Effector memory CD4+T cells in mesenteric lymph nodes mediate bone loss in food-allergic enteropathy model mice, creating IL-4 dominance.

Intestinal inflammation can be accompanied by osteoporosis, but their relationship, mediated by immune responses, remains unclear. Here, we investigated a non-IgE-mediated food-allergic enteropathy model of ovalbumin (OVA) 23-3 mice expressing OVA-specific T-cell-receptor transgenes. Mesenteric lymph nodes (MLNs) and their pathogenic CD4+T cells were important to enteropathy occurrence and exacerbation when the mice were fed an egg-white (EW) diet. EW-fed OVA23-3 mice also developed bone loss and increased CD44hiCD62LloCD4+T cells in the MLNs and bone marrow (BM); these changes were attenuated by MLN, but not spleen, resection. We fed an EW diet to F1 cross offspring from OVA23-3 mice and a mouse line expressing the photoconvertible protein KikGR to track MLN CD4+T cells. Photoconverted MLN CD44hiCD62LloCD4+T cells migrated predominantly to the BM; pit formation assay proved their ability to promote bone damage via osteoclasts. Significantly greater expression of IL-4 mRNA in MLN CD44hiCD62LloCD4+T cells and bone was observed in EW-fed OVA23-3 mice. Anti-IL-4 monoclonal antibody injection canceled bone loss in the primary inflammation phase in EW-fed mice, but less so in the chronic phase. This novel report shows the specific inflammatory relationship, via Th2-dominant-OVA-specific T cells and IL-4 production, between MLNs and bone, a distant organ, in food-allergic enteropathy.

A New CD10 Antibody Inhibits the Growth of Malignant Mesothelioma.

Malignant mesotheliomas (MMs) are aggressive therapy-resistant tumors that generally have a poor prognosis. We previously reported the establishment of four new monoclonal antibodies (mAbs) for the diagnosis and treatment of MM. In this report, we characterized one of these antibodies, JMAM-1. The molecules whose antibodies were calibrated were picked up, transfected assuming CD10, and elucidated by fluorescence activated cell sorter. Survival experiments were performed using tumor-bearing mice model. JMAM-1 mAb was found to bind with CD10 antigen. The Kaplan-Meier survival curve showed a small but prolonged survival effect. JMAM-1 mAb-treated MSTO-211H cells showed increased cell cycle arrest involved by cyclin-dependent-kinase. JMAM-1 antibody has cytostatic effect and may be a candidate for the treatment of MM. Among mesothelioma, CD10-positive cases have been reported to have a poorer prognosis than negative cases, which can be used as a tool for diagnosis.

Microsatellite instability and mismatch repair protein expressions in lymphocyte-predominant breast cancer.

The frequency of microsatellite instability (MSI) is reportedly extremely low in breast cancer, despite widespread clinical expectations that many patients would be responsive to immune-checkpoint inhibitors (ICI). Considering that some triple-negative breast cancers (TNBC) responded well to ICI in a clinical trial and that a high density of tumor-infiltrating lymphocytes (TILs) is frequently observed in other cancers with high levels of microsatellite instability (MSI-H), we hypothesized that some TNBC with a high density of TILs would be MSI-H. Medullary carcinoma (MedCa) of the breast, a rare histological type, is characterized by a high density of TILs. Considering that MedCa of the colon is often MSI-H, we suspected that MedCa in breast cancer might also include MSI-H tumors. Therefore, we conducted MSI tests on such breast cancers with a high density of TILs. The MSI status of 63 TIL-high TNBC and 38 MedCa tumors, all from Asian women who had undergone curative surgery, were determined retrospectively. DNA mismatch repair (MMR) proteins and PD-L1 expression were also investigated immunohistochemically. All samples were microsatellite stable, being negative for all microsatellite markers. TIL-high TNBC with low MLH1 protein had higher levels of PD-L1 in stromal immune cells (P = .041). MedCa tumors showed significantly higher PD-L1 expression in immune cells than in TIL-high TNBC (<.001). We found that MSI-H tumors were absent in TIL-high breast cancers. Examination of MMR proteins, not a purpose of Lynch syndrome screening, may merit further studies to yield predictive information for identifying patients who are likely to benefit from ICI.

