Active Projects

2020 Development Grants

Evaluating novel transcription modulators for therapeutic impact

Evaluating splicing modulators for therapeutic impact in cohesin-mutant AML and MDS cells

Benjamin Martin, Zuzana Tothova (DFCI), and Karen Adelman

Cohesin is a multi-subunit protein complex that forms a ring-like structure around DNA. Cohesin is essential for sister chromatid cohesion, chromosome organization into looped domains, DNA damage repair and transcription regulation. Germline loss-of-function mutations in cohesin subunits cause a family of developmental disorders termed cohesinopathies. In addition, cohesin is one of the most frequently mutated protein complexes in cancer, including myeloid malignancies, with recurrent somatic loss-of-function mutations in core components of the cohesin ring and its modulators. Importantly, cancer-associated mutations in cohesin rarely affect chromosome integrity, but instead selectively impair gene-regulatory functions. However, how cohesin affects gene activity remains enigmatic, offering no clues towards intervention. Consequently, there are no targeted therapeutic approaches available to treat disease involving cohesin mutations. Recently, we discovered that cohesin mutations common in myeloid malignancies such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) disrupt RNA splicing. We propose to define the aberrant RNA species generated in cohesin-mutant AML cells, using state-of-the-art molecular and computational approaches to capture nascent transcripts and characterize RNA processing. Through detailed investigation of gene activity and splicing profiles in cohesin-mutant AML cells, we hope to discover genes with alternative splicing events that may present opportunities for therapeutic targeting. Our goal is to leverage this knowledge to develop targeted approaches that will selectively kill cohesin-mediated disease. The findings from these studies have the potential to lead directly to one or more clinical trials within the next several years.

HIV-1 Vaccine using SPLANDID Antigen Presentation Technology

Application of the SPLANDID Antigen Presentation Technology to HIV-1 Vaccine Development

Alessandro Piai, Yongfei Cai, Bing Chen, and James J. Chou.

The HIV-1 envelope glycoprotein (Env) is a transmembrane protein sitting in the viral membrane and it is also a major target for B-cell based vaccine development. Previous large clinical trials of vaccine candidates involving recombinant Env preparations mostly focused on various soluble forms of its ectodomain. These efforts have been disappointing, however, probably because we do not fully understand how effective antibodies are generated in some infected patients and what is the best form of the Env that can induce such an antibody response by vaccination. To facilitate Env immunogen design, we have recently developed an antigen presentation technology known as SPLANDID that allows presentation of transmembrane immunogens in a membrane environment on nanoparticles suitable for in vivo immunogenicity studies. This HMS patented technology now affords the opportunity to test novel HIV-1 Env immunogens that include the membrane-related components in a membrane environment and better mimic the native Env on the virion surface. We plan to use the new technology to display membrane-bound Env immunogens and evaluate their potential as vaccine candidates by defining their antigenicity in vitro and testing their immunogenicity in animals.

 

A novel biologic and therapeutic target for diabetes

A novel biologic and therapeutic target for the treatment of diabetes

José Rivera-Feliciano, Timothy R. Kunz, Elias S. Peterson and Douglas A. Melton

It is estimated that more than 422 million people in the world have diabetes; by 2021 the cost burden of diabetes in the United States is on track to be $512 billion. Diabetes, characterized by elevated blood glucose (sugar) levels, results from either beta-cell malfunction (Type 2) or beta-cell demise after an autoimmune attack (Type 1). The hormone insulin, produced by pancreatic beta-cells, reduces circulating levels of glucose after a meal primarily by shuttling glucose to muscle and fat. Current strategies to treat diabetics include insulin injection, augmenting endogenous insulin secretion, increasing glucose absorption, or increasing glucose excretion. Hypoglycemic (low blood glucose) episodes after insulin injection are life threatening and this risk usually results in patients underdosing. Here we describe the discovery of a novel peptide hormone, we call ERSEQ08, present in human beta-cells, that can reduce blood glucose levels in mice. Importantly, this effect is independent of insulin action. Surprisingly, ERSEQ08 lowers blood glucose, in a glucose dependent manner, without causing hypoglycemia—thus overcoming one of the major setbacks with current diabetic treatments. While it is well known that pancreatic beta cells make Insulin, this new finding may represent a second system by which beta cells regulate glucose metabolism.

