Pre-existing cross-reactive neutralizing activity against SARS-CoV-2 and seasonal coronaviruses prior to the COVID-19 pandemic (2014-2019) with limited immunity against recent emerging SARS-CoV-2 variants, Vietnam.

OBJECTIVES: SARS-CoV-2 transmission and epidemic potential is related to the population's immunity levels. As such, assessing different regions' preexisting immune responses to SARS-CoV-2 is important to understand the transmission potential of emerging SARS-CoV-2 variants. DESIGN: In 975 serum samples from Vietnam (2014 to 2019), anti-SARS-CoV-2 Immunoglobulin G levels were determined by enzyme-linked immunosorbent assay. Plaque reduction neutralization test (PRNT) was performed using Wuhan strain and variants of concern (VOCs). Cross-reactivity was confirmed by analyzing B-cell receptor (BCR) repertoire sequences and identifying BCR repertoire sequences-derived T-cell epitopes. RESULTS: Overall, 20.9% (n = 76/364) and 9.2% (n = 7) demonstrated SARS-CoV-2 neutralizing activity (PRNT50) against the Wuhan and Alpha strain, respectively. Neutralizing activity against Beta, Gamma, and Delta strains was absent (PRNT50<5) in all samples. Cross-reactive epitopes against SARS-CoV-2 and other coronavirus spike proteins were detected in the N-terminal domain, S2, and receptor-binding domain regions. CONCLUSIONS: Following BCR and major histocompatibility complex analysis, T-cell receptor-recognized epitope motif (TREM) among pathogenic coronaviruses and coronaviruses spike proteins were the top TREM peptide, suggesting that pre-existing immunity against SARS-CoV-2 in Vietnam was due to exposure to common cold coronaviruses. With limited immunity against emerging VOCs, further monitoring, and control of the epidemic, along with COVID-19 vaccine programs against VOCs, are necessary.

Povidone-iodine-induced transient triiodothyronine thyrotoxicosis in a Japanese patient with prolonged habitual gargling: A case report and literature review.

RATIONALE: Iodine-induced hyperthyroidism and triiodothyronine (T3) thyrotoxicosis in patients who routinely gargle with povidone-iodine (PVP-I) gargling solution are rare in Japan. PATIENT CONCERNS: A 50-year-old man presented to our hospital for a close examination of an enlarged thyroid, which was noted during a complete health checkup. The thyroid was slightly enlarged with no palpable nodules. He had an increased appetite but no weight gain. He had been routinely gargling with PVP-I gargling solution 4 times daily for >10 years. He had no history of thyroid disease. DIAGNOSES: Test results revealed suppressed thyroid-stimulating hormone, normal free thyroxine, and increased free triiodothyronine levels, leading to the diagnosis of T3 thyrotoxicosis. INTERVENTIONS: The patient agreed to stop gargling with PVP-I gargle solution. OUTCOMES: The free triiodothyronine and thyroid-stimulating hormone levels returned to normal at 18 and 21 weeks, respectively, after discontinuation of PVP-I gargling. After an improvement in thyroid function, he gained 5 kg in 1 year. LESSONS: To our knowledge, this is the first case report that describes PVP-I gargle-induced T3 thyrotoxicosis in a healthy individual without thyroid disease. In Japan, which is an iodine-sufficient country, considering the possibility of high-dose iodine intake-induced thyrotoxicosis due to long-term PVP-I gargling or other causes is necessary, even in individuals with no history of thyroid disease.

Idiotope-Driven T-Cell/B-Cell Collaboration-Based T-Cell Epitope Prediction Using B-Cell Receptor Repertoire Sequences in Infectious Diseases.

