Generation and characterization of CD19-iCre mice as a tool for efficient and specific conditional gene targeting in B cells

The Cre/loxP system is a powerful tool for generating conditional gene knockout (KO) mice and elucidate gene function in vivo. CD19-Cre and Mb1-iCre transgenic mice are commonly used for generating B cell-specific KO mice and investigate the development, as well as the physiological and pathophysiological roles of B cells. However, the CD19-Cre line low efficiency and the Mb1-iCre line occasional ectopic recombination represent challenges for their use. Thus, we developed a CD19-codon-improved Cre (CD19-iCre) knock-in mouse with the T2A-iCre sequence inserted into the Cd19 locus, just before the stop codon. The CD19-iCre mice were compared with existing models, crossed with the Rosa26-EYFP reporter mice, and their recombination activity in B cells carrying different Cre alleles was assessed. CD19-iCre mice showed more effective Cre recombination in the early B cell developmental stages compared with the CD19-Cre mice. The efficiencies of the CD19-iCre and Mb1-iCre lines were similar; however, the B lineage-specific recombination was more stringent in the CD19-iCre line. Furthermore, the utility value of the CD19-iCre model was superior than that of the CD19-Cre mice regarding deletion efficiency in IL10-floxed mice. Thus, the CD19-iCre line is a valuable tool for highly efficient gene targeting specific to the B cell compartment.

High sensitivity cardiac troponin T is a useful biomarker for predicting prognosis of the patients with sarcoidosis

Background

Cardiac involvement is one of the most significant prognostic factors for the patients with sarcoidosis. In spite of the advancement of diagnostic tools, such as cardiac magnetic resonance imaging or 18F-fluoro-2-deoxyglucose positron emission tomography, there is still significant room for improvement in cardiac screening and prognostic prediction.

Purpose

To evaluate the prognostic factors for the patients with sarcoidosis.

Methods and results

We prospectively studied 133 patients with sarcoidosis and evaluated clinical data including biomarkers. The mean age at diagnosis was 62.1±12.8 years. During a mean follow up period of 5.6±4.1 years, nine patients died and 27 patients suffered from cardiac events (cardiac death, heart failure admission, arrhythmic event). We divided patients into two groups according to cardiac events, event group had high serum high-sensitivity cardiac troponin T (hs-cTnT) (0.028±0.017 vs. 0.015±0.011 ng/ml, p<0.001), high BNP (409.2±634.0 vs. 122.4±195.8 pg/ml, p<0.001), low EF (43.1±16.4 vs. 59.2±15.5%, p<0.001). This was observed even if those patients were not diagnosed with cardiac involvement at the enrollment. On the other hand, there were no significant differences in the values of angiotensin-converting enzyme, lysozyme, soluble interleukin-2 receptor, or calcium in both groups. Multivariate analysis revealed that hs-cTnT was an independent biomarker to predict cardiac events (hs-cTnT >0.014 ng/ml: HR 3.2, 95% CI 1.02 to 10.19, p=0.046).

Conclusion

Hs-cTnT was a useful biomarker for predicting cardiac events for the patients with sarcoidosis even if cardiac involvement was not detected at initial evaluation.

Figure 1

Funding Acknowledgement

Type of funding source: None

Prognostic impact of atrial fibrillation in patients with hypertrophic cardiomyopathy in a community-based Japanese cohort: results from Kochi RYOMA study

Background

The prognostic impact of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is not fully elucidated.

Purpose

The aim of this study was to examine the prevalence and prognostic impact of AF in a prospectively assembled community-based HCM patient cohort in an aged Japanese community.

Methods

In 2004, we established a cardiomyopathy registration network in Kochi Prefecture, Japan, consisting of 9 hospitals, and finally 293 patients with HCM were followed.

Results

The ages at registration and at diagnosis were 63±14 and 56±16 years, respectively, and 197 patients (67%) were men. 86 patients (29%) showed AF. During follow-up period of 6.1±3.2 years, 44 patients died. In those patients, HCM-related deaths occurred in 23 patients with an annual mortality rate of 1.3%. Regarding HCM-related adverse events including HCM-related deaths, appropriate ICD discharge, heart failure admission and hospitalization for embolic events, a total of 77 cardiovascular events in 70 patients occurred. Multivariate analysis revealed that presence of AF, left ventricular (LV) outflow obstruction, NYHA functional class III, and lower LV fractional shortening at registration were significant predictors of these adverse events. During the follow-up period, additional 31 patients (11%) developed new-onset AF. Importantly, the incidence of HCM-related adverse events was significantly higher in patients with new AF observed from its onset compared with those with AF at registration (log-rank p=0.029) (Figure 1).

