A mouse model of pemphigus vulgaris by adoptive transfer of naive splenocytes from desmoglein 3 knockout mice

BACKGROUND

Pemphigus vulgaris (PV) is an autoimmune blistering disease caused by antidesmoglein3 (anti-Dsg3) IgG autoantibodies. Recently, we developed a PV mouse model by adoptive transfer of splenocytes from recombinant Dsg3-immunized Dsg3(-/-) mice to Rag2(-/-) immunodeficient mice that expressed Dsg3.

OBJECTIVES

We determined whether the adoptive transfer of naive splenocytes from nonimmunized Dsg3(-/-) mice induces the anti-Dsg3 IgG production and the PV phenoytpe in recipient mice.

METHODS

We adoptively transferred naive Dsg3(-/-) splenocytes into Rag2(-/-) mice and compared their PV phenoytpe with those mice receiving immunized Dsg3(-/-) splenocytes. The numbers of splenocytes and their subpopulations required for anti-Dsg3 IgG production were examined.

RESULTS

Mice that received naive Dsg3(-/-) splenocytes produced anti-Dsg3 IgG, which bound to keratinocyte cell surfaces in vivo, and developed the PV phenotype, including oral erosions with suprabasilar acantholysis. Antibody production and the appearance of the PV phenotype were delayed by approximately 2 weeks in mice that received naive splenocytes compared with mice that received immunized splenocytes. However, once the PV phenotypes developed, there were no apparent differences in disease severity between the two models. Interestingly, the anti-Dsg3 IgG titres were significantly lower in mice that received naive splenocytes than in mice that received immunized splenocytes, suggesting that the former antibodies were more potent than the latter. The frequency of anti-Dsg3 IgG production depended on the number of transferred naive splenocytes. Both CD4+ T cells and B220+ B cells from naive Dsg3(-/-) mice were essential for the production of anti-Dsg3 IgG antibodies.

CONCLUSIONS

Dsg3-specific naive lymphocytes in Dsg3(-/-) mice can be primed and activated by the endogenous Dsg3 in recipient mice to produce pathogenic anti-Dsg3 IgG without active immunization. This approach using naive lymphocytes provides a unique model to dissect immunological mechanisms of tolerance against peripheral autoimmune targets.

Autologous hematopoietic stem cell transplantation for refractory antiphospholipid syndrome causing myocardial necrosis

Autologous hematopoietic stem cell transplantation (HSCT) is currently being evaluated as a treatment for autoimmune diseases, including systemic lupus erythematosus (SLE), that are associated with a very severe prognosis. We describe a 27-year-old woman with SLE with a 10-year history of refractory antiphospholipid syndrome (APS). She developed progressive myocardial necrosis despite treatment with corticosteroids, cyclophosphamide (CYC), cyclosporine, and immunopheresis. After conditioning with CYC, fludarabine, and antithymocyte globulin, autologous HSCT using CD34(+) selection was performed. After transplantation, the clinical symptoms caused by APS remitted, and the serum anticardiolipin antibody level decreased. Remission has persisted for 21 months after transplantation. Although a longer follow-up is required for the assessment of efficacy, autologous HSCT may cure patients with refractory APS.

Detection of circulating autoantibodies using living keratinocyte staining on MCA-B1 method in dogs with pemphigus foliaceus

In this study, we compared the sensitivity and specificity of three immunofluorescence techniques used to detect circulating autoantibodies in dogs with pemphigus foliaceus (PF); living keratinocyte staining on a canine keratinocyte cell line, MCA-B1, indirect immunofluorescence (IIF) on canine lip and IIF on bovine esophagus. Sera from canine PF cases were positive in four out of 27 dogs (14.8%) using living keratinocyte staining on MCA-B1 cells method, and five (18.5%) and eight sera (29.6%) using IIF on canine lip and bovine esophagus methods, respectively. By contrast, none of the 31 sera from dogs with non-pemphigus dermatoses reacted with MCA-B1 cells, whereas two (6.5%) as well as five sera (16.1%) obtained from those dogs showed positive reactivity with IIF on canine lip and bovine esophagus, respectively. Our results suggest that, although it exhibits the least sensitivity, the positive reactivity obtained by living keratinocyte staining on MCA-B1 cells can support the diagnosis of canine PF.

