scholarly journals Use of a β1 Integrin-deficient Human T Cell to Identify β1 Integrin Cytoplasmic Domain Sequences Critical for Integrin Function

1998 ◽  
Vol 9 (10) ◽  
pp. 2715-2727 ◽  
Author(s):  
Nadine C. Romzek ◽  
Estelle S. Harris ◽  
Cheryl L. Dell ◽  
Jeffrey Skronek ◽  
Elizabeth Hasse ◽  
...  

T cell activation rapidly and transiently regulates the functional activity of integrin receptors. Stimulation of CD3/T cell receptor, CD2 or CD28, as well as activation with phorbol esters, can induce within minutes an increase in β1 integrin-mediated adhesion of T cells to fibronectin. In this study, we have produced and utilized a mutant of the Jurkat T cell line, designated A1, that lacks protein and mRNA expression of the β1 integrin subunit but retains normal levels of CD2, CD3, and CD28 on the cell surface. Activation-dependent adhesion of A1 cells to fibronectin could be restored upon transfection of a wild-type human β1 integrin cDNA. Adhesion induced by phorbol 12-myristate 13-acetate-, CD3-, CD2-, and CD28 stimulation did not occur if the carboxy-terminal five amino acids of the β1 tail were truncated or if either of two well-conserved NPXY motifs were deleted. Scanning alanine substitutions of the carboxy-terminal five amino acids demonstrated a critical role for the tyrosine residue at position 795. The carboxy-terminal truncation and the NPXY deletions also reduced adhesion induced by direct stimulation of the β1 integrin with the activating β1 integrin-specific mAb TS2/16, although the effects were not as dramatic as observed with the other integrin-activating signals. These results demonstrate a vital role for the amino-terminal NPXY motif and the carboxy-terminal end of the β1 integrin cytoplasmic domain in activation-dependent regulation of integrin-mediated adhesion in T cells. Furthermore, the A1 cell line represents a valuable new cellular reagent for the analysis of β1 integrin structure and function in human T cells.

1991 ◽  
Vol 34 (6) ◽  
pp. 713-719 ◽  
Author(s):  
R. DITZIAN-KADANOFF ◽  
L. PARKS ◽  
B. EVAVOLD ◽  
J. QUINTANS ◽  
T. J. SWARTZ

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1352-1352
Author(s):  
Frank Grünebach ◽  
Katrin Kayser ◽  
Silke Appel ◽  
Markus M. Weck ◽  
Martin R. Müller ◽  
...  

Abstract Dendritic cells are professional antigen-presenting cells (APC) with the unique capacity to initiate primary immune responses. Recently, it was demonstrated that transfection of DC with RNA coding for specific antigens can elicit an effective T cell response in vitro and in vivo. 4-1BB (CD137) is a member of a family of receptors found on the surface of cells of the immune system. It plays an important role in the costimulation of T-cells: it enhances T-cell proliferation, cytokine production and cytotoxic effector functions and suppresses the induction of apoptosis. It is predominantly expressed on activated T-cells, and its ligand 4-1BBL is expressed on activated APC including DC. In the present study we analyzed the effects of 4-1BBL on the stimulatory capacity of DC. Monocyte derived DC were electroporated with in vitro transcribed RNA encoding the tumor-associated antigen Her-2/neu. Additionally these cells were cotransfected with in vitro transcribed RNA coding for the human 4-1BBL with the aim to enhance the costimulatory functions of the cells and therefore the induction of Her-2/neu specific cytotoxic T-cells (CTL). Standard 51Cr-release assays performed after two restimulations showed specific cytotoxic activity of the induced CTL against autologous DC transfected with Her-2/neu RNA and against the HLA-matched allogeneic Her-2/neu+/HLA-A2+ renal cell carcinoma cell line A498 whereas DC transfected with irrelevant RNA as well as Her-2/neu-/HLA-A2+ CROFT cells and the Her-2/neu+/HLA-A2- cell line SK-OV-3 were spared. There was no lysis of K562 cells, thus excluding a NK-cell mediated killing. In this experimental setting the specific lysis rate of target cells could nearly be doubled by the coadministration of Her-2/neu RNA and an equal amount of 4-1BBL RNA (50% vs 90% specific lysis at effector to target ratio of 30:1). Interestingly, overexpression of 4-1BBL had no effect on the stimulation of allogeneic T cells by electroporated DC in a mixed lymphocyte reaction, indicating that 4-1BBL increases the induction of antigen specific T cell responses rather than the unspecific stimulation of bulk T lymphocytes. Furthermore, FACS analysis of DC transfected with 4-1BBL plasmid DNA or in vitro transcribed 4-1BBL RNA showed higher expression of the costimulatory molecules CD80, CD86, CD40 and the T-cell adhesion molecule CD54 as compared to the controls indicating that 4-1BBL signaling can mediate activation of DC and thus increase their stimulatory capacity. In the context of immunotherapies for cancer patients the findings of our study could contribute to optimise the in vitro manipulation of DC for the induction of antigen-specific CTL responses.


