Profile of a Serial Killer: Cellular and Molecular Approaches to Study Individual Cytotoxic T‐Cells following Therapeutic Vaccination

Abstract

T-cell vaccination may prevent or treat cancer and infectious diseases, but further progress is required to increase clinical efficacy. Step-by-step improvements of T-cell vaccination in phase I/II clinical studies combined with very detailed analysis of T-cell responses at the single cell level are the strategy of choice for the identification of the most promising vaccine candidates for testing in subsequent large-scale phase III clinical trials. Major aims are to fully identify the most efficient T-cells in anticancer therapy, to characterize their TCRs, and to pinpoint the mechanisms of T-cell recruitment and function in well-defined clinical situations. Here we discuss novel strategies for the assessment of human T-cell responses, revealing in part unprecedented insight into T-cell biology and novel structural principles that govern TCR-pMHC recognition. Together, the described approaches advance our knowledge of T-cell mediated-protection from human diseases.

Simultaneous Coexpression of Memory-related and Effector-related Genes by Individual Human CD8 T Cells Depends on Antigen Specificity and Differentiation

“…As such, the reverse transcription was completed using an oligo-(dT) primer that The TCR clonotype repertoire analysis of directly ex vivo sorted single tumor-and virus-specific T cells was first compared with that of single T cells generated by in vitro limiting dilution cultures, which has long been the method of choice for assessing TCR BV gene segment usage. 19 Despite a large usage of the 22 different TCR BV families, in line with our previous reports, 29,30 we observed highly similar proportions of TCR BV family usage ( Fig. 3A) and of individual TCR clonotype signatures ( Fig.…”

“…18 Cellular immune responses generated following therapeutic vaccines have also been described as highly diverse in terms of phenotype and functionality. 19 Recently Flatz and colleagues identified previously unrecognized subsets of CD8 pos T cells based upon analysis of gene-expression patterns within single cells and showed that they were differentially induced by different vaccines. 20 These studies emphasize the strong need to delineate the qualitative attributes of vaccine-induced CD8 pos T cell responses, not only at the phenotypic/functional levels but as well by defining the genetic signatures of single cells.…”

Vaccine-Induced Effector-Memory CD8+ T Cell Responses Predict Therapeutic Efficacy against Tumors

“…The efficacy of therapeutic vaccines against cancer, however, lacks defined immune correlates of tumor eradication after (therapeutic) vaccination based on features of Ag-specific T cell responses. In this study, we examined CD8 + T cell responses elicited by various peptide and TLR agonist-based vaccine formu- C D8 + T cells play a central role in the control of and protection against intracellular pathogens and malignant cells (1,2). The differentiation of naive CD8 + T cells into effector and memory cell populations is accompanied by substantial plasticity regarding phenotype and functional capacity (3,4), emphasizing the multifaceted and important role of this T cell subset.…”

Chronic Myelocytic Leukemia (CML) Patient-Derived Dendritic Cells Transfected with Autologous Total RNA Induces CML-Specific Cytotoxicity

“…Inoculation with CML tumor lysate produces an enhancement in CML-DC antigen-presenting function [19][20][21], but it may also induce autoimmune diseases when used in humans [12]. DNA-loaded DCs using constructed plasmids could induce specific CTL reactions [21], but these plasmids present a potential risk because they may persist in DCs for months by integrating into the genome or remaining active as unintegrated DNA in non-dividing cells [11,[22][23][24]. RNA-loaded DCs can generate specific CTL effects and induce polyclonal CD8?…”