Deoxyribonucleoside triphosphate pools in herpes simplex type 1 infected cells

Area of Science:

• Biochemistry
• Virology
• Cell Biology

Background:

• Deoxyribonucleoside triphosphates (dNTPs) are essential for DNA synthesis and repair.
• Cellular dNTP pools are tightly regulated and vary with cell cycle status.
• Herpes simplex virus (HSV) infection is known to impact host cell metabolism.

Purpose of the Study:

• To investigate the impact of HSV infection on dNTP pools in wild-type and deoxypyrimidine kinase-deficient BHK cells.
• To characterize changes in the levels of deoxyadenosine triphosphate (dATP), deoxycytidine triphosphate (dCTP), deoxyguanosine triphosphate (dGTP), and deoxythymidine triphosphate (dTTP).

Main Methods:

• Analysis of dNTP pools in exponentially growing and serum-starved wild-type BHK C13 cells.
• Analysis of dNTP pools in a mutant BHK cell line lacking thymidine kinase and deoxycytidine kinase activities.
• Comparison of dNTP pools before and after HSV infection in both cell types.

Main Results:

• Serum-starved cells exhibited low dNTP levels, while exponentially growing cells showed expanded pools, with dCTP being the largest and dGTP the smallest.
• HSV infection caused significant alterations in all dNTP pools.
• A pronounced 25- to 50-fold expansion of the dTTP pool was observed post-infection.
• dCTP and dGTP pools increased, whereas the dATP pool significantly decreased.
• These changes occurred in both wild-type and mutant cell lines.

Conclusions:

• HSV infection profoundly disrupts cellular dNTP homeostasis.
• The dramatic increase in dTTP suggests a specific role in viral DNA replication or a host response.
• The observed dNTP pool alterations are independent of cellular thymidine and deoxycytidine kinase activities.