Week 6- Immune Response to Infection Flashcards
What are the 4 main steps in the response to infection?
- Phagocyte detection
- Innate immune response
- Adaptive immune response
- Formation of memory cells
Which immune response out of innate or adaptive is faster?
Innate (quick acting) whereas adaptive is slower and longer lasting
What type of receptors are involved with the innate immune response?
Germline encoded
What are the humoral components of the innate immune response?
Lectin, antimicrobial peptides, complement
What are the cellular components of the innate immune response?
Neutrophils, macrophages, NK cells, dendritic cells
How many receptors are involved with the innate immune response?
Few
What type of receptors are involved with the adaptive immune response?
Variable receptors that mature over time
How many receptors are involved with the adaptive immune response?
Many
What are the humoral components of the adaptive immune response?
Antibodies and complement
What are the cellular components of the adaptive immune response?
T killer, reg, cytotoxic cells, B lymphocytes, plasma cells
What are the 2 things that trigger an immune response?
Tissue damage
Detection of a pathogen
What 2 cells are the first responders and in what order do they act?
Neutrophils and macrophages with neutrophils acting first
Describe the first response
Microbes detect pathogens which causes gene expression in naive host cells to change, they then produce chemo/cytokines which activates host cells after signal transduction
What 2 molecules communicate with leukocytes? When and where are they produced
Interleukins and interferons, they are only produced locally in a response as they are very toxic
What can the uncontrolled activity of phagocytes lead to?
Granulomas, excess inflammation and tissue damage
How are macrophages activated?
Cytokines activate T cells which produce own cytokines activating macrophages
Which cytokine defends against mycobacterium?
Interferon gamma
What 2 types of cells can kill infected cells?
Cytotoxic T cells or NK cells
What are soluble mediator mechanisms that the humoral innate response utilises?
Lectin binding to neutralize cell attachment/entry Antibody like peptides Iron chelation (prevents replication) Complement mediated bacterial destruction
What are cellular mediator mechanisms that the humoral innate response utilises?
Acidification and digestion in phagosomes
Nitrogen and oxygen free radicals
What are the main functions of a T cell?
Killing infected cells, helping B cells produce antibodies, activating phagocytes
How are T cells activated?
By cytokine production of APC
How do antibodies enhance the antimicrobial response?
Helping with phagocytosis and complement activation
What cells do T cells activate?
Phagocytes
What is the timing of the innate response?
0-12hrs after the infection
What is the timing of the adaptive response?
1-5 days after infection
