Cyclooxygenase upregulation in cytomegalovirus-infected gingival fibroblasts: Implications for periodontal disease

Objective

To assess the changes in the expression of COX-1 and COX-2 in primary gingival fibroblasts upon infection with two strains of human cytomegalovirus (CMV).

Methods

Primary human gingival fibroblasts (HGFs) were cultured and infected with two strains of human CMV the laboratory strain (Towne) and a clinical isolate (B52) at a multiplicity of infection of 0.5. The relative mRNA levels of COX-1 and COX-2 were evaluated using multiplex reverse transcriptase quantitative polymerase chain reaction with specific hydrolysis probes. Additionally, immunofluorescence was performed for COX-2, IE1, and IE2 viral proteins.

Results

At 24 h post infection, CMV infection of HGFs resulted in a decrease in COX-1 transcripts in cells infected with both the Towne strain and B52 clinical isolate, and in non-infected cells. Conversely, COX-2 transcripts increased in infected cells (Towne and B52); they were significantly higher in B52 infected cells, similar to the immunofluorescence detection results for COX-2.

Conclusions

Infection of HGFs with CMV increased in both mRNA and protein expression of COX-2. Furthermore, the B52 isolate induced higher COX-2 expression than the Towne laboratory strain. This study provides a basis for understanding the putative relationships between CMV infection and inflammatory responses in gingival diseases.