Table of Contents > Allergies > B-cells Print

B-cells

Image

Also listed as: WAS
Related terms
Background
Author information
Bibliography
Types of b-cells
Development and function
Antigen recognition
T-cell dependent activation
T-cell independent activation

Related Terms
  • Antibodies, auto recessive, B-cells, bone marrow, bone marrow transplant, CBC, genetic disorder, immune system, immunodeficiency, inherited disorder, inherited immunodeficiency, leukocytes, leukemia, lymphoma, lymphocytes, malignancy, platelets, pneumonia, red blood cells, T-cells, thrombocytes, thrombocytopenia, tumor, WASP, white blood cells, Wiskott Aldrich syndrome, Wiskott-Aldrich syndrome protein, X-linked.

Background
  • Wiskott-Aldrich syndrome (WAS) is an inherited, immunodeficiency disorder that occurs almost exclusively in males. The recessive genetic disorder is caused by a mutation in the WAS (Wiskott-Aldrich syndrome) gene, which is an X-linked trait. The gene mutation leads to abnormalities in B- and T-lymphocytes (white blood cells), as well as blood platelet cells. In a healthy individual, the T-cells provide protection against viral and fungal infection, the B cells produce antibodies, and platelets are responsible for blood clotting to prevent blood loss after a blood vessel injury.
  • Individuals diagnosed with WAS suffer from recurrent infections, eczema and thrombocytopenia (low levels of platelets).
  • Before 1935, patients only lived an average of eight months. Today, patients usually live an average of eight years, according to a recent case study. The cause of death is usually attributed to extensive blood loss. However, cancer (especially leukemia) is common and often fatal among WAS patients.
  • The only possible cure for WAS is a bone marrow transplant. However, if a patient's family member is not a possible match for a bone marrow donation, patients may have to wait years for a potential donor. Other aggressive treatments may also increase a patient's life expectancy. For instance, one study found that patients who underwent splenectomy (removal of the spleen) lived to be more than 25 years old. The spleen may harbor too many platelets, and cause a decrease in the number of platelets in circulation. Antibiotics, antivirals, antifungals, chemotherapeutic agents, immunoglobulins and corticosteroids have also been used to relieve symptoms and treat infections and cancer associated with WAS.
  • Researchers estimate that about four people per one million live male births develop the disease in the United States.
  • The syndrome is named after Dr. Robert Anderson Aldrich, an American pediatrician who described the disease in a family of Dutch-Americans in 1954, and Dr Alfred Wiskott, a German pediatrician who discovered the syndrome in 1937. Wiskott described three brothers with a similar disease, whose sisters were unaffected.

Author information
  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography
  1. Binder V, Albert MH, Kabus M, et al. The genotype of the original Wiskott phenotype. N Engl J Med. 2006 Oct 26;355(17):1790-3.
  2. Jin Y, Mazza C, Christie JR, et al. Mutations of the Wiskott-Aldrich Syndrome Protein (WASP): hotspots, effect on transcription, and translation and phenotype/genotype correlation. Blood. 2004 Dec 15;104(13):4010-9. Epub 2004 Jul 29.
  3. Natural Standard: The Authority on Integrative Medicine. .
  4. St. Jude Children's Research Hospital. Inherited Immunodeficiencies: Wiskott-Aldrich Syndrome (WAS). .
  5. U.S. Immune Deficiency Foundation. The Wiskott Aldrich Syndrome. .

Types of b-cells
  • Naïve B-cells: Naïve B-cells are present in the bloodstream. They are mature B-cells that have not been exposed to an antigen yet. These cells have antigen-specific antibodies immunoglobulin M (IgM) and immunoglobulin D (IgD) on their surfaces. These naïve B-cells are able to recognize their cognate antigen. Since there are millions of B-cells in the body, and naïve B-cells only live a few days, more than 90% of these cells die before they come into contact with an antigen.
  • Plasma B-cells: Plasma B-cells, or plasma cells, are large B-cells that have been exposed to an antigen. They secrete large amounts of antibodies. They are sometimes called antibody factories. Plasma B-cells have large amounts of rough endoplasmic reticulum, which is a system of membranous tubes and sacs containing ribosomes that produce the membrane-bound antibodies. These plasma cells are found in the spleen and lymph nodes.
  • Memory B-cells: Memory B-cells are formed from activated B-cells. These cells are specific to an antigen that has previously entered the body. Memory B-cells, which are present in the bone marrow, lymph nodes, and spleen, are able to respond quickly when they are exposed to the same antigen in the future. Lower levels of the antigen are able to activate memory B-cells better than naïve B-cells. Therefore, the memory B-cells enable the immune system to react more quickly if their cognate antigen enters the body in the future. Memory B-cells have a prolonged life span and they can survive for many years (up to a lifetime).
  • B-1 cells: B-1 cells express the CD5 protein on their surfaces, which can bind to another protein called CD72. It has been suggested that the CD5-CD72 link mediates interaction among B-cells.
  • B-1 cells express more immunoglobulin M (IgM) than immunoglobulin G (IgG) and their receptors show polyspecificity. This means that they are able to identify several different antigens if they are present in high quantities. However, they have a preference for other immunoglobulins, self-antigens, and common bacteria. These cells respond to antigens that are T-cell independent. This means that the B-1 cells are activated without the help of T-cells.
  • Most B-1 cells are found in the abdominal and chest cavities. Low quantities of B1-cells are also found in the lymph nodes and spleen.
  • B-2 cells: B-2 cells are considered conventional B-cells. They respond to antigens that are T-cell dependent. This means that T-cells are needed to activate the B-1 cells.