The potential to bypass insulin resistance presents a novel therapeutic paradigm to treat diabetes. As a biologic, this hormone may complement or replace some of the therapies used as the current standard of care in diabetes treatment. As an inroad into a novel signaling system controlling glucose homeostasis, this discovery has the potential to lead to a new kind of drug for diabetics.

Our main objectives using the Q-FASTR funds are: to test the activity of recombinant human ERSEQ08 protein to lower blood glucose levels in mice; to develop a cell-based assay to identify ERSEQ08’s mechanism of action; and, to find the minimal active fragment required for ERSEQ08’s function.

Development of an inexpensive at-home influenza kit

Development of an inexpensive at-home influenza kit and detection technology

Sarah Boswell, Jason Qian, Zhixiang Lu, Mary Pettit, and Michael Springer

Influenza is a major drain on the US economy. Antiviral drugs are most effective against influenza when taken early, often before patients seek medical help. Tests exist for influenza but are only effective when influenza titer is high and/or require sophisticated medical equipment. Here we will build off of methods we are combining and developing for the specific detection of barcoded microorganisms (a DARPA funded project) to develop and optimize a quantitative, cheap, rapid, sensitive, selective, and field-deployable method for detecting influenza. We aim to develop this influenza detection system into an affordable ‘at-home’ system allowing individuals to detect influenza early, thereby increasing the efficacy of antiviral drugs and eliminating unnecessary trips to the ER.

Protein therapeutics for treatment of chronic/inflammatory pain

Protein therapeutics for treatment of chronic and inflammatory pain

Bruce Bean, Clifford Woolf, Jeff Way, and Peter Sorger

 

Chronic and inflammatory pain affect millions and new treatments are urgently

needed. Despite significant investment in opioid safety and formulation, there is little exploration of drugs with fundamentally novel mechanisms of action. Our goal is to develop such medicines based on novel protein therapeutics that block pain sensation by silencing multiple NaV sodium channels in nociceptors. The failure of NaV1.7 inhibitors as analgesics1 suggests that blocking more than one channel will be necessary. We will therefore take an approach involving a multivalent scaffold and small proteins that inhibit several NaV channels with tunable selectivity and potency. Activity will be measured by differential screening against human iPSC-derived sensory, cortical, and motor neurons. Over a two year period we expect to achieve hit/lead generation for 10-30 distinct molecules and optimization of the most active for testing in animals.

2020 Pilot Grants

Target Identification of Neuroprotective Kinase Inhibitors for AD

Target Identification of Neuroprotective Kinase Inhibitors for Alzheimer’s and Related Dementias

Mark Albers, Peter Sorger, Gary Bradshaw

Alzheimer’s dementia (AD) affects nearly 6 million US patients and costs > $250B/year. No therapies slow its devastating course. We have discovered a root cause of neuronal cell death in disease-relevant regions of autopsied AD brains: inflammation caused by cytoplasmic double stranded RNA (cdsRNA). cdsRNA triggers neurodegeneration in mouse models that can be recapitulated in cultured human neural cells. This proposal focuses on small molecule kinases inhibitors that we have shown to block cdsRNA-mediated neuronal death. The active molecules (some of which are approved therapeutics) are annotated as JAK kinase inhibitors but this class of compounds is known to have a complex poly-pharmacology. Moreover, not all JAK inhibitors on signal transduction in neurons rescue cell death. We have therefore conducted a genome-wide CRISPR/Cas9 screen and found than none of the three members of the JAK family rescue cdsRNA-mediated neuronal death when knocked down. Thus, JAK kinase inhibition does not appear to be sufficient (and perhaps not even necessary) to rescue neuronal death. We propose to identify “off-target” proteins – most likely kinases - that are preferentially bound by neuroprotective JAK inhibitors relative to inactive molecules. We will confirm the relevance of these targets by generating knockout human neural cells using CRISPR/Cas9 and then proceed to small molecule screening. This will allow us to leverage extensive experience in kinase inhibitors, particularly those exhibiting therapeutically relevant poly-pharmacology, to target AD and other neurodegenerative diseases.

