Interferons increase transcription of a major histocompatibility class I gene via a 5' interferon consensus sequence

Interferons (IFNs) augment expression of major histocompatibility class I genes in many cells. To study the effect of IFNs on transcription of class I genes, we prepared and tested activity of chloramphenicol acetyltransferase (CAT) hybrid genes in which the cat gene is under the control of the 5' flanking region of the murine H-2Ld gene. NIH 3T3 cells transiently transfected with a cat construct having the sequence from position -210 to -134 showed a four- to fivefold increase in CAT activity when treated with IFN-alpha/beta. This sequence contains the IFN consensus sequence (ICS) shared among IFN-inducible genes, as well as the class I regulatory element (CRE) that controls up and down regulation of class I gene expression. To determine the precise sequence requirement for the IFN action, the ICS and CRE were independently placed upstream of the class I or a heterologous simian virus 40 promoter, and CAT activity was tested. The ICS, but not the CRE, enhanced activity of both promoters by about twofold upon exposure to IFN-alpha/beta, although greater responses were noted when the ICS and CRE were combined. These results demonstrate that the ICS alone is capable of enhancing promoter activity in response to IFN-alpha/beta treatment and that the CRE exerts a synergistic effect. Further, we show that the ICS functions as an inducible enhancer since it acts regardless of its orientation and distance in the simian virus 40 promoter.

[A case of vesical malacoplakia diagnosed by randomized biopsy of the urinary bladder]

Vesical malacoplakia is a relatively rare disease and commonly diagnosed by characteristic cystoscopical findings and histological determination using biopsy specimen. We report here a case of a 53-year-old housewife, with atypical cystoscopical findings, which looked like carcinoma in situ, and in which randomized biopsy helped to make the final diagnosis. This case was successfully controlled by anti-bacterial agents.

[Cholesteatoma of the ureter: a case report]

A 68-year-old woman was hospitalized complaining of right flank pain. The excretory pyelogram revealed that the right kidney was hydronephrosis, and a retrograde pyelogram showed stringy filling defects in the middle portion of the right ureter. Suspecting a right ureter tumor, a right ureteronephrectomy was performed. The pathological diagnosis was ureteral cholesteatoma which is a rare condition with reports of only 9 cases in the Japanese literature. Although the possibilities of malignant change has been debatable, long term follow up would be mandatory.

Tissue-specific and developmental expression of human transthyretin gene in transgenic mice

To analyze the regulation of transthyretin gene expression we have produced transgenic mice by microinjecting cloned human transthyretin genes into fertilized eggs of C57BL/6 mice. The 7.6-kilobase (kb) human transthyretin gene containing about 500 base pairs (bp) in the upstream region was used for microinjection. Seven out of nine transgenic mice had detectable amounts of human transthyretin in serum when analyzed by enzyme-linked immunosorbent assay. Transthyretin mRNA was detected in liver and yolk sac but not in other tissues including brain. The amount of mRNA was variable among transgenic mice and was about one-tenth of mouse endogenous transthyretin mRNA. Human and mouse transthyretin mRNAs were detected in liver of fetus and yolk sac at 13 days of gestation and unlike yolk sac the level of mRNA in liver increased gradually during development and reached the maximum at around 17 days of gestation. Human transthyretin was associated with mouse transthyretin to form tetramers as judged from the dilution curve of enzyme-linked immunosorbent assay and the spur formation in Ouchterlony assay.

