Pretreatment quality of life and survival in patients with lung cancer: a systematic review and meta-analysis.

BACKGROUND: Although many studies have explored the correlation between quality of life and survival, none have reported this relationship for specific cancers assessed at distinct time points. This meta-analysis aimed to investigate the impact of pretreatment Global Quality of Life (QOL) and functioning QOL, including physical, social, role, emotional, and cognitive QOLs, on mortality risk in patients with lung cancer. METHODS: A literature search was conducted across the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and PubMed databases for articles published between their inception and December 2022. Subsequently, 11 studies were selected based on predefined eligibility criteria to investigate the relationship between pretreatment QOLs and mortality risk in patients with lung cancer. RESULTS: Pretreatment global, physical, social, role, and emotional QOLs were significantly associated with mortality risk as follows: Global QOL (hazard ratio [HR] = 1.08 95% confidence interval [CI] = 1.03-1.13); Physical QOL (HR = 1.04 95% CI = 1.02-1.05); Social QOL (HR = 1.02 95% CI = 1.01-1.03; Role QOL (HR = 1.01 95% CI = 1.01-1.02); Emotional QOL (HR = 1.01 95% CI = 1.00-1.03). CONCLUSIONS: These findings underscore the importance of early QOL assessment after diagnosis as well as early provision of physical, social, and psychological support accommodating each patient's demands. TRIAL REGISTRATION: The International Prospective Register of Systematic Reviews registration number CRD42023398206, Registered on February 20, 2023.

Factors Influencing Life Space Mobility in Cancer Survivors Following Hematopoietic Stem Cell Transplantation - Physical Function, Depression, Fatigue, Neighborhood Walkability, and Employment Status.

BACKGROUND/OBJECTIVE: The level of physical activity in the daily lives of cancer survivors following hematopoietic stem cell transplantation (HSCT) is crucial for maintaining their physical and mental health. Considering that life space mobility (LSM) may limit physical activity, maintaining and expanding LSM is particularly essential for post-HSCT survivors. This study aimed to identify factors influencing LSM in post-HSCT survivors. METHODS: Thirty cancer survivors after HSCT (14 women, mean age 52.0 ± 12.3 years, 196-3017 days post-HSCT) were included in this cross-sectional study. The assessment encompassed patient characteristics, employment status, life space (Life Space Assessment; LSA), physical function (handgrip strength, isometric knee extension strength, 5 chair standing test, walking speed), depression (Self-rating Depression Scale; SDS), fatigue (Cancer Fatigue Scale), and neighborhood walkability (Walk Score®). The association between LSA and each factor was compared by correlation analysis. Subsequently, multiple regression analysis was conducted, with LSA as the dependent variable and independent variables being outcome measures exhibiting a significant correlation with LSA. RESULTS: Variables significantly correlated with LSA included SDS (r =-0.65, p < .01), employment status (r=-0.60, p < .01), handgrip strength (r = 0.43, p = .02), and isometric knee extension strength (r = 0.40, p = .03). Results of multiple regression analysis show that SDS (ß = -0.53, p < .01), employment status (ß = 0.48, p < .01), and isometric knee extension strength (ß = 0.27, p = .02) were significantly associated with LSA (R2 = 0.74). CONCLUSION: Depression, employment status, and isometric knee extension strength were identified as factors related to LSM in post-HSCT survivors.

Effects of taxane-induced peripheral neuropathy on hand dexterity impairment: evaluation of quantitative and subjective assessments.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) commonly involves hand dexterity impairment. However, the factors affecting hand dexterity impairment are unknown and there is currently no established treatment. The purpose of the current study was to clarify factors influencing hand dexterity impairment in taxane-induced peripheral neuropathy using subjective and objective assessments. METHODS: We assessed patient characteristics, treatment-related factors, subjective symptoms of CIPN (Patient Neurotoxicity Questionnaire [PNQ]), psychological symptoms, and upper limb dysfunction (Quick Disabilities of the Arm, Shoulder and Hand [Quick DASH]). Quantitative assessments were pinch strength, sensory threshold, hand dexterity impairment, and grip force control. Multiple regression analysis was performed using hand dexterity impairment as the dependent variable and age and PNQ, Quick DASH, and control of grip force as independent variables. RESULTS: Forty-three breast cancer patients were included in the analysis. Hand dexterity impairment in taxane-induced peripheral neuropathy patients was significantly correlated with age, grip force control, and PNQ sensory scores (p < 0.008). Multiple regression analysis demonstrated that PNQ sensory scores and grip force control were significantly associated with hand dexterity impairment (p < 0.01). CONCLUSION: Subjective symptoms (numbness and pain) and grip force control contributed to impaired hand dexterity in taxane-induced peripheral neuropathy.

