Proteomic Approaches to Dissect Host SUMOylation during Innate Antiviral Immune Responses

SUMOylation is a highly dynamic ubiquitin-like post-translational modification that is essential for cells to respond to and resolve various genotoxic and proteotoxic stresses. Virus infections also constitute a considerable stress scenario for cells, and recent research has started to uncover the diverse roles of SUMOylation in regulating virus replication, not least by impacting antiviral defenses. Here, we review some of the key findings of this virus-host interplay, and discuss the increasingly important contribution that large-scale, unbiased, proteomic methodologies are making to discoveries in this field. We highlight the latest proteomic technologies that have been specifically developed to understand SUMOylation dynamics in response to cellular stresses, and comment on how these techniques might be best applied to dissect the biology of SUMOylation during innate immunity. Furthermore, we showcase a selection of studies that have already used SUMO proteomics to reveal novel aspects of host innate defense against viruses, such as functional cross-talk between SUMO proteins and other ubiquitin-like modifiers, viral antagonism of SUMO-modified antiviral restriction factors, and an infection-triggered SUMO-switch that releases endogenous retroelement RNAs to stimulate antiviral interferon responses. Future research in this area has the potential to provide new and diverse mechanistic insights into host immune defenses.     

Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization

Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy.     

Predictors of delay in diagnosis and treatment in diffuse large B‐cell lymphoma and impact on survival

There is a paucity of data on the impact of diagnostic and treatment delays on outcomes in haematological malignancies, particularly in patients with diffuse large B‐cell lymphoma (DLBCL). Our database of patients treated for DLBCL between 2002 and 2010 was interrogated. Univariate and multivariate analyses were performed to determine the relationship between sociodemographic or disease‐specific variables and delays. Cox Regression analysis was used to discern the impact of delays on survival. Patients (n = 278) waited a median of 4 weeks before seeking medical attention. It took a median of 8 weeks for a non‐haematology physician to diagnose DLBCL and refer to a haematologist. A median of 3 weeks elapsed between specialist consultation and chemotherapy initiation. In multivariate logistic regression analysis, bone marrow involvement [odds ratio (OR) = 0·41, P = 0·018], Charlson comorbidity index (OR = 1·42, P = 0·017) and urgent inpatient chemotherapy (OR = 0·40, P = 0·012) were associated with diagnostic delays >6 weeks. Lack of pathological diagnosis at the time of haematology referral was the only factor that independently predicted for treatment delays >4 weeks (OR = 8·25, P < 0·01). Diagnostic or treatment delays did not impact survival or progression‐free survival. In conclusion, selected disease and patient‐related factors are associated with delays in management of DLBCL, but do not impact outcomes.     

The molecular basis of pediatric long chain 3-hydroxyacyl-CoA dehydrogenase deficiency associated with maternal acute fatty liver of pregnancy.

Mitochondrial long chain fatty acid beta-oxidation provides the major source of energy in the heart. Deficiencies of human beta-oxidation enzymes produce sudden, unexplained death in childhood, acute hepatic encephalopathy, skeletal myopathy, or cardiomyopathy. Long chain 3-hydroxyacyl-CoA dehydrogenase [LCHAD; long-chain-(S)-3-hydroxyacyl-CoA:NAD+ oxidoreductase, EC 1.1.1.211] catalyzes the third step in beta-oxidation, and this activity is present on the C-terminal portion of the alpha subunit of mitochondrial trifunctional protein. We used single-stranded conformation variance analysis of the exons of the human LCHAD (alpha subunit) gene to determine the molecular basis of LCHAD deficiency in three families with children presenting with sudden unexplained death or hypoglycemia and abnormal liver enzymes (Reye-like syndrome). In all families, the mothers had acute fatty liver and associated sever complications during pregnancies with the affected infants. The analysis in two affected children revealed a G to C mutation at position 1528 (G1528C) of the alpha subunit of the trifunctional protein on both alleles. This is in the LCHAD domain and substitutes glutamine for glutamic acid at position 474 of mature alpha subunit. The third child had this G1528C mutation on one allele and a different mutation (C1132T) creating a premature termination codon (residue 342) on the second allele. Our results demonstrate that mutations in the LCHAD domain of the trifunctional protein alpha subunit in affected offspring are associated with maternal acute fatty liver of pregnancy. This is the initial delineation of the molecular basis of isolated LCHAD deficiency.     

Barriers and Facilitators to Online Portal Use Among Patients and Caregivers in a Safety Net Health Care System: A Qualitative Study

Background

Patient portals have the potential to support self-management for chronic diseases and improve health outcomes. With the rapid rise in adoption of patient portals spurred by meaningful use incentives among safety net health systems (a health system or hospital providing a significant level of care to low-income, uninsured, and vulnerable populations), it is important to understand the readiness and willingness of patients and caregivers in safety net settings to access their personal health records online.

Objective

To explore patient and caregiver perspectives on online patient portal use before its implementation at San Francisco General Hospital, a safety net hospital.

Methods

We conducted 16 in-depth interviews with chronic disease patients and caregivers who expressed interest in using the Internet to manage their health. Discussions focused on health care experiences, technology use, and interest in using an online portal to manage health tasks. We used open coding to categorize all the barriers and facilitators to portal use, followed by a second round of coding that compared the categories to previously published findings. In secondary analyses, we also examined specific barriers among 2 subgroups: those with limited health literacy and caregivers.

Results

We interviewed 11 patients and 5 caregivers. Patients were predominantly male (82%, 9/11) and African American (45%, 5/11). All patients had been diagnosed with diabetes and the majority had limited health literacy (73%, 8/11). The majority of caregivers were female (80%, 4/5), African American (60%, 3/5), caregivers of individuals with diabetes (60%, 3/5), and had adequate health literacy (60%, 3/5). A total of 88% (14/16) of participants reported interest in using the portal after viewing a prototype. Major perceived barriers included security concerns, lack of technical skills/interest, and preference for in-person communication. Facilitators to portal use included convenience, health monitoring, and improvements in patient-provider communication. Participants with limited health literacy discussed more fundamental barriers to portal use, including challenges with reading and typing, personal experience with online security breaches/viruses, and distrust of potential security measures. Caregivers expressed high interest in portal use to support their roles in interpreting health information, advocating for quality care, and managing health behaviors and medical care.

Conclusions

Despite concerns about security, difficulty understanding medical information, and satisfaction with current communication processes, respondents generally expressed enthusiasm about portal use. Our findings suggest a strong need for training and support to assist vulnerable patients with portal registration and use, particularly those with limited health literacy. Efforts to encourage portal use among vulnerable patients should directly address health literacy and security/privacy issues and support access for caregivers.