AB0787 RECEIVER OPERATING CHARACTERISTIC ANALYSIS OF JOINT INFLAMMATION IN RELATION TO DISEASE ACTIVITY IN RHEUMATOID ARTHRITIS ASSESSED USING A NOVEL COMBINED THERMAL AND ULTRASOUND IMAGING

Background:

A novel combined thermal and ultrasound (CTUS) imaging approach in rheumatoid arthritis (RA) was recently shown to be superior to either imaging modality alone in terms of correlation with the 28-joint disease activity score (DAS28).

Objectives:

To determine the performance of CTUS imaging in identifying RA patients with at least moderate disease activity (DAS28 > 3.2).

Methods:

Bilateral hand (22 joints) thermal and ultrasound (US) imaging was performed. Thermal imaging provides the surface temperature readings at the joints with MAX, AVG and MIN derived per patient by summing the temperature differences with a control temperature, for the respective maximum (Tmax), average (Tavg) and minimum (Tmin) temperatures at each joint. US imaging assesses joint inflammation by summing up the power Doppler (PD) and grey-scale (GS) joint inflammation scores (graded 0-3 at each joint recess) at each joint to obtain the respective total PD and total GS scores per patient. CTUS imaging utilizes data from both thermal and US imaging to derive the MAX (PD), AVG (PD) and MIN (PD) by multiplying MAX, AVG and MIN by a factor of 2 when a patient’s Total PD > median score, which otherwise remained the same as the MAX, AVG and MIN. The results of the imaging parameters were compared between patients with DAS28 ≤ 3.2 and those with DAS28 > 3.2. Sensitivity (Sn), specificity (Sp) and receiver operating characteristic (ROC) curve analysis was performed to determine if the use of CTUS imaging can help identify patients with DAS28 > 3.2.

Results:

In this cross-sectional study, 814 joints from 37 RA patients (75.7% female; 75.7% Chinese; baseline mean disease duration, 30.9 months; baseline mean DAS28, 4.43) were imaged. The mean (SD) values for the CTUS—but not single modality—imaging parameters (Table 1) were all significantly greater among patients with DAS28 > 3.2 versus those with DAS28 ≤ 3.2 (P-values were all <0.01). Based on cut-off levels of (a) MAX (PD) ≥ 94.5, (b) MIN (PD) ≥ 42.3 and (c) AVG (PD) ≥ 64.6 in identifying patients with DAS28 > 3.2, the respective area under the ROC curves (AUCs) (95%CIs) were (a) 0.731 (0.541, 0.921) with Sn = 58.1%; Sp = 100.0%; negative predictive value (NPV) = 31.6%; positive predictive value (PPV) = 100.0%; accuracy = 64.9%, (b) 0.758 (0.591, 0.925) with Sn = 61.3%; Sp = 100.0%; NPV = 33.3%; PPV = 100.0%; accuracy = 67.6% and (c) 0.763 (0.596, 0.931) with Sn = 61.3%; Sp = 100.0%; NPV = 33.3%; PPV = 100.0%; accuracy = 67.6%.

Conclusion:

The severity of joint inflammation as detected by CTUS—but not single modality—imaging parameters were significantly greater among patients with DAS28 > 3.2 versus those with DAS28 ≤ 3.2. For the first time ever, by applying ROC analysis, this has helped to determine cut-off MAX (PD), MIN (PD) and AVG (PD) levels for identifying patients with DAS28 > 3.2; the usefulness of these cut-off levels will require further validation in independent RA cohorts.

Table 1.

Comparison of imaging parameters between patient groups.

Imaging ParameterDAS28 Mean (95% CI)Difference (95% CI)P-valueDAS28 ≤ 3.2DAS28 > 3.2MAX (PD)75.25 (58.8, 91.7)119.5 (101.12, 137.87)-44.25 (-70.49, -18.01)0.0022**MIN (PD)33.72 (25.82, 41.61)57.51 (47.63, 67.39)-23.79 (-37.13, -10.45)0.0012**AVG (PD)50.72 (39.45, 61.98)85.39 (71.89, 98.88)-34.67 (-53.27, -16.07)0.0008***MAX67.38 (50.75, 84.02)82.23 (74.71, 89.75)-14.85 (-34.11, 4.42)0.1268MIN30.27 (22.06, 38.47)40.02 (35.02, 45.03)-9.75 (-22.18, 2.66)0.1198AVG45.45 (33.94, 56.96)59.11 (52.99, 65.23)-13.66 (-29.04, 1.72)0.0801Total PD2.83 (-0.23, 5.9)3.65 (2.71, 4.58)-0.82 (-3.39, 1.77)0.5269Total GS6.67 (1.31, 12.02)6.58 (4.12, 9.04)0.09 (-6.21, 6.38)0.9780

Statistically significant: **P<0.01, ***P<0.001.