Negative regulation of the major histocompatibility class I gene in undifferentiated embryonal carcinoma cells

Murine embryonal carcinoma F9 cells, which do not express appreciable levels of major histocompatibility complex (MHC) class I mRNA, start to express the mRNA and proteins upon differentiation induced by retinoic acid (RA). To investigate the molecular mechanism of this regulation, we examined in F9 cells transient expression of the chloramphenicol acetyltransferase (CAT) gene directed by the 5' flanking region of a MHC class I gene, H-2Ld. The native 1.4-kilobase H-2Ld 5' upstream region gave very low CAT activity in undifferentiated F9 cells. Deletion between positions -210 and -135 relative to the cap site resulted in a 4- to 5-fold increase in CAT activity as compared with constructs containing the region. However, all of these constructs, regardless of the deletion, expressed comparable CAT activity in differentiated F9 cells. These data suggest the presence of a negative cis-acting element that is under developmental control. Further analysis revealed that the sequence conferring the negative regulation resides between positions -195 and -161. This region, highly conserved among the MHC class I genes, is found to be capable of increasing CAT activity in NIH 3T3 cells that express the class I genes constitutively. Further, this regulatory sequence, when connected to the simian virus 40 promoter, produced repressive and enhancing effects in F9 and NIH 3T3 cells, respectively. Based on these results, we suggest that the expression of MHC class I genes during development involves switching from negative to positive regulation dictated by the class I regulatory element located between positions -195 and -161.

[A case of metastatic urinary bladder tumor from a gastric remnant carcinoma]

We report a case of a metastatic urinary bladder tumor from gastric remnant carcinoma. On August 23, 1984, a 70-year-old-woman visited us with the complaint of dysuria. She had undergone gastrectomy for gastric ulcer 25 years earlier. Cystoscopy revealed a non-stalk tumor in the dome of the bladder and the examination of the upper gastro-intestinal tract revealed gastric remnant carcinoma. We treated her with adriamycin, cis-diamminedichloroplatinum and mitomycin C but unfortunately she died of cachexia two weeks later. An autopsy revealed that the urinary bladder tumor was a signet ring cell carcinoma, metastasized from gastric remnant carcinoma.

Expression and function of a nonglycosylated major histocompatibility class I antigen

The major histocompatibility class I antigens, expressed in most somatic cells, have carbohydrate moieties. We constructed mutant mouse MHC class I genes in which codons for the N-linked glycosylation sites were replaced by those of other amino acids. L cell transformants expressing the nonglycosylated class I antigens allowed us to investigate biological roles of carbohydrates with the highest specificity possible. The nonglycosylated antigen was unchanged in its overall serological specificities, and was recognized by alloreactive cytotoxic T cells. Further, the antigen was capable of mediating cytotoxic activity of vesicular stomatitis virus-specific T cells. These studies indicate that carbohydrates are not essential for immunological function of the MHC class I antigens. Cell surface expression of the nonglycosylated antigen was markedly reduced as compared with the native antigen, which was not attributable to accelerated degradation or rapid shedding. We conclude that the primary role of carbohydrates of the class I antigens is to facilitate the intracellular transport of the nascent proteins to the plasma membrane. The possible involvement of carbohydrate-receptor interactions in this process is discussed.

Intracellular transport blockade caused by disruption of the disulfide bridge in the third external domain of major histocompatibility complex class I antigen

The third external domain of major histocompatibility class I antigens has a highly conserved disulfide bridge between cysteine-203 and cysteine-259. To elucidate the functional significance of this disulfide bridge, we have produced a mutant H-2Ld gene by site-directed mutagenesis in which the codon for cysteine-203 is changed to a codon for serine, which is unable to form a disulfide bridge. The mutant H-2Ld gene was introduced into mouse L cells and its expression has been studied. No measurable expression of the H-2Ld antigen was detected on the cell surface of the transformants by antibody-binding assays. However, a large quantity of the mutant H-2Ld antigen was found in the cytoplasm of the transformants as observed by immunoprecipitation of metabolically labeled lysate and by immunocytochemistry of membrane-permeabilized cells, using an antibody specific for the first external domain of the H-2Ld antigen. The mutant antigen was glycosylated and associated, at least in part, with beta 2-microglobulin. Subcellular fractionation experiments indicated that the transport of the antigen was blocked between the endoplasmic reticulum and the plasma membrane. It is concluded that structural integrity of the third external domain is a prerequisite for intracellular transport of class I antigens. On the basis of these findings we suggest that the domain structure containing the disulfide bridge serves as a signal structure necessary for receptor-mediated intracellular transport and that this requirement is the evolutionary basis for high conservation of similar structures present throughout the immunoglobulin supergene family.

