Immunology Lecture 1

Front 1

What are the four major classes of the immune system?

Back 1

Extracellular bacteria, parasites and fungi

Intracellular bacteria and parasites

Intracellular viruses

Extracellular Parasicitic worms

Front 2

What is the chief function of immunity?

Back 2

To discriminate between self and non-self.

Front 3

Immunological diseases can be grouped into two large categories. What are they?

Back 3

Deficiency

Dysfunction

Front 4

Explain Immunodeficiency.

Back 4

Result of absence of one or more elements of the immune system.

Cause is congenital or acquired.

Front 5

Explain Immune dysfunction.

Back 5

Response occurs that is detrimental to the host.

Foreign antigen or self antigen.

Or Inappropriate regulation of an effector response resulting in absence of protective response.

Front 6

According to Gel and Coombs, dysfunctional immune response is classified as ___ diseases.

Back 6

Hypersensitivity (Types 1-IV).

Front 7

Hypersensitivity Type I.

Back 7

Think: "Allergy". IgE

Immediate Hypersensitivity. Aberrant production and activity of IgE against normally nonpathogenic Ag. IgE binds mast cells which causes crosslinking and release of mediators (Histamine, leukotrienes, etc.) as well as chemotaxins and cytokines. Causes allergy symptoms.

Front 8

Hypersensitivity Type II.

Back 8

Think: "Cell Ag and Cytolysis". IgG and complement.

Ab directed against cell membrane-associated Ag. Results in cytolysis.

1. Complement (Cytotoxic Ab)
ex: hemolytic anemias

2. Effector Lymphocytes that bind via Antibody Dependent Cellular Cytotoxicity, ADCC.
ex: virus-induced immunological diseases

Front 9

Hypersensitivity Type III.

Back 9

Think: "Soluble Ag-Ab immune complex & acute inflammatory injury". IgG and complement.

Soluble Ag-Ab immune complex activates complement. Ag is self or foreign (microbial). Complex is deposited on membrane surface of organs. Complement activated (C3a, C5a) are chemotaxin for acute inflammatory cells.
ex: rheumatoid arthritis, systemic lupus erythematosus, and postinfectious arthritis

Front 10

Hypersensitivity Type IV.

Back 10

Think: "Delayed & Macrophage- T Cell- Ag". TH1, TH2, and CTL.

Delayed Type Hypersensitivity involves macrophage, T cell, Ag interaction that cause cytokine secretion, and potential granuloma formation (A granuloma is a medical term for a ball-like collection of immune cells trying to destroy a foreign substance). Vigorous immune response.
ex: Tb, leprosy, sarcoidosis, and contact dermatitis (like a chemical irritant).

Front 11

What would you be suspicious of if a patient presents with chronic infection or chronic inflammatory status, poor wound healing, constant fatigue and malaise, or unresponsive to a vaccine?

Back 11

Suspected immunodeficiency.

Front 12

Define iatrogenic.

Back 12

Disruption in homeostasis can cause immunodeficiency, for example through induced iatrogenic.

Iatrogenic artifact refer to adverse effects or complications caused by or resulting from medical treatment or advice. In addition to harmful consequences of actions by physicians, iatrogenesis can also refer to actions by other healthcare professionals, such as psychologists, therapists, pharmacists, nurses, dentists, and others.

Front 13

The immune system controls malignant cells through a mechanism called ___.

Back 13

Immune Surveillance.

Front 14

Hyporeactivity or ___ includes Congenital immunodeficiency, Acquired immunodeficiency, Malnutrition, and Young/Old age.

Back 14

Immunodeficiency.

Front 15

Hyperreactivity is aberrant immune response and includes ___ and ___.

Back 15

Systemic autoimmunity and Organ-Specific autoimmunity.

Front 16

What is the definition of immunopathology?

Back 16

General term for damage to normal tissue due to the immune reaction to infectious agents or agents.
ex: rheumatic fever, and leprosy.

