Chronic Inflammation Permanently Reshapes Tissue-Resident Immunity in Celiac Disease.

Tissue-resident lymphocytes play a key role in immune surveillance, but it remains unclear how these inherently stable cell populations respond to chronic inflammation. In the setting of celiac disease (CeD), where exposure to dietary antigen can be controlled, gluten-induced inflammation triggered a profound depletion of naturally occurring Vγ4+/Vδ1+ intraepithelial lymphocytes (IELs) with innate cytolytic properties and specificity for the butyrophilin-like (BTNL) molecules BTNL3/BTNL8. Creation of a new niche with reduced expression of BTNL8 and loss of Vγ4+/Vδ1+ IELs was accompanied by the expansion of gluten-sensitive, interferon-γ-producing Vδ1+ IELs bearing T cell receptors (TCRs) with a shared non-germline-encoded motif that failed to recognize BTNL3/BTNL8. Exclusion of dietary gluten restored BTNL8 expression but was insufficient to reconstitute the physiological Vγ4+/Vδ1+ subset among TCRγδ+ IELs. Collectively, these data show that chronic inflammation permanently reconfigures the tissue-resident TCRγδ+ IEL compartment in CeD. VIDEO ABSTRACT.

Conveying the pathogenesis of type 1 diabetes to the blind, low-vision and diverse needs communities through sensory stimulation.

To educate members of the blind, low-vision and diverse needs communities on the pathogenesis of the chronic autoimmune disease, type 1 diabetes, members of our team with research expertise in immune-mediated diseases, participated in the 2023 Monash Sensory Science (MSS) Exhibition. Using QR code linked audio commentary, participants were guided through tactile displays demonstrating normal insulin action in the regulation of blood glucose levels and its vital role in providing energy to tissues, followed by displays describing the various stages of the immune system's aberrant attack and the eventual complete destruction of the insulin producing beta-cells of the pancreatic islets in type 1 diabetes. These models conveyed to the participants the huge effect that this autoimmune-mediated disease has on the quality of life of affected individuals including the subsequent lifelong reliance on insulin injections to maintain glucose homeostasis. This MSS Exhibition provided a unique opportunity for our researchers to engage with under-represented members of the community and to raise awareness about such a debilitating and common autoimmune disease.

Crystal structures of pertussis toxin with NAD+ and analogs provide structural insights into the mechanism of its cytosolic ADP-ribosylation activity.

Bordetella pertussis is the causative agent of whooping cough, a highly contagious respiratory disease. Pertussis toxin (PT), a major virulence factor secreted by B. pertussis, is an AB5-type protein complex topologically related to cholera toxin. The PT protein complex is internalized by host cells and follows a retrograde trafficking route to the endoplasmic reticulum, where it subsequently dissociates. The released enzymatic S1 subunit is then translocated from the endoplasmic reticulum into the cytosol and subsequently ADP-ribosylates the inhibitory alpha-subunits (Gαi) of heterotrimeric G proteins, thus promoting dysregulation of G protein-coupled receptor signaling. However, the mechanistic details of the ADP-ribosylation activity of PT are not well understood. Here, we describe crystal structures of the S1 subunit in complex with nicotinamide adenine dinucleotide (NAD+), with NAD+ hydrolysis products ADP-ribose and nicotinamide, with NAD+ analog PJ34, and with a novel NAD+ analog formed upon S1 subunit crystallization with 3-amino benzamide and NAD+, which we name benzamide amino adenine dinucleotide. These crystal structures provide unprecedented insights into pre- and post-NAD+ hydrolysis steps of the ADP-ribosyltransferase activity of PT. We propose that these data may aid in rational drug design approaches and further development of PT-specific small-molecule inhibitors.

Impedance Response of a Thin Film on an Electrode: Deciphering the Influence of the Double Layer Capacitance.

The different contributions of the interfacial capacitance are identified in the case of passive materials or thin protective coatings deposited on the electrode surface. The method is based on a graphical analysis of the EIS results to determine both the passive-film capacitance in the high-frequency domain and the double-layer capacitance in the low-frequency domain. The proposed analysis is shown to be independent of the physicochemical origins of the frequency dispersion of the interfacial capacitances which results, from an analysis point of view of the experimental results, in the use of a constant-phase element However, for a correct evaluation of the thin-film properties such as its thickness, the high-frequency data must be corrected for the double-layer contribution. In particular, it is shown that if the double-layer capacitance gives a frequency-dispersed response, it is necessary to correct the high-frequency part for the double-layer constant-phase elements. This is first demonstrated on synthetic data and then used for the determination of the thickness of thin oxide film formed on Al in neutral pH solution.

