T cell epitopes of type II collagen in HLA-DRB1*0101 or DRB1*0405-positive Japanese patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a T cell-mediated autoimmune disease, but target antigens (autoantigens) responsible for T cell activation remain unclear. Type II collagen (CII) is a candidate autoantigen that is largely confined to the articular cartilage. To investigate whether CII is an important antigen in patients with RA, we examined peripheral blood T cell reactivity to CII in HLA-DRB1*0101 and DRB1*0405-positive RA patients. Reactivities to candidate T cell epitopes of CII were also examined. Peripheral blood T cell reactivity to CII and CII peptides (256-271, 429-442, 593-610, 1064-1081) were detected by measurement of IL-2, IFN-gamma, and IL-4 in culture supernatant of PBMC after in vitro antigen stimulation. Cytokine concentration was measured by ELISA. In DRB1*0101-positive patients, T cell reactivity to CII as detected by measurement of IL-2 production in culture supernatant, was present in 4 out of 9 patients. IL-2 production upon stimulation with CII 256-271 peptide was found in all of these 4 patients. In DRB1*0405-positive patients, high frequency of positive T cell response to CII was detected in 9 out of 11 patients. IFN-gamma production was also detected in 4 out of 6 patients producing IL-2 by stimulation with CII. T cell response to CII 256-271 and/or CII 1064-1081 was detected in these patients. In DRB1*0101-positive RA patients, CII 256-271 peptide might function as a T cell epitope, whereas either CII 256-271 or CII 1064-1081 peptide may be a major T cell epitope in DRB1*0405-positive RA patients. In DRB1*0405-positive RA patients, CII reactive T cells might play a crucial role in the development of RA through IFN-gamma production.     

Cytologic findings and differential diagnoses of primary thyroid MALT lymphoma with striking plasma cell differentiation and amyloid deposition

We report two cases of thyroid mucosa‐associated lymphoid tissue (MALT) lymphoma with associated amyloid protein deposition. While other primary thyroid neoplasms sush as medullary carcinoma and plasmacytoma with associated amyloid protein are known to occur and have been previously described by fine‐needle aspiration cytology (FNAC), to our knowledge, the current cases are the first of thyroid MALT lymphoma with amyloid deposition to be detailed in the cytopathology literature. Case 1 was a 73‐year‐old female with chronic thyroiditis. FNAC suspected MALT lymphoma. The amyloid material was not noticed, nevertheless it existed. Case 2 was a 71‐year‐old female with a nodule of the thyroid. Malignant lymphoma and medullary carcinoma were suspected by FNAC. The possibility of medullary carcinoma was excluded by a measurement of serum calcitonin and carcinoembryonic antigen. After follow‐up for two years, the nodule was diagnosed as MALT lymphoma associated with plasma cell differentiation and amyloidosis by the fourth FNAC. When we encounter small round cell tumors associated with amyloid in thyroid FNAC, we should consider not only medullary carcinoma but also MALT lymphoma. Diagn. Cytopathol. 2014;42:73–77. © 2013 Wiley Periodicals, Inc.     

Dorfin localizes to the ubiquitylated inclusions in Parkinson's disease,dementia with Lewy bodies,multiple system atrophy,and amyotrophic lateral sclerosis

In many neurodegenerative diseases, the cytopathological hallmark is the presence of ubiquitylated inclusions consisting of insoluble protein aggregates. Lewy bodies in Parkinson's disease and dementia with Lewy bodies disease, glial cell inclusions in multiple system atrophy, and hyaline inclusions in amyotrophic lateral sclerosis (ALS) are representative of these inclusions. The elucidation of the components of these inclusions and the mechanisms underlying inclusion formation is important in uncovering the pathogenesis of these disorders. We hypothesized that Dorfin, a perinuclearly located E3 ubiquitin ligase, participates in the formation of ubiquitylated inclusions in a wide range of neurodegenerative diseases. Here, we report that affinity-purified anti-Dorfin antibody labeled ubiquitylated inclusions of Parkinson's disease, dementia with Lewy bodies disease, multiple system atrophy, and sporadic and familial ALS. A double-immunofluorescence study revealed that Dorfin shows a distribution pattern parallel to that of ubiquitin. Furthermore, by a filter trap assay, we detected that Dorfin is present in the ubiquitylated high-molecular weight structures derived from these diseases. These results suggest that Dorfin plays a crucial role in the formation of ubiquitylated inclusions of alpha-synucleinopathy and ALS. However, because we failed to show the direct binding of alpha-synuclein with Dorfin, future investigations into the binding partner(s) of Dorfin will be needed to deepen our understanding of the pathophysiology of alpha-synucleinopathy and ALS.     

