Productive and abortive replication of human cytomegalovirus at different environmental pH values

Abstract

SummaryThe influence of environmental pH on eytomegalovirus replication cycle was studied. A productive cycle was observed at pH values of 6.5 or higher while at pH values of 5.8, 6.0, 6.2 only virus-induced early events were expressed. ,It has been previously shown that the development of some viruses, such as vesicular stomatitis virus (VSV) (3), poliovirus (11) and herpes simplex virus (4) can be affected by environmental pH.I~OLZMA~ (t0), studying the relationship between different strains of herpes simplex virus {HSV) and the pH of the medium, has shown that the optimal extracellular pH for HSV multiplication may vary between 6.5--7.3. Furthermore Lh~cz and Bt~ADSTREET (4) demonstrated that an overlay medium at pH 6.3 completely inhibits plaque formation by herpes simplex virus but not its replication.Little is known, however, about the effect of extracellular pH on the replication cycle of human cytomegalovirus (HCMV). HCMV is characterized by a long replication cycle and, in contrast to what happens in cells infected by other cytocidal herpesviruses, host cell macromolecule synthesis is not inhibited. In fact, cells infected by HCMV show increased RNA (13) and DNA (12) synthesis and various cellular enzymes are stimulated; all this suggests that cellular functions are probably involved in HCMV replication and this is supported by the fact that in actinomyein pretreated cells a complete rep]ieation cycle of HCMV is inhibited (5). All these data prompted us to study the influence of environmental pH on the replication cycle of HCMV.

Reactivation of Cytomegalovirus in Endometrial Cells by Estradiol

“…Zerbini et al [23] have demonstrated that in human embryo tissue culture acidic medium inhibits the produc tion of CMV viral progeny, allowing only the expression of the immediate early and early antigens of the virus [21]. It is possible that hormones enable the expression of late viral genome functions, i.e., late proteins which are inhibited by the low pH.…”

Human Decidual Cells Activity in Women with Spontaneous Abortions of Probable CMV Aetiology During the First Trimester of Gestation. An Immunohistochemical Study with CMV-Associated Antigen

“…The mechanism by which estradiol cares modulate the state of CMV in endometrial cells is unknown. Zerbini et al (42) have demonstrated that in human embryo tissue culture acidic medium inhibits the production of CMV viral progeny, allowing only the expression of the immediate early and early antigens of the virus (3). It is possible that hormones enable the expression of the late viral genome functions, i.e., late proteins which are inhibited by the low pH.…”

Influence of cell cycle on the efficiency of transfection with purified human cytomegalovirus DNA

“…Selected human sera with high titres of antibodies against the different HCMV antigens (GM181 :CMV LA1/320, EA neg, IEA neg) ; AF407 : CMV LA 1/320; EA 1/320, IEA 1/320) and HSV late antigens (FP27:HSV LA1/640) were used in the various tests (13).…”