21 results on '"Ganesan AP"'
Search Results
2. The hormonal effects of Tribulus terrestris and its role in the management of male erectile dysfunction -- an evaluation using primates, rabbit and rat.
- Author
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Gauthaman K and Ganesan AP
- Abstract
Hormonal effects of Tribulus terrestris (TT) were evaluated in primates, rabbit and rat to identify its usefulness in the management of erectile dysfunction (ED). TT extract was administered intravenously, as a bolus dose of 7.5, 15 and 30mg/kg, in primates for acute study. Rabbits and normal rats were treated with 2.5, 5 and 10mg/kg of TT extract orally for 8 weeks, for chronic study. In addition, castrated rats were treated either with testosterone cypionate (10mg/kg, subcutaneously; biweekly for 8 weeks) or TT orally (5mg/kg daily for 8 weeks). Blood samples were analyzed for testosterone (T), dihydrotestosterone (DHT) and dehydroepiandrosterone sulphate (DHEAS) levels using radioimmunoassay. In primates, the increases in T (52%), DHT (31%) and DHEAS (29%) at 7.5mg/kg were statistically significant. In rabbits, both T and DHT were increased compared to control, however, only the increases in DHT (by 30% and 32% at 5 and 10mg/kg) were statistically significant. In castrated rats, increases in T levels by 51% and 25% were observed with T and TT extract respectively that were statistically significant. TT increases some of the sex hormones, possibly due to the presence of protodioscin in the extract. TT may be useful in mild to moderate cases of ED. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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3. Intra-tumoral T cells in pediatric brain tumors display clonal expansion and effector properties.
- Author
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Upadhye A, Meza Landeros KE, Ramírez-Suástegui C, Schmiedel BJ, Woo E, Chee SJ, Malicki D, Coufal NG, Gonda D, Levy ML, Greenbaum JA, Seumois G, Crawford J, Roberts WD, Schoenberger SP, Cheroutre H, Ottensmeier CH, Vijayanand P, and Ganesan AP
- Subjects
- Humans, Child, Antigens, Neoplasm immunology, Immunotherapy methods, Child, Preschool, Male, Female, Adolescent, Lymphocytes, Tumor-Infiltrating immunology, Single-Cell Analysis methods, Transcriptome, Clone Cells, Brain Neoplasms immunology, Brain Neoplasms pathology, Brain Neoplasms genetics, T-Lymphocytes immunology
- Abstract
Brain tumors in children are a devastating disease in a high proportion of patients. Owing to inconsistent results in clinical trials in unstratified patients, the role of immunotherapy remains unclear. We performed an in-depth survey of the single-cell transcriptomes and clonal relationship of intra-tumoral T cells from children with brain tumors. Our results demonstrate that a large fraction of T cells in the tumor tissue are clonally expanded with the potential to recognize tumor antigens. Such clonally expanded T cells display enrichment of transcripts linked to effector function, tissue residency, immune checkpoints and signatures of neoantigen-specific T cells and immunotherapy response. We identify neoantigens in pediatric brain tumors and show that neoantigen-specific T cell gene signatures are linked to better survival outcomes. Notably, among the patients in our cohort, we observe substantial heterogeneity in the degree of clonal expansion and magnitude of T cell response. Our findings suggest that characterization of intra-tumoral T cell responses may enable selection of patients for immunotherapy, an approach that requires prospective validation in clinical trials., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)
- Published
- 2024
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4. Melanoma-reactive T cells take up residence.
- Author
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Ganesan AP and Ottensmeier CHH
- Subjects
- CD8-Positive T-Lymphocytes, Humans, Melanoma
- Published
- 2021
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5. M1 hot tumor-associated macrophages boost tissue-resident memory T cells infiltration and survival in human lung cancer.
