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Soren K, Bollikanda RK, Das T, Patel S, Gnaneshwari K, Malakar P, Kumar A, Kantevari S, Chakravarty S. Development of CRID3-Based Anti-inflammatory Agents to Ameliorate Chronic Hypoxia-Induced Memory Impairment in Zebrafish Models. ACS Chem Neurosci 2024; 15:2504-2519. [PMID: 38902941 DOI: 10.1021/acschemneuro.4c00154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024] Open
Abstract
Chronic hypoxic exposure triggers the onset and progression of cognitive dysfunction; however, the mechanisms underlying chronic hypoxia-induced neuroinflammation and its contribution to cognitive dysfunction remain poorly understood. Although inflammation and hypoxia are interdependent, numerous recent studies have linked the development of various human diseases to hypoxia-induced inflammation. In this study, we focused on the NLRP3 inflammasome with novel analogues of cytokine release inhibitory drug 3 (CRID3), a class of small molecule inhibitors for the NLRP3 inflammasome, to investigate their potential contribution to alleviating chronic hypoxia-induced neuroinflammation using the zebrafish model. The designed CRID3 analogues 6a-q were prepared from 2-methyl furan-3-carboxylate, following a four-step reaction sequence and fully characterized by NMR and mass spectral analysis. The administration of CRID3 analogues 6a-q led to a notable reduction in neuroinflammation and an increase in glial proliferation markers in both sexes. In addition, we investigated the potential effects of CRID3 analogues 6a-q through various behavioral tasks to assess their role in ameliorating post-hypoxic behavioral deficits and cognitive impairment. Notably, the study revealed that post-chronic hypoxia, male zebrafish exhibited significantly higher levels of inflammatory marker expression than females. Furthermore, we observed that the neurogenic response to treatment with CRID3 derivative 6o varied depending on the sex, with females showing a sex-specific differential increase in neurogenesis compared to males. This work emphasizes the significance of considering sex differences into account in developing therapeutic strategies for neurological disorders, as shown by the sex-specific molecular and behavioral changes in zebrafish cognitive impairment and neuroinflammation.
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Ferrer P, Berry AA, Bucsan AN, Prajapati SK, Krishnan K, Barbeau MC, Rickert DM, Guerrero SM, Usui M, Abebe Y, Patil A, Chakravarty S, Billingsley PF, Pa'ahana-Brown F, Strauss K, Shrestha B, Nomicos E, Deye GA, Sim BKL, Hoffman SL, Williamson KC, Lyke KE. Repeat controlled human Plasmodium falciparum infections delay bloodstream patency and reduce symptoms. Nat Commun 2024; 15:5194. [PMID: 38890271 PMCID: PMC11189388 DOI: 10.1038/s41467-024-49041-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/22/2024] [Indexed: 06/20/2024] Open
Abstract
Resistance to clinical malaria takes years to develop even in hyperendemic regions and sterilizing immunity has rarely been observed. To evaluate the maturation of the host response against controlled repeat exposures to P. falciparum (Pf) NF54 strain-infected mosquitoes, we systematically monitored malaria-naïve participants through an initial exposure to uninfected mosquitoes and 4 subsequent homologous exposures to Pf-infected mosquitoes over 21 months (n = 8 males) (ClinicalTrials.gov# NCT03014258). The primary outcome was to determine whether protective immunity against parasite infection develops following repeat CHMI and the secondary outcomes were to track the clinical signs and symptoms of malaria and anti-Pf antibody development following repeat CHMI. After two exposures, time to blood stage patency increases significantly and the number of reported symptoms decreases indicating the development of clinical tolerance. The time to patency correlates positively with both anti-Pf circumsporozoite protein (CSP) IgG and CD8 + CD69+ effector memory T cell levels consistent with partial pre-erythrocytic immunity. IFNγ levels decrease significantly during the participants' second exposure to high blood stage parasitemia and could contribute to the decrease in symptoms. In contrast, CD4-CD8 + T cells expressing CXCR5 and the inhibitory receptor, PD-1, increase significantly after subsequent Pf exposures, possibly dampening the memory response and interfering with the generation of robust sterilizing immunity.
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Basuthakur P, Roy A, Ghosh S, Vijay V, Sinha D, Radhakrishnan M, Kumar A, Patra CR, Chakravarty S. Pro-angiogenic Terbium Hydroxide Nanorods Improve Critical Limb Ischemia in Part by Amelioration of Ischemia-Induced Endothelial Injury. ACS APPLIED BIO MATERIALS 2024. [PMID: 38848346 DOI: 10.1021/acsabm.4c00252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Critical limb ischemia (CLI) refers to a severe condition resulting from gradual obstruction in the supply of blood, oxygen, and nutrients to the limbs. The most promising clinical solution to CLI is therapeutic angiogenesis. This study explored the potency of pro-angiogenic terbium hydroxide nanorods (THNR) for treatment of CLI, with a major focus on their impact on ischemia-induced maladaptive alterations in endothelial cells as well as on vascularization in ischemic limbs. This study demonstrated that, in hypoxia-exposed endothelial cells, THNR improve survival and promote proliferation, migration, restoration of nitric oxide production, and regulation of vascular permeability. Based on molecular studies, these attributes of THNR can be traced to the stimulation of PI3K/AKT/eNOS signaling pathways. Besides, Wnt/GSK-3β/β-catenin signaling pathways may also play a role in the therapeutic actions of THNR. Furthermore, in the murine model of CLI, THNR administration can integrally re-establish blood perfusion with concomitant reduction of muscle damage and inflammation. Additionally, improvement of locomotor activities and motor coordination in ischemic limbs in THNR treated mice is also evident. Overall, the study demonstrates that THNR have the potential to be developed as an efficacious and cost-effective alternative clinical therapy for CLI, using a nanomedicine approach.
