A high-throughput differential scanning fluorimetry method for rapid detection of thermal stability and iron saturation in lactoferrin.

Thermal stability and iron saturation of lactoferrin (LF) are of great significance not only for the evaluation of the biological activities of LF but also for the optimization of the isolation and drying process parameters. Differential scanning calorimetry (DSC) is a well-established and efficient method for thermal stability and iron saturation detection in LF. However, multiple DSC measurements are typically performed sequentially, thus time-consuming and low throughput. Herein, we introduced the differential scanning fluorimetry (DSF) approach to overcome such limitations. The DSF can monitor LF thermal unfolding with a commonly available real-time PCR instrument and a fluorescent dye (SYPRO orange or Glomelt), and the measured melting temperature of LF is consistent with that determined by DSC. On the basis of that, a new quantification method was established for determination of iron saturation levels using the linear correlation of the degree of ion saturation of LF with DSF measurements. Such DSF method is simple, inexpensive, rapid (<15 min), and high throughput (>96 samples per experiment), and provides a valuable alternative tool for thermal stability detection of LF and other whey proteins.

Deep learning-accelerated T2WI: image quality, efficiency, and staging performance against BLADE T2WI for gastric cancer.

PURPOSE: The purpose of our study is to investigate image quality, efficiency, and diagnostic performance of a deep learning-accelerated single-shot breath-hold (DLSB) against BLADE for T2-weighted MR imaging (T2WI) for gastric cancer (GC). METHODS: 112 patients with GCs undergoing gastric MRI were prospectively enrolled between Aug 2022 and Dec 2022. Axial DLSB-T2WI and BLADE-T2WI of stomach were scanned with same spatial resolution. Three radiologists independently evaluated the image qualities using a 5-scale Likert scales (IQS) in terms of lesion delineation, gastric wall boundary conspicuity, and overall image quality. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated in measurable lesions. T staging was conducted based on the results of both sequences for GC patients with gastrectomy. Pairwise comparisons between DLSB-T2WI and BLADE-T2WI were performed using the Wilcoxon signed-rank test, paired t-test, and chi-squared test. Kendall's W, Fleiss' Kappa, and intraclass correlation coefficient values were used to determine inter-reader reliability. RESULTS: Against BLADE, DLSB reduced total acquisition time of T2WI from 495 min (mean 4:42 per patient) to 33.6 min (18 s per patient), with better overall image quality that produced 9.43-fold, 8.00-fold, and 18.31-fold IQS upgrading against BALDE, respectively, in three readers. In 69 measurable lesions, DLSB-T2WI had higher mean SNR and higher CNR than BLADE-T2WI. Among 71 patients with gastrectomy, DLSB-T2WI resulted in comparable accuracy to BLADE-T2WI in staging GCs (P > 0.05). CONCLUSIONS: DLSB-T2WI demonstrated shorter acquisition time, better image quality, and comparable staging accuracy, which could be an alternative to BLADE-T2WI for gastric cancer imaging.

Nomogram for preoperative estimation of histologic grade in gastrointestinal neuroendocrine tumors.

Background: The treatment strategies and prognosis for gastroenteropancreatic neuroendocrine tumors were associated with tumor grade. Preoperative predictive grading could be of great benefit in the selection of treatment options for patients. However, there is still a lack of effective non-invasive strategies to detect gastrointestinal neuroendocrine tumors (GI-NETs) grading preoperatively. Methods: The data on 147 consecutive GI-NETs patients was retrospectively collected from January 1, 2012, to December 31, 2019. Logistic regression was used to construct a predictive model of gastrointestinal neuroendocrine tumor grading using preoperative laboratory and imaging parameters.The validity of the model was assessed by area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA). Results: The factors associated with GI-NETs grading were age, tumor size, lymph nodes, neuron-specific enolase (NSE), hemoglobin (HGB) and sex, and two models were constructed by logistic regression for prediction. Combining these 6 factors, the nomogram was constructed for model 1 to distinguish between G3 and G1/2, achieving a good AUC of 0.921 (95% CI: 0.884-0.965), and the sensitivity, specificity, accuracy were 0.9167, 0.8256, 0.8630, respectively. The model 2 was to distinguish between G1 and G2/3, and the variables were age, tumor size, lymph nodes, NSE, with an AUC of 0.847 (95% CI: 0.799-0.915), and the sensitivity, specificity, accuracy were 0.7882, 0.8710, 0.8231, respectively. Two online web servers were established on the basis of the proposed nomogram to facilitate clinical use. Both models showed an excellent calibration curve through 1000 times bootstrapped dataset and the clinical usefulness were confirmed using decision curve analysis. Conclusion: The model served as a valuable non-invasive tool for differentiating between different grades of GI-NETs, personalizing the calculation which can lead to a rational treatment choice.

