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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Heterogeneous response of cancer-associated fibroblasts to the glucose deprivation through mitochondrial calcium uniporter

Highlights: • CAFs from a tumor mass are heterogeneous under the glucose deficient condition. • CAFs survive under glucose deficient condition by activation of TGF-β and calcium. • Calcium influx to mitochondria is critical for survival of glucose-deficient CAFs. • MCU in CAFs could be a feasible target for the development of anticancer drugs. Cancer-associated fibroblasts (CAFs) are an abundant component of the tumor microenvironment and have distinct features from normal fibroblasts (NFs). However, the discriminative nature of heterogeneous CAFs under glucose starvation remains unknown. In this study, we investigated the changes in the mitochondrial calcium concentration and relevant intracellular machinery in CAFs under glucose-deficient conditions. Xenografted tumor masses were dissected into multiple pieces and subjected to the CAF isolation using magnetically activated cell sorting (MACS). NFs were separated from the normal lung and skin. Under glucose starvation, CAFs from the tumor mass exhibited heterogeneity in cell proliferation, ATP production and calcium concentration. Compared to NFs, mitochondrial calcium concentration was significantly higher in glucose-starved CAFs with upregulation of mitochondrial calcium uniporter (MCU) that led to enhancement of ATP production and cell growth. Intriguingly, treatment of glucose-starved CAFs with oligomycin increased apoptosis by disrupted calcium homeostasis following overactivation of the mPTP. Moreover, oligomycin-induced apoptosis was mitigated by calcium chelation. This study demonstrated that the discriminative calcium influx to mitochondria through MCU coordinated cell growth and apoptosis in glucose-starved CAFs but not in NFs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

LncRNA HOTTIP from synovial fibroblast-derived exosomes: A novel molecular target for rheumatoid arthritis through the miR-1908–5p/STAT3 axis

Rheumatoid arthritis (RA) is a chronic inflammation mediated by autoimmune responses. HOTTIP, a long noncoding RNA (lncRNA), participates in cell proliferation and invasion. However, the correlation between HOTTIP and RA remains unclear. Therefore, this study aimed to clarify how HOTTIP works in RA and to investigate its role in the development of RA. Flow cytometry was used to analyze cell cycle progression. Binding between HOTTIP, signal transducer and activator of transcription 3 (STAT3) and miR-1908–5p was demonstrated by dual-luciferase assays. Quantitative real-time polymerase chain reaction (qRT–PCR) was used to measure the expression of T cell differentiation-related proteins. We found that HOTTIP was upregulated in rheumatoid arthritis synovial fibroblasts (RASFs). HOTTIP directly bound to miR-1908–5p and negatively modulated miR-1908–5p expression while positively regulating STAT3. The effects of HOTTIP overexpression on regulating the balance of the Th17/Treg cell ratio were partly reversed by miR-1908–5p overexpression. In addition, in vivo experiments demonstrated that overexpression of HOTTIP aggravated inflammation in RA mice, which was demonstrated by hematoxylin and eosin (HE) staining and the increased expression levels of CD4{sup +} interleukin (IL)-17{sup +}, forkhead Box P3 (FOXP3) and retinoid-related orphan receptor gamma-t (RORγt). In summary, our study suggests that HOTTIP plays a damaging role in RA by promoting inflammation, which may be related to the regulation of miR-1908–5p expression and the STAT3 signaling pathway. These results suggest that the regulation of HOTTIP may be a promising therapeutic strategy for RA.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

TWIST2 inhibits EMT and induces oxidative stress in lung cancer cells by regulating the FGF21-mediated AMPK/mTOR pathway