Association between quality of life and mortality risk in patients with breast cancer: a systematic review and meta-analysis.

BACKGROUND: Patients with breast cancer present with various problems that have an adverse effect on the quality of life (QOL). However, the association between the QOL and mortality among patients with breast cancer remains controversial. Therefore, this systematic review and meta-analysis aimed to determine whether QOL impacts prognosis in patients with breast cancer. METHODS: The databases of CINAHL, Scopus, and PubMed databases were searched to retrieve observational studies that assessed the QOL and mortality risk in patients with breast cancer published before December 2022. RESULTS: Among the 119,061 articles retrieved, six observational studies were included in the meta-analysis. Physical QOL (hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 1.01-1.07, p = 0.003), emotional QOL (HR: 1.01, 95% CI: 1.00-1.03, p = 0.05), and role QOL (HR: 1.01, 95% CI: 1.00-1.01, p = 0.007) showed significant associations with mortality risk. In contrast, global QOL, cognitive QOL, and social QOL showed no associations with mortality risk. Subgroup analysis performed according to treatment time points revealed that the post-treatment physical QOL was associated with mortality risk. CONCLUSIONS: Physical QOL, emotional QOL, and role QOL are associated with mortality risk in patients with breast cancer. Furthermore, post-treatment physical QOL showed a more significant association with prolonged survival than pre-treatment physical QOL.

TIFAB regulates the TIFA-TRAF6 signaling pathway involved in innate immunity by forming a heterodimer complex with TIFA.

Nuclear factor κB (NF-κB) is activated by various inflammatory and infectious molecules and is involved in immune responses. It has been elucidated that ADP-ß-D-manno-heptose (ADP-Hep), a metabolite in gram-negative bacteria, activates NF-κB through alpha-kinase 1 (ALPK1)-TIFA-TRAF6 signaling. ADP-Hep stimulates the kinase activity of ALPK1 for TIFA phosphorylation. Complex formation between phosphorylation-dependent TIFA oligomer and TRAF6 promotes the polyubiquitination of TRAF6 for NF-κB activation. TIFAB, a TIFA homolog lacking a phosphorylation site and a TRAF6 binding motif, is a negative regulator of TIFA-TRAF6 signaling and is implicated in myeloid diseases. TIFAB is indicated to regulate TIFA-TRAF6 signaling through interactions with TIFA and TRAF6; however, little is known about its biological function. We demonstrated that TIFAB forms a complex not with the TIFA dimer, an intrinsic form of TIFA involved in NF-κB activation, but with monomeric TIFA. The structural analysis of the TIFA/TIFAB complex and the biochemical and cell-based analyses showed that TIFAB forms a stable heterodimer with TIFA, inhibits TIFA dimer formation, and suppresses TIFA-TRAF6 signaling. The resultant TIFA/TIFAB complex is a "pseudo-TIFA dimer" lacking the phosphorylation site and TRAF6 binding motif in TIFAB and cannot form the orderly structure as proposed for the phosphorylated TIFA oligomer involved in NF-κB activation. This study elucidated the molecular and structural basis for the regulation of TIFA-TRAF6 signaling by TIFAB.

Effects of Group Exercise Intervention on Quality of Life and Physical Parameters in Patients with Childhood Cancer: A Systematic Review.

BACKGROUND: Although the survival rates of childhood cancer are increasing, children diagnosed as having cancer experience psychological and physical problems and a declining quality of life (QOL). METHODS: A systematic review of PubMed databases was conducted up to September 2023 to identify studies reporting the effects of group exercise intervention in children with cancer. The inclusion criteria were pre-specified, including children aged ≤19 years old who received group exercise intervention and interventional studies written in English. Studies involving non-exercise intervention or non-group intervention were excluded. RESULTS: Five studies were included in the present review. In three studies, QOL and physical parameters were improved after group exercise intervention, and in two studies, only physical parameters were improved. Improvements in QOL were achieved through psychosocial variables, improved scores of subscales of pain and hurt, nausea, and procedure-related anxiety, and reduced cancer-related fatigue. All studies had high numbers of participants who completed the intervention. However, all studies showed a high risk of bias regarding the selection of the reported results, and most studies showed a high risk of bias regarding deviations from the intended intervention and outcome measurement. CONCLUSION: The reviewed studies showed that group exercise intervention for children with cancer could improve their QOL and/or physical parameters.