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Varghese SM, Patel S, Nandan A, Jose A, Ghosh S, Sah RK, Menon B, K V A, Chakravarty S. Unraveling the Role of the Blood-Brain Barrier in the Pathophysiology of Depression: Recent Advances and Future Perspectives. Mol Neurobiol 2024:10.1007/s12035-024-04205-5. [PMID: 38730081 DOI: 10.1007/s12035-024-04205-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024]
Abstract
Depression is a highly prevalent psychological disorder characterized by persistent dysphoria, psychomotor retardation, insomnia, anhedonia, suicidal ideation, and a remarkable decrease in overall well-being. Despite the prevalence of accessible antidepressant therapies, many individuals do not achieve substantial improvement. Understanding the multifactorial pathophysiology and the heterogeneous nature of the disorder could lead the way toward better outcomes. Recent findings have elucidated the substantial impact of compromised blood-brain barrier (BBB) integrity on the manifestation of depression. BBB functions as an indispensable defense mechanism, tightly overseeing the transport of molecules from the periphery to preserve the integrity of the brain parenchyma. The dysfunction of the BBB has been implicated in a multitude of neurological disorders, and its disruption and consequent brain alterations could potentially serve as important factors in the pathogenesis and progression of depression. In this review, we extensively examine the pathophysiological relevance of the BBB and delve into the specific modifications of its components that underlie the complexities of depression. A particular focus has been placed on examining the effects of peripheral inflammation on the BBB in depression and elucidating the intricate interactions between the gut, BBB, and brain. Furthermore, this review encompasses significant updates on the assessment of BBB integrity and permeability, providing a comprehensive overview of the topic. Finally, we outline the therapeutic relevance and strategies based on BBB in depression, including COVID-19-associated BBB disruption and neuropsychiatric implications. Understanding the comprehensive pathogenic cascade of depression is crucial for shaping the trajectory of future research endeavors.
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Goswami D, Patel H, Betz W, Armstrong J, Camargo N, Patil A, Chakravarty S, Murphy SC, Sim BKL, Vaughan AM, Hoffman SL, Kappe SH. A replication competent Plasmodium falciparum parasite completely attenuated by dual gene deletion. EMBO Mol Med 2024; 16:723-754. [PMID: 38514791 PMCID: PMC11018819 DOI: 10.1038/s44321-024-00057-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 03/23/2024] Open
Abstract
Vaccination with infectious Plasmodium falciparum (Pf) sporozoites (SPZ) administered with antimalarial drugs (PfSPZ-CVac), confers superior sterilizing protection against infection when compared to vaccination with replication-deficient, radiation-attenuated PfSPZ. However, the requirement for drug administration constitutes a major limitation for PfSPZ-CVac. To obviate this limitation, we generated late liver stage-arresting replication competent (LARC) parasites by deletion of the Mei2 and LINUP genes (mei2-/linup- or LARC2). We show that Plasmodium yoelii (Py) LARC2 sporozoites did not cause breakthrough blood stage infections and engendered durable sterilizing immunity against various infectious sporozoite challenges in diverse strains of mice. We next genetically engineered a PfLARC2 parasite strain that was devoid of extraneous DNA and produced cryopreserved PfSPZ-LARC2. PfSPZ-LARC2 liver stages replicated robustly in liver-humanized mice but displayed severe defects in late liver stage differentiation and did not form liver stage merozoites. This resulted in complete abrogation of parasite transition to viable blood stage infection. Therefore, PfSPZ-LARC2 is the next-generation vaccine strain expected to unite the safety profile of radiation-attenuated PfSPZ with the superior protective efficacy of PfSPZ-CVac.
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Radhakrishnan M, Vijay V, Supraja Acharya B, Basuthakur P, Patel S, Soren K, Kumar A, Chakravarty S. Uncovering Sex-Specific Epigenetic Regulatory Mechanism Involving H3k9me2 in Neural Inflammation, Damage, and Recovery in the Internal Carotid Artery Occlusion Mouse Model. Neuromolecular Med 2024; 26:3. [PMID: 38407687 DOI: 10.1007/s12017-023-08768-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/01/2023] [Indexed: 02/27/2024]
Abstract
Cerebral ischemic stroke is one of the foremost global causes of death and disability. Due to inadequate knowledge in its sequential disease mechanisms, therapeutic efforts to mitigate acute ischemia-induced brain injury are limited. Recent studies have implicated epigenetic mechanisms, mostly histone lysine acetylation/deacetylation, in ischemia-induced neural damage and death. However, the role of lysine methylation/demethylation, another prevalent epigenetic mechanism in cerebral ischemia has not undergone comprehensive investigation, except a few recent reports, including those from our research cohort. Considering the impact of sex on post-stroke outcomes, we studied both male and female mice to elucidate molecular details using our recently developed Internal Carotid Artery Occlusion (ICAO) model, which induces mild to moderate cerebral ischemia, primarily affecting the striatum and ventral hippocampus. Here, we demonstrate for the first time that female mice exhibit faster recovery than male mice following ICAO, evaluated through neurological deficit score and motor coordination assessment. Furthermore, our investigation unveiled that dysregulated histone lysine demethylases (KDMs), particularly kdm4b/jmjd2b are responsible for the sex-specific variance in the modulation of inflammatory genes. Building upon our prior reportage blocking KDMs by DMOG (Dimethyloxalylglycine) and thus preventing the attenuation in H3k9me2 reduced the post-ICAO transcript levels of the inflammatory molecules and neural damage, our present study delved into investigating the differential role of H3k9me2 in the regulation of pro-inflammatory genes in female vis-à-vis male mice underlying ICAO-induced neural damage and recovery. Overall, our results reveal the important role of epigenetic mark H3k9me2 in mediating sex-specific sequential events in inflammatory response, elicited post-ICAO.