Development and validation of a dual-energy CT-based model to estimate the malignant probability of distal gastric wall thickening.

Background: This study developed and validated a viable model for the preoperative diagnosis of malignant distal gastric wall thickening based on dual-energy spectral computed tomography (DEsCT). Methods: The imaging data of 208 patients who were diagnosed with distal gastric wall thickening using DEsCT were retrospectively collected and divided into a training cohort (n=151) and a testing cohort (n=57). The patient's clinical data and pathological information were collated. The multivariable logistic regression model was built using 5 selected features, and subsequently, a 10-fold cross-validation was performed to identify the optimal model. A nomogram was established based on the training cohort. Finally, the diagnostic performance of the best model was compared to the existing conventional CT scheme through evaluating the discrimination ability in the testing cohort in terms of the receiver operating characteristic curve (ROC), calibration, and clinical usefulness. Results: Stepwise regression analysis identified 5 candidate variables with the smallest Akaike information criteria (AIC), namely, the venous phase spectral curve [VP_ SC; odds ratio (OR) 8.419], focal enhancement (OR 3.741), arterial phase mixed (OR 1.030), tumor site (OR 0.573), and diphasic shape change (DP_shape change; OR 2.746). The best regression model with 10-fold cross-validation consisting of VP_SC and focal enhancement was built using the 5 candidate variables. The average area under the ROC curve (AUC) of the model from the 10-fold cross-validation was 0.803 (sensitivity of 69.2%, specificity of 94.1%, and accuracy of 74.8%). In the testing cohort, the DEsCT model identified using the regression model performed better (AUC 0.905, sensitivity 81.3%, specificity 85.4%, and accuracy 84.2%) than did the conventional CT scheme (AUC 0.852, sensitivity 80.0%, specificity 76.6%, and accuracy 77.2%). The nomogram based on the DEsCT model showed good calibration and provided a better net benefit for predicting malignancy of distal gastric wall thickening. Conclusions: Comprehensive assessment with the DEsCT-based model can be used to facilitate the individualized diagnosis of malignancy risk in patients presenting with distal gastric wall thickening.

Macrophage exosomes transfer angiotensin II type 1 receptor to lung fibroblasts mediating bleomycin-induced pulmonary fibrosis.

BACKGROUND: Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis, partially by activating lung fibroblasts. However, how macrophages communicate with lung fibroblasts is largely unexplored. Exosomes can mediate intercellular communication, whereas its role in lung fibrogenesis is unclear. Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis. METHODS: In vivo, bleomycin (BLM)-induced lung fibrosis model was established and macrophages infiltration was examined. The effects of GW4869, an exosomes inhibitor, on lung fibrosis were assessed. Moreover, macrophage exosomes were injected into mice to observe its pro-fibrotic effects. In vitro, exosomes derived from angiotensin II (Ang II)-stimulated macrophages were collected. Then, lung fibroblasts were treated with the exosomes. Twenty-four hours later, protein levels of α-collagen I, angiotensin II type 1 receptor (AT1R), transforming growth factor-ß (TGF-ß), and phospho-Smad2/3 (p-Smad2/3) in lung fibroblasts were examined. The Student's t test or analysis of variance were used for statistical analysis. RESULTS: In vivo, BLM-treated mice showed enhanced infiltration of macrophages, increased fibrotic alterations, and higher levels of Ang II and AT1R. GW4869 attenuated BLM-induced pulmonary fibrosis. Mice with exosomes injection showed fibrotic features with higher levels of Ang II and AT1R, which was reversed by irbesartan. In vitro, we found that macrophages secreted a great number of exosomes. The exosomes were taken by fibroblasts and resulted in higher levels of AT1R (0.22 ±â€Š0.02 vs. 0.07 ±â€Š0.02, t = 8.66, P = 0.001), TGF-ß (0.54 ±â€Š0.05 vs. 0.09 ±â€Š0.06, t = 10.00, P < 0.001), p-Smad2/3 (0.58 ±â€Š0.06 vs. 0.07 ±â€Š0.03, t = 12.86, P < 0.001) and α-collagen I (0.27 ±â€Š0.02 vs. 0.16 ±â€Š0.01, t = 7.01, P = 0.002), and increased Ang II secretion (62.27 ±â€Š7.32 vs. 9.56 ±â€Š1.68, t = 12.16, P < 0.001). Interestingly, Ang II increased the number of macrophage exosomes, and the protein levels of Alix (1.45 ±â€Š0.15 vs. 1.00 ±â€Š0.10, t = 4.32, P = 0.012), AT1R (4.05 ±â€Š0.64 vs. 1.00 ±â€Š0.09, t = 8.17, P = 0.001), and glyceraldehyde-3-phosphate dehydrogenase (2.13 ±â€Š0.36 vs. 1.00 ±â€Š0.10, t = 5.28, P = 0.006) were increased in exosomes secreted by the same number of macrophages, indicating a positive loop between Ang II and exosomes production. CONCLUSIONS: Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.

