Perspectives on immune checkpoint ligands: expression, regulation, and clinical implications

In the tumor microenvironment, immune checkpoint ligands (ICLs) must be expressed in order to trigger the inhibitory signal via immune checkpoint receptors (ICRs). Although ICL expression frequently occurs in a manner intrinsic to tumor cells, extrinsic factors derived from the tumor microenvironment can fine-tune ICL expression by tumor cells or prompt non-tumor cells, including immune cells. Considering the extensive interaction between T cells and other immune cells within the tumor microenvironment, ICL expression on immune cells can be as significant as that of ICLs on tumor cells in promoting anti-tumor immune responses. Here, we introduce various regulators known to induce or suppress ICL expression in either tumor cells or immune cells, and concise mechanisms relevant to their induction. Finally, we focus on the clinical significance of understanding the mechanisms of ICLs for an optimized immunotherapy for individual cancer patients.

A first nation-wide assessment of soil-transmitted helminthiasis in Fijian primary schools, and factors associated with the infection, using a lymphatic filariasis transmission assessment survey as surveillance platform

BACKGROUND

Soil-transmitted helminthiasis (STH) is endemic in Fiji but its prevalence is not known and likely to have changed after a decade of mass drug administration (MDA) for lymphatic filariasis (LF). By linking with LF transmission assessment surveys (LF-TAS), we undertook the first nation-wide assessment of STH in Fijian primary schools, as well as an analysis of factors associated with STH infections.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional assessment for STH was conducted in all four Divisions of Fiji from 2014 to 2015. In the Western, Central, and Northern Divisions, schools were sub-sampled after LF-TAS, while, in the Eastern Division, schools were selected via simple random sampling. For the diagnosis of STH, stool samples were examined by coproscopy with a single Kato-Katz thick smear (KK) and the formol-ether-acetate concentration technique, except for the samples from the Eastern Division where only KK was used. Mean prevalence of any STH among class 1-2 students at the national level was 10.5% (95% CI: 6.9-15.5). Across the three Divisions via LF-TAS, the prevalence levels for ascariasis were 8.7% (95% CI: 4.3-16.6), hookworm 3.9% (95% CI: 2.3-6.6) and trichuriasis 0%. In the Eastern Division, ascariasis prevalence was 13.3% (95% CI: 6.4-25.6), and hookworm 0.7% (95% CI: 0.2-2.5), with one case of trichuriasis. Among class 3-8 students, ascariasis prevalence was lower. Lower risk of any STH was associated with wearing shoes (adjusted OR 0.54, 95% CI: 0.32-0.90) and having piped water from the Fiji Water Authority at home (adjusted OR 0.48, 95% CI: 0.25-0.92).

CONCLUSIONS

After a decade of community-based LF-MDA, STH in school-age children in Fiji is now close to 10%, but localities of endemicity remain. Preventive chemotherapy should be maintained in areas with elevated STH prevalence alongside targeted delivery of integrated WASH interventions. LF-TAS has provided an opportunity to develop future public health surveillance platforms.

Validation and clinical utility of the Korean version of the Quality of Recovery-15 with enhanced recovery after surgery: a prospective observational cohort study

BACKGROUND

The 15-item Quality of Recovery (QoR-15) scale is a validated patient-reported outcome questionnaire that measures the quality of postoperative recovery. This study aimed to validate a translated Korean version of QoR-15 (QoR-15K) in a broad range of surgical patients.

METHODS

After Korean translation of the original English version of the QoR-15, we performed psychometric validation of the QoR-15K to evaluate the quality of recovery after surgery. The validity, reliability, responsiveness, and clinical feasibility of the QoR-15K were evaluated. A subgroup analysis in patients with video-assisted lung resection was performed.

RESULTS

Among 193 patients, 188 (97.4%) completed the QoR-15K after surgery. We found good convergent validity between the postoperative QoR-15K and the global QoR visual analogue scale (ρ=0.61, P<0.001). The negative correlation between the QoR-15K score and the extent of surgery (ρ=-0.33, P<0.001), the duration of surgery (ρ=-0.33, P<0.001), and the severity of postoperative pain (ρ=-0.40, P<0.001) supported construct validity. The postoperative QoR-15K showed good internal consistency (Cronbach α=0.90), split-half reliability (0.81), and test-retest reliability (0.95; 95% confidence interval [CI], 0.94-0.96). The QoR-15K score decreased from 140 (preoperative, inter-quartile range [IQR] 128-146) to 100 (postoperative day 1, IQR 75-122), median difference -36.5 (95% CI, -41 to -32.5; P<0.0001). The QoR-15K indicated excellent responsiveness with Cliff's effect size -0.78 (95% CI, -0.84 to -0.71). Subgroup analysis yielded similar results.

