muramidase and Whooping-Cough

Innate immunity plays an important role in protection against respiratory infections in humans and animals. Host defense peptides such as beta-defensins represent major components of innate immunity. We recently developed a novel porcine model of pertussis, an important respiratory disease of young children and infants worldwide. Here, we investigated the role of porcine beta-defensin 1 (pBD-1), a porcine defensin homologue of human beta-defensin 2, in conferring protection against respiratory infection with Bordetella pertussis. In this model, newborn piglets were fully susceptible to infection and developed severe bronchopneumonia. In contrast, piglets older than 4 weeks of age were protected against infection with B. pertussis. Protection was associated with the expression of pBD-1 in the upper respiratory tract. In fact, pBD-1 expression was developmentally regulated, and the absence of pBD-1 was thought to contribute to the increased susceptibility of newborn piglets to infection with B. pertussis. Bronchoalveolar lavage specimens collected from older animals as well as chemically synthesized pBD-1 displayed strong antimicrobial activity against B. pertussis in vitro. Furthermore, in vivo treatment of newborn piglets with only 500 mug pBD-1 at the time of challenge conferred protection against infection with B. pertussis. Interestingly, pBD-1 displayed no bactericidal activity in vitro against Bordetella bronchiseptica, a closely related natural pathogen of pigs. Our results demonstrate that host defense peptides play an important role in protection against pertussis and are essential in modulating innate immune responses against respiratory infections.

Topics: Animals; Animals, Newborn; Antimicrobial Cationic Peptides; beta-Defensins; Bordetella pertussis; Bronchoalveolar Lavage Fluid; Female; Immunity, Innate; Lactoferrin; Lung; Muramidase; Pertussis Vaccine; Proteins; Respiratory Mucosa; Sodium Chloride; Swine; Whooping Cough

The influence of extracts from oak bark, St. John's-wort leaves and pine buds on natural immunity characteristics of mice has been studied. The injection of these extracts into mice has been found to enhance their resistance to infection with Staphylococcus aureus and Bordetella pertussis virulent cultures, to decrease the enzymatic activity of 5'-nucleotidase in the peritoneal exudate macrophages of mice and to increase the level of lysozyme in their blood. The action of these extracts has proved to depend on their dosage and the time of observation.

Topics: 5'-Nucleotidase; Animals; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Guinea Pigs; Immunity, Innate; Lethal Dose 50; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Muramidase; Nucleotidases; Plant Extracts; Plants, Medicinal; Staphylococcal Infections; Time Factors; Trees; Whooping Cough

The effect of blastolysin, a glycopeptide of the cell walls of L. bulgaricus, on the resistance of mice to infections caused by S. typhimurium and B. pertussis, lysozyme levels in the blood serum and 5'-nucleotidase activity of peritoneal macrophages was studied. The changes in the nonspecific resistance of mice due to the effect of blastolysin depended on the administration route and the type of the developing infection. It activated the enzymatic activity of the peritoneal macrophages and changed the lysozyme levels in the blood serum of mice. The optimal protective effect of blastolysin was achieved on intramuscular injection in a dose of 100 micrograms.

Topics: 5'-Nucleotidase; Animals; Anti-Bacterial Agents; Antibiotics, Antineoplastic; Glycopeptides; Immunity, Innate; Macrophages; Mice; Muramidase; Nucleotidases; Peritoneal Cavity; Salmonella Infections; Salmonella typhimurium; Stimulation, Chemical; Whooping Cough

Topics: Animals; Antibody Formation; Blood Bactericidal Activity; Complement System Proteins; Cortisone; Diphtheria; Diphtheria Toxoid; Drug Combinations; Hydrocortisone; Immunity; Immunity, Active; Immunosuppressive Agents; Muramidase; Pertussis Vaccine; Properdin; Rabbits; Tetanus; Tetanus Toxoid; Time Factors; Vaccination; Whooping Cough

Topics: Anti-Infective Agents, Local; Antiviral Agents; Dermatologic Agents; Humans; Muramidase; Tissue Extracts; Whooping Cough