Early Prediction for Persistent Inflammation-Immunosuppression Catabolism Syndrome in Surgical Sepsis Patients.

OBJECTIVE: To find the predictors for persistent inflammation-immunosuppression catabolism syndrome in ICU surgical septic patients. DESIGN: Single center observation study. PARTICIPANTS: Inclusion: 1) patients ≥18, 2) admitted to the ICU after major surgery or transferred to the ICU within 48 hours after the diagnosis of sepsis following the definition of sepsis-3.0. Exclusion: 1) pregnant or lactating patients, 2) patients with severe immune deficiency, 3) patients that expired within 14 days after the diagnosis of sepsis. RESULTS: A total of 169 participants were included. After propensity score matching, PICS patients were found to have higher intensive care unit (ICU) mortality (32.4% vs 12.4%, p=0.046), 90-day mortality (32.4% vs 9.1%, p=0.006), and ICU-acquired infection rate (44.1% vs 12.7%, p<0.001), and longer ICU stays (29 vs 11 days, p<0.001) comparing to non-PICS patients. In multivariate logistic regression, it demonstrated that the SOFA score, Charlson co-morbidity index (CCI), albumin level on the ICU day 1, and lymphocyte count on the ICU day 3 were statistically significant. Sensitivity analysis was conducted with the receiver operating characteristic curve for a combination of the four parameters and the area under the curve was 0.838 (95% confidence interval 0.774-0.901). CONCLUSION: The chronic disease condition and decreased immunity in the early course of sepsis were crucial for PICS. The combination of CCI, SOFA score, albumin level on ICU Day 1 and lymphocyte count on ICU Day 3 can be early predictor for PICS.

Author Correction: Mir-21 Mediates the Inhibitory Effect of Ang (1-7) on AngII-induced NLRP3 Inflammasome Activation by Targeting Spry1 in lung fibroblasts.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Histogram analysis of DCE-MRI for chemoradiotherapy response evaluation in locally advanced esophageal squamous cell carcinoma.

AIMS: The aim of the study was to predict and assess treatment response by histogram analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to patients with locally advanced esophageal squamous cell carcinoma receiving chemoradiotherapy (CRT). MATERIALS AND METHODS: Seventy-two patients with locally advanced esophageal squamous cell carcinoma who underwent DCE-MRI before and after chemoradiotherapy were enrolled and divided into the complete response (CR) group and the non-CR group based on RECIST. The histogram parameters (10th percentile, 90th percentile, median, mean, standard deviation, skewness, and kurtosis) of pre-CRT and post-CRT were compared using a paired Student's t test in the CR and non-CR groups, respectively. The histogram parameter differences between the CR and the non-CR groups were compared using an unpaired Student's t test. A receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance. RESULTS: The histogram parameters of Ktrans values were observed to have significantly decreased after chemoradiotherapy in the CR group. The CR responders showed significantly higher median, mean, and 10th and 90th percentile of pre-Ktrans values than those of the non-CR group. The histogram analysis indicated the decreased heterogeneity in the CR group after CRT. Esophageal cancer with higher pre-Ktrans and lower post-Ktrans values indicated a good treatment response to CRT. Pre-Ktrans-10th showed the best diagnostic performance in predicting the chemoradiotherapy response. CONCLUSIONS: The histogram parameters of Ktrans are useful in the assessment and prediction of the chemoradiotherapy response in patients with advanced esophageal squamous cell carcinoma. DCE-MRI could serve as an adjunctive imaging technique for treatment planning.

