Effect of Human or Mouse IL-7 on the Homeostasis of Porcine T Lymphocytes.

Due to the inconsistent fluctuation of blood supply for transfusion, much attention has been paid to the development of artificial blood using other animals. Although mini-pigs are candidate animals, contamination of mini-pig T cells in artificial blood may cause a major safety concern. Therefore, it is important to analyze the cross-reactivity of IL-7, the major survival factor for T lymphocytes, between human, mouse, and mini-pig. Thus, we compared the protein sequences of IL-7 and found that porcine IL-7 was evolutionarily different from human IL-7. We also observed that when porcine T cells were cultured with either human or mouse IL-7, these cells did not increase the survival or proliferation compared to negative controls. These results suggest that porcine T cells do not recognize human or mouse IL-7 as their survival factor.

Tumor microenvironment dictates regulatory T cell phenotype: Upregulated immune checkpoints reinforce suppressive function.

BACKGROUND: Regulatory T (Treg) cells have an immunosuppressive function in cancer, but the underlying mechanism of immunosuppression in the tumor microenvironment (TME) is unclear. METHODS: We compared the phenotypes of T cell subsets, including Treg cells, obtained from peripheral blood, malignant effusion, and tumors of 103 cancer patients. Our primary focus was on the expression of immune checkpoint (IC)-molecules, such as programmed death (PD)-1, T-cell immunoglobulin and mucin-domain containing (TIM)-3, T cell Ig and ITIM domain (TIGIT), and cytotoxic T lymphocyte antigen (CTLA)-4, on Treg cells in paired lymphocytes from blood, peritumoral tissue, and tumors of 12 patients with lung cancer. To identify the immunosuppressive mechanisms acting on tumor-infiltrating Treg cells, we conducted immunosuppressive functional assays in a mouse model. RESULTS: CD8+, CD4+ T cells, and Treg cells exhibited a gradual upregulation of IC-molecules the closer they were to the tumor. Interestingly, PD-1 expression was more prominent in Treg cells than in conventional T (Tconv) cells. In lung cancer patients, higher levels of IC-molecules were expressed on Treg cells than on Tconv cells, and Treg cells were also more enriched in the tumor than in the peri-tumor and blood. In a mouse lung cancer model, IC-molecules were also preferentially upregulated on Treg cells, compared to Tconv cells. PD-1 showed the greatest increase on most cell types, especially Treg cells, and this increase occurred gradually over time after the cells entered the TME. PD-1 high-expressing tumor-infiltrating Treg cells displayed potent suppressive activity, which could be partially inhibited with a blocking anti-PD-1 antibody. CONCLUSIONS: We demonstrate that the TME confers a suppressive function on Treg cells by upregulating IC-molecule expression. Targeting IC-molecules, including PD-1, on Treg cells may be effective for cancer treatment.

Polyvinylidene Fluoride Alters Inflammatory Responses by Activation-induced Cell Death in Macrophages.

Carbon nanotubes (CNTs) are nanomaterials that have been employed in generating diverse materials. We previously reported that CNTs induce cell death in macrophages, possibly via asbestosis. Therefore, we generated CNT-attached polyvinylidene fluoride (PVDF), which is an established polymer in membrane technology, and then examined whether CNT-attached PVDF is immunologically safe for medical purposes compared to CNT alone. To test this, we treated RAW 264.7 murine macrophages (RAW cells) with CNT-attached PVDF and analyzed the production of nitric oxide (NO), a potent proinflammatory mediator, in these cells. RAW cells treated with CNT-attached PVDF showed reduced NO production in response to lipopolysaccharide. However, the same treatment also decreased the cell number suggesting that this treatment can alter the homeostasis of RAW cells. Although cell cycle of RAW cells was increased by PVDF treatment with or without CNTs, apoptosis was enhanced in these cells. Taken together, these results indicate that PVDF with or without CNTs modulates inflammatory responses possibly due to activation-induced cell death in macrophages.

CCR7 expression alters memory CD8 T-cell homeostasis by regulating occupancy in IL-7- and IL-15-dependent niches.

