Search PubMed⌕ Search

Biomedical subjects

Jeffrey L Bennett

Publications and source records attributed to Jeffrey L Bennett.

10 recordsLinked to original sources
PubMed2026

Barcoded oligonucleotide system (BOLT) for targeted organ delivery.

The therapeutic potential of oligonucleotides (oligos) is limited by insufficient delivery to extrahepatic tissues. In vitro assays often fail to accurately predict in vivo behavior, while testing each oligo candidate in animals remains inherently low throughput. Here, we conceive a barcoded oligonucleotide system (BOLT), a platform that enables high-throughput in vivo evaluations of small-molecule ligands and identifies tissue-specific oligo delivery. BOLT integrates rational design of oligo barcodes, modular conjugation chemistry, and next-generation sequencing (NGS)-based quantification, allowing simultaneous evaluation of many chemically diverse ligand-oligo conjugates within a single animal. Notably, this platform is applicable in both mice and nonhuman primates (NHPs). Using BOLT, we discovered ligands with tropism for tissues such as the brain, lung, and muscle. Collectively, these results indicate that the BOLT platform can accelerate the discovery of tissue-targeting ligands for broad oligo therapeutics.

Journal Article↗
PubMed2022

Heterogeneity of Acetylcholine Receptor Autoantibody-Mediated Complement Activity in Patients With Myasthenia Gravis.

BACKGROUND AND OBJECTIVES: Autoantibodies targeting the acetylcholine receptor (AChR), found in patients with myasthenia gravis (MG), mediate pathology through 3 mechanisms: complement-directed tissue damage, blocking of the acetylcholine binding site, and internalization of the AChR. Clinical assays, used to diagnose and monitor patients, measure only autoantibody binding. Consequently, they are limited in providing association with disease burden, understanding of mechanistic heterogeneity, and monitoring therapeutic response. The objective of this study was to develop a cell-based assay that measures AChR autoantibody-mediated complement membrane attack complex (MAC) formation. METHODS: An HEK293T cell line-modified using CRISPR/Cas9 genome editing to disrupt expression of the complement regulator genes (CD46, CD55, and CD59)-was used to measure AChR autoantibody-mediated MAC formation through flow cytometry. RESULTS: Serum samples (n = 155) from 96 clinically confirmed AChR MG patients, representing a wide range of disease burden and autoantibody titer, were tested along with 32 healthy donor (HD) samples. AChR autoantibodies were detected in 139 of the 155 (89.7%) MG samples through a cell-based assay. Of the 139 AChR-positive samples, autoantibody-mediated MAC formation was detected in 83 (59.7%), whereas MAC formation was undetectable in the HD group or AChR-positive samples with low autoantibody levels. MAC formation was positively associated with autoantibody binding in most patient samples; ratios (mean fluorescence intensity) of MAC formation to AChR autoantibody binding ranged between 0.27 and 48, with a median of 0.79 and an interquartile range of 0.43 (0.58-1.1). However, the distribution of ratios was asymmetric and included extreme values; 16 samples were beyond the 10-90 percentile, with high MAC to low AChR autoantibody binding ratio or the reverse. Correlation between MAC formation and clinical disease scores suggested a modest positive association (rho = 0.34, p = 0.0023), which included a subset of outliers that did not follow this pattern. MAC formation did not associate with exposure to immunotherapy, thymectomy, or MG subtypes defined by age-of-onset. DISCUSSION: A novel assay for evaluating AChR autoantibody-mediated complement activity was developed. A subset of patients that lacks association between MAC formation and autoantibody binding or disease burden was identified. The assay may provide a better understanding of the heterogeneous autoantibody molecular pathology and identify patients expected to benefit from complement inhibitor therapy.

Autoantibodies↗
PubMed2006

Screening random peptide libraries with subacute sclerosing panencephalitis brain-derived recombinant antibodies identifies multiple epitopes in the C-terminal region of the measles virus nucleocapsid protein.

Infectious and inflammatory diseases of the CNS are often characterized by a robust B-cell response that manifests as increased intrathecal immunoglobulin G (IgG) synthesis and the presence of oligoclonal bands. We previously used laser capture microdissection and single-cell PCR to analyze the IgG variable regions of plasma cells from the brain of a patient with subacute sclerosing panencephalitis (SSPE). Five of eight human IgG1 recombinant antibodies (rAbs) derived from SSPE brain plasma cell clones recognized the measles virus (MV) nucleocapsid protein, confirming that the antibody response in SSPE targets primarily the agent causing disease. In this study, as part of our work on antigen identification, we used four rAbs to probe a random phage-displayed peptide library to determine if epitopes within the MV nucleocapsid protein could be identified with SSPE brain rAbs. All four of the SSPE rAbs enriched phage-displayed peptide sequences that reacted specifically to their panning rAb by enzyme-linked immunosorbent assay. BLASTP searches of the NCBI protein database revealed clear homologies in three peptides and different amino acid stretches within the 65 C-terminal amino acids of the MV nucleocapsid protein. The specificities of SSPE rAbs to these regions of the MV nucleocapsid protein were confirmed by binding to synthetic peptides or to short cDNA expression products. These results indicate the feasibility of using peptide screening for antigen discovery in central nervous system inflammatory diseases of unknown etiology, such as multiple sclerosis, neurosarcoidosis, or Behcet's syndrome.

Amino Acid Sequence↗
PubMed2006

The B cell response in multiple sclerosis.

