Identification of an HLA-DQ6-derived peptide recognized by mouse MHC class I H-2Db-restricted CD8+ T cells in HLA-DQ6 transgenic mice

Summary CD8⁺ T cells from C57BL/6(B6) mice show cytotoxicity to B cell blasts prepared from syngeneic transgenic mice expressing HLA-DQ6 molecules in a mouse MHC class I H-2D^b restricted manner. Although these results suggest that CD8⁺ T cells recognize peptides derived from DQ6 molecule bound to H-2D^b on target cells, no direct evidence so far has been obtained. To clarify this, we synthesized 23 peptides corresponding to DQ6α orβ chain and carrying the motifs of D^b-binding peptides, and examined their capacity to induce cytotoxicity in the CD8⁺ T cell line. We show here that DQA1-2, one of these peptides, induced cytotoxicity of the CD8⁺ T cells when this peptide was pulsed to H-2D^b expressing target cells, as efficiently as HLA-DQ6 expressing target cells did. Thus, our results suggest that DQA1-2 can be naturally processed from DQ6 molecules and recognized by the CD8⁺ T cells in the context of H-2D^b molecules. These results suggest that allogeneic HLA class II molecules are involved in the rejection not only as the ligand for T cell receptor of alloreactive CD4⁺ T cells but also as self-peptides bound to HLA class I molecules recognized by CD8⁺ T cells.     

A CASE OF GASTRIC CARCINOMA WITH MASSIVE EOSINOPHILS

This report describes a 67-year-old male with inoperable gastric cancer accompanied by marked tissue and peripheral eosinophilia without evidence of allergic disorders or parasitic infestation. Autopsy revealed an advanced gastric cancer of scirrhous type with metastases to pancreas, bone marrow, ileum, lungs, and lymph nodes. Excessive numbers of mature eosinophils were present in univolved bone marrow, liver and spleen as well as among the signet ring cell component of the cancer in either primary or metastatic sites. The primary cancer also possessed a component of tubular adenocarcinoma which was associated with only a few eosinophils. Hence, we speculate that an eosinophil mobilizing (chemotactic and/or proliferating) factor (s) was produced by the signet ring cancer cells.     

Localization of efferent neurons innervating the pharyngeal constrictor muscles and the cervical esophagus muscle in the cat by means of the horseradish peroxidase method

Following horseradish peroxidase (HRP) injection into the cephalopharyngeal muscle (CeP), the hyopharyngeal muscle (HP), the thyropharyngeal muscle (TP), the cricopharyngeal muscle (CP) and the cervical esophagus muscle (CE) of the cat, labeled neurons were identified in the nucleus retrofacialis and the rostral part of the nucleus ambiguus ipsilaterally. The rostral end of the labeled cell column was located more rostrally for CeP and HP than for TP, CP and CE. No difference was noted within the former two or within the latter three. The level of the caudal end of the labeled cell column became more caudal in the order of CeP, HP, TP and CP. The caudal end was located more rostral for CE than for TP. The neurons for CE were located more ventro-laterally than those for the other muscles.     

Analysis of 8-hydroxydeoxyguanosine 5'-monophosphate (8-OH-dGMP) as a reliable marker of cellular oxidative DNA damage after gamma-irradiation

In order to improve 8-hydroxyguanine (8-OH-Gua) detection in DNA, we digested isolated DNA with nuclease P1 and analyzed for 8-hydroxydeoxyguanosine 5'-monophosphate (8-OH-dGMP) using a high-performance liquid chromatography system equipped with an electrochemical detector (HPLC-ECD). The amount of 8-OH-Gua in the DNA was expressed as the ratio of 8-OH-dGMP to deoxycytidine monophosphate (dCMP). Using this analysis, the background level of 8-OH-Gua in DNA from human lung carcinoma cells (A549) was several-fold lower than that obtained by a previous method. A549 cells were exposed to 20-60 Gy of gamma-radiation and an increase in 8-OH-Gua concentration was observed with increasing gamma-ray dose (0.3 residues per 10(7) dCMP per Gy). Moreover, by an immunohistochemical procedure using a commercial FITC-kit, 8-OH-Gua was clearly detected in A549 cells and the fluorescence intensity of cells with oxidative DNA damage increased with the doses of gamma-irradiation. Using an endonuclease nicking assay, we also found that gamma-rays decreased 8-OH-Gua repair activity. The results indicate that 8-OH-dGMP is a useful and sensitive marker for estimating oxidative damage in DNA.     