Conclusions

In an unselected HCM registry in an aged Japanese community, presence of AF, particularly new-onset AF, was associated with unfavorable clinical outcomes. AF is not just a marker of the disease stage but an important trigger of HCM-related adverse events.

Figure 1

Funding Acknowledgement

Type of funding source: None

Heterogeneous subsets of B-lineage regulatory cells (Breg cells)

B cells represent a key cellular component of humoral immunity. Besides antigen presentation and antibody production, B cells also play a role in immune regulation and induction of tolerance through several mechanisms. Our understanding of B-lineage cells with regulatory ability has been revolutionized by the delineation of heterogeneous subsets of these cells. Specific environmental signals may further determine the polarization and function of B-lineage regulatory cells. With the availability of new genetic, molecular and pharmacological tools, considerable advances have been made toward our understanding of the surface phenotype, developmental processes and functions of these cells. These exciting discoveries, some of which are still controversial, also raise many new questions, which makes the inhibitory function of B cells a rapidly growing field in immunopathology. Here we review highlights of the regulatory activity of B cells and the recent advances in the function and phenotype of these B-cell subsets in healthy and diseased states.

Tet2 and Tet3 in B cells are required to repress CD86 and prevent autoimmunity

A contribution of epigenetic modifications to B cell tolerance has been proposed but not directly tested. Here we report that deficiency of ten-eleven translocation (Tet) DNA demethylase family members Tet2 and Tet3 in B cells led to hyperactivation of B and T cells, autoantibody production and lupus-like disease in mice. Mechanistically, in the absence of Tet2 and Tet3, downregulation of CD86, which normally occurs following chronic exposure of self-reactive B cells to self-antigen, did not take place. The importance of dysregulated CD86 expression in Tet2- and Tet3-deficient B cells was further demonstrated by the restriction, albeit not complete, on aberrant T and B cell activation following anti-CD86 blockade. Tet2- and Tet3-deficient B cells had decreased accumulation of histone deacetylase 1 (HDAC1) and HDAC2 at the Cd86 locus. Thus, our findings suggest that Tet2- and Tet3-mediated chromatin modification participates in repression of CD86 on chronically stimulated self-reactive B cells, which contributes, at least in part, to preventing autoimmunity.

Morphological lymphocytic reaction, patient prognosis and PD-1 expression after surgical resection for oesophageal cancer

BACKGROUND

Immune checkpoint inhibitors, such as antibody against programmed cell death protein (PD-1), have demonstrated antitumour effects in patients with malignancies, including oesophageal cancer. A lymphocytic reaction observed by pathological examination is a manifestation of the host immune response to tumour cells. It was hypothesized that a stronger lymphocytic reaction to tumours might be associated with favourable prognosis in oesophageal cancer.

METHODS

Using a database of resected oesophageal cancers, four morphological components of lymphocytic reactions (peritumoral, intranest, lymphoid and stromal) to tumours were evaluated in relation to clinical outcome, PD-1 expression by immunohistochemistry and total lymphocyte count in blood.

RESULTS

Resected oesophageal cancer specimens from 436 patients were included in the study. Among the four morphological components, only peritumoral reaction was associated with patient prognosis (multivariable P for trend <0·001); patients with a higher peritumoral reaction had significantly longer overall survival than those with a lower reaction (multivariable hazard ratio 0·48, 95 per cent c.i. 0·34 to 0·67). The prognostic effect of peritumoral reaction was not significantly modified by other clinical variables (all P for interaction >0·050). Peritumoral reaction was associated with total lymphocyte count in the blood (P < 0·001), supporting the relationship between local immune response and systemic immune competence. In addition, higher morphological peritumoral reaction was associated with high PD-1 expression on lymphocytes in tumours (P = 0·034).