- Author
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Garrido-Martin EM, Mellows TWP, Clarke J, Ganesan AP, Wood O, Cazaly A, Seumois G, Chee SJ, Alzetani A, King EV, Hedrick CC, Thomas G, Friedmann PS, Ottensmeier CH, Vijayanand P, and Sanchez-Elsner T
- Subjects
- Female, Humans, Lung Neoplasms mortality, Male, Survival Analysis, Lung Neoplasms genetics, T-Lymphocytes metabolism, Tumor-Associated Macrophages metabolism
- Abstract
Background: The role of tumor-associated macrophages (TAMs) in determining the outcome between the antitumor effects of the adaptive immune system and the tumor's anti-immunity stratagems, is controversial. Macrophages modulate their activities and phenotypes by integration of signals in the tumor microenvironment. Depending on how macrophages are activated, they may adopt so-called M1-like, antitumor or M2-like, protumor profiles. In many solid tumors, a dominance of M2-like macrophages is associated with poor outcomes but in some tumor types, strong M1-like profiles are linked to better outcomes. We aimed to investigate the interrelationship of these TAM populations to establish how they modulate the efficacy of the adaptive immune system in early lung cancer., Methods: Macrophages from matched lung (non-tumor-associated macrophages (NTAMs)) and tumor samples (TAMs) from resected lung cancers were assessed by bulk and single-cell transcriptomic analysis. Protein expression of genes characteristic of M1-like (chemokine (C-X-C motif) ligand 9) or M2-like (matrix metallopeptidase 12) functions was confirmed by confocal microscopy. Immunohistochemistry related the distribution of TAM transcriptomic signatures to density of CD8
+ tissue-resident memory T cells (TRM ) in tumors and survival data from an independent cohort of 393 patients with lung cancer., Results: TAMs have significantly different transcriptomic profiles from NTAMs with >1000 differentially expressed genes. TAMs displayed a strong M2-like signature with no significant variation between patients. However, single-cell RNA-sequencing supported by immuno-stained cells revealed that additionally, in 25% of patients the M2-like TAMs also co-expressed a strong/hot M1-like signature (M1hot ). Importantly, there was a strong association between the density of M1hot TAMs and TRM cells in tumors that was in turn linked to better survival. Our data suggest a mechanism by which M1hot TAMs may recruit TRM cells via CXCL9 expression and sustain them by making available more of the essential fatty acids on which TRM depend., Conclusions: We showed that in early lung cancer, expression of M1-like and M2-like gene signatures are not mutually exclusive since the same TAMs can simultaneously display both gene-expression profiles. The presence of M1hot TAMs was associated with a strong TRM tumor-infiltrate and better outcomes. Thus, therapeutic approaches to re-program TAMs to an M1hot phenotype are likely to augment the adaptive antitumor responses., Competing Interests: Competing interests: PV reports grants and personal fees from Pfizer, from null, outside the submitted work., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.)- Published
- 2020
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6. NOX4 Inhibition Potentiates Immunotherapy by Overcoming Cancer-Associated Fibroblast-Mediated CD8 T-cell Exclusion from Tumors.
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Ford K, Hanley CJ, Mellone M, Szyndralewiez C, Heitz F, Wiesel P, Wood O, Machado M, Lopez MA, Ganesan AP, Wang C, Chakravarthy A, Fenton TR, King EV, Vijayanand P, Ottensmeier CH, Al-Shamkhani A, Savelyeva N, and Thomas GJ
- Subjects
- Animals, CD8-Positive T-Lymphocytes, Cell Line, Tumor, Humans, Immunotherapy, Mice, NADPH Oxidase 4, Reactive Oxygen Species, Cancer-Associated Fibroblasts, Neoplasms
- Abstract
Determining mechanisms of resistance to αPD-1/PD-L1 immune-checkpoint immunotherapy is key to developing new treatment strategies. Cancer-associated fibroblasts (CAF) have many tumor-promoting functions and promote immune evasion through multiple mechanisms, but as yet, no CAF-specific inhibitors are clinically available. Here we generated CAF-rich murine tumor models (TC1, MC38, and 4T1) to investigate how CAFs influence the immune microenvironment and affect response to different immunotherapy modalities [anticancer vaccination, TC1 (HPV E7 DNA vaccine), αPD-1, and MC38] and found that CAFs broadly suppressed response by specifically excluding CD8
+ T cells from tumors (not CD4+ T cells or macrophages); CD8+ T-cell exclusion was similarly present in CAF-rich human tumors. RNA sequencing of CD8+ T cells from CAF-rich murine tumors and immunochemistry analysis of human tumors identified significant upregulation of CTLA-4 in the absence of other exhaustion markers; inhibiting CTLA-4 with a nondepleting antibody overcame the CD8+ T-cell exclusion effect without affecting Tregs. We then examined the potential for CAF targeting, focusing on the ROS-producing enzyme NOX4, which is upregulated by CAF in many human cancers, and compared this with TGFβ1 inhibition, a key regulator of the CAF phenotype. siRNA knockdown or pharmacologic inhibition [GKT137831 (Setanaxib)] of NOX4 "normalized" CAF to a quiescent phenotype and promoted intratumoral CD8+ T-cell infiltration, overcoming the exclusion effect; TGFβ1 inhibition could prevent, but not reverse, CAF differentiation. Finally, NOX4 inhibition restored immunotherapy response in CAF-rich tumors. These findings demonstrate that CAF-mediated immunotherapy resistance can be effectively overcome through NOX4 inhibition and could improve outcome in a broad range of cancers. SIGNIFICANCE: NOX4 is critical for maintaining the immune-suppressive CAF phenotype in tumors. Pharmacologic inhibition of NOX4 potentiates immunotherapy by overcoming CAF-mediated CD8+ T-cell exclusion. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/9/1846/F1.large.jpg. See related commentary by Hayward, p. 1799 ., (©2020 American Association for Cancer Research.)- Published
- 2020
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7. A Survey on the Experience of Singaporean Trainees in Obstetrics/Gynecology and Family Medicine of Sexual Problems and Views on Training in Sexual Medicine.
