Precise immunological evaluation rationalizes the design of a self-adjuvanting vaccine composed of glycan antigen,TLR1/2 ligand,and T-helper cell epitope

Sialyl-Tn (STn), overexpressed on various tumors, has been investigated for its application in anti-cancer vaccine therapy. However, Theratope, an STn-based vaccine, failed in the phase III clinical trial due to poor immunogenicity and epitope suppression by the foreign carrier protein. We therefore developed a self-adjuvanting STn based-vaccine, a conjugate of clustered STn (triSTn) antigen, TLR1/2 ligand (Pam₃CSK₄), and T-helper (Th) cell epitope, and found that this three-component self-adjuvanting vaccine effectively resulted in the production of anti-triSTn IgG antibodies. We herein analyzed immune responses induced by this self-adjuvanting vaccine in detail. We newly synthesized two-component vaccines, i.e., Pam₃CSK₄- or Th epitope-conjugated triSTn, as references to evaluate the immune-stimulating functions of Pam₃CSK₄ and Th epitope. Immunological evaluation of the synthesized vaccine candidates revealed that Pam₃CSK₄ was essential for antibody production, indicating that the uptake of triSTn antigen by antigen-presenting cells (APCs) was promoted by the recognition of Pam₃CSK₄ by TLR1/2. The function of the Th epitope was also confirmed. Th cell activation was important for boosting antibody production and IgG subclass switching. Furthermore, flow cytometric analyses of immune cells, including T cells, B cells, dendritic cells, and other monocytes, were first employed in the evaluation of self-adjuvanting vaccines and revealed that the three-component vaccine was able to induce antigen-specific immune responses for efficient antibody production without excessive inflammatory responses. Importantly, the co-administration of Freund''s adjuvants was suggested to cause excessive myeloid cell accumulation and decreased plasma cell differentiation. These results demonstrate that vaccines can be designed to achieve the desired immune responses via the bottom-up construction of each immune element.

Detailed analysis of a three-component self-adjuvanting vaccine revealed that conjugate vaccines can be designed to achieve the desired immune responses via bottom-up construction of the necessary immune elements.     

Species differences in vacuolation of the choroid plexus induced by the piperidine-ring drug disobutamide in the rat, dog, and monkey

A subchronic oral toxicity study of disobutamide, a piperidine ring compound with antiarrhythmic activity, was conducted at doses of 30, 100, and 250 mg/kg in rats, 45 mg/kg in dogs, and 90 mg/kg in monkeys. Numerous vacuoles were observed in various organs such as the liver, kidneys, heart, lungs, spleen, thymus, stomach, and choroid plexus in these animals. The epithelium of the choroid plexus (CP), however, showed severe vacuolation in rats and monkeys but not in dogs. The vacuoles corresponded to enlarged and myelin-figured lysosomes observed by electron microscopy, revealing morphological characteristics which have been reported as drug-induced phospholipidosis. In a further study, the drug penetration to cerebrospinal fluid (CSF) and the drug concentration in CP were examined in these animals. Daily po doses of 250, 45, and 90 mg/kg were, respectively, administered to rats, dogs, and monkeys to maintain approximate equivalency in peak blood concentrations across species, over a course of 35 days. The concentration of the drug in the CP was higher in rats and monkeys than in dogs, and the CSF/serum ratio of the drug concentration was extremely high in rats. The uptake of the drug by the CP in vitro was high in rats, monkeys, and dogs, in this order. In dogs, both direct contact of the drug with the CP during incubation and intraventricular administration induced vacuolation in the epithelium. From these results it was concluded that differences of the drug's penetration into the CSF and its uptake by the choroid plexus epithelium are responsible for the species differences of CP vacuolation in the animals.     

Repeated Necrotizing Lymphadenitis with MEFV Gene Mutations

We herein report a 36-year-old man with repeated necrotizing lymphadenitis due to MEFV gene mutations. The patient''s chief complaints were a fever and painful cervical lymphadenopathy. We diagnosed him with necrotizing lymphadenitis based on the pathological findings of the lymph nodes and the exclusion of other differential diseases. The same episode recurred four times. We speculated the involvement of autoinflammatory backgrounds and detected MEFV gene mutations of E148Q (homo), P369S, and R408Q. Considering the elevation of interleukin-18, these mutations probably played roles in the repeated necrotizing lymphadenitis.     

Risk Factors for Complications Associated with Peripherally Inserted Central Catheters During Induction Chemotherapy for Acute Myeloid Leukemia

Objective Peripherally inserted central catheters (PICCs) are widely used in patients with hematologic malignancies. However, the risks of PICC-related complications during chemotherapy for acute myeloid leukemia (AML) are not fully understood. Methods We conducted a retrospective review of 128 adult patients with AML who received induction therapy by way of PICC insertion between 2012 and 2019. Results The median duration of PICC insertion was 30 days. The incidence rate of catheter-related bloodstream infection (CRBSI) was 2.4% at 30 days, and women were more likely to suffer from CRBSI than men. Local reactions at the insertion site were observed in 56 patients; however, these events did not predict CRBSI. The incidence rates of catheter-related thrombosis (CRT) were 1.6% at 30 days. Obesity put patients at an increased risk for CRT. Unexpected PICC removal occurred in 59 patients, and women were at a higher risk of catheter removal than men. Conclusion Low PICC-related complication rates, possibly associated with high rates of catheter removal, were observed during intensive chemotherapy for AML. Women and obese patients require careful monitoring of their PICC. Procedures to achieve appropriate PICC removal without increasing the complication rate need to be considered.     

