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Immune system

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An 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 Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with immune system

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Infection-fighting antibodies made in plants as effective as costlier conventional version

Medicine & Health / Research

created Feb 08, 2010 | popularity 4.7 / 5 (3) | comments 0 | with audio podcast

The first head-to-head comparison of therapeutic monoclonal antibodies produced from plants versus the same antibodies produced from mammalian cells has shown that plant-produced antibodies can fight infection equally well.


A molecule that destroys normal metabolism is found

A molecule that destroys normal metabolism is found

Biology / Cell & Microbiology

created Feb 04, 2010 | popularity not rated yet | comments 0

Overeating in mice triggers a molecule once considered to be only involved in detecting and fighting viruses to also destroy normal metabolism, leading to insulin resistance and setting the stage for diabetes. ...


Antibodies attack immune proteins

Medicine & Health / Research

created Feb 01, 2010 | popularity 5 / 5 (1) | comments 0

Two studies published online on February 1 in the Journal of Experimental Medicine reveal that patients with a rare autoimmune disease produce antibodies that attack microbe-fighting immune proteins called cytokines. These ...


Dead neuron clean-up crew in peripheral nervous system found

Dead neuron clean-up crew in peripheral nervous system found

Medicine & Health / Neuroscience

created Jan 29, 2010 | popularity 4.4 / 5 (5) | comments 0 | with audio podcast

(PhysOrg.com) -- Death is messy, especially in the developing nervous system. During embryonic development, more nerve cells (neurons) are produced than we will ever need or use. About half of those unnecessary ...


Blood test can predict rheumatoid arthritis before symptoms arise

Medicine & Health / Diseases

created Jan 28, 2010 | popularity not rated yet | comments 0

Researchers from University Hospital in Umea, Sweden, have identified several cytokines, cytokine-related factors, and chemokines that increase significantly prior to rheumatoid arthritis (RA) disease onset. These findings ...


Scientists find potential new way to enhance vaccines

Medicine & Health / Research

created Jan 27, 2010 | popularity not rated yet | comments 0 | with audio podcast

Researchers at The Scripps Research Institute have discovered a potential new way to stimulate the immune system to prevent or clear a viral infection. By blocking the action of a key protein in the mouse immune system, they ...


Safety in numbers -- a cloud-based immune system for computers

Technology / Computer Sciences

created Jan 27, 2010 | popularity 3.3 / 5 (3) | comments 1 | with audio podcast

A new approach for managing bugs in computer software has been developed by a team led by Prof. George Candea at EPFL. The latest version of Dimmunix, available for free download, enables entire networks of computers to cooperate ...


'Good' bacteria keep immune system primed to fight future infections

'Good' bacteria keep immune system primed to fight future infections

Medicine & Health / Research

created Jan 27, 2010 | popularity 4.7 / 5 (6) | comments 1 | with audio podcast

Scientists have long pondered the seeming contradiction that taking broad-spectrum antibiotics over a long period of time can lead to severe secondary bacterial infections. Now researchers from the University ...


Two-pronged immune response offers hope for effective Salmonella vaccine

Medicine & Health / Research

created Jan 25, 2010 | popularity 5 / 5 (1) | comments 1 | with audio podcast

Research from Malawi, Birmingham and Liverpool has renewed hope that an effective vaccine could be developed against nontyphoidal strains of Salmonella. The work, funded by the Wellcome Trust and GlaxoSmithKline, suggests that t ...


First evidence that the brain’s native dendritic cells can muster an immune response

First evidence that the brain’s native dendritic cells can muster an immune response

Medicine & Health / Research

created Jan 22, 2010 | popularity 3 / 5 (1) | comments 0

(PhysOrg.com) -- Since their initial discovery in 1973, dendritic cells, the sentinels of the immune system, have turned up in a number of places other than the immune organs. They stand guard in the heart, ...


New study focuses on protein dynamics

Chemistry / Biochemistry

created Jan 21, 2010 | popularity not rated yet | comments 0

A discovery by associate professor of chemistry and biochemistry Brian Baker and his research group at the University of Notre Dame reveals the importance of dynamic motion by proteins involved in the body's immune response. ...


PrEP treatment prevented HIV transmission in humanized mice

Medicine & Health / HIV & AIDS

created Jan 21, 2010 | popularity not rated yet | comments 0 | with audio podcast

Systemic pre-exposure administration of antiretroviral drugs provides protection against intravenous and rectal transmission of HIV in mice with human immune systems, according to a new study published January 21, 2010 in ...


Hungry immune guardians are snappier

Hungry immune guardians are snappier

Biology / Cell & Microbiology

created Jan 20, 2010 | popularity 5 / 5 (3) | comments 0 | with audio podcast

German researchers have discovered an elementary mechanism which regulates vital immune functions in healthy people. In situations of hunger which mean stress for the body's cells, the body releases more antimicrobial ...


Researcher discovers how new HIV vaccine candidate can control HIV progression

Medicine & Health / HIV & AIDS

created Jan 19, 2010 | popularity 5 / 5 (3) | comments 0 | with audio podcast

(PhysOrg.com) -- Researchers from the University of Toronto and Mount Sinai Hospital have made significant findings about how a new HIV vaccine candidate (Delta 5) can reduce -- and in some cases stop -- HIV progression by ...


Cancer stem cells suppress immune response against brain tumor

Cancer stem cells suppress immune response against brain tumor

Medicine & Health / Cancer

created Jan 15, 2010 | popularity 3.7 / 5 (3) | comments 0 | with audio podcast

Cancer-initiating cells that launch glioblastoma multiforme, the most lethal type of brain tumor, also suppress an immune system attack on the disease, scientists from The University of Texas M. D. Anderson ...