• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.439-445
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• 2021

Coccidiosis in chickens is an intestinal parasitic disease caused by protozoan parasites named Eimeria spp. In some Eimeria infections, intestinal lymphocytes are known to highly express chicken NK-lysin (cNK-lysin), an antimicrobial peptide with anticoccidial activity. Therefore, this study aims to investigate the expression of cNK-lysin in E. necatrix-infected chickens and its role in E. necatrix infection. The expression of cNK-lysin transcript was significantly increased in E. necatrix sporozoites-treated lymphocytes. In E. necatrix infection, cNK-lysin transcript was induced in intestinal lymphocytes but not in the spleen. The recombinant cNK-lysin exhibited anticoccidial activity against E. necatrix sporozoites as well as immunomodulatory activity on macrophages by inducing proinflammatory cytokines. These results indicated that E. necatrix infection induces high local expression of cNK-lysin and the secreted cNK-lysin helps protect coccidiosis.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.69-77
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• 2022

Antimicrobial peptides (AMPs) play an important role in innate immunity against pathogenic infections. AMPs exterminate pathogenic bacteria by disrupting cell membranes or inhibiting intracellular molecules. NK-2, first identified in pigs and derived from NK-lysin, has antimicrobial effects against bacteria and parasites. In this study, chimeric peptides (cpNK) of chicken and pig NK-2 and cpNK-derived peptides (cpNK-a1 and cpNK-a2) were synthesized, and their antimicrobial effects against various pathogenic bacteria such as Escherichia coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were investigated. The structure of chimeric peptides from chicken and pig NK-2, cpNK, include α-helix like NK-2 and peptide net charge was +9 like porcine NK-2. The cpNK peptide showed powerful bactericidal effects against most bacterial species, including MRSA, especially against gram-negative bacteria. Furthermore, cpNK-derived short peptides, cpNK-a1 and a2 also showed bactericidal activity, but the effects were weaker than those of cpNK. Therefore, we conclude that cpNK- and cpNK-derived short peptides have the potential to be used as antibiotic alternatives.

• The Korean Journal of Community Living Science
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• v.18 no.4
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• pp.715-724
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• 2007

홍화 (Carthamus tinctorius)는 오래 전부터 각종 감염성 질환이나 암을 치료하는데 효과가 있는 것으로 알려져 왔다. 최근 각종 천연산물에 사람과 동물의 건강을 증진시키는 효과가 있는 것이 밝혀지면서, 홍화의 면역조절 효과에 대한 관심이 높아지고 있으나 이에 대한 과학적 자료가 부족한 실정이다. 따라서, 본 연구는 홍화의 면역 조절 활성을 확인하기 위해 수행되었으며, 면역능 실험을 위해 주로 이용되는 실험용 닭(White Leghorn chickens)에게 홍화잎을 첨가한 실험식이를 3주간 급여한 후 관련 요인들을 분석하였다. 실험 결과, 홍화잎을 섭취한 실험동물에서 비장 면역세포의 증식이 많았고, $Y{\delta}$-TCR+ 세포의 비율이 높아졌으며, 십이지장에서는 IFN-Y, IL-8, IL-10, IL-15 및 NK-lysin 같은 사이토카인의 발현이 높아졌다. 따라서, 홍화잎은 식이와 함께 급여하였을 때 면역 증강 효과가 있는 것으로 밝혀졌으며, 홍화잎을 이용한 각종 제품 개발이 기대된다.