Self-recognition through Dectin-1 exacerbates liver inflammation

Dectin-1 is a well-characterized C-type lectin receptor involved in anti-fungal immunity through the recognition of polysaccharides; however, molecular mechanisms and outcomes initiated through self-recognition have not been fully understood. Here, we purified a water-soluble fraction from mouse liver that acts as a Dectin-1 agonist. To address the physiological relevance of this recognition, we utilized sterile liver inflammation models. The CCl4-induced hepatitis model showed that Dectin-1 deficiency led to reduced inflammation through decreased inflammatory cell infiltration and lower pro-inflammatory cytokine levels. Moreover, in a NASH model induced by streptozotocin and a high-fat diet, hepatic inflammation and fibrosis were ameliorated in Dectin-1-deficient mice. The Dectin-1 agonist activity was increased in the water-soluble fraction from NASH mice, suggesting a potential pathogenic cycle between Dectin-1 activation and hepatitis progression. In vivo administration of the fraction into mice induced hepatic inflammation. These results highlight a role of self-recognition through Dectin-1 that triggers hepatic innate immune responses and contributes to the exacerbation of inflammation in pathogenic settings. Thus, the blockade of this axis may provide a therapeutic option for liver inflammatory diseases.

Dectin-1/IL-15 Pathway Affords Protection against Extrapulmonary Aspergillus fumigatus Infection by Regulating Natural Killer Cell Survival

Aspergillus fumigatus is a ubiquitous, yet potentially pathogenic, mold. The immune system employs innate receptors, such as dectin-1, to recognize fungal pathogens, but the immunological networks that afford protection are poorly explored. Here, we investigated the role of dectin-1 in anti-A. fumigatus response in an experimental model of acute invasive aspergillosis. Mice lacking dectin-1 presented enhanced signs of inflammation, with increased production of inflammatory cytokines and neutrophil infiltration, quickly succumbing to the infection. Curiously, resistance did not require T/B lymphocytes or IL-17. Instead, the main effector function of dectin-1 was the preservation of the NK cell population in the kidneys by the provision of the cytokine IL-15. While the depletion of NK cells impaired host defense in wild-type mice, IL-15 administration restored antifungal responses in dectin-1-deficient mice. Our results uncover a new effector mechanism for dectin-1 in anti-Aspergillus defense, adding an alternative approach to understand the pathophysiology of this infection.

Mycobacterial mycolic acids trigger inhibitory receptor Clec12A to suppress host immune responses

Mycobacteria often cause chronic infection. To establish persistence in the host, mycobacteria need to evade host immune responses. However, the molecular mechanisms underlying the evasion strategy are not fully understood. Here, we demonstrate that mycobacterial cell wall lipids trigger an inhibitory receptor to suppress host immune responses. Mycolic acids are major cell wall components and are essential for survival of mycobacteria. By screening inhibitory receptors that react with mycobacterial lipids, we found that mycolic acids from various mycobacterial species bind to mouse Clec12A, and more potently to human Clec12A. Clec12A is a conserved inhibitory C-type lectin receptor containing immunoreceptor tyrosine-based inhibitory motif (ITIM). Innate immune responses, such as MCP-1 production, and PPD-specific recall T cell responses were augmented in Clec12A-deficient mice after infection. In contrast, human Clec12A transgenic mice were susceptible to infection with M. tuberculosis. These results suggest that mycobacteria dampen host immune responses by hijacking an inhibitory host receptor through their specific and essential lipids, mycolic acids. The blockade of this interaction might provide a therapeutic option for the treatment or prevention of mycobacterial infection.

Immune discrimination of environmental spectrum through C-type lectin receptors

Our bodies are continuously assaulted by infection and tissue damage; most of these injurious insults are primarily sensed by immune receptors to maintain tissue homeostasis. Although immune recognition of proteins or nucleic acids has been well characterized, the molecular mechanisms by which immune receptors discriminate lipids to elicit suitable immune responses remain elusive. Recent studies have demonstrated that the C-type lectin receptor (CLR) family functions as immune sensors for adjuvant lipids derived from pathogens and damaged-tissues, thereby promoting innate/acquired immunity. In this review, we will discuss how these receptors recognize lipid components to initiate appropriate, but sometimes deleterious, immune responses against environmental stimuli. We will also discuss an aspect of inhibitory CLRs; their ligands might reflect normal self which silences the immune response regarded as "silence"-associated molecular patterns or may be associated with escape strategies of pathogens as "evasion"-associated molecular patterns.

The key entity of a DCAR agonist, phosphatidylinositol mannoside Ac1PIM1: its synthesis and immunomodulatory function

Ac₁PIM₁ is a potential biosynthetic intermediate for phosphatidylinositol mannosides (PIMs) from Mycobacterium tuberculosis. We achieved the first synthesis of Ac₁PIM₁ by utilizing an allyl-type protecting group strategy and regioselective phosphorylation of inositol. A very potent agonist of an innate immune receptor DCAR, which is better than previously known agonists, is demonstrated.

