Lecture 1 (8/21 & 8/23)

Question 1

What is immunology?

Answer 1

The state of protection from infectious disease - invasion by “non-self” agents.

Has specific and nonspecific components.

Question 2

What is the body’s first layer of defense?

Answer 2

Physical barriers: nonspecific, inborn, and unchanging.

Question 3

What is the body’s second layer of defense?

Answer 3

A specific response:

Two branches

Recognizes intra and extracellular pathogens

Tolerant of self

Remembers

Question 4

Specificy resides in and is solely characteristic to which cells?

Answer 4

lymphocytes

Question 5

What does the process of immunity involve?

Answer 5

Trapping and processing the invader;

Binding and recognition of the invader;

Destruction of the invader;

Memory of the invader

Question 6

What are the two types of immunity?

Answer 6

Innate and adaptive

Question 7

Discuss in terms of time how long it takes for antibodies to build up against pathogens for both innate and adaptive immunity.

Answer 7

Innate immunity can take a matter of hours;

Adaptive immunity can take days to build up immunity.

Question 8

The nonspecific component of innate immunity is based on what four barriers? Describe each.

Answer 8

Anatomic: skin (mechanical barrier retards the entry of microbes by having a pH of 3-5) and Mucous membranes (Mucous entraps foreign microorganisms and cilia propel the microorganisms out of the body)

Physiologic: temperature (inhibits growth of some pathogens; fever response can also inhibit the growth of some pathogens), Low pH (acidic pH of stomach kills most ingested microorganisms); Chemical Mediators (lysozyme cleaves bacterial cell wall; interferon induces antiviral state in uninfected cells; complement lyses microorganisms or facilitates phagocytosis)

Phagocytic/Endocytic Barriers: various cells internalize (endocytose) and break down foreign macromolecules; specialized cells internalize (phagocytose), kill, and digest whole microorganisms

Inflammatory Barriers: tissue damage and infection induce leakage of vascular fluid, containing serum proteins with antibacterial activity, and influx of phagocytic cells into the affected area

Question 9

Name a few components of anatomic barriers as they relate to innate immunity.

Answer 9

Skin/Mucous Membranes: epidermis and dermis form the physical barrier, keratin, and cilia

Other components: sebum, fluids mucus, normal flora, structures

Question 10

Name a few components of physiological barriers as they relate to innate immunity.

Answer 10

Temperature, pH, O² tension, and soluble factors such as: enzymes (lysozymes, lactoperioxidase), inferferon (cytokine), complement, and lactoferrin (binds iron and sequesters it away)

Question 11

What is endocytosis/phagocytosis based on?

Answer 11

Concentration

Question 12

Determine which of the following forms of endocytosis/phagocytosis are selective, specific, nonspecific: pinocytosis, receptor-mediated endocytosis, and phagocytosis.

Answer 12

Pinocytosis: (the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane) non-specific

Receptor-mediated endocytosis: (a process by which cells internalize molecules (endocytosis) by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being internalized) selective

Phagocytosis: (ingestion of bacteria or other material by phagocytes and ameboid protozoans) done by specific cells

Question 13

Phagocytosis of bacteria occurs in 5 steps. Describe those steps in detail.

Answer 13

1. Bacteria becomes attached to the membrane evaginations called pseudopodia
2. Bacteria is ingested forming a phagosome
3. Phagosome fuses with lysosome
4. Lysozomal enzymes digest captured material
5. Digestion products are release from the cell

Question 14

The binding of which molecule will stimulate a signal transduction that will alter the gene’s phenotype?

Answer 14

TLR