A recent comparison of two rhesus cytomegalovirus (RhCMV) genomes revealed that the region at the right end of the U(L) genome component (U(L)b') undergoes genetic alterations similar to those observed in serially passaged human cytomegalovirus (HCMV). To determine the coding content of authentic wild-type RhCMV in this region, the U(L)b' sequence was amplified from virus obtained from naturally infected rhesus macaques without passage in vitro. A total of 24 open reading frames (ORFs) potentially encoding >99 amino acid residues were identified, 10 of which are related to HCMV ORFs and 15 to previously listed RhCMV ORFs. In addition, the analysis revealed a cluster of three novel alpha chemokine-like ORFs, bringing the number of predicted alpha chemokine genes in this region to six. Three of these six genes exhibit a high level of sequence diversity, as has been observed for the HCMV alpha chemokine gene UL146.

Implicit with the use of animal models to test human cytomegalovirus (HCMV) vaccines is the assumption that the viral challenge of vaccinated animals reflects the anticipated virus-host interactions following exposure of vaccinated humans to HCMV. Variables of animal vaccine studies include the route of exposure to and the titer of challenge virus, as well as the genomic coding content of the challenge virus. This study was initiated to provide a better context for conducting vaccine trials with nonhuman primates by determining whether the in vivo phenotype of culture-passaged strains of rhesus cytomegalovirus (RhCMV) is comparable to that of wild-type RhCMV (RhCMV-WT), particularly in relation to the shedding of virus into bodily fluids and the potential for horizontal transmission. Results of this study demonstrate that two strains containing a fulllength UL/b region of the RhCMV genome, which encodes proteins involved in epithelial tropism and immune evasion, were persistently shed in large amounts in bodily fluids and horizontally transmitted, whereas a strain lacking a complete UL/b region was not shed or transmitted to cagemates. Shedding patterns exhibited by strains encoding a complete UL/b region were consistent with patterns observed in naturally infected monkeys, the majority of whom persistently shed high levels of virus in saliva for extended periods of time after seroconversion. Frequent viral shedding contributed to a high rate of infection, with RhCMV-infected monkeys transmitting virus to one naïve animal every 7 weeks after introduction of RhCMV-WT into an uninfected cohort. These results demonstrate that the RhCMV model can be designed to rigorously reflect the challenges facing HCMV vaccine trials, particularly those related to horizontal transmission.Human cytomegalovirus (HCMV) is a ubiquitous betaherpesvirus with a worldwide seroprevalence of 50 to Ͼ90% in adults (8,14). HCMV elicits a subclinical outcome for the majority of infections in immunocompetent individuals but is a significant pathogen in those without a fully functional immune system. Groups at increased risk for HCMV clinical sequelae include immunologically immature fetuses, immunosuppressed transplant recipients, and immunodeficient AIDS patients. The nearly 4-decade quest for a vaccine that confers protective immunity against HCMV infection has focused primarily on inhibiting primary infection in women without preconceptional immunity to HCMV to prevent transplacental transmission of the virus to the fetus (30). Progress on this front has been reported for a subunit vaccine directed at viral glycoprotein B (gB), which is essential for virus attachment to fibroblasts and is a prominent target of neutralizing antibodies during natural infection (38). A clinical trial with seronegative pregnant women demonstrated that vaccination against gB can reduce primary infection in the vaccine recipients by 50% compared to levels of infection in unvaccinated controls (49). The absence of complete protection in the vaccinees suggests that...

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, bioinformaticians and computational biologists. The diagrams of the C19DMap, curated from the literature, are integrated with relevant interaction and text mining databases. We demonstrate the application of network analysis and modelling approaches by concrete examples to highlight new testable hypotheses. This framework helps to find signatures of SARS-CoV-2 predisposition, treatment response or prioritisation of drug candidates. Such an approach may help deal with new waves of COVID-19 or similar pandemics in the long-term perspective.

SUMMARY GROWTH FACTORS AFFECTING OCULAR CELLSThe eye is a target tissue for peptide growth factors from all of the major families of growth factors: epidermal growth factor (EOF), fibroblasts growth factor (FOF), platelet-derived growth factor (PDOF) , insulin-like growth factor (IOF), and transforming growth factor beta (TOF�) (see references in reviews by Bennett and Schultzl.l and Schultz et aIY). ROLE OF TGFa IN OCULAR DEVELOPMENT AND WOUND HEALING

The use of animal models of human cytomegalovirus (HCMV) infection is critical to refine HCMV vaccine candidates. Previous reports have demonstrated that immunization of rhesus monkeys against rhesus cytomegalovirus (RhCMV) can reduce both local and systemic replication of RhCMV following experimental RhCMV challenge. These studies used prime/boost combinations of DNA expression plasmids alone or DNA priming and boosting with either inactivated virion particles or modified vaccinia virus Ankara (MVA) expressing the same antigens. Viral outcomes included reduced RhCMV replication at the site of subcutaneous inoculation and RhCMV viremia following intravenous inoculation. Since shedding of cytomegalovirus from mucosal surfaces is critical for horizontal transmission of the virus, DNA priming/MVA boosting was evaluated for the ability to reduce oral shedding of RhCMV following subcutaneous challenge. Of six rhesus monkeys vaccinated exclusively against RhCMV glycoprotein B (gB), phosphoprotein 65 (pp65), and immediate-early 1 (IE1), half showed viral loads in saliva that were lower than those of control monkeys by 1 to 3 orders of magnitude. Further, there was a strong association of memory pp65 T cell responses postchallenge in animals exhibiting the greatest reduction in oral shedding. These results highlight the fact that a DNA/MVA vaccination regimen can achieve a notable reduction in a critical parameter of viral replication postchallenge. The recently completed clinical trial of a gB subunit vaccine in which the rate of HCMV infection was reduced by 50% in the individuals receiving the vaccine is consistent with the results of this study suggesting that additional immunogens are likely essential for maximum protection in an outbred human population.The nearly 40-year quest for a vaccine that confers protective efficacy against congenital infection with human cytomegalovirus (HCMV) remains unmet, although considerable progress has been made. Complexities in HCMV's natural history, incompletely defined correlates of immune protection, and financial and logistical factors in designing sufficiently powered clinical trials all contribute to the absence of a licensed HCMV vaccine(s). Animal model studies with rhesus monkey, mouse, and guinea pig systems have demonstrated that multiple vaccine strategies, including approaches based on those proposed for HCMV, are effective at limiting the extent of challenge virus replication. Immunization of HCMV-negative women with recombinant gB has been clinically evaluated (50,51). A recently completed phase II trial assessed the efficacy of the vaccine to decrease cases of maternal HCMV infection (34). The endpoint of this study was the time to HCMV infection (50, 51), and the trial ended earlier than planned because vaccine efficacy exceeded goals. The results offer strong encouragement that vaccination regimes directed at prominent neutralizing epitopes can significantly decrease the rate of primary infection in HCMV-negative women. The impressive, but less than 100%, level ...