Introduction to Innate Immunity Flashcards
What are the roles of the immune system (IS)?
- Defense (Host)
- Against disease by pathogenic infectious organisms - Protection against some tumors
- Vaccines
- infections
- Cancer therapy - Chronic immune responses (Long term conditions)
- sepsis
-autoimmunity
-Type-2 Diabetes
Describe the myeloid lineage.
Hematopoietic Stem Cell (common progenitor) -> Myeloid lineage
-> Neutrophil
->Mast cell and Basophil
->Eosinophil
->Monocytes -> differentiate -> Dendritic cell
-> Macrophage
Innate immunity is…
Rapid
Halts infection
No memory
The immediate response to infection includes:
- Awareness
-> Detection of pathogens to signal their presence - Immediate response
-> Resident tissue cells/factors
-> Recruitment of cells from the blood - chemical signals generated
3.Signals sent to the acquired response
-> Provision of immunity - long lasting
-> The desired response of vaccination
Name the nonspecific anatomic barriers?
Skin
Mucous Membranes
Name the nonspecific physiological barriers.
Temperature
Low pH
Chemical mediators
Other nonspecific barriers include.
Phagocytic/endocytic
Inflammatory
Skin Mechanism
Mechanical Barrier
Retards entry of microbe
An acidic environment (pH 3-5) retards the growth of microbes
Mucous Membrane mechanism
Mucus entraps foreign microorganisms
Cilia propel microorganisms out of the body
Temperature mechanism
Normal body temperature inhibits the growth of some pathogens
Fever- inhibits the growth of some pathogens
Low pH mechanism
Acidity of stomach kills most ingested microorganisms
Examples of Chemical mediators
- Lysozyme
- Interferons
- Complement
- Toll-like receptors
- Collectins
Lysozyme
Cleaves bacterial cell wall
Interferon
Induces antiviral state in uninfected cells
Complement
Lysis microorganisms
Facilitates phagocytosis
Toll-like receptors
Recognise microbial molecules
Signal cell to secrete immunostimulatory cytokines
Collectins
Disrupt cell wall of pathogen
Phagocytic barrier mechanism
Specialised cells - blood monocytes, neutrophils, tissue macrophages
Phagocytose - > kill and digest whole microorganism
Endocytic barriers
Internalize (endocytose)
Break down foreign macromolecules.
Inflammatory barrier mechanism
Tissue damage + infection induce leakage of vascular fluid
Contains serum proteins with antibacterial activity
Influx of phagocytic cells into the affected area
What is inflammation?
Complex biological response to harmful stimuli - pathogen/injury
What are signs of inflammation?
Redness
Swelling
Heat
Pain
Latin for Redness
Rubor
Latin for Swelling
Tumor
Latin for heat
Calor
Latin for pain
Dolor
Latin for loss of function
Functio laesa
Explain how a tissue becomes inflamed upon a pin piercing a skin’s surface.
Pin entry - bacteria enters (foreign matter)
Bacteria sensed by cells underneath and by histamines
Chemotactic factors
Dilation and increased leakiness of local blood vessels
Migration of macrophages and neutrophil to site of infection
Consumes bacteria + debris -> tissue heals
Importance of Natural Killer cell?
Immune surveillance of cancer + viral infected cells
Importance of Dentritic cell?
Antigen presentation + cytokine production
Importance of Macrophages?
Phagocytosis + cytokine production
Importance of Neutrophil?
Phagocytosis + enzyme production
eN(neutrophil)zyme
