Amino acids and immune function

British Journal Of Nutrition, Journal Year: 2007, Volume and Issue: 98(2), P. 237 - 252

Published: April 3, 2007

A deficiency of dietary protein or amino acids has long been known to impair immune function and increase the susceptibility animals humans infectious disease. However, only in past 15 years have underlying cellular molecular mechanisms begun unfold. Protein malnutrition reduces concentrations most plasma. Findings from recent studies indicate an important role for responses by regulating: (1) activation T lymphocytes, B natural killer cells macrophages; (2) redox state, gene expression lymphocyte proliferation; (3) production antibodies, cytokines other cytotoxic substances. Increasing evidence shows that supplementation specific with disease enhances status, thereby reducing morbidity mortality. Arginine, glutamine cysteine precursors are best prototypes. Because a negative impact imbalance antagonism among on nutrient intake utilisation, care should be exercised developing effective strategies enteral parenteral provision maximum health benefits. Such measures based knowledge about biochemistry physiology acids, their roles responses, nutritional pathological states individuals expected treatment outcomes. New metabolism leucocytes is critical development means prevent treat immunodeficient diseases. These nutrients hold great promise improving preventing diseases humans.

Language: Английский

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Dopamine as a Prolactin (PRL) Inhibitor

Endocrine Reviews, Journal Year: 2001, Volume and Issue: 22(6), P. 724 - 763

Published: Dec. 1, 2001

Dopamine is a small and relatively simple molecule that fulfills diverse functions. Within the brain, it acts as classical neurotransmitter whose attenuation or overactivity can result in disorders such Parkinson's disease schizophrenia. Major advances cloning characterization of biosynthetic enzymes, transporters, receptors have increased our knowledge regarding metabolism, release, reuptake, mechanism action dopamine. reaches pituitary via hypophysial portal blood from several hypothalamic nerve tracts are regulated by PRL itself, estrogens, neuropeptides neurotransmitters. binds to type-2 dopamine functionally linked membrane channels G proteins suppresses high intrinsic secretory activity lactotrophs. In addition inhibiting release controlling calcium fluxes, activates interacting intracellular signaling pathways gene expression lactotroph proliferation. Thus, homeostasis should be viewed context fine balance between an inhibitor many hypothalamic, systemic, local factors acting stimulators, none which has yet emerged primary releasing factor. The generation transgenic animals with overexpressed mutated genes expanded understanding dopamine-PRL interactions physiological consequences their perturbations. humans, differs respects laboratory animals, affected drugs used clinical practice. Hyperprolactinemia major neuroendocrine-related cause reproductive disturbances both men women. treatment hyperprolactinemia greatly benefited progressively more effective selective dopaminergic drugs.

Language: Английский

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Neuroimmune Interactions: From the Brain to the Immune System and Vice Versa

Physiological Reviews, Journal Year: 2017, Volume and Issue: 98(1), P. 477 - 504

Published: Dec. 24, 2017

Because of the compartmentalization disciplines that shaped academic landscape biology and biomedical sciences in past, physiological systems have long been studied isolation from each other. This has particularly case for immune system. As a consequence its ties with pathology microbiology, immunology as discipline largely grown independently physiology. Accordingly, it taken time immunologists to accept concept system is not self-regulated but functions close association nervous These associations are present at different levels organization. At local level, there clear evidence production use factors by central neuroendocrine mediators Short-range interactions between cells peripheral nerve endings innervating organs allow recruit neuronal elements fine tuning response. Reciprocally, play regulatory role participate elimination plasticity synapses during development well synaptic adulthood. whole organism long-range engage rest body fight against infection pathogenic microorganisms permit regulate functioning. Alterations communication pathways can account many pathological conditions were initially attributed strict organ dysfunction. applies particular psychiatric disorders several immune-mediated diseases. review will show how our understanding this balance short-range evolved over time, since first demonstrations influences on brain functions. The necessary complementarity these two modes then be discussed. Finally, few examples illustrate dysfunction results what was formerly considered psychiatry pathologies.

Language: Английский

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Immunosenescence: emerging challenges for an ageing population

Immunology, Journal Year: 2007, Volume and Issue: 120(4), P. 435 - 446

Published: Feb. 20, 2007

Summary It is now becoming apparent that the immune system undergoes age‐associated alterations, which accumulate to produce a progressive deterioration in ability respond infections and develop immunity after vaccination, both of are associated with higher mortality rate elderly. Immunosenescence, defined as changes age, has been gathering interest scientific health‐care sectors alike. The rise its recognition pertinent timely given increasing average age corresponding failure increase healthy life expectancy. This review attempts highlight age‐dependent defects innate adaptive systems. While discussing mechanisms contribute immunosenescence, emphasis on extrinsic factors, particular attention will be focused thymic involution. Finally, we illuminate potential therapies could employed help us live longer, fuller healthier life.

