scholarly journals Human Cytomegalovirus modifies placental small extracellular vesicle secretion and composition towards a proviral phenotype to enhance infection of fetal recipient cells

2021 ◽  
Author(s):  
Mathilde Bergamelli ◽  
Hélène Martin ◽  
Yann Aubert ◽  
Jean-Michel Mansuy ◽  
Marlène Marcellin ◽  
...  

Although placental small extracellular vesicles (sEVs) are extensively studied in the context of pregnancy, little is known about their role during human cytomegalovirus (hCMV) congenital infection, especially at the beginning of pregnancy. In this study, we examined the consequences of hCMV infection on sEVs production and composition using an immortalized human cytotrophoblast cell line derived from first trimester placenta. By combining complementary approaches of biochemistry, imaging techniques and quantitative proteomic analysis, we showed that hCMV infection increased the yield of sEVs produced by cytotrophoblasts and modified their protein composition towards a proviral phenotype. We further demonstrated that sEVs secreted by hCMV-infected cytotrophoblasts potentiated infection in naive recipient cells of fetal origin, including neural stem cells. Importantly, the enhancement of hCMV infection was also observed with sEVs prepared from either an ex vivo model of infected histocultures from early placenta or from the amniotic fluid of patients naturally infected by hCMV at the beginning of pregnancy. Based on these findings, we propose that placental sEVs could be key actors favoring viral dissemination to the fetal brain during hCMV congenital infection.

2015 ◽  
Vol 89 (13) ◽  
pp. 6792-6804 ◽  
Author(s):  
Xiao-Jun Li ◽  
Xi-Juan Liu ◽  
Bo Yang ◽  
Ya-Ru Fu ◽  
Fei Zhao ◽  
...  

ABSTRACTHuman cytomegalovirus (HCMV) infection of the developing fetus frequently results in major neural developmental damage. In previous studies, HCMV was shown to downregulate neural progenitor/stem cell (NPC) markers and induce abnormal differentiation. As Notch signaling plays a vital role in the maintenance of stem cell status and is a switch that governs NPC differentiation, the effect of HCMV infection on the Notch signaling pathway in NPCs was investigated. HCMV downregulated mRNA levels of Notch1 and its ligand, Jag1, and reduced protein levels and altered the intracellular localization of Jag1 and the intracellular effector form of Notch1, NICD1. These effects required HCMV gene expression and appeared to be mediated through enhanced proteasomal degradation. Transient expression of the viral tegument proteins of pp71 and UL26 reduced NICD1 and Jag1 protein levels endogenously and exogenously. Given the critical role of Notch signaling in NPC growth and differentiation, these findings reveal important mechanisms by which HCMV disturbs neural cell developmentin vitro. Similar eventsin vivomay be associated with HCMV-mediated neuropathogenesis during congenital infection in the fetal brain.IMPORTANCECongenital human cytomegalovirus (HCMV) infection is the leading cause of birth defects that primarily manifest as neurological disabilities. Neural progenitor cells (NPCs), key players in fetal brain development, are the most susceptible cell type for HCMV infection in the fetal brain. Studies have shown that NPCs are fully permissive for HCMV infection, which causes neural cell loss and premature differentiation, thereby perturbing NPC fate. Elucidation of virus-host interactions that govern NPC proliferation and differentiation is critical to understanding neuropathogenesis. The Notch signaling pathway is critical for maintaining stem cell status and functions as a switch for differentiation of NPCs. Our investigation into the impact of HCMV infection on this pathway revealed that HCMV dysregulates Notch signaling by altering expression of the Notch ligand Jag1, Notch1, and its active effector in NPCs. These results suggest a mechanism for the neuropathogenesis induced by HCMV infection that includes altered NPC differentiation and proliferation.


Author(s):  
Cláudia Fernandes ◽  
Augusta Marques ◽  
Maria de Jesus Chasqueira ◽  
Mónica Cró Braz ◽  
Ana Rute Ferreira ◽  
...  