Twist related protein 2 (TWIST2) plays an important role in bone development, tumorigenesis, tumour progression and epithelial mesenchymal transition (EMT). At present, there are few reports about the role of TWIST2 in lung cancer, which need to be further explored. Therefore, the purpose of this study is to explore the role and molecular mechanism of TWIST2 in the occurrence and development of lung cancer. The expression of TWIST2 in tissues of patients and cell lines was measured using RT-qPCR and western blotting. MTT and CCK8 assays were used to detect cell proliferation and viability. Western blotting was used to measure the expression of EMT-related proteins, including E-cadherin, N-cadherin, Vimentin and Slug. The results revealed that TWIST2 is lowly expressed in the tissues of lung cancer patients and cell lines. Further studies found that overexpression of TWIST2 significantly induced apoptosis and promoted the expression of E-cadherin, as well as inhibiting the expression of N-cadherin, Vimentin and Slug. More importantly, TWIST2 induced oxidative stress in lung cancer cells. In addition, TWIST2 regulated the FGF21 and AMPK/mTOR signalling pathway, which is involved in the molecular mechanism of the gene in lung cancer cells. We suggest that the mechanism of TWIST2 inhibition of the progression of lung cancer is by regulating the FGF21-mediated AMPK/mTOR signalling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Construction of extracellular matrix-based 3D hydrogel and its effects on cardiomyocytes

Highlights: • SOD and Triton X-100 could efficiently decellularize cells to get cardiac ECM. • Main proteins of cECM were fibronectin, collagen, elastin, fibrillin, laminin, etc. • 75% cECM-containing 3D hydrogel promoted cell proliferation and anti-apoptosis. • cECM3DH facilitated the differentiation of ESCs into CMs. • APcECM3DH was more conducive to NCM and ESC-derived CM maturation. Some discoveries resulted from 2-dimensional (2D) cultured cardiac cells have been disqualified in animal testing and later clinical trials. Extracellular matrix (ECM) plays a vital role in cardiac homeostasis, cardiac ECM (cECM)-based 3D cell cultures can mimics the physiological and pathological conditions in vivo closely, it is hopeful of addressing this challenge. Construction of cECM-based 3-dimensional (3D) hydrogel (cECM3DH) and its effects on cell behaviors were studied here. The results indicated that cellular compartments could be efficiently removed from heart tissue via sodium dodecyl sulfonate (SDS)- and Triton X-100-mediated decellularization, remaining the natural fibrous network structure and major proteins. 3D hydrogel consisted of 1 × 10{sup 7} cells/mL cells and 75% cECM could promote the proliferation and anti-apoptosis ability of human embryonic kidney (HEK)-293T cells. 0.25% trypsin or 0.20% collagenase was suitable to retrieve these cells from 3D hydrogel for further researches. Compared with 2D culture system, cECM3DH could significantly increase the proportion of GATA 4{sup +} cardiomyocytes (CMs) derived from heart tissue of neonatal mouse or induced differentiation of embryonic stem cells (ESCs) (P < 0.05) The expression levels of mature genes including cTnT, JCN, CaV1.2, MYL2, CASQ2, NCX1, and Cx43 of these CMs in adult pig cECM-based 3D hydrogel (APcECM3DH) were significantly higher than that in 2D culture system and in newborn piglet cECM-based 3D hydrogel (NPcECM3DH), respectively (P < 0.05). Therefore, cECM3DH supports the generation of primary CMs and ESC-derived CMs, APcECM3DH was more conducive to promoting CM maturation, which contributes to building 3D model for pathogenesis exploration, drug screening, and regenerative medicine of heart diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

EPS8 supports pancreatic cancer growth by inhibiting BMI1 mediated proteasomal degradation of ALDH7A1