Vasculitis and crescentic glomerulonephritis in a newly established congenic mouse strain derived from ANCA-associated vasculitis-prone SCG/Kj mice.

Lupus nephritis (LN) is the secondary glomerulonephritis (GN) involved in systemic lupus erythematosus (SLE) and a typical immune complex-type GN. Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is an autoimmune disease characterized by systemic vasculitis and pauci-immune-type crescentic glomerulonephritis (CrGN) with ANCA production. Human AAV causes death due to lung haemorrhage and end-stage renal disease, for which renal replacement therapies are necessary. The SLE/AAV overlap syndrome was recently reported in humans. The spontaneous crescentic glomerulonephritis-forming/Kinjoh (SCG/Kj) mouse is a unique model of human AAV showing production of myeloperoxidase (MPO)-ANCA. We previously discovered seven disease susceptibility quantitative trait loci (QTL) derived from SCG/Kj mice by linkage analysis. To investigate the individual functions of each QTL, and to identify AAV susceptibility genes, we introduced them into a B6/lpr background to establish SCG/Kj interval congenic mice (SICM). B6/lpr.C1scg mice, a type of SICM, exhibited the production of autoantibodies, including MPO-ANCA. The GN in B6/lpr.C1scg mice was not pauci-immune type: deposition of immunoglobulins and complement components was observed in nephritic glomeruli, similar to that in LN. The incidence of GN in female B6/lpr.C1scg mice was 100%. Granulocyte infiltration was also observed in the glomerular tuft and crescents. B6/lpr.C1scg mice also displayed vasculitis in multiple organs, most frequently the lung and kidney. Vasculitis was characterized by the infiltration of mononuclear cells to vascular walls followed by granulocyte infiltration, resembling human lupus vasculitis. The incidence of lung vasculitis was over 90% in male and female B6/lpr.C1scg mice. Blood MPO-ANCA levels were significantly associated with histopathological disease phenotypes. MPO deposition was observed in nephritic glomeruli, and granulocytes infiltrated into inflamed vessels and glomeruli. These observations suggest that the activation of granulocytes and local MPO release contribute to the pathogenesis of GN and vasculitis. As a monocongenic mouse, B6/lpr.C1scg mice show the association between murine chromosome 1 segment and autoimmunity. This strain can be used as a model of the SLE/AAV overlap syndrome, and will be useful for elucidating the mechanism of ANCA generation and the pathogenesis of CrGN and vasculitis, as well as in the search for genetic factors related to AAV.

Development of novel monoclonal antibodies with specific binding affinity for denatured human CD26 in formalin-fixed paraffin-embedded and decalcified specimens.

A 110-kDa type II transmembrane glycoprotein with dipeptidyl peptidase IV (DPPIV) activity in its extracellular region, CD26 has a multitude of biological functions and plays an important role in the regulation of inflammatory responses and tumor biology. Our work has focused on CD26 as a novel therapeutic target for various tumors and immune disorders, and we have recently developed a humanized anti-CD26 monoclonal antibody (mAb), YS110, which has promising safety profile and clinical activity in patients with malignant pleural mesothelioma. The development of an anti-human CD26 mAb that can clearly and reliably detect the denatured CD26 molecule in formalin-fixed paraffin-embedded (FFPE) tissues in the clinical setting is therefore of the utmost importance. To develop novel anti-CD26 mAbs capable of binding to denatured CD26, we immunized mice with urea-treated CD26 protein. Hybridoma supernatants were screened for specific reactivity with human CD26 by immunostaining through the use of a set of FFPE human CD26-positive or negative tumor cell lines. This screening method enables us to develop novel anti-human CD26 mAbs suitable for immunohistochemical staining of CD26 in FFPE non-tumor and tumor tissue sections with reliable clarity and intensity. Specifically, these mAbs display strong binding affinity to denatured human CD26 rather than undenatured human CD26, and are capable of detecting denatured human CD26 in decalcified specimens. These novel anti-CD26 mAbs are potentially useful for the analysis of CD26 expression in cancer patients with bony metastasis, and may help decide the appropriateness of YS110 therapy for future cancer patients.