Development and function
  • Millions of B-cells are produced daily in the bone marrow.
  • Once the B-cell reaches maturity, it has a B-cell receptor (BCR) on its surface. The BCR is a protein that distinguishes the B-cell from other lymphocytes (immune system cells). At this stage, the B-cells can express (but do not secrete) immunoglobulin M (IgM) and immunoglobulin D (IgD) on their cell surfaces. This mature cell is now able to respond to antigens.
  • The mature B-cells circulate in the bloodstream and lymph nodes, searching for foreign substances like bacteria and viruses that may harm the body. These B-cells are also called naïve cells because they have not encountered an antigen yet. These cells can be activated in either a T-cell dependent or independent manner.
  • After a B-cell detects and binds to an antigen, it internalizes it. The B-cell then attaches parts of the antigen's proteins to a major histocompatibility complex (MHC) class II molecule. This complex is then transported to the outside of the cell membrane where a T-cell can identify it. Once the T-cell identifies the processed antigen, it binds to the complex on the B-cells surface. This process activates the T-cell to produce cytokines, which are chemical messengers for cells. When cytokines are produced, the B-cell is activated to produce more antibodies against the antigen.
  • The activated B-cell begins to divide, and it becomes an antibody-producing cell called a plasma cell.
  • The plasma cell produces immunoglobulin that is secreted on the cell surface. Some of the daughter cells of the plasma cell undergo isotype switching. During this process, other isotypes of immunoglobulin, including IgA, IgE ,and IgG, are secreted.
  • If the B-cell starts to mature abnormally, it will die in a process called apoptosis (programmed cell death).

Antigen recognition
  • The main difference between B-cells and T-cells is how they recognize antigens. B-cells are able to recognize their cognate antigen in its unprocessed form via immunoglobulins on their surfaces.
  • T-cells, on the other hand, identify their cognate antigen in a processed form. An antigen-presenting cell, like a B-cell, macrophage, or dendritic cell, must first break down the antigen. The T-cell receptor recognizes the processed antigen.

T-cell dependent activation
  • Most antigens are T-cell dependent. This means that T-cells are needed in order for the most antibodies to be produced. This type of immune response is also called cell-mediated immunity.
  • If an antigen is T-cell dependent, the first signal occurs when the B-cell receptor detects and binds to the antigen. This triggers the B-cell to internalize and digest the antigen. It attaches the antigen to a MHC (major histocompatibility complex) class II protein and presents it to a special type of T-cell called a TH2-cell. The T-cell detects and binds to the antigen-MHC complex on the surface of the B-cell. This triggers the T-cell to release chemical messengers called cytokines.
  • The second signal occurs when cytokines are released. This triggers the B-cells to multiply and become plasma cells. The plasma cells are able to produce many different types of immunoglobulin, in a process called isotype switching. Memory B-cells are also produced in response to T-cell dependent antigens.

T-cell independent activation
  • Antigens may also be T-cell independent. This means that T-cells are not needed to activate the B-cells. There are two types of T-cell independent activation - type 1 T cell-independent activation and type 2 T-cell independent activation.
  • During type 1 activation, the antigen is a polyclonal activator. This means the antigen is non-specific to a particular antibody. Therefore, the antigen activates a large percentage of the B-cells at one time because many different B-cells are able to recognize the antigen.
  • During type 2 activation, a minimum number of identical antigens are needed to trigger the B-cell. During this process, macrophages (another type of white blood cell) present many antigens to the B-cell, which triggers the antibodies on the surfaces of B-cells to cross-link.

Copyright © 2011 Natural Standard (www.naturalstandard.com)


The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

62 Marshall St
Rochester, NY 14607
585-454-2667
585-454-0343 (fax)
Email Our Store
Driving Directions

  STORE HOURS
 Mon8:00am-8:00pm
 Tue8:00am-8:00pm
 Wed8:00am-8:00pm
 Thu8:00am-8:00pm
 Fri8:00am-8:00pm
 Sat9:00am-7:00pm
 Sun10:00am-7:00pm
 

Co-op Connections

Follow us on Instagram!

Follow us on Twitter!

Join our Facebook community!

Email newsletter sign up

Email Newsletter Archive
Click here>>

Download The Rutabaga Rap

Rutabaga Rap Archive
Click here>>

About Our Co-op

Current Job Openings
See current openings>>

Top 10 Reasons for Shopping
Learn more>>

Why become an owner?
Learn why>>

Owner Application
Download (pdf)>>

All About Co-ops
Learn more>>

Our Board of Directors
Learn more>>

Global Ends Policy
Learn more>>

Bylaws
Learn more>>

Advertise in Our Newsletter
Learn more>>

Job Application
Download (pdf)>>

Discover your local co-op!