Characterization of Natural Killer Cell Profile in a Cohort of Infected Pregnant Women and Their Babies and Its Relation to CMV Transmission.

Human cytomegalovirus (CMV) is a common herpesvirus causing lifelong latent infection in most people and is a primary cause of congenital infection worldwide. Given the role of NK cells in the materno-fetal barrier, we investigated peripheral blood NK cell behavior in the context of CMV infection acquired during pregnancy. We analyzed the NK phenotype and CD107a surface mobilization on PBMCs from CMV-transmitting and non-transmitting mothers and newborns with or without congenital infection. NK cells from non-transmitting mothers showed the typical phenotype of CMV-adaptive NK cells, characterized by higher levels of NKG2C, CD57, and KIRs, with reduced NKG2A, compared to transmitting ones. A significantly higher percentage of DNAM-1+, PD-1+, and KIR+NKG2A-CD57+PD-1+ CD56dim cells was found in the non-transmitting group. Accordingly, NK cells from congenital-CMV (cCMV)-infected newborns expressed higher levels of NKG2C and CD57, with reduced NKG2A, compared to non-congenital ones. Furthermore, they showed a significant expansion of CD56dim cells co-expressing NKG2C and CD57 or with a memory-like (KIR+NKG2A-CD57+NKG2C+) phenotype, as well as a significant reduction of the CD57-NKG2C- population. Degranulation assays showed a slightly higher CD107a geomean ratio in NK cells of mothers who were non-transmitting compared to those transmitting the virus. Our findings demonstrate that both CMV-transmitting mothers and cCMV newborns show a specific NK profile. These data can guide studies on predicting virus transmission from mothers and congenital infection in infants.

Human cytomegalovirus modulates mTORC1 to redirect mRNA translation within quiescently infected monocytes.

Human cytomegalovirus (HCMV) utilizes peripheral blood monocytes as a means to systemically disseminate throughout the host. Following viral entry, HCMV stimulates non-canonical Akt signaling leading to the activation of mTORC1 and the subsequent translation of select antiapoptotic proteins within infected monocytes. However, the full extent to which the HCMV-initiated Akt/mTORC1 signaling axis reshapes the monocyte translatome is unclear. We found HCMV entry alone was able to stimulate widescale changes to mRNA translation levels and that inhibition of mTOR, a component of mTORC1, dramatically attenuated HCMV-induced protein synthesis. Although monocytes treated with normal myeloid growth factors also exhibited increased levels of translation, mTOR inhibition had no effect, suggesting HCMV activation of mTOR stimulates the acquisition of a unique translatome within infected monocytes. Indeed, polyribosomal profiling of HCMV-infected monocytes identified distinct prosurvival transcripts that were preferentially loaded with ribosomes when compared to growth factor-treated cells. Sirtuin 1 (SIRT1), a deacetylase that exerts prosurvival effects through regulation of the PI3K/Akt pathway, was found to be highly enriched following HCMV infection in an mTOR-dependent manner. Importantly, SIRT1 inhibition led to the death of HCMV-infected monocytes while having minimal effect on uninfected cells. SIRT1 also supported a positive feedback loop to sustain Akt/mTORC1 signaling following viral entry. Taken together, HCMV profoundly reshapes mRNA translation in an mTOR-dependent manner to enhance the synthesis of select factors necessary for the survival of infected monocytes.IMPORTANCEHuman cytomegalovirus (HCMV) infection is a significant cause of morbidity and mortality among the immunonaïve and immunocompromised. Peripheral blood monocytes are a major cell type responsible for disseminating the virus from the initial site of infection. In order for monocytes to mediate viral spread within the host, HCMV must subvert the naturally short lifespan of these cells. In this study, we performed polysomal profiling analysis, which demonstrated HCMV to globally redirect mRNA translation toward the synthesis of cellular prosurvival factors within infected monocytes. Specifically, HCMV entry into monocytes induced the translation of cellular SIRT1 to generate an antiapoptotic state. Defining the precise mechanisms through which HCMV stimulates survival will provide insight into novel anti-HCMV drugs able to target infected monocytes.

Noninvasive Prediction of Congenital Cytomegalovirus Infection After Maternal Primary Infection.

