Immunity
2 types
Innate and adaptive
Innate
Type of immunity
Non-specific
Attacks everything
Adaptive
Type of immunity
Specific; T and B cells
Have to make an individual T and B cell to every individual pathogen the body encounters
Goal: creates memory cells
1st Tier
Apart of innate immunity
Skin and mucous membranes
Acidity, salt keratin, oil (skin)
Lysozyme in tears
Hydrochloric acid in stomach
Not very good; penetrated very easily
EX: Cuts
2nd Tier
Part of innate immunity
Fever
Inflammation
Complement
Phagocytosis
Natural killer cells
Fever
2nd tier of innate
Universal sign of infection; can get it with everything
Other things can give this; certain cancers
Body’s attempt to raise core body temperature so microorganisms can’t grow
Not always necessary to treat
Unless immunocompromised
Antipyretics used to treat (Tylenol)
Seizure threshold: above 105 adults, about 103 (kids 2 and younger)
Inflammation
Apart of 2nd tier of innate
Can get with everything
Goal is to heal
Immunovascular response to tissue injury
Opening blood vessels and bringing in WBCs
This chronically is not good
Complement
Apart of 2nd tier of innate
Cascade of proteins
One protein making another and another…creates a membrane attack complex
Puncture hole, fill with fluid, causes to lyse
Two types:
Classical
Alternative
Attracts white blood cells
Classical
Complement in the adaptive immunity
B cells will bring complement to area to help kill
Alternative
Complement in the innate immunity
Random compliments flowing in the body killing things at random
Phagocytosis
Apart of 2nd tier of innate
Neutrophils, Macrophages, Dendritic
Only dendritic and macrophages are antigen presenters
Natural killer cells
Apart of 2nd tier of innate
Target viruses and cancer cells; things inside the cell, kill similar to cytotoxic T-cells
Creates hole, fill with fluid, causes apoptosis
White Blood Cells
2Never Let My Engine Blow
Neturophils: phagocytes (60%)
Lymphocytes: T and B cells (30 %)
Macrophages: Monocytes (8%)
Eosinophils: parasitic worm infection (Helmond) (2%)
Basophiles: Allergies: Histamine (0%)
Humoral
Antibody-mediated
B cell
Part of adaptive
Cell-mediated
T cells
Macrophages in lungs chew up infected cell displayed
Activate:
MHC I and MHC II
Part of adaptive
Red Bone Marrow
T and B cells made here
B cells stay here to mature
Thymus
Where T cells go to mature
Learn self tolerance
Won’t attack own tissue
T regulatory cells
Secondary Lymphatic Organs
Spleen and lymph nodes
Where T and B cells go after they mature
Naive: have not encountered antigen yet
Ex:
Infection in lungs; WBCs engulf (macrophage) the infected cell
Migrates to this place
Then presented on MHC molecule
MHC
Major Histocompatibility Complex
Receptor sticks out of cell
T cells require antigen presentation
B cells latch on to antigen (B cell receptor)
Technically an antibody
Clonal Selection
Activated B cell proliferates
Makes lots of copies
Antibodies
IgM
IgG
IgA
IgE
IgD
IgM
Antibody
1st responder
IgA
Antibody
Secretions
Sweat, milk, and tears
IgG
Antibody
Most abundant
IgE
Antibody
Allergies
IgM vs. IgG
Second time exposed to pathogen, there is a huge IgG response because of memory cells
How antibodies mark for destruction
Neutralization: block receptors
Opsonization: coat antigen with antibody; causes them to clump/stick together
Phagocytosis: antibodies recruit to come kill
Activate complement
Antibody-D: activate natural killer cells
Antibody structure
Double Y
Big ones: Heavy chains
Small ones: Light chains
Variable region
Part that binds to antigen
changes
Constant region
Stays the same
Embedded in membranes
MHC I
Cytotoxic T cells
CD8
MHC II
Macrophages, dendritic cells
T Helper cells
CD4
T Helper Cells
Help; activate:
Cytotoxic T cells, b cells
Secrete cytokines
Don’t kill
Cytotoxic T cells
Activated by MHC I molecules
Seek out and destroy any virus that looks like that antigen
Created perforation, brings granzymes, causes apoptosis
Immune Disorders
Born with lack of T cells
Born with lack of B cells
Born with lack of both
SCID: severe combined immunodeficiency disease
HIV: acquired; not born with
Invades T helper cells and kills them
immunocompromised
Interferons
Part of Innate
Cytokines produced by many eukaryotic cells in response to intracellular infection
Two Types: Type I and Type II
Antiviral
Vasodilation
Blood cells getting bigger
Swelling in inflammation
Ice: vasoconstriction
Hypersensitivities
Immune system is attacking something that doesn’t need to be attacked
4 Types
Type 1 Hypersensitivity
Allergy
Body is making IgE antibodies, basophils; releases histamine (cytokine)
Histamine: causes vasodilation, bronchoconstriction
Swelling and redness; shortness of breath
Topical: Skin rash
Breathable: pollen
Injectants: anything that is injected, and bees; usually life-threatening
Ingestants: anything you can ingest; nuts
Anaphylaxes: epi-fast acting
Type 2 Hypersensitvity
Cytotoxic
Antigen and antibody binding
A blood; can’t get B blood
Hemolytic Blastosis Fatalis
A neg; baby A pos
Grave’s Disease (Hyperthyroidism)
Myasthenia Gravis (Muscular joints)
Type 3 Hypersensitvity
Immune Complex
Happens to partial antigen
Floats around in blood
Going to deposit somewhere in tissue
Lupus and RA
Type 4 Hypersensitvity
Delayed hypersensitvity
Exposed and then reacts days later
Cytotoxic T cells
Poison Ivy; TB skin test