Antibody Gene Therapy Mitigates The Immunosuppressive Effects Of 3,4-Methylenedioxymethamphetamine (Mdma) In The Periphery Of Male Balb/C Mice

3,4-Methylenedioxymethamphetamine (MDMA) is currently one of the most popular club psychostimulant and hallucinogens. MDMA's primary site of action is in the brain where it produces a “euphoric” feeling, this euphoria comes with a multitude of acute toxicities. In the periphery, MDMA acts as an immunosuppressive agent in the periphery decreasing the robust activity of the adaptive and innate immune systems. Conversely, MDMA has been demonstrated to elicit a neuroinflammatory response in the CNS. This response is linked to glial activation and the subsequent overproduction of cytotoxic mediators. A treatment that could potentially mitigate these effects would be beneficial. In our laboratory, we are developing an anti-MDMA/methamphetamine (METH) dual-acting antibody gene therapy as a treatment for substance use disorders. Utilizing AAV8 as our gene therapy vector, we packaged the single chain-Fc fusion fragment 7F9-Fc to create AAV-7F9-Fc. AAV-7F9-Fc expresses anti-MDMA/METH antibodies systemically that work as pharmacokinetic antagonists to slow and possibly reduce entry of drug into the brain and other organs. After a single injection dose, we have achieved effective and sustained long-term serum concentrations of antibodies in mice up to 7 months. With strong similarities between the chemical backbone of METH and MDMA, we hypothesized that AAV-7F9-Fc would also be able to bind to MDMA in serum and reduce the immunomodulatory effects induced by MDMA. If proven effective, this treatment could provide some protection against the toxic effects of METH and MDMA during rehabilitation and recovery. We hypothesized that an AAV delivered antibody fusion fragment (AAV-7F9-Fc) will provide extended protection from MDMA-induced neuroinflammation and systemic immune suppression. To test this hypothesis, we evaluated an acute model of MDMA in which male BALB/c mice received an ip injection every 2 hr for 4 consecutive doses. BALB/c mice were divided into eight groups (n=5/group); 1) Saline + Saline, 2) Saline + MDMA (10 mg/kg 2hr × 4), 3) Saline + MDMA (3 mg/kg 2hr × 4), 4) Saline + MDMA (1 mg/kg 2hr × 4) 5) AAV-7F9-Fc + Saline, 6) AAV-7F9-Fc + MDMA (10 mg/kg 2hr × 4), 7) Empty Vector + saline & 8) Empty Vector + MDMA (10 mg/kg 2hr × 4). After dosing completion, serum cytokine levels were measured by multiplex analysis, and CNS proinflammatory cytokine and glial cell activation markers by qRT-PCR. Our results indicate significant decreases (p< 0.05) in the serum concentration of proinflammatory cytokine IL-2 & IFN-g and increases in the anti-inflammatory cytokine IL-10 (p< 0.05) in response to the 10 mg/kg MDMA dose. In the striatum, 10 mg/kg MDMA elicited a significant increase in expression of IL-1b and astrocyte activation marker GFAP. AAV-7F9-Fc treatment mitigated the increase of IL-10 in the serum and IL-1b in the striatum. These results indicate that in addition to its previously reported protection against METH, AAV-7F9-Fc has the therapeutic potential to mitigate an immunomodulatory cascade in the periphery and CNS resulting from a binge MDMA exposure.