Mint3-depletion-induced energy stress sensitizes triple-negative breast cancer to chemotherapy via HSF1 inactivation.

Given the lack of therapeutic targets, the conventional approach for managing triple-negative breast cancer (TNBC) involves the utilization of cytotoxic chemotherapeutic agents. However, most TNBCs acquire resistance to chemotherapy, thereby lowering the therapeutic outcome. In addition to oncogenic mutations in TNBC, microenvironment-induced mechanisms render chemoresistance more complex and robust in vivo. Here, we aimed to analyze whether depletion of Munc18-1 interacting protein 3 (Mint3), which activates hypoxia-inducible factor 1 (HIF-1) during normoxia, sensitizes TNBC to chemotherapy. We found that Mint3 promotes the chemoresistance of TNBC in vivo. Mint3 depletion did not affect the sensitivity of human TNBC cell lines to doxorubicin and paclitaxel in vitro but sensitized tumors of these cells to chemotherapy in vivo. Transcriptome analyses revealed that the Mint3-HIF-1 axis enhanced heat shock protein 70 (HSP70) expression in tumors of TNBC cells. Administering an HSP70 inhibitor enhanced the antitumor activity of doxorubicin in TNBC tumors, similar to Mint3 depletion. Mint3 expression was also correlated with HSP70 expression in human TNBC specimens. Mechanistically, Mint3 depletion induces glycolytic maladaptation to the tumor microenvironment in TNBC tumors, resulting in energy stress. This energy stress by Mint3 depletion inactivated heat shock factor 1 (HSF-1), the master regulator of HSP expression, via the AMP-activated protein kinase/mechanistic target of the rapamycin pathway following attenuated HSP70 expression. In conclusion, Mint3 is a unique regulator of TNBC chemoresistance in vivo via metabolic adaptation to the tumor microenvironment, and a combination of Mint3 inhibition and chemotherapy may be a good strategy for TNBC treatment.

Structural Characterization of TRAF6 N-Terminal for Therapeutic Uses and Computational Studies on New Derivatives.

Tumor necrosis factor receptor-associated factors (TRAFs) are a protein family with a wide variety of roles and binding partners. Among them, TRAF6, a ubiquitin ligase, possesses unique receptor binding specificity and shows diverse functions in immune system regulation, cellular signaling, central nervous system, and tumor formation. TRAF6 consists of an N-terminal Really Interesting New Gene (RING) domain, multiple zinc fingers, and a C-terminal TRAF domain. TRAF6 is an important therapeutic target for various disorders and structural studies of this protein are crucial for the development of next-generation therapeutics. Here, we presented a TRAF6 N-terminal structure determined at the Turkish light source "Turkish DeLight" to be 3.2 Å resolution at cryogenic temperature (PDB ID: 8HZ2). This structure offers insight into the domain organization and zinc-binding, which are critical for protein function. Since the RING domain and the zinc fingers are key targets for TRAF6 therapeutics, structural insights are crucial for future research. Separately, we rationally designed numerous new compounds and performed molecular docking studies using this template (PDB ID:8HZ2). According to the results, 10 new compounds formed key interactions with essential residues and zinc ion in the N-terminal region of TRAF6. Molecular dynamic (MD) simulations were performed for 300 ns to evaluate the stability of three docked complexes (compounds 256, 322, and 489). Compounds 256 and 489 was found to possess favorable bindings with TRAF6. These new compounds also showed moderate to good pharmacokinetic profiles, making them potential future drug candidates as TRAF6 inhibitors.

