Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

USMLE immunology > cellular components pt2 > Flashcards

cellular components pt2 Flashcards

1
Q

What is the primary function of regulatory T (Treg) cells?

A

Treg cells prevent autoimmunity by maintaining tolerance through suppression of CD4+ and CD8+ T cell effector functions. They produce anti-inflammatory cytokines such as IL-10 and TGF-β.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What markers identify regulatory T cells (Tregs)?

A

Tregs are identified by expression of CD3, CD4, CD25, and FOXP3.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What syndrome is caused by FOXP3 gene deficiency?

A

FOXP3 gene deficiency leads to IPEX syndrome (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked), characterized by autoimmunity, endocrinopathy, and other disorders.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do cytotoxic T cells function, and what do they release?

A

Cytotoxic T cells kill virus-infected, neoplastic, or donor graft cells by releasing granules containing perforin and granzyme B. They express CD8, which binds to MHC I.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are antigen-presenting cells (APCs), and name a few examples?

A

APCs include B cells, dendritic cells, Langerhans cells, and macrophages. They process and present antigens to T cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two signals required for T-cell activation?

A

Signal 1: Antigen presentation via MHC II or MHC I to the TCR on CD4+ or CD8+ T cells.
Signal 2: Costimulatory signal from B7 (CD80/86) on the APC interacting with CD28 on the T cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the process of T-cell activation.

A

APC processes antigen and migrates to the lymph node.
Exogenous antigen is presented on MHC II to CD4+ cells or endogenous/cross-presented antigen on MHC I to CD8+ cells.
Costimulatory signal (B7-CD28) triggers proliferation and survival.
Activated T cells produce cytokines and gain the ability to target virus-infected cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the two signals required for B-cell activation and class switching?

A

Th cell activation and recognition of antigen by B-cell receptor.
CD40 on B cells binding to CD40L on Th cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Outline the steps in B-cell activation and class switching.

A

Th cell activation occurs as described.
Antigen binds to the B-cell receptor, leading to receptor-mediated endocytosis.
Exogenous antigen is presented on MHC II to Th cells.
CD40-CD40L interaction occurs.
Th cells secrete cytokines, promoting Ig class switching.
B cells produce IgM, undergo class switching, and mature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the role of Th cell cytokines in B-cell class switching?

A

Th cell cytokines determine which immunoglobulin class (e.g., IgG, IgA) the B cell will produce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to B cells after activation?

A

Activated B cells initially produce IgM, then undergo class switching and affinity maturation for improved antigen specificity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the activators of macrophages ?

A

LPS
mannose
nucleic aid
double stranded RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how dos phagocytosis happen ?

A

engulfing of the pathogen into the phagosome
using with the lysosome
death of the pathogen by thee release of reactive oxygen species by. thee lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what cytokines are released by macrophages ?

A

IL 1 and INF gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the effects of interferon gamma ?

A

its a cachectin
causes vasular leaks
can cause DIC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

wht is the function of :
IL 1
L 6
IL 8
IL 12

A

IL 1 endogenous pyrogen
IL 6 pyrogen that simulates acute phase proteins
IL 8 attracts neutrophils , chemotaxis
IL 12 promotes Th12 development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

when do we find the band from of neutrophils ?

A

in bacterial infections
it indicates a left shift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the function of neutrophils ?

A

phaoytosis only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the cytokines for chemotaxis of neutrophils?

A

IL 8
C5a

20
Q

what are the functions of natural killer cells ?

A

part of the innate immunity
kill any human cell that is infected
any cell with no MHC 1 expression
produce INF gamma to activate macrophages

21
Q

what are the CD associated with natural killer cells ?

A

CD 16
CD 56 just a marker

22
Q

what is the function of CD 16 on NKC ?

A

uses antibody dependent cellular cytotoxicity (ADCC)
whee both the innate and adaptive immunity work together

23
Q

which cytokinee stimulate eosinophils ?

A

IL 2 rom Th2

24
Q

what interleukin is used for the treatment of renal cell carcinoma and melanoma ?

A

Aldelslukin ( IL 6 )

25
Q

which interleukin is responsible for IgE and IgA production ?

A

IgE - IL 4
IgA - IL 5

26
Q

what type of immune response is associated with intracellular infections ?

A

Th1

27
Q

what type of hypersensitivity reaction is associated with the PPD test ?

A

delayed type (type 4)
Th1 stimulation

28
Q

what is a superantigen ?

A

activates a massive number of Th cells
may caus vasodilatation and shocck

29
Q

what organisms are responsible for toxic shock syndrome ?

A

staph aureus ( TSST 1)
strp pyogens

30
Q

what are thee two forms of leprosy and what dos. the different presentations depend on ?

A

tuberculoid leprosy localized type ( strong Th1 reaction)
lepromatous diffuse type ( weaker Th1 response )

31
Q

what are the two types of IBD and what type of immune response is associated with each type?

A

Crohns - non caseating granuloma Th1
UC - Th2 response

32
Q

what is the relationship between macrophage and TH1 ?

A

Th1 produces IFN gamma which stimulates macrophages and macrophages form IL12 which activates TH1

33
Q

what is the presentation of someone who has a defect in IL 12 receptor ?

A

low levels off IFN gamma
sus to
disseminated mycobacterium inf
disseminated salmonella
severe reaction after BC vaccine

too treat give IFN gamma

34
Q

what has a similar presentation to a person with a lack of IL 12 receptor ?

A

missing IFN gamma receptor
but does not improve once given interferon gamma
treatment is to start stem cell transplantation and antimicrobial therapy

35
Q

what CD is used to present Treg ?

A

CD3
CD4
CD25
FOXP3

36
Q

which pair of receptor and ligand is used for the activation of class switching inn B cells ?

A

CD40 and CD40 L

37
Q

what is the point of conjugated vaccines ?

A

to allow for a response from both t cells and b cells for a stronger immune response
b cells react to the polysaccharides
t cells react to the proteins

38
Q

which D is used to gain entry into B cells by EBV ?

A

CD21

39
Q

what are the main jobs for antibodies ?

A

opsonization
neutralization
activation of complement

40
Q

what are the triggers for class switching in b cells ?

A

IL 4
IL 5
CD40
D40L

41
Q

which is the first ab to be secreted in infection ?

A

IgM

42
Q

which antibody is associated with encapsulated bacteria ?

A

IgG

43
Q

which antibody is found on mucosal surfaces ?

A

IgA

44
Q

what type of response is associated with live attenuated vaccines ?

A

ell mdiatd rresponse

45
Q

what type of immune response is associated with killed vaccine ?

A

humoral response

USMLE immunology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions