1
|
Kelly CD, Stoehr AM, Nunn C, Smyth KN, Prokop ZM. Sexual dimorphism in immunity across animals: a meta-analysis. Ecol Lett 2018; 21:1885-1894. [PMID: 30288910 DOI: 10.1111/ele.13164] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/16/2018] [Accepted: 09/03/2018] [Indexed: 01/03/2023]
Abstract
In animals, sex differences in immunity are proposed to shape variation in infection prevalence and intensity among individuals in a population, with females typically expected to exhibit superior immunity due to life-history trade-offs. We performed a systematic meta-analysis to investigate the magnitude and direction of sex differences in immunity and to identify factors that shape sex-biased immunocompetence. In addition to considering taxonomic and methodological effects as moderators, we assessed age-related effects, which are predicted to occur if sex differences in immunity are due to sex-specific resource allocation trade-offs with reproduction. In a meta-analysis of 584 effects from 124 studies, we found that females exhibit a significantly stronger immune response than do males, but the effect size is relatively small, and became non-significant after controlling for phylogeny. Female-biased immunity was more pronounced in adult than immature animals. More recently published studies did not report significantly smaller effect sizes. Among taxonomic and methodological subsets of the data, some of the largest effect sizes were in insects, further supporting previous suggestions that testosterone is not the only potential driver of sex differences in immunity. Our findings challenge the notion of pervasive biases towards female-biased immunity and the role of testosterone in driving these differences.
Collapse
Affiliation(s)
- Clint D Kelly
- Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, succursale Centre-Ville, Montreal, QC, H3C 3P8, Canada
| | - Andrew M Stoehr
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, USA
| | - Charles Nunn
- Department of Evolutionary Anthropology, Duke University, Science Drive, Durham, NC, 27708, USA.,Duke Global Health Institute, Duke University, Trent Drive, Durham, NC, 27710, USA
| | - Kendra N Smyth
- Department of Evolutionary Anthropology, Duke University, Science Drive, Durham, NC, 27708, USA.,University Program in Ecology, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Zofia M Prokop
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland
| |
Collapse
|
2
|
Riede SJ, van der Vinne V, Hut RA. The flexible clock: predictive and reactive homeostasis, energy balance and the circadian regulation of sleep–wake timing. J Exp Biol 2017; 220:738-749. [DOI: 10.1242/jeb.130757] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
ABSTRACT
The Darwinian fitness of mammals living in a rhythmic environment depends on endogenous daily (circadian) rhythms in behavior and physiology. Here, we discuss the mechanisms underlying the circadian regulation of physiology and behavior in mammals. We also review recent efforts to understand circadian flexibility, such as how the phase of activity and rest is altered depending on the encountered environment. We explain why shifting activity to the day is an adaptive strategy to cope with energetic challenges and show how this can reduce thermoregulatory costs. A framework is provided to make predictions about the optimal timing of activity and rest of non-model species for a wide range of habitats. This Review illustrates how the timing of daily rhythms is reciprocally linked to energy homeostasis, and it highlights the importance of this link in understanding daily rhythms in physiology and behavior.
Collapse
Affiliation(s)
- Sjaak J. Riede
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
| | - Vincent van der Vinne
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
| | - Roelof A. Hut
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
| |
Collapse
|
3
|
Carlton ED, Demas GE. Glucose and insulin modulate sickness responses in male Siberian hamsters. Gen Comp Endocrinol 2017; 242:83-91. [PMID: 26542473 PMCID: PMC4853293 DOI: 10.1016/j.ygcen.2015.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 09/20/2015] [Accepted: 11/01/2015] [Indexed: 01/04/2023]
Abstract
Mounting a sickness response is an energetically expensive task and requires precise balancing of energy allocation to ensure pathogen clearance while avoiding compromising energy reserves. Sickness intensity has previously been shown to be modulated by food restriction, body mass, and hormonal signals of energy. In the current study, we tested the hypothesis that sickness intensity is modulated by glucose availability and an endocrine signal of glucose availability, insulin. We utilized male Siberian hamsters (Phodopus sungorus) and predicted that pharmacological induction of glucoprivation with 2-deoxy-d-glucose (2-DG), a non-metabolizable glucose analog that disrupts glycolysis, would attenuate energetically expensive sickness symptoms. Alternatively, we predicted that treatment of animals with insulin would enhance energetically expensive sickness symptoms, as insulin would act as a signal of increased glucose availability. Upon experimental treatment with lipopolysaccharide (LPS), we found that glucose deprivation resulted in increased sickness-induced hypothermia as compared to control- and insulin-treated animals; however, it did not have any effects on sickness-induced anorexia or body mass loss. Insulin treatment resulted in an unexpectedly exaggerated sickness response in animals of lesser body masses; however, in animals of greater body masses, insulin actually attenuated sickness-induced body mass loss and had no effects on hypothermia or anorexia. The effects of insulin on sickness severity may be modulated by sensitivity to sickness-induced hypoglycemia. Collectively, these results demonstrate that both glucose availability and signals of glucose availability can modulate the intensity of energetically expensive sickness symptoms, but their effects differ among different sickness symptoms and are sensitive to energetic context.
