Immunology - Intro to Immune Response Flashcards
What are Antibodies?
Proteins produced in response to an antigen
What is an Antigen?
Any substance which can stimulate an immune response
What is the Complement System?
Circulate on blood as inactive precursor proteins. Activated in inflamed/infected tissue. Activation results in downstream cleaving and further activation (Complement Cascade)
Immune System Components - Cells
Phagocytes = Neutrophils, Monocytes & Macrophages and Dendritic cells
Lymphocytes = T cells, B cells and Natural Killer cells
Mast cells, Eosinophils and Basophils
Immune System Components = Soluble Factors
Antibodies
Complement System Proteins
Cytokines
Acute Phase Proteins
What are Cytokines?
Small proteins and peptides produced in response to infection, inflammation and tissue damage.
E.g. interferons, TNF-a, chemokines, interleukins
What are the Phagocytic Cells?
Monocytes
Macrophages
Neutrophils
What are Monocytes?
Circulate in blood
Migrate into tissue and become macrophages
What are Macrophages?
Long-lived tissue resident phagocytes
Limit inflammation, involved in tissue repair and wound healing and antigen presentation
What are Neutrophils?
Circulate in blood
Short lived
Constantly regenerating
Rapidly recruited to inflamed, damage and infected tissue
What are Dendritic Cells?
Present in “immature state” in peripheral tissue
Phagocytose antigens
Mature and migrate into secondary lymphoid tissues where they aid antigen presentation
What are Mast Cells?
Reside in tissues and protect mucosal surfaces
What are Basophils and Eosinophils?
Circulate in blood
Recruited to sited of infection by inflammatory signals
Role of Mast Cells, Basophils and Eosinophils
Highly granular cells
Release chemicals in response to large pathogens that cannot be phagocytosed
What are Natural Killer Cells?
Large granular lymphocytes
Can kill tumour cells and virally infected cells
Also kill antibody-bound cells and pathogens
Role of T Cells and B Cells
Mature cells constantly circulate through blood, lymph and secondary lymphoid tissues
Inactive until they meet a pathogen/antigen
What do B Cells do?
Production and secretion of antibodies against extracellular pathogens
What kinds of T cells are there and what is their role?
Defence against intracellular pathogens
Helper T Cells = Regulators of immune system
Cytotoxic T Cells = Kill virally infected body cells
What is the response of the Innate Immune System like?
Rapid response
Same general response to many pathogens
What is the response of the Adaptive Immune System like?
Slow response
Unique response for each pathogen
Mediated by T and B cells
Responsible for immunological memory
What are the Primary Lymphoid Tissues?
Sites of leukocyte development
Bone marrow, thymus
What are the Secondary Lymphoid Tissues?
Sites of initiation of adaptive immune response
Contain T cells, B cells and dendritic cells
Spleen, Lymph nodes, Adenoid, Tonsils
What is the role of the Lymphatic System?
Drain fluid from body tissue
Lymph nodes trap pathogens and antiges in lymph
What is Lymphoedema?
Lymphatic obstruction
Risk of infection
