Biochemical and immunomodulatory insights of extracellular matrix from decellularized human whole cervix: recellularization andin vivoECM remodeling interplay

Extracellular matrix (ECM) rich whole organ bio-scaffolds, preserving structural integrity and essential growth factors, has potential towards regeneration and reconstruction. Women with cervical anomalies or trauma can benefit from clinical cervicovaginal repair using constructs rich in site specific ECM. In this study, complete human cervix decellularization was achieved using a modified perfusion-based stir bench top decellularization method. This was followed by physico-chemical processes including perfusion of ionic agents, enzymatic treatment and washing using detergent solutions for a duration of 10-12 d. Histopathological analysis, as well as DNA quantification confirmed the efficacy of the decellularization process. Tissue ultrastructure integrity was preserved and the same was validated via scanning electron microscopy and transmission electron microscopy studies. Biochemical analysis and structural characterizations like Fourier transform infrared, Raman spectroscopy of decellularized tissues demonstrated preservation of important proteins, crucial growth factors, collagen, and glycosaminoglycans.In vitrostudies, using THP-1 and human umbilical vein endothelial cell (HUVEC) cells, demonstrated macrophage polarization from M1 to M2 and vascular functional genes enhancement, respectively, when treated with decellularized human cervical matrix (DHCp). Crosslinked DHC scaffolds were recellularized with site specific human cervical epithelial cells and HUVEC, showing non-cytotoxic cell viability and enhanced proliferation. Furthermore, DHC scaffolds showed immunomodulatory effectsin vivoon small rodent model via upregulation of M2 macrophage genes as compared to decellularized rat cervix matrix scaffolds (DRC). DHC scaffolds underwent neo-vascularization followed by ECM remodeling with enhanced tissue integration.

17-β Estradiol (E2) distinctly regulates the expression of IL-4 and IL-13 in Th2 cells via modulating the interplay between GATA3 and PU.1

17-β Estradiol (E2) has long standing known functions in regulating human physiology as well as immune system. E2 is known to elicit a protective role against experimental autoimmune encephalomyelitis (EAE) and has been used as a drug for treatment against multiple sclerosis. Moreover, E2 regulates the adaptive immune system by directly affecting the T helper cell subsets differentiation and antibody secretion mediated by B cells. Reports have shown that E2 promotes Th1 and Treg cell differentiation; whereas it attenuated the Th17 and Tfh cell differentiation. Albeit multiple and contrasting studies, the mechanisms of behind E2 action on Th2 cells remained understudied. Hence, we sought to dissect the impact of E2 in Th2 cell differentiation. In this study, we elucidated the molecular mechanisms behind E2-mediated regulation of the differentiation of Th2 cells. We observed that E2 significantly attenuated the IL-4-secreting Th2 population in an ERα-dependent manner. We validated these findings using ICI 182, 780, an antagonist to ERα, not ERβ and ectopically overexpressing ERα in Th2 cells. We further determined that ERα alters the recruitment of GATA3 and PU.1 to Il4 gene by directly interacting with them. This altered recruitment was observed to be stronger at Il4 than Il13 locus. Interestingly, we detected a distinct recruitment of GATA3 and PU.1 at Il13 gene; however, there was no E2-mediated broad alteration in the recruitment of histone-modifiers at Il13 locus. These findings suggest that E2 regulates Il4 in a distinctly separate mechanism as opposed to Il13 locus in Th2 cells.

Performance and cell toxicity studies for the use of graphene oxide-bimetallic oxide hybrids in the absorptive removal of Pb(II) from wastewater: fixed-bed column study with regeneration

The current study involves the removal of Pb(II) ions from an aqueous solution using GO/Mn-Fe hybrids in a fixed bed column study. The capability of the hybrid in the Pb removal was examined using a continuous flow fixed bed column which revealed that the hybrid had the maximum adsorption capacity of 172.768 mg/g at a flow rate of 2 mL/min, bed height of 1 cm, and influent concentration of 200 mg/L. The breakthrough curves obtained from the experiments were examined using three different models, i.e., Bohart-Adams model, Thomas Model, and Yoon-Nelson model, wherein all the models showed high correlation coefficient values. Three consecutive adsorption-desorption cycles in the column yielded regeneration efficiencies of 91.71%, 88.31%, and 85.41%. The column life factor indicated that the fixed bed would have enough capacity to avoid a zero breakthrough time for up to 9 cycles, implying that GO/Mn-Fe could be used as a cheap and efficient adsorbent in the removal of Pb(II) from contaminated water. The adsorption mechanism was postulated based on the characterization of the spent adsorbent by FTIR and SEM. The phenomenon of the adsorption process can be described in accordance with the surface complex formation theory, which suggests that an increase in pH decreases the competition between metal ions and protons, favoring metal ion adsorption. The toxicity of the synthesized hybrid was evaluated on HeLa cells and compared to the toxicity of GO. Increasing the concentration of GO/Mn-Fe hybrid from 50 to 250 g/mL resulted in a decrease in cell viability from 91.90 to 56.52%, whereas increasing the concentration of GO resulted in a decrease in cell viability from 61.59 to 37.19%. The study clearly demonstrates the use of GO/Mn-Fe hybrid as an adsorbent for efficient sequestration of Pb(II) ions with lower environmental toxicity.