CONCLUSIONS

The QoR-15K is valid and has excellent reliability, a high degree of responsiveness, and clinical feasibility as a metric of quality of recovery in Korean surgical population.

CLINICAL TRIAL REGISTRATION

NCT04169087.

Sterile Neutrino Search at the NEOS Experiment

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

Synthetic lethal screening reveals FGFR as one of the combinatorial targets to overcome resistance to Met-targeted therapy

Met is a receptor tyrosine kinase that promotes cancer progression. In addition, Met has been implicated in resistance of tumors to various targeted therapies such as epidermal growth factor receptor inhibitors in lung cancers, and has been prioritized as a key molecular target for cancer therapy. However, the underlying mechanism of resistance to Met-targeting drugs is poorly understood. Here, we describe screening of 1310 genes to search for key regulators related to drug resistance to an anti-Met therapeutic antibody (SAIT301) by using a small interfering RNA-based synthetic lethal screening method. We found that knockdown of 69 genes in Met-amplified MKN45 cells sensitized the antitumor activity of SAIT301. Pathway analysis of these 69 genes implicated fibroblast growth factor receptor (FGFR) as a key regulator for antiproliferative effects of Met-targeting drugs. Inhibition of FGFR3 increased target cell apoptosis through the suppression of Bcl-xL expression, followed by reduced cancer cell growth in the presence of Met-targeting drugs. Treatment of cells with the FGFR inhibitors substantially restored the efficacy of SAIT301 in SAIT301-resistant cells and enhanced the efficacy in SAIT301-sensitive cells. In addition to FGFR3, integrin β3 is another potential target for combination treatment with SAIT301. Suppression of integrin β3 decreased AKT phosphorylation in SAIT301-resistant cells and restored SAIT301 responsiveness in HCC1954 cells, which are resistant to SAIT301. Gene expression analysis using CCLE database shows that cancer cells with high levels of FGFR and integrin β3 are resistant to crizotinib treatment, suggesting that FGFR and integrin β3 could be used as predictive markers for Met-targeted therapy and provide a potential therapeutic option to overcome acquired and innate resistance for the Met-targeting drugs.

Clinical characteristics of patients with tuberculosis-destroyed lung

SETTING

Multicentre study.

OBJECTIVE

To define the clinical characteristics of patients with tuberculosis (TB) destroyed lung due to past TB.

DESIGN

We reviewed patients with TB-destroyed lung between May 2005 and June 2011.

RESULTS

A total of 595 patients from 21 hospitals were enrolled. The mean age was 65.63 ± 0.47 (mean ± standard error); 60.5% were male. The mean number of lobes involved was 2.59 ± 0.05. Pleural thickening was observed in 54.1% of the patients. Mean forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC, bronchodilator response and number of exacerbations per year were respectively 2.06 ± 0.03 l (61.26% ± 0.79), 1.16 ± 0.02 l (49.05% ± 0.84), 58.03% ± 0.70, 5.70% ± 0.34, and 0.40 ± 0.04. The number of lobes involved was significantly correlated with FVC and FEV(1), and with the number of exacerbations per year. Use of long-acting muscarinic antagonists or long-acting beta-2 agonists plus inhaled corticosteroids resulted in bronchodilatory effects. Multivariable regression analysis showed that age, initial FEV(1) (%) and number of exacerbations during follow-up were independent factors affecting change in FEV(1).

CONCLUSION

Decreased lung function with exacerbation, and progressive decline of FEV(1) were observed in patients with TB-destroyed lung.

Netrin-1 protects hypoxia-induced mitochondrial apoptosis through HSP27 expression via DCC- and integrin α6β4-dependent Akt, GSK-3β, and HSF-1 in mesenchymal stem cells