Aldehyde dehydrogenase 7 family member A1 (ALDH7A1) is an enzyme catalyzing lipid peroxidation of fatty aldehydes. It plays a critical role in sustaining high oxygen consumption rate (OCR) and ATP production in pancreatic ductal adenocarcinoma (PADC). However, why PADC cells maintain a relatively high level of ALDH7A1 concentration is still not well understood. In the current study, we explored the interplay between epidermal growth factor receptor kinase substrate 8 (EPS8) and ALDH7A1 in PADC cells. PADC cell lines MIA PaCa-2 and AsPANC-1 were used for in vitro and in vivo studies. The co-IP assay showed mutual interactions between Flag-EPS8 and Myc-ALDH7A1 in both MIA PaCa-2 and AsPANC-1 cells. EPS8 knockdown resulted in decreased ALDH7A1 protein levels and increased poly-ubiquitination. An interaction was observed between ALDH7A1 and BMI1 but not between BMI1 and EPS8. BMI1 knockdown reduced ALDH7A1 poly-ubiquitination and degradation caused by EPS8 knockdown. Dual EPS8 and ALDH7A1 knockdown had a synergistic effect on suppressing PADC cell proliferation in vitro and in vivo. In conclusion, this study revealed that EPS8 supports PADC growth by interacting with ALDH7A1 and inhibiting BMI1 mediated proteasomal degradation of ALDH7A1.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

NMIIA promotes tumorigenesis and prevents chemosensitivity in colorectal cancer by activating AMPK/mTOR pathway

Non-muscle myosin IIA (NMIIA) has been reported to be involved in the carcinogenesis and malignant progression of various human tumors. However, the role and potential mechanism of NMIIA in the biological functions and apoptosis in colorectal cancer (CRC) remain elusive. In this study, we found that NMIIA was overexpressed in CRC tissues and significantly associated with poor survival in CRC patients. In addition, NMIIA promoted CRC cell proliferation and invasion via activating the AMPK/mTOR pathway in vitro, and NMIIA knockdown inhibited CRC growth in vivo. Meanwhile, NMIIA knockdown downregulated the CSCs markers (CD44 and CD133) expression in CRC cells. Furthermore, AMPK/mTOR pathway activation effectively reversed the NMIIA knockdown-induced inhibition of proliferation, invasion and stemness in CRC cells. Finally, NMIIA protects CRC cells from 5-FU-induced apoptosis and proliferation inhibition through the AMPK/mTOR pathway. Taken together, these results indicate that NMIIA plays a pivotal role in CRC growth and progression by regulating AMPK/mTOR pathway activation, and it may act as a novel therapeutic target prognostic factor in CRC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Incomplete radiofrequency ablation induced chemoresistance by up-regulating heat shock protein 70 in hepatocellular carcinoma

Highlights: • iRFA treatment inhibited cisplatin-induced pyroptosis of HCC cells. • Heat shock protein 70 was involved in the suppression of NLRP3 activation. • iRFA treatment decreased the cisplatin sensitivity of HCC through regulating HSP70. Radiofrequency ablation (RFA) is a common minimally invasive treatment for hepatocellular carcinoma (HCC). Incomplete RFA (iRFA) due to the sub-lethal heat shock challenge of some cell populations leads to the generation of transformed survivor cells with enhanced chemoresistance. However, the underlying mechanism of iRFA on HCCs chemoresistance remains unknown. In the present study, we investigated the effect of iRFA on HCCs sensitivity to cisplatin. Cells treated with the sub-lethal heat shock challenge were used to mimic iRFA treatment in vitro. An orthotopic implantation HCC model was established and also performed iRFA treatment. Flow cytometry, transwell assay, and cell counting kit-8 assay were used to determine the effect of iRFA treatment on cisplatin-induced HCC cell apoptosis, invasion, and cell viability. ELISA and Western blot were used to detect the effect of iRFA treatment on cisplatin-induced HCC cell pyroptosis. We found that iRFA treatment increased the HCC cell proliferation and invasion ability, and inhibited cisplatin-induced pyroptosis. Further experiments showed that iRFA treatment induced upregulation of HSP70, which inhibited the cisplatin-induced NLRP3 inflammasome activation, leading to inhibition of pyroptosis. HSP70 knockdown or NLRP3 overexpression could reverse the effect of iRFA treatment in vitro. In vivo, HSP70 knockdown reversed the chemosensitivity of HCC to cisplatin, which was decreased by iRFA. In conclusion, we demonstrated that iRFA induced drug resistance by HSP70-mediated inhibition of cell pyroptosis in HCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

