19 results on '"George R, Ambalathingal"'
Search Results
2. Limited Recognition of Highly Conserved Regions of SARS-CoV-2
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Srividhya Swaminathan, Katie E. Lineburg, George R. Ambalathingal, Pauline Crooks, Emma J. Grant, Sonali V. Mohan, Jyothy Raju, Archana Panikkar, Laetitia Le Texier, Zheng Wei Marcus Tong, Keng Yih Chew, Michelle A. Neller, Kirsty R. Short, Harsha Gowda, Stephanie Gras, Rajiv Khanna, and Corey Smith
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SARS-CoV-2 ,COVID-19 ,antigen-specific CD8+ T cells ,conservation ,Microbiology ,QR1-502 - Abstract
ABSTRACT Understanding the immune response to severe acute respiratory syndrome coronavirus (SARS-CoV-2) is critical to overcome the current coronavirus disease (COVID-19) pandemic. Efforts are being made to understand the potential cross-protective immunity of memory T cells, induced by prior encounters with seasonal coronaviruses, in providing protection against severe COVID-19. In this study we assessed T-cell responses directed against highly conserved regions of SARS-CoV-2. Epitope mapping revealed 16 CD8+ T-cell epitopes across the nucleocapsid (N), spike (S), and open reading frame (ORF)3a proteins of SARS-CoV-2 and five CD8+ T-cell epitopes encoded within the highly conserved regions of the ORF1ab polyprotein of SARS-CoV-2. Comparative sequence analysis showed high conservation of SARS-CoV-2 ORF1ab T-cell epitopes in seasonal coronaviruses. Paradoxically, the immune responses directed against the conserved ORF1ab epitopes were infrequent and subdominant in both convalescent and unexposed participants. This subdominant immune response was consistent with a low abundance of ORF1ab encoded proteins in SARS-CoV-2 infected cells. Overall, these observations suggest that while cross-reactive CD8+ T cells likely exist in unexposed individuals, they are not common and therefore are unlikely to play a significant role in providing broad preexisting immunity in the community. IMPORTANCE T cells play a critical role in protection against SARS-CoV-2. Despite being highly topical, the protective role of preexisting memory CD8+ T cells, induced by prior exposure to circulating common coronavirus strains, remains less clear. In this study, we established a robust approach to specifically assess T cell responses to highly conserved regions within SARS-CoV-2. Consistent with recent observations we demonstrate that recognition of these highly conserved regions is associated with an increased likelihood of milder disease. However, extending these observations we observed that recognition of these conserved regions is rare in both exposed and unexposed volunteers, which we believe is associated with the low abundance of these proteins in SARS-CoV-2 infected cells. These observations have important implications for the likely role preexisting immunity plays in controlling severe disease, further emphasizing the importance of vaccination to generate the immunodominant T cells required for immune protection.
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- 2022
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3. SARS-CoV-2-specific T cells generated for adoptive immunotherapy are capable of recognizing multiple SARS-CoV-2 variants.
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Archana Panikkar, Katie E Lineburg, Jyothy Raju, Keng Yih Chew, George R Ambalathingal, Sweera Rehan, Srividhya Swaminathan, Pauline Crooks, Laetitia Le Texier, Leone Beagley, Shannon Best, Matthew Solomon, Katherine K Matthews, Sriganesh Srihari, Michelle A Neller, Kirsty R Short, Rajiv Khanna, and Corey Smith
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Adoptive T-cell immunotherapy has provided promising results in the treatment of viral complications in humans, particularly in the context of immunocompromised patients who have exhausted all other clinical options. The capacity to expand T cells from healthy immune individuals is providing a new approach to anti-viral immunotherapy, offering rapid off-the-shelf treatment with tailor-made human leukocyte antigen (HLA)-matched T cells. While most of this research has focused on the treatment of latent viral infections, emerging evidence that SARS-CoV-2-specific T cells play an important role in protection against COVID-19 suggests that the transfer of HLA-matched allogeneic off-the-shelf virus-specific T cells could provide a treatment option for patients with active COVID-19 or at risk of developing COVID-19. We initially screened 60 convalescent individuals and based on HLA typing and T-cell response profile, 12 individuals were selected for the development of a SARS-CoV-2-specific T-cell bank. We demonstrate that these T cells are specific for up to four SARS-CoV-2 antigens presented by a broad range of both HLA class I and class II alleles. These T cells show consistent functional and phenotypic properties, display cytotoxic potential against HLA-matched targets and can recognize HLA-matched cells infected with different SARS-CoV-2 variants. These observations demonstrate a robust approach for the production of SARS-CoV-2-specific T cells and provide the impetus for the development of a T-cell repository for clinical assessment.
