Enhanced safety and efficacy of protease-regulated CAR-T cell receptors.

Regulatable CAR platforms could circumvent toxicities associated with CAR-T therapy, but existing systems have shortcomings including leakiness and attenuated activity. Here, we present SNIP CARs, a protease-based platform for regulating CAR activity using an FDA-approved small molecule. Design iterations yielded CAR-T cells that manifest full functional capacity with drug and no leaky activity in the absence of drug. In numerous models, SNIP CAR-T cells were more potent than constitutive CAR-T cells and showed diminished T cell exhaustion and greater stemness. In a ROR1-based CAR lethality model, drug cessation following toxicity onset reversed toxicity, thereby credentialing the platform as a safety switch. In the same model, reduced drug dosing opened a therapeutic window that resulted in tumor eradication in the absence of toxicity. SNIP CARs enable remote tuning of CAR activity, which provides solutions to safety and efficacy barriers that are currently limiting progress in using CAR-T cells to treat solid tumors.

A clinical study of the local injection of a freshly manufactured 35 kDa hyaluronan fragment for treating chronic wounds.

This study manufactured a 35 kDa hyaluronan fragment (HA35) by enzymatically degrading high-molecular-weight HA using hyaluronidase PH20 derived from bovine testis. The research then examined the therapeutic efficacy of locally administered, tissue-permeable HA35 in alleviating chronic wounds and their associated neuropathic pain. For 20 patients with nonhealing wounds and associated pain lasting over three months, 100 mg of HA35 was injected daily into the healthy skin surrounding the chronic wound for 10 days. Self-assessments before and after treatment indicated that HA35 significantly enhanced wound healing. This was evidenced by the formation of fresh granulation tissue on the wounds (p < 0.0001); reduced darkness, redness, dryness, and damage in the skin surrounding the wounds (p < 0.0001), and a decrease in wound size (p < 0.001). Remarkably, HA35 injections alleviated pain associated with chronic wounds within 24 hours (p < 0.0001). It can be concluded that the low-molecular-weight hyaluronan fragment HA35 potentially enhances the immune response and angiogenesis during wound healing.

Characterization, Bioactivity, and Biodistribution of 35 kDa Hyaluronan Fragment.

It has been reported that hyaluronic acid (HA) with a 35 kDa molecular weight (HA35) acts biologically to protect tissue from injury, but its biological properties are not yet fully characterized. This study aimed to evaluate the cellular effects and biodistribution of HA35 compared to HA with a 1600 kDa molecular weight (HA1600). We assessed the effects of HA35 and HA1600 on cell migration, NO and ROS generation, and gene expression in cultured macrophages, microglia, and lymphocytes. HA35 was separately radiolabeled with 99mTc and 125I and administered to C57BL/6J mice for in vivo biodistribution imaging. In vitro studies indicated that HA35 and HA1600 similarly enhanced cell migration through HA receptor binding mechanisms, reduced the generation of NO and ROS, and upregulated gene expression profiles related to cell signaling pathways in immune cells. HA35 showed a more pronounced effect in regulating a broader range of genes in macrophages and microglia than HA1600. Upon intradermal or intravenous administration, radiolabeled HA35 rapidly accumulated in the liver, spleen, and lymph nodes. In conclusion, HA35 not only exhibits effects on cellular bioactivity comparable to those of HA1600 but also exerts biological effects on a broader range of immune cell gene expression. The findings herein offer valuable insights for further research into the therapeutic potential of HA35 in inflammation-mediated tissue injury.