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Watson FN, Shears MJ, Kalata AC, Duncombe CJ, Seilie AM, Chavtur C, Conrad E, Cruz Talavera I, Raappana A, Sather DN, Chakravarty S, Sim BKL, Hoffman SL, Tsuji M, Murphy SC. Ultra-low volume intradermal administration of radiation-attenuated sporozoites with the glycolipid adjuvant 7DW8-5 completely protects mice against malaria. Sci Rep 2024; 14:2881. [PMID: 38311678 PMCID: PMC10838921 DOI: 10.1038/s41598-024-53118-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 01/28/2024] [Indexed: 02/06/2024] Open
Abstract
Radiation-attenuated sporozoite (RAS) vaccines can completely prevent blood stage Plasmodium infection by inducing liver-resident memory CD8+ T cells to target parasites in the liver. Such T cells can be induced by 'Prime-and-trap' vaccination, which here combines DNA priming against the P. yoelii circumsporozoite protein (CSP) with a subsequent intravenous (IV) dose of liver-homing RAS to "trap" the activated and expanding T cells in the liver. Prime-and-trap confers durable protection in mice, and efforts are underway to translate this vaccine strategy to the clinic. However, it is unclear whether the RAS trapping dose must be strictly administered by the IV route. Here we show that intradermal (ID) RAS administration can be as effective as IV administration if RAS are co-administrated with the glycolipid adjuvant 7DW8-5 in an ultra-low inoculation volume. In mice, the co-administration of RAS and 7DW8-5 in ultra-low ID volumes (2.5 µL) was completely protective and dose sparing compared to standard volumes (10-50 µL) and induced protective levels of CSP-specific CD8+ T cells in the liver. Our finding that adjuvants and ultra-low volumes are required for ID RAS efficacy may explain why prior reports about higher volumes of unadjuvanted ID RAS proved less effective than IV RAS. The ID route may offer significant translational advantages over the IV route and could improve sporozoite vaccine development.
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Sreeja V, Jose A, Patel S, Menon B, Athira KV, Chakravarty S. Pharmacogenetics of selective serotonin reuptake inhibitors (SSRI): A serotonin reuptake transporter (SERT)-based approach. Neurochem Int 2024; 173:105672. [PMID: 38157886 DOI: 10.1016/j.neuint.2023.105672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/12/2023] [Accepted: 12/27/2023] [Indexed: 01/03/2024]
Abstract
Neuropsychiatric disorders are considered to be the most common cause of disability worldwide. Serotonin and its transporter is a prominent paradigm in mood disorders. Response to selective serotonin reuptake inhibitors (SSRI) is altered due to heterogeneity in the serotonin transporter gene, SLC6A4 (solute carrier family 6 member 4). The reported polymorphisms are found to be in different regions of the transporter gene: promoter region (5-HTTLPR and various single nucleotide polymorphisms within it), intron (STin2), and exon 9 (I425V). The long and short alleles of the 5-HTTLPR gene, which are prevalent among variations, may mediate differential effects. In long allelic variant carriers, an increased response to SSRI and timely recovery is due to increased availability of SERT. Whereas, SERT availability is significantly decreased in short allelic carriers, necessitating a reduction in SSRI dosage due to the increased risk of adverse drug reactions. Thus, pharmacogenetic investigations are required to understand the impact of functional variations on the efficacy and tolerability of SSRI. Identifying the carrier variants may aid in clear-decision making of the treatment regimen, aiding the approach of personalized medication.
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Sudarshana KA, Sarma MJ, Radhakrishnan M, Chakravarty S, Srihari P, Mehta G. A protocol for directly accessing geminal C-4 diarylated pyrazol-5(4 H)-ones via tandem C-H aryne insertion and their inceptive neurobiological evaluation. Org Biomol Chem 2024; 22:714-719. [PMID: 38165701 DOI: 10.1039/d3ob01932b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Geminal C-4 diarylation of substituted pyrazol-5(4H)-ones with in situ generated arynes as the aryl source has been achieved in a one-flask operation. All the newly accessed C4-gem-diarylated pyrazolone entities were found to be non-cytotoxic with varying AChE enzyme inhibitory activities and BBB permeability attributes that augur well for further advancement towards CNS therapeutics for untreatable disorders.
