Beta-defensin 10

Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.

Objective: Coccidiosis is a protozoan infection that can result in hemorrhagic diarrhea, depression, weakness, weight loss, and even mortality in young animals. β-defensin-1 is an antimicrobial peptide produced largely by epithelial cells in the skin and mucosa. It possesses antifungal, antibacterial, antiparasitic, and antiviral properties. The goal of this study was to evaluate how β-defensin-1 levels changed in coccidiosis-infected calves. Materials and methods: The sample included 10 coccidiosis-positive calves and 7 healthy calves, for a total of 17 calves of diverse breeds and older than 15 days. To assess the level of β-defensin-1, blood samples were obtained from the vena jugularis of the animals. The concentrations of β-defensin-1 in the serum were measured using a commercial ELISA kit. Results: Although the serum β-defensin-1 level decreased in infected animals, the drop was not statistically significant when compared to the control group. Conclusion: According to the study's findings, there was no significant change in the serum β-defensin-1 level in coccidiosis-infected calves. We believe that it will be advantageous to conduct additional studies with a larger sample size in order to acquire more precise results.

Studies described so far suggest that human β-defensin 2 is an important protein of innate immune response which provides protection for the human organism against invading pathogens of bacterial, viral, fungal, as well as parasitical origin. Its pivotal role in enhancing immunity was proved in infants. It may also be considered a marker of inflammation. Its therapeutic administration has been suggested for maintenance of the balance of systemic homeostasis based on the appropriate composition of the microbiota. It has been suggested that it may be an important therapeutic tool for modulating the response of the immune system in many inflammatory diseases, offering new treatment modalities. For this reason, its properties and role in the human body discussed in this review should be studied in more detail.