Recombinant BCG Tokyo (Ag85A) protects cynomolgus monkeys (Macaca fascicularis) infected with H37Rv Mycobacterium tuberculosis

One tuberculosis vaccine candidate that has shown a promising degree of protective efficacy in guinea pigs is recombinant BCG Tokyo (Ag85A)(rBCG-Ag85A[Tokyo]). As a next step, cynomolgus monkeys were utilized because they are susceptible to Mycobacterium tuberculosis and develop a continuous course of infection that resembles that in humans both clinically and pathologically. The recombinant BCG vaccine was administered once intradermally in the back skin to three groups of cynomolgus monkeys, and its protective efficacy was compared for 4 months with that of its parental BCG Tokyo strain. Vaccination of the monkeys with the rBCG-Ag85A[Tokyo] resulted in a reduction of tubercle bacilli CFU (p<0.01) and lung pathology in animals challenged intratracheally with 3000 CFU H37Rv M. tuberculosis. Vaccination prevented an increase in the old tuberculin test after challenge with M. tuberculosis and reaction of M. tuberculosis-derived antigen. Thus, it was shown in monkeys that rBCG-Ag85A[Tokyo] induced higher protective efficacy than BCG Tokyo. This warrants further clinical evaluation.

[Comparison of usefulness between variable numbers of tandem repeats (VNTR) analysis and restriction fragment length polymorphism (RFLP) in the genotyping of Mycobacterium avium]

OBJECTIVES

Comparison of usefulness of IS1245 RFLP and VNTR in M. avium genotyping.

MATERIALS AND METHODS

Thirty-six cases (55 strains) from sputum and BALF and twelve cases (29 strains) isolated from blood of HIV-infected patients were used. VNTR and RFLP using IS1245 were performed.

RESULT

Multiple samples were taken from 16 patients and 52 clinical isolates were used for VNTR and RFLP for comparison. (1) VNTR and RFLP results were identical in 12 out of 16 cases whose samples were collected several times. (2) Eight isolates were obtained from one patient. In this eight isolates, there were the cases of M. avium polyclonal infection and of mixed infection with M. intracellulare. VNTR patterns were two types and RFLP were 5 kinds of different in this case. (3) VNTR patterns of six isolates from one HIV-infected patient were identical, but there were three variations in RFLP patterns. There were three cases of mixed infections with M. tuberculosis or M. intracellulare, and six strains polyclonal infection of M. avium (7.1 %) in 84 isolates. These 6 clinical isolates were derived from sputum or BALF (5 strains) and HIV-infected blood (one strain). VNTR patterns were similar in four pairs (9 strains) who did not contact closely, but they were distinguished clearly by RFLP. Seventeen strains had three or less IS1245-related bands in RFLP analyses of 89 strains.

DISCUSSION

As there is a possibility of polyclonal infection with M. avium and mixed infection with other species, the single clonal infection should be confirmed first by VNTR. When single colony was obtained, VNTR and RFLP were performed for genotyping of M. avium. Furthermore, strains with less bands by RFLP should be carefully judged in terms of both VNTR and RFLP. It is recommended that the specimens should be collected from each patient several times.

Lack of correlation between embB mutation and ethambutol MIC in Mycobacterium tuberculosis clinical isolates from China

Seventy-four Mycobacterium tuberculosis clinical isolates from China were subjected to drug susceptibility testing using ethambutol, isoniazid, rifampin, and ofloxacin. The results revealed that the presence of embB mutations did not correlate with ethambutol resistance but was associated with multiple-drug resistance, especially resistance to both ethambutol and rifampin.

Detection of streptomycin resistance in Mycobacterium tuberculosis clinical isolates from China as determined by denaturing HPLC analysis and DNA sequencing

China is regarded by the World Health Organization as a major hot-spot region for Mycobacterium tuberculosis infection. Streptomycin has been deployed in China for over 50 years and is still widely used for tuberculosis treatment. We have developed a denaturing HPLC (DHPLC) method for detecting various gene mutations conferring drug resistance in M. tuberculosis. The present study focused on rpsL and rrs mutation analysis. Two hundred and fifteen M. tuberculosis clinical isolates (115 proved to be streptomycin-resistant and 100 susceptible by a routine proportional method) from China were tested to determine the streptomycin minimal inhibitory concentration (MIC), and subjected to DHPLC and concurrent DNA sequencing to determine rpsL and rrs mutations. The results showed that 85.2% (98/115) of streptomycin-resistant isolates harbored rpsL or rrs mutation, while rpsL mutation (76.5%, 88/115) dominated. MIC of 98 mutated isolates revealed no close correlation between mutation types and levels of streptomycin resistance. No mutation was found in any of the susceptible isolates. The DHPLC results were completely consistent with those of sequencing. The DHPLC method devised in this study can be regarded as a useful and powerful tool for detection of streptomycin resistance. This is the first report to describe DHPLC analysis of mutations in the rpsL and rrs genes of M. tuberculosis in a large number of clinical isolates.

BCG vaccination enhances resistance to M. tuberculosis infection in guinea pigs fed a low casein diet

In order to examine the relationship between malnutrition and tuberculosis development in vivo, a malnourished guinea pig model fed with a low casein (5%) diet was developed. After being fed with the low casein diet, the guinea pigs were infected with Mycobacterium (M.) tuberculosis Kurono strain by aerosol infection, and seven weeks later were subjected to histopathologic examination, colony-forming unit (CFU) assay, fluorescence-activated cell sorter (FACS) analysis and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-12 and inducible nitric oxide synthase (iNOS) mRNA. Another group of guinea pigs were vaccinated subcutaneously with 10(6) CFU BCG Tokyo for three weeks and then similarly infected by aerosol. Eighty-eight% (7/8) of the malnourished guinea pigs succumbed to mycobacterial infection within 85 days after infection, while the malnourished guinea pigs vaccinated with BCG Tokyo survived. CFU assay showed that lung and splenic CFUs were higher in the low casein diet-fed groups than in the control diet (20% casein)-fed groups, although both groups had significantly lower CFUs after vaccination with BCG Tokyo (p<0.01). Examination of lung histopathology revealed that pulmonary granulomas were large and disorganized in the groups fed the low casein diet. The number of visible lesions on the surfaces of the fixed lungs in guinea pigs fed control diet+BCG and low casein diet+BCG was low significantly. Pan T-, CD4-, CD8- and Mac antigen-positive cells were also recognized in the infected lung tissues of low casein-fed guinea pigs and Pan T-, CD4- and Mac antigen-positive cells increased after vaccination with BCG Tokyo. Expression of IFN-gamma, TNF-alpha, IL-12 and iNOS mRNA was also recognized in the infected lung tissues of low casein-fed guinea pigs and IFN-gamma and TNF-alpha mRNA expression was enhanced with BCG vaccination. These results indicate that malnutrition exacerbates mycobacterial infection and that malnourished infected hosts may be protected by BCG vaccination.

