Introduction to Immunity and the Immune System

Antibodies mediate many different functions which are in large part determined by its ___.

Antibodies mediate many different functions which are in large part determined by its ISOTYPE.

T or F. Cellular immunity is a part of the adaptive immune response.

True

True or False. Antigens can be both immunogens and haptens.

True

What is immunology?

1. The study of host defenses and immune responses 2. The cellular and molecular events that occur after the host has encountered a microbe or foreign macromolecule. 3. The study of pathologies of the immune system that arise due to immune dysfunction.

What are some characteristics of innate immunity?

1. 1st line of defense 2. Provides a variety of germ-line encoded defense mechanisms. 3. Have this immunity prior to exposure 4. Rapid

Describe the binding of linear determinants (epitopes) to antibodies.

1. Bind mostly to unfolded, denatured proteins 2. In some cases, can bind to both native (folded) and denature (unfolded) proteins

What are some characteristics of mast cells?

1. Bind to IgE 2. Release mediators of inflammation 3. Stain with basic dyes

Describe the binding of conformational determinants (epitopes) to antibodies.

1. Binds AA residues of folded proteins 2. Does not bind to denatured proteins

What are some characteristics of basophils?

1. Circulate in the blood 2. Stain with basic dyes 3. Have Fc receptors on their surface

What are some characteristics of eosinophils?

1. Defend against parasitic organisms 2. Increase levels of eosinophils is associated with atopy or allergies. 3. Stain with acidic dyes

What are some characteristics of NK Cells?

1. Derived from lymphoid progenitor cells 2. Not antigen specific (part of innate response) 3. Kill virally infected cells 4. Do not require sensitization

What are some characteristics of mature dendritic cells?

1. Express high levels of both class II MHC molecules and co- stimulatory molecules. 2. Migrates to the lymph node where it acts as a potent stimulator of T lymphocytes.

What are some characteristics of immature dendritic cells?

1. Found in blood and non-lymphoid tissues 2. Express low levels of MHC proteins and do not express co- stimulatory molecules.

What are some characteristics of monocytes/macrophages?

1. Involved in innate and adaptive defense 2. Produce cytokines 3. Exhibit antimicrobial and cytotoxic activities. 4. Express MHC class II molecules on their cell surface. 5. Can be induced to express costimulatory molecules.

What are some characteristics of dendritic cells?

1. Known as interdigitating reticular cells. 2. Phagocytic 3. Fully differentiate once they interact with pathogen

Name some proteins located in the granules of neutrophils.

1. Lysozyme 2. Collagenase 3. Elastase 4. Cathepsin G 5. Defensins 6. Cathelicidins.

What are some characteristics of neutrophils?

1. Most abundant 2. Short-lived (2-3 days) 3. Attracted to inflammatory sites 4. Granules contain lysozyme, collagenase, elastase, cathepsin G, defensins, cathelicidins.

What are some characteristics of active immunity?

1. Occurs follow vaccinations and infections 2. Specific 3. Long-lived 4. Leads to the selection & maturation of antigen specific cell 5. Adaptive immunity

What are some characteristics of adaptive immunity?

1. Produces memory cells 2. Antigen specific 3. Diverse 4. Clonal expansion: cells proliferate to reach sufficient number to fight off infection

What are some characteristics of lymphocytes?

1. Provide adaptive immunity 2. 20-30% of WBC 3. Have antigen specific receptors 4. Undergo clonal selection giving rise to both memory and effector cells.

What are some characteristics of humoral immunity?

1. Provided by the non-cellular portion of the blood. 2. Part of the adaptive (specific) response. 3. Provided by antibodies

What are some characteristics of Cellular immunity?

1. Provided primarily by T-cells 2. Helper T-cells activate macrophages 3. Cytotoxic T-cells kill infected cells

What is passive immunity? What are some characteristics of it?

1. The immunity that is provided by transferring the antibodies from one individual to another. 2. Specific 3. Short-lived (days to months) 4. No memory

What is a hapten?

A foreign particle that does not elicit an immune response.

Describe the binding of neoantigenic determinants (epitopes) to antibodies.

Binds to proteins that have been modified (i.e., glycosylation, phosphorylation, ubiquitination, acetylation, & proteolysis)

How are the immune system and nervous system similar?

Both are sensory systems

Antigen-binding site of antibodies is located where on the antibody?

Fab region

True or False. Humoral immunity is part of the innate immune response.

False. Humoral immunity is part of the ADAPTIVE immune response.

True or False. Passive immunity is very specific and can produce memory cells.

False. Passive immunity IS specific, however, it CANNOT produce memory cells.

___ ____ is provided by transferring the antibodies from one individual to another.

PASSIVE IMMUNITY is provided by transferring the antibodies from one individual to another.