Related topics: proceedings of the national academy of sciences , cells , immune cells , immune response , rheumatoid arthritis



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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Scientists identify DNA that regulates antibody production

Medicine & Health / Research

created 10 hours ago | popularity not rated yet | comments 0

(PhysOrg.com) -- When foreign invaders trip the immune system’s alarm, antibodies need to be specially sculpted to attack them head on. New research now shows that gene segments called enhancers control the reshuffling of ...


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Vaccine being developed to help smokers quit

Medicine & Health / Medications

created 10 hours ago | popularity 4.5 / 5 (4) | comments 2

(PhysOrg.com) -- Glaxo-SmithKline has joined forces with Nabi Pharmaceuticals to produce a vaccine to help smokers give up their addiction permanently.


New findings suggest strategy to help generate HIV-neutralizing antibodies

Medicine & Health / HIV & AIDS

created Nov 19, 2009 | popularity not rated yet | comments 0

New discoveries about anti-HIV antibodies may bring researchers a step closer to creating an effective HIV vaccine, according to a new paper co-authored by scientists at the Vaccine Research Center of the National Institute ...


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 ...


Immune system activated in schizophrenia

Medicine & Health / Diseases

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

Researchers at the Swedish medical university Karolinska Institutet have discovered that patients with recent-onset schizophrenia have higher levels of inflammatory substances in their brains. Their findings offer hope of ...


Genetic link to vitamin A deficiency

Medicine & Health / Research

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

(PhysOrg.com) -- Almost half of UK women may be lacking an important source of vitamin A due to a previously undiscovered genetic variation, scientists at Newcastle University have found.


Microsoft co-founder Allen treated for lymphoma (AP)

Microsoft co-founder Allen treated for lymphoma

Technology / Other

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

(AP) -- Microsoft Corp. co-founder and billionaire investor Paul Allen has been diagnosed with non-Hodgkin's lymphoma and is undergoing chemotherapy.


The indefinite self-renewal of specialized cells without the need for stem cell intermediates

The indefinite self-renewal of specialized cells without the need for stem cell intermediates

Biology / Cell & Microbiology

created Nov 16, 2009 | popularity 3 / 5 (2) | comments 1

(PhysOrg.com) -- Is the indefinite expansion of adult cells possible without recourse to stem cell intermediates? The team led by Michael Sieweke at the Centre d'immunologie de Marseille Luminy, France has ...


Researchers create compound that boosts anti-inflammatory fat levels

Medicine & Health / Research

created Nov 16, 2009 | popularity 3.7 / 5 (3) | comments 1

UC Irvine pharmacology researchers have discovered a way to boost levels of a natural body fat that helps decrease inflammation, pointing to possible new treatments for allergies, illnesses and injuries related to the immune ...


Scientists begin to unravel what makes pandemic H1N1 tick

Medicine & Health / Diseases

created Nov 16, 2009 | popularity 5 / 5 (2) | comments 0

As the number of deaths related to the pandemic H1N1 virus, commonly known as "swine flu," continues to rise, researchers have been scrambling to decipher its inner workings and explain why the incidence is lower than expected ...


Faithful mothers have healthier babies

Medicine & Health / Research

created Nov 12, 2009 | popularity not rated yet | comments 0

Faculty of 1000 reviewers examine a study from New Zealand on whether prolonged exposure to the father's semen protects new mothers against pre-eclampsia and having an undersized baby.


Interstitial macrophages: immune cells that prevent asthma

Medicine & Health / Research

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

The continual presence in the air of the microbe-derived molecule LPS promotes asthma in some individuals. What prevents inhalation of LPS from promoting asthma in most individuals is not well understood. However, researchers ...


Eating, drinking and lifestyle changes can boost immunity to ward off seasonal flu

Medicine & Health / Health

created Nov 05, 2009 | popularity 4 / 5 (2) | comments 0

College students looking to stay healthy during flu and exam season need to focus on three very important factors, says a nutritionist at Washington University in St. Louis.


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 ...


Daily dose of color may boost immunity this flu season

Medicine & Health / Health

created Nov 03, 2009 | popularity 2 / 5 (1) | comments 0

Hoping to keep the flu at bay? A strong immune system helps. Enjoying the bounty of colorful fruits and vegetables available right now can be an important step toward supporting your family's immune system this cold/flu season.