Using a baculovirus display library to identify MHC class I mimotopes

We have developed a baculovirus-based display system for identifying antigen mimotopes for MHC class I-specific T cells. The mouse MHC class I molecule, Dd, was displayed on baculovirus-infected insect cells with a library of 9- and 10-mer peptides tethered via a flexible linker to the N terminus of beta2 microglobulin. As a test case, the library was screened by flow cytometry by using a multimeric fluorescent alphabetaTCR from a mouse T cell specific for Dd plus an unknown self peptide. A mimotope was identified that, when bound to Dd, stimulated the T cell to secret IL-2. The sequence of the mimotope was used to identify a self peptide present in a mouse protein, Spin. The Spin peptide, when complexed with Dd, also activated the T cell. This technique should be generally useful in identifying and manipulating MHC class I peptide mimotopes and epitopes.     

Molecular and cellular analyses of HLA class II-associated susceptibility to autoimmune diseases in the Japanese population

It is well known that individuals who are positive for particular HLA class II alleles show a high risk of developing autoimmune diseases. HLA class II molecules expressed on antigen-presenting cells present antigenic peptides to CD4⁺ T cells. Their extensive polymorphism affects the structures of peptides bound to HLA class II molecules to create individual differences in immune responses to antigenic peptides. In order to gain a better understanding of mechanisms of the association between HLA class II alleles and susceptibility to autoimmune diseases, it is important to identify self-peptides presented by disease-susceptible HLA class II molecules and triggering disease-causative T cells. Many of the autoimmune diseases are observed in all ethnic groups, whereas the incidence of diseases, clinical manifestations and disease-susceptible HLA class II alleles are different among various ethnic groups for some autoimmune diseases. These phenomena suggest that differences in autoimmune self-peptide(s) in the context of disease-susceptible HLA class II molecules may cause these differences. Therefore, comparisons among disease-susceptible HLA class II alleles, autoantigenic peptides, and clinical manifestations of autoimmune diseases in different ethnic groups would be helpful in elucidating the pathogenesis of the diseases. In this review, we describe our recent findings on (1) the uniqueness of both clinical manifestations and the HLA-linked genetic background of Asian-type (opticospinal form) multiple sclerosis, (2) the characteristics of glutamic acid decarboxylase 65 (GAD65) or β₂-glycoprotein I (β₂-GPI) autoreactive T cells in Japanese patients with insulin-dependent diabetes mellitus (IDDM) or anti-β₂-GPI antibody-associated autoimmunity, respectively, and (3) the generation of an efficient delivery system of peptides to the HLA class II-restricted antigen presentation path-way by utilizing a class II-associated invariant chain peptide (CLIP)-substituted invariant chain, which may be applicable to an evaluation of the "molecular mimicry hypothesis" for the activation of autoreactive T cells.     

血管活性肠肽参与电针对大鼠胃粘膜损伤的保护作用

目的：探讨血管活性肠肽(VIP)参与电针对胃粘膜损伤大鼠保护作用的机制。方法：采用束缚冷应激胃粘膜损伤大鼠模型，通过放射免疫测定法和中枢迷走背核复合体(DVC)微量注射，观察电针对各组外周血、胃粘膜和脑组织的VIP含量的变化，胃粘膜血流量(GMBF)、损伤指数(LI)和跨壁电位差(PD)的影响。结果：电针模型组外周血、胃粘膜和脑组织VIP含量均增加，GMBF、PD也明显增加，LI下降；中枢DVC微量注射VIP后，外周血和胃粘膜中VIP含量增加。结论：VIP作为信号分子，通过神经内分泌免疫网络系统对胃粘膜损伤具有整体调控作用。     

中华按蚊抗菌肽defensinA编码基因cDNA克隆与序列分析

目的克隆中华按蚊defensin编码基因，并对其序列进行分析。方法提取中华按蚊总RNA。据文献报道合成1对引物deft、def2，RTPCR扩增中华按蚊defensin编码基因，克隆于T-载体，序列测定与分析。结果RT—PCR扩增中华按蚊cDNA获大约308bp片段，测定目的片段序列，结果显示，克隆基因cDNA序列长度为308bp，推导编码64个氨基酸，序列分析显示中华按蚊defensin编码基因与冈比亚按蚊defensin编码基因有高度同源性（95％）。分析结果显示，中华按蚊defensin编码基因为新基因，定名为中华按蚊defensinA。结论克隆出中华按蚊defensinA编码基因，为进一步研究该基因打下了基础。     