[Evaluation of accuracy of clinical diagnosis of TB by annual autopsy report]

PURPOSE

To investigate the accuracy of clinical diagnosis of TB in Japan in recent years and to compare them with previous studies.

METHOD

Data (sex, age, clinical diagnosis, pathological diagnosis as cause of death) on deceased cases clinically or pathologically diagnosed ante mortem as having tuberculosis was collected from annual reports of the pathological autopsy cases in 1984, 1989, 1994, and 1999-2004. Information on TB death from population statistics in those 9 years also was collected and compared with data of autopsied cases.

RESULT

Autopsy rate in these years was stably around 10 %. Comparison of gender ratio and mean age between the two surveys showed similar numbers. During 1999-2004, 1725 death cases were diagnosed as TB clinically or pathologically. Number of pathologically proven pulmonary TB cases was 429 and that of miliary TB was 283. 55.7% of pulmonary tuberculosis and only 21.9% of miliary tuberculosis were correctly diagnosed before death. Out of 156 cases clinically diagnosed as non-TB diseases but proven as TB pathologically, 30.8% of clinical diagnosis was pneumonia and/or bronchitis, followed by diagnoses of interstitial pneumonia, respiratory failure, pneumoconiosis and lung cancer. However, the main clinical diagnoses of 175 miss-diagnosed miliary TB cases were diseases other than pulmonary diseases such as renal failure, malignant diseases and sepsis.

CONCLUSION

In order to reduce undiagnosed pulmonary TB cases and to prevent nosocomial TB infection, differential diagnosis among pneumonia and/or bronchitis cases should be done. In case of miliary TB, not only pneumonia but also diseases other than pulmonary diseases such as renal failure, malignant diseases and sepsis should be included in the list differential diagnosis.

Emergence of ofloxacin resistance in Mycobacterium tuberculosis clinical isolates from China as determined by gyrA mutation analysis using denaturing high-pressure liquid chromatography and DNA sequencing

A high rate of double point mutations in gyrA (56% of 87 ofloxacin-resistant Mycobacterium tuberculosis clinical isolates) indicates the emergence of fluoroquinolone resistance. This is the first report to describe denaturing high-pressure liquid chromatography analysis of mutations in gyrA of M. tuberculosis in a large number of clinical isolates.

[Microbiologically identified isolates of Mycobacterium heckeshornense in two patients]

PURPOSE

To identify mycobacteria isolated from sputa of a 51-year-old female and a 72-year-old male patient with pneumoconiosis.

OBJECT AND METHOD

Mycobacteria species were isolated from sputa of a 51-year-old female. The culture was always negative in spite of positive smears before the final isolation in 1988. A 72-year-old male patient suffered from pneumoconiosis and the acid-fast bacillus was isolated by routine sputum examination in 2003. These two strains of acid-fast bacilli were identified as Mycobacterium heckeshornense by partial sequencing of 16S rRNA and rpoB and conventional methods (biochemical and routine culture methods).

RESULT

These two strains grew on 1% Ogawa's slant medium at 37 degrees C and 42 degrees C, but not at 28 degrees C. They formed yellowish colonies in the dark (Scotochromogen). They were classified as a slowly growing Mycobacteria. As it was difficult to distinguish M. heckeshornense from M. xenopi by conventional methods including growth rate, temperature range of mycobacterial growth, light coloration reaction, biochemical and biological tests, virulence using guinea pigs and drug susceptibility test were further explored. Finally two were identified as M. heckeshornense by summing of these results.

CONCLUSION

Mycobacteria species that grow at 42 degrees C for four weeks, imply M. xenopi with a DDH method. It is essential to perform both sequencing of 16S rRNA and rpoB gene and a biochemical method for the purpose of distinguishing M. heckeshornense from M. xenopi.

Imaging of pulmonary granulomas using a photon imager

To clarify the location of pulmonary granulomas in vivo, we prepared a Mycobacterium tuberculosis H37Rv mutant in which the gene for a green fluorescent protein (GFP) (GFP-H37Rv) was introduced. Five weeks after aerosol infection with GFP-H37Rv, the infected lungs from guinea pigs and mice were subjected to imaging using a photon imager. Pulmonary granulomas more than 1 mm in diameter were localized clearly by the photon imager. Therefore, if a method for binding a dye (GFP, fluorescein isothiocyanate [FITC], etc.) specifically to M. tuberculosis can be developed, it will be possible to visualize granulomas using a photon imager.

Repeated exposure to low-dose diesel exhaust after allergen challenge exaggerates asthmatic responses in mice

BACKGROUND

In conjunction with allergens, diesel exhaust particles act as an adjuvant to enhance IgE responses, inducing expression of cytokines/chemokines and adhesion molecules, and increasing airway hyper-responsiveness (AHR). As most studies were designed to expose animals to diesel exhaust throughout the periods of both sensitization and allergen challenge, it remains unclear whether diesel exhaust (DE) exposure exaggerates airway responses in asthmatic animals.

OBJECTIVE

To study effects of exposure to low-dose DE on AHR and allergic airway inflammation in asthmatic mice.

METHODS

BALB/c mice were sensitized by intraperitoneal injection of ovalbumin and challenged by intranasal administration with ovalbumin. They were exposed to low-dose DE for 7 h/day, 5 days/week, for up to 12 weeks. AHR to methacholine was evaluated by whole-body plethysmography as well as bronchoalveolar lavage cell analysis and cytokine gene expression in lungs.

RESULTS

Repeated exposure of asthmatic mice to low-dose DE resulted in increased AHR and gene expression of several pro-asthmatic cytokines/chemokines, but these effects rapidly subsided with continued exposure to DE.

CONCLUSION

Repeated exposure to low-dose DE after ovalbumin challenge exaggerates allergic responses in mice, but effects are not prolonged with continuous DE exposure.

[Identification of mycobacteria by sequencing of rpoB gene and 16S rRNA]

PURPOSE

To classify a specific Mycobacterium among various mycobacteria utilizing sequencing of rpoB gene. To classify mycobacteria not identified by DNA-DNA hybridization (DDH) using sequencing of rpoB and 16S rRNA gene.

OBJECTS AND METHODS

Classification of 106 Mycobacteria strains, one Nocardia strain, one Rhodococcus strain, four Gordona strains was made by using partial sequencing of rpoB and 16S rRNA (RIDOM). Thereafter, 38 mycobacteria clinical strains not identified by DDH were classified utilizing the DNA sequencing data.