C-C receptor 7 (CCR7) is important to allow T cells and dendritic cells to migrate toward CCL19- and CCL21-producing cells in the T-cell zone of the spleen and lymph nodes. The role of this chemokine receptor in regulating the homeostasis of effector and memory T cells during acute viral infection is poorly defined, however. In this study, we show that CCR7 expression alters memory CD8 T-cell homeostasis following lymphocytic choriomeningitis virus infection. Greater numbers of CCR7-deficient memory T cells were formed and maintained compared with CCR7-sufficient memory T cells, especially in the lung and bone marrow. The CCR7-deficient memory T cells also displayed enhanced rates of homeostatic turnover, which may stem from increased exposure to IL-15 as a consequence of reduced exposure to IL-7, because removal of IL-15, but not of IL-7, normalized the numbers of CCR7-sufficient and CCR7-deficient memory CD8 T cells. This result suggests that IL-15 is the predominant cytokine supporting augmentation of the CCR7(-/-) memory CD8 T-cell pool. Taken together, these data suggest that CCR7 biases memory CD8 T cells toward IL-7-dependent niches over IL-15-dependent niches, which provides insight into the homeostatic regulation of different memory T-cell subsets.

Estrogenic endocrine-disrupting chemicals modulate the production of inflammatory mediators and cell viability of lipopolysaccharide-stimulated macrophages.

Estrogenic endocrine-disrupting chemicals (EDCs) are exogenous substances that act as competitive inhibitors of estrogen in the endocrine system. By disrupting the endocrine system, EDCs can cause severe disabilities and diseases, including cancers and altered sexual development. Although the influence of these molecules in the endocrine system is evident, the effects of EDCs on the immune system as well as their cytotoxicity have been poorly examined. Therefore, we selected 21 EDCs that are commonly found in Korean ecosystems, such as surface waters and effluents, and studied their immunologic effects by comparing nitric oxide (NO) production and cytotoxicity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (RAW cells), a macrophage cell line. Among the EDCs tested, fenitrothion (FTH) inhibited the messenger RNA (mRNA) expression of inducible NO synthase (iNOS), resulting in reduced NO production, while treatment with andostenedione (AD), diethyl phthalate, di-n-butyl phthalate (DBP), estriol, or molinate decreased production of NO in an iNOS-independent fashion. In contrast, benzo(a)pyrene (B(a)P) increased the production of NO in RAW cells. In addition, AD, DBP, or FTH inhibited the mRNA expression of tumor necrosis factor alpha or interleukin-1 beta. Treatment with 17-α-ethynylestradiol, 17-ß-estradiol, 4-n-butyl phenol, or alachlor induced apoptosis of RAW cells, while dicyclohexyl phthalate and B(a)P caused cell death in an apoptosis-independent manner. These data suggest that EDCs can influence the immune response to pathogens by modulating the functions of macrophages.

Diverse influences of androgen-disrupting chemicals on immune responses mounted by macrophages.

Androgen-disrupting chemicals (ADCs) can alter male sexual development. Although the effects of ADCs on hormone disruption have been studied, their influence on the immune response is not fully understood. To investigate the effects of ADCs on innate immunity, we tested eight candidate ADCs for their influence on macrophages by measuring nitric oxide (NO) production and cell viability. Our results showed that treatment with a mixture of lipopolysaccharide and hexachlorobenzene increased NO production in RAW 264.7 cells, a murine macrophage cell line. In contrast, compared to exposure to a negative control, exposure to di-2-ethylhexyl adipate (DEHA), benzylbutyl phthalate (BBP), testosterone (TTT), or permethrin decreased NO production. DEHA, BBP, and TTT inhibited NO production in an inducible nitric oxide synthase-dependent manner. Treatment with bisphenol A (BPA), nonylphenol (NNP), or tributyltin chloride (TBTC) reduced NO production and induced cell death. While BPA induced RAW 264.7 cell death through apoptosis, NNP and TBTC caused cell death through necrosis. These results offer insights into the influences of ADCs on the innate immune system.

Single-walled carbon nanotubes induce cell death and transcription of TNF-α in macrophages without affecting nitric oxide production.