Structure-function analyses of a pertussis-like toxin from pathogenic Escherichia coli reveal a distinct mechanism of inhibition of trimeric G-proteins.

Pertussis-like toxins are secreted by several bacterial pathogens during infection. They belong to the AB5 virulence factors, which bind to glycans on host cell membranes for internalization. Host cell recognition and internalization are mediated by toxin B subunits sharing a unique pentameric ring-like assembly. Although the role of pertussis toxin in whooping cough is well-established, pertussis-like toxins produced by other bacteria are less studied, and their mechanisms of action are unclear. Here, we report that some extra-intestinal Escherichia coli pathogens (i.e. those that reside in the gut but can spread to other bodily locations) encode a pertussis-like toxin that inhibits mammalian cell growth in vitro We found that this protein, EcPlt, is related to toxins produced by both nontyphoidal and typhoidal Salmonella serovars. Pertussis-like toxins are secreted as disulfide-bonded heterohexamers in which the catalytic ADP-ribosyltransferase subunit is activated when exposed to the reducing environment in mammalian cells. We found here that the reduced EcPlt exhibits large structural rearrangements associated with its activation. We noted that inhibitory residues tethered within the NAD+-binding site by an intramolecular disulfide in the oxidized state dissociate upon the reduction and enable loop restructuring to form the nucleotide-binding site. Surprisingly, although pertussis toxin targets a cysteine residue within the α subunit of inhibitory trimeric G-proteins, we observed that activated EcPlt toxin modifies a proximal lysine/asparagine residue instead. In conclusion, our results reveal the molecular mechanism underpinning activation of pertussis-like toxins, and we also identified differences in host target specificity.

A qualitative study on stress, coping strategies and feasibility of music intervention among women with cancer receiving chemotherapy during COVID-19 pandemic in Vietnam.

Breast and gynaecological cancer (BGC) patients receiving chemotherapy may experience high levels of stress during the COVID-19 pandemic. Music interventions may be effective in lowering their stress levels. This study explored stressors, coping strategies, and the feasibility of music interventions among BGC patients in Vietnam. An exploratory qualitative study with individual face-to-face semi-structured interviews was conducted. A convenience sample of BGC patients receiving chemotherapy was recruited from the oncology centre of a public hospital in Vietnam. Twenty patients were interviewed with open-ended questions developed based on the transactional model of stress and coping to explore stress-causing factors and coping strategies and based on guidelines for music therapy practice to explore their music preferences and perceptions. Field notes and interview transcripts were analysed following the qualitative content analysis approach. Two stressor themes were identified: undesirable experiences during treatment and patients' inability to fulfil their own roles and responsibilities. Our findings revealed a new coping strategy-self-realisation of responsibilities towards the family-that is not listed in the transactional model of stress and coping. Future psychological interventions for stress management among BGC patients should focus on raising the patients' awareness of their values and responsibilities towards their families. Three categories of preferred music genres for stress reduction were identified: religious, softly melodic, and revolutionary music. The patients were aware of the positive effects of music and had different musical preferences. This study also explored the acceptance of music interventions and facilitators and barriers to implementing them among BGC patients in Vietnam. The findings suggest that before implementing music interventions, the musical preferences, religions, and beliefs of each individual should be considered to achieve desirable results. Music interventions for BGC patients receiving chemotherapy in Vietnam are feasible. Further intervention studies are needed to evaluate their effectiveness.

Thyroid Peroxidase Antibodies in Infertile Women with Polycystic Ovary Syndrome.