Netrin (Ntn) has the potential to be successfully applied as an anti-apoptotic agent with a high affinity for tissue, for therapeutic strategies of umbilical cord blood-derived mesenchymal stem cells (UCB-MSC), although the mechanism by which Ntn-1 protects hypoxic injury has yet to be identified. Therefore, the present study examined the effect of Ntn-1 on hypoxia-induced UCB-MSC apoptosis, as well as the potential underlying mechanisms of its protective effect. Hypoxia (72 h) reduced cell viability (MTT reduction, and [³H]-thymidine incorporation) and cell number, and induced apoptosis (annexin and/or PI positive), which were reversed by Ntn-1 (10 ng/ml). Moreover, Ntn-1 decreased the increase of hypoxia-induced Bax, cleaved caspase-9, and -3, but blocked the decrease of hypoxia-reduced Bcl-2. Next, in order to examine the Ntn-1-related signaling cascade in the protection of hypoxic injury, we analyzed six Ntn receptors in UCB-MSC. We identified deleted in colorectal cancer (DCC) and integrin (IN) α6β4, except uncoordinated family member (UNC) 5A–C, and neogenin. Among them, IN α6β4 only was detected in lipid raft fractions. In addition, Ntn-1 induced the dissociation of DCC and APPL-1 complex, thereby stimulating the formation of APPL-1 and Akt2 complex. Ntn-1 also reversed the hypoxia-induced decrease of Akt and glycogen synthase kinase 3β (GSK-3β) phosphorylation, which is involved in heat shock factor-1 (HSF-1) expression. Ntn-1-induced phospho-Akt and -GSK-3β were inhibited by DCC function-blocking antibody, IN a6b4 function-blocking antibody, and the Akt inhibitor. Hypoxia and/or Ntn-1 stimulated heat shock protein (HSP)27 expression, which was blocked by HSF-1-specific small interfering RNA (siRNA). Furthermore, HSP27-specific siRNA reversed the Ntn-1-induced increase of phospho-Akt. Additionally, HSP27-specific siRNA attenuated the Ntn-1-reduced loss of mitochondrial membrane injury via the inhibition of cytochrome c (cyt c) release and formation of cyt c and HSP27 complex. Moreover, the inhibition of each signaling protein attenuated Ntn-1-induced blockage of apoptosis. In conclusion, Ntn-1-induced HSP27 protected hypoxic injury-related UCB-MSC apoptosis through DCC- and IN α6β4-dependent Akt, GSK-3β, and HSF-1 signaling pathways.

Chronic obstructive lung disease-related health care utilisation in Korean adults with obstructive lung disease

OBJECTIVES

The numbers of nationwide epidemiological surveys about chronic obstructive pulmonary disease (COPD) prevalence and prospective cohort studies for health care utilisation are limited. We investigated COPD-related health care utilisation in adults with obstructive lung disease in the second Korean National Health and Nutritional Survey (KNHANES II) in 2001 using Korean national medical insurance claim data.

METHODS

Among people aged >40 years, obstructive lung disease (OLD) is defined according to Global Initiative for Chronic Obstructive Lung Disease criteria. Data from a total of 1942 subjects were linked with Korean national medical insurance claims data, and we investigated their COPD-related out-patient visits from 2002 to 2005.

RESULTS

Among the 1942 subjects, 256 (13.2%) had airflow obstruction. COPD-related out-patient visits were reported for 8.2% of patients without airway obstruction, 18.1% of those with mild airway obstruction, and 33.9% of those with moderate to very severe airway obstruction. Multivariate analysis revealed that previous COPD diagnosis by a physician (OR 2.54; P = 0.02) and lower socio-economic status (OR 0.45; P = 0.02) were independent predictors of COPD-related out-patient visits in subjects with OLD.

CONCLUSIONS

Of the subjects with airway obstruction, those with poor financial status utilised COPD-related health care services less frequently, and those previously diagnosed as having COPD by a physician utilised the services more frequently.

Impact of short-term exposure to fluoroquinolones on ofloxacin resistance in HIV-negative patients with tuberculosis

SETTING

Seoul, Korea, a country with an intermediate tuberculosis (TB) burden and low prevalence of human immunodeficiency virus (HIV) infection.

OBJECTIVES

To determine the frequency of ofloxacin (OFX) resistance in Mycobacterium tuberculosis, and to assess whether short-term use of fluoroquinolones (FQNs) induces ofloxacin-resistant M. tuberculosis.

DESIGN

The subject cohort consisted of 2788 patients with culture-confirmed TB with drug susceptibility testing data; only four were HIV-positive. The patients were divided into two groups: those who were or were not recently exposed to FQNs.

RESULTS

Of the 2788 isolates, the rates of OFX resistance were 1.1% and 8.5% in initially treated and retreated patients, respectively (P < 0.05). Of the 94 OFX-resistant isolates, 83 (88.3%) were multidrug-resistant (MDR). There was no difference in rates of OFX resistance throughout the study period, or between the FQN-exposed (1/39, 2.6%) and control groups (93/2749, 3.4%). The median duration of FQN treatment was 7 days (range 1-47 days). One OFX-resistant isolate in the FQN-exposed group was MDR.

CONCLUSION

The rate of OFX-resistant M. tuberculosis was low and stationary throughout the study period in Korea. Most OFX resistance was accompanied by MDR, and the frequency of OFX-resistant M. tuberculosis was low in subjects taking short-term FQNs.

