What are B cells?
B cells are a type of lymphocyte that are responsible for the humoral immunity component of the adaptive immune system. These white blood cells produce antibodies, which play a key part in immunity. Each B cell contains a single round nucleus.
Lymphocytes account for about 25% of white blood cells, and B cells represent approximately 10% of total lymphocytes.
Introducing Next-Gen Cell Separation with Akadeum’s Microbubbles: Fast, Easy, and Gentle Cell Enrichment
Where do B cells originate? Where do B cells mature?
B cells both originate from and mature in the bone marrow, which is the soft fatty tissue inside bones.
How Do B Cells Function?
B cells produce antibodies, or Y-shaped chromosomes that are created by the immune system to stop foreign substances from harming the body. B cells have B cell receptors (BCRs) on their surface, which they use to bind to a specific protein.
Once the B cells bind to this protein, called an antigen, they release antibodies that stick to the antigen and prevent it from harming the body. Then, the B cells secrete cytokines to attract other immune cells. They also present the antigens to T cells, which they recognize using their T cell receptors (TCRs). The T cells destroy the antigens.
How are B cells activated?
When infectious agents, such as bacteria, enter the body, pieces of their machinery can be visible on the surface of their cells. These pieces are called antigens, and B cells activate when they encounter and recognize antigens.
B cells have B cell receptors (BCRs) on their surface, and these BCRs bind to specific antigens. Once the cell binds to the antigens, activation begins.
Using Akadeum’s microbubble-based enrichment allows for a highly purified population of B cells to be obtained, while BCR percentages remain similar to starting material. The isolation protocol does not disturb these receptors or skew the isolated population.
How do B cells recognize antigens?
B cells recognize infectious agents by the shape of the antigens on their surfaces. The cells descended from a single B cell produce the same antibodies and remember the invader and antigens that led to their formation. This memory means that B cells produce the antibodies that counteracted the original antigen, protecting the immune system from a second attack.
Using Akadeum’s microbubble-based enrichment maintains B cell function, and the isolated B cells retain their antigen-presenting capacity. For more information, you can read the Researcher Spotlight:
What is B cell isolation?
B cell isolation is the separation of B cells from other cell populations. B cells are identified by their surface markers, CD19 and CD20.
Activated B cells become plasma cells and produce large amounts of antibodies. These activated B cells can be identified using the CD138 marker.
Using Akadeum’s microbubble-based enrichment demonstrates that B cells were not artificially activated by Akadeum isolation and maintained their capacity for plasma cell differentiation as shown by CD138 induction. For more information, you can read the Researcher Spotlight:
What are the methods of B cell isolation?
There are a few different approaches to B cell isolation.
One method is selection. Positive selection is when B cells are targeted by the removal mechanism and retained for downstream analysis. On the other hand, negative selection is when other cell types are removed to leave the B cells untouched. Our Human B Cell Isolation Kit harnesses negative selection to provide high purity cell samples.
For more information on these selection methods, read our article on Positive Selection vs. Negative Selection.
B cell depletion is another approach, where a single cell type—in this case, B cells—is removed from a biological sample.
What is the difference between B cells and T cells?
There are two types of lymphocytes: B cells and T cells. They are both critical parts of the immune response and are interconnected, because T cells are required to activate B cells.
While both B cells and T cells are involved in triggering the immune response, the main difference between the two is that T cells can only recognize viral antigens on the outside of infected cells and B cells can only identify the surface antigens of the infectious agents themselves.
The same cell isolation methods used for T cell isolation can be used for B cell isolation.
What diseases affect B cells?
An unusually high B cell count can indicate several issues in the human body:
- Multiple myeloma
- DiGeorge syndrome
- Chronic lymphocytic leukemia
- Blood cancer
A low B cell count could be a sign of acute lymphoblastic leukemia or a disease that weakens the immune system, such as HIV. Additionally, lymphocytopenia (also known as lymphopenia) can be caused by a low lymphocyte count.
Is it possible to isolate DNA from B cells?
Yes. DNA is encased in the nucleus of cells, and B cells have nuclei.
How do I enrich my mouse splenocyte sample for B cells?
Analysis of B cell function and regulation requires a highly purified population of unaltered B cells, but traditional separation technologies like magnetic bead-based sorting can be harsh on cells and ultimately produce less-than desirable results. Red blood cells can also negatively affect the purity of a sample.
Buoyancy-Activated Cell Sorting (BACS) microbubble technology from Akadeum is a truly novel, non-invasive method for capturing unaltered cells in their natural physiological state.
Download this app note to see how researchers in laboratories across the country have used Akadeum’s Mouse B Cell Isolation Kit to investigate critical aspects of B cell biology, including the distribution of B cell receptors (BCRs), the antigen-presenting capacity of B cells, and the differentiation potential of B cells following enrichment.