Biodegradable Multi-layered Silk Fibroin-PCL Stent for the Management of Cervical Atresia: In Vitro Cytocompatibility and Extracellular Matrix Remodeling In Vivo

Cervical atresia is a rare congenital Müllerian duct anomaly that manifests as the absence or deformed nonfunctional presence of the cervix. Herein, a multi-layered biodegradable stent is fabricated using a homogeneous blend of silk fibroin with polycaprolactone using hexafluoroisopropanol as a common solution. Briefly, a concentric cylinder of 3D honeycomb layer is sandwiched within electrospun sheets for fixing at the cervico-uterine junction to pave the way of cervical reconstruction. An average length of 40 mm with 3 mm diameter is fabricated for the hybrid stent design. SEM evidences an evenly distributed pore architecture of the electrospun layer, and mechanical characterization of stent reveals a tensile strength of 1.7 ± 0.2 MPa, with a Young's modulus of 5.9 ± 0.1 MPa. Physico-chemical characterization confirms the presence of silk fibroin and poly caprolactone within the engineered stent. Following 14 days of pepsin enzymatic degradation, 18% degradation and a contact angle measurement of 97° are observed. In vitro cytocompatibility studies are performed using site-specific primary human cervical squamous, columnar epithelial cells, and human endometrial stromal cells. The study demonstrates non-cytotoxic cells' viability (no significant toxicity), improved cell anchoring, adherence among the stent layers, and proliferation in the 3D microenvironment. Furthermore, in vivo subcutaneous studies in the rodent model indicate that the implanted stent undergoes constructive remodeling, neo-tissue creation, neo-vasculature formation, and re-epithelialization while maintaining patency for 2 months.

IL-10/IL-6 ratio from nasal & oral swab samples, acts as an inflammatory indicator for COVID-19 patients infected with the delta variant

Background

Hyper-inflammatory immune response of SARS-CoV-2 is often characterized by the release of multiple pro-inflammatory cytokines with an impact on the expression of numerous other interleukins (ILs). However, from oral and nasal swab samples the specific quantitative association of the different IL-markers with the disease progression and its relationship with the status of vaccination remains unclear.

Materials and methods

Patients' combined oral and nasal swab samples were collected from both non-vaccinated and double-vaccinated individuals with high (Ct value < 25) and low (Ct value > 30) viral loads, along with uninfected donors. None of the patients were critically ill, or needed ICU support. The expression of different cytokines (IL6, IL10, IL1B, IFNG) and mucin (MUC5AC, MUC1) markers were assessed between different groups by qRT-PCR. The important cytokine markers differentiating between vaccinated and non-vaccinated patients were identified by PCA.

Conclusion

IL6 expression was higher in non-vaccinated COVID-19 patients infected with delta-variant irrespective of their viral-load compared to uninfected individuals. However, in double-vaccinated patients, only in high viral-load patients (Ct value < 25), IL6 expression increased. In high viral-load patients, irrespective to their vaccination status, IL10 expression was lower compared to the uninfected control group. Surprisingly, IL10 expression was lower in double-vaccinated patients with Ct value > 30. IL1B, and IFNG expression remained unaltered in uninfected and infected individuals. However, MUC5AC expression was lower in non-vaccinated patients with Ct value < 25 compared to control group. Our study unveiled that IL10/IL6 ratio can be used as a biomarker for COVID-19 patients upon proper establishment of it in a clinical setting.

Synthesis and characterization of two self-assembled [Cu6Gd3] and [Cu5Dy2] complexes exhibiting the magnetocaloric effect, slow relaxation of magnetization, and anticancer activity

Two new paths for coordination driven self-assembly reactions under the binding support of 2-((1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H₂L) have been discovered from the reactions of Cu(ClO₄)₂·6H₂O, NEt₃ and GdCl₃/DyCl₃·6H₂O in MeOH/CHCl₃ (2 : 1) medium. A similar synthetic protocol is useful to provide two different types of self-aggregated molecular clusters [Cu₆Gd₃(L)₃(HL)₃(μ₃-Cl)₃(μ₃-OH)₆(OH)₂]ClO₄·4H₂O (1) and [Cu₅Dy₂(L)₂(HL)₂(μ-Cl)₂(μ₃-OH)₄(ClO₄)₂(H₂O)₆](ClO₄)₂·2NHEt₃Cl·21H₂O (2). The adopted reaction procedure established the importance of the HO^- and Cl^- ions in the mineral-like growth of the complexes, derived from solvents and metal ion salts. In the case of complex 1, one Gd^III center has been trapped at the central position of the core upheld by six μ₃-OH and three μ₃-Cl groups, whereas for complex 2 one Cu^II center was trapped using four μ₃-hydroxo and two μ-chlorido groups. The magnetothermal behavior of 1 has been examined for a magnetocaloric effect of -ΔS_m = 11.3 J kg^-1 K^-1 at 2 K for ΔH = 7 T, whereas the magnetic susceptibility measurements of 2 showed slow magnetic relaxation with U_eff = 15.8 K and τ₀ = 9.8 × 10^-7 s in zero external dc field. Cancer cell growth inhibition studies proved the potential of both the complexes with interestingly high activity for the Cu₆Gd₃ complex against human lung cancer cells. Both complexes 1 and 2 also exhibited DNA and human serum albumin (HSA) binding abilities in relation to the involved binding sites and thermodynamics.

