The Nature of Immunity Flashcards
What are four main types of pathogens that can cause disease?
- Bacteria
- Viruses
- Fungi
4.Parasites (protozoa and worms)
Two examples of bacteria and the diseases they cause
- Salmonella enteritis which causes food poisoning
2.Mycobacterium tuberculosis which cause tuberculosis
Four examples of viruses and the diseases they cause
- SARs and covid19
- Variola and smallpox
- Influenza and the flue
- HIV and AIDs
Two examples of fungi an the diseases they cause
- Epidermophyton floccosum and ring worm
- Candia albicans which causes thrush
Give an example of a parasite and the disease it causes
Plasmodium falciparum which cause malaria
For each of the following challenges bacteria give the response the immune system the human immune system has in place
- Diverse Nature of pathogens
2.Vast range of pathogens - Rapid growth of microbes
- Minimise Damage to the Host
- Vast range of defense mechanisms
- Vast range of antigen receptors as a part of the adaptive immune response
- Rapid inflammatory response
- Regulatory Mechanisms
An immune response to infection can be broken down into two sections
- Recognition
- Response (Defense)
What are the cardinal features of the immune system?
- Specificity
- Immunological Memory
3.Self-discrimination
What are the three levels of defense in the immune system?
- Physical barriers: skin, mucosal membranes
- Innate immune system present in tissues
- Adaptive immune system which is triggered by the innate immune system
The key players in innate immunity or the rapid response of the immune system are
1.Macrophages
2.Mast cells
3.Compliment proteins
4. Neutrophils
The key players in the adaptive or slow immune response are the
- B cells
- T cells
When pathogens enter the body the compliment system is activated. Briefly describe what occurs upon the activation of the compliment system
-The lectin pathway is activated by mannose binding to a pathogens surface
-This leads to Cb3 covalently binding to the surface of the pathogen.
-The pathogen is then tagged/opsonized, inflammatory cells are recruited and pathogens are perforated (killer ts)
-this combination leads to the death of the pathogen
What are the differences between the innate and adaptive immune reponse?
1rapid (i) vs slow (a)
2.fixed vs variable
3. Limited specificity vs various highly selective specificities
4. Constant during response vs Improves during response
Which cells are involved in the innate immune response?
- Neutrophils
- Mast Cells
- Macrophages
Give examples of proinflammatory cytokines that may be released by Macrophages
IL-1beta
IL-6
TNF-alpha
Give examples of anti-microbial cytokines that make be secreted by macrophages
HBD1
HBD2
HBD3
HBD4
LL37
Why is histamine an important cytokine
Histamine secreted by mast cells activated WBC chemotaxis, air way smooth muscles constriction and increase permeability in the vesicles which are important to the immune response
Explain the difference between Phagocytosis and Pinocytosis
These two are both forms of endocytosis but pinocytosis is morse suitable for extracellular elements that are less than 0.5 micrometers while phagocytosis removes pathogens grater than 0.5 micrometers
What are the 4 main steps of phagocytosis
- Recognition vis PRRs (pathogen recognition receptors)
- Internalization of the pathogen
- Phagosome Formation
- Phagolysosome Maturation
Examples of PRRs are Toll-Like Receptors. There are 10 TLRs what do they recognise?
TLRs 1,2,4 and 6 recognize bacterial lipids
TLRs 3, 7 and 8 recognise viral RNA
TLR 9 recognizes bacterial DNA
TLRs 5 and 10 recognise bacterial and parasitic proteins
Explain what happens in the recognition step of the innate immune response
- The bacterial cell surfaced induces cleavage and activation of the complement pathway.
- One complement fragment bonds covalently yo the the bacterium while the other attracts the effector cell.
- The complement receptor on the effector cell the binds to the complement fragment in the bacterium.
- The effector cell engulfs via phagocytosis or pinocytosis, killing and breaking down the bacterium
Cell mediated immunity is facilitated by which two cells?
- Cd4 T cells (helper Ts)
- Cd8 T cells (killer Ts)
What are the pros of innate immunity
- Generic defense
- Regonises common structure characteristics of pathogens (tlrs)
- Inherited recognition repertoire
- Quickly activated (within minutes)
What is the one con ofc innate immunity?
It has a moderate efficiency and doesn’t evolve beyond its baseline function
What are the pros of adaptive immunity
- Its recognition is for specific types of antigens and pathogens
- Somatically generated repertoire
- Highly efficient
What is the con of adaptive immunity?
The only downside to adaptive immunity is that the process takes around 96 hours after infection to become activated