- Author
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Huang Z, Choong DS, Ganesan AP, and Logan S
- Abstract
Introduction: Asian patients may have more difficulty seeking help for their sexual problems because of a largely conservative culture. Residents from both obstetrics and gynecology (OBGYN) and family medicine (FM) departments are ideally placed to address sexual problems., Aim: This survey explored the experience of residents from OBGYN and FM in managing sexual problems and their views on training in sexual medicine (SM)., Method: An anonymized questionnaire collecting data on trainee characteristics, exposure to male and female sexual problems, and training in SM was sent to all FM and OBGYN residents in Singapore. These residents had completed their medical registration with the Singapore Medical Council and were at various stages of specialty training in both FM and OBGYN residency programs in Singapore., Main Outcome Measure: Trainees' exposure to male and female sexual problems and their views on training in Sexual Medicine., Results: The overall response from the survey was 63.5% (122/192)-54% (70/129) and 69% (52/75) of FM and OBGYN residents responded, respectively. 63% were female, with 22% being senior residents, and 55% attended Singaporean medical schools. About one quarter (30/122) of the respondents encountered patients with sexual problems at least monthly. Most would refer these patients directly to specialists, psychologists, and sex therapists. More than 80% of residents were not confident in managing sexual problems in either sex (89% for male problems; 83% for female problems). Among the recognized categories, only 30% felt confident to manage erectile dysfunction, 26% for vaginismus, while less than 10% felt confident to manage libido, arousal, or orgasm disorders. 95% of the residents agreed that SM should be part of both training curricula, with 70% and 25% suggesting at junior and senior residency, respectively. 93% of them were interested to obtain further knowledge and skills in SM through their core training curriculum and from seminars., Conclusions: This survey reported a significant number of residents in OBGYN and FM departments are regularly exposed to patients with sexual problems but lack the skills to manage them. OBGYN residents were more familiar with managing female sexual problems while FM residents tend to have more experience in male sexual problems. Almost universally, the residents in FM and OBGYN were very keen to acquire skills in SM, and the results support the incorporation of appropriate knowledge and skills into both national residency program curricula. Huang Z, Choong DS, Ganesan AP, et al. A Survey on the Experience of Singaporean Trainees in Obstetrics/Gynecology and Family Medicine of Sexual Problems and Views on Training in Sexual Medicine. J Sex Med 2019;8:107-113., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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8. Single-cell transcriptomic analysis of tissue-resident memory T cells in human lung cancer.