Bone mineral density, vertebral fractures and trabecular bone score in primary ovarian insufficiency

PURPOSE

Bone health in primary ovarian insufficiency (POI) is under-investigated. We assessed patients with spontaneous POI for vertebral fractures (VFs) and related parameters of bone health.

METHODS

70 cases with spontaneous POI (age 32.5 ± 7.0 years) and an equal number of controls were assessed for BMD, TBS, and VFs. BMD at the lumbar-spine (L1-L4), left hip, non-dominant forearm, and TBS (iNsight software) were measured on a dual-energy X-ray absorptiometry (DXA) machine. VFs were assessed by Genant's classification. Serum FSH, LH, estradiol, T4, TSH, iPTH, serum 25(OH)D, total calcium, and inorganic phosphorus were measured.

RESULTS

BMD at the lumbar-spine, hip and forearm was reduced by 11.5%, 11.4% and 9.1% in POI as compared to controls (P < 0.001). Degraded or partially degraded microarchitecture on TBS was observed in 66.7% of patients and 38.2% of controls (P = 0.001). 15.7% of the POI patients had VFs, compared to 4.3% of controls (P = 0.045). Age, duration of amenorrhea and duration of HRT use were the significant predictors of TBS (P < 0.01). Serum 25(OH)D was the significant determinant of VFs. TBS abnormalities were higher in patients with POI and VFs. BMD was not significantly different in patients with and without VFs.

CONCLUSION

Thus, lumbar-spine osteoporosis, impaired TBS and VFs were present in 35.7%, 66.7% and 15.7% of patients with spontaneous POI in their early third decade. This indicates need for rigorous investigations for impaired bone health in these young patients and management with HRT, vitamin-D, and possible need for bisphosphonate therapy.

Screening for cardiac allograft rejection among heart transplant recipients using an electrocardiogram-based deep learning model

Background

Current approaches utilizing non-invasive methods to screen for cardiac allograft rejection (gene expression profiling and cell free DNA) have yet to be broadly integrated into heart transplant management and have shown limited discrimination (AUCs of 0.68 and 0.77, respectively). Changes in the electrocardiogram (ECG) have been reported at the time of severe cardiac rejection, including low voltages and conduction abnormalities. It remains unknown if subtle ECG changes correlating with cardiac allograft rejection can be detected earlier using machine learning methods.

Purpose

We sought to develop an artificial intelligence (AI) model to detect cardiac allograft rejection based on the 12 lead ECG.

Methods

We identified all patients who underwent a heart transplant at 3 hospital sites within a single health system from Jan 1998 through Apr 2021 and extracted digital 12-lead ECG data as well as endomyocardial biopsy pathology results from the electronic medical record. We partitioned our data into a training (80%), validation (10%), and test set (10%) based on a group stratification sampling. Each patient was present in only one set and each set had a positivity rate of 2.6% with 6,074/758/758 ECGs belonging to 1,146/140/141 unique patients in each set respectively. Cardiac allograft rejection was defined as moderate or severe acute cellular rejection based on International Society for Heart and Lung Transplantation (ISHLT) guidelines. A convolutional neural network, using the 12-lead ECG data as input, was trained with hyperparameter optimization for regularization, learning rate adjustments, and class weights. Model performance metrics were based on the test data and estimated using the final model architecture.

Results

1,587 heart transplant recipients who had at least one endomyocardial biopsy were evaluated for inclusion. We limited our sample to ECGs performed within 30 days of the biopsy date (7,590 ECGs, representing 1,425 unique patients). Our study population had a median age of 55.8 years and 28.7% were female. The median number of ECG-biopsy pairs per patient was 5. The majority of endomyocardial biopsy results were classified as none or mild rejection (97.1%), and 2.9% had moderate/severe rejection. The ECG-based AI model detected cardiac allograft rejection with an area under the receiver operative curve (AUC) of 0.84 in the test set. The sensitivity, specificity, positive and negative predictive values were 95%, 52.6%. 5.2% and 99.7% respectively.

Conclusions

An AI-ECG model appears to outperform novel non-invasive laboratory tests (gene expression profiling and cell free DNA) for detecting cardiac allograft rejection and does not require a blood draw or the additional complexities surrounding sample processing. This model relies on a readily available and relatively inexpensive test, the ECG. In addition, AI predictions can be made available within a few minutes following ECG acquisition.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Mayo Clinic

Vertebral fractures, trabecular bone score and their determinants in chronic hypoparathyroidism

PURPOSE

Patients with hypoparathyroidism are at risk of vertebral fractures (VFs) despite high bone mineral density (BMD). We investigated this paradox by assessing trabecular bone score (TBS) and hip structural analysis (HSA) in non-surgical chronic hypoparathyroidism (cHypoPT) with and without VFs.

METHODS

152 cHypoPT patients (age 40.2 ± 13.4 years, M: F = 81:71) with a median follow-up of 8 (2-13) years were assessed for BMD, VFs, TBS, and HSA and compared with 152 healthy controls. VFs at T₇-L₄ were assessed by Genant's method. Average serum total calcium and phosphorus during follow-up were assessed.