Biological Effects of IL-26 on T Cell-Mediated Skin Inflammation, Including Psoriasis.

Psoriasis is a chronic inflammatory skin disease characterized mainly by epidermal hyperplasia, scaling, and erythema; T helper 17 cells have a role in its pathogenesis. Although IL-26, known as a T helper 17 cytokine, is upregulated in psoriatic skin lesions, its precise role is unclear. We investigated the role of IL-26 in the imiquimod-induced psoriasis-like murine model using human IL-26 transgenic mice. Erythema symptoms induced by daily applications of imiquimod increased dramatically in human IL-26 transgenic mice compared with controls. Vascularization and immune cell infiltration were prominent in skin lesions of human IL-26 transgenic mice. Levels of fibroblast growth factor (FGF) 1, FGF2, and FGF7 were significantly upregulated in the skin lesions of imiquimod-treated human IL-26 transgenic mice and psoriasis patients. In vitro analysis demonstrated that FGF1, FGF2, and FGF7 levels were elevated in human keratinocytes and vascular endothelial cells following IL-26 stimulation. Furthermore, IL-26 acted directly on vascular endothelial cells, promoting proliferation and tube formation, possibly through protein kinase B, extracellular signal-regulated kinase, and NF-κB pathways. Moreover, similar effects of IL-26 were observed in the murine contact hypersensitivity model, indicating that these effects are not restricted to psoriasis. Altogether, our data indicate that IL-26 may be a promising therapeutic target in T cell-mediated skin inflammation, including psoriasis.

Establishment of anti-mesothelioma monoclonal antibodies.

BACKGROUND: Mesotheliomas are aggressive, therapy-resistant tumors that are predicted to increase in incidence at least until 2020. The prognosis of patients with mesothelioma is generally poor because they are typically diagnosed at a late stage and their tumors are resistant to current conventional therapies. For these reasons, improved diagnosis and therapy are urgently required. To address these issues, the aim of our research was to develop novel mesothelioma-specific monoclonal antibodies (mAbs) as diagnostic and therapeutic agents. METHODS: To develop anti-mesothelioma mAbs useful for diagnosis and therapy, we repeatedly immunized a BALB/c mouse with viable mesothelioma cells, alternating between those from three mesothelioma cell lines. We hybridized the spleen cells from this immunized mouse with P3U1 myeloma cells. We then screened supernatants harvested from the hybridoma clones by assessing whether they bound to a mesothelioma cell line not used for immunization and altered its morphology. We designed this developmental strategy to reduce the risk of obtaining clonotypic mAbs against a single mesothelioma cell line. RESULTS: Our newly generated mouse anti-human mAbs immunostained clinical samples of mesotheliomas. One of the newly generated mAbs did not react with any other tumor cell line tested. Two other mAbs significantly inhibited the proliferation of mesothelioma cells. CONCLUSION: These newly generated anti-mesothelioma mAbs are potentially useful as diagnostic and therapeutic agents for mesothelioma. Moreover, our novel strategy for establishing antitumor mAbs may facilitate the development of new diagnostic and therapeutic techniques for mesotheliomas and other malignancies.

Establishment of a Therapeutic Anti-Pan HLA-Class II Monoclonal Antibody That Directly Induces Lymphoma Cell Death via Large Pore Formation.