C-Type Lectin Receptor DCAR Recognizes Mycobacterial Phosphatidyl-Inositol Mannosides to Promote a Th1 Response during Infection

Phosphatidyl-inositol mannosides (PIM) are glycolipids unique to mycobacteria and other related bacteria that stimulate host immune responses and are implicated in mycobacteria pathogenicity. Here, we found that the FcRγ-coupled C-type lectin receptor DCAR (dendritic cell immunoactivating receptor; gene symbol Clec4b1) is a direct receptor for PIM. Mycobacteria activated reporter cells expressing DCAR, and delipidation of mycobacteria abolished this activity. Acylated PIMs purified from mycobacteria were identified as ligands for DCAR. DCAR was predominantly expressed in small peritoneal macrophages and monocyte-derived inflammatory cells in lungs and spleen. These cells produced monocyte chemoattractant protein-1 (MCP-1) upon PIM treatment, and absence of DCAR or FcRγ abrogated MCP-1 production. Upon mycobacterial infection, Clec4b1-deficient mice showed reduced numbers of monocyte-derived inflammatory cells at the infection site, impaired IFNγ production by T cells, and an increased bacterial load. Thus, DCAR is a critical receptor for PIM that functions to promote T cell responses against mycobacteria.

Mycobacterium tuberculosis β-gentiobiosyl diacylglycerides signal through the pattern recognition receptor Mincle: total synthesis and structure activity relationships

Mycobacterium tuberculosis H37Ra produces a range of immunogenic β-gentiobiosyl diacylglycerides. We report the total synthesis of several candidate structures and show that these compounds signal weakly through mouse, but not human, Mincle. Structure-activity relationships reveal a striking dependence upon acyl chain length for gentiobiosyl diacylglyceride signalling through Mincle. Significantly, a truncated β-glucosyl diglyceride was shown to provide potent signalling through both human and mouse Mincle and could activate murine bone marrow derived dendritic cells.

Corynomycolic acid-containing glycolipids signal through the pattern recognition receptor Mincle

Glucose monocorynomycolate is revealed to signal through both mouse and human Mincle. Glycerol monocorynomycolate is shown to selectively signal through human Mincle, with the activity residing predominantly in the 2′S-isomer.

Comparison between fractionated high dose rate irradiation and continuous low dose rate irradiation in spheroids

Recent interest in clinical brachytherapy focuses on the possible radiobiological equivalence between fractionated high dose rate (HDR) and continuous low dose rate (LDR) irradiations. This study is designed to compare the radiobiological effects between the two in vitro using multicellular spheroids of human tumor. Both HDR and LDR irradiations were delivered by 137Cs source, the dose rates of which were as 1.18 Gy/min and 5.5 mGy/min, respectively. Fractionated HDR irradiation of various fraction sizes was applied twice a day. We found that: (1) The fractionated HDR irradiation (8 Gy/2 fr/day) was more effective radiobiologically than continuous LDR irradiation (8 Gy/day) and the ratio of radiobiological effects of these irradiations was estimated as 0.82, based on the 50% spheroid cure dose (SCD50); (2) the radiobiological effectiveness was independent of the fraction size of HDR irradiation administrated, and the repair of sublethal damage (SLD) was absent, suggesting that the sparing effect of fractionated HDR irradiations was absent in spheroids. Our findings could provide important information for the clinical usage of the fractionated HDR radiotherapy to replace continuous LDR radiotherapy.

DNA fragmentation induced by a cytoplasmic extract from irradiated cells

Apoptosis is a mode of cell death characterized by distinct morphological features and DNA fragmentation. The program that leads to apoptosis has been considered to be predominantly extranuclear, and a signal transduction pathway to the nucleus exists during apoptosis, while characteristic events occur in the nucleus. As for radiation-induced apoptosis, the signal transduction pathway remains unclear, especially the sites where the primary effect of radiation occurs. In this study, we demonstrate that a cytoplasmic extract prepared from irradiated cells has the ability to cause DNA fragmentation and that caspase-3 is activated in this extract. Normal nuclei of HeLa S3 cells were added to a cytoplasmic extract made from HL60 cells which had been irradiated with 30 Gy of 137Cs gamma rays and were incubated. Agarose gel electrophoresis of the added nuclei showed a characteristic DNA laddering pattern. This reaction was blocked by a caspase-3 inhibitor but not by an ICE inhibitor. These observations suggest that a signal transduction pathway from an unknown target of gamma radiation may exist upstream of caspase-3 during radiation-induced apoptosis.

