Prof Graham Ogg

Research Area: Immunology
Technology Exchange: Bioinformatics, Cell sorting, Cellular immunology, Drug discovery, Flow cytometry, Immunohistochemistry, Microscopy (Confocal), Protein interaction and Vaccine production and evaluation
Keywords: T cells, atopic disease, dermatitis, varicella zoster virus, CD1a, nuocytes, filaggrin and ILC2
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Schematic of pathogenesis of atopic eczema

Schematic of pathogenesis of atopic eczema

Keratinocytes sample their environment and can engulf fluorescent particles

Keratinocytes sample their environment and can engulf fluorescent particles

Skin and mucosae frequently represent the first point of contact with pathogens and allergens, yet we still know relatively little of the role of the surface immune system in clearing such challenges. This is crucially important in understanding the mechanisms of skin diseases and related diseases, and for optimising approaches to cutaneous drug and vaccine delivery. The aim of the group is therefore to understand, at the molecular and cellular level, the role of human cutaneous immune responses in mechanisms of disease, treatment and vaccination.  As well as contributing to an understanding of disease pathogenesis, we aim to translate our findings to changes in clinical practice.

Name Department Institution Country
Prof Vincenzo Cerundolo Investigative Medicine Division University of Oxford United Kingdom
Professor Paul Klenerman Experimental Medicine Division University of Oxford United Kingdom
Reader Persephone Borrow NDM Research Building University of Oxford United Kingdom

Gutowska-Owsiak D, Greenwald L, Watson C, Selvakumar TA, Wang X, Ogg GS. 2014. The histamine-synthesizing enzyme histidine decarboxylase is upregulated by keratinocytes in atopic skin. Br J Dermatol, 171 (4), pp. 771-778. Read abstract | Read more

BACKGROUND: Histamine is an abundant mediator accumulating in the skin of atopic patients, where it is thought to be derived from immune cells. While keratinocytes express histidine decarboxylase (HDC), levels of the enzyme in normal or diseased epidermis and factors that influence its expression in human keratinocytes are not known. OBJECTIVES: To assess levels of HDC in inflammatory skin diseases and factors influencing its expression. METHODS: Normal and filaggrin-insufficient human keratinocytes, organotypic epidermal models and skin samples were investigated for the expression of HDC. The effect of cytokines, bacterial and allergen stimuli exposure and functional changes in differentiation were evaluated in vitro. RESULTS: We detected abundant expression of the HDC protein in all models studied; expression was increased in atopic skin samples. Filaggrin-insufficient keratinocytes maintained HDC levels, but exposure of keratinocytes to thymic stromal lymphopoietin, tumour necrosis factor-α, lipopolysaccharide (LPS) and house dust mite (HDM) extract increased HDC expression in vitro. Furthermore, filaggrin expression in cultured keratinocytes increased following histamine depletion. CONCLUSIONS: Keratinocytes express abundant HDC protein, and the levels increase in atopic skin. LPS, HDM and cytokines, which are implicated in allergic inflammation, promote the expression of the enzyme and upregulate histamine levels in keratinocytes. Actively produced histamine influences keratinocyte differentiation, suggesting functional relevance of the axis to atopic dermatitis. The findings therefore identify a new point of therapeutic intervention. Hide abstract

Xue L, Salimi M, Panse I, Mjösberg JM, McKenzie ANJ, Spits H, Klenerman P, Ogg G. 2014. Prostaglandin D2 activates group 2 innate lymphoid cells through chemoattractant receptor-homologous molecule expressed on TH2 cells Journal of Allergy and Clinical Immunology, 133 (4), Read abstract | Read more