Prospective analysis of percutaneous central venous catheterization in infants <4.0 kg undergoing cardiac surgery

Our previous study showed that the success rate of cannulation of the internal jugular vein (IJV) was significantly decreased in infants weighing less than 4.0 kg. We prospectively evaluated results of central venous catheterization in 101 infants weighing less than 4.0 kg undergoing cardiac surgery. The first attempt was routinely performed on the right IJV. If the first attempt failed, the anesthesiologist was free to choose the cannulation site. We examined the effects of patient weight and the experience of the anesthesiologist on successful central catheterization and efficacy of the external jugular vein (EJV) if the first attempt failed. The first right IJV cannulation was successful in 53 infants (52.5%) and the overall successful catheterization rate was 82.2%. Success rates of cannulation of the right IJV, left IJV, and EJV were 64, 13, and 6%, respectively. Body weight contributed significantly to successful catheterization, but the experience of the anesthesiologist did not. These results suggest that EJV cannulation improves the successful central catheterization in infants weighing less than 4.0 kg if IJV cannulation fails. Body weight of an infant, but not the experience of the anesthesiologist, contributed to successful catheterization in this patient population.

Sub-genomic replicons of Tick-borne encephalitis virus

We constructed three sub-genomic replicons of Tick-borne encephalitis virus (TBEV) (Oshima REP, Oshima REP-GFP and Oshima REP-Neo) by deleting genes coding for structural proteins without or with insertion of green fluorescent protein (GFP) or Neo genes, respectively. BHK cells transfected with Oshima REP expressed the viral non-structural antigens in immunofluorescent and western blot analyses. GFP and viral antigens were co-expressed in the transfected cells with Oshima REP-GFP. G418-resistant cells harboring Oshima REP-Neo consistently expressed the antigens without showing any apparent CPE. These replicons constructed in this study will be useful in studies on the replication, assembly and packaging of TBEV, and to develop vaccines and gene-delivering systems.

A severe hepatic disorder with myelodysplastic syndrome, treated with cytarabine ocfosfate, in a dog

An 8-year-old female Shih Tzu was presented with weight loss and vomiting. Alanine aminotransferase was high and abdominal radiographs revealed hepato- and splenomegaly. Mild anaemia, neutrophilia with left shift, eosinophilia, a thrombocytosis with dysplastic features of eosinophils and platelets, were detected. The animal was initially considered to have hepatitis and was treated accordingly, but clinical signs persisted. Histological examination of liver biopsy samples showed disruption of the hepatic lobule, with extensive infiltration by haemopoietic cells. Further investigation of the bone marrow suggested a diagnosis of myelodysplastic syndrome. The animal was treated with cytarabine ocfosfate, a prodrug of cytosine arabinoside, and appeared to recover.

[Pulmonary dirofilariasis resected by video-assisted thoracoscopy; report of a case]

A 35-year-old female was admitted for biopsy of abnormal shadow on chest X-ray. She was operated on for partial wedge resection of the right lower lobe by video-assisted thoracoscopy without complication. Pathological findings in operation showed inflammatory benign tissues and suggested pulmonary dirofilariasis. Serologic examination was negative after operation, however histological diagnosis supported pulmonary dirofilariasis because a pulmonary artery embolism of calcified tissues consisted of non-human cells. There may be many cases due to old infections like this one, so it is important to consider it for diagnosis and perform more positive surgical procedures. We review a case of pulmonary dirofilariasis safely resected by video-assisted thoracoscopy for diagnosis by exclusion.

