Difference Between T Cells and B Cells

Introduction

The immune system protects the body from foreign substances which are harmful to the body. Bacteria, viruses, fungi, and toxins are included in the foreign substances. The immune system comprises an extensive network of cells, organs, proteins, and tissue present in the body. The immune system can be recognized and eliminated faulty cells. Sometimes immune system fails to fight against diseases. The immune system mainly consists of a range of components WBC, spleen, bone marrow, lymphatic system, thymus, tonsils, adrenals, and appendix.

T cells and B cells are two lymphocytes produced in lymphoid organs. The thymus gland and bone marrow are two organs of the primary lymphatic system. B cells are produced and mature in bone marrow while T cells are born in the bone marrow and migrated and mature in the thymus gland. In this tutorial, we will learn about T cells and B Cells in depth.

T cells

T cells are an important part of the immune system. T cells are one of the primary lymphocytes that fight with the antigen in the body. T cells are also known as T lymphocytes. T cells are borne in the bone marrow of the primary lymphoid organ and migrate and mature in the thymus gland.

These T cells are not activated till they find their own antigen. T cells start multiplication in the thymus and differentiate into helper, regulatory, cytotoxic, or memory T cells. These cells are sent to the lymphatic system or blood to circulate through it. Once it is stimulated by a specific antigen, cytokines which a chemical messenger secreted by helper T cells. The cytokines stimulate the differentiation of B cells into plasma cells. The immune reactions are controlled by regulatory T cells. Cytokines activated the cytotoxic T cells which destroy infected cells and cancer cells.

Characteristics of T cells

• T cells are borne in the bone marrow and migrate and mature in the thymus.

• Antibodies are not produced by T cells.

• It's responsible for self-medicated immunity.

• Its targets and destroys infected cells and cancer cells.

• Cytokines, a chemical messenger released by helper T cells regulate the immune system.

• Infected cells and other intercellular pathogens are directly destroyed by cytotoxic T cells.

• T cell receptors are not able to recognize the whole antigen so they react only to a small part of antigens.

• T cells are helper, regulatory, cytotoxic, or memory T cells.

Functions of T cells

• It directly kills the infected cells.

• It produces cytokines, a chemical messenger, and regulates the immune system.

• It also activates other immune systems.

B cells

In the adaptive immune system, B cells are one of the lymphocyte components. Its plays an important role in immunity. B cells are born and mature in the bone marrow which is a primary lymphoid organ. Each B cell possesses a single round nucleus. To prevent the entry of foreign substances, which causes harmful effects on the body, these B cells produce antibodies. B cells have B cell receptors (BCRs) on their surfaces that are used to bind to a specific protein.

The antigen is formed when B cells bind to the specific protein. They release antibodies that stick to the antigen and save the body from harmful foreign substances. To attract other immune cells B cells secrete cytokines. B cells identify the pathogen by the shape of the antigen present on the surface. The pieces of antigen which is present on the surface of the cells can be visible when the pathogen enters the body. The antigen and B cells are activated when they recognize the antigen.

Characteristics of B cells

• B cells are borne and mature in the bone marrow.

• Plasma cells are formed from most of the B cells. To some extent, B Cells formed memory cells.

• Plasma cells which are from B cells generate antibodies.

• With the help of T cells, B cells become generated.

• B cells are plasma cells, memory cells, and immunoglobulins.

Functions of B cells

• B cells produce antibodies to fight against pathogens.
• They can destroy the antibodies.
• To attract other immune cells B cells secrete cytokines

Similarities between T and B cells

Both T and B cells are lymphocytes, a type of white blood cell. They originated from the bone marrow of the primary lymphoid organ. T and B cells can recognize pathogens and are involved in the immune response.

Difference between T and B cells

T cells	B cells
T cells are born in the bone marrow and migrated and mature in the thymus.	B cells are produced and mature in bone marrow
Inside the lymph cells mature cells occur	Outside the lymph cells mature cells occur
TCR receptor is present.	BCR receptor is present
It identifies the antigen on the outside of the infected cells	It identifies the antigen on the surface of the bacteria, and virus.
Longer life span	Shorter life span
Move to the site of infection	Does not move to the site of infection
Four types of T-cells - helper, regulatory, cytotoxic, or memory T cells	Two types of B cells - helper and plasma cells.

Conclusion

T cells and B cells are two types of lymphocytes produced in the lymphoid organs. T cells are borne in the bone marrow and migrated and mature in the thymus. There are four types of T cells namely helper, regulatory, cytotoxic, or memory T cells, and have a longer life span. B cells are produced and mature in the bone marrow. There are two types of B cells plasma and helper cells with and short life span and short life span. Both T and B cells can recognize pathogens and are involved in the immune response.

FAQs

Q1. What is the thymus?

Ans. The thymus gland is present just above the upper chest and it's a small gland. In the thymus, the T cells mature in the thymus. Most of the T cells are produced by the thymus before birth.

Q2. What are cytotoxic T cells?

Ans. Its primary function is to destroy and kill the toxic pathogen. Once cytotoxic T cells recognize a pathogen their main aim is to remove the infected cells. The process by which they remove the virally infected cells is known as apoptosis.

Q3. What are antigens and antibodies?

Ans. The antigen is a germ or foreign substance that enters our body. The different antigens that can attract our body are viruses, allergens, toxins, bacteria, etc. While antibodies fight against various antigens and protect the body from diseases.

Q4. How T cells are activated?

Ans. T cells are activated when they find their own antigen. After finding a recognizable antigen-presenting cell (APC), the T cell gets a signal to mature. Once a cell gets all three types of signals it matures into effector cells. If they receive only one signal it is of no use.

Q5. What is the BCR receptor?

Ans. BCR receptor is also known as B cell receptor. It is a protein present on the surface of B cells. It acts as a defensive mechanism in the body. The main aim of the BCR receptor is to bind and destroy pathogens.