BROOKDALE RETREAT 2011

Alexander Panda2010 Brookdale Leadership in Aging Fellow

Yale University School of Medicine

June 08, 2011

Where we started:

• Evidence for immunosenescence in DCs: a more generalized defect in TLR-induced cytokine production than we observed previously in monocytes from older subject

• TLR-induced cytokine production in DCs can predict vaccine response to influenza (in contrast to our results in monocytes)

• Decreased surface and intracellular TLR expression arises from both transcriptional and post-transcriptional mechanisms

Age-associated alterations in Toll-like receptor (TLR)–induced CD80/86 expression in mDCs in older, compared to young adults. Age-associated defects (n=104) in CD80 expression in mDCs following stimulation with indicated TLR ligands.

CD80 CD86 CD80 CD86 CD80 CD86 CD80 CD86 CD80 CD86-50

-40

-30

-20

-10

0

10

20

30

40

50OLDER

YOUNG

Pam3Cys TLR 1/2

LTATLR 2/6

PolyICTLR 3

Flagellin TLR 5

R848TLR 7/8

Ga

ted

mD

Cs

% C

ha

ng

e

Age-associated alterations in Toll-like receptor (TLR)–induced CD80/86 expression in mDCs and pDCs in older, compared to young adults

TLR-induced cytokine production in DCs can predict vaccine response to influenza

Identification a potential new marker for immunosenescence in young adults: a CD86 high population on mDCs, only present in young adults

When gating on mDCs a CD86 high population is seen in young individuals. This CD86 high population was not seen in old individuals.

Young Young

Young Young

Old Old

Old Old

Stimulated Stimulated

Unstimulated control Unstimulated control

Data in Monocytes:

• post-translational defect in TLR1 surface expression without a defect in TLR1 transcription

• Role of chaperones associated with TLR expression

• PRAT4A

PRAT4A Protein Expression is Decreased in Older Adults

Older (n=49)Young (n=48)

* p< 0.0001

Detection of intracellular PRAT4A in mDCs of young (n=30) and old (n=30) individuals by FACS analysis

% g

ated

mD

Cs

Age-associated decrease in PRAT4A protein expression. Shown are percent positive mDCs (compared with isotype control). Values indicate the mean ± SEM. (p < 0.001, t-test)

Detection of intracellular PRAT4A in pDCs of young (n=30) and old (n=30) individuals by FACS analysis

% g

ated

pD

Cs

Age-associated decrease in PRAT4A protein expression. Shown are percent positive pDCs (compared with isotype control). Values indicate the mean ± SEM. (p < 0.001, t-test)

Plans:

• PRAT4A expression analysis by real-time quantitative-PCR (qPCR)

• Cloning and sequencing of PRAT4A of PRAT4A gene in old and young individuals to account for potential splicing variants

• Cloning of PRAT4A gene and transfection of bead isolated monocytes to evaluate the potential for rescuing TLR responses

• Confocal Microscopy to evaluate age associated differences in the distribution and/or redistribution of PRAT4A in bead isolated monocytes

Acknowledgements

Feng QianLin ZhangDonna CarranoSubhasis MohantyDavid van Duin

Al ShawRuth MontgomerySteve MalawistaErol FikrigRuslan MedzhitovTakuma Shibata (Tokyo University)Kensuke Miyake (Tokyo University)Fran Newman (Saint Louis University)Robert Belshe (Saint Louis University)

Program on Aging: Mary Tinetti Heather Allore Sandra Ginter Joanne McGloin

Virginia Towle Peter Charpentier Study Nurses

Yale Health Plan: Ravi Durvasula Michael Rigsby

Claude D. Pepper Older AmericansIndependence Center Hartford Foundation Center of ExcellenceIn Aging NIH/NIAID