- Author
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Clarke J, Panwar B, Madrigal A, Singh D, Gujar R, Wood O, Chee SJ, Eschweiler S, King EV, Awad AS, Hanley CJ, McCann KJ, Bhattacharyya S, Woo E, Alzetani A, Seumois G, Thomas GJ, Ganesan AP, Friedmann PS, Sanchez-Elsner T, Ay F, Ottensmeier CH, and Vijayanand P
- Subjects
- Cell Proliferation, Clone Cells, Cytotoxicity, Immunologic genetics, Hepatitis A Virus Cellular Receptor 2 metabolism, Humans, Lung metabolism, Lung pathology, Lymphocyte Subsets immunology, Lymphocytes, Tumor-Infiltrating immunology, Programmed Cell Death 1 Receptor metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Transcription, Genetic, Gene Expression Profiling, Immunologic Memory genetics, Lung Neoplasms genetics, Lung Neoplasms immunology, Single-Cell Analysis, T-Lymphocytes immunology, Transcriptome genetics
- Abstract
High numbers of tissue-resident memory T (T
RM ) cells are associated with better clinical outcomes in cancer patients. However, the molecular characteristics that drive their efficient immune response to tumors are poorly understood. Here, single-cell and bulk transcriptomic analysis of TRM and non-TRM cells present in tumor and normal lung tissue from patients with lung cancer revealed that PD-1-expressing TRM cells in tumors were clonally expanded and enriched for transcripts linked to cell proliferation and cytotoxicity when compared with PD-1-expressing non-TRM cells. This feature was more prominent in the TRM cell subset coexpressing PD-1 and TIM-3, and it was validated by functional assays ex vivo and also reflected in their chromatin accessibility profile. This PD-1+ TIM-3+ TRM cell subset was enriched in responders to PD-1 inhibitors and in tumors with a greater magnitude of CTL responses. These data highlight that not all CTLs expressing PD-1 are dysfunctional; on the contrary, TRM cells with PD-1 expression were enriched for features suggestive of superior functionality., (© 2019 Clarke et al.)- Published
- 2019
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9. Development of Asthma in Inner-City Children: Possible Roles of MAIT Cells and Variation in the Home Environment.
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Chandra S, Wingender G, Greenbaum JA, Khurana A, Gholami AM, Ganesan AP, Rosenbach M, Jaffee K, Gern JE, Wood R, O'Connor G, Sandel M, Kattan M, Bacharier L, Togias A, Horner AA, and Kronenberg M
- Subjects
- Asthma etiology, CD4-Positive T-Lymphocytes immunology, Child, Child, Preschool, Cities, Cohort Studies, Dust immunology, Environment, Female, Humans, Infant, Interferon-gamma immunology, Lymphocyte Activation immunology, Lymphocyte Count methods, Male, Natural Killer T-Cells immunology, Risk, Asthma immunology, Mucosal-Associated Invariant T Cells immunology
- Abstract
Humans have populations of innate-like T lymphocytes with an invariant TCR α-chain that recognize nonpeptide Ags, including invariant NKT (iNKT) cells and mucosal-associated invariant T (MAIT) cells. iNKT cell involvement in human asthma is controversial, whereas there has been little analysis of MAIT cells. Using peripheral blood cells from 110 participants from the Urban Environment and Childhood Asthma (URECA) birth cohort study, these cells were analyzed for number and function. We determined whether iNKT cell or MAIT cell frequency at 1 y is correlated with the cytokine polarization of mainstream CD4
+ T cells and/or the development of asthma by age 7 y. Dust samples from 300 houses were tested for iNKT cell antigenic activity. Our results show that a higher MAIT cell frequency at 1 y of age was associated with a decreased risk of asthma by age 7 y. The frequency of MAIT cells was associated with increased production of IFN-γ by activated CD4+ T cells from the URECA cohort. iNKT cell antigenic activity in bedroom dust samples was associated with higher endotoxin concentration and also with reduced risk of asthma. In conclusion, MAIT cell frequency at 1 y may reflect the tendency of the immune system toward Th1 responses and is associated with protection from asthma. Additionally, iNKT cell antigenic activity may be a marker of houses with increased microbial exposures and therefore also with protection from asthma., (Copyright © 2018 by The American Association of Immunologists, Inc.)- Published
- 2018
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10. Alu-dependent RNA editing of GLI1 promotes malignant regeneration in multiple myeloma.