2002 ◽  
Vol 22 (12) ◽  
pp. 4241-4255 ◽  
Author(s):  
Michael P. Loreto ◽  
Donna M. Berry ◽  
C. Jane McGlade

ABSTRACT Adaptor proteins assemble multiprotein signaling complexes, enabling the transduction of intracellular signals. While many adaptor proteins positively regulate signaling in this manner, a subgroup of adaptors function as negative regulators. Here we report the identification of a hematopoiesis-specific adaptor protein that we have designated Src-like adaptor protein 2 (SLAP-2). SLAP-2 is most closely related to SLAP and contains a Src homology 3 (SH3) domain and an SH2 domain, as well as an amino-terminal myristoylation site that mediates SLAP-2 association with membranes. Following stimulation of primary thymocytes with anti-CD3 and anti-CD28, SLAP-2 coimmunoprecipitates with tyrosine-phosphorylated c-Cbl and an unidentified protein of approximately 72 kDa. In activated Jurkat T cells, SLAP-2 also binds an additional 70-kDa phosphoprotein, identified as ZAP-70. Binding of SLAP-2 to both p72 and ZAP-70 is dependent on its SH2 domain, while c-Cbl interacts with the carboxy-terminal region. Overexpression of wild-type SLAP-2 alone or in combination with c-Cbl in Jurkat T cells leads to inhibition of T-cell antigen receptor-induced activation of nuclear factor of activated T cells. The inhibitory effect of SLAP-2 requires the carboxy-terminal c-Cbl binding region. Expression of SLAP-2 with SYK or ZAP-70 in COS cells or Jurkat T cells causes the degradation of these kinases, and SLAP-2 overexpression in Jurkat T cells reduces the surface expression of CD3. These results suggest that the mechanism of action of SLAP-2 and the related protein SLAP is to promote c-Cbl-dependent degradation of the tyrosine kinases SYK and ZAP-70 and down-regulation of CD3 at the cell surface.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1490
Author(s):  
Victoria Matyushenko ◽  
Irina Isakova-Sivak ◽  
Igor Kudryavtsev ◽  
Arina Goshina ◽  
Anna Chistyakova ◽  
...  

Background: New coronavirus SARS-CoV-2, a causative agent of the COVID-19 pandemic, has been circulating among humans since November 2019. Multiple studies have assessed the qualitative and quantitative characteristics of virus-specific immunity in COVID-19 convalescents, however, some aspects of the development of memory T-cell responses after natural SARS-CoV-2 infection remain uncovered. Methods: In most of published studies T-cell immunity to the new coronavirus is assessed using peptides corresponding to SARS-CoV-1 or SARS-CoV-2 T-cell epitopes, or with peptide pools covering various parts of the viral proteins. Here, we determined the level of CD4+ and CD8+ memory T-cell responses in COVID-19 convalescents by stimulating PBMCs collected 1 to 6 months after recovery with sucrose gradient-purified live SARS-CoV-2. IFNγ production by the central and effector memory helper and cytotoxic T cells was assessed by intracellular cytokine staining assay and flow cytometry. Results: Stimulation of PBMCs with live SARS-CoV-2 revealed IFNγ-producing T-helper effector memory cells with CD4+CD45RA−CCR7− phenotype, which persisted in circulation for up to 6 month after COVID-19. In contrast, SARS-CoV-2-specific IFNγ-secreting cytotoxic effector memory T cells were found at significant levels only shortly after the disease, but rapidly decreased over time. Conclusion: The stimulation of immune cells with live SARS-CoV-2 revealed a rapid decline in the pool of effector memory CD8+, but not CD4+, T cells after recovery from COVID-19. These data provide additional information on the development and persistence of cellular immune responses after natural infection, and can inform further development of T cell-based SARS-CoV-2 vaccines.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A197-A197
Author(s):  
Brendan Horton ◽  
Brendan Horton ◽  
Duncan Morgan ◽  
Noor Momin ◽  
Vidit Bhandarkar ◽  
...  

