Final Flashcards
(32 cards)
Susceptibility
Immunity
Innate immunity
Adaptive immunity
Lack of resistance to a disease
Ability to fight off a disease
Defense against any pathogens
Resistance to a specific pathogen (immunity)
Physical vs Chemical
Physical - Prevention entry
Chemical - Substance in the body that inhibits microbial growth
Plasma vs Formed elements
Plasma - Fluid component
Formed Elements - Cellular component (Leukocytes) for both innate and adaptive immune system
Granulocytes vs Agranulocytes
Granulocytes
Basophil
Neutrophil aka polymorphonuclear leukocytes (PMN)
Eosinophil
Agranulocytes
Lymphocyte - NK (innate), T cells & B cells (adaptive)
Monocyte - when stimulated, leaves blood stream and enters tissues and turns into macrophages
Phagocytosis
Clears away debris (dead cells & denatured proteins)
Removes foreign materials (microbial infection)
Diapedisis - phagocytes squeeze b/t endothelial cells
Fixed vs Free macrophages
Fixed - do not leave tissures
Kupffer’s cells - Liver macrophages
Alveolar - Lung macrophages
Microglial Cell - Nervous system
Free - wanderers
Roams around and gather at the site of infection/inflammation
Inflammation
Redness
Edema
Pain
Heat
Loss of Function
Complement System
over 30 proteins
produced in liver circulates all over
Not adaptavle and does not change
Destroys microbes by
- Cytolysis
- Inflammation
- Phagocytosis
Inactive until split into fragments
i.e. C1, C2, C3
How does the innate immune system recognize foreign materials such as bacteria?
Toll-like receptors (TLR) attaches to the Pathogen-associated molecular patterns (PAMP)
TLR induces cytokines - regulates intensity and duration of immune responses
Innate Immue
- TLR on host cells recognizes & attaches to the PAMP of bacterial cell
- TLR induces cytokines - sends out signal
Adatptive Immune system
- APC (b cells, macrophages, dentritic cell)
- Engulf pathogen
- Remenants of pathogen is presented on the surface by MCH I and MCH II
- MCH I attracts T Cytotoxic cell via TCR - CD8 - recognizes infected cells aka target cells and sends signal (perforin & granzymes) for apoptosis.
- MCH II attracts TCR (t cell receptors) on the T-helper cell - CD4 - and binds to B cells and release cytokines to activate macrophage to engulf pathogen. Also, B-cells starts to divide into plasma cells -> antibodies & memory cells (clonal expansion)
Bone Marrow
Produces Lymphocytes
- One group of lymphocytes migrates to thymus - creating T-cells (Cellular)
- Second group matures in bone marrow - creating B-cells (Humoral)
Humoral vs Cellular Immunity
Humoral
Blood, phlegm, black bile, yellow bile
B cells (Bone Marrow), carries Ig.
- Bursa of Fabricius in Birds
- produces antibodies
- divides into 2 daughter cells (plasma & Memory) which synthesize and secretes antibodies (clonal expansion)
- Plasma cells - produces antibodies
- Memory cells - Long lived and secondary response cells.
- Activation typically requires T helper cell (T dependent antigen)
- Fragments combined with MHC (major histocompatibility Complex)
- Antigen processing & Presentation, marks for destruction
Cellular
T cells (Thymus)
- Responds to antigen by T cell receptors (TCR)
- requires antigen presenting cells (APC) by MCH class I or II
- T helper cells helps humoral immunity
- T cytotoxic cell can become cytotoxic T lymphoctye (CTL) and recognize/destroy infected cells/cancer cels
- classified by glycoproteins
- T helper cells are CD4 (Binds to MHC Class II on b cells & antigen presenting cells
- T cytotoxic cells are CD8 (binds to MHC class I)
- Target cells are self carrying endogenous antigens
- CTLs recognizes Antigen & MCH I which induces apoptosis to the target cell and releases perforin/granzymes
How does innate immune system recognize foreign materials/ bacterias?
How does antibodies recognize antigens?
Host Toll like receptors (TLR) attaches to the pathogen assoiciated molecular patterns (PAMP)
Epitopes
Antigens
Proteins or polysaccharide
- Capsule
- Cell wall
- Flagella
- Fimbriae
- Toxin
- Viral Coat
Not all antigens are from microbes, could be pollen, egg whites, Surface of blood cells, Serum from another species or surface transplanted tissue/organs
Epitope vs Hapten
Epitope - How antibodies recognize antigens
Hapten - Needs to bind with carrier molecue = Hapten-carrier conjugate
Antibody
Globular protein
aka Ig
Has 2 identical site that binds to epitopes (antigen binding site)
Has variable region and constant region
Stem is Fc region
IgG
IgM
IgA
IgD
IgE
IgG - fix complement, most abundant, enhances phagocytosis, nuetralizes toxins/viruses, protects fetus and newborn
IgM - ** Fix complement,** Agglutinates microbes, first to respond infection
IgA - Mucosal protection, in secretions
IgD - On B cells, initates immune response
IgE - On mast cells, basophils and blood, Allergic reactions, lysis parasites, least abundant
Antibody binding to antigen
Agglutination
Opsonization - enhances phagocytosis by coating antigen w/ antibody
Neutralization - blocks adhesion of bacteria/virus to mucosa
Activation of complement - causes inflammation & cell lysis
Cytoxocity - destruction of target cell by macrophages, eosinophils, NK cells
Precipitation Reactions
involves soluble antigens/antibodies, IgG or IgM
Antibody binds to antigens forming lattice structure and cloudy precipitate
Zone of equivalence: visible precipitate
Complement fixation
when antibody binds to antigen has the ability to start a cascade of events carried out by complement proteins
ELISA
Enzyme Linked Immunosorbent Assay
Enzyme linked to antibody as indicator
ie. pregnancy test
Direct ELISA
- Antibody in well
- Patient sample is added
- Complementary antigen binds to antibody
- Enzyme linked antibody is added and binds to antigen
- Enzyme substrate is added and reaction produces color
Indirect ELISA
- Antigen in well
- Patient serum is added
- Complementary antiboy binds to antigen
- Enzyme linked anti HISG is added and binds to antibody
- Enzyme substrate is added and reaction causes color
Hypersensitivity Reactions
Response to antigens (allergens) leading to damage
Anaphylatic
Cytotoxic
Immune comples
Cell mediated (delayed type)
Anaphylatic type I
IgE attaches to mast cells and basophils
Antigen binds to 2 adjacent IgE
Mast cells & basophils undergo degranulation and releases: Histamine, Leukotrienes, Prostaglandin
serves as chemotactic agents
attracts neutrophils and eosinophils causing inflammatory symptoms:
- swelling
- distention of capillaries
- Increased mucous secretion
- Involuntary smooth muscle contraction
Anaphylactic Type I
Systemic vs Localized
Systemic
- dramtic drop in blood pressure
- Cirulatory collapse and death in minutes
Localized
- Ingested or inhaled allergens
- Hives, Hay fever, asthma
Anaphylatic Type IV
Delayed type hypersensitivity due to T cells
Delay due to the time required for T cells to migrate to site of allergen
Cytokines attracts macrophages and TC cells and initiates tissue damamge
