Chapter 16: Adaptive Immunity

Adaptive Immunity

Develops after birth, exposure to pathogens. The body’s ability to recognize and defend itself against invaders.

What are the five attributes of adaptive immunity ?

1. Specificity

2. Inducibility

3. Clonality

4. Unresponsiveness

5. Memory

What are the two types of adaptive immunity ?

1. Cell-mediated immune response

2. Antibody immune response

What cell type is responsible for cell mediated immune response ?

Cytotoxic T cells

What cell type is responsible for antibody immune response ?

B cells

Specificity

Many B and T cells

Inducibility

Only activates adaptive immunity when you need it.

Clonality

Make copies for protection

Unresponsiveness to self

Memory

Long term immunity

What is the purpose of the lymphatic system?

Screen the tissues of the body for foreign antigens.

What are the two primary lymphoid organs ?

Red bone marrow & Thymus. Where B and T cells mature.

What are the secondary lymphoid organs ?

Lymph nodes, spleen, tonsils, MALT

Antigen

Molecules the body recognizes as foreign and worthy of attack.

Epitope

Recognized by 3D regions.

What are the three classifications of antigens ?

1. Exogenous

2. Endogenous

3. Auto-antigens

Exogenous

Outside or on surface, include toxins of microbial cell walls, membranes, flagella, and pili.

Endogenous

Inside, produced by microbes that reproduce.

Auto-antigens

Derived from normal cellular processes. Programs B and T cells to recognize.

What is the major histocompatability complex or MHC?

Activates T cells. Group of antigen first identified in graft patient. Important in determining compatibility of tissues for tissue grafting.

What cells are MHC class I found on?

All cells except RBC’s. Activates cytotoxic T cells and marker is CD8.

What cells are MHC class II found on?

Professional antigen presenting cells. Activates Helper T cells and marker is CD4.

Where are T cells created and matured?

Produced in red bone marrow and matured in the thymus.

What is TCR and it’s function?

T cell receptor. Does not recognize epitopes directly and only bind epitopes associated with MHC protein.

What are the three types of T cells?

1. Cytotoxic T lymphocyte

2. Helper T lymphocyte

3. Regulatory T lymphocyte (shut down immune response with pathogens)

What is the process of clonal deletion of T cells?

Killed in response to our own tissues. Only one chance.

Where are B cells created and where are they found in the body?

Primarily in spleen, lymph nodes, MALT

What is a BCR?

B cell receptor

What are antibodies? How are they different than the BCR?

Are immunoglobulins similar to BCR’s secreted by activated B cells called plasma cells.

What are the five functions of antibodies?

1. Activation of complement and inflammation

2. Neutralization- bind and prevent interference

3. Opsonization- coating outside of pathogen, trigger phagocytosis.

4. Agglutination- clumping, happens if you give the wrong blood type.

5. Antibody-dependent cellular cytotoxicity

What are the five class of antibodies ?

1. IgM

2. IgG

3. IgA

4. IgE

5. IgD

IgM

First antibody produced during immune response.

IgG

Most common and longest-lasting antibody.

IgA

Associated with bodily secretions

IgE

Involved in response to parasitic infections and allergies.

IgD

Exact functions is not known, B cell development.

What are cytokines?

Soluble regulatory proteins that act as intracellular signals. Secreted by various leukocytes. Chemical signals.

What are five groups of cytokines?

1. Interleukins

2. Interferons

3. Growth factors

4. Tumor necrosis factor

5. Chemokines

Interleukins

Signal among leukocytes, WBC’s communicate

Interferons

Antiviral proteins that may act as cytokines.

Growth factors

Proteins that stimulate stem cells to divide in bone marrow. Promote growth in stem cells.

Tumor Necrosis Factor

Secreted by macrophages and T cells to kill tumor cells, regulate immune response and inflammation.

Chemokines

Chemostatic cytokines that signal leukocytes to move.

What does cell mediated immunity help protect against ?

Cancer cells, intracellular Protozoa and intracellular bacteria.

What happens after a cytotoxic T cell is activated ?

Kills targets

What are two ways in which cytotoxic T cells kill targets?

1. Perforin-Granzyme pathway

2. CD95 pathway

Perforin-Granzyme Pathway

Involves synthesis of special killing protein.

CD95 Pathway

Mediated through glycoprotein on body cells.

Memory T cells

Some activated T cells become memory T cells. Last up to month or years in lymphoid tissues.

Plasma cells

Majority of cells produced during B cell proliferation. Only secrete antibodies. Short-lived cells that die within a few days of activation.

How long can memory B cells live?

Decades

What is a antibody immune response?

Activated only in response to specific pathogens.

Primary immune response

Small amounts of antibodies and may take days to produce enough antibodies.

Secondary immune response

Much faster than primary immune response. Memory cells respond to another exposure to antigen.

Naturally acquired immunity

Response against antigens encountered in daily life.

Artificially acquired immunity

Response to antigens introduced via vaccine.

What type of immunity is produced by the body when a person gets a disease?

Naturally Acquired Active Immunity