To develop a new therapeutic monoclonal Antibody (mAb) for Hodgkin lymphoma (HL), we immunized a BALB/c mouse with live HL cell lines, alternating between two HL cell lines. After hybridization, we screened the hybridoma clones by assessing direct cytotoxicity against a HL cell line not used for immunization. We developed this strategy for establishing mAb to reduce the risk of obtaining clonotypic mAb specific for single HL cell line. A newly established mouse anti-human mAb (4713) triggered cytoskeleton-dependent, but complement- and caspase-independent, cell death in HL cell lines, Burkitt lymphoma cell lines, and advanced adult T-cell leukemia cell lines. Intravenous injection of mAb 4713 in tumor-bearing SCID mice improved survival significantly. mAb 4713 was revealed to be a mouse anti-human pan-HLA class II mAb. Treatment with this mAb induced the formation of large pores on the surface of target lymphoma cells within 30 min. This finding suggests that the cell death process induced by this anti-pan HLA-class II mAb may involve the same death signals stimulated by a cytolytic anti-pan MHC class I mAb that also induces large pore formation. This multifaceted study supports the therapeutic potential of mAb 4713 for various forms of lymphoma.

Identification of a probiotic bacteria-derived activator of the aryl hydrocarbon receptor that inhibits colitis.

The aryl hydrocarbon receptor (AhR) recognizes environmental xenobiotics and is originally thought to be involved in the metabolism (detoxification) of the substances. Recently, AhR is highlighted as an important regulator of inflammation. Notably, accumulating evidence suggests that activation of the AhR suppresses inflammatory bowel diseases (IBDs). Therefore, non-toxic AhR activators become attractive drug candidates for IBD. This study identified 1,4-dihydroxy-2-naphthoic acid (DHNA), a precursor of menaquinone (vitamin K2) abundantly produced by Propionibacterium freudenreichii ET-3 isolated from Swiss-type cheese, as an AhR activator. DHNA activated the AhR pathway in human intestinal epithelial cell line Caco2 cells and in the mouse intestine. Oral treatment of mice with DHNA induced anti-microbial proteins RegIIIß and γ in the intestine, altered intestinal microbial flora and inhibited dextran sodium sulfate (DSS)-induced colitis, which recapitulated the phenotypes of AhR activation in the gut. As DHNA is commercially available in Japan as a prebiotic supplement without severe adverse effects, DHNA or its derivatives might become a promising drug candidate for IBD via AhR activation. The results also implicate that intestinal AhR might act not only as a sensor for xenobiotics in diet and water but also for commensal bacterial activity because DHNA is a precursor of vitamin K2 produced by vitamin K2-synthesizing commensal bacteria as well as propionic bacteria. Hence, DHNA might be a key bacterial metabolite in the host-microbe interaction to maintain intestinal microbial ecosystem.

Establishment of monoclonal anti-human CD26 antibodies suitable for immunostaining of formalin-fixed tissue.

BACKGROUND: A T cell costimulatory molecule with dipeptidyl peptidase IV (DPPIV) activity in its extracellular region, CD26 is a multifunctional molecule associated with various proteins such as adenosine deaminase, caveolin-1, CXCR4, collagen, and fibronectin, while playing an important role in the regulation of inflammatory responses and tumor biology. We have focused on CD26 as a novel therapeutic target for various tumors and immune disorders, and have developed a humanized anti-CD26 monoclonal antibody (mAb), YS110, which is currently being evaluated in a phase I clinical trial for patients with CD26-expressing tumors, including malignant mesothelioma. Since detection of tumor CD26 expression is required for determining potential eligibility for YS110 therapy, the development of anti-human CD26 mAb that can clearly and reliably detect the denatured CD26 molecule in the formalin-fixed paraffin-embedded tissues is critical. METHODS: To develop novel anti-CD26 mAbs capable of binding to the denatured CD26, we immunized mice with CD26 protein denatured in urea buffer. After the fusion of splenocytes and myeloma cells, the mAbs were screened for specific reactivity with human CD26 by flow cytometry, enzyme-linked immunosorbent assay, and immunohistochemistry. The binding competitiveness of novel anti-CD26 mAbs with the humanized anti-CD26 mAb YS110 was also examined. RESULTS: We have succeeded in developing novel anti-human CD26 mAbs suitable for immunohistochemical staining of CD26 in formalin-fixed tissue sections with reliable clarity and intensity. Importantly, some of these mAbs exhibit no cross-reactivity with the humanized anti-CD26 mAb. CONCLUSIONS: These novel mAbs are potentially useful as companion diagnostic agents to analyze CD26 expression in the clinical setting while advancing future CD26-related research. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5987140221097729.

