Effects of distant metastasis and peripheral CA 15-3 on the induction of spontaneous T cell responses in breast cancer patients.

Tumor-specific memory T cells are detectable in the bone marrow (BM) of a majority of breast cancer patients. In vitro they can be reactivated to IFN-gamma producing, cytotoxic effector cells and reject autologous, xenotransplanted tumors in NOD/SCID mice after specific restimulation with autologous dendritic cells (DC). In this study, we demonstrate the presence of specific tumor-reactive BM memory T cells in altogether 56 out of 129 primarily operated breast cancer patients by short-term IFN-gamma EliSpot assays with unstimulated T cells and tumor antigen presenting, autologous DCs. We observed tumor-reactive BM memory T cells predominantly in patients with primarily metastatic disease (P = 0.011) or with increased concentrations of tumor marker CA 15-3 in the peripheral blood (P = 0.004), respectively. Memory T cell reactivity against HLA-A(*0201)-restricted peptides from the tumor-associated antigens MUC1, Hpa(16-24) and Hpa(183-191) was also detected particularly in patients with elevated peripheral CA 15-3 concentrations (P < 0.05). Altogether these data indicate that the systemic presence of tumor-derived antigens promotes an induction of tumor-specific cellular immune responses in the human BM.

Intratumoral cytokines and tumor cell biology determine spontaneous breast cancer-specific immune responses and their correlation to prognosis.

Spontaneous immune responses in cancer patients have been described. Yet their clinical relevance and the conditions for their generation remain unclear. We characterized conditions that determine immune responses in primary breast cancer patients. We used tetramer analysis, ex vivo IFN-gamma ELISPOT, cytotoxicity assays, and ELISA in 207 untreated patients and 12 Her-2/neu-specific CD8 T-cell lines to evaluate tumor-specific T cells (TC) in the bone marrow or MUC1-specific antibodies in the blood. Multiplex analysis was performed to quantify 27 intratumoral cytokines, chemokines, and growth factors. Results were compared with multiple pathologic and clinical parameters of the patients and tumors. Forty percent of the patients showed tumor-specific TC responses. These correlated with tumors of high differentiation, estrogen receptor expression, and low proliferative activity, and with a reduced cancer mortality risk. High tumor cell differentiation correlated with increased intratumoral, but not plasma, concentrations of IFN-alpha and reduced transforming growth factor (TGF)beta1. In an in vitro priming experiment these two cytokines increased or inhibited, respectively, the capacity of dendritic cells to induce tumor-reactive TC. Tumor-specific B-cell responses, mainly of IgM isotype, were detectable in 50% of the patients and correlated with advanced tumor stage, increased TGFbeta1, reduced IFN-alpha, and absence of TC responses. We show here that different types of immune responses are linked to distinct cytokine microenvironments and correlate with prognosis-relevant differences in tumor pathobiology. These findings shed light on the relation between immune response and cancer prognosis.

The shaping of a polyvalent and highly individual T-cell repertoire in the bone marrow of breast cancer patients.

We analyzed the T-cell repertoires from the bone marrow of 39 primary operated breast cancer patients and 11 healthy female donors for the presence and frequencies of spontaneously induced effector/memory T lymphocytes with peptide-HLA-A2-restricted reactivity against 10 breast tumor-associated antigens (TAA) and 3 normal breast tissue-associated antigens by short-term IFN-gamma enzyme-linked immunospot (ELISpot) analysis. Sixty-seven percent of the patients recognized TAAs with a mean frequency of 144 TAA reactive cells per 10(6) T cells. These patients recognized simultaneously an average of 47% of the tested TAAs. The T-cell repertoire was highly polyvalent and exhibited pronounced interindividual differences in the pattern of TAAs recognized by each patient. Strong differences of reactivity were noticed between TAAs, ranging from 100% recognition of prostate-specific antigen(p141-149) to only 25% recognition of MUC1(p12-20) or Her-2/neu(p369-377). In comparison with TAAs, reactivity to normal breast tissue-associated antigens was lower with respect to the proportions of responding patients (30%) and recognized antigens (27%), with a mean frequency of only 85/10(6) T cells. Healthy individuals also contained TAA-reactive T cells but this repertoire was more restricted and the frequencies were in the same range as T cells reacting to normal breast tissue-associated antigens. Our data show a highly individual T-cell repertoire for recognition of TAAs in breast cancer patients. This has potential relevance for T-cell immune diagnostics, for tumor vaccine design, and for predicting immune responsiveness.

