Letteratura scientifica selezionata sul tema "CLAUT TISSUE CULTURE"

Aim. The aim of the work was to determine the conditions for development of in vitro culture, induction of callus formation, and long-term tissue culture of Zingeria biebersteiniana (Claus) P. Smirn. Methods. In vitro clonal propagation, tissue culture techniques. Results. The seed germination rate was found to increase significantly after long-term cold stratification. The protocol for seed sterilization was developed, which yielded 57.3% of aseptic plants. Collections of in vitro and pot cultured plants were created. Experiments on the adaptation of in vitro propagated plants to pot culture conditions revealed a high level of their survival. The optimal medium for in vitro clonal propagation was MS, supplemented with 0.1 mg/L NAA; while the most effective media for induction of callus formation and for long-term tissue culture was B5 supplemented with 2 mg/L 2,4-D and 0.1 mg/L BAP. Conclusions. The protocols and conditions for seed germination, in vitro clonal propagation, induction of callus formation, as well as long-term tissue culture of Z. biebersteiniana have been developed. The developed techniques of in vitro culture can be used for conservation and restoration of genetic diversity of the species, as well as to obtain sufficient plant material for further studies.

Abstract Zingeria biebersteiniana (Claus) P. Smirn (2n = 4) is an insufficiently explored model plant and its research prospects are wide. At the same time, it is included in the Red List of Russia due to the narrow ecological amplitude of the species. During the work for the first time for this species, the conditions for the induction of callusogenesis and somatic organogenesis were studied. Aseptic plants were obtained by sterilization with 5 % sodium hypochlorite solution; seed stratification increased seed germination rate. Since rooting is often a problem by in vitro cultivation, various concentrations of the main components of MS nutrient medium were studied. It was found that for the induction of root formation the optimal composition of the nutrient medium contains 1/8-1/2 concentrations of mineral salts and vitamins according to the recipe MS. The study of the possibility of induction of callus formation was carried out on seeds and on leaf explants. For induction of callusogenesis on seeds, the greatest effectiveness was shown by MS with the addition of 4 mg/l 2,4-D, for further reproduction of callus - MS with the addition of 0.1-0.5 mg/l 2,4-D; however, it was not possible to achieve callus formation on leaf explants. The highest frequency of somatic organogenesis in callus tissue was achieved on MS with the addition of 1 mg/l BAP and 1/12 mg/l IAA.

