scholarly journals Do carotenoids buffer testosterone-induced immunosuppression? An experimental test in a colourful songbird

2007 ◽  
Vol 3 (4) ◽  
pp. 375-378 ◽  
Author(s):  
Kevin J McGraw ◽  
Daniel R Ardia

Testosterone (T) is hypothesized to be an important honesty reinforcer of animal sexual signals. Owing to its immunosuppressive effects, only those individuals that can immunologically withstand high T levels can develop the most exaggerated traits. To date, few studies have isolated phenotypic or genotypic buffers that provide ‘high-quality’ animals with such an advantage. Dietary carotenoid pigments may in fact confer such a benefit because when in high supply carotenoids boost immunocompetence and coloration in animals like birds and fishes. We examined the experimental effect of T elevation on carotenoid and immune status in male and female zebra finches ( Taeniopygia guttata ) and found that T was immunostimulatory in a generalized cell-mediated challenge. We also detected a significant interaction between T treatment and the change in plasma carotenoids that occurred during the immune challenge; the relationship between blood carotenoid change and immunity was positive in controls and negative in T-implanted birds. This suggests that, while correlationally birds with high carotenoid stores were inherently better at mounting strong immune responses, experimentally administered T induced birds to deplete carotenoids for maximizing their health. Our findings highlight a nutrient-specific mechanism by which animals escape high immune costs of T elevation and thus can still elevate ornamentation.

1992 ◽  
Vol 4 (9) ◽  
pp. 1055-1063 ◽  
Author(s):  
E. M. Riley ◽  
O. Olerup ◽  
S. Bennett ◽  
P. Rowe ◽  
S. J. Allen ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Heidi Makrinioti ◽  
Andrew Bush ◽  
James Gern ◽  
Sebastian Lennox Johnston ◽  
Nikolaos Papadopoulos ◽  
...  

Bronchiolitis is the most common cause of hospitalization in infancy and is associated with a higher risk for the development of childhood asthma. However, not all children hospitalized with bronchiolitis will develop asthma. The mechanisms underlying asthma development following bronchiolitis hospitalization are complex. Immune responses to respiratory viruses may underlie both bronchiolitis severity and long-term sequela (such as asthma). Interferons (IFNs) are important components of innate immune responses to respiratory viruses and could influence both asthma development and asthma exacerbations. However, the nature of the relationship between interferon production and wheezing illnesses is controversial. For example, low peripheral blood IFN responses at birth have been linked with recurrent wheeze and asthma development. In contrast, there is evidence that severe illnesses (e.g., hospitalization for bronchiolitis) are associated with increased IFN responses during acute infection (bronchiolitis hospitalization) and a higher risk for subsequent asthma diagnosis. Furthermore, mechanistic studies suggest that bronchial epithelial cells from asthmatic children have impaired IFN responses to respiratory viruses, which may enable increased viral replication followed by exaggerated secondary IFN responses. This review aims to discuss controversies around the role of IFNs as drivers of susceptibility to asthma development following bronchiolitis hospitalization. Past evidence from both mechanistic and cohort studies are discussed. We will highlight knowledge gaps that can inform future research study design.


Parasitology ◽  
2016 ◽  
Vol 144 (3) ◽  
pp. 263-273 ◽  
Author(s):  
THOMAS B. NUTMAN

SUMMARYThe majority of the 30–100 million people infected withStrongyloides stercoralis, a soil transmitted intestinal nematode, have subclinical (or asymptomatic) infections. These infections are commonly chronic and longstanding because of the autoinfective process associated with its unique life cycle. A change in immune status can increase parasite numbers, leading to hyperinfection syndrome, dissemination, and death if unrecognized. Corticosteroid use and HTLV-1 infection are most commonly associated with the hyperinfection syndrome.Strongyloidesadult parasites reside in the small intestine and induce immune responses both local and systemic that remain poorly characterized. Definitive diagnosis ofS. stercoralisinfection is based on stool examinations for larvae, but newer diagnostics – including new immunoassays and molecular tests – will assume primacy in the next few years. Although good treatment options exist for infection and control of this infection might be possible,S. stercoralisremains largely neglected.


2021 ◽  
pp. jeb.241349
Author(s):  
Chloe Peneaux ◽  
Gabriel E. Machovsky-Capuska ◽  
John A. Endler ◽  
Andrea S. Griffin

Producing colored signals often requires consuming dietary carotenoid pigments. Evidence that food deprivation can reduce coloration, however, raises the question of whether other dietary nutrients contribute to signal coloration, and furthermore, whether individuals can voluntarily select food combinations to achieve optimal coloration. We created a 2-way factorial design to manipulate macronutrient and carotenoid access in common mynas (Acridotheres tristis) and measured eye patch coloration as a function of the food combinations individuals selected. Mynas had access to either water or carotenoid-supplemented water and could eat either a standard captive diet or choose freely between three nutritionally defined pellets (protein, lipid, carbohydrate). Mynas supplemented with both carotenoids and macronutrient pellets had higher color scores than control birds. Male coloration tended to respond more to nutritional manipulation than females, with color scores improving in macronutrient- and carotenoid-supplemented individuals compared to controls. All mynas consuming carotenoids had higher levels of plasma carotenoids, but only males showed a significant increase by the end of the experiment. Dietary carotenoids and macronutrient intake consumed in combination tended to increase plasma carotenoid concentrations the most. These results demonstrate for the first time that consuming specific combinations of macronutrients along with carotenoids contribute to optimizing a colorful signal and point to sex-specific nutritional strategies. Our findings improve our knowledge of how diet choices affect signal expression and, by extension, how nutritionally impoverished diets, such as those consumed by birds in cities, might affect sexual selection processes and ultimately population dynamics.