Heparanase: a new metastasis-associated antigen recognized in breast cancer patients by spontaneously induced memory T lymphocytes.

Increased expression and secretion of heparanase (Hpa) by tumor cells promotes tumor invasion through extracellular matrices, tissue destruction, angiogenesis, and metastasis. Here, we show the existence in breast cancer patients of Hpa-specific T lymphocytes by fluorescence-activated cell sorting flow cytometry using Hpa peptide-MHC class I tetramers. We furthermore show memory T-cell responses in a high proportion of breast cancer patients to Hpa-derived HLA-A2-restricted peptides, leading to production of IFN-gamma and to generation of antitumor CTLs lysing breast cancer cells. Such CTLs recognized endogenously processed respective Hpa peptides on Hpa-transfected and Hpa-expressing untransfected breast carcinoma cells. According to these results and to the fact that such cells were not found in healthy people, Hpa seems to be an attractive new tumor-associated antigen and its HLA-A2-restricted peptides ought to be good candidates for peptide vaccination to reactivate memory immune responses to invasive and metastatic cancer cells.

Enrichment of functional CD8 memory T cells specific for MUC1 in bone marrow of patients with multiple myeloma.

Multiple myeloma (MM) is one of the most common hematologic malignancies. Despite extensive therapeutical approaches, cures remain rare exceptions. An important issue for future immunologic treatments is the characterization of appropriate tumor-associated antigens. Recently, a highly glycosylated mucin MUC1 was detected on a majority of multiple myeloma cell lines. We analyzed bone marrow and peripheral blood of 68 patients with HLA-A2-positive myeloma for the presence and functional activity of CD8 T cells specific for the MUC1-derived peptide LLLLTVLTV. Forty-four percent of the patients with MM contained elevated frequencies of MUC1-specific CD8 T cells in freshly isolated samples from peripheral blood (PB) or bone marrow (BM) compared with corresponding samples from healthy donors. BM-residing T cells possessed a higher functional capacity upon specific reactivation than PB-derived T cells with regard to interferon gamma (IFN-gamma) secretion, perforin production, and cytotoxicity.

Specifically activated memory T cell subsets from cancer patients recognize and reject xenotransplanted autologous tumors.

Bone marrow of breast cancer patients was found to contain CD8(+) T cells specific for peptides derived from breast cancer-associated proteins MUC1 and Her-2/neu. Most of these cells had a central or effector memory phenotype (CD45RA(-)CD62L(+) or CD45RA(-)CD62L(-), respectively). To test their in vivo function, we separated bone marrow-derived CD45RA(+) naive or CD45RA(-)CD45RO(+) memory T cells, stimulated them with autologous dendritic cells pulsed with tumor lysate, and transferred them into NOD/SCID mice bearing autologous breast tumors and normal skin transplants. CD45RA(-) memory but not CD45RA(+) naive T cells infiltrated autologous tumor but not skin tissues after the transfer. These tumor-infiltrating cells had a central or effector memory phenotype and produced perforin. Many of them expressed the P-selectin glycoprotein ligand 1 and were found around P-selectin(+) tumor endothelium. Tumor infiltration included cluster formation in tumor tissue by memory T cells with cotransferred dendritic cells. It was associated with the induction of tumor cell apoptosis and significant tumor reduction. We thus demonstrate selective homing of memory T cells to human tumors and suggest that tumor rejection is based on the recognition of tumor-associated antigens on tumor cells and dendritic cells by autologous specifically activated central and effector memory T cells.