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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 response

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Researchers discover antibody receptor identity, propose renaming immune-system gene

Researchers discover antibody receptor identity, propose renaming immune-system gene

Medicine & Health / Research

created Nov 20, 2009 | popularity 5 / 5 (2) | comments 0

Researchers at the University of Alabama at Birmingham (UAB) have uncovered the genetic identity of a cellular receptor for the immune system's first-response antibody, a discovery that sheds new light on ...


New culprit for viral infections among elderly -- an overactive immune response

New culprit for viral infections among elderly -- an overactive immune response

Biology / Cell & Microbiology

created Nov 18, 2009 | popularity 5 / 5 (1) | comments 0

Researchers at Yale School of Medicine have found that exaggerated responses of the immune system explain why the elderly succumb to viral infections more readily than younger people. Published in the November ...


Use of rib cartilage grafts in rhinoplasty results in patient satisfaction, few complications

Medicine & Health / Other

created Nov 17, 2009 | popularity not rated yet | comments 0

Rib cartilage from human donors is well tolerated as a grafting material in nasal plastic surgery and yields positive functional, structural and cosmetic results, even in complex cases, according to a report in the November/December ...


Role of Statins in Reducing H1N1 Mortality Rates Studied

Medicine & Health / Research

created Nov 13, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- Vanderbilt University Medical Center researchers are studying statins, the class of drugs long associated with lowering cholesterol, as a way to reduce H1N1-related deaths.


High fat diet increases inflammation in the mouse colon

Medicine & Health / Health

created Nov 12, 2009 | popularity 3 / 5 (1) | comments 0

(PhysOrg.com) -- In mice fed a diet high in fat and low in fiber, vitamin D and calcium -- the so-called Western diet -- expression of a series of genes collectively associated with immune and inflammatory responses was altered. ...


People with less education could be more susceptible to the flu

Medicine & Health / Research

created Nov 10, 2009 | popularity not rated yet | comments 0

People who did not earn a high school diploma could be more likely to get H1N1 and the vaccine might be less effective in them compared to those who earned a diploma, new research shows.


Hundreds of genes distinguish patients likely to survive advanced melanoma

Medicine & Health / Cancer

created Nov 09, 2009 | popularity not rated yet | comments 0

Although the chances of surviving advanced melanoma aren't very good with current therapies, some patients can live for years with cancer that has spread beyond the skin to other organs. Now it may be possible to identify ...


Nanoparticles for gene therapy improve

Nanoparticles for gene therapy improve

Nanotechnology / Bio & Medicine

created Nov 06, 2009 | popularity 5 / 5 (5) | comments 3

(PhysOrg.com) -- About five years ago, Professor Janet Sawicki at the Lankenau Institute in Pennsylvania read an article about nanoparticles developed by MIT's Robert Langer for gene therapy, the insertion ...


New Synthetic Molecules Trigger Immune Response to HIV and Prostate Cancer

New Synthetic Molecules Trigger Immune Response to HIV and Prostate Cancer

Chemistry / Biochemistry

created Nov 05, 2009 | popularity 4.7 / 5 (9) | comments 0

(PhysOrg.com) -- Researchers at Yale University have developed synthetic molecules capable of enhancing the body’s immune response to HIV and HIV-infected cells, as well as to prostate cancer cells. Their ...


Initial results show pregnant women mount strong immune response to one dose of 2009 H1N1 vaccine

Medicine & Health / Medications

created Nov 02, 2009 | popularity not rated yet | comments 0

Healthy pregnant women mount a robust immune response following just one dose of 2009 H1N1 influenza vaccine, according to initial results from an ongoing clinical trial sponsored by the National Institute of Allergy and ...


Fibre may keep asthma, diabetes at bay, study finds

Medicine & Health / Health

created Oct 28, 2009 | popularity 4.8 / 5 (8) | comments 1

Insoluble dietary fibre, or roughage, not only keeps you regular, say Australian scientists, it also plays a vital role in the immune system, keeping certain diseases at bay.


Scientists use world's fastest supercomputer to create the largest HIV evolutionary tree

Medicine & Health / HIV & AIDS

created Oct 27, 2009 | popularity 3 / 5 (1) | comments 0

Supporting Los Alamos National Laboratory's role in the international Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium, researchers are using the Roadrunner supercomputer to analyze vast quantities of genetic sequences ...


HHS' Sebelius: Ample flu vaccine will be available (AP)

HHS' Sebelius: Ample flu vaccine will be available

Medicine & Health / Medications

created Oct 26, 2009 | popularity not rated yet | comments 0

(AP) -- Health and Human Services Secretary Kathleen Sebelius said Monday the swine flu vaccine "is coming out the door as fast as it comes off the production line."


Health officials recommend gap between flu spray vaccines

Medicine & Health / Medications

created Oct 16, 2009 | popularity not rated yet | comments 0

Both seasonal flu and 2009 H1N1 flu vaccines may be given to a patient at the same visit, as long as they're not both in the nasal spray form, health officials said.


Protein interaction network can respond Helicobacter pylori infection?

Medicine & Health / Research

created Oct 16, 2009 | popularity not rated yet | comments 0

Helicobacter pylori (H pylori) is a gram negative bacterium which infects about 50% of the world population. H pylori colonization causes a strong systemic immune response. Various tools have been employed to identify the rela ...