Endogenous protein and enzyme fragments induce immunoglobulin E-independent activation of mast cells via a G protein-coupled receptor, MRGPRX2.

Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E-dependent and E-independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas-related G protein-coupled receptors (MRGPRs). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin-10 fragment) that act as bioactive peptides and induce immunoglobulin E-independent mast cell activation via MRGPRX2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX2 responds various as-yet-unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells.

A mechanism for mercury oxidation in coat-derived exhausts.

This paper evaluates an elementary reaction mechanism for Hg0 oxidation in coal-derived exhausts consisting of a previously formulated homogeneous mechanism with 102 steps and a new three-step heterogeneous mechanism for unburned carbon (UBC) particles. Model predictions were evaluated with the extents of Hg oxidation monitored in the exhausts from a pilot-scale coal flame fired with five different coals. Exhaust conditions in the tests were very similar to those in full-scale systems. The predictions were quantitatively consistent with the reported coal-quality impacts over the full range of residence times. The role of Cl atoms in the homogeneous mechanism is hereby supplanted with carbon sites that have been chlorinated by HCl. The large storage capacity of carbon for Cl provided a source of Cl for Hg oxidation over a broad temperature range, so initiation was not problematic. Super-equilibrium levels of Cl atoms were not required, so Hg was predicted to oxidize in systems with realistic quench rates. Whereas many fundamental aspects of the heterogeneous chemistry remain uncertain, the information needed to characterize Hg oxidation in coal-derived exhausts is now evident: complete gas compositions (CO, hydrocarbons, H2O, O2 NOx, SOx), UBC properties (size, total surface area), and the ash partitioning throughout the exhaust system are required.

Differential induction of interferon (IFN)-inducible protein 10 following differentiation of a monocyte, macrophage cell lineage is related to the changes of nuclear proteins bound to IFN stimulus response element and kappaB sites.

We examined chemokine gene expression following the differentiation of a monocyte, macrophage cell lineage. The human monoblastic cell line, U937 was differentiated to macrophages by the treatment with either phorbol 12-myristate 13-acetate (PMA), retinoic acid (RA), or vitamin D3 (VitD3). The gene expression of interferon (IFN)-inducible protein 10 (IP-10) (a CXC chemokine) was markedly augmented by the IFNgamma treatment in PMA- or RA-differentiated U937 cells, but only marginally in undifferentiated or VitD3-treated cells. In contrast, another inducible gene expression of monocyte chemotactic protein-1 (a CC chemokine) and the activation of the transcriptional factor (FcRFgamma) bound to the gamma response region were similarly or less abundantly induced by IFNgamma treatment in PMA- or RA-differentiated U937 cells, indicating that increased IP-10 mRNA induction was not due to the augmented ability of the cells to respond to the presence of IFNgamma. Increased expression of IFNgamma-induced IP-10 mRNA following the differentiation of U937 cells was mediated largely by augmented transcriptional activity of the gene and was related to differentiation-dependent changes of the proteins bound to IFN stimulus response element (ISRE) and kB sites, suggesting that these nuclear proteins may determine the IP-10 mRNA inducibility by IFNgamma.

Clinical study of the pumping pressure changes in the temporomandibular joint space before and after arthroscopic surgery.

When arthroscopy of the temporomandibular joint (TMJ) is performed, we often observe differences in the resistance of hydraulic pressure during intra-articular pumping. It can be speculated that intra-articular adhesion and contracture of the capsule and ligament may cause these differences in resistance. In order to measure the changes in intra-articular hydraulic pressure before and after arthroscopic ablation surgery, seven cases were examined by balloon pumping technique. We concluded that the values of intra-articular hydraulic pressure are implicated in the severity of the internal derangement of TMJ.

Interleukin-1beta induces tissue- and cell type-specific expression of adhesion molecules in vivo.