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Lazzari E, Mondala PK, Santos ND, Miller AC, Pineda G, Jiang Q, Leu H, Ali SA, Ganesan AP, Wu CN, Costello C, Minden M, Chiaramonte R, Stewart AK, Crews LA, and Jamieson CHM
- Subjects
- Adenosine Deaminase metabolism, Adult, Aged, Animals, Case-Control Studies, Disease Progression, Drug Resistance, Neoplasm genetics, Female, Gene Knockdown Techniques, Humans, In Vitro Techniques, Male, Mice, Middle Aged, Multiple Myeloma drug therapy, Multiple Myeloma metabolism, Neoplasm Recurrence, Local metabolism, Neoplasm Transplantation, Prognosis, RNA Editing genetics, RNA-Binding Proteins metabolism, Adenosine Deaminase genetics, Multiple Myeloma genetics, Neoplasm Recurrence, Local genetics, RNA, Messenger metabolism, RNA-Binding Proteins genetics, Zinc Finger Protein GLI1 metabolism
- Abstract
Despite novel therapies, relapse of multiple myeloma (MM) is virtually inevitable. Amplification of chromosome 1q, which harbors the inflammation-responsive RNA editase adenosine deaminase acting on RNA (ADAR)1 gene, occurs in 30-50% of MM patients and portends a poor prognosis. Since adenosine-to-inosine RNA editing has recently emerged as a driver of cancer progression, genomic amplification combined with inflammatory cytokine activation of ADAR1 could stimulate MM progression and therapeutic resistance. Here, we report that high ADAR1 RNA expression correlates with reduced patient survival rates in the MMRF CoMMpass data set. Expression of wild-type, but not mutant, ADAR1 enhances Alu-dependent editing and transcriptional activity of GLI1, a Hedgehog (Hh) pathway transcriptional activator and self-renewal agonist, and promotes immunomodulatory drug resistance in vitro. Finally, ADAR1 knockdown reduces regeneration of high-risk MM in serially transplantable patient-derived xenografts. These data demonstrate that ADAR1 promotes malignant regeneration of MM and if selectively inhibited may obviate progression and relapse.
- Published
- 2017
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11. Obstructive sleep apnoea as a presenting manifestation of non-Hodgkin lymphoma in a child.
- Author
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Ganesan AP, Jiang W, Kuo DJ, and Bhattacharjee R
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- Adolescent, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Biopsy, Burkitt Lymphoma diagnosis, Burkitt Lymphoma drug therapy, Humans, Male, Sleep Apnea, Obstructive diagnosis, Tomography, X-Ray Computed, Treatment Outcome, Burkitt Lymphoma complications, Sleep Apnea, Obstructive etiology
- Published
- 2017
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12. Tissue-resident memory features are linked to the magnitude of cytotoxic T cell responses in human lung cancer.
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Ganesan AP, Clarke J, Wood O, Garrido-Martin EM, Chee SJ, Mellows T, Samaniego-Castruita D, Singh D, Seumois G, Alzetani A, Woo E, Friedmann PS, King EV, Thomas GJ, Sanchez-Elsner T, Vijayanand P, and Ottensmeier CH
- Subjects
- Adenocarcinoma mortality, Adult, Aged, Aged, 80 and over, Antigens, CD genetics, Carcinoma, Squamous Cell mortality, Female, Gene Expression Profiling, Hepatitis A Virus Cellular Receptor 2 genetics, Humans, Immunotherapy, Integrin alpha Chains genetics, Lung Neoplasms mortality, Lymphocytes, Tumor-Infiltrating metabolism, Male, Middle Aged, Prognosis, Programmed Cell Death 1 Receptor genetics, Receptors, Antigen, T-Cell genetics, Squamous Cell Carcinoma of Head and Neck, Survival Rate, T-Lymphocytes, Cytotoxic metabolism, Tumor Necrosis Factor Receptor Superfamily, Member 9 genetics, Adenocarcinoma immunology, Carcinoma, Squamous Cell immunology, Head and Neck Neoplasms immunology, Immunologic Memory immunology, Lung Neoplasms immunology, Lymphocytes, Tumor-Infiltrating immunology, T-Lymphocytes, Cytotoxic immunology
- Abstract
Therapies that boost the anti-tumor responses of cytotoxic T lymphocytes (CTLs) have shown promise; however, clinical responses to the immunotherapeutic agents currently available vary considerably, and the molecular basis of this is unclear. We performed transcriptomic profiling of tumor-infiltrating CTLs from treatment-naive patients with lung cancer to define the molecular features associated with the robustness of anti-tumor immune responses. We observed considerable heterogeneity in the expression of molecules associated with activation of the T cell antigen receptor (TCR) and of immunological-checkpoint molecules such as 4-1BB, PD-1 and TIM-3. Tumors with a high density of CTLs showed enrichment for transcripts linked to tissue-resident memory cells (T
RM cells), such as CD103, and CTLs from CD103hi tumors displayed features of enhanced cytotoxicity. A greater density of TRM cells in tumors was predictive of a better survival outcome in lung cancer, and this effect was independent of that conferred by CTL density. Here we define the 'molecular fingerprint' of tumor-infiltrating CTLs and identify potentially new targets for immunotherapy.- Published
- 2017
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13. The elucidation of non-classical MHC class II antigen processing through the study of viral antigens.
