PURPOSE: The treatment options for metastatic soft tissue sarcomas (STSs) are limited. In most cases, immunotherapy with immune checkpoint inhibitors has not been successful so far. Macrophages dominate the immune landscape of STSs; thus, combinatorial strategies aiming at both tumor-infiltrating lymphocytes and macrophages may represent a particularly relevant treatment approach for metastatic or recurrent STSs. METHODS: In this cohort study, 66 patients who underwent surgery for STSs were enrolled. Tumor cells and tumor-infiltrating immune cells were analyzed using flow cytometry and immunohistochemistry. In cell suspensions obtained from surgical resections, human T cells were activated by superparamagnetic polymer beads and cultured at a concentration of 0.3 × 106/µl in the absence or presence of therapeutic monoclonal antibodies (anti-PD-1, anti-CD47, and anti-PD-1 + anti-CD47). Supernatants from cell suspensions were analyzed using multiplex Luminex cytokine bead-based immunoassays. RESULTS: The most profound response to anti-CD47 therapy was observed in an undifferentiated pleiomorphic sarcoma which also displayed high expression of CD47 in the tumor microenvironment. Both anti-PD-1 and anti-CD47 therapies drastically increased the production of pro-inflammatory cytokines in the tumor microenvironment of STSs, but co-administration of both agents did not further increase cytokine secretion. Furthermore, all patient samples treated with a combination of both anti-PD-1 and anti-CD47 antibodies showed a dramatic reduction in cytokine secretion. CONCLUSION: Our findings suggest that anti-PD-1 and anti-CD47 therapies do not enhance each other, and the combined application of anti-PD-1 and anti-CD47 agents in vitro limits rather than potentiates their efficacy.

• Keywords
• Combined immunotherapy, Don’t eat me signal, Immune checkpoint inhibitor sarcoma, Leiomyosarcoma, Undifferentiated pleiomorphic sarcoma,
• MeSH
• Cytokines metabolism   MeSH
• Immunotherapy * MeSH
• Cohort Studies MeSH
• Humans MeSH
• Tumor Microenvironment MeSH
• Sarcoma * drug therapy   MeSH
• Suspensions MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cytokines MeSH
• Suspensions MeSH

BACKGROUND: Salivary gland carcinomas (SGC) are extremely rare malignancies with only limited treatment options for the metastatic phase of the disease. Treatment with anti-CD47 antibodies could represent a potent therapy for SGCs by promoting the phagocytic clearance of tumor cells through various mechanisms. However, the efficacy of anti-CD47 therapy is largely dependent on the expression of CD47 within the tumor microenvironment (TME). MATERIALS AND METHODS: In 43 patients with SGC, we were the first to investigate the CD47 expression in both tumor cells and tumor-infiltrating immune cells (TIIC) in the center and periphery of primary tumors. We also correlated the data with the clinicopathological variables of the patients and offered novel insights into the potential effectiveness of anti-CD47 therapy in SGCs. RESULTS: We observed that the CD47+ tumor cells are outnumbered by CD47+ TIICs in mucoepidermoid carcinoma. In the tumor center, the proportion of CD47+ tumor cells was comparable to the proportion of CD47+ TIICs in most histological subtypes. In low-grade tumors, significantly higher expression of CD47 was observed in TIICs in the periphery of the tumor as compared to the center of the tumor. CONCLUSION: The reason for a high expression of 'don't eat me' signals in TIICs in the tumor periphery is unclear. However, we hypothesize that in the tumor periphery, upregulation of CD47 in TIICs could be a mechanism to protect newly recruited leukocytes from macrophage-mediated phagocytosis, while also allowing the removal of old or exhausted leukocytes in the tumor center.

• Keywords
• CD47, Don’t eat me signal, Immunotherapy, Metastatic SGC treatment, Mucoepidermoid carcinoma, Oral Cancer, Salivary gland cancer, Tumor microenvironment, Tumor-infiltrating lymphocytes,
• MeSH
• CD47 Antigen metabolism   MeSH
• Phagocytosis MeSH
• Immunologic Factors MeSH
• Immunotherapy MeSH
• Humans MeSH
• Cell Line, Tumor MeSH
• Tumor Microenvironment * MeSH
• Salivary Gland Neoplasms * therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• CD47 Antigen MeSH
• CD47 protein, human MeSH Browser
• Immunologic Factors MeSH

Peripheral blood monocytes, which serve as precursors for tissue macrophages and dendritic cells (DC), play a key role in the immune response to kidney allograft, reparation processes and homeostasis regulation. In this prospective study, we used multicolor flow cytometry to monitor the phenotypic patterns of peripheral monocytes in subjects with uncomplicated outcomes and those with acute rejection. We found a reciprocal increase in the proportion of "classical monocytes" (CD14+CD16-) along with a decline in pro-inflammatory "intermediary" (CD14+CD16+) and "non-classical" (CD14lowCD16+) monocytes in subjects with normal outcomes. In subjects with acute rejection, we observed no reduction in "intermediary" monocytes and no increase in "classical" monocytes. Patients with uncomplicated outcomes exhibited downregulated HLA-DR in all three monocyte subpopulations. However, non-classical monocytes were unaffected in subjects with acute rejection. Expression of CD47 was downregulated after transplantation, while patients with antibody-mediated rejection and donor-specific antibodies showed higher pre-transplant values. In monocytes isolated at the time of biopsy, CD47 expression was higher in individuals with acute rejection compared to patients with normal outcomes one year post-transplant. Expression of CD209 (DC-SIGN) and the proportion of CD163+CD206+ subpopulations were upregulated during the first week after kidney transplantation. CD209 was also upregulated in samples taken on the day of biopsy confirming acute rejection. Our data demonstrate that kidney allograft transplantation is associated with phenotypic changes in peripheral blood monocytes during acute rejection.

• MeSH
• Adult MeSH
• Phenotype MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Monocytes pathology   MeSH
• Prospective Studies MeSH
• Graft Rejection etiology   pathology   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Kidney Transplantation adverse effects   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH