Related Experiment Videos
Appearance of hematogenous cells in the white matter of myelin-deficient Jimpy mice
Abstract:
Various cells from the monocyte-macrophage line, a few neutrophils and some lymphocytes were found in the non-myelinated white matter of Jimpy mice, though there was no vascular injury to the brain parenchyma. Some of the lymphocytes appearing in the white matter were in close contact with macrophages, and occasionally with young oligodendrocytes. Such lymphocytes were mainly of the small type with few cell organelles in a scanty cytoplasm, though a few were of the medium type with a moderate amount of cell organelles in an enriched cytoplasm. Macrophages in the non-myelinated white matter displayed a highly heterogeneous cytoplasm. In particular, "cytoplasmic compartments" in macrophages displayed specific structures differing from the inclusion bodies generally seen in phagocytic cells. The contents of such "cytoplasmic compartments" were rather similar to parts of the macrophage's own cytoplasm, though they were isolated from the cytoplasm by a membrane and gaps. Our findings would seem to support the previous presumption that inherited myelin deficiency in Jimpy mice is induced by a T-cell mediated autoimmune response.
Insights
In Jimpy mice, immune cells like lymphocytes and macrophages infiltrate the white matter, suggesting a T-cell mediated autoimmune response causes inherited myelin deficiency.
Area of Science:
- Neuroimmunology
- Cell Biology
- Genetics
Background:
- Jimpy mice exhibit inherited myelin deficiency.
- The underlying cause of this myelin disorder is not fully understood.
- Previous hypotheses suggested an autoimmune component.
Purpose of the Study:
- To investigate the cellular composition of the non-myelinated white matter in Jimpy mice.
- To explore the interaction between immune cells and neural cells in this model.
- To provide evidence supporting or refuting an autoimmune etiology for myelin deficiency.
Main Methods:
- Histological examination of brain tissue from Jimpy mice.
- Identification and characterization of infiltrating cells (monocytes, macrophages, neutrophils, lymphocytes).
- Ultrastructural analysis of macrophages and their cytoplasmic compartments.
Main Results:
- Presence of monocyte-macrophage lineage cells, neutrophils, and lymphocytes in the white matter without vascular injury.
- Lymphocytes were observed in close proximity to macrophages and oligodendrocytes.
- Macrophages exhibited unique cytoplasmic compartments with membrane-bound structures, distinct from typical phagocytic inclusions.
Conclusions:
- The observed immune cell infiltration and interactions support the hypothesis of a T-cell mediated autoimmune response.
- This autoimmune process is implicated as the cause of inherited myelin deficiency in Jimpy mice.
- Findings provide cellular-level evidence for the autoimmune etiology of this genetic myelin disorder.