RESULTS

The lumbar spine and hip BMD were higher by 25.4 and 13.4% in cHypoPT than controls (P < 0.001). Paradoxically, VFs (30.9 vs.7.9%), including multiple (12.5 vs. 2.6%) were higher in cHypoPT (P < 0.001). Though overall average TBS (1.411 ± 0.091) was normal in cHypoPT, 25.4% of the females had subnormal TBS, more in post than pre-menopausal women (52.3 vs. 14%, P = 0.002) and as compared to males (6.1%, P = 0.001). TBS correlated with menopausal status and follow-up serum calcium-phosphorus product. For every gm/cm² rise in BMD, TBS increase was only 0.227 in cHypoPT compared to 0.513 in controls. Frequency of VFs increased with declining TBS (P = 0.004). HSA was comparable between cHypoPT with and without VFs. 23.4% of cHypoPT with VFs had subnormal TBS.

CONCLUSION

31% of cHypoPT patients had VFs. TBS indicated degraded bone microarchitecture in 50% of the post-menopausal cHypoPT women. However, TBS has limitations to detect abnormal bone microarchitecture in cHypoPT as only one-fourth of patients with VFs showed low TBS.

COVID-19 pandemic: the delta variant, T-cell responses, and the efficacy of developing vaccines

Background

The mayhem COVID-19 that was ushered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) was declared pandemic by the World Health Organization in March 2020. Since its initial outbreak in late 2019, the virus has affected hundreds of million adults in the world and killing millions in the process. After the approval of newly developed vaccines, severe challenges remain to manufacture and administer them to the adult population globally in quick time. However, we have witnessed several mutations of the virus leading to ‘waves’ of viral spread and mortality. WHO has categorized these mutations as variants of concern (VOCs) and variants of interest (VOIs). The mortality due to COVID-19 has also been associated with various comorbidities and improper immune response. This has created further complications in understanding the nature of the SARS-CoV2–host interaction that has fuelled doubts in the efficacy of the approved vaccines. Whether there is requirement of booster dose and whether the impending wave could affect the children are some of the hotly debated topics.

Materials and Methods

A systematic literature review of PubMed, Medline, Scopus, Google Scholar was utilized to understand the nature of Delta variant and how it alters our T-cell responses and cytokine production and neutralizes vaccine-generated antibodies.

Conclusion

In this review, we discuss the variants of SARS-CoV2 with specific focus on the Delta variant. We also specifically review the T-cell response against the virus and bring a narrative of various factors that may hold the key to fight against this marauding virus.

Piecewise Isothermal Nucleic Acid Testing (PINAT) for Infectious Disease Detection with Sample-to-Result Integration at the Point-of-Care

We developed a piecewise isothermal nucleic acid test (PINAT) as a platform technology for diagnosing pathogen-associated infections, empowered by an illustrative novel methodology that embeds an exclusive DNA-mediated specific probing reaction with the backbone of an isothermal reverse transcription cum amplification protocol for detecting viral RNA. In a point-of-care format, this test is executable in a unified single-step, single-chamber procedure, leading to seamless sample-to-result integration in an inexpensive, scalable, pre-programmable, and customizable portable device, with mobile-app-integrated interpretation and analytics involving minimal manually operative procedures. The test exhibited a high sensitivity and specificity of detection when assessed using 200 double-blind patient samples for detecting SARS-CoV-2 infection by the Indian Council of Medical Research (ICMR), and subsequently using 170 double-blind patient samples in a point-of-care format outside controlled laboratory settings as performed by unskilled technicians in an organized clinical trial. We also established its efficacy in detecting Influenza A infection by performing the diagnosis at the point of collection with uncompromised detection rigor. The envisaged trade-off between advanced laboratory-based molecular diagnostic procedures and the elegance of common rapid tests renders the method ideal for deployment in resource-limited settings towards catering the needs of the underserved.

Calcitriol and Retinoic acid antagonize each other to suppress the production of IL-9 by Th9 cells

Distinct T helper cells, including Th9 cells help maintain homeostasis in the immune system. Vitamins play pivotal role in the immune system through many mechanisms, including regulating the differentiation of T helper cells. Calcitriol (1,25-dihydroxyvitamin D3) and retinoic acid possess hormone-like properties and are the bioactive metabolites of vitamin D and A, respectively, that signal through heterodimers containing the common retinoid X receptor. In contrast to individual treatment with the vitamins that significantly attenuates IL-9 production from Th9 cells, Th9 cells treated with both vitamins demonstrated IL-9 production similar to untreated Th9 cells. This is associated with reciprocal expression of PU.1 and Foxp3. While the recruitment of PU.1 was significantly impaired to the Il9 gene in the presence of calcitriol or retinoic acid in Th9 cells, addition of both vitamins together increased the recruitment of PU.1 to the Il9 gene. Calcitriol and retinoic acid together impaired the recruitment of HDAC1 to the Il9 gene without impacting Gcn5 recruitment. Importantly, retinoic acid negated the effect of calcitriol and impaired the binding of VDR on the Il9 gene by dampened VDR-RXR formation. Collectively, our data show that calcitriol and retinoic acid antagonize each other to regulate the differentiation of Th9 cells.

