ANAPHY LEC - Immune System

Immunity

Ability to destroy pathogens; further preventing infectious cases

1st line of Immunity

Skin, Mucous membrane & secretions, Normal Flora

Normal Flora

probiotics or good bacteria

2nd line of immunity

Innate immune cells, inflammation, complement, and antimicrobial substances

Examples of innate immune cells

phagocytes (macrophages, neutrophils, and dendritic cells), natural killer (NK) cells, and other cells like mast cells, basophils, and eosinophils

Complement

can coat pathogens, making them more easily recognized and engulfed by phagocytic cells

3rd line of immune system

Specialized lymphocystes (i.e. B cells & T cells)

B Cells

Produce Antibodies to neutralize foreign invaders

T cells

DIRECT KILLERS; involved in cell-mediated immunity, directly attacking infected or cancerous cells

Helper T cell

Type of T cell: coordinate the immune response by activating B cells and other immune cells.

Cytotoxic T cells

Type of T cell: directly kill infected or cancerous cells.

Regulatory T cells

Type of T cell: help to dampen the immune response and prevent autoimmunity.

Memory T cells

Type of T cell: provide a faster response upon subsequent encounters with the same antigen. 

NK Cells

RAPID; can kill infected or stressed cells more quickly than T cells; don't recognize specific antigens

Innate/ Natural Immunity

aka non-specific response; immunity present at birth

Adaptive / Acquired Immunity

aka specific response; develops throughout life after exposure to specific pathogens or antigens

Skin

barrier in the 1st line of defense

tears, saliva, urine

washes away pathogens

Langerhans cells

found in the epidermis; initiating immune responses by capturing antigens and presenting them to T cells in lymph nodes.

Phagocytic Cells

ingest and destroy foreign substances

Dendritic cells

aka interdigitating dendritic cells; T Cells responding against protein antigens

Fever

increases metabolic rate inhibiting microbial multiplication; inactivates enzymes

Interferon

signaling proteins produced by the body's cells in response to viral infections and other threats

Type I Interferon

Type of Interferon: antiviral properties and can also induce the expression of other immune-modulating molecules. 

Type II Interferon

Type of Interferon: produced by T cells and natural killer cells; plays a role in cell-mediated immunity, inflammation, and tissue repair.

Type III Interferons

Type of Interferon: induced by viral infections and are known to play a role in antiviral defense and modulating immune responses.

Classical Pathways

Type of Complement Pathway: activation pathways triggered by the binding of antibody-antigen complexes to the C1 complex

Alternate Pathways

Type of Complement Pathway: helps to recognize and eliminate pathogens through direct killing or stimulation of phagocytosis, and it can be activated spontaneously or by contact with foreign surfaces

Humoral Immunity

provided by B Cells and involves body fluuids; provides immunity to toxins

Cell Mediated Immunity

provided by T Cells; provides immunity to fungi

Antibodies

aka gamma globulins/immunoglobins; attaches to multiple cells making clumps

Cytosis

Candy coating of bacteria for phago

Neutralization

antibodies block the activity of pathogen

Agglutination

multiple pathogen are connected by antibody molecules

Opsonization

pathogen bound by antibodies are more efficiently engulfed

Complement activation

antibodies bound to pathogens activate complement cascade inducing lysis of the cell

Enhanced NK cell activity

abnormal body cells that are bound by antibodies are recognized by NK Cells and are lysed

Active Immunity

uses own/natural antibodies; long term

Passive Immunity

uses ready-made/external antibodies; absence of T memory Cells

Natural Active Immunity

produces antibodies in response to exposure to pathogenic infection; challenge and response

Artificial Active Immunity

producing antibodies in response to the controlled exposure to an attenuated pathogen; Vaccination

Natural Passive Immunity

Receiving antibodies from other organism; breast milk

Artificial Passive Immunity

Receiving manufactured antibodies via external delivery; blood transfusions with antibodies

Antigens

substance that stimulate adaptive immune response (specific)

Foreign Antigens

introduced from outside the body

Haptens

small molecules capable of combining larger molecules to stimulate adaptive immune system response

Self-Antigens

molecules produced by the body that stimulate an immune system response

Autoimmune Disease

result when self-antigen stimulate unwanted destruction of normal tissue

IgG

crosses placenta to protect fetus

IgM

complement activation, agglutination, and neutralization; early stage of immunization

IgA

agglutination and neutralization; protect against pathogen

IgD

part of B cell receptor; activates basophils and mast cells

IgE

Trigger release of histamines from basophils and mast cells; protect against parasitic worm

Lymphocytes

White blood cells formed in the bone marrow and active in the lymphatic tissue

Bone Marrow

place of maturation of B cells

Thymus Gland

place of maturation of T cells