Modulatory signalling in immune cells:
Download
1 / 34

Modulatory signalling in immune cells: SLAM family receptors and SAP-related adaptors - PowerPoint PPT Presentation


  • 121 Views
  • Uploaded on

Modulatory signalling in immune cells: SLAM family receptors and SAP-related adaptors André Veillette 414A November 2004. Fc g RIII (NK cells). TCR (T-cells). Fc e RI (mast cells). a. gg. gg. ge. de. b. zz. Immunoreceptors. NCRs NKG2D (NK cells). BCR (B-cells). DAP-12.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Modulatory signalling in immune cells: SLAM family receptors and SAP-related adaptors' - dara


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Modulatory signalling in immune cells:

SLAM family receptors and

SAP-related adaptors

André Veillette

414A

November 2004


FcgRIII

(NK cells)

TCR

(T-cells)

FceRI

(mast cells)

a

gg

gg

ge

de

b

zz

Immunoreceptors

NCRs

NKG2D

(NK cells)

BCR

(B-cells)

DAP-12

Iga/Igb

= ITAM


PH

TCR signalling

MHC

CD4

TCR

CD4

TCR

Ag/MHC

P

P

P

P

P

P

ge

P

P

de

SH2

zz

SH2

PH

P

P

Lck

P

FynT

FynT

SH2

Lck

SH2

Itk

Zap-70

Zap-70

protein tyrosine phosphorylation

Itk


T-cell signalling

Modulatory

signalling

Positive

signalling

Inhibitory

signalling

PAG

(ITIMs)

Csk-PEP

SHP-1

c-Cbl

TCR-CD4/CD8

Src kinases

Zap-70

Btk kinases

CD28

PI 3’ kinase

ICOS

?

SLAM

?

SAP

? ? ? ? ? ? ?

Cytokine

production

(TH1 vs TH2)

Anergy

Maturation

Memory

Apoptosis


SAP family of adaptors

SH2

SAP

(T-cells, NK cells, NK-T-cells, ?some B-cells)

EAT-2

(NK cells, macrophages,

DCs, ?some B-cells)

SH2


  • X-linked lymphoproliferative disease (XLP)

  • - caused by inactivating point mutations or deletions in the sap gene;

  • characterized by abnormal response to EBV infection, resulting in fatal infectious mononucleosis, as well as a high frequency

    • of malignant lymphomas;

  • - SAP-deficient mice exhibit abnormal CD4+ T-cell help (decreased TH2 functions; +/- increased TH1 functions), decreased Ig production and memory B-cell generation, altered anti-viral responses and absent NK-T-cells.


  • Y

    Y

    Y

    Y

    Y

    Y

    Y

    Y

    Y

    Y

    SAP family adaptors associate

    with SLAM-related receptors

    NTB-A

    Ly-9

    CRACC

    CD48

    CD84

    SLAM

    measles

    Ligands

    Ly-9

    V

    2B4

    CRACC

    SLAM

    NTB-A

    CD84

    C2

    V

    V

    V

    V

    V

    V

    C2

    C2

    C2

    C2

    C2

    C2

    Y

    Y

    Y

    Y

    : TIYxxV/Imotif

    Y

    Y

    Y

    Y

    Y

    Y

    Y

    : TVYxxV/Imotif

    Y

    Y

    Y

    Y

    Y

    Y



    XLP is likely caused by multiple

    SLAM-related receptor dysfunctions

    Ig production

    memory B-cells

    ?

    TH2

    functions

    NK cell

    cytotoxicity

    ?

    SLAM

    NTB-A

    CD84

    ?

    SAP

    Ly-9

    2B4

    NK cell

    cytotoxicity



    • SLAM (CD150)

    • expressed on activated T-cells, B-cells,

      • macrophages and dendritic cells;

  • self-ligand;

  • SLAM is the lymphoid-specific receptor

  • for measles virus in humans;

  • - anti-SLAM stimulation modulates IFN-g secretion

  • by activated T-cells;

  • defective TCR-induced IL-4 production in

  • slam-/-mice.


  • SAP is required for SLAM-induced

    protein tyrosine phosphorylation


    PH

    -

    -

    ?Ras

    ?

    ?Itk

    ?Akt

    SLAM

    MHC

    CD4

    TCR

    SLAM

    SH2

    SAP

    P

    P

    P

    P

    P

    P

    Lck

    P

    P

    P

    P

    SH2

    SH2

    P

    P

    kinase

    P

    FynT

    Zap-70

    Ras-GAP

    Dok

    SHIP-1

    Itk

    IL-4 production


    Possible mechanism(s) by which SAP

    induces protein tyrosine phosphorylation:

    1) displacement of a protein tyrosine phosphatase;

    2) recruitment of a protein tyrosine kinase;

    3) both.


    A

    - SAP

    ligand

    SLAM

    + ligand

    SH2

    SH2

    SH2

    SH2

    SHP-2

    SHP-2

    tyrosine phosphorylation

    B

    + SAP

    ligand

    SLAM

    + ligand

    SAP

    SAP

    SH2

    SH2

    P

    P

    tyrosine phosphorylation

    SAP: a natural blocker of SH2 domain-mediated interactions?



    SLAM

    MHC

    CD4

    TCR

    SLAM

    SH2

    SAP

    P

    P

    P

    P

    P

    P

    Lck

    P

    P

    P

    P

    SH2

    SH2

    P

    P

    FynT

    PH

    P

    FynT

    Zap-70

    Itk

    How does SAP promote recruitment of FynT?

    SH3

    SH2


    SAP is a bifunctional adaptor that

    links SLAM to FynT

    SAP

    SLAM

    FynT

    SH2

    pY

    SH3

    SH3

    P

    P

    P

    P


    The FynT SH3 domain binds a novel arginine-based

    motif at the surface of the SAP SH2 domain

    SH2 domain

    1 30

    SAP(m)MDAVTVYHGKISRETGEKLLLATGLDGSYLLRDSESVPGVYCLCVLYQGYIYTYRVSQTETGSWSAE

    SAP(h)MDAVAVYHGKISRETGEKLLLATGLDGSYLLRDSESVPGVYCLCVLYHGYIYTYRVSQTETGSWSAE

    EAT-2(m)MD.LPYYHGCLTKRECEALLLKGGVDGNFLIRDSESVPGALCLCVSFKKLVYSYRIFREKHGYYRIE

    EAT-2(h)MD.LPYYHGRLTKQDCETLLLKEGVDGNFLLRDSESIPGVLCLCVSFKNIVYTYRIFREKHGYYRIQ

    68 126

    SAP(m)TAPGVHKRFFRKVKNLISAFQKPDQGIVTPLQYPVE.KSSGRGPQAPTG.RRDSDICLNAP

    SAP(h)TAPGVHKRYFRKIKNLISAFQKPDQGIVIPLQYPVEKKSSARSTQGTTGIREDPDVCLKAP

    EAT-2(m)TDAHTPRTIFPNLQELVSKYGKPGQGLVVHLSNPIMRNNLC...QRGRRMELELNVYENTDEEYVDVLP

    EAT-2(h)TAEGSPKQVFPSLKELISKFEKPNQGMVVHLLKPIKRTSPS...LRWRGLKLELETFVNSNSDYVDVLP

    A

    1

    B

    C

    D

    E

    tail

    *

    *

    *

    *

    *

    *

    *

    F

    2

    G




    SH3

    SH3

    P

    P

    P

    P

    P

    A common mechanism for signalling

    by SLAM-related receptors

    SLAM

    CD48

    SLAM

    2B4

    Y

    Y

    SH2

    SH2

    Y

    SAP

    SAP

    P

    Y

    Y

    P

    P

    Y

    FynT

    FynT

    Y

    SHIP-1

    Dok-1/2

    Ras-GAP

    Vav-1

    SHIP-1

    c-Cbl

    Modulation

    of IL-4

    Modulation of cytotoxicity

    Modulation of IFN-g


    Role of FynT

    in SAP-dependent signalling in vivo?