The First Reported Case of COVID-19 Myocarditis Managed with Biventricular Impella Support

Introduction

SARS-CoV-2, responsible for COVID-19, is a pandemic that has taken the world by storm. We present the only contemporary reported case of COVID-19 myocarditis leading to recovery with utilization of biventricular impella for temporary mechanical circulatory support. No cases have been reported regarding utilization of Bi-V impella as therapy for management of SARS-CoV-2..

Case Report

We present a 35 year old-woman with history of systemic sclerosis who was found to have 5 days of generalized malaise associated with fevers and cough. On arrival she was found tachycardic at 112 bpm and febrile 101.8 F. She tested positive for COVID-19 via nasal CPR. Cardiac enzymes were found elevated on admission with troponin T elevated at 0.28. On day two of hospitalization patient had spontaneous PEA arrest secondary to hypoxemia. Transthoracic echocardiogram(TTE) revealed EF <10% and RV impairment which compare to prior which had normal ejection fraction. Labs showed elevated lactic acidosis of 10. Invasive hemodynamics assessment RA 21 mmHg, PA 32/23(mean 26 mmHg) and PCWP 18 mmHg. Calculated PAPi 0.76, CO 2.1 L/min and CI of 1.2 L/min/m^2. Decision was made to place right and left sided ventricular impellas for mechanical circulatory support. She was started on IVIG for COVID-19 myocarditis along with remdesivir and solumedrol. After two weeks of continuous temporary mechanical circulatory support(TMCS), patient hemodynamics improved and she was able to be weaned from her need for TMCS. Repeat echocardiogram demonstrated recovery and remodeling with an LVEF of 60% and no significant valvular disease. She was discharge home at day 23 with no neurological deficit.

Summary

The use of biventricular continuous microaxial flow devices during acute COVID-19 myocarditis is key to allow ventricular rest and optimal offloading without the increased risk of surgically placed TMCS such as Centrimag or VA or VV ECMO. With recent emergency use by the FDA, its wide adaptation remains sparse. Our case demonstrates a unique approach to management of COVID-19 myocarditis. It is the only reported case in the literature utilizing biventricular Impella devices for circulatory support without the concurrent use of ECMO. Due to the success in this patient, this promising approach warrants continued investigation in the management of COVID myocarditis and cardiogenic shock.

Mechanical properties of cell- and microgel bead-laden oxidized alginate-gelatin hydrogels

3D-printing technologies, such as biofabrication, capitalize on the homogeneous distribution and growth of cells inside biomaterial hydrogels, ultimately aiming to allow for cell differentiation, matrix remodeling, and functional tissue analogues. However, commonly, only the mechanical properties of the bioinks or matrix materials are assessed, while the detailed influence of cells on the resulting mechanical properties of hydrogels remains insufficiently understood. Here, we investigate the properties of hydrogels containing cells and spherical PAAm microgel beads through multi-modal complex mechanical analyses in the small- and large-strain regimes. We evaluate the individual contributions of different filler concentrations and a non-fibrous oxidized alginate-gelatin hydrogel matrix on the overall mechanical behavior in compression, tension, and shear. Through material modeling, we quantify parameters that describe the highly nonlinear mechanical response of soft composite materials. Our results show that the stiffness significantly drops for cell- and bead concentrations exceeding four million per milliliter hydrogel. In addition, hydrogels with high cell concentrations (≥6 mio ml^-1) show more pronounced material nonlinearity for larger strains and faster stress relaxation. Our findings highlight cell concentration as a crucial parameter influencing the final hydrogel mechanics, with implications for microgel bead drug carrier-laden hydrogels, biofabrication, and tissue engineering.

Calcitriol attenuates TLR2/IL-33 signaling pathway to repress Th9 cell differentiation and potentially limits the pathophysiology of rheumatoid arthritis

There is limited information regarding the TLR2 signaling pathway involved in Th9 cell differentiation. The role of calcitriol in regulating TLR2-mediated Th9 cell development is unknown. Thus, we aimed to unravel the TLR2 signaling pathway in Th9 cells and its regulation by calcitriol. We have used n = 5-6 animals for each murine experiment. Human studies involved five healthy volunteers. Moreover, ten healthy individuals and ten RA patients were included in the study. Murine and human Th9 cells were treated with Calcitriol (100 nM) and Pam₃CSK₄ (2 µg/mL). The number of IL-9+ve cells was determined by flow cytometry. Real-time PCR was used to assess the gene expression. Serum 25(OH)D₃ levels were determined by HPLC. We observed that TLR2 signals via IL-33/ST2 in Th9 cells. Increased TLR2 expression associated with increased IL9 expression and augmented disease severity in RA patients. Calcitriol attenuated TLR2 signaling in murine and human Th9 cells. Low serum vitamin D3 level negatively associated with increased IL-9 and TLR2 expression and disease severity in RA patients. Our data suggest a potential role of calcitriol to ameliorate the disease severity of RA patients.