CONCLUSION

These findings should help to improve risk-adapted therapeutic strategies and help stratify patients in the future clinical setting of immunotherapy for oesophageal cancer.

Cytohistology of morule in cribriform-morular variant of papillary thyroid carcinoma

INTRODUCTION

Cribriform-morular variant (CMV) is a rare variant of papillary thyroid carcinoma. It frequently occurs in association with familial adenomatous polyposis (FAP), although some cases are sporadic. Herein, we report a case of CMV and analyse morule cytohistology.

CASE REPORT

The patient was a 47-year-old woman with no familial history of FAP. A 3.0-cm unifocal mass was identified in the left thyroidal lobe. Fine-needle aspiration cytology revealed papillary clusters of atypical cells with nuclear grooves, which was suspected to be conventional papillary thyroid carcinoma. Histologically, the tumour comprised a papillary and cribriform growth of atypical cells with cytoplasmic accumulation and nuclear translocation of b-catenin. In addition, frequent morule formation was identified.

DISCUSSION

In this case, we performed morule analysis through correlative light and electron microscopy (CLEM), and revealed its ultrastructure. Although CMV is a rare form of thyroid carcinoma, it should be considered along with its distinct clinicopathological characteristics.

The COMMD3/8 complex determines GRK6 specificity for chemoattractant receptors

Nakai et al. show that the COMMD3/8 complex functions as an adaptor that selectively recruits GRK6 to chemoattractant receptors and promotes B cell migration and humoral immune responses.

Lymphocyte migration is mediated by G protein–coupled receptors (GPCRs) that respond to chemoattractive molecules. After their activation, GPCRs are phosphorylated by different GPCR kinases (GRKs), which produces distinct functional outcomes through β-arrestins. However, the molecular machinery that targets individual GRKs to activated GPCRs remains elusive. Here, we identified a protein complex consisting of copper metabolism MURR1 domain–containing (COMMD) 3 and COMMD8 (COMMD3/8 complex) as an adaptor that selectively recruits a specific GRK to chemoattractant receptors and promotes lymphocyte chemotaxis. COMMD8, whose stability depended on COMMD3, was recruited to multiple chemoattractant receptors. Deficiency of COMMD8 or COMMD3 impaired B cell migration and humoral immune responses. Using CXC-chemokine receptor 4 (CXCR4) as a model, we demonstrated that the COMMD3/8 complex selectively recruited GRK6 and induced GRK6-mediated phosphorylation of the receptor and activation of β-arrestin–mediated signaling. Thus, the COMMD3/8 complex is a specificity determinant of GRK targeting to GPCRs and represents a point of regulation for immune responses.

Clinical utility of exhaled carbon monoxide in assessing preoperative smoking status and risks of postoperative morbidity after esophagectomy

Whereas smoking constitutes a significant risk factor for postesophagectomy morbidity, there is no reliable method to assess the smoking status of patients prior to the procedure. Since exhaled carbon monoxide (CO) is an indicator of recent smoking, this paper hypothesizes that this is a useful parameter in assessing current smoking status and may help predict morbidity following esophagectomy. Sixty-nine patients, who had undergone elective three-incision esophagectomy with two- or three-field lymphadenectomy for esophageal cancer, were prospectively studied between February 2015 and September 2017. At surgical admission, they were asked about their smoking history, their exhaled CO levels were evaluated, and they were grouped into three based on their CO levels. These were 0 parts per million (ppm), >0 and <7 ppm, and ≥7 ppm. Their postoperative morbidity was also assessed. Approximately 13.5% of the patients showed high levels of exhaled CO ≥ 7 ppm, despite preoperatively reporting smoking cessation for over a month. Morbidities of the Clavien-Dindo classification (CDc) ≥ II increased as exhaled CO levels increased and severe morbidity of CDc ≥ IIIb frequently was observed in patients with exhaled CO levels ≥7 ppm. The logistic regression analysis showed that exhaled CO level ≥7 ppm was an independent risk factor for severe postesophagectomy morbidity. Overall, the results of this study suggest that exhaled CO levels may be useful in estimating current smoking status and that it may also help give an estimation of the risk of postesophagectomy morbidity.