    fyn-/- T-cells exhibit TH2 and, to a lesser extent,

    TH1 cytokine defects in response to TCR stimulation


    Creation of a sapR78A “knock-in” mouse

    floxed sapR78A allele

    *

    *

    cgggcg

    TGA

    ATG

    sapR78A

    loxP

    exon 1

    exon 2

    exon 3

    exon 4

    R78A

    SH2 domain


    sap+

    sap+

    sap-

    sap-

    sapR78A

    sapR78A

    Anti-CD3:

    Anti-CD28:

    0.3

    1

    3.0

    0

    0.3

    0

    3.0

    1

    0

    0

    P+I

    Cytokine production defect in T-cells from sapR78A mice

    IFN-g

    IL-4

    2500

    400

    350

    2000

    300

    IFN-g (pg.ml-1)

    250

    1500

    IL-4 (pg.ml-1)

    200

    1000

    150

    100

    500

    50

    0

    0

    Anti-CD3:

    Anti-CD28:

    0.3

    1

    3.0

    0

    0.3

    0

    3.0

    1

    P+I

    0

    0

    IL-13

    Proliferation

    300000

    300

    250000

    250

    cpm

    200000

    200

    IL-13 (pg.ml-1)

    150000

    150

    100000

    100

    50000

    50

    0

    0

    Anti-CD3:

    Anti-CD28:

    Anti-CD3:

    Anti-CD28:

    0.3

    1

    0.3

    1

    3.0

    0

    3.0

    0

    0.3

    0

    3.0

    1

    P+I

    0.3

    0

    3.0

    1

    0

    0

    0

    0

    P+I


    Defective IgE production in sapR78A mice

    A

    B

    9

    8

    10

    7

    sap+

    6

    day 0

    8

    sap-

    day 14

    5

    IgE (mg.ml-1)

    sapR78A

    6

    4

    IgE (mg.ml-1)

    4

    3

    2

    2

    1

    0

    0

    0

    14

    28

    35

    42

    49

    70

    sapR78A

    sap+

    sap-

    time (days)

    C

    D

    40

    35

    35

    30

    30

    day 0

    25

    25

    day 14

    20

    IgE (mg.ml-1)

    20

    IgG1 (mg.ml-1)

    15

    15

    10

    10

    5

    5

    0

    0

    sap-

    sapR78A

    control

    fyn-/-

    sap-

    sapR78A

    control

    fyn-/-


    DC

    ?

    MHC

    TCR

    ?

    T-cell

    SAP

    FynT

    FynT

    IL-4

    IL-13

    Regulation of TH2 cytokine production by SAP-FynT pathway



    Defective TH2 cytokine production in

    slam-/- T-cells


    Regulation of TH2 cytokine production by

    the SLAM-SAP-FynT pathway

    DC

    MHC

    MHC

    SLAM

    SLAM

    TCR

    TCR

    SLAM

    T-cell

    SAP

    SAP

    FynT

    FynT

    FynT

    FynT

    P

    GATA-3

    IFN-g

    IL-4

    IL-13


    Conclusions

    1) SAP, a small SH2 domain-containing adaptor

    mutated in XLP, is necessary for modulatory

    signalling through SLAM-related receptors;

    2) SAP functions by recruiting the Src-related PTK

    FynT, rather than by displacing a PTP;

    3) SAP links SLAM-related receptors to FynT

    through binding of a unique surface in

    the SAP SH2 domain to the FynT SH3 domain;

    4) Defects in SAP-mediated recruitment of FynT

    to SLAM receptors are likely to underlie

    at least part of the pathophysiology of XLP.


    Riyan Chen

    Romain Roncagalli

    Oliver Utting

    James Taylor

    Laurent Doucet

    Ming-Chao Zhong

    Mario-Ernesto Cruz-Munoz

    Marceline Côté

    Xiaochu Shi

    Shaohua Zhang

    Dominique Davidson

    Sylvain Latour

    Collaborators:

    Pam Schwartzberg

    Rusung Tan

    Yusuke Yanagi

    Luo Yin


    ad