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Major histocompatibility complex (MHC) class I gene expression in single neurons of the central nervous system: differential regulation by interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha.

Neumann H, Schmidt H, Cavalié A, Jenne D, Wekerle H - J. Exp. Med. (1997)

Bottom Line: The effect of tetrodotoxin is at least partly reverted by the neurotransmitter glutamate.In contrast to IFN-gamma, treatment with TNF-alpha did neither upregulate TAP1/TAP2 nor beta2-microglobulin gene expression, but induced MHC class I heavy chain gene transcription in all neurons.Consequently, no MHC class I molecules were detectable on the membranes of TNF-alpha-treated neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroimmunology, Max-Planck-Institute for Psychiatry, Martinsried, Germany.

ABSTRACT
This study examined the effect of the pro-inflammatory cytokines interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) on the induction of MHC class I-related genes in functionally mature brain neurons derived from cultures of dissociated rat hippocampal tissue. Patch clamp electrophysiology combined with single cell RT-PCR demonstrated that approximately 50% of the untreated neurons contained mRNA for MHC class I heavy chains, while, with few exceptions, the cells failed to transcribe beta2-microglobulin and TAP1/TAP2 gene transcripts. No constitutive expression of MHC class I protein was detectable by confocal laser microscopy on the surface of neurons. All neurons transcribed the alpha-chain of the interferon-type II receptor (binding IFN-gamma) along with the p55 receptor for TNF-alpha. Sustained exposure to IFN-gamma resulted in transcription of beta2-microglobulin and TAP1/TAP2 genes and MHC class I surface expression in a minor part of the neurons, but did not alter their electrophysiological activities as assessed by whole cell electrophysiology. Suppression of neuronal electric activity by the sodium channel blocker tetrodotoxin drastically increased to almost 100% IFN-gamma-mediated induction of MHC class I chains, of both TAP transporters, and of membrane expression of MHC class I protein. The effect of tetrodotoxin is at least partly reverted by the neurotransmitter glutamate. In contrast to IFN-gamma, treatment with TNF-alpha did neither upregulate TAP1/TAP2 nor beta2-microglobulin gene expression, but induced MHC class I heavy chain gene transcription in all neurons. Consequently, no MHC class I molecules were detectable on the membranes of TNF-alpha-treated neurons.

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IFN-g receptor immunoreactivity in hippocampal  neurons. Double immunofluorescence for IFN-γ receptor  α-chain (A), MAP-2 (B) and  phase contrast (C). Scale bar:  20 μm.
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Figure 5: IFN-g receptor immunoreactivity in hippocampal neurons. Double immunofluorescence for IFN-γ receptor α-chain (A), MAP-2 (B) and phase contrast (C). Scale bar: 20 μm.

Mentions: There is clear evidence that proinflammatory cytokines can modulate neuronal function, but it has remained open, whether the cytokines act directly on the neurons, or indirectly, via local glial cells. We examined cultured untreated neurons for expression of receptors for IFN-γ and TNF-α, prerequisites of direct cytokine effects. Transcripts for the IFN-γ receptor α-chain were detected in 8/8 neurons analyzed (Fig. 4 B). The sequence of the amplified rat IFN-γ receptor PCR-product (submitted to GenBank, accession number U 68272) was homologous (83%) to the IFN-γ receptor sequence of the mouse, and in agreement with transcripts amplified from peripheral lymph organs. To corroborate IFN-γ expression in hippocampal neurons we performed immunofluorescence labeling of the IFN-γ receptor. IFN-γ receptor α-chain immune reactivity was detectable in neurons as well as in glial cells (Fig. 5). Almost all of hippocampal neurons identified by MAP2 staining (98 ± 3%, mean ± SEM) were labeled with antibodies to the IFN-γ binding receptor.


Major histocompatibility complex (MHC) class I gene expression in single neurons of the central nervous system: differential regulation by interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha.

Neumann H, Schmidt H, Cavalié A, Jenne D, Wekerle H - J. Exp. Med. (1997)

IFN-g receptor immunoreactivity in hippocampal  neurons. Double immunofluorescence for IFN-γ receptor  α-chain (A), MAP-2 (B) and  phase contrast (C). Scale bar:  20 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196130&req=5

Figure 5: IFN-g receptor immunoreactivity in hippocampal neurons. Double immunofluorescence for IFN-γ receptor α-chain (A), MAP-2 (B) and phase contrast (C). Scale bar: 20 μm.
Mentions: There is clear evidence that proinflammatory cytokines can modulate neuronal function, but it has remained open, whether the cytokines act directly on the neurons, or indirectly, via local glial cells. We examined cultured untreated neurons for expression of receptors for IFN-γ and TNF-α, prerequisites of direct cytokine effects. Transcripts for the IFN-γ receptor α-chain were detected in 8/8 neurons analyzed (Fig. 4 B). The sequence of the amplified rat IFN-γ receptor PCR-product (submitted to GenBank, accession number U 68272) was homologous (83%) to the IFN-γ receptor sequence of the mouse, and in agreement with transcripts amplified from peripheral lymph organs. To corroborate IFN-γ expression in hippocampal neurons we performed immunofluorescence labeling of the IFN-γ receptor. IFN-γ receptor α-chain immune reactivity was detectable in neurons as well as in glial cells (Fig. 5). Almost all of hippocampal neurons identified by MAP2 staining (98 ± 3%, mean ± SEM) were labeled with antibodies to the IFN-γ binding receptor.

Bottom Line: The effect of tetrodotoxin is at least partly reverted by the neurotransmitter glutamate.In contrast to IFN-gamma, treatment with TNF-alpha did neither upregulate TAP1/TAP2 nor beta2-microglobulin gene expression, but induced MHC class I heavy chain gene transcription in all neurons.Consequently, no MHC class I molecules were detectable on the membranes of TNF-alpha-treated neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroimmunology, Max-Planck-Institute for Psychiatry, Martinsried, Germany.

ABSTRACT
This study examined the effect of the pro-inflammatory cytokines interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) on the induction of MHC class I-related genes in functionally mature brain neurons derived from cultures of dissociated rat hippocampal tissue. Patch clamp electrophysiology combined with single cell RT-PCR demonstrated that approximately 50% of the untreated neurons contained mRNA for MHC class I heavy chains, while, with few exceptions, the cells failed to transcribe beta2-microglobulin and TAP1/TAP2 gene transcripts. No constitutive expression of MHC class I protein was detectable by confocal laser microscopy on the surface of neurons. All neurons transcribed the alpha-chain of the interferon-type II receptor (binding IFN-gamma) along with the p55 receptor for TNF-alpha. Sustained exposure to IFN-gamma resulted in transcription of beta2-microglobulin and TAP1/TAP2 genes and MHC class I surface expression in a minor part of the neurons, but did not alter their electrophysiological activities as assessed by whole cell electrophysiology. Suppression of neuronal electric activity by the sodium channel blocker tetrodotoxin drastically increased to almost 100% IFN-gamma-mediated induction of MHC class I chains, of both TAP transporters, and of membrane expression of MHC class I protein. The effect of tetrodotoxin is at least partly reverted by the neurotransmitter glutamate. In contrast to IFN-gamma, treatment with TNF-alpha did neither upregulate TAP1/TAP2 nor beta2-microglobulin gene expression, but induced MHC class I heavy chain gene transcription in all neurons. Consequently, no MHC class I molecules were detectable on the membranes of TNF-alpha-treated neurons.

Show MeSH
Related in: MedlinePlus