Minimally invasive esophagectomy may contribute to long-term respiratory function after esophagectomy for esophageal cancer

Evidence suggests that minimally invasive esophagectomy has several advantages with regard to short-term outcomes, compared to open esophagectomy in esophageal cancer patients. However, the impact of minimally invasive esophagectomy on long-term respiratory function remains unknown. The objective of this study is to assess the association between use of the minimally invasive esophagectomy and long-term respiratory dysfunction in esophageal cancer patients after esophagectomy. This retrospective single institution study using prospectively collected data included 87 consecutive esophageal cancer patients who had undergone esophagectomy. All patients underwent a respiratory function test before, and one year after esophagectomy. Logistic regression analysis was used to compute the hazard ratio for long-term respiratory dysfunction. Minimally invasive esophagectomies were performed in 53 patients, and open esophagectomies in 34 patients. The two groups showed no significant differences in terms of postoperative complications and postoperative course. Nor were any differences observed between the two groups in terms of volume capacity (L) and forced expiratory volume 1.0 (L) before esophagectomy (P > 0.34). However, one year after esophagectomy, the decreases in volume capacity and forced expiratory volume 1.0 were significantly less in the minimally invasive esophagectomy group than in the open esophagectomy group (P = 0.04 and P = 0.007, respectively). Multivariate analyses revealed that minimally invasive esophagectomy was an independent favorable factor for maintenance of forced expiratory volume 1.0 (hazard ratio = 0.17, 95% confidence interval 0.04-0.71; P = 0.01). Minimally invasive esophagectomy may be an independent favorable factor for maintenance of long-term respiratory function in esophageal cancer patients after esophagectomy.

Pyloroplasty may reduce weight loss 1 year after esophagectomy

Weight loss after esophagectomy is common and is associated with unfavorable prognosis. However, the clinical features and surgical methods that influence postesophagectomy weight loss are not well characterized. This study aims to determine those features (especially the surgical methods) that may affect postoperative weight loss. We reviewed 221 esophageal cancer patients who had undergone esophagectomy at Kumamoto University Hospital (Kumamoto, Japan) between November 2012 and June 2015. Among these, we recruited 106 patients who had undergone transthoracic esophagectomy with gastric conduit reconstruction, had no cancer recurrence within 1 year, and no missing follow-up data. We tabulated the body weight changes and risk factors associated with weight loss exceeding 10% at 1-year postesophagectomy. The mean body weights at baseline and 1-year postsurgery were 60.3 kg (standard error (SE): 0.91) and 52.6 (SE: 0.91), respectively. One year postsurgery, the body weights had changed as follows: mean: -12.2%; median: -12.9%; standard deviation: 9.06; range: -36.1-18.56%; interquartile range: -10.5 to -14.0%. In the multivariate logistic regression analysis, the absence of pyloroplasty was the sole risk factor for more than 10% weight loss (OR: 3.22; 95% CI: 1.08-11.9; P = 0.036). Our data suggest that pyloroplasty with esophagectomy can overcome the post-surgical weight loss.

Sensitive detection of fluorescence in western blotting by merging images

The western blotting technique is widely used to analyze protein expression levels and protein molecular weight. The chemiluminescence method is mainly used for detection due to its high sensitivity and ease of manipulation, but it is unsuitable for detailed analyses because it cannot be used to detect multiple proteins simultaneously. Recently, more attention has been paid to the fluorescence detection method because it is more quantitative and is suitable for the detection of multiple proteins simultaneously. However, fluorescence detection can be limited by poor image resolution and low detection sensitivity. Here, we describe a method to detect fluorescence in western blots using fluorescence microscopy to obtain high-resolution images. In this method, filters and fluorescent dyes are optimized to enhance detection sensitivity to a level similar to that of the chemiluminescence method.

Combined effects of electric toothbrushing and dentifrice on artificial stain removal: An in vitro study

Background

This in vitro study aimed to clarify the combined effect of electric toothbrushing and dentifrice on the removal of artificial stain.

