Limited Effect of CpG ODN in Preventing Type 1 Diabetes in NOD Mice

Type 1 diabetes is considered as Th1 cell mediated autoimmune disease and the suppression of Th1 cells or the activation of Th2 cells has been regarded as a plausible immunologic intervention for the prevention of type 1 diabetogenesis in a rodent model. CpG ODN is an immunostimulatory sequence primarily present in bacterial DNA, viral DNA and BCG. CpG ODN is conventionally classified as a Th1 cell activator, which has been clinically applied to cancer, allergy and infectious disease. Recently, there was a promising report of that CpG ODN administration suppressed the development of type 1 diabetes in NOD mice by inducing Th2 cell mediated cytokine. However, the antidiabetogenic effect of CpG ODN on NOD mice is controversial. Thus, two studies were serially undertaken with various kinds of CpG motif to find a more optimal sequence and administration method. In the first study, CpG ODN was vaccinated four times and pancreatic inflammation and the quantity of serum insulin subsequently evaluated. In the second study, the amounts of IFN gamma and IL-4 in sera were measured as representative cytokines of Th1 and Th2 cells, respectively. As a result, vaccination or continuous injection of CpG ODN failed to show a preventive effect on type 1 diabetogenesis in NOD mice. Structural differences of CpG ODN also had no affect on the result. CpG ODN also consistently showed affect on the pancreatic pathology. The productions of IFN gamma and IL-4 were detected only in the K and D type CpG ODN administration groups. Comparison of the two cytokines leads to the conclusion that CpG ODN generated a Th1-weighted response in both study groups. It was assumed that CpG ODN failed to produce Th2-weighted cytokine milieu, which can overcome the genetically determined phenotype of NOD mice. Given these results, it was concluded that the immunotherapeutic application of CpG ODN on Type 1 diabetes had clear limitations.

Expression of Toll-like Receptors on the Macrophages Activated by Bacterial Superantigens / 감염과화학요법

BACKGROUND: Staphylococcal enterotoxin B (SEB) as a prototype superantigen is known to play a pivotal role in toxic shock syndrome and severe sepsis. However, the precise mechanism initiating the activation of innate effector cells by SEB is unclear. Recently, Toll-like receptors (TLRs), the sensor of pathogen associated molecular pattern (PAMP), have been reported to be expressed abundantly in monocytic lineage-cells. The purpose of this study is to investigate whether TLRs are involved in the SEB-induced immune cell activation and to prove the differential TLRs expression in response to SEB and/or lipopolysaccharide (LPS). MATERIALS AND METHODS: SEB was purified by dye ligand affinity chromatography. The mRNA expression of TLR1-9 in human peripheral blood mononuclear cells (PBMC) and human monocyte- like THP-1 cell line stimulated by SEB and/or LPS was detected by RT-PCR. RESULTS: The treatment of PBMC with SEB elicited significant changes in the expression of several TLRs. Interestingly, the mRNAs of TLR1 and TLR5 were clearly up-regulated in PBMC, whereas mRNA of TLR4 was down-regulated in the very early period of stimulation within 1-2 hours, and subsequently up-regulated 3 hours later after the stimulation. The up-regulation of mRNA of TLR4 was detected in PBMC stimulated by LPS. The up-regulation was more prominent in the cells exposed concomitantly to SEB and LPS. The mRNA expression pattern of TLR4 in THP-1 cell line stimulated by SEB or LPS was comparable to those of PBMC. CONCLUSION: This study indicates that SEB triggers inflammatory signals on macrophages and PBMC by engaging TLRs, particularly TLR4. The combination of LPS and SEB synergistically modulates TLR4 signaling.

Susceptibility of several strains of mice to Echinostoma hortense infection

Susceptibilities of 5 different mice strains, including C3H/HeN, BALB/c, C57BL6, FvB and ICR, to Echinostoma hortense infection, was evaluated. The worm expulsion rate, worm size and egg production were observed from 1 to 8 weeks after infection with 30 metacercariae. C3H/HeN and ICR mice showed the highest worm maturation rates. The worm recovery rate and the number of eggs per gram (EPG) of feces was also higher in C3H/HeN and ICR mice than in BALB/c, C57BL6, and FvB mice. It is suggested that E. hortense is highly infectious to ICR and C3H/HeN mice, but not to the other strains of mice. Based on the results obtained, we believe that the susceptibility of different mouse strains to E. hortense infection is dependent on the genetic and immunologic background of mice.

