Lecture 7: the three levels of host defense

Question 1

Physical defenses are

Answer 1

Cellular barriers
Antimicrobial molecules

Question 2

Innate immunity is

Answer 2

Blood related (mobile)
-cells
-complement
-interferon

Question 3

Adaptive immunity contains

Answer 3

Cellular
Humoral

Question 4

What physical barriers help prevents infection of parvo?

Answer 4

Stomach
Acidity
Small Intestine
Sudden pH change
Peristalsis- gut movement
Epithelial barrier
Mucus
Bile - antimicrobial substances and enzymes
Gut flora - compete for nutrients and space.

Question 5

Parvo enters through

Answer 5

Ingested
Entry through:
The oral mucosa into the tonsils or LN of the throat
Invades lymphoid cells.
Avoids pH barriers of stomach.

Question 6

How might adaptive immunity help prevent infection of parvo (previously infected/immunized)?

Answer 6

By giving the animal high levels of IgG they are able to get rid of the virus much quicker

Question 7

How does parvo work

Answer 7

Virus attaches to cells by binding to their transferrin receptor.
Viremia followed by widespread infection of:
Rapidly dividing cells → bone marrow, lining of the small intestine
Other tissues may also be affected.
Thrombocytes - thrombocytopenia
Myocardium

Question 8

Possible innate protective mechanisms for parvo?

Answer 8

Interferon
Cell mediated immunity.
-NK cells
Antiviral interferons – IFN-α and IFN-β
Sentinel cells – macrophages and dendritic cells

Question 9

Why is parvo so severe

Answer 9

One reason that canine parvovirus is such a severe disease is that it weakens the immune system by killing off lymphocytes.

Question 10

Possible adaptive immune protection for parvo?

Answer 10

Antigen presentation by dendritic cells
Activation of Th1 cells
Activation of cytotoxic T cells
Activation of B cells to produce IgG
Activation of Th2 cells
Activation of B cells to produce IgA

Question 11

What Types of Immunity are Involved in Defense Against Canine Parvovirus?

Answer 11

Innate Fixed
-Physical barriers
Innate Mobile
-NK Cells
Adaptive Immunity
-Mucosal antibody
-Systemic antibody
-Antibody dependent cell cytotoxicity
-Cytotoxic T cells
Complement

Question 12

Overview of Antibody Mediated Viral Immunity

Answer 12

Fc- mediated cell lysis?
Fc – tail region of Ab
NK cells and some granulocytes, bind Ig, and kill cells.
Antibody mediated cell cytotoxicity