Abstract Human cytomegalovirus (HCMV) is the leading congenital infection agent in the world. The importance of screening this infection has been debated, as 10–15% of the asymptomatic newborns with HCMV at birth will present late sequelae. The aim of this study was to test the feasibility of using saliva pools from newborns in a screening program for congenital HCMV infection, in two Portuguese hospitals. The screening was based on the use of pools of 10 saliva samples for detection of viral DNA by real-time PCR. Whenever there was a positive pool, the samples were tested individually, and for each positive sample the result was confirmed with a urine sample collected in the first 2 weeks of life. The study involved 1492 newborns. One hundred and fifty pools were screened, with 14 positive results in saliva, but only 10 were confirmed in urine samples, giving a prevalence of congenital HCMV infection in both hospitals of 0.67% (CI95% 0.36 to 1.23%). Conclusion: The overall prevalence of congenital HCMV infection in both hospitals was 0.67%. The use of saliva pools proved to be effective for the screening of this congenital infection, allowing timely screening and confirmation in a large population, with associated cost reduction. What is Known:• Newborn screening for HCMV is desirable.• Saliva is a good and practical sample. What is New:• The feasibility of using saliva pools for a large-scale screening.• The cost reduction of this strategy.


2020 ◽  
Vol 29 ◽  
pp. 096368972092505
Author(s):  
Yuan Qiao ◽  
Helena Kolibaba ◽  
Yukiko Mori ◽  
Tao Liu ◽  
Huijun Chen ◽  
...  

This paper aimed to evaluate whether human cytomegalovirus (HCMV) infection in extravillous cytotrophoblasts (EVT) could shift the balance between regulatory T (Treg) and T-helper type 17 (Th17) cells in vitro. In this study, primary EVT isolated from first trimester placental tissues were infected with HCMV, and conditional media were harvested after cultivation for 72 h. T lymphocytes were cultured in the presence or absence of HCMV-infected conditional media. The frequencies of Th17 or Treg cells from HCMV group were significantly lower or higher than those from the control group, with the expression of corresponding key cytokines at both messenger ribonucleic acid and secretion levels, respectively. The ratio of Treg to Th17 cells was significantly lower in HCMV group than that in control group ( P < 0.01). In conclusion, tiled Th17/Treg balance at maternal–fetal interface exists after HCMV infection.


2002 ◽  
Vol 15 (4) ◽  
pp. 680-715 ◽  
Author(s):  
Maria Grazia Revello ◽  
Giuseppe Gerna

SUMMARY Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection and mental retardation. HCMV infection, while causing asymptomatic infections in most immunocompetent subjects, can be transmitted during pregnancy from the mother with primary (and also recurrent) infection to the fetus. Hence, careful diagnosis of primary infection is required in the pregnant woman based on the most sensitive serologic assays (immunoglobulin M [IgM] and IgG avidity assays) and conventional virologic and molecular procedures for virus detection in blood. Maternal prognostic markers of fetal infection are still under investigation. If primary infection is diagnosed in a timely manner, prenatal diagnosis can be offered, including the search for virus and virus components in fetal blood and amniotic fluid, with fetal prognostic markers of HCMV disease still to be defined. However, the final step for definite diagnosis of congenital HCMV infection is detection of virus in the blood or urine in the first 1 to 2 weeks of life. To date, treatment of congenital infection with antiviral drugs is only palliative both prior to and after birth, whereas the only efficacious preventive measure seems to be the development of a safe and immunogenic vaccine, including recombinant, subunit, DNA, and peptide-based vaccines now under investigation. The following controversial issues are discussed in the light of the most recent advances in the field: the actual perception of the problem; universal serologic screening before pregnancy; the impact of correct counseling on decision making by the couple involved; the role of prenatal diagnosis in ascertaining transmission of virus to the fetus; the impact of preconceptional and periconceptional infections on the prevalence of congenital infection; and the prevalence of congenitally infected babies born to mothers who were immune prior to pregnancy compared to the number born to mothers undergoing primary infection during pregnancy.


2021 ◽  
Author(s):  
Eleanor C. Semmes ◽  
Itzayana G. Miller ◽  
Jennifer A. Jenks ◽  
Courtney E. Wimberly ◽  
Stella J. Berendam ◽  
...  

