Autoepitopes on autoantigen centromere protein-A (CENP-A) are restricted to the N-terminal region, which has no homology with histone H3

Anti-centromere autoantibodies (ACA) are commonly found in the serum of patients with a limited type of scleroderma and other systemic autoimmune diseases. CENP-A is one of the major antigens against ACA and a histone H3-like protein. To analyse the autoantigenic epitopes of CENP-A, a series of truncated peptides of human CENP-A were expressed in Escherichia coli and immunoblotting analysis was performed with 91 ACA+ sera. Eighty sera (88%) with the ACA reacted to the 52-amino acids N-terminal region which is not homologous to H3, while no sera reacted to the C-terminus which has a sequence similarity with H3. Moreover, ELISA was also employed in this study using two synthetic peptides corresponding to the amino acid sequences 3-17 (peptide A) and 25-38 (peptide B). Peptides A and B were reactive to 78 (86%) and 79 (87%) of ACA, respectively. Core antigens of hepatitis B virus (HBV) and hepatitis C virus (HCV) have similar sequences to peptide A and/or peptide B, but three sera containing HBV without ACA and five sera containing HCV without ACA were found to be reactive to neither peptide. Centromere localization of CENP-A is dependent on the H3-like C-terminal domain which is not autoantigenic, while the antigenic N-terminal domain, which might play unidentified functional roles, should be an important region for the induction of ACA.     

Epitopes and functional responses defined by a panel of anti-Fas (CD95) monoclonal antibodies

Fas (CD95) is a cell surface glycoprotein that mediates apoptotic cell death when cross-linked with agonistic anti-Fas monoclonal antibodies (MAbs) or the endogenous Fas ligand. In this study, we investigated the in vitro biological properties of a panel of anti-human Fas MAbs. We found that five anti-Fas MAbs of IgG1 subclass (B.E28, B.G30, B.L25, DX2, and B.G34) induced marked apoptotic cell death in Fas-expressing leukemia cells, although this killing was delayed when compared to the cytolytic effect mediated by the prototypic anti-Fas MAb of IgM subclass (clone CH-11). On the other hand, four clones (ZB4, B.G27, B.D29, and B.K14) efficiently blocked apoptotic cell death induced by the CH-11 MAb or Fas ligand. The ability of these MAbs to inhibit cell death appeared to correlate with their relative affinity for the Fas molecule. Furthermore, different clones recognized the same epitope and elicited different effects (induction or inhibition of cell killing); conversely, different clones elicited the same effect but recognized different epitopes. These results suggest that the different biological effects of anti-Fas MAbs would not be mediated in an epitope-restricted manner. The relative binding affinity might correlate to some extent with the biological properties of the MAb.     

A new pseudo-peptide of Arg-Gly-Asp (RGD) with inhibitory effect on tumor metastasis and enzymatic degradation of extracellular matrix

A series of pseudo-peptide analogs of the Arg-Gly-Asp (RGD) sequence of fibronectin have been synthe-sized, and their anti-metastatic effects in mice and inhibitory effects on tumor cell invasion in vitro have been examined. The partially modified retro pseudo-peptide of RGD, R_rev-COCH₂CO-D (FC-63), was more effective in inhibiting tumor metastasis than the original RGDS peptide. Replacement of the malonyl moiety of FC-63 with a carboxyethylene linkage (R_rev-COCH₂CH₂-D, FC-303 ) achieved more potent inhibition of lung metastasis of melanoma cells than FC-63. Among the analogs, FC-336, a p-xylylendiamine derivative having two FC-303 moieties, showed the most potent inhibitory effect on experimental lung metastasis produced by i.v. co-injection with B16-BL6 melanoma or colon 26 M3.1 cells in a dose-dependent manner. Multiple administrations of FC-336 after tumor inoculation also showed efficient therapeutic potency against spontaneous lung metastasis of B16-BL6 melanoma in mice. Furthermore, FC-336 effectively inhibited the invasion, migration and adhesion of tumor cells in vitro, but its inhibitory effects were not more than those of RGDS peptide. Zymography analysis revealed that FC-336 inhibited the degradation of gelatin substrate by matrix metalloproteinases (MMPs) produced by tumor cells, while the RGDS peptide did not affect the enzymatic degradation. These findings indicate that the pseudo-peptides of the RGD sequence, possessing the inhibitory property of the degradation by MMPs differently from original RGD-containing peptides, may be advantageous and useful in preventing tumor metastasis. © Rapid Science 1998     

