Resp Immunology, Allergy, Host Defence Flashcards
What are the Lymph Nodes of the Lungs
- Pulmonary Lymph Nodes (in angles of bifurcation of lobar bronchi)
- Bronchopulmonary Hilar Lymph Nodes (in Lung Hilum)
- Tracheobronchial Lymph Nodes (above or below the trachial bifurcation)
- Paratracheal Lymph Nodes (each side of trachea)
What is BALT and what does it do?
- Additional lymphoid tissue
- Acquires antigens from airways & initiates local immune repsonses
What are some elements of the Innate Immune System?
- Epithelial barriers
- Phagocytes
- Dendritic Cells
- NK Cells
What are some elements of the Adaptive Immune System?
- B lymphocytes
- Antibodies
- T lymphocytes
- Effector T Cells
Why is the Lamina Propria important in Immunity?
Rich in:
- Plasma cells
- Effector T cells
- Macrophages
- Mast Cells
Describe Mucociliary Transport
= important defense mechanism to protect body against invading particles including bacteria
- Goblet cells secrete mucus
- Cilia stick out from laminal surface -> beat in asymmetric rhythm to move mucus
Function of Resp Epithelial Cells
- Express pattern recog receptors (like TLRs & NODs)
When activated: - secrete chemokines & cytokines -> recruit immune cells
- secrete antimicrobial compounds into lumen
How do Immune Cells regulate the function of the Epithelial Barrier?
- Immune cells in lamina propria and BALT secrete IL-22
- IL-22 promotes epithelial proliferation and barrier integrity
What are the 2 types of Lung Macrophages and what do they do?
Alveolar Macrophages:
- well positioned to phagocytose inhaled particles
Interstitial Macrophages:
- activated if barrier is breached
What is the action of Macrophages?
- Recognise pathogens through pattern recog receptors (Toll-like receptors - TLR-4, TLR-6, etc.// Mannose receptors, Scavenger receptors)
- Pattern recog leads to inflamm and leucocyte recruitment
- Vasodilation, increased permeability, heat and swelling
- Inflamm cells migrate into tissue releasing inflamm mediators causing pain
Where are Microfold (M) Cells and what do they do?
Where:
- line epithelium adjacent to the BALT
Function:
- M Cells transport antigen along basal surface to the APCs
What do Cytotoxic T cells do?
Kill virus-infected host cell
What do CD4+ T cells differentiate into?
- T helper cells
What do T helper cells do?
- Activate B cells to differentiate into plasma cells
What is IgA and the 2 types?
- Major immunoglobulin (Antibody) in the mucosal tract
- Serum IgA and Secretory IgA