A modified human ELISPOT assay to detect specific responses to primary tumor cell targets

• Main Authors: Kwak Larry W, Baseler Michael, Troke Angela, Ulderich Tracy, Shafer-Weaver Kimberly A, Strobl Susan L, Malyguine Anatoli, Neelapu Sattva S
• Format: Article
• Language: English
• Published: BMC 2004-03-01
• Series: Journal of Translational Medicine
• Online Access: http://www.translational-medicine.com/content/2/1/9

<p>Abstract</p> <p>Background</p> <p>The desired outcome of cancer vaccination is to induce a potent T cell response which can specifically recognize and eliminate autologous tumor cells <it>in vivo</it>. Accordingly, immunological assays that demonstrate recognition of native tumor cells (tumor-specific) may be more clinically relevant than assays that demonstrate recognition of tumor protein or peptide (antigen-specific).</p> <p>Methods</p> <p>Towards this goal, we adapted the IFN-γ ELISPOT assay to measure immune responses against autologous primary tumor cells in vaccinated cancer patients. As a model system to develop the assay, we utilized peripheral blood mononuclear cells (PBMC) directly isolated from follicular lymphoma patients vaccinated with tumor-derived idiotype protein.</p> <p>Results</p> <p>After optimizing several variables, we demonstrated that the modified IFN-γ ELISPOT assay could be used to reliably and reproducibly determine the tumor-reactive T cell frequency in the PBMC of these patients. The precursor frequency of tumor-reactive T cells was significantly higher in the postvaccine PBMC, compared with prevaccine samples in all patients tested. Furthermore, the specificity of these T cells was established by the lack of reactivity against autologous normal B cells.</p> <p>Conclusions</p> <p>These results demonstrate the feasibility of quantitating tumor-specific T cell responses when autologous, primary tumor cells are available as targets.</p>