Lethal hit delivery by cytotoxic T lymphocytes (CTL) towards B lymphoma cells occurs as a binary, "yes/no" process. In non-hematologic solid tumors, however, CTL often fail to kill target cells during 1:1 conjugation. Here we describe a mechanism of "additive cytotoxicity" by which time-dependent integration of sublethal damage events, delivered by multiple CTL transiting between individual tumor cells, mediates effective elimination.
View Article and Find Full Text PDFBackground: Prevalence of type 2 diabetes (T2D) is increasing worldwide. T2D prevention by lifestyle intervention is effective. Pragmatic scalable interventions are needed, with evidence to efficiently target and monitor such interventions.
View Article and Find Full Text PDFModulation of the immune response by established tumors may contribute to the limited success of therapeutic vaccination for the treatment of cancer compared with vaccination in a preventive setting. We analyzed the contribution of the CD4+ T-cell population to the induction or suppression of tumor-specific CD8+ T cells in a tumor model in which eradication of tumors crucially depends on CD8+ T cell-mediated immunity. Vaccine-mediated induction of protective antitumor immunity in the preventive setting (i.
View Article and Find Full Text PDFThe onset and regulation of a specific immune response results from communication between T cells and antigen-presenting cells (APCs), which form molecular interactions at the site of cell-cell contact--and this is known as the immunological synapse. Initially, the immunological synapse was viewed as a stereotypical adhesion and signalling device with a defined molecular structure and signalling processes. However, as we discuss here, T-cell-APC interactions comprise a diverse range of contact modes and distinct molecular arrangements.
View Article and Find Full Text PDFThe fate of naive CD8(+) T cells is determined by the environment in which they encounter MHC class I presented peptide Ags. The manner in which tumor Ags are presented is a longstanding matter of debate. Ag presentation might be mediated by tumor cells in tumor draining lymph nodes or via cross-presentation by professional APC.
View Article and Find Full Text PDFNaive T cells can be tolerized in the periphery by diverse mechanisms. However, the extent to which memory T cells are susceptible to tolerance induction is less well defined. Vaccination of mice with a minimal CTL epitope derived from human adenovirus type 5 E1A in IFA s.
View Article and Find Full Text PDFDisruption of one copy of the human CREB binding protein (CBP or CREBBP) gene leads to the Rubinstein-Taybi syndrome (RTS), a developmental disorder characterized by retarded growth and mental functions, broad thumbs, broad big toes and typical facial abnormalities. The CREB binding protein (CBP) is an essential transcriptional coactivator for many different transcription factors. CBP has the intrinsic ability to acetylate histones and other proteins, which is regarded as an important step in transcription activation.
View Article and Find Full Text PDFTriggering of 4-1BB, a member of the TNFR family, through in vivo administration of agonistic anti-4-1BB Ab delivers a powerful costimulatory signal to CTL. We found this signal to effectively replace the need for CD4(+) T cell help in the cross-priming of tumor-specific CTL immunity. Furthermore, 4-1BB Ab can convert an otherwise tolerogenic peptide vaccine into a formulation capable of efficient CTL priming.
View Article and Find Full Text PDFAdequate spontaneous activation of tumor-specific T lymphocytes in tumor-bearing hosts is rare, despite the expression of tumor antigens that are potentially highly immunogenic. For example, failure of the immune system to raise competent responses against established tumors expressing the human adenovirus E1A-antigen allows this tumor to grow in immunocompetent mice. We show that systemic in vivo administration of agonistic anti-CD40 antibodies into tumor-bearing mice results in tumor eradication mediated by CD8(+) T cells.
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