To compare the rate of positive thyroid peroxidase antibodies (TPO Ab) between women with different polycystic ovary syndrome (PCOS) phenotypes and women without PCOS. This is a retrospective cohort study. Women with PCOS at My Duc Hospital between June 1, 2020, and March 27, 2021, were matched with non-PCOS women by age. TPO Ab (cut-off: 34 IU/mL) and thyroid-stimulating hormone (TSH) levels were measured as markers of Hashimoto thyroiditis and thyroid function, respectively. One thousand eight hundred eight infertile women were included, 904 with PCOS (mean age 29.0 ± 3.58 years) and 904 without PCOS (29.1 ± 3.4 years; controls). Women with PCOS had a higher body mass index (22.8 ± 3.84 vs. 19.9 ± 2.23 kg/m2, p < 0.001), but most were not overweight/obese. Rates of positive TPO Ab in women with versus without PCOS were 8.2% and 8.4%, respectively (p = 0.932). Rates of positive TPO Ab in patients with PCOS phenotype A, B, C, or D were not statistically different (7.5%, 2.9%, 20.0%, and 7.8%, respectively). Median TSH concentrations were similar in the PCOS and control groups (1.84 mIU/L vs. 1.78 mIU/L, respectively; p = 0.194). Based on a linear regression model, there was no correlation between either BMI or the estradiol to progesterone ratio and TPO Ab status. In a large population of infertile women with PCOS who were mostly lean patients, rates of positive TPO Ab across all four PCOS phenotypes did not differ significantly from those in women without PCOS. These findings did not support the hypothesis that PCOS is a risk factor for Hashimoto thyroiditis.

T cell receptor recognition of hybrid insulin peptides bound to HLA-DQ8.

HLA-DQ8, a genetic risk factor in type I diabetes (T1D), presents hybrid insulin peptides (HIPs) to autoreactive CD4+ T cells. The abundance of spliced peptides binding to HLA-DQ8 and how they are subsequently recognised by the autoreactive T cell repertoire is unknown. Here we report, the HIP (GQVELGGGNAVEVLK), derived from splicing of insulin and islet amyloid polypeptides, generates a preferred peptide-binding motif for HLA-DQ8. HLA-DQ8-HIP tetramer+ T cells from the peripheral blood of a T1D patient are characterised by repeated TRBV5 usage, which matches the TCR bias of CD4+ T cells reactive to the HIP peptide isolated from the pancreatic islets of a patient with T1D. The crystal structure of three TRBV5+ TCR-HLA-DQ8-HIP complexes shows that the TRBV5-encoded TCR ß-chain forms a common landing pad on the HLA-DQ8 molecule. The N- and C-termini of the HIP is recognised predominantly by the TCR α-chain and TCR ß-chain, respectively, in all three TCR ternary complexes. Accordingly, TRBV5 + TCR recognition of HIP peptides might occur via a 'polarised' mechanism, whereby each chain within the αßTCR heterodimer recognises distinct origins of the spliced peptide presented by HLA-DQ8.

T cell receptor cross-reactivity between gliadin and bacterial peptides in celiac disease.

The human leukocyte antigen (HLA) locus is strongly associated with T cell-mediated autoimmune disorders. HLA-DQ2.5-mediated celiac disease (CeD) is triggered by the ingestion of gluten, although the relative roles of genetic and environmental risk factors in CeD is unclear. Here we identify microbially derived mimics of gliadin epitopes and a parental bacterial protein that is naturally processed by antigen-presenting cells and activated gliadin reactive HLA-DQ2.5-restricted T cells derived from CeD patients. Crystal structures of T cell receptors in complex with HLA-DQ2.5 bound to two distinct bacterial peptides demonstrate that molecular mimicry underpins cross-reactivity toward the gliadin epitopes. Accordingly, gliadin reactive T cells involved in CeD pathogenesis cross-react with ubiquitous bacterial peptides, thereby suggesting microbial exposure as a potential environmental factor in CeD.

Improved versus worsened endocrine function after transsphenoidal surgery for nonfunctional pituitary adenomas: rate, time course, and radiological analysis.