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- 2022
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4. 'Off-the-shelf’ allogeneic antigen-specific adoptive T-cell therapy for the treatment of multiple EBV-associated malignancies
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Debottam Sinha, Sriganesh Srihari, Kirrliee Beckett, Laetitia Le Texier, Matthew Solomon, Archana Panikkar, George R Ambalathingal, Lea Lekieffre, Pauline Crooks, Sweera Rehan, Michelle A. Neller, Corey Smith, and Rajiv Khanna
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background Epstein-Barr virus (EBV), an oncogenic human gammaherpesvirus, is associated with a wide range of human malignancies of epithelial and B-cell origin. Recent studies have demonstrated promising safety and clinical efficacy of allogeneic ‘off-the-shelf’ virus-specific T-cell therapies for post-transplant viral complications.Methods Taking a clue from these studies, we developed a highly efficient EBV-specific T-cell expansion process using a replication-deficient AdE1-LMPpoly vector that specifically targets EBV-encoded nuclear antigen 1 (EBNA1) and latent membrane proteins 1 and 2 (LMP1 and LMP2), expressed in latency II malignancies.Results These allogeneic EBV-specific T cells efficiently recognized human leukocyte antigen (HLA)-matched EBNA1-expressing and/or LMP1 and LMP2-expressing malignant cells and demonstrated therapeutic potential in a number of in vivo models, including EBV lymphomas that emerged spontaneously in humanized mice following EBV infection. Interestingly, we were able to override resistance to T-cell therapy in vivo using a ‘restriction-switching’ approach, through sequential infusion of two different allogeneic T-cell therapies restricted through different HLA alleles. Furthermore, we have shown that inhibition of the programmed cell death protein-1/programmed death-ligand 1 axis in combination with EBV-specific T-cell therapy significantly improved overall survival of tumor-bearing mice when compared with monotherapy.Conclusion These findings suggest that restriction switching by sequential infusion of allogeneic T-cell therapies that target EBV through distinct HLA alleles may improve clinical response.
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- 2021
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5. Rapid whole‐blood assay to detect SARS‐CoV‐2‐specific memory T‐cell immunity following a single dose of AstraZeneca ChAdOx1‐S COVID‐19 vaccine
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Katie E Lineburg, Michelle A Neller, George R Ambalathingal, Laetitia Le Texier, Jyothy Raju, Srividhya Swaminathan, Lea Lekieffre, Caitlyn Smith, Sweera Rehan, Pauline Crooks, Archana Panikkar, Sriganesh Srihari, Rajiv Khanna, and Corey Smith
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COVID‐19 ,SARS‐CoV‐2 ,T cells ,vaccine ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Objectives With the ongoing emergence of SARS‐CoV‐2 variants and potential to evade vaccine‐induced neutralisation, understanding the magnitude and breadth of vaccine‐induced T‐cell immunity will be critical for the ongoing optimisation of vaccine approaches. Strategies that provide a rapid and easily translatable means of assessing virus‐specific T‐cell responses provide an opportunity to monitor the impact of vaccine rollouts in the community. In this study, we assessed whether our recently developed SARS‐CoV‐2 whole‐blood assay could be used effectively to analyse T‐cell responses following vaccination. Methods Following a median of 15 days after the first dose of the ChAdOx1‐S (AstraZeneca®) vaccine, peripheral blood was isolated from 58 participants. Blood was incubated overnight with an overlapping set of spike protein peptides and assessed for cytokine production using a cytometric bead array. Results The majority of vaccine recipients (51/58) generated a T helper 1 response (IFN‐γ and/or IL‐2) following a single dose of ChAdOx1‐S. The magnitude of the IFN‐γ and IL‐2 response strongly correlated in vaccine recipients. While the production of other cytokines was evident in individuals who did not generate IFN‐γ and IL‐2, they showed no correlation in magnitude, nor did we see a correlation between sex or age and the magnitude of the response. Conclusions The whole‐blood cytokine assay provides a rapid approach to assessing T‐cell immunity against SARS‐CoV‐2 in vaccine recipients. While the majority of participants generated a robust SARS‐CoV‐2‐specific T‐cell response following their first dose, some did not, demonstrating the likely importance of the booster dose in improving T‐cell immunity.
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- 2021
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- View/download PDF
6. Rapid detection of SARS‐CoV‐2‐specific memory T‐cell immunity in recovered COVID‐19 cases
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Katie E Lineburg, Sriganesh Srihari, Mohammed Altaf, Srividhya Swaminathan, Archana Panikkar, Jyothy Raju, Pauline Crooks, George R Ambalathingal, Jose Paulo Martins, Katherine K Matthews, Michelle A Neller, Rajiv Khanna, and Corey Smith
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antigen‐specific ,COVID‐19 ,SARS‐CoV‐2 ,T‐cell response ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Objectives There is emerging evidence that SARS‐CoV‐2‐specific memory T‐cell responses are likely to provide critical long‐term protection against COVID‐19. Strategies to rapidly assess T‐cell responses are therefore likely to be important for assessing immunity in the global population. Methods Here, we have developed a rapid immune‐monitoring strategy to assess virus‐specific memory T‐cell responses in the peripheral blood of COVID‐19 convalescent individuals. We validated SARS‐CoV‐2‐specific memory T‐cell responses detected in whole blood using in vitro expansion with SARS‐CoV‐2 proteins. Results T‐cell immunity characterised by the production of IFN‐γ and IL‐2 could be consistently detected in the whole blood of recovered participants. T cells predominantly recognised structural SARS‐CoV‐2 proteins. In vitro expansion demonstrated that while CD8+ T cells recognised nucleocapsid protein, spike protein and ORF3a, CD4+ T cells more broadly targeted multiple SARS‐CoV‐2 proteins. Conclusion These observations provide a timely monitoring approach for identifying SARS‐CoV‐2 cellular immunity and may serve as a diagnostic for the stratification of risk in immunocompromised and other at‐risk individuals.
