Publications by authors named "Jessica Prince"

23 Publications

  • Page 1 of 1

Radiosensitisation of Hepatocellular Carcinoma Cells by Vandetanib.

Cancers (Basel) 2020 Jul 13;12(7). Epub 2020 Jul 13.

University College London Cancer Institute, University College London, London WC1E 6BT, UK.

Hepatocellular Carcinoma (HCC) is increasing in incidence worldwide and requires new approaches to therapy. The combination of anti-angiogenic drug therapy and radiotherapy is one promising new approach. The anti-angiogenic drug vandetanib is a tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) and RET proto-oncogene with radio-enhancement potential. To explore the benefit of combined vandetanib and radiotherapy treatment for HCC, we studied outcomes following combined treatment in pre-clinical models.

Methods: Vandetanib and radiation treatment were combined in HCC cell lines grown and . In addition to 2D migration and clonogenic assays, the combination was studied in 3D spheroids and a syngeneic mouse model of HCC.

Results: Vandetanib IC 50 s were measured in 20 cell lines and the drug was found to significantly enhance radiation cell kill and to inhibit both cell migration and invasion . , combination therapy significantly reduced cancer growth and improved overall survival, an effect that persisted for the duration of vandetanib treatment.

Conclusion: In 2D and 3D studies and in a syngeneic model , the combination of vandetanib plus radiotherapy was more efficacious than either treatment alone. This new combination therapy for HCC merits evaluation in clinical trials.
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http://dx.doi.org/10.3390/cancers12071878DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7408860PMC
July 2020

Is spiritual care required in the GP training pathway?

Educ Prim Care 2019 11 17;30(6):395. Epub 2019 Sep 17.

University of Oxford.

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http://dx.doi.org/10.1080/14739879.2019.1666304DOI Listing
November 2019

Views regarding the report: 'Improving GP websites- the perspective of teenagers' by Bruce et al. (2019).

Educ Prim Care 2019 11 7;30(6):398. Epub 2019 Sep 7.

Medical Sciences Division, University of Oxford,

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http://dx.doi.org/10.1080/14739879.2019.1663134DOI Listing
November 2019

Protective HLA alleles are associated with reduced LPS levels in acute HIV infection with implications for immune activation and pathogenesis.

PLoS Pathog 2019 08 26;15(8):e1007981. Epub 2019 Aug 26.

Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America.

Despite extensive research on the mechanisms of HLA-mediated immune control of HIV-1 pathogenesis, it is clear that much remains to be discovered, as exemplified by protective HLA alleles like HLA-B*81 which are associated with profound protection from CD4+ T cell decline without robust control of early plasma viremia. Here, we report on additional HLA class I (B*1401, B*57, B*5801, as well as B*81), and HLA class II (DQB1*02 and DRB1*15) alleles that display discordant virological and immunological phenotypes in a Zambian early infection cohort. HLA class I alleles of this nature were also associated with enhanced immune responses to conserved epitopes in Gag. Furthermore, these HLA class I alleles were associated with reduced levels of lipopolysaccharide (LPS) in the plasma during acute infection. Elevated LPS levels measured early in infection predicted accelerated CD4+ T cell decline, as well as immune activation and exhaustion. Taken together, these data suggest novel mechanisms for HLA-mediated immune control of HIV-1 pathogenesis that do not necessarily involve significant control of early viremia and point to microbial translocation as a direct driver of HIV-1 pathogenesis rather than simply a consequence.
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http://dx.doi.org/10.1371/journal.ppat.1007981DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6730937PMC
August 2019

Frontline Science: Late CD27 stimulation promotes IL-7Rα transcriptional re-expression and memory T cell qualities in effector CD8 T cells.

J Leukoc Biol 2019 11 14;106(5):1007-1019. Epub 2019 Jun 14.

Department of Pathology and Human Immune Therapy Center, University of Virginia, Charlottesville, Virginia, 22908, USA.

