Definition

Noun: A lymphokine is a type of cytokine, which is a signaling protein, that is secreted by a specific type of white blood cell called a helper T cell. This secretion occurs in response to stimulation by antigens (foreign substances). The primary function of a lymphokine is to act as a chemical messenger, influencing and regulating the activity of other cells within the immune system, such as by activating macrophages to destroy pathogens.

Usage Examples

• The lymphokine interleukin-2 is crucial for the proliferation of T cells.
• Researchers are studying how specific lymphokines modulate the inflammatory response.
• The activation of macrophages is a key effect of this particular lymphokine.

Advanced Usage

• In immunology, the term lymphokine is often used in contrast to "monokine" (a cytokine produced by monocytes or macrophages). Together, they were historically classified under the broader term "cytokine," which is now the more common and inclusive term.
• The discovery of lymphokines was fundamental to understanding cell-mediated immunity.

Variants and Related Words

• Cytokine (n): The broader category of small proteins released by cells, especially those of the immune system, that have a specific effect on the interactions and communications between cells. All lymphokines are cytokines, but not all cytokines are lymphokines.
• Interleukin (n): A major group of lymphokines; they are cytokines that signal between white blood cells (leukocytes).
• Chemokine (n): A subclass of cytokines with chemotactic properties, meaning they direct the movement of immune cells toward sites of infection or inflammation.

Synonyms

• Immune mediator
• Signaling molecule (in an immunological context)

Related Phrases and Concepts

• Lymphokine-activated killer (LAK) cell: A white blood cell that has been stimulated and turned into a tumor-killing cell by exposure to lymphokines, particularly interleukin-2.
• Lymphokine release: The process by which helper T cells secrete these proteins upon antigen recognition.

Noun

1. a cytokine secreted by helper T cells in response to stimulation by antigens and that acts on other cells of the immune system (as by activating macrophages)