RESULTS

Pairs of M. kansasii and M. gastri, M. abscessus and M. chelonae, M.fortuitum (ATCC49404) and M. polcinum, M. peregrinum and M. septicum, M. farucinogense and M. senegalense and M. fortuitum (ATCC49403), Rhodococcus, Nocardia and Gordona strains were classified using sequencing of rpoB gene. Even though sequencing of rpoB and 16S rRNA gene was utilized, it was impossible to classify M. tuberculosis complex, M. avium family, M. marinum and M. ulcerans, and M. fortitum subsp. fortuitum and M. fortuitum subsp. acetamidolyticus. The 38 mycobacteria clinical strains not identified by DDH were successfully classified using sequencing of both rpoB and 16S rRNA. These sequencing analyses showed that M. heckeshornense, M. branderi, M. intermedium, M. shimoidei, M. wolinskyi, M. malmoense and M. lentiflavum could be identified. Thirty six clinical isolates (94.7%) and 32 clinical isolates (84.2%) were identified by rpoB sequencing and 16S rRNA sequencing (RIDOM), respectively.

CONCLUSION

The classification ratio of mycobacteria including Nocardia, Rhodococcus and Gordona is 69.6% for sequencing of 16S rRNA and 89.3% for sequencing of rpoB gene. Sequencing of rpoB is useful for classification of mycobacteria due to its genetic diversity, but has some limitation in its application. In order to classify mycobacteria more accurately, it is important to combine sequencing of rpoB and 16S rRNA and biochemical/biological tests.

Protective efficacy of recombinant (Ag85A) BCG Tokyo with Ag85A peptide boosting against Mycobacterium tuberculosis-infected guinea pigs in comparison with that of DNA vaccine encoding Ag85A

A recombinant form of BCG Tokyo with an Ag85A gene insert was administered once subcutaneously to guinea pigs and its protective efficacy was compared with that of a DNA vaccine encoding Ag85A from Mycobacterium tuberculosis administered twice to guinea pigs by epidermal gene gun bombardment. Vaccination with either the recombinant BCG Tokyo or Ag85A DNA significantly reduced the severity of pulmonary pathology and the number of pulmonary and splenic colony-forming units (cfu) (p<0.001). The recombinant BCG Tokyo was better than Ag85A DNA in terms of protective efficacy against M. tuberculosis. When immunogenic synthetic Ag85A peptide was further used as a booster together with recombinant BCG Tokyo (Ag85A) or Ag85A DNA, lung pathology was improved significantly and the number of pulmonary CFU was reduced significantly. Neither recombinant BCG Tokyo, Ag85A DNA, nor the parental BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. The spleen tissues from guinea pigs vaccinated with recombinant BCG Tokyo or Ag85A DNA expressed IFN-gamma and IL-2 mRNA at significantly high levels (p<0.001) as evaluated by reverse transcription polymerase chain reaction. It is concluded that peptide boosting is important for the induction of higher protective efficacy by recombinant BCG Tokyo or a tuberculosis DNA vaccine and both recombinant BCG Tokyo (Ag85A) and Ag85A DNA vaccine induce Th2 cytokine mRNA expression significantly.

Nude rat (F344/N-rnu) tuberculosis

As many mononuclear cells from Mycobacterium tuberculosis-infected lung tissues are not available for fluorescence-activated cell sorter (FACS) analysis and the tuberculin test is not feasible in a mouse tuberculosis model, we attempted to develop a rat tuberculosis model. We have previously reported that rat tuberculosis is associated with granulomas that lack central necrosis. In order to develop a better animal model of tuberculosis in immunocompromised humans (tuberculosis associated with HIV infection or tuberculosis of the elderly), we infected F344/N-rnu nude rats with M. tuberculosis via the airborne route. The animals developed pulmonary granulomas with central necrosis encapsulated by dense collagen fibres, closely resembling those of human tuberculosis. The nude rats died of disseminated tuberculosis by the 85th day after aerosol infection, while F344 wild-type rats did not. Interestingly, T-cells that were reactive with anti-CD4 antibody and anti-CD8 antibody, indicating the presence of remnant thymus, were observed in the infected lung tissues of the nude rats. Therefore, T-cell precursors may be present in nude rats. The nude rat tuberculosis model mimics tuberculosis in immunocompromised humans and may provide a suitable model for immunological studies in vivo.

Temperature-mediated heteroduplex analysis for the detection of drug-resistant gene mutations in clinical isolates of Mycobacterium tuberculosis by denaturing HPLC, SURVEYOR nuclease

Denaturing high-performance liquid chromatography (DHPLC) is a relatively new technique, which utilizes heteroduplex formation between wild-type and mutated DNA strands to identify point mutations. Heteroduplex molecules are separated from homoduplex molecules by ion-pair, reverse-phase liquid chromatography on a special column matrix with partial heat denaturation of the DNA strands. In order to investigate the application of this method for point mutation detection in drug-resistant genes of Mycobacterium tuberculosis, katG, rpoB, embB, gyrA, pncA and rpsL genes, which are responsible for isoniazid, rifampicin, ethambutol, fluoroquinolone, pyrazinamide and streptomycin resistance, respectively, were detected by temperature-mediated DHPLC in 10 multidrug-resistant and 10 drug-susceptible clinical isolates. The DHPLC data were compared with those from a conventional MIC test. The results show that DHPLC is cost-effective with high capacity and accuracy, and is potentially useful for genotypic screening for mutations associated with anti-tuberculosis drug resistance.

Mice strain differences in effects of fetal exposure to diesel exhaust gas on male gonadal differentiation

We have shown that in ICR pregnant mice exposed to diesel exhaust (DE), mRNA expression of mällerian inhibiting substance (MIS) and a steroid hormone transcription factor (Ad4BP/SF-1), which are essential in male gonadal differentiation, decreases in a DE concentration-dependent manner. To further investigate whether these effects differ among strains, we conducted the present study in 3 different strains: ICR mice, ddY mice, and C57BL/6J mice. The response to DE exposure differed among the 3 strains. In C57BL/6J male fetuses, only MIS mRNA expression significantly decreased, and in ddY male fetuses, there was no change in either MIS or Ad4BP/SF-1 mRNA expression. Although there was no definite correlation between mouse strain characteristics and differences in the effects of DE, our findings suggest strain-related variations in DE sensitivity with respect to gene expression regulating male gonadal differentiation.

