COPA mutations impair Golgi-ER transport causing hereditary autoimmune-mediated lung disease and arthritis

COPA mutati ons impair Golg i -ER t ransport caus ing heredi tary auto immune-mediated

lung d isease and arthr iti s

To n y S h u m , M DA s s i s t a n t P r o f e s s o r

P u l m o n a r y & C r i ti c a l C a r eC a r d i o v a s c u l a r R e s e a r c h I n s ti t u t e

U n i v e r s i t y o f C a l i f o r n i a S a n F r a n c i s c os h u m l a b . u c s f. e d u

A pati ent with auto immune-assoc iated lung and jo int d isease

• ID: 30 yo female with JIA, advanced ILD• CC: coughing up blood• PMH:

– JIA: Presented joint pain 2 yrs (knees, ankles, hands/fingers)– ILD: soon developed shortness of breath, diagnosed ILD (follicular

bronchiolitis, lymphoid aggregates)

• FH: sister and deceased aunt with similar medical history• SH: non-smoker• ROS: achy joints, no URI symptoms but slight fever• Exam:

– Hypoxemic, tachypneic– Lungs with diffuse crackles– Coughing up scant bright red blood

More Data:

• Representative CT • ANA neg• CCP/RF neg• MPO Ab – highly elevated• Hand films – no erosions

A fa m i l y w i t h a ra re d i s o rd e r o f a u t o i m m u n e -a s s o c i a t e d l u n g l u n g a n d j o i n t d i s e a s e

• Clinical Features:

• High-titer autoantibodies: ANCA, ANA

• Inflammatory arthritis and ILD

• Immunosuppression required (e.g. mycophenolate)

Geneti c L inkage IDs a S ing le Reg ion of S ign ifi cance on Chr 1

Noah Zaitlen

LOD=3.5

LOD score > 3.0 = 1000 to 1 odds that linkage did not occur by chance

W E S I D s a s i n g l e ra re , n o n - sy n o ny m o u s va r i a n t u n d e r C h r 1 l i n ka g e p e a k

• M i s s e n s e m u t a ti o n i n C O PA c .G 7 2 1 A : p . E 2 4 1 K

• M i n o r a l l e l e f re q u e n c y : n o t re p o r t e d ( i . e . ve r y ra re )

• P re d i c t e d c r i p p l i n g ( AV S I F T, Po l y p h e n )

• S a n g e r va l i d a t e d i n > 1 5 s u b j e c t s

B ay l o r- H o p k i n s C e n t e r fo r M e n d e l i a n G e n o m i c s i n d e p e n d e n t l y I D s C O PA m u t a ti o n s i n 2 fa m i l i e s

w i t h exa c t s a m e c l i n i c a l p h e n o t y p e A

B

U C S F

L . F a n

C

B a y l o r B a y l o r

U C S FM . W a t e r fi e l d

D

E

T o r o n t o ( S . D e l l )

Pati ent autoanti bodies

I m m u n o g l o b u l i n l e v e l s , a b s o l u t e l y m p h o c y t e c o u n t s a n d C D 4 t o C D 8 c e l l ra ti o s w e re n o r m a l

L u n g s o f u n r e l a t e d p a ti e n t s r e v e a l s g e r m i n a l c e n t e r fo r m a ti o n &

i n fi l t ra ti n g C D 4 T c e l l s

Immune-mediated kidney disease

4 COPA mutati ons are d i scovered in 5 fam i l ies a l l located in h igh ly conser ved WD40 domain

Coatomer Subunit A lpha (COPA )

• U b i q u i t o u s l y ex p re s s e d• S u b u n i t o f C o a t P ro t e i n C o m p l ex I

( C O P I )• E n a b l e s p ro t e i n t ra n s p o r t b e t w e e n

t h e G o l g i a n d E R• N o d i s e a s e a s s o c i a ti o n s re p o r t e d i n