We previously demonstrated that CD27 co-stimulation during a primary CD8 T-cell response was critical for the expression of IL-7Rα on acute effector CD8 T cells, providing an essential element in the generation of CD8 T-cell memory to infectious pathogens. IL-7 plays a critical role in the generation and maintenance of memory CD8 T cells, and IL-7Rα has been regarded as a functional marker of long-lived memory precursor effector cells. While IL-7Rα is downregulated acutely upon TCR stimulation, the regulation of the emergence of IL-7Rα expressing cells around the peak of primary CD8 responses is less clear. Re-expression could be a default outcome after withdrawal of TCR stimulation. Alternatively, specific stimuli could actively antagonize the downregulation or promote the recovery of IL-7Rα in Ag-activated CD8 T cells. By utilizing agonistic mAb and transgenic models, here we show: (1) CD27 stimulation acts directly on CD8 T cells to enhance IL-7Rα-expressing effectors; (2) CD27 stimulation neither alleviates the downregulation of IL-7Rα upon TCR signaling nor promotes the expansion/survival of IL-7Rα-expressing effectors, but facilitates IL-7Rα re-expression; (3) CD27 stimulation regulates Il7ra mRNA abundance but not protein distribution. Importantly, CD27 stimulation promotes not only IL-7Rα, but also the common γ chain of the receptor and the downstream signaling mediated by pSTAT5. Our results demonstrate a previously unappreciated role of CD27 stimulation as a positive regulator of IL-7Rα during CD8 T-cell responses, provide insights into the mechanistic basis by which CD27 stimulation influences CD8 T-cell memory differentiation, and highlight the potential of targeting CD27-CD70 axis to enhance IL-7 signaling for antiviral/antitumor immunotherapy.
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http://dx.doi.org/10.1002/JLB.1HI0219-064RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6824422PMC
November 2019

Diacylglycerol Lipase-β Is Required for TNF-α Response but Not CD8 T Cell Priming Capacity of Dendritic Cells.

Cell Chem Biol 2019 07 16;26(7):1036-1041.e3. Epub 2019 May 16.

Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319 Charlottesville, VA 22904, USA; Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; University of Virginia Cancer Center, University of Virginia, Charlottesville, VA 22903, USA. Electronic address:

Diacylglycerol lipase-β (DAGLβ) hydrolyzes arachidonic acid (AA)-esterified diacylglycerols to produce 2-arachidonoylglycerol (2-AG) and downstream prostanoids that mediate inflammatory responses of macrophages. Here, we utilized DAGL-tailored activity-based protein profiling and genetic disruption models to discover that DAGLβ regulates inflammatory lipid and protein signaling pathways in primary dendritic cells (DCs). DCs serve as an important link between innate and adaptive immune pathways by relaying innate signals and antigen to drive T cell clonal expansion and prime antigen-specific immunity. We discovered that disruption of DAGLβ in DCs lowers cellular 2-AG and AA that is accompanied by reductions in lipopolysaccharide (LPS) stimulated tumor necrosis factor α secretion. Cell-based vaccination studies revealed that DC maturation ex vivo and immunogenicity in vivo was surprisingly unaffected by DAGLβ inactivation. Collectively, we identify DAGLβ pathways as a means for attenuating DC inflammatory signaling while sparing critical adaptive immune functions and further expand the utility of targeting lipid pathways for immunomodulation.
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http://dx.doi.org/10.1016/j.chembiol.2019.04.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6641989PMC
July 2019

Small bowel adenocarcinoma in a patient with Lynch syndrome.

BMJ Case Rep 2018 Aug 16;2018. Epub 2018 Aug 16.

General surgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.

A 49-year-old male patient, morbidly obese, with a background of Lynch syndrome and subtotal colectomy for colon cancer in 2007, presented with severe abdominal pain in December 2015. Since then, the patient presented multiple times to the emergency department with severe diffuse abdominal pain. After extensive examination, no clear cause for the pain was identified and it was thought to be secondary to adhesions, incisional hernias and psychological. Examinations via radiological imaging were challenging due to body habitus and claustrophobia. In September 2017, the patient was admitted from outpatient clinic with severe abdominal pain, weight loss and anaemia. A CT scan of abdomen and pelvis demonstrated a dilated jejunal loop with a possible tumour. Surgery confirmed a small bowel tumour and, nearly 2 years after the initial presentation, the patient was diagnosed with adenocarcinoma of the jejenum. The patient underwent surgical excision and his symptoms subsided.
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http://dx.doi.org/10.1136/bcr-2018-225273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6101339PMC
August 2018

HLA Class I Downregulation by HIV-1 Variants from Subtype C Transmission Pairs.

J Virol 2018 04 14;92(7). Epub 2018 Mar 14.

Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA

HIV-1 downregulates human leukocyte antigen A (HLA-A) and HLA-B from the surface of infected cells primarily to evade CD8 T cell recognition. HLA-C was thought to remain on the cell surface and bind inhibitory killer immunoglobulin-like receptors, preventing natural killer (NK) cell-mediated suppression. However, a recent study found HIV-1 primary viruses have the capacity to downregulate HLA-C. The goal of this study was to assess the heterogeneity of HLA-A, HLA-B, and HLA-C downregulation among full-length primary viruses from six chronically infected and six newly infected individuals from transmission pairs and to determine whether transmitted/founder variants exhibit common HLA class I downregulation characteristics. We measured HLA-A, HLA-B, HLA-C, and total HLA class I downregulation by flow cytometry of primary CD4 T cells infected with 40 infectious molecular clones. Primary viruses mediated a range of HLA class I downregulation capacities (1.3- to 6.1-fold) which could differ significantly between transmission pairs. Downregulation of HLA-C surface expression on infected cells correlated with susceptibility to NK cell suppression of virus release. Despite this, transmitted/founder variants did not share a downregulation signature and instead were more similar to the quasispecies of matched donor partners. These data indicate that a range of viral abilities to downregulate HLA-A, HLA-B, and HLA-C exist within and between individuals that can have functional consequences on immune recognition. Subtype C HIV-1 is the predominant subtype involved in heterosexual transmission in sub-Saharan Africa. Authentic subtype C viruses that contain natural sequence variations throughout the genome often are not used in experimental systems due to technical constraints and sample availability. In this study, authentic full-length subtype C viruses, including transmitted/founder viruses, were examined for the ability to disrupt surface expression of HLA class I molecules, which are central to both adaptive and innate immune responses to viral infections. We found that the HLA class I downregulation capacity of primary viruses varied, and HLA-C downregulation capacity impacted viral suppression by natural killer cells. Transmitted viruses were not distinct in the capacity for HLA class I downregulation or natural killer cell evasion. These results enrich our understanding of the phenotypic variation existing among natural HIV-1 viruses and how that might impact the ability of the immune system to recognize infected cells in acute and chronic infection.
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http://dx.doi.org/10.1128/JVI.01633-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5972908PMC
April 2018

Wide variation in susceptibility of transmitted/founder HIV-1 subtype C Isolates to protease inhibitors and association with in vitro replication efficiency.

Sci Rep 2016 11 30;6:38153. Epub 2016 Nov 30.

Emory Vaccine Centre, Atlanta GA, USA.

The gag gene is highly polymorphic across HIV-1 subtypes and contributes to susceptibility to protease inhibitors (PI), a critical class of antiretrovirals that will be used in up to 2 million individuals as second-line therapy in sub Saharan Africa by 2020. Given subtype C represents around half of all HIV-1 infections globally, we examined PI susceptibility in subtype C viruses from treatment-naïve individuals. PI susceptibility was measured in a single round infection assay of full-length, replication competent MJ4/gag chimeric viruses, encoding the gag gene and 142 nucleotides of pro derived from viruses in 20 patients in the Zambia-Emory HIV Research Project acute infection cohort. Ten-fold variation in susceptibility to PIs atazanavir and lopinavir was observed across 20 viruses, with ECs ranging 0.71-6.95 nM for atazanvir and 0.64-8.54 nM for lopinavir. Ten amino acid residues in Gag correlated with lopinavir EC (p < 0.01), of which 380 K and 389I showed modest impacts on in vitro drug susceptibility. Finally a significant relationship between drug susceptibility and replication capacity was observed for atazanavir and lopinavir but not darunavir. Our findings demonstrate large variation in susceptibility of PI-naïve subtype C viruses that appears to correlate with replication efficiency and could impact clinical outcomes.
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http://dx.doi.org/10.1038/srep38153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5128871PMC
November 2016

Balance between transmitted HLA preadapted and nonassociated polymorphisms is a major determinant of HIV-1 disease progression.

J Exp Med 2016 09 22;213(10):2049-63. Epub 2016 Aug 22.

Emory Vaccine Center, Emory University, Atlanta, GA 30322 Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322

HIV-1 adapts to a new host through mutations that facilitate immune escape. Here, we evaluate the impact on viral control and disease progression of transmitted polymorphisms that were either preadapted to or nonassociated with the new host's HLA. In a cohort of 169 Zambian heterosexual transmission pairs, we found that almost one-third of possible HLA-linked target sites in the transmitted virus Gag protein are already adapted, and that this transmitted preadaptation significantly reduced early immune recognition of epitopes. Transmitted preadapted and nonassociated polymorphisms showed opposing effects on set-point VL and the balance between the two was significantly associated with higher set-point VLs in a multivariable model including other risk factors. Transmitted preadaptation was also significantly associated with faster CD4 decline (<350 cells/µl) and this association was stronger after accounting for nonassociated polymorphisms, which were linked with slower CD4 decline. Overall, the relative ratio of the two classes of polymorphisms was found to be the major determinant of CD4 decline in a multivariable model including other risk factors. This study reveals that, even before an immune response is mounted in the new host, the balance of these opposing factors can significantly influence the outcome of HIV-1 infection.
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http://dx.doi.org/10.1084/jem.20151984DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5030801PMC
September 2016

Genomic Modifiers of Natural Killer Cells, Immune Responsiveness and Lymphoid Tissue Remodeling Together Increase Host Resistance to Viral Infection.