Material and Methods

Twenty-five bovine incisors were cut at the cervix and the crown was embedded in auto-cured acrylic resin. Specimens were abraded using #240 SiC paper to obtain a flat enamel surface, and 20 specimens were treated with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution to produce surface staining. They were divided into four groups: 1) brushing with an electric toothbrush and whitening dentifrice (group S+B); 2) brushing with an electric toothbrush and fluoride dentifrice (group S+C); 3) brushing with an electric toothbrush and no dentifrice (group S); and 4) no brushing (control group). The remaining five specimens were used as a baseline. Color values (L*, a*, and b* were measured before brushing (0 min), and at 1 min, 5 min, 10 min, and 20 min using a microscopic area spectrophotometer. The color change (ΔE) was calculated by subtracting the baseline values from the final color values obtained at each time point. The data were statistically analyzed using two-way repeated-measures analysis of variance and Tukey’s honest significant difference test as a post hoc test (p<0.05).

Results

The L* values of groups S+B and S+C increased over time (p<0.05), but no significant differences were observed in group S and the control group at any of the time points (p>0.05). Groups S+B and S+C demonstrated greater ΔE values than group S.

Conclusions

The combination of electric toothbrushing and dentifrice removed the artificial stain more effectively than brushing without dentifrice. However, the stain removal was limited. The two dentifrices evaluated in this study exhibited similar stain removal effects.

Key words:Color change, stain removal, dentifrice, electric toothbrush, whitening effect.

The activated conformation of integrin β7 is a novel multiple myeloma-specific target for CAR T cell therapy

Cancer-specific cell-surface antigens are ideal targets for monoclonal antibody (mAb)-based immunotherapy but are likely to have previously been identified in transcriptome or proteome analyses. Here, we show that the active conformer of an integrin can serve as a specific therapeutic target for multiple myeloma (MM). We screened >10,000 anti-MM mAb clones and identified MMG49 as an MM-specific mAb specifically recognizing a subset of integrin β₇ molecules. The MMG49 epitope, in the N-terminal region of the β₇ chain, is predicted to be inaccessible in the resting integrin conformer but exposed in the active conformation. Elevated expression and constitutive activation of integrin β₇ conferred high MMG49 reactivity on MM cells, whereas MMG49 binding was scarcely detectable in other cell types including normal integrin β₇⁺ lymphocytes. T cells transduced with MMG49-derived chimeric antigen receptor (CAR) exerted anti-MM effects without damaging normal hematopoietic cells. Thus, MMG49 CAR T cell therapy is promising for MM, and a receptor protein with a rare but physiologically relevant conformation can serve as a cancer immunotherapy target.

Monitoring sputum culture in resected esophageal cancer patients with preoperative treatment

Pneumonia is a major cause of postesophagectomy mortality and worsens the long-term survival in resected esophageal cancer patients. Moreover, preoperative treatments such as chemotherapy or chemoradiotherapy (which have recently been applied worldwide) might affect the bacterial flora of the sputum. To investigate the association among preoperative treatments, the bacterial flora of sputum, and the clinical and pathological features in resected esophageal cancer patients, this study newly investigates the effect of preoperative treatments on the bacterial flora of sputum. We investigated the association among preoperative treatments, the bacterial flora of sputum, and clinical and pathological features in 163 resected esophageal cancer patients within a single institution. Pathogenic bacteria such as Candida (14.1%), Staphylococcus aureus (6.7%), Enterobacter cloacae (6.1%), Haemophilus parainfluenzae (4.9%), Klebisiella pneumoniae (3.7%), Methicillin-resistant Staphylococcus aureus (MRSA) (3.7%), Pseudomonas aeruginosa (2.5%), Escherichia coli (1.8%), Streptococcus pneumoniae (1.8%), and Haemophilus influenzae (1.2%) were found in the sputum. The pathogen detection rate in the present study was 34.3% (56/163). In patients with preoperative chemotherapy and chemoradiotherapy, the indigenous Neisseria and Streptococcus species were significantly decreased (P= 0.04 and P= 0.04). However, the detection rates of pathogenic bacteria were not associated with preoperative treatments (all P> 0.07). There was not a significant difference of hospital stay between the sputum-monitored patients and unmonitored patients (35.5 vs. 49.9 days; P= 0.08). Patients undergoing preoperative treatments exhibited a significant decrease of indigenous bacteria, indicating that the treatment altered the bacterial flora of their sputum. This finding needs to be confirmed in large-scale independent studies or well-designed multicenter studies.