Neurological Outcomes of Chemotherapy-Induced Peripheral Neuropathy in Patients With Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis aimed to determine whether chemotherapy-induced peripheral neuropathy (CIPN) affects the risk of falls and physical function in patients with cancer. METHODS: A literature search was conducted in the CINAHL, Scopus, and PubMed databases for articles published from January 1950 to April 2022. Seven review authors retrieved studies using predetermined eligibility criteria, extracted the data, and evaluated the quality. RESULTS: Nine studies were included in the analysis. Patients with CIPN had a significantly higher risk of falls than those without CIPN (risk ratio = 1.38, 95% confidence interval [CI] =1.18-1.62). Patients with CIPN had lower grip strength (standardized mean difference [SMD] =-0.42, 95% CIs = -0.70 to -0.14, P = .003), longer chair stand time (SMD = 0.56, 95% CIs = -0.01 to 1.17, P = .05), worse timed up and go test time (SMD = 0.79, 95% CIs = 0.41 to 1.17, P < .0001), and lower mean Fullerton Advanced Balance scale score (SMD = -0.81, 95% CIs = -1.27 to -0.36, P = .005) than patients without CIPN. There were no significant differences in gait speed (P = .38) or Activities-specific Balance Confidence Scale score (P = .09) between patients with and without CIPN. CONCLUSIONS: This systematic review and meta-analysis demonstrated that patients with CIPN are prone to falls and impaired balance function and muscle strength.

Antiviral effect and safety of nafamostat mesilate in patients with mild early-onset COVID-19: An exploratory multicentre randomized controlled clinical trial.

OBJECTIVES: This study aimed to evaluate the antiviral effects and safety of nafamostat in early-onset patients with coronavirus disease 2019 (COVID-19). METHODS: In this exploratory multicentre randomized controlled trial, patients were assigned to three groups within 5 days of symptom onset, with 10 participants in each group: nafamostat at either 0.2 mg/kg/h or 0.1 mg/kg/h or a standard-of-care group. The primary endpoint was area under the curve for decrease in SARS-CoV-2 viral load in nasopharyngeal samples from baseline to day 6. RESULTS: Of the 30 randomized patients, 19 received nafamostat. Overall, 10 patients received low-dose nafamostat, 9 patients received high-dose nafamostat, and 10 received standard-of-care. The detected viruses were Omicron strains. The regression coefficient for area under the curve for decrease in viral load as the response variable and nafamostat dose per body weight as the explanatory variable showed a significant relationship of -40.1 (95% confidence interval, -74.1 to -6.2; P = 0.022). Serious adverse events were not observed in either group. Phlebitis occurred in ca. 50% of patients treated with nafamostat. CONCLUSIONS: Nafamostat exerts virus load-reducing effects in patients with early-onset COVID-19.

Real-Time Search-Assisted Multiplexed Quantitative Proteomics Reveals System-Wide Translational Regulation of Non-Canonical Short Open Reading Frames.

Abnormal expression of histone deacetylases (HDACs) is reported to be associated with angiogenesis, metastasis and chemotherapy resistance regarding cancer in a wide range of previous studies. Suberoylanilide hydroxamic acid (SAHA) is well known to function as a pan-inhibitor for HDACs and recognized as one of the therapeutic drug candidates to epigenetically coordinate cancer cell fate regulation on a genomic scale. Here, we established a Real-Time Search (RTS)-assisted mass spectrometric platform for system-wide quantification of translated products encoded by non-canonical short open reading frames (ORFs) as well as already annotated protein coding sequences (CDSs) on the human transciptome and applied this methodology to quantitative proteomic analyses of suberoylanilide hydroxamic acid (SAHA)-treated human HeLa cells to evaluate proteome-wide regulation in response to drug perturbation. Very intriguingly, our RTS-based in-depth proteomic analysis enabled us to identify approximately 5000 novel peptides from the ribosome profiling-based short ORFs encoded in the diversified regions on presumed 'non-coding' nucleotide sequences of mRNAs as well as lncRNAs and nonsense mediated decay (NMD) transcripts. Furthermore, TMT-based multiplex large-scale quantification of the whole proteome changes upon differential SAHA treatment unveiled dose-dependent selective translational regulation of a limited fraction of the non-canonical short ORFs in addition to key cell cycle/proliferation-related molecules such as UBE2C, CENPF and PRC1. Our study provided the first system-wide landscape of drug-perturbed translational modulation on both canonical and non-canonical proteome dynamics in human cancer cells.

Recent Findings in Physical Exercise for Cancer Survivors.