Dietary resveratrol prevents the development of food allergy in mice.

BACKGROUND: Resveratrol is a bioactive polyphenol enriched in red wine that exhibits many beneficial health effects via multiple mechanisms. However, it is unclear whether resveratrol is beneficial for the prevention of food allergy. This study investigated whether resveratrol inhibited the development of food allergy by using a mouse model of the disease. METHODOLOGY/PRINCIPAL FINDINGS: Mice fed standard diet or standard diet plus resveratrol were sensitized by intragastric administration of ovalbumin (OVA) and mucosal adjuvant cholera toxin (CT). Several manifestations of food allergy were then compared between the mice. The effects of resveratrol on T cells or dendritic cells were also examined by using splenocytes from OVA-specific T cell-receptor (TCR) transgenic DO11.10 mice or mouse bone marrow-derived dendritic cells (BMDCs) in vitro. We found that mice fed resveratrol showed reduced OVA-specific serum IgE production, anaphylactic reaction, and OVA-induced IL-13 and IFN-ã production from the mesenteric lymph nodes (MLNs) and spleens in comparison to the control mice, following oral sensitization with OVA plus CT. In addition, resveratrol inhibited OVA plus CT-induced IL-4, IL-13, and IFN-ã production in splenocytes from DO11.10 mice associated with inhibition of GATA-3 and T-bet expression. Furthermore, resveratrol suppressed the OVA plus CT-induced CD25 expression and IL-2 production in DO11.10 mice-splenocytes in association with decreases in CD80 and CD86 expression levels. Finally, resveratrol suppressed CT-induced cAMP elevation in association with decreases in CD80 and CD86 expression levels in BMDCs. CONCLUSIONS/SIGNIFICANCE: Ingestion of resveratrol prevented the development of a food allergy model in mice. Given the in vitro findings, resveratrol might do so by inhibiting DC maturation and subsequent early T cell activation and differentiation via downregulation of CT-induced cAMP activation in mice. These results suggest that resveratrol may have potential for prophylaxis against food allergy.

Activation of the aryl hydrocarbon receptor pathway may ameliorate dextran sodium sulfate-induced colitis in mice.

The aryl hydrocarbon receptor (AhR) recognizes numerous small xenobiotic and natural molecules, such as dioxin and natural chemicals, and is involved in the metabolism of these compounds. AhR also has a regulatory role in inflammatory responses. This study investigated whether the activation of the AhR pathway affects dextran sodium sulfate (DSS)-induced colitis, an ulcerative colitis-like model, in mice. DSS-induced colitis was ameliorated by pretreatment with a potent AhR activator, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in mice. In addition, the mice pretreated with TCDD showed increased prostaglandin E2 (PGE2) production in the colon, and inhibition of PGE2 production by indomethacin abrogated the inhibitory effects of TCDD on DSS-induced colitis. Collectively, the activation of the AhR pathway by TCDD may ameliorate DSS-induced colitis, at least in part, through PGE2 production.

Thymic stromal lymphopoietin is a critical mediator of IL-13-driven allergic inflammation.

Both thymic stromal lymphopoietin (TSLP) and IL-13 are essential cytokines for the development of allergic inflammation. However, a causal link between TSLP and IL-13 has not yet been fully elucidated. This study aimed to investigate whether IL-13 induces TSLP expression and whether the induction contributes to the development of allergic inflammation. We found that IL-13 induced TSLP expression in mouse nasal tissue specimens in a Stat6-dependent manner. In addition, intranasal challenge of mice with IL-13 induced TSLP expression in the nasal epithelium. Importantly, intranasal IL-13 challenge induced eosinophilia and goblet cell hyperplasia in the nasal mucosa in mice, which was inhibited by the blockade of TSLP activity with anti-TSLP Ab. These findings suggest that TSLP is an important mediator of IL-13-driven allergic inflammation in the nasal mucosa. Taken together with the recent findings that IL-13 is a critical downstream element for TSLP-driven allergic inflammation, TSLP may function both upstream and downstream of IL-13, thus providing an additional rationale as to why TSLP plays such a central role in the development of allergic inflammation.