The protein 4.1R downregulates VEGFA in M2 macrophages to inhibit colon cancer metastasis

Highlights: • Protein 4.1R knockout reduced the phagocytosis of M2 macrophages. • Co-culture with 4.1R knockout M2 macrophages enhances the malignancy of colon cancer. • Protein 4.1R knockout upregulates vascular endothelial growth factor A secreted by M2 macrophages. • Protein 4.1R knockout activates the PI3K/AKT signaling pathway and promotes the progression of colon cancer. M2 macrophages are crucial components of the tumour microenvironment and have been shown to be closely related to tumour progression. Co-culture with 4.1R{sup −/−} M2 macrophages enhances the malignancy of colon cancer (CC), but the mechanism remains unclear. Here, we report that protein 4.1R knockout reduced the phagocytosis of M2 macrophages (M-CSF/IL-4-treated bone marrow cells) and promoted MC38 colon cancer cell proliferation, migration, invasion, tumour formation and epithelial-mesenchymal transition (EMT), which are regulated by M2 macrophages. Further mechanistic dissection revealed that the 4.1R knockout upregulated vascular endothelial growth factor A (VEGFA) secreted by M2 macrophages and promoted colon cancer progression by activating the PI3K/AKT signalling pathway. In summary, our present study identified that 4.1R downregulates VEGFA secretion in M2 macrophages and delays the malignant potential of colon cancer by inhibiting the PI3K/AKT signalling pathway.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1992

Potentiation of lymphocyte proliferative responses by nickel sulfide

Crystalline nickel sulfide (NiS) induced a spleen cell proliferation that resembles a mixed lymphocyte reaction (MLR). It depended on cell-cell interaction, induced high levels of interleukin-1 (IL-1) and interleukin-2 (IL-2) and the responding cell subpopulation was composed of CD4+ T lymphocytes. Furthermore, the proliferation was inhibited in a dose-dependent manner by magnesium. Crystalline NiS also increased significantly the spleen cell proliferative response to concanavalin A (Con A) and lipopolysaccharide (LPS) with magnesium potentiating the combined effects of crystalline NiS and mitogens. Interestingly, crystalline NiS did not show any effect on the induction of IL-2 by Con A. The results described herein suggest that crystalline NiS can potentiate both antigenic (MLR) and mitogenic (Con A and LPS) proliferative responses in vitro. Crystalline NiS appears to potentiate these responses by acting in the form of ionic nickel on several intracellular targets for which magnesium ions have different noncompetitive interactions. The effects of magnesium on the potentiating action of crystalline NiS are different depending upon the type of primary stimulatory signal for proliferation (mitogenic or antigenic).

NASA Discipline Cell Biology↗
DOE OSTI2021

RNA binding protein DAZAP1 promotes HCC progression and regulates ferroptosis by interacting with SLC7A11 mRNA

Highlights: • DAZAP1 effectively promotes HCC progression. • DAZAP1 negatively regulates ferroptosis in HCC cells. • DAZAP1 interacts with SLC7A11 mRNA, and positively regulates its stability. RNA-binding proteins (RBPs) closely regulate the whole lifecycle of most RNA molecules, from the very early stage of transcription to RNA decay. Dysregulation of RBPs significantly affects the fate of cancer-related transcripts. Therefore, it is imperative to fully understand the complicated RBP-RNA regulatory networks in malignant diseases and to explore novel therapeutic targets. The RBP DAZAP1 (deleted in azoospermia-associated protein 1), originally identified as an important protein in spermatogenesis, had rarely been studied in the context of carcinogenesis. The role of DAZAP1 in hepatocellular carcinoma (HCC) was unveiled in this study. The relative expression of DAZAP1 was significantly upregulated in HCC and was positively associated with several key malignant characteristics and poor postoperative survival in patients. DAZAP1 knockdown by small interfering RNA markedly inhibited HCC cell proliferation, migration and invasion. Furthermore, DAZAP1 significantly reduced cellular sensitivity to sorafenib (SF), which had been proven to be an inducer of ferroptosis by targeting the system Xc{sup −} (composed of a light chain, xCT/SLC7A11, and a heavy chain, 4F2 heavy chain). At the mechanistic level, DAZAP1 was identified as a potent inhibitor of ferroptosis and an efficient binding partner of SLC7A11 mRNA. Further study revealed that DAZAP1 interacted with the 3′UTR (untranslated region) of SLC7A11 mRNA and positively regulated its stability. In our work, we clarified novel functions of DAZAP1 and preliminarily revealed its underlying mechanism in ferroptosis, which may be conducive to the exploration of biomarkers and therapeutic targets in HCC patients.

