Biomedical subjects

Violeta McGaughy

Publications and source records attributed to Violeta McGaughy.

2 recordsLinked to original sources

PubMed2004

Passive or active immunization with myelin basic protein impairs neurological function and exacerbates neuropathology after spinal cord injury in rats.

Myelin-reactive T-cells are activated by traumatic spinal cord injury (SCI) in rodents and humans. Despite the historical association of these cells with experimental and clinical neuropathology, recent data suggest a neuroprotective role for myelin-reactive T-cells. Because of the biological and therapeutic implications of these findings, we attempted to reproduce the original neuroprotective vaccine protocols in a model of rat SCI. Specifically, MBP-reactive T-cell function was enhanced in SCI rats via passive or active immunization. Locomotor function was assessed using a standardized locomotor rating scale (Basso-Beattie-Bresnahan scale) and was correlated with myelin and axon sparing. The functional and anatomical integrity of the rubrospinal pathway also was analyzed using the inclined plane test and anatomical tract tracing. MBP-immunized rats exhibited varying degrees of functional impairment, exacerbated lesion pathology, greater rubrospinal neuron loss, increased intraspinal T-cell accumulation, and enhanced macrophage activation relative to SCI control groups. These data are consistent with the conventional view of myelin-reactive T-cells as pathological effector cells.

Animals↗

PubMed2003

Hematogenous macrophages express CD8 and distribute to regions of lesion cavitation after spinal cord injury.

Historically, CD4 and CD8 antigens have been used to designate functionally distinct T-lymphocyte subsets. However, these antigens also have been described on macrophages in the normal and pathologic central nervous system (CNS). Signaling through CD4 or CD8 may impart unique functions in macrophage subsets that express these antigens. In the current study, the distribution and temporal patterns of expression of CD4 and CD8 were evaluated on various cell types within the traumatically injured spinal cord. The data reveal divergent patterns of CD4 and CD8 expression on unique macrophage populations. Specifically, we show sustained elevations of CD4 expression on microglia and macrophages throughout the lesion site and spared white matter. In contrast, CD8 is predominantly associated with hematogenous macrophages that are recruited from the blood during the first week postinjury. The distribution of CD8-positive cells is restricted to areas of necrotic cavitation. Differential signaling of resident and recruited macrophages through CD4 or CD8 may explain the apparent dichotomy of CNS-macrophage-mediated injury and repair.

Animals↗