A subcytotoxic dose of subtilase cytotoxin prevents lipopolysaccharide-induced inflammatory responses, depending on its capacity to induce the unfolded protein response.

Subtilase cytotoxin (SubAB) is the prototype of a newly identified family of AB(5) cytotoxins produced by Shiga toxigenic Escherichia coli. SubAB specifically cleaves the essential endoplasmic reticulum (ER) chaperone BiP (GRP78), resulting in the activation of ER stress-induced unfolded protein response (UPR). We have recently shown that the UPR following ER stress can suppress cellular responses to inflammatory stimuli during the later phase, in association with inhibition of NF-kappaB activation. These findings prompted us to hypothesize that SubAB, as a selective UPR inducer, might have beneficial effects on inflammation-associated pathology via a UPR-dependent inhibition of NF-kappaB activation. The pretreatment of a mouse macrophage cell line, RAW264.7, with a subcytotoxic dose of SubAB-triggered UPR and inhibited LPS-induced MCP-1 and TNF-alpha production associated with inhibition of NF-kappaB activation. SubA(A272)B, a SubAB active site mutant that cannot induce UPR, did not show such effects. In addition, pretreatment with a sublethal dose of SubAB, but not SubA(A272)B, protected the mice from LPS-induced endotoxic lethality associated with reduced serum MCP-1 and TNF-alpha levels and also prevented the development of experimental arthritis induced by LPS in mice. Collectively, although SubAB has been identified originally as a toxin associated with the pathogenesis of hemolytic uremic syndrome, the unique ability of SubAB to selectively induce the UPR may have the potential to prevent LPS-associated inflammatory pathology under subcytotoxic conditions.

Genetic dissection of vasculitis, myeloperoxidase-specific antineutrophil cytoplasmic autoantibody production, and related traits in spontaneous crescentic glomerulonephritis-forming/Kinjoh mice.

The spontaneous crescentic glomerulonephritis-forming/Kinjoh (SCG/Kj) mouse is a model of human crescentic glomerulonephritis and vasculitis associated with the production of the myeloperoxidase (MPO)-specific antineutrophil cytoplasmic autoantibody (MPO-ANCA). Although the disease is mediated initially by mutation of the Fas gene (lpr), SCG/Kj mice also have non-Fas predisposing genetic factors. To define these factors, genome-wide quantitative trait locus (QTL) mapping was performed on female (B(6)x SCG/Kj) F(2) intercross mice. Fourteen non-Fas QTLs were identified. QTLs of glomerulonephritis were located on chromosomes 1, 10, 13, 16, and 17, vasculitis on chromosomes 1 and 17, splenomegaly on chromosome 1, hypergammaglobulinemia on chromosomes 1, 2, 4, 6, 7, 11, 13, and 17, antinuclear Ab on chromosomes 1, 8, 10, and 12, and MPO-ANCA production on chromosomes 1 and 10. Significant QTLs derived from SCG/Kj on chromosomes 1, 2, 7, and 13 were designated Scg-1 to Scg-5, respectively, and those derived from B(6) on chromosomes 4, 6, 17, and 10 were designated Sxb-1 to Sxb-4, respectively. Two loci linked to MPO-ANCA production on chromosomes 1 and 10 were designated Man-1 and Man-2 (for MPO-ANCA), respectively. Although both Scg-1 and Scg-2 were on chromosome 1 and shared several functions, it was of interest that aberrant MPO-ANCA production was exclusively controlled by Man-1, the centromeric half region of the Scg-2 chromosomal segment. We also examined the epistatic effects between the lpr mutation and non-Fas susceptibility genes. QTLs are discussed in relation to previously described loci, with emphasis on their candidate genes.

[A 65-year-old man with rigid-bradykinetic parkinsonism, vertical gaze palsy, difficulty of eye-lid opening, and marked pseudo-bulbar palsy].