OBJECTIVE: To develop and internally validate a noninvasive method for the prediction of congenital cytomegalovirus (CMV) infection after primary maternal CMV infection. METHODS: We conducted a secondary analysis of a multicenter randomized placebo-controlled trial of CMV hyperimmune globulin to prevent congenital infection. Women were eligible if they had primary CMV infection, defined as detectable plasma CMV-specific immunoglobulin (Ig)M and CMV-specific IgG with avidity less than 50% before 24 weeks of gestation or IgG seroconversion before 28 weeks, and were carrying a singleton fetus without ultrasonographic findings suggestive of CMV infection. Antibody assays were performed in a single reference laboratory. Congenital infection was defined as CMV detection in amniotic fluid, neonatal urine or saliva, or postmortem tissue. Using backward elimination, we developed logit models for prediction of congenital infection using factors known at randomization. The performance of the model was assessed using leave-one-out cross-validation (a method of internal validation). RESULTS: Of 399 women enrolled in the trial, 344 (86%) had informative data for this analysis. Congenital infection occurred in 68 pregnancies (20%). The best performing model included government-assisted insurance, IgM index 4.5 or higher, IgG avidity less than 32%, and whether CMV was detectable by polymerase chain reaction in maternal plasma at the time of randomization. Cross-validation showed an average area under the curve of 0.76 (95% CI 0.70-0.82), indicating moderate discriminatory ability. More parsimonious one-, two-, and three-factor models performed significantly less well than the four-factor model. Examples of prediction with the four-factor model: for a woman with government-assisted insurance, avidity less than 32%, IgM index 4.5 or higher, and detectable plasma CMV, probability of congenital infection was 0.69 (95% CI 0.53-0.82); for a woman with private insurance, avidity 32% or greater, IgM index less than 4.5, and undetectable plasma CMV, probability of infection was 0.03 (95% CI 0.02-0.07). CONCLUSION: We developed models to predict congenital CMV infection in the presence of primary maternal CMV infection and absence of ultrasonographic findings suggestive of congenital infection. These models may be useful for patient counseling and decision making.

Infections at the maternal-fetal interface: an overview of pathogenesis and defence.

Infections are a major threat to human reproductive health, and infections in pregnancy can cause prematurity or stillbirth, or can be vertically transmitted to the fetus leading to congenital infection and severe disease. The acronym 'TORCH' (Toxoplasma gondii, other, rubella virus, cytomegalovirus, herpes simplex virus) refers to pathogens directly associated with the development of congenital disease and includes diverse bacteria, viruses and parasites. The placenta restricts vertical transmission during pregnancy and has evolved robust mechanisms of microbial defence. However, microorganisms that cause congenital disease have likely evolved diverse mechanisms to bypass these defences. In this Review, we discuss how TORCH pathogens access the intra-amniotic space and overcome the placental defences that protect against microbial vertical transmission.

Recomendaciones para el diagnóstico y manejo de la infección por citomegalovirus en la mujer embarazada y el recién nacido / Recommendations for the diagnosis and management of cytomegalovirus infection in pregnant woman and newborn infant

Resumen La Sociedad Chilena de Infectología, a través de su Comité de Infecciones Neonatales, en conjunto con la Sociedad Chilena de Obstetricia y Ginecología, proponen un documento de diagnóstico y manejo de la Infección por Citomegalovirus en la Mujer Embarazada y el Recién Nacido. Esta guía aborda el manejo de la infección en el binomio, su enfrentamiento diagnóstico y terapéutico, orientado al equipo de salud que atiende a mujeres embarazadas y recién nacidos con infección por citomegalovirus (CMV) en Chile. Considera la situación epidemiológica global y latinoamericana, con recomendaciones para la evaluación clínica y de laboratorio; establece criterios de diagnóstico, propone enfoques terapéuticos de acuerdo a la situación clínica, analiza las medidas de prevención y establece una propuesta nacional para el seguimiento de esta enfermedad. Se ha puesto especial énfasis en entregar, de forma práctica, y con la mayor evidencia posible, las recomendaciones para el manejo del binomio con infección por CMV.

Abstract The Chilean Society of Infectology, through its Neonatal Infections Committee in conjunction with the Chilean Society of Obstetrics and Gynecology, propose a document for the Diagnosis and Management of Cytomegalovirus Infection in Pregnant Woman and Newborn Infant. This guideline suggests the management of mother and child infection, its diagnostic and therapeutic options. Considers the global and Latin American epidemiology, with recommendations for clinical and laboratory evaluation; diagnostic criteria, therapeutic approaches according to the clinical situation, analyzes prevention measures and establishes a national proposal for monitoring this disease.

Limited replication of human cytomegalovirus in a trophoblast cell line.

