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
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