Collapse
Affiliation(s)
- Elizabeth D Carlton
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Gregory E Demas
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
4
|
Mukherjee A, Haldar C. Effect of 2-deoxy-d-glucose induced metabolic stress on testicular steroidogenesis and antioxidant status in golden hamster,Mesocricetus auratus: Role of photoperiod. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 153:40-50. [DOI: 10.1016/j.jphotobiol.2015.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 09/02/2015] [Accepted: 09/03/2015] [Indexed: 02/06/2023]
|
5
|
Carlton ED, Cooper CL, Demas GE. Metabolic stressors and signals differentially affect energy allocation between reproduction and immune function. Gen Comp Endocrinol 2014; 208:21-9. [PMID: 25125082 PMCID: PMC4253682 DOI: 10.1016/j.ygcen.2014.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 11/23/2022]
Abstract
Most free-living animals have finite energy stores that they must allocate to different physiological and behavioral processes. In times of energetic stress, trade-offs in energy allocation among these processes may occur. The manifestation of trade-offs may depend on the source (e.g., glucose, lipids) and severity of energy limitation. In this study, we investigated energetic trade-offs between the reproductive and immune systems by experimentally limiting energy availability to female Siberian hamsters (Phodopus sungorus) with 2-deoxy-d-glucose, a compound that disrupts cellular utilization of glucose. We observed how glucoprivation at two levels of severity affected allocation to reproduction and immunity. Additionally, we treated a subset of these hamsters with leptin, an adipose hormone that provides a direct signal of available fat stores, in order to determine how increasing this signal of fat stores influences glucoprivation-induced trade-offs. We observed trade-offs between the reproductive and immune systems and that these trade-offs depended on the severity of energy limitation and exogenous leptin signaling. The majority of the animals experiencing mild glucoprivation entered anestrus, whereas leptin treatment restored estrous cycling in these animals. Surprisingly, virtually all animals experiencing more severe glucoprivation maintained normal estrous cycling throughout the experiment; however, exogenous leptin resulted in lower antibody production in this group. These data suggest that variation in these trade-offs may be mediated by shifts between glucose and fatty acid utilization. Collectively, the results of the present study highlight the context-dependent nature of these trade-offs, as trade-offs induced by the same metabolic stressor can manifest differently depending on its intensity.
Collapse
Affiliation(s)
- Elizabeth D Carlton
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Candace L Cooper
- Department of Biology, Claflin University, Orangeburg, SC 29115, USA
| | - Gregory E Demas
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
6
|
Abstract
BACKGROUND Because endometriosis is diagnosed predominantly in young women, exposures occurring during childhood or adolescence may have a major impact on the disease. However, potential risk factors during this time period have received little attention. Our objective was to investigate relationships between childhood and adolescent exposures and the risk of endometriosis. METHODS E3N is a prospective cohort of 98,995 French women aged 40-65 at enrollment in 1990. Follow-up questionnaires were sent every 2-3 years. Using a nested case-control design, we computed odds ratios (ORs) and 95% confidence intervals using unconditional logistic regression models. RESULTS A total of 2684 endometriosis cases were reported as surgically ascertained among the 75,918 included women. There were inverse relationships of endometriosis risk with menarcheal age (test for trend, P < 0.0001) and with menstrual cycle length before 17 years of age (test for trend, P = 0.06), whereas menstrual cycle regularity before 17 years of age was not associated with risk. There were modest associations of endometriosis risk with exposure to pet animals (OR = 1.12 [95% confidence interval =1.02-1.22]) or living in a farm for 3 or more consecutive months during childhood (1.12 [1.02-1.24]), although with no link to any specific type of farm animal. In addition, there were positive linear associations between endometriosis risk and level of indoor exposure to passive smoking during childhood (up to 1.34 [1.09-1.64] with several hours exposure a day), experiencing food deprivation during World War II (1.34 [0.94-1.91]), and walking activity at 8-15 years of age (1.17 [1.05-1.31] for 5+ hours a week). CONCLUSIONS This large study suggests that some exposures during childhood or adolescence may influence the risk of endometriosis. Further research is needed to confirm and better understand these relationships.
