• IMMUNE NETWORK
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• v.22 no.2
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• pp.16.1-16.20
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• 2022

The gastrointestinal tract is the first organ directly affected by fasting. However, little is known about how fasting influences the intestinal immune system. Intestinal dendritic cells (DCs) capture antigens, migrate to secondary lymphoid organs, and provoke adaptive immune responses. We evaluated the changes of intestinal DCs in mice with short-term fasting and their effects on protective immunity against Listeria monocytogenes (LM). Fasting induced an increased number of CD103⁺CD11b^- DCs in both small intestinal lamina propria (SILP) and mesenteric lymph nodes (mLN). The SILP CD103⁺CD11b^- DCs showed proliferation and migration, coincident with increased levels of GM-CSF and C-C chemokine receptor type 7, respectively. At 24 h post-infection with LM, there was a significant reduction in the bacterial burden in the spleen, liver, and mLN of the short-term-fasted mice compared to those fed ad libitum. Also, short-term-fasted mice showed increased survival after LM infection compared with ad libitum-fed mice. It could be that significantly high TGF-β2 and Aldh1a2 expression in CD103⁺CD11b^- DCs in mice infected with LM might affect to increase of Foxp3⁺ regulatory T cells. Changes of major subset of DCs from CD103⁺ to CD103^- may induce the increase of IFN-γ-producing cells with forming Th1-biased environment. Therefore, the short-term fasting affects protection against LM infection by changing major subset of intestinal DCs from tolerogenic to Th1 immunogenic.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.127-138
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• 2013

This study investigated the effects of feeding the broilers that are exposed to extreme heat stress (EHS, $33{\pm}2^{\circ}C$) with extreme heat stress diet (EHSD) containing adequate amount of soy oil and other nutrients on their growth performance. 500 broiler chickens (Ross 308) were randomized into five dietary treatment groups according to a randomized block design on the day they were hatched. Each group was further divided into four repeat pens with each repeat pen comprising 25 chickens. The five dietary treatment groups were: T1 (Normal ambient condition + basal diet (BD), T2 (EHS +BCD), T3 (EHS + extreme heat stress diet (EHSD) prepared from BD with tallow replaced with soy oil and containing molasses 2%), T4 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2% and methionine and lysine of 1.5 times greater quantities than in BD), and T5 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2%, methionine and lysine of 1.5 times greater quantities than in BD, and vitamin C 200 ppm) with inverse lighting. The body weight gain of the broilers increased significantly in T4 and T5 as compared with that in T1 and T2. Weights of the lymphoid organ, bursa of Fabricius, thymus, and spleen were similar between all groups. Serum concentrations of IgG, IgG and IgM were higher in T4 and T5 than inT1 and T2, but the corticosterone concentration decreased significantly in them. In T4 and T5, Lactobacillus in the cecum increased, but Escherichia, coliform, and total aerobic bacteria decreased rather significantly, compared with those in T1 and T2. Contents of acetic acid, propionic acid and total SCFA were significantly higher in T4 and T5 than in T1 and T2.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.78-87
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• 2013

In this study, the effect of extreme heat diet on growth performance, lymphoid organ, blood immunoglobulin and cecum microflora change in broilers exposed to continuous lighting and extreme heat stress (EHS) was studied. Broilers raised under normal environment temperature ($25^{\circ}C$ or extreme heat stress temperature ($33{\pm}2^{\circ}C$, and consumed chow diet (CD) or extreme heat stress diet (EHSD). Five hundred Ross 308 day-old commercial broilers were arranged in a completely randomized block design of 5 treatment groups with 4 repetitions (25 heads per repetition pen). The broilers were divided into: T1 (normal environment+CD), T2 (EHS+CD), T3 (EHS+EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses), T4 (EHS+EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses, and 1.5 times more methionine and lysine than CD), and T5 (EHS+EHSD in which the tallow in CD was substituted by soy oil, contained 5% molasses, 1.5 times more methionine and lysine than CD, and 300ppm of vitamin C). The EHS significantly reduced the body weight gain and feed intake. The blood immunoglobulin, bursa of Fabricius, thymus, and spleen weight were significantly reduced when broilers were exposed to EHS. Compared to the normal environment temperature group, the cecum Lactobacillus sp. was low in the EHS treatment group, while Escherichia sp., Salmonella sp. and total aerobic bacteria in the EHS treatment group were high. A statistically significant difference was acknowledged between the treatment groups.