Background Activation of the group 2 innate lymphoid cell (ILC2) population leads to production of the classical type 2 cytokines, thus promoting type 2 immunity. Chemoattractant receptor-homologous molecule expressed on T H2 cells (CRTH2), a receptor for prostaglandin D2 (PGD2), is expressed by human ILC2s. However, the function of CRTH2 in these cells is unclear. Objectives We sought to determine the role of PGD2 and CRTH2 in human ILC2s and compare it with that of the established ILC2 activators IL-25 and IL-33. Methods The effects of PGD 2, IL-25, and IL-33 on the cell migration, cytokine production, gene regulation, and receptor expression of ILC2s were measured with chemotaxis, ELISA, Luminex, flow cytometry, quantitative RT-PCR, and QuantiGene assays. The effects of PGD2 under physiologic conditions were evaluated by using the supernatant from activated mast cells. Results PGD2 binding to CRTH2 induced ILC2 migration and production of type 2 cytokines and many other cytokines. ILC2 activation through CRTH2 also upregulated the expression of IL-33 and IL-25 receptor subunits (ST2 and IL-17RA). The effects of PGD 2 on ILC2s could be mimicked by the supernatant from activated human mast cells and inhibited by a CRTH2 antagonist. Conclusions PGD2 is an important and potent activator of ILC2s through CRTH2 mediating strong proallergic inflammatory responses. Through IgE-mediated mast cell degranulation, these innate cells can also contribute to adaptive type 2 immunity; thus CRTH2 bridges the innate and adaptive pathways in human ILC2s. © 2013 American Academy of Allergy, Asthma & Immunology. Hide abstract

Pan X, Huang LC, Dong T, Peng Y, Cerundolo V, McGowan S, Ogg G. 2014. Combinatorial HLA-peptide bead libraries for high throughput identification of CD8+ T cell specificity Journal of Immunological Methods, 403 (1-2), pp. 72-78. Read abstract | Read more

Comprehensive antigenic characterization of a T cell population of unknown specificity is challenging. Existing MHC class I expression systems are limited by the practical difficulty of probing cell populations with an MHC class I peptide library and the cross-reactivity of T cells that are able to recognise many variants of an index peptide. Using emulsion PCR and emulsion in vitro transcription/translation of a random library of peptides conjugated to CD8-null HLA-A*0201 on beads, we probed HLA-A*0201-restricted T cells with specificity for influenza, CMV and EBV. We observed significant enrichment for sequences containing HLA-A2 anchors and correct viral fragments for all T cell populations. HLA bead display provides a novel approach to identify the specificity of T cells. © 2013 Elsevier B.V. Hide abstract

Salimi M, Barlow JL, Saunders SP, Xue L, Gutowska-Owsiak D, Wang X, Huang LC, Johnson D et al. 2013. A role for IL-25 and IL-33-driven type-2 innate lymphoid cells in atopic dermatitis. J Exp Med, 210 (13), pp. 2939-2950. Read abstract | Read more

Type 2 innate lymphoid cells (ILC2s, nuocytes, NHC) require RORA and GATA3 for their development. We show that human ILC2s express skin homing receptors and infiltrate the skin after allergen challenge, where they produce the type 2 cytokines IL-5 and IL-13. Skin-derived ILC2s express the IL-33 receptor ST2, which is up-regulated during activation, and are enriched in lesional skin biopsies from atopic patients. Signaling via IL-33 induces type 2 cytokine and amphiregulin expression, and increases ILC2 migration. Furthermore, we demonstrate that E-cadherin ligation on human ILC2 dramatically inhibits IL-5 and IL-13 production. Interestingly, down-regulation of E-cadherin is characteristic of filaggrin insufficiency, a cardinal feature of atopic dermatitis (AD). ILC2 may contribute to increases in type 2 cytokine production in the absence of the suppressive E-cadherin ligation through this novel mechanism of barrier sensing. Using Rag1(-/-) and RORα-deficient mice, we confirm that ILC2s are present in mouse skin and promote AD-like inflammation. IL-25 and IL-33 are the predominant ILC2-inducing cytokines in this model. The presence of ILC2s in skin, and their production of type 2 cytokines in response to IL-33, identifies a role for ILC2s in the pathogenesis of cutaneous atopic disease. Hide abstract

Pan X, Huang LC, Dong T, Peng Y, Cerundolo V, McGowan S, Ogg G. 2014. Combinatorial HLA-peptide bead libraries for high throughput identification of CD8⁺ T cell specificity. J Immunol Methods, 403 (1-2), pp. 72-78. Read abstract | Read more

Comprehensive antigenic characterization of a T cell population of unknown specificity is challenging. Existing MHC class I expression systems are limited by the practical difficulty of probing cell populations with an MHC class I peptide library and the cross-reactivity of T cells that are able to recognise many variants of an index peptide. Using emulsion PCR and emulsion in vitro transcription/translation of a random library of peptides conjugated to CD8-null HLA-A*0201 on beads, we probed HLA-A*0201-restricted T cells with specificity for influenza, CMV and EBV. We observed significant enrichment for sequences containing HLA-A2 anchors and correct viral fragments for all T cell populations. HLA bead display provides a novel approach to identify the specificity of T cells. Hide abstract