ADRENOCORTICAL CARCINOMA IN INFANCY

A case of adrenocortical carcinoma associated with congenital heart defect in a 6-month-old Japanese girl is reported. A fist-sized tumor was incidentally noted in the right hypochondrium upon admission for cardiac surgery. No clinical endocrinopathy was evident in this case. The resected tumor was encapsulated with smooth surface and no invasion to adjacent tissues or organs was observed. Histologically, the tumor was composed of small cells with granular or clear cytoplasm, and occasional giant cells with single or multiple nuclei. By electron microscopy, the tumor cells showed various nuclear contours with distinct nucleoli and had a moderate amount of cytoplasm containing abundant rough endoplasmic reticulum and mitochondria with variable-sized electron-dense granules. Intercellular desmosome-llke junctions were observed in some tumor cells. Immunohistochemlcally, the tumor cells contained granules positive for estriol, progesterone and Cortisol. These morphological findings including electron microscopic features suggested that the tumor cells had a malignant character.     

Malignant fibrous histiocytoma of the pancreas

An extremely rare case of malignant fibrous histiocytoma In the pancreas Is reported. A 70-year-old man complained of upper abdominal discomfort. A tumor in the head of the pancreas was demonstrated by ultrasonography and computed tomography. The surgical specimen revealed a relatively well demarcated tumor, 9 × 7 × 6.5cm in size. Microscopically, fibroblastic, histiocytic, and muitinucleated giant tumor cells were observed in the myxoid area, but some tumor cells had proliferated in a storiform-pleomorphlc pattern. Immunohtstochemically, some tumor cells were positive for lysozyme, α-1-antitrypsin, α-1-antichymotrypsin, and vimentin. Electron microscopically, tumor cells showed a combination of fibroblastic and histiocytic features. The patient Is currently well with no evidence of recurrence or metastasis 22 months after operation.     

Low uptake of [H]2-deoxy-d-glucose by cultured rat Schwann cells

[³H]2-Deoxy-d-glucose (2-DG) was used to investigate the glucose uptake in cultured rat Schwann cells from postnatal Sprague-Dawley rat sciatic nerves. The glucose uptake of Schwann cells slightly increased in a time- and dose-dependent manner. However, the maximal uptake level was much lower than that of ethylnitrosourea (ENU)-induced transformed rat schwannoma-like cells and fibroblasts. By autoradiography of the cultured system, we were able to visualize the accumulation of [³H]2-DG grains in the schwannoma-like cells and fibroblasts, but not in Schwann cells.     

Spatiotemporal changes of coxsackievirus and adenovirus receptor in rat hearts during postnatal development and in cultured cardiomyocytes of neonatal rat

Coxsackievirus B is the most common cause of viral myocarditis and is particularly virulent in neonates and children. Adenovirus is also a leading cause of the disease. The determinant of tropism for both viruses is considered to be the expression of coxsackievirus and adenovirus receptor (CAR) in target organs. However, developmental change and physiological localization of CAR in the heart are unknown. We examined expression levels of CAR in rat hearts by quantitative real-time polymerase chain reaction and Western blot analysis and found that CAR decreased gradually during postnatal development, although CAR was detectable, even in adults. Immunohistochemistry revealed CAR on the whole surface of cardiomyocytes in immature rat hearts. In contrast, CAR was detected predominantly on intercalated disks in the adult heart and was accumulated especially at the contact point between the cultured cardiomyocytes, even though they were prepared from the neonatal rat heart. In conclusion, CAR was expressed abundantly on the whole surface of cardiomyocytes in immature rat hearts. Both the expression level and the localization of CAR are possible determinants of the susceptibility to viral myocarditis of neonates and children.     

Protective effect of recombinant neutrophil elastase inhibitor (R-020) on sepsis-induced organ injury in rat

Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and punctureinduced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.     

Clinical significance of measurement of resting energy expenditure in childhood

1. Biliary atresia (BA), as a common disease in Japan, and cystic fibrosis (CF), as an extremely uncommon disease in Japan, were selected to assess the clinical significance of measurement of energy expenditure (EE). 2. Energy expenditure was significantly higher in children with BA than in normal children. 3. Measurement of EE in BA lead to clues to resolving its mechanism by novel assessment of interleukin-6 and leptin. 4. Energy expenditure in children with CF is also higher, but this has been addressed by nutritional intervention with additional calories. 5. Individualization of EE measurement is necessary in the analysis of pathological mechanisms and nutritional management of patients with both common and uncommon diseases.