Tumor-induced peripheral immunosuppression promotes brain metastasis in patients with non-small cell lung cancer.

INTRODUCTION: Brain metastases are a significant source of morbidity and mortality for patients with lung cancer. Lung cancer can induce local and systemic immunosuppression, promoting tumor growth and dissemination. One mechanism of immunosuppression is tumor-induced expansion of programmed death-ligand 1 (PD-L1) expressing myeloid cells. Here, we investigate peripheral blood immune phenotype in NSCLC patients with or without brain metastasis. METHODS: Peripheral blood was collected from patients with lung metastatic brain tumors and pre-metastatic lung cancer. Immunosuppressive monocytes, myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs) were quantified through flow cytometry. T cell reactivity was analyzed via ELISpot. Brain metastasis conditioned media was collected from tumor-derived cell cultures and analyzed for cytokines by ELISA. Naïve monocytes were stimulated with brain metastasis conditioned media to evaluate PD-L1 stimulation. RESULTS: Patients with brain metastatic lung carcinoma demonstrated increased peripheral monocyte PD-L1, MDSC abundance, and Treg percentage compared to early stage pre-metastatic patients and healthy controls. Patients with elevated peripheral monocyte PD-L1 had less reactive T cells and worse survival. Brain metastasis conditioned media stimulation increased monocyte PD-L1, and conditioned media IL-6 levels correlated with PD-L1 induction. Treatment with anti-IL-6 or anti-IL-6 receptor antibodies reduced PD-L1 expression. In summary, patients with lung cancer and brain metastases exhibit multiple markers of peripheral immunosuppression. CONCLUSIONS: The frequency of PD-L1+ myeloid cells correlated with the presence of brain metastases. Tumor-derived IL-6 was capable of inducing PD-L1+ myeloid cells in vitro, suggesting that monitoring of immunosuppressive factors in peripheral blood may identify new targets for therapeutic intervention in selected patients.

Invasive pulmonary aspergillosis after treatment with tocilizumab in a patient with COVID-19 ARDS: a case report.

Tocilizumab, an interleukin-6 receptor antagonist, has been used to treat critically ill patients with coronavirus disease-2019. We present the case of a previously immunocompetent man with coronavirus disease-2019 who developed invasive pulmonary aspergillosis after treatment with tocilizumab, illustrating the importance of considering opportunistic infections when providing immune modulating therapy.

Long-term glioblastoma survival following recovery from cytomegalovirus colitis: A case report.

Survival outcomes for patients with glioblastoma (GBM) are universally poor with only a small percentage of patients surviving five years beyond initial diagnosis. Activation of the immune system against tumor cells is the basis of immunotherapy and aims to facilitate long-term immune surveillance and tumor suppression. Cytomegalovirus (CMV) has emerged as an immunologic target in GBM given that tumor cells have been shown to express the CMV-associated proteins IE1 and pp65. Moreover, vaccine therapy targeting CMV antigens has promoted improved survival outcomes with long-term survivors. In this report, we present the case of a 69 year-old woman with GBM who survived seven years post-diagnosis. Following tumor resection, the patient underwent concomitant radiation and temozolomide therapy that was complicated by CMV colitis and abdominal abscesses. Despite not receiving adjuvant temozolomide, the patient demonstrated a five year progression-free survival before requiring re-resection for radiation necrosis. Following re-resection, the patient survived for two additional years. As the patient's tumor stained positive for CMV antigens IE1 and pp65, it is hypothesized that she developed an immune response against CMV during recovery that contributed to anti-tumor surveillance and prolonged survival. Overall, this case supports further investigation into the role of CMV and immunotherapy in GBM.