PLoS Pathog 2016 Feb 4;12(2):e1005419. Epub 2016 Feb 4.

Department of Medicine, Division of Nephrology, University of Virginia, Charlottesville, Virginia, United States of America.

The MHC class I D(k) molecule supplies vital host resistance during murine cytomegalovirus (MCMV) infection. Natural killer (NK) cells expressing the Ly49G2 inhibitory receptor, which specifically binds D(k), are required to control viral spread. The extent of D(k)-dependent host resistance, however, differs significantly amongst related strains of mice, C57L and MA/My. As a result, we predicted that relatively small-effect modifier genetic loci might together shape immune cell features, NK cell reactivity, and the host immune response to MCMV. A robust D(k)-dependent genetic effect, however, has so far hindered attempts to identify additional host resistance factors. Thus, we applied genomic mapping strategies and multicolor flow cytometric analysis of immune cells in naive and virus-infected hosts to identify genetic modifiers of the host immune response to MCMV. We discovered and validated many quantitative trait loci (QTL); these were mapped to at least 19 positions on 16 chromosomes. Intriguingly, one newly discovered non-MHC locus (Cmv5) controlled splenic NK cell accrual, secondary lymphoid organ structure, and lymphoid follicle development during MCMV infection. We infer that Cmv5 aids host resistance to MCMV infection by expanding NK cells needed to preserve and protect essential tissue structural elements, to enhance lymphoid remodeling and to increase viral clearance in spleen.
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http://dx.doi.org/10.1371/journal.ppat.1005419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4742223PMC
February 2016

Replicative fitness of transmitted HIV-1 drives acute immune activation, proviral load in memory CD4+ T cells, and disease progression.

Proc Natl Acad Sci U S A 2015 Mar 17;112(12):E1480-9. Epub 2015 Feb 17.

Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329; Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322;

HIV-1 infection is characterized by varying degrees of chronic immune activation and disruption of T-cell homeostasis, which impact the rate of disease progression. A deeper understanding of the factors that influence HIV-1-induced immunopathology and subsequent CD4(+) T-cell decline is critical to strategies aimed at controlling or eliminating the virus. In an analysis of 127 acutely infected Zambians, we demonstrate a dramatic and early impact of viral replicative capacity (vRC) on HIV-1 immunopathogenesis that is independent of viral load (VL). Individuals infected with high-RC viruses exhibit a distinct inflammatory cytokine profile as well as significantly elevated T-cell activation, proliferation, and CD8(+) T-cell exhaustion, during the earliest months of infection. Moreover, the vRC of the transmitted virus is positively correlated with the magnitude of viral burden in naive and central memory CD4(+) T-cell populations, raising the possibility that transmitted viral phenotypes may influence the size of the initial latent viral reservoir. Taken together, these findings support an unprecedented role for the replicative fitness of the founder virus, independent of host protective genes and VL, in influencing multiple facets of HIV-1-related immunopathology, and that a greater focus on this parameter could provide novel approaches to clinical interventions.
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http://dx.doi.org/10.1073/pnas.1421607112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4378387PMC
March 2015

Transmitted virus fitness and host T cell responses collectively define divergent infection outcomes in two HIV-1 recipients.

PLoS Pathog 2015 Jan 8;11(1):e1004565. Epub 2015 Jan 8.

Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America; Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America.

Control of virus replication in HIV-1 infection is critical to delaying disease progression. While cellular immune responses are a key determinant of control, relatively little is known about the contribution of the infecting virus to this process. To gain insight into this interplay between virus and host in viral control, we conducted a detailed analysis of two heterosexual HIV-1 subtype A transmission pairs in which female recipients sharing three HLA class I alleles exhibited contrasting clinical outcomes: R880F controlled virus replication while R463F experienced high viral loads and rapid disease progression. Near full-length single genome amplification defined the infecting transmitted/founder (T/F) virus proteome and subsequent sequence evolution over the first year of infection for both acutely infected recipients. T/F virus replicative capacities were compared in vitro, while the development of the earliest cellular immune response was defined using autologous virus sequence-based peptides. The R880F T/F virus replicated significantly slower in vitro than that transmitted to R463F. While neutralizing antibody responses were similar in both subjects, during acute infection R880F mounted a broad T cell response, the most dominant components of which targeted epitopes from which escape was limited. In contrast, the primary HIV-specific T cell response in R463F was focused on just two epitopes, one of which rapidly escaped. This comprehensive study highlights both the importance of the contribution of the lower replication capacity of the transmitted/founder virus and an associated induction of a broad primary HIV-specific T cell response, which was not undermined by rapid epitope escape, to long-term viral control in HIV-1 infection. It underscores the importance of the earliest CD8 T cell response targeting regions of the virus proteome that cannot mutate without a high fitness cost, further emphasizing the need for vaccines that elicit a breadth of T cell responses to conserved viral epitopes.
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http://dx.doi.org/10.1371/journal.ppat.1004565DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4287535PMC
January 2015