We examined the tissue distribution of adhesion molecule gene expression in mice treated intravenously with interleukin (IL)-1 beta. E-selectin mRNA expression was selectively induced in the heart by IL-1 beta, but only slight or no induction was observed in other organs. On the other hand, intercellular adhesion molecule-1 mRNA expression was inducible in all organs examined, although it showed the strongest induction in the lung and the weakest responses in the brain and skin. Vascular cell adhesion molecule-1 mRNA was also inducible in all organs with the exception of the skin, but it was induced most markedly in the lung and the heart. The accessibility of IL-1 beta to the heart was less than that to other organs except the brain. Similar tissue-specific induction of these mRNAs was also seen when tumor necrosis factor (TNF)-alpha or lipopolysaccharide was substituted for IL-1 beta. Analysis of E-selectin mRNA expression in the heart by in situ hybridization indicated that expression was most prominent in microvascular endothelial cells and some other stromal cells, but this transcript was not seen in the lung. Although intercellular adhesion molecule-1 mRNA expression was restricted to the endothelium lining the capillaries and small arteries in the heart, its distribution in the lung covered not only the endothelium but also the cells composing the alveolar septa. In contrast, vascular cell adhesion molecule-1 mRNA expression was most prominent in endothelial cells of larger vessels in both the heart and the lung. Our results demonstrate that expression of adhesion molecules is tissue- and cell type-specific and that endothelial cells differentially express adhesion molecules depending on the size of the blood vessels.

Putative pheromone receptors related to the Ca2+-sensing receptor in Fugu.

By a combination of PCR with degenerate primers and low stringency probing, we have isolated a large family of genes related to the Ca2+-sensing receptor from the genome of Fugu rubripes. One of the genes (type I) is the Fugu homologue of the Ca2+-sensing receptor. The remaining genes can be divided into five classes (type II-VI) on the bases of gene structure. In several types, the genes occur in clusters as tandem arrays. These genes appear to be the homologues of the vomeronasal pheromone receptors recently described in rodents. The Fugu genes are expressed in the tissues of the nose, suggesting that they may have a similar physiological role.

[Neutron activation analysis of biological samples].

Multi-element analysis by neutron activation analysis (NAA) in respect to medical applications is discussed. Examples of trace element determinations in pathological human liver tissues, human serum, and rat liver are given. A very sensitive method for determining fluorinated drug in very small samples of human serum by neutron activation is also described. Each biological samples (ca. 100-200 mg, lyophilized matter) was irradiated for short time (10 s or 5 min.) and for long time (24 hrs) in Rikkyo University Research Reactor or Musashi Institute of Technology Research Reactor. Concentration of 12 elements (127I, 55Mn, 26Mn, 65Cu, 23Na, 41K, 37Cl, 27Al, 48Ca, 36S, 58Fe, 64Zn) in human pathological liver, Futraful (19F) (anti-cancer fluorinated drug) clearance of human serum, and calcium uptake (48Ca) in liver of rats were determined by NAA.

Increased soluble IL-2 receptor in serum of patients with systemic lupus erythematosus.

We estimated the concentration of soluble IL-2R (sIL-2R) in the serum of patients with systemic lupus erythematosus (SLE) and examined the relationship between the serum levels of sIL-2R and clinical features or laboratory data. We found that elevated levels of sIL-2R were present in the serum of SLE patients with discoid rash, and sIL-2R concentrations were correlated with the soluble CD4 and soluble CD8 concentrations but not with classical serological marker, anti-DNA antibody or complement titer.

Gene structure of Enterococcus hirae (Streptococcus faecalis) F1F0-ATPase, which functions as a regulator of cytoplasmic pH.