AbstractHuman cytomegalovirus (HCMV) is the most common congenital infection and a leading cause of stillbirth, neurodevelopmental impairment, and pediatric hearing loss worldwide. Development of a maternal vaccine or therapeutic to prevent congenital infection has been hindered by limited knowledge of the immune responses that protect against placental HCMV transmission in maternal primary and nonprimary infection. To identify protective antibody responses, we measured anti-HCMV IgG binding and anti-viral functions in maternal and cord blood sera from HCMV transmitting (n=41) and non- transmitting (n=40) mother-infant dyads identified via a large U.S.-based public cord blood bank. In a predefined immune correlate analysis, maternal monocyte-mediated antibody-dependent cellular phagocytosis (ADCP) and high avidity IgG binding to HCMV envelope glycoproteins were associated with decreased risk of congenital HCMV infection. Moreover, HCMV-specific IgG engagement of FcγRI and FcγRIIA, which mediate non-neutralizing antibody responses, was enhanced in non-transmitting mother-infant dyads and strongly correlated with ADCP. These findings suggest that Fc effector functions including ADCP protect against placental HCMV transmission. Taken together, our data indicate that future active and passive immunization strategies to prevent congenital HCMV infection should target Fc-mediated non-neutralizing antibody responses.


2015 ◽  
Vol 89 (9) ◽  
pp. 5134-5147 ◽  
Author(s):  
Takako Tabata ◽  
Matthew Petitt ◽  
Martin Zydek ◽  
June Fang-Hoover ◽  
Nicholas Larocque ◽  
...  

ABSTRACTHuman cytomegalovirus (HCMV) is a major cause of birth defects that include severe neurological deficits, hearing and vision loss, and intrauterine growth restriction. Viral infection of the placenta leads to development of avascular villi, edema, and hypoxia associated with symptomatic congenital infection. Studies of primary cytotrophoblasts (CTBs) revealed that HCMV infection impedes terminal stages of differentiation and invasion by various molecular mechanisms. We recently discovered that HCMV arrests earlier stages involving development of human trophoblast progenitor cells (TBPCs), which give rise to the mature cell types of chorionic villi—syncytiotrophoblasts on the surfaces of floating villi and invasive CTBs that remodel the uterine vasculature. Here, we show that viral proteins are present in TBPCs of the chorion in cases of symptomatic congenital infection.In vitrostudies revealed that HCMV replicates in continuously self-renewing TBPC lines derived from the chorion and alters expression and subcellular localization of proteins required for cell cycle progression, pluripotency, and early differentiation. In addition, treatment with a human monoclonal antibody to HCMV glycoprotein B rescues differentiation capacity, and thus, TBPCs have potential utility for evaluation of the efficacies of novel antiviral antibodies in protecting and restoring placental development. Our results suggest that HCMV replicates in TBPCs in the chorionin vivo, interfering with the earliest steps in the growth of new villi, contributing to virus transmission and impairing compensatory development. In cases of congenital infection, reduced responsiveness of the placenta to hypoxia limits the transport of substances from maternal blood and contributes to fetal growth restriction.IMPORTANCEHuman cytomegalovirus (HCMV) is a leading cause of birth defects in the United States. Congenital infection can result in permanent neurological defects, mental retardation, hearing loss, visual impairment, and pregnancy complications, including intrauterine growth restriction, preterm delivery, and stillbirth. Currently, there is neither a vaccine nor any approved treatment for congenital HCMV infection during gestation. The molecular mechanisms underlying structural deficiencies in the placenta that undermine fetal development are poorly understood. Here we report that HCMV replicates in trophoblast progenitor cells (TBPCs)—precursors of the mature placental cells, syncytiotrophoblasts and cytotrophoblasts, in chorionic villi—in clinical cases of congenital infection. Virus replication in TBPCsin vitrodysregulates key proteins required for self-renewal and differentiation and inhibits normal division and development into mature placental cells. Our findings provide insights into the underlying molecular mechanisms by which HCMV replication interferes with placental maturation and transport functions.


2003 ◽  
Vol 77 (15) ◽  
pp. 8187-8195 ◽  
Author(s):  
Masakazu Terauchi ◽  
Hideki Koi ◽  
Chikako Hayano ◽  
Noriko Toyama-Sorimachi ◽  
Hajime Karasuyama ◽  
...  

