B Cell & T Cell
🧬 Functions of B Cells and T Cells
B cells and T cells are the two main types of lymphocytes involved in adaptive immunity, and they have distinct but complementary roles.
🔵 B Cells (Bone Marrow–derived)
Function | Explanation |
|---|---|
🧫 Antibody Production | Upon activation, B cells become plasma cells and produce antibodies specific to antigens. |
🧠Memory Formation | Some B cells become memory B cells that respond quickly upon re-exposure to the same antigen. |
🎯 Antigen Presentation | B cells can act as antigen-presenting cells (APCs) by displaying processed antigen on MHC II to helper T cells. |
🛡 Neutralization & Opsonization | Antibodies produced by B cells neutralize toxins, block viruses, and tag pathogens for destruction by phagocytes. |
🔴 T Cells (Thymus–derived)
T Cell Type | Function |
|---|---|
Helper T cells (CD4+) | - Activate B cells, cytotoxic T cells, and macrophages - Secrete cytokines to coordinate the immune response |
Cytotoxic T cells (CD8+) | - Kill virus-infected, cancerous, or damaged cells by inducing apoptosis using perforin and granzymes |
Regulatory T cells (Tregs) | - Suppress immune responses to prevent autoimmunity and maintain self-tolerance |
Memory T cells | - Persist long-term after infection and respond faster upon re-exposure to the same antigen |
🧠Summary:
Feature | B Cells | T Cells |
|---|---|---|
Main Role | Produce antibodies | Directly kill infected cells or help other immune cells |
Antigen Recognition | Bind free-floating antigens | Recognize antigens presented on MHC |
Immunity Type | Humoral immunity | Cell-mediated immunity |