A role of T cells in anti-tumor immunity is well established. In colon cancer the
presence of tumor infiltrating lymphocytes with a Th1-type signature is predictive
of favorable clinical outcome (1). On the other hand, we recently identified a ratio
of Th2 over Th1 tumor infiltrating lymphocytes superior to the median value as
an independent predictive factor of reduced overall survival in pancreatic cancer
(2). The quality of anti-tumor immunity largely depends on the cytokine milieu of
the tumor microenvironment. Active vaccination and adoptive transfer of antitumor
T cells have been proposed for anti-tumor immunotherapeutic approaches
(3). However, due to the immunosuppressive microenvironment present in
advanced tumors it is unknown whether these effectors would be appropriately
attracted into the tumor and keep their pro-inflammatory Th1-type phenotype.
Aim of the project is to address these questions using biological samples from
patients with pancreatic cancer available through ongoing collaborations.
Candidate molecules possibly interfering with homing capability and polarization
stability will be tested by real-time PCR on surgical samples. Tumor-specific Th1
cells will be obtained from healthy donors and the effect of different components
of the tumor microenvironment (i.e., tumor cells, cancer associated fibroblasts,
activated macrophages and Th2 cells isolated and expanded from surgical
samples) on T cell homing will be tested in migration assays. To determine the
stability of Th1 cell polarization specificity assays will be performed in the
presence of Th2 cytokines or the supernatant of tumor cells, cancer associated
fibroblasts and macrophages conditioned by the same supernatants and INF-γ
released measured. If none of the candidate molecules will prove to be implicated
we will perform purification of the active protein(s) by mass spectrometry.
Strategies to overcome possible impairment of tumor antigen-specific Th1 cells
will be then designed.
1. Galon J, Costes A, Sanchez-Cabo F, Kirilowsky A, Mlecnik B, Lagorce-Pagès C,
Tosolini M, Camus M, Berger A, Wind P, Zinzindohoué F, Bruneval P, Cugnenc PH,
Trajanoski Z, Fridman WH, Pagès F. Type, density, and location of immune cells
within human colorectal tumors predict clinical outcome. Science 2006;313:1960
2. De Monte L, Reni M, Tassi E, Clavenna D, Papa I, Recalde H, Braga M, Di Carlo
V, Doglioni C, Protti MP. Intratumor T helper type 2 cell infiltrate correlates with
cancer-associated fibroblasts thymic stromal lymphopoietin production and
reduced survival in pancreatic cancer. J Exp Med 2011;208:469
3. Dougan M, Dranoff G. Immune therapy for cancer. Annu Rev Immunol
2009;27:83

Pancreatic cancer is a very aggressive disease with dismal prognosis (1) characterized by a marked desmoplastic stroma, which is believed to promote disease progression (2). We recently identified a complex cross-talk among pancreatic cancer cells, cancer associated fibroblasts (CAFs) and dendritic cells (DCs) leading to Th2-type inflammation that correlates with overall survival after surgery in pancreatic cancer patients (3). This cross-talk is mediated by the release of pro-inflammatory cytokines by cancer cells with activation of CAFs to secrete the thymic stromal lymphopoietin (TSLP), which in turn activates resident DCs endowed with Th2 polarizing capability and which secrete Th2 attractant chemokines.
Aim of the project is to investigate whether and how TSLP and other Th2-type inflammation related tumor-derived factor(s) affect the immune cells present in the tumor microenvironment. The experiments will be performed using biological samples from pancreatic cancer patients available through ongoing collaborations. First, TSLP and supernatant of cancer cells and CAFs (isolated and expanded from surgical samples) will be used to condition in vitro DCs, T cells and monocytes/macrophages purified by peripheral blood. Specific phenotypic and functional studies will be performed to identify specific alterations. Second, functional genomics studies to identify genes/gene products consistently up- or down-modulated by conditioned immune cells will be performed. Specifically, we expect to compare untreated and DCs conditioned with TLSP and/or tumor-derived supernatants, untreated and tumor-specific CD4+ Th1 cells conditioned with TLSP and/or tumor-derived supernatants and untreated and monoyets/macrophages conditioned with TLSP and/or tumor-derived supernatants. Third, the identified signatures will be validated in vivo in immune cells infiltrating pancreatic cancer samples by immunohistochemistry and flow cytometry.


1. Hidalgo M. Pancreatic cancer. N Engl J Med 2010;362:1605
2. Kleeff J, Beckhove P, Esposito I, Herzig S, Huber PE, Löhr JM, Friess H. Pancreatic cancer microenvironment. Int. J. Cancer 2007;121:699
3. De Monte L, Reni M, Tassi E, Clavenna D, Papa I, Recalde H, Braga M, Di Carlo V, Doglioni C, Protti MP. Intratumor T helper type 2 cell infiltrate correlates with cancer-associated fibroblasts thymic stromal lymphopoietin production and reduced survival in pancreatic cancer. J Exp Med 2011;208:469