MIMG C185A PROBLEM SET 2: DETAILED SOLUTIONS AND EXPLANATIONS | NEW 2026 / 2027 UPDATE | | COMPLETE A+ GUIDE

MIMG C185A PROBLEM SET 2: DETAILED SOLUTIONS AND
EXPLANATIONS | NEW UPDATE | | COMPLETE A+
GUIDE

PROBLEMreSETre2

Questionre1re(100repoints)
Yourearerearestudentrefromreanreimmunologyrelab.reYoureperformrethreereindependent experimentsreu fd




singredifferreent mouserestrainsreandreyourewant toreexplainreyourreresultsrewithrewhatreyourehaverele
fd fd




arnedrefromreMIMGre185.

a) Inretherefirst set ofreexperiments,reyoureinfect tworestrains ofremicerewithreextracellularrebacter
fd fd fd fd




ia.reYouretestretreheirreserumrecytokinerelevelsreandregetretherefollowingreresults:re+++re(stro
ngreresponse),re++reorre+re(lowerreresreponse),re+/-re(partialreresponse),re-
re(noreresponse).

Cytokines Strainre1reMicereTh2 Strainre2reMicereTh1 Normallevelre(u
fd




+reExtracellularreBacteria +reExtracellularreBacteria nreinfected)
IFN -/+ +++ +
IL-4 +++ -/+ +
IL-5 ++ - +
IL-10 ++ - +
TNF - ++ +

Brieflyexplain(2-
3sentences)rewhatarethedifferences betweenstrain1andstrain2inresponseretoretheresamereinfec
fd fd




tion.re(re15repoints)

Serumrefromrestrain 1remicereshowrehigherrethanrenormalreIL-4,reIL-5reandreIL-
fd




10reandrelowerrethanrenormalreIFNandTNF.Serum fromstrain2mice have lowerthannormalIL fd fd fd




-4,IL-5and IL- fd




10and higherrethan normalIFNandreTNF.reThis suggestsan imbalancereinthereTh1/Th2reresponse;
fd fd fd fd




strainre1refavorsreTh2reandrestrain 2refavorsreTh1. fd




Whichrestrainreofremicerewillresurviverebetter?reExplainreyourreanswerreinrenoremorerethanre3resen
tences.re(15 pointres)
fd




Strain 1,reTh2reextracellularresponsere(thequestion says extracellularrebacteriasoextracellularrere
fd fd fd




sponsreerewillreberegoodretoresurvive)
Th1re(intracellularreresponse)reactivatesrecellularreresponsesrewhilereTh2reactivatesreBrecellsretoreprod
ucereantibreodies.

,DownloadedrebyreJexreJengare()

, PROBLEMreSETre2
b) Inretheresecondresetreofreexperiments,reyouretestretherefunctionreofrelymphocytesrefromret
woreadditionalremoureserestrains (A andreB).reYoureisolatereTrecellsreandreNKrecells,reand
fd fd




retestretheirreresponseretorecytokinerestimurelation.reInrestrainreA,reTrecellsreandreNKrecell
srerespondrenormallyretoreIL-7reandreIL-
21,rehowever,retheirreproliferativereresponseretoreIL-2reandreIL-
15reisrediminished.reTrecellsreandreNKrecellsrefromrestrainreBrerespondrenormallyretoreallr
ecytokines.re++re(strorengreproliferativereresponse),re-re(noreproliferativereresponse).

Cellretype Cytokine StrainreA StrainreB Normalremice
Trecell IL-2 - ++ ++
IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
NKrecells IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
Brieflyexplainre(2-
3resentences)rewhatreisretheredefect inrestrainreA andrewhyredo cellsrefromrethismouserebehaverethis
fd fd fd fd




way.re(20repoinrets)

IL-2Rredeficiency that isreseeninrebothreIL-2reand IL-15
fd fd




c) Inretherethirdresetreofreexperiments,reyourehavere5redifferent mouserestrains,reeachreofrewhichrei
fd




sredeficient inreonereofrethereproteinsreofretherecomplement cascade.r e Usingre+re(fullresponse),r
fd fd




e+/-re(partialreresponse)reorre-
(noreresponse),reindicaterewhetherreeachreevent willretakereplace.re(1repoint each)
fd fd




YoureaddreE.recolireto
YoureaddreSRBCreto fd

reseruremofnon-
micree immunizedwitfd

immuneremicereandre
YoureaddreSRBCret
hreSRreBCreandrelo monreitorreopsonizati
oremirecereimmuniz
okreforreprodreuctio on
edrewithSreRBCan
nreofreanaphylatoxrei (Hint:reE.coli expresses mannose onrei
dlook forreSRreBCr fd fd fd




ns (Classical) tsr e cellresurface)
fd


fd


elysis (Lectin)