Calcitriol Regulates the Differentiation of IL-9-Secreting Th9 Cells by Modulating the Transcription Factor PU.1

Vitamin D can modulate the innate and adaptive immune system. Vitamin D deficiency has been associated with various autoimmune diseases. Th9 cells are implicated in the pathogenesis of numerous autoimmune diseases. Thus, we investigated the role of calcitriol (active metabolite of vitamin D) in the regulation of Th9 cell differentiation. In this study, we have unraveled the molecular mechanisms of calcitriol-mediated regulation of Th9 cell differentiation. Calcitriol significantly diminished IL-9 secretion from murine Th9 cells associated with downregulated expression of the Th9-associated transcription factor, PU.1. Ectopic expression of VDR in Th9 cells attenuated the percentage of IL-9-secreting cells. VDR associated with PU.1 in Th9 cells. Using a series of mutations, we were able to dissect the VDR domain involved in the regulation of the Il9 gene. The VDR-PU.1 interaction prevented the accessibility of PU.1 to the Il9 gene promoter, thereby restricting its expression. However, the expression of Foxp3, regulatory T cell-specific transcription factor, was enhanced in the presence of calcitriol in Th9 cells. When Th9 cells are treated with both calcitriol and trichostatin A (histone deacetylase inhibitor), the level of IL-9 reached to the level of wild-type untreated Th9 cells. Calcitriol attenuated specific histone acetylation at the Il9 gene. In contrast, calcitriol enhanced the recruitment of the histone modifier HDAC1 at the Il9 gene promoter. In summary, we have identified that calcitriol blocked the access of PU.1 to the Il9 gene by reducing its expression and associating with it as well as regulated the chromatin of the Il9 gene to regulate expression.

Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development

Mechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatio-temporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.

Size-dependent cellular uptake and TLR4 attenuation by gold nanoparticles in lung adenocarcinoma cells

AIM

To elucidate uptake mechanisms and immunomodulatory potential of differently sized gold nanoparticles (GNPs) in lung adenocarcinoma cells (A549) to enable their use as an adjunct therapy for treating inflammation-linked lung cancer.

METHODS

Internalization of the synthesized (5, 15 and 30 nm) GNPs by various endocytosis pathways was determined. Immunomodulatory mechanisms induced by differently sized GNPs in A549 cells in the presence of TLR4 and TLR9 ligands were evaluated.

RESULTS

GNPs were size-dependently internalized efficiently by A549 cells. Various sized GNPs downregulated the expression of proinflammatory signaling molecules (5 nm most potent). Mechanistically, 5-nm GNPs attenuated TLR4 signaling by downregulating TLR4 expression in A549 cells.

CONCLUSION

Our study suggests the use of immunomodulatory GNPs as an adjunct therapy against inflammation-linked lung cancer.

Standardized microgel beads as elastic cell mechanical probes

Cell mechanical measurements are gaining increasing interest in biological and biomedical studies. However, there are no standardized calibration particles available that permit the cross-comparison of different measurement techniques operating at different stresses and time-scales. Here we present the rational design, production, and comprehensive characterization of poly-acrylamide (PAAm) microgel beads mimicking size and overall mechanics of biological cells. We produced mono-disperse beads at rates of 20-60 kHz by means of a microfluidic droplet generator, where the pre-gel composition was adjusted to tune the beads' elasticity in the range of cell and tissue relevant mechanical properties. We verified bead homogeneity by optical diffraction tomography and Brillouin microscopy. Consistent elastic behavior of microgel beads at different shear rates was confirmed by AFM-enabled nanoindentation and real-time deformability cytometry (RT-DC). The remaining inherent variability in elastic modulus was rationalized using polymer theory and effectively reduced by sorting based on forward-scattering using conventional flow cytometry. Our results show that PAAm microgel beads can be standardized as mechanical probes, to serve not only for validation and calibration of cell mechanical measurements, but also as cell-scale stress sensors.

A Decade of Th9 Cells: Role of Th9 Cells in Inflammatory Bowel Disease

T helper cell subsets play a critical role in providing protection against offending pathogens by secreting specific cytokines. However, unrestrained T helper cell responses can promote chronic inflammation-mediated inflammatory diseases. Dysregulated T helper cell responses have been suggested to be involved in the pathogenesis of multiple inflammatory diseases, including allergic airway inflammation, rheumatoid arthritis, and inflammatory bowel disease (IBD) among others. Aberrant pro-inflammatory responses induced by Th1, Th2, and Th17 subsets are known to trigger IBD. IBD is a chronic inflammatory disease characterized by weight loss, diarrhea, pain, fever, and rectal bleeding. It poses a major health burden worldwide owing to the increased risk of colorectal cancer development. Despite numerous therapeutic advancements, IBD still remains a major health burden due to the inefficiency of the conventional therapies. Recently, IL-9-secreting Th9 cells are known to be involved in the pathogenesis of IBD. However, the role of Th9 cells and their secretory cytokine IL-9 in IBD is unclear. The functional relevance of Th9 cells is also relatively understudied in IBD. Thus, investigating the actual role of various T helper cell subsets including Th9 cells in IBD is essential to develop novel therapies to treat IBD. Here, we highlight the role of Th9 cells in promoting IBD. We discuss the mechanisms that might be employed by Th9 cells and IL-9 in promoting IBD and thereby propose potential targets for the treatment of Th9 cell-mediated IBD.

Shoulder Periarthritis and its Imaging Features in Patients with Type 1 Diabetes Mellitus

Aim: There is limited information on periarthritis/adhesive capsulitis of the shoulder (ACS) in patients with type-1-diabetes mellitus (T1D). We assessed the prevalence and characteristics of ACS in patients with type-1-diabetes mellitus.

