Antigen-driven T-cell selection in patients with cervical cancer as evidenced by T-cell receptor analysis and recognition of autologous tumor

Next Generation Sequencing-Based Identification of T-Cell Receptors for Immunotherapy Against Hepatocellular Carcinoma

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains a global health concern, and HBV proteins may be ideal targets for T cell-based immunotherapy for HCC. There is a need for fast and efficient identification of HBV-specific T cell receptors (TCRs) for the development of TCR-transduced T (TCR-T) cell-based immunotherapy. Two widely employed TCR identification approaches, T cell clonal expansion and single-cell sequencing, involve a TCR singularization process for the direct identification of Vα and Vβ pairs of TCR chains. Clonal expansion of T cells is well known to have tedious time and effort requirements due to the use of T cell cultures, whereas single-cell sequencing is limited by the requirements of cell sorting and the preparation of a single-cell immune-transcriptome library as well as the massive cost of the whole procedure. Here, we present a next-generation sequencing (NGS)-based HBV-specific TCR identification that does not require the TCR singularization process. Conclusion: Two pairing strategies, ranking-based strategy and α-β chain mixture-based strategy, have proved to be useful for NGS-based TCR identification, particularly for polyclonal T cells purified by a peptide-major histocompatibility complex (pMHC) multimer-based approach. Functional evaluation confirmed the specificity and avidity of two identified HBV-specific TCRs, which may potentially be used to produce TCR-T cells to treat patients with HBV-related HCC.

HER-2/neu vaccine-primed autologous T-cell infusions for the treatment of advanced stage HER-2/neu expressing cancers

This phase I study evaluated the feasibility of expanding HER-2/neu (HER2) vaccine-primed peripheral blood T-cells ex vivo and assessed the safety of T-cell infusions. Eight patients with HER2(+) treatment refractory metastatic cancers were enrolled. T-cells could be expanded to predefined parameters in seven patients (88%). Ninety-two percent of adverse events were grade 1 or 2. Three of seven patients developed infusion-related inflammatory reactions at their disease sites. HER2-specific T-cells significantly increased in vivo compared to pre-infusion levels (p = 0.010) and persisted in 4/6 patients (66%) over 70 days after the first infusion. Partial clinical responses were observed in 43% of patients. Levels of T-regulatory cells in peripheral blood prior to infusion (p < 0.001), the level of HER2-specific T-cells in vivo (p = 0.030), and development of diverse clonal T-cell populations (p < 0.001) were associated with response. The generation of HER2 vaccine-primed autologous T-cells for therapeutic infusion is feasible and well tolerated. This approach provides a foundation for the application of T-cell therapy to additional solid tumor types.

MHC multimer-guided and cell culture-independent isolation of functional T cell receptors from single cells facilitates TCR identification for immunotherapy

Adoptive therapy using T cells redirected to target tumor- or infection-associated antigens is a promising strategy that has curative potential and broad applicability. In order to accelerate the screening process for suitable antigen-specific T cell receptors (TCRs), we developed a new approach circumventing conventional in vitro expansion-based strategies. Direct isolation of paired full-length TCR sequences from non-expanded antigen-specific T cells was achieved by the establishment of a highly sensitive PCR-based T cell receptor single cell analysis method (TCR-SCAN). Using MHC multimer-labeled and single cell-sorted HCMV-specific T cells we demonstrate a high efficacy (approximately 25%) and target specificity of TCR-SCAN receptor identification. In combination with MHC-multimer based pre-enrichment steps, we were able to isolate TCRs specific for the oncogenes Her2/neu and WT1 even from very small populations (original precursor frequencies of down to 0.00005% of CD3(+) T cells) without any cell culture step involved. Genetic re-expression of isolated receptors demonstrates their functionality and target specificity. We believe that this new strategy of TCR identification may provide broad access to specific TCRs for therapeutically relevant T cell epitopes.

