Lecture 1 immunology Flashcards
What did Edward Jenner do?
Edward Jenner discovered in 1796 that cowpox could protect humans from smallpox, leading to the development of vaccination. Smallpox had been a deadly disease for centuries, with variolation practiced in Africa, India, and China before being introduced to Europe. A global eradication campaign led by the World Health Organization began in 1967, and by 1980, smallpox was officially declared eradicated.
What did Robert Koch do?
Proved that infectious diseases are caused by micro organisms.
What did Louis Pasteur do?
Developed a rabies vaccine.
What did Emily von Behring and Shibasaburo Kitasato do?
Discovered antibody activity in the serum of animals immune to diphteria or tetanus.
What did Elie Metchnikoff do?
Discovered that microorganisms could be digested by cells he called macrophages.
What did Ralph Steinman do?
Pioneered dendritic cell immunotherapy.
What did Katalin Kariko do?
Developed mRNA-based vaccines including against COVID19.
What is immunology?
The study of all aspects of host defence against infection.
What is immunity?
The ability to resist infection.
What is an antigen?
Any substance capable of being recognised by the immune system.
What is an antibody or immunoglobulin?
A protein that binds specifically to an antigen.
What are the 5 groups of organisms that are responsible for pathogenic infections?
Viruses, bacteria, fungi e.g., candida albicans, protozo e.g., plasmodium spp, helminths/worms e.g., strongyloides (parasitic round worms).
What are examples of primary immune system lymphoid organs?
Bone marrow. Where all blood cells/immune cells arise from from stem cells. Also the thymus because T cells need to migrate from bone marrow to thymus where they undergo final moderation.
What are the organs in the secondary immune system?
Lymph nodes which are connected by lymphatic system, appendix, kidney, large intestine, spleen.
What is hematopoiesis?
The development of blood cells. Myeloid cells give rise to innate immune system cells which works independent of antigen and receptor recognition. Lymphoid cells give rise to cells that can recognise antigens (e.g., B cells T cells)
What are some prevalent cells in blood?
Red. 2 million per microlitre of blood.
White blood cells. 5000 per microlitre.
Platelets (fragments of cytoplasm). around 250,000 per microlitre.
What are the phases of the immune response?
Innate immunity which is pre existing initial protection against infection. Then adaptive immunity which develops more slowly and adapts to the specific pathogen and mediates the later defence against infection.
What is the first innate immunity 0-4 hour phase after infection?
Recognition by preformed nonspecific effectors.
What is the 4-96 hour early induced response?
Recruitment of effector cells. Recognition of activation of effector cells.
What is the adaptive immune response after 96 hours?
Transport of antigen to lymphoid organs. Primarily spleen and lymph nodes. Recognition by naive B and T cells. Clonal expansion and differentiation to effector cells. After 3 or 4 days all three mechanisms work together.
What are the stages to innate immunity?
- First response/barrier to infectious disease is formed by innate/non-adaptive defences
- Exposure to infectious particles occurs through epithelial surfaces e.g. skin, internal mucosal surfaces of the respiratory, GI and urogenital tracts
- Pathogens are detected by receptors on the surface of epithelium that discriminate between foreign and host cells (macrophages e.g., as have a large number of receptors to detect pathogens).
- Inflammatory response/inflammation occurs
- Contains infection/prevent infection being established
What do myeloid leukocytes differentiate into?
60-70% are granulocytes- predominantly neutrophils. the remainder are mainly macrophages (precursors and dendritic cells).
What are the steps to the adaptive immune response?
First stage initiated in local lymphoid tissue in response to antigens that activate antigen presenting cells (APC):dendritic cells. Antigen on APC activates lymphocytes to recognise specific pathogen proteins. Clones of antigen specific lymphocytes are produced specific to the pathogen. Antigen specific effector T cells and antibody secreting B cells are generated by clonal expansion and differentiation over several days (induced by innate immune responses continue).
What are some examples of cells of the immune system and their function?
Dendritic cell
Antigen uptake in peripheral sites
Antigen presentation
Neutrophil
Phagocytosis and activation of bactericidal mechanisms
Eosinophil
Killing of antibody-coated parasites
Basophil
Unknown function
Mast cell
Release of granules containing histamine and active agents