T-cell recognition of antigen epitopes is a crucial step for the induction of adaptive immune responses, and the identification of such T-cell epitopes is, therefore, important for understanding diverse immune responses and controlling T-cell immunity. A number of bioinformatic tools exist that predict T-cell epitopes; however, many of these methods highly rely on evaluating conventional peptide presentation by major histocompatibility complex (MHC) molecules, but they ignore epitope sequences recognized by T-cell receptor (TCR). Immunogenic determinant idiotopes are present on the variable regions of immunoglobulin molecules expressed on and secreted by B-cells. In idiotope-driven T-cell/B-cell collaboration, B-cells present the idiotopes on MHC molecules for recognition by idiotope-specific T-cells. According to the idiotype network theory formulated by Niels Jerne, such idiotopes found on anti-idiotypic antibodies exhibit molecular mimicry of antigens. Here, by combining these concepts and defining the patterns of TCR-recognized epitope motifs (TREMs), we developed a T-cell epitope prediction method that identifies T-cell epitopes derived from antigen proteins by analyzing B-cell receptor (BCR) sequences. This method allowed us to identify T-cell epitopes that contain the same TREM patterns between BCR and viral antigen sequences in two different infectious diseases caused by dengue virus and SARS-CoV-2 infection. The identified epitopes were among the T-cell epitopes detected in previous studies, and T-cell stimulatory immunogenicity was confirmed. Thus, our data support this method as a powerful tool for the discovery of T-cell epitopes from BCR sequences.

Characterization of Metal-Specific T-Cells in Inflamed Oral Mucosa in a Novel Murine Model of Chromium-Induced Allergic Contact Dermatitis.

The element chromium (Cr) is a component of several types of alloys found in the environment, or utilized in dentistry, that may cause intraoral metal contact allergy. However, the pathological mechanism of intraoral Cr allergy remains unclear because there is no established animal model of Cr allergy in the oral mucosa. In this study, we established a novel murine model of Cr-induced intraoral metal contact allergy and elucidated the immune response in terms of cytokine profiles and T-cell receptor repertoire. Two sensitizations with Cr plus lipopolysaccharide solution into the postauricular skin were followed by a single Cr challenge of the oral mucosa to generate the intraoral metal contact allergy model. Histological examination revealed that CD3+ T-cells had infiltrated the allergic oral mucosa one day after exposure to the allergen. The increase in T-cell markers and cytokines in allergic oral mucosa was also confirmed via quantitative PCR analysis. We detected Cr-specific T-cells bearing TRAV12D-1-TRAJ22 and natural killer (NK) T-cells in the oral mucosa and lymph nodes. Our model demonstrated that Cr-specific T-cells and potent NKT-cell activation may be involved in the immune responses of Cr-induced intraoral metal contact allergy.

Type IVb Hypersensitivity Reaction in the Novel Murine Model of Palladium-Induced Intraoral Allergic Contact Mucositis.

Palladium (Pd) is a component of several alloy types that are widely used in our environment, including several dental alloy types that cause adverse reactions such as hypersensitivity in the oral mucosa. However, the pathological mechanism of intraoral Pd allergies remains unclear because its animal model in the oral mucosa has not been established. In this study, we established a novel murine model of Pd-induced allergies in the oral mucosa, and explored the immune response of cytokine profiles and T cell diversity in terms of the T cell receptor. The Pd-induced allergy mouse was generated by two sensitizations with PdCl2, plus a lipopolysaccharide solution into the postauricular skin followed by a single Pd challenge of the buccal mucosa. Significant swelling and pathological features were histologically evident at five days after the challenge, and CD4-positive T cells producing high levels of T helper 2 type cytokines had accumulated in the allergic oral mucosa. Characterization of the T cell receptor repertoire in Palladium allergic mice indicated that Pd-specific T cell populations were limited in V and J genes but were diverse at the clonal level. Our model demonstrated that a Pd-specific T cell population with Th2 type response tendencies may be involved in the Pd-induced intraoral metal contact allergy.

Cross-Reactivity of Intraoral Allergic Contact Mucositis in the Nickel-Sensitized Ear Model of Metal Allergy.

Cross-reactivity of metal allergies can make metal allergy treatment complicated because the background of immune response in cross-reactions remains unknown. In clinical settings, cross-reactivity among several metals has been suspected. However, the precise mechanism of immune response in cross-reactivity is unclear. Two sensitizations with nickel, palladium, and chromium plus lipopolysaccharide solution into the postauricular skin were followed by a single nickel, palladium, and chromium challenge of the oral mucosa to generate the intraoral metal contact allergy mouse model. Results showed that the infiltrating T cells in nickel-sensitized, palladium- or chromium-challenged mice expressed CD8+ cells, cytotoxic granules, and inflammation-related cytokines. Thus, nickel ear sensitization can cause cross-reactive intraoral metal allergy.