Activation of lymphocytes by HHV-6 antigen in normal children and adults

We investigated the immune reaction of lymphocytes in response to human herpes virus-6 (HHV-6) in normal children and adults. Cell proliferation was assayed by measurement of the incorporation of 5-bromo-2'-deoxyuridine (BrdU) by enzyme-linked immunosorbent assay (ELISA), and changes in expression of interleukin-2 receptors (IL-2Rs) (alpha-, beta3-, and gamma-chain) were assayed by flow cytometry. Incorporation of BrdU and expression of IL-2Rs (alpha-, beta-, and gamma-chain) in CD4+, CD8+, and CD45RO+ lymphocytes were increased when peripheral blood mononuclear cells (PBMC) from HHV-6 seropositive children aged 3 to 12 years and adults were cultured with HHV-6 antigen compared with control antigen. In contrast, cord blood mononuclear cells (CBMC) and PBMC from seronegative children did not show cell proliferation and changes in expression of IL-2Rs. In seropositive children less than 2 years of age, the magnitude of cell proliferation was low and IL-2Rs (alpha-, beta-, and gamma-chain) in CD8+ cells and IL-2Rs (alpha-chain) in CD45RO+ cells were increased. These data suggest that children below the age of 2 had immature lymphocytic response to HHV-6 antigen. Deletion of monocytes from PBMC and the addition of a mixture of anti-IL-2Rs (alpha-, beta-, and gamma-chain) antibodies reduced cell proliferation in response to HHV-6, suggesting the requirement of the presence of monocytes and expression of IL-2Rs.

SN-38, a metabolite of the camptothecin derivative CPT-11, potentiates the cytotoxic effect of radiation in human colon adenocarcinoma cells grown as spheroids

BACKGROUND AND PURPOSE

CPT-11 (7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxycamptothecin) is anew semisynthesized derivative of camptothecin. SN-38 (7-ethyl-10-hydroxycamptothecin), a metabolite of CPT-11, plays a key role in the action of CPT-11.

MATERIALS AND METHODS

To determine whether SN-38 potentiates the cytotoxic effect of radiation, we investigated the interaction of SN-38 and radiation in vitro in monolayer cultures and multicellular spheroids of HT-29 human colon adenocarcinoma cells.

RESULTS

HT-29 spheroids were more resistant to both SN-38 and irradiation than monolayer cells. SN-38 at a concentration of 2.5 microg/ml, which by itself was not cytotoxic, greatly increased the lethal effects of radiation in spheroids, but not in monolayer cultures. Exposure to SN-38 following irradiation inhibited the potentially lethal damage repair (PLDR) in spheroids. It is suggested that the mechanism of the radiosensitization by SN-38 is due to the PLDR inhibition.

CONCLUSIONS

These results indicate that CPT-11 may play a role as radiosensitizer and that a combination of CPT-11 and irradiation could prove to be a particularly effective strategy with which to treat human colon adenocarcinoma.

The effect of iodine-based contrast agents on the levels of radiation-induced chromosomal aberrations

The effects of iodine-based contrast agents on the repair of radiation-induced chromosomal damage were investigated employing peripheral blood from a healthy male donor. The blood samples were irradiated with 0.5-4.0 Gy 137Cs gamma rays. Contrast agents and NaCl solutions of various concentrations were added to the blood within the first 15 min or at 60 min after irradiation, and the samples were subsequently cultured for 45 h at 37 degrees C. Significantly elevated frequencies of chromosomal abnormalities caused by postirradiation treatment with hypertonic contrast agents appeared to increase with increasing hypertonicity. Elevated aberration frequencies were found to be greatest in the samples treated within 15 min of irradiation. The contrast agents had little effect if they were added at 60 min after irradiation, probably because the process of chromosome rejoining had been completed. Isotonic iodine-based contrast agents did not enhance the frequencies of chromosomal aberrations to a significant degree.

Cytokines released by human peripheral blood mononuclear cells inhibit the production of early and late cytomegalovirus proteins

Cytomegalovirus-infected human fibroblasts are susceptible to lysis by natural killer cells and cytotoxic T cells. The purpose of this study was to determine whether non-lytic mechanisms might also contribute to the control of cytomegalovirus infection. The appearance of cytomegalovirus proteins in infected fibroblasts was determined by flow cytometry. Infected fibroblasts incubated with peripheral blood mononuclear cells for 3 days expressed less early and late proteins than fibroblasts incubated without peripheral blood mononuclear cells. Supernatants generated by the cocultivation of peripheral blood mononuclear cells with cytomegalovirus-infected fibroblasts inhibited the production of cytomegalovirus early and late proteins. The soluble factors in supernatants which contributed to the inhibitory effect were identified as interferons alpha, beta and gamma, and tumor necrosis factors alpha and beta. The ability of supernatants to inhibit the production of cytomegalovirus early protein was mimicked by combinations of corresponding recombinant cytokines. The inhibition of cytomegalovirus protein production by cytokines produced by peripheral blood mononuclear cells may contribute to early containment of cytomegalovirus infection.

