<<–2/”>a href=”https://exam.pscnotes.com/5653-2/”>p>T cells and B cells, their differences, similarities, and more:
Introduction
T cells and B cells are two crucial types of lymphocytes (white blood cells) that play pivotal roles in our adaptive immune system. This system allows our bodies to recognize and remember specific pathogens, mounting targeted responses upon re-exposure. While both cell types are vital for immunity, they have distinct functions and characteristics.
Key Differences Between T Cells and B Cells (Table Format)
| Feature | T Cells | B Cells |
|---|---|---|
| Primary Function | Cell-mediated immunity (directly kill infected or abnormal cells) | Humoral immunity (produce antibodies to neutralize pathogens) |
| Maturation Site | Thymus | Bone marrow |
| Receptor Type | T-cell receptor (TCR) | B-cell receptor (BCR) |
| Target Recognition | Recognize antigens presented on the surface of infected cells by MHC Molecules | Recognize free-floating antigens |
| Effector Mechanisms | Cytotoxic T cells kill infected cells, Helper T cells activate other immune cells | Plasma cells secrete antibodies, Memory B cells provide long-term immunity |
| Diversity | High diversity of TCRs | High diversity of BCRs (antibodies) |
| Lifespan | Relatively long-lived | Variable lifespan (plasma cells short-lived, memory B cells long-lived) |
Advantages and Disadvantages of T Cells
- Advantages:
- Direct killing of infected or cancerous cells
- Regulation of the immune response
- Long-term memory of pathogens
- Disadvantages:
- Requires antigen presentation by MHC molecules
- Can be involved in autoimmune diseases
Advantages and Disadvantages of B Cells
- Advantages:
- Production of antibodies that can neutralize pathogens
- Long-term memory of pathogens
- Can provide passive immunity (through antibody transfer)
- Disadvantages:
- Limited to extracellular pathogens
- Antibody production can sometimes be misdirected (autoimmune diseases)
Similarities Between T Cells and B Cells
- Both originate from hematopoietic stem cells in the bone marrow.
- Both are lymphocytes, a type of white blood cell.
- Both are essential components of the adaptive immune system.
- Both possess highly diverse receptors (TCRs and BCRs) to recognize a wide range of antigens.
- Both can develop into memory cells, providing long-term immunity.
FAQs on T Cells and B Cells
What is the role of T cells in COVID-19 infection?
- T cells play a crucial role in fighting COVID-19 by directly killing infected cells and helping to coordinate the immune response.
Can B cells fight cancer?
- Yes, B cells can produce antibodies that target cancer cells. This is the basis for some cancer immunotherapies.
What happens when T cells or B cells malfunction?
- Malfunctions in T cells or B cells can lead to immunodeficiencies (weakened immune system) or autoimmune diseases (where the immune system attacks the body’s own Tissues).
Are T cells and B cells the only cells involved in the immune response?
- No, there are many other cells involved, including macrophages, dendritic cells, natural killer (NK) cells, and more. T cells and B cells are key players in the adaptive immune response.
Let me know if you’d like more details on any specific aspect!