Unit 3 ( Immunity and Hypersenitvites)

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