BackgroundMolecular subtypes of breast cancer and presence of tumor-infiltrating immune cells have both been implicated as important predictive and prognostic factors for improved risk stratification and treatment individualization of breast cancer patients. Their association, however, has not been studied in detail. The aim of this study was to evaluate the expression of the T cell markers CD8, FoxP3, CD3 and ζ-chain in molecular subtypes of the invasive margin and tumor center of breast cancer and corresponding sentinel nodes and to deduct prognostic information from these findings.MethodsTumor and sentinel node sections from 177 patients with primary, invasive, unilateral early-stage breast cancer were stained by immunohistochemistry and T-cell phenotypes quantified manually. Clinical data were collected from medical records.ResultsThe degree of T-cell infiltration and expression of all markers differed significantly among the molecular subtypes, being highest in non-luminal, more aggressive tumors: more T-cell infiltration and higher expression of all markers were associated with hormone receptor negativity, higher proliferation and higher histological grades, but also with larger tumor size. Basal-like tumors, and most remarkably their tumor centers, hosted the highest number of FoxP3+ T-cells with an unfavorable ratio to cytotoxic CD8+ T-cells. T-cell infiltration was generally higher in the invasive margin than the tumor center. A scoring system based on densities of CD3 and CD8 could significantly separate molecular subtypes (p < 0.001).ConclusionsThus, immunological patterns with functional implications within each subtype are associated with prognostic factors. These findings should be further validated in studies using larger patient populations and longer follow-up.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0983-9) contains supplementary material, which is available to authorized users.

Treatment with granulocyte colony-stimulating factor plus erythropoietin may improve haemoglobin levels in patients with ringsideroblastic anaemia (RARS) and reduce bone marrow apoptosis. We studied bone marrow from 10 RARS patients, two of whom were also investigated after successful treatment. Mononuclear, erythroid and CD34+ cells were analysed with regard to proliferation, apoptosis, clonogenic capacity and oncoprotein expression, in the presence or absence of Fas-agonist, Fas-blocking antibody 2 and caspase-3 inhibitor. During culture, RARS bone marrow cells showed higher spontaneous apoptosis (P < 0.05) and caspase activity (P < 0.05)) than bone marrow cells from healthy donors. Eight out of nine patients had reduced growth of erythroid colony-forming units (CFU-E) (< 10% of control) and granulocyte-macrophage CFU (CFU-GM) (< 50% of control) from CD34+ cells. Fas ligation increased apoptosis and decreased colony growth equally in RARS and controls, but caused significantly more caspase activation in RARS (P < 0.01). Fas-blocking antibody showed no significant inhibitory effect on spontaneous apoptosis or ineffective haematopoiesis, as measured using phosphatidylserine exposure, the terminal deoxynucleotide transferase-mediated dUTP-biotin nick-end labelling technique, caspase activity or clonogenic growth. Caspase inhibition reduced apoptosis, increased proliferation and enhanced erythroid colony growth from CD34+ cells in RARS, but showed no effect on normal cells. CFU-E improved > 1000% after successful treatment. Thus, erythroid apoptosis in RARS is initiated at the CD34+ level and growth factor treatment may improve stem cell function. Enhanced caspase activation at the stem cell level, albeit not mediated through endogenous activation of the Fas receptor, contributes to the erythroid apoptosis in RARS.

Arginase 1 (ARG1) is an important enzyme in amino acid metabolism that also exerts immunoregulatory function. High ARG1 expression, which is associated with cell cycle arrest and functional unresponsiveness in T cells, has been observed after trauma, infections and in cancer patients. We studied ARG1 expression in early-stage breast cancer patients (stage 1, n = 20; stage 2, n = 23) by multi-parametric flow cytometry and immunohistochemistry. Despite a low tumor burden, ARG1 expression was significantly increased in blood-derived myeloid cells of breast cancer patients compared with healthy controls. The ARG1hi myeloid population in the blood of cancer patients contained a high frequency of CD14+ cells and was, therefore, distinct from the granulocytic ARG1+ population observed in control individuals. Expression of ARG1 in patient blood cells correlated with tumor grade and was significantly reduced after surgical tumor removal. ARG1+ myeloid cells could also be detected in tumors and tumor-draining lymph nodes, where ARG1 expression levels exceeded those measured in the blood. We conclude that even patients with early-stage breast cancer exhibit tumor-related changes of ARG1 expression. The level of ARG1-mediated immunomodulation at this early stage remains to be determined. However, high ARG1 expression is likely to interfere with antitumor T-cell responses and immunotherapeutic interventions, making ARG1 or its downstream effector interesting therapeutic targets.

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