Novel therapeutic targets for treating pain/chronic itch

Identifying novel therapeutic targets for treating pain and chronic itch

 

David Ginty, Nikhil Sharma, Jing Peng

 

The perception of painful stimuli begins with detection of noxious stimuli by somatosensory neurons called nociceptors. Itch-inducing compounds, on the other hand, are detected by neurons called pruriceptors. We have recently identified the genes expressed in all somatosensory neuron subtypes, including nociceptors and pruriceptors, throughout development and into adulthood. This analysis revealed six transcriptionally distinct subtypes of nociceptors and two subtypes of pruriceptors, each with strikingly distinct gene expression profiles. Importantly, our findings reveal new candidate therapeutic targets to block nociceptors and pruriceptors. We found that select members of the GPCR superfamily, which account for nearly 1/3 of known drug targets, are expressed in nociceptors and pruriceptors, but not other sensory neuron subtypes. We will to leverage our knowledge of somatosensory neurons and the newly identified GPCRs they express to develop new drugs for treating pain and chronic itch while avoiding undesirable side effects. We will focus on drugs that activate Gi/o-coupled GPCRs expressed in nociceptors and pruriceptors because activation of these GPCR subtypes silence neuronal activity.

Structure-guided discovery of novel antibiotics

Structure-guided discovery of novel antibiotics inhibiting bacterial cell wall formation

Francois Thelot and Maofu Liao

The emergence of drug-resistant Gram-negative bacteria causes a significant global health problem, because the available antibiotics are limited and the discovery of new compounds cannot keep pace with the emergence of drug-resistant strains. The difficulty to combat these pathogens is largely due to their unique dual-membrane cell wall which efficiently blocks the entry of antibiotics. Lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria plays key roles in cell wall formation and antibiotic resistance. Thus, LPS biosynthesis is a particularly attractive target for developing new classes of antibiotics. LPS is synthesized in the inner membrane and subsequently transported to the outer membrane, a process critically dependent on two ATP-binding cassette transporters (MsbA and LptB2FGC). My laboratory has made important contributions in characterizing the structure and function of these LPS transporters. Here we propose to leverage our experience and mechanistic insights of MsbA to develop novel antibiotics. This will be achieved by establishing a targeted screening pipeline that comprises chemical screen, cryo-electron microscopy (cryo-EM), computational docking, and activity assays. Once established, this pipeline can be applied to target many other bacterial membrane transporters.

2019 Development Grants

Monoclonal antibody-based therapeutics for AHF

Monoclonal antibody-based therapeutics for Argentine hemorrhagic fever

Lars Clark, Brian Gowen (USU), and Jonathan Abraham

Viral hemorrhagic fevers (VHFs) pose continuing threats to public health. Most have limited treatment options or vaccines, which underscores a point of vulnerability in public health. Passive immunization is an attractive treatment strategy; for example, transfusion of the monoclonal antibody (mAb) cocktail ZMappTM was a lead approach during the 2014-2016 Ebola virus outbreak. Results of testing in humans with ZMappTM did not reach statistical significance, suggesting that further studies would be required to fine-tune the approach. A mAb derived from the blood of an Ebola survivor, mAb114, was also recently deployed for testing in humans in the ongoing Ebola virus outbreak in the Democratic Republic of Congo.

While these investigational therapies are promising, there remains a large, unmet need for therapies against all agents that cause VHFs. We chose to focus on Argentine hemorrhagic fever (AHF) caused by the arenavirus Junin because antibody transfusions have a well-established track record of successfully treating this infection. We will isolate mAbs from the blood of AHF survivors, characterize the molecular basis for their antiviral activity, and test these for therapeutic effect in small animal models. We will also determine if the antibodies we isolate cross-react with Machupo, Guanarito, Sabia, and Chapare viruses, which are related arenaviruses that cause VHFs in South America and lack effective therapies. Once completed, the work would position candidate mAbs for pre-clinical testing in non-human primates, thus facilitating their translation into human use.

