Gaghan Carissa, Gorrell Kaitlin, Taha-Abdelaziz Khaled, Sharif Shayan, Kulkarni Raveendra R
Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
Department of Animal and Veterinary Sciences, Clemson University, Clemson, SC 29634, USA.
Microorganisms. 2023 Mar 17;11(3):771. doi: 10.3390/microorganisms11030771.
Necrotic enteritis (NE) is an economically important disease of chickens. We have recently shown that inflammatory responses in chickens inoculated orally with virulent were spatially regulated. Here, we used previously virulence-characterized strains, avirulent CP5 and virulent CP18 and CP26, to assess the severity of NE and immune responses in broiler chickens when inoculated intracloacally. The results showed that CP18- and CP26-infected birds had a reduced weight gain and developed milder/less severe NE lesions, as determined by the gross lesions scores, suggesting a subclinical-grade infection. Gene expression analysis in infected birds revealed three statistically significant observations compared to uninfected-control: (1) Increased expression of anti-inflammatory/immunoregulatory interleukin (IL)-10/transforming growth factor (TGF)β in cecal tonsil (CT) and bursa of Fabricius in the CP18/CP26-infected groups. (2) Increased CT transcription of pro-inflammatory IL-1β, IL-6 and interferon (IFN)γ and decreased Harderian gland (HG) expression of IFNγ in the CP18/CP26-infected birds. (3) Increased HG or bursal expression of IL-4 and IL-13 in CP5-infected birds. Collectively, intracloacal inoculation seems to induce a highly regulated inflammatory response in the CT and other mucosal lymphoid organs and an intracloacal infection model may be useful in evaluating immune responses in chickens with subclinical NE.
坏死性肠炎（NE）是鸡的一种具有重要经济意义的疾病。我们最近发现，口服强毒株接种的鸡体内的炎症反应存在空间调节。在此，我们使用先前已鉴定毒力的菌株、无毒力的CP5以及强毒力的CP18和CP26，来评估肉仔鸡经泄殖腔接种后的NE严重程度和免疫反应。结果显示，通过大体病变评分确定，感染CP18和CP26的鸡体重增加减少，且出现的NE病变较轻/不太严重，提示为亚临床级感染。与未感染对照相比，感染鸡的基因表达分析有三个具有统计学意义的观察结果：（1）CP18/CP26感染组盲肠扁桃体（CT）和法氏囊中抗炎/免疫调节性白细胞介素（IL）-10/转化生长因子（TGF）β的表达增加。（2）CP18/CP26感染鸡的CT中促炎性IL-1β、IL-6和干扰素（IFN）γ转录增加，而哈德氏腺（HG）中IFNγ的表达减少。（3）CP5感染鸡的HG或法氏囊中IL-4和IL-13的表达增加。总体而言，经泄殖腔接种似乎能在CT和其他黏膜淋巴器官中诱导高度调节的炎症反应，且泄殖腔感染模型可能有助于评估亚临床NE鸡的免疫反应。