Involvement of gene 49 in recombination of bacteriophage T4

The role of T4 gene 49 in recombination was investigated using its conditional-lethal amber (am) and temperature-sensitive (ts) mutants. When measured in genetic tests, defects in gene 49 produced a recombination-deficient phenotype. However, DNA synthesized in cells infected with a ts mutant (tsC9) at a nonpermissive temperature appeared to be in a recombinogenic state: after restitution of gene function by shifting to a permissive temperature, the recombinant frequency among progeny increased rapidly even when DNA replication was blocked by an inhibitor. Growth of a gene 49-defective mutant was suppressed by an additional mutation in gene uvsX, but recombination between rII markers was not.

[Analysis of lectin-affinity of alpha fetoprotein-diagnostic approach]

Lectin affinities of AFP were analyzed using Con A sepharose chromatography and crossed immuno-affino-electrophoresis. With Con A, AFP was divided into three subfractions, nonbound, loosely-bound and tightly-bound by chromatography, or two subfractions, nonbound and bound by electrophoresis. Con A nonbound subfraction was small in percentage in hepatocellular carcinoma (HCC), neonatal hepatitis, congenital biliary atresia (CBA), liver cirrhosis (LC) and cord sera. In contrast with these, the increase of Con A non-bound AFP was observed in yolk sac tumor (YST) and metastatic liver cancer (Meta). With LCA, AFP was divided into three subfractions: nonbound, loosely bound and tightly bound. Loosely bound fraction was very small in every specimen. AFPs from cord sera and LC showed uniform LCA affinity pattern, but AFPs from HCC were not uniform. Our data suggest that the analyses of lectin affinity of AFP serve as a diagnostic tool in differentiating (1) HCC from YST, (2) HCC from Meta, (3) CBA or neonatal hepatitis from YST and (4) LC from some cases of HCC.

Effects of the tumor promoter teleocidin on human hepatoma cells in tissue culture

The tumor promoter teleocidin inhibited the proliferation of human HUH hepatoma cells in tissue culture. HUH cells cultured with teleocidin developed elongated cytoplasm. In addition, these biological effects of teleocidin were associated with a remarkable decrease in the amount of cellular fibronectin. The synthesis of structural proteins and the number of cell surface receptors for epidermal growth factor were not altered in cells treated with teleocidin, suggesting that teleocidin acted selectively on some of the cellular constituents such as fibronectin. The present data also suggest a possible relationship between the cellular fibronectin content and the biological characters of HUH cells.

Progressive multifocal leukoencephalopathy. A case report and review of the literature

Progressive multifocal leukoencephalopathy developed in a 70-year-old man with hepatoma treated with oncostatica. The brain showed multiple demyelinated lesions in the upper half of the cerebral white matter. The lesions consisted of proliferation of hypertrophied astrocytes and glial cells with abnormally large nuclei. These nuclei were shown to be filled with DNA by DAPI staining and reacted specifically with anti-JC antibody by immunofluorescence. Papova-like virions were confirmed on both the sections and negatively-stained brain extract under electron microscopy. The sixteen cases so far reported in Japan were reviewed.

Human fetal organ alkaline phosphatases

The properties of human fetal alkaline phosphatase (ALP) have been compared with those of purified human adult hepatic and intestinal ALPs. The ALPs from different human fetal organs were divided into two groups. One terminated universal type was presented in fetal liver, spleen, adrenal, kidney, lung, heart, pancreas, thymus and bone, and was similar to adult hepatic-type ALP. The other terminated intestinal type was presented in fetal intestine and meconium and was similar to adult intestinal ALP. The activity of human fetal intestinal ALP increased markedly with the advance of intra-uterine life during fetal development, and that of human fetal thymus ALP increased slightly.