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Shears MJ, Reynolds RA, Duncombe CJ, Watson FN, Staubus WJ, Chavtur C, Seilie AM, Tran TM, Chakravarty S, Hoffman SL, Murphy SC. Plasmodium knowlesi in pig-tailed macaques: a potential new model for malaria vaccine research. Malar J 2023; 22:379. [PMID: 38093306 PMCID: PMC10720125 DOI: 10.1186/s12936-023-04788-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/11/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Plasmodium knowlesi is an established experimental model for basic and pre-clinical malaria vaccine research. Historically, rhesus macaques have been the most common host for malaria vaccine studies with P. knowlesi parasites. However, rhesus are not natural hosts for P. knowlesi, and there is interest in identifying alternative hosts for vaccine research. The study team previously reported that pig-tailed macaques (PTM), a natural host for P. knowlesi, could be challenged with cryopreserved P. knowlesi sporozoites (PkSPZ), with time to blood stage infection equivalent to in rhesus. Here, additional exploratory studies were performed to evaluate PTM as potential hosts for malaria vaccine studies. The aim was to further characterize the parasitological and veterinary health outcomes after PkSPZ challenge in this macaque species. METHODS Malaria-naïve PTM were intravenously challenged with 2.5 × 103 PkSPZ and monitored for blood stage infection by Plasmodium 18S rRNA RT-PCR and thin blood smears. Disease signs were evaluated by daily observations, complete blood counts, serum chemistry tests, and veterinary examinations. After anti-malarial drug treatment, a subset of animals was re-challenged and monitored as above. Whole blood gene expression analysis was performed on selected animals to assess host response to infection. RESULTS In naïve animals, the kinetics of P. knowlesi blood stage replication was reproducible, with parasite burden rising linearly during an initial acute phase of infection from 6 to 11 days post-challenge, before plateauing and transitioning into a chronic low-grade infection. After re-challenge, infections were again reproducible, but with lower blood stage parasite densities. Clinical signs of disease were absent or mild and anti-malarial treatment was not needed until the pre-defined study day. Whole blood gene expression analysis identified immunological changes associated with acute and chronic phases of infection, and further differences between initial challenge versus re-challenge. CONCLUSIONS The ability to challenge PTM with PkSPZ and achieve reliable blood stage infections indicate this model has significant potential for malaria vaccine studies. Blood stage P. knowlesi infection in PTM is characterized by low parasite burdens and a benign disease course, in contrast with the virulent P. knowlesi disease course commonly reported in rhesus macaques. These findings identify new opportunities for malaria vaccine research using this natural host-parasite combination.
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Raghavan A, Tripathy C, Radhakrishnan M, Chakravarty S, Ghosh S. Potential of Zinc Oxide-Graphene Quantum Dots and Zinc Oxide-Nitrogen-Doped Graphene Quantum Dot Nanocomposites as Neurotrophic Agents. ACS APPLIED BIO MATERIALS 2023; 6:4208-4216. [PMID: 37728547 DOI: 10.1021/acsabm.3c00413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Over the past few decades, zinc oxide nanoparticles have also proven to be essential to a variety of scientific research sectors, including antimicrobial therapy, tissue engineering, bioimaging, biosensors, drug delivery, gene delivery, and bioimaging. There is an urgent need to establish and develop unique alternative treatment modalities to treat neurodegenerative disorders due to the shortcomings of the existing drugs. As a possible therapy for brain diseases and disorders, the ability of the nanoparticles to cross the blood-brain barrier (BBB) as well as their reduced toxicity, solubility, and biodegradability has lately attracted attention. Scientists are quietly turning their attention to develop green synthesis of nanoparticles as an alternative to the physical and chemical techniques of producing the same. Existing literature has emphasized the use of ZnO for the potential treatment of cerebral ischemia and its neuroprotective properties. This work discusses the potential of ZnO prepared using Gynura cusimba extract and its nanocomposites with graphene quantum dots (GQDs) and its nitrogen doped variant, N-GQDs as neurotrophic agents, in accordance with our previous report on the use of GQDs and N-GQDs as neurotrophic agents. Pristine ZnO nanoparticles as well as composites were duly characterized by using several techniques to confirm the formation of the nanocomposites. Biological evaluation using the neurite outgrowth assay following the cell viability assay revealed that incorporation of GQDs and N-GQDs enhanced the neurite length in comparison to that of pristine ZnO with the nanocomposites of N-GQDs showing comparatively better results, corroborated by the real-time PCR studies as well.
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Karale UB, Shinde A, Gaikwad VR, Kalari S, Gourishetti K, Radhakrishnan M, Poornachandra Y, Amanchy R, Chakravarty S, Andugulapati SB, Rode HB. Iron mediated reductive cyclization/oxidation for the generation of chemically diverse scaffolds: An approach in drug discovery. Bioorg Chem 2023; 139:106698. [PMID: 37418784 DOI: 10.1016/j.bioorg.2023.106698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/03/2023] [Accepted: 06/20/2023] [Indexed: 07/09/2023]
Abstract
Chemically diverse scaffolds represent a main source of biologically important starting points in drug discovery. Herein, we report the development of such diverse scaffolds from nitroarene/ nitro(hetero)arenes using a key synthetic strategy. In a pilot-scale study, the synthesis of 10 diverse scaffolds was achieved. The 1,7-phenanthroline, thiazolo[5,4-f]quinoline, 2,3-dihydro-1H-pyrrolo[2,3-g]quinoline, pyrrolo[3,2-f]quinoline, 1H-[1,4]oxazino[3,2-g]quinolin-2(3H)-one, [1,2,5]oxadiazolo[3,4-h]quinoline, 7H-pyrido[2,3-c]carbazole, 3H-pyrazolo[4,3-f]quinoline, pyrido[3,2-f]quinoxaline were obtained from nitro hetero arenes in ethanol using iron-acetic acid treatment followed by reaction under oxygen atmosphere. This diverse library is compliant with the rule of five for drug-likeness. The mapping of chemical space represented by these scaffolds revealed a significant contribution to the underrepresented chemical diversity. Crucial to the development of this approach was the mapping of biological space covered by these scaffolds which revealed neurotropic and prophylactic anti-inflammatory activities. In vitro, neuro-biological assays revealed that compounds 14a and 15a showed excellent neurotropic potential and neurite growth compared to controls. Further, anti-inflammatory assays (in vitro and in vivo models) exhibited that Compound 16 showed significant anti-inflammatory activity by attenuating the LPS-induced TNF-α and CD68 levels by modulating the NFkB pathway. In addition, treatment with compound 16 significantly ameliorated the LPS-induced sepsis conditions, and pathological abnormalities (in lung and liver tissues) and improved the survival of the rats compared to LPS control. Owing to their chemical diversity along with bioactivities, it is envisaged that new quality pre-clinical candidates will be generated in the above therapeutic areas using identified leads.