Disclosure of Interests:

None declared

The Cytokine Receptor IL-7Rα Impairs IL-2 Receptor Signaling and Constrains the In Vitro Differentiation of Foxp3+ Treg Cells

IL-7 receptor signaling is essential for the generation and maintenance of conventional T cells. Immunosuppressive Foxp3⁺ Treg cells, however, express uniquely low amounts of the IL-7-proprietary IL-7Rα so that they are impaired in IL-7 signaling. Because Treg cells depend on IL-2, the loss of IL-7Rα has been considered irrelevant for Treg cells. In contrast, here, we report that IL-7Rα downregulation is necessary to maximize IL-2R signaling. Although IL-7Rα overexpression promoted IL-7 signaling, unexpectedly, IL-2 signaling was suppressed in the same cells. Mechanistically, we found that γc, which is a receptor subunit shared by IL-7R and IL-2R, directly binds and pre-associates with IL-7Rα, thus limiting its availability for IL-2R binding. Consequently, overexpression of signaling-deficient, tailless IL-7Rα proteins inhibited IL-2R signaling, demonstrating that IL-7Rα sequesters γc and suppresses IL-2R signaling by extracellular interactions. Collectively, these results reveal a previously unappreciated regulatory mechanism of IL-2 receptor signaling that is governed by IL-7Rα abundance.

Innovative CAR-T Cell Therapy for Solid Tumor; Current Duel between CAR-T Spear and Tumor Shield

Novel engineered T cells containing chimeric antigen receptors (CAR-T cells) that combine the benefits of antigen recognition and T cell response have been developed, and their effect in the anti-tumor immunotherapy of patients with relapsed/refractory leukemia has been dramatic. Thus, CAR-T cell immunotherapy is rapidly emerging as a new therapy. However, it has limitations that prevent consistency in therapeutic effects in solid tumors, which accounts for over 90% of all cancer patients. Here, we review the literature regarding various obstacles to CAR-T cell immunotherapy for solid tumors, including those that cause CAR-T cell dysfunction in the immunosuppressive tumor microenvironment, such as reactive oxygen species, pH, O₂, immunosuppressive cells, cytokines, and metabolites, as well as those that impair cell trafficking into the tumor microenvironment. Next-generation CAR-T cell therapy is currently undergoing clinical trials to overcome these challenges. Therefore, novel approaches to address the challenges faced by CAR-T cell immunotherapy in solid tumors are also discussed here.

HIF-1α Mediates Osteoclast-Induced Mandibular Condyle Growth via AMPK Signaling

During the mandibular condylar growth, the absorption of calcified cartilage matrix induced by osteoclasts is crucial for the continuous endochondral osteogenesis. Meanwhile, recent studies showed that subchondral bone resided within the low-oxygen microenvironment, and our previous study revealed that hypoxia-inducible transcription factor 1α (HIF-1α) promoted osteoclastogenesis under hypoxia. However, whether HIF-1α regulates the function of osteoclasts in the mandibular condyle cartilage remains elusive. Our study indicated that severe deformity of the mandibular condyle was displayed in 10-wk-old osteoclast-specific HIF-1α conditional knockout (CKO) mice, accompanied by shortened length of condylar process and disorganized fibrocartilage. In 1-, 2-, and 4-wk-old CKO mice, the size of the hypertrophic layer and chondrocytic layer was significantly thickened. In the chondrocytic layer, chondrocytes were atrophied, showing a form of apoptosis in 4-wk-old CKO mice. Furthermore, an increase in the thickness of the fibrous and proliferating layer was observed in 10-wk-old CKO mice, as well as a significant decrease in that of the chondrocytic and hypertrophic chondrocyte layers. Interestingly, the articular surface of the condylar process abnormally presented a horizontal concave shape, and a disk-like acellular connective tissue appeared. In addition, genetic ablation of HIF-1α blunted cartilage matrix loss by subchondral osteoclast deficiency, resulting in a high subchondral bone mass phenotype, accompanied with a decreased number of blood vessels, alkaline phosphatase staining, and vascular endothelial growth factor (VEGF) expression. Mechanistically, the number of osteoclasts in the center of the condyle in CKO mice was significantly reduced by attenuated expression of adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling. These findings reveal a novel influence of HIF-1α function in osteoclasts on maintenance of osteoclast-induced resorption of calcified cartilage matrix via AMPK signaling, as well as subchondral bone formation through VEGF-dependent angiogenesis in bone marrow.

