HTLV-I-infected T cells activate autologous CD4+ T cells susceptible to HTLV-I infection in a co-stimulatory molecule-dependent fashion

A vigorous production of human T lymphotropic virus type I (HTLV-I)-infected CD4⁺ T cells is closely associated with the development of adult T cell leukemia (ATL) and neurological disease. However, the immunological mechanisms leading to generation of the HTLV-I-infected cells are not fully clarified. The modulation of CD80 and CD86 expression on the HTLV-I-infected cells and its physiological role in the interaction of infected CD4⁺ T cells with uninfected CD4⁺ T cells was examined. The HTLV-I-infected CD4⁺ T cell lines established from ATL patients and normal donors by infecting their CD4⁺ T cells with the virus expressed CD80, CD86, and HLA-DR, and induced a proliferation of autologous and allogenic CD4⁺ T cells. While the CD4⁺ T cells stimulated with the autologous HTLV-I-infected cells for 7 days expressed CD80 and CD86 but not HTLV-I gene products, they expressed HTLV-I gag antigen after 4 weeks. The interaction of HTLV-I-infected and -uninfected CD4⁺ T cells was profoundly suppressed by a combination of CD80 and CD86 monoclonal antibodies. These results suggest that the induction of CD80 and CD86 on HTLV-I-infected CD4⁺ T cells participates actively in the generation of the virus-infected progenitor cells.     

Energetic characteristics of the new transthyretin variant A25T may explain its atypical central nervous system pathology

Transthyretin (TTR) is a tetrameric protein that must misfold to form amyloid fibrils. Misfolding includes rate-limiting tetramer dissociation, followed by fast tertiary structural changes that enable aggregation. Amyloidogenesis of wild-type (WT) TTR causes a late-onset cardiac disease called senile systemic amyloidosis. The aggregation of one of > 80 TTR variants leads to familial amyloidosis encompassing a collection of disorders characterized by peripheral neuropathy and/or cardiomyopathy. Prominent central nervous system (CNS) impairment is rare in TTR amyloidosis. Herein, we identify a new A25T TTR variant in a Japanese patient who presented with CNS amyloidosis at age 42 and peripheral neuropathy at age 44. The A25T variant is the most destabilized and fastest dissociating TTR tetramer published to date, yet, surprising, disease onset is in the fifth decade. Quantification of A25T TTR in the serum of this heterozygote reveals low levels relative to WT, suggesting that protein concentration influences disease phenotype. Another recently characterized TTR CNS variant (D18G TTR) exhibits strictly analogous characteristics, suggesting that instability coupled with low serum concentrations is the signature of CNS pathology and protects against early-onset systemic amyloidosis. The low A25T serum concentration may be explained either by impaired secretion from the liver or by increased clearance, both scenarios consistent with A25T's low kinetic and thermodynamic stability. Liver transplantation is the only known treatment for familial amyloid polyneuropathy. This is a form of gene therapy that removes the variant protein from serum preventing systemic amyloidosis. Unfortunately, the choroid plexus would have to be resected to remove A25T from the CSF-the source of the CNS TTR amyloid. Herein we demonstrate that small-molecule tetramer stabilizers represent an attractive therapeutic strategy to inhibit A25T misfolding and CNS amyloidosis. Specifically, 2-[(3,5-dichlorophenyl)amino]benzoic acid is an excellent inhibitor of A25T TTR amyloidosis in vitro.     

Expression of membrane-bound and soluble receptor activator of NF-kappaB ligand (RANKL) in human T cells

The receptor activator of NF-kappaB ligand (RANKL) and its receptor RANK are critical regulators for immune responses as well as bone remodeling. RANKL is a type II transmembrane protein that has two forms-a membrane-anchored protein and a secreted protein. In this report, we demonstrate for the first time the kinetical expression of two forms of RANKL in human T cells using two monoclonal antibodies (mAbs) against human RANKL, which we newly derived. Freshly isolated T cells rarely expressed mRANKL, while the activation of T cells induced a substantial but minimal level of mRANKL as well as the accumulation of considerable amounts of sRANKL. The addition of the metalloprotease inhibitor KB-R8301 efficiently suppressed the release of sRANKL from activated T cells or RANKL-transfectants, and reciprocally enhanced the mRANKL expression. The membrane form of RANKL was also expressed on the infiltrating T cells in the rheumatoid synovial fluid and in the gingival tissues of patients with periodontitis. Our results demonstrate that the expression of mRANKL on T cells is strictly limited, and the majority of RANKL protein produced by T cells may be active in the soluble form after shedding. The mAbs that were derived in this study may be useful for investigating the regulation and function of RANKL in immune responses and bone remodeling.     