60 APPLIED LIFE SCIENCES↗
NASA NTRSDate not supplied

Differential Responses to Mechanostimulation in Embryonic Stem Cells Versus the Embryoid Body Model of Development Assessed at Single Cell RNA-Seq Resolution

Mechanicalforces generated by gravity have shaped life on Earth and impact gene expression and morphogenesis during early development. In contrast disuse canreduce normal mechanical loading, resulting in altered cell and tissue function. Although loading in adult mammals is known to promote increased cell proliferation and differentiation, little is known about how cells respondto this stimulusduring early development. In this study we sought to understand, with single cell RNA-sequencing resolution, how a 60-minute pulse of 50xg hypergravity-generated 5kPa hydrostatic pressure, influences transcriptomic regulation of developmental processes in the Embryoid Body (EB) model. Our study included both day-9 EBs and progenitor mouse embryonic stem cells (ESCs) with or without the hydrostatic pressurepulse. Single cell tSNE mapping shows limited transcriptome shifts in response to thispulse in either ESCs or EBs; this pulse,however, induces greater positional shifts in EB mapping compared to ESCs, indicating the influence of mechanotransduction is more pronounced in later states of cell commitment within the developmental program.We assessed ESCs and EBs for differentially expressed (DE) genes with hydrostatic pressurepulse and found approximately 1/3 DE genes were shared. However, gene ontology (GO) pathway analysis show that EBs have choreographed responses associated with upregulation ofpathways formulticellular development, mechanical signal transduction, and DNA damage repair. Cluster transcriptome analysis of the EBs showsmechanostimulationpromotes maintenance of transitory cell phenotypes in early development,including EB cluster co-expression of markers for progenitor, post-implant epiblast and primitive endoderm phenotypes versus expression exclusivity in the non-pulsed clusters. Pseudotime analysisidentified three branching cell types susceptible tohydrostatic pressureinduction of cell fate decisions. In summary, this study provides novel evidence that ESC maintenance and EB development can be regulated by mechanostimulation,and that stem cells committed to a differentiation program are more sensitive to force-induced changes to their transcriptome.

Cassandra Juran↗
NASA NTRS2002

Inhibition of caspases prevents ototoxic and ongoing hair cell death

Sensory hair cells die after acoustic trauma or ototoxic insults, but the signal transduction pathways that mediate hair cell death are not known. Here we identify several important signaling events that regulate the death of vestibular hair cells. Chick utricles were cultured in media supplemented with the ototoxic antibiotic neomycin and selected pharmacological agents that influence signaling molecules in cell death pathways. Hair cells that were treated with neomycin exhibited classically defined apoptotic morphologies such as condensed nuclei and fragmented DNA. Inhibition of protein synthesis (via treatment with cycloheximide) increased hair cell survival after treatment with neomycin, suggesting that hair cell death requires de novo protein synthesis. Finally, the inhibition of caspases promoted hair cell survival after neomycin treatment. Sensory hair cells in avian vestibular organs also undergo continual cell death and replacement throughout mature life. It is unclear whether the loss of hair cells stimulates the proliferation of supporting cells or whether the production of new cells triggers the death of hair cells. We examined the effects of caspase inhibition on spontaneous hair cell death in the chick utricle. Caspase inhibitors reduced the amount of ongoing hair cell death and ongoing supporting cell proliferation in a dose-dependent manner. In isolated sensory epithelia, however, caspase inhibitors did not affect supporting cell proliferation directly. Our data indicate that ongoing hair cell death stimulates supporting cell proliferation in the mature utricle.