OBJECTIVE: The impact of transsphenoidal surgery for nonfunctional pituitary adenomas (NFAs) on preoperative hypopituitarism relative to the incidence of new postoperative endocrine deficits remains unclear. The authors investigated rates of hypopituitarism resolution and development after transsphenoidal surgery. METHODS: Over a 5-year period, 305 transsphenoidal surgeries for NFAs performed at The California Center for Pituitary Disorders were retrospectively reviewed. RESULTS: Patients with preoperative endocrine deficits (n = 153, 50%) were significantly older (mean age 60 vs 54 years; p = 0.004), more frequently male (65% vs 44%; p = 0.0005), and had larger adenomas (2.4 cm vs 2.1 cm; p = 0.02) than patients without preoperative deficits (n = 152, 50%). Of patients with preoperative endocrine deficits, 53% exhibited symptoms. Preoperative deficit rates were 26% for the thyroid axis; 20% and 16% for the male and female reproductive axes, respectively; 13% for the adrenocorticotropic hormone (ACTH)/cortisol axis, and 19% for the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. Laboratory normalization rates 6 weeks and 6 months after surgery without hormone replacement were 26% and 36% for male and 13% and 13% for female reproductive axes, respectively; 30% and 49% for the thyroid axis; 3% and 3% for the cortisol axis; and 9% and 22% for the IGF-1 axis (p < 0.05). New postoperative endocrine deficits occurred in 42 patients (13.7%). Rates of new deficits by axes were: male reproductive 3% (n = 9), female reproductive 1% (n = 4), thyroid axis 3% (n = 10), cortisol axis 6% (n = 19), and GH/IGF-1 axis 4% (n = 12). Patients who failed to exhibit any endocrine normalization had lower preoperative gland volumes than those who did not (0.24 cm(3) vs 0.43 cm(3), respectively; p < 0.05). Multivariate analyses revealed that no variables predicted new postoperative deficits or normalization of the female reproductive, cortisol, and IGF-1 axes. However, increased preoperative gland volume and younger age predicted the chances of a patient with any preoperative deficit experiencing normalization of at least 1 axis. Younger age and less severe preoperative hormonal deficit predicted normalization of the thyroid and male reproductive axes (p < 0.05). CONCLUSIONS: After NFA resection, endocrine normalization rates in this study varied with the hormonal axis and were greater than the incidence of new endocrine deficits. Low preoperative gland volume precluded recovery. Patient age and the severity of the deficiency influenced the recovery of the thyroid and male reproductive axes, the most commonly impaired axes and most likely to normalize postoperatively. This information can be of use in counseling patients with hypopituitarism who undergo NFA surgery.

Incidence of headache as a presenting complaint in over 1000 patients with sellar lesions and factors predicting postoperative improvement.

INTRODUCTION: Due to the high incidence of headaches and pituitary tumors, neurosurgeons often evaluate patients with benign-appearing sellar lesions and headaches without insight into whether the headache is attributable to the lesion. We sought to evaluate the incidence of headache as a presenting complaint in patients undergoing transsphenoidal surgery for various pathologies and to identify factors predicting postoperative improvement. METHODS: We conducted a 5-year retrospective review of our first 1015 transsphenoidal surgeries since establishing a dedicated pituitary center. RESULTS: Of 1015 patients, 329 (32%) presented with headache. Of these 329 patients, 241 (73)% had headache as their chief complaint. Headache was most common in patients with apoplexy (84%), followed by Rathke's cleft cysts (RCCs) (60%). Multivariate analyses revealed diagnosis (P = 0.001), younger age (P = 0.001), and female gender (P = 0.006) to be associated with headache. Of patients presenting with headaches, 11% reported improvement at 6-week follow-up and 53% improved at 6-month follow-up. Multivariate analyses revealed gross total resection (GTR; P = 0.04) and decreased duration of headache (P = 0.04) to be associated with improvement, while diagnosis, age, gender, lesion size, whether headache was a chief complaint, and location of headache were not associated with improvement (P > 0.05). CONCLUSION: In analyzing over 1000 consecutive patients undergoing transsphenoidal surgery, younger patients, females, and patients with RCCs and apoplexy were more likely to present with headache. Patients who underwent GTR and had shorter duration of headache were more likely to experience headache improvement. This information can be used to counsel patients preoperatively.

Genome Sequences of Mycobacteriophages Luchador and Nerujay.

Luchador and Nerujay are two newly isolated mycobacteriophages recovered from soil samples using Mycobacterium smegmatis. Their genomes are 53,387 bp and 53,455 bp long and have 96 and 97 predicted open reading frames, respectively. Nerujay is related to subcluster A1 phages, and Luchador represents a new subcluster, A14.

Morbidity of repeat transsphenoidal surgery assessed in more than 1000 operations.