BackgroundTumor infiltrating T cells (TIL) are highly correlated with response to checkpoint blockade immunotherapy (CBT) in melanoma. However, in non-small cell lung cancer (NSCLC), 61% of patients have TIL, but only 32% respond to CBT. It is unknown how these T cell-inflamed tumors are resistant to CBT. Understanding and overcoming this resistance would greatly increase the number of cancer patients who benefit from CBT.MethodsTo understand lung-specific anti-tumor immune responses, a NSCLC cell line derived from an autochthonous murine lung cancer (KP cell line) was transplanted into syngeneic C57BL/6 mice subcutaneously or intravenously. To study antigen-specific responses, the KP cell line was engineered with SIY and 2C TCR transgenic T cells, which are specific for SIY, were adoptively transferred into tumor-bearing animals.ResultsSubcutaneous KP tumors responded to CBT (aCTLA-4 and aPD-L1) with significant tumor regression while lung KP tumors were CBT resistant. Immunohistochemistry found that this was not due to lack of T cell infiltration, as lung tumors contained 10-fold higher numbers of CD8+ TIL than subcutaneous tumors. Single cell RNA sequencing of TIL uncovered that CD8+ TIL in lung lesions had blunted effector molecule expression that correlated with a lack of IL-2 signaling. Adoptive transfer of naïve, tumor-reactive 2C T cells resulted in equally robust T cell proliferation in both the inguinal and mediastinal lymph nodes (LNs). However, RNA sequencing of adoptively transferred 2C T cells isolated 3-days after transfer from draining LNs identified that T cells activated in the mediastinal LN had reduced levels of IL-2 signaling and blunted effector functions early during priming. Flow cytometry confirmed that T cells primed in the mediastinal LNs did not express CD25, GZMB, or IFN-g, while T cells in inguinal LNs upregulated all three of these effector molecules. Delivery of IL-2 and IL-12 during priming was sufficient to restore effector molecule expression on 2C T cells in mediastinal LNs. Analysis of published patient data identified that a subset of lung cancer patients showed a sizable population of CD8+ TIL with low IL-2 signaling and low expression of effector molecules, including common targets of CBT.ConclusionsImmunotherapy resistance in T cell-inflamed tumors is due to defective CD8+ T cell effector differentiation. IL-2-based therapies could enhance differentiation of functional CD8+ effector T cells and could turn immunotherapy resistant tumors to immunotherapy sensitive tumors. This is the first mechanistic study providing evidence for a distinct type of T cell dysfunction resistant to current CBT.Ethics ApprovalThis study was approved by MIT’s Committee on Animal Care, protocol number 0220-006-23.


Blood ◽  
2001 ◽  
Vol 97 (9) ◽  
pp. 2764-2771 ◽  
Author(s):  
Beth D. Harrison ◽  
Julie A. Adams ◽  
Mark Briggs ◽  
Michelle L. Brereton ◽  
John A. Liu Yin

Abstract Effective presentation of tumor antigens is fundamental to strategies aimed at enrolling the immune system in eradication of residual disease after conventional treatments. Myeloid malignancies provide a unique opportunity to derive dendritic cells (DCs), functioning antigen-presenting cells, from the malignant cells themselves. These may then co-express leukemic antigens together with appropriate secondary signals and be used to generate a specific, antileukemic immune response. In this study, blasts from 40 patients with acute myeloid leukemia (AML) were cultured with combinations of granulocyte-macrophage colony-stimulating factor, interleukin 4, and tumor necrosis factor α, and development to DCs was assessed. After culture, cells from 24 samples exhibited morphological and immunophenotypic features of DCs, including expression of major histocompatibility complex class II, CD1a, CD83, and CD86, and were potent stimulators in an allogeneic mixed lymphocyte reaction (MLR). Stimulation of autologous T-cell responses was assessed by the proliferative response of autologous T cells to the leukemic DCs and by demonstration of the induction of specific, autologous, antileukemic cytotoxicity. Of 17 samples, 11 were effective stimulators in the autologous MLR, and low, but consistent, autologous, antileukemic cytotoxicity was induced in 8 of 11 cases (mean, 27%; range, 17%-37%). This study indicates that cells with enhanced antigen-presenting ability can be generated from AML blasts, that these cells can effectively prime autologous cytotoxic T cells in vitro, and that they may be used as potential vaccines in the immunotherapy of AML.