Multiple sclerosis (MS) plaques and CSF contain increased amounts of intrathecally synthesized IgG, manifest as oligoclonal bands (OCBs) after protein electrophoresis. OCBs are not unique to MS and are also produced in infectious diseases of the CNS, in which the oligoclonal IgG has been shown to be antibody directed against the disease-causing agent. Thus, analysis of antibody specificity may identify the causative agent/antigen in MS. This review discusses recent studies that have analyzed the phenotypes of B cells in MS which infiltrate the CNS and the molecular features of their antigen-binding regions. Together with histologic studies showing the presence of ectopic lymphoid follicles in the meninges of some MS patients, this data supports the notion of a targeted and compartmentalized humoral response in MS.

Animals↗
PubMed2006

Natalizumab and progressive multifocal leukoencephalopathy: migrating towards safe adhesion molecule therapy in multiple sclerosis.

Natalizumab, a humanized monoclonal antibody against alpha4beta1 integrin, was shown in clinical trials to dramatically reduce the relapse rate, development of new magnetic resonance imaging (MRI) lesions and progression of disability in patients with relapsing multiple sclerosis. Following its expedited approval, sales of the drug were discontinued owing to the emergence of two cases of progressive multifocal leukoencephalopathy (PML), a rare but deadly viral infection of the central nervous system (CNS) associated with immunosuppression. Owing to the effect of natalizumab on central nervous system leukocyte recruitment, the emergence of PML has been attributed to diminished immunosurveillance. The lack of additional opportunistic or CNS infections among natalizumab-treated patients, however, suggests that alternate mechanisms may contribute to the infectious risk. This review examines how the inhibition of alpha4beta1-mediated adhesion might establish a unique milieu for the development of PML and how future approaches to selective adhesion molecule therapy in multiple sclerosis might avoid a similar fate.

Antibodies, Monoclonal↗
PubMed2004

Acute ocular motor mononeuropathies: prospective study of the roles of neuroimaging and clinical assessment.

The role for immediate neuroimaging in patients 50 years of age or older with acute isolated third, fourth, and sixth nerve palsies is controversial. We prospectively evaluated 66 patients, aged 50 years and older (median 67 years, range 50-85), with acute isolated ocular motor mononeuropathies. Our purpose was to evaluate both the role of neuroimaging and the role of clinical assessment in determining etiology. We found that clinical features, including time to maximal diplopic symptoms, were not predictive of etiology (median 2 days to maximal diplopic symptoms for both peripheral microvascular and other etiologies). The presence of any common vascular risk factor, including diabetes mellitus, hypertension, hypercholesterolemia, or coronary artery disease, was significantly associated with peripheral microvascular etiology in this cohort (p=0.0004, Fisher's exact test). Despite the high prevalence of peripheral microvascular ischemia as an etiology in this age group, other causes were identified by magnetic resonance imaging (MRI) or computed tomography (CT) scanning in 14% of patients. Diagnoses included brainstem and skull base neoplasms, brainstem infarcts, aneurysms, demyelinating disease, and pituitary apoplexy. Neuroimaging procedures may have a role in the initial evaluation of patients 50 years of age or older with acute ocular motor mononeuropathies.

Abducens Nerve Diseases↗
PubMed2004

B-lymphocyte and plasma cell clonal expansion in monosymptomatic optic neuritis cerebrospinal fluid.

The CD19+ B-lymphocyte and CD138+ plasma cell repertoires in cerebrospinal fluid from four patients with monosymptomatic optic neuritis (ON) were analyzed by single-cell reverse transcriptase polymerase chain reaction. Amplified heavy (H)- and light (L)-chain antibody segments were sequenced and used to identify the rearranged germline and J segment of closest homology. Both the B-cell and plasma cell repertoires from ON cerebrospinal fluid demonstrated significant clonal expansion. Up to 75% of the amplified H- and L-chain sequences were contained in overrepresented populations and were somatically mutated, consistent with an antigen-targeted response. The relationship between clonal populations within the CD19+ B lymphocyte and CD138+ plasma cell populations suggests ongoing mutational pressure to refine antigen binding. Our observations demonstrate that an antigen-driven clonal B-lymphocyte and plasma cell response is prominent in the initial stages of central nervous system demyelination and suggest that detection of the disease-relevant antigens in ON may bear on the inciting antigens in chronic inflammatory disorders such as multiple sclerosis.

Amino Acid Sequence↗
PubMed2004

Genetic disorders and the optic nerve: a clinical survey.

Genetic disorders can cause a broad range of optic nerve pathology. Clinical symptoms and examination findings of optic nerve dysfunction may provide early clues to the presence of inherited genetic disease. For many disorders, molecular genetic testing is available for the diagnosis of affected individuals and the identification of unaffected carriers. This article surveys a broad array of systemic genetic disorders affecting the optic nerve, reviewing their ocular manifestations, systemic findings, and clinical genetics.

Genetic Diseases, Inborn↗
PubMed2002

Developmental neurogenetics and neuro-ophthalmology.

The field of developmental neurogenetics has burgeoned over the past decade. Through the combined efforts of developmental biologists, geneticists, and clinicians, genetic defects resulting in neuro-ophthalmic disorders such as holoprosencephaly, microphthalmia, dominant optic atrophy, and optic nerve colobomas have been identified and characterized at the molecular level. Experimental studies in model organisms are continuing to identify novel genes critical for ocular and central nervous system development. Mutations in some of these genes have revealed a spectrum of pathology similar to that observed in septo-optic dysplasia, Möebius syndrome, and Duane retraction syndrome. This review examines our current knowledge of the molecular genetics of neuro-ophthalmic disease and focuses on several candidate genes for afferent and efferent visual system disorders.

Developmental Biology↗