Targeting apoptotic pathways for ALS, AD, PD

Targeting apoptotic pathways for ALS, Alzheimer’s Disease and Parkinson’s Disease

Sooyeon Jo, Laurel Heckman (BCH), Clifford Woolf (BCH), and Bruce Bean

The proposed work follows our recent discovery that targeting a class of voltage-dependent potassium channels inhibits death of motor neurons derived from induced pluripotent stem cells (iPSCs) from patients with ALS. These experiments were motivated by single cell RNA-expression data showing altered expression of a channel regulatory subunit in ALS motor neurons compared to their isogenic controls. This discovery serendipitously converged with an ongoing project developing small molecule modulators of these channels as investigational tools. We have now found that one of these compounds mitigates cell death of ALS patient iPSC-derived motor neurons. We therefore propose to test its ability to delay disease progression in a mouse model of ALS, to develop more potent inhibitors with drug-like properties, and to test the efficacy of these modulators in animal models of Parkinson’s disease and Alzheimer’s disease as a new treatment paradigm for preventing neurodegeneration by inhibiting apoptosis.

Development of a sleeve gastrectomy-induced metabolite as therapy for T2D and obesity

Development of synthetic analogs of a sleeve gastrectomy-induced metabolite as a novel therapy for type 2 diabetes and obesity

Sloan Devlin, Snehal N. Chaudhari, and Eric Sheu (BWH)

New therapies are needed to address the related worldwide epidemics of obesity and type 2 diabetes (T2D). Bariatric surgery is currently the most effective and sustainable treatment for obesity. While weight loss occurs 6 months-1 year following surgery, patients see immediate resolution of their diabetic phenotypes within hours of surgery. This remarkable remission of T2D is maintained for over 7 years, suggesting that the change is durable. We have identified a metabolite whose levels are significantly increased in both mice and humans following surgery and that ameliorates diabetic phenotypes in vivo in an acute mouse model. The goal of this research is to develop analogs of this metabolite as a potential therapy for T2D and obesity.

Next-generation AAV therapies for chronic pain

Next-generation AAV therapies for management of intractable chronic pain

Aurel Nagy, Sinisa Hrvatin, Spencer Price, and Michael Greenberg

Chronic pain represents an enormous unmet need (~$635 billion in the US in 2011). The primary treatment for severe chronic pain, opioid administration, causes unacceptable side effects including addiction and fatal respiratory depression while failing to provide therapeutic relief in patients seeking care.1 Without effective alternatives, opioid prescription

numbers continue to climb: there were 70,237 prescription-opioid-overdose-related deaths in 2017.2,3 The opioid epidemic highlights the urgent need for new therapeutics to manage chronic pain. Gene therapy, the delivery of genetic material to permanently change gene expression in target cells, could provide long-term pain management with a single dose and is

therefore, worthy of investigation. Recombinant adeno-associated virus (rAAV)-delivered gene therapies in particular have shown striking clinical success recently, suggesting a prime opportunity to develop rAAV-based therapeutics for treating chronic pain.

We propose to generate a rAAV that specifically targets nociceptors, the neurons that transduce pain, to deliver ligand-gated silencing ion channels that will allow patients to control pain without opioids. Current rAAV engineering approaches lack the cell-type-specificity required to selectively infect nociceptors while sparing non-nociceptor neuronal

subtypes however, and off-target silencing of these cells could cause unacceptable toxicity and anesthesia. We developed PESCA, the Paralleled Enhancer Single-Cell Assay, to overcome this limitation and engineer rAAVs that drive unprecedentedly cell-type-specific payload expression. Through PESCA, we aim to create a next-generation therapy that will provide lasting and patient-controlled relief upon administration of a single dose, revolutionizing treatment for the most debilitating and common chronic health condition in the world.