Methods: Consecutive 267 patients attending 'Diabetes of Young Clinic' were screened for ACS. Those with clinical features of ACS were further assessed by 'shoulder pain and disability index' (SPADI), radiograph and MRI of the shoulder. The average glycemic status (HbA1c) during preceding 2 years was assessed in patients with and without ACS. Controls were age and sex matched healthy subjects (1:1 ratio).

Results: Sixteen of 267 patients (6.0%) with type-1-diabetes had clinical features of ACS, unlike none of the healthy controls (P < 0.001). Internal and external rotation of the shoulders was the most frequently restricted movements in ACS. Thickened coracohumeral ligament and axillary pouch obliteration was characteristic MRI feature, present in 80.0% in 73.3% cases, respectively. Though 14/16 type-1-diabetes patients with ACS were symptomatic, they never reported these complaints in diabetic clinic with the treating physicians. On regression analysis (odds ratio; 95% CI), duration of diabetes (1.1; 1.03-1.17, P < 0.01), retinopathy (3.6; 1.05-12.52, P = 0.04), and limited joint mobility (6.4; 1.88-21.95, P < 0.01) were independent predictors for presence of ACS in type-1-diabetes. The mean HbA1c and lipid levels were comparable in patients with or without ACS.

Conclusions: Six percent of patients with type-1-diabetes had ACS, which can be detected on clinical screening and confirmed by imaging to help initiate early treatment.

Fatigue-Assisted Grain Growth in Al Alloys

Stress-assisted grain growth at room temperature is known for materials with nanocrystalline grains. For larger grain sizes, the grain growth usually takes place at higher homologous temperatures even under stress. Here we report, for the first time, significant grain growth at room temperature under fatigue loading in microcrystalline grains (≥10 μm) in Al 7075. We demonstrate that this grain growth at room temperature is similar to non-uniform grain growth due to grain rotation and coalescence rather than the thermally and the stress-assisted driven grain growth. We show that the grain growth is associated with the formation of a strong near-Cu {112}<111> texture component as a result of fatigue-assisted deformation. These changes in microstructural features (viz., grain size, grain orientations and texture) are fundamentally important in understanding the cyclic crack induced deformation behavior and for predicting the fatigue lifetime in structural materials.

Striking the right immunological balance prevents progression of tuberculosis

INTRODUCTION

Tuberculosis (TB) caused by infection with Mycobacterium tuberculosis (Mtb) is a major burden for human health worldwide. Current standard treatments for TB require prolonged administration of antimycobacterial drugs leading to exaggerated inflammation and tissue damage. This can result in the reactivation of latent TB culminating in TB progression. Thus, there is an unmet need to develop therapies that would shorten the duration of anti-TB treatment and to induce optimal protective immune responses to control the spread of mycobacterial infection with minimal lung pathology.

FINDINGS

Granulomata is the hallmark structure formed by the organized accumulation of immune cells including macrophages, natural killer cells, dendritic cells, neutrophils, T cells, and B cells to the site of Mtb infection. It safeguards the host by containing Mtb in latent form. However, granulomata can undergo caseation and contribute to the reactivation of latent TB, if the immune responses developed to fight mycobacterial infection are not properly controlled. Thus, an optimal balance between innate and adaptive immune cells might play a vital role in containing mycobacteria in latent form for prolonged periods and prevent the spread of Mtb infection from one individual to another.

CONCLUSION

Optimal and well-regulated immune responses against Mycobacterium tuberculosis may help to prevent the reactivation of latent TB. Moreover, therapies targeting balanced immune responses could help to improve treatment outcomes among latently infected TB patients and thereby limit the dissemination of mycobacterial infection.

The insect repellents: A silent environmental chemical toxicant to the health

In recent years, a large number of insect repellents have been developed with the idea of consumer benefits. In addition to already known advantageous application of insect repellents, there is increasing concern about the potential toxicity in environment leading to health caused by random use of these compounds. An increasing number of evidence suggests that insect repellents may trigger undesirable hazardous interactions with biological systems with a potential to generate harmful effects including intermediate metabolites. Biotransformation followed by bioaccumulation (vice e versa) may be an important phenomenon for toxic response of this chemicals. In this review, we have summarized the current state of knowledge on the insect repellent toxicity, including biochemical pathway alteration under in vitro and in vivo conditions considering different classes of organisms, from lower to higher vertebrate. Furthermore, we have tried to incorporate the effects of insect repellent in light of some clinical reports. We hope this review would provide useful information on potential side effects of uncontrolled use of insect repellents.

Systemic innate immune activation in food protein-induced enterocolitis syndrome

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy of infancy whose pathophysiology is poorly understood.

OBJECTIVES

We set out to identify and phenotype allergen-responsive cells in peripheral blood of a cohort of subjects undergoing supervised food challenge for FPIES.

METHODS

We profiled antigen-responsive cells in PBMCs by flow cytometry, and examined cells in whole blood obtained before and after challenge by CyTOF mass cytometry and RNAseq.

RESULTS

Using a CD154-based detection approach, we observed that milk, soy, or rice-responsive T cells, and TNF-α-producing CD154⁺ T cells, were significantly lower in those with outgrown FPIES compared with those with active FPIES. However, levels were within the normal range and were inconsistent with a role in the pathophysiology of FPIES. Profiling of whole blood by CyTOF demonstrated profound activation of cells of the innate immune system after food challenge, including monocytes, neutrophils, natural killer cells, and eosinophils. Activation was not observed in children with outgrown FPIES. We confirmed this pattern of innate immune activation in a larger cohort by RNAseq. Furthermore, we observed pan-T-cell activation and redistribution from the circulation after a positive food challenge but not in those who had outgrown their FPIES.

