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Lane, B. J.

Publications and source records attributed to Lane, B. J..

5 recordsLinked to original sources

Spatial multi-omics identify an immunosuppressive lipid-laden macrophage niche in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is histologically a subtype of diffuse large B-cell lymphoma (DLBCL), sharing genetic and transcriptomic similarity, but with distinct clinical features, particularly its confinement to the CNS and higher relapse risk. The microenvironmental basis for its divergence from systemic DLBCL remains unclear. Using spatial transcriptomic approaches (Xenium/GeoMx digital spatial profiling) in a comparative study of PCNSL (n=17) and DLBCL (n=76), we found that PCNSL, unlike systemic DLBCL, is dominated by an immunosuppressive macrophage compartment enriched for cholesterol-metabolism programs. In independent cohorts of PCNSL profiled by single-cell RNA sequencing, we validated the presence of a recurrent population of lipid-laden macrophages (LLMs): TREM2/GPNMB-expressing, lipid-remodeled cells transcriptionally distinct from resident microglia and consistent with an infiltrating monocyte origin, not previously characterized in CNS lymphoma. LLMs formed immunosuppressive niches with regulatory T cells, and using Cellscape hyperplex proteomic imaging we demonstrate that LLM-Treg spatial interactions are associated with chemotherapy response. To test whether LLMs are lymphoma-driven and functionally important, we developed an immunocompetent syngeneic PCNSL mouse model, driven by Myd88L252P and Cd79b mutations with Bcl2 overexpression. Monocyte-derived macrophages in lymphoma-bearing brain regions acquired an LLM-like state, not seen in lymphoma-free brain regions or in splenic tumors driven by the same oncogenic lesions. TREM2-SYK signaling sustained this state, and SYK inhibition reversed its tumor-supportive activity ex vivo. These findings identify the LLM program as a targetable immunosuppressive myeloid state in CNS lymphoma.

cancer biology↗

Rapid prey capture learning drives a slow resetting of network activity in rodent binocular visual cortex

Neurons within primary visual cortex (V1) possess stable firing rate set points to which they faithfully return when perturbed by passive sensory manipulations. Chronic recordings in vivo suggest that these set points are present early in postnatal development and are stable through adulthood, raising the possibility that once they are established, they are largely immutable. Here we challenge this idea, using an ethological, vision-dependent prey capture learning paradigm in juvenile (critical period) rats. Juvenile rats rapidly (in one day) became proficient at catching crickets. This learning was impaired when V1 was inactivated, and was accompanied by an increase in the number of binocular V1 (V1b) neurons with firing reliably tied to specific behavioral epochs during hunts, indicating that hunting drives rapid functional plasticity within V1b. Remarkably, this rapid learning set in motion a slow, state-dependent increase