The main difference between antibody-mediated immunity and cell-mediated immunity is that antibody-mediated immunity produces antigen-specific antibodies, while cell-mediated immunity does not produce antibodies.
Antibody-mediated immunity and cell-mediated immunity are two types of adaptive immunity. Adaptive immunity is the process of eliminating pathogens and preventing their growth by involving specialized cells and antibodies in the immune system.
Key Areas Covered
1. What is Antibody-Mediated Immunity
– Definition, Features, Importance
2. What is Cell-Mediated Immunity
– Definition, Features, Importance
3. Similarities Between Antibody-Mediated Immunity and Cell Mediated Immunity
– Outline of Common Features
4. Difference Between Antibody-Mediated Immunity and Cell Mediated Immunity
– Comparison of Key Differences
Key Terms
Antibody-Mediated Immunity, Cell-Mediated Immunity
What is Antibody-Mediated Immunity
Antibody-mediated immunity or humoral immunity is the adaptive immunity in which the body responds to a pathogen by forming antibodies. B cells are the type of cells responsible for the formation of antibodies. Notably, the three processes of antibody-mediated immunity are the activation and differentiation of B cells, antibody production, and the generation of primary and secondary immune responses. However, antibody-mediated immunity is essential for acting against pathogens that grow in extracellular spaces.
Figure 1: Antibody-Mediated Immunity
Furthermore, antibodies destroy pathogens in three ways. They bind to the specific molecules on the pathogen’s surface, neutralizing the pathogen. This neutralization prevents the entry of the pathogen into the cells. It is also vital to prevent bacterial toxins. The antibody-caught pathogens are subjected to phagocytosis by macrophages and other cells. This process is called opsonization. The binding of antibodies to the pathogens activates the complement system. The complement proteins bind to the antibody-bound pathogens and recruit phagocytic cells.
What is Cell-Mediated Immunity
Cell-mediated immunity is the other type of adaptive immunity that produces mature T cells, macrophages, and the production of cytokines against pathogens. Also, the two types of cells involved in cell-mediated immunity are helper T cells and cytotoxic T cells. The three steps in cell-mediated immunity are the activation of T cells by displaying antigens with MHC complexes, T cell binding and activation, and the differentiation of the activated T cells into effector cells and memory T cells.
Figure 2: Cell-Mediated Immunity
Moreover, T cells are produced in the bone marrow and undergo maturation in the thymus. After they enter the bloodstream, T cells occur in the blood and lymphoid tissue. Antigens are presented by antigen-presenting cells (APCs) to the T cells along with the major histocompatibility complexes (MHC). Once T cells encounter an antigen, they proliferate and differentiate into armed effector cells. The cytotoxic T cells destroy the infected cells by inducing apoptosis. T helper cells stimulate plasma B cells to produce antibodies.
Also, IgG and IgM are the two main types of antibodies produced by T helper cells in response to plasma B cells. The memory T cells are differentiated T cells, but their action requires activation by the specific antigen. The prominent feature of cell-mediated immunity is that it destroys intracellular pathogens.
Similarities Between Antibody-Mediated Immunity and Cell Mediated Immunity
- Antibody-mediated immunity and cell-mediated immunity are two types of adaptive immunity.
- They produce specific immune responses against pathogens.
- They use specialized cells and antibodies to attack pathogens and prevent their growth.
Difference Between Antibody-Mediated Immunity and Cell Mediated Immunity
Definition
Antibody-mediated immunity refers to immunity conferred to an individual through the activity of B cells and their progeny, which produce circulating antibodies in response to the presence of a foreign substance and recognize the substance upon renewed exposure. In contrast, cell-mediated immunity refers to immunity independent of antibodies but dependent on the recognition of antigen by T cells and their subsequent destruction of cells bearing the antigen or on the secretion by T cells of lymphokines that enhance the ability of phagocytes to eliminate the antigen.
Type of Cells
Antibody-mediated immunity mediates through B cells, while cell-mediated immunity mediates through T cells.
Process
Antibody-mediated immunity operates through the formation of antibodies, while cell-mediated immunity operates through antigen presentation to T cells.
Type of Pathogens
Antibody-mediated immunity acts against pathogens that invade body fluids, while cell-mediated immunity acts against pathogens that invade body cells.
Importance
Antibody-mediated immunity hardly operates on transplants, while cell-mediated immunity operates against cancer cells.
Conclusion
In brief, antibody-mediated immunity and cell-mediated immunity are two types of adaptive immunity that generate specific immune responses against pathogens. Antibody-mediated immunity mediates through B cells through the formation of antibodies. Also, it acts against pathogens that invade body fluids. Additionally, it works on transplants. In comparison, cell-mediated immunity mediates through T cells. Also, it operates through the presentation of antigens to T cells. Importantly, it acts against pathogens invading body cells. Additionally, it operates against cancer. Therefore, the main difference between antibody-mediated and cell-mediated immunity is the type of cells and response in each immunity.
References:
- Henderson, E. (2022, January 7). Humoral vs cell-mediated immunity. News. https://www.news-medical.net/health/Humoral-vs-Cell-mediated-Immunity.aspx
Image Courtesy:
- “Antibodies” By AaronMatthewWhite – Own work (CC-BY SA 3.0) via Commons Wikimedia
- “TransferFactors” By AaronMatthewWhite – Own Work (CC-BY SA 3.0) via Commons Wikimedia
Leave a Reply