Detection of human cytomegalovirus early and late antigen and DNA production in cell culture and the effects of dimethyl sulfoxide, dexamethasone, and DNA inhibitors on early antigen induction

Abstract

Recently a conventional method for the laboratory diagnosis of human cytomegalovirus (HCMV) infection was improved by using centrifugation culture to enhance viral adsorption and by detecting HCMV early antigen and DNA. Comparison of the sensitivity of three rapid methods using commercial diagnostic reagents for the detection of HCMV early antigen (EA), late antigen (LA), and DNA was quantitatively evaluated in centrifugation cultures of human fibroblast cells (MRC-5) infected with HCMV. HCMV-EA was first detected 4 hours after infection, and the number of antigen-positive cells increased rapidly thereafter. Using biotinylated DNA probe, viral DNA was first detected 12 hours postinfection; the number of DNA-positive cells increased slowly. HCMV-LA was first seen 48 hours postinfection, and the number of LA-positive cells also increased thereafter. Thus detection of HCMV-EA was the most rapid and sensitive method for HCMV diagnosis. Several chemical compounds have been used to enhance HCMV replication. The effect of dimethyl sulfoxide (DMSO), dexamethasone (DEX), 5-bromo-2-deoxyuridine (BrdU), 5-fluoro-deoxyuridine (FdU), and cytosine arabinoside (Ara-C) on HCMV-EA induction was evaluated in centrifugation cultures of MRC-5 cells infected with HCMV. Infected cells treated with 1% DMSO alone or with DMSO plus DEX (10(-5) M) have been shown to increase the number of HCMV-EA-positive cells three- to fivefold over the untreated control cultures. The enhancing effects of Ara-C, BrdU, and BrdU plus FdU were demonstrated only occasionally.

Antiviral activity of Conyza canadensis (L.) Cronquist extracts grown in Tunisia

“…After that, the cells were observed under an immunofluorescence microscope. Because the extracts were dissolved in dimethylsulphoxide (DMSO) which positively affects the infectivity of the viruses (Li and Fong, 1990), DMSO was also included in the wells without any extract. The antiviral activity was determined by counting the number of cells infected by the virus (presenting fluorescent nuclei) in comparison with the number of infected cells in the reference well (no presence of any antiviral agent).…”

Physical and chemical methods for enhancing rapid detection of viruses and other agents

“…The treatment of cell cultures with hormones, DMSO, and/or calcium can enhance the detection of certain viruses (160,318,(320)(321)(322) (117,139,289,307). Viruses also can induce heat shock proteins (34,78,140,204,205).…”

Physical and chemical methods for enhancing rapid detection of viruses and other agents.

“…The treatment of cell cultures with hormones, DMSO, and/or calcium can enhance the detection of certain viruses (160,318,(320)(321)(322). The beneficial effects of these agents can depend on culture confluency.…”