Huang LC, Pan X, Yang H, Wan LK, Stewart-Jones G, Dorrell L, Ogg G. 2013. Linking genotype to phenotype on beads: high throughput selection of peptides with biological function. Sci Rep, 3 pp. 3030. Read abstract | Read more

Although peptides are well recognised biological molecules in vivo, their selection from libraries is challenging because of relative low affinity whilst in linear conformation. We hypothesized that multiplexed peptides and DNA on the surface of beads would provide a platform for enhanced avidity and the selection of relevant peptides from a library (ORBIT bead display). Using human immunodeficiency virus (HIV-1) gp120 as a target, we identify peptides that inhibit HIV-1 replication in vitro through blocking of protein:protein interaction with the co-receptor CCR5. The bead display approach has many potential applications for probing biological systems and for drug lead development. Hide abstract

Crack LR, Jones L, Malavige GN, Patel V, Ogg GS. 2012. Human antimicrobial peptides LL-37 and human β-defensin-2 reduce viral replication in keratinocytes infected with varicella zoster virus. Clin Exp Dermatol, 37 (5), pp. 534-543. Read abstract | Read more

BACKGROUND: There is mounting evidence that antimicrobial peptides have an important role in cutaneous defence, but the expression of these antimicrobial peptides in atopic eczema (AE) is still unclear. There are several families of antimicrobial peptides, including cathelicidins and human β-defensins. Patients with AE are more susceptible to severe cutaneous viral infections, including varicella zoster virus (VZV). AIM: To characterize the functional activity of the antimicrobial peptides LL-37 (human cathelicidin) and human β-defensin (hBD)-2 keratinocytes were infected with VZV, in a skin-infection model. METHODS: Flow-cytometry analysis was used to investigate LL-37 expression in normal human keratinocytes, and quantitative PCR was used to determine viral loads in infected HaCaT keratinocytes and B cells, with and without exogenous LL-37 and hBD-2. RESULTS: LL-37 expression was present in keratinocytes, and both exogenous LL-37 and hBD-2 significantly reduced VZV load in infected keratinocytes and B cells. Specific antibodies blocked the antiviral action exhibited by these antimicrobial peptides. Pre-incubation of VZV with LL-37, but not hBD-2, further reduced VZV load. CONCLUSIONS: Both LL-37 and hBD-2 have an antiviral effect on VZV replication in the keratinocyte HaCaT cell line and in B cells, but their mechanism of action is different. Evidence of the relationship between antimicrobial peptide expression and higher susceptibility to infections in AE skin is still emerging. Developing novel antiviral therapies based on antimicrobial peptides may provide improved treatment options for patients with AE. Hide abstract

Malavige GN, McGowan S, Atukorale V, Salimi M, Peelawatta M, Fernando N, Jayaratne SD, Ogg G. 2012. Identification of serotype-specific T cell responses to highly conserved regions of the dengue viruses. Clin Exp Immunol, 168 (2), pp. 215-223. Read abstract | Read more

Determining previous infecting dengue virus (DENV) serotypes has been difficult due to highly cross-reactive immune responses from previous DENV infections. Determining the correlates of serotype-specific immune responses would be crucial in understanding dengue transmission in the community and would also help to determine the correlates of protective immune responses. Therefore, we set out to define highly conserved, serotype-specific regions of the DENVs. Serotype-specific and highly conserved regions of the four DENV serotypes were identified using Basic Local Alignment Search Tool (BLAST) searches and custom perl scripts. Using ex-vivo and cultured enzyme-linked immunospot (ELISPOT) assays, we identified serotype-specific T cell epitopes within the four DENV serotypes in healthy adult donors from Sri Lanka. We identified T cell responses to 19 regions of the four DENV serotypes. Six peptides were from the NS2A region and four peptides were from the NS4A region. All immune donors responded to peptides of at least two DENV serotypes, suggesting that heterologous infection is common in Sri Lanka. Eight of 20 individuals responded to at least two peptides of DENV-4, despite this serotype not being implicated previously in any of the epidemics in Sri Lanka. The use of these regions to determine past and current infecting DENV serotypes will be of value to characterize further the dynamics of silent dengue transmission in the community. In addition, these T cell responses to these regions could be used to characterize DENV serotype-specific immune responses and thus possibly help us to understand the immune correlates of a protective immune response. Hide abstract