Human squamous cell carcinomas evade the immune response by down-regulation of vascular E-selectin and recruitment of regulatory T cells

Squamous cell carcinomas (SCCs) of the skin are sun-induced skin cancers that are particularly numerous in patients on T cell immunosuppression. We found that blood vessels in SCCs did not express E-selectin, and tumors contained few cutaneous lymphocyte antigen (CLA)(+) T cells, the cell type thought to provide cutaneous immunosurveillance. Tumors treated with the Toll-like receptor (TLR)7 agonist imiquimod before excision showed induction of E-selectin on tumor vessels, recruitment of CLA(+) CD8(+) T cells, and histological evidence of tumor regression. SCCs treated in vitro with imiquimod also expressed vascular E-selectin. Approximately 50% of the T cells infiltrating untreated SCCs were FOXP3(+) regulatory T (T reg) cells. Imiquimod-treated tumors contained a decreased percentage of T reg cells, and these cells produced less FOXP3, interleukin (IL)-10, and transforming growth factor (TGF)-beta. Treatment of T reg cells in vitro with imiquimod inhibited their suppressive activity and reduced FOXP3, CD39, CD73, IL-10, and TGF-beta by indirect mechanisms. In vivo and in vitro treatment with imiquimod also induced IL-6 production by effector T cells. In summary, we find that SCCs evade the immune response at least in part by down-regulating vascular E-selectin and recruiting T reg cells. TLR7 agonists neutralized both of these strategies, supporting their use in SCCs and other tumors with similar immune defects.

Depressed type 1 cytokine synthesis by superantigen-activated CD4+ T cells of women with human papillomavirus-related high-grade squamous intraepithelial lesions

Carcinoma of the cervix is causally related to infection with the human papillomavirus (HPV), and T cells play a pivotal role in the immune response of the host to rid itself of HPV infection. Therefore, we assessed the T-cell function of women with HPV-related cervical neoplasia against a superantigen, Staphylococcus enterotoxin B (SEB). Each woman provided a cervical brush specimen for HPV DNA testing and Papanicolaou (Pap) smears for the staging of cervical lesions. They also provided a blood specimen for determination of the ability of CD4(+) T and CD8(+) T cells to synthesize Th1 (interleukin-2 [IL-2], gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) and Th2 (IL-10) cytokines in response to activation with SEB. Compared with control subjects with self-attested negative Pap smears, women with high-grade squamous intraepithelial lesions (HSIL) had significantly lower percentages of activated CD4(+) T cells that produced IL-2 (P = 0.045), IFN-gamma (P = 0.040), and TNF-alpha (P = 0.015) and a significantly lower percentage of activated CD8(+) T cells that produced IL-2 (P < 0.01). These data indicate that women with HPV-related cervical HSIL show a decrease in Th1 cytokine production by activated CD4(+) T cells and suggested that compromised T-helper functions may negatively impact the function of cytotoxic CD8(+) T cells.

Proteomic analyser with applications to diagnostics and vaccines

This paper describes a method for proteomic analysis with applications to diagnostics and vaccines. A panel of N (> or = 1) reagents called X(j), with j = 1 to N, is used. The binding strength of each of the X(j) reagents to each other is measured, for example by an ELISA assay, giving an N x N matrix K. The matrix K is used to define another set of N reagents called Y(j), with j = 1 to N, each of which is a linear combination of the X(j) reagents and each of which is tailored to be complementary to one of the X(j) reagents. Each of the N pairs of reagents X(j) and Y(j) defines an axis in an N-dimensional shape space. The definition of these axes facilitates proteomic analysis of diverse biological samples, for example, mixtures of proteins such as serum samples or T cell extracts. A method for defining and measuring similarity between pairs of biological samples and between sets of biological samples in the context of the set of N reagent pairs is described. This leads to methods for using the N reagent pairs in the diagnosis of diseases and in the formulation of preventive and therapeutic vaccines. The relationship of this work to previous research on shape space is discussed.