Immune system
hideAn immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens and tumour cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly. Detection is complicated as pathogens can evolve rapidly, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts.
To survive this challenge, multiple mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. Vertebrates such as humans have even more sophisticated defense mechanisms. The immune systems of vertebrates consist of many types of proteins, cells, organs, and tissues, which interact in an elaborate and dynamic network. As part of this more complex immune response, the human immune system adapts over time to recognise specific pathogens more efficiently. This adaptation process is referred to as "adaptive immunity" or "acquired immunity" and creates immunological memory. Immunological memory created from a primary response to a specific pathogen, provides an enhanced response to secondary encounters with that same, specific pathogen. This process of acquired immunity is the basis of vaccination.
Disorders in the immune system can result in disease. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's Thyroiditis, rheumatoid arthritis, diabetes mellitus type 1 and lupus erythematosus. Immunology covers the study of all aspects of the immune system which has significant relevance to human health and diseases. Further investigation in this field is expected to play a serious role in promotion of health and treatment of diseases.
For more information about Immune system, read the full article at
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News tagged with immune function
Two molecules affecting brain plasticity
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Nov 25, 2009 |
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(PhysOrg.com) -- You wouldn't want a car with no brakes. It turns out that the developing brain needs them, too.
Sweet -- sugared polymer a new weapon against allergies and asthma
Nov 19, 2009 |
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Scientists at Johns Hopkins and their colleagues have developed sugar-coated polymer strands that selectively kill off cells involved in triggering aggressive allergy and asthma attacks. Their advance is a significant step ...
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Sleep and Cancer: Uncomfortable Bedfellows
17 hours ago |
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(PhysOrg.com) -- Newly-diagnosed cancer patients face a number of life-long challenges, but a new study from the Duke Clinical Research Institute suggests that a lack of sleep may be one of the most persistent and disruptive. ...
Scientists crack mystery of protein's dual function
Dec 13, 2009 |
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Researchers at The Scripps Research Institute have solved a 10-year-old mystery of how a single protein from an ancient family of enzymes can have two completely distinct roles in the body. In addition to providing guidance ...
Study reveals H1N1 unexpected weakness
Dec 10, 2009 |
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The H1N1 influenza virus has been keeping a secret that may be the key to defeating it and other flu viruses as well.
Think again about keeping little ones so squeaky clean
Dec 08, 2009 |
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A new Northwestern University study suggests that American parents should ease up on antibacterial soap and perhaps allow their little ones a romp or two in the mud --- or at least a much better acquaintance with everyday ...
Scientists reveal key structure from ebola virus
Dec 08, 2009 |
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Scientists at The Scripps Research Institute have determined the structure of a critical protein from the Ebola virus, which, though rare, is one of the deadliest viruses on the planet killing between 50 and 90 percent of ...
Exercise reduces death rate in prostate cancer patients
Dec 08, 2009 |
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As little as 15 minutes of exercise a day can reduce overall mortality rates in patients with prostate cancer, according to findings presented at the American Association for Cancer Research Frontiers in Cancer Prevention ...
Study Results Suggest Adult Stem Cells May Help Repair Muscle Cells Damaged by Heart Attack
Dec 07, 2009 |
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(PhysOrg.com) -- Adult stem cells may help repair heart tissue damaged by heart attack according to the findings of a new study to be published in the December 8 issue of the Journal of the American College of Cardiology. Resul ...
Appetite, consumption controlled by clockwork genes at cross-purposes in flies
Dec 06, 2009 |
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One of the pioneers in research on sleep:wake circadian genes, Amita Sehgal, Ph.D., has discovered that fruit flies' appetite and consumption are controlled by two rival sets of clocks, one in neurons and the other in the ...
Cholesterol-lowering drugs also may protect stem cell transplant patients from GVHD
Dec 04, 2009 |
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Cholesterol-lowering drugs known as statins are among the most prescribed medicines in the U.S. Now a new study by researchers at Fred Hutchinson Cancer Research Center indicates that statins may protect stem cell transplant ...
FDA-approved drug may slow beta cell destruction in type 1 diabetes patients
Dec 04, 2009 |
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New findings by UT Southwestern researchers suggest that a drug already used to treat autoimmune disorders might also help slow the destruction of insulin-producing cells in patients recently diagnosed with ...
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