CNS drug delivery by targeting a BBB regulator

Developing novel therapeutic approaches for CNS drug delivery by targeting a newly identified key regulator of the blood brain barrier

Urs Langen and Chenghua Gu

A major obstacle in treating neurological diseases and brain tumors is to deliver drugs or antibodies across the ‘blood brain barrier’ (BBB). My lab’s recent discoveries have changed our understanding of how the BBB restricts blood-brain communication. The BBB is formed by a single layer of endothelial cells that lines the blood vessel walls and act as a gatekeeper for the brain. Historically, the restricted permeability of brain vasculature has been attributed to tight junctions. However, substances can also cross endothelial cells by transcytosis, and we discovered that transcytosis is actively inhibited in brain endothelial cells. We identified a

novel multi-transmembrane protein Mfsd2a as a key regulator for BBB function, and demonstrated that interfering with Mfsd2a and its downstream pathway upregulates transcytosis and causes the BBB to become permeable. We propose to develop therapeutic agents that specifically target Mfsd2a function as a strategy to facilitate drug delivery across the BBB.

Interleukin-17 as a novel erythropoiesis stimulating agent

Interleukin-17 as a novel erythropoiesis stimulating agent

Merav Socolovsky (UMASS), Jeffrey Way, and Allon Klein

Anemia occurs in multiple clinical settings, including cancer, chronic inflammation or kidney disease, increasing morbidity and mortality. Existing treatments are limited to erythropoietin (Epo) and to glucocorticoids. Glucocorticoids have severe side effects, while Epo is contra-indicated in cancer-associated anemia, and is ineffective in conditions such as myelodysplastic syndrome. To address this gap, we undertook single-cell RNA-sequencing of early erythroid progenitors (Tusi et al., Nature 2018). We discovered they express an interleukin-17 receptor (Il-17ra); that IL-17a enhances the erythroid response to Epo, through an Il-17ra-dependent high affinity interaction, in both human and mouse cultures; and we have preliminary evidence of efficacy in vivo. Here we will determine how to translate these findings to the stimulation of erythropoiesis in vivo.

Engineered proteins for treatment of pancreatitis

Engineered proteins for treatment of pancreatitis

Katherine Redfield, Daniel Heid, Dominik Niopek, Jeffrey Way, Jungmin Lee, and Pamela Silver

We are developing a treatment for pancreatitis based on a protease inhibitor with enhanced pharmacokinetics and tissue distribution. Initial experiments indicate that an engineered protein lead compound can be inexpensively produced at high levels, is active in vitro, and is active in initial animal tests.

2019 Pilot Grants

Evaluating splicing modulators for therapeutic impact

Evaluating splicing modulators for therapeutic impact in cohesin-mutant AML and MDS cells

Benjamin Martin, Zuzana Tothova (DFCI), and Karen Adelman

Cohesin is a multi-subunit protein complex that forms a ring-like structure around DNA. Cohesin is essential for sister chromatid cohesion, chromosome organization into looped domains, DNA damage repair and transcription regulation. Germline loss-of-function mutations in cohesin subunits cause a family of developmental disorders termed cohesinopathies. In addition, cohesin is one of the most frequently mutated protein complexes in cancer, including myeloid malignancies, with recurrent somatic loss-of-function mutations in core components of the cohesin ring and its modulators. Importantly, cancer-associated mutations in cohesin rarely affect chromosome integrity, but instead selectively impair gene-regulatory functions. However, how cohesin affects gene activity remains enigmatic, offering no clues towards intervention. Consequently, there are no targeted therapeutic approaches available to treat disease involving cohesin mutations. Recently, we discovered that cohesin mutations common in myeloid malignancies such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) disrupt RNA splicing. We propose to define the aberrant RNA species generated in cohesin-mutant AML cells, using state-of-the-art molecular and computational approaches to capture nascent transcripts and characterize RNA processing. Through detailed investigation of gene activity and splicing profiles in cohesin-mutant AML cells, we hope to discover genes with alternative splicing events that may present opportunities for therapeutic targeting. Our goal is to leverage this knowledge to develop targeted approaches that will selectively kill cohesin-mediated disease. The findings from these studies have the potential to lead directly to one or more clinical trials within the next several years.