In recent years, the number of cancer survivors has been increasing each year due to advances in the early diagnosis and treatment of cancer. Cancer survivors present a variety of physical and psychological complications due to cancer and its treatment. Physical exercise is an effective nonpharmacological treatment for complications in cancer survivors. Furthermore, recent evidence has shown that physical exercise improves the prognosis of cancer survivors. The benefits of physical exercise have been widely reported, and guidelines for physical exercise for cancer survivors have been published. These guidelines recommend that cancer survivors engage in moderate- or vigorous-intensity aerobic exercises and/or resistance training. However, many cancer survivors have a poor commitment to physical exercise. In the future, it is necessary to promote physical exercise among cancer survivors through outpatient rehabilitation and community support.

In Silico and In Vitro Evaluation of Some Amidine Derivatives as Hit Compounds towards Development of Inhibitors against Coronavirus Diseases.

Coronaviruses, including SARS-CoV-2, SARS-CoV, MERS-CoV and influenza A virus, require the host proteases to mediate viral entry into cells. Rather than targeting the continuously mutating viral proteins, targeting the conserved host-based entry mechanism could offer advantages. Nafamostat and camostat were discovered as covalent inhibitors of TMPRSS2 protease involved in viral entry. To circumvent their limitations, a reversible inhibitor might be required. Considering nafamostat structure and using pentamidine as a starting point, a small set of structurally diverse rigid analogues were designed and evaluated in silico to guide selection of compounds to be prepared for biological evaluation. Based on the results of in silico study, six compounds were prepared and evaluated in vitro. At the enzyme level, compounds 10-12 triggered potential TMPRSS2 inhibition with low micromolar IC50 concentrations, but they were less effective in cellular assays. Meanwhile, compound 14 did not trigger potential TMPRSS2 inhibition at the enzyme level, but it showed potential cellular activity regarding inhibition of membrane fusion with a low micromolar IC50 value of 10.87 µM, suggesting its action could be mediated by another molecular target. Furthermore, in vitro evaluation showed that compound 14 inhibited pseudovirus entry as well as thrombin and factor Xa. Together, this study presents compound 14 as a hit compound that might serve as a starting point for developing potential viral entry inhibitors with possible application against coronaviruses.

Aberrant accumulation of NIK promotes tumor growth by dysregulating translation and post-translational modifications in breast cancer.

BACKGROUND: In vivo investigations with cancer cells have powerful tools to discover cancer progression mechanisms and preclinical candidate drugs. Among these in vivo experimental models, the establishment of highly malignancy cell lines with xenograft has been frequently used. However, few previous researches targeted malignancy-related genes whose protein levels translationally changed. Therefore, this study aimed to identify malignancy-related genes which contributed to cancer progression and changed at the protein level in the in vivo selected cancer cell lines. METHODS: We established the high malignancy breast cancer cell line (LM05) by orthotopic xenograft as an in vivo selection method. To explore the altered genes by translational or post-translational regulation, we analyzed the protein production by western blotting in the highly malignant breast cancer cell line. Functional analyses of the altered genes were performed by in vitro and in vivo experiments. To reveal the molecular mechanisms of the regulation with protein level, we evaluated post-translational modification by immunoprecipitation. In addition, we evaluated translational production by click reaction-based purification of nascent protein. RESULTS: As a result, NF-κB inducing kinase (NIK) increased at the protein level and promoted the nuclear localization of NF-κB2 (p52) and RelB in the highly malignant breast cancer cell line. The functional analyses indicated the NIK upregulation contributed to tumor malignancy via cancer-associated fibroblasts (CAFs) attraction and partially anti-apoptotic activities. Additionally, the immunoprecipitation experiment revealed that the ubiquitination of NIK decreased in LM05 cells. The decline in NIK ubiquitination was attributed to the translational downregulation of cIAP1. CONCLUSIONS: Our study identified a dysregulated mechanism of NIK production by the suppression of NIK post-modification and cIAP1 translation. The aberrant NIK accumulation promoted tumor growth in the highly malignant breast cancer cell line.

Reactive oxygen species are associated with the inhibitory effect of N-(4-hydroxyphenyl)-retinamide on the entry of the severe acute respiratory syndrome-coronavirus 2.

