Immune System Flashcards Preview

Step 1 > Immune System > Flashcards

Flashcards in Immune System Deck (30):
0

IL-1

Fever
Acute inflammation, chemokine secretion

From macrophages

1

IL-2

stimulates T cell growth, and activates NK cells

From T cells

2

IL-3

Stimulates growth & differentiation of cells in BONE marrow

From T cells

3

IL-4

Induce Th2 differentiation & B cell growth/switching

From Th2 cells

4

IL-5

B cell growth & switch to IgA, & eosinophils

From Th2 cells

5

IL-6

Fever & acute phase proteins

From macrophages & Th2 cells

6

IL-10

ANTI-inflammatory!
Inhibits activated T cells & Th1 cells

From Th2 cells & Tregs

7

IL-8

Neutrophil chemotaxis

From macrophages

8

IL-12

Differentiation of T cells to Th1 cells, activate NK cells

From macrophages & B cells

9

TNF-alpha

Septic shock! Activates endothelium
Also insulin resistance

From macrophages

10

INF-gamma

*anti-viral & anti-tumor!
Activates macrophages & Th1 cells, inhibit Th2 cells

From Th1 cells

11

Case: Young child > 6 mo. old w/ recurrent bacterial infections, low # B cells, and low Igs of all classes.

"Bruton's Agammaglobulinemia;" X-linked Recessive.
tyrosine kinase gene defect --> no B cell maturation
=> no opsonization

12

Case:
Patient has anaphylaxis to blood transfusion, also some Hx of sinopulmonary infections & chronic GI infections.

Selective IgA deficiency. *common.
LOW IgA, but normal IgM & IgG.
* anaphylaxis to transfusion bc contained IgA!
*may have false-positive beta-hCG tests (has heterophile Ab)

13

Case:
Age 20-30, recent increase in sinopulmonary infections. Low plasma cell on work-up.

"CVID" = Common Variable ImmunoDeficiency
(mech unknown, can be acquired as young adult)
B cell maturation defect -> normal # B cells but low plasma cells & Ig
* increased risk auto-immune disease

14

DiGeorge Syndrome

22q11 del. => fail to form 3rd & 4th pharyngeal arches
1. tetany (hyperCa2+ bc missing parathyroids)
2. recurrent fungal or viral infections (T cell def bc thymus aplasia)
3. congenital heart and great vessel defects

15

Cause of disseminated mycobacterial infections

IL-12 deficiency --> decreased Th1 response => low IFN-gamma

16

Case:
Patient with...
1. Coarse Facies, 2. cold/non-inflamed staph abscesses
3. retained primary teeth, 4. eczema, 5. high IgE

Hyper-IgE syndrome/Job's Syndrome
= failure to produce IFN-gamma => neutrophils can't respond to chemotactic stimuli

17

2 causes of SCID (Severe Combined Immunodeficiency)

1. defective IL-2 (X-linked Recessive)
2. Adenosine DeAminase def. (AR)
=> failure to thrive bc recurrent serious infections of all kinds
* absent germinal centers & T cells

18

Patient presents w/ this triad:
1. cerebellar defects/ataxia
2. spider angiomas
3. IgA deficiency

= Ataxia-Telangiectasia
(ATM gene mut --> DNA repair problem)
*increased AFP

19

Case: patient presents w/...
1. thrombocytopenic purpura
2. eczema
3. recurrent pyogenic infections
tests show: high IgA & IgE, low IgM

Wiskott-Aldrich Syndrome (WAS mut., X-linked).
= T cells can't recognize actin skeleton

* risk inf. by: N meningitis, H influ, Strep pneumo, PCP

20

Case:
Infant w/ recurrent bacterial infections but NO pus formation. Also had slow healing umbilical stump.

LAD-1 (Leukocyte Adhesion Deficiency)
= defect in LFA-1 => lymphocytes can't migrate INTO tissues
(diapedesis blocked)
* also: neutrophilia.

21

Case:
Patient w/ recurrent staph & strep infections.
Other Hx: partial albino & peripheral neuropathy

Chediak-Higashi Syndrome (AR)
= Lysosomal trafficking gene mut
--> lysosome-phagosome fusion problem.
*giant granules in neutrophils

22

patient w/ lack of NADPH oxidase.
Disease = __?__

= Chronic Granulomatous Disease,
--> granulomatous skin lesions
*increased risk infection w/ catalase + organisms
(Staph aureus, E. coli, aspergillus)

23

positive selection (B & T cells)

only cells that recognize self-MHC survive

24

Negative selection (B & T cells)

cells that react to self-Ag killed (prevent autoimmune rxns)

25

BCR vs. Antibody

same function (bind antigens)... But:
BCR = attached to plasma membrane, w/ transmembrane segment
Antibody = secreted from plasma cells (NO transmembrane domain)

26

CD4 T Cells = "helpers" bc...?

- Help activate APCs (via CD40L)
- Help CD8 cells (IL-2 expression)
- Help B cells (CD40L, increase activation, etc.)

27

Congenital triad for Toxoplasmosis

(from cat feces, risk mostly to pregnant women bc...)
congenital toxoplasmosis =
1. chorioretinitis
2. hydrocephalus
3. intracranial calcifications
=> to protect fetus, Tx mother w/ sulfadiazine & pyrimethamine!!

28

Live attenuated virus vaccines:

Smallpox
Yellow Fever
VZV (chicken pox)
Sabin Polio vaccine
MMR
influenza (intranasal)

29

E Coli Virulence factors (5)

1. Lipid A (LPS): TNF-a => fever, IL... => shock
2. K1 capsular polysacch: --l phagocytosis & cmplmt...=> meningitis!
3. P fimbriae: adhesion to uroepithelium => UTIs
4. Heat labile/stable toxins: fluid & electrolyte secretion => diarrhea
5. verotoxin: --l 60S ribosome = --l protein synth => bloody diarrhea