Human herpesvirus 7 infection associated with central nervous system manifestations

The clinical features of infection with human herpesvirus 7 (HHV-7) are not well described. Exanthem subitum is the only illness that is confirmed to be caused by HHV-7. We report two children who had exanthem subitum associated with central nervous system manifestations. Two strains of HHV-7 were isolated sequentially from peripheral blood mononuclear cells and saliva of the some child who had exanthem subitum complicated with acute hemiplegia in childhood. Two strains were confirmed to be HHV-7 by means of monoclonal antibodies to human herpesvirus 6 (HHV-6) and HHV-7, polymerase chain reaction, and DNA analysis. During the convalescent period, the antibody titer to HHV-7 rose from less than 1:10 to 1:320, whereas the antibody titer to HHV-6 remained less than 1:10. Another child with exanthem subitum complicated by acute hemiplegia had serologic evidence of primary HHV-7 infection. These two cases demonstrate a new relationship between HHV-7 and central nervous system symptoms.

Molecular genetic diagnosis of von Hippel-Lindau disease: analysis of five Japanese families

We analyzed deoxyribonucleic acids from blood samples of five Japanese von Hippel-Lindau (VHL) disease families (three familial cases, two new mutations) for the presence of VHL gene mutations by single-strand conformational polymorphism analysis and direct sequencing. Four of the five families showed germ line mutations in VHL gene, comprising 2 missense mutations, 1 deletion, and 1 splice-site mutation. Two families had VHL gene mutations at exon 1; 1 family at exon 3; and 1 family at the splice-site adjacent to exon 3. Presymptomatic patients were accurately diagnosed by these methods. However, one family did not show a VHL gene mutation in the germ line but showed a somatic mutation at exon 2 in the hemangioblastoma tissue. The consequence of the somatic mutation was a microdeletion leading to a frameshift mutation. Our study is the first report of VHL gene analyses of Japanese VHL disease families, and suggests that not only germ line mutation, but also somatic mutation can lead to development of a tumor associated with the VHL disease.

Tumor suppressor gene p53 mutations in human prostate cancer

The genetic background underlying the growth and development of human prostatic cancer is not yet clear. Here we searched for possible mutations in the entire coding region of tumor suppressor gene p53 in primary human prostatic carcinomas, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. We found p53 gene mutations in 4 of 21 cases (19%). DNA sequencing of the polymerase chain reaction products revealed missense point mutations that resulted in amino acid changes in exon 5 or 3 in three cases and single base deletions in exon 7 in two cases. One case contained both a missense point mutation and a single base deletion. Three of these four cases were pathologically diagnosed as poorly differentiated adenocarcinomas, and three of the four cases were clinically localized to stage C or D. None of seven noncancerous prostate tissues nor three well-differentiated adenocarcinoma tissues showed any mutations. The present results suggest that p53 gene mutation is involved in the late progression steps of human prostate carcinogenesis.

Clinical manifestations associated with human herpesvirus 7 infection

Twenty two cases of human herpesvirus 7 (HHV-7) infection are described. HHV-7 infection occurred later than human herpesvirus 6 (HHV-6) infection and induced exanthem subitum in 47.1% of the children. HHV-7 infection was associated with exanthem subitum and the other symptoms that were observed in HHV-6 infection.

Expression of transforming growth factor-beta 1 in human bladder cancer

BACKGROUND

Elevated expression of transforming growth factor-beta 1 (TGF-beta 1) has been reported in several types of human cancer. However, the significance of TGF-beta 1 expression in clinical bladder cancer is not well known.

METHODS

The levels of TGF-beta 1 expression were quantitated using a polymerase chain reaction-based method in tissue specimens obtained from 51 patients with bladder cancer.

RESULTS

Transforming growth factor-beta 1 expression in bladder cancer was higher than that found in normal bladder epithelium (P < 0.01). Significantly higher levels of TGF-beta 1 transcripts were observed in low and intermediate grade (Grade 1 and 2) tumors than in high grade (Grade 3) tumors (P < 0.02). Superficial (pTa and pT1) tumors had higher levels of TGF-beta 1 than invasive (pT2 or higher) tumors (P < 0.05).

CONCLUSIONS

These results suggest that enhanced expression of TGF-beta 1 is specific to low grade and stage bladder cancer. Transforming growth factor-beta 1 may play an important role in the early stages of human bladder cancer development, and TGF-beta 1 expression could provide a new relevant tumor marker for determining tumor progression in patients with bladder cancer.