Several viruses, including human cytomegalovirus (HCMV), are thought to replicate in the placenta. However, there is little understanding of the molecular mechanisms involved in HCMV replication in this tissue. We investigated replication of HCMV in the extravillous trophoblast cell line SGHPL-4, a commonly used model of HCMV replication in the placenta. We found limited HCMV protein expression and virus replication in SGHPL-4 cells. This was associated with a lack of trophoblast progenitor cell protein markers in SGHPL-4 cells, suggesting a relationship between trophoblast differentiation and limited HCMV replication. We proposed that limited HCMV replication in trophoblast cells is advantageous to vertical transmission of HCMV, as there is a greater opportunity for vertical transmission when the placenta is intact and functional. Furthermore, when we investigated the replication of other vertically transmitted viruses in SGHPL-4 cells we found some limitation to replication of Zika virus, but not herpes simplex virus. Thus, limited replication of some, but not all, vertically transmitted viruses may be a feature of trophoblast cells.

The association between maternal cytomegalovirus urinary excretion and congenital infection rate.

BACKGROUND: In utero Cytomegalovirus (CMV) vertical transmission occurs predominantly during primary maternal infection. There are no known non-invasive methods for diagnosis of fetal infection before delivery, however some risk factors have been suggested. We aimed to evaluate the association between maternal CMV urinary excretion and congenital CMV infection. METHODS: A retrospective cohort study of all women who were diagnosed with primary CMV infection during pregnancy in a single university affiliated tertiary medical center, between 2012 and 2016. We examined congenital CMV infection and disease rates among infants born to women with and without CMV urinary excretion. RESULTS: Overall, 126 women were included, 77 in the positive urinary excretion group, and 49 in the negative urinary excretion group. There was no difference in maternal symptoms between the groups. We found no difference in congenital CMV infection and disease rates between infants born to women with and without urinary excretion of CMV (congenital infection rate 37.1% vs. 24.4%, p = 0.209, congenital disease rate of 18.2% vs. 22.4%, p = 0.648). Women with positive urinary CMV excretion had lower IgG avidity values (36.7% vs 54.6%, p = 0.007), with no additional difference in serology pattern. Compared to asymptomatic women, those with CMV related symptoms did not have significantly higher rates of urinary excretion of CMV (70% vs. 60.5%, p = 0.38) or congenital infection rates (40.7% vs. 31.2%, p = 0.48). CONCLUSION: Among infants of women with primary CMV infection in pregnancy, we did not find an association between urinary excretion of CMV and congenital CMV infection.

Maternal CMV seroprevalence rate in early gestation and congenital cytomegalovirus infection in a Chinese population.

Background Congenital human cytomegalovirus (CMV) infection remains largely unrecognized and underemphasized in medical practice. This study aimed to describe the maternal CMV seroprevalence rate in early gestation and congenital CMV infection in a Chinese population. Methods This prospective cohort study was conducted in three hospitals in China from 2015 through 2018. Pregnant women were enrolled in early gestation and followed up in middle and late gestation with serological testing. CMV serostatus was determined by IgG testing in serum during early gestation. Their newborns were screened for cCMV infection by PCR testing in both saliva and urine at two time points. The cCMV prevalence, maternal seroprevalence and associated factors were analyzed. Results In China, the CMV seroprevalence was 98.11% (6602/6729, 95% CI: 97.76%-98.41%), and the cCMV prevalence was 1.32% (84/6350, 95% CI: 1.07%-1.64%). Over 98% of cCMV-positive newborns were from pregnant women who were seropositive in early gestation in China. The prevalence of cCMV infection in newborns from seropositive and seronegative pregnant women was similar (crude prevalence: 1.33% vs 0.82%, P = 1.00; estimated prevalence: 1.27% vs 1.05%, P = 0.32). Pregnant women who were under 25 years old or primiparous had a lower seroprevalence. Newborns from pregnant women under 25 years old or from twin pregnancies had a higher prevalence of cCMV infection. Conclusion in China, the cCMV prevalence was high, and the rates were similar in newborns from pregnant women who were seropositive and seronegative in early gestation. The vast majority of cCMV newborns were from seropositive mothers.Trial registration: ClinicalTrials.gov identifier: NCT02645396..

Characteristics and serology of pregnant women with cytomegalovirus immunoglobulin G seroconversion during pregnancy in Japan.