The Abundance and Availability of Cytokine Receptor IL-2Rβ (CD122) Constrain the Lymphopenia-Induced Homeostatic Proliferation of Naive CD4 T Cells

Lymphopenia-induced homeostatic proliferation (LIP) is a critical mechanism for restoring T cell immunity upon lymphodepleting insults or infections. LIP is primarily driven by homeostatic cytokines, such as IL-7 and IL-15, but not all T cells respond with the same efficiency to homeostatic proliferative cues. Although CD8 T cells vigorously proliferate under lymphopenic conditions, naive CD4 T cells are substantially impaired in their response to homeostatic cytokines, and they fail to fully expand. In this study, we show that the availability of IL-2Rβ (CD122), which is a receptor subunit shared by IL-2 and IL-15, affects both the cytokine responsiveness and the LIP of naive CD4 T cells in the mouse. The enumeration of surface IL-2Rβ molecules on murine naive CD4 and naive CD8 T cells revealed a 5-fold difference in IL-2Rβ abundance. Notably, it was the limited availability of IL-2Rβ that impaired CD4 T cell responsiveness to IL-15 and suppressed their LIP. As such, forced IL-2Rβ expression on CD4 T cells by transgenesis bestowed IL-15 responsiveness onto naive CD4 T cells, which thus acquired the ability to undergo robust LIP. Collectively, these results identify IL-2Rβ availability as a new regulatory mechanism to control cytokine responsiveness and the homeostatic proliferation of murine CD4 T cells.

Aquatic Exercise at Thermoneutral Water Temperature Enhances Antitumor Immune Responses

Despite the broad rehabilitative potential of aquatic exercises, the relationship between aquatic exercise and the immune system has not been fully elucidated to date. In particular, there are few specific and delicate immunological approaches to the effect of water temperature on immunity. Thus, we examined the effect of water temperature on immunity during aquatic exercise. The animal tumor model was adopted to examine the impact of aquatic exercise at thermoneutral temperature (TT; 29°C) on immunity compared with aquatic exercise at body temperature (BT; 36°C). Tumor-bearing mice were made to swim in TT water or in BT water for 3 wk and immune cells and their functional activity were analyzed using FACS. Tumor growth was significantly suppressed in mice that exercised in TT than in BT water. The tumor control correlated with the increased number of NK (2-fold), γδT cells (2.5-fold), NKT (2.5-fold), and cytotoxic CD8⁺ T cells (1.6-fold), which play a critical role in anti-tumor immune responses. Furthermore, the functional activity was dramatically improved in the TT group, showing enhanced production of IFNγ in CD8⁺ T cells compared with the BT group. This study demonstrates that aquatic exercise in TT water may improve protective immune responses more effectively than in BT water. Although the effects of water temperature on immune function need further verification in humans, this study suggests that water temperature in human hydrotherapy may be important for improving immune function.

Specific Inhibition of Soluble γc Receptor Attenuates Collagen-Induced Arthritis by Modulating the Inflammatory T Cell Responses

IL-17 produced by Th17 cells has been implicated in the pathogenesis of rheumatoid arthritis (RA). It is important to prevent the differentiation of Th17 cells in RA. Homodimeric soluble γc (sγc) impairs IL-2 signaling and enhances Th17 differentiation. Thus, we aimed to block the functions of sγc by inhibiting the formation of homodimeric sγc. The homodimeric form of sγc was strikingly disturbed by sγc-binding DNA aptamer. Moreover, the aptamer effectively inhibited Th17 cell differentiation and restored IL-2 and IL-15 signaling impaired by sγc with evidences of increased survival of T cells. sγc was highly expressed in SF of RA patients and increased in established CIA mice. The therapeutic effect of PEG-aptamer was tested in CIA model and its treatment alleviated arthritis pathogenesis with impaired differentiation of pathogenic Th17, NKT1, and NKT17 cells in inflamed joint. Homodimeric sγc has pathogenic roles to exacerbate RA progression with differentiation of local Th17, NKT1, and NKT17 cells. Therefore, sγc is suggested as target of a therapeutic strategy for RA.