Effect of lipopolysaccharide on circadian clock genes <Emphasis Type="Italic">Per2</Emphasis> and <Emphasis Type="Italic">Bmal1</Emphasis> in mouse ovary

In mammals, circadian rhythms are associated with multiple physiological events. The aim of the present study was to examine the effect of lipopolysaccharide (LPS) on circadian systems in the ovary. Immature female mice were received an intra-peritoneal injection of equine chorionic gonadotropin (eCG) and LPS. Total RNA was collected from the ovary at 6-h intervals throughout a 48 h of experimental period. The expression of the circadian genes period 2 (Per2) and brain and muscle ARNT-like 1 (Bmal1) such as circadian genes was measured by quantitative PCR. Although expression of Per2 and Bmal1 in the ovary did not display clear diurnal oscillation, LPS suppressed the amplitude of Per2 expression. Additionally, LPS inhibited the expression of cytochrome P450 aromatase (CYP19) and luteinizing hormone receptor (LHr) genes in the ovary of eCG-treated mice. Our data suggest that Per2 may be associated with the inhibition of CYP19 and LHr expression by LPS in the ovaries of immature mice.     

Induction of protumoral CD11chigh macrophages by glioma cancer stem cells through GM‐CSF

Cancer stem cells (CSCs) are maintained under special microenvironment called niche, and elucidation and targeting of the CSC niche will be a feasible strategy for cancer eradication. Tumor‐associated macrophages (TAMs) are known to be involved in cancer progression and thus can be a component of CSC niche. Although TAMs are known to play multiple roles in tumor progression, involvement of CSCs in TAM development fully remains to be elucidated. Using rat C6 glioma side population (SP) cells as a model of glioma CSCs, we here show that CSCs induce the TAM development by promoting survival and differentiation of bone marrow‐derived monocytes. CSC‐induced macrophages can be separated into two distinct subsets of cells, CD11c^low and CD11c^high cells. Interestingly, only the CD11c^high subset of cells have protumoral activity, as shown by intracranial transplantation into immune‐deficient mice together with CSCs. These CD11c^high macrophages were observed in the tumor formed by co‐transplantation with CSCs. Furthermore, CSCs produced GM‐CSF and anti‐GM‐CSF antibody inhibited CSC‐induced TAM development. In conclusion, CSCs have the ability to self‐create their own niche involving TAMs through CSC‐derived GM‐CSF, which can thus be a therapeutic target in view of CSC niche disruption.     

Hepatocyte growth factor stimulates proliferation of respiratory epithelial cells during postpneumonectomy compensatory lung growth in mice

Although it is known that the lung undergoes compensatory growth after pulmonary resection, mechanisms by which lung cells exhibit compensatory proliferation are not well defined. We investigated the involvement of hepatocyte growth factor (HGF) in postpneumonectomy compensatory lung regeneration in mice, because HGF has mitogenic and morphogenic actions on lung epithelial cells. Following left pneumonectomy, alveolar and airway epithelial cells underwent compensatory DNA synthesis, reaching maximal levels 5 d after the surgery. Before changes in DNA synthesis in lung epithelial cells, expression of HGF mRNA and protein levels in the remaining lung, liver, and kidney were changed in response to left pneumonectomy, and these changes were associated with postoperative increases in plasma HGF levels. c-Met/HGF receptor expression was localized predominantly in alveolar type II and airway epithelial cells, whereas c-Met/HGF receptor mRNA expressions were transiently upregulated before the peak in lung DNA synthesis. Neutralization of endogenous HGF by an antibody in pneumonectomized mice suppressed the compensatory DNA synthesis in lung epithelial cells, whereas administration of recombinant HGF to pneumonectomized mice stimulated DNA synthesis in lung epithelial cells. These results strongly suggest that HGF has a role as a pulmotrophic factor in postpneumonectomy compensatory lung regeneration.