negative regulation of humoral immune response mediated by circulating immunoglobulin

Definition

Target type: biologicalprocess

Any process that stops, prevents, or reduces the frequency, rate, or extent of a humoral immune response mediated by circulating immunoglobulin. [GOC:add]

Negative regulation of humoral immune response mediated by circulating immunoglobulin is a complex process that involves the suppression of antibody production by B cells. Circulating immunoglobulins, primarily IgG, play a key role in this regulation through various mechanisms:

1. **Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC):** IgG antibodies bind to antigens on the surface of target cells, such as B cells, and recruit natural killer (NK) cells or other cytotoxic cells. These effector cells then release cytotoxic substances that kill the target B cells, leading to a decrease in antibody production.

2. **Complement Activation:** IgG antibodies can activate the complement system, a series of proteins in the blood that can lead to cell lysis and inflammation. Complement activation can directly kill B cells or enhance the killing of B cells by other immune cells.

3. **Fc Receptor-Mediated Signaling:** IgG antibodies can bind to Fc receptors on the surface of B cells, triggering intracellular signaling pathways that ultimately lead to suppression of B cell activation and antibody production. This can involve various mechanisms, including:
* **Induction of apoptosis:** Triggering programmed cell death in B cells.
* **Negative feedback loops:** Suppressing the expression of genes required for B cell activation and differentiation.
* **Cytokine production:** Inducing the production of cytokines that inhibit B cell function.

4. **Direct Inhibition of B Cell Activation:** IgG antibodies can directly bind to B cell receptors, preventing their activation by antigens and thus inhibiting antibody production.

5. **Immunological Tolerance:** Circulating IgG antibodies can help establish immunological tolerance by removing or suppressing B cells that are reactive to self-antigens. This prevents the development of autoimmune diseases.

The negative regulation of humoral immune response mediated by circulating immunoglobulin is essential for maintaining immune homeostasis and preventing excessive or inappropriate antibody production. It plays a critical role in controlling inflammation, preventing autoimmune diseases, and regulating the immune response to infections.'
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Compounds (20)