174 research outputs found

    Characterisation of anti-glycan monoclonal antibodies

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    The aims of this thesis are to establish the therapeutic value of two anti-glycan mAbs produced in-house, to develop an immunisation protocol with the aim of improving the immunogenicity tumour-associated glycolipids with the intention of producing therapeutically valuable mAbs and to determine the implication of a mAb with the ability to induce apoptosis in colorectal cancer. The anti-glycan mAbs 692/29 and 505/4 have previously been produced in-house and this study aimed to determine their fine specificity using a glycan array. 692/29 displayed binding predominantly to Lewis b as well as Lewis y-containing glycans. 505/4 was discovered to bind to sialyl Lewis a as well as sialyl di-Lewis a, with no cross-reactivity with other blood group antigens. This was compared to other anti-Lewis mAbs, with differences in specificity being observed. Characterisation of 505/4 mAb distribution showed binding to 80% of colorectal tumours and low levels of binding to normal tissues by IHC, suggesting it may be therapeutically useful. This thesis aimed to assess the ability of 505/4 and 692/29 to meditate immune mediated and non-immune mediated cell death as well as to determine whether non-immune-mediated cell death would be a desirable therapeutic property. Resistance to apoptosis is one of the hallmarks of cancer cells and mAbs stimulating apoptosis may not be very effective. Alternatively, cancer cells are driven to initiate apoptosis by genomic and other aberrations thus if pro-apoptotic pathways are stimulated these cells may be more susceptible to death than normal cells. To investigate the significance of apoptosis in cancer a large tissue microarray of colorectal tumours was assessed for apoptosis and its relationship to patient prognosis. Cleaved caspase-3 is a good marker of apoptosis as it is the executioner caspase for both the extrinsic and intrinsic pathways. Immunohistochemical analysis of colorectal tumour samples revealed that a high expression of cleaved caspase-3 in tumour was associated with good prognosis in colorectal cancer. This suggested that some tumours were still susceptible to apoptotic death but some are resistant and an alternative mechanism of cell death may be an advantage in these tumours. High expression of cleaved caspase-3 in the tumour-associated stroma was also an independent marker of good prognosis in colorectal cancer. This may be because apoptosis of the tumour-associated stroma reduces the level of pro-tumour signals originating from tumour-associated immune cells and stromal cells. As the tumour microenvironment can act in an immunosuppressive and pro-tumour manner, the ability of a mAb to induce direct cell death without the need for effector cells or complement would be an advantage. Lewis y and Lewis b are blood group antigens commonly overexpressed on the surface of a range of cancers. Characterisation of effector functions of 505/4 and 692/29 demonstrated that both mAbs have the ability to mediate apoptosis by antibody dependent cellular cytotoxicity, complement dependent cytotoxicity and cause direct cell death in an oncosis-like manner. Comparison with other anti-Lewis mAbs demonstrated that a number of anti-Lewis mAbs can induce direct cell death independently of apoptosis. Thus, they could effectively target apoptotic sensitive and resistant colorectal cancers. Tumours aberrantly express glycolipids and these molecules may be involved in a number of cellular pathways. In addition a large proportion of anti-glycan mAbs, including 505/4 and 692/29 in this thesis, have displayed the ability to induce direct cell death. Therefore this thesis aimed to develop an immunisation protocol capable of increasing the immunogenicity of tumour-associated glycolipid for the production of anti-tumour glycolipid mAbs directed against ovarian cancer. This study suggests that the incorporation of tumour glycolipid into liposomes and their immunisation along with the iNKT cell adjuvant α-galactosylceramide, elicits an anti-tumour glycolipid immune response, which can yield IgG mAbs capable of binding a high proportion of ovarian cancers. In summary, this thesis confirmed specificity of 692/29 to Lewis y and Lewis b and 505/4 to sialyl Lewis a and sialyl di-Lewis a. Furthermore, this thesis demonstrated a promising tissue distribution of 505/4 in vitro. Characterisation of mAb effector functions suggest that both Lewis y and sialyl Lewis a directed mAbs have the ability to cause direct cell death, independently of apoptosis in antigen positive cells, as well as the ability to cause immune-mediated cell death. This may be an important factor in the immune-suppressive tumour microenvironment. Furthermore, this thesis provides the basis for the production of new anti-glycolipid antibodies that may also be able to induce direct cell death