We report a 65-year-old man with rigid-bradykinetic parkinsonism, vertical gaze palsy, difficulty in eye-lid opening, and marked pseudo-bulbar palsy. He felt difficulty of it, hand movement at 59 years old. When he was 60 years old, monotonous speech and slowness of movement appeared. He visited a neurologist who noted vertical gaze palsy, neck rigidity, and bradykinesia. He was diagnosed as progressive supranuclear palsy (PSP) and given 300 mg L-Dopa/Benserazide by the neurologist. This medication improved his rigidity and bradykinesia. At 62 years of the age, his eye-lids closed involuntary and it was difficult to open. In addition, he began to complain of wearing-off, autonomic symptoms, and dysphagia. Anti-parkinsonian drugs were increased, but his bradykinesia progressed. At 64 years of the age, he was admitted to the Neurology Service of Juntendo Hospital. On admission, he was alert and not demented. No aphasia, apraxia, or agnosia was noted. In the cranial nerves, upward and downward gaze were markedly restricted. His face was hypomimic and seborrhoic. It was difficult to swallow liquid or solid for him. No weakness was noted, but he walked in small steps with freezing and falling tendency to backward. Rigidity was noted on his extremities and stronger on his left side than right. Tremor was absent. Bradykinesia of his body and extremities was marked. No cerebellar ataxia was noted. Deep tendon reflexes were within normal range. Planter response was flexor bilaterally. Myerson's sign was noted. Sensory and autonomic function were normal. He was treated with L-Dopa, Pergolide, and Bromocriptine. However, these medications improved his bradykinesia and gait disturbance only slightly, dysphagia became progressively worse. He developed aspiration pneumonia when he was 65 years old and admitted to Juntendo Hospital. A large amount of sputum was aspirated from his trachea. Two days after from admission, he was found dead on his bed. He was discussed in a neurological CPC and the chief discussant arrived at a conclusion that the patient had progressive supranuclear palsy (PSP). Other differential diagnoses included Parkinson's disease, pallido-nigroluysian atrophy (PNLA), multiple system atrophy (MSA), and corticobasal degeneration(CBD). Many participants considered that PSP or PNLA was most likely. Post-mortem exmination revealed marked nigral neuronal loss and gliosis. The globus pallidus and the luysian body changed mildly. However, the frontal cortex was relatively spared, there were many ballooned neurons in the cortical layer. Other parts were spared. With sliver (Bodian and Gallyas-Braak) and anti-phsphorylated tau stain, abundant astrocytic plaques, neurofibrillary tangles, and argyrophilic threads on the frontal cortex, striatum, and substantia nigra were seen. There was no tufted astrocyte which was hallmark of diagnosis of PSP. In addition, several Lewy bodies were seen in the brainstem. Because astrocyte plaque was considered specific for pathology of CBD, the pathologist revealed that the pathological diagnosis of this patient was CBD. Nevertheless, discussion was focused on the relatively mild degeneration of the frontal cortex for CBD.

Gain-of-function polymorphism in mouse and human Ltk: implications for the pathogenesis of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE), a complex multigenic disease, is a typical antibody-mediated autoimmune disease characterized by production of autoantibodies against a variety of autoantigens and immune complex-type tissue inflammation, most prominently in the kidney. Evidence suggests that genetic factors predisposing to aberrant proliferation/maturation of self-reactive B cells initiate and propagate the disease. In SLE-prone New Zealand Black (NZB) mice and their F1 cross with New Zealand White (NZW) mice, B cell abnormalities can be ascribed mainly to self-reactive CD5+ B1 cells. Our genome-wide scans to search for susceptibility genes for aberrant activation of B1 cells in these mice showed evidence that the gene, Ltk, encoding leukocyte tyrosine kinase (LTK), is a possible candidate. LTK is a receptor-type protein tyrosine kinase, belonging to the insulin receptor superfamily, and is mainly expressed in B lymphocyte precursors and neuronal tissues. Sequence and functional analyses of the gene revealed that NZB has a gain-of-function polymorphism in the LTK kinase domain near YXXM, a binding motif of the p85 subunit of phosphatidylinositol 3-kinase (PI3K). SLE patients also had this type of Ltk polymorphism with a significantly higher frequency compared with the healthy controls. Our findings suggest that these polymorphic LTKs cause up-regulation of the PI3K pathway and possibly form one genetic component of susceptibility to abnormal proliferation of self-reactive B cells in SLE.

