Chapter 16 study guide Microbio

Adaptive immunity

A specific, targeted, and remembered response to viral infection that is mainly mediated by lymphocytes.

Cell-mediated immune response

An immune defense that does not use antibodies and instead relies of T cells, macrophages, and chemical signals called cytokines to destroy infected cells

Antigens

Foreign molecules that are identified and targeted by the immune system as “non-self”

Epitopes

The specific 3D structures that an immunoglobulin (antibody) or TCR can bind to. These are also the units that compose antigens

Major Histocompatibility Complex (MHC)

A large group of genes encoding cell surface proteins that display peptide fragments to T cells, helping the immune system distinguish self from non-self. These proteins act as molecular identification tags on cell surfaces.

Antigen-Presenting Cells (APCs)

Crucial for initiating adaptive immune responses by presenting antigens to T cells

Cytokines

Soluble regulatory proteins that act as chemical messengers between immune cells, facilitating intercellular communication

Antibodies

Also known as immunoglobulins, these are Y-shaped proteins manufactured by the immune system to find and destroy harmful pathogens

Clonal expansion

Interleukin-2 (IL-2) stimulates the Tc (Cytotoxic T cell) to divide rapidly, creating a clone of identical Tc cells.

It is the rapid multiplication of genetically identical cells produced from a single parent cell.

Apoptosis

The programmed, orderly self-destruction of a cell. Uses internal enzymes to break down old or damaged cells without causing harm or swelling to nearby tissue

Antibody-mediated immune response

Also known as humoral immunity, this is an adaptive immune process driven by B lymphocytes (B cells).

Specificity

Attribute of adaptive immunity in which each immune response targets a unique antigen

Inducibility

Attribute of adaptive immunity in which the response is activated only when an antigen is present

Clonality

Attribute of adaptive immunity in which activated lymphocytes proliferate into identical clones

Self-tolerance

Attribute of adaptive immunity in which the immune system is unresponsive to the body’s own antigens

Memory

Attribute of adaptive immunity in which a faster and stronger response occurs upon re-exposure to the same antigen

Where to B lymphocytes (B cells) originate?

In pluripotent stem cells in the bone marrow

Where do B lymphocytes mature

In the bone marrow

What are B lymphocytes primarily responsible for

They are responsible for Humoral (antibody-mediated) immunity

What to B lymphocytes protect against

Free bacteria, toxins, and viruses in body fluids

B lymphocytes are activated by what type of antigen?

Exogenous antigens which are presented on MHC II receptors

B lymphocytes differentiate into what?

Plasma B cells which secrete antibodies

T lymphocytes originate where?

In pluripotent cells in the bone marrow

T lymphocytes mature where?

They mature in the thymus

T-lymphocytes are responsible for what type of immunity

They are responsible for cell-mediated immunity

Where do T lymphocytes circulate

In the lymph and blood

T lymphocytes are activated by what type of antigen?

Endogenous antigens which are presented on MHC I receptors

Cytotoxic T cells (T_c )

Possess CD8 co-receptors and directly kills infected cells

Helper T cells (T _H)

Possess CD4 co-receptors and regulate immune responses

What do T lymphocytes defend against

Viruses, bacteria, and cancer cells WITHIN host cells

Exogenous antigens

Antigens found outside of body cells.

Examples of exogenous antigens

Toxins, Microbial cell wall components, flagella, and pili

Endogenous antigens

Antigens produced by microbes that are reproducing inside host cells

Example of endogenous antigens

Viral proteins inside an infected cell

Autoantigens

Antigens derived from normal cellular processes. Normally, the immune system exhibits tolerance to these antigens which prevents an attack

Foreign molecule recognition

The immune system recognizes and targets antigens as foreign

Microbial sources of antigens

Bacterial cell walls, flagella, pili; proteins of viruses, fungi, and protozoa.

Environmental sources of antigens

Food particles, dust, pollen