Hormetic Effects of Yttrium on Male Sprague-Dawley Rats.

To evaluate hormesis induced by Yttrium (Y) nitrate in male rats, Y was offered to F0 mother rats and F1 offspring at concentrations of 0, 20, 80, and 320 ppm daily from gestational day (GD) 0 through postnatal day 70 (PND 70). The F1 offspring were evaluated with respect to motor function, learning and memory, and histopathology. Administration of Y improved motor function in a dose dependent manner. In the 20 ppm group, body weight and spatial learning and memory were increased, while the latter was decreased in the 320 ppm group. Additionally, in the 20 ppm and 80 ppm, but not the 320 ppm groups, Y reduced the anogenital distance, which indicated an anti-androgen effect. These results suggest that Y follows a hormetic concentration-related trend with an inverted U-shape.

Dynamic contrast-enhanced MRI for advanced esophageal cancer response assessment after concurrent chemoradiotherapy.

PURPOSE: We aimed to evaluate the treatment response of patients with esophageal cancer after concurrent chemoradiation therapy (CRT) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). METHODS: This retrospective study included 59 patients with histologically confirmed esophageal squamous cell carcinoma. The patients underwent DCE-MRI before and 4 weeks after CRT. Patients with complete response were defined as the CR group; partial response, stable disease, and progressive disease patients were defined as the non-CR group. DCE-MRI parameters (Ktrans, Ve, and Kep) were measured and compared between pre- and post-CRT in the CR and non-CR groups, respectively. Pre-CRT and post-CRT parameters were used to calculate the absolute change and the ratio of change. DCE-MRI parameters were compared between the CR and non-CR groups. Receiver operating characteristic (ROC) curves were used to verify diagnostic performance. RESULTS: Patients with higher T-stage esophageal cancer might present with poorer response. After CRT, the Ktrans and Kep values significantly decreased in the CR group, whereas only Kep value decreased in the non-CR group. The post-Ktrans and post-Kep values were observed to be significantly lower in the CR group than in the non-CR group. The absolute change and ratio of change of both Ktrans and Kep were higher in the CR group than in the non-CR group. Based on ROC analysis, the ratio of change in Ktrans was the best parameter to assess treatment response (AUC= 0.840). CONCLUSION: DCE-MRI parameters are valuable in predicting and assessing concurrent CRT response for advanced esophageal cancer.

A fluorescent probe based on a Tb3+/Cu2+ co-functionalized MOF for urinary sarcosine detection.

A novel luminescent probe based on a Tb3+/Cu2+ heterometallic metal-organic framework (MOF) was first designed for beamed monitoring of urinary sarcosine, a differential metabolite that can indicate the progression of prostate cancer (PCa). The fluorescent probe presented high selectivity towards sarcosine in urine. It also displayed good sensitivity with a comparatively low detection limit and a fast response to sarcosine within 5 min. Moreover, such high selectivity and sensitivity towards sarcosine is not subject to interference from other coexisting species in urine. At the same time, this fluorescent material also demonstrated the possibility for recycling. The excellent sensing performance of this Ln-MOF (lanthanide MOF) enables it to be further employed as a serviceable tool for PCa diagnosis and monitoring.

Subchronic Oral Toxicity of Silica Nanoparticles and Silica Microparticles in Rats.

OBJECTIVE: To investigate the subchronic oral toxicity of silica nanoparticles (NPs) and silica microparticles (MPs) in rats and to compare the difference in toxicity between two particle sizes. METHODS: Sprague-Dawley rats were randomly divided into seven groups: the control group; the silica NPs low-, middle-, and high-dose groups; and the silica MPs low-, middle-, and high-dose groups [166.7, 500, and 1,500 mg/(kg•bw•day)]. All rats were gavaged daily for 90 days, and deionized water was administered to the control group. Clinical observations were made daily, and body weights and food consumption were determined weekly. Blood samples were collected on day 91 for measurement of hematology and clinical biochemistry. Animals were euthanized for necropsy, and selected organs were weighed and fixed for histological examination. The tissue distribution of silicon in the blood, liver, kidneys, and testis were determined. RESULTS: There were no toxicologically significant changes in mortality, clinical signs, body weight, food consumption, necropsy findings, and organ weights. Differences between the silica groups and the control group in some hematological and clinical biochemical values and histopathological findings were not considered treatment related. The tissue distribution of silicon was comparable across all groups. CONCLUSION: Our study demonstrated that neither silica NPs nor silica MPs induced toxicological effects after subchronic oral exposure in rats.