- Author
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Veerappan Ganesan AP and Eisenlohr LC
- Subjects
- Animals, Humans, Antigen Presentation, Antigens, Viral immunology, Antigens, Viral metabolism, CD4-Positive T-Lymphocytes immunology, Histocompatibility Antigens Class II metabolism
- Abstract
By convention, CD4
+ T cells are activated predominantly by Major Histocompatibility Complex class II-bound peptides derived from extracellular (exogenous) antigens. It has been known for decades that alternative sources of antigen, particularly those synthesized within the antigen-presenting cell, can also supply peptides but the impact on TCD4+ responses, sometimes considerable, has only recently become appreciated. This review focuses on the contributions that studies of viral antigen have made to this shift in perspective, concluding with discussions of relevance to rational vaccine design, autoimmunity and cancer immunotherapy., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2017
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14. Endogenous antigen processing drives the primary CD4+ T cell response to influenza.
- Author
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Miller MA, Ganesan AP, Luckashenak N, Mendonca M, and Eisenlohr LC
- Subjects
- Animals, Disease Models, Animal, Humans, Mice, Virion immunology, Antigens immunology, CD4-Positive T-Lymphocytes immunology, Influenza, Human immunology
- Abstract
By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with major histocompatibility complex class II molecules. Alternative pathways of epitope production have been identified, but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome and γ-interferon-inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses.
- Published
- 2015
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15. Epigenomic analysis of primary human T cells reveals enhancers associated with TH2 memory cell differentiation and asthma susceptibility.
- Author
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Seumois G, Chavez L, Gerasimova A, Lienhard M, Omran N, Kalinke L, Vedanayagam M, Ganesan AP, Chawla A, Djukanović R, Ansel KM, Peters B, Rao A, and Vijayanand P
- Subjects
- Adolescent, Adult, Aged, Binding Sites genetics, Binding Sites immunology, Cell Differentiation immunology, Cells, Cultured, Core Binding Factor Alpha 3 Subunit genetics, DNA Methylation genetics, Epigenomics, Female, GATA3 Transcription Factor genetics, Genome-Wide Association Study, Histones genetics, Histones immunology, Humans, Immunologic Memory immunology, Male, MicroRNAs genetics, Middle Aged, Polymorphism, Single Nucleotide, Promoter Regions, Genetic genetics, Protein Binding genetics, Protein Binding immunology, Sequence Analysis, RNA, T-Box Domain Proteins genetics, Young Adult, T-bet Transcription Factor, Asthma genetics, Asthma immunology, Genetic Predisposition to Disease, Th1 Cells immunology, Th2 Cells immunology
- Abstract
A characteristic feature of asthma is the aberrant accumulation, differentiation or function of memory CD4(+) T cells that produce type 2 cytokines (TH2 cells). By mapping genome-wide histone modification profiles for subsets of T cells isolated from peripheral blood of healthy and asthmatic individuals, we identified enhancers with known and potential roles in the normal differentiation of human TH1 cells and TH2 cells. We discovered disease-specific enhancers in T cells that differ between healthy and asthmatic individuals. Enhancers that gained the histone H3 Lys4 dimethyl (H3K4me2) mark during TH2 cell development showed the highest enrichment for asthma-associated single nucleotide polymorphisms (SNPs), which supported a pathogenic role for TH2 cells in asthma. In silico analysis of cell-specific enhancers revealed transcription factors, microRNAs and genes potentially linked to human TH2 cell differentiation. Our results establish the feasibility and utility of enhancer profiling in well-defined populations of specialized cell types involved in disease pathogenesis.
- Published
- 2014
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16. Toward a Network Model of MHC Class II-Restricted Antigen Processing.
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Miller MA, Ganesan AP, and Eisenlohr LC
- Abstract
The standard model of Major Histocompatibility Complex class II (MHCII)-restricted antigen processing depicts a straightforward, linear pathway: internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4(+) T cells (TCD4+). Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell.
- Published
- 2013
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17. Tumor-infiltrating regulatory T cells inhibit endogenous cytotoxic T cell responses to lung adenocarcinoma.