Diesel exhaust affects immunological action in the placentas of mice

We investigated the effect of diesel exhaust (DE) on pregnancy and fetal development in mice at day 14 postcoitum (pc) with a special focus on the placenta. The number of absorbed fetuses increased in groups exposed to DE, and congestion was observed in histological sections of placentas. During placental absorption expression of CYP1A1 mRNA decreased to undetectable levels, whereas expression of TNF alpha mRNA increased approximately twofold over that of the control. Levels of CYP1A1 mRNA in normal placentas from DE-exposed mice were unchanged. mRNA levels of inflammatory cytokines IL-2, IL-5, IL-12 alpha, IL-12 beta, and GM-CSF increased in placentas exposed to DE (0.3 and 3.0 mg diesel exhaust particles (DEP)/m3). Expression of IL-5 mRNA was markedly increased in DE-exposed placentas, although levels were barely detectable in control placentas. IL-6 mRNA expression was increased approximately 10-fold in placentas exposed to DE (3.0 mg DEP/m3). It has been reported that expression of mRNA encoding proteins involved in immune function in the placenta is increased during fetal absorption in mice. In the present study, expression of such mRNA by the placenta was increased by DE exposure. Because it is believed that expression of mRNA in the placenta also affects fetal development, DE may promote fetal absorption. These findings suggest that in mice exposure to DE affects fetal absorption and placental function by modifying expression of immune-related genes during early gestation and expression of endocrine-related genes during late gestation.

Newly designed primer sets available for evaluating various cytokines and iNOS mRNA expression in guinea pig lung tissues by RT-PCR

Guinea pigs are often used as an animal model of human tuberculosis (TB). However, there are few methods available for pursuing the immunological processes involved in guinea pig TB. In this study, we developed for the first time systematic reverse transcription (RT)-PCR for evaluation of guinea pig mRNA expression. RT-PCR primer sets were newly designed for detection of cytokines and inducible nitric oxide synthase (iNOS) mRNA in guinea pig TB. Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, interleukin (IL)-1beta, IL-2, IL-10, IL-12p40, granulocyte-macrophage-colony stimulating factor (GM-CSF) and iNOS mRNA expression were detected significantly and reproducibly when these primer sets were used. The data by real-time PCR were comparable with those of RT-PCR. We showed that these RT-PCR primer sets could be used to examine mRNA expression semi-quantitatively in guinea pig tissues, and conclude that these newly designed primer sets for conventional RT-PCR will be useful for studying the immunological processes in guinea pig tuberculosis experiments to investigate and evaluate efficacy of new vaccines or anti-mycobacterial drugs.

Pulmonary tuberculosis in spontaneously diabetic goto kakizaki rats

As a clinical association is thought to exist between diabetes and tuberculosis, this study was set up to examine whether GK/Jcl diabetic rats are more susceptible to Mycobacterium tuberculosis infection than non-diabetic rats. GK/Jcl diabetic rats were infected aerially with M. tuberculosis and their capacity to control mycobacterial growth, granuloma formation, cytokine secretion by alveolar macrophages and nitric oxide (NO) production was examined. The rats developed large granulomas but not necrotic lesions in their lungs, liver or spleen. This is consistent with a significant increase in number of colony-forming units of M. tuberculosis in the lungs (p<0.01). Expression levels of interferon-gamma, tumor necrosis factor (TNF)-alpha and interleukin (IL)-12 mRNA were lower in GK/Jcl diabetic rats than those in control Wistar rats. Alveolar macrophages from GK/Jcl rats secreted less TNF-alpha and IL-12, and produced less NO compared with those from Wistar rats. No significant difference was observed between phagocytosis of tubercle bacilli by alveolar macrophages from GK/Jcl or Wistar rats. These data show that there is a close association between experimental tuberculosis and diabetes in animals, and that alveolar macrophages from GK/Jcl diabetic rats are not fully activated by M. tuberculosis infection.

Effect of silver-carrying photocatalyst "Hikari-Gintech" on mycobacterial growth in vitro

The antimycobacterial activity of "Hikari-Gintech" powder, which has photocatalytic activity, was examined in vitro. Both powder dissolved in liquid and Hikari-Gintech-coated cloths showed strong antimycobacterial activity against Mycobacterium tuberculosis H37Rv, M. bovis BCG Pasteur, multi-drug-resistant M. tuberculosis (a clinical isolate) and M. avium. Hikari-Gintech powder appeared to affect mycobacterial cell wall metabolism rather than mycobacterial DNA because no damage to mycobacterial DNA was detected after spraying with Hikari-Gintech solution.

Pathological and immunological profiles of rat tuberculosis

To investigate the pathological and immunological profiles of rat tuberculosis, Lewis female rats were infected aerially with Mycobacterium tuberculosis. Histopathology, immunological profiles of mononuclear cells from M. tuberculosis-infected rat lung tissue, and the expression patterns of cytokine and iNOS mRNAs were examined over time. M. tuberculosis induced granulomatous lesions in the lungs, spleen, lymph nodes and liver, but these lesions lacked central necrosis. Multinucleate giant cells were observed in late-phase tuberculosis. CD4(+) and CD8(+) T cells increased with time and reached a peak 5 weeks after infection, decreasing gradually thereafter. ED1 antigen, suggestive of alveolar macrophages, was expressed at a high level in early phase tuberculosis and remained at the same level even in the late phase. OX62 antigen increased gradually and reached a peak 5 weeks after infection. Interferon-gamma, tumour necrosis factor-alpha and iNOS mRNAs were expressed strongly over time, but their expression decreased 12 weeks after infection. Because rat tuberculosis is very similar to murine tuberculosis and it is easy to obtain mononuclear cells from M. tuberculosis-infected rat lung tissue, the rat tuberculosis model appears to be suitable for immunological studies in vivo.

STAT1 knockout mice are highly susceptible to pulmonary mycobacterial infection

This study was designed to determine the roles of STAT1 protein in defense against mycobacterial infection. Airborne infection of STAT1 knockout (KO) mice with a Mycobacterium tuberculosis Kurono strain induced multiple necrotic lesions in lungs, spleen and liver, while that in wild-type (WT) mice did not. The STAT1 KO mice succumbed to mycobacterial infection by the 35th day after infection. Compared with the levels in WT mice, inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha, interferon-gamma and IL-12 mRNA levels were significantly lower in the lung of STAT1 KO mice. Interestingly, granulomatous lesion development in STAT1 KO mice was inhibited significantly by treatment with exogenous recombinant murine IL-12. Therefore, STAT1 regulates IL-12 expression and appears to be a critical transcription factor in controling mycobacterial infection.

Inhalation of diesel exhaust for three months affects major cytokine expression and induces bronchus-associated lymphoid tissue formation in murine lungs

The authors investigated the effects of exposure to diesel exhaust (DE) on murine lung tissues in vivo. BALB/c and C57BL/6 mice were exposed to DE with low (100 microg/m(3)) and high (3 mg/m(3)) DE particle levels for 3 months. The authors then examined morphological changes and the expression of mRNAs for various cytokines (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1beta, IL-4, IL-6, IL-10, IL-12p40, and interferon [IFN]-gamma) and inducible nitric oxide synthase (iNOS) in the lungs, as well as TNF-alpha, IL-1beta, IL-10, IL-12p40, and Mac-1 mRNA expression in alveolar macrophages (AMs). TNF-alpha, IL-12p40, IL-4, and IL-10 mRNA expression were mildly increased, whereas IL-1beta mRNA and iNOS expression were slightly decreased, in the low- and high-level exposure groups. Flow cytometry of bronchoalveolar lavage fluid revealed a significant increase in Mac-1-positive cells in the high-level exposure group. On histological examination, bronchus-associated lymphoid tissue (BALT), containing B and T lymphocytes, had developed only in the high-level exposure group. Chronic inhalation of DE influences cytokine expression in the murine lung, and induces phagocytosis and BALT development. These findings suggest that DE may provoke immunological responses by acting as a foreign body in the lung, and that even low-level exposure may induce allergic reactions.