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- 2020
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7. Proteome‐wide analysis of T‐cell response to BK polyomavirus in healthy virus carriers and kidney transplant recipients reveals a unique transcriptional and functional profile
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George R Ambalathingal, Ross S Francis, Dillon Corvino, Sriganesh Srihari, Blake T Aftab, Corey Smith, and Rajiv Khanna
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adaptive immunity ,cellular immunity ,immunology ,immunotherapy ,infectious diseases ,innate immune cells ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Objectives Cellular immunity against BK polyomavirus (BKV)‐encoded antigens plays a crucial role in long‐term protection against virus‐associated pathogenesis in transplant recipients. However, in‐depth understanding on dynamics of these cellular immune responses is required to develop better immune monitoring and immunotherapeutic strategies. Methods Here, we have conducted a proteome‐wide analysis of BKV‐specific T‐cell responses in a cohort of 53 healthy individuals and 26 kidney transplant recipients to delineate the functional and transcriptional profile of these effector cells and compared these characteristics to T cells directed against cytomegalovirus, which is also known to cause significant morbidity in transplant recipients. Results Profiling of BKV‐specific CD4+ and CD8+ T cells revealed that kidney transplant recipients with high levels of circulating viraemia showed significantly reduced T‐cell reactivity against large T and/or small T antigens when compared to healthy donors. Interestingly, T cells specific for these antigens showed strong cross‐recognition to orthologous JC virus (JCV) peptides, including those exhibiting varying degrees of sequence identity. Ex vivo functional and phenotypic characterisation revealed that the majority of BKV‐specific T cells from renal transplant recipients expressed low levels of the key transcriptional regulators T‐bet and eomesodermin, which was coincident with undetectable expression of granzyme B and perforin. However, in vitro stimulation of T cells with BKV epitopes selectively enhanced the expression of T‐bet, granzyme B and cellular trafficking molecules (CCR4, CD49d and CD103) with minimal change in eomesodermin and perforin. Conclusions These observations provide an important platform for the future development of immune monitoring and adoptive T‐cell therapy strategies for BKV‐associated diseases in transplant recipients, which may also be exploited for similar therapeutic value in JCV‐associated clinical complications.
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- 2020
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8. Ablation of CD8+ T cell recognition of an immunodominant epitope in SARS-CoV-2 Omicron variants BA.1, BA.2 and BA.3
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Srividhya Swaminathan, Katie E. Lineburg, Archana Panikkar, Jyothy Raju, Lawton D. Murdolo, Christopher Szeto, Pauline Crooks, Laetitia Le Texier, Sweera Rehan, Michael J. Dewar-Oldis, Peter J. Barnard, George R. Ambalathingal, Michelle A. Neller, Kirsty R. Short, Stephanie Gras, Rajiv Khanna, and Corey Smith
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,Uncategorized - Abstract
The emergence of the SARS-CoV-2 Omicron variant has raised concerns of escape from vaccine-induced immunity. A number of studies have demonstrated a reduction in antibody-mediated neutralization of the Omicron variant in vaccinated individuals. Preliminary observations have suggested that T cells are less likely to be affected by changes in Omicron. However, the complexity of human leukocyte antigen genetics and its impact upon immunodominant T cell epitope selection suggests that the maintenance of T cell immunity may not be universal. In this study, we describe the impact that changes in Omicron BA.1, BA.2 and BA.3 have on recognition by spike-specific T cells. These T cells constitute the immunodominant CD8+ T cell response in HLA-A*29:02+ COVID-19 convalescent and vaccinated individuals; however, they fail to recognize the Omicron-encoded sequence. These observations demonstrate that in addition to evasion of antibody-mediated immunity, changes in Omicron variants can also lead to evasion of recognition by immunodominant T cell responses.