N-(4-hydroxyphenyl)-retinamide (4-HPR) inhibits the dihydroceramide Δ4-desaturase 1 (DEGS1) enzymatic activity. We previously reported that 4-HPR suppresses the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) spike protein-mediated membrane fusion through a decrease in membrane fluidity in a DEGS1-independent manner. However, the precise mechanism underlying the inhibition of viral entry by 4-HPR remains unclear. In this study, we examined the role of reactive oxygen species (ROS) in the inhibition of membrane fusion by 4-HPR because 4-HPR is a well-known ROS-inducing agent. Intracellular ROS generation was found to be increased in the target cells in a cell-cell fusion assay after 4-HPR treatment, which was attenuated by the addition of the antioxidant, α-tocopherol (TCP). The reduction in membrane fusion susceptibility by 4-HPR treatment in the cell-cell fusion assay was alleviated by TCP addition. Furthermore, fluorescence recovery after photobleaching analysis showed that the lateral diffusion of glycosylphosphatidylinositol-anchored protein and SARS CoV-2 receptor was reduced by 4-HPR treatment and restored by TCP addition. These results indicate that the decrease in SARS-CoV-2 spike protein-mediated membrane fusion and membrane fluidity by 4-HPR was due to ROS generation. Taken together, these results demonstrate that ROS production is associated with the 4-HPR inhibitory effect on SARS-CoV-2 entry.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia.

OBJECTIVES: To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19. METHODS: We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO2). RESULTS: There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO2 were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group. CONCLUSION: Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO2 were observed in the combination group.

Dysfunctional Sars-CoV-2-M protein-specific cytotoxic T lymphocytes in patients recovering from severe COVID-19.

Although the importance of virus-specific cytotoxic T lymphocytes (CTL) in virus clearance is evident in COVID-19, the characteristics of virus-specific CTLs related to disease severity have not been fully explored. Here we show that the phenotype of virus-specific CTLs against immunoprevalent epitopes in COVID-19 convalescents might differ according to the course of the disease. We establish a cellular screening method that uses artificial antigen presenting cells, expressing HLA-A*24:02, the costimulatory molecule 4-1BBL, SARS-CoV-2 structural proteins S, M, and N and non-structural proteins ORF3a and nsp6/ORF1a. The screen implicates SARS-CoV-2 M protein as a frequent target of IFNγ secreting CD8+ T cells, and identifies M198-206 as an immunoprevalent epitope in our cohort of HLA-A*24:02 positive convalescent COVID-19 patients recovering from mild, moderate and severe disease. Further exploration of M198-206-specific CD8+ T cells with single cell RNA sequencing reveals public TCRs in virus-specific CD8+ T cells, and shows an exhausted phenotype with less differentiated status in cells from the severe group compared to cells from the moderate group. In summary, this study describes a method to identify T cell epitopes, indicate that dysfunction of virus-specific CTLs might be an important determinant of clinical outcomes.

A tetravalent peptide that binds to the RANK-binding region of TRAF6 via a multivalent interaction efficiently inhibits osteoclast differentiation.

Inhibition of osteoclast differentiation is a promising approach for the treatment of osteoporosis and rheumatoid arthritis. Receptor activator of nuclear factor kappa B (NF-κB) (RANK), which is an essential molecule for osteoclast differentiation, interacts with tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) to transduce downstream signals. Both RANK and TRAF6 have homo-trimeric structures, forming a multivalent interaction between the Pro-X-Glu-X-X-(aromatic/acidic) motif of RANK and the C-terminal domain of TRAF6 (TRAF-C), that markedly increases the binding affinity. Here, we designed a tetravalent peptide, RANK-tet, containing the TRAF-C-binding motif of RANK and found that RANK-tet binds to TRAF-C with high affinity. In contrast, a monomeric form of RANK-tet (RANK-mono) with the same TRAF-C-binding motif did not bind to TRAF-C, clearly indicating the multivalent interaction is strictly required for the high-affinity binding to TRAF-C. RANK-tet did not bind to a series of TRAF-C-mutants with an amino acid substitution in the RANK-binding region, indicating that RANK-tet specifically targets the RANK-binding region of TRAF-C. A cell-permeable form of RANK-tet that has poly-Arg residues at each C-terminal of the TRAF-C-binding motif efficiently inhibited the RANK ligand (RANKL)-induced differentiation of bone marrow cells to osteoclasts. Thus, this compound can be an effective anti-osteoclastogenic agent.