Expression of Toll-like Receptors on the Macrophages Activated by Bacterial Superantigens / 감염과화학요법

BACKGROUND: Staphylococcal enterotoxin B (SEB) as a prototype superantigen is known to play a pivotal role in toxic shock syndrome and severe sepsis. However, the precise mechanism initiating the activation of innate effector cells by SEB is unclear. Recently, Toll-like receptors (TLRs), the sensor of pathogen associated molecular pattern (PAMP), have been reported to be expressed abundantly in monocytic lineage-cells. The purpose of this study is to investigate whether TLRs are involved in the SEB-induced immune cell activation and to prove the differential TLRs expression in response to SEB and/or lipopolysaccharide (LPS). MATERIALS AND METHODS: SEB was purified by dye ligand affinity chromatography. The mRNA expression of TLR1-9 in human peripheral blood mononuclear cells (PBMC) and human monocyte- like THP-1 cell line stimulated by SEB and/or LPS was detected by RT-PCR. RESULTS: The treatment of PBMC with SEB elicited significant changes in the expression of several TLRs. Interestingly, the mRNAs of TLR1 and TLR5 were clearly up-regulated in PBMC, whereas mRNA of TLR4 was down-regulated in the very early period of stimulation within 1-2 hours, and subsequently up-regulated 3 hours later after the stimulation. The up-regulation of mRNA of TLR4 was detected in PBMC stimulated by LPS. The up-regulation was more prominent in the cells exposed concomitantly to SEB and LPS. The mRNA expression pattern of TLR4 in THP-1 cell line stimulated by SEB or LPS was comparable to those of PBMC. CONCLUSION: This study indicates that SEB triggers inflammatory signals on macrophages and PBMC by engaging TLRs, particularly TLR4. The combination of LPS and SEB synergistically modulates TLR4 signaling.

The p16INK4A Expression in Stomach Cancer , Colon Cancer and Hepatoma Cell Lines / 대한암학회지

PURPOSE: The p16(INK4A) gene encodes a specific inhibitor of cell cycle progression. In recent years, genetic deletion and altered expression of p16(INK4A) gene were frequently showed in many human cancers. So, the p16(INK4A) gene is considered as tumor suppressor gene. However, there has been a few data for the p16(INK4A) in gastric cancer, colon cancer, and hepatoma.So.we investigated the genetic deldtion and altered expression of p16(INK4A) in gastric cancer, colon cancer and hepatoma cell lines. MATERIALS AND METHODS: The homozygous deletion of p16(INK4A) was examined by using PCR and the protein expression of p16(INK4A) by using Western blotting in cancer cell lines established from Korean patients: stomach cancer, colon cancer and hepatoma cell lines. RESULTS: Homozygous deletion of p16(INK4A) was detected only 1 stomach cancer cell line out of 13 cell lines examined. The p16(INK4A) was detected in 3 of 13 cancer cell line. These results showed the low frequency of p16(INK4A) homozygous deletion and high frequency of p16(INK4A) expression alteration in stomach cancer, colon cancer and hepatoma cell lines. CONCLUSION: In this study, it may be suggested that the altered pl6(INK4A) expression as well as p16(INK4A) gene deletion play important role in oncogenesis. Further studies to determine the mechanism of p16(INK4A) gene inactivation are expected.

In Vitro Growth Inhibition of Human Ovarian Cancer Cell Lines by Mitosene Analogues / 대한암학회지

No abstract available

Biological Properties of a Polyene Antifungal Substance(AF1) Produced from Streptomyces sp. WCM-9 / 대한의진균학회지

BACKGROUND: Pathogenic fungi infect humans, especially immunocompromised patients, with superficial or deeply invasive pattern. In the past 20 years, fungal infections have been increased dramatically resulted by increment of organ transplantation, cancer, AIDS patients, or use of broad-spectrum antibacterial agents. Fungal infections are now important causes of morbidity and mortality of hospitalized patients. but there is no effective antifungal antibiotics as well as antibacterial antibiotics OBJECTIVE: Effective new antifungal antibiotics are needed for the treatment of mycosis. So in an effort to develop effective antifungal antibiotics, we screened over 600 isolates of Streptomyces sp. from soil. METHODS: Antifungal producing strain was selected using disk diffusion method, An antifungal substance (AF1) was purified with ethyl acetate extraction, silica gel column chromatography and reverse phase HPLC. MICs of AF1 were detected by agar dilition method. RESULTS: The compound showed UV maxima of 307, 321, 340, 359 nm indicating methylpentaene. Minimum inhibitory concentrations of the AF1 were 3.7 microgram/ml against mold, and 3.7 - 7.4 microgram/ml against Candida species. AFI was also active against Crytococcus neoformans, with MIC of 0.9 microgram/ml. The concentration of AF1 for K+ ion release from human red blood cell and hemolysis were 5 microgram/ml. CONCLUSION: The antibiotic purified from culture broth of Streptomyces sp. WCM-9 was a polyene antifungal antibiotic which have broad spectrum antifungal activity.

Tumor cell growth inhibitory factor in the culture filtrate of the streptomyces 1. in vitro cytotoxicity of tumor cell growth inhibitory factor

No abstract available.