The prognostic value of gray-white matter ratio on brain computed tomography in adult comatose cardiac arrest survivors.

BACKGROUND: Recent studies suggested that the gray-white matter ratio (GWR) determined from brain computed tomography (CT) scans may be a reliable predictor of poor neurological outcomes. The aim of study was to evaluate the association between the GWR and the outcomes in adult comatose cardiac arrest (CA) survivors in Chinese. METHODS: A total of 58 CA patients who had CT scans within 72 h of resuscitation between January 2011 and December 2015 were included in this single-center retrospective study. Gray and white matter attenuations (Hounsfield units) were measured, and the GWRs were calculated according to previous studies. The study analyzed the prognostic values of the GWRs in predicting poor outcomes (Cerebral Performance Category 3-5). RESULTS: The attenuation values of gray matter were significantly higher in the good outcome group than in the poor one. All GWRs were significantly higher in the good outcome group (p < 0.05). A GWR (basal ganglia) < 1.18 predicted poor outcomes with a sensitivity and specificity of 50.0% and 87.5%, respectively (p = 0.021). GWR (cerebrum) showed the best predictive performance when CT was performed within 24-72 h (p = 0.003). No significant differences were found between GWR and poor outcomes when CT was performed within the first 24 h. CONCLUSION: Low GWRs which were obtained from brain CT scans in comatose CA patients after restoration of spontaneous circulation were associated with poor neurological outcomes. GWR from brain CT can be a useful parameter for prognostic prediction aiding to an optimal clinical decision process in comatose CA survivors.

Mir-21 Mediates the Inhibitory Effect of Ang (1-7) on AngII-induced NLRP3 Inflammasome Activation by Targeting Spry1 in lung fibroblasts.

MicroRNA-21 (mir-21) induced by angiotensin II (AngII) plays a vital role in the development of pulmonary fibrosis, and the NLRP3 inflammasome is known to be involved in fibrogenesis. However, whether there is a link between mir-21 and the NLRP3 inflammasome in pulmonary fibrosis is unknown. Angiotensin-converting enzyme 2/angiotensin(1-7) [ACE2/Ang(1-7)] has been shown to attenuate AngII-induced pulmonary fibrosis, but it is not clear whether ACE2/Ang(1-7) protects against pulmonary fibrosis by inhibiting AngII-induced mir-21 expression. This study's aim was to investigate whether mir-21 activates the NLRP3 inflammasome and mediates the different effects of AngII and ACE2/Ang(1-7) on lung fibroblast apoptosis and collagen synthesis. In vivo, AngII exacerbated bleomycin (BLM)-induced lung fibrosis in rats, and elevated mir-21 and the NLRP3 inflammasome. In contrast, ACE2/Ang(1-7) attenuated BLM-induced lung fibrosis, and decreased mir-21 and the NLRP3 inflammasome. In vitro, AngII activated the NLRP3 inflammasome by up-regulating mir-21, and ACE2/Ang(1-7) inhibited NLRP3 inflammasome activation by down-regulating AngII-induced mir-21. Over-expression of mir-21 activated the NLRP3 inflammasome via the ERK/NF-κB pathway by targeting Spry1, resulting in apoptosis resistance and collagen synthesis in lung fibroblasts. These results indicate that mir-21 mediates the inhibitory effect of ACE2/Ang(1-7) on AngII-induced activation of the NLRP3 inflammasome by targeting Spry1 in lung fibroblasts.

[Laser scanning confocal microscopic imaging for Ca2 + oscillations of pancreatic acinar cells in mice].

