Margaret K. Hostetter, MD
Research in the Hostetter laboratory has expanded into three main areas. (1) Heparin binding motifs in Candida albicans and their role in biofilm. After identifying 55 C. albicans proteins that contain putative heparin binding motifs, Kris Orsborn and Julianne Green showed that alanine mutation of a particular motif decreased heparin binding. An antibody made to a peptide encompassing the most potent heparin binding motif inhibited binding to heparin in vitro. In vivo studies in a biofilm model are underway. (2) Role of candidal vaginal colonization in preterm birth. Aashvini Belosay, PhD, is currently characterizing the cytokine profile released by C. albicans incubated with vaginal epithelium. (3) Genetics of disseminated staphylococcal osteomyelitis. Exome sequencing of parent/child trios identified de novo mutations implicating a novel pathway for susceptibility to disseminated staphylococcal disease. In vitro experiments to identify the functional correlates of these mutations are underway.
David I. Bernstein, MD, MA
The pivotal trial for a genital herpes vaccine composed of herpes simplex type 2 glycoprotein D (cd) and adjuvanted with MPL and Alum was published in the NEJM. Although two large trials showed efficacy in women this trial showed no efficacy for prevention of genital herpes caused by HSV type 2 (HSV-2) but surprisingly demonstrated efficacy against HSV-1 genital herpes. Therefore we have begun evaluations using a different vaccine strategy, live attenuated HSV vaccines. To date the live vaccine has proven to be more effective than the gD vaccine in our animal model of genital herpes. We have also completed enrollment in the largest study of congenital CMV, enrolling 100,000 newborns at 6 centers around the USA. Results will more accurately determine the burden of disease in diverse populations.
Turning to GI viruses we completed the first human trial of a vaccine for norovirus and found it to be moderately protective as noted in the recent NEJM publication. We are currently directing a study of a new bivalent vaccine which will evaluate safety and efficacy. The rotavirus vaccine we developed continued to prevent hospitalizations and deaths around the world.
Rebecca Brady, MD
For this period, approximately 60% of Dr. Brady's effort was devoted to clinical patient care. She was the CCHMC lead investigator for an NIH, DMID‐sponsored clinical trial of influenza vaccines in post‐partum breastfeeding women and their infants. Dr. Brady also served as a co‐investigator for many clinical trials performed at the Gamble Program for Clinical Studies, CCHMC Infectious Diseases Division.
Rhonda Cardin, PhD
The Cardin lab previously showed that the viral chemokine receptor M33 encoded by murine cytomegalovirus (CMV) is required for long term latent infection of the bone marrow. In 2011, we pursued the identification of cell types in the bone marrow and spleen of mice which are latently infected with cytomegalovirus using a combination of immunomagnetic bead enrichment and cell sorting. We have identified several myeloid lineage cells which could harbor latent virus and are in the process of demonstrating that virus can be recovered from these populations. In collaboration with Dr. Helen Farrell in Australia, we continue to characterize the role of the cytomegalovirus-encoded chemokine receptors during infection. Also, in collaboration with Dr. David Bernstein, we have characterized several new guinea pig cytomegalovirus isolates which will be a useful tool for understanding multi-strain congenital CMV infection in newborn infants as well as for evaluation of vaccine strategies in our guinea pig cytomegalovirus model. In our studies, we find that the newly isolated guinea pig cytomegalovirus crosses the placenta and infects the developing fetus. Human CMV is the leading infectious cause of congenital hearing loss, with approximately 0.5-2.0% of newborn infants experiencing hearing loss within the first 2-4 years of life. Our next studies will determine whether co-infection of pregnant guinea pigs with multiple strains of guinea pig cytomegalovirus leads to increased hearing loss in the newborn guinea pigs. Lastly, we have characterized a live-attenuated HSV-2 vaccine in our guinea pig model of genital herpes, and although promising, further studies are needed to show that the vaccine controls recurrent vaginal shedding, and thus, would be a useful vaccine which limits HSV-2 transmission.
Beverly Connelly, MD
Dr. Connelly's focus is on hospital quality improvement, specifically in reducing healthcare associated infections. She has collaborations hospital-wide, with major efforts on the reduction of surgical site infections and has centered efforts in the area of spinal fusion procedures with spin-offs for all device associated infections.
Tibor Farkas, PhD, DVM
In 2011, we completed a pilot study to establish the pathobiology of recovirus infection by experimental inoculation of rhesus macaques with the prototype Tulane virus (PLoS One, 2012). We demonstrated the development of acute gastroenteritis (diarrhea, fever, seroconversion, virus shedding) and the presence of TV in cells in the lamina propria of duodenal biopsies but not in enterocytes. This study along with our previous studies further indicates that recoviruses are a promising surrogate and disease model for human noroviruses. In a separate study that investigated the prevalence of recoviruses, we obtained serological evidence for recovirus infections in several non-human primate species (not only in rhesus macaques) and in both conventional and SPF colonies in several National Primate Research Centers (NPRC). The significance and economic impact of recovirus gastroenteritis in NPRCs were also estimated (J. Med. Primatology, 2012).