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Basuthakur P, Roy A, Patra CR, Chakravarty S. Therapeutic potentials of terbium hydroxide nanorods for amelioration of hypoxia-reperfusion injury in cardiomyocytes. BIOMATERIALS ADVANCES 2023; 153:213531. [PMID: 37429046 DOI: 10.1016/j.bioadv.2023.213531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/06/2023] [Accepted: 06/17/2023] [Indexed: 07/12/2023]
Abstract
Myocardial hypoxia reperfusion (H/R) injury is the paradoxical exacerbation of myocardial damage, caused by the sudden restoration of blood flow to hypoxia affected myocardium. It is a critical contributor of acute myocardial infarction, which can lead to cardiac failure. Despite the current pharmacological advancements, clinical translation of cardioprotective therapies have proven challenging. As a result, researchers are looking for alternative approaches to counter the disease. In this regard, nanotechnology, with its versatile applications in biology and medicine, can confer broad prospects for treatment of myocardial H/R injury. Herein, we attempted to explore whether a well-established pro-angiogenic nanoparticle, terbium hydroxide nanorods (THNR) can ameliorate myocardial H/R injury. For this study, in vitro H/R-injury model was established in rat cardiomyocytes (H9c2 cells). Our investigations demonstrated that THNR enhance cardiomyocyte survival against H/R-induced cell death. This pro-survival effect of THNR is associated with reduction of oxidative stress, lipid peroxidation, calcium overload, restoration of cytoskeletal integrity and mitochondrial membrane potential as well as augmentation of cellular anti-oxidant enzymes such as glutathione-s-transferase (GST) and superoxide dismutase (SOD) to counter H/R injury. Molecular analysis revealed that the above observations are traceable to the predominant activation of PI3K-AKT-mTOR and ERK-MEK signalling pathways by THNR. Concurrently, THNR also exhibit apoptosis inhibitory effects mainly by suppression of pro-apoptotic proteins like Cytochrome C, Caspase 3, Bax and p53 with simultaneous restoration of anti-apoptotic protein, Bcl-2 and Survivin. Thus, considering the above attributes, we firmly believe that THNR have the potential to be developed as an alternative approach for amelioration of H/R injury in cardiomyocytes.
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Pérez-Martín M, Chakravarty S. Editorial: Women in neurogenesis. Front Neurosci 2023; 17:1285728. [PMID: 37790592 PMCID: PMC10543259 DOI: 10.3389/fnins.2023.1285728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023] Open
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Watson FN, Shears MJ, Kalata AC, Duncombe CJ, Seilie AM, Chavtur C, Conrad E, Talavera IC, Raappana A, Sather DN, Chakravarty S, Sim BKL, Hoffman SL, Tsuji M, Murphy SC. Ultra-low volume intradermal administration of radiation-attenuated sporozoites with the glycolipid adjuvant 7DW8-5 completely protects mice against malaria. RESEARCH SQUARE 2023:rs.3.rs-3243319. [PMID: 37609210 PMCID: PMC10441511 DOI: 10.21203/rs.3.rs-3243319/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Malaria is caused by Plasmodium parasites and was responsible for over 247 million infections and 619,000 deaths in 2021. Radiation-attenuated sporozoite (RAS) vaccines can completely prevent blood stage infection by inducing protective liver-resident memory CD8+ T cells. Such T cells can be induced by 'prime-and-trap' vaccination, which here combines DNA priming against the P. yoelii circumsporozoite protein (CSP) with a subsequent intravenous (IV) dose of liver-homing RAS to "trap" the activated and expanding T cells in the liver. Prime-and-trap confers durable protection in mice, and efforts are underway to translate this vaccine strategy to the clinic. However, it is unclear whether the RAS trapping dose must be strictly administered by the IV route. Here we show that intradermal (ID) RAS administration can be as effective as IV administration if RAS are co-administrated with the glycolipid adjuvant 7DW8-5 in an ultra-low inoculation volume. In mice, the co-administration of RAS and 7DW8-5 in ultra-low ID volumes (2.5 μL) was completely protective and dose sparing compared to standard volumes (10-50 μL) and induced protective levels of CSP-specific CD8+ T cells in the liver. Our finding that adjuvants and ultra-low volumes are required for ID RAS efficacy may explain why prior reports about higher volumes of unadjuvanted ID RAS proved less effective. The ID route may offer significant translational advantages over the IV route and could improve sporozoite vaccine development.
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Raghavan A, Radhakrishnan M, Soren K, Wadnerkar P, Kumar A, Chakravarty S, Ghosh S. Biological Evaluation of Graphene Quantum Dots and Nitrogen-Doped Graphene Quantum Dots as Neurotrophic Agents. ACS APPLIED BIO MATERIALS 2023. [PMID: 37167607 DOI: 10.1021/acsabm.3c00099] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Over time, developments in nano-biomedical research have led to the creation of a number of systems to cure serious illnesses. Tandem use of nano-theragnostics such as diagnostic and therapeutic approaches tailored to the individual disease treatment is crucial for further development in the field of biomedical advancements. Graphene has garnered attention in the recent times as a potential nanomaterial for tissue engineering and regenerative medicines owing to its biocompatibility among the several other unique properties it possesses. The zero-dimensional graphene quantum dots (GQDs) and their nitrogen-doped variant, nitrogen-doped GQDs (N-GQDs), have good biocompatibility, and optical and physicochemical properties. GQDs have been extensively researched owing to several factors such as their size, surface charge, and interactions with other molecules found in biological media. This work briefly elucidates the potential of electroactive GQDs as well as N-GQDs as neurotrophic agents. In vitro investigations employing the N2A cell line were used to evaluate the effectiveness of GQDs and N-GQDs as neurotrophic agents, wherein basic investigations such as SRB assay and neurite outgrowth assay were performed. The results inferred from immunohistochemistry followed by confocal imaging studies as well as quantitative real-time PCR (qPCR) studies corroborated those obtained from neurite outgrowth assay. We have also conducted a preliminary investigation of the pattern of gene expression for neurotrophic and gliotrophic growth factors using ex vivo neuronal and mixed glial cultures taken from the brains of postnatal day 2 mice pups. Overall, the studies indicated that GQDs and N-GQDs hold prospect as a framework for further development of neuroactive compounds for relevant central nervous system (CNS) purposes.
