Immunity to Microorganisms-L12 Flashcards Preview

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Flashcards in Immunity to Microorganisms-L12 Deck (10):
1

Mechanisms of innate immunity

1. Skin
2. pH barriers
3. Flushing
4. Lysozyme--destroys cell walls
5. Phagocytes
6. Complement

2

Staph aureus protein A

Binds to and blocks opsonizing action of IgG

3

Strep pneumonia

Antiphagocytic capsule

4

M protein

Antiphagocytic factor

5

Antibody can:

-Prevent attachment to epithelium (Secreted IgA)
-Trigger complement
-Bind to antiphagocytic M proteins or capsules and act as an opsonin
-Neutralize toxins
-Neutralize spreading factors

6

Facultative intracellular parasites

-Can survive inside the phagosome. Activated macrophages may be able to kill better. TH1 response.

7

Cell mediated immunity is important for:

-Listeria monocytogenes
-Mycobacterium tuberculosis
-Mycobacterium leprae

8

Most important mechanisms in the clearance of parasites

T cell response. Cytotoxic T cells may kill cells infected with parasites. T cells activate macrophages that kill many different parasites.

9

Mechanisms by which parasites escape the immune response

1. Inaccessibility--form cysts or hide in host cells
2. Avoidance of recognition--vary cell surface antigen expression or pick up self antigen
3. Immunosuppression
4. Survive inside macrophages

10

Mechanisms of antiviral immunity

-Antibody--neutralize the virus
-Localized IgA responses
-Ab mediated lysis of virions (with complement)
-Cytotoxic T cells
-Interferons--gamma interferon activates macrophages