Enterococcus hirae (formerly Streptococcus faecalis) ATCC 9790 has an F1F0-ATPase which functions as a regulator of the cytoplasmic pH but does not synthesize ATP. We isolated four clones which contained genes for c, b, delta, and alpha subunits of this enzyme but not for other subunit genes. It was revealed that two specific regions (upstream of the c-subunit gene and downstream of the gamma-subunit gene) were lost at a specific site in the clones we isolated, suggesting that these regions were unstable in Escherichia coli. The deleted regions were amplified by polymerase chain reaction, and the nucleotide sequences of these regions were determined. The results showed that eight genes for a, c, b, delta, alpha, gamma, beta, and epsilon subunits were present in this order. Northern (RNA) blot analysis showed that these eight genes were transcribed to one mRNA. The i gene was not found in the upper region of the a-subunit gene. Instead of the i gene, this operon contained a long untranslated region (240 bp) whose G + C content was only 30%. There was no typical promoter sequence such as was proposed for E. coli, suggesting that the promoter structure of this species is different from that of E. coli. Deduced amino acid sequences suggested that E. hirae H(+)-ATPase is a typical F1F0-type ATPase but that its gene structure is not identical to that of other bacterial F1F0-ATPases.

Microangiopathic hemolytic anemia in a graft-versus-host disease patient treated with cyclosporine A and prednisolone.

A 38-year-old male patient with chronic myelocytic leukemia in the first chronic phase underwent bone marrow transplantation (BMT) from an HLA identical sibling. He developed chronic graft-versus-host disease and his condition gradually deteriorated. Fourteen months after BMT, acute progressive anemia, thrombocytopenia, reticulocytosis, increased serum lactic dehydrogenase and increased serum bilirubin were revealed following treatment with cyclosporine A (240 mg/day i.v.), prednisolone (60 mg/day i.v.) and azathioprine (100 mg/day p.o.). Red blood cell fragmentations were also found microscopically. At that time, the serum cyclosporine A trough level was 1,300 ng/ml by the polyclonal antibody RIA method. These symptoms were resolved by discontinuation of cyclosporine A and administrations of aspirin, cilostazol, and dipyridamole as anti-platelet agents. We consider this phenomenon to be micro-angiopathic hemolytic anemia due to a serum high cyclosporine A level which resulted from the concomitant use of cyclosporine A with prednisolone.

Correlations between IL-2 enhancing activity and clinical parameters in patients with rheumatoid arthritis and systemic lupus erythematosus.

In a previous paper (Tomura, K. et al. Tohoku J. Exp. Med., 1989, 159, 171-183), we discovered IL-2 enhancing factor(s) designated B cell derived-growth enhancing factor-2 (BGEF-2), which enhanced IL-2 dependent cell proliferation, and reported that BGEF-2 was produced by B cells of the patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) only when they were in the active stage of the disease. In this paper, we studied relationship between each IL-2 enhancing activity from B cell supernatant of the patients with these diseases and clinical parameters. IL-2 enhancing activities did not correlate with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), but correlated with plasma concentrations of gamma-globulin from the patients with RA and SLE in the active stages. IL-2 enhancing activities correlated with hypocomplementemia and leukocytopenia in the patients with SLE, and also correlated with RAHA titer in the patients with RA. Moreover, on several patients with RA or SLE in the active stages, diminution of IL-2 enhancing activity was found when they were in the remission stage after treatments. These findings suggested that IL-2 enhancing activity (i.e., BGEF-2 activity) correlated with activity of these diseases and supported the hypothesis that BGEF-2 played an important role in the polyclonal B cell activation and autoantibody production in patients with these diseases.

Expression of Leu M1 antigen on a monoclonal B cell line established from a patient with rheumatoid arthritis.

