Basics of Immunology Flashcards
Define immunology (2)
- A branch of biomedical sciences concerned with immunity or immune system
- Study of host defence against infection and disorders of the immune system
What are the organs that make up the immune system? (8)
- Bone marrow
- Spleen
- Thymus
- Tonsils
- Mucous membranes
- Skin
- Lymphatic vessels
- Lymph nodes
What are the 3 classes of immune cells? (and the names of each cell in each class)
- Lymphocytes (T-cells, B-cells, and NK cells)
- Granulocytes (neutrophils, eosinophils, and basophils)
- Monocytes/macrophages
What is innate immunity? (4)
- First line immune response (present at birth)
- Relying on mechanisms that exist before infections
- Rapid (within minutes) but non-specific
- Inflammation
What is acquired immunity? (3)
- Second line immune response
- T-cells and B-cells involved
- Developed from immunological memory
Innate immunity vs. acquired immunity. Which is adaptive, and which is non-adaptive?
Innate = non-adaptive
Acquired = adaptive
What are the cells that make up innate immunity? (7)
- Natural killers
- Dendritic cells
- Mast cells
- Neutrophils
- Basophils
- Eosinophils
- Macrophages
What do NK cells do?
Cytotoxic, kill infected cells and cancer cells
What do dendritic cells do?
Antigen-presenting, important to acquired immunity
What do mast cells do?
Rich in histamine and heparin, possess antibacterial and antiparasitic functions
What do neutrophils do?
Patrol for microbial infections and one of the first responders to the site of inflammation
What do basophils do?
Fight parasite infections and mediate allergic reactions
What do eosinophils do?
Possess antibacterial and antiparasitic functions
What do macrophages do?
Phagocytosis and present antigens along with dendritic cells
What are the pattern recognition receptors in innate immune response? (5)
- Toll-like receptors (TLRs)
- NOD-like receptors (NLRs)
- C-type lectin receptors (CLRs)
- RIG-1 like receptors (RLRs)
- AIM2-like receptors (ALRs)
What are damage-associated molecular patterns (DAMPs)? (2)
- Endogenous molecules released from damaged and dying cells during infection and inflammation, such as high mobility group box 1 protein (HMGB1) and heat shock proteins (HLPs)
- Interacting with pattern recognition receptors (PRRs)
The innate immune system can detect missing-self (mainly via NK cells). What does that mean? (2)
- Recognizing molecules expressed in healthy cells but not in infected cells/pathogens
- Inhibiting innate immune response against host cells/tissues
MHC is essential for ________ _________
acquired immunity
Where are MHC class I molecules found?
What do they do?
- Identified in all nucleated cells
- Present normal self-antigens and foreign pathogen antigens to cytotoxic T cells
Where are MHC class II molecules found?
What do they do?
- Identified in macrophages, dendritic cells and B cells
- Present foreign pathogen antigens to helper T cells
Acquired immunity - What is cell mediated immunity? (4)
- Antigen-specific cytotoxic T-cells
- Release cytokines in response to the antigen
- Do not involve antibodies
- Kill infected cells
Acquired immunity - What is humoral immunity? (4)
- B-cells
- Mediated by secreted antibodies
- Attack and neutralize antigens (such as microbes) outside cells
- Prevent microbial penetration into body cells
Describe the process of T-cell maturation (4)
- Bone marrow: hematopoietic stem cells → lymphoid progenitor cells (migrate to the thymus)
- Thymus: lymphoid progenitor cells → functional T-cells with specific markers (such as TCR, CD4 and CD8)
- CD4+ T-cells: helper T-cells, secrete cytokines to stimulate the differentiation of B cells into plasma cells
- CD8+ T-cells: cytotoxic T-cells, bind and kill infected cells and cancer cells
What activates cytotoxic T-cells?
Activated by simultaneous interactions of surface molecules between cytotoxic T cell and antigen-presenting cell (APC) → T cell proliferation
