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1.
Unmethylated CpG dinucleotides in bacterial DNA or synthetic oligodeoxynucleotides (ODN) cause B cell proliferation and Ig secretion, monocyte cytokine secretion, and activation of NK cell lytic activity and IFN-gamma secretion in vivo and in vitro. The potent immune activation by CpG ODN suggests possible utility for enhancing immune responses to vaccines. Mice immunized with recombinant hepatitis B virus surface Ag and a CpG ODN as an immune enhancer have titers of Abs against HBsAg (anti-HBs) that are five times higher than those of mice immunized with HBsAg and the standard adjuvant, aluminum hydroxide (alum). Ab titers in mice immunized with HBsAg and both CpG ODN plus alum were 35 times higher than the titers in mice immunized with alum alone, indicating a strong synergistic interaction between the CpG ODN and alum. ODN without CpG motifs had little or no immune-enhancing activity at the doses used herein. Alum induces a Th2 humoral response (mostly IgG1) and no CTL. In contrast, CpG ODN gives a strong Thl response with predominantly IgG2a Abs and CTL, even when mixed with alum. In vitro studies to determine possible mechanisms of CpG immune-enhancing effects show that CpG ODN induce expression of costimulatory molecules on Ag-presenting cells and drive B cell isotype switching in the appropriate cytokine milieu. These studies demonstrate that CpG ODN are promising new immune enhancers for vaccination applications.  相似文献   

2.
Intra-abdominal infections in children that follow perforation of viscus often involve the gastrointestinal aerobic and anaerobic bacterial flora. These organisms possess various virulence factors and exhibit potential synergy. The intra-abdominal infection is biphasic, with the Enterobacteriaceae as the major pathogens in the peritonitis stage, and the Bacteroides fragilis group predominating in the abscess stage. Experiments with animals and experience in patients support the need to use single or combined antimicrobial agent therapy that is effective against both Enterobacteriaceae and the B. fragilis group.  相似文献   

3.
Mucosal immunity is difficult to induce with subunit vaccines unless such vaccines are administered with a mucosal adjuvant such as cholera toxin (CT); however, CT is toxic in humans. Synthetic oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG) are potent adjuvants for the induction of Th1-like systemic immune responses against parenterally delivered proteins. Here, we show in mice that intranasal delivery of hepatitis B surface Ag, which alone has no effect, elicits good immune responses when given with CpG oligodeoxynucleotides and/or CT. Overall, CpG is superior to CT for the induction of humoral and cell-mediated systemic immunity as well as mucosal immune responses (IgA) at local (lung) and distant (feces) sites. Furthermore, CpG and CT act synergistically, giving stronger responses than those observed with 10 times more of either adjuvant alone. Ab isotypes were predominantly IgG1 (Th2-like) with CT, mixed IgG1/IgG2a (Th0) with CpG, and predominantly IgG2a (Th1-like) with CpG and CT together.  相似文献   

4.
Occupational medicine in Poland has a long tradition, dating back to the establishment of the first health-care institutions for industrial workers at an early stage of Poland's industrialization. Legal foundations of the industrial health-care system, based on the Soviet model, were enacted in 1953. During its most dynamic period of development (1970s and 1980s) the industrial health-care system provided medical services to about 6 million workers. The process of the political and economic transition in Poland began in 1989, and since 1991 there have been numerous transformations in the structure and function of industrial health services. The present article describes the main stages of the transformation process, occupational health training, research, advisory bodies, and the system for setting of hygienic standards.  相似文献   

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