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- 2023
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9. Pretransplant Cytomegalovirus-Specific Cellular Immunity and Risk of Viral Reactivation Following Lung Transplantation: A Prospective Cohort Study
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Katie E. Lineburg, Rajiv Khanna, Debottam Sinha, Michelle A Neller, Pauline Crooks, Katherine K. Matthews, Michelle Grant, Mohammed Altaf, George R Ambalathingal, Peter Hopkins, Corey Smith, Sweera Rehan, and Daniel C. Chambers
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Cellular immunity ,medicine.medical_treatment ,Congenital cytomegalovirus infection ,030230 surgery ,03 medical and health sciences ,0302 clinical medicine ,Immunity ,Humans ,Immunology and Allergy ,Medicine ,Lung transplantation ,Prospective Studies ,Prospective cohort study ,Immunity, Cellular ,Viral reactivation ,Lung ,business.industry ,Incidence (epidemiology) ,virus diseases ,medicine.disease ,surgical procedures, operative ,Infectious Diseases ,medicine.anatomical_structure ,Cytomegalovirus Infections ,Immunology ,Latent Infection ,030211 gastroenterology & hepatology ,business ,Lung Transplantation - Abstract
Cytomegalovirus (CMV) remains a significant burden in lung transplant recipients. Deficiencies in T-cell immunity posttransplant increase the risk of CMV-associated complications. However, it is not clear if underlying poor pretransplant immunity increases risk. To assess this, we recruited 39 prospective lung transplant patients and performed QuantiFERON-CMV on their peripheral blood. More than a third of prospective CMV-seropositive transplant recipients were CMV non-immune reactive (CMV-NIR) pretransplant. CMV-NIR status was associated with a significantly higher incidence of CMV reactivation posttransplant, demonstrating that dysfunctional CMV immunity in prospective lung transplant recipients is associated with an increased risk of viral reactivation posttransplant.
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- 2020
10. Autologous CMV-specific T cells are a safe adjuvant immunotherapy for primary glioblastoma multiforme
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Pauline Crooks, Michelle A Neller, David G. Walker, Corey Smith, Sweera Rehan, J. Paulo Martins, George R Ambalathingal, Beth Morrison, Laetitia Le Texier, Leone Beagley, Katherine K. Matthews, Sriganesh Srihari, Archana Panikkar, Rajiv Khanna, and Katie E. Lineburg
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Adult ,Male ,0301 basic medicine ,Oncology ,medicine.medical_specialty ,T-Lymphocytes ,medicine.medical_treatment ,Cytomegalovirus ,Disease-Free Survival ,Blood Transfusion, Autologous ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Cancer immunotherapy ,Internal medicine ,medicine ,Adjuvant therapy ,Humans ,Prospective Studies ,Prospective cohort study ,business.industry ,General Medicine ,Immunotherapy ,Middle Aged ,Gene signature ,Survival Rate ,Clinical trial ,030104 developmental biology ,Lymphocyte Transfusion ,030220 oncology & carcinogenesis ,Female ,Clinical Medicine ,Glioblastoma ,business ,Adjuvant ,Follow-Up Studies - Abstract
Background The recent failure of checkpoint-blockade therapies for glioblastoma multiforme (GBM) in late-phase clinical trials has directed interest towards adoptive cellular immunotherapies (ACT). In this open-label, first-in-human trial, we have assessed the safety and therapeutic potential of cytomegalovirus (CMV)-specific ACT in an adjuvant setting for patients with primary GBM, with an ultimate goal to prevent or delay recurrence and prolong overall survival. Methods Twenty-eight patients with primary GBM were recruited to this prospective study, 25 of whom were treated with in vitro-expanded autologous CMV-specific T cells. Participants were monitored for safety, progression-free survival (PFS), overall survival (OS) and immune reconstitution. Results No participants showed evidence of ACT-related toxicities. Of 25 evaluable participants, ten were alive at the completion of follow-up, while five were disease free. Reconstitution of CMV-specific T-cell immunity was evident and CMV-specific ACT may trigger bystander effect leading to additional T-cell responses to non-viral tumour-associated antigens through epitope spreading. Long-term follow-up of participants treated before recurrence showed significantly improved OS when compared to those who progressed before ACT (median 23 months, range 7-65 vs. median 14 months, range 5-19; p=0.018). Gene expression analysis of the ACT products indicated that a favourable T-cell gene signature was associated with improved long-term survival. Conclusion Data presented in this study demonstrate that CMV-specific ACT can be safely used as an adjuvant therapy for primary GBM and, if offered before recurrence, this therapy may improve overall survival of GBM patients. Trial registration anzctr.org.au: ACTRN12615000656538Funding Source:National Health & Medical Research Council (Australia)Trial registration: anzctr.org.au: ACTRN12615000656538Funding Source: Philanthropic funding &National Health & Medical Research Council (Australia).