Drug-induced sarcoidosis-like reaction three months after BNT162b2 mRNA COVID-19 vaccination: A case report and review of literature.

BACKGROUND: A 70-year-old man with hepatitis C virus-related recurrent hepatocellular carcinoma was admitted for further diagnosis of a 1 cm iso-hyperechoic nodule in segment (S) 5. CASE SUMMARY: Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) revealed the nodule in S5 with a defect at the hepatobiliary phase, hyperintensity on diffusion weighted imaging (DWI) and hypointensity on apparent diffusion coefficient (ADC) map. Contrast-enhanced computed tomography revealed hypervascularity at the early phase, and delayed contrast-enhancement was observed at the late phase. Contrast-enhanced ultrasound (US) revealed incomplete defect at the late vascular phase. Inflammatory liver tumor, lymphoproliferative disease, intrahepatic cholangiocarcinoma (small duct type) and bile duct adenoma were suspected through the imaging studies. US guided biopsy, however, showed a noncaseating hepatic sarcoid-like epithelioid granuloma (HSEG), and histopathological analysis disclosed spindle shaped epithelioid cells harboring Langhans-type multinucleated giant cells. One month after admission, EOB-MRI signaled the disappearance of the defect at the hepatobiliary phase, of hyperintensity on DWI, of hypointensity on ADC map, and no stain at the early phase. CONCLUSION: That the patient had received BNT162b2 messenger RNA (mRNA) coronavirus disease 2019 vaccination 3 mo before the occurrence of HSEG, and that its disappearance was confirmed 4 mo after mRNA vaccination suggested that the drug-induced sarcoidosis-like reaction (DISR) might be induced by the mRNA vaccination. Fortunately, rechallenge of drug-induced DISR with the third mRNA vaccination was not confirmed.

Usefulness of a mobile phone application for respiratory rate measurement in adult patients.

AIMS: Respiratory rate measurement is one of the core nursing skills for early detection of deterioration of a patient's condition. Nevertheless, it is sometimes bothersome to visually measure respiratory rate over 1 min. Respiratory rate measurement using a mobile phone application "RRate" has been reported to be accurate and completed in a short time. However, it has only been investigated in children. The aim of this study was to validate the "RRate" compared with the 1-min method in adult patients. METHODS: This was a cross-sectional study in the setting of a nursing school. Videos of the movement of the thorax during respiration of adult patients were made. Nursing students watched these videos and measured respiratory rate with each method. Bland-Altman analysis was used to calculate bias and limits of agreement. The times taken for the measurements were compared using a t test. RESULTS: A total of 59 nursing students participated. When compared to the reference measurement, the one measured using "RRate" and the one measured over 1 min showed a bias of 0.40 breaths per minute and 0.65 breaths per minute, limits of agreement of -2.86 to 3.67 breaths per minute and -2.11 to 3.41 breaths per minute, respectively. The mean measurement time for "RRate" was 22.8 s (95% CI 13.9-36.6), which was significantly shorter than the 65.8 s (95% CI 61.0-73.2) for the measurement over 1 min (p < .001). CONCLUSIONS: Respiratory rate can be measured accurately in a shorter time using a mobile phone application in adult patients.

Pharmacological MEK inhibition promotes polyclonal T-cell reconstitution and suppresses xenogeneic GVHD.

Rapid immune reconstitution without developing graft-versus-host disease (GVHD) is required for the success of allogeneic hematopoietic stem cell transplantation. Here, we analyzed the effects of pharmacological MEK inhibition on human polyclonal T-cell reconstitution in a humanized mouse GVHD model utilizing deep sequencing-based T-cell receptor (TCR) repertoire analysis. GVHD mice exhibited a skewed TCR repertoire with a common clone within target organs. The MEK inhibitor trametinib ameliorated GVHD and enabled engraftment of diverse T-cell clones. Furthermore, trametinib also ameliorated GVHD sparing diverse T cell repertoire, even when it was given from day 15 through 28. Although tacrolimus also reduced development of GVHD, it disturbed diverse T cell reconstitution and resulted in skewed TCR repertoire. Thus, trametinib not only suppresses GVHD-inducing T cells but also promotes human T cell reconstitution in vivo, providing a novel rationale for translational studies targeting human GVHD.

