Sanchez-Perez, L. | Search bioRxiv

bioRxiv2025

IL-12 Secreting CAR-T Cells Reprogram the Tumor Microenvironment and Improve Efficacy Against Heterogeneous Models of Glioblastoma

BackgroundGlioblastoma (GBM) remains uniformly lethal due to pronounced intratumoral heterogeneity and a highly immunosuppressive microenvironment that limits the efficacy of targeted therapies. MethodsWe engineered chimeric antigen receptor (CAR) T cells targeting EGFRvIII and armored them with a single-chain interleukin-12 (scIL12) payload. These cells were tested in syngeneic, orthotopic GBM mouse models exhibiting heterogeneous EGFRvIII expression. CAR T cells were delivered intracranially without lymphodepletion. ResultsIntracranial administration of of scIL12-secreting CAR-T cells eradicated tumors without requiring lymphodepletion, achieving 50% long-term survival. Survival benefits depended entirely on endogenous CD8 T cells, as efficacy was abolished in CD8-deficient hosts and unaffected by NK cell depletion. Notably, therapeutic efficacy was abrogated by lymphodepletion, underscoring the necessity of an intact endogenous immune response. Mechanistically, scIL12 enhanced CAR-T cell persistence and reprogrammed tumor-associated microglia, indicating potential epitope spreading through polyclonal endogenous CD8+ T-cell responses, which facilitate the elimination of EGFRvIII-negative tumor cells. ConclusionsThis study demonstrates the pleiotropic benefits of IL-12 armored CAR-T cells with improved targeting of antigen-positive tumor cells and simultaneous remodeling of the microenvironment to engage adaptive immunity against antigen-negative clones. This strategy offers a potential clinically actionable approach to improve outcomes in GBM by circumventing the need for toxic lymphodepletion and addressing tumor heterogeneity.

immunology↗

bioRxiv2020

Parental feeding preferences rather than sibling competition determine the death of smaller nestlings in asynchronous broods

Hatching asynchrony is a reproductive tactic that, through the creation of competitive hierarchies among offspring, allows parents for a quick adjustment of brood size via the death of smaller nestlings. This strategy is considered to be adaptive in case of unpredictable and/or poor environments in which it would guarantee that at least larger nestlings will fledge. Brood reduction is the usual outcome in asynchronously hatched broods since first-hatched nestlings are larger and get a disproportionately larger share of the food delivered by parents, often leading the youngest nestling to starve to death soon after hatching. However, we still do not know the proximate mechanisms of such brood reduction. One possibility is that the smallest nestling is not fed because larger nestlings outcompete it, which implies that nestlings control resource allocation. Alternatively, parents might actively ignore the persistent begging from their smallest nestling, which would involve that parents control food allocation. To determine whether parents or nestlings ultimately induce brood reduction in this situation, we experimentally created asynchronous broods of Eurasian blackbird (Turdus merula) nestlings and quantified food allocation by parents in two different situations: when sibling competition was allowed and, alternatively, when competition was prevented by physically separating nestlings within the nests by using wooden barriers. Our results showed that experimentally introduced smaller nestlings received less food than their larger nestmates both when competition among nestlings was allowed and when it was prevented. When adult males and females are considered separately, males fed the smallest nestling less often regardless of whether sibling competition was allowed or not, but adult females showed no differences. We can conclude that the smallest nestling starves mainly because parents actively ignore its begging. The higher competitive ability of the larger nestlings seem to have little effect given that although the smallest nestling is fed at a higher rate when physical interactions are prevented by the wooden barrier than when not, this difference is not significant. These findings suggest that parents rather than nestlings have the main control over food allocation.

animal behavior and cognition↗