A restriction enzyme based cloning method to assess the in vitro replication capacity of HIV-1 subtype C Gag-MJ4 chimeric viruses.

J Vis Exp 2014 Aug 31(90). Epub 2014 Aug 31.

Emory Vaccine Center at Yerkes National Primate Research Center, Emory University; Department of Pathology and Laboratory Medicine, Emory University;

The protective effect of many HLA class I alleles on HIV-1 pathogenesis and disease progression is, in part, attributed to their ability to target conserved portions of the HIV-1 genome that escape with difficulty. Sequence changes attributed to cellular immune pressure arise across the genome during infection, and if found within conserved regions of the genome such as Gag, can affect the ability of the virus to replicate in vitro. Transmission of HLA-linked polymorphisms in Gag to HLA-mismatched recipients has been associated with reduced set point viral loads. We hypothesized this may be due to a reduced replication capacity of the virus. Here we present a novel method for assessing the in vitro replication of HIV-1 as influenced by the gag gene isolated from acute time points from subtype C infected Zambians. This method uses restriction enzyme based cloning to insert the gag gene into a common subtype C HIV-1 proviral backbone, MJ4. This makes it more appropriate to the study of subtype C sequences than previous recombination based methods that have assessed the in vitro replication of chronically derived gag-pro sequences. Nevertheless, the protocol could be readily modified for studies of viruses from other subtypes. Moreover, this protocol details a robust and reproducible method for assessing the replication capacity of the Gag-MJ4 chimeric viruses on a CEM-based T cell line. This method was utilized for the study of Gag-MJ4 chimeric viruses derived from 149 subtype C acutely infected Zambians, and has allowed for the identification of residues in Gag that affect replication. More importantly, the implementation of this technique has facilitated a deeper understanding of how viral replication defines parameters of early HIV-1 pathogenesis such as set point viral load and longitudinal CD4+ T cell decline.
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http://dx.doi.org/10.3791/51506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364379PMC
August 2014

HIV transmission. Selection bias at the heterosexual HIV-1 transmission bottleneck.

Science 2014 Jul 10;345(6193):1254031. Epub 2014 Jul 10.

Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA. Rwanda-Zambia HIV Research Group: Zambia-Emory HIV Research Project, Lusaka, Zambia. Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA.

Heterosexual transmission of HIV-1 typically results in one genetic variant establishing systemic infection. We compared, for 137 linked transmission pairs, the amino acid sequences encoded by non-envelope genes of viruses in both partners and demonstrate a selection bias for transmission of residues that are predicted to confer increased in vivo fitness on viruses in the newly infected, immunologically naïve recipient. Although tempered by transmission risk factors, such as donor viral load, genital inflammation, and recipient gender, this selection bias provides an overall transmission advantage for viral quasispecies that are dominated by viruses with high in vivo fitness. Thus, preventative or therapeutic approaches that even marginally reduce viral fitness may lower the overall transmission rates and offer long-term benefits even upon successful transmission.
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http://dx.doi.org/10.1126/science.1254031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289910PMC
July 2014

Multiparametric analysis of host response to murine cytomegalovirus in MHC class I-disparate mice reveals primacy of Dk-licensed Ly49G2+ NK cells in viral control.

J Immunol 2013 Nov 25;191(9):4709-19. Epub 2013 Sep 25.