Characterization of Oita virus 296/1972 of Rhabdoviridae isolated from a horseshoe bat bearing characteristics of both lyssavirus and vesiculovirus

Oita virus 296/1972 was isolated from the blood of a wild horseshoe bat, Rhinolophus cornutus (Temminck) in 1972. We investigated the pathogenicity of this virus in mice in relation to its histological, immunohistochemical and ultrastructural characteristics and the entire sequence of nucleoprotein gene. This virus caused lethal encephalitis in mice through intracerebral route. This susceptibility of mice was until 3 weeks of age. Immunohistochemical analysis using the convalescent sera obtained from survived adult mice after intracerebral inoculation revealed that many neurons were positive in the cytoplasm, besides no cross reactivity with normal and rabies virus-infected mouse brain tissues to this anti-sera. Ultrastructural analysis disclosed many bullet-shaped and enveloped virions in neurons. These morphological characteristics of the virions are consistent of that of viruses in the family Rhabdoviridae. Budding from endoplasmic membrane suggests that this virus has a similarity with lyssaviruses. Molecular analysis of cDNA coding a tentative nucleoprotein sequence revealed homology with those of viruses in the family Rhabdoviridae. Distance matrix analysis of this gene sequence with those of other rhabdoviruses isolated from mammals disclosed the discrete position of this virus in the phylogenic tree of rhabdoviridae infecting mammals and we renamed this virus as Oita rhabdovirus.

In vitro and in vivo analysis of human herpesvirus-6 U90 protein expression

In order to establish a reliable method for the detection of human herpesvirus-6 (HHV-6) B antigens in peripheral blood mononuclear cells (PBMCs) collected from HHV-6 infected patients, we created a polyclonal antibody against the HHV-6 B U90 protein (IEA/ex3) and used it to examine the expression of this protein in virus-infected cells and patients' PBMCs. This antibody reacted with 170 and 195 kDa proteins in HHV-6 B-infected cord blood mononuclear cells. The IEA/ex3 antigen was detected in cord blood mononuclear cells at 6 hr post-infection, and the number of infected cells reached its maximum at 48 hr post-infection. The antigen stained in a punctate pattern and partially localized to the promyelocytic leukemia (PML) protein body. We also examined 60 PBMC samples from 60 febrile children (3-19 months old) and detected IEA/ex3 antigen in the PBMCs by laser-scanning microscopy. HHV-6 was isolated from 31 of the 60 samples. The sensitivity and specificity of the antigen detection were 84% (26/31) and 97% (28/29), respectively, in the samples with virus detected. The mean number of antigen-positive PBMCs was 409/10(6) cells in 20 samples with viral isolation. A significant correlation (r = 0.566; P = 0.008) was observed between the viral load and number of antigen-positive cells. Although IEA/ex3 antigen was detected by laser-scanning microscopy in PBMCs (without cultivation) collected from six patients with isolated virus, it was detected in only one sample by conventional fluorescence microscopy. Increasing the intensity by cultivation (24 hr) resulted in a higher detection rate (5/6) even by conventional fluorescence microscopy, which is available in most hospital laboratories.

Localized character of 4f electrons in CeRhx (x=2,3) and CeNix (x=2,5)

We have measured Ce 4f spectral weights of extremely alpha-like Ce transition metal intermetallic compounds CeRhx (x=2,3) and CeNix (x=2,5) by using the bulk-sensitive resonant photoemission technique at the Ce M5(3d(5/2)-->4f) edge. High energy resolution and longer escape depth of photoemitted electron at this photon energy enabled us to distinguish the sharp Kondo resonance tails at the Fermi level, which can be well described by the Gunnarsson-Schönhammer calculation based on the Anderson impurity Hamiltonian. On the other hand, the itinerant 4f band description shows big discrepancies, which implies that Ce 4f electrons retain localized characters even in extremely alpha-like compounds.

Right Ventricle of Patients Undergoing Congenital Cardiac Surgery Differentially Expresses Haem Oxygenase-1 and Heat Shock Protein 70 Genes

Reactive oxygen species are implicated in the pathogenesis of cardiac hypertrophy. Haem oxygenase-1 (HO-1), the rate-limiting enzyme in haem catabolism, is induced by oxidative stress and confers protection against oxidative tissue injuries. We used Northern blotting to examine expression of HO-1 and heat shock protein 70 (HSP70) in the hypertrophic cardiac muscle of eight patients (one infant and seven children) who underwent surgery for congenital heart disease. Levels of HO-1 and HSP70 mRNA were significantly increased in all specimens, but the orders of magnitude of the increases were different, suggesting that the genes expressing HO-1 and HSP70 are regulated separately.