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- 2020
11. Ablation of CD8
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Srividhya, Swaminathan, Katie E, Lineburg, Archana, Panikkar, Jyothy, Raju, Lawton D, Murdolo, Christopher, Szeto, Pauline, Crooks, Laetitia, Le Texier, Sweera, Rehan, Michael J, Dewar-Oldis, Peter J, Barnard, George R, Ambalathingal, Michelle A, Neller, Kirsty R, Short, Stephanie, Gras, Rajiv, Khanna, and Corey, Smith
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Immunodominant Epitopes ,SARS-CoV-2 ,Spike Glycoprotein, Coronavirus ,Humans ,COVID-19 ,CD8-Positive T-Lymphocytes ,Antibodies, Viral ,Antibodies, Neutralizing - Abstract
The emergence of the SARS-CoV-2 Omicron variant has raised concerns of escape from vaccine-induced immunity. A number of studies have demonstrated a reduction in antibody-mediated neutralization of the Omicron variant in vaccinated individuals. Preliminary observations have suggested that T cells are less likely to be affected by changes in Omicron. However, the complexity of human leukocyte antigen genetics and its impact upon immunodominant T cell epitope selection suggests that the maintenance of T cell immunity may not be universal. In this study, we describe the impact that changes in Omicron BA.1, BA.2 and BA.3 have on recognition by spike-specific T cells. These T cells constitute the immunodominant CD8
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- 2022
12. Low antigen abundance limits efficient T-cell recognition of highly conserved regions of SARS-CoV-2
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Pauline Crooks, Harsha Gowda, Archana Panikkar, Zhen Tong, Katie E. Lineburg, Rajiv Khanna, Sonali Mohan, Stephanie Gras, Kirsty R. Short, Michelle A Neller, Corey Smith, Emma J. Grant, Laetitia Le Texier, George R Ambalathingal, Keng Chew, Jyothy Raju, and Srividhya Swaminathan
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Subdominant ,viruses ,T cell ,biochemical phenomena, metabolism, and nutrition ,Biology ,medicine.disease_cause ,Virology ,Epitope ,medicine.anatomical_structure ,Immune system ,Epitope mapping ,Antigen ,medicine ,CD8 ,Coronavirus - Abstract
SummaryUnderstanding the immune response to severe acute respiratory syndrome coronavirus (SARS-CoV-2) is critical to overcome the current coronavirus disease (COVID-19) pandemic. Efforts are being made to understand the potential cross-protective immunity of memory T cells, induced by prior encounters with seasonal coronaviruses, in providing protection against severe COVID-19. In this study we assessed T-cell responses directed against highly conserved regions of SARS-CoV-2. Epitope mapping revealed 16 CD8+ T-cell epitopes across the nucleocapsid (N), spike (S) and ORF3a proteins of SARS-CoV-2 and five CD8+ T-cell epitopes encoded within the highly conserved regions of the ORF1ab polyprotein of SARS-CoV-2. Comparative sequence analysis showed high conservation of SARS-CoV-2 ORF1ab T-cell epitopes in seasonal coronaviruses. Paradoxically, the immune responses directed against the conserved ORF1ab epitopes were infrequent and subdominant in both convalescent and unexposed participants. This subdominant immune response was consistent with a low abundance of ORF1ab encoded proteins in SARS-CoV-2 infected cells. Overall, these observations suggest that while cross-reactive CD8+ T cells likely exist in unexposed individuals, they are not common and therefore are unlikely to play a significant role in providing broad pre-existing immunity in the community.
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- 2021
13. Rapid whole‐blood assay to detect SARS‐CoV‐2‐specific memory T‐cell immunity following a single dose of AstraZeneca ChAdOx1‐S COVID‐19 vaccine
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Lea Lekieffre, Sweera Rehan, Rajiv Khanna, George R Ambalathingal, Archana Panikkar, Sriganesh Srihari, Katie E. Lineburg, Michelle A Neller, Caitlyn Smith, Pauline Crooks, Srividhya Swaminathan, Laetitia Le Texier, Jyothy Raju, and Corey Smith
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business.industry ,Short Communication ,medicine.medical_treatment ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Immunology ,Short Communications ,T cells ,Booster dose ,RC581-607 ,SARS‐CoV‐2 ,Neutralization ,Vaccination ,medicine.anatomical_structure ,Cytokine ,COVID‐19 ,Immunity ,vaccine ,Immunology and Allergy ,Medicine ,Immunologic diseases. Allergy ,business ,Memory T cell ,General Nursing ,Whole blood - Abstract
Objectives With the ongoing emergence of SARS‐CoV‐2 variants and potential to evade vaccine‐induced neutralisation, understanding the magnitude and breadth of vaccine‐induced T‐cell immunity will be critical for the ongoing optimisation of vaccine approaches. Strategies that provide a rapid and easily translatable means of assessing virus‐specific T‐cell responses provide an opportunity to monitor the impact of vaccine rollouts in the community. In this study, we assessed whether our recently developed SARS‐CoV‐2 whole‐blood assay could be used effectively to analyse T‐cell responses following vaccination. Methods Following a median of 15 days after the first dose of the ChAdOx1‐S (AstraZeneca®) vaccine, peripheral blood was isolated from 58 participants. Blood was incubated overnight with an overlapping set of spike protein peptides and assessed for cytokine production using a cytometric bead array. Results The majority of vaccine recipients (51/58) generated a T helper 1 response (IFN‐γ and/or IL‐2) following a single dose of ChAdOx1‐S. The magnitude of the IFN‐γ and IL‐2 response strongly correlated in vaccine recipients. While the production of other cytokines was evident in individuals who did not generate IFN‐γ and IL‐2, they showed no correlation in magnitude, nor did we see a correlation between sex or age and the magnitude of the response. Conclusions The whole‐blood cytokine assay provides a rapid approach to assessing T‐cell immunity against SARS‐CoV‐2 in vaccine recipients. While the majority of participants generated a robust SARS‐CoV‐2‐specific T‐cell response following their first dose, some did not, demonstrating the likely importance of the booster dose in improving T‐cell immunity., Strategies that provide a rapid and easily translatable means of assessing SARS‐CoV‐2‐specific T‐cell responses provide an opportunity to monitor the impact of vaccine rollouts in the community. In this study, we assessed whether our recently developed SARS‐CoV‐2 whole‐blood assay could be used effectively to analyse T‐cell responses following vaccination. We demonstrated that the whole‐blood cytokine assay provides a rapid approach to assessing T‐cell immunity against SARS‐CoV‐2 in vaccine recipients.
