Related topics: cells , immune cells , vaccine , proceedings of the national academy of sciences , cancer
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.
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News tagged with immune system
Researchers Build Artificial Immune System to Solve Computational Problems
Technology / Computer Sciences
Dec 03, 2009 |
4.8 / 5 (14) |
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(PhysOrg.com) -- By mimicking the way that a living body acquires immunity to disease through vaccination, researchers have designed an artificial immune system to solve optimization problems more effectively ...
Mechanism discovered by which body's cells encourage tuberculosis infection
Dec 10, 2009 |
4 / 5 (1) |
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Scientists have discovered a signaling pathway that tuberculosis bacteria use to coerce disease-fighting cells to switch allegiance and work on their behalf. Epithelial cells line the airways and other surfaces ...
Study reveals H1N1 unexpected weakness
Dec 10, 2009 |
4.8 / 5 (19) |
7
The H1N1 influenza virus has been keeping a secret that may be the key to defeating it and other flu viruses as well.
Researchers demonstrate that stem cells can be engineered to kill HIV
Medicine & Health / HIV & AIDS
Dec 08, 2009 |
4.9 / 5 (18) |
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(PhysOrg.com) -- UCLA AIDS Institute researchers have for the first time demonstrated that human blood stem cells can be engineered to target and kill HIV-infected cells.
Implant-based cancer vaccine is first to eliminate tumors in mice
Nov 25, 2009 |
4.7 / 5 (31) |
7
(PhysOrg.com) -- A cancer vaccine carried into the body on a carefully engineered, fingernail-sized implant is the first to successfully eliminate tumors in mammals, scientists report this week in the journal ...
Enzyme necessary for development of healthy immune system
Dec 22, 2009 |
not rated yet |
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Mice without the deoxycytidine kinase (dCK) enzyme have defects in their adaptive immune system, producing very low levels of both T and B lymphocytes, the major players involved in immune response, according to a study by ...
IBM Reveals Five Innovations that Will Change Cities in the Next Five Years (w/ Video)
Dec 17, 2009 |
3.4 / 5 (9) |
1
Today, IBM unveiled a list of innovations that have the potential to change how people live, work and play in cities around the globe over the next five to ten years.
Biological catch-22 prevents induction of antibodies that block HIV
Medicine & Health / HIV & AIDS
Dec 15, 2009 |
4.5 / 5 (2) |
2
Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking ...
'Shoot-'em-up' video game increases teenagers' science knowledge
Dec 08, 2009 |
4.3 / 5 (7) |
2
While navigating the microscopic world of immune system proteins and cells to save a patient suffering from a raging bacterial infection, young teenage players of the "Immune Attack" video game measurably improved their understanding ...
Scientists reveal malaria parasites' tactics for outwitting our immune systems
Nov 30, 2009 |
4.8 / 5 (6) |
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Malaria parasites are able to disguise themselves to avoid the host's immune system, according to research funded by the Wellcome Trust and published today in the journal Proceedings of the National Academy of ...
Researchers discover biological basis of 'bacterial immune system'
Nov 30, 2009 |
4.8 / 5 (4) |
1
(PhysOrg.com) -- Bacteria don’t have easy lives. In addition to mammalian immune systems that besiege the bugs, they have natural enemies called bacteriophages, viruses that kill half the bacteria on Earth every two days.
Researchers discover biological basis of 'bacterial immune system'
Nov 25, 2009 |
4.8 / 5 (4) |
0
Bacteria don't have easy lives. In addition to mammalian immune systems that besiege the bugs, they have natural enemies called bacteriophages, viruses that kill half the bacteria on Earth every two days.
Study redefines placebo effect as part of effective treatment
Medicine & Health / Psychology & Psychiatry
Dec 22, 2009 |
not rated yet |
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Researchers used the placebo effect to successfully treat psoriasis patients with one quarter to one half of their usual dose of a widely used steroid medication, according to an early study published online today in the ...
Mutation leads to new and severe form of bacterial disease
Dec 18, 2009 |
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(PhysOrg.com) -- Everybody gets sick, but how sick you get is in your genes. New research now reveals a mutation on a gene that makes children susceptible to a severe form of mycobacterial disease. The work not only supports ...
Breakthrough on causes of inflammatory bowel disease
Dec 17, 2009 |
4.3 / 5 (4) |
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New research by the University of Adelaide could help explain why some people are more prone to Crohn's disease, ulcerative colitis and other autoimmune diseases.
