Difference between Humoral and Cell-Mediated Immunity

Humoral immunity and cell-mediated immunity is a part of active immunity. They are the mechanisms which protect our body against diseases when our innate immune system fails. As a part of active immunity, they take place after a couple of days the infection starts. 

The Functions Include:

• Recognition of specific non-self-antigens and presence of self-antigens.

• Generate responses to eliminate specific pathogens or pathogen-infected cells.

• Development of immunological cells.

In this topic, we will further discuss humoral immunity and cell-mediated immunity

and their differences. 

What is Humoral Immunity?

Humoral immune activity is one of the mechanisms of the active immune system and is  associated with circulating antibodies in contrast to cellular immunity. The wide range antibody activities is a response to rapid production of antigen-specific B cells during infections which increases antibody titres with enhanced affinity for the inciting agent and more directed and effective response.

What is Cell-Mediated Immunity?

Cell-mediated immunity is a type of adaptive immune response that does not involve antibodies but it does involve the activation of NK cell and macrophages and the production of antigen-specific cytotoxic T-lymphocytes and the release of several cytokines in response to a foreign antigen. Cell-mediated immunity plays an important role in controlling viral, chlamydia, rickettsia and protozoan infections such as trypanosomes as antibodies cannot penetrate and attack intracellular pathogens which multiply within the host cells.

 Humoral and Cell-Mediated Immune Response

The humoral immune system starts with the production of proactive antibodies against infection or reinfection by common microorganisms such as staphylococci and streptococci. B- Lymphocytes, which have specific antigen receptors react when they come to contact with the specific antigen by producing plasma cells. These plasma cells produce antigen-specific antibodies and memory cells which enable the body to rapidly produce antibodies if the same antigen appears later. The differentiation of B-cells is stimulated by interleukin-2 (IL-2) which is secreted by CD4+ T cells and foreign antigens processed by macrophages.

Antibodies which are produced by plasma B-cells are found mainly in the blood spleen and lymph nodes and they eliminate antigens in several ways. Some of them are, by activating the complement system and neutralizing viruses and bacterial toxins. Another method is by coating the antigen by opsonization or forming an antigen-antibody complex to stimulate phagocytosis which promotes antigen clumping and prevents antigens from attaching to host cells.

The mechanism of cell-mediated immunity takes a different approach than humoral immunity. This mechanism protects the body through the following activities:

• The response starts by activating antigen-specific cytotoxic T-lymphocytes or CTLs which can destroy body cells which show epitopes of foreign antigen on their surfaces such as cells with intracellular bacteria, cancer cells which show tumor antigens and virus-infected cells.

• It also activates NK cells and macrophages which enable them to destroy intracellular pathogens.

• The response stimulates the cells to produce a wide range of cytokines that regulates the function of other cells involved in adaptive immune responses and innate immune responses.

Cell-mediated immunity is directed primarily towards microbes which survive phagocytes and microbes that infect non-phagocytic cells. It also plays a major role in delayed transplant rejection. 

Difference between Humoral Immunity and Cell-Mediated Immunity

There are various differences between humoral immunity and cell-mediated immunity

and we will discuss them below.

Cell-Mediated Immunity vs Humoral Immunity

Similarities Humoral and Cell-Mediated Immunity

The similarities between humoral and cell-mediated immunity are:

• Both types of immunity systems are active immunities and have a lag period

• Both humoral and cell-mediated are active against several types of pathogens.

• Both immunity systems are not effective in immune-deficient individuals.

Humoral and Cell-Mediated Immunity: What's the Difference?

Active immunity is the immunity instilled in organisms as a result of antigen exposure. It's controlled by two distinct mechanisms:

• Immunity mediated by cells

• Immunity against Humoral Infection.

Both immune routes attack pathogens in distinct ways, with different targets, components, and methods of killing them.

Continue reading to learn more about humoral and cell-mediated immunity, as well as the differences between the two.

Humoral Immunity vs Cell-mediated Immunity

In the table below, the distinction between humoral and cell-mediated immunity is shown.

Immunity against Humoral Infection

Antibodies play a role in humoral immunity. It demonstrates a rapid response to infections. It's the first line of defense against extracellular microbes trying to get into the host's system. B-cells create antibodies that bind to antigens and neutralize bacteria.

The Immunity that is mediated by cells

T-helper and cytotoxic T-cells have a role in cell-mediated immunity. T-helper cells release cytokines that activate phagocytic cells, which phagocytose and destroy infections.

Similarities between Humoral Immunity and Cell-mediated Immunity

The parallels between cell-mediated and humoral immunity are as follows:

• Immunity mediated by humor and immunity mediated by cells are both active immunities.

• Both have a time lag.

• Both have antibacterial capabilities and can be used to treat a variety of infections.

•  In both of them, immunological memories are present.

•  In immune-compromised patients, both systems are ineffectual.

There are a few distinctions between humoral and cell-mediated immune responses. Continue to visit Vedantu's website to learn more about the differences between humoral and cell-mediated immunity.