UNLABELLED: OBJECT.: While transsphenoidal surgery is associated with low morbidity, the degree to which morbidity increases after reoperation remains unclear. The authors determined the morbidity associated with repeat versus initial transsphenoidal surgery after 1015 consecutive operations. METHODS: The authors conducted a 5-year retrospective review of the first 916 patients undergoing transsphenoidal surgery at their institution after a pituitary center of expertise was established, and they analyzed morbidities. RESULTS: The authors analyzed 907 initial and 108 repeat transsphenoidal surgeries performed in 916 patients (9 initial surgeries performed outside the authors' center were excluded). The most common diagnoses were endocrine inactive (30%) or active (36%) adenomas, Rathke's cleft cysts (10%), and craniopharyngioma (3%). Morbidity of initial surgery versus reoperation included diabetes insipidus ([DI] 16% vs 26%; p = 0.03), postoperative hyponatremia (20% vs 16%; p = 0.3), new postoperative hypopituitarism (5% vs 8%; p = 0.3), CSF leak requiring repair (1% vs 4%; p = 0.04), meningitis (0.4% vs 3%; p = 0.02), and length of stay ([LOS] 2.8 vs 4.5 days; p = 0.006). Of intraoperative parameters and postoperative morbidities, 1) some (use of lumbar drain and new postoperative hypopituitarism) did not increase with second or subsequent reoperations (p = 0.3-0.9); 2) some (DI and meningitis) increased upon second surgery (p = 0.02-0.04) but did not continue to increase for subsequent reoperations (p = 0.3-0.9); 3) some (LOS) increased upon second surgery and increased again for subsequent reoperations (p < 0.001); and 4) some (postoperative hyponatremia and CSF leak requiring repair) did not increase upon second surgery (p = 0.3) but went on to increase upon subsequent reoperations (p = 0.001-0.02). Multivariate analysis revealed that operation number, but not sex, age, pathology, radiation therapy, or lesion size, increased the risk of CSF leak, meningitis, and increased LOS. Separate analysis of initial versus repeat transsphenoidal surgery on the 2 most common benign pituitary lesions, pituitary adenomas and Rathke's cleft cysts, revealed that the increased incidence of DI and CSF leak requiring repair seen when all pathologies were combined remained significant when analyzing only pituitary adenomas and Rathke's cleft cysts (DI, 13% vs 35% [p = 0.001]; and CSF leak, 0.3% vs 9% [p = 0.0009]). CONCLUSIONS: Repeat transsphenoidal surgery was associated with somewhat more frequent postoperative DI, meningitis, CSF leak requiring repair, and greater LOS than the low morbidity characterizing initial transsphenoidal surgery. These results provide a framework for neurosurgeons in discussing reoperation for pituitary disease with their patients.

Factors predicting postoperative hyponatremia and efficacy of hyponatremia management strategies after more than 1000 pituitary operations.

OBJECT: Syndrome of inappropriate antidiuretic hormone secretion-induced hyponatremia is a common morbidity after pituitary surgery that can be profoundly symptomatic and cause costly readmissions. The authors calculated the frequency of postoperative hyponatremia after 1045 consecutive operations and determined the efficacy of interventions correcting hyponatremia. METHODS: The authors performed a retrospective review of 1045 consecutive pituitary surgeries in the first 946 patients treated since forming a dedicated pituitary center 5 years ago. Patients underwent preoperative and daily inpatient sodium checks, with outpatient checks as needed. RESULTS: Thirty-two patients presented with hyponatremia; 41% of these patients were symptomatic. Postoperative hyponatremia occurred after 165 operations (16%) a mean of 4 days after surgery (range 0-28 days); 19% of operations leading to postoperative hyponatremia were associated with postoperative symptoms (38% involved dizziness and 29% involved nausea/vomiting) and 15% involved readmission for a mean of 5 days (range 1-20 days). In a multivariate analysis including lesion size, age, sex, number of prior pituitary surgeries, surgical approach, pathology, lesion location, and preoperative hypopituitarism, only preoperative hypopituitarism predicted postoperative hyponatremia (p = 0.006). Of patients with preoperative hyponatremia, 59% underwent medical correction preoperatively and 56% had persistent postoperative hyponatremia. The mean correction rates were 0.4 mEq/L/hr (no treatment; n = 112), 0.5 mEq/L/hr (free water restriction; n = 24), 0.7 mEq/L/hr (salt tablets; n = 14), 0.3 mEq/L/hr (3% saline; n = 20), 0.7 mEq/L/hr (intravenous vasopressin receptor antagonist Vaprisol; n = 22), and 1.2 mEq/L/hr (oral vasopressin receptor antagonist tolvaptan; n = 9) (p = 0.002, ANOVA). While some patients received more than 1 treatment, correction rates were only recorded when a treatment was given alone. CONCLUSIONS: After 1045 pituitary operations, postoperative hyponatremia was associated exclusively with preoperative hypopituitarism and was most efficiently managed with oral tolvaptan, with several interventions insignificantly different from no treatment. Promptly identifying hyponatremia in high-risk patients and management with agents like tolvaptan can improve safety and decrease readmission. For readmitted patients with severely symptomatic hyponatremia, the intravenous vasopressin receptor antagonist Vaprisol is another treatment option.