Multiplex editing the human genome

Multiplex editing the human genome

 

Eriona Hysolli, Yuting Chen, and George Church

 

We aim to make cells virus-resistant by recoding human cells. This universal ultrasafe and virus-resistant cell line will be utilized for safe manufacturing of therapeutics and avoid bioreactor contamination like the Genzyme incident of 2009.

Non-invasive intracellular delivery of molecules for therapeutic applications

A high-throughput platform for the non-invasive intracellular delivery of molecules for therapeutic applications

Martina Righi and Johan Paulsson

Existing methods for intracellular delivery of drugs, proteins or nucleic acids have either been system specific and inefficient, or based on methods like electroporation or chemical treatment that can greatly perturb cells. A recent method, now in co-development by a biotech startup and a pharma giant as a novel cell therapy platform, improved this process by squeezing cells through narrow constrictions, which slightly and temporarily deforms cells and porates the membrane. This allows for efficient uptake of many types of components while reducing the stress on cells. We developed, and Harvard patented, an alternative methodthat could more gently squeeze cells of varying sizes.

Target validation and testing of a broad-spectrum antiviral

Target validation and in vivo testing of a broad-spectrum antiviral

Melissanne de Wispelaere and Priscilla Yang

Dengue virus (DENV) and other flaviviruses are human pathogens that cause significant disease. About 40% of the world lives in areas with substantial risk of DENV transmission. Up to 100 million people are infected annually with an estimated 500,000 hospitalizations and 20,000 deaths due to dengue hemorrhagic fever and dengue shock syndrome2. DENV presents a long-standing challenge for vaccine development due to antigenic diversity of the four DENV serotypes and the propensity of non-protective antibodies to enhance infection and disease severity4. There are no specific antivirals to counteract DENV.

We discovered QL47 and related tricyclic quinolones as potent covalent, host-targeted antivirals with broadspectrum activity against DENV and other RNA viruses of biomedical significance. Due to their broad-spectrum activity against the Flaviviridae and other viruses and their high natural barrier to resistance these compounds are of interest as antivirals. We have performed medicinal chemistry optimization to generate YKL-04-085, a candidate suitable for testing antiviral efficacy in vivo and have also performed chemoproteomic experiments to

identify the cellular targets responsible for antiviral activity. We propose to validate the antiviral target(s) of QL47/YKL-04-085 and to evaluate the antiviral activity of YKL-04-085 in a murine model of viral infection.

2018 Development Grants

Development of a new precision therapeutic for an important cancer target

Development of a new precision therapeutic for an important cancer target
Vidyasiri Vemulapalli, Jonathan LaRochelle, and Stephen Blacklow

The focus of this proposal is to develop a new class of potent and selective small molecule inhibitors of a genetically validated cancer target for further therapeutic development by enhancing the potency of our initial hit. Our inhibitors will occupy a unique niche in the landscape of small molecule precision therapeutics in cancer.

Targeting neuro-immune signaling to treat bacterial infections

Targeting neuro-immune signaling to treat bacterial infections
Felipe Pinho-Ribeiro, Pankaj Baral, Kimbria Blake, Samantha Choi, Liwen Deng, and Isaac Chiu

Bacterial skin and soft tissue infections (SSTIs) are increasingly common due to the rise in prevalence of multi-drug resistant pathogens, necessitating novel non-antibiotic based treatments. While methicillin-resistantStaphylococcus aureus (MRSA) and Streptococcus pyogenesare the two leading causes of SSTIs, up to 20% of SSTIs are also caused by gram-negative bacteria. We have found that skin-innervating neurons play a key role in suppressing neutrophil function and the innate immune response against SSTIs. We have developed an approach to treat bacterial infections by targeting this neuro-immune axis using botulinum neurotoxins (BoNTs) serotype A and serotype E, thereby blocking neuro-immune signaling and enhancing host immunity. In this project, we determine whether this therapeutic approach is broadly applicable by testing BoNTs against S. pyogenes, MRSA, and P. aeruginosa infections. We are in active discussions to partner with companies that produce both of these products. Utilizing BoNTs to enhance host immunity could be a transformative approach to treat challenging bacterial infections.