Skewing of the B cell receptor repertoire in myalgic encephalomyelitis/chronic fatigue syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by fatigue and post-exertional malaise, accompanied by various signs of neurological and autonomic dysfunction. ME/CFS is often triggered by an infectious episode and associated with an aberrant immune system. Here we report that ME/CFS is a disorder characterized by skewed B cell receptor gene usage. By applying a next-generation sequencing to determine the clone-based IGHV/IGHD/IGHJ repertoires, we revealed a biased usage of several IGHV genes in peripheral blood B cells from ME/CFS patients. Results of receiver operating characteristic (ROC) analysis further indicated a possibility of distinguishing patients from healthy controls, based on the skewed B cell repertoire. Meanwhile, B cell clones using IGHV3-30 and IGHV3-30-3 genes were more frequent in patients with an obvious infection-related episode at onset, and correlated to expression levels of interferon response genes in plasmablasts. Collectively, these results imply that B cell responses in ME/CFS are directed against an infectious agents or priming antigens induced before disease onset.

Clonal Expansion of Tumor-Infiltrating T Cells and Analysis of the Tumor Microenvironment within Esophageal Squamous Cell Carcinoma Relapsed after Definitive Chemoradiation Therapy.

(1) Background: Comparable prognoses after definitive chemoradiation therapy (CRT) to surgery alone for esophageal squamous cell carcinoma (ESCC) have been previously reported; however, no robust prognostic markers have been established. The clonality of tumor-infiltrating lymphocytes (TILs) and tumor microenvironments (TMEs) in ESCC relapsed after CRT were examined to explore prognostic markers. (2) Methods: Clonality of TIL and TME were examined in ESCC with and without preceding CRT, as well as oral squamous cell carcinoma (OSCC) and healthy volunteers as controls. The clonality of TIL was assessed by T-cell receptor (TCR) α and ß repertoire analyses and evaluated by diversity indices. The TME was assessed by quantitative polymerase chain reaction evaluating PD-L1 and CD8B. (3) Results: The clonal expansion of TIL was significantly induced within ESCCs and OSCCs, when compared to healthy volunteers, and was mostly induced within ESCCs after definitive CRT. Diversity indices of TIL were not associated with the prognosis, but the ratio of PD-L1 mRNA to CD8B mRNA in TME was significantly associated with a poor prognosis after salvage surgery (p = 0.007). (4) Conclusions: The clonal expansion of TIL is induced after definitive CRT for ESCC, and the ratio of PD-L1 mRNA to CD8B mRNA within tumor tissues is a prognostic marker candidate for salvage esophagectomy after CRT.

Experience as an Informal Caregiver and Discussions Regarding Advance Care Planning in Japan.

CONTEXT: Advance care planning (ACP) is vital for end-of-life care management. Experiences as informal family caregivers might act as a catalyst to promote ACP. OBJECTIVES: We investigated the association between ACP discussions and caregiving experiences. METHODS: A nationwide survey in Japan was conducted in December 2016 using a quota sampling method to select a sample representative of the general Japanese population. The responses of 3167 individuals aged 20-84 years (mean age: 50.9 ± 16.8) were analyzed. The outcome was measured by asking if respondents had ever engaged in ACP discussions. The exposure was measured by asking whether and for how long respondents had experience as informal caregivers for family members. We analyzed informal caregiving experience related to the occurrence of ACP discussions using multivariable logistic regression models that adjusted for possible covariates. RESULTS: Respondents with informal caregiving experience had significantly higher odds of having ACP discussions than those without caregiving experience (adjusted odds ratio: 1.93, 95% CI = 1.63, 2.29). Stronger effects were identified in younger adults (aged 20-65 years) and those with a higher education level (education duration > 12 years) than in older adults (aged ≥65 years) and those with a lower education level, respectively. CONCLUSION: Experiences as informal caregivers for family members may facilitate ACP discussions among Japanese adults, especially younger adults with higher educational attainment. Our findings may help health-care providers screen those at risk for inadequate ACP discussions, and informal caregiving experience should be considered when health-care providers initiate discussions of end-of-life care.