Effects of L-arginine on spontaneous contraction of the rat portal vein

The effects of L-arginine on spontaneous contraction of endothelium-denuded longitudinal preparations of the rat portal vein were studied. L-arginine increased the frequency of spontaneous contraction concentration-dependently between 10 microM and 1 mM. Changes in contraction amplitude and duration were not remarkable. D-arginine had a negligible effect on spontaneous contraction. N(omega)-nitro-L-arginine (1 mM) did not affect spontaneous contraction or the response to L-arginine. Addition of N(G)-monomethyl-L-arginine (1 mM), l-lysine (1 mM) or N-ethymaleimide (0.1 mM) increased the frequency of spontaneous contractions and inhibited the effect of L-arginine. Glibenclamide (10 microM) did not affect spontaneous contraction or the response to L-arginine. Spontaneous increase in concentration of intracellular Ca2+, estimated as the ratio of Fura-PE3 fluorescence occurred synchronously with spontaneous contraction. Spontaneous increase in concentration of intracellular Ca2+ occurred more frequently in the presence of L-arginine (1 mM). L-arginine (1 mM) also increased the number of action potential bursts/min in the longitudinal smooth muscle layer. L-arginine (1 mM) also depolarized cell membranes. This study indicates that L-arginine increases the frequency of spontaneous contraction of longitudinal muscle in the rat portal vein by membrane depolarization through mechanisms that do not involve nitric oxide or the inhibition of ATP-sensitive K+ channels.     

Ro52 functionally interacts with IgG1 and regulates its quality control via the ERAD system

The 52-kDa form of SSA/Ro protein (Ro52) is one of autoantigens associated with autoimmune disorders such as systemic lupus erythematosus and Sj?gren's syndrome. Anti-SSA/Ro antibodies, the biological function of which remains unknown, are frequently found in the serum of these patients. Recent functional genomic approaches have shown that Ro52/TRIM21 is one of the TRIM family proteins with a RING-finger domain which is closely associated with E3 ubiquitin ligase activity. We found by using yeast-two hybrid screening that Ro52 has an E3 activity in vitro and interacts with human IgG1 heavy chain. We also found that IgG1 heavy chain was modified with polyubiquitination by Ro52 and degraded through the ubiquitin-proteasome system in mammalian cells. Our results also showed that Ro52 interacts with the molecular chaperone p97/VCP, which is thought to function in the endoplasmic reticulum associated degradation (ERAD) system. It is likely that Ro52 plays a role in proteasomal degradation of unfolded IgG1, which is retrogradely transferred from the endoplasmic reticulum to the cytosol. Taken together, our findings suggest that Ro52 plays a significant role in quality control of IgG1 through the ERAD system.     

Expression of thioredoxin and thioredoxin-binding protein-2 in the liver of patients with chronic hepatitis C as a predictor of response to interferon therapy

Oxidative stress contributes to the pathogenesis of various hepatic injuries. Thioredoxin (TRX) is an indicator of oxidative stress, reported to be increased in the serum of patients with chronic hepatitis C with the progression of fibrosis. The aim of this study was to evaluate the clinical significance of the expression of TRX and thioredoxin-binding protein-2 (TBP-2), which is a negative regulator of TRX function, in the liver of patients with chronic hepatitis C and the relationship of this to the efficacy of interferon (IFN) treatment. A retrospective study was performed using the liver biopsy specimens obtained before IFN treatment from 69 patients with chronic serotype 1 hepatitis C virus (HCV) infection. TRX and TBP-2 mRNA levels in the liver biopsy specimens were amplified by real-time RT-PCR. The serum TRX protein level was estimated with a sandwich enzyme-linked immunosorbent assay kit, and the expression of TRX protein in the liver was examined immunohistochemically in 19 patients. There was no association between the serum TRX level and the TRX level in the liver. There was a significant correlation between the expression level of TRX protein in the liver and the TRX mRNA level in the liver. TRX and TBP-2 levels in the liver tended to decrease slightly with increased fibrosis stage, although not significantly. The TRX level in the liver tended to increase with hepatitis activity index, although not significantly. TBP-2 mRNA levels in the liver were significantly higher in responders than non-responders to the IFN therapy (p<0.05). Among patients who had a high viral load of >850 KIU/ml, the TRX level in the livers of non-responders was significantly lower than that in the livers of responders (p<0.05). TRX and TBP-2 mRNA levels in the liver before IFN therapy may predict the outcome of IFN therapy in patients with chronic serotype 1 HCV infection.     

