back a re-emphasis on its broader ability to dictate inflammatory events. Emerging evidence indicates that much remains to be discovered regarding the complex and intertwined roles of TGF-beta in inflammation, T cell lineage commitment, antibody generation, immune suppression, and tolerance. While it may appear that TGF-beta has multiple, ill-defined, contradictory and overlapping modes of activity that are impossible to unravel, the current excitement for dissecting how TGF-beta controls immunity defines a challenge worthy of pursuit. The lung is particularly vulnerable to the influences of TGF-beta, which is produced by its immune and non-immune cell populations. In its absence, lung pathology becomes lethal, whereas TGF-beta overproduction also has untoward consequences, potentially leaving one breathless, and underscoring the paradoxical, but essential contribution of TGF-beta to tissue and immune homeostasis.

Aberrant innate immune responses in TLR-ligand activated HLA-B27 transgenic rat cells.

BACKGROUND: Commensal enteric microbiota initiate and perpetuate immune-mediated colitis in HLA-B27 transgenic (TG) rats but not wildtype (non-TG) littermates. However, the role of the innate immune response to bacterial components has not been established. METHODS: We examined responses induced by bacterial adjuvants through Toll-like receptor (TLR) and NOD2 signaling in T-cell-depleted splenocytes from HLA-B27 TG rats versus non-TG controls. RESULTS: We found that various bacterial adjuvants induced TNF production by cells obtained from specific pathogen-free (SPF) and germ-free (GF, sterile) TG and non-TG rats. Peptidoglycan-polysaccharide (PG-PS), lipopolysaccharide (LPS), and CpG DNA motifs stimulated higher levels of TNF production by SPF TG rat spleen cells compared to non-TG cells. CD11b/c cell depletion eliminated PG-PS and LPS-induced TNF and dramatically reduced CpG-stimulated TNF production. Both SPF and GF TG rat spleens contain more cells that express high levels of CD11b/c and show enhanced mRNA expression of TLR-2 and TLR-4 compared to non-TG rat spleens. In contrast, constitutive and bacterial-induced IL-10 production was markedly lower in TG cells compared to non-TG cells of rats from the same SPF or GF housing conditions. Notably, the ratio of TNF to IL-10 produced after TLR ligand activation was significantly higher in TG than non-TG cells. CONCLUSIONS: HLA-B27 TG rats have an aberrant cell composition, altered functional TLR expression, and an intrinsic defect in IL-10 production in response to TLR ligands, which may result in exaggerated proinflammatory responses to commensal enteric bacteria and uncontrolled inflammation in this colitis model.

Reduced responsiveness of HLA-B27 transgenic rat cells to TGF-beta and IL-10-mediated regulation of IFN-gamma production.

BACKGROUND: We have reported that commensal luminal bacterial components induce an active in vitro IFN-gamma response in mesenteric lymph node (MLN) and intestinal cells from specific pathogen-free (SPF) HLA-B27 transgenic (TG) rats with chronic colitis but not in cells from non-diseased SPF non-TG, germ-free (GF) non-TG or GF TG rats. METHODS: The study examined IL-12 stimulation of MLN IFN-gamma responses to luminal bacteria and regulation of these responses by suppressive cytokines. RESULTS: Exogenous IL-12 significantly increased the bacterial lysate-induced IFN-gamma response in SPF TG MLN cells, while bacterial lysate and IL-12 synergistically induced IFN-gamma from low baseline levels in cells obtained from both SPF and GF non-TG rats, and in GF TG cells. TGF-beta fully counteracted the effects of IL-12 and bacterial lysate on non-TG cells by almost completely inhibiting IFN-gamma production. In contrast, TG cells were less responsive to TGF-beta-mediated downregulation with a substantial residual IFN-gamma response to IL-12 plus bacterial lysate. Further experiments showed that CD4+/CD25+ cells had no inhibitory effect on the IFN-gamma production and were not required for TGF-beta-mediated suppression. Addition of exogenous IL-10 also partially inhibited IFN-gamma production by non-TG cells but did not affect TG cells. Conversely, exogenous IL-12 preferentially suppressed bacterial lysate-induced TGF-beta and IL-10 production in TG rat cells. CONCLUSIONS: An attenuated response to regulatory signals leads to uncontrolled potentiated induction of effector IFN-gamma responses to commensal bacteria in HLA-B27 TG rats that spontaneously develop chronic intestinal inflammation.

CD4(+) T lymphocytes mediate colitis in HLA-B27 transgenic rats monoassociated with nonpathogenic Bacteroides vulgatus.