Retinoblastoma gene mutations in primary human bladder cancer

Inactivation of the retinoblastoma (RB) gene is known to be implicated in the pathogenesis of several types of human cancers. Since structural alterations of the RB gene have not been well examined in human bladder cancer, we looked for mutations in the entire coding region of this gene using polymerase chain reaction (PCR) and single-strand conformational polymorphism analysis of RNA. We also examined allelic loss of the RB gene using PCR-based restriction fragment length polymorphism analysis. Of 30 samples obtained from patients with bladder cancer, eight (27%) were found to have RB gene mutations. DNA sequencing of the PCR products revealed five cases with single point mutations and three cases with small deletions. These mutations included one (10%) of ten low-grade (grade 1) tumours, four (50%) of eight intermediate-grade (grade 2) tumours and three (25%) of 12 high-grade (grade 3) tumours. Likewise, mutations were found in four (21%) of 19 superficial (pTa and pT1) tumours and four (36%) of 11 invasive (pT2 or greater) tumours. In 15 informative cases, loss of heterozygosity at the RB locus was shown in five cases (33%), three cases with RB mutations and two without them. These results suggest that RB gene mutations are involved in low-grade and superficial bladder cancers as well as in high-grade and invasive cancers.

Polymorphisms in the human DNA polymerase beta gene

Recently, evidence has accumulated that mutations in DNA repair genes might be associated with certain steps in carcinogenesis. The DNA polymerase beta gene is one of the DNA repair genes, and mutations in it have been detected in 83% of human colorectal cancers. To assess the involvement of polymerase beta gene mutations in the development of human prostate cancers, we performed sequence analyses of human DNA samples. Unexpectedly, we found six regions that were polymorphic. This information should be taken into consideration at the time of sequence analysis of the DNA polymerase beta gene.

Somatic mutations of the von Hippel-Lindau tumor suppressor gene in sporadic central nervous system hemangioblastomas

Hemangioblastoma is one of the benign tumors in the central nervous system. It is often associated with the von Hippel-Lindau (VHL) disease, a well known hereditary tumor syndrome. It is believed that inactivation of both alleles of VHL tumor suppressor gene is essential in the tumorigenic processes in hemangioblastomas associated with VHL disease. The molecular basis for the development of sporadic hemangioblastomas is not known. Here, we analyzed 13 cases of primary sporadic hemangioblastomas for somatic mutations of VHL gene with single strand conformational polymorphism analyses of the tumor DNAs. We detected abnormal single strand conformational polymorphism pattern in 7 tumors (54%). Of these 7 possibly mutated tumors, we successfully characterized 3 tumors by direct sequencing. We were unable to sequence 4 tumors because of the poor quality of DNA obtained from paraffin blocks. Somatic mutations in the 3 tumors were 2 missense mutations and 1 microdeletion. These mutations were observed in 1 tumor in exon 1 and 2 tumors in exon 2. Our results suggest that mutations of VHL tumor suppressor gene are involved in the development of at least 20% of sporadic central nervous system hemangioblastomas.

Impaired cell-mediated immunity to cytomegalovirus (CMV) in leukemic children with prolonged CMV viruria

To determine the role of cell-mediated immunity (CMI) to cytomegalovirus (CMV) in leukemic children after CMV infection, CMI to CMV antigen was studied using CMV-specific lymphocyte blastogenic responses (LBR) and interferon (IFN) production. Four children, who continuously secreted CMV in urine more than 2 years after symptomatic CMV infection (CMV disease) (group 1), showed impaired LBR to CMV antigen, though they had normal LBR to phytohemagglutinin (PHA) and concanavalin A (Con A). Impairment of LBR either to AD-169 strains or autologous and heterologous wild strains was observed. IFN production was not detected in three of four children. Six leukemic children, who had no viruria after cessation of CMV disease (group 2), showed good responses to CMV antigens. IFN was detected in all six children in group 2. Eight leukemic children, who were seropositive to CMV at the onset of leukemia (group 3), showed good responses to CMV antigens and IFN production. These results suggest that impaired cell-mediated immunity to CMV antigen might contribute to prolonged excretion of CMV in urine in leukemic children.

Human herpesvirus 7: another causal agent for roseola (exanthem subitum)

Human herpesvirus 7 (HHV-7) was isolated from peripheral blood mononuclear cells of two infants with typical exanthem subitum. The HindIII-, BamHI-, and EcoRI-digested DNA patterns of the isolated viruses were very similar to that of the prototype HHV-7 (RK strain), but different from that of human herpesvirus 6 (HHV-6). During the convalescent period of the first patient, the titer of antibody to HHV-7 rose from < 1:10 to 1:320 by an immunofluorescence antibody test, whereas the titer of antibody to HHV-6 remained < 1:10. In the second patient, who had two independent episodes of exanthem subitum during 2 months, both HHV-6 and HHV-7 were sequentially isolated; seroconversion to HHV-6 occurred during the first episode and to HHV-7 during the second episode. In addition, sera from another 15 children who had episodes of exanthem subitum were serologically tested for antibodies to HHV-6 and HHV-7 by immunofluorescence antibody test. Five of seven patients had seroconversion to HHV-7 just after having typical signs and symptoms of exanthem subitum. These results suggest that HHV-7 is one of the causative agents of exanthem subitum.