1988 ◽  
Vol 168 (5) ◽  
pp. 1899-1916 ◽  
Author(s):  
J A Bluestone ◽  
R Q Cron ◽  
M Cotterman ◽  
B A Houlden ◽  
L A Matis

Analyses of TCR-bearing murine and human T cells have defined a unique subpopulation of T cells that express the TCR-gamma/delta proteins. The specificity of TCR-gamma/delta T cells and their role in the immune response have not yet been elucidated. Here we examine alloreactive TCR-gamma/delta T cell lines and clones that recognize MHC-encoded antigens. A BALB/c nu/nu (H-2d)-derived H-2k specific T cell line and derived clones were both cytolytic and released lymphokines after recognition of a non-classical H-2 antigen encoded in the TL region of the MHC. These cells expressed the V gamma 2/C gamma 1 protein in association with a TCR-delta gene product encoded by a Va gene segment rearranged to two D delta and one J delta variable elements. A second MHC-specific B10 nu/nu (H-2b) TCR-gamma/delta T cell line appeared to recognize a classical H-2D-encoded MHC molecule and expressed a distinct V gamma/C gamma 4-encoded protein. These data suggest that many TCR-gamma/delta-expressing T cells may recognize MHC-linked antigens encoded within distinct subregions of the MHC. The role of MHC-specific TCR-gamma/delta cells in immune responses and their immunological significance are discussed.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A161-A161
Author(s):  
Diana DeLucia ◽  
Tiffany Pariva ◽  
Roland Strong ◽  
Owen Witte ◽  
John Lee

BackgroundIn advanced prostate cancer (PCa), progression to castration-resistant PCa (CRPC) is inevitable and novel therapies for CRPC are needed. Adoptive transfer of T cells targeting tumor antigens is a promising approach in the cancer field. Unfortunately, identifying antigens expressed exclusively in prostate tumor cells has been challenging. Since the prostate is not an essential organ, we alternatively selected prostate-restricted epithelial antigens (PREAs) expressed in both malignant and normal prostate tissue for transgenic T cell studies.MethodsRNA-seq data sets identifying genes enriched in PCa were cross-referenced with the NIH Genotype-Expression database to identify PREAs. Using a novel molecular immunology approach, select PREAs and major histocompatibility complex class I (MHC-I) molecules were co-expressed in HEK293F cells, from which MHC–peptide complexes were efficiently isolated. Peptides were eluted and sequenced by mass spectrometry. Peptide–MHC binding was validated with a T2 stabilization assay and peptide immunodominance was determined using an interferon-γ (IFN-γ) ELISpot assay following stimulation of healthy HLA-A2+ peripheral blood mononuclear cells (PBMC) with peptide pools. Following peptide stimulation, CD8+ T cells with peptide-specific T cell receptors (TCR) were enriched by peptide–MHC-I dextramer labeling and fluorescence activated cell sorting for single cell TCR α/β chain sequencing.ResultsWe identified 11 A2+ peptides (8 previously unpublished) from prostatic acid phosphatase (ACPP), solute carrier family 45 member 3 (SLC45A3), and NK3 homeobox 1 (NKX3.1) that bound to HLA-A2 with varying affinities. Extended culture stimulation of PBMC with peptide pools from each PREA, compared to the standard overnight culture, revealed a greater number of IFN-γ producing cells overall and a greater breadth of response across all the peptides. Antigen specific CD8+ T cells were detectable at low frequencies in both male and female healthy PBMC for 7 of the 11 peptides. Dextramer-sorted antigen-specific cells were used for single-cell paired TCR αβ sequencing and transgenic T cell development.ConclusionsThrough this work we identified HLA-A2-presented antigenic peptides from the PREAs ACPP, SLC45A3, and NKX3.1 that can induce the expansion of IFN-γ producing CD8+ T cells. Through peptide–MHC-I dextramer labeling, we isolated PREA-specific CD8+ T cells and characterized TCR αβ sequences with potential anti-tumor functionality. Our results highlight a rapid and directed platform for the development of MHC-I-restricted transgenic CD8+ T cells targeting lineage-specific proteins expressed in prostate epithelia for adoptive therapy of advanced PCa.


1996 ◽  
Vol 26 (11) ◽  
pp. 2565-2572 ◽  
Author(s):  
Ariane Volkmann ◽  
Jacques Neefjes ◽  
Brigitta Stockinger
Keyword(s):  
T Cells ◽  
T Cell ◽  

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