Non-NASA Center↗
DOE OSTI2022

EMC3 regulates mesenchymal cell survival via control of the mitotic spindle assembly

Eukaryotic cells transit through the cell cycle to produce two daughter cells. Dysregulation of the cell cycle leads to cell death or tumorigenesis. Herein, we found a subunit of the ER membrane complex, EMC3, as a key regulator of cell cycle. Conditional deletion of Emc3 in mouse embryonic mesoderm led to reduced size and patterning defects of multiple organs. Emc3 deficiency impaired cell proliferation, causing spindle assembly defects, chromosome mis-segregation, cell cycle arrest at G2/M, and apoptosis. Upon entry into mitosis, mesenchymal cells upregulate EMC3 protein levels and localize EMC3 to the mitotic centrosomes. Further analysis indicated that EMC3 works together with VCP to tightly regulate the levels and activity of Aurora A, an essential factor for centrosome function and mitotic spindle assembly: while overexpression of EMC3 or VCP degraded Aurora A, their loss led to increased Aurora A stability but reduced Aurora A phosphorylation in mitosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Biophysical principles of choanoflagellate self-organization

Inspired by the patterns of multicellularity in choanoflagellates, the closest living relatives of animals, we quantify the biophysical processes underlying the morphogenesis of rosette colonies in the choanoflagellate Salpingoeca rosetta . We find that rosettes reproducibly transition from an early stage of 2-dimensional (2D) growth to a later stage of 3D growth, despite the underlying variability of the cell lineages. Our perturbative experiments demonstrate the fundamental importance of a basally secreted extracellular matrix (ECM) for rosette morphogenesis and show that the interaction of the ECM with cells in the colony physically constrains the packing of proliferating cells and, thus, controls colony shape. Simulations of a biophysically inspired model that accounts for the size and shape of the individual cells, the fraction of ECM, and its stiffness relative to that of the cells suffices to explain our observations and yields a morphospace consistent with observations across a range of multicellular choanoflagellate colonies. Overall, our biophysical perspective on rosette development complements previous genetic perspectives and, thus, helps illuminate the interplay between cell biology and physics in regulating morphogenesis.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1992

Experiments with suspended cells on the Space Shuttle

Spaceflight experiments since 1981 have demonstrated that certain cell functions are altered by micro-g. Biophysical models suggest that cell membranes and organelles should not be affected directly by gravity, however, the chemical microenvironment surrounding the cell and molecular transport could be altered by reduced gravity. Most experiments have used suspended live cells in small chambers without stirring or medium exchange. Flight results include increased attachment of anchorage-dependent human cells to collagen coated microcarriers, reduced secretion of growth hormone from pituitary cells, decreased mitogenic response of lymphocytes, increased Interferon-alpha by lymphocytes, increased Interleukin-1 and Tumor Necrosis Factor secretion by macrophages. Related experiments on cells immediately postflight and on procaryotic cells have shown significant changes in secretory capacity, cell proliferation, differentiation and development. Postulated mechanism include altered cell-cell interactions, altered calcium ion transport, effects on cell cytoskeleton, transport of transmitters and interactions with receptors. The discussion includes use of new molecular methods, considerations for cell environmental control and a preview of several experiments planned for the Shuttle and Spacelab flights to study the basic effects of microgravity on cellular physiology and potential interactions of spaceflight with radiation damage and cellular repair mechanisms.