BackgroundDespite compelling preclinical data, agonistic anti-CD137 antibodies have been hampered by failure to delineate hepatotoxicity from efficacy in clinical studies.1 2 A new generation of both systemic and targeted CD137 agonists that are now entering clinical development rely on biologic agents with suboptimal properties for CD137 agonism due to their relatively large sizes and long circulating half-lives.3–5 These properties may limit their tissue penetration and cause sustained agonism resulting in overstimulation and activation-induced cell death of lymphocytes due to continuous exposure.BCY12491 is a tumor-targeted immune cell agonist (TICATM) that exemplifies a new class of fully synthetic immunomodulators with constrained bicyclic peptides (Bicycles®) targeting a tumor antigen and a co-stimulatory molecule. We developed this new class of synthetic molecules with antibody-like affinities and target selectivity to circumvent the beforementioned barriers to optimal targeted CD137 agonistic therapeutics. BCY12491 (EphA2/CD137 TICA) is designed to deliver a highly potent CD137 agonist to EphA2 overexpressing tumor tissue with an intermittent dosing schedule maximizing anti-tumor activity while circumventing the need for continuous systemic exposure.MethodsBCY12491 bioactivity was assessed in vitro using a CD137 reporter assay and by measuring cytokine production from primary human PBMC/tumor cell co-cultures. BCY12491 in vivo activity was determined in huCD137-syngeneic tumor models by measuring tumor growth kinetics and using tumor immune cell and transcriptional profiling by FACS, IHC, and Nanostring.ResultsBCY12491 engages EphA2 and CD137 with high affinity resulting in picomolar potency in co-culture assays consisting of EphA2-expressing tumor cell lines and CD137-expressing Jurkat NF-kappaB-luciferase reporter cells. Moreover, BCY12491 caused EphA2-dependent CD137 agonism in primary human PBMCs co-cultured with tumor cells with varied levels of EphA2 expression. Treatment of MC38 tumors in immunocompetent mice with BCY12491 leads to a profound reprogramming of the tumor immune microenvironment including increased T cell infiltration and stimulation of NF-kappaB signaling, costimulatory signaling, cytotoxicity and cytokine/chemokine signaling functional pathways. BCY12491 treatment leads to MC38 tumor regressions, complete responses, and immunogenic memory without continuous drug exposure in the periphery. This anti-tumor activity is dependent on CD8+ T cells, but not on NK 1.1+ cells.ConclusionsBCY12491 is a potent EphA2-dependent CD137 agonist with optimal target binding, pharmacologic, and pharmacokinetic properties that enable anti-tumor TME remodeling and complete responses in vivo with intermittent dosing. This work unleashes a new and tractable avenue to testing a novel class of therapeutic CD137 agonists in humans for the treatment of cancer.Ethics ApprovalThe care and use of animals were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of WuXi AppTec and conducted in accordance with the regulations of the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).ReferencesSegal NH, Logan TF, Hodi FS, et al. Results from an integrated safety analysis of urelumab, an agonist anti-CD137 monoclonal antibody. Clin Cancer Res 2017;23(8):1929–1936.Chester C, Sanmamed MF, Wang J, Melero I. Immunotherapy targeting 4-1BB: mechanistic rationale, clinical results, and future strategies. Blood 2018;131(1): 49–57.Hinner MJ, Aiba RSB, Jaquin TJ, et al. Tumor-Localized Costimulatory T-Cell Engagement by the 4-1BB/HER2 Bispecific Antibody-Anticalin Fusion PRS-343. Clin Cancer Res. 2019;25(19):5878–5889.Claus C, Ferrara, C, Xu W, et al. Tumor-targeted 4-1BB agonists for combination with T cell bispecific antibodies as off-the-shelf therapy. Sci Transl Med 2019;11(496): eaav5989.Eskiocak U, Guzman W, Wolf B, et al. Differentiated agonistic antibody targeting CD137 eradicates large tumors without hepatotoxicity. JCI Insight 2020;5(5):e133647.

BackgroundAfter disappointing first clinical experiences with agonistic anti-CD137 (4-1BB) antibodies, a new generation of both systemic and targeted CD137 agonists is entering clinical development.1–3 These strategies rely on biologic agents with suboptimal properties for CD137 agonism due to their relatively large sizes and long circulating half-lives. These properties may limit their tissue penetration and cause sustained agonism resulting in overstimulation and activation-induced cell death of lymphocytes due to continuous exposure.Fully synthetic constrained bicyclic peptides (Bicycles™) with antibody-like affinities and target selectivity are uniquely suited to circumvent the above barriers to optimal targeted CD137 agonistic therapeutics. BT7480 is a tumor-targeted immune cell agonist (TICA) designed to deliver a highly potent CD137 agonist to Nectin-4 overexpressing tumor tissue with a flexible dosing schedule maximizing anti-tumor activity while circumventing the need for continuous systemic exposure.MethodsBT7480 functional activity in vitro was analyzed by measuring IL-2 and IFN gamma production from primary human PBMC/tumor cell co-cultures. BT7480 in vivo activity was determined in huCD137-syngeneic tumor models using tumor immune cell and transcriptional profiling by FACS, IHC, and Nanostring as well as tumor growth kinetics as read-outs.ResultsBT7480 binds potently and simultaneously to Nectin-4 and CD137 as assessed biochemically and caused Nectin-4-dependent CD137 agonism in primary human PBMC co-cultured with tumor cells. Treatment of Nectin-4 expressing tumors in immunocompetent mice with BT7480 leads to profound reprogramming of the tumor immune microenvironment including increased T cell infiltration and upregulation of a cytotoxic cell gene signature. BT7480 treatment induces complete tumor regressions and subsequent resistance to tumor re-challenge. TICA-dependent anti-tumor activity and established immunologic memory are dependent on cytotoxic T cells. Importantly, BT7480 in vivo activity is not dependent on continuous plasma exposure since once weekly dosing of BT7480 provides a maximum anti-tumor activity despite minimal BT7480 plasma exposure after day 2.BT7480 demonstrates linear pharmacokinetics in non-human primates and appears well tolerated at exposures in excess of the predicted efficacious exposure in humans.ConclusionsBT7480 is a highly potent Nectin-4 expression dependent CD137 agonist with optimal target binding, pharmacologic, and pharmacokinetic properties that enable intermittent dosing for curative effect through modulation of tumor immune microenvironment in syngeneic mouse tumor models. BT7480 is currently being evaluated in IND-enabling safety studies.Ethics ApprovalThe care and use of animals were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of WuXi AppTec and conducted in accordance with the regulations of the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).ReferencesHinner, et al. Tumor-localized costimulatory t-cell engagement by the 4-1BB/HER2 Bispecific antibody-anticalin fusion PRS-343. Clin. Cancer Res 2019 Oct 1;25(19):5878–5889.Claus, et al. Tumor-targeted 4-1BB agonists for combination with T cell bispecific antibodies as off-the-shelf therapy. Sci. Transl. Med 2019 Jun 12;11(496):eaav5989.Eskiocak, et al. Differentiated agonistic antibody targeting CD137 eradicates large tumors without hepatotoxicity. JCI Insight 2020 Mar 12;5(5):e133647.

