antibodies & aquiring immunity

IgG

Most abundant, 80% of all in blood

Blood, lymph, and intestines

Protects against bacteria and viruses, enhancing phagocytosis and complement system

The only class of antibody to cross placenta from mother to fetus

Is IgG

IgA

0-15 %

Sweat, tears, saliva, mucus breastmilk, G.I. secretions

Localized protection of mucous membranes, levels decrease during stress

IgM

5-10%

Blood, lymph

Secreted by plasma cells after exposure to antigen, activate compliment, Cause agglutination and lysis of microbes, serve as antigen receptors of B cells

Igd

0.2%

Found Surfaces of B cells as Antigen receptors: help Activate B cells

IgE

Least common, 0.1%

Found on mast cells and basophils

Involved in allergic and hypersensitivity reactions:

Naturally acquired active immunity

1. Exposure to microbe

2. Formation of: Antibody-secreting plasma cells, cytotoxic T cells, B and T memory cells

Naturally acquired passive immunity

Antibodies transferred from mother to fetus either via

placenta( IgG) or

breast-feeding (IgA)

Artificially acquired active immunity

Antigens introduced via vaccination

Give in to prevent infection:Body produces memory cells

Artificially acquired passive immunity

Injection of immunoglobulins/Antibodies

Given to treat infection

Positive selection process of T cells maturation

Selects T cells capable of recognizing self – MHC proteins

And those that can’t are destroyed

Negative selection of T cells maturation

Prompts apoptosis of T cells that bind to self-antigens displayed by self – MHC

Define memory T cell

Cell that remains in lymphatic tissue and recognizes invading antigens even years after first encounter

Define B cell

Type of cell that Differentiate into antibody-producing plasma cells

Define plasma cell

A cell that is a descendent of B cell that produces/secretes antibodies

Define memory B cell

Is a descendent of B cell that remains after immune response ready to attack same antigen If enters in future

AIDS

Acquired immunodeficiency syndrome

Person experiences assortment of infections due to destruction of immune cells by HIV virus

HIV

Human immunodeficiency virus

which cell cells does HIV primarily target

Helper T cells (CD4+)