Fighting infections Flashcards
4 components of the immune system
Physical barrier
Complement system
Cellular components
Cytokines
Neutrophils
Large multi lobed nucleus
Functions of neutrophils
Reactive oxygen and nitrogen species
Phagocytosis
Antimicrobial peptides
Functions of macrophages
Phagocytosis Inflammatory mediators Antigen presentation Reactive oxygen and nitrogen species Cytokines Complement proteins
Functions of dendritic cells
Antigen presentation Costimulatory signals Cytokines Reactive oxygen species Interferons
Pattern recognition receptors
Mannose receptors
Toll-like receptors
Receptors for opsinins
7TM alpha helical receptors
IL-12 is produced by
macrophages and dendritic cells
Function of IL-12
Promote NK cytolysis
Stimulates IFNy production in T and NK cells
Granulocytes
Neutrophils, eosinophils, basophils
Vasodilators
Histamine, bradykinin, eicosanoids, CGRP, nitric oxide
Bradykinin
Inflammatory substances formed from plasma precursor
4 hypersensitivity reactions
I: immediate hypersensitivity (allergy)
II: autoantibodies
III: deposition of immune complexes
IV: T cell mediated tissue injury
4 stages of adaptive immune response
Antigen recognition
Lymphocyte activation
Effectors responses
Homeostasis
Effector responses
T cells
B cells
Cytokines
How are B cell activated?
Engagement of surface antibodies and costimulatory signals from T cells
Down regulation of B cell activation
Engagement of Fc receptor
IgM
First to be produced, neutral antibody in the peritoneum, complement activation
IgD
Naive B cell antibody recognition
IgA
Epithelial / mucosal immunity
IgE
Helminthic parasites and immediate hypersensitivity
IgG
Secondary exposure, neonatal immunity, antibody dependent cell mediated cytotoxicity
IgG binding FcR on neutrophils and macrophages promotes
phagocytosis
IgE Fc binding causes
eosinophil activation and mast cell degranulation
Th1 cells activate
macrophages and cytotoxic T cells
Th2 cells
Provide costimulatory help to B cells