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- 2021
14. Rapid detection of SARS‐CoV‐2‐specific memory T‐cell immunity in recovered COVID‐19 cases
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José Paulo Martins, Archana Panikkar, Sriganesh Srihari, Srividhya Swaminathan, Katherine K. Matthews, George R Ambalathingal, Mohammed Altaf, Corey Smith, Jyothy Raju, Michelle A Neller, Katie E. Lineburg, Rajiv Khanna, and Pauline Crooks
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lcsh:Immunologic diseases. Allergy ,0301 basic medicine ,Cellular immunity ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,viruses ,Immunology ,Biology ,SARS‐CoV‐2 ,03 medical and health sciences ,0302 clinical medicine ,Immunity ,COVID‐19 ,medicine ,Immunology and Allergy ,General Nursing ,Whole blood ,T‐cell response ,Original Articles ,biochemical phenomena, metabolism, and nutrition ,In vitro ,030104 developmental biology ,medicine.anatomical_structure ,antigen‐specific ,Original Article ,lcsh:RC581-607 ,Memory T cell ,CD8 ,030215 immunology - Abstract
Objectives There is emerging evidence that SARS‐CoV‐2‐specific memory T‐cell responses are likely to provide critical long‐term protection against COVID‐19. Strategies to rapidly assess T‐cell responses are therefore likely to be important for assessing immunity in the global population. Methods Here, we have developed a rapid immune‐monitoring strategy to assess virus‐specific memory T‐cell responses in the peripheral blood of COVID‐19 convalescent individuals. We validated SARS‐CoV‐2‐specific memory T‐cell responses detected in whole blood using in vitro expansion with SARS‐CoV‐2 proteins. Results T‐cell immunity characterised by the production of IFN‐γ and IL‐2 could be consistently detected in the whole blood of recovered participants. T cells predominantly recognised structural SARS‐CoV‐2 proteins. In vitro expansion demonstrated that while CD8+ T cells recognised nucleocapsid protein, spike protein and ORF3a, CD4+ T cells more broadly targeted multiple SARS‐CoV‐2 proteins. Conclusion These observations provide a timely monitoring approach for identifying SARS‐CoV‐2 cellular immunity and may serve as a diagnostic for the stratification of risk in immunocompromised and other at‐risk individuals., T‐cell immunity is likely critical for the control of COVID‐19. We have developed a rapid assay to detect T‐cell immunity in whole blood, and demonstrate the effectiveness of this assay in individuals who have recovered from COVID‐19.
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- 2020
15. T-cell adoptive immunotherapy for BK nephropathy in renal transplantation
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Corey Smith, George R Ambalathingal, George John, Leo Francis, Sadia Jahan, Sweera Rehan, Carla Scuderi, Michelle A Neller, Pauline Crooks, and Rajiv Khanna
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medicine.medical_specialty ,medicine.medical_treatment ,T-Lymphocytes ,Short Communication ,Urology ,030230 surgery ,medicine.disease_cause ,Immunotherapy, Adoptive ,Nephropathy ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,BK virus ,Biopsy ,medicine ,Humans ,T‐cell adoptive immunotherapy ,Transplantation ,Polyomavirus Infections ,Everolimus ,medicine.diagnostic_test ,business.industry ,BKPyV nephropathy ,Australia ,Middle Aged ,medicine.disease ,Kidney Transplantation ,Tacrolimus ,Tumor Virus Infections ,Infectious Diseases ,chemistry ,Leukocytes, Mononuclear ,030211 gastroenterology & hepatology ,Female ,Hemodialysis ,business ,medicine.drug ,Cidofovir - Abstract
Introduction BK virus (BKPyV) nephropathy occurs in 1%‐10% of kidney transplant recipients, with suboptimal therapeutic options. Case A 54‐year‐old woman received a transplant in March 2017. BKPyV was detected at 1.5 × 102 copies/mL within a month, necessitating halving of mycophenolate and addition of leflunomide. Allograft histology in December showed polyomavirus nephropathy treated with intravenous immunoglobulin and cessation of mycophenolate. In February 2018, cidofovir and ciprofloxacin were commenced. In April, tacrolimus was reduced while introducing everolimus. A second graft biopsy in August showed increasing polyoma virus infection and a subsequent biopsy in September for worsening renal function showed 30% of tubular reactivity for simian virus 40 (SV40). Allogeneic BKPyV‐reactive T cells were generated from the patient's daughter and infused over 10 sessions starting late September. The fourth allograft biopsy in November 2018 demonstrated involvement of BKPyV in 50% of tubules. Allograft function continued to decline, requiring hemodialysis from December 2018. Allograft nephrectomy after 6 months showed
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- 2020
16. Proteome‐wide analysis of T‐cell response to BK polyomavirus in healthy virus carriers and kidney transplant recipients reveals a unique transcriptional and functional profile
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Blake T. Aftab, George R Ambalathingal, Corey Smith, Sriganesh Srihari, Rajiv Khanna, Ross S Francis, and Dillon Corvino
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lcsh:Immunologic diseases. Allergy ,0301 basic medicine ,lymphocytes ,Cellular immunity ,viruses ,T cells ,Eomesodermin ,cellular immunity ,030230 surgery ,Biology ,infectious diseases ,Epitope ,immunology ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Antigen ,Immunology and Allergy ,Cytotoxic T cell ,innate immune cells ,General Nursing ,virus diseases ,Original Articles ,adaptive immunity ,Acquired immune system ,Granzyme B ,030104 developmental biology ,Immunology ,Original Article ,immunotherapy ,viral infection ,lcsh:RC581-607 - Abstract