OBJECTIVE: To establish a simple but effective method of laser scanning confocal microscopic imaging for Ca2+ oscillations of pancreatic acinar cells in adult mice. METHODS: Pancreatic acinar cells from adult Kunming mice were isolated acutely with collagenase, and then loaded with fluo-4-AM, a Ca2+ indicator. A laser scanning confocal microscope armed with 488 nm laser was employed to record the dynamic fluorescent signals in-time and synchronously while acetylcholine (ACh) was added in the pancreatic acinar cells. RESULTS: (1) The classic pancreatic acinar cell Ca2+ oscillations were induced by a certain concentration of ACh (100 nmol/L) successfully and steadily, which could be blocked by atropine completely. (2) Plasmic Ca2+ oscillations from different parts of one acinar cell were usually with different amplitudes and almost the same frequencies. But both of amplitudes and frequencies were different among different cells. (3) The acinar cell Ca2+ oscillations were induced by ACh in a concentration-dependent manner. CONCLUSION: The laser scanning confocal microscopic imaging for adult mouse pancreatic acinar cell Ca2+ oscillations was established successfully. The features of being easy to use, direct to see lively, high efficiency and good flexibility make it a popular tool for researchers to choose.

Congo red modulates ACh-induced Ca(2+) oscillations in single pancreatic acinar cells of mice.

AIM: Congo red, a secondary diazo dye, is usually used as an indicator for the presence of amyloid fibrils. Recent studies show that congo red exerts neuroprotective effects in a variety of models of neurodegenerative diseases. However, its pharmacological profile remains unknown. In this study, we investigated the effects of congo red on ACh-induced Ca(2+) oscillations in mouse pancreatic acinar cells in vitro. METHODS: Acutely dissociated pancreatic acinar cells of mice were prepared. A U-tube drug application system was used to deliver drugs into the bath. Intracellular Ca(2+) oscillations were monitored by whole-cell recording of Ca(2+)-activated Cl(-) currents and by using confocal Ca(2+) imaging. For intracellular drug application, the drug was added in pipette solution and diffused into cell after the whole-cell configuration was established. RESULTS: Bath application of ACh (10 nmol/L) induced typical Ca(2+) oscillations in dissociated pancreatic acinar cells. Addition of congo red (1, 10, 100 µmol/L) dose-dependently enhanced Ach-induced Ca(2+) oscillations, but congo red alone did not induce any detectable response. Furthermore, this enhancement depended on the concentrations of ACh: congo red markedly enhanced the Ca(2+) oscillations induced by ACh (10-30 nmol/L), but did not alter the Ca(2+) oscillations induced by ACh (100-10000 nmol/L). Congo red also enhanced the Ca(2+) oscillations induced by bath application of IP3 (30 µmol/L). Intracellular application of congo red failed to alter ACh-induced Ca(2+) oscillations. CONCLUSION: Congo red significantly modulates intracellular Ca(2+) signaling in pancreatic acinar cells, and this pharmacological effect should be fully considered when developing congo red as a novel therapeutic drug.

Anti-collagen XVII single-chain Fv antibody blocks the autoimmune reaction mediated by pathogenic autoantibodies in bullous pemphigoid.

BACKGROUND: Pathogenic autoantibodies in bullous pemphigoid (BP) recognize the non-collagenous 16A domain (NC16A) of collagen XVII (COL17), a hemidesmosomal component at the skin membrane. This immune inflammation involves activation of the complement cascade via the classical pathway. With similar antigen binding activity, Fab and single-chain variable fragments (scFv) of pathogenic anti-COL17 antibodies can interfere with COL17 binding of autoantibodies, blocking subsequent complement activation and granulocyte activation. OBJECTIVE: To characterize the biological functions of human anti-COL17 scFv antibody. METHODS: We constructed scFv antibodies against the corresponding antigen from parental Fab by expression in Escherichia coli. IgG autoantibodies against COL17 were purified by affinity chromatography from serum of BP patients. The inhibitory effects of anti-COL17 scFv on binding of BP autoantibodies to the NC16A domain of human COL17 antigen were observed by inhibition ELISA, immunofluorescence, and inhibition of complement activation. Reactive oxygen production assay and BP cryosection model were performed to assess the inhibitory effect of scFv on granulocyte activation and then the dermal-epidermal separation. RESULTS: ELISA and Western blot showed specific binding of scFv to COL17. We found that anti-COL17 scFv can inhibit the binding of intact IgG purified from BP parents to the corresponding COL17 antigen and then subsequent C1q and C3 activation and granulocyte activation in vitro. Most importantly, we confirmed that recombinant scFv can inhibit BP-IgG induced dermal-epidermal separation by BP cryosection model. CONCLUSION: The anti-COL17 scFv antibody can inhibit the binding of BP-IgG autoantibodies to COL17, thereby affecting subsequent complement activation and granulocyte activation in vitro. Our results suggest that blocking pathogenic epitopes using engineered scFv is an efficient BP therapy.