[Mycobacterium shinshuense isolated from cutaneous ulcer lesion of right lower extremity in a 37-year-old woman]

PURPOSE

Second clinical infection case of Mycobacterium shinshuense was presented, we tried the identification of M. shinshuense that is isolated from skin.

OBJECT

Mycobacteria species isolated from cutaneous ulcer lesion of right lower extremity in a 37-year-old woman.

METHOD

Identification by DNA-DNA Hybridization, 16S rRNA and rpoB method as genomic level and conventional method.

RESULT

It did not grow on 1% Ogawa's slant medium at both 37 degrees C and 42 degrees C, but grew at 28 degrees C. It formed yellowish colonies in the dark. It was difficult to distinguish M. shinshuense from M. ulcerans and M. marinum by DNA-DNA hybridization (DDH) and DNA sequencing. To identify that it is M. shinshuense, growth rate, temperature range of mycobacterial growth, light coloration reaction, biochemical and biological tests, and drug susceptibility testing were further explored. Finally it was identified as M. shinshuense based on these CONSIDERATION: For Mycobacteria species which grow 2 weeks after inoculation at 28 degrees C, and which is identified as M. marinum by DDH method, it is necessary to identify with sequence and conventional method.

Rat neutrophils prevent the development of tuberculosis

To understand the role of neutrophils in the development of rat tuberculosis in vivo, we utilized lipopolysaccharide (LPS)-induced neutrophilia in the lungs. LPS (50 micro g/ml) was administered intratracheally to male Fischer rats. Rats were then infected with Mycobacterium tuberculosis by an airborne route. Intratracheal injection of LPS significantly blocked the development of pulmonary granulomas and significantly reduced pulmonary CFU (P < 0.01). LPS treatment with amphotericin B (an LPS inhibitor) or neutralizing anti-rat neutrophil antibody reversed the development of pulmonary lesions. LPS-induced transient neutrophilia prevented early mycobacterial infection. The timing of LPS administration was important. When given intratracheally at least 10 days after aerial infection, LPS did not prevent development of tuberculosis. Neutrophils obtained by bronchoalveolar lavage killed M. tuberculosis cells. These results indicate clearly that neutrophils participate actively in defense against early-phase tuberculosis.

Rapid accumulation of eosinophils in lung lesions in guinea pigs infected with Mycobacterium tuberculosis

Guinea pig eosinophils were positively identified in bronchoalveolar lavage populations and in the lung granulomas of Mycobacterium tuberculosis-infected guinea pigs. It is possible that the rapid influx of these cells, and their subsequent degranulation during acute pulmonary tuberculosis, may play a key role in the susceptibility of this animal model.

Potential action of IL-4 and IL-13 as fibrogenic factors on lung fibroblasts in vitro

BACKGROUND

Asthma is characterized by chronic inflammation of the airway with the presence of Th2 cytokines. Airway remodeling in asthma is closely related to clinical manifestations. Lung myofibroblasts play a critical role in the airway remodeling and Th2 cytokines may modulate their behavior. We examined the effect of two major Th2 cytokines, IL-4 and IL-13, on differentiation of lung fibroblasts to myofibroblasts. We hypothesized that these cytokines would stimulate fibroblast proliferation in association with decreased prostaglandin E(2) (PGE(2)).

METHODS

Lung fibroblasts were incubated with IL-4 and IL-13 with or without Th1 cytokine interferon-gamma (IFN-gamma) in vitro. Differentiation of lung fibroblasts to myofibroblasts was characterized by the expression of alpha-smooth muscle actin (alpha-SMA) as well as a morphological and immunohistochemical analysis. Fibroblast proliferation stimulated by IL-4 and IL-13 was assessed with the MTT assay. We also investigated the effect of these cytokines on cyclooxygenase (COX) gene expression and PGE(2) production.

RESULTS

IL-4 and IL-13 increased alpha-SMA expression and myofibroblastic differentiation. This effect was attenuated by IFN-gamma and dexamethasone failed to have an influence on differentiation. IL-4 and IL-13 stimulated fibroblast proliferation. These cytokines downregulated the expression of both COX-1 and COX-2 genes and decreased the production of PGE(2).

CONCLUSIONS

IL-4 and IL-13 induce differentiation of fibroblasts to myofibroblasts and this response is attenuated by IFN-gamma. IL-4 and IL-13 stimulate fibroblast proliferation and this effect is at least partly due to suppressed COX gene expressions and subsequently decreased PGE(2) production. These findings suggest that IL-4 and IL-13 directly act on lung fibroblast to induce a fibrogenic response.

Interleukin-15 as an immune adjuvant to increase the efficacy of Mycobacterium bovis bacillus Calmette-Guérin vaccination

Interleukin-15 (IL-15) transgenic mice which had been inoculated with Mycobacterium bovis bacillus Calmette-Guérin (BCG) 24 weeks previously showed resistance against airborne infection with Mycobacterium tuberculosis H37Rv accompanied by an increased CD8(+)-Tc1-cell response. IL-15 may be used as an immune adjuvant given with BCG vaccination to enhance its biologic efficacy.

Significance of immunological detection of human telomerase reverse transcriptase: re-evaluation of expression and localization of human telomerase reverse transcriptase

Human telomerase reverse transcriptase (hTERT) is a catalytic subunit of telomerase and is a potentially useful diagnostic marker for cancers. There have been few studies in which immunological detection of hTERT has been attempted and its subcellular localization has not been precisely defined. In the present study, we re-evaluated expression and localization of hTERT in cancer and normal cells using a newly developed antibody. Immunohistochemistry revealed that hTERT is expressed in approximately 80% of gynecological cancers, but some premalignant lesions exhibited weak expression of hTERT. Interestingly, not only nuclei but also cytoplasm of cancer cells were positive for hTERT staining. This finding was supported by the results of Western blot analysis of cell lines, in which both nuclear and cytoplasmic extracts exhibited significant hTERT bands. Cytoplasmic hTERT in cancer cells may be functional because the telomeric repeat amplification protocol assay of cytoplasmic extracts showed high levels of telomerase activity. Unexpectedly, not all normal primary cells and telomerase-negative cancer cell lines lacked hTERT expression; some exhibited weak TERT signals. In Western analysis, hTERT signals did not always correlate with telomerase activity of the various cell types. These findings suggest that functional hTERT is expressed in both the nucleus and cytoplasm of cancer cells and that hTERT expression does not strictly reflect telomerase activity. Further analysis is needed to clarify the biological significance of cytoplasmic hTERT.

