Introduction: Growth-arrested feeder cells following Mitomycin C treatment are instrumental in stem cell culture allowing development of regenerative strategies and alternatives to animal testing in drug discovery. The concentration of Mitomycin C and feeder cell type was described to affect feeder performance but the criticality of feeder cell exposure density was not addressed. We hypothesize that the exposure cell density influences the effectiveness of Mitomycin C in an arithmetic manner.
Methods: Three different exposure cell densities of Swiss 3T3 fibroblasts were treated with a range of Mitomycin C concentrations for 2h. The cells were replaced and the viable cells counted on 3, 6, 9, 12 and 20days. The cell extinctions were compared with doses per cell which were derived by dividing the product of concentration and volume of Mitomycin C solution with exposure cell number.
Results: The periodic post-treatment feeder cell extinctions were not just dependent on Mitomycin C concentration but also on dose per cell. Analysis of linearity between viable cell number and Mitomycin C dose per cell derived from the concentrations of 3 to 10μg/ml revealed four distinct categories of growth-arrest. Confluent cultures exposed to low concentration showed growth-arrest failure.
Discussion: The in vitro cell density titration can facilitate prediction of a compound's operational in vivo dosing. For containing the growth arrest failure, an arithmetic volume derivation strategy is proposed by fixing the exposure density to a safe limit. The feeder extinction characteristics are critical for streamlining the stem cell based pharmacological and toxicological assays.
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http://dx.doi.org/10.1016/j.vascn.2016.05.006 | DOI Listing |
Am J Respir Cell Mol Biol
January 2025
The University of Texas Medical Branch at Galveston, Microbiology and Immuology, Galveston, Texas, United States.
Exposure to influenza A virus (IAV), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) is well-known to increase the risk of pneumonia in humans. Type I interferon (IFN-I) is a hallmark response to acute viral infections, and alveolar macrophages (AMs) constitute the first line of airway defense against opportunistic bacteria. Our study reveals that virus-induced IFN-I receptor (IFNAR1) signaling directly impairs AM-dependent antibacterial protection.
View Article and Find Full Text PDFSci Transl Med
January 2025
Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
At this stage in the COVID-19 pandemic, most infections are "breakthrough" infections that occur in individuals with prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure. To refine long-term vaccine strategies against emerging variants, we examined both innate and adaptive immunity in breakthrough infections. We performed single-cell transcriptomic, proteomic, and functional profiling of primary and breakthrough infections to compare immune responses from unvaccinated and vaccinated individuals during the SARS-CoV-2 Delta wave.
View Article and Find Full Text PDFJ Neuroophthalmol
January 2025
Department of Ophthalmology (JGJ-C, TE, Y-HC, LRD, RAG), Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Frank H. Netter Medical School (JGJ-C), North Haven, Connecticut; and Department of Anesthesiology (DZ), Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
Background: Patients with craniosynostosis are at high risk of developing elevated intracranial pressure (ICP) causing papilledema and secondary optic atrophy. Diagnosing and monitoring optic neuropathy is challenging because of multiple causes of vision loss including exposure keratopathy, amblyopia, and cognitive delays that limit examination. Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are an optical coherence tomography (OCT) finding reported in association with papilledema and optic neuropathy.
View Article and Find Full Text PDFJAMA Netw Open
January 2025
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland.
Importance: Sensitivity to environmental stress and adversity may influence lung cancer risk, highlighting a critical link between psychosocial factors and cancer etiology.
Objective: To evaluate whether genetically estimated sensitivity to environmental stress and adversity is associated with lung cancer risk.
Design, Setting, And Participants: Data were obtained from a genome-wide association study identifying 37 independent genetic variants strongly associated with sensitivity to environmental stress and adversity and a cross-ancestry genome-wide meta-analysis from the International Lung Cancer Consortium.
Drug Deliv Transl Res
January 2025
Kinimmune, Inc. St. Louis, 63141, Missouri, USA.
PD-L1/PD-1 checkpoint inhibitors (CPIs) are mainstream agents for cancer immunotherapy, but the prognosis is unsatisfactory in solid tumor patients lacking preexisting T-cell reactivity. Adjunct therapy strategies including the intratumoral administration of immunostimulants aim to address this limitation. CpG oligodeoxynucleotides (ODNs), TLR9 agonists that can potentiate adaptive immunity, have been widely investigated to tackle PD-L1/PD-1 resistance, but clinical success has been hindered by inconsistent efficacy and immune-related toxicities caused by systemic exposure.
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