ANTIVIRALS
(6th yr MBChB)
,Introduction
• A virus is an infective agent that typically consists of a nucleic acid
molecule in a protein coat.
• Its too small to be seen by light microscopy, and is able to multiply
only within the living cells of a host and not by itself.
• The nucleic acid in the protein coat can either be RNA or DNA
which can be double stranded or single.
• Once it infects a susceptible host, it directs the cell machinery of
the host to replicate itself by integrating its genetic material into
the host machinery.
, Examples of Viruses
Double stranded DNA viruses
Eg Adenoviruses, polyomaviruses, adenoviruses, and herpesviruses, poxviruses
Double stranded RNA viruses
Reoviridae, Orthoreoviruses, Cypovirus, Rotavirus, Bluetongue virus, Phytoreoviruses
, Viral replication
1.Adsorption: this is the attachment of the of virus to host cell.
2. Penetration into susceptible host cells.
3. Un coating of viral nucleic acid: The cell enzymes( lysosomes) strip off the protein cot of the
viruses and expose the genome
4. Transcription: production of viral mRNA from a viral genome
5. Translation: viral genome enters nucleoplasm and utilizes host nucleic acid machinery for
synthesis for new viral protein. It also modifies the cell to irreversibly produce more viral genom
7.Assembly (maturation) of viral particles: the viral protein code assembles into capsid and vira
genes
7. Release : new virions are released after they have matured budded and ruptured from the ho
cell.
(6th yr MBChB)
,Introduction
• A virus is an infective agent that typically consists of a nucleic acid
molecule in a protein coat.
• Its too small to be seen by light microscopy, and is able to multiply
only within the living cells of a host and not by itself.
• The nucleic acid in the protein coat can either be RNA or DNA
which can be double stranded or single.
• Once it infects a susceptible host, it directs the cell machinery of
the host to replicate itself by integrating its genetic material into
the host machinery.
, Examples of Viruses
Double stranded DNA viruses
Eg Adenoviruses, polyomaviruses, adenoviruses, and herpesviruses, poxviruses
Double stranded RNA viruses
Reoviridae, Orthoreoviruses, Cypovirus, Rotavirus, Bluetongue virus, Phytoreoviruses
, Viral replication
1.Adsorption: this is the attachment of the of virus to host cell.
2. Penetration into susceptible host cells.
3. Un coating of viral nucleic acid: The cell enzymes( lysosomes) strip off the protein cot of the
viruses and expose the genome
4. Transcription: production of viral mRNA from a viral genome
5. Translation: viral genome enters nucleoplasm and utilizes host nucleic acid machinery for
synthesis for new viral protein. It also modifies the cell to irreversibly produce more viral genom
7.Assembly (maturation) of viral particles: the viral protein code assembles into capsid and vira
genes
7. Release : new virions are released after they have matured budded and ruptured from the ho
cell.