The purpose of this study is to show that anti-Leu M1 antibody (anti-CD15), which has different staining characteristics in lymphoid and non-lymphoid cells, reacted against the surface antigen of a defined monoclonal B cell line. This antibody recognizes the sugar moiety, lacto-N-fucopentaose (LNF-III), which is linked to the cell membrane protein in several kinds of cells, but not in B cells. However, a human monoclonal B-cell line (TKS-1) which was established from the peripheral blood of a patient with rheumatoid arthritis, expressed the Leu M1 antigen spontaneously. The analysis of surface markers using a fluorescence-activated cell sorter (FACS) has revealed that the surface markers of TKS-1 were anti-mu, delta, kappa, HLA-DR, DQ, Leu 12 (CD19) and Leu M1 (CD15). TKS-1 cells were not reactive with any of the following antibodies: anti-OK M1 (CD11b), Leu M2, Leu M3 (CD14), Leu M4, Leu 1 (CD5), Leu 2 (CD8), Leu 3 (CD4), Leu 4 (CD3), Leu 7 and Leu 11 (CD16). In addition, TKS-1 was positive to Epstein-Barr nuclear antigen, weakly positive to non-specific esterase without staining inhibition by NaF, and negative to peroxidase. TKS-1 cells produced IgM in the culture supernatant and have kappa-light chain rearrangement in its DNA. As shown in other studies, distribution of Leu M1 is very wide. This antigen is not a specific immunodiagnostic marker to distinguish the cell type. We conclude that it is possible to express Leu M1 antigen on the membrane of a B-cell lineage cell.

IL-2 enhancing factor(s) in B cell supernatants from patients with rheumatoid arthritis or systemic lupus erythematosus.

Culture supernatants of B cells from patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) in the active stage enhanced interleukin 2 (IL-2) dependent proliferation of CTLL A/J cells. This activity, designated B cell-derived growth-enhancing factor-2 (BGEF-2), was recovered by gel filtration of a molecular weight between 15,000 and 20,000. BGEF-2 itself did not show IL-2 activity nor IL-1 activity, and BGEF-2 activity was not detected in the following cytokines: Interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), tumor necrosis factor (TNF), interleukin 4 (IL-4), interleukin 5 (IL-5) and interleukin 6 (IL-6). Furthermore, BGEF-2 was distinguishable from B cell-derived growth-enhancing factor described in a previous paper [Kang et al. (1987) J. Immunol., 139, 1154-1160]. BGEF-2 was produced by B cells from patients with RA or SLE only when the patients were in the active stage. BGEF-2 enhanced IL-2-dependent growth of peripheral blood T cells from patients with active RA, but did not enhance the growth of T cells from healthy volunteers. These results suggest that BGEF-2 is a B cell-derived lymphokine which plays an important role in the pathogenesis of RA and SLE.

Characterization of a B cell-derived growth-enhancing factor produced by a human B cell line established from a patient with rheumatoid arthritis.

A human B cell line, TKS-1, which was established from the peripheral blood of a patient with rheumatoid arthritis, was found to spontaneously produce a factor which enhances the activity of interleukin 1 (IL-1). This factor, designated B cell-derived growth-enhancing factor (BGEF), enhanced IL-1-induced proliferation of peanut agglutinin nonagglutinated thymocytes. BGEF also enhanced IL-1-induced production of interleukin 2 (IL-2) by both thymocytes and a human T cell clone, HSB.2 C5B2. BGEF alone did not induce the production of IL-2. BGEF failed to induce proliferation of the IL-2-dependent T cell clone, and did not enhance its response to IL-2. The activity of BGEF was not blocked by antisera against human IL-1-alpha or human IL-1-beta. Gel filtration analysis revealed that BGEF has a m.w. of 60,000 to 65,000 in its native state. We concluded that BGEF differed from IL-1 and IL-2, but is a novel factor produced by TKS-1 cells. In addition, we found that partially purified B cells from patients with rheumatoid arthritis produced factors which enhanced the activity of IL-1.

Aberration of monokine production and monocyte subset in patients with systemic lupus erythematosus.

We measured the production of interleukin 1 (IL-1) and prostaglandin by adherent cells from patients with systemic lupus erythematosus (SLE). Compared to normal subjects, IL-1 production in the patients was lower but prostaglandin E1 production was higher. Furthermore, examination of monocyte subsets in patients with SLE using monoclonal anti-monocyte/granulocyte antibodies disclosed abnormal expression of membrane antigens on monocytes. It is speculated that aberration of monocyte function is related to impaired monokine production and that membrane antigens play a role in immunodysregulation in patients with SLE.