Biology subjects

de Aguiar Ferreira, C.

Publications and source records attributed to de Aguiar Ferreira, C..

3 recordsLinked to original sources

bioRxiv2024

Priming versus propagating: distinct immune effects of an alpha- versus beta-particle emitting radiopharmaceutical when combined with immune checkpoint inhibition

Radiopharmaceutical therapy (RPT) enhances tumor response to immune checkpoint inhibitors (ICI) in preclinical models, but the effects of different radioisotopes have not been thoroughly compared. To evaluate mechanisms of response to RPT+ICI, we used NM600, an alkylphosphocholine selectively taken up by most tumors. Effects of 90Y-, 177Lu-, and 225Ac-NM600 + ICIs were compared in syngeneic murine models, B78 melanoma (poorly immunogenic) and MC38 colorectal cancer (immunogenic). 90Y-/177Lu-/or 225Ac-NM600 delivering 2 Gy mean tumor dose promoted tumor regression and improved survival when combined with ICIs in syngeneic mice bearing B78 or MC38 tumors. Regardless of the administered isotope, this combination was optimized with early ICI administration (days -3/0/3) relative to day 1 RPT. 90Y-NM600+ICI produced the greatest anti-tumor response for MC38, whereas high linear energy transfer (LET) alpha particle radiation from 225Ac-NM600+ICI was most effective against poorly immunogenic B78 tumors. Flow cytometry and single cell RNA and T cell receptor (TCR) sequencing illuminated distinct mechanisms of 90Y- or 177Lu-NM600 in promoting expansion of existing adaptive immunity and of 225Ac-NM600 in promoting immune priming when combined with ICI. Antitumor immune response can be achieved with appropriate application of - or {beta}- emitting RPT in combination with ICIs in diverse murine tumor models.

cancer biology↗

bioRxiv2024

Effects of clinically relevant radionuclides on the activation of a type I interferon response by radiopharmaceuticals in syngeneic murine tumor models

Radiopharmaceutical therapies (RPT) activate a type I interferon (IFN1) response in tumor cells. We hypothesized that the timing and amplitude of this response varies by isotope. We compared equal doses delivered by 90Y, 177Lu, and 225Ac in vitro as unbound radionuclides and in vivo when chelated to NM600, a tumor-selective alkylphosphocholine. Response in murine MOC2 head and neck carcinoma and B78 melanoma was evaluated by qPCR and flow cytometry. Therapeutic response to 225Ac-NM600+anti-CTLA4+anti-PD-L1 immune checkpoint inhibition (ICI) was evaluated in wild-type and stimulator of interferon genes knockout (STING KO) B78. The timing and magnitude of IFN1 response correlated with radionuclide half-life and linear energy transfer. CD8+/Treg ratios increased in tumors 7 days after 90Y- and 177Lu-NM600 and day 21 after 225Ac-NM600. 225Ac-NM600+ICI improved survival in mice with WT but not with STING KO tumors, relative to monotherapies. Immunomodulatory effects of RPT vary with radioisotope and promote STING-dependent enhanced response to ICIs in murine models. TeaserThis study describes the time course and nature of tumor immunomodulation by radiopharmaceuticals with differing physical properties.

cancer biology↗

bioRxiv2022

Profound immunomodulatory effects of 225Ac-NM600 drive enhanced anti-tumor responsein prostate cancer

An immunosuppressive tumor microenvironment has hampered the efficacy of immunotherapy in prostate cancer. However, radiation-induced immunological effects can partly mediate anti-tumor effects by promoting a pro-inflammatory environment potentially responsive to immunotherapy. Herein, we examined the immunomodulatory properties of a radiopharmaceutical therapy (RPT) with NM600 radiolabeled with either a beta or alpha emitter in two prostate cancer models. 225Ac-NM600, but not 177Lu-NM600, promoted significant anti-tumor effects and improved overall survival. Immunomodulatory effects were dose, radionuclide, and tumor type-dependent. 225Ac-NM600 elicited an array of immunomodulatory effects such as increased CD8/Treg ratio, activation of effector and memory T cells, abrogation of infiltrating suppressor cells (e.g., Tregs and MDSCs), and increased levels of Th1 cytokine and pro-inflammatory chemokines. Importantly, we demonstrate the need to carefully characterize the immune responses elicited by RPT both pre-clinically and clinically to maximize tumor control and avoid potential counterproductive immunosuppressive effects. TeaserTargeted alpha therapy can create a pro-inflammatory tumor micro-environment that partly explains stronger anti-tumor responses in prostate cancer

immunology↗