Development of New Antiviral Compounds

Development of New Antiviral Compounds
Jim Hogle, Hari Arthanari, David Scott, Han Chen, and Donald Coen

Herpesviruses cause severe diseases, particularly in immunocompromised and immune-naive individuals. Currently approved anti-herpesvirus drugs have important drawbacks, including limited efficacy, toxicities, and drug resistance, driving a need for new, improved agents. We have been exploring new targets for anti-herpesvirus drugs starting with a combination of structural, biochemical, and genetic studies. Using high throughput screening, we have identified compounds that selectively inhibit such targets in vitro, with some compounds selectively inhibiting viral replication in cell culture. We have evidence that at least one of these compounds “hits the target” in infected cells. We propose to optimize this compound into leads for further development towards anti-herpesvirus drugs.

Isoguvacine and benzodiazepine derivatives for the treatment of tactile hypersensitivity and anxiety in ASD

Isoguvacine and benzodiazepine derivatives for the treatment of tactile hypersensitivity and anxiety in Autism Spectrum Disorders
Lauren Orefice and David Ginty

Autism spectrum disorders (ASD) are neurodevelopmental disorders characterized by impairments in social communication and interactions, and restricted and repetitive behaviors. ASD is well-established to be associated with aberrant reactivity in multiple sensory domains, including touch, and indeed aberrant sensory reactivity is now considered a key diagnostic feature of ASD. We have used a range of mouse genetic models of ASD combined with behavioral testing, synaptic analyses, and electrophysiology to define both the etiology of aberrant tactile sensitivity in ASD and the contribution of somatosensory dysfunction to the expression of ASD-like traits (Orefice et al., Cell, 2016; Orefice et al., unpublished; Tasnim et al., unpublished). We found that mutations in genes associated with both syndromic and non-syndromic forms of ASD cause tactile dysfunction, and that the RTT- and autism-associated genes Mecp2, Shank3, and Gabrb3 function cell autonomously in peripheral somatosensory neurons for normal tactile behaviors. Remarkably, these somatosensory deficits during development contribute to aberrant social behaviors, including anxiety-like behaviors and social interactions, in adulthood. Our findings raise the exciting possibility that GABAA receptor agonists, which attenuate the activity of peripheral mechanosensory neurons, may be useful for treating tactile hypersensitivity and thus anxiety and social impairments in ASD patients. A key consideration for our work is that physicians are reluctant to prescribe GABAA receptor agonists and positive allosteric modulators because of undesirable side effects, including sedation, and serious complications associated with interference of brain development. Therefore, we aim to use peripherally-restricted GABAA receptor agonists and modulators, compounds that do not cross the blood-brain barrier, to treat tactile dysfunction and core ASD behaviors. Importantly, peripherally-restricted GABAA receptor drugs should not promote undesirable side effects observed with all currently used, FDA-approved GABAA receptor agonists that act in the brain. Thus, for this Q-FASTR application, we proposed to determine the efficacy of isoguvacine, a known peripherally-restricted GABAA receptor agonist, as well as novel isoguvacine and nonbenzodiazepine derivatives designed to be peripherally-restricted, for treating tactile hypersensitivity and core ASD behaviors in animal models of ASD. Indeed, we were able to show that isoguvacine reduces tactile sensitivity in mice. Also, chronic isoguvacine treatment improves a subset of ASD-related phenotypes in mice such as overall body condition, body weight, and anxiety-like behaviors. This project, which was co-funded by BBA, has moved into Lab1636, a major strategic R&D alliance between Harvard and the healthcare investment firm Deerfield, where these results will be validated and advanced to late-stage preclinical development.