Preferential expression of T(h)2-type chemokine and its receptor in atopic dermatitis

Lesional skin of patients with atopic dermatitis (AD) is histologically characterized by hypertrophy of the skin, and the infiltration of a large number of eosinophils and T cells into the dermis. Recent studies have indicated that Th2 cells play a crucial role in the pathogenesis of AD skin. Chemokines and their receptors are implicated in the development of symptoms of various skin diseases such as AD and psoriasis vulgaris (psoriasis). We have examined the in situ expression of a typical Th2-type chemokine, thymus- and activation-regulated chemokine (TARC), and its receptor (CCR4) using immunohistochemical techniques. TARC was found to be highly expressed in the basal epidermis of the lesional skin of AD patients and only slightly in the non-lesional skin. On the other hand, no positive cells were seen in the lesional skin of psoriasis. Consistently, CCR4+ cells were present predominantly in the lesional skin of AD patients, but not in the non-lesional skin. In contrast, in the lesional skin of psoriasis patients, cells positive for CCR5, which is expressed on Th1 cells, were abundantly present. Interestingly, psoralen plus ultraviolet A therapy reduced the number of CCR4+ cells in the AD skin lesions. These results suggest that Th2-type cytokines such as TARC are involved in the pathogenesis of skin lesions in AD patients through the preferential recruitment of Th2 cells.     

A novel synthetic route to poly(β-ketone)s via poly(alkoxyethyne)s

Isopropoxyethyne (1a) and tert-butoxyethyne (1b) were polymerized using group 5 and 6 transition metal catalysts to give poly(isopropoxyethyne) (2a) and poly(tert-butoxyethyne) (2b) , respectively. The weight-average molecular weight (M?_w) of the resulting poly(alkoxyethyne)s was up to 1.0 × 10⁴. Among the transition metal catalysts, a tungsten alkoxide or a molybdenum alkoxide having low Lewis acidity were found to effectively promote the polymerization without causing side reactions. Poly(tert-butoxyethyne) was successfully converted to poly(β-ketone) 3 by acid hydrolysis of the tert-butyl vinyl moiety.     

Cloning and sequencing of cDNAs corresponding to mite major allergen Der f II

A cDNA library corresponding to mite protein was screened employing anti-Der f II antibody. Two possible clones were obtained, which contained plasmids, pFL1 and pFL11, respectively. Both plasmids had insertions of about 500 base pairs. The DNA sequences of the two insertions were determined, from which the amino acid sequences were deduced. The amino acid sequence of the purified native Der f II protein could be determined to 45 residues from the N-terminus. As a result of comparison, we concluded that the cDNAs prepared from live mite Dermatophagoides farinae corresponded to the mite allergen, Der f II.     

Shared amino acid sequences in the NDβN and Nα regions of the T cell receptors of tumor-infiltrating lymphocytes within malignant glioma

The purpose of this study was to assess the V-(D)-J junctional region of the T cell receptor (TCR), the CDR3 region, which is responsible for glioma-specific antigen contact in αβ TCR-mediated recognition. We sequenced the TCR α and β chians of Vα7, and Vβ13.1 cDNA derived from tumor-infiltrating lymphocytes (TIL) of 12 glioma patients and also the corresponding clones from the patients' peripheral blood lymphocytes (PBL). A shared Vβ13.1 DJ sequence of the CDR3 region, NDβN, was demonstrated in 49 of 66 Vβ13.1⁺ clones (74.2 %) from the glioma TIL, whereas only 4 of 33 clones (12.1 %) were observed in the Vβ13.1⁺ clones from the PBL (p < 0.001). A common VDJ sequence, FCASS (Vβ13.1)-YRLPWGTSDS (NDβN)-GELFF(Jβ2.2), was observed not only in the gliomas from each patient, but also among all the patients with a preference for Vβ13.1. In contrast, the amino acid sequences of the Vβ13.1⁺ PBL clones were diverse and random. Next, we sequenced subclones from other Vβ subfamilies randomly selected to compare their VDJ region rearrangements (Vβ3 and Vβ5.1). In contrast to Vβ13.1, the amino acid sequences of these junctional regions were completely different in these subclones. The V-J junctional region of the α chain is dominated by a few clones in some patients, and no shared amino acid sequences were detected in the TCR Vα junctional region. However, in the Nα region of the Vα7-bearing TIL clones, arginine was used in 27 of 44 clones (61.4%) compared to only 3 of 12 clones from the PBL (p < 0.05). These results are consistent with the hypothesis that a clonal expansion/accumulation of glioma lineage-specific T cells occurred in vivo at the tumor site and that these T cells may be recognizing glioma-specific antigens.     

