@article {714, title = {Distinct spatial and molecular features of notch pathway assembly in regulatory T cells.}, journal = {Sci Signal}, volume = {5}, year = {2012}, month = {2012 Jul 24}, pages = {ra53}, abstract = {

Variations in the spatial localization of signaling components and crosstalk among signaling cascades are mechanisms through which diversity in signaling networks is generated. The receptor Notch provides an example of regulation by spatial localization: In the canonical Notch signaling pathway, Notch is cleaved to produce the Notch intracellular domain (NICD, also known as NIC), which translocates to the nucleus to regulate gene expression. We describe a T cell receptor-dependent, non-nuclear distribution and function of the processed receptor Notch, which was associated with the improved survival of regulatory T cells (T(regs)) in vitro and in vivo and was compromised by T cell-specific deletion of Notch1. Unlike a nuclear-restricted mutant of NICD, mutant NICD that underwent nuclear export or was targeted to the plasma membrane protected Notch1(-/-) T(regs) from apoptosis induced by nutrient deprivation and oxidative stress. Notch signaling integrated with phosphatidylinositol 3-kinase signaling and mammalian target of rapamycin complex 2 (mTORC2) for this cell survival function. Biochemical and imaging approaches revealed a membrane-proximal complex containing NICD and the mTORC2 component Rictor, and this complex was stabilized by specific interactions with the Notch ligand Delta-like-1 and mediated the survival of T(regs). Together, our evidence for the spatial control of Notch and the crosstalk of Notch signaling with other pathways reveals coupling between the localization of Notch and diverse intracellular signaling pathways.

}, keywords = {Animals, Apoptosis, Blotting, Western, Carrier Proteins, Cell Line, Cell Membrane, Cell Survival, Flow Cytometry, Gene Knockout Techniques, Humans, Immunoprecipitation, Intercellular Signaling Peptides and Proteins, Mice, Mice, Inbred C57BL, Microscopy, Fluorescence, Phosphatidylinositol 3-Kinase, Rapamycin-Insensitive Companion of mTOR Protein, Receptor Cross-Talk, Receptor, Notch1, Signal Transduction, T-Lymphocytes, Regulatory, Trans-Activators, Transcription Factors}, issn = {1937-9145}, doi = {10.1126/scisignal.2002859}, author = {Perumalsamy, Lakshmi R and Marcel, Nimi and Kulkarni, Sneha and Radtke, Freddy and Sarin, Apurva} } @article {719, title = {Functional tumor infiltrating TH1 and TH2 effectors in large early-stage cervical cancer are suppressed by regulatory T cells.}, journal = {Int J Gynecol Cancer}, volume = {22}, year = {2012}, month = {2012 Sep}, pages = {1130-7}, abstract = {

OBJECTIVE: Analysis of tumor-infiltrating lymphocytes (TILs) is one of the cornerstones for the understanding of immune responses prevailing in the tumor microenvironment. We studied TILs from squamous cell carcinoma of the cervix ex vivo without proliferating them in vitro before analysis.

METHODS: Whereas TILs were magnetic activated cell separation enriched and flow sorted into CD4 CD25 (regulatory T cells [Tregs]), CD4 CD25 (effector T cells [Teffs]) were directly purified by flow cytometry, and both these subsets were characterized phenotypically and functionally. Tissue sections were probed for interleukin 4 (IL-4) and interferon γ.

RESULTS: Effector T cells constitutively expressed both interferon γ and IL-4 prototypical cytokines of TH1 and TH2, respectively, and were able to proliferate and secrete higher quantities of both cytokines in response to anti-CD3/anti-CD28 and autologous tumor lysates. Only 53\% of cervical cancer Tregs were FOXP3, elaborated transforming growth factor β1, and IL-10 and were able to inhibit both T helper subsets.

CONCLUSIONS: Intratumoral Teffs represented functionally active subsets of both TH1 and TH2 that were not anergic but were suppressed by multiple Treg subsets, which comprised FOXP3 + Tregs and Tregs secreting transforming growth factor β1 and IL-10. These results imply that the microenvironment of cervical carcinomas harbored both TH1 and TH2 subsets of CD4 Teffs that were functionally active but were perhaps unable to perform because of the overpowering effect of Tregs.

}, keywords = {Carcinoma, Squamous Cell, Cytokines, Female, Flow Cytometry, Humans, Immune Tolerance, Interferon-gamma, Lymphocyte Activation, Lymphocytes, Tumor-Infiltrating, Neoplasm Staging, T-Lymphocytes, Regulatory, Th1 Cells, Th2 Cells, Uterine Cervical Neoplasms}, issn = {1525-1438}, doi = {10.1097/IGC.0b013e318262aa53}, author = {Adurthi, Sreenivas and Mukherjee, Geetashree and Krishnamurthy, H and Sudhir, Krishna and Bafna, Uttamchand D and Umadevi, Kswamy and Jayshree, Rudrapatna Subramanyam} }