    Characterisation of anti-glycan monoclonal antibodies

    Get PDF
    The aims of this thesis are to establish the therapeutic value of two anti-glycan mAbs produced in-house, to develop an immunisation protocol with the aim of improving the immunogenicity tumour-associated glycolipids with the intention of producing therapeutically valuable mAbs and to determine the implication of a mAb with the ability to induce apoptosis in colorectal cancer. The anti-glycan mAbs 692/29 and 505/4 have previously been produced in-house and this study aimed to determine their fine specificity using a glycan array. 692/29 displayed binding predominantly to Lewis b as well as Lewis y-containing glycans. 505/4 was discovered to bind to sialyl Lewis a as well as sialyl di-Lewis a, with no cross-reactivity with other blood group antigens. This was compared to other anti-Lewis mAbs, with differences in specificity being observed. Characterisation of 505/4 mAb distribution showed binding to 80% of colorectal tumours and low levels of binding to normal tissues by IHC, suggesting it may be therapeutically useful. This thesis aimed to assess the ability of 505/4 and 692/29 to meditate immune mediated and non-immune mediated cell death as well as to determine whether non-immune-mediated cell death would be a desirable therapeutic property. Resistance to apoptosis is one of the hallmarks of cancer cells and mAbs stimulating apoptosis may not be very effective. Alternatively, cancer cells are driven to initiate apoptosis by genomic and other aberrations thus if pro-apoptotic pathways are stimulated these cells may be more susceptible to death than normal cells. To investigate the significance of apoptosis in cancer a large tissue microarray of colorectal tumours was assessed for apoptosis and its relationship to patient prognosis. Cleaved caspase-3 is a good marker of apoptosis as it is the executioner caspase for both the extrinsic and intrinsic pathways. Immunohistochemical analysis of colorectal tumour samples revealed that a high expression of cleaved caspase-3 in tumour was associated with good prognosis in colorectal cancer. This suggested that some tumours were still susceptible to apoptotic death but some are resistant and an alternative mechanism of cell death may be an advantage in these tumours. High expression of cleaved caspase-3 in the tumour-associated stroma was also an independent marker of good prognosis in colorectal cancer. This may be because apoptosis of the tumour-associated stroma reduces the level of pro-tumour signals originating from tumour-associated immune cells and stromal cells. As the tumour microenvironment can act in an immunosuppressive and pro-tumour manner, the ability of a mAb to induce direct cell death without the need for effector cells or complement would be an advantage. Lewis y and Lewis b are blood group antigens commonly overexpressed on the surface of a range of cancers. Characterisation of effector functions of 505/4 and 692/29 demonstrated that both mAbs have the ability to mediate apoptosis by antibody dependent cellular cytotoxicity, complement dependent cytotoxicity and cause direct cell death in an oncosis-like manner. Comparison with other anti-Lewis mAbs demonstrated that a number of anti-Lewis mAbs can induce direct cell death independently of apoptosis. Thus, they could effectively target apoptotic sensitive and resistant colorectal cancers. Tumours aberrantly express glycolipids and these molecules may be involved in a number of cellular pathways. In addition a large proportion of anti-glycan mAbs, including 505/4 and 692/29 in this thesis, have displayed the ability to induce direct cell death. Therefore this thesis aimed to develop an immunisation protocol capable of increasing the immunogenicity of tumour-associated glycolipid for the production of anti-tumour glycolipid mAbs directed against ovarian cancer. This study suggests that the incorporation of tumour glycolipid into liposomes and their immunisation along with the iNKT cell adjuvant α-galactosylceramide, elicits an anti-tumour glycolipid immune response, which can yield IgG mAbs capable of binding a high proportion of ovarian cancers. In summary, this thesis confirmed specificity of 692/29 to Lewis y and Lewis b and 505/4 to sialyl Lewis a and sialyl di-Lewis a. Furthermore, this thesis demonstrated a promising tissue distribution of 505/4 in vitro. Characterisation of mAb effector functions suggest that both Lewis y and sialyl Lewis a directed mAbs have the ability to cause direct cell death, independently of apoptosis in antigen positive cells, as well as the ability to cause immune-mediated cell death. This may be an important factor in the immune-suppressive tumour microenvironment. Furthermore, this thesis provides the basis for the production of new anti-glycolipid antibodies that may also be able to induce direct cell death

    Rates, predictive factors and effectiveness of ustekinumab intensification to 4- or 6-weekly intervals in Crohn's disease