Role of costimulatory molecules in autoimmunity

The precise mechanisms by which self-reactive T cells are activated and tolerance to self-antigens is broken are still not fully understood. It is widely accepted that dysregulation of costimulation contributes to the initiation and maintenance of autoimmunity due to activation of self-reactive T cells. Many of the costimulatory molecules thought to be essential for T cell activation have been identified. The CD28/CD152 (CTLA-4)-CD80/CD86 and CD40-CD154 (CD40 ligand) interactions are such receptor/ligand pairs that have been shown to be important in interactions between antigen-presenting cells and T cells. In vivo studies using costimulatory molecule-specific antibodies and fusion proteins and genetically manipulated animals have greatly increased our understanding of the role of these costimulatory molecules in the regulation of cellular processes that lead to autoimmunity and resultant autoimmune diseases.     

Colocalization of a carnosine-splitting enzyme,tissue carnosinase (CN2)/cytosolic non-specific dipeptidase 2 (CNDP2), with histidine decarboxylase in the tuberomammillary nucleus of the hypothalamus

Carnosine is a naturally occurring dipeptide (β-alanyl-l-histidine) present in mammalian tissues such as the brain and skeletal muscles. Carnosine is not only a radical scavenger but also a possible neurotransmitter-like molecule that regulates neuronal functions such as hypothalamic control of the autonomic nervous system. CN2 (CNDP2) is a cytosolic enzyme that can hydrolyze carnosine to yield l-histidine and β-alanine. In order to understand the functions of carnosine and CN2 in the brain, we have investigated the immunohistochemical localization of CN2 in the hypothalamus. CN2-immunoreactivity was highly concentrated in neuronal cells in the dorsal part of the tuberomammillary nucleus of the posterior hypothalamus. Since the tuberomammillary nucleus is the exclusive origin of histaminergic neurons, we further investigated whether CN2 is present in the histaminergic neurons. We found that CN2-immunoreactivity was colocalized with that of histidine decarboxylase, which is the key enzyme for histamine biosynthesis specifically expressed in the histaminergic neurons of the tuberomammillary nucleus. These results suggest that CN2 is highly expressed in the histaminergic neurons in the tuberomammillary nucleus, implying that it may supply histidine to histaminergic neurons for histamine synthesis.     

Isolation and radiation hybrid mapping of a dinucleotide repeat polymorphism at the human calcium-sensing receptor (CASR) locus

Calcium-sensing receptor (CASR) in parathyroid gland regulates calcium homeostasis by sensing decreases in extracellular calcium levels and effecting an increase in secretion of parathyroid hormone. A polymorphic dinucleotide (CA) sequence was isolated from a genomic clone containing the human CASR gene and was mapped to 3q13.3–q21. This polymorphism will be useful in the genetic study of disorders affecting calcium metabolism, such as hypercalcemia, hypocalcemia, osteoporosis, hyperparathyroidism, and hypoparathyroidism. Received: June 2, 1998 / Accepted: June 24, 1998     

Studies on the fragments of FDP in 4 patients with DIC]

We previously studied fibrinolysis and fibrinogenolysis by analyzing fragments of fibrin/fibrinogen degradation products (FDP) employing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. In this report, we characterized the fragments of FDP in four patients with disseminated intravascular coagulation (DIC), that were caused by various diseases. In the patients suffering from acute lymphoblastic leukemia (case 1) and acute suppurative cholangitis (case 3), DD and DY/X fragments resulting from fibrinolysis accounted for the most part of the FDP fragments. In case 3, D fragments resulting from fibrinogenolysis were also observed to much less extent. In a DIC associated with acute myeloblastic leukemia (case 2), both fibrinolysis and fibrinogenolysis were increased and resulted in high levels of D, Y and DY/X fragments, concomitant with moderate levels of DD and high molecular weight (HMW) fragments in the patient's sera. The increased fibrinogenolysis in this case was attributed to accelerated activation of plasmin. In a DIC patient of case 4, who underwent an operation due to hepatocellular carcinoma, marked increase in DY/X and HMW fragments and slight increase in DD fragment were observed on the day of operation. Hyperfibrinolysis documented in case 4 was explained by both increased production of thrombin and moderately accelerated activation of plasmin. Both qualitative and quantitative changes in the fragments of FDP during the courses of treatment in two cases of DIC were also noted. In summary, each underlying disease expresses characteristic pattern of FDP fragments in DIC.