Gutowska-Owsiak D, Schaupp AL, Salimi M, Selvakumar TA, McPherson T, Taylor S, Ogg GS. 2012. IL-17 downregulates filaggrin and affects keratinocyte expression of genes associated with cellular adhesion. Exp Dermatol, 21 (2), pp. 104-110. Read abstract | Read more

Atopic eczema and psoriasis are common skin diseases. While it is well established that the pathogenesis of these diseases varies, both are characterized by impairment in epidermal barrier function and abnormal IL-17 expression in the skin and peripheral blood. Recent findings indicated that filaggrin is essential during barrier formation and its insufficiency underlies the pathogenesis of atopic eczema. Filaggrin downregulation has also been reported in psoriasis. It is clear that Th1/Th2 bias influences expression of the protein, but an analysis of the effects of interleukin-17 (IL-17) on the expression of the protein and profilaggrin-processing enzymes has not yet been reported. In addition, the effect of the cytokine on components of functional epidermal barrier, tight junctions and adhesion/desmosomal proteins, has not been elucidated. Keratinocytes were exposed to interleukin-17A, and microarray analysis was performed. Filaggrin protein level was assessed by western blot. We have observed a significant decrease in profilaggrin mRNA level in interleukin-17A-exposed cultures (P = 0.008). Expression of processing enzymes was also altered, indicating an indirect effect of the cytokine on filaggrin production/degradation. Moreover, expression of many genes involved in cellular adhesion was also decreased. A significant downregulation of filaggrin at the protein level was detected by western blot in immortal and primary keratinocytes. Gene ontology analysis indicated changes in keratinization, epidermal differentiation and formation of the cornified envelope. We conclude that IL-17A downregulates the expression of filaggrin and genes important for cellular adhesion which could affect epidermal barrier formation. This effect potentially contributes to barrier dysfunction and could become a possible therapeutic target. Hide abstract

Aslam A, Chan H, Warrell DA, Misbah S, Ogg GS. 2010. Tracking antigen-specific T-cells during clinical tolerance induction in humans. PLoS One, 5 (6), pp. e11028. Read abstract | Read more

Allergen immunotherapy presents an opportunity to define mechanisms of induction of clinical tolerance in humans. Significant progress has been made in our understanding of changes in T cell responses during immunotherapy, but existing work has largely been based on functional T cell assays. HLA-peptide-tetrameric complexes allow the tracking of antigen-specific T-cell populations based on the presence of specific T-cell receptors and when combined with functional assays allow a closer assessment of the potential roles of T-cell anergy and clonotype evolution. We sought to develop tools to facilitate tracking of antigen-specific T-cell populations during wasp-venom immunotherapy in people with wasp-venom allergy. We first defined dominant immunogenic regions within Ves v 5, a constituent of wasp venom that is known to represent a target antigen for T-cells. We next identified HLA-DRB1*1501 restricted epitopes and used HLA class II tetrameric complexes alongside cytokine responses to Ves v 5 to track T-cell responses during immunotherapy. In contrast to previous reports, we show that there was a significant initial induction of IL-4 producing antigen-specific T-cells within the first 3-5 weeks of immunotherapy which was followed by reduction of circulating effector antigen-specific T-cells despite escalation of wasp-venom dosage. However, there was sustained induction of IL-10-producing and FOXP3 positive antigen-specific T cells. We observed that these IL-10 producing cells could share a common precursor with IL-4-producing T cells specific for the same epitope. Clinical tolerance induction in humans is associated with dynamic changes in frequencies of antigen-specific T-cells, with a marked loss of IL-4-producing T-cells and the acquisition of IL-10-producing and FOXP3-positive antigen-specific CD4+ T-cells that can derive from a common shared precursor to pre-treatment effector T-cells. The development of new approaches to track antigen specific T-cell responses during immunotherapy can provide novel insights into mechanisms of tolerance induction in humans and identify new potential treatment targets. Hide abstract

Malavige GN, Jones L, Kamaladasa SD, Wijewickrama A, Seneviratne SL, Black AP, Ogg GS. 2008. Viral load, clinical disease severity and cellular immune responses in primary varicella zoster virus infection in Sri Lanka. PLoS One, 3 (11), pp. e3789. Read abstract | Read more

