Tatsuhide Kunishita

Chronic experimental allergic encephalomyelitis in guinea pigs induced by proteolipid protein

A chronic experimental allergic encephalomyelitis (EAE) was produced in Hartley guinea pigs with bovine white matter proteolipid protein (PLP), in which the levels of myelin basic protein (MBP) and galactocerebroside (GC) were less than 0.014% and 0.13%, respectively, by our method of purification. Cells of an MBP-specific T-cell line did not proliferate in the presence of 100 micrograms of PLP and antigen-presenting cells. Eleven animals were sensitized with 250 micrograms of PLP in Freunds complete adjuvant. Three guinea pigs developed paraplegia about 45 days after sensitization. Histological examination of the three animals revealed marked demyelinating lesions in the spinal cord, particularly in the dorsal columns and subpial regions of the lateral and anterior columns. Another guinea pig without apparent clinical symptoms had demyelinating plaques in the dorsal columns of the spinal cord and periventricular white matter of the brain. Antibodies to PLP were highly elevated in the animals with demyelinating plaques but antibodies to MBP and GC were not elevated in the serum samples. Skin response to PLP was positive in sensitized animals, but was not related to the clinical state. Since none of four strain 13 guinea pigs developed chronic EAE, it seems to be strain specific. These results suggest that PLP is encephalitogenic and produces demyelination in the central nervous system without contamination by MBP or GC in Hartley guinea pigs.

Experimental allergic encephalomyelitis induced by proteolipid apoprotein in Lewis rats

Experimental allergic encephalomyelitis (EAE) was induced in inbred Lewis rats by sensitization with bovine white matter proteolipid apoprotein (PLP). 18-61 days after a single injection of 100 micrograms of PLP, 12 of 31 rats (39%) developed clinical EAE and 18 of 23 (78%) showed pathologic EAE with significant demyelination. Lymphocyte proliferative responses and antibodies to PLP were elevated but did not correlate with the clinical or pathologic state. This is the first demonstration of PLP-induced EAE with significant demyelination in rats and will contribute to the study of autoimmune demyelination.

Both N-terminal and C-terminal fragments of Presenilin 1 colocalize with neurofibrillary tangles in neurons and dystrophic neurites of senile plaques in Alzheimer's disease

Presenilin 1 (PS1) is a causative gene for chromosome 14‐linked familial Alzheimers disease. The gene product is known to be cleaved into N‐terminal fragments (PS1‐N) and C‐terminal fragments (PS1‐C). To understand the pathophysiological role of PS1, we conducted immunohistochemical studies using antibodies specific for PS1‐N and PS1‐C in sporadic Alzheimers disease (AD). Both antibodies showed punctuate staining exclusively in neurons and their processes in both control and AD brains. PS1‐N immunolabeling colocalized with neurofibrillary tangles (NFTs) in 36% of NFT‐bearing neurons and with dystrophic neurites in 28% of senile plaques (SPs). PS1‐C immunolabeling colocalized with dystrophic neurites in 70% of NFT‐bearing SPs and with intraneuronal NFTs in 32% of NFT‐bearing neurons. Both antibodies did not detect PHF‐tau‐positive neuropil threads and Aβ amyloid fibrils. The colocalization was also found in 33–38% of NFT‐bearing neurons in progressive supranuclear palsy. These results indicate that both PS1‐N and PS1‐C fragments are deposited in part of NFT‐bearing neurons and dystrophic neurites in SPs; both are the pathologic hallmarks of AD. J. Neurosci. Res. 53:99–106, 1998.

Heterogeneous induction of 72-kDa heat shock protein (HSP72) in cultured mouse oligodendrocytes and astrocytes

The expression of 72-kDa heat shock protein (HSP72) in cultured mouse oligodendrocytes and astrocytes exposed to heat shock was investigated by double immunolabelling with anti-HSP72 monoclonal antibody (C92F3B-1) and antibodies against galactocerebroside (GalC) or glial fibrillary acidic protein (GFAP). After 3 h recovery from heat shock, an intermediate level of HSP72 immunolabelling was localized in the nucleolus and cytoplasm of astrocytes (less than 25%) and to a lesser extent in oligodendrocytes (less than 2%). After 8-48 h, HSP72 was expressed intensely in the cytoplasm and nuclear matrix of oligodendrocytes (20-40%), while weak/intermediate immunostaining was detectable in astrocytes (5-15%). The levels of HSP72 expressed in oligodendrocytes and astrocytes decreased around 72-120 h, but a few oligodendrocytes (4%) remained intensely immunolabelled. These results indicate that heat shock induces HSP72 in both oligodendrocytes and astrocytes. However, this response is heterogeneous.

