BIOL 5500 – Immunology Exam 1 Study Guide | Key Immune Cell Functions (Eosinophils, Basophils & More) | Verified Notes 2025

Immunology Exam 1 - BIOL 5500 Functions of Key Immune Cells Eosinophils: These cells play a crucial role in combating multicellular parasites, particularly helminths. Additionally, they contribute to immune responses associated with allergies. Basophils: Their primary function is to serve as major mediators in carrying out allergic reactions, releasing histamine and other inflammatory substances. Mast Cells: Like basophils, mast cells are involved in allergic responses and inflammation, helping to trigger immune reactions upon encountering allergens. Granulocytes and Their Roles Similarities Between Granulocytes: Among the granulocytes, basophils and mast cells share the most similarities in function, both contributing to allergic and inflammatory responses. Neutrophils: These are the most abundant granulocytes in circulation and play essential roles in: Migration to infection sites Phagocytosis (engulfing pathogens) Initiating the respiratory burst to kill microbes Neutrophil-Related Disorders Chronic Granulomatous Disease (CGD): This condition occurs when neutrophils have defects in NADPH oxidase, impairing their ability to generate reactive oxygen species and kill pathogens effectively. Leukocyte Adhesion Deficiency (LAD): This disorder arises when neutrophils lack adhesion molecules necessary for migration, preventing them from reaching infection sites. Chediak-Higashi Syndrome: A condition where neutrophils exhibit defects in phagocytosis and granule function, leading to impaired immune responses. Neutrophil Migration Process The movement of neutrophils from the bloodstream to infection sites involves several key steps: 1. Rolling: Neutrophils slow down by transiently interacting with endothelial cells. 2. Integrin Activation: Signals activate integrins, strengthening the bond between neutrophils and endothelial cells. 3. Stable Adhesion: Neutrophils firmly adhere to the endothelial layer. 4. Migration Through Endothelium: They move through the vessel wall to reach the infected tissue. Understanding these immune cell functions and disorders is fundamental for grasping immunological responses and disease mechanisms.