immune physiology innate and adaptive immunity

Primary functions of the immune system…

Distinguish being self and not self entities

Distinguishing self and not self entities is crucial for…

Maintaining homeostasis

Protecting body from pathogens

Non self refers to…

Foreign entities

Foreign entities are…

Bacteria

Viruses

Fungi

Tumor cells that can cause disease

Immune system also recognizes non self antigens that include…

Food and drug molecules that may provoke an immune response

Types of immunity are…

Innate immunity

Adaptive immunity

Innate immunity is…

First line of defense

Non specific

Rapid response to pathogens

In-born does not require exposure

Adaptive immunity is…

Highly specific

Develops over time

Requires expose to specific antigens to mount an effective response

Innate immunity includes…

Leukocytes

Phagocytic cells

Natural killer cells

Leukocytes include…

Neutrophils

Monocytes

Natural killer cells

Phagocytic cells include…

Neutrophils

Macrophages

Phagocytic cells role is…

Engulf and destroy pathogens

Non leukocyte cells include…

Physical barriers like skin and mucosal surfaces

Physical barriers prevent…

Pathogen entry

Phagocytosis uses…

Lysosomal enzymes

Inflammatory response is initiated when…

A break in epithelial barrier

A break in epithelial layer results…

Recruitment in immune cells of the site of infection

Chemical mediators are…

Histamine

Cytokines

Histamines and cytokines are realeased…

To facilitate communication between immune cells

Communication between immune cells…

Amplifies the immune response

Adaptive immunity is characterized by…

Specificity

Memory

Specificity and memory allows…

More effective response upon subsequent exposures to the same pathogen

T lymphocytes and B lymphocytes are…

Primary players in adaptive immunity

T cells are…

Educated in thymus

Learn to recognize specific antigens

B cells…

Mature in bone marrow

Learn to recognize specific antigens

Humoral immunity is…

Production of antibodies by B cells in response to specific antigens

Antibodies are called…

Immunoglobulins

The five cases of immunoglobulins are…

IgG

IgA

IgD

IgE

IgM

B cell activation occurs…

An antigen binds to its specific receptor

When an antigen binds to a B cell….

Leads to colonal selection and expansion

Colonal selection and expansion in B cells produce…

Antibodies

Resident macrophages detect…

Bacteria

Resident macrophages initiate the response by….

Releasing chemokines to attract other immune cells like neutrophils and monocytes

Neutrophils and monocytes willl…

Migrate to the site of infection

How do neutrophils and monocytes migrate…

Extravasation

Extravasation is…

Squeezing between endothelial cells

Signs of inflammation…

Redness

Heat

Swelling

Pain

Redness heat swelling and pain result from…

Increased blood flow and accumulation of immune cells at site of infection

Neutrophils release…

Enzymes and chemicals

Enzymes and chemicals from neutrophils…

Damage surrounding tissues

From damage of surrounding cells…

Pus formation as dead cells and debris accumulate

Excessive inflammation can…

Lead to tissue damage and chronic inflammatory conditions

Primary immune response…

Upon first exposure

5-18 days

May become ill

Vaccination does…

Mimics by stimulating adaptive immune system

Creation of memory cells without causing disease

Passive immunity is conferred through…

transfer of antibodies from another being

The transfer of antibodies…

Do immediate but temporary protection

Passive immunity is crucial for…

Newborns

Newborns receive antibodies through…

Placenta

Breast milk

The placenta and breast milk particularly produce…

Colostrum

Therapeutic antibodies are…

Biologics used in modern medicine to provide immunity against specific diseases

Therapeutic antibody examples are…

Humira and Herceptin

Antibodies bind to antigens on target cells to…

Mark for destruction

Binding of antibodies activate…

Complete cascade

Complement cascade is…

Enhancing the immune responses

Complement cascade leads to…

Lysis of target cells

Complement cascade is important because…

Clears infections

Prevents spread of pathogens within the body

Types of T lymphocytes

Helper T cells

Cytotoxic T cells

Regulatory T cells

Helper T cells also known as…

Th cells

Cytotoxic T cells also known as…

Tc cells

Regulatory T cells also known as…

Treg

Th cells express…

CD4

T cells play a role in….

Orchestrating immune response by activating other immune cells

Tc cells express…

CD8

Cytotoxic T cells are responsible for….

Directly killing infected or cancerous cells

Treg maintains…

Immune tolerance and suppress excessive inflammatory responses

T cells can NOT…

Soluble antigens

T cells require antigens to…

Be presented by antigen-presenting cells

Antigen presenting cells known as…

APCs

APCs include…

Dendritic cells and macrophages

Dendritic cells and macrophages can…

Process and present antigens to T cells

Initiate immune response

APCs and T cells interaction is critical for…

T cell activation

Subsequent immune response against pathogens

Major histocompatibility complex also known as…

MHC

MHC molecules…

Are essential for immune system to recognize foreign antigens

What do MHC molecules do

Present antigens on the surface of cells to T cells to make an immune response

MHC class 1…

Is recognized by CD8

MHC class II is…

Recognized by CD4

MHC cells must…

Be recognized as self to prevent autoimmune reactions

T cells when activated…

Migrate to infected tissues to combat pathogens

When activated T cells will…

Encounter APCs that display antigens via MHC molecules

When recognized the antigen MHC complex…

T cells will undergo clonal selection and expansion

When T cells undergo clonal selection…

Leads to a robust immune response

Interaction between T cells and APCs is crucial because…

Activates CD4 and CD8 T cells

When CD4 and CD8 are activated…

Proliferate and differentiate into effector cells

HIV targets…

CD4 cells

HIV leads to…

Immunodeficiency and increased susceptibility to infections

CD8 will…

Kill target cells through release of cytotoxic granules containing performing and granzymes

Performing and granzymes induce…

Apoptosis in infected cells

CD8 T cells are essential for…

Controlling intracelluar pathogens and transplant rejection

Natural killer cells are…

Innate immune system

NK cells help…

Tumor immunity and can respond rapidly to viral infections

NKT cells are a subset of NK cells and…

Part of adaptive immunity

NKT cells recognize…

Lipid antigens presented by CD1 molecules

Treg cells are important for…

Maintaining tolerance to self antigens

Mucosal sites where exposure and non self antigens are frequent

Allergies are…

Exaggerated immune response to harmless antigens

Allergies result in…

Tissue damage and inflammation

Immediate hypersensitivity reactions…

Involve Th2 cells that promote IgE production

IgE production and Th2 cells will…

Recruit eosinophils and cause sneezing and itching

Delayed type hypersensitivity are…

Mediated by T cells and do not involve antibodies

Because delayed type sensitivity do not involve antibodies…

Require corticosteroids for treatment

Autoimmune diseases occur when…

Immune system attacks self antigens