Effect of atrial natriuretic peptide on adiponectin in patients with heart failure

BACKGROUND: The adipocyte-specific cytokine adiponectin, has cardioprotective effects, correlates with endogenous cardiac natriuretic peptides and adipocyte has guanylyl cyclase-A receptors of natriuretic peptides. AIMS: To evaluate the effect of carperitide (atrial natriuretic peptide; ANP) on plasma adiponectin in patients with heart failure. METHODS AND RESULTS: Seventy-five patients admitted to our hospital with decompensated heart failure were randomised (1:2) to nitroglycerin (group I: n = 23) or carperitide infusion (group II: n = 52). Blood samples were collected at baseline and after 7 days. Plasma levels of total and high-molecular weight (HMW) adiponectin, ANP and brain natriuretic peptide (BNP) were measured. There were no differences in baseline characteristics between the two groups. In group I, plasma levels of total and HMW adiponectin were significantly decreased (21.1+/-2.5 to 18.6+/-2.5 microg/mL, p<0.05, 12.3+/-1.8 to 10.8+/-1.7 microg/mL, p<0.05, respectively) concomitant with the decrease in plasma levels of ANP and BNP. In group II, plasma levels of total and HMW adiponectin were significantly increased (17.3+/-1.3 to 19.7+/-1.6 microg/mL, p<0.0001, 9.8+/-1.0 to 10.5+/-1.0 microg/mL, p<0.05, respectively) concomitant with the increase in ANP. CONCLUSIONS: These findings indicate that carperitide infusion increases plasma levels of total and HMW adiponectin in patients with heart failure.     

胃十二指肠疾病与血浆激素关系的初步研究

对64例胃十二指肠疾病患者(包括慢性残表性胃炎23例,萎缩性胃炎5例,胃溃疡10例,十二指肠溃疡14例及胃癌12例)的血浆生长抑索(SS)、血管活性肠肽(VIP)、胃动素(MTL)及血清胃泌素(Gas)的研究表明,血浆SS水平在胃十二指肠溃疡组及胃癌组均低于正常对照组(P<0.001);血浆VIP浓度在胃溃疡时升高最明显,与正常组及各疾病组比较均有显著性差异(P<0.01);十二指肠溃疡及胃癌组的血浆MTL含量均高于正常对照组(P<0.05);血清Gas水平在浅表性胃炎和萎缩性胃炎时均高于正常对照组(P<0.01).     

Pittsburgh B Compound Positron Emission Tomography in Patients With AL Cardiac Amyloidosis

BackgroundIt remains unknown whether the noninvasive evaluation of the degree of amyloid deposition in the myocardium can predict the prognosis of patients with light chain (AL) cardiac amyloidosis.ObjectivesThe purpose of this study was to demonstrate that ¹¹C-Pittsburgh B compound positron emission tomography (¹¹C-PiB PET) is useful for prognostication of AL cardiac amyloidosis by noninvasively imaging the myocardial AL amyloid deposition.MethodsThis study consecutively enrolled 41 chemotherapy-naïve AL cardiac amyloidosis patients. The amyloid deposit was quantitatively assessed with amyloid P immunohistochemistry in endomyocardial biopsy specimens and was compared with the degree of myocardial ¹¹C-PiB uptake on PET. The primary endpoint was a composite of all-cause death, heart transplantation, and acute decompensated heart failure.ResultsThe degree of myocardial ¹¹C-PiB PET uptake was significantly higher in the cardiac amyloidosis patients compared with normal subjects and correlated well with the degree of amyloid deposit on histology (R² = 0.343, p < 0.001). During follow-up (median: 423 days, interquartile range: 93 to 1,222 days), 24 patients experienced the primary endpoint. When the cardiac amyloidosis patients were divided into tertiles by the degree of myocardial ¹¹C-PiB PET uptake, patients with the highest PiB uptake experienced the worst clinical event-free survival (log-rank p = 0.014). The degree of myocardial PiB PET uptake was a significant predictor of clinical outcome on multivariate Cox regression analysis (adjusted hazard ratio: 1.185; 95% confidence interval: 1.054 to 1.332; p = 0.005).ConclusionsThese proof-of-concept results show that noninvasive evaluation of myocardial amyloid load by ¹¹C-PiB PET reflects the degree of amyloid deposit and is an independent predictor of clinical outcome in AL cardiac amyloidosis patients.     