1995 ◽  
Vol 1995 ◽  
pp. 200-200
Author(s):  
A.M. Mackenzie ◽  
T.G. Rowan ◽  
S.D. Carter ◽  
J.B. Dixon ◽  
J. Tebble

The effects of husbandry conditions on the immune responses of suckled and bucket-reared calves has previously been reported by Mackenzie et al. (1993 a; 1993b; 1994) and there was a trend for weaning to result in decreased lymphocyte transformation test responses to mitogens along with increased humoral responses to the antigen keyhole limpet haemocyanin (KLH). Mean worker have made measurements of behavioural, endocrine and immune responses to attempt to determine the welfare status of domestic animals. However, there have been few studies where attempts have been made to measure all three parameters together. This pilot study was designed to investigate the relationship between husbandry conditions which may result in behavioural, endocrine and immune changes and to consider possible relationships in these parameters.


2018 ◽  
pp. 1497-1519
Author(s):  
Shraga Fisherman

In the current study described in this chapter, we examined the relationship between body image and well-being among religiously observant male and female youth from four age groups: 16, 17, 19, and 22. MANOVA analysis of age x gender produced a significant interaction regarding body image. Various trends were found among the two genders according to age group. Among the girls, there is a moderate rise in body image (BI) with age, whereas among the boys there is an obvious decline between 17 and 19, followed by an increase. The boys' BI scores were significantly higher than those of the girls aged 16, 17, and 19, but not for age 22. There were significant and positive correlations between BI and well-being for all age groups and both genders. There were high correlations among the girls relative to those among the boys.


Author(s):  
Graham Pawelec ◽  
Ludmila Müller ◽  
Tamas Fülöp ◽  
Deborah Dunn-Walters

The immune system defends against infection, but older people paradoxically suffer not only from failing immunity resulting in increased susceptibility to infections and decreased responsiveness to vaccination, but at the same time increased inflammation and immunopathology accompanying immune responses. Interventions to reduce such deleterious effects while enhancing protective immunity are challenging but need to be confronted if we are to deal successfully with the increasing numbers of elderly and frail people in modern societies. To do this, we need to understand the mechanisms responsible for age-associated increased susceptibility to infections and immune-influenced chronic degenerative diseases of ageing. Defining relevant age-associated alterations and identifying reliable biomarkers for monitoring clinically-relevant immune status in the elderly population is crucial to overcoming these problems. Here, we briefly outline age-associated changes to immunity collectively termed ‘immunosenescence’.


2019 ◽  
Vol 116 (50) ◽  
pp. 25106-25114 ◽  
Author(s):  
Wenqian Li ◽  
Jun Yan ◽  
Yan Yu

Receptors of innate immune cells function synergistically to detect pathogens and elicit appropriate immune responses. Many receptor pairs also appear “colocalized” on the membranes of phagosomes, the intracellular compartments for pathogen ingestion. However, the nature of the seemingly receptor colocalization and the role it plays in immune regulation are unclear, due to the inaccessibility of intracellular phagocytic receptors. Here, we report a geometric manipulation technique to directly probe the role of phagocytic receptor “colocalization” in innate immune regulation. Using particles with spatially patterned ligands as phagocytic targets, we can decouple the receptor pair, Dectin-1 and Toll-like receptor (TLR)2, to opposite sides on a single phagosome or bring them into nanoscale proximity without changing the overall membrane composition. We show that Dectin-1 enhances immune responses triggered predominantly by TLR2 when their centroid-to-centroid proximity is <500 nm, but this signaling synergy diminishes upon receptor segregation beyond this threshold distance. Our results demonstrate that nanoscale proximity, not necessarily colocalization, between Dectin-1 and TLR2 is required for their synergistic regulation of macrophage immune responses. This study elucidates the relationship between the spatial organization of phagocytic receptors and innate immune responses. It showcases a technique that allows spatial manipulation of receptors and their signal cross-talk on phagosomes inside living cells.


2020 ◽  
Vol 7 (11) ◽  
pp. 3216-3232
Author(s):  
Annalisa Pinsino ◽  
Neus G. Bastús ◽  
Martí Busquets-Fité ◽  
Laura Canesi ◽  
Paola Cesaroni ◽  
...  

Here we discuss the potential of engineered nanoparticles to act as agents affecting the immune status in different environmentally relevant species, with a focus on the emerging experimental models launched by the EU Horizon 2020 project PANDORA.


2018 ◽  
Vol 41 (1) ◽  
pp. 41-59 ◽  
Author(s):  
Terence D. Sanger

Dystonia is a collection of symptoms with involuntary muscle activation causing hypertonia, hyperkinetic movements, and overflow. In children, dystonia can have numerous etiologies with varying neuroanatomic distribution. The semiology of dystonia can be explained by gain-of-function failure of a feedback controller that is responsible for stabilizing posture and movement. Because postural control is maintained by a widely distributed network, many different anatomic regions may be responsible for symptoms of dystonia, although all features of dystonia can be explained by uncontrolled activation or hypersensitivity of motor cortical regions that can cause increased reflex gain, inserted postures, or sensitivity to irrelevant sensory variables. Effective treatment of dystonia in children requires an understanding of the relationship between etiology, anatomy, and the specific mechanism of failure of postural stabilization.


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