Respiratory Immunology Quiz

Immunological Processes in the Respiratory Tract

• Epithelial cells form a tight barrier with intercellular junctions, including tight and adherens junctions, and have specialized functions such as ciliary movement, mucin secretion, and secretion of surfactant proteins.
• Resident macrophages in the lungs recognize and dispose of inhaled microbes, phagocytose, present antigens, and produce cytokines, playing a major role in maintaining lung homeostasis.
• Dendritic cells in the respiratory tract sample the lung environment and, upon antigen recognition, migrate to draining lymph nodes to present antigens to naïve T cells.
• The innate immune response involves the recruitment of immune cells and activation of the adaptive immune response through the recognition of microbial pathogens and damaged host cells by pattern recognition receptors (PRRs).
• The nasal-associated lymphoid tissue (NALT) contains immune cells that recognize antigens and induce immune responses, leading to the activation of memory cells and antibody production.
• The effector functions of antibodies, including IgA, IgG, and IgM, involve opsonization, antibody-dependent cell-mediated cytotoxicity, complement activation, neutralization, and transport across epithelium.
• Selective IgA deficiency (SIgAD) is a primary humoral immunodeficiency characterized by low IgA levels and is associated with respiratory tract infections, GI infections, and autoimmune diseases.
• IgA and IgM are transported across mucosal epithelial surfaces through transcytosis mediated by the poly-Ig receptor (pIgR) and the J chain.
• The germinal center reaction involves the formation of secondary follicles with dark and light zones, where B cells undergo somatic hypermutation and affinity maturation, and interact with follicular dendritic cells and Tfh cells to induce class switching and differentiation.
• The lecture outline covers pre-lecture clicker questions, objectives, immune tissue of the respiratory tract, innate and adaptive immune responses, post-lecture clicker questions, and sample questions.
• The text references sources such as "Murray and Nadel's Textbook of Respiratory Medicine" and "Principles of Mucosal Immunology" for detailed information on respiratory immunology.
• The content provides a comprehensive understanding of the immunological processes in the respiratory tract, including the innate and adaptive immune responses, effector functions of antibodies, and specific immunodeficiencies.