T-cell receptor repertoire of cytomegalovirus-specific cytotoxic T-cells after allogeneic stem cell transplantation.

Cytomegalovirus (CMV) infection is a major complication during allogeneic stem cell transplantation (allo-SCT). However, mechanisms of adaptive immunity that drive this remain unclear. To define early immunological responses to CMV after transplantation, we using next-generation sequencing to examine the repertoire of T-cell receptors in CD8+/CMV pp65 tetramer+ cells (CMV-CTLs) in peripheral blood samples obtained from 16 allo-SCT recipients with HLA-A*24:02 at the time of CMV reactivation. In most patients, TCR beta repertoire of CMV-CTLs was highly skewed (median Inverse Simpson's index: 1.595) and, 15 of 16 patients shared at least one TCR-beta clonotype with ≥ 2 patients. The shared TCRs were dominant in 12 patients and, two clonotypes were shared by about half of the patients. Similarity analysis showed that CDR3 sequences of shared TCRs were more similar than unshared TCRs. TCR beta repertoires of CMV-CTLs in 12 patients were also analyzed after 2-4 weeks to characterize the short-term dynamics of TCR repertoires. In ten patients, we observed persistence of prevailing clones. In the other two patients, TCR repertoires became more diverse, major clones declined, and new private clones subsequently emerged. These results provided the substantive clue to understand the immunological behavior against CMV reactivation after allo-SCT.

Adoptive transfer of zoledronate-expanded autologous Vγ9Vδ2 T-cells in patients with treatment-refractory non-small-cell lung cancer: a multicenter, open-label, single-arm, phase 2 study.

BACKGROUND: Not all non-small cell lung cancer (NSCLC) patients possess drug-targetable driver mutations, and response rates to immune checkpoint blockade therapies also remain unsatisfactory. Therefore, more effective treatments are still needed. Here, we report the results of a phase 2 clinical trial of adoptive cell therapy using zoledronate-expanded autologous Vγ9Vδ2 T-cells for treatment-refractory NSCLC. METHODS: NSCLC patients who had undergone at least two regimens of standard chemotherapy for unresectable disease or had had at least one treatment including chemotherapy or radiation for recurrent disease after surgery were enrolled in this open-label, single-arm, multicenter, phase 2 study. After preliminary testing of Vγ9Vδ2 T-cell proliferation, autologous peripheral blood mononuclear cells were cultured with zoledronate and IL-2 to expand the Vγ9Vδ2 T-cells. Cultured cells (>1×109) were intravenously administered every 2 weeks for six injections. The primary endpoint of this study was progression-free survival (PFS), and secondary endpoints included overall survival (OS), best objective response rate (ORR), disease control rate (DCR), safety and immunomonitoring. Clinical efficacy was defined as median PFS significantly >4 months. RESULTS: Twenty-five patients (20 adenocarcinoma, 4 squamous cell carcinoma and 1 large cell carcinoma) were enrolled. Autologous Vγ9Vδ2 T-cell therapy was administered to all 25 patients, of which 16 completed the foreseen course of 6 injections of cultured cells. Median PFS was 95.0 days (95% CI 73.0 to 132.0 days); median OS was 418.0 days (179.0-479.0 days), and best overall responses were 1 partial response, 16 stable disease (SD) and 8 progressive disease. ORR and DCR were 4.0% (0.1%-20.4%) and 68.0% (46.5%-85.1%), respectively. Severe adverse events developed in nine patients, mostly associated with disease progression. In one patient, pneumonitis and inflammatory responses resulted from Vγ9Vδ2 T-cell infusions, together with the disappearance of a massive tumor. CONCLUSIONS: Although autologous Vγ9Vδ2 T-cell therapy was well tolerated and may have an acceptable DCR, this trial did not meet its primary efficacy endpoint. TRIAL REGISTRATION NUMBER: UMIN000006128.

Circulation of gut-preactivated naïve CD8+ T cells enhances antitumor immunity in B cell-defective mice.