Division of Nephrology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908;

MHC class I D(k) and Ly49G2 (G2) inhibitory receptor-expressing NK cells are essential to murine CMV (MCMV) resistance in MA/My mice. Without D(k), G2(+) NK cells in C57L mice fail to protect against MCMV infection. As a cognate ligand of G2, D(k) licenses G2(+) NK cells for effector activity. These data suggested that D(k)-licensed G2(+) NK cells might recognize and control MCMV infection. However, a role for licensed NK cells in viral immunity is uncertain. We combined classical genetics with flow cytometry to visualize the host response to MCMV. Immune cells collected from individuals of a diverse cohort of MA/My × C57L offspring segregating D(k) were examined before infection and postinfection, including Ly49(+) NK subsets, receptor expression features, and other phenotypic traits. To identify critical NK cell features, automated analysis of 110 traits was performed in R using the Pearson correlation, followed with a Bonferroni correction for multiple tests. Hierarchical clustering of trait associations and principal component analyses were used to discern shared immune response and genetic relationships. The results demonstrate that G2 expression on naive blood NK cells was predictive of MCMV resistance. However, rapid G2(+) NK cell expansion following viral exposure occurred selectively in D(k) offspring; this response was more highly correlated with MCMV control than all other immune cell features. We infer that D(k)-licensed G2(+) NK cells efficiently detected missing-self MHC cues on viral targets, which elicited cellular expansion and target cell killing. Therefore, MHC polymorphism regulates licensing and detection of viral targets by distinct subsets of NK cells required in innate viral control.
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http://dx.doi.org/10.4049/jimmunol.1301388DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3820117PMC
November 2013

Role of transmitted Gag CTL polymorphisms in defining replicative capacity and early HIV-1 pathogenesis.

PLoS Pathog 2012 29;8(11):e1003041. Epub 2012 Nov 29.

Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America.

Initial studies of 88 transmission pairs in the Zambia Emory HIV Research Project cohort demonstrated that the number of transmitted HLA-B associated polymorphisms in Gag, but not Nef, was negatively correlated to set point viral load (VL) in the newly infected partners. These results suggested that accumulation of CTL escape mutations in Gag might attenuate viral replication and provide a clinical benefit during early stages of infection. Using a novel approach, we have cloned gag sequences isolated from the earliest seroconversion plasma sample from the acutely infected recipient of 149 epidemiologically linked Zambian transmission pairs into a primary isolate, subtype C proviral vector, MJ4. We determined the replicative capacity (RC) of these Gag-MJ4 chimeras by infecting the GXR25 cell line and quantifying virion production in supernatants via a radiolabeled reverse transcriptase assay. We observed a statistically significant positive correlation between RC conferred by the transmitted Gag sequence and set point VL in newly infected individuals (p = 0.02). Furthermore, the RC of Gag-MJ4 chimeras also correlated with the VL of chronically infected donors near the estimated date of infection (p = 0.01), demonstrating that virus replication contributes to VL in both acute and chronic infection. These studies also allowed for the elucidation of novel sites in Gag associated with changes in RC, where rare mutations had the greatest effect on fitness. Although we observed both advantageous and deleterious rare mutations, the latter could point to vulnerable targets in the HIV-1 genome. Importantly, RC correlated significantly (p = 0.029) with the rate of CD4+ T cell decline over the first 3 years of infection in a manner that is partially independent of VL, suggesting that the replication capacity of HIV-1 during the earliest stages of infection is a determinant of pathogenesis beyond what might be expected based on set point VL alone.
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http://dx.doi.org/10.1371/journal.ppat.1003041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3510241PMC
April 2013

Photorefractive keratectomy with mitomycin-C for the combined treatment of myopia and subepithelial infiltrates after epidemic keratoconjunctivitis.

J Cataract Refract Surg 2012 Jun;38(6):1028-33

Ophthalmic Consultants of Long Island, Rockville Centre, New York, USA.

Purpose: To report the use of photorefractive keratectomy (PRK) with mitomycin-C (MMC) to treat concomitant myopia and visually significant infiltrates associated with epidemic keratoconjunctivitis (EKC).

Setting: Ophthalmic Consultants of Long Island, Nassau University, Long Island, New York, USA.

Design: Interventional case series.

Methods: Consecutive patients with myopia and recalcitrant subepithelial infiltrates after EKC were treated with custom wavefront PRK (Visx S4 IR) and MMC with a target of emmetropia in all cases.

Results: The study evaluated 6 eyes of 3 patients. One year after treatment, all eyes attained an uncorrected distance visual acuity of 20/20 or better. There was no recurrence of infiltrates within the ablation zone in any eye.

Conclusion: The use of topical MMC in conjunction with PRK to treat subepithelial infiltrates due to EKC provided good visual and refractive results.
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http://dx.doi.org/10.1016/j.jcrs.2011.12.039DOI Listing
June 2012

Refractive surgery after Descemet's stripping endothelial keratoplasty.

Curr Opin Ophthalmol 2012 Jul;23(4):242-5

Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10467, USA.

Purpose Of Review: Descemet's stripping endothelial keratoplasty (DSEK) has become a preferred surgical correction for endothelial dysfunction. Patient dissatisfaction secondary to refractive error is emerging as a significant complaint after anatomically successful DSEK. This article reviews refractive surgeries after DSEK to address this problem.