Atrial natriuretic peptide modulates auditory brainstem response of rat

Conclusion: These findings suggest that Atrial natriuretic peptide (ANP) exhibits an inhibitory effect on auditory brainstem response (ABR) and is involved in the neuromodulation of the auditory nervous system. Objectives: ANP may alter electrophysiological properties of the cochlea and play a role in auditory action. Methods: This study was undertaken to examine and clarify the role of ANP in the rat auditory system using ABR audiometry. The mean ABR thresholds and the latencies for wave II at the ABR threshold altered at given frequencies throughout the study. Results: Intra-arterial infusion of ANP (0.1 mg/kg, 4 mg/kg, and 8 mg/kg; bolus injection) resulted in a significant increase in ABR thresholds. A significant shift in the ABR wave II latency was observed at lower frequency (1 kHz and 2 kHz). There was a little change in latency at 20 kHz. Increased amount of ANP significantly altered the ABR in rats.     

Plasma N terminal pro-brain natriuretic peptide and cardiotrophin 1 are raised in unstable angina

OBJECTIVE—To compare circulating concentrations of N terminal pro-brain natriuretic peptide (N-BNP) and cardiotrophin 1 in stable and unstable angina.
DESIGN AND SETTING—Observational study in a teaching hospital.
PATIENTS—15 patients with unstable angina, 10 patients with stable angina, and 15 controls.
MAIN OUTCOME MEASURES—Resting plasma N-BNP and cardiotrophin 1 concentrations.
RESULTS—N-BNP concentration (median (range)) was 714 fmol/ml (177-3217 fmol/ml) in unstable angina, 169.5 fmol/ml (105.7-399.5 fmol/ml) in stable angina (p = 0.005 v unstable angina), and 150.5 fmol/ml (104.7-236.9 fmol/ml) in controls (p < 0.0001 v unstable angina; NS v stable angina). Cardiotrophin 1 concentration was 142.5 fmol/ml (42.2-527.4 fmol/ml) in unstable angina, 73.2 fmol/ml (41.5-102.1 fmol/ml) in stable angina (p < 0.05 v unstable angina), and 27 fmol/ml (6.9-54.1 fmol/ml) in controls (p < 0.0005 v stable angina; p < 0.0001 v unstable angina). Log cardiotrophin 1 correlated with log N-BNP in unstable angina (r = 0.93, p < 0.0001).
CONCLUSIONS—Both circulating N-BNP and cardiotrophin 1 are raised in unstable angina, while cardiotrophin 1 alone is raised in stable angina. The role of cardiotrophin 1 and the relation between cardiotrophin 1 and N-BNP in myocardial ischaemia remain to be defined.


Keywords: cardiotrophin 1; brain natriuretic peptide; angina pectoris     

NT-proBNP in heart failure: therapy decisions and monitoring

With increasing cardiac dysfunction, a complex neurohormonal response results in increasing circulating levels of an array of plasma hormones. Increments in plasma levels of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) and their amino-terminal congeners are more closely related to cardiac structure and function and to cardiovascular prognosis than changes in other plasma neurohormones. Reports suggest that changes in plasma BNP levels in the course of treatment of acutely decompensated heart failure provide a more powerful prognostic indicator of the likelihood of survival or recurrent decompensation than symptomatic assessment. This observation requires a randomised controlled trial in which changes in peptide levels determine aggression and duration of in-patient therapy in order to establish whether this indicator can improve results from management of acute in-patient heart failure. Plasma BNP or NT-proBNP is a powerful independent predictor of mortality and morbidity in long-term follow-up of heart failure cohorts. In addition, it appears likely to be a good predictor of beneficial response to the addition of beta blockade to anti-heart failure pharmacotherapy. Finally, adjustment of therapy for heart failure according to serial measurements of NT-proBNP promises to improve outcomes in comparison with adjusting therapy according to unassisted clinical acumen.