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    Background: The UNITI trial reports efficacy of ustekinumab (UST) dose intensification in Crohn's disease (CD) from 12- to 8-weekly, but not 4-weekly. We aimed 1) to assess the cumulative incidence of UST dose intensification to 4- or 6-weekly, 2) to identify factors associated with dose intensification, and 3) to assess the effectiveness of this strategy. Methods: We performed a retrospective, observational cohort study in NHS Lothian including all UST treated CD patients (2015–2020). Results: 163 CD patients were treated with UST (median follow-up: 20.3 months [13.4–38.4]), of whom 55 (33.7%) underwent dose intensification to 4-weekly (n = 50, 30.7%) or 6-weekly (n = 5, 3.1%). After 1 year 29.9% were dose intensified. Prior exposure to both anti-TNF and vedolizumab (HR 9.5; 1.3–70.9), and concomitant steroid use at UST start (HR 1.8; 1.0–3.1) were associated with dose intensification. Following dose intensification, 62.6% patients (29/55) remained on UST beyond 1 year. Corticosteroid-free clinical remission was achieved in 27% at week 16 and 29.6% at last follow-up. Conclusion: One third of CD patients treated with UST underwent dose intensification to a 4- or 6-weekly interval within the first year. Patients who failed both anti-TNF and vedolizumab, or required steroids at initiation were more likely to dose intensify.</p

    Effectiveness and Safety of Adalimumab Biosimilar SB5 in IBD:Outcomes in Originator to SB5 Switch, Double Biosimilar Switch and Bio-Naieve SB5 Observational Cohorts

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    BACKGROUND AND AIMS: Multiple adalimumab [ADA] biosimilars are now approved for use in inflammatory bowel disease [IBD]; however, effectiveness and safety data remain scarce. We aimed to investigate long-term outcomes of the ADA biosimilar SB5 in IBD patients following a switch from the ADA originator [SB5-switch cohort] or after start of SB5 [SB5-start cohort]. METHODS: We performed an observational cohort study in a tertiary IBD referral centre. All IBD patients treated with Humira underwent an elective switch to SB5. We identified all these patients in a biological prescription database that prospectively registered all ADA start and stop dates including brand names. Data on IBD phenotype, C-reactive protein [CRP], drug persistence, ADA drug and antibody levels, and faecal calprotectin were collected. RESULTS: In total, 481 patients were treated with SB5, 256 in the SB5-switch cohort (median follow-up: 13.7 months [IQR 8.6–15.2]) and 225 in the SB5-start cohort [median follow-up: 8.3 months [4.2–12.8]). Of the SB5-switch cohort, 70.8% remained on SB5 beyond 1 year; 90/256 discontinued SB5, mainly due to adverse events [46/90] or secondary loss of response [37/90]. In the SB5-start cohort, 81/225 discontinued SB5, resulting in SB5-drug persistence of 60.3% beyond 1 year. No differences in clinical remission [p = 0.53], CRP [p = 0.80], faecal calprotectin [p = 0.40] and ADA trough levels [p = 0.55] were found between baseline, week 26 and week 52 following switch. Injection site pain was the most frequently reported adverse event. CONCLUSION: Switching from ADA originator to SB5 appeared effective and safe in this study with over 12 months of follow-up

    Human umbilical cord perivascular cells improve human pancreatic islet transplant function by increasing vascularization

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    Islet transplantation is an efficacious therapy for type 1 diabetes; however, islets from multiple donor pancreata are required, and a gradual attrition in transplant function is seen. Here, we manufactured human umbilical cord perivascular mesenchymal stromal cells (HUCPVCs) to Good Manufacturing Practice (GMP) standards. HUCPVCs showed a stable phenotype while undergoing rapid ex vivo expansion at passage 2 (p2) to passage 4 (p4) and produced proregenerative factors, strongly suppressing T cell responses in the resting state and in response to inflammation. Transplanting an islet equivalent (IEQ):HUCPVC ratio of 1:30 under the kidney capsule in diabetic NSG mice demonstrated the fastest return to normoglycemia by 3 days after transplant: Superior glycemic control was seen at both early (2.7 weeks) and later stages (7, 12, and 16 weeks) versus ratios of 1:0, 1:10, and 1:50, respectively. Syngeneic islet transplantation in immunocompetent mice using the clinically relevant hepatic portal route with a marginal islet mass showed that mice transplanted with an IEQ:HUCPVC ratio of 1:150 had superior glycemic control versus ratios of 1:0, 1:90, and 1:210 up to 6 weeks after transplant. Immunodeficient mice transplanted with human islets (IEQ:HUCPVC ratio of 1:150) exhibited better glycemic control for 7 weeks after transplant versus islet transplant alone, and islets transplanted via the hepatic portal vein in an allogeneic mouse model using a curative islet mass demonstrated delayed rejection of islets when cotransplanted with HUCPVCs (IEQ:HUCPVC ratio of 1:150). The immunosuppressive and proregenerative properties of HUCPVCs demonstrated long-term positive effects on graft function in vivo, indicating that they may improve long-term human islet allotransplantation outcomes