Recent Findings: There are various surgical options available to treat refractive compromise following DSEK. Cataract extraction with intraocular lens (IOL) implantation is a well tolerated option to restore visual acuity after DSEK in cases with significant lens opacities. Laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) can otherwise successfully correct simple refractive errors. Phototherapeutic keratectomy (PTK) may be employed in cases wherein visually significant subepithelial fibrosis and scarring become evident after DSEK.

Summary: To obtain maximum visual rehabilitation, patients undergoing DSEK may require further refractive surgeries. Cataract extraction, LASIK, PRK, PTK, and various combination procedures have been shown to optimize corneal clarity and visual acuity in patients who previously had successful DSEK with subsequent refractive errors. Technological advancements and continued research are necessary to perfect optimal timing and outcomes of these secondary refractive surgeries.
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http://dx.doi.org/10.1097/ICU.0b013e3283543b79DOI Listing
July 2012

Impact of HLA-B*81-associated mutations in HIV-1 Gag on viral replication capacity.

J Virol 2012 Mar 11;86(6):3193-9. Epub 2012 Jan 11.

HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.

HIV-1 attenuation resulting from immune escape mutations selected in Gag may contribute to slower disease progression in HIV-1-infected individuals expressing certain HLA class I alleles. We previously showed that the protective allele HLA-B*81 and the HLA-B*81-selected Gag T186S mutation are strongly associated with a lower viral replication capacity of recombinant viruses encoding Gag-protease derived from individuals chronically infected with HIV-1 subtype C. In the present study, we directly tested the effect of this mutation on viral replication capacity. In addition, we investigated potential compensatory effects of various polymorphisms, including other HLA-B*81-associated mutations that significantly covary with the T186S mutation. Mutations were introduced into a reference subtype B backbone and into patient-derived subtype C sequences in subtype B and C backbones by site-directed mutagenesis. The exponential-phase growth of mutant and wild-type viruses was assayed by flow cytometry of a green fluorescent protein reporter T cell line or by measurement of HIV-1 reverse transcriptase activity in culture supernatants. Engineering of the T186S mutation alone into all patient-derived subtype C sequences failed to yield replication-competent viruses, while in the subtype B sequence, the T186S mutation resulted in impaired replication capacity. Only the T186S mutation in combination with the T190I mutation yielded replication-competent viruses for all virus backbones tested; however, these constructs replicated slower than the wild type, suggesting that only partial compensation is mediated by the T190I mutation. Constructs encoding the T186S mutation in combination with other putative compensatory mutations were attenuated or defective. These results suggest that the T186S mutation is deleterious to HIV-1 subtype C replication and likely requires complex compensatory pathways, which may contribute to the clinical benefit associated with HLA-B*81.
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http://dx.doi.org/10.1128/JVI.06682-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3302318PMC
March 2012

A multicenter randomized controlled fellow eye trial of pulse-dosed difluprednate 0.05% versus prednisolone acetate 1% in cataract surgery.

Am J Ophthalmol 2011 Oct 25;152(4):609-617.e1. Epub 2011 Jun 25.

Ophthalmic Consultants of Long Island, Rockville Centre, New York 11570, USA.

Purpose: To compare the effects of 2 corticosteroids on corneal thickness and visual acuity after cataract surgery.

Design: Multicenter, randomized, contralateral-eye, double-masked trial.

Methods: Fifty-two patients (104 eyes) underwent bilateral phacoemulsification. The first eye randomly received difluprednate 0.05% or prednisolone acetate 1%; the fellow eye received the alternative. Before surgery, 7 doses were administered over 2 hours; 3 additional doses were given after surgery, before discharge. For the remainder of the day, corticosteroids were administered every 2 hours, then 4 times daily during week 1 and twice daily during week 2. Corneal pachymetry, visual acuity, and corneal edema were evaluated before surgery and at days 1, 15, and 30 after surgery. Endothelial cell counts were evaluated before surgery and at 30 days after surgery. Retinal thickness was evaluated before surgery and at 15 and 30 days after surgery.

Results: Corneal thickness at day 1 was 33 μm less in difluprednate-treated eyes (P = .026). More eyes were without corneal edema in the difluprednate group than in the prednisolone group at day 1 (62% vs 38%, respectively; P = .019). Uncorrected and best-corrected visual acuity at day 1 were significantly better with difluprednate than prednisolone by 0.093 logMAR lines (P = .041) and 0.134 logMAR lines (P < .001), respectively. Endothelial cell density was 195.52 cells/mm(2) higher in difluprednate-treated eyes at day 30 (P < .001). Retinal thickness at day 15 was 7.74 μm less in difluprednate-treated eyes (P = .011).

