Ch 1 Immune Mechanisms

Question 1

genes that encode MHC are located on what chromosome? B2 microglobulin?

Answer 1

6 (short arm); 15

Question 2

what order are the regions of MHC molecules encoded on chrom 6?

Answer 2

class II (HLA -DP, DQ, DR) class III, and class I (HLA- a,b,c)

Question 3

what does class III MHC polypeptide region encode?

Answer 3

complement (Factor B, C4, C2); TNFa, lymphotoxin a & b; HSP

Question 4

besides MHC II peptides, what other proteins are encoded on chrom 6 class II region

Answer 4

HLA-E (NK cell recognition), HLA-F (localized to ER and Golgi), HLA-G (on fetal derived placental cells), HLA-H (iron metabolism)

Question 5

How do HSV and CMV evade MHC I presentation?

Answer 5

block TAP; remove class I molecule from ER, respectively

Question 6

in MHC II processing, what occupies the binding cleft and what protein facilitates?

Answer 6

in ER, invariant chain is in binding cleft, cleaved to CLIP in vesicle by proteolytic enzymes, then HLA-DM (intracellular protein) removes CLIP for peptide to be bound

Question 7

IPEX

Answer 7

immune dysregulation due to mutation in foxp3; characterized by watery diarrhea, eczema and endocrinopathy

Question 8

what is Bim?

Answer 8

pro-apoptotic factor in the BCL2 family. activated by t cells binding self-antigen without costimulation. apoptosis occurs through mitochondrial pathway

Question 9

what does FasL do?

Answer 9

FasL (cd95L) binds with Fas (cd95) on same or nearby cells when t cell is self reactive. leads to apoptosis via caspase cascade

Question 10

what is Alps caused by and what is it?

Answer 10

mutation in Fas or caspase 10; lymphocytes don’t know when to die and they accumulate in lymph tissue and there are autoimmune problems

Question 11

What is the receptor for CCL5 (RANTES)

Answer 11

CCR1, 3, 5

Question 12

CCL11 (eotaxin)

Answer 12

CCR3

Question 13

CCL17 (TARC)

Answer 13

CCR4

Question 14

CXCL8 (IL8)

Answer 14

CXCR1, 2

Question 15

CCL17, CCL22

Answer 15

CCR4 (pro Th2 response)

Question 16

mutation in what confers malaria protection?

Answer 16

DARC/duffy (mutation in GATA of DARC gene)

Question 17

ICAM1

Answer 17

CD54 binds LFA1 and MAC1, binding for Rhinovirus A and B

Question 18

ICAM2

Answer 18

CD102 binds LFA1

Question 19

icam3

Answer 19

cd50 binds LFA1 and CD18

Question 20

icam4

Answer 20

CD 242 binds LFA1 and CD18

Question 21

vcam1

Answer 21

cd106 binds VLA4 (a4B1); vascular

Question 22

PECAM

Answer 22

CD 31 binds CD 31 and 38; platelets

Question 23

MadCam

Answer 23

binds mucosal addressin (a4B7); mucosa; important for gut homing

Question 24

NCAM

Answer 24

CD 56 binds VLa4 (a4B1); neuronal

Question 25

chemokine associated with heparin induced thrombocytopenia

Answer 25

CXCL4

Question 26

how is CCR5 related to HIV?

Answer 26

homozygous - NO infection; heterozygous - slow progression

Question 27

CXCR4

Answer 27

considered T trophic in HIV

Question 28

CCL3L1 and HIV

Answer 28

low level leads to higher HIV acquisition, high viral load, worse disease; also known as fractalkine and can predispose to atherosclerosis

Question 29

What is the only x linked complement deficiency?

Answer 29

properidin