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Bhat UA, Kumar SA, Chakravarty S, Patel AB, Kumar A. Differential Effects of Chronic Ethanol Use on Mouse Neuronal and Astroglial Metabolic Activity. Neurochem Res 2023:10.1007/s11064-023-03922-y. [PMID: 37069415 DOI: 10.1007/s11064-023-03922-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/19/2023]
Abstract
Chronic alcohol use disorder, a major risk factor for the development of neuropsychiatric disorders including addiction to other substances, is associated with several neuropathology including perturbed neuronal and glial activities in the brain. It affects carbon metabolism in specific brain regions, and perturbs neuro-metabolite homeostasis in neuronal and glial cells. Alcohol induced changes in the brain neurochemical profile accompany the negative emotional state associated with dysregulated reward and sensitized stress response to withdrawal. However, the underlying alterations in neuro-astroglial activities and neurochemical dysregulations in brain regions after chronic alcohol use are poorly understood. This study evaluates the impact of chronic ethanol use on the regional neuro-astroglial metabolic activity using 1H-[13C]-NMR spectroscopy in conjunction with infusion of [1,6-13C2]glucose and sodium [2-13C]acetate, respectively, after 48 h of abstinence. Besides establishing detailed 13C labeling of neuro-metabolites in a brain region-specific manner, our results show chronic ethanol induced-cognitive deficits along with a reduction in total glucose oxidation rates in the hippocampus and striatum. Furthermore, using [2-13C]acetate infusion, we showed an alcohol-induced increase in astroglial metabolic activity in the hippocampus and prefrontal cortex. Interestingly, increased astroglia activity in the hippocampus and prefrontal cortex was associated with a differential expression of monocarboxylic acid transporters that are regulating acetate uptake and metabolism in the brain.
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Karanam SR, Srinivas Y, Chakravarty S. A statistical model approach based on the Gaussian Mixture Model for the diagnosis and classification of bone fractures. INTERNATIONAL JOURNAL OF HEALTHCARE MANAGEMENT 2023. [DOI: 10.1080/20479700.2022.2161146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Richie TL, Church LWP, Murshedkar T, Billingsley PF, James ER, Chen MC, Abebe Y, KC N, Chakravarty S, Dolberg D, Healy SA, Diawara H, Sissoko MS, Sagara I, Cook DM, Epstein JE, Mordmüller B, Kapulu M, Kreidenweiss A, Franke-Fayard B, Agnandji ST, López Mikue MSA, McCall MBB, Steinhardt L, Oneko M, Olotu A, Vaughan AM, Kublin JG, Murphy SC, Jongo S, Tanner M, Sirima SB, Laurens MB, Daubenberger C, Silva JC, Lyke KE, Janse CJ, Roestenberg M, Sauerwein RW, Abdulla S, Dicko A, Kappe SHI, Lee Sim BK, Duffy PE, Kremsner PG, Hoffman SL. Sporozoite immunization: innovative translational science to support the fight against malaria. Expert Rev Vaccines 2023; 22:964-1007. [PMID: 37571809 PMCID: PMC10949369 DOI: 10.1080/14760584.2023.2245890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Malaria, a devastating febrile illness caused by protozoan parasites, sickened 247,000,000 people in 2021 and killed 619,000, mostly children and pregnant women in sub-Saharan Africa. A highly effective vaccine is urgently needed, especially for Plasmodium falciparum (Pf), the deadliest human malaria parasite. AREAS COVERED Sporozoites (SPZ), the parasite stage transmitted by Anopheles mosquitoes to humans, are the only vaccine immunogen achieving >90% efficacy against Pf infection. This review describes >30 clinical trials of PfSPZ vaccines in the U.S.A., Europe, Africa, and Asia, based on first-hand knowledge of the trials and PubMed searches of 'sporozoites,' 'malaria,' and 'vaccines.' EXPERT OPINION First generation (radiation-attenuated) PfSPZ vaccines are safe, well tolerated, 80-100% efficacious against homologous controlled human malaria infection (CHMI) and provide 18-19 months protection without boosting in Africa. Second generation chemo-attenuated PfSPZ are more potent, 100% efficacious against stringent heterologous (variant strain) CHMI, but require a co-administered drug, raising safety concerns. Third generation, late liver stage-arresting, replication competent (LARC), genetically-attenuated PfSPZ are expected to be both safe and highly efficacious. Overall, PfSPZ vaccines meet safety, tolerability, and efficacy requirements for protecting pregnant women and travelers exposed to Pf in Africa, with licensure for these populations possible within 5 years. Protecting children and mass vaccination programs to block transmission and eliminate malaria are long-term objectives.