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Ganesan AP, Johansson M, Ruffell B, Yagui-Beltrán A, Lau J, Jablons DM, and Coussens LM
- Subjects
- Animals, Antibodies, Monoclonal therapeutic use, Antineoplastic Agents, Alkylating administration & dosage, Antineoplastic Agents, Alkylating therapeutic use, CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes pathology, Carboplatin administration & dosage, Carboplatin therapeutic use, Cisplatin therapeutic use, Cisplatin toxicity, Cytotoxicity, Immunologic, Humans, Interleukin-2 Receptor alpha Subunit immunology, Lung Neoplasms pathology, Lymphocyte Count, Lymphocyte Depletion, Lymphocytes, Tumor-Infiltrating pathology, Lymphopenia genetics, Lymphopenia immunology, Mice, Mice, Mutant Strains, Mice, Transgenic, Random Allocation, T-Lymphocyte Subsets immunology, T-Lymphocyte Subsets pathology, T-Lymphocytes, Cytotoxic pathology, T-Lymphocytes, Regulatory pathology, Tumor Escape, Tumor Microenvironment immunology, Adenocarcinoma immunology, Carcinoma, Non-Small-Cell Lung immunology, Lung Neoplasms immunology, Lymphocytes, Tumor-Infiltrating immunology, T-Lymphocytes, Cytotoxic immunology, T-Lymphocytes, Regulatory immunology
- Abstract
Immune cells comprise a substantial proportion of the tumor mass in human nonsmall cell lung cancers (NSCLC), but the precise composition and significance of this infiltration are unclear. In this study, we examined immune complexity of human NSCLC as well as NSCLC developing in CC10-TAg transgenic mice, and revealed that CD4(+) T lymphocytes represent the dominant population of CD45(+) immune cells, and, relative to normal lung tissue, CD4(+)Foxp3(+) regulatory T cells (Tregs) were significantly increased as a proportion of total CD4(+) cells. To assess the functional significance of increased Tregs, we evaluated CD8(+) T cell-deficient/CC10-TAg mice and revealed that CD8(+) T cells significantly controlled tumor growth with antitumor activity that was partially repressed by Tregs. However, whereas treatment with anti-CD25-depleting mAb as monotherapy preferentially depleted Tregs and improved CD8(+) T cell-mediated control of tumor progression during early tumor development, similar monotherapy was ineffective at later stages. Because mice bearing early NSCLC treated with anti-CD25 mAb exhibited increased tumor cell death associated with infiltration by CD8(+) T cells expressing elevated levels of granzyme A, granzyme B, perforin, and IFN-γ, we therefore evaluated carboplatin combination therapy resulting in a significantly extended survival beyond that observed with chemotherapy alone, indicating that Treg depletion in combination with cytotoxic therapy may be beneficial as a treatment strategy for advanced NSCLC.
- Published
- 2013
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18. An integrated nano-scale approach to profile miRNAs in limited clinical samples.
- Author
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Seumois G, Vijayanand P, Eisley CJ, Omran N, Kalinke L, North M, Ganesan AP, Simpson LJ, Hunkapiller N, Moltzahn F, Woodruff PG, Fahy JV, Erle DJ, Djukanovic R, Blelloch R, and Ansel KM
- Abstract
Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030.
- Published
- 2012
19. Immune microenvironments in solid tumors: new targets for therapy.
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Shiao SL, Ganesan AP, Rugo HS, and Coussens LM
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- Animals, Chronic Disease, Humans, Immunotherapy, Inflammation immunology, Neoplasms drug therapy, Neoplasms radiotherapy, Neoplasms immunology, Neoplasms therapy, Tumor Microenvironment immunology
- Abstract
Leukocytes and their soluble mediators play important regulatory roles in all aspects of solid tumor development. While immunotherapeutic strategies have conceptually held clinical promise, with the exception of a small percentage of patients, they have failed to demonstrate effective, consistent, and durable anti-cancer responses. Several subtypes of leukocytes that commonly infiltrate solid tumors harbor immunosuppressive activity and undoubtedly restrict the effectiveness of these strategies. Several of these same immune cells also foster tumor development by expression of potent protumor mediators. Given recent evidence revealing that immune-based mechanisms regulate the response to conventional cytotoxic therapy, it seems reasonable to speculate that tumor progression could be effectively diminished by combining cytotoxic strategies with therapies that blunt protumor immune-based effectors and/or neutralize those that instead impede development of desired anti-tumor immunity, thus providing synergistic effects between traditional cytotoxic and immune-modulatory approaches., (© 2011 by Cold Spring Harbor Laboratory Press)
- Published
- 2011
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20. Airway ion transport impacts on disease presentation and severity in cystic fibrosis.
