Brainscape's Knowledge GenomeTM

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


See full index

Immunology > T cells > Flashcards

T cells Flashcards

1
Q

Site of genereration of T cells

A

Thymus

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

Functions of T cell subsets

A

CD8 (cytotoxic ) cells - Kill virus infected cells, tumour cells
CD4 (helper) cells - Produce cytokines, help B cells, macrophages

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

Structure of T cell receptor

A 
Alpha and beta chains
Variable and constant regions
Associated with signalling chains of CD3
T cell receptor recognises peptide on MHC
CD4 binds to MHC II
CD8 binds to MHC 1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Site of location of immature T cells in Thymus

A

Cortex

Medulla has mature T cells

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

Protein responsible for VDJ rearrangement in T cell receptor

A

RAG gene -RAG 1,2

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

Role of IL-2

A

-IL-2 required for driving resting T cells
-Drives T reg cell induction
Acting via CD25
Induces Foxp3- master regulator of Treg cells

Calcineurin inhibiors -inhibit IL-2 induction

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

Role of AIRE,FEZF2

A

Autoimmune regulator
Turns on expression of tissue specific Ags at low levels in thymus
Leads to deletion of high affinity T cells, induction of regulatory T cells

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

Disease condition due to mutation of AIRE

A

Autoimmune Polyendocrine Syndrome 1
Chronic mucocutaneous candidiasis -due to ab against Th17
Autoimmune hypoparathyroidism
Autoimmune Addisons disease

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

Signals in T cell activation

A

Signal 1-MHC and peptide

Signal 2 -Co-stimulation [mediated by B7.1(CD80),B7.2(CD86)]

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

Role of CD28 on T cells

A

Leads to activation by interacting with costimulatory molecules

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

Role of CTLA4

A

Induced slowly on T cells following activation
Stronger binding to B7 molecules
Generates negative signal-> turns off T cells

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

Mechanisms of peripheral T cell tolerance

A
  1. Inhibitory molecule engagement
  2. Anergy
  3. Clonal ignorance
  4. Treg cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Inhibitory molecule engagement mechanism

A 
CTLA4,PD-1 molecules expressed on T cells
Dysfunction lead to autoimmunity
PD1 blockade (check point inhibitor) ->immune S/E
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Clonal ignorance mechanism

A

Lymphocytes ignore low levels of self antigens- not enough to signal antigen receptor
If some exposure -secrete antiinflammatory cytokines-IL-10,TGF beta - turn into T reg cells

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

Immune mechanism of villous atrophy in coeliac

A

HLA DQ2 or DQ8 restricted T cell immune reaction

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

Marker of memory T cell

A

CD45 RO

17
Q

MHC class I expressed by all cells except

A

RBC

18
Q

Cytokine responsible for hyperalgesia

A

IL-1 beta

19
Q

T cell immunodeficiencies

A

Idiopathic CD4 lymphopenia
Chronic mucocutaneous candidiasis
Hyper IgE syndrome

20
Q

Markers of Treg cells

A

CD4 +
CD25 expression( IL-2R alpha)
foxp3 expression -master regulator of T cells

21
Q

MOA of superantigens

A

Bind outside MHC:peptide groove to Vbeta chain of T cell receptor
Does not require processing for MHC presentation
Stimulates 2-20% of T cells -> massive cytokine release-> TSS

22
Q

Subsets of helper T cells

A

Th1,Th2, Th 17

23
Q

Cytokines secreted by Th1 cells

A

INF-gamma, TNF, lymphotoxin

24
Q

Pathogenesis of MSMD(Mendelian Susceptibility to Mycobacterial Disease)

A

Deficiency of Th1 pathway
Th1 diffrentiate in response to IL-12,INF -gamma
Mainly involving intracellular pathogens
Non tuberculous mycobacteria,Invasive salmonellosis
TB,Severe viral infections

25
Q

Th2 cell deficiency causes which infections

A 
Th-2 differentiate in response to IL-4
Secrete IL-4,5,6,10,13
Role in atopy , defence against helminths
IL-4,IL-13 -> IgE production by B cells
IL-5 -> Eosinophils
26
Q

Role of Th 17 cells

A

Differentiate in response to IL-1,IL-6,IL-23
Secrete IL-17, IL-22
IL-17-Acts on many cells- release chemokines,cytokines that attract neutrophils. Stimulates keratinocytes
IL-22 -Stimulate release of defensins, other AMP
Defense against Candida, staphylococcus
Role in autoimmune disease

27
Q

Role of helper T cells

A

Express CXCR5, ICOS
Secrete IL-21
Help B cells -class switching, affinity maturation

28
Q

Diagnosis of chronic mucocutaneous candidiasis

A

NBT test -negative in CGD

29
Q

IL secreted by Treg cells to suppress immune system

A

TGF beta, IL-10

30
Q

Disorders of Neutrophil phagocytic function

A

CGD
Chediak Higashi
Leukocyte adhesion deficiency
Neutrophil enzyme deficiency -MPO, G6PD

31
Q

Interleukins produced by each T cells subset

A

Th1 -INF-gamma,lymphotoxin,TNF (intracellular pathog)
Th2 -IL-4, IL-5,IL-6,IL-10,IL-13,TGF beta (helminths)
Th17 -IL-17 (defence against candida and Staph)

32
Q

T cell imp in pathogenesis of sarcoidosis

A

Th1 helper T cell

33
Q

Mechanism by which HSV escapes APC

A

Production of Tap inhibitor protein-prevents transport of peptides to MHC
Adeno virus- produces pn that anchors MHC in ER-> no surface expression of MHC
CMV -accelerates transport of peptides out of ER- less chance of binding to MHC

34
Q

Main molecular defect in X linked SCID

A

Deficiency of cytokine receptor gamma common chain

35
Q

Defect in autosomal recessive SCID

A

JAK -3, IL-7 R alpha ,ZAP 70 defy, CD3 defy, RAG-1,2 deficiency

36
Q

Role of important classes of interleukins

A

IL 1- Macro, monocyte, DC -> inflammatory response, fever
IL- 2 -Proliferation of Tcells
IL- 3 -Hematopoietic lymphoid growth
IL- 4 -Acts on B cells -Ig E switching
IL- 5- Eosinophil growth and activation
IL-6 -Differentiation of activated B cells to plasma cell
IL- 8 -neutrophil chemotaxis
IL-11 - stimulates megakaryocytes-> platelets

37
Q

IL-17 inhibitor in psoriasis

A

Secukinumab, Ixekizumab, Brodalumab

38
Q

IL-12/23 inhibitors

A

Ustekinumab

39
Q

TNF alpha inhibitors

A

Etanercept,adalimumab, Infliximab

Immunology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions