Immunology: Cytokines and Acute Phase Reactants immuno

These flashcards cover key concepts regarding cytokines and acute phase reactants relevant to immunology, facilitating exam preparation.

What are cytokines?

Small proteins secreted by cells that act as chemical messengers to regulate immunity, inflammation, and blood cell formation.

Define chemokines.

A subclass of cytokines that specifically induce chemotaxis— the directed movement of immune cells toward the site of infection or inflammation.

What is a chemotaxin?

Any chemical substance that attracts cells, especially leukocytes, to the site of infection or tissue injury.

What is the role of Tumor Necrosis Factor (TNF)?

TNF is a cytokine involved in systemic inflammation that mediates inflammation, induces fever, promotes cell death, and stimulates the release of other cytokines.

What are interferons (IFNs) and their main function?

Group of cytokines produced by virus-infected cells that protect neighboring cells from viral infection and modulate immune responses.

What are interleukins (ILs)?

A large group of cytokines that mediate communication between leukocytes and regulate cell growth, differentiation, and immune activation.

What are positive acute phase reactants (APRs)?

Plasma proteins whose concentrations increase during inflammation; produced mainly by the liver in response to cytokines.

List three examples of positive Acute Phase Reactants.

C-Reactive Protein (CRP), Haptoglobin, Ceruloplasmin.

What is C-Reactive Protein (CRP) and its function?

A positive acute phase reactant that binds to dead or dying cells and certain bacteria, activating the complement system and promoting phagocytosis.

What is the function of Interleukin-1 (IL-1)?

Promotes inflammation and fever.

What role does Haptoglobin play during inflammation?

It binds free hemoglobin released from red blood cells to prevent oxidative damage and conserve iron.

What is the significance of Procalcitonin (PCT)?

A biomarker that rises during systemic bacterial infections and is used clinically for sepsis and severe bacterial inflammation.

What functions does Interleukin-10 (IL-10) have?

It is anti-inflammatory and suppresses immune responses.

Describe two functions of Tumor Necrosis Factor (TNF).

Mediates inflammation and immune responses; induces fever by acting on the hypothalamus.

What is the function of Interferon-gamma (IFN-γ)?

Promotes immune modulation and macrophage activation.

What is the role of Interleukin-6 (IL-6)?

Stimulates acute phase protein production by the liver.

What distinguishes IL-4 among interleukins?

It promotes antibody production, particularly IgE.

How do Interferons inhibit viral replication?

They induce antiviral proteins in neighboring cells.

What is the primary purpose of Interleukin-2 (IL-2)?

Stimulates T-cell proliferation.

What are the types of interferons and their roles?

IFN-α and IFN-β: antiviral responses; IFN-γ: immune modulation and macrophage activation.