Tachibana Tetsuya, Mimura Rena, Khan Sakirul, Cline Mark A
Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan.
Research Center for Global and Local Infectious Diseases, Oita University, Yufu, Oita 879-5593, Japan.
J Poult Sci. 2024 Dec 6;61:2024025. doi: 10.2141/jpsa.2024025. eCollection 2024.
Unmethylated cytosine-phosphate-guanine (CpG) motifs are often found in bacteria and viruses, but are rare in mammals. In mammals, CpG oligodeoxynucleotides (CpG ODN) stimulate the innate immune system via toll-like receptor 9 (TLR9). However, TLR9 is absent in birds; instead, TLR21 serves as the receptor for CpG ODN. While CpG ODN induce behavioral and physiological changes in mammals, there is limited research on their effects on behavioral and physiological parameters in birds. The aim of the present study was to determine whether intraperitoneal injection of K3, a synthetic class B CpG ODN, affected food intake, voluntary activity, cloacal temperature, blood constituents, and feed passage from the crop in chicks (). Additionally, the effects of K3 (GC), which contains GpC motifs instead of CpG motifs, were investigated to determine the importance of these CpG motifs. Intraperitoneal injection of K3 significantly increased the mRNA expression of interleukin-1β, interleukin-6, interleukin-8, and interferon-γ in the spleen. These changes were not observed with K3 (GC) administration. Intraperitoneal injection of K3 significantly decreased food intake but did not affect voluntary activity. K3 also significantly increased cloacal temperature, tended to increase plasma glucose and corticosterone concentrations and significantly decreased feed passage from the crop. In contrast, K3 (GC) showed no effects on these parameters. These results demonstrate that class B CpG ODN is associated with anorexia, hyperthermia, and reduced feed passage through the digestive tract in chicks during bacterial and viral infections.
未甲基化的胞嘧啶-磷酸-鸟嘌呤（CpG）基序在细菌和病毒中经常出现，但在哺乳动物中却很少见。在哺乳动物中，CpG寡脱氧核苷酸（CpG ODN）通过Toll样受体9（TLR9）刺激先天免疫系统。然而，鸟类中不存在TLR9；相反，TLR21充当CpG ODN的受体。虽然CpG ODN在哺乳动物中会引起行为和生理变化，但关于它们对鸟类行为和生理参数影响的研究却很有限。本研究的目的是确定腹腔注射合成的B类CpG ODN K3是否会影响雏鸡的采食量、自主活动、泄殖腔温度、血液成分以及嗉囊中的饲料通过情况。此外，还研究了含有GpC基序而非CpG基序的K3（GC）的作用，以确定这些CpG基序的重要性。腹腔注射K3可显著增加脾脏中白细胞介素-1β、白细胞介素-6、白细胞介素-8和干扰素-γ的mRNA表达。给予K3（GC）时未观察到这些变化。腹腔注射K3可显著减少采食量，但不影响自主活动。K3还可显著提高泄殖腔温度，倾向于增加血浆葡萄糖和皮质酮浓度，并显著减少嗉囊中的饲料通过量。相比之下，K3（GC）对这些参数没有影响。这些结果表明，在细菌和病毒感染期间，B类CpG ODN与雏鸡的厌食、体温过高以及消化道饲料通过量减少有关。
