Intro to Immunology Flashcards
10 physical barriers to Infections
- Removal of particles
- Skin
- Stomach acidity
- Normal flora-compete with pathogens in gut and stomach
- Flushing of urinary tract
- Lysozyme in tears
- Mucus, cilia lining trachea
- Mucus and phagocytes in lungs
- Blood and lymph proteins
- Rapid pH change
Antibody that crosses epithelial tissue?
IgA can be secreted across epithelial tissue = Secretory IgA
IgG stays in blood stream and lymph tissues
General Innate Immune System:
- Does not require previous exposure
- Phagocytosis
- Recognizes PAMPs with receptors called PRRs
Major players of Innate IS:
DC, macrophages, neutrophils, mast cells
myeloid precursors
Professional APCs?
DC, macrophages, B cells : break down foreign molecules and display it as MCH II molecules
Interferons=
mediate an early response to VIRAL infections by innate system
First to response?
First recruited?
–Resident macrophages
–Neutrophils (first responders)
Complement System:
Goal=
Activiation=
Goal=control inflammation
Classical pathway: activated by antibodies or mannose binding lectin bound to the pathogen surface.
–>opsonization, chemotaxis, increased blood flow & permeability.
Cytokines=
secreted molecules involved in cell-to- cell signaling.
They are proteins/glycoproteins
–soluble!
Chemokines=
large family of cytokines taht can attract cells into inflamed tissues and play a role in leukocyte homing. “Direct traffic”
Interferons: Type 1 (alpha and beta):
Type 2 (gama):
Limit spread of VIRAL infections Type 1 (alpha and beta): produced by VIRAL INFECTED cells
Type 2 (gama): released by activated Th1 cells (adaptive IS)
Interleukins
Produced by T cells
Cause neighboring cells to divide and differentiate
Colony Stimulating Factors (CSFs)
direct division and differerntiation of bone marrow stem cells and precursors of blood leukocytes
Tumor Necrosis Factors (TNFs)
Important in mediating inflammation and cytotoxic reactions
Transforming Growth Factors (TGFs)
Important in regulating cell division and tissue repair.
Adaptive IS:
- acquired ability
- Pathogen specific receptors
- Mediated by the binding of antigens to T cell receptors and Abs/Igs
- 10-14 days to kick in
- Has memory. 2nd response is faster and stronger `
APCs
Link innate and adaptive immune systems.
- Essential for activation of T cells
- MHC II molecules
Major players of adaptive IS:
T cells
B cells –> plasma cells
(lymphoid precursors)
epitope:
Restricted part of the antigen where the antibody binds.
Fc region
Constant region of antibody that can bind Fc receptor on phagocytes
-adapter between the phagocyte and the pathogen
Active Immunity:
Natural active immunity by acquiring infection or immunization.
Creates memory cells–>long lasting
Passive Immunity:
acquisition of preformed immune cells/abs via the transfer of cells/abs from an immune person. Newborns have maternal IgG antibodies.
NO memory response
SCID (Severe Combined Immunodeficiency )
No lymphoid precursor cells.
B & T cell immunodeficiencies
Recurrent infections with wide range of pathogens
Cluster of Differentiation (CD) Molecules: All leukocyte groups= T lymphocytes= T helper cells= Cytotoxic T cell=
All leukocyte groups= CD45+
T lymphocytes=CD45+, CD3+(T cell receptor)
T helper cells=CD45+, CD3+, CD4+ (MHC II binder)
Cytotoxic T cell=CD45+, CD3+, CD4+, CD8+ (MHC I binder)
Pluripotent SC –> Lymphoid Progenitor Signal?
IL-3
Adaptive Immunity cells
Pluripotent SC –> Myeloid Progenitor Signal?
IL-3 & GMCSF (granulocyte/monocyte colony stimulation factor)
Innate Immunity cells
6 categories of cytokines
Interferons Interleukins Colony stimulating factors Chemokines Tumor necrosis factors Transforming growth factors
