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

Experiments illuminate key component of plants' immune systems

Plants, like humans and animals, have over millions of years evolved complex immune systems that fend off invading pathogens. But unlike many animals, plants lack adaptive immunity conferred by antibodies. This means each ...

How new loops in DNA packaging help us make diverse antibodies

Diversity is good, especially when it comes to antibodies. It's long been known that a gene assembly process called V(D)J recombination allows our immune system to mix and match bits of genetic code, generating new antibodies ...

Study answers longstanding cell-development riddle

During the lifetime of a body—whether human, fish or any other type of vertebrate—cells die, making room for fresh new cells to carry on vital processes. The dead cells must be cleared away, though, and debris removal ...

New hair follicles can corral skin cancer

The same genetic mutations that can trigger cancer in some tissues are relatively harmless in others. A new Yale study has identified an unlikely source of protection against some forms of skin cancer—hair follicle regeneration.

How worms snare their hosts

Acanthocephala are parasitic worms that reproduce in the intestines of various animals, including fish. However, only certain species of fish are suitable as hosts. A study by the University of Bonn now shows how the parasites ...

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.

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