Highly Sensitive Detection and Localization of Maternally Acquired Human Cytomegalovirus in Placental Tissue by In Situ Polymerase Chain Reaction

Abstract

Transplacental transmission of human cytomegalovirus (CMV) can result in congenital malformations, although details on the mechanisms of transmission and the location of CMV in infected placentae need to be described.METHODS. Placental tissue from term (third trimester) deliveries was screened for CMV infection by polymerase chain reaction (PCR), in situ PCR (IS-PCR), and IS reverse-transcriptase PCR (IS RT-PCR).RESULTS. CMV DNA was detected in tissue samples from 11 placentae that had been determined to be negative for CMV during routine pathological examination. IS-PCR demonstrated the presence of CMV DNA in all cell types within placental villi, and IS RT-PCR further defined this result by identifying viral transcripts from all stages of replication. CMV DNA and RNA were shown to be highly concentrated in placental trophoblast cells. The infecting viruses were detected with primers specific for the major immediate early section of the genome (UL122/123), the UL21.5 virion gene, and the glycoprotein B (gB) gene and were determined to be predominantly genotype gB2. Therefore, maternal and fetal host factors, as well as viral load and possibly viral genotype, may all affect the outcome of placental CMV infection.CONCLUSION. Placental villi are involved in the transfer of blood from maternal to fetal circulation. Infection and replication of CMV within placental trophoblasts suggests that these structures may be involved in the transmission of CMV.

Cytomegalovirus Infection of Human Syncytiotrophoblast Cells Strongly Interferes with Expression of Genes Involved in Placental Differentiation and Tissue Integrity

“…Previous work with term placentas demonstrated the permissivity of purified trophoblasts for CMV infection, using the laboratory-adapted strain, AD169 (15). Syncytiotrophoblast infection was demonstrated in vivo in a study of thirdtrimester placenta, using in situ hybridization and PCR techniques (11). Another study of purified syncytiotrophoblast cultures demonstrated that these cells could be permissively infected with a number of laboratory-adapted strains of CMV, as with clinical isolates, although infection efficiencies differed amongst different strains (18).…”

“…In addition to serving as a gateway to the fetus, the placenta may be directly injured by CMV, conceivably leading to intrauterine growth retardation and fetal disease (7-10). Thus, study of CMV placental infection may facilitate improved understanding of these potentially diverse mechanisms of viral-mediated fetal injury.A number of reports have identified CMV in placental tissue from clinical samples (11)(12)(13)(14). Several in vitro models for studying CMV-placental interactions have also been developed (15-20).…”

“…A number of reports have identified CMV in placental tissue from clinical samples (11)(12)(13)(14). Several in vitro models for studying CMV-placental interactions have also been developed (15)(16)(17)(18)(19)(20).…”

Vaccine-Derived Neutralizing Antibodies to the Human Cytomegalovirus gH/gL Pentamer Potently Block Primary Cytotrophoblast Infection

“…These cells build a bridge at the fetal-maternal interface and can be efficiently infected by HCMV in vitro and in vivo (10,(43)(44)(45)(46). In addition, infection of CTB in early gestation often results in placental developmental abnormalities (44,(46)(47)(48).…”

Modeling of Human Cytomegalovirus Maternal-Fetal Transmission in a Novel Decidual Organ Culture

“…Indeed, HCMV DNA and gene expression has been found in clinical samples taken from placentas early and late in gestation (45,50,54,68). Accumulating experimental and clinical evidence indicates that, in addition to serving in viral transmission, the placenta may be actively injured by HCMV, conceivably contributing to the observed IUGR and fetal disease (1,50,59,60).…”