Effects of experimental food restriction and body-mass changes on the avian T-cell-mediated immune response

2001 ◽  
Vol 79 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Carlos Alonso-Alvarez ◽  
José L Tella

The T-cell-mediated immune response (CMI) of birds, measured with the phytohaemagglutinin skin test, is in most cases positively correlated with their body mass. This correlation, however, does not imply causality, since high-quality birds may be more immunocompetent as well as heavier at the time of sampling. We assessed this relationship experimentally by measuring the changes in body mass and CMI in individual captive yellow-legged gulls (Larus cachinnans) maintained with food provided ad libitum (control group), with no food (fasting group), or with one-third of their daily food requirements (subfeeding group). We identified a direct, nonlinear relationship between food intake, body mass, and CMI. Before the experiment started, body mass of birds (corrected for size) fed ad libitum did not correlate with their CMI, while a positive correlation was found after food restriction. This suggests that birds may reach a threshold above which increases in food intake and body mass do not enhance CMI. Thereafter, food restriction caused decreases in CMI that were significantly correlated with the percentage of body mass lost by each bird. However, for birds that lost similar proportions of body mass, changes in CMI varied according to food-restriction treatment, the subfeeding group exhibiting a stronger CMI than the fasting group.

2018 ◽  
Author(s):  
Xue-na Gong ◽  
Hao Zhang ◽  
Di Zhang ◽  
Wan-long Zhu

AbstractThis study investigates the energy strategies of a small mammal in response to food shortages as a function of food restriction (FR), metabolic rate and ambient temperature. We subjected tree shrews (Tupaia belangeri) to FR and measured body mass, survival rate, resting metabolic rate (RMR), nonshivering thermogenesis (NST) and cytochrome c oxidase (COX) activity of brown adipose tissue (BAT). Cold-exposed animals restricted to 80% of ad libitum food intake had significantly increased RMR and NST and decreased body mass and survival rates compared with those kept at room temperature on the same FR level. Animals classified has having a high RMR consumed 30.69% more food than those classified as having a low RMR, but showed no differences in body mass or survival when restricted to 80% of ad libitum food intake. These results indicate that tree shrews, known for their relatively high metabolic rates, are sensitive to periods of FR, which supports the metabolic switch hypothesis. Our findings are also consistent with the prediction that small mammals with food hoarding behaviors, like tree shrews, may have a lower tolerance for food shortages than non-hoarding species.


2016 ◽  
Vol 66 (2) ◽  
pp. 201-217 ◽  
Author(s):  
Wen-rong Gao ◽  
Wan-long Zhu ◽  
Fang-yan Ye ◽  
Mu-lin Zuo ◽  
Zheng-kun Wang

Physiological adjustments are important strategies for small mammals in response to variation in food availability. To determine the physiological mechanisms affected by food restriction and refeeding, tree shrews were restricted to 85% of initial food intake for 4 weeks and refedad libitumfor another 4 weeks. Changes in food intake, body mass, thermogenesis, body composition, mitochondrial cytochromecoxidase activity, uncoupling protein-1 content in brown adipose tissue and serum leptin levels were measured. The results showed that body mass, body fat mass and serum leptin levels significantly decreased in food restricted tree shrews, and increased when the restriction ended, showing a short “compensatory growth” rather than over-weight or obesity compared withad libitumcontrols. Resting metabolic rate, non-shivering thermogenesis, brown adipose tissue mass (mg), and uncoupling protein-1 content decreased significantly in response to food restriction, and returned to the control levels after the animals were refedad libitum, while the brown adipose tissue mass (%) and cytochromecoxidase activity remained stable during food restriction and refeeding. Food intake increased shortly after refeeding, which perhaps contributed to the rapid regaining of body mass. These results suggest thatTupaia belangerican adjust the status of its physiology integratively to cope with the lack of food by means of decreasing body mass, thermogenesis and serum leptin levels. Leptin may act as a starvation signal to predominantly mediate the reduction in body mass and energy expenditure.


2020 ◽  
Vol 70 (2) ◽  
pp. 175-187
Author(s):  
Peng Hong-bi ◽  
Hou Dong-min ◽  
Zhang Di ◽  
Zhu Wan-long

Abstract The metabolic switch hypothesis refers to an ability to adjust metabolic rate. It plays a key role in animals adapted to periods of food shortage, enabling them to “switch down” their resting metabolic rate and to survive and maintain their weight indefinitely on limited rations. The present study investigates the energy strategies of a small mammal in response to food shortages as a function of food restriction, metabolic rate and ambient temperature. We subjected tree shrews (Tupaia belangeri) to food restriction and measured body mass, survival rate, resting metabolic rate, non-shivering thermogenesis and cytochrome c oxidase activity of brown adipose tissue. Cold-exposed animals restricted to 80% of ad libitum food intake had significantly increased resting metabolic rate and non-shivering thermogenesis and decreased body mass and survival rates compared with those kept as control group on the same ood restriction level. Animals classified as having a high resting metabolic rate consumed 30.69% more food than those classified as having a low resting metabolic rate, but showed no differences in body mass or survival when restricted to 80% of ad libitum food intake. These results indicate that tree shrews, known for their relatively high metabolic rates, are sensitive to periods of food restriction, which supports the metabolic switch hypothesis. Our findings are also consistent with the prediction that small mammals with food hoarding behaviors, like tree shrews, may have a lower tolerance for food shortages than non-hoarding species.


