Glucose oxidation-dependent survival of activated B cells provides a putative novel therapeutic target for lupus treatment

Aberrant metabolic demand is observed in immune/inflammatory disorders, yet the role in pathogenesis remains unclear. Here, we discover that in lupus, activated B cells, including germinal center B (GCB) cells, have remarkably high glycolytic requirement for survival over T cell populations, as demonstrated by increased metabolic activity in lupus-activated B cells compared to immunization-induced cells. The augmented reliance on glucose oxidation makes GCB cells vulnerable to mitochondrial ROS-induced oxidative stress and apoptosis. Short-term glycolysis inhibition selectively reduces pathogenic activated B in lupus-prone mice, extending their lifespan, without affecting T follicular helper cells. Particularly, BCMA-expressing GCB cells rely heavily on glucose oxidation. Depleting BCMA-expressing activated B cells with APRIL-based CAR-T cells significantly prolongs the lifespan of mice with severe autoimmune disease. These results reveal that glycolysis-dependent activated B and GCB cells, especially those expressing BCMA, are potentially key lupus mediators, and could be targeted to improve disease outcomes.

Abstract 1321: New mouse models of metastatic lung cancer

INTRODUCTION: Lung cancer is the leading cause of cancer deaths worldwide and greater than 75% of human lung cancer deaths can be attributed to metastasis. Metastatic disease in most existing mouse models of pulmonary adenocarcinoma is typically sporadic and often requires aging mice for several months. These factors limit the usefulness of most current mouse models for basic and pre-clinical research aimed at identifying mechanisms and effective treatments of metastatic disease. We have developed two novel mouse models of metastatic lung cancer and report here on changes in protein expression and immune cell recruitment in the lungs of these models.

METHODS AND RESULTS: Mouse models were generated by adding mutations in Dicer1, an RNAse III enzyme within the microRNA (miRNA) biosynthesis pathway, to a mouse model of Kras-driven pulmonary adenocarcinoma. For both models, tumorigenesis was induced by conditional expression of an oncogenic allele of Kras (KrasG12D), deletion of both alleles of Trp53 and deletion of one allele of Dicer1 in one cell type and the expression of a truncated Dicer1 allele in a different cell type. In the absence of Dicer1 truncation, mice expressing KrasG12D and deleting Trp53 in club cells have a reported median survival of 28.6 weeks after tumor induction. We detected accelerated development of pulmonary adenocarcinoma and lymph node metastasis (12.1 weeks) only when we induced tumorigenesis in club cells and truncated DICER1 in alveolar type II (ATII) cells. Induction of tumorigenesis in ATII cells and truncation of DICER1 in club cells did not accelerate tumorigenesis or metastasis. To evaluate the molecular and cellular changes in the different phenotypes of these models we have characterized protein expression, using spatial proteomics, and immune cell recruitment, using flow cytometry.

CONCLUSIONS: Through cell type specific truncation/deletion of Dicer1 we have generated a new mouse model that rapidly develops pulmonary adenocarcinomas and metastatic disease. Our findings support our hypothesis that tumorigenesis and metastasis are influenced by miRNA regulated communication between different cell types. Preliminary flow cytometry and spatial proteomic analyses have suggested cellular targets underlying phenotypic differences between our two mouse models. These models have potential for both understanding the basic processes of metastasis and for pre-clinical studies aimed at preventing and/or treating metastatic lung cancer.

Citation Format: Paige Ramkissoon, Julie Wells, Richard S. Maser, Jiayuan Shi, Zheng Gong, Qing Li, Brian Hoffmann, Anne Marchini, Elaine Bechtel, Rosalinda Doty, Gary Ren, Carol J. Bult. New mouse models of metastatic lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1321.

Directional detector of gamma ray sources

This work describes the design, development, and characterization of an ionization chamber to detect and locate gamma ray sources with intensities down to 100 mu Gy h(-1). The results show that sources of x ray and gamma radiation in the energy range of 14 to 1,250 keV can be located. The directional sensitivity of this type of monitor is dependent on several parameters, such as photon energy, intensity, and the degree of complexity in terms of the number and type of sources in a contaminated area. An application important to the Army is to identify hotspots in a contaminated area and thereby indicate to personnel safer paths around them. Another possible use for this type of monitor may be in security applications in the prevention of shipping or storing clandestine sources.

Measurement of neutron and gamma radiation in a mixed field

This paper describes a study of dosimeters with a range of 0 to 0.2 mGy that were developed by the authors and built by the Federal Emergency Management Agency (FEMA). These instruments are a type of air-filled ion chamber that is self-reading by means of an internal carbon fiber electrometer. Two types of these dosimeters were constructed: one with an ion chamber wall made of a conductive hydrogenous material, and the other device made with a conductive wall lining of non-hydrogenous material. Both types of dosimeters have the same sensitivity for gamma radiation, but greatly different sensitivities for fast neutrons, thus making it possible to measure gamma radiation and neutron doses separately in a mixed radiation field. The results indicate that such pairs of dosimeters can be used for the first time to accurately monitor personnel for gamma ray and neutron doses in real time. Since the difference in neutron sensitivities is due to the properties of wall materials, periodic calibrations of the dosimeter system can be accomplished using only gamma rays after the material constants are measured. The absolute number of neutron induced transmutations in sulfur was required for this work. Methods and techniques which were applied to determine this quantity are described in the text. This approach was one of several dosimetric procedures utilized in this investigation.

Calf-ovary protein kinases dependent on adenosine 3':5' -monophosphate. Analysis by electrophoresis and electro-focusing on polyacrylamide get

High resolving power and quantitative application polyacrylamide-gel electrophopresis at various pore sizes and electrofocusing provide resolution of a calf-ovarian protein-kinase system at an increased level of magnification, as well as optimal preparative routes. Three protein kinases dependent on adenosine 3':5' -monophosphate are distinguished by polyacrylamide gel electrophoresis in calf ovarian cytosol. These enzymes which are observed in the pH range 7.5--10.2, appear to be aggregates of a commonsubmit or monomer. The three kinases are, by the criteria of polyacylamide gel electrophoresis, distinct from three adenosine-3':5' -monophosphate-binding proteins found in the calf ovarian system. Analysis by electrofocusing on polyacrylamide gel shows that conventionally purified preparations of the major kinase of cytosol contain an overwhelming majority of contaminant proteins.

Characterization of calf-ovary adenosine;3':5'-monophosphate-dependent protein kinases and adenosine-3':5'-monophosphate-binding proteins

Protein phosphokinase activity from the calf ovary cytosol (105000 X g supernatant fraction) has been resolved by chromatography and polyacrylamide gel electrophoresis into two major protein kinases, PK-H1 and PK-H2, both dependent on adenosine 3':5'-monophosphate (cyclic AMP). The enzymes have similar molecular weights (230000) and substrate specificities but differ in their cyclic-AMP-dependency and stimulation by cyclic AMP. The differences have been explained by the presence in PK-H1 of a unique cyclic-AMP-binding protein which has little catalytic activity associated with it. The cyclic-AMP-binding protein has a high affinity for cyclic AMP and in addition is able to inhibit the activity of the isolated catalytic subunit. The ovarian cyclic-AMP-dependent protein kinases have properties similar to those found in other tissues. They can be dissociated into catalytic and regulatory subunits and are inhibited by a heat-stable protein inhibitor isolated from rabbit skeletal muscle. Preincubation of the cytosol with high levels of cyclic AMP resulted in additional cyclic-AMP-dependent protein kinases and cyclic-AMP-binding proteins which include protein kinases and binding proteins of greater than 400 000 molecular weight.