Contributions
Abstract: P766
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Microbiology and Virology
Introduction: Clostridium perfringens epsilon toxin (ETX) has been proposed as a possible trigger for new multiple sclerosis (MS) lesion formation. ETX selectively targets central nervous system endothelial cells and kills mature oligodendrocytes leading to demyelination. Two separate studies have indicated that MS patients have increased immunoreactivity to ETX, indicating increased exposure of MS patients to ETX.
Objectives and aims: The goal of this study was to directly detect ETX in MS patient samples versus healthy controls (HC). To detect ETX in human samples, peripheral lymphocytes were examined for the presence of ETX. Peripheral lymphocytes were chosen because they express the putative ETX receptor, the myelin and lymphocyte protein MAL. If present in the blood stream, we hypothesized that ETX would bind to lymphocytes expressing MAL.
Methods and results: RT-qPCR analysis confirmed MAL expression in human lymphocytes. Interestingly, CD4+ cells had the highest levels of MAL expression, followed by CD8+ cells, and then CD19+ cells. Using flow cytometry, ex vivo experiments revealed ETX binds with significant preference to CD4+ cells, followed by CD8+ and CD19+ cells, indicating that ETX binding correlates with MAL expression. Because of ETX's increased affinity for CD4+ cells, ETX bound to peripheral CD4+ cells isolated from MS patients and HC were examined by flow cytometry using a highly sensitive monoclonal anti-ETX antibody we developed. MS patients included RRMS patients with and without contrast enhancing lesions (+RRMS and -RRMS, respectively), and SPMS patients. ETX-positive CD4+ cells were detected in significantly more MS patients than HC. Interestingly, the -RRMS cohort had the highest percentage of ETX-positive patients and ETX-positive CD4+ cells compared to HC.
Conclusions: By directly detecting ETX on CD4+ cells, our preliminary results indicate that MS patients have increased exposure to ETX compared to HC. These results support the hypothesis that Clostridium perfringens ETX may play a role in triggering MS lesions.
Disclosure: Research was in part funded by the National Institutes of Health, National Multiple Sclerosis Society and Biogen, Inc. Related to this work, we posses US patent No. 9,758,573.
Abstract: P766
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Microbiology and Virology
Introduction: Clostridium perfringens epsilon toxin (ETX) has been proposed as a possible trigger for new multiple sclerosis (MS) lesion formation. ETX selectively targets central nervous system endothelial cells and kills mature oligodendrocytes leading to demyelination. Two separate studies have indicated that MS patients have increased immunoreactivity to ETX, indicating increased exposure of MS patients to ETX.
Objectives and aims: The goal of this study was to directly detect ETX in MS patient samples versus healthy controls (HC). To detect ETX in human samples, peripheral lymphocytes were examined for the presence of ETX. Peripheral lymphocytes were chosen because they express the putative ETX receptor, the myelin and lymphocyte protein MAL. If present in the blood stream, we hypothesized that ETX would bind to lymphocytes expressing MAL.
Methods and results: RT-qPCR analysis confirmed MAL expression in human lymphocytes. Interestingly, CD4+ cells had the highest levels of MAL expression, followed by CD8+ cells, and then CD19+ cells. Using flow cytometry, ex vivo experiments revealed ETX binds with significant preference to CD4+ cells, followed by CD8+ and CD19+ cells, indicating that ETX binding correlates with MAL expression. Because of ETX's increased affinity for CD4+ cells, ETX bound to peripheral CD4+ cells isolated from MS patients and HC were examined by flow cytometry using a highly sensitive monoclonal anti-ETX antibody we developed. MS patients included RRMS patients with and without contrast enhancing lesions (+RRMS and -RRMS, respectively), and SPMS patients. ETX-positive CD4+ cells were detected in significantly more MS patients than HC. Interestingly, the -RRMS cohort had the highest percentage of ETX-positive patients and ETX-positive CD4+ cells compared to HC.
Conclusions: By directly detecting ETX on CD4+ cells, our preliminary results indicate that MS patients have increased exposure to ETX compared to HC. These results support the hypothesis that Clostridium perfringens ETX may play a role in triggering MS lesions.
Disclosure: Research was in part funded by the National Institutes of Health, National Multiple Sclerosis Society and Biogen, Inc. Related to this work, we posses US patent No. 9,758,573.