Expression of heme oxygenase-1 in rat ontogeny

Heme oxygenase (HO), the heme-degrading enzyme, plays an important role in heme catabolism. Among three isozymes, HO-1 is an inducible form expressed mainly in macrophages. In rat ontogeny, HO-1 immunoreactivity was detected in mononuclear cells in the yolk sac at 10 days of gestation. HO-1-expressing cells were then detected in the fetal liver and their numbers increased during the gestational period. The numbers of HO-1-positive cells and HO-1 mRNA levels in the liver peaked at 18 days of gestation. Most of the macrophages expressed both HO-1 and a macrophage scavenger receptor. Macrophages in the fetal liver showed marked hemophagocytosis. Macrophages in the lung, spleen, bone marrow, and other tissues also expressed HO-1. HO-1 immunoreactivity was also observed in syncytial cells of the chorionic villi, the endodermal layer of the yolk sac, and renal tubules of the fetus. Intestinal mucosal epithelial cells expressed HO-1 after birth. These findings imply that HO-1 is crucial for macrophages in heme catabolism from an early stage of ontogeny. HO-1 expression in non-macrophagic cells may be required for other purposes such as protection from oxidative stress and various stimuli.     

CD69-null mice protected from arthritis induced with anti-type II collagen antibodies

CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients.     

An improved method for recovery of F-defective Sendai virus expressing foreign genes from cloned cDNA

An improved system is described to recover non-transmissible Sendai virus that lack the envelope fusion (F) gene from cloned cDNA. The system (1) used plasmids that expressed the F and the HN viral envelope proteins, as well as the plasmids that expressed the viral NP, P, and L proteins as helper plasmids for recovery, and (2) overlaid packaging cells that expressed the F protein. With this improved system, we have succeeded in recovery of F-defective Sendai virus expressing two foreign proteins, and expression vectors that do not contain the EGFP reporter gene. This system may provide the basis for constructing recombinant F-defective Sendai virus for preventing and treating human diseases in the form of vaccines and vectors for gene therapy.     

Low-grade fibromyxoid sarcoma arising in the big toe

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor. Reported herein is a case of LGFMS arising in the big toe. The patient was a 58-year-old man who underwent excision of the tumor. The tumor was well-demarcated. Histologically, there were proliferating spindle-shaped tumor cells arranged in a whorled growth pattern, and the stroma showed hyalinized collagen bundles and a myxoid matrix. Nuclear mitotic figures were conspicuous in part. A large rosette-like structure with hyalinized stroma was found, which is characteristic of LGFMS. The differential diagnosis included tumor occurrence in adults; tending to arise in distal extremities; and having bland fibromyxoid histological features, such as fibroma of tendon sheath, low-grade myxofibrosarcoma and acral myxoinflammatory fibroblastic sarcoma. It was not possible to detect the FUS/CREB3L2 and FUS/CREB3L1 fusion genes from the formalin-fixed and paraffin-embedded tissue, although the histological features of the present case were typical of LGFMS. LGFMS may become more common with time, and unique cases may accumulate.     

Molecular characterization and heterogeneity of feline immunodeficiency virus isolates

Summary We have molecularly cloned the complete genomic DNA of TM2 strain of feline immunodeficiency virus (FIV) isolated in Japan and compared its nucleotide and the deduced amino acid sequence with those of previously described U.S. isolates, FIV Petaluma and FIV PPR. The infectious molecular clone of FIV TM2 is different from FIV Petaluma in host cell range; the clone can not infect Crandell feline kidney cells which were permissive for FIV Petaluma. The amino acid sequence homologies, ingag, pol, andenv genes between FIV TM2 and Petaluma were 90%, 87%, and 81%, respectively. On the other hand, comparative analysis of each gene between FIV Petaluma and PPR showed 96, 95, and 85%, respectively. These results suggested that the genomic diversity was present among FIV strains isolated from geographically distant areas. Interestingly,tat- andrev-like short open reading frames contained in-frame stop codons in the FIV Petaluma but not in the FIV TM2.     

Distribution of Antigens Detected with MB1, MB2 and MB3 on Non-hematopoietic Human Organs and Various Tumors

We have examined the distribution of antigens detected by MB1, MB2 and MB3 on non-hematopoietic normal human tissues and various types of benign and malignant tumors. MB1 and MB2 reacted with various organs, such as the epithelium of various glands, smooth muscle cells, vascular endothelial cells, and peripheral nerve tissue. The distributions of these two antibodies were essentially identical. Reactivity with MB3 was confined to the ductal eDithelium of salivary glands, the pancreas, and sweat glands, and the cortex of the adrenal gland. lmmunoblotting analysis demonstrated that MB1 and MB2 reacted with a few bands of an extract of myometrial cytoskeletal fraction and salivary gland cytosol fraction, whereas MB3 failed to show any bands on these materials. The reactivities of MB1 and MB2 with various neoplasms were similar to those in normal organs, with slight variations of staining pattern and preponderance in well differentiated tumors. Exceptionally, carcinoid tumor and small round cell tumors, such as small cell carcinoma or neuroblastoma, were not reactive with MB1 and MB2. MB3 reacted with several cases of well differentiated benign and malignant epithelial tumors in various organs, and exceptional cases of malignant schwannoma and glioma. These results indicate that the antigens detected by MB1 and MB2 are distributed broadly on non-hematopoietic normal organs, whereas those detected by MB3 are confined to exceptional cases of epithelial and non-epithelial tumors. Thus, although the use of MB1, MB2 and MB3 is of little value for differential diagnosis of various tumors, these three antibodies may be useful for determining of the origin of some tumor types. Acta Pathol Jpn 42: 339–346, 1992.     

Augmentation of antibody responses of mice to inhaled protein antigens by simultaneously inhaled bacterial lipopolysaccharides

Serum antibody responses of mice to repeatedly inhaled protein antigens such as bovine serum albumin and ovalbumin, plus or minus bacterial lipopolysaccharide (LPS) in the form of an aerosol were studied. Results showed that the levels of responses to inhaled protein antigens varied, depending on the mouse strain-antigen combination and that LPS inhaled simultaneously with the antigens definitely augmented the responses which were not otherwise very high. LPS extracted from Klebsiella O3 (LPS-K) but not LPS from Escherichia coli O55 (LPS-E), which was inhaled at the time of initial inhalation of antigen, significantly intensified the priming for the secondary antibody response to the antigen subsequently inhaled. Both LPS-K and LPS-E, however, definitely acted to augment the response when they were inhaled repeatedly together with the antigen. Oral administration of antigen or antigen plus LPS-K did not induce any detectable antibody response in our experiment, ruling out the possibility that the antigen and LPS stimulated the immune system via alimentary canal rather than via lung. Tissue distribution of the radioactivity soon after inhalation of 131I-labeled antigen and decay speed of the radioactivity were not significantly changed by LPS-K inhaled simultaneously. This suggested that the augmentation of responses was not mediated by the action of LPS to modulate the air-blood barrier against the entry of antigen via lung. All the results prove for the first time that inhaled LPS displays a definite adjuvant action on antibody responses to inhaled antigens.