[Correlation between peripheral venous oxygen saturation and hemodynamic parameters in patients with pulmonary hypertension]

Objective: To investigate the correlation of peripheral venous oxygen saturation (SpvO(2)) with mixed venous oxygen saturation (SvO(2)), pulmonary vascular resistance (PVR) and cardiac index (CI) in patients with pulmonary hypertension (PH), in order to predict these parameters using SpvO(2) and assess the prognosis of patients. Methods: Hospitalized patients diagnosed with PH by right heart catheterization in the Guangzhou Institute of Respiratory Diseases from July 2015 to October 2016 were retrospectively analyzed. Parameters during the right heart catheterization, including SvO(2,)SpvO(2,)cardiac output (CO) and mean pulmonary arterial pressure (mPAP) were recorded, while CI, PVR and other parameters were indirectly calculated. The correlation between SpvO(2) and SvO(2,)CO, CI, mPAP, PVR and other parameters were respectively analyzed and compared between groups. Results: A total of 77 PH patients were selected, which comprised of 39 males and 38 females. The results revealed that SpvO(2) was correlated positively with SvO(2,)CI and PaO(2) (P<0.05), but negatively with PVR, total pulmonary resistance (TPR), systemic vascular resistance, right atrial diameter and right ventricular diameter (P<0.05). In the group with SpvO(2) <65%, the dilation of the right atrium and right ventricle was more significant, the WHO heart function grade was worse, CI, systemic systolic pressure and mean systemic pressure were lower, and PVR and TPR were higher, as compared to those in the group with SpvO(2) ≥65%. (P<0.05). Conclusions: There was good consistency between SpvO(2) and SvO(2). Furthermore, SpvO(2) could indirectly reflect the CI, PVR and changes in right heart structure of PH patients, providing reference for the clinical prediction of CI and PVR, as well as the prognosis of PH patients, through the use of SpvO(2). Low SpvO(2) indicated a severe condition and poor prognosis.

[Outcomes of severe primary fetal hydrothorax treated by prenatal intervention]

Objective: To investigate the effect of intrauterine intervention on severe primary fetal hydrothorax. Methods: Twelve cases with severe fetal primary hydrothorax who underwent prenatal intervention from January 2014 to December 2017 in Guangdong Women and Children Hospital were retrospectively reviewed. Results: The median gestational age of prenatal diagnosis was 30.8 weeks (24.0-33.0 weeks) . All cases were excluded congenital chromosomal abnormalities by prenatal diagnosis, and had no complications of pregnancy during prenatal diagnosis and had hydrothorax. Three cases (3/12) were right hydrothorax, the other 9 cases (9/12) were bilateral. Thoracoamniotic shunting was performed in 7 cases (7/12) . Thoracentesis was performed in 5 cases (5/12) , and the hydrothorax reappeared soon after operation in 4 cases, shunt placement was performed again. The hydrothorax was dissolved in 2 cases, released in 6 cases.Tube falling off occurred in 1 case,treatment was abandoned in 1 case and intrauterine fetal death happened in 1 case, and 1 case wasn't rechecked by ultrasonic due to premature birth following thoracentesis. In 10 cases who had deliveries, 5 newborns (5/10) were premature, 6 newborns (6/10) underwent assisted mechanical ventilation, 8 newborns (8/10) underwent thoracic close drainage, all of them were discharged when hydrothorax resolved. Conclusions: Antenatal intervention may improve the chance of survival in severe primary fetal hydrothorax. Thoracoamniotic shunting is the first-choice for the primary severe fetal hydrothorax.