Collapse
|
7
|
Martin LB, Coon CA. Photoperiod-driven variation in an allergic response is independent of allergen exposure. CAN J ZOOL 2012. [DOI: 10.1139/z2012-075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Allergy prevalence and severity varies seasonally in humans, presumably due to intra-annual changes in allergen exposure. However, it is possible that seasonality of allergic responses is also influenced by seasonal changes in the immune system. Here, we asked whether extended exposure to different day lengths would alter allergic responses to pentadecylcatechol (PDC), an allergenic component of poison ivy ( Toxicodendron radicans (L.) Kuntze), in Siberian hamsters ( Phodopus sungorus (Pallas, 1773)), a species exhibiting extensive seasonal variation in immune functions. We found that contact dermatitis responses were larger in short day-length (SD) housed animals than in long day-length (LD) housed animals even though sensitization and challenge dosages of allergen were identical. Furthermore, SD animals were smaller and had regressed reproductive tissues compared with LD animals, results typically observed in this species in response to photoperiod. These data suggest that endogenous changes in immune functions, perhaps via melatonin, may underlie some seasonal variation in allergic responses.
Collapse
Affiliation(s)
- Lynn B. Martin
- University of South Florida, Department of Integrative Biology, 4202 E Fowler Avenue, Tampa, FL 33620, USA
| | - Courtney A.C. Coon
- University of South Florida, Department of Integrative Biology, 4202 E Fowler Avenue, Tampa, FL 33620, USA
| |
Collapse
|
8
|
Yang DB, Xu YC, Wang DH. Partial removal of brown adipose tissue enhances humoral immunity in warm-acclimated Mongolian gerbils (Meriones unguiculatus). Gen Comp Endocrinol 2012; 175:144-52. [PMID: 22080042 DOI: 10.1016/j.ygcen.2011.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 11/28/2022]
Abstract
Temperate rodent species experience marked seasonal fluctuations in environmental temperatures. High thermoregulatory demands during winter usually weaken immune function. Brown adipose tissue (BAT) plays a crucial role in adaptive thermoregulatory process. Thus, we proposed the hypothesis that BAT might participate in the regulation of seasonal changes in immune function. The present study examined the trade-off between thermoregulation and immune function and the potential role of BAT in regulating seasonal changes in immune function in Mongolian gerbils. Specifically, surgical removal of interscapular BAT (34% of total BAT) was performed in male gerbils, and subsequently acclimated to either warm (23 ± 1 °C) or cold (4 ± 1 °C) conditions. Gerbils were then challenged with innocuous antigens and the immune responses were measured. Resting metabolic rate (RMR) and nonshivering thermogenesis (NST) were increased under cold conditions. However, the cost of thermoregulation during cold acclimation did not suppress T-cell mediated immunity and humoral immunity or decrease spleen mass, thymus mass and white blood cells. Partial removal of BAT significantly enhanced humoral immunity in warm-acclimated, but not in cold-acclimated gerbils. T-cell mediated immunity, white blood cells and immune organs were not affected by BAT removal under both warm and cold conditions. Collectively, our results imply that BAT has a suppressive effect on humoral immunity in warm-acclimated gerbils and differential effects of BAT on humoral immunity under different temperatures (e.g., summer and winter) might be benefit to their survival.
Collapse
Affiliation(s)
- Deng-Bao Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | | | | |
Collapse
|
9
|
Glucose supplement reverses the fasting-induced suppression of cellular immunity in Mongolian gerbils (Meriones unguiculatus). ZOOLOGY 2011; 114:306-12. [DOI: 10.1016/j.zool.2011.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 04/12/2011] [Accepted: 04/29/2011] [Indexed: 11/24/2022]
|
10
|
Xu DL, Wang DH. Fasting suppresses T cell-mediated immunity in female Mongolian gerbils (Meriones unguiculatus). Comp Biochem Physiol A Mol Integr Physiol 2010; 155:25-33. [DOI: 10.1016/j.cbpa.2009.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 09/02/2009] [Accepted: 09/02/2009] [Indexed: 10/20/2022]
|
11
|
Abstract
Defending self against nonself is a major problem in a world in which individuals are under constant pressure from parasites that gain fitness benefits at a cost to their host. Defences that have evolved are diverse, and range from behavioural adaptations to physiochemical barriers. The immune defence is a final line of protection and is therefore of great importance. Given this importance, variability in immune defence would seem counterintuitive, yet that is what is observed. Ecological immunology attempts to explain this variation by invoking costs and trade-offs, and in turn proposing that the optimal immune defence will vary over environments. Studies in this field have been highly successful in establishing an evolutionary ecology framework around immunology. However, in order enrich our understanding of this area, it is perhaps time to broaden the focus to include parasites as more than simply elicitors of immune responses. In essence, to view immunity as produced by the host, the environment, and the active involvement of parasites.
Collapse
Affiliation(s)
- Ben M Sadd
- Institute for Integrative Biology (IBZ), Experimental Ecology ETH Zentrum, CHN, Zurich, Switzerland
| | - Paul Schmid-Hempel
- Institute for Integrative Biology (IBZ), Experimental Ecology ETH Zentrum, CHN, Zurich, Switzerland
| |
Collapse
|