Bursa of Fabricius

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In birds, the bursa of Fabricius (Latin: bursa cloacalis or bursa fabricii) is the site of hematopoiesis. It is a specialized organ that, as first demonstrated by Bruce Glick and later by Max Dale Cooper and Robert Good, is necessary for B cell (part of the immune system) development in birds. Mammals generally do not have an equivalent organ; the bone marrow is often the site of both hematopoiesis and B cell development. The bursa is present in the cloaca of birds and is named after Hieronymus Fabricius, who described it in 1621. [1]

Contents

Description

The bursa is an epithelial and lymphoid organ that is found only in birds. The bursa develops as a dorsal diverticulum of the proctadael region of the cloaca. The luminal (interior) surface of the bursa is plicated with as many as 15 primary and 7 secondary plicae or folds. These plicae have hundreds of bursal follicles containing follicle-associated epithelial cells, lymphocytes, macrophages, and plasma cells. Lymphoid stem cells migrate from the fetal liver to the bursa during ontogeny. In the bursa, these stem cells acquire the characteristics of mature, immunocompetent B cells. The bursa is active in young birds. It atrophies after about six months. [2]

Research history

In 1956, Bruce Glick showed that removal of the bursa in newly hatched chicks severely impaired the ability of the adult birds to produce antibodies. [3] [4] In contrast, removal of the bursa in adult chickens has little effect on the immune system. This was a serendipitous discovery that came about when a fellow graduate, Timothy S. Chang, who was teaching a course on antibody production obtained chickens from Glick that had been bursectomised (removal of the bursa). When these chickens failed to produce antibody in response to an immunization with Staphylococcus bacteria, the two students realized that the bursa is necessary for antibody production. Their initial attempts to publish their findings were thwarted by an editor who commented that "further elucidation of the mechanism ... should be attempted before publication.” [5]

The role of the thymus in the immune response was also identified shortly after the discovery of bursa's role in antibody responses. In thymectomized animals, the ability to reject allografts, and to mount delayed hypersensitivity responses, was drastically reduced. By the mid-1960s, immunologists [6] were convinced that there were indeed two separate arms of the immune system: one dealing exclusively with the production of circulating antibodies (humoral immunity), and another that is involved in the delayed hypersensitivity-type reactions and graft rejections (cell-mediated immunity).

Diseases

Infectious bursal disease (IBD) is a viral disease in poultry. Typically, the virus attacks the bursa of young birds, preventing development of the immune system.

Related Research Articles

<span class="mw-page-title-main">Thymus</span> Endocrine gland

The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule.

<span class="mw-page-title-main">Lymphatic system</span> Organ system in vertebrates

The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphoid tissues and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation..

<span class="mw-page-title-main">B cell</span> Type of white blood cell

B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasma membrane where they serve as a part of B-cell receptors. When a naïve or memory B cell is activated by an antigen, it proliferates and differentiates into an antibody-secreting effector cell, known as a plasmablast or plasma cell. Additionally, B cells present antigens and secrete cytokines. In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricius, a lymphoid organ where they were first discovered by Chang and Glick, which is why the 'B' stands for bursa and not bone marrow as commonly believed.

<span class="mw-page-title-main">Lymphocyte</span> Subtype of white blood cell

A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include T cells, B cells, and Innate lymphoid cells (ILCs), of which natural killer cells are an important subtype. They are the main type of cell found in lymph, which prompted the name "lymphocyte". Lymphocytes make up between 18% and 42% of circulating white blood cells.

<span class="mw-page-title-main">Infectious bursal disease</span> Viral disease of poultry

Infectious bursal disease (IBD), also known as Gumboro disease, infectious bursitis, and infectious avian nephrosis, is a highly contagious disease of young chickens and turkeys caused by infectious bursal disease virus (IBDV), characterized by immunosuppression and mortality generally at 3 to 6 weeks of age. The disease was first discovered in Gumboro, Delaware in 1962. It is economically important to the poultry industry worldwide due to increased susceptibility to other diseases and negative interference with effective vaccination. In recent years, very virulent strains of IBDV (vvIBDV), causing severe mortality in chicken, have emerged in Europe, Latin America, South-East Asia, Africa, and the Middle East. Infection is via the oro-fecal route, with affected birds excreting high levels of the virus for approximately 2 weeks after infection. The disease is easily spread from infected chickens to healthy chickens through food, water, and physical contact.