Developmental and aging changes in the expression patterns of beta-amyloid in the brains of normal and down syndrome cases

Immunohistochemical staining with polyclonal antibodies to synthetic amyloid (residues 1-28 of A4) was performed on normal and Down syndrome brains from fetuses to adults. Positive staining appeared in the cytoplasmic processes of astrocytes in the subpial layer and white matter of developing brains, and reappeared in astrocytic fibers of the subpial layer as well as in cerebrovascular and plaque core amyloid in elderly brains. The reappearance of positively stained astrocytes and amyloid occurred earlier in adult Down syndrome patients. The results indicate that the A4 protein is a developmental protein, and its reappearance in Alzheimer and adult Down syndrome brains may be related to the regeneration process.

Mild encephalitogenic activity of basic protein—acidic lipid complex from myelin and detection of immune complexes in experimental allergic encephalomyelitis

Further biochemical and pathological investigation of basic protein--acidic lipid complex from canine cerebral myelin show the presence of sulfatide, phosphatidylserine, ganglioside and basic protein in the molar ratio of approximately 6 : 3 : 1 : 1 and that it is associated with mild encephalitogenic activity in guinea pigs in comparison to intact myelin and basic protein. Circulating immune complexes were detected in the sera of guinea pigs with clinical signs of experimental allergic encephalomyelitis and immunofluorescent staining showed the deposition of immune complexes of immunoglobulin and complement in vessels of white matter and meninges and in the choroid plexus.

Ia restriction of murine encephalitogenic T-cell lines in vitro and in vivo.

To clarify the functional role of the I region-associated (Ia) antigen in autoimmune central nervous system disorders, we generated long-term cultured lines of encephalitogenic T cells responsive to myelin basic protein from SJL strain mice (H-2s) and investigated genetic restriction in proliferative and encephalitogenic activities of the lines. These cell lines bear a Lyt 1+,2- phenotype, and show antigen-specific and I-As restricted proliferative responses in vitro. These lines induced full-blown experimental allergic encephalomyelitis (EAE) in immuno-compromised recipients carrying the I-As genotype. These data demonstrate that encephalitogenic T lymphocytes recognize the antigen in combination with the Ia antigen to induce EAE.

Passive transfer of experimental allergic encephalomyelitis induced by proteolipid apoprotein

In an attempt to obtain insight into the pathogenesis of proteolipid apoprotein (PLP)-induced experimental allergic encephalomyelitis (EAE) in Lewis rats (Yamamura et al. 1986), PLP-sensitized lymph node cells or spleen cells were passively transferred into normal or irradiated (400 rad) recipients after incubation with concanavalin A or PLP. Clinical EAE manifested by paraparesis was successfully transferred into irradiated recipients with 2 - 2.5 X 10(8) of the primary cultured cells and histologic EAE could be transferred with as few as 5 X 10(7) cells into naive recipients. This is the first demonstration of passive EAE induced with PLP-sensitized lymphoid cells and suggests the pathogenetic importance of cell-mediated immunity to PLP.

Activation of Effector Cells of Experimental Allergic Encephalomyelitis in Lewis Rats: Comparison of T-Cell Lines with Primary Cultured Lymph Node Cells

We studied the mechanism of activation of effector cells in experimental allergic encephalomyelitis (EAE) by using T-cell lines (EAE/TL) reactive against guinea pig myelin basic protein generated from in vivo primed lymph node cells (LNC) of Lewis rats. EAE-effector cells are activated in the presence of a specific antigen and antigen-presenting cells (APC) with a compatible Ia antigen. The antigen presentation occurs during the first 18 h. EAE-effector cells cannot be activated by allogeneic stimulator cells, but a nonspecific T-cell mitogen, concanavalin A, can activate the effector cells in the presence of syngeneic as well as allogeneic APC.