A monoclonal antibody to the alpha2 domain of murine major histocompatibility complex class I that specifically kills activated lymphocytes and blocks liver damage in the concanavalin A hepatitis model.

We earlier found that a rat monoclonal antibody (mAb) RE2 can induce rapid death of murine activated, but not resting, lymphocytes and lymphocyte cell lines, in a complement-independent manner, a cell death differing from typical apoptosis or necrosis. We here found that this cell death is independent of pathways involving Fas, caspase, and phosphoinositide-3 kinase. With the advantage of producing human B cell line transfectants with stable expression of human/mouse xeno-chimeric MHC class I genes, we found that RE2 epitope resides on the murine class I alpha2 domain. However, the alpha3 domain plays a key role in transducing the death signal, which mediates extensive aggregation of the MHC class I-integrin-actin filament system, giving rise to membrane blebs and pores. In mouse models with T/NKT cell activation-associated fulminant hepatitis, administration of mAb RE2 almost completely inhibited the development of liver cell injuries. Taken collectively, this form of cell death may be involved in homeostatic immune regulation, and induction of this form of cell death using the mAbs may be potentially therapeutic for subjects with immunological diseases mediated by activated lymphocytes.

Transcriptional regulation of Fcgr2b gene by polymorphic promoter region and its contribution to humoral immune responses.

FcgammaRIIB1 molecules serve as negative feedback regulator for B cell Ag receptor-elicited activation of B cells; thus, any impaired FcgammaRIIB1 function may possibly be related to aberrant B cell activation. We earlier found deletion polymorphism in the Fcgr2b promoter region among mouse strains in which systemic autoimmune disease-prone NZB, BXSB, MRL, and autoimmune diabetes-prone nonobese diabetic, but not NZW, BALB/c, and C57BL/6 mice have two identical deletion sites, consisting of 13 and 3 nucleotides. In this study, we established congenic C57BL/6 mice for NZB-type Fcgr2b allele and found that NZB-type allele down-regulates FcgammaRIIB1 expression levels in germinal center B cells and up-regulates IgG Ab responses. We did luciferase reporter assays to determine whether NZB-type deletion polymorphism affects transcriptional regulation of Fcgr2b gene. Although NZW- and BALB/c-derived segments from position -302 to +585 of Fcgr2b upstream region produced significant levels of luciferase activities, only a limited activity was detected in the NZB-derived sequence. EMSA and Southwestern analysis revealed that defect in transcription activity in the NZB-derived segment is likely due to absence of transactivation by AP-4, which binds to the polymorphic 13 nucleotide deletion site. Our data imply that because of the deficient AP-4 binding, the NZB-type Fcgr2b allele polymorphism results in up-regulation of IgG Ab responses through down-regulation of FcgammaRIIB1 expression levels in germinal center B cells, and that such polymorphism may possibly form the basis of autoimmune susceptibility in combination with other background contributing genes.

Mixed multiple system atrophy and progressive supranuclear palsy: a clinical and pathological report of one case.

We report a patient who showed pathological features of both multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) at autopsy. The clinical features included severe cerebellar ataxia, autonomic failure, and rigid-akinetic parkinsonism. The clinical diagnosis was MSA. Pathological examination showed severe neuronal loss with gliosis in the putamen, substantia nigra, inferior olive, and the pontine nucleus, and numerous glial cytoplasmic inclusions. In addition, moderate neuronal loss with gliosis was observed in the globus pallidus and subthalamic nucleus, and neurofibrillary tangles and tufted astrocytes were seen in the basal ganglia and the brain stem. These findings indicate that the patient had both MSA and PSP. Double-labeling immunofluorescence in the brain stem showed alpha-synuclein immunoreactivity localized in the oligodendrocytes and phosphorylated tau immunoreactivity in the neurons and the glia. Co-existence of synucleinopathy and tauopathy is rare.