Unit 3 ( Immunity and Hypersenitvites)

Immunity

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