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Restriction of measles virus gene expression in measles inclusion body encephalitis
K Baczko1, U G Liebert, R Cattaneo
1Institut für Virologie und Immunbiologie, Universität Würzburg, Federal Republic of Germany.
Abstract:
Measles virus (MV) infection in brain tissue of a patient with measles inclusion body encephalitis was characterized by immunologic and biochemical techniques. Of the five major structural proteins of MV, only nucleocapsid (N) protein and phosphoprotein (P protein) were consistently detected in diseased brain areas. In contrast, hemagglutinin protein was seen only occasionally, and no membrane and fusion proteins were found in any of the sections studied. Messenger RNAs (mRNAs) specific for these five viral proteins were detected in all brain extracts examined; however, the mRNAs for the envelope proteins were clearly underrepresented in comparison with lytically infected cells. Only the mRNAs for N and P proteins appeared active in in vitro translations. These findings indicate quantitative differences in the pattern of mRNA expression in brain tissue and a restricted expression of MV envelope proteins in infected cells as observed in subacute sclerosing panencephalitis.
Insights
Measles virus (MV) infection in the brain shows restricted expression of viral envelope proteins. Only nucleocapsid (N) and phosphoprotein (P) are consistently detected, indicating altered gene expression in infected brain tissue.
Area of Science:
- Virology
- Neuroscience
- Molecular Biology
Background:
- Measles virus (MV) can cause severe neurological complications, including measles inclusion body encephalitis (MIBE).
- Understanding the molecular mechanisms of MV replication in the central nervous system is crucial for developing effective treatments.
Purpose of the Study:
- To characterize the expression of MV structural proteins and their corresponding mRNAs in the brain tissue of a patient with MIBE.
- To investigate potential quantitative differences in viral gene expression within the infected brain.
Main Methods:
- Immunohistochemistry was used to detect viral proteins in brain tissue.
- RNA extraction and Northern blot hybridization were employed to detect viral mRNAs.
- In vitro translation assays were performed to assess mRNA activity.
Main Results:
- Nucleocapsid (N) and phosphoprotein (P) were consistently detected in diseased brain areas.
- Hemagglutinin protein was occasionally observed, while membrane and fusion proteins were absent.
- mRNAs for all five MV proteins were present, but envelope protein mRNAs were underrepresented compared to lytically infected cells.
- Only N and P protein mRNAs showed activity in in vitro translation.
Conclusions:
- Measles virus infection in the brain exhibits restricted expression of viral envelope proteins.
- Quantitative differences in mRNA expression patterns exist in infected brain tissue.
- These findings provide insights into the pathogenesis of MV-induced neurological disease, similar to subacute sclerosing panencephalitis (SSPE).