OBJECTIVE: Investigate the characteristics and serology of pregnant women with cytomegalovirus (CMV) immunoglobulin (Ig)G seroconversion during pregnancy to understand the risk factors associated with primary CMV infection and the occurrence of fetal congenital CMV infection. MATERIALS AND METHODS: We retrospectively studied 3202 pregnant women who were CMV IgG-negative in early pregnancy and were retested for IgG in late pregnancy. Characteristics were compared between participants with and without IgG seroconversion, and serological parameters were compared between participants with and without fetal congenital CMV infection. RESULTS: Twenty-six participants showed CMV IgG seroconversion and fifteen showed fetal congenital CMV infection. Seroconversion rates were significantly higher in teens (5.0%) than in older women (20s: 0.8%; 30s and over: 0.6%) (p < 0.001). Titers of CMV IgM at IgG seroconversion were higher in women without (median 8.66) than with (median 6.54) congenital infection (p = 0.045). The congenital infection rate was high when IgM titers at IgG seroconversion were low (47.1% with 4.00-12.00 titers and 100% with 1.21-3.99 IgM titers) (p = 0.048). CONCLUSIONS: Nulliparous pregnant teenagers have a high risk of CMV IgG seroconversion and the CMV IgM titer at IgG seroconversion may help predict the occurrence of fetal congenital CMV infection.

Donor and Recipient Matching in Facial Vascularized Composite Allotransplantation: A Closer Look at the Donor Pool.

BACKGROUND: Identifying a donor for facial vascularized composite allotransplant recipients can be a lengthy, emotionally challenging process. Little is known about the relative distribution of key donor characteristics among potential donors. Data on actual wait times of patients are limited, making it difficult to estimate wait times for future recipients. METHODS: The authors retrospectively reviewed charts of nine facial vascularized composite allotransplant patients and provide data on transplant wait times and patient characteristics. In addition, they analyzed the United Network for Organ Sharing database of dead organ donors. After excluding donors with high-risk characteristics (e.g., active cancer or risk factors for blood-borne disease transmission), the authors calculated the distribution of relevant donor-recipient matching criteria (i.e., ethnicity, body mass index, age, ABO blood group, cytomegalovirus, Epstein-Barr virus, hepatitis C virus) among 65,201 potential donors. RESULTS: The median wait time for a transplant was 4 months (range, 1 day to 17 months). The large majority of United Network for Organ Sharing-recorded deaths from disease were white (63 percent) and male (58 percent). Female donors of black, Hispanic, or Asian descent are underrepresented, with 7, 5, and 1 percent of all recorded deaths from disease, respectively. Potential donors show cytomegalovirus and Epstein-Barr virus seropositivity of 65 and 95 percent, respectively. The number of annual hepatitis C-positive donors increased over time. CONCLUSIONS: Actual facial vascularized composite allotransplant wait times vary considerably. Although most patients experience acceptable wait times, some with underrepresented characteristics exceed acceptable levels. Cytomegalovirus-seropositive donors present a large portion of the donor pool, and exclusion for seronegative patients may increase wait time. Hepatitis C-seropositive donors may constitute a donor pool for underrepresented patient groups in the future.

Low Maternal Immunoglobulin G Avidity and Single Parity as Adverse Implications of Human Cytomegalovirus Vertical Transmission in Pregnant Women with Immunoglobulin M Positivity.

Human cytomegalovirus (CMV) is the leading cause of neurological sequelae in infants. Understanding the risk factors of primary CMV infection is crucial in establishing preventive strategies. Thus, we conducted a retrospective cohort study to identify risk factors of vertical transmission among pregnant women with immunoglobulin (Ig) M positivity. The study included 456 pregnant women with IgM positivity. Information on age, parity, occupation, clinical signs, IgM levels, and IgG avidity index (AI) was collected. The women were divided into infected and non-infected groups. The two groups showed significant differences in IgM level, IgG AI, number of women with low IgG AI, clinical signs, and number of pregnant women with single parity. In the multiple logistic regression analysis, pregnant women with single parity and low IgG AI were independent predictors. Among 40 women who tested negative for IgG antibody in their previous pregnancy, 20 showed low IgG AI in their current pregnancy. Among the 20 women, 4 had vertical transmission. These results provide better understanding of the risk factors of vertical transmission in pregnant women with IgM positivity.

Transmission of cell-associated human cytomegalovirus isolates between various cell types using polymorphonuclear leukocytes as a vehicle.