Review↗
DOE OSTI2023

The Helix-Loop-Helix motif of human EIF3A regulates translation of proliferative cellular mRNAs

Improper regulation of translation initiation, a vital checkpoint of protein synthesis in the cell, has been linked to a number of cancers. Overexpression of protein subunits of eukaryotic translation initiation factor 3 (eIF3) is associated with increased translation of mRNAs involved in cell proliferation. In addition to playing a major role in general translation initiation by serving as a scaffold for the assembly of translation initiation complexes, eIF3 regulates translation of specific cellular mRNAs and viral RNAs. Mutations in the N-terminal Helix-Loop-Helix (HLH) RNA-binding motif of the EIF3A subunit interfere with Hepatitis C Virus Internal Ribosome Entry Site (IRES) mediated translation initiation in vitro . Here we show that the EIF3A HLH motif controls translation of a small set of cellular transcripts enriched in oncogenic mRNAs, including MYC . We demonstrate that the HLH motif of EIF3A acts specifically on the 5' UTR of MYC mRNA and modulates the function of EIF4A1 on select transcripts during translation initiation. In Ramos lymphoma cell lines, which are dependent on MYC overexpression, mutations in the HLH motif greatly reduce MYC expression, impede proliferation and sensitize cells to anti-cancer compounds. These results reveal the potential of the EIF3A HLH motif in eIF3 as a promising chemotherapeutic target.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

A consensus mathematical model of vaccine-induced antibody dynamics for multiple vaccine platforms and pathogens

Introduction: Vaccine platforms used in successful, licensed vaccines have varied among pathogens. However, antibody level is still the main clinical correlate of protection in most approved vaccines. Decisions as to the best vaccine platform to pursue for a given pathogen may be informed through improved understanding of the process of antibody generation and its temporal dynamics, as well as the relationship between these processes and the type of vaccine. Methods: We have analyzed the dynamics of antibody generation for different vaccine platforms against diverse pathogens, and developed a consensus mathematical model that captures antibody dynamics across these diverse systems. Initially, the model was fitted to a rich dataset of antibody and immune cell concentrations in a SARS-CoV-2 vaccine experiment. We then used concepts from machine learning, such as transfer learning, to apply the same model to a variety of systems, involving different pathogens, vaccine platforms, and booster dose use/timing, fixing most parameter values relating to the dynamics of the immune system. Results: The model includes B cell proliferation and differentiation, as well as the generation of plasma cells, which secrete large amounts of antibody, and memory B cells. Overall, the model describes antibody generation in all systems tested well and shows that the main differences across platforms are related to the dynamics of antigen presentation. Discussion: This model can be used to predict antibody generation in pairs of vaccine platform/pathogen, allowing for the use of in silico results to narrow down experimental burden in vaccine development.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1997

Signal transduction in T lymphocytes in microgravity

More than 120 experiments conducted in space in the last 15 years have shown that dramatic changes are occurring in several types of single cells during their exposure to microgravity. One focus of today's research on cells in space is on signal transduction, especially those steps involving the cytoskeleton and cell-cell interactions. Signal transduction is often altered in microgravity as well as in hypergravity. This leads to changes in cell proliferation, genetic expression and differentiation. Interesting examples are leukocytes, HeLa cells, epidermoid cells and osteoblastic cells. Signalling pathways were studied in T lymphocytes in microgravity by several investigators after the discovery that mitogenic activation in vitro is virtually nil at 0g. T cells are a good model to study signal transduction because three extracellular signals (mitogen, IL-1 and IL-2) are required for full activation, and two classical pathways (via proteins G and PKC) are activated within the cell. In addition, low molecular weight GTP-binding proteins (Ras and Rap) are interacting with the cytoskeleton. The data at 0g support the notion that the expression of IL-2 receptor is inhibited at 0g, while mitogen binding and the transmission of IL-1 by accessory cells occur normally. In addition, alterations of the cytoskeleton suggest that the interaction with Rap proteins is disturbed. Data obtained with phorbol esters indicate that the function of PKC is changed in microgravity. Similar conclusions are drawn from the results with epidermoid cells A431.

short duration↗