Author(s):  
Wan-long Zhu ◽  
Li-xin Chen ◽  
Xue-na Gong ◽  
Hao Zhang

To investigate the relationship between the energy strategies in response to food restriction and the levels of metabolism in small mammals, body mass, resting metabolic rate (RMR), nonshivering thermogenesis (NST) and cytochrome c oxidase (COX) activity were measured in Apodemus chevrieri that were subjected to different levels of food restriction (FR). The results showed that cold-exposed group had significantly increased RMR and NST, but decreased body mass and survival rate after being restricted to 80% of ad libitum food intake compared with their counterparts maintained at room temperature. A. chevrieri with higher RMR consumed higher food intake than individuals with lower RMR, whereas no differences were observed in body mass and survival rate between two groups after being restricted to 80% of ad libitum food intake. The results suggest that A. chevrieri characterized by higher levels of metabolism are sensitive to periods of FR, providing a support for the “metabolism switch hypothesis”.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1365.2-1365
Author(s):  
X. Fan ◽  
D. Guo ◽  
C. T. Ng ◽  
A. Law ◽  
Z. Y. Poon ◽  
...  

Background:Patients with systemic lupus erythematosus (SLE) suffer from severe morbidity and mortality1-4, either from the disease itself or from side effects of immunosuppression5. Discovery of novel effective therapies with less toxicity is an urgent need.Objectives:The aim of this study is to elucidate the therapeutic potential and working mechanism of cytokine CXCL5 in lupus mice.Methods:Treatment with CXCL5, bone marrow (BM)-MSCs, standard of care (SOC) with combination of methylprednisolone and cyclophosphamide was given to 16-week-old Faslprmice. Mice were monitored for 10 weeks. Splenic immune cell subsets were measured by flow cytometry. Circulating cytokine and immunoglobulin were detected by Luminex technology. Renal function was evaluated by urinary spot albumin creatinine ratio. In situ renal immune cell infiltration and complement 3 deposition were detected by Haematoxylin and Eosin (H&E) staining and immunohistochemistry.Results:CXCL5 demonstrated consistent and potent immunosuppressive capacity in suppressing SLE with reduced autoantibody secretion, lymphoproliferation and preserved kidney function. With further exploration, we proved that CXCL5 reduced the proliferation of helper T cells (TH1 and TH2) in thein vitrofunctional assay. When we administrated CXCL5 to lupus mice, it promoted the proliferation of regulatory T cells and reduced the proliferation of TH17 cells, macrophages and neutrophils. Multiple proinflammatory cytokines including IL-2, IL-6, IL-12, IL-17A, KC/CXCL1, MIP-1β/CCL4 and TNF-α were also reduced. When combined with SOC, CXCL5 boosted its therapeutic effect and reduced the relevant indices of disease activity. When we correlated the effect of four different treatment groups (CXCL5, BM-MSCs, SOC, and CXCL5 plus SOC) on mice survival and target cell changes, we found that TH17 cells were the key effector cells involved in the pathogenesis of SLE.Conclusion:These findings demonstrated that CXCL5 dampens inflammation in the pre-clinical model of systemic lupus erythematosus via the orchestral effect of regulating neutrophil trafficking and suppressing helper T cell-mediated immune response. Administrating exogenous CXCL5 might be an attractive option to treat patients with lupus.References:[1]Ji S, Guo Q, Han Y, Tan G, Luo Y, Zeng F. Mesenchymal stem cell transplantation inhibits abnormal activation of Akt/GSK3beta signaling pathway in T cells from systemic lupus erythematosus mice.Cell Physiol Biochem.2012;29(5-6):705-712.[2]Peng SL. Altered T and B lymphocyte signaling pathways in lupus.Autoimmun Rev.2009;8(3):179-183.[3]Ferucci ED, Johnston JM, Gaddy JR, et al. Prevalence and incidence of systemic lupus erythematosus in a population-based registry of American Indian and Alaska Native people, 2007-2009.Arthritis Rheumatol.2014;66(9):2494-2502.[4]Jakes RW, Bae SC, Louthrenoo W, Mok CC, Navarra SV, Kwon N. Systematic review of the epidemiology of systemic lupus erythematosus in the Asia-Pacific region: prevalence, incidence, clinical features, and mortality.Arthritis Care Res (Hoboken).2012;64(2):159-168.[5]Sattwika PD, Mustafa R, Paramaiswari A, Herningtyas EH. Stem cells for lupus nephritis: a concise review of current knowledge.Lupus.2018;27(12):1881-1897.Acknowledgments:The work was supported by SMART II Centre Grant (NMRC/CG/M011/2017_SGH) and SingHealth Foundation (SHF/FG638P/2016).Disclosure of Interests:None declared


1981 ◽  
Vol 19 (1) ◽  
pp. 76-81 ◽  
Author(s):  
I A Bakker-Woudenberg ◽  
P de Bos ◽  
W B van Leeuwen ◽  
M F Michel

2021 ◽  
Vol 551 ◽  
pp. 155-160
Author(s):  
Caiyan Li ◽  
Meidong Liu ◽  
Ke Liu ◽  
Muyuan Li ◽  
Yanjuan Liu ◽  
...  

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