Characterization of T-cell receptor V beta repertoire in ovarian tumour-reacting CD3+ CD8+ CD4- CTL lines

Clonal expansion of T cells that are specific for autologous ovarian tumor among tumor-infiltrating T cells in humans

OBJECTIVE

The purpose of this study was to determine whether oligoclonally expanding tumor-infiltrating lymphocytes (TIL) were tumor-specific.

STUDY DESIGN

Peripheral blood lymphocytes (PBL) from an ovarian tumor-bearing patient were stimulated in vitro with an autologous cancer cell line (SMOV-2). Then genes coding for the third complementarity-determining region of the T cell receptor (TCR) beta chain were amplified by reverse transcription-polymerase chain reaction and separated by single-strand conformation polymorphism. Accumulated TCR clonotypes in vitro and in vivo in TIL were compared.

RESULTS

Clonal expansion of T cells was generated from PBL by stimulation with SMOV-2. A portion of the proliferated clonotypes was found to be identical to those accumulated in TIL in vivo.

CONCLUSION

This is the first demonstration that accumulating T cell clones in TIL recognize antigen(s) on an autologous tumor. Further characterization of such T cell clonotypes may lead to tumor antigen-specific immunotherapy.

Oligoclonal T cells in human cancer

Many solid tumors are characterised by the infiltration of lymphocytes and their presence has been correlated with a more favourable prognosis. These tumor-infiltrating lymphocytes (TIL), have been shown to possess specific cytolytic reactivity towards autologous tumours, thus suggesting that tumour cells may express antigens capable of eliciting an immune response. Expression of such tumour-associated antigens (TAA) in combination with appropriate accessory signals would lead to the in vivo accumulation of T cells with anti-tumour specificity. Analysis of the composition of the specific T-cell receptor (TCR) of TIL could thus provide information on the nature of the antigen(s) recognised by TIL. In this review, different aspects of the presence of clonal T cells in patients with cancer are discussed.

MHC class I bound peptides of a colon carcinoma cell line, a Ki-ras gene-targeted progeny cell line and a B cell line

MHC class I associated peptides on cancer cells represent potential targets for CD8+ cytotoxic T cell activity against tumor cells. We eluted the naturally bound MHC class I peptides of a colon carcinoma cell line and compared them to peptides isolated from a B cell line and a slow-growing activated Ki-ras-disrupted colon cancer cell line. While we failed to detect any significant differences in class I associated peptides due to the presence or absence of activated Ki-ras in colon cancer cell lines, the colon cancer cell lines and B cell line presented vastly different peptide repertoires in the context of HLA-A*0201 molecules.

Analysis of TCR usage in human tumors: a new tool for assessing tumor-specific immune responses

Tumor-infiltrating lymphocytes (TILs), through displaying a T-cell receptor (TCR) repertoire as heterogeneous as that of normal peripheral blood T cells, show overexpression of TCR variable-gene segments that include clonally expanded TCR sequences. Here, Marialuisa Sensi and Giorgio Parmiani analyze the available information on TCR usage by T cells present in the infiltrate of histologically different tumors and suggest that the analysis of TCR sequences represents a powerful new tool to assess the in vivo immune response to growing tumors. Ultimately, this strategy may lead to the identification and manipulation of T-cell populations endowed with antitumor reactivity.