Pseudomonas aeruginosa induces MUC5AC production via epidermal growth factor receptor

Hypersecretory disease associated with Pseudomonas aeruginosa (PA) infections is characterised by increased goblet cells and increased mucin production. Recently, an epidermal growth factor receptor (EGFR) signalling cascade was shown to be a common pathway through which many stimuli induce mucin MUC5AC expression in airways by differentiation to a goblet cell phenotype. This study looked at whether PA products induce EGFR expression and activation and thus result in mucin MUC5AC production. Human airway epithelial (NCI-H292) cells were stimulated with PA culture supernatant (Sup). MUC5AC protein production, MUC5AC and EGFR messenger ribonucleic acid (mRNA) expression, and phosphorylated EGFR and phosphorylated p44/42 mitogen-activated protein kinase (MAPK) were all examined using enzyme-linked immunosorbent assay, by in situ hybridisation and by immunoblotting. PA Sup induced MUC5AC mRNA and subsequent protein expression, EGFR and p44/42 MAPK phosphorylation and EGFR mRNA expression. Induction of MUC5AC mRNA and protein expression and EGFR and p44/42 MAPK phosphorylation were inhibited completely by pretreatment with a selective EGFR tyrosine kinase inhibitor. Pretreatment with a selective inhibitor of MAPK kinase prevented MUC5AC production and p44/42 MAPK phosphorylation but not EGFR phosphorylation. The authors conclude that PA products induce mucin MUC5AC production in human airway epithelial cells via the expression and activation of epidermal growth factor receptor.

A case of parenchymal pulmonary endometriosis

Pulmonary Endometriosis is a rare disease entity and we report a 23-year-old single woman with a history of hemoptysis in association with menstruation. She was previously treated effectively with hormone therapy for 3 months, but decided to undergo surgical resection because of the high cost of hormone therapy. Radiographic finding of the chest showed haziness in the right lower lung field, and chest CT showed a ground-glass appearance in the posterobasal and laterobasal segment. The patient underwent basal segmentectomy of the right lower lobe. There was no incidence of hemoptysis during her menstruation following the operation.

Pulmonary lymphangioleiomyomatosis in Korea

BACKGROUND

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease occurring in women of reproductive age and leading to progressive respiratory failure in spite of treatment. In Korea the first case was reported in 1984 and by 1997 a total of 23 cases had been reported. The clinical findings of these Korean cases are reviewed.

METHODS

The details of 10 cases of LAM on file at Seoul National University Hospital were reviewed together with those of 13 cases previously reported from other Korean institutes. Two, including the only one to be reported in a man, were excluded after reviewing the clinical, radiological, and pathological findings, leaving a total of 21 cases in the present study.

RESULTS

All 21 patients were women and in all cases the disease was proven pathologically. The mean (SD) age at onset of symptoms was 32 (8.6) years. The most common symptoms were dyspnoea and pneumothorax which were seen in 19 (90%) and 13 (76%) patients, respectively. Pulmonary function tests showed decreased transfer factor (TLCO) (100%) and airflow limitation (67%). All the cases had characteristic cysts on high resolution computed tomographic (HRCT) scanning. The overall severity score based on HRCT scans correlated with the percentage predicted TLCO/VA (p = 0.03) and FEV1/FVC (p = 0.02). The patients were all treated with medroxyprogesterone and/or tamoxifen. Follow up was possible in 10 cases. Two of these patients appeared to stabilise with no appreciable change clinically or in lung function on medroxyprogesterone and/or tamoxifen, but the remaining patients all deteriorated with two dying of respiratory insufficiency and one of infection following lung transplantation.

CONCLUSIONS

As in other countries, in Korea LAM occurs exclusively in women and progresses despite hormonal treatment.

Biochemical and molecular characterization of a strain KA/S2 of Acanthamoeba castellanii isolated from Korean soil

A strain, KA/S2, isolated from Korean soil and morphologically assigned to Acanthamoeba castellanii, was characterized by isoenzyme analysis, and total proteins profile, and mitochondrial (Mt) DNA restriction fragment length polymorphism (RFLP), and compared with four reference strains assigned to the species (the authenitic Castellani, Neff, Ma, and Chang strains). It was found that four isoenzyme, total proteins, and Mt DNA RFLP patterns by eight restriction endonucleases of the strain KA/S2 were identical with those of the Neff strain, isolated from soil of California, USA. The Chang strain was unique in its morphology and total protein patterns. Interstrain polymorphisms of isoenzyme profiles and Mt DNA RFLP patterns were observed among the Castellani, Neff, Ma, and Chang strains. Mt DNA RFLP was confirmed to be highly appropriate for the strain characterization and identification of Acanthamoeba spp.