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28 terms

Chapter 49 (short review trickier things)

Freeman Biology
STUDY
PLAY
Tears
Produce lysozyme that digests bacterial cell walls
Macrophages secrete? in inflammatory response
-Chemokines (recruit immune cells by forming gradient)

-Cytokines (attract other imune cells and activate cells involved in tissue repair. Induce fever)
Mast cells
Mast cells release chemical messengers that cause blood vessels near wound to constrict, secrete histamine, dialates blood vessels slightly farher from wound and increase delivery of immune cells and blood to that area
Neutrophils and macrophages in inflammatory response
Phagocytosis
- remove pathogen by engulfing and digesting
Leukocytes
white blood cells
lymphocytes
Aquired immune response cells
B cells
Produce antibodies
T cells
recognize and kills host cells that are being infected with a virus
Clonal Selection Theory
1. Each lymphocyte has thousands of unique receptors on surface (lock and key w/ anigen)
2. Activate lymphocyte divides and clones
3. Some turn into memory cells
Epitopes
Regions on antigen that bind to bcr, tcr, and antibodies
Gene Recombination
1. DNA with full V,J, and C segments
2. One V is joined with one J and the C randomly
3. Transcription occurs
4. RNA processing
5. Translation resulrs in a protein with UNIQUE AA senquence with ability to bind to unique antigen

Is the molecular mechanism responsible for acquired immune systems specificity and diversity
Anti-self receptors
Confuse self with non self. Are destroyed before birth. If they are not destroyed they can lead to a variety of autoimmune diseases
MHC
Protein complex on cell surfaces
"Holds flag that says this is me" that is recognized by sensor proteins on leukocytes
- unique to individual,
Antigen Presentation
1. Dendritic cell ingests antigen
2. Antigen enters endosome or ER
3. Enzyme breaks up antigen; pieces bind to MHC
4. MHC-antigen complex is transported to cell surface
5. MHC presents antigen on surface
Universal donor and universal acceptor?
(Example of cell surface feature recognition)
Donor = O
Acceptor = AB
Sensor proteins
Are antibodies
Class l [2 Different types of MHC regions]
Surface all cells except red blood cells (erythrocytes)
-Put flag or relay signal i've been affected and need to be destroyed

Recognized by lymphocyte type:
Cytotoxic

Using protein type:
CD8
Class ll [2 Different types of MHC regions]
Surface of macrophages, b-cells, and dendritic cells

Recognized by lymphocyte type:
Helper

Using protein type:
CD4
T-Cell Activation
1. T-cell receptor binds to peptide on MHC protein and becomes activated

MHC Class l = CD8 cells = Clonal expansion = cytotoxic T cells

MHC Class ll = CD4 cells = Helper T cells activate other cells and release cytokines (chem signals showing other cells where to go)
B Cell Activation
Does not need Dendritic cell, act w/i antigen itself

1. B cell binds to foreign peptides, process them, and display them on surface via MHC
2. B cell interacts with T cell, activating it
3. Cytokines from T cell activate B cell
4. Activated B cell divides, producing plasma cells, which produce antibodies
5. Antibodies will bind to antigens and mark them for destruction
Agglutination
Process by which antibodies will bind to bacteria. Antibodies have at least 2 binding sites, so they can bind to at least 2 antigens causing them to clump together. Then cells are digested by macrophages/neutrophils
SCID
Severe Combined Immune Deficiency
-Born with it
- Genetic defect in one enzyme responsible for DNA recomb maturing into lymphocytes
- So unable to generate normal T/B cell receptors
- Usually die before 2 years old
HIV
Human immunodeficency virus
- Suffer progressive loss of CD4 T cells (which become helper t cells so you can't activate b cells)
-Eventually develop AIDS
2 ways to eliminate a virus
1. Cell Mediated response
- takes place at cell surface, limits spread of infection by preventing new generations of virus particles from maturing

2. Humoral Response: takes place in blood and lymph
-virus blocked from contacting plasma membranes of new host cells, phagocytic cells destroy virus
Cell Mediated Response
1. T cell makes contact and releases granules
2. Granules induce cell to self destruct, virus cannot replicate
Humoral Response
1. Antibodies coat virus
2. Virus cannot infect cell
3. Free floating virus is tagged and destroyed by neutrophil
Memory Cells
Daughter cells produced by activated B cells and T cells
- Bind antigen of reinfection and trigger secondary immune response, faster and more efficently than primary response
Vaccines
Memory Cells
- Epitopes from pathogens or killed/weakened version of the pathogen
- body mounts primary response, produces memory cells
- Does not work for viruses with constantly changing epitopes like HIV