Objectives Cellular immunity against BK polyomavirus (BKV)‐encoded antigens plays a crucial role in long‐term protection against virus‐associated pathogenesis in transplant recipients. However, in‐depth understanding on dynamics of these cellular immune responses is required to develop better immune monitoring and immunotherapeutic strategies. Methods Here, we have conducted a proteome‐wide analysis of BKV‐specific T‐cell responses in a cohort of 53 healthy individuals and 26 kidney transplant recipients to delineate the functional and transcriptional profile of these effector cells and compared these characteristics to T cells directed against cytomegalovirus, which is also known to cause significant morbidity in transplant recipients. Results Profiling of BKV‐specific CD4+ and CD8+ T cells revealed that kidney transplant recipients with high levels of circulating viraemia showed significantly reduced T‐cell reactivity against large T and/or small T antigens when compared to healthy donors. Interestingly, T cells specific for these antigens showed strong cross‐recognition to orthologous JC virus (JCV) peptides, including those exhibiting varying degrees of sequence identity. Ex vivo functional and phenotypic characterisation revealed that the majority of BKV‐specific T cells from renal transplant recipients expressed low levels of the key transcriptional regulators T‐bet and eomesodermin, which was coincident with undetectable expression of granzyme B and perforin. However, in vitro stimulation of T cells with BKV epitopes selectively enhanced the expression of T‐bet, granzyme B and cellular trafficking molecules (CCR4, CD49d and CD103) with minimal change in eomesodermin and perforin. Conclusions These observations provide an important platform for the future development of immune monitoring and adoptive T‐cell therapy strategies for BKV‐associated diseases in transplant recipients, which may also be exploited for similar therapeutic value in JCV‐associated clinical complications., This manuscript provides comprehensive profiling of BK polyomavirus T‐cell responses in healthy virus carriers and kidney transplant recipients.
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- 2020
17. 'Off-the-shelf’ allogeneic antigen-specific adoptive T-cell therapy for the treatment of multiple EBV-associated malignancies
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Lea Lekieffre, Pauline Crooks, George R Ambalathingal, Debottam Sinha, Rajiv Khanna, Sweera Rehan, Sriganesh Srihari, Matthew Solomon, Michelle A Neller, Laetitia Le Texier, Corey Smith, Kirrliee Beckett, and Archana Panikkar
- Subjects
lymphocytes ,0301 basic medicine ,Epstein-Barr Virus Infections ,Herpesvirus 4, Human ,Cancer Research ,Lymphoma ,T-Lymphocytes ,medicine.medical_treatment ,Mice ,0302 clinical medicine ,HLA Antigens ,hemic and lymphatic diseases ,Immunology and Allergy ,Vector (molecular biology) ,Immune Checkpoint Inhibitors ,RC254-282 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Molecular Medicine ,Female ,immunotherapy ,Programmed cell death ,Cell Survival ,T cell ,Immunology ,Human leukocyte antigen ,adoptive ,Virus ,Viral Matrix Proteins ,03 medical and health sciences ,Antigen ,In vivo ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Transplantation, Homologous ,Cell Proliferation ,Pharmacology ,Immune Cell Therapies and Immune Cell Engineering ,business.industry ,Immunotherapy ,tumor-infiltrating ,immunity ,Xenograft Model Antitumor Assays ,030104 developmental biology ,Epstein-Barr Virus Nuclear Antigens ,Cancer research ,business ,cellular - Abstract
BackgroundEpstein-Barr virus (EBV), an oncogenic human gammaherpesvirus, is associated with a wide range of human malignancies of epithelial and B-cell origin. Recent studies have demonstrated promising safety and clinical efficacy of allogeneic ‘off-the-shelf’ virus-specific T-cell therapies for post-transplant viral complications.MethodsTaking a clue from these studies, we developed a highly efficient EBV-specific T-cell expansion process using a replication-deficient AdE1-LMPpoly vector that specifically targets EBV-encoded nuclear antigen 1 (EBNA1) and latent membrane proteins 1 and 2 (LMP1 and LMP2), expressed in latency II malignancies.ResultsThese allogeneic EBV-specific T cells efficiently recognized human leukocyte antigen (HLA)-matched EBNA1-expressing and/or LMP1 and LMP2-expressing malignant cells and demonstrated therapeutic potential in a number of in vivo models, including EBV lymphomas that emerged spontaneously in humanized mice following EBV infection. Interestingly, we were able to override resistance to T-cell therapy in vivo using a ‘restriction-switching’ approach, through sequential infusion of two different allogeneic T-cell therapies restricted through different HLA alleles. Furthermore, we have shown that inhibition of the programmed cell death protein-1/programmed death-ligand 1 axis in combination with EBV-specific T-cell therapy significantly improved overall survival of tumor-bearing mice when compared with monotherapy.ConclusionThese findings suggest that restriction switching by sequential infusion of allogeneic T-cell therapies that target EBV through distinct HLA alleles may improve clinical response.