BACKGROUND: HLA-B27/beta2 microglobulin transgenic (TG) rats develop spontaneous colitis when raised under specific pathogen-free (SPF) conditions or after mono-association with Bacteroides vulgatus (B. vulgatus), whereas germ-free TG rats fail to develop intestinal inflammation. SPF HLA-B27 TG rnu/rnu rats, which are congenitally athymic, remain disease free. These results indicate that commensal intestinal bacteria and T cells are both pivotal for the development of colitis in TG rats. However, it is not known if T cells are also required in the induction of colitis by a single bacterial strain. The aim of this study was therefore to investigate the role of T cells in the development of colitis in B. vulgatus-monoassociated HLA-B27 TG rats. METHODS: HLA-B27 TG rnu/rnu and rnu/+ rats were monoassociated with B. vulgatus for 8-12 weeks. CD4(+) T cells from mesenteric lymph nodes (MLNs) of B. vulgatus-monoassociated rnu/+ TG donor rats were transferred into B. vulgatus-monoassociated rnu/rnu TG recipients. RESULTS: B. vulgatus-monoassociated rnu/+ rats showed higher histologic inflammatory scores and elevated colonic interferon-gamma mRNA, cecal myeloperoxidase, and cecal IL-1beta levels compared to those in rnu/rnu TG rats that did not contain T cells. After transfer of CD4(+) cells from colitic B. vulgatus-monoassociated rnu/+ TG donor rats, B. vulgatus-monoassociated rnu/rnu TG recipients developed colitis that was accompanied by B. vulgatus-induced IFN-gamma production by MLN cells in vitro and inflammatory parameters similar to rnu/+ TG rats. CONCLUSIONS: These results implicate CD4(+) T cells in the development of colitis in HLA-B27 TG rats monoassociated with the nonpathogenic bacterial strain B. vulgatus.

Luminal bacterial antigen-specific CD4+ T-cell responses in HLA-B27 transgenic rats with chronic colitis are mediated by both major histocompatibility class II and HLA-B27 molecules.

Rats transgenic (TG) for the human major histocompatibility complex (MHC) class I HLA-B27 and beta2-microglobulin genes develop chronic colitis under specific pathogen-free (SPF) but not sterile (germ-free, GF) conditions. We investigated the role of antigen-presenting molecules involved in generating immune responses by CD4+ mesenteric lymph node (MLN) cells from colitic HLA-B27 TG rats to commensal enteric micro-organisms. All TG MLN cells expressed HLA-B27. A higher level of MHC class II was expressed on cells from TG rats, both SPF and GF, compared to non-TG littermates. In contrast, rat MHC class I expression was lower on TG than non-TG cells. Both TG and non-TG antigen presenting cells (APC) pulsed with caecal bacterial antigens induced a marked interferon-gamma (IFN-gamma) response in TG CD4+ T lymphocytes but failed to stimulate non-TG cells. Blocking MHC class II on both TG and non-TG APC dramatically inhibited their ability to induce TG CD4+ T cells to produce IFN-gamma. Blocking HLA-B27 on TG APC similarly inhibited IFN-gamma responses. When the antibodies against MHC class II and HLA-B27 were combined, no APC-dependent IFN-gamma response was detected. These data implicate both native rat MHC class II and TG HLA-B27 in CD4+ MLN T-cell IFN-gamma responses to commensal enteric microflora in this colitis model.

Dysregulated luminal bacterial antigen-specific T-cell responses and antigen-presenting cell function in HLA-B27 transgenic rats with chronic colitis.

HLA-B27/beta2 microglobulin transgenic (TG) rats spontaneously develop T-cell-mediated colitis when colonized with normal commensal bacteria, but remain disease-free under germ-free conditions. We investigated regulation of in vitro T-cell responses to enteric bacterial components. Bacterial lysates prepared from the caecal contents of specific pathogen-free (SPF) rats stimulated interferon-gamma (IFN-gamma) production by TG but not non-TG mesenteric lymph node (MLN) cells. In contrast, essentially equivalent amounts of interleukin-10 (IL-10) were produced by TG and non-TG cells. However, when cells from MLNs of non-TG rats were cocultured with TG MLN cells, no suppression of IFN-gamma production was noted. Both non-TG and TG antigen-presenting cells (APC) pulsed with caecal bacterial lysate were able to induce IFN-gamma production by TG CD4+ cells, although non-TG APC were more efficient than TG APC. Interestingly, the addition of exogenous IL-10 inhibited non-TG APC but not TG APC stimulation of IFN-gamma production by cocultured TG CD4+ lymphocytes. Conversely, in the presence of exogenous IFN-gamma, production of IL-10 was significantly lower in the supernatants of TG compared to non-TG APC cultures. We conclude that commensal luminal bacterial components induce exaggerated in vitro IFN-gamma responses in HLA-B27 TG T cells, which may in turn inhibit the production of regulatory molecules, such as IL-10. Alterations in the production of IFN-gamma, and in responses to this cytokine, as well as possible resistance of TG cells to suppressive regulation could together contribute to the development of chronic colitis in TG rats.