Front 17

The immune system consists of two overlapping compartments: ___ and ___.

Back 17

Innate immune system and the adaptive immune system.

Front 18

Innate Immune System.

Always/Never present
Constitutive/Selective activity
Specific/Nonspecific
Memory/No Memory
1st/2nd line of defense
Rapid/Slow

Back 18

Always present
Constitutive
Nonspecific
No Memory
1st line of defense
Rapid

Front 19

What does the innate immune system include?

Back 19

Physical Barriers- skin, GI lining, respiratory and genitourinal tracts.

Phagocytic cells- neutrophils, and macrophages.

Protective Chemicals- stomach acid pH and lipids on skin surface.

Enzymes- lysozyme in saliva, intestinal secretions.

Alternate complement pathway- cascase of serum proteins that are activated by bacterial walls.

Front 20

Define Adaptive or Acquired immune system.

Back 20

Only in Vertebrae. Must be induced. Ag-Specific (proteins, carbs, lipids, and nucleic acids). Memory is stronger after the primary response. Regulation discriminates between self and nonself, prevents autoimmune reactions. Slow with days to weeks.

Front 21

Cells of the Adaptive immune system.

Back 21

B Lymphocytes
T Lymphocytes (CD4 and CD8)

Front 22

T Cell Function: Helper Activity.

Back 22

Helps lymphocytes respond to Ag.

CD4, subdivided by phenotype

Front 23

T Cell Function: Delayed Type Hypersensitivity.

Back 23

Activate macrophages to phagocytose pathogens.

CD4

Front 24

T Cell Function: T Cell Mediated Cytotoxicity.

Back 24

Cytotoxic T cells bind to and kill target cells (virus infected and tumor).

CD8

Front 25

T Cell Function: Suppressor T Cells/Treg Cells.

Back 25

Down-regulate the responses of other lymphocytes.

Front 26

Immunoglobins, aka Ab, are produced by B cell lineage and include 5 subtypes. What are they and bonus for the order of most abundant to least.

Note: on surface of B cell or secreted.

Back 26

IgG, IgA, IgM, IgE, IgD.

"G-A-M-E-D"

Front 27

What are the two types of T cell receptors (TCR) called? Note that these are on the T cell surface, not receptors for T cells.

Back 27

ab (alpha beta) and gd (gamma delta) TCR.

Front 28

TCR recognize what?

Back 28

Epitope (Ep). A small region of the antigen (Ag).

Front 29

In a given B or T cell all of its own Ag specific receptors are identical. Except for when?

Back 29

Some B cells can express IgM and IgD simultaneously.

Front 30

The region of the Ig or TCR that binds to the Ep is called the ___.

Back 30

Paratope.

Front 31

Explain VDJ joining which leads to combinatorial diversity.

Back 31

Variable region of the TCR or Ab that contains the paratope is made during B and T cell development PRIOR to exposure of a given Ag. DNA encoding region is V, D, and J segments. Called the GERMLINE configuration. Make one contiguous exon. Note: light chain is just V and J.

Front 32

Explain clonal selection.

Back 32

Generation of an active immune response against a particular Ag. Takes a few days. Activation occurs first with binding of Ag and release of cytokines from helper T cells. Blast cells undergo proliferation with a 100fold increase. Differentiation into effector cells and memory cells for secondary response is the last step.

Front 33

Adaptive immune system has memory. Explain.

Back 33

First response is called the primary response. Second is secondary response and is due to memory cells:

Higher Ab levels
Increased IgG and other Ig
Shorter lag period
Higher Affinity for Ag

Vaccination "primes" and is why boosters are done.

Front 34

Explain how the immune system is tightly regulated.

Back 34

Self-reactive B and T cells are eliminated or inhibited during development through apoptosis. Permanent inactivationis clonal anergy. Inhibition is increased by suppressor T cells, Inhibitory cytokines produced by macrophages, Ab that react with Ag binding site of Ab and T cell receptors- anti-idiotypic Ab.