Cryo-EM analysis of the T3S injectisome reveals the structure of the needle and open secretin

The bacterial type III secretion system, or injectisome, is a syringe shaped nanomachine essential for the virulence of many disease causing Gram-negative bacteria. At the core of the injectisome structure is the needle complex, a continuous channel formed by the highly oligomerized inner and outer membrane hollow rings and a polymerized helical needle filament which spans through and projects into the infected host cell. Here we present the near-atomic resolution structure of a needle complex from the prototypical Salmonella Typhimurium SPI-1 type III secretion system, with local masking protocols allowing for model building and refinement of the major membrane spanning components of the needle complex base in addition to an isolated needle filament. This work provides significant insight into injectisome structure and assembly and importantly captures the molecular basis for substrate induced gating in the giant outer membrane secretin portal family.

[Analysis of the characteristics of electrocardiogram in patients of different genders with pulmonary hypertension]

Objective: To analyze the characteristics of ECG in patients with pulmonary hypertension(PH) and explore their correlation with pulmonary vascular resistance(PVR), mean pulmonary arterial hypertension(mPAP) and cardiac index(CI). Methods: A total of 186 patients with right heart catheterization were enrolled in the Department of Respiratory of the First Affiliated Hospital of Guangzhou Medical University from August 2015 to October 2017. Patients with normal pulmonary artery pressure, incomplete clinical data and repeated examinations were excluded and there were 101 patients with pulmonary hypertension included. The results of ECG parameters and right heart catheterization were collected to analyze the ECG characteristics of patients with different genders and their correlation with PVR, mPAP and CI. Results: Among all PH patients, the duration of QRS axial in male group was significantly longer than that of the female group [(110.38±15.829) vs. (98.63±18.041) ms, P<0.001], and the S wave amplitude in V5 was significantly higher compared to female group [(1.304±1.356) vs. (0.648±0.663) mv, P<0.001]. Their heart rate-corrected QT interval (QTc), QRS axis, S wave amplitude in Ⅰ, S and R wave amplitude in V1, R/S ratio in V1, S wave amplitude V5, all had a correlation with their PVR and the S wave amplitude in V1 was negatively correlated with PVR (r=-0.441, P<0.001). In the male group, PVR was not correlated with R/S ratio in V1 and S wave amplitude in V5. While PVR in the female group was significantly correlated with QTc, R wave amplitude in V1, R / S ratio in V1. In all PH patients, their P wave duration in Ⅱ, QRS axis and S wave amplitude in Ⅰ, S wave and R wave amplitude in V1, S wave amplitude in V5, QTc, R/S ratio in V1, all had correlations with mPAP (P<0.05). In male group, mPAP was not correlated with QTc, P wave duration in Ⅱ, and the S wave amplitude in V5 (P>0.05). The mPAP in the female group was only related to the S wave and R wave amplitude in V1, and S amplitude in Ⅰ and S wave amplitude in V5 (P<0.05). The CI was positively correlated with the S wave amplitude in V1 (r=0.34, P<0.001), and negatively correlated with the QRS axis (r=-0.219, P=0.04); CI in male group was not correlated with QRS axis(P=0.073), but correlated with QTc (r=-0.296, P=0.044). Conclusion: There were gender differences in QRS duration and S wave amplitude in V5 in patients with pulmonary hypertension. The QRS axis and the S wave amplitude in V1 were related to the heart index. There was a difference in the correlation between ECG and PVR, mPAP and CI in patients of different genders with pulmonary hypertension.

Evaluation of the 3dMDface system as a tool for soft tissue analysis

OBJECTIVES

To evaluate the accuracy of three-dimensional stereophotogrammetry by comparing values obtained from direct anthropometry and the 3dMDface system. To achieve a more comprehensive evaluation of the reliability of 3dMD, both linear and surface measurements were examined.

SETTING AND SAMPLE POPULATION

UCLA Section of Orthodontics. Mannequin head as model for anthropometric measurements.

MATERIAL AND METHODS

Image acquisition and analysis were carried out on a mannequin head using 16 anthropometric landmarks and 21 measured parameters for linear and surface distances. 3D images using 3dMDface system were made at 0, 1 and 24 hours; 1, 2, 3 and 4 weeks. Error magnitude statistics used include mean absolute difference, standard deviation of error, relative error magnitude and root mean square error. Intra-observer agreement for all measurements was attained.