Polymorphonuclear leukocytes (PMNs) are regarded as vehicles for the hematogenous dissemination of human cytomegalovirus (HCMV). In cell culture, this concept has been validated with cell-free laboratory strains but not yet with clinical HCMV isolates that grow strictly cell-associated. We, therefore, aimed to evaluate whether PMNs can also transmit such isolates from initially infected fibroblasts to other cell types, which might further clarify the role of PMNs in HCMV dissemination and provide a model to search for potential inhibitors. PMNs, which have been isolated from HCMV-seronegative individuals, were added for 3 h to fibroblasts infected with recent cell-associated HCMV isolates, then removed and transferred to various recipient cell cultures. The transfer efficiency in the recipient cultures was evaluated by immunofluorescence staining of viral immediate early antigens. Soluble derivatives of the cellular HCMV entry receptor PDGFRα were analyzed for their potential to interfere with this transfer. All of five tested HCMV isolates could be transferred to fibroblasts, endothelial and epithelial cells with transfer rates ranging from 2 to 9%, and the transferred viruses could spread focally in these recipient cells within 1 week. The PDGFRα-derived peptides IK40 and GT40 reduced transfer by 40 and 70% when added during the uptake step. However, when added during the transfer step, only IK40 was effective, inhibiting transmission by 20% on endothelial cells and 50-60% on epithelial cells and fibroblasts. These findings further corroborate the assumption of cell-associated HCMV dissemination by PMNs and demonstrate that it is possible to inhibit this transmission mode.

Pregnancy and viral infections: Mechanisms of fetal damage, diagnosis and prevention of neonatal adverse outcomes from cytomegalovirus to SARS-CoV-2 and Zika virus.

Some maternal infections, contracted before or during pregnancy, can be transmitted to the fetus, during gestation (congenital infection), during labor and childbirth (perinatal infection) and through breastfeeding (postnatal infection). The agents responsible for these infections can be viruses, bacteria, protozoa, fungi. Among the viruses most frequently responsible for congenital infections are Cytomegalovirus (CMV), Herpes simplex 1-2, Herpes virus 6, Varicella zoster. Moreover Hepatitis B and C virus, HIV, Parvovirus B19 and non-polio Enteroviruses when contracted during pregnancy may involve the fetus or newborn at birth. Recently, new viruses have emerged, SARS-Cov-2 and Zika virus, of which we do not yet fully know the characteristics and pathogenic power when contracted during pregnancy. Viral infections in pregnancy can damage the fetus (spontaneous abortion, fetal death, intrauterine growth retardation) or the newborn (congenital anomalies, organ diseases with sequelae of different severity). Some risk factors specifically influence the incidence of transmission to the fetus: the timing of the infection in pregnancy, the order of the infection, primary or reinfection or chronic, the duration of membrane rupture, type of delivery, socio-economic conditions and breastfeeding. Frequently infected neonates, symptomatic at birth, have worse outcomes than asymptomatic. Many asymptomatic babies develop long term neurosensory outcomes. The way in which the virus interacts with the maternal immune system, the maternal-fetal interface and the placenta explain these results and also the differences that are observed from time to time in the fetal­neonatal outcomes of maternal infections. The maternal immune system undergoes functional adaptation during pregnancy, once thought as physiological immunosuppression. This adaptation, crucial for generating a balance between maternal immunity and fetus, is necessary to promote and support the pregnancy itself and the growth of the fetus. When this adaptation is upset by the viral infection, the balance is broken, and the infection can spread and lead to the adverse outcomes previously described. In this review we will describe the main viral harmful infections in pregnancy and the potential mechanisms of the damages on the fetus and newborn.

Clinical outcome and the role of antivirals in congenital cytomegalovirus infection.

Congenital cytomegalovirus (cCMV) infection is a leading cause of hearing loss and neurological disabilities in children worldwide. Although a minority of infants with cCMV will have symptoms at a birth, these children are at high risk of long-term sequelae. Most infants with cCMV have no clinical signs at birth (asymptomatic), but 10-15% will develop hearing loss. The diagnosis of cCMV relies on detection of the virus from urine or saliva within the first three weeks of life, with saliva PCR being the preferred method due to ease of collection and high sensitivity of the assay. Measures to prevent mother-to-child transmission of CMV are limited, and antiviral therapy with valganciclovir for 6 months is the standard of care for infants with symptomatic cCMV. As more infants with cCMV are being identified through newborn screening, studies are urgently needed to address antiviral treatment in asymptomatic infants and the implementation of prevention strategies to prevent fetal infection. This article is part of the symposium "New drugs and vaccines for DNA virus infections: a symposium in memory of Mark Prichard."