Purpose: To evaluate and compare long-term efficacy of cultivated limbal epithelial cell transplant (CLET) and conjunctival limbal autograft (CLAU) in uniocular limbal stem cell deficiency (LSCD) in chemically injured eyes. Methods: This was a retrospective, interventional, comparative study, and comprised of sixty- one patients with unilateral severe LSCD who underwent CLET (10) and CLAU (51 patients). Surgical Procedure: Surgical procedure in CLET included superficial keratectomy, excision of fibrovascular tissue, securing amniotic membrane supporting cultured limbal stem cells and placement of bandage contact lens. CLAU included superficial keratectomy, excision of fibrovascular tissue, securing limbal stem cells graft with / without amniotic membrane transplant (AMT). Results: Following CLET ocular surface improved in all 10 patients and visual acuity improved significantly in three cases. CLAU was performed in 33 eyes and combined CLAU + AMT in 18 eyes. Visual acuity improved significantly in 26 (51%) eyes. Ocular surface and symblepharon grades improved in all patients during a mean 58.7±21.9 months follow up. Conclusion: CLET and CLAU is safe and effective in rehabilitating the ocular surface before penetrating keratoplasty (PKP) in uniocular severe LSCD. CLET has the advantage of avoiding iatrogenic limbal stem cell deficiency. CLAU enabled us to repair symblepharon simultaneously by taking extra conjunctiva.

Bioactive chemicals are described as dietary components that affect people who consume those substances in their physiological as well as cellular function. Flavonoids, anthocyanins, tannins, berets, carotenoids, plant sterols and glucosinolates are all included. These may well be present most often in fruits and vegetables; offer anti - oxidant, anti-inflammatory but also antiviral activities; and therefore, can shield humans toward chronic disorders and metabolism. These favorable effects empower researchers to create novel functional foods containing prospective protective and healthful. Cardiovascular disease is the cardiac or blood vessel dysfunctional action. An inadequate heart and blood vessel function boosts the heart attack risk, heart failure, sudden death, stroke and heart rhythm disorders, resulting to diminished standard of health and a shorter life expectancy. Plant tissue culture is an effective venue for the generation of secondary metabolites along with its diverse implications. Diverse plant- based strategies including such callus or suspension cultivation are utilized generally in the synthesis of secondary plant metabolites. Several novel approaches which aim to have a rather significant and neglected influence on secondary metabolite synthesis.