Introduction to Immunology Flashcards
What are 3 types of cells involved in innate immunity?
- neutrophils
- macrophages
- Natural Killer (NK) cells
What are 3 types of soluble factors involved in innate immunity?
- Acute-phase proteins
- Cytokines
- Complement
What are 5 cell types involved in acquired immunity?
- T lymphocytes
- B lymphocytes
- dendritic cells
- eosinophils
- basophils/mast cells
What is 1 type of soluble factor involved in acquired immunity?
antibodies
What is the acute inflammatory response?
innate response to tissue damage
What are 5 features of the acute-phase inflammatory response?
- Rise in body temperature (fever)
- Production of proteins (acute phase proteins) mainly by liver (CRP, SAP, MBL)
- CRP + SAP bind to molecules on cell wall of bacteria + fungi - pattern recognition
- MBL binds to mannose sugar molecules not often found on mammalian cells
- molecules are non-specific but direct phagocytes to identify + ingest infectious agent
What are the 3 key types of acute phase proteins, mainly produced by the liver, during the acute phase response?
- CRP
- Serum amyloid protein
- Mannan-binding lectin
What are cytokines?
- small proteins, carry messages between cells e.g. stimulate activation, killing, secretion, proliferation.
- kick-start acquired immune response
What 3 things can the cells of the innate immune system be divided into (remember: comprise of neutrophils, macrophages, NK cells)?
- Granluar leukocytes:
1. NK cells
2. Macrophages
3. Granulocytes (neutrophils, eosinophils, basophils)
What is the structure of neutrophils?
Polymorphonuclear (PMN) neutrophils - multi-lobed nucleus
What proportion of the circulating WBCs is formed by neutrophils?
50-70%
What is the broad function of neutrophils?
phagocytic
What is the structure of eosinophils?
bi-lobed nucleus
What proportion of the circulating WBC are eosinophils?
1-3%
What is the role of eosinophils in innate immunity?
immune response to parasites, helminths and allergic responses
What proportino of WBC are basophils?
<1%
What are 2 functions of basophils in innate immunity?
- not phagocytic - release granules containing histamines, serotonin, prostaglandins
- important in Th2 responses - kickstarting acquired immune response
What is the function of NK cells?
identify + kill virus-infected + tumour cells, complex recognition system - recognise HLA molecule of virus infected cell or tumour + kill them
What is the structure of macrophages?
mononuclear phagocytes
What are the 2 main functions of macrophages?
- garbage disposal
- present foreign cells to immune system
What are antigens?
glycoprotein molecules which react with antibodies or T cells; not all can induce immune response - those that can are termed immunogens
What is the structure of the most basic antibody?
bivalent - 2 binding sites
What proportion of serum Ig is formed by each Ig type?
- IgG: 75%
- IgM: 10%
- IgA: 15%
- IgE: <1%
- IgD: <1%
What are 2 important characteristics of IgG?
- crosses the placenta - protection of newborns
- long serum half-life