C O PA o r C O P I

Brandizzi F and Barlow C Nat Rev Mol Cell Biol 2013

COPA expression & local izati on appear normal in pati ents

c

CO – controlPA – patient

COPI is important for retrograde transport of proteins

K KX X

Adapted from Brandizzi F and Barlow C Nat Rev Mol Cell Biol 2013

The COPA WD40 domain is cr iti cal for retrograde transport of KKXX proteins

Eugster A EMBO J 2000

Mutant COPA has impaired binding to KKXX proteins

K K X X*

ER stress and the UPR have been impl icated in autoimmunity & lung disease

• Lu ng d i s e a s e– M i s fo l d e d s u r f a c t a n t p r o t e i n s l e a d s t o E R

s t r e s s a n d p r o p e n s i t y t o l u n g i n fl a m m a ti o n a n d s c a r r i n g

• Auto i mmune d i s e a s e– E R s t r e s s r e s u l t s i n :

• N F K B - m e d i a t e d i m m u n e a c ti v a ti o n• A b e r r a n t a n ti g e n p r e s e n t a ti o n i n c e l l s u n d e r g o i n g

a u t o p h a g y o r a p o p t o s i s• G e n e r a ti o n o f a u t o a n ti g e n s• S h a p i n g o f C D 4 T h e l p e r c e l l s u b s e t s

Nogee NEJM 2001, Lawson PNAS 2011, Todd Nat Rev Imm 2008, Hasnain Immunol Cell Biol 2012

Pati ent lungs demonstrate increase in ER stress protein BiP

Pati ent BLCLs demonstrate elevated levels of ER stress

CO – controlHC – healthy carrierPA – patientTG – thapsigargin

Expression of mutant COPA causes an increase in ER stress

How might ER stress be l inked to the c l inical phenotype in pati ents?

ER stress results in generati on of Th17 priming cytokines in APCs

• KDEL-retained antigen in B lymphocytes induces a proinflammatory response: a possible role for endoplasmic reticulum stress in adaptive T cell immunity. J Immunol 2008

• HLA-B27 misfolding and the unfolded protein response augment interleukin-23 production and are associated with Th17 activation in transgenic rats. Arthritis Rheum 2009

• Endoplasmic reticulum stress-induced transcription factor, CHOP, is crucial for dendritic cell IL-23 expression. Proc Natl Acad Sci 2010

• Proinflammatory Th17 cells are expanded and induced by dendritic cells in spondylarthritis-prone HLA-B27-transgenic rats. Arthritis Rheum 2012

BLCLs with mutant COPA express Th17 priming cytokines

Th17 primingTh2 primingTh1 priming

CO – controlHC – healthy carrierPA – patientTG – thapsigargin

CD4 T ce l l s f rom pati ents are po lar ized to Th17 phenotype

BA

S u m m a r y• WD40 COPA mutati ons cause auto immune-

assoc iated lung & jo int d isease

• 1 s t descr ipti on of a ves icu lar t raffi cking defect as cause of auto immunity

• Identi fi cati on of a novel molecular l ink between ER Stress and auto immunity

• Identi fi cati on of a putati ve immunolog ica l mechanisms by which:

m u t a n t C O PA E R S t re s s T h 1 7 c e l l s⟶ ⟶

A c k n o w l e d g e m e n t s

S H U M L A B• B i r t h e J e s s e n • C h r i s L a w• M a x J a n• W i n t L w i n• O s c a r E s t r a d a

T h e p a ti e n t s & t h e i r f a m i l i e s

F u n d i n g a g e n c i e s :

B AY L O R C O L L E G E O F M E D I C I N E• L e v i W a t k i n s & J o r d a n O r a n g e• W. W i s z n i e w s k i & J i m L u p s k i

U C S F• N o a h Z a i t l e n • P u i K w o k & P a u l Ta n g • K i r k J o n e s• F e r o z P a p a & M a i k e T h a m s e n• M i k e R o s e n b l u m• M i k e W a t e r fi e l d , M i c k i e C h e n g

& M a r k A n d e r s o n• R a n d y S c h e k m a n ( U C B e r k e l e y )

To r o n t o S i c k K i d s• S h a r o n D e l l

R 0 1 H L 1 2 25 3 3

P l e a s e v i s i t u s @ : s h u m l a b . u c s f . e d u