Frequent somatic mutations and loss of heterozygosity of the von Hippel-Lindau tumor suppressor gene in primary human renal cell carcinomas

We analyzed 47 primary sporadic human renal cell carcinomas (39 clear cell and 8 non-clear cell) for mutations of the von Hippel-Lindau (VHL) tumor suppressor gene using the polymerase chain reaction and single strand conformational polymorphism analysis of DNA. All of the positive cases in single strand conformational polymorphism analyses were further characterized by direct sequencing. Somatic mutations were detected in 22 (56%) of 39 clear cell renal carcinomas including 15 deletions, 3 insertions, 3 missense mutations, and 1 nonsense mutation. Nineteen of these mutations predicted to produce truncation of the VHL protein. These mutations mainly occurred in the last one-third region of exons 1, 2, and 3. In addition, loss of heterozygosity of the VHL gene was observed in 16 (84%) of 19 informative clear cell renal carcinomas. No somatic mutations were detected in 8 non-clear cell carcinomas. These results show that the VHL tumor suppressor gene is one of the major tumor suppressor genes in human renal cell carcinomas, especially in the clear cell subtype renal cell carcinoma. Clear cell carcinoma might be distinguished from other pathological types of renal cell carcinomas by molecular genetic techniques.

DNA polymerase beta gene mutation in human prostate cancer

DNA polymerase beta is a nuclear protein essential to DNA repair in mammalian cells. A high frequency of mutations in this gene has been reported in colorectal cancers. To clarify the tumorigenesis steps of human prostate cancers in the molecular basis, we examined the entire coding region of the human DNA polymerase beta gene in human prostate cancer tissues using polymerase chain reaction, single-strand conformational polymorphism analysis of RNA, and sequencing analysis. Consequently, we detected DNA polymerase beta gene mutations in 2 of 12 cases (17%). The first case is an A to G transition at nucleotide 893, resulting in a substitution of the amino acid from tyrosine to cysteine. In the second case, we found an A to G transition at nucleotide 305, a T deletion at nucleotide 569, and an A insertion into the 6 repeats of A from nucleotide 612 to 617. This T deletion shifted the subsequent reading frame and resulted in the premature termination at codon 163 instead of 336. The two cases were advanced grade and stage. Present results suggest that polymerase beta gene mutations, although they occurred at relatively low frequency, are involved in certain cases of human prostate carcinogenesis.

Cloning and characterization of a chromosomal gene cluster, pah, that encodes the upper pathway for phenanthrene and naphthalene utilization by Pseudomonas putida OUS82

A 25-kb DNA SalI fragment cloned from the chromosomal DNA of Pseudomonas putida OUS82, which utilizes phenanthrene (Phn+) and naphthalene (Nah+), carried all of the genes necessary for upper naphthalene catabolism. Cosmid recombinant pIP7 complemented both the Nah- and Phn- defects of OUS8211 (Trp-Nah-Phn-Sal+[salicylate utilizing]Hna+[1-hydroxy-2-naphthoate utilizing]) and only the Phn- defect of OUS8212 (Trp-Nah-Phn-Sal-Hna+). The results indicate that strain OUS82 uses different pathways after o-hydroxycarboxylic aromatics in the catabolism of naphthalene and phenanthrene.

Identification and characterization of genes encoding polycyclic aromatic hydrocarbon dioxygenase and polycyclic aromatic hydrocarbon dihydrodiol dehydrogenase in Pseudomonas putida OUS82

Naphthalene and phenanthrene are transformed by enzymes encoded by the pah gene cluster of Pseudomonas putida OUS82. The pahA and pahB genes, which encode the first and second enzymes, dioxygenase and cis-dihydrodiol dehydrogenase, respectively, were identified and sequenced. The DNA sequences showed that pahA and pahB were clustered and that pahA consisted of four cistrons, pahAa, pahAb, pahAc, and pahAd, which encode ferredoxin reductase, ferredoxin, and two subunits of the iron-sulfur protein, respectively.