RESULTS

Overall mean errors were lower than 1.00 mm for both linear and surface parameter measurements, except in 5 of the 21 measurements. The three longest parameter distances showed increased variation compared to shorter distances. No systematic errors were observed for all performed paired t tests (P<.05). Agreement values between two observers ranged from 0.91 to 0.99.

CONCLUSIONS

Measurements on a mannequin confirmed the accuracy of all landmarks and parameters analysed in this study using the 3dMDface system. Results indicated that 3dMDface system is an accurate tool for linear and surface measurements, with potentially broad-reaching applications in orthodontics, surgical treatment planning and treatment evaluation.

Soluble γc receptor attenuates anti-tumor responses of CD8+ T cells in T cell immunotherapy

Previous studies have shown that soluble common γ-chain (sγc) modulates CD4⁺ T cell immunity with antagonistic functions in γc cytokine signaling. However, the role of sγc in functional properties of effector CD8⁺ T cells has not been fully defined. In this study, we report a new mechanism by which the anti-tumor activity of mouse CD8⁺ T cells is suppressed in sγc of their own producing. While sγc significantly inhibits cytotoxicity of CD8⁺ T cells, blocking sγc production by genetic modification leads to potentiated effector function of CD8⁺ T cells, establishing persistent CD8⁺ T cells. This is due to the modulation of IL-2 and IL-15 signaling, which is required for expansion and survival of CD8⁺ T cells as well as for optimal cytotoxic activity. More efficient management of tumor growth was achieved by an adoptive transfer of sγc-deficient CD8⁺ T cells than that of wild-type or sγc-overexpressing CD8⁺ T cells. Blocking of IL-2 and IL-15 signaling by sγc attenuates the capacity of CD8⁺ T cells to mount an optimal response to the tumor, with both quantitative and qualitative effects on antigen-specific CD8⁺ T cells. These results could have a critical implication for the generation and survival of optimal effector T cells for adoptive immunotherapy of cancer.

Estimation of dispersion curves of water-loaded structures by using approximated acoustic mass

For coupled structures surrounded by heavy fluids, it is difficult to obtain dispersion curves from an eigenvalue analysis, because the external fluid term in the coupled equation includes transcendental functions for frequency and wavenumber. Thus, in this study, the acoustic mass of the external fluid was approximated as a function of frequency or wavenumber only. The coupled equation can then be used to calculate eigenvalues, and can estimate dispersion curves from an eigenvalue analysis. Because of this assumption, those dispersion curves will contain errors. Accordingly, those errors were evaluated in this study through a comparison with a dispersion curve derived from forced responses. The acoustic mass was also evaluated for a water-loaded plate; this can be formulated theoretically. As a result, the acoustic mass is less sensitive to frequency changes than wavenumber changes, and using the fluid term defined at a low frequency has advantages when estimating the dispersion curve. Finally, the generality of the proposed method was identified through the application for a submerged cylindrical shell.

The function of cancer-shed gangliosides in macrophage phenotype: involvement with angiogenesis

Tumor-derived gangliosides in the tumor microenvironment are involved in the malignant progression of cancer. However, the molecular mechanisms underlying the effects of gangliosides shed from tumors on macrophage phenotype remain unknown. Here, we showed that ganglioside GM1 highly induced the activity and expression of arginase-1 (Arg-1), a major M2 macrophage marker, compared to various gangliosides in bone marrow-derived macrophages (BMDM), peritoneal macrophages and Raw264.7 macrophage cells. We found that GM1 bound to macrophage mannose receptor (MMR/CD206) and common gamma chain (γc). In addition, GM1 increased Arg-1 expression through CD206 and γc-mediated activation of Janus kinase 3 (JAK3) and signal transducer and activator of transcription- 6 (STAT-6). Interestingly, GM1-stimulated macrophages secreted monocyte chemoattractant protein-1 (MCP-1/CCL2) through a CD206/γc/STAT6-mediated signaling pathway and induced angiogenesis. Moreover, the angiogenic effect of GM1-treated macrophages was diminished by RS102895, an MCP-1 receptor (CCR2) antagonist. From these results we suggest that tumor-shed ganglioside is a secretory factor regulating the phenotype of macrophages and consequently enhancing angiogenesis.