Lecture 21: Immunity to Infection Flashcards Preview

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Flashcards in Lecture 21: Immunity to Infection Deck (27):
1

The principal protective immune response against BACTERIA in extracellular space and in plasma consists of specific ___1____ that ____2____ bacteria for phagocytosis by macrophages and neutrophils

Specific antibody and complement can also LYSE gram __3___ bacteria and OPSONIZE gram __4___ bacteria

1. antibodies
2. opsonize

3. negative

4. positive

2

Specific antibodies neutralize toxins produced by bacteria or viruses?

BACTERIA

(Tetanus Toxoid --> antibody binds to toxin before it can interact with the cell surface)

3

Describe how the following BACTERIAS are destroyed by the body.

1. Erythrogenic toxin Streptococcus
pyogenes

2. Staph. Aureus

3. Strep. Pneumoniae

4. Neisseria Meningitidis

1. Strep. Pyogenes
** Neutralization w/ ANTIBODY (gram +)

2. Staph. Aureus
**Ab/Complement to opsonisize

3. Strep. Pneumoniae
**Ab/Complement to opsonisize

4. Neisseria Meningitidis
** MAC** (gram -)
- lyse and ingest via complement

4

Immunity against intracellular bacteria is principally cell-mediated and consists of______cells that activate macrophages by the production of cytokines.

What is an example of such a disease?

CD4+ Th1

Myobacterium Tuberculosis

- recruit MHCII via DC cells like Langerhan Cells in the skin when testing for TB

5

PROTECTION FROM VIRUSES:

 Viruses are obligatory microbes found where? (intra/extracellular)
 
Innate immunity against viruses is mediated by what 2 things?
 

1. intracellular

2. cytokines and NK cells

6

What do the following describe for viruses?

1. Specific cytotoxic T lymphocytes (CTLs).
 
2. Specific antibodies, synthesized prior to T cell mediated killing of infected cells.

ADAPTIVE IMMUNITY against viruses

(ex: influenza)

7

What is usually produced immediately in a cell?

Next?

third?

1. IFN alpha, TNF-a & IL-12

2. NK mediated killing

3. CD8 cytotoxic killing

8

Antigen presenting cells are resident in almost all tissues and are found in particularly large numbers at _____ sites.

What cells are present in large numbers initially in the cell?

Macrophages and neutrophils possess receptors, which enable them to bind and do what to microorganisms?

1. mucosal

2. Neutrophils

3. phagocytose

9

What B cell types are present 3-4 days after antigen entry?

What isotope appears after 2-3 weeks?

What follows the production of Ab?

What is the final result of all this?

1. IgM

2. IgG

3. CTL (cytotoxic T lymphocytes)

4. IMMUNOLOGICAL MEMORY

10

In diseases caused by exotoxigenic organisms (e.g., Clostridium tetani toxin causes tetanus), the function of the immune response is not only to ELIMINATE the invading organism but also to do what to any toxin?

How does this occur?

neutralize any toxin.

- Antibody blocking the combination between the toxin and its target

(toxin blocks the inhibitory neuron action potential leading to chronic muscle contraction)

11

Neutralization by antibody binding is found in response only to what type of organisms?

Toxin Producing BACTERIA (not viruses!!!)

- need antibody for tetanus toxin for example

12

The following describe direct mechanisms for virus or bacteria?

1. Cytotoxic T lymphocytes
2. NK cells
3. Interferons

VIRAL infectious agents (not bacterial)

13

The following describe direct mechanisms for virus or bacteria?

1. Neutrophils and macrophages
2. Antibody
3. Ab + Complement (to surface antigen)
4. Activated Macrophages (TMMI)

VIRAL and BACTERIAL!!!!

BOTH

14

What are 3 EXTRAcellular microorganisms?

3 Intracellular?

1. Bacteria
2. Fungi (single celled eukaryote)
3. Parasite (multicellular euk.)

INSIDE the cell:

1. Bacteria
2. protozoa
3. Viruses

15

True or False:

Antibody directed complement lysis (MAC) is used to digest gram + bacteria.

FALSE

- for gram negative only!

(Opsonization & Phagocytosis is for both gram negative & positive)

16

Which is gram (-) and which is gram (+)?

1. Neisseria
2. Staph. Aureus

1. Neisseria (-)
2. Staph. Aureus (+)

17

How is Strep. Pneumonia removed from the system?

- anti-phygocytic capsule prevents recognition by innate imune mechanisms

****require both ANTIBODY and COMPLEMENT to promote efficient clearance by phagocytes

18

What can protect from Neisseria GONORRHEA ?

What protects against Candida Albicans fungus?

How are parasites like SCHISTOSOME MANSONI removed from the system? What specific cells are involved?

1. Secretory IgA

2. Phagocytic cells activated by cytokines

a) AB + COMPLEMENT
b) Antibody dependent Cellular Cytotoxicity (ADCC)
- mediated by eosonophils!

19

How is tuberculosis eliminated? What is generally ineffective?

What kind of microorganism is this? (intra/extracellular)

1. Th1 TMMI

2. Antibody is ineffective since it is
--->
3. INTRACELLULAR

20

What is involved in viral intracellular microorganisms?

1. Complement
2. Antibody and complement coated viruses
3. Interferons(IFN), NK cells, Antibody, CTL

21

What produces IFN alpha?

IFN - beta?

What is the function of Type 1 IFN? (either alpha or beta)

What is an example of a Type II IFN and what produces it?

1. IFN - a = LEUKOCYTES

2. IFN - B = FIBROBLASTS (any cell in the body)

3. Prevent the synthesis of viral proteins

4. IFN - GAMMA produced by Th1 lymphocytes

22

What is the target of IGN - Gamma?

Macrophages & APCs

23

What 2 enzymes does the antiviral interferon stimulate?

1. Synthetase
2. Protein Kinase

24

What is the function of the following antiviral IFN enzymes:

1. Synthetase
2. Protein Kinase

1. Synthetase
- activates ribonuclease to degrade viral mRNA
(RNAase)

2. Protein Kinase
- phosphorylates EIF-2
- phosphorylated EIF-2 cannot help in the formation of initiation complex for PROTEIN SYNTHESIS and viral mRNA is untranslated

25

What system of killing is necessary for the following pathogens? (test)

1. Influenza virus
2. Candida albicans
3. Streptococcus pneumoniae
4. Neisseria meningitidis

1. Influenza virus - MANY mechanisms

2. Candida albicans - AB/Complement Phagocytosis
(fungi --> need cytokine activated phagocytes)

3. Streptococcus pneumoniae - Ab/Complement

4. Neisseria meningitidis
- Antibody directing complement LYSIS = MAC

26

What system of killing is necessary for the following pathogens? (test)

5.Clostridium tetani
6. Mycobacterium tuberculosis
7. Schistosoma mansoni

5.Clostridium tetani
- ANTIBODY

6. Mycobacterium
tuberculosis
= CD4+ Th1 cells!

7. Schistosoma mansoni
= IgE and Eosonophils
(parasite)

27

Mechanisms of anti-viral immunity include all of the folllowing except:

1. Ab/complement mediated viral lysis
2. Ab/complement mediated opsonization for enhanced phagocytosis
3. Ab neutralization of toxins
4. Intracellular destruction by activated macrophages
5. NK cells

3. Ab neutralization of toxins!!!

- this is only for BACTERIA


Ex: TETANUS toxin (bacterial)