Related topics: cells · immune cells · immune response · bacteria · protein

New tuberculosis tests pave way for cow vaccination programs

Skin tests that can distinguish between cattle that are infected with tuberculosis (TB) and those that have been vaccinated against the disease have been created by an international team of scientists. The traditional TB ...

Japanese scientists embrace creepy-crawlies

Firms in Japan are changing people's perceptions about common spiders, worms and insect larvae. These seemingly unwanted creatures have unique features that could be useful for many applications that benefit humans, according ...

Nanotechnology delivers hepatitis B vaccine

Brazilian and European researchers have demonstrated exactly how a nanotechnology-based compound delivers an oral vaccine against hepatitis B to the immune system. When particles containing silica and an antigen combine, ...

Pharmaconutrition: Modern drug design for functional studies

Antonella Di Pizio and Maik Behrens of the Leibniz-Institute for Food Systems Biology at the Technical University of Munich, together with their cooperation partners, have developed highly effective activators for the bitter ...

page 1 from 23

Immune system

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.

This text uses material from Wikipedia, licensed under CC BY-SA