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Watson FN, Duncombe CJ, Kalata AC, Conrad E, Chakravarty S, Sim BKL, Hoffman SL, Tsuji M, Shears MJ, Murphy SC. Sex-Specific Differences in Cytokine Induction by the Glycolipid Adjuvant 7DW8-5 in Mice. Biomolecules 2022; 13:biom13010008. [PMID: 36671393 PMCID: PMC9855660 DOI: 10.3390/biom13010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
7DW8-5 is a potent glycolipid adjuvant that improves malaria vaccine efficacy in mice by inducing IFN-γ and increasing protective CD8+ T cell responses. The addition of 7DW8-5 was previously shown to improve the efficacy of a CD8+ T cell-mediated heterologous 'prime-and-trap' malaria vaccine against Plasmodium yoelii sporozoite challenge in inbred female mice. Here, we report significant differential sex-specific responses to 7DW8-5 in inbred and outbred mice. Male mice express significantly less IFN-γ and IL-4 compared to females following intravenous 7DW8-5 administration. Additionally, unlike in female mice, 7DW8-5 did not improve the vaccine efficacy against sporozoite challenge in prime-and-trap vaccinated male mice. Our findings highlight the importance of including both female and male sexes in experimental adjuvant studies.
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KC N, Church LWP, Riyahi P, Chakravarty S, Seder RA, Epstein JE, Lyke KE, Mordmüller B, Kremsner PG, Sissoko MS, Healy S, Duffy PE, Jongo SA, Nchama VUNN, Abdulla S, Mpina M, Sirima SB, Laurens MB, Steinhardt LC, Oneko M, Li M, Murshedkar T, Billingsley PF, Sim BKL, Richie TL, Hoffman SL. Increased levels of anti-PfCSP antibodies in post-pubertal females versus males immunized with PfSPZ Vaccine does not translate into increased protective efficacy. Front Immunol 2022; 13:1006716. [PMID: 36389797 PMCID: PMC9641621 DOI: 10.3389/fimmu.2022.1006716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/30/2022] [Indexed: 11/25/2022] Open
Abstract
Background While prior research has shown differences in the risk of malaria infection and sickness between males and females, little is known about sex differences in vaccine-induced immunity to malaria. Identifying such differences could elucidate important aspects of malaria biology and facilitate development of improved approaches to malaria vaccination. Methods Using a standardized enzyme-linked immunosorbent assay, IgG antibodies to the major surface protein on Plasmodium falciparum (Pf) sporozoites (SPZ), the Pf circumsporozoite protein (PfCSP), were measured before and two weeks after administration of a PfSPZ-based malaria vaccine (PfSPZ Vaccine) to 5-month to 61-year-olds in 11 clinical trials in Germany, the US and five countries in Africa, to determine if there were differences in vaccine elicited antibody response between males and females and if these differences were associated with differential protection against naturally transmitted Pf malaria (Africa) or controlled human malaria infection (Germany, the US and Africa). Results Females ≥ 11 years of age made significantly higher levels of antibodies to PfCSP than did males in most trials, while there was no indication of such differences in infants or children. Although adult females had higher levels of antibodies, there was no evidence of improved protection compared to males. In 2 of the 7 trials with sufficient data, protected males had significantly higher levels of antibodies than unprotected males, and in 3 other trials protected females had higher levels of antibodies than did unprotected females. Conclusion Immunization with PfSPZ Vaccine induced higher levels of antibodies in post-pubertal females but showed equivalent protection in males and females. We conclude that the increased antibody levels in post-pubertal females did not contribute substantially to improved protection. We hypothesize that while antibodies to PfCSP (and PfSPZ) may potentially contribute directly to protection, they primarily correlate with other, potentially protective immune mechanisms, such as antibody dependent and antibody independent cellular responses in the liver.
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Chakravarty S, Shears MJ, James ER, Rai U, Kc N, Conteh S, Lambert LE, Duffy PE, Murphy SC, Hoffman SL. Efficient infection of non-human primates with purified, cryopreserved Plasmodium knowlesi sporozoites. Malar J 2022; 21:247. [PMID: 36030292 PMCID: PMC9418655 DOI: 10.1186/s12936-022-04261-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/17/2022] [Indexed: 11/29/2022] Open
Abstract
Background Plasmodium falciparum (Pf) sporozoite (SPZ) vaccines are the only candidate malaria vaccines that induce > 90% vaccine efficacy (VE) against controlled human malaria infection and the only malaria vaccines to have achieved reproducible VE against malaria in adults in Africa. The goal is to increase the impact and reduce the cost of PfSPZ vaccines by optimizing vaccine potency and manufacturing, which will benefit from identification of immunological responses contributing to protection in humans. Currently, there is no authentic animal challenge model for assessing P. falciparum malaria VE. Alternatively, Plasmodium knowlesi (Pk), which infects humans and non-human primates (NHPs) in nature, can be used to experimentally infect rhesus macaques (Macaca mulatta) to assess VE. Methods Sanaria has, therefore, produced purified, vialed, cryopreserved PkSPZ and conducted challenge studies in several naïve NHP cohorts. In the first cohort, groups of three rhesus macaques each received doses of 5 × 102, 2.5 × 103, 1.25 × 104 and 2.5 × 104 PkSPZ administered by direct venous inoculation. The infectivity of 1.5 × 103 PkSPZ cryopreserved with an altered method and of 1.5 × 103 PkSPZ cryopreserved for four years was tested in a second and third cohort of rhesus NHPs. The lastly, three pig-tailed macaques (Macaca nemestrina), a natural P. knowlesi host, were challenged with 2.5 × 103 PkSPZ cryopreserved six years earlier. Results In the first cohort, all 12 animals developed P. knowlesi parasitaemia by thick blood smear, and the time to positivity (prepatent period) followed a non-linear 4-parameter logistic sigmoidal model with a median of 11, 10, 8, and 7 days, respectively (r2 = 1). PkSPZ cryopreserved using a modified rapid-scalable method infected rhesus with a pre-patent period of 10 days, as did PkSPZ cryopreserved four years prior to infection, similar to the control group. Cryopreserved PkSPZ infected pig-tailed macaques with median time to positivity by thin smear, of 11 days. Conclusion This study establishes the capacity to consistently infect NHPs with purified, vialed, cryopreserved PkSPZ, providing a foundation for future studies to probe protective immunological mechanisms elicited by PfSPZ vaccines that cannot be established in humans. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04261-z.
