Cytolytic T-cell response against Epstein-Barr virus in lung cancer patients and healthy subjects

<p>Abstract</p> <p>Background</p> <p>This study aimed to examine whether EBV seropositive patients with lung cancer have an altered virus-specific CTL response, as compared to age-matched healthy controls and whether any variation in this response could be attributed to senescence.</p> <p>Methods</p> <p>Peripheral blood mononuclear cells from lung cancer patients, age-matched and younger healthy individuals were used to measure EBV-specific CTLs after in vitro amplification with the GLCTLVAML and RYSIFFDYM peptides followed by HLA-multimer staining.</p> <p>Results</p> <p>Lung cancer patients and aged-matched controls had significantly lesser EBV-specific CTL than younger healthy individuals. Multimer positive populations from either group did not differ with respect to the percentage of multimer positive CTLs and the intensity of multimer binding.</p> <p>Conclusions</p> <p>This study provides evidence that patients with lung cancer exhibit an EBV-specific CTL response equivalent to that of age-matched healthy counterparts. These data warrant the examination of whether young individuals have a more robust anti-tumor response, as is the case with the anti-EBV response.</p

Foxp3 expression in human cancer cells

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Naturally occurring tumor-specific CD8(+) T-cell precursors in individuals with and without cancer

Boosting pre-existing, naturally occurring cytolytic CD8(+) T-cell (CTLs) responses directed against class-I MHC-restricted peptides of tumor antigens, represents a primary goal of cancer immunotherapy. The number of pre-existing antitumor CTLs and their impaired function has been incriminated as the most likely candidates for the reduced clinical efficacy of these trials. This study was scheduled to determine possible differences in the frequency and the function of naturally occurring CTL precursors (pCTLs) against multiple peptides derived from the cancer-testis antigens MAGE-A1 and MAGE-A3, and the overexpressed antigen hTERT, in newly diagnosed lung cancer patients as compared with aged-matched healthy individuals. The cumulative frequency of circulating peptide-specific pCTLs was found significantly higher in the cancer patients, varied widely and was not affected by radiotherapy and chemotherapy. Furthermore, this frequency was greatly different between the various tumor-antigen peptides. Under the light of recent evidence provided from animal models, these results indicate that the peptide-specific pCTL frequency might represent an important determinant for the fate of cancer immunotherapy. In addition, our results show that tumor-specific pCTLs of cancer patients can present functional differences regarding their proliferative capacity, intensity of multimer staining and lytic capacity, when compared with those of healthy individuals. Hence, our findings could have an important role for the design of improved immunotherapeutic approaches for lung cancer. Immunology and Cell Biology (2010) 88, 575-585; doi:10.1038/icb.2010.8; published online 9 February 201

Three-dimensional colon cancer organoids model the response to CEA-CD3 T-cell engagers

Rationale: The CEA-CD3 T cell bispecific antibody cibisatamab (CEA-TCB) is currently undergoing clinical trials. Here we study its performance against three-dimensional tumor organoids in cocultures with T cells as compared to a higher affinity CEACAM5-CD3 (CEACAM5-TCB) bispecific antibody using time-lapse confocal microscopy. Methods: Pre-labelled spheroids derived from colon cancer cell lines and primary organoids derived from four colorectal cancer surgical specimens, which expressed different graded levels of CEA, were exposed in cocultures to T lymphocytes. Cocultures were treated with CEA-CD3 T-cell engagers and were followed by live confocal microscopy. Caspase 3 activation detected in real-time was used as an indicator of tumor cell death. Co-cultures were also set up with autologous tumor-associated fibroblasts to test the co-stimulatory effect of a fibroblast activated protein (FAP)- targeted 4-1BBL bispecific antibody fusion protein currently undergoing clinical trials. Results: Tumor-cell killing of 3D colon carcinoma cultures was dependent on the levels of surface CEA expression, in such a way that the lower affinity agent (CEA-TCB) did not mediate killing by human preactivated T cells below a certain CEA expression threshold, while the high affinity construct (CEACAM5-TCB) remained active on the low CEA expressing organoids. Modelling heterogeneity in the levels of CEA expression by coculturing CEA high and low organoids showed measurable but weak bystander killing. Cocultures of tumor organoids, autologous fibroblasts and T cells allowed to observe a costimulatory effect of anti-FAP-4-1BBL both to release IFNγ and to attain more efficacious tumor cell killing. Conclusion: Three-dimensional tumor cocultures with T cells using live confocal microscopy provide suitable models to test the requirements for colon-cancer redirected killing as elicited by CEA-targeted T-cell engagers undergoing clinical trials and treatment allow combinations to be tested in a relevant preclinical system