Engagement of the T cell receptor (TCR) initiates a complex signaling cascade that culminates in activation of several key transcription factors, including NF-?B. NF-?B induces expression of a wide array of genes required for T cell proliferation and effector differentiation. We have recently identified the POLKADOTS signalosome, and we have demonstrated that this complex cytoplasmic structure plays an essential role in the TCR-to-NF-?B cascade. The purpose of our proposed studies is to elucidate the molecular mechanisms by which the POLKADOTS signalosome precisely controls activation of NF-?B. This work will be accomplished via collaboration between the groups of Brian Schaefer, who identified the POLKADOTS signalosome, and Wolfgang Losert, who has developed algorithms for quantitative analysis of patterns of protein distribution. By combining the expertise of our respective groups, we expect this work to lead to new hypotheses and conclusions regarding how changes in protein distribution are mechanistically connected to the signaling function of the POLKADOTS signalosome. We will achieve these goals through three Aims: The goal of Aim 1 is to quantitatively define discrete functional domains within POLKADOTS signalosome, to better define how the POLKADOTS signalosome simultaneously controls both Bcl10 signal transmission to NF-?B and proteolysis of Bcl10, limiting NF-?B activation. Our studies in Aim 2 will analyze the contribution of intact, dynamic microtubules to the transport and aggregation of POLKADOTS signalosomes, to determine whether this aggregation process is a mechanism of kinetic regulation of TCR signaling to NF-?B.
In Aim 3, we will determine how actin cytoskeletal dynamics regulate selective autophagy of Bcl10, revealing mechanisms controlling the selective proteolysis of Bcl10, and, more generally, mechanisms regulating p62-dependent selective autophagy. Together, we expect these data to yield new mechanistic insights regarding how signalosomes simultaneously coordinate diverse signal regulatory activities. We furthermore predict the innovative analytical methods developed in the course of this research could be readily translated to other signaling systems. Our work will thus suggest new avenues for exploring molecular mechanisms of signal transduction in a wide array of biological pathways important to human health.

Public Health Relevance

The NF-?B (NF-kappaB) signaling pathway is centrally important for the activation of many immune response mechanisms. We have recently identified the POLKADOTS signalosome, a TCR-induced cytoplasmic cluster of signaling proteins that plays an essential role in the TCR-to-NF-?B cascade. By elucidating the molecular mechanisms by which the POLKADOTS signalosome regulates T cell receptor activation of NF-?B, we expect to identify potential targets for novel immunomodulatory drugs, which could ultimately be used to treat a wide array of human diseases/pathologies, including cancer, autoimmunity, and graft rejection.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project--Cooperative Agreements (U01)
Project #
3U01GM109887-03S1
Application #
9277056
Study Section
Program Officer
Marino, Pamela
Project Start
2014-07-02
Project End
2018-04-30
Budget Start
2016-05-01
Budget End
2017-04-30
Support Year
3
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Henry M. Jackson Fdn for the Adv Mil/Med
Department
Type
DUNS #
144676566
City
Bethesda
State
MD
Country
United States
Zip Code
20817
Ilina, Olga; Campanello, Leonard; Gritsenko, Pavlo G et al. (2018) Intravital microscopy of collective invasion plasticity in breast cancer. Dis Model Mech 11:
Traver, Maria K; Paul, Suman; Schaefer, Brian C (2017) T Cell Receptor Activation of NF-?B in Effector T Cells: Visualizing Signaling Events Within and Beyond the Cytoplasmic Domain of the Immunological Synapse. Methods Mol Biol 1584:101-127
Lagraoui, Mouna; Sukumar, Gauthaman; Latoche, Joseph R et al. (2017) Salsalate treatment following traumatic brain injury reduces inflammation and promotes a neuroprotective and neurogenic transcriptional response with concomitant functional recovery. Brain Behav Immun 61:96-109
Presa, Maximiliano; Chen, Yi-Guang; Grier, Alexandra E et al. (2015) The Presence and Preferential Activation of Regulatory T Cells Diminish Adoptive Transfer of Autoimmune Diabetes by Polyclonal Nonobese Diabetic (NOD) T Cell Effectors into NSG versus NOD-scid Mice. J Immunol 195:3011-9
Ho, Yik-Khuan; Zhi, Huijun; Bowlin, Tara et al. (2015) HTLV-1 Tax Stimulates Ubiquitin E3 Ligase, Ring Finger Protein 8, to Assemble Lysine 63-Linked Polyubiquitin Chains for TAK1 and IKK Activation. PLoS Pathog 11:e1005102
Soloviova, Kateryna; Puliaiev, Maksym; Haas, Mark et al. (2015) Intrinsic Differences in Donor CD4 T Cell IL-2 Production Influence Severity of Parent-into-F1 Murine Lupus by Skewing the Immune Response Either toward Help for B Cells and a Sustained Autoantibody Response or toward Help for CD8 T Cells and a Downregula J Immunol 195:2985-3000
Paul, Suman; Schaefer, Brian C (2015) Visualizing TCR-induced POLKADOTS formation and NF-?B activation in the D10 T-cell clone and mouse primary effector T cells. Methods Mol Biol 1280:219-38