Single-walled carbon nanotubes (SWCNTs) are potent nanomaterials that have diverse shapes and features. The utilization of these molecules for drug delivery is being investigated; thus, it is important to determine whether they alter immune responses against pathogens. In this study, we show that macrophages treated with a mixture of lipopolysaccharide and SWCNTs produced normal levels of nitric oxide and inducible nitric oxide synthase mRNA. However, these treatments induced cell death, presumably via necrosis. In addition, treating cells with SWCNTs induced the expression of tumor necrosis factor-α mRNA, a potent pro-inflammatory cytokine. These results suggest that SWCNTs may influence immune responses, which could result in unexpected effects following their administration for the purpose of drug delivery.

Arterial micro-calcification of vascular access is associated with aortic arch calcification and arterial stiffness in hemodialysis patients.

Vascular calcification of the coronary arteries or aorta is an independent risk factor for cardiovascular outcome, but clinical significance of arterial micro-calcification (AMC) of vascular access is unclear in hemodialysis (HD) patients. Sixty-five patients awaiting vascular access operation were enrolled. We compared surrogate markers of cardiovascular morbidity such as aortic arch calcification (AoAC) by chest radiography, arterial stiffness by brachial-ankle pulse wave velocity (baPWV) and endothelial dysfunction by flow-mediated dilatation (FMD) between patients with and without AMC of vascular access on von Kossa staining. AMC of vascular access was detected in 36 (55.4%). The AMC-positive group had significantly higher incidence of AoAC (63.9% vs. 20.7%, p < 0.001) and higher baPWV (26.5 ± 9.4 m/s vs. 19.8 ± 6.6 m/s, p = 0.006) than the AMC-negative group. There was no significant difference in FMD between the two groups (5.4 ± 2.6% vs. 5.7 ± 3.5%, p = 0.764). The AMC-positive group had higher incidence of diabetes mellitus, higher systolic blood pressure and wider pulse pressure than the AMC-negative group. This study suggests that AMC of vascular access may be associated with cardiovascular morbidity via AoAC and arterial stiffness in HD patients.

Successful transplant of a kidney with fibromuscular dysplasia having higher glomerular filtration rate than the contralateral kidney.

Fibromuscular dysplasia is the second-most commonly encountered anatomic abnormality in potential renal donors. Normotensive patients with medial fibroplasia and low-grade lesions have been used as renal donors. However, no studies have reported the optimal choice of a kidney for donation where the kidney with fibromuscular dysplasia had a larger volume and a higher glomerular filtration rate than the unaffected side. Herein, we report a case of renal transplant using a kidney with fibromuscular dysplasia that had higher glomerular filtration rate than the normal side. After transplant, hypertension and abnormal serum creatinine did not occur in either the donor or the recipient during 12 months' follow-up.

Usefulness of continuous renal replacement therapy for correcting hypernatremia in a patient with severe congestive heart failure.

Continuous renal replacement therapy (CRRT) is used as an alternative to intermittent hemodialysis (IHD) in patients who have acute kidney injury (AKI) and cannot tolerate IHD. Several studies have reported the usefulness of CRRT in treating sepsis, which is a non-renal indication for CRRT. Recently, CRRT was also introduced as a useful tool for treating severe congestive heart failure (CHF). By using CRRT, we successfully treated hypernatremia in a patient with severe CHF, without observing any fluid overload. Therefore, we report this case to suggest that CRRT should be considered for the treatment of hypernatremia in patients with severe CHF.

Clinical usefulness of BK virus plasma quantitative PCR to prevent BK virus associated nephropathy.