CONCLUSIONS

Our data demonstrate a compelling role of systemic innate immune activation in adverse reactions elicited by foods in FPIES. Further investigation is needed to identify the mechanism of antigen specificity of adverse reactions to foods in FPIES.

Th9 Cells: New Member of T Helper Cell Family

T Helper cells (CD4+ T cells) constitute one of the key arms of adaptive immune responses. Differentiation of naïve CD4+ T cells into multiple subsets ensure a proper protection against multitude of pathogens in immunosufficient individual. After differentiation, T helper cells secrete specific cytokines that are critical to provide immunity against various pathogens. The recently discovered Th9 cells secrete the pleiotropic cytokine, IL-9. Although IL-9 was cloned more than 25 years ago and characterized as a Th2 cell-specific cytokine, not many studies were carried out to define the function of IL-9. This cytokine has been demonstrated to act on multiple cell types as a growth factor. After the discovery of Th9 cells as an abundant source of IL-9, renewed focus has been generated. In this chapter, I discuss the biology and development of IL-9-secreting Th9 cells. Furthermore, I highlight the role of Th9 cells and IL-9 in health and diseases.

IL-9 Signaling Pathway: An Update

Since the discovery of IL-9 almost three decades back as a growth factor, we have come a long way to understand its pleiotropic functions in the immune system. Despite its many functions, IL-9 still remains as an understudied cytokine. In the last decade, renewed emphasis has been provided to understand the biology of IL-9. Any growth factor or cytokine signals via its cognate receptor to mediate biological functions. In this chapter, we discuss the IL-9 signal transduction in different cell types, which would then exert its distinct functions.

Nanomaterial and toxicity: what can proteomics tell us about the nanotoxicology?

1. In the last few years, a substantial scientific work is focused to identify the potential toxicity of nanomaterials by studying the cellular pathways under in vitro and in vivo conditions. Owing to high surface area to volume ratio nanoparticles (NPs) can pass through cell membranes which might be responsible for creating adverse interactions in biological systems. Simultaneously, researchers are also interested to assess the fate of NP inside the living system, which may lead to altered protein expression as well as protein corona formation. 2. According to published reports, NP-mediated toxicity involves altered cellular system including cell morphology, cell differentiation, cell metabolism, cell mobility, cellular immunity, which is derived from the side effects of nanoformulation and leading to apoptosis and necrosis. These results indicate the existence of potential toxic effect of these particles to human health. 3. The advent of proteomics with sophisticated technical improvement coupled with advanced bioinformatics has led to identify altered proteins due to nanomaterial exposure that could provide a new avenue to biomarker discovery. 4. This review aims to provide the current status of safe production and use of nanomaterials.

Infections in infancy and the presence of antinuclear antibodies in adult life

There has been limited success defining environmental factors important to the development of connective tissue diseases such as systemic lupus erythematosus (SLE). Recent work has suggested that the perinatal environment may be important. To investigate this we measured antinuclear antibodies (ANA) in a general population with well-defined early lives to see whether fetal and infant growth and infections were associated with ANA positivity in adult life. Included in our investigation were 1334 individuals (668 men, 666 women) from the Hertfordshire cohort study. ANA was measured using an ANA ELISA and confirmed using immunofluorescence. We investigated associations between the presence of ANA and early growth and infectious exposure in infancy in men and women combined, but with adjustment for gender throughout. A positive ANA was present in 73 (10.9%) of men and 81 (12.2%) women. Of these, 26 women and 14 men were positive using IF on HEP2 cells. Sharing a bedroom during childhood was associated with a higher risk of being ANA positive (odds ratio (OR), 1.42, 95% confidence interval (CI) 1.00-2.01, P = 0.05). A record of diarrhoeal illness (OR 2.12 95% CI 1.07, 4.23, P = 0.03) and rubella or mumps during the first year of life (OR 16.12, 95% CI 2.92, 88.94, P = 0.001) was also significantly associated with ANA in adult life. Higher ANA titres by Inova ELISA were associated with infections in the first year of life from mumps (2.74-fold higher, 95% CI 0.98, 7.64, P = 0.05) and rubella (3.90-fold higher, 95% CI 1.89, 8.04, P < 0.001). In addition, higher ANA titres were also associated with mumps (1.26-fold higher, 95% CI 1.02, 1.56, P = 0.03) between one and five years of age. Our results suggest that a developing immune system exposed to increased infection is more likely to produce ANA in adult life and perhaps begin the pathological process that leads to SLE.

Essential vitamins for an effective T cell response

Effective adaptive immune responses rely upon appropriate activation of T cells by antigenic peptide-major histocompatibility complex on the surface of antigen presenting cells (APCs). Activation relies on additional signals including co-stimulatory molecules on the surface of the APCs that promote T cell expansion. The immune response is further sculpted by the cytokine environment. However, T cells also respond to other environmental signals including hormones, neurotransmitters, and vitamins. In this review, we summarize the mechanisms through which vitamins A and D impact immune responses, particularly in the context of T cell responses.