The immune alert system of human bodies usually goes off after invasion by bacteria, viruses, and parasites. The cellular activity in the immune system set-off a chain reaction.
The macrophages are deployed to help in attacking the pathogens. Examples of these macrophages are basophils and dendritic cells or neutrophils.
Sometimes the body becomes overwhelmed with these invaders. These macrophages turn into T cells and B cells that learn particular foreign threats and attack them.
So, what is the main difference between T cells and B cells? The T cells can only recognize the viral antigens outside the infected cell while B cells can recognize the surface of both bacteria and viruses.
This article provides further explanation of the differences between T cells and B cells. Take the time to read through it and learn more about their similarities.
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Comparison Table (T Cells Vs B Cells)
|Basic Terms||T Cells||B Cells|
|Description||These are lymphocyte types developed in the thymus to mediate immune response against infected cells in the body.||These are lymphocyte types developed in the bone marrow to recognize a specific pathogen in the body.|
|Position||Occur inside the lymph nodes||Occur outside the lymph nodes|
|Membrane Receptor||Bear TCR receptor||Bear BCR receptor|
|Recognition of Antigens||Recognize viral antigens from the outside of the infected cells.||Recognize antigens on the surface of bacteria and viruses.|
|Distribution||Occur in the parafollicular areas of the lymph nodes and the periarteriolar lymphoid sheath of the spleen.||Occur in the germinal centers, subcapsular and medullary cords of lymph nodes, spleen, gut, and respiratory tract.|
|Surface Antibodies||Lack surface antigens||Have surface antigens|
|Secretion||Secreted by lymphokines||Secreted by antibodies|
|Type of Immunity||Cell-mediated immunity||Antibody-mediated immunity|
|Proportions in the Blood||80%||20%|
|Types||Helper T cells
Cytotoxic T cells
|The movement to the Infected Site||Move to the site of infection||Do not move to the infection site|
|Tumor Cells and Transplants||Act against tumor cells and transplant||Do not act against tumor cells and transplant.|
|Inhibitory Effect||Suppressor T cells have an inhibitory effect on the immune system||Do not have an inhibitory effect on the immune system|
|Defend against||Pathogens such as viruses, fungi, and protists enter the body.||Both bacteria and viruses in the bloodstream or lymph.|
|Blast Formation||Can be seen after treatment of mitogens such as Concanavalin A.||Can be seen after the interaction with bacterial endotoxin and Epstein-Barr virus.|
|Receptors for the C3 complement||Absent||Present|
|IgM||Absent on the surface||Present on the surface|
|Observation under an electron microscope||No display of cytoplasmic projections.||Display smooth and microvilli|
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What Are T Cells?
T cells are types of lymphocytes that originate from the Thymus. These cells are also known as T lymphocytes that are produced in the bone marrow and migrate to the thymus for maturity.
T cells are further differentiated into helper T cells, cytotoxic T cells, and suppressor T cells. The helper T cells are responsible for recognizing antigens and activating both B cells and Cytotoxic T cells.
The B cells secrete antibodies and cytotoxic T cells destroy the infected cells through apoptosis. The suppresser T Cells modulate the immune system to withstand self-antigens and prevent autoimmune diseases.
Both cytotoxic and helper T cells are known for identifying various antigens in the circulatory system. These antigens usually present themselves on the surface of the APS.
Examples of APS cells are Macrophages, dendritic cells, Langerhans cells, and B cells. These cells later phagocytize pathogens and present the epitopes on their surfaces.
Major histocompatibility complexes (MHC) are the crucial molecules that present in the epitopes on the surface of the APS cells. The molecule is classified into class 1 and class 2.
The MHC class 1 occurs on the surface of cytotoxic T cells and class 2 on the surface of helper T cells. The T cell receptors later bond the T cells with MHC molecules on the APS cells.
The CD4 and CD8 coreceptors are also identified to stabilize the binding. The CD4 coreceptors occur on the helper T cells and CD8 coreceptors occur on the cytotoxic T cells.
The CD3 coreceptors are responsible for transmitting to the cell about the binding of the MHC complex to the T cells. It occurs on the surface of the cytotoxic T cells.
The immunity stimulated by the T cells is usually antigen specificity. Cell-mediated immunity is the type of immunity triggered by T cells.
What Are B Cells?
B cells are types of lymphocytes that are developed in the bone marrow. These cells are also known as B lymphocytes that enhance antibody-mediated immunity.
B cells are responsible for producing antigen-specific antibodies. The immunoglobulin ends up invading the pathogen. The B cells bind with the antigen in the circulation through B cell receptors.
The B cells undergo differentiation during the binding process to release antibody-producing plasma and memory cells.
Some antigens might require helper T cell participation with the plasma cells to produce antibodies. These T-dependent antigens bind with helper T cells to stimulate the production of antibodies.
The antibodies produced by the T-dependent antigens have high affinity while the T-independent antigens have low affinity. The T-independent antigens produce IgG and IgM antibodies.
Keep in mind that the immunoglobulin in the T-dependent agent circulation is more specific when it comes to offering both primary and secondary immune responses.
The naïve B cells provide primary immune responses and memory B cells offer secondary immune responses. B cells offer protection against antigens.
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Main Differences between T Cells and B Cells
- T cells originate from the thymus. B cells originate from bone marrow.
- T cells occur, insider, the lymph nodes. B cells occur outside the lymph nodes.
- T cells bear TCR. B cells bear BCR.
- T cells have a longer lifespan. B cells have a shorter lifespan.
- B cells have surface antigens. T cells lack surface antigens.
- T cells involved in cell-mediated immunity. B cells involve antibody-mediated immunity.
- T cells move to the site of infection. B cells do not move to the site of infection.
Similarities between T Cells and B Cells
- Both originate from the bone marrow.
- Both are types of lymphocytes.
- Both occur in the blood.
- Both are subdivisions of white blood cells.
- Both occur in the lymphatic system.
- Both entail adaptative immunity.
- Both can recognize various pathogenic antigens
- Both are motile and nucleated cells.
- Both are nonphagocytic cells.
Understanding how T cells and B cells work is quite important. It is another way of telling the differences between T cells and B cells. These cells are responsible for improving the immune system by attacking pathogens.
The main difference between T cells and B cells is based on the region of development. T cells originate in the bone marrow and migrate to the thymus for maturation. B cells are developed in the bone marrow.
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