We continued our work on the molecular characterization of novel avian picornaviruses that were identified in our laboratory last year (Virus Genes, 2011). In a new study that targeted the identification of novel enteric RNA viruses in wild and laboratory rodents, we described novel picorna-, noro- and astroviruses in both laboratory and wild mice (Veterinary Microbiology, 2012 and Virus Genes, in revision). These findings suggest that our understanding of the complexity of the rodent enteric viral flora is still limited. Viruses described in laboratory mice are relevant to biomedical research that heavily relies on the mouse model. Because of the diversity of rodent species and their pivotal role as vectors or reservoirs in the spread of several human infectious diseases, coupled with the unknown diversity and often close relationship of rodent enteric viruses to human pathogens these findings can also have public health relevance.
Robert W. Frenck, MD
Dr. Frenck continues with his interest in clinical vaccine trials with special interest in enteric diseases and vaccines to prevent the infections. The successful completion of the first ever human challenge model with a G2 strain of norovirus led to collaboration with an industrial partner, LigoCyte, to test the efficacy of their candidate G2 norovirus vaccine in preventing norovirus among people administered the G2 challenge strain. Dr. Frenck also is heading a VTEU project to test the safety and immunogenicity of a vaccine against Shigella sonnei, the most common cause of Shigella in the United States. Finally, Dr. Frenck continues to head efforts at CCHMC testing candidate vaccines against Staphylococcus aureus and Streptococcus pneumoniae. His work on the S. pneumoniae vaccine was integral to the data collected which led to the licensure of the 13-valent conjugate pneumococcal vaccine in children and more recently adults.
Jason Jiang, PhD
Noroviruses (NVs) and rotaviruses (RVs) are two important causes of acute gastroenteritis. In the past year we have made significant progress in understanding the virus/host interaction and receptors for the two virus species. For norovirus, we have completed the first human volunteer challenge study on a GII.4 norovirus and demonstrated a strong association of GII.4 infection with the histo-blood types of the volunteers. Following this study, we initiated two additional studies: 1) further improve the model by determining the minimal doses of the challenge pool, and 2) apply the human challenge model to evaluate a norovirus VLP vaccine (both studies were funded by LigoCyte). In the study of developing norovirus P particle vaccine, we have established a norovirus challenge model using gnotobiotic pigs (collaboration with Virginia Tech). We also performed translation studies on designing antivirals and antibodies (chicken IgYs) against norovirus for potential therapeutic and prophylactic treatment against noroviruses. For rotavirus, we discovered a new receptor binding pattern of rotaviruses recognizing the type A antigens by characterization of three strains in another [P] genogroup from those described in our previous studies. We also performed a comprehensive phylogenetic analysis of rotaviruses based on sequences of the surface spike protein VP8* of rotaviruses, which is important for future study on the genetic relatedness of rotaviruses with HBGAs. Our P particle presented rotavirus chimeric vaccine candidates have been licensed to PATH and LigoCyte for further development. Furthermore, our studies on the evaluation of TV as a surrogate for human noroviruses are ongoing. Finally, we have initiated a new study on characterization of norovirus replication in human intestinal organoids developed from stem cells with some interesting observations. This study will be continued in the near future.
Monica M. McNeal, MS
The Laboratory for Specialized Clinical Studies provides lab support for a large number of clinical studies involving vaccine trials and vaccine development. Influenza virus vaccines and rotavirus vaccines continue to be important for overall health of children in the US and around the world. The lab is committed to help establish clinical labs in India to support rotavirus vaccine trials in that country. In addition, the lab consults with other labs around the world to provide training and support for establishing quality assays to support vaccine trials. Additional projects include using animal models to investigate the effects of malnutrition on oral rotavirus vaccines and the anti-viral effects of hyaluronan regulation of host defenses in the intestinal tract.
