The immunity induced in an organism by the exposure of a foreign antigen is called Active Immunity. The active immunity is mediated through two distinct mechanisms, and they are named as (1) Cell-mediated immunity and
(2) Humoral immunity. These two immune pathways show considerable differences in their components, their targets, and the method of killing of pathogens. Cell-mediated immunity: The cell-mediated immunity is facilitated by the activated TH cells (T-Helper cells) and Cytotoxic T Lymphocytes (CTLs). Cytokines secreted by the TH cells activate the phagocytic cells. These activated phagocytic cells then phagocytosis and kill the
microbes. The cell-mediated immunity is particularly important against the bacterial and protozoan pathogens. Humoral Immunity (antibody-mediated immunity): The Humoral immunity is mediated through antibodies. Antibodies are produced by the B cells. These antibodies bound to specific microbial antigens. Binding of antibodies to antigens neutralize the microbes and target them for elimination by various effector mechanisms. The humoral
immunity is the major defense mechanism against the extracellular microbes trying to invade the host systems.Cell-mediated vs Humoral Immunity
(Similarities and Differences between Cell-Mediated and Humoral Immunity)
The present post discusses the Similarities and Differences between Cell-mediated and Humoral Immune Systems with a Comparison Table.
Similarities between Cell-mediated and Humoral Immunity
Ø Both the cell-mediated and humoral immune systems are active
immunities.
Ø Both the systems are effective against a wide variety of microbial pathogens.
Ø In both cases, there will be a lag period.
Ø Immunological memory is present in both the systems.
Ø Both the systems are ineffective in immune deficient individuals.
Sl. No.Cell-mediated ImmunityHumoral-Immunity 1
The cell-mediated immune response is mediated by T-cells.
The humoral immune response is mediated by antibodies (produced by B-cells).
2
Antibodies are not formed in cell-mediated immune response.
Antibodies are formed in humoral immune response.
3
Receptors are used in cell-mediated immunity to detect antigens.
Antibodies are used in humoral immunity to detect antigens.
4
T-cell receptors binds to the T-cells and then the T-cell themselves binds to the antigen.
Here the B-cells produce antibodies and the antibodies bind to the antigen.
5
It protect against fungi, virus and intracellular bacterial pathogens.
It protect against extracellular bacterial and viral pathogens.
6
Cells involved in cell-mediated immunity: Macrophage, Helper T cells, Natural killer T cells and Cytotoxic T cells.
Cells involved in humoral immunity: T-Lymphocytes, B-Lymphocytes and Macrophages.
7
Cell-mediated immunity mediates delayed hypersensitivity (type IV).
Humoral immunity mediates immediate hypersensitivity (type I, II and III)
8
Cell-mediated immune response provides the immunological surveillance.
Humoral immunity does not provide immunological surveillance.
9
It can eliminate tumor cells and thus can provide immunity against cancer
It cannot eliminate tumor cells.
10
Cell-mediated immune response also participates in the rejection of organ transplants.
Humoral immunity may be involved in the early graft rejection due to pre-formed antibodies.
11
Only the T cell dependent antigens led to cell mediated immunity.
In humoral immunity response, the B cells directly bind to soluble antigen and results in the antibody production.
12
Both CD4+ and CD8+ T cells are involved in cell mediated immune response.
Only TH cells are involved in humoral immune response.
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