Conclusions: In this high-dose pulsed-therapy regimen, difluprednate reduced inflammation more effectively than prednisolone acetate, resulting in more rapid return of vision. Difluprednate was superior at protecting the cornea and reducing macular thickening after cataract surgery.
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http://dx.doi.org/10.1016/j.ajo.2011.03.018DOI Listing
October 2011

Mutagenesis of tyrosine and di-leucine motifs in the HIV-1 envelope cytoplasmic domain results in a loss of Env-mediated fusion and infectivity.

Retrovirology 2011 May 14;8:37. Epub 2011 May 14.

Emory Vaccine Center at the Yerkes National Primate Research Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia 30329, USA.

Background: The gp41 component of the Human Immunodeficiency Virus (HIV) envelope glycoprotein (Env) contains a long cytoplasmic domain (CD) with multiple highly conserved tyrosine (Y) and dileucine (LL) motifs. Studies suggest that the motifs distal to major endocytosis motif (Y712HRL), located at residues 712-715 of Env, may contribute to Env functionality in the viral life cycle. In order to examine the biological contribution of these motifs in the biosynthesis, transport, and function of Env, we constructed two panels of mutants in which the conserved Y- and LL-motifs were sequentially substituted by alternative residues, either in the presence or absence of Y712. Additional mutants targeting individual motifs were then constructed.

Results: All mutant Envs, when expressed in the absence of other viral proteins, maintained at least WT levels of Env surface staining by multiple antibodies. The Y712 mutation (Y712C) contributed to at least a 4-fold increase in surface expression for all mutants containing this change. Sequential mutagenesis of the Y- and LL-motifs resulted in a generally progressive decrease in Env fusogenicity. However, additive mutation of dileucine and tyrosine motifs beyond the tyrosine at residue 768 resulted in the most dramatic effects on Env incorporation into virions, viral infectivity, and virus fusion with target cells.

Conclusions: From the studies reported here, we show that mutations of the Y- and LL-motifs, which effectively eliminate the amphipathic nature of the lytic peptide 2 (LLP2) domain or disrupt YW and LL motifs in a region spanning residues 795-803 (YWWNLLQYW), just C-terminal of LLP2, can dramatically interfere with biological functions of HIV-1 Env and abrogate virus replication. Because these mutant proteins are expressed at the cell surface, we conclude that tyrosine and di-leucine residues within the cytoplasmic domain of gp41 play critical roles in HIV-1 replication that are distinct from that of targeting the plasma membrane.
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http://dx.doi.org/10.1186/1742-4690-8-37DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3117779PMC
May 2011

X-linked idiopathic infantile nystagmus associated with a missense mutation in FRMD7.

Mol Vis 2007 Nov 29;13:2233-41. Epub 2007 Nov 29.

Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.

Purpose: Infantile nystagmus is a clinically and genetically heterogeneous eye movement disorder. Here we map and identify the genetic mutation underlying X-linked idiopathic infantile nystagmus (XL-IIN) segregating in two Caucasian-American families.

Methods: Eye movements were recorded using binocular infrared digital video-oculography. Genomic DNA was prepared from blood or buccal-cells, and linkage analysis was performed using short tandem repeat (STR) and single nucleotide polymorphism (SNP) markers. Pedigree and haplotype data were managed using Cyrillic, and LOD scores calculated using MLINK. Mutation profiling of PCR-amplified exons was performed by dye-terminator cycle-sequencing and analyzed by automated capillary electrophoresis.

Results: Video-oculography of affected males recorded conjugate, horizontal, pendular nystagmus with increasing-velocity waveforms in primary gaze converting to jerk nystagmus in eccentric gaze. Linkage analysis detected significantly positive two-point LOD scores (Z) at markers DXS8078 (Z=4.82, recombination fraction [theta]=0) and DXS1047 (Z=3.87, theta=0). Haplotyping indicated that the IIN locus mapped to the physical interval DXS8057-(11.59 Mb)-rs6528335 on Xq25-q26. Sequencing of positional-candidate genes detected a c.425T>G transversion in exon-6 of the gene for FERM domain containing-7 (FRMD7) that cosegregated with affected and carrier status. In addition, the same change was found to cosegregate with IIN in a genetically unrelated family but was not detected in 192 control individuals.

Conclusions: The c.425T>G change is predicted to result in the missense substitution of the phylogenetically conserved leucine at codon 142 for an arginine (p.L142R), and supports a causative role for FRMD7 mutations in the pathogenesis of XL-IIN.
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November 2007