We have continued to support rotavirus vaccine trials conducted in numerous countries around the world. We are analyzing clinical samples collected from a trial conducted in a developing country aimed at increasing the effectiveness of rotavirus vaccines and are scheduled to participate in several more trials in the upcoming year. We have continued our support for developing laboratory capabilities in India to support rotavirus vaccine trials in that country. A new project this year is to develop an animal model to look at malnutrition and intestinal enteropathy in relation to rotavirus vaccine take. Another new project involves developing and qualifying new assays to measure antibody responses to new rotavirus vaccines. We have continued our support of influenza vaccine trials by running assays to determine the responses after vaccination. We have developed and qualified a neutralization assay for influenza and are using this assay in a number of clinical trials. We are continuing our lab support for a CMV vaccine trial and are developing a neutralization assay for this study. We are continuing our support for surveillance studies involving rotavirus and respiratory infections and have added a realtime rt-PCR assay to quantify norovirus in stool samples from children less than 5 years of age. Most recently we have been chosen to support a Shigella vaccine trial and have transferred assays and technology to the lab for these future studies.
Nancy Sawtell, PhD
Most of the human population world-wide has been infected by herpes simplex viruses. Following the initial lytic infection, HSVs establish permanent latent infections within neurons in both the peripheral and central nervous systems. Reactivation of latent virus not only results in viral disease (new infections, blindness and encephalitis) but also contributes to HIV infection, diabetes, cardiovascular and neurodegenerative diseases. No effective vaccine is available and no therapy eliminates latency or prevents reactivation. The long-term goal of ongoing research in the Sawtell lab is to find interventions for recurrent HSV episodes by defining mechanisms that control establishment and reactivation of HSV-1 latency. The gene expression cascade during HSV-1 lytic infection begins with activation of immediate-early (IE) gene transcription by the virion protein VP16 with host factors Oct-1 and HCF-1. In contrast, the initial events in the reactivation from latency are still poorly defined. Our central hypothesis is that regulation of both VP16 expression and activity underlie the establishment of latency and reactivation from latency. These two levels of control involve multiple positive and negative inputs to allow or inhibit viral replication in the neuron in vivo. An additional focus of the lab is to determine the influence of host genetics on the HSV disease outcome. Utilizing advanced recombinant inbred mice together with a group of low passage clinical isolates is allowing us to map the intersection between host and viral genetics.
Elizabeth Schlaudecker, MD, MPH
Dr. Schlaudecker has studied the immunologic response to influenza immunization in pregnant women with the support of a Procter Scholars award. The hemagglutination inhibition titers were significantly decreased in pregnant women compared to non-pregnant women after immunization, suggesting that pregnant women may demonstrate a less robust response to immunization.
Mary Staat, MD, MPH
Through Dr. Staat’s large epidemiology and surveillance program developed in 1997, she has been able to develop optimal methods of detecting the changes and manifestations of infectious diseases of children within CCHMC and for the population of Hamilton County, and to compare these findings to national trends. Recognizing that CCHMC captures essentially all Hamilton County children requiring hospitalization or care in the emergency department has allowed Dr. Staat to conduct studies to determine the population-based rates of Hamilton County hospitalizations and emergency department visits for many pediatric infectious diseases using unique methods such as capture-recapture methods to determine disease burden and case-cohort and case-control designs to determine the post-licensure effectiveness of rotavirus and influenza vaccines. Studies published last year included the effectiveness of rotavirus vaccine post-licensure, the direct and indirect effects of the rotavirus immunization program, parent and physician perspectives on porcine circovirus and rotavirus vaccine and the post-licensure effectiveness of influenza vaccine in children.
Dr. Staat has also utilized data from her large international adoption center to publish studies to assist in the development of evidence-based guidelines for internationally adopted children. This past year, her manuscript on the country-specific prevalence of intestinal parasites and the optimal protocol for screening stool specimens was published.
Ming Tan, PhD
Dr. Tan's research focused on two directions: 1) development of norovirus (NoV) P protein-based complexes into useful vaccines and vaccine platforms and 2) elucidation of NoV-host interaction. For the first direction, we have provided solid evidence to show the NoV P particle as a capable platform for antigen presentation. A chimeric P particle containing the spike protein VP8* of rotavirus (RV) has been shown to be a good dual vaccine candidate against both NoVs and RVs. The technology of P particle-VP8* chimeric vaccine has been licensed to LigoCyte and PATH Vaccine Solution, a pharmaceutical and a vaccine company, respectively, for further development under support from Bill and Melinda Gate Foundation. In addition, we have developed a new protein complex system to turn dimeric/oligomeric antigens into large, polyvalent complexes for increased immunogenicity. This protein complex system can be used as multivalent vaccines and vaccine platforms. For the second direction, we elucidated the structures of histo-blood group antigen (HBGA) binding sites of two more NoVs, a GII.9 and a GI.8 strains, which shed light into the complex interactions between the diverse NoV and polymorphic HBGAs. These similar interactions have been recently extended to RVs. A number of papers have been published and a new patent has been applied. Our research outcomes provide valuable data and strategies for future development of vaccine and antivirals against NoVs and other infectious diseases.