Kallikrein 6 secreted by oligodendrocytes regulates the progression of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), and experimental autoimmune encephalomyelitis (EAE) is a well‐established animal model of the disease. Here, we examined the pathophysiological role of Kallikrein 6 (Klk6), a serine protease produced by oligodendrocytes (OLs), in EAE using Klk6 knockout (Klk6?/?) mice. Compared with Klk6+/+ (wild‐type) mice, Klk6?/? mice showed milder EAE symptoms, including delayed onset and milder paralysis. Loss of Klk6 suppressed matrix metalloprotease‐9 expression and diminished the infiltration of peripheral inflammatory cells into the CNS by decreasing blood–brain barrier (BBB) permeability and reducing expression levels of inflammatory cytokines, chemokines and their receptors. Scanning electron microscopic analysis revealed demyelination characterized by myelin detachment from the axons in the early phase of EAE progression (days 3–7) in Klk6+/+ mice but not in Klk6?/? mice. Interestingly, anti‐MOG (myelin oligodendrocyte glycoprotein) autoantibody was also detected in the cerebrospinal fluid (CSF) and spinal cord on day 3 after MOG immunization. Furthermore, treatment of primary cultured OLs with anti‐MOG autoantibody induced oligodendroglial morphological changes and increases in myelin basic protein and Klk6 expression. We also developed a novel enzyme‐linked immunoabsorbent assay method for detecting activated KLK6 in human CSF. In human autopsy brain samples, expression of active KLK6 was detected in OLs using an antibody that specifically recognizes the protein's activated form. Taken together, our findings demonstrate that Klk6 secreted by OLs plays a critical role in the pathogenesis of EAE/MS and that it might serve as a potential therapeutic target for MS.     

Impact on perceived postnatal support,maternal anxiety and symptoms of depression in new mothers in Nepal when their husbands provide continuous support during labour

Background

when a husband provides continuous support during his wife's labour, his presence is considered effective in reducing her dissatisfaction with the childbirth process. The impact of this on the postnatal well-being of a new mother, however, is not clear.

Objective

to examine the impact on postnatal support, maternal anxiety and symptoms of depression experienced by new mothers in Nepal when their husband supported them continuously during labour.

Method

the study involved 231 Nepali women, of whom 77 were supported continuously by their husbands, 75 by female friends, and 79 were not supported by any companion during childbirth. They were contacted at six to eight weeks post partum, when postpartum support questionnaires, a state-trait anxiety inventory and the Edinburgh postnatal depression scale were administered. Structural equation modelling was conducted.

Findings

observations showed that continuous support from a husband during his wife's labour was related to a greater degree of postnatal support than those who were not supported by their husband during labour (β=0.23, p<0.001). Similarly, the more the women considered they were being supported, the less likely they were to experience maternal anxiety (β=−0.52, p<0.001), which in turn was associated with a lower level of depression (β=0.43, p<0.001). These findings were consistent, even after adjustments for the effect of female support during the postnatal period.

Conclusion

the study suggests that continuous support from husbands during labour has a direct impact on the perceived postnatal support, and an indirect impact on anxiety and depression in new mothers in Nepal.     

Predictive factors for recurrence of ovarian mature cystic teratomas after surgical excision

Objective

To study the recurrence rate and predictive factors for recurrence after surgical excision of ovarian mature cystic teratomas (MCT).

Study design

Retrospective study of 382 patients who underwent surgical excision of MCT and whose post-surgical follow-up data were available over six months. Patients who underwent concomitant oophorectomy or had a history of oophorectomy were excluded. Medical records were reviewed for evidence of recurrence. The Cox-hazard model was used for the estimation of predictive factors for recurrence. Categorical data were compared using the Chi-square and Fisher's exact tests.

Results

There were 16 recurrences within a mean follow-up period of 43.0 months, with a recurrence rate of 4.2%. Young age (<30 years old, Y) (hazard ratio (HR) 2.98; 95% confidence interval (CI) 1.04–8.62, P = 0.043), large cyst (≥8 cm in diameter, L) (HR 2.75; 95% CI 1.03–7.37, P = 0.044), and bilaterality (B) (HR 2.88; 95% CI 1.07–7.76, P = 0.036) were shown to be significant predictive factors. When a patient had all these three factors, the recurrence rate was 21.0%, otherwise 3.4% (P < 0.01). Patients with Y + L, Y + B, and B + L also showed significantly higher recurrence rate (21.4%, 15.9%, and 11.4%, respectively).

Conclusion

The long-term recurrence rate after surgical excision of MCT in this study is 4.2%. A patient with young age (<30 years old) or large cyst (≥8 cm in diameter) or bilateral cysts is at high risk of recurrence, which is even higher when a patient has more than one of these factors.