High REE in Sumo wrestlers attributed to large organ-tissue mass

PURPOSE: It is unknown whether high resting energy expenditure (REE) in athletes is attributable to changes in organ-tissue mass and/or metabolic rate. The purpose of this study was to examine the contribution of organ-tissue mass of fat-free mass (FFM) components to REE for Sumo wrestlers who have large FFM and REE. We investigated the relationship between the REE measured by indirect calorimetry and the REE calculated from organ-tissue mass using a previously published approach. METHODS: Ten Sumo wrestlers and 11 male untrained college students (controls) were recruited to participate in this study. FFM was estimated by two-component densitometry. Contiguous magnetic resonance imaging (MRI) images with a 1-cm slice thickness were obtained from the top of head to the ankle joints, and the cross-sectional area and volume were determined for skeletal muscle (SM), liver, kidney, and brain. The volume of adipose tissue, heart, and residual was calculated from each equation. The volume units were converted into mass by an assumed constant density. The measured REE was determined by indirect calorimetry. The calculated REE was estimated as the sum of individual organ-tissue masses (seven body compartments) multiplied by their metabolic rate constants. RESULTS: The measured REE for Sumo wrestlers (2286 kcal x d(-1)) was higher (P<0.01) than for controls (1545 kcal x d(-1)). Sumo wrestlers had a greater amount of FFM and FFM components (e.g., SM, liver, and kidney), except for brain. The ratio of measured REE to FFM and the measured REE adjusted by FFM were similar between the two groups. The measured REE values for Sumo wrestlers were not significantly different from the calculated REE values. CONCLUSIONS: The high REE for Sumo wrestlers can be attributed not to an elevation of the organ-tissue metabolic rate, but to a larger absolute amount of low and high metabolically active tissue including SM, liver, and kidney.     

Feasibility study for the quantification of total protein content by multiple prompt gamma-ray analysis

Protein is an important nutrient in foods. The classical nitrogen analysis method is the Kjeldahl technique, which is time-consuming and inconvenient. As a convenient method to quantify protein content in biological samples, the feasibility of application of multiple prompt gamma-ray analysis (MPGA) to the quantification was studied. Results for protein content are reported for several reference materials and prove the method to be reliable.     

A questionnaire about radiation safety management of the draining-water system at nuclear medicine facilities

We conducted a questionnaire survey about radiation-safety management condition in Japanese nuclear medicine facilities to make materials of proposition for more reasonable management of medical radioactive waste. We distributed a questionnaire to institutions equipped with Nuclear Medicine facilities. Of 1,125 institutions, 642 institutes (52.8%) returned effective answers. The questionnaire covered the following areas: 1) scale of an institution, 2) presence of enforcement of radiotherapy, 3) system of a tank, 4) size and number of each tank, 5) a form of draining-water system, 6) a displacement in a radioactive rays management area, 7) a measurement method of the concentration of medical radioactive waste in draining water system, 8) planned and used quantity of radioisotopes for medical examination and treatment, 9) an average displacement of hospital for one month. In most institutions, a ratio of dose limitation of radioisotope in draining-water system was less than 1.0, defined as an upper limitation in ordinance. In 499 hospitals without facilities of hospitalization for unsealed radioisotope therapy, 473 hospitals reported that sum of ratios of dose limits in a draining-water system was less than 1.0. It was calculated by used dose of radioisotope and monthly displacement from hospital, on the premise that all used radioisotope entered in the general draining-water system. When a drainage including radioactivity from a controlled area join with that from other area before it flows out of a institution, it may be diluted and its radioactive concentration should be less than its upper limitation defined in the rule. Especially, in all institutions with a monthly displacement of more than 25,000 m3, the sum of ratio of the concentration of each radionuclide to the concentration limit dose calculated by used dose of radioisotope, indicated less than 1.0.     

TNF-related apoptosis-inducing ligand (TRAIL) frequently induces apoptosis in Philadelphia chromosome-positive leukemia cells

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and Fas ligand (FasL) have been implicated in antitumor immunity and therapy. In the present study, we investigated the sensitivity of Philadelphia chromosome (Ph1)-positive leukemia cell lines to TRAIL- or FasL-induced cell death to explore the possible contribution of these molecules to immunotherapy against Ph1-positive leukemias. TRAIL, but not FasL, effectively induced apoptotic cell death in most of 5 chronic myelogenous leukemia-derived and 7 acute leukemia-derived Ph1-positive cell lines. The sensitivity to TRAIL was correlated with cell-surface expression of death-inducing receptors DR4 and/or DR5. The TRAIL-induced cell death was caspase-dependent and enhanced by nuclear factor kappa B inhibitors. Moreover, primary leukemia cells from Ph1-positive acute lymphoblastic leukemia patients were also sensitive to TRAIL, but not to FasL, depending on DR4/DR5 expression. Fas-associated death domain protein (FADD) and caspase-8, components of death-inducing signaling complex (DISC), as well as FLIP (FLICE [Fas-associating protein with death domain-like interleukin-1-converting enzyme]/caspase-8 inhibitory protein), a negative regulator of caspase-8, were expressed ubiquitously in Ph1-positive leukemia cell lines irrespective of their differential sensitivities to TRAIL and FasL. Notably, TRAIL could induce cell death in the Ph1-positive leukemia cell lines that were refractory to a BCR-ABL-specific tyrosine kinase inhibitor imatinib mesylate (STI571; Novartis Pharma, Basel, Switzerland). These results suggested the potential utility of recombinant TRAIL as a novel therapeutic agent and the possible contribution of endogenously expressed TRAIL to immunotherapy against Ph1-positive leukemias.