Company: CERO
Filing Date: 2025-12-05
Form Type: S-1
Source: 0001213900-25-118817
Chunk: 168

Company: CERO THERAPEUTICS HOLDINGS, INC.
Filing Date: 2025-12-05
Form: S-1
Chunk 168
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 RAC1 GTPase which is similarly targeted by TLR signaling, especially TLR9 and TLR2. However, it has been shown that the intracellular portion of TIM-4 is not required for phagocytosis, and therefore the extracellular domain (“ECD”) of TIM-4 appears to function as a tether during phagocytosis to allow intracellular signaling by other transmembrane phagocytic molecules with which it associates, such as the integrins which are expressed ubiquitously on T cells. Since CER-1236 contains only the ECD of TIM-4, binding to TIM-4-L on tumor cells recruits the cell-surface phagocytosis machinery, and simultaneously directly activates CER-1236 T cells through the intracellular CD3ξ and CD28 costimulatory domains. Phagocytosis and cytokine secretion are further enhanced by the TLR2 intracellular signaling domain. 96 In preclinical studies, CER-1236 empowers T cells with phagocytic and cytotoxic potency In an in vitroevaluation of the phagocytic potential of CER-1236, CER-transduced T cells demonstrated robust phagocytosis of TIM-4-L. CER-1236 T cells were produced by transducing donor T cells using a lentiviral vector encoding for the chimeric receptor CER-1236, yielding a high percentage of T cells expressing the TIM-4 receptor, in similar CD4:CD8 ratios to untransduced cells. CER-1251 T cells, which express matching intracellular signaling domains but are unable to bind to TIM-4-L due to a mutation in the gene encoding for the TIM-4 binding site, were also produced as a negative control. TIM-4-L-coated agarose beads were prelabeled with pHrodo red, a pH-sensitive dye which displays limited fluorescence at neutral pH but generates significant fluorescence in acidic pH. The post-phagocytic fusion of phagosomes and lysosomes leads to a drop in pH which can be detected by pH-sensitive dyes. As is illustrated in the graphic below, CER-1236 T cells co-cultured with TIM-4-L-coated beads displayed significant phagocytic activity with up to 60% of CER-T cells acquiring a pHrodo red signal, indicative of bead capture and internalization. By contrast, untransduced T cells and CER-