The gut microbiome has garnered attention as an effective target to boost immunity and improve cancer immunotherapy. We found that B cell-defective (BCD) mice, such as µ-membrane targeted deletion (µMT) and activation-induced cytidine deaminase (AID) knockouts (KOs), have elevated antitumor immunity under specific pathogen-free but not germ-free conditions. Microbial dysbiosis in these BCD mice enriched the type I IFN (IFN) signature in mucosal CD8+ T cells, resulting in up-regulation of the type I IFN-inducible protein stem cell antigen-1 (Sca-1). Among CD8+ T cells, naïve cells predominantly circulate from the gut to the periphery, and those that had migrated from the mesenteric lymph nodes (mLNs) to the periphery had significantly higher expression of Sca-1. The gut-educated Sca-1+ naïve subset is endowed with enhanced mitochondrial activity and antitumor effector potential. The heterogeneity and functional versatility of the systemic naïve CD8+ T cell compartment was revealed by single-cell analysis and functional assays of CD8+ T cell subpopulations. These results indicate one of the potential mechanisms through which microbial dysbiosis regulates antitumor immunity.

Cross-Reactivity of Palladium in a Murine Model of Metal-Induced Allergic Contact Dermatitis.

Metal allergy is usually diagnosed by patch testing, however, the results do not necessarily reflect the clinical symptoms because of cross-reactivity between different metals. In this study, we established the novel mouse model of cross-reactive metal allergy, and aimed to elucidate the immune response in terms of T-cell receptor repertoire. This model was classified into two groups: the sensitization to nickel and challenge with palladium group, and the sensitization to chromium and challenge with palladium group. This model developed spongiotic edema with intra- and peri-epithelial infiltration of CD4+ T cells in the inflamed skin that resembles human contact dermatitis. Using T cell receptor analysis, we detected a high proportion of T cells bearing Trav8d-1-Traj49 and Trav5-1-Traj37 in the Ni- and Cr-sensitized Pd-challenged mice. Furthermore, mucosal-associated invariant T cells and invariant natural killer T cells were also detected. Our results indicated that T cells bearing Trav8d-1-Traj49 and Trav5-1-Traj37 induced the development of palladium-cross reactive allergy, and that mucosal-associated invariant T and invariant natural killer T cells were also involved in the cross-reactivity between different metals.

Antiferromagnet-Semiconductor Van Der Waals Heterostructures: Interlayer Interplay of Exciton with Magnetic Ordering.

Van der Waals (vdW) heterostructures have attracted great interest because of their rich material combinations. The discovery of two-dimensional magnets has provided a new platform for magnetic vdW heterointerfaces; however, research on magnetic vdW heterointerfaces has been limited to those with ferromagnetic surfaces. Here, we report a magnetic vdW heterointerface using layered intralayer-antiferromagnetic MPSe3 (M = Mn, Fe) and monolayer transition-metal dichalcogenides (TMDs). We found an anomalous upshift of the excitonic peak in monolayer TMDs below the antiferromagnetic transition temperature in the MPSe3, capturing a signature of the interlayer exciton-magnon coupling. This is a concept extended from single materials to heterointerfaces. Moreover, this coupling strongly depends on the in-plane magnetic structure and stacking direction, showing its sensitivity to their magnetic interfaces. Our finding offers an opportunity to investigate interactions between elementary excitations in different materials across interfaces and to search for new functions of magnetic vdW heterointerfaces.

A Workshop on Writing Letters to the Editor.

This article was migrated. The article was marked as recommended. Background: Writing letters to the editor based on critical appraisal can serve as the first step in scholarly activity. The workshop in this study focused on educating physicians about the best ways to write letters to the editor. Methods: We conducted a 90-minute workshop as a part of scientific conference. Participants were physicians and medical students who chose to join this workshop. We developed the following learning outcomes for participants: 1) to be able to explain falsificationism; 2) to be able to explain how to check author instructions; 3) to be able to explain how to write a letter to the editor. Results: Twenty-eight participants, including three medical students, attended the workshop. Participants' satisfaction with the workshop had a mean of 4.5 points out of 5 (standard deviation: 0.5). Nearly 80% of participants achieved the learning outcomes. Four participants' groups submitted letters within a month after the workshop, and all four were published. These four groups encompassed a total of 13 authors. In addition, none of the first author of each letter had previously written a clinical research paper. Findings and Discussion: This workshop improved not only the participants' knowledge but it also led to the concrete result of four published letters. Japanese physicians would be able to use this framework to write letters to the editor.