SWR mice are highly susceptible to pulmonary infection with Mycobacterium tuberculosis

Inbred mice differ in their abilities to control the growth of Mycobacterium tuberculosis in the lung and can as a result be regarded as either resistant or susceptible strains. In this study we report that the SWR mouse is both highly susceptible and in addition appears incapable of establishing a characteristic state of chronic disease after low-dose aerosol infection. In comparison to C57BL/6 mice, SWR mice were unable to contain the bacterial load in the lungs, resulting in progressive fatal disease. Histologic analysis of the lung tissue revealed evidence of a florid inflammatory cell response in the SWR mice leading to degeneration and necrosis and consolidation of a large percentage of the lung surface area. Digestion of infected lungs and analysis by flow cytometry demonstrated an initially similar but eventually higher number of lymphocytes accumulating in the SWR mice. Additionally, in contrast to the C57BL/6 mice, SWR mice had a significantly lower percentage of CD4 T cells in the lungs showing evidence of proliferation and positive intracellular staining for gamma interferon during the first two months of infection, and a lower percentage of both CD4 and CD8T cells exhibiting differentiation to an effector/memory phenotype during the first month of infection. We propose that further investigation of the SWR mouse may provide a new animal model for immunocompetent individuals apparently unable to effectively control the growth of M. tuberculosis in the lung.

Mycobacterial infection in TLR2 and TLR6 knockout mice

To investigate the role of TLR in the development of murine tuberculosis in vivo, TLR2 and TLR6 knockout (KO) mice were infected with Mycobacterium tuberculosis by placing them in the exposure chamber of an airborne infection apparatus. Both TLR2 and TLR6 KO mice survived until sacrifice at 12 weeks after infection. Infected TLR2 KO mice developed granulomatous pulmonary lesions with neutrophil infiltration, which were slightly larger in size than those in wild-type mice. Pulmonary levels of the mRNAs for inducible nitric oxide synthase (iNOS), TNF-alpha, TGF-beta, IL-1beta, and IL-2 were significantly lower, but levels of the mRNAs for IL-4 and IL-6 were higher, than in wild-type (WT) mice. No significant difference was recognized in cytokine mRNA expression between TLR2 KO and WT mice at 12 weeks after infection. DNA binding by NF-kappaB was low in TLR2 KO mice. On the other hand, TLR6 KO mice were not different from WT mice in terms of pulmonary histopathology, mRNA expression and CFU assay. Therefore, TLR2 does not play an essential role in the pathogenesis of murine tuberculosis, although it is important for defense against mycobacterial infection.

Diesel exhaust particles upregulate eotaxin gene expression in human bronchial epithelial cells via nuclear factor-kappa B-dependent pathway

Fine particles derived from diesel engines, diesel exhaust particles (DEP), have been shown to augment gene expression of several inflammatory cytokines in human airway epithelial cells in vitro. However, it remains unclear whether or not DEP have any effect on the expression and production of eotaxin, an important chemokine involved in eosinophil recruitment into the airways. We studied the effects of DEP by using a conventional suspended DEP and by a recently established in vitro cell exposure system to diesel exhaust (Abe S, Takizawa H, Sugawara I, and Kudoh S, Am J Respir Cell Mol Biol 22: 296-303, 2000). DEP showed a dose-dependent stimulatory effect on eotaxin production by normal human peripheral airway epithelial cells as well as by bronchial epithelial cell line BET-1A as assessed by specific ELISA. mRNA levels increased by DEP were shown by RT-PCR. DEP showed an additive effect on IL-13-stimulated eotaxin expression. DEP induced NF-kappaB activation by EMSA as previously reported but did not induce signal transducer and activator of transcription (STAT) 6 activation according to Western blot analysis. Finally, antioxidant agents (N-acetyl cysteine and pyrrolidine dithiocarbamate), which inhibited NF-kappaB activation but failed to affect STAT6 activation, almost completely attenuated DEP-induced eotaxin production, whereas these agents failed to attenuate IL-13-induced eotaxin production. These findings suggested that DEP stimulated eotaxin gene expression via NF-kappaB-dependent, but STAT6-independent, pathways.

Interferon regulatory factor 1 in mycobacterial infection

In order to understand the role of IRF-1 in the development of murine tuberculosis in vivo, IRF-1 knockout mice were infected with Mycobacterium tuberculosis by placing them in the exposure chamber of an airborne infection apparatus. These knockout mice developed multifocal necrotic lesions in the lung, liver and spleen tissues and died of disseminated tuberculosis within 43 days of infection. Compared with the levels in wild-type mice, the pulmonary inducible NO synthase (iNOS) mRNA expression level was significantly lower, but IL-18 and IL-6 mRNA levels were higher. There was no statistically significant difference in the expression of IFN-gamma and TNF-alpha mRNA between the IRF-1 knockout and wild-type mice. IRF-1 is indirectly responsible for iNOS mRNA expression and plays an important role in the pathogenesis of murine tuberculosis.

Mycobacterial infection in natural killer T cell knockout mice

To gain a better understanding of the pathological role of natural killer (NK) T cells in murine tuberculosis, NKT knockout (KO) mice (J(alpha)281(-/-)mice) were utilized. Eight-week-old NKT KO mice of BALB/c origin and wild-type (WT) mice were infected with Mycobacterium tuberculosis Kurono strain by the airborne route using an airborne infection apparatus, and their capacity to control mycobacterial growth, granuloma formation, and cytokine production were examined. The NKT KO mice developed granulomatous lesions in the lungs; there was no statistically significant difference in pulmonary granuloma size between NKT KO and WT mice (p<0.01). The average CFU values increased 3 weeks post-infection, but decreased 9 and 11 weeks post-infection, in the lungs of NKT KO mice. When stimulated with Kurono strain in vitro, splenic cells from NKT KO mice produced less IFN-gamma than did those from WT mice. Expression of mRNA for IL-2, IL-4, IL-6, IL-10 and IL-12 p40 was slightly lower in NKT KO mice compared with WT mice. Our data indicate that NKT cells play a detrimental role in late-phase mycobacterial infection, although Th1 cells are essential in early-phase mycobacterial infection.