Marek's disease is a highly contagious viral neoplastic disease in chickens. It is named after József Marek, a Hungarian veterinarian who described it in 1907. Marek's disease is caused by an alphaherpesvirus known as "Marek's disease virus" (MDV) or Gallid alphaherpesvirus 2 (GaHV-2). The disease is characterized by the presence of T cell lymphoma as well as infiltration of nerves and organs by lymphocytes. Viruses related to MDV appear to be benign and can be used as vaccine strains to prevent Marek's disease. For example, the related herpesvirus found in turkeys (HVT), causes no apparent disease in the birds, and continues to be used as a vaccine strain for prevention of Marek's disease.

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Immune tolerance, or immunological tolerance, or immunotolerance, is a state of unresponsiveness of the immune system to substances or tissue that would otherwise have the capacity to elicit an immune response in a given organism. It is induced by prior exposure to that specific antigen and contrasts with conventional immune-mediated elimination of foreign antigens. Tolerance is classified into central tolerance or peripheral tolerance depending on where the state is originally induced—in the thymus and bone marrow (central) or in other tissues and lymph nodes (peripheral). The mechanisms by which these forms of tolerance are established are distinct, but the resulting effect is similar.

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Lymphopoiesis (lĭm'fō-poi-ē'sĭs) is the generation of lymphocytes, one of the five types of white blood cells (WBCs). It is more formally known as lymphoid hematopoiesis.

<span class="mw-page-title-main">Tonsil</span> Set of lymphoid organs in the mouth and throat

The tonsils are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil, two tubal tonsils, two palatine tonsils, and the lingual tonsils. These organs play an important role in the immune system.

<span class="mw-page-title-main">Microbial symbiosis and immunity</span>

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Within the immune system, Follicular B cells are a type of B cell that reside in primary and secondary lymphoid follicles of secondary and tertiary lymphoid organs, including spleen and lymph nodes. Antibody responses against proteins are believed to involve follicular B cell pathways in secondary lymphoid organs.

<span class="mw-page-title-main">Ocular immune system</span>

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<span class="mw-page-title-main">Chicken as biological research model</span> Use of the bird species for research on live beings

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<span class="mw-page-title-main">Max Dale Cooper</span> American immunologist

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References

  1. ↑ Ribatti D, Crivellato E, Vacca A (2006). "The contribution of Bruce Glick to the definition of the role played by the bursa of Fabricius in the development of the B cell lineage". Clin. Exp. Immunol. 145 (1): 1–4. doi:10.1111/j.1365-2249.2006.03131.x. PMC   1942006 . PMID   16792666.
  2. ↑ "MeSH Browser".
  3. ↑ Glick, B; Chang, TS; Jaap, RG (1 January 1956). "The Bursa of Fabricius and Antibody Production". Poultry Science. 35 (1): 224–225. doi: 10.3382/ps.0350224 .
  4. ↑ Glick, Bruce (1983). "Bursa of Fabricius". In Farner, Donald S.; King, James R.; Parkes, Kenneth C. (eds.). Avian Biology. pp. 443–500. doi:10.1016/B978-0-12-249407-9.50015-6. ISBN   9780122494079.
  5. ↑ Sternberg, SS (Nov 2003). "Bottoms up to a Nobel-worthy chicken's bottom". The American Journal of Surgical Pathology. 27 (11): 1471–2. doi:10.1097/00000478-200311000-00011. PMID   14576482.
  6. ↑ Cooper, MD; Raymond, DA; Peterson, RD; South, MA; Good, RA (Jan 1, 1966). "The functions of the thymus system and the bursa system in the chicken". The Journal of Experimental Medicine. 123 (1): 75–102. doi:10.1084/jem.123.1.75. PMC   2138128 . PMID   5323079.
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