The expression of B7-H1 on keratinocytes in chronic inflammatory mucocutaneous disease and its regulatory role

PD-1 and its ligands, B7-H1/PD-L1 and B7-DC/PD-L2, have been identified recently as CD28-B7 family molecules that are implicated in immune regulation. Lichen planus (LP) is a T cell-mediated chronic inflammatory mucocutaneous disease. We investigated the expression and function of PD-1 and its two ligands in LP. Immunohistochemical examination revealed the abundant expression of PD-1 and B7-H1 in infiltrating T cells and macrophages, and lower-level expression of B7-DC on macrophages in the subepithelium. Interestingly, substantial expression of B7-H1 on keratinocytes (KCs) was found close to the numerous T cell infiltrates in the subepithelium. Unstimulated cultured KCs expressed both B7-H1 and B7-DC, and their expression was upregulated by proinflammatory cytokines, particularly IFN-gamma. The T-cell proliferative responses and IFN-gamma production that were induced by IFN-gamma-treated KCs were augmented preferentially by anti-B7-H1 mAb, but not by anti-B7-DC mAb. These results indicate the regulatory role of B7-H1 on KCs in the interactions with T cells. Our results suggest that the induction of B7-H1 on KCs may play an important role in tolerance induction in the inflamed oral mucosa and skin.     

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.     

足底板对类风湿性关节炎患者足底压的影响

目的 :测定类风湿性关节炎病人足底压 ,评价足底板的生物力学效应。方法 :12名女性类风湿性关节炎病人和 8名健康女性进行年龄和体重匹配。用 F- Scan系统进行动态足底压测量 ,Kistler床反力平台用以校正测量精确性。测量足底峰压和垂直分力 ,评价足底板的生物力学表现。结果 :类风湿性关节炎病人中足底压明显高于健康人。使用足底板后 ,足底总的峰压明显降低 ,前足、后足峰压减低 ,中足峰压增高。而垂直分力改变不大。结论 :足底板能显著降低足底压力 ,使足底压力重分布 ,减轻类风湿足痛。特殊设计的足底板对类风湿足痛的治疗能起重要的作用     

PTEN loss in intraductal carcinoma of the prostate has low incidence in Japanese patients

Clinical and genomic features of prostate cancer (PCa) vary considerably between Asian and Western populations. PTEN loss is the most frequent abnormality in intraductal carcinoma of the prostate (IDC-P) in Western populations. However, its prevalence and significance in Asian populations have not yet been well studied. In the present study, we evaluated PTEN expression in IDC-P in a Japanese population and its association with ERG expression. This study included 45 and 59 patients with PCa with and without IDC-P, respectively, who underwent radical prostatectomy. PTEN loss was observed in 10 patients with PCa with IDC-P (22%) and nine patients with PCa without IDC-P (17%). ERG expression was relatively frequent in patients with PCa with PTEN loss, although a significant difference was not observed. The co-occurrence of PTEN loss and ERG expression was observed in four patients with PCa with IDC-P and one without IDC-P. PTEN loss and ERG expression did not affect progression-free survival, regardless of the presence of IDC-P. The frequency of PTEN loss in IDC-P is lower in Asian patients than in Western patients. Our results indicate that mechanisms underlying IDC-P in Asian populations are different from those of Western populations.     

Clinicopathological features of hereditary breast cancer

The possible role of germline mutations ofBRCA1 andBRCA2 as causative agents of familial breast cancer was assessed. Their possible involvement in the carcinogenesis of hereditary breast cancer was investigated using 63 clinically suspect families. Twenty-one lineages (33.3%) had mutations in one of the twoBRCA genes. This relatively low incidence suggested that germline mutations in unknown genes are involved in the carcinogenesis of hereditary breast cancer in the Japanese population. However, the clinicopathological features characteristic of hereditary breast cancer, such as early disease onset, a high incidence of bilateral breast cancer, and a high incidence of multiple primary carcinomas in other organs were confirmed in the present study.