Relative importance of STAT4 in murine tuberculosis

This study was designed to determine the roles of STAT proteins in defence against mycobacterial infection. Airborne infection of STAT4 knockout (KO) mice with a Mycobacterium tuberculosis strain induced large granulomas with massive neutrophil infiltration over time, while that in STAT6 KO mice did not. The STAT4 KO mice succumbed to mycobacterial infection by the 80th day after infection. Compared with the levels in wild-type (WT) and STAT6 KO mice, pulmonary inducible nitric oxide synthase, interferon-alpha, -beta and -gamma mRNA levels were significantly lower in STAT4 KO mice, but expression of interleukin-2, -6, -12 and -18 mRNAs was slightly higher up to the fifth week after aerial infection. Therefore, STAT4, but not STAT6, appears to be a critical transcription factor in mycobacterial regulation.

Vaccination of guinea pigs with DNA encoding Ag85A by gene gun bombardment

A DNA vaccine encoding Ag85A from Mycobacterium tuberculosis was administered to guinea pigs by epidermal gene gun bombardment and its protective efficacy was determined. Vaccination with Ag85A DNA twice significantly reduced the severity of pulmonary pathology and number of pulmonary colony-forming units (CFU) (p<0.01). When immunogenic synthetic Ag85A peptide was used as a booster, lung pathology was improved significantly and pulmonary CFU were reduced dramatically. Neither Ag85A DNA nor BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. When the vaccinated guinea pigs were followed up for 7 months, the pulmonary lesions became fibrotic in guinea pigs vaccinated with Ag85A DNA plus Ag85A peptide, or BCG Tokyo, and no tubercle bacilli were detected. The protective efficacy of the tuberculosis Ag85A DNA vaccine was improved significantly by peptide boosting. It is concluded that dosage and peptide boosting are important in the induction of higher protective efficacy by a tuberculosis DNA vaccine.

Role of interferon-gamma in the development of murine bronchus-associated lymphoid tissues induced by silica in vivo

Exposure to silica is associated with the development of chronic airflow obstruction as well as pulmonary fibrosis, probably mediated in part by silica-induced small airway disease. To elucidate the mechanism of mucosal immune responses in the small airways, we analyzed the roles of interferon-gamma (IFN-gamma) using mice deficient of this cytokine in silicotic lung. IFN-gamma knockout mice (-/-) and wild-type C57BL/6 mice were treated with either a single fibrogenic dose of silica or an equivalent volume of saline and euthanized 21 days after intratracheal instillation. Total cell counts in bronchoalveolar lavage fluids increased in silica-instilled mice compared to saline-instilled mice, but there were no significant differences between IFN-gamma knockout mice and wild-type mice treated with silica. Morphometric estimation for fibrotic lesions within the lung did not show any differences between these mice. However, bronchus-associated lymphoid tissues (BALT), which are known to be involved in the mucosal immune responses, were significantly larger in the lungs of IFN-gamma knockout mice than in those of wild-type mice treated with silica. In addition, we evaluated the development of BALT in interleukin 4 (IL-4) knockout mice in order to clarify the effect of Th2 cytokine. Morphometric estimation for BALT did not show any differences between IL-4 knockout mice and wild-type mice in silicotic lung. These results suggest that IFN-gamma has an inhibitory effect on the development of BALT and may be involved in small airway disease in silicotic lung.

Differential secretion of cytokines and adhesion molecules by HUVEC stimulated with low concentrations of bleomycin

Bleomycin (BLM) is known to induce lung inflammation and subsequent fibrosis. Endothelial cells have been reported to play an important role, producing cytokines and adhesion molecules during the inflammatory process in pulmonary fibrosis. To examine the effects of BLM on endothelial cells, we investigated the expression profiles of various cytokines and adhesion molecules produced by endothelial cells stimulated with BLM. Increased expressions of interleukin-8 and monocyte chemoattractant protein-1 measured as protein as well as mRNA by human umbilical vein endothelial cells (HUVECs) were detected after exposure to BLM. Similarly, increased expressions of E-selectin and intercellular adhesion molecule-3 were detected both at the protein and mRNA levels. Under these conditions, a small but significant decrease of [3H]thymidine uptake was detected. These findings indicate that HUVEC were stimulated to secrete cytokines and express adhesion molecules in the presence of low concentrations of BLM which have a mildly inhibitory effect on cellular proliferation.

Long-term inhalation of diesel exhaust affects cytokine expression in murine lung tissues: comparison between low- and high-dose diesel exhaust exposure

The authors investigated the effect of diesel exhaust (DE) on cytokine expression in murine lung tissues. BALB/c mice were exposed to DE for 1 month at different dose levels of DE (low dose: diesel exhaust particles [DEP] 100 micro g/m(3); high dose: 3mg/m(3)). After exposure, the authors examined mRNA expression of cytokines (tumor nocrosis factor alpha [TFN-alpha], Interleukin [IL]-1beta, IL-4, IL-6, IL-10, IL-12p40, and interferon gamma [IFN-gamma] and inducible nitric oxide synthase (iNOS) in the lung, and also measured the secretion of TNF-alpha and IL-10 protein by alveolar macrophages (AM). The mRNA expression levels of inflammatory cytokines (TNF-alpha, IL-1beta, IL-6, IL-12p40, IFN-gamma) and iNOS, which are important for host defense, were suppressed significantly. However, the IL-10 mRNA level was increased by DE exposure. The IL-4 mRNA level was increased by low-dose DE exposure but suppressed by high-dose DE exposure. TNF-alpha and IL-10 secretion by AM paralleled mRNA expression. Chronic inhalation of DE affects cytokine expression in murine lung. These results suggest that DE alters immunological responses in the lung and may increase susceptibility to pathogens, and that increased IL-4 expression by low-dose DE exposure may induce allergic reaction such as asthma.

Study on the roles of cytokines involved in mycobacterial infection

The roles of various cytokines in early-phase mycobacterial infection were investigated utilizing murine tuberculosis models. Among them, IFN-gamma and TNF-alpha are very important in protective immunity against mycobacterial infection. This finding is closely associated with human tuberculosis. It is reported that persons with IFN-gamma receptor 1 deficiency and patients with rheumatoid arthritis and Crohn's disease are susceptible to Mycobacterium tuberculosis. It is expected that a novel immunotherapy and a diagnostic method of tuberculosis are developed by clarifying roles of various cytokines immunologically in early-phase mycobacterial infection.

Role of interleukin (IL)-1 type 1 receptor in mycobacterial infection

It is important to gain a better understanding of IL-1-mediated signaling events in mycobacterial infection. In order to clarify the role of IL-1 receptor type 1 (IL-1 R1) in IL-1 R1, knockout (KO) mice were infected with either Mycobacterium tuberculosis H37Rv or Kurono strain by the respiratory route, and their ability to control mycobacterial growth, pulmonary granuloma formation, and cytokine mRNA expression was investigated. IL-1 R1 KO mice developed significantly larger (P< 0.01) granulomatous lesions with neutrophil infiltration in their lungs than wild-type mice did after infection with the M. tuberculosis Kurono strain. The number of mycobacterial colonies in lungs and spleen increased from five weeks post-infection. Interferon-y production by spleen cells was low in IL-1 R1 KO mice. It is concluded that the IL-1 R1 is essential for IL-1-mediated signaling events in mycobacterial infection.