Language: Английский

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Causes, consequences, and reversal of immune system aging

Journal of Clinical Investigation, Journal Year: 2013, Volume and Issue: 123(3), P. 958 - 965

Published: March 1, 2013

The effects of aging on the immune system are manifest at multiple levels that include reduced production B and T cells in bone marrow thymus diminished function mature lymphocytes secondary lymphoid tissues. As a result, elderly individuals do not respond to challenge as robustly young. An important goal research is define cellular changes occur molecular events underlie them. Considerable progress has been made this regard, information provided rationale for clinical trials rejuvenate system.

Language: Английский

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Stress hormones and immune function

Cellular Immunology, Journal Year: 2008, Volume and Issue: 252(1-2), P. 16 - 26

Published: Jan. 1, 2008

Language: Английский

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Seasonal changes in vertebrate immune activity: mediation by physiological trade-offs

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2007, Volume and Issue: 363(1490), P. 321 - 339

Published: July 18, 2007

Animals living in temporally dynamic environments experience variation resource availability, climate and threat of infection over the course year. Thus, to survive reproduce successfully, these organisms must allocate resources among competing physiological systems such a way as maximize fitness changing environments. Here, we review evidence supporting hypothesis that trade-offs, particularly those between reproductive immune systems, mediate part seasonal changes detected defences many vertebrates. Abundant recent work has significant energetic nutritional costs defence. Sometimes are sufficiently large affect (e.g. output, growth or survival), indicating selection for appropriate allocation strategies probably occurred past. Because hormones often orchestrate allocations endocrine mediators activity discussed. Many hormones, including melatonin, glucocorticoids androgens have extensive consistent effects on system, they change systematic fashions Finally, modified framework within which conduct future studies ecological immunology is proposed, viz. heightened appreciation complex but intelligible nature vertebrate system. Although other factors besides trade-offs undoubtedly influence defence animals, growing literature supports role consequences sometimes produce.

Language: Английский

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Prolactin: The New Biology of an Old Hormone

Annual Review of Physiology, Journal Year: 2002, Volume and Issue: 64(1), P. 47 - 67

Published: March 1, 2002

▪ Abstract Prolactin (PRL) is a paradoxical hormone. Historically known as the pituitary hormone of lactation, it has had attributed to more than 300 separate actions, which can be correlated quasi-ubiquitous distribution its receptor. Meanwhile, PRL-related knockout models have mainly highlighted irreplaceable role in functions lactation and reproduction, suggests that most other reported target tissues are presumably modulated by, rather strictly dependent on, PRL. The multiplicity PRL actions animals direct opposition paucity arguments suggest involvement human pathophysiology effects on reproduction. Although many experimental data argue for progression some tumors, such breast prostate cancers, drugs lowering circulating levels ineffective. This observation opens new avenues research into understanding whether local production involved tumor growth and, if so, how extrapituitary synthesis regulated. Finally, physiological relevance variants, antiangiogenic 16K-like fragments, needs elucidated. review aimed at critically discussing these recent findings renewed manner should considered multifunctional

Language: Английский

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Insights into thymic aging and regeneration

Immunological Reviews, Journal Year: 2005, Volume and Issue: 205(1), P. 72 - 93

Published: May 9, 2005

Summary: The deterioration of the immune system with progressive aging is believed to contribute morbidity and mortality in elderly humans due increased incidence infection, autoimmunity, cancer. Dysregulation T‐cell function thought play a critical part these processes. One consequences an process termed thymic involution, where thymus undergoes reduction size profound changes its anatomy associated loss epithelial cells decrease thymopoiesis. This decline output newly developed T results diminished numbers circulating naïve impaired cell‐mediated immunity. A number theories have been forwarded explain this ‘thymic menopause’ including possible progenitors or cells, capacity rearrange receptor genes alterations production growth factors hormones. Although date no interventions fully restore host, systemic administration various cytokines hormones bone marrow transplantation resulted activity age. In review, we shall examine current literature on involution discuss several interventional strategies currently being explored subjects.

Language: Английский

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Thyroid Hormones as Modulators of Immune Activities at the Cellular Level

Thyroid, Journal Year: 2011, Volume and Issue: 21(8), P. 879 - 890

Published: July 11, 2011

Background: Increasing evidence suggests that thyroid hormones, L-thyroxine (T4) and 3,3′,5-triiodo-L-thyronine (T3), are modulators of the immune response. In monocytes, macrophages, leukocytes, natural killer cells, lymphocytes, a wide range functions such as chemotaxis, phagocytosis, generation reactive oxygen species (ROS), cytokine synthesis release altered under hypo- hyperthyroid conditions. Summary: Hyperthyroidism decreases proinflammatory activities monocytes whereas enhancement phagocytosis increased levels ROS may occur during hypothyroidism. The expression molecules macrophage inflammatory protein-1α interleukin-1β increases in However, Kupffer respiratory burst, nitric oxide synthase activity, tumor necrosis factor-α result from T3 levels. Thyroid hormones also affect cell activity cell-mediated responses. Still, for many cells no clear correlation has been found so far between abnormally high or low T4 effects observed on Conclusions: this review we outline contributions to different aspects innate adaptive relationship is complex modulate responses through both genomic nongenomic mechanisms. Future studies molecular signaling mechanisms involved cross-talk system support development new strategies improve clinical

Language: Английский

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