The present study investigated the clinical usefulness of plasma real-time polymerase chain reaction (PCR) (plasma-PCR) in the prevention of BK virus-associated nephropathy (BKVAN). First, we investigated the diagnostic value of plasma BK-PCR, urine BK-PCR, and urine cytology for the prediction of BKVAN retrospectively. Then we designed a prospective study of regular plasma-PCR monitoring and pre-emptive immunosuppression (IS) reduction based on the result. In the retrospective cohort, the prevalence of BKVAN was 3.7% (14/379) and the positive rate of decoy cells, urine-PCR (>1 × 10(10) copies/ml), and plasma-PCR (>1 × 10(4) copies/ml) was 18.6%, 11.1%, and 5.5%, respectively. Plasma-PCR was superior to urine-PCR or urine cytology in specificity and positive predictive value for detection of BKVAN. In prospective study, regular monitoring of plasma-PCR detected significant BKV viremia in 8.3% (12/145) and BKVAN in 1 patient (0.6%). After IS reduction, BKV viremia was eliminated in 91.6% (11/12) within 103 days (25-254). In patients with viremia, the frequency of acute rejection did not increase and allograft function did not differ significantly compared with those in patients without viremia during the first year post-transplant (P > 0.05, in both). Plasma-PCR is useful to predict an increased risk for BKVAN, and regular monitoring is effective to prevent the development of BKVAN.

IL-6 is an independent risk factor for resistance to erythropoiesis-stimulating agents in hemodialysis patients without iron deficiency.

Anemia is a common complication in dialysis patients because of their relative erythropoietin deficiency. Despite treatment with erythropoiesis-stimulating agents (ESAs), some patients experienced ESA hyporesponsiveness. We evaluated the clinical and laboratory factors that affect ESA hyporesponsiveness and investigated the relationships between hepcidin, inflammatory markers, and the iron profiles of hemodialysis patients. Sixty-eight patients receiving hemodialysis at a single institution were evaluated in a cross-sectional study. The patients were divided into tertiles based on the ESA hyporesponsiveness index (EHRI), defined as the weekly ESA dose per kilogram of body weight divided by the hemoglobin level. The mean EHRI values for each tertile were 3.3 ± 1.2 (T1), 10.2 ± 2.9 (T2), and 24.5 ± 11.6 (T3). The mean serum erythropoietin levels were significantly higher in the Q3 and Q4 groups. Thus, patients with ESA hyporesponsiveness showed relative resistance to erythropoietin therapy. In univariate and multivariate analyses, patients in the third tertile of EHRI showed significantly higher mean interleukin-6 (IL-6) levels. Serum C-reactive protein (CRP) levels showed a similar trend, but the differences were not significant. Serum hepcidin levels tended toward lower mean values in the third tertile of EHRI. No relationship was observed between hepcidin and inflammatory markers or iron status. In conclusion, IL-6, but not CRP, is a strong predictor of ESA hyporesponsiveness in hemodialysis patients who have sufficient iron. It may be difficult to use hepcidin as an independent clinical marker because of the many factors that influence it and their interactions.

Risk factors for progression of aortic arch calcification in patients on maintenance hemodialysis and peritoneal dialysis.

Vascular calcification is accelerated during dialysis and is known to be an important risk factor for cardiovascular disease. Progression of aortic arch calcification (AoAC) can be simply estimated with an AoAC score (AoACS) using plain chest radiography. The objective of this study was to evaluate risk factors for AoAC progression. The enrolled subjects were 125 newly treated hemodialysis patients and 59 peritoneal dialysis patients. In the patients who had undergone chest radiography before initial dialysis therapy and every year, we estimated AoACS and then divided the patients into two groups based on the presence or absence of AoAC progression. We also compared the baseline clinical and biochemical profiles in the two groups. Eighty-five (46.2%) were men (mean age, 58.6 ± 12.7 years). Seventy-six patients (41.3%) had AoAC before initial dialysis, with a mean AoACS of 13.0 ± 20.4%. The mean duration of follow-up was 2.7 ± 1.0 years. Half of the patients (50%) had progressive AoAC. Age >65 years (p = 0.003), dialysis duration (p = 0.004), diabetes (p = 0.015), and the presence of AoAC at baseline (p = 0.001) were related to AoAC progression. No significant association was found between AoAC progression and the baseline clinical parameters, including gender, obesity, hypertension, and dialysis modality. In a multivariate analysis, dialysis duration (p = 0.003) and the presence of AoAC at baseline (p < 0.001) were independent risk factors for AoAC progression in patients undergoing dialysis. The duration of dialysis and the presence of AoAC before initial dialysis were significantly related to the progression of AoAC in these patients. The results suggest that patients should be carefully managed from the predialysis stage to prevent AoAC progression and to reduce cardiovascular morbidity.