    Evaluating the effect of a digital health intervention to enhance physical activity in people with chronic kidney disease (Kidney BEAM): a multicentre, randomised controlled trial in the UK

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    BACKGROUND: Remote digital health interventions to enhance physical activity provide a potential solution to improve the sedentary behaviour, physical inactivity, and poor health-related quality of life that are typical of chronic conditions, particularly for people with chronic kidney disease. However, there is a need for high-quality evidence to support implementation in clinical practice. The Kidney BEAM trial evaluated the clinical effect of a 12-week physical activity digital health intervention on health-related quality of life. METHODS: In a single-blind, randomised controlled trial conducted at 11 centres in the UK, adult participants (aged ≥18 years) with chronic kidney disease were recruited and randomly assigned (1:1) to the Kidney BEAM physical activity digital health intervention or a waiting list control group. Randomisation was performed with a web-based system, in randomly permuted blocks of six. Outcome assessors were masked to treatment allocation. The primary outcome was the difference in the Kidney Disease Quality of Life Short Form version 1.3 Mental Component Summary (KDQoL-SF1.3 MCS) between baseline and 12 weeks. The trial was powered to detect a clinically meaningful difference of 3 arbitrary units (AU) in KDQoL-SF1.3 MCS. Outcomes were analysed by an intention-to-treat approach using an analysis of covariance model, with baseline measures and age as covariates. The trial was registered with ClinicalTrials.gov, NCT04872933. FINDINGS: Between May 6, 2021, and Oct 30, 2022, 1102 individuals were assessed for eligibility, of whom 340 participants were enrolled and randomly assigned to the Kidney BEAM intervention group (n=173) or the waiting list control group (n=167). 268 participants completed the trial (112 in the Kidney BEAM group and 156 in the waiting list control group). All 340 randomly assigned participants were included in the intention-to treat population. At 12 weeks, there was a significant improvement in KDQoL-SF.13 MCS score in the Kidney BEAM group (from mean 44·6 AU [SD 10·8] at baseline to 47·0 AU [10·6] at 12 weeks) compared with the waiting list control group (from 46·1 AU [10·5] to 45·0 AU [10·1]; between-group difference of 3·1 AU [95% CI 1·8-4·4]; p<0·0001). INTERPRETATION: The Kidney BEAM physical activity platform is an efficacious digital health intervention to improve mental health-related quality of life in patients with chronic kidney disease. These findings could facilitate the incorporation of remote digital health interventions into clinical practice and offer a potential intervention worthy of investigation in other chronic conditions. FUNDING: Kidney Research UK

    Influence of Prior Influenza Vaccination on Antibody and B-Cell Responses

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    Currently two vaccines, trivalent inactivated influenza vaccine (TIV) and live attenuated influenza vaccine (LAIV), are licensed in the USA. Despite previous studies on immune responses induced by these two vaccines, a comparative study of the influence of prior influenza vaccination on serum antibody and B-cell responses to new LAIV or TIV vaccination has not been reported. During the 2005/6 influenza season, we quantified the serum antibody and B-cell responses to LAIV or TIV in adults with differing influenza vaccination histories in the prior year: LAIV, TIV, or neither. Blood samples were collected on days 0, 7–9 and 21–35 after immunization and used for serum HAI assay and B-cell assays. Total and influenza-specific circulating IgG and IgA antibody secreting cells (ASC) in PBMC were detected by direct ELISPOT assay. Memory B cells were also tested by ELISPOT after polyclonal stimulation of PBMC in vitro. Serum antibody, effector, and memory B-cell responses were greater in TIV recipients than LAIV recipients. Prior year TIV recipients had significantly higher baseline HAI titers, but lower HAI response after vaccination with either TIV or LAIV, and lower IgA ASC response after vaccination with TIV than prior year LAIV or no vaccination recipients. Lower levels of baseline HAI titer were associated with a greater fold-increase of HAI titer and ASC number after vaccination, which also differed by type of vaccine. Our findings suggest that the type of vaccine received in the prior year affects the serum antibody and the B-cell responses to subsequent vaccination. In particular, prior year TIV vaccination is associated with sustained higher HAI titer one year later but lower antibody response to new LAIV or TIV vaccination, and a lower effector B-cell response to new TIV but not LAIV vaccination

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
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