Cytotoxicity against varicella zoster virus infected targets in children with acute leukemia

To eliminate the role of natural killer (NK), antibody-dependent cell-mediated cytotoxicity (ADCC), and polymorphonuclear leukocyte (PMN)-mediated cytotoxicity in Varicella zoster virus (VZV) infections, peripheral blood mononuclear cell (PBMC)-mediated NK and ADCC, and phorbol myristate acetate-stimulated PMN-mediated cytotoxicity against VZV-infected targets were studied in children with leukemia. Natural killer and PMN-mediated cytotoxic activity was depressed for 6 months after complete remission and ADCC activity was depressed for 1 year after complete remission. The magnitude of three cytotoxic mechanisms in leukemic children gradually increased while they continued in complete remission. These results suggested that decreased cytotoxic activities of PBMC and PMN might contribute to serious VZV infections and susceptibility to herpes zoster in leukemic children.

Cytofluorographic analysis of effects of interferons on expression of human cytomegalovirus proteins

The appearance of cytomegalovirus (CMV) proteins in infected fibroblasts was determined by flow cytometry. The sequential production of immediate early (IE), early (E), and late (L) proteins reacting with respective monoclonal antibodies (mAbs) E13, 58/5, and 24/4 was determined in fibroblasts infected with the AD-169 strain of CMV. The percentage of cells expressing CMV proteins and the intensity of fluorescence within cells were determined from day 1 to day 7 post-infection. The effect of interferons (IFNs) alpha, beta, gamma on expression of CMV proteins was analyzed using flow cytometry. IFNs inhibited E and L protein production at days 3 and 6 post-infection in a dose-dependent manner. This inhibitory effect on protein expression was associated with a reduction in release of infectious CMV into culture media. The method described here for detection of CMV proteins using flow cytometry may be useful for basic studies of gene expression and for diagnostic purposes.

Flow cytometric analysis of effects of cytokines on the expression of varicella-zoster virus glycoproteins

Varicella-zoster virus (VZV)-infected human embryonic fibroblast (HEF) cells were stained with monoclonal antibodies directed against VZV glycoprotein I, II and IV, and then labeled with fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. The cells were analyzed by flow cytometry. VZV-infected cells expressing VZV glycoproteins were clearly distinguished from uninfected cells. This method was useful for analyzing expression of VZV glycoproteins in different experimental conditions. Interferon alpha, beta, and gamma and tumor necrosis factor (TNF)-alpha reduced the percentage of positive cells and the mean fluorescence intensity of the cells expressing VZV glycoproteins. Interleukin(IL)-1 beta, IL-6 and TNF-beta had little effect on the expression of VZV glycoproteins.

Chemotaxis of polymorphonuclear leukocytes to varicella-zoster virus antigens

Chemotaxis of polymorphonuclear leukocytes (PMNs) to various varicella-zoster virus (VZV) antigens was studied using a membrane filter method. Chemotactic activity of PMNs was detected in the presence of sonicated VZV antigen and soluble VZV skin test antigen. This activity was reduced when sonicated VZV antigen was treated with human seropositive serum or murine monoclonal antibodies which reacted with glycoprotein (GP) I or GP II of VZV. However, chemotaxis of PMNs was not reduced when sonicated VZV antigen was treated with human seronegative serum or a murine monoclonal antibody which reacted with GP IV. These results suggest that GP I and GP II act as chemoattractants to PMNs, and this mechanism might contribute to the resolution of the skin lesions of varicella and herpes zoster.

Antibody response determined with antibody-dependent cell-mediated cytotoxicity (ADCC), neutralizing antibody, and varicella skin test in children with natural varicella and after varicella immunization

Humoral and cellular immune responses were examined in 115 children with varicella and in 21 children who had been immunized with live varicella vaccine. Antibody determined with antibody-dependent cell-mediated cytotoxicity (ADCC) was detected earlier than neutralizing antibody (NT) in both groups. While humoral and cellular immunity were detected simultaneously in the natural varicella group, cellular immunity was detected earlier than humoral immunity in the immunized group. This suggests that ADCC, rather than NT, is involved in the early stages of recovery from varicella-zoster virus (VZV) infection.

Expression of ABH and Lewis blood group antigens in combined hepatocellular-cholangiocarcinoma. Possible evidence for the hepatocellular origin of combined hepatocellular-cholangiocarcinoma

Expression of ABH, Lewis, and sialyl Lea antigens was studied in five combined hepatocellular-cholangiocarcinomas. Formalin-fixed liver tissues were immunostained for those antigens using well-characterized monoclonal antibodies and an avidin-biotin-peroxidase complex (ABC) method. Results were compared with those obtained in normal liver tissues and cholangiocarcinomas, and also with the previous observations of the authors on hepatocellular carcinomas. Although not detected in normal parenchymal liver cells, A, H, Lewis, and sialyl Lea antigens were found in combined hepatocellular-cholangiocarcinoma cells. Incompatible A antigen also was detected in one blood type O patient. Distribution and intensity of the antigens were similar to those in hepatocellular carcinomas and different from those in cholangiocarcinomas. No preferential accumulation of blood-group antigens could be found in the area of cholangiocarcinoma-like differentiation of the combined hepatocellular-cholangiocarcinoma. The observations suggested that Regional morphological differentiation of the hepatocellular-cholangiocarcinoma might not be always associated with the change in the expression of the blood group antigens. Moreover, the expression was essentially the same between the hepatocellular-cholangiocarcinoma and the typical hepatocellular carcinoma. The hepatocellular-cholangiocarcinoma, therefore could be a variant of the hepatocellular carcinoma.