- Published
- 2021
18. BK Polyomavirus: Clinical Aspects, Immune Regulation, and Emerging Therapies
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Corey Smith, Rajiv Khanna, George R Ambalathingal, Ross S Francis, and Mark J. Smyth
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0301 basic medicine ,Microbiology (medical) ,Epidemiology ,medicine.medical_treatment ,viruses ,Hematopoietic stem cell transplantation ,Review ,030230 surgery ,Antiviral Agents ,Virus ,Nephropathy ,Pathogenesis ,03 medical and health sciences ,Immunocompromised Host ,0302 clinical medicine ,Immune system ,medicine ,Humans ,Polyomavirus Infections ,General Immunology and Microbiology ,business.industry ,Public Health, Environmental and Occupational Health ,virus diseases ,Immunosuppression ,Immunotherapy ,medicine.disease ,Tumor Virus Infections ,030104 developmental biology ,Infectious Diseases ,BK Virus ,Immunology ,business ,Hemorrhagic cystitis - Abstract
SUMMARYBK polyomavirus (BKV) causes frequent infections during childhood and establishes persistent infections within renal tubular cells and the uroepithelium, with minimal clinical implications. However, reactivation of BKV in immunocompromised individuals following renal or hematopoietic stem cell transplantation may cause serious complications, including BKV-associated nephropathy (BKVAN), ureteric stenosis, or hemorrhagic cystitis. Implementation of more potent immunosuppression and increased posttransplant surveillance has resulted in a higher incidence of BKVAN. Antiviral immunity plays a crucial role in controlling BKV replication, and our increasing knowledge about host-virus interactions has led to the development of improved diagnostic tools and clinical management strategies. Currently, there are no effective antiviral agents for BKV infection, and the mainstay of managing reactivation is reduction of immunosuppression. Development of immune-based therapies to combat BKV may provide new and exciting opportunities for the successful treatment of BKV-associated complications.
- Published
- 2017
19. Prophylactic and therapeutic adenoviral vector-based multivirus-specific T-cell immunotherapy for transplant patients
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George R Ambalathingal, John J. Miles, Mark J. Smyth, Andrea Schuessler, Scott B. Campbell, Corey Smith, Ross S Francis, Yide Wong, Vijayendra Dasari, Rajiv Khanna, and Daniel C. Chambers
- Subjects
0301 basic medicine ,lcsh:QH426-470 ,lcsh:Cytology ,Antigen presentation ,Priming (immunology) ,Biology ,medicine.disease_cause ,Virology ,Article ,Virus ,Epitope ,BK virus ,Viral vector ,lcsh:Genetics ,03 medical and health sciences ,030104 developmental biology ,Immunity ,In vivo ,Immunology ,Genetics ,medicine ,Molecular Medicine ,lcsh:QH573-671 ,Molecular Biology - Abstract
Viral infections including cytomegalovirus, Epstein-Barr virus, adenovirus, and BK virus are a common and predictable problem in transplant recipients. While cellular immune therapies have been successfully used to tackle infectious complications in transplant recipients, manufacturing immunotherapies to address the multitude of possible pathogens can be technically challenging and labor-intensive. Here we describe a novel adenoviral antigen presentation platform (Ad-MvP) as a tool for rapid generation of multivirus-specific T-cells in a single step. Ad-MvP encodes 32 CD8+ T-cell epitopes from cytomegalovirus, Epstein-Barr virus, adenovirus, and BK virus as a contiguous polyepitope. We demonstrate that Ad-MvP vector can be successfully used for rapid in vitro expansion of multivirus-specific T-cells from transplant recipients and in vivo priming of antiviral T-cell immunity. Most importantly, using an in vivo murine model of Epstein-Barr virus-induced lymphoma, we also show that adoptive immunotherapy with Ad-MvP expanded autologous and allogeneic multivirus-specific T-cells is highly effective in controlling Epstein-Barr virus tumor outgrowth and improving overall survival. We propose that Ad-MvP has wide ranging therapeutic applications in greatly facilitating in vivo priming of antiviral T-cells, the generation of third-party T-cell banks as “off-the-shelf” therapeutics as well as autologous T-cell therapies for transplant patients.
- Published
- 2016
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