ABSTRACT Human cytomegalovirus (HCMV) downregulates the class I major histocompatibility complexes (MHCs), HLA-A and -B, in infected fibroblasts to escape from antigen-specific cytotoxic T lymphocytes. The HCMV genes responsible for the downregulation of MHCs are US2, US3, US6, and US11, which encode type I membrane proteins working at the endoplasmic reticulum (ER). However, it is largely unknown whether HCMV downregulates the class I MHC molecules in placental extravillous cytotrophoblasts (EVT), which express HLA-C, -E, and -G to protect a semiallogenic fetus from maternal natural killer (NK) cells at the fetomaternal interface. Here, we report that differentiated EVT prepared from human first-trimester chorionic villi persistently express class I MHC molecules upon HCMV infection. When these US proteins were expressed in uninfected EVT, they were localized at the ER in the entire cytoplasm. However, subsequent HCMV infection resulted in dissociation of these US proteins from the ER, which relocated toward the cell membrane. In fibroblasts, these US proteins were localized at the ER before and after HCMV infection. These results suggest that the US gene products are not integrated into ER of HCMV-infected EVT and fail to downregulate class I MHC molecules.


2020 ◽  
Vol 65 (3) ◽  
Author(s):  
Hang Su ◽  
Xiaohua Ye ◽  
Daniel C. Freed ◽  
Leike Li ◽  
Zhiqiang Ku ◽  
...  

ABSTRACT Human cytomegalovirus (HCMV) is a ubiquitous pathogen that can cause developmental disorders following congenital infection and life-threatening complications among transplant patients. Potent neutralizing monoclonal antibodies (MAbs) are promising drug candidates against HCMV infection. HCMV can infect a broad range of cell types. Therefore, single neutralizing antibodies targeting one HCMV glycoprotein often lack either potency or broad cell-type coverage. We previously characterized two human-derived HCMV neutralizing MAbs. One was the broadly neutralizing MAb 3-25, which targets the antigenic domain 2 of glycoprotein B (gB). The other was the highly potent MAb 2-18, which specifically recognizes the gH/gL/pUL128/130/131 complex (pentamer). To combine the strengths of gB- and pentamer-targeting MAbs, we developed an IgG–single-chain variable fragment (scFv) bispecific antibody by fusing the 2-18 scFv to the heavy-chain C terminus of MAb 3-25. The resulting bispecific antibody showed high-affinity binding to both gB and pentamer. Functionally, the bispecific antibody demonstrated a combined neutralization breadth and potency of the parental MAbs in multiple cell lines and inhibited postinfection viral spreading. Furthermore, the bispecific antibody was easily produced in CHO cells at a yield above 1 g/liter and showed a single-dose pharmacokinetic profile comparable to that of parental MAb 3-25 in rhesus macaques. Importantly, the bispecific antibody retained broadly and potent neutralizing activity after 21 days in circulation. Taken together, our research provides a proof-of-concept study for developing bispecific neutralizing antibody therapies against HCMV infection.


2020 ◽  
Author(s):  
Mathilde Bergamelli ◽  
Hélène Martin ◽  
Mélinda Bénard ◽  
Jérôme Ausseil ◽  
Jean-Michel Mansuy ◽  
...  

ABSTRACTCurrently, research on the use of non-invasive biomarkers as diagnosis and prognosis tools during pathological pregnancies is in full development. Among these, placenta-derived small extracellular vesicles (sEVs) are considered as serious candidates, since their composition is modified during many pregnancy pathologies. Moreover, sEVs are found in maternal serum and can thus be easily purified from a simple blood sample. In this study, we describe the isolation of sEVs from a histoculture model of first trimester placental explants. Using bead-based multiplex cytometry and electron microscopy combined with biochemical approaches, we characterized these sEVs and defined their associated markers and ultrastructure. We next examined the consequences of infection by human cytomegalovirus on sEVs secretion and characteristics. We observed that infection led to increased levels of expression of several surface markers, without any impact on the secretion and integrity of sEVs. Our findings open the prospect for the identification of new predictive biomarkers for the severity and outcome of this congenital infection early during pregnancy, which are still sorely lacking.


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