BACKGROUND: In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. METHODOLOGY: We used IFNgamma ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. PRINCIPAL FINDINGS: Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNgamma ELISpot responses of patients (P<0.001, r = -0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. CONCLUSIONS: Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses. Hide abstract

Black AP, Ardern-Jones MR, Kasprowicz V, Bowness P, Jones L, Bailey AS, Ogg GS. 2007. Human keratinocyte induction of rapid effector function in antigen-specific memory CD4+ and CD8+ T cells. Eur J Immunol, 37 (6), pp. 1485-1493. Read abstract | Read more

The ability of human keratinocytes to present antigen to T cells is controversial and, indeed, it has been suggested that keratinocytes may promote T cell hyporesponsiveness. Furthermore, it is unclear whether keratinocytes can process antigen prior to MHC class I and class II presentation. We tested the ability of keratinocytes to induce functional responses in epitope-specific CD4+ and CD8+ memory T cells using peptides, protein and recombinant expression vectors as sources of antigen. Keratinocytes were able to efficiently process and present protein antigen to CD4+ T cells, resulting in cytokine secretion (Th1 and Th2). This interaction was dependent on keratinocyte expression of HLA class II and ICAM-1, which could be induced by IFN-gamma. In addition, keratinocytes could present virally encoded or exogenous peptide to CD8+ T cells, resulting in T cell cytokine production and target cell lysis. Finally, T cell lines grown using keratinocytes as stimulators showed no loss of function. These findings demonstrate that keratinocytes are able to efficiently process and present antigen to CD4+ and CD8+ memory T cells and induce functional responses. The findings have broad implications for the pathogenesis of cutaneous disease and for transcutaneous drug or vaccine delivery. Hide abstract

Ardern-Jones MR, Black AP, Bateman EA, Ogg GS. 2007. Bacterial superantigen facilitates epithelial presentation of allergen to T helper 2 cells. Proc Natl Acad Sci U S A, 104 (13), pp. 5557-5562. Read abstract | Read more

Although clinical and laboratory evidence support roles for both staphylococcal infection and environmental allergens in the pathogenesis of atopic dermatitis, human studies have largely considered these variables independently. We sought to test the hypothesis that staphylococcal superantigen influences the allergen-specific T cell response. We first mapped a Der p 1 epitope and used HLA DRB1*1501 class II tetramer-based cell sorted populations to show that specific CD4(+) T cells were able to recognize the peptide presented by HLA DR-matched keratinocytes. We observed that staphylococcal enterotoxin B (SEB) enhanced the IL-4 Der p 1-specific T cell response. This response was mediated by two synergistic mechanisms: first, SEB-induced IFN-gamma promoted class II and intercellular adhesion molecule-1 expression by presenting keratinocytes; and second, SEB-induced IL-4 directly amplified allergen-specific CD4(+) T cell production of many cytokines. We propose that handling of staphylococcal infection is a critical step in the amplification of the allergen-specific T cell response, linking two common disease associations and with implications for the prevention and treatment of atopic disease. Hide abstract

Malavige GN, Jones L, Black AP, Ogg GS. 2007. Rapid effector function of varicella-zoster virus glycoprotein I-specific CD4+ T cells many decades after primary infection. J Infect Dis, 195 (5), pp. 660-664. Read abstract | Read more

Glycoprotein I (gI) of varicella-zoster virus (VZV) contributes to viral virulence and is therefore a potentially important target for T cell control of viral replication. Persisting effector function of gI-specific T cells after primary infection has not been previously examined. We have shown that, many decades after infection, relatively high frequencies gI-specific interferon- gamma responses are detectable ex vivo and are dominated by CD4(+) T cells. We characterized the optimal peptide of the strongest response in our cohort showing restriction through DRB4*01. These findings are consistent with gI-specific CD4(+) T cell involvement in the control of VZV replication. Hide abstract

Seneviratne SL, Jones L, King AS, Black A, Powell S, McMichael A, Ogg GS. 2002. Allergen-specific CD8(+) T cells and atopic disease JOURNAL OF CLINICAL INVESTIGATION, 110 (9), pp. 1283-1291. | Read more

Champagne P, Ogg GS, King AS, Knabenhans C, Ellefsen K, Nobile M, Appay V, Rizzardi GP et al. 2001. Skewed maturation of memory HIV-specific CD8 T lymphocytes NATURE, 410 (6824), pp. 106-111. | Read more