17.3 Immune Responses - BIO

Adaptive immune response

Antigen, molecule that stimulates an immune reaction by B and T cells, and divided into 2 subcategories

Macrophage

First cell types to respond to infection, triggers adaptive immunity

The adaptive immune response begins….

When a macrophage engulfs a bacterium and dismantles it, antigen are displayed on the macrophage surface

Second steps of response

At a lymph node, helper T cells initiate and coordinate the immune responds, helper T cells bind to antigens on the macrophage

Third step

Binding activates the T cells initiate, which divides into a memory and effector cell

Fourth step

the effector cell releases cytokines that activate other cells

Cytokines activate (5)

The cell mediated, and humoral immune responses

Cell mediated immunity (6)

Defensive cells kill body cells that are defective

Cytotoxic T cells

Provide cell mediated immunity by physically binding to and destroying “suspicious” cells, mid to bacteria antigens and release toxic chemicals to kill cell

Humoral immunity ( 7)

Begins with cytokines stimulating the differentiation of B cells into plasma cells

Antibodies

Proteins that recognize specific antigens

Constant regions

Comprised of amino acid sequences at are similar in al antibody molecules

Variable regions

Differ a great deal among antibodies, determine the specific target antigen to which antibody binds

Antibodies that bind to antigens…

Have three effects, inactive pathogens, make pathogens more obvious and activate complement proteins

Passive or active immune

Free antibodies in persons IS might is result of this

Memory cells

Linger after the initial exposure to the antigens in the vaccine, thanks to this the secondary IR is faster and stronger