MIIM - The Immune System and the Response to Infection - Week 4 Flashcards
What are the four principles of immune responses?
Immunological recognition
Immune effector functions
Immune regulation
Immunological memory
What are pathogen associated molecular patterns?
Microbial molecules that are unique to microbes but are shared within discrete taxonomic groups like LPS and flagella
Which evolved second, the innate or adaptive immune system? what was this evolution in response to?
Innate evoled first - adaptive evolved in response to microbes that were able to evade the innate immune system.
Do both the innate and adaptive immune system aid in anti-tumour activity?
Yes
Define specific and non-specific immune system.
Specific is the adaptive immune system
Non-specific is the innate immune system
Which immune system is the first line of defence?
Innate
Name 8 organs and tissues associated with the immune system.
Adenoids
Tonsils
Thymus
Lymph nodes
Lymph vessels
Spleen
Peyer’s patches
Bone marrow
Skin
Name 8 examples of the 1st line of defence.
Lysozyme in tears
Skin surface including fatty acids and normal flora
Rapid pH change in the GIT
Removal of particles by cilia in the nasopharynx
Mucus lining the tracea
Stomach pH of 2
Normal GIT flora
Flushingof the urinary tract
Which is more rapid, innate or adaptive?
Innate
What are the most common WBCs in our bodies?
Neutrophils
What cell is the origin for all blood cells?
Pluripotent haemopoietic stem cells
Name 3 kinds of specialised plasma factors that mediate innate immunity.
C-reactive proteins
Mannose binding lectin
Complement proteins
Where are complement proteins, and can they be upregulated?
Made in the liver, upregulated in response to an infection
Define acute phase proteins.
Proteins that are rapidly produced in response to an infection
What process does mannose binding lectin trigger?
Complement cascade
What process does c-reactive proteins trigger?
Complement cascade
What is the critical step of complement cascade?
Breakdown of C3
Define complement terms -a and -b.
-a is used for a smaller cleaved protein fragment
-b is the larger fragment
Describe three pathways to activate the complement cascade.
Classical - antibody binding
Lectin - mannose binding
Alternate - pathogen surfaces
What is C3b responsible for?
Coats microbes inducing phagocytosis
Define opsonisation.
Coating with a phagocytosis-inducing molecule
What complement proteins are responsible for pore formation and lysis?
C5-C9
What three complement proteins are responsible for recruitment of inflammatory cells, and what is this process called?
C4a, C4a, and C5a.
This is chemotaxis (they also induce inflammation)
Name 7 leucocytes of the innate immune systen.
Neutrophils
Monocytes
Macrophages
Dendritic cells
Eosinophils
NK cells
Basophils
What 4 innate immune leucocytes engulf extracellular material?
Neutrophils
Monocytes
Macrophages
Dentritic cells
What two innate immune leucocytes kill eukaryotic parasites or altered cells?
Eosinophils
NK cells
Which innate immune leucocyte releases immunomodulatory compounds?
Basophils
How do macrophages activate T cells?
After phagocytosis, they present foreign antigens to the T cells, which activates them.
What are cytokines?
Proteins secreted by cells that interacts with and affects the behaviour of nearby cells with the appropriate receptors.
What are chemokines?
A secreted protein that attracts cells with the appropriate receptors.
Describe the five stages of phagocytosis.
Pseudopod engulfs the bacteria
Phagosome formation and acidification
Phagolysosome formation
Lysosomal protein degradation of the bacteria
Release of bacterial fragments
Name 6 ways phagocytes can kill bacteria.
Acidification
Antimicrobial peptides
Enzymes
Competitors
Toxic nitrogen intermediates
Toxic oxygen intermediates
Where do B- and T-cells mature?
B-cells mature in the bone marrow
T-cells mature in the thymus
Where do mature B- and T-cells end up after maturation?
B-cells go to the blood
T-cells go to the blood and lymph
What three actions does a B lymphocyte have?
Neutralisation of a microbe via antibodies (agglutination)
Phagocytosis
Complement activation
What three actions does a helpter T-cell have?
Activation of macrophages
Inflammation
Activation of T- and B-lymphocytes
What action do cytotoxic T-cells have?
It kills cells that express microbial antigens
What action do natural killer cells have?
It kills cells expressing abnormal glycoproteins
What are humoral and cellular immunity, and under what kind of immune system (innate or adaptive) do they fall under?
Humoral - B-cell response
Cellular - T-cell response
They both fall under the adaptive immune system
What are the 2 main functions of humoral immunity?
Blocks infections and eliminates extracellular microbes
What are the 3 main functions of cellular immunity?
Activates macrophages to kill phagocytosed microbes
Kills infected cells
Eliminates reservoirs of infection
Name 4 immune recognition features of adaptive immunity.
Each lymphocyte recognises a single antigen
The lymphocyte population is highly diverse in antigen receptors
It responds to a large variety of antigens
It can discriminate self from non-self
What is the main response of adaptive immune response.
Clonal expansion
Which immune system prevents injury to the host during the response to foreign entigens.
Adaptive immune response