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Karanam SR, Srinivas Y, Chakravarty S. A systematic approach to diagnosis and categorization of bone fractures in X-Ray imagery. INTERNATIONAL JOURNAL OF HEALTHCARE MANAGEMENT 2022. [DOI: 10.1080/20479700.2022.2097765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Wahl I, Obraztsova AS, Puchan J, Hundsdorfer R, Chakravarty S, Sim BKL, Hoffman SL, Kremsner PG, Mordmüller B, Wardemann H. Clonal evolution and TCR specificity of the human T FH cell response to Plasmodium falciparum CSP. Sci Immunol 2022; 7:eabm9644. [PMID: 35687696 DOI: 10.1126/sciimmunol.abm9644] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
T follicular helper (TFH) cells play a crucial role in the development of long-lived, high-quality B cell responses after infection and vaccination. However, little is known about how antigen-specific TFH cells clonally evolve in response to complex pathogens and what guides the targeting of different epitopes. Here, we assessed the cell phenotype, clonal dynamics, and T cell receptor (TCR) specificity of human circulating TFH (cTFH) cells during successive malaria immunizations with radiation-attenuated Plasmodium falciparum (Pf) sporozoites. Repeated parasite exposures induced a dynamic, polyclonal cTFH response with high frequency of cells specific to a small number of epitopes in Pf circumsporozoite protein (PfCSP), the primary sporozoite surface protein and well-defined vaccine target. Human leukocyte antigen (HLA) restrictions and differences in TCR generation probability were associated with differences in the epitope targeting frequency and indicated the potential of amino acids 311 to 333 in the Th2R/T* region as a T cell supertope. But most of vaccine-induced anti-amino acid 311 to 333 TCRs, including convergent TCRs with high sequence similarity, failed to tolerate natural polymorphisms in their target peptide sequence, thus demonstrating that the TFH cell response was limited to the vaccine strain. These data suggest that the high parasite diversity in endemic areas will limit boosting of the vaccine-induced TFH cell response by natural infections. Our findings may guide the further design of PfCSP-based malaria vaccines able to induce potent T helper cell responses for broad, long-lasting antibody responses.
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James ER, Matheny S, Overby J, Sim BKL, Eappen AG, Li T, Li ML, Richie TL, Chakravarty S, Gunasekera A, Murshedkar T, Billingsley PF, Hoffman SL. A First for Human Vaccinology: GMP Compliant Radiation Attenuation of Plasmodium falciparum Sporozoites for Production of a Vaccine Against Malaria. Front Immunol 2022; 13:851028. [PMID: 35242146 PMCID: PMC8886114 DOI: 10.3389/fimmu.2022.851028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 01/25/2022] [Indexed: 11/23/2022] Open
Abstract
Ionizing radiation (UV, X-ray and ɣ) administered at an appropriate dose to pathogenic organisms can prevent replication while preserving metabolic activity. We have established the GMP process for attenuation by ionizing radiation of the Plasmodium falciparum (Pf) sporozoites (SPZ) in Sanaria® PfSPZ Vaccine, a protective vaccine against malaria. Mosquitoes raised and infected aseptically with Pf were transferred into infected mosquito transport containers (IMTC) and ɣ-irradiated using a 60Co source. PfSPZ were then extracted, purified, vialed, and cryopreserved. To establish the appropriate radiation conditions, the irradiation field inside the IMTCs was mapped using radiochromic film and alanine transfer dosimeters. Dosimeters were irradiated for times calculated to provide 120-170 Gy at the minimum dose location inside the IMTC and regression analysis was used to determine the time required to achieve a lower 95% confidence interval for 150 Gy. A formula incorporating the half-life of 60Co was then used to construct tables of irradiation times for each calendar day. From the mapping studies, formulae were derived to estimate the minimum and maximum doses of irradiation received inside the IMTC from a reference dosimeter mounted on the outside wall. For PfSPZ Vaccine manufacture a dose of 150 Gy was targeted for each irradiation event, a dose known to completely attenuate PfSPZ. The reference dosimeters were processed by the National Institute of Standards and Technology. There have been 587 irradiation events to produce PfSPZ Vaccine during 13 years which generated multiple lots released for pre-clinical studies and clinical trials. The estimated doses at the minimum dose location (mean 154.3 ± 1.77 Gy; range 150.0-159.3 Gy), and maximum dose location (mean 166.3 ± 3.65 Gy, range 155.7 to 175.3 Gy), in IMTCs were normally distributed. Overall dose uniformity was 1.078 ± 0.012. There was no siginifcant change in measured dose over 13 years. As of January 2022, 21 clinical trials of PfSPZ Vaccine have been conducted, with 1,740 volunteers aged 5 months to 61 years receiving 5,648 doses of PfSPZ Vaccine totalling >5.3 billion PfSPZ administered. There have been no breakthrough infections, confirming the consistency and robustness of the radiation attenuation process.
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