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Leal T, Fajac I, Wallace HL, Lebecque P, Lebacq J, Hubert D, Dall'Ava J, Dusser D, Ganesan AP, Knoop C, Cumps J, Wallemacq P, and Southern KW
- Subjects
- Adolescent, Adult, Age Factors, Biological Transport, Child, Child, Preschool, Cystic Fibrosis genetics, Cystic Fibrosis Transmembrane Conductance Regulator physiology, Diseases in Twins, Female, Forced Expiratory Volume, Humans, Male, Nasal Mucosa physiopathology, Perfusion, Potentiometry, Severity of Illness Index, Siblings, Sodium metabolism, Cystic Fibrosis physiopathology, Ion Transport physiology
- Abstract
Objectives: Abnormal airway ion transport is a feature of cystic fibrosis. The aim of this study was to investigate whether distinct components of ion transport are associated with the clinical expression and severity of the disease., Design and Methods: Univariate and multivariate analyses were used to study interaction effects between nasal potential difference parameters and clinical status, recorded at stable conditions, in 75 F508del homozygous young adults., Results: All patients demonstrated increased sodium and reduced chloride conductances. Less sodium transport abnormalities were related to better respiratory function and nutrition. Presentation with digestive symptoms at diagnosis was associated with lower chloride conductance. With an accuracy of 85% good nutritional status was linked to more preserved lung function, increasing age and more preserved chloride conductance., Conclusions: Ion transport abnormalities have distinct clinical outcomes. Sodium conductance relates to respiratory function and nutrition; chloride conductance to nutrition and presentation with digestive symptoms at diagnosis.
- Published
- 2008
- Full Text
- View/download PDF
21. Sexual effects of puncturevine (Tribulus terrestris) extract (protodioscin): an evaluation using a rat model.
- Author
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Gauthaman K, Ganesan AP, and Prasad RN
- Subjects
- Analysis of Variance, Androgens metabolism, Animals, Aphrodisiacs therapeutic use, Body Weight drug effects, Copulation drug effects, Diosgenin therapeutic use, Dose-Response Relationship, Drug, Drugs, Chinese Herbal therapeutic use, Ejaculation drug effects, Female, Male, Models, Animal, Organ Size drug effects, Penis blood supply, Random Allocation, Rats, Rats, Sprague-Dawley, Regional Blood Flow drug effects, Saponins therapeutic use, Aphrodisiacs pharmacology, Diosgenin analogs & derivatives, Diosgenin pharmacology, Drugs, Chinese Herbal pharmacology, Saponins pharmacology, Sexual Behavior, Animal drug effects
- Abstract
Objective: Apart from its claims for improvement of sexual functions in men, the puncturevine plant (Tribulus terrestris: TT) has long been considered as an energizer and vitalizer in the indigenous system of medicine. Sexual behavior and intracavernous pressure (ICP) measurements were taken in rats to scientifically validate the claim of TT [containing protodioscin (PTN)] as an aphrodisiac., Materials and Methods: Forty sexually mature male Sprague-Dawley rats were randomly divided into four groups of 10 each. Group I served as a control group and groups II, III, and IV were treated with three different doses of TT extract (2.5, 5 and 10 mg/kg body weight, respectively), orally, once daily for 8 weeks. Weight was recorded and the rats from all four groups were subjected to sexual behavior studies with primed females and various parameters namely mount and intromission frequencies (MF and IF, respectively), mount, intromission and ejaculation latencies (ML, IL, and EL, respectively) as well as postejaculatory interval (PEI) were recorded. In addition, blood pressure and ICP were recorded for all rats at the end of study., Results: Increases in body weight (by 9, 23, and 18% for groups II, III & IV) and ICP (by 43% and 26% for groups III and IV) were statistically significant compared to the control group. Increases in MF (by 27% and 24%) and IF (by 19% and 22%) for the groups III and IV were statistically significant. Decreases in ML (by 16%, 23%, and 22% for groups II, III, and IV) and PEI (by 20% for group III) were statistically significant compared to the control., Conclusions: The weight gain and improvement in sexual behavior parameters observed in rats could be secondary to the androgen increasing property of TT (PTN) that was observed in our earlier study on primates. The increase in ICP which confirms the proerectile aphrodisiac property of TT could possibly be the result of an increase in androgen and subsequent release of nitric oxide from the nerve endings innervating the corpus cavernosum.
- Published
- 2003
- Full Text
- View/download PDF
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