How B-Cells Protect Your Body From Infection (2024)

B-cells are a type of white blood cell that produces antibodies. B-cells play a significant role in protecting your body from infection. B-cells are also calledB-lymphocytes.

Without B-cells, your body would be less able to fight common bacteria and viruses, and you would lack the long-lasting "memory antibody" function that is typical after recovering from an infection or after being immunized.

This article discusses B-cells and their function in your immune system.

B-Cells Function

B-cells are a kind of white blood cell called a lymphocyte. Thereare two main types of lymphocytes: B-cells and T-cells.

The primary function of B-cells is to make antibodies in response to foreign invaders. B-cells become "activated" when they encounter antigens, which can be any substance the body thinks is foreign, such as a piece of a virus, or a patch of a bacterium's cutter capsule.T-cells are also involved in this process.

Antibodies serve as flags or flares over a battle site. They recruit other defensive molecules in the bloodstream to the site, working toward killing the infection-causing organism. They also signal other immune cells to attack the invader.

Types of B-Cells

B-cells can differentiate into memory cells and plasma cells. Each type helps protect you from infection in different ways.

Plasma B-Cells

Plasma cells mass-produce large proteins—called antibodies or immunoglobulins—that attach to the surface of foreign agents. Each plasma B-cell makes antibodies to only one antigen and can produce up to 10,000 antibodies per second.

Plasma B-cells are also called plasmacytes or effector cells.

Memory B-Cells

Memory B-cells have a longer lifespan. They remember a specific antigen and respond quickly when they see it again. These are the cells that give us long-lasting immunity to different invaders.

When you get immunized, the vaccine contains antigens that stimulate the B-cells to produce antibodies that will then attack the virus, bacteria, or toxin you are being immunized against. This mimics what happens in your body when you are infected with that germ,but without the same risks of the disease caused by the germ or toxin.

Because B-cells have long memories, they can produce antibodies against germs and toxins for months and years, giving you a period of immunity.

Where Do B-Cells Mature?

B-cells, like other white blood cells, arise from hematopoietic stem cells that residewithin the spongy bone marrow, especially in certain bones like the hip bone and vertebrae. These blood-forming cells give rise to B-cells through a series of steps.

A young B-cell, called a naive B-cell, circulates in the bloodstream, usually ending up in the spleen or lymph nodes. Once activated, the B-cell continues to produce antibodies for the remainder of its life.

Conditions That Affect B-Cells

Abnormal B-cells can affect the way your immune system works, causing conditions such as autoimmune disease or certain types of cancer.

Autoimmune Diseases

Sometimes plasma B-cells produce antibodies to antigens that are on our own cells or autoantibodies, and this can be a component of various autoimmune diseases, such as:

• Rheumatoid arthritis
• Lupus
• Multiple sclerosis
• Type 1 diabetes

These are instances of the immune system attacking healthy tissues to produce a disease.

Cancers

B-cells may be malignantly transformed into B-cell cancers, such as:

• Chronic lymphocytic leukemia
• Acute lymphoblastic leukemia
• Lymphoma

The exact cell that becomes cancerous may be more mature or more immature. The cell that gives rise to cancer may be closer in form and function to an actual B-cell, versus more closely resembling an immature blood-forming cell that would eventually give rise to an adult B cell, if healthy.

Summary

B-cells are a type of white blood cell or lymphocyte. They help fight infection by producing antibodies when your immune system detects an antigen, such as a virus particle, bacteria, or something else that it recognizes as foreign.

B-cells can be either plasma cells or memory cells. Plasma cells produce antibodies in response to an infection. Memory cells are responsible for providing longer-term immunity to pathogens the immune system has encountered in the past.

Certain health conditions such as autoimmune diseases and some cancers can affect the way B-cells work.

By Indranil Mallick, MD
Indranil Mallick, MD, DNB, is a radiation oncologist with a special interest in lymphoma.