Effects of diesel exhaust on murine alveolar macrophages and a macrophage cell line

To investigate the effects of diesel exhaust particles (DEP) and mycobacterial infection on macrophages, we examined protein and mRNA expression levels of various cytokines, including tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-12, and IL-18 in BALB/c mouse alveolar macrophages (AM) and a macrophage cell line (RAW264.7) after in vitro stimulation with diesel exhaust (DE), with and without Mycobacterium bovis bacillus Calmette-Guérin (BCG). The cells were exposed to DE freshly generated in an in vitro system. When AM were exposed to DE (mean DEP exposure level, 300 microg/m3), the levels of TNF-alpha and IL-12 decreased significantly (by 51% to 61% for TNF-alpha and by 69% to 78% for IL-12), whereas those of IL-1beta and IL-18 remained unchanged. When AM were exposed to DE and then treated with BCG, the level of TNF-alpha decreased by 45 % to 71%, whereas the level of IL-1beta increased by 154%, compared with AM treated with BCG alone. Similarly, RAW2264.7 cells were stimulated with DE with and without M. bovis BCG and cytokine mRNA levels examined by reverse transcriptase-polymerase chain reaction (R7-PCR). Longer exposure to DE decreased TNF-alpha and IL-12 mRNA levels in the RAW264.7 cells. When the cells were exposed to DE and subsequently treated with BCG, levels of TNF-alpha, IL-1beta, and IL12 mRNAs decreased compared with those of cells treated with BCG alone. These results show that DE exposure has complex and diverse effects on cytokine production by AM, and that longer exposure (>8 hours) may suppress cytokine production by AM in vitro. Longer exposure of DE may therefore suppress the host defense in the lung and may increase susceptibility to lung infections such as mycobacterial infection.

Pulmonary granulomas of guinea pigs induced by inhalation exposure of heat-treated BCG Pasteur, purified trehalose dimycolate and methyl ketomycolate

This study was designed to determine the identity of granulomatogenic substances in Mycobacterium bovis BCG Pasteur. When heat-treated BCG Pasteur bacilli were introduced into the lungs of guinea-pigs by an inhalation exposure apparatus, pulmonary granulomas without necrosis developed. Furthermore, when four kinds of mycolates derived from M. tuberculosis Aoyama B strain were introduced into the lungs by the same method, only trehalose 6,6'-dimycolate (TDM) and methyl ketomycolate induced pulmonary granulomas without central necrosis. The pulmonary granulomas consisted of epithelioid macrophages and lymphocytes. When a mixture of TDM and anti-TDM antibody was introduced into the lungs, development of granulomatous lesions was reduced. These data indicate that TDM and methyl ketomycolate are potent granulomatogenic reagents.

The omega-hydroxy palmitic acid induced apoptosis in human lung carcinoma cell lines H596 and A549

We have found that omega-hydroxy palmitic acid (16-hydroxy palmitic acid, omega-HPA) has both cell growth inhibiting and cell death inducing actions on human lung adenosquamous carcinoma cell line H596 and adenocarcinoma cell line A549. Further, these effects were dose- and time-dependent in both cell lines. However, in squamous carcinoma cell line H226, omega-HPA had no cytotoxic effect. On the other hand, in the human small cell lung carcinoma (SCLC) cell line H128, this compound showed weak cytotoxicity. The sensitivity toward omega-HPA was higher in H596 cells than in A549 cells. In both H596 and A549 cells, cell growth was inhibited to 24.4 and 9.4%, respectively, by treatment with 100 microM omega-HPA for 12 h. In the 24 h treatment cells, growth inhibition was increased to 100 and 38.1%, respectively. In cytotoxicity experiments, the number of dead cells increased with incubation times in the presence of omega-HPA: on three days incubation with 100 microM omega-HPA, viability was 0 and 13.5%, respectively, in H596 and A549 cells. Further, the fragmentation of DNA to oligonucleosomal-sized ladder fragments, which is an index of apoptosis, was observed in both cell lines on treatment with omega-HPA. Therefore, it is assumed that these cell deaths induced by omega-HPA, were apoptosis in these cell lines. Since the number of dead cells following treatment with omega-HPA decreased by treatment with omega-HPA in combination with Z-VAD-fmk, a caspase family inhibitor, it is thought that apoptotic cell death was related to caspase activity.

Relative importance of NF-kappaB p50 in mycobacterial infection

To understand the role of NF-kappaB in the development of murine tuberculosis in vivo, NF-kappaB p50 knockout mice were infected with Mycobacterium tuberculosis by placing them in the exposure chamber of an airborne-infection apparatus. These mice developed multifocal necrotic pulmonary lesions or lobar pneumonia. Compared with the levels in wild-type mice, pulmonary inducible nitric oxide synthase, interleukin-2 (IL-2), gamma interferon, and tumor necrosis factor alpha mRNA levels were significantly low but expression of IL-10 and transforming growth factor beta mRNAs were within the normal ranges. The pulmonary IL-6 mRNA expression level was higher. Therefore, NF-kappaB and its interaction with host cells play an important role in the pathogenesis of tuberculosis.

Biological characteristics and chemosensitivity profile of four human anaplastic thyroid carcinoma cell lines

Anaplastic thyroid carcinoma is a rapidly growing, aggressive neoplasm affecting the elderly which does not respond to most of the therapies. We established cultured cell lines from four untreated tumors. The cultures grew in a monolayer of spindle-shaped cells in three cell lines and of small polygonal cells in one line, having relatively long doubling times and chromosomal abnormalities. The xenotransplantation of the lines in athymic nude mice produced tumors with a histology similar to the original tumors. The immunocytochemical staining showed the expression of PCNA, HLA-class 1, cytokeratin, vimentin and FAS (fatty acid synthase) but not CEA, desmin or P-glycoprotein. The lines secreted TPA, IL-6, IL-8 and few or no thyroid-related hormones in the culture supernatant. One cell line produced G-CSF. The chemosensitivity assay revealed intrinsic drug resistance to nine out of 11 antineoplastic agents. The reverse transcriptase-polymerase chain reaction (RT-PCR) detected MRP (multidrug resistance-associated protein) mRNA but not mdr (multidrug resistance protein)-1 and mdr-3 mRNAs. This finding indicates that the multidrug resistance of these lines is mediated by a P-glycoprotein-unrelated mechanism. The RT-PCR also presented FAS mRNA in all the lines, and IL-6 and IL-8 mRNAs in some of the lines.