Molecular hybridization methods for determination of serum HBV-DNA

Molecular hybridization methods for determination of hepatitis B virus DNA (HBV-DNA) in serum were studied. A simple method by which serum was treated with sodium hydroxide, followed by dot hybridization procedure on filter sheets provides a sensitive and direct result for detecting HBV-DNA. Another method in which DNAs extracted from Dane particle fraction were subjected to the molecular hybridization method on a filter membrane, provided similar results although this method is time consuming. The third method in which serum was directly spotted on filter sheets, followed by alkaline-treatment seems to be less sensitive. Three filter papers, NC filter, Zeta-Probe and Biodyne, on which molecular hybridization was performed, gave similar sensitivity.

Growth and diarrhoeal disease surveillance in a rural Ghanaian pre-school child population

This paper is a report of the first year of follow-up on 250 pre-school children in a village in Ghana. The mean weight for age and the mean height for age at the start of the study, ranged between 81 and 97% and 91 and 101.4% of the median WHO reference standards respectively. Classified according to Waterlow (1973) 59.6% of the children were normal, 27.2% were thin, 8.9% were stunted, 3.4% were wasted and 0.9% were stunted and wasted. The mean velocity of height gain was 26.8 cm/year at birth; 9.6 cm/year at age of six months and thereafter the rate decreased almost linearly to a rate of 5 cm/year at the age of 60 months. The curve for weight velocity had a similar shape to that of the height. The rate was on the average 5 kg/year at birth, and 1.7 kg/year at age of six months. Children over 30 months of age gained approximately, 0.5 kg/year compared to an expected gain of about 2 kg/year. The mean incidence of diarrhoeal diseases was 1.9 episodes per child per year. 34.4% of the cohort did not report on any episode of diarrhoea over the one year period. Highest incidence occurred in children between the ages of 7 and 12 months. Children who were less than 80% of the standard weight for age at the start of the study had significantly more diarrhoeal episodes than the rest. The mean incidence of diarrhoeal diseases per year increased as both height for age and weight for height decreased. It is suggested that primary intervention against diarrhoeal morbidity might be better aimed at improving childhood nutrition.

Immunization of acute leukemic children with a live varicella vaccine (Oka strain)

A total of 52 acute leukemic children have been safely and effectively vaccinated with live varicella (Oka strain) vaccine given under close clinical and immunological observation. The incidence of zoster in the vaccinated children group was slightly less than that in the group that had experienced natural varicella.

Biologic and biophysical markers of a live varicella vaccine strain (Oka): identification of clinical isolates from vaccine recipients

Possible biologic and biophysical markers of the Oka vaccine strain of varicella-zoster virus (VZV) were explored. The ratio between the infectivity of the vaccine strain in guinea-pig embryo fibroblasts and that in human embryo fibroblasts was consistently higher than the corresponding ratios for wild-type strains; this result seemed to correlate with the passage history of the vaccine strain in guinea-pig embryo fibroblasts. According to profiles of cleavage of digested DNA by various restriction endonucleases, the mobility of one fragment (K) produced by restriction endonuclease Hpa I was unique to the Oka strain. Nine clinical isolates from vaccine recipients (seven with varicella and two with zoster) were examined by both methods (infectivity and cleavage profiles) to determine whether or not these strains were vaccine derived. The laboratory judgments obtained by the two methods were in agreement and were consistent with clinical conclusions concerning five of the strains. Since the test of relative infectivity is simple and convenient, it is suitable for differentiation of the vaccine strain from other wild-type strains; if the results are not conclusive, profiles of cleavage by Hpa I may be helpful in reaching a definite judgment.

Application of live attenuated measles and mumps vaccines in children with acute leukemia

Eight children with acute leukemia in remission were immunized with live attenuated measles vaccine and 4 with mumps vaccine. Immunological examinations before vaccination showed that the numbers of white blood cells, percentages of lymphocytes, levels of immunoglobulins and responses to skin tests with DNCB, PPD, PHA and varicella antigen were within normal ranges in most of these children. Chemotherapy against leukemia was stopped for 2 weeks, from one week before to one week after vaccination. One child had a transient fever 10 days after measles vaccination, but no side reactions were observed in the others. Seroconversion was observed in all but one child who received measles vaccine, and neutralizing antibodies have persisted for at least 4 weeks and at most 3 years, when this study was terminated.