Faculty Opinions recommendation of In situ programming of leukaemia-specific T cells using synthetic DNA nanocarriers.

ABSTRACT Theiler's murine encephalomyelitis virus (TMEV) persists in the mouse central nervous system principally in macrophages, and infected macrophages in culture undergo apoptosis. We have detected abundant apoptotic cells in perivascular cuffs and inflammatory, demyelinating lesions of SJL mice chronically infected with TMEV. T cells comprised 74% of apoptotic cells, while 8% were macrophages, 0.6% were astrocytes, and ∼17% remained unidentified. In situ hybridization revealed viral RNA in ∼1% of apoptotic cells.

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823 CD4 T cells are essential for an anti-tumor effect in a B78 murine melanoma tumor model

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0823 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A873-A873

Author(s):

Arika Feils ◽

Mackenzie Heck ◽

Anna Hoefges ◽

Peter Carlson ◽

Luke Zangl ◽

...

Keyword(s):

T Cells ◽

Tumor Growth ◽

Cd4 T Cells ◽

Tumor Response ◽

Immune Cell ◽

Cd8 T Cell ◽

Mhc I ◽

Mhc Ii ◽

Flow Cytometric

BackgroundMice bearing B78 melanoma tumors can be cured using an in situ vaccine (ISV) regimen that includes radiation (RT) together with immunocytokine (tumor-targeting mAb conjugated to IL-2). B78 melanoma cells, derived from B16 cells, express minimal to no MHC-I but express MHC-II upon IFN-g/TNF-a stimulation. Although B78 cells are primarily MHC-I-deficient, an increased CD8 T cell infiltration into the tumor microenvironment (TME) has been shown following ISV.1 To further investigate the potential role of specific immune cell lineages in the B78 anti-tumor response to ISV, immune subset depletion studies and flow cytometric analyses were performed.MethodsC57BL/6 mice bearing B78 tumors were depleted of immune cell subsets with mAbs (anti-CD4, anti-CD8, anti-NK1.1, or Rat IgG control) for 3 weeks during the course of treatment. Treatment groups included no treatment, RT (12 Gy), or ISV (RT D0 and immunocytokine D5-D9). 6 mice/group (repeated three times) were followed for survival/tumor growth, and flow cytometry studies included 4 mice/group, sacrificed on D8 and D13 following the start of ISV.ResultsMice depleted of CD4 T cells during the course of ISV showed a significant reduction of anti-tumor effect as compared to mice treated with ISV/Rat IgG (pConclusionsThese studies suggest that CD4 T cells are essential for an anti-tumor response in the B78 melanoma model. In vivo depletion data show that CD4 T cells, but not CD8 or NK cells, are required for a decrease in tumor growth via ISV. Flow cytometric analyses suggest an interplay between CD4 and CD8 T cells as indicated by a decrease in CD8/IFN-g expression following ISV in the absence of CD4 T cells. The role that MHC-I and MHC-II expression plays in this CD4/CD8 T cell anti-tumor response is under investigation. In future studies, B78 melanoma may serve as a critical syngeneic model for development of more effective immunotherapy treatment regimens.Ethics ApprovalAll animal experiments were performed in accordance with protocols approved by Animal Care and Use Committees of the University of Wisconsin-Madison.ReferenceMorris Z, Guy E, Francis D, et al. In situ tumor vaccination by combining local radiation and tumor-specific antibody or immunocytokine treatments. Cancer Res 2016;76(13):3929-3941.

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Direct demonstration of immunoglobulin chain RNA in thymus T cells by in situ hybridization

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.75.6.2905 ◽

1978 ◽

Vol 75 (6) ◽

pp. 2905-2908 ◽

Cited By ~ 10

Author(s):

U. Storb

Keyword(s):

T Cells ◽

In Situ Hybridization ◽

Direct Demonstration

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762 A combination of functional biomarkers improves identification of the tumor-specific reactive T cell repertoire

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0762 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A810-A810

Author(s):

Arianna Draghi ◽

Katja Harbst ◽

Inge Svane ◽

Marco Donia

Keyword(s):

T Cells ◽

T Cell ◽

De Novo ◽

Autologous Tumor ◽

T Cell Repertoire ◽

Cell Repertoire ◽

Simple Method ◽

Functional Biomarkers

BackgroundDetecting the entire repertoire of tumor-specific reactive T cells is essential for investigating the broad range of T cell functions in the tumor-microenvironment. At present, assays identifying tumor-specific functional activation measure either upregulation of specific surface molecules, de novo production of the most common antitumor cytokines or mobilization of cytotoxic granules.MethodsIn this study, we combined transcriptomic analyses of tumor-specific reactive tumorinfiltrating lymphocytes (TILs), TIL-autologous tumor cell co-cultures and commonly used established detection protocols to develop an intracellular flow cytometry staining method encompassing simultaneous detection of intracellular CD137, de novo production of TNF and IFNy and extracellular mobilization of CD107a.ResultsThis approach enabled the identification of a larger fraction of tumor-specific reactive T cells in vitro compared to standard methods, revealing the existence of multiple distinct functional clusters of tumor-specific reactive TILs. Publicly available datasets of fresh tumor single-cell RNA-sequencing from four cancer types were investigated to confirm that these functional biomarkers identified distinct functional clusters forming the entire repertoire of tumor-specific reactive T cells in situ.ConclusionsIn conclusion, we describe a simple method using a combination of functional biomarkers that improves identification of the tumor-specific reactive T cell repertoire in vitro and in situ.

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In Situ Regulation of DC Subsets and T Cells Mediates Tumor Regression in Mice

Science Translational Medicine ◽

10.1126/scitranslmed.3000359 ◽

2009 ◽

Vol 1 (8) ◽

pp. 8ra19-8ra19 ◽

Cited By ~ 144

Author(s):

O. A. Ali ◽

D. Emerich ◽

G. Dranoff ◽

D. J. Mooney

Keyword(s):

T Cells ◽

Tumor Regression

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Stm Studies at Electrochemically Controlled Interfaces

MRS Proceedings ◽

10.1557/proc-332-393 ◽

1994 ◽

Vol 332 ◽

Author(s):

S.M. Lindsay ◽

J. Pan ◽

T.W. Jing

Keyword(s):

Electron Tunneling ◽

Point Contact ◽

Localized States ◽

Scanning Tunneling ◽

Zero Field ◽

Tunneling Microscopy ◽

Dna Oligomers ◽

Synthetic Dna ◽

Quantum Point

ABSTRACTWe use electrochemical methods to control the adsorption of molecules onto an electrode for imaging in-situ by scanning tunneling microscopy. Measurements of the barrier for electron tunneling show that the mechanism of electron transfer differs from vacuum tunneling. Barriers depend upon the direction of electron tunneling, indicating the presence of permanently aligned dipoles in the tunnel gap. We attribute a sharp dip in the barrier near zero field to induced polarization. We propose a ‘tunneling’ process consisting of two parts: One is delocalization of quantum-coherent states in parts of the molecular adlayer that hybridize strongly (interaction ≥ kT) with Bloch states in the metal. This gives rise to a quantum-point-contact conductance, Gc ≤ 2e2/h at a height zo. The other part comes from the exponential decay of the tails of localized states, G = Gc exp{−2K(z − z0)}. Because measured decay lengths, (2K‘)−1, are small (≈ 1 Å), STM contrast is dominated by the contour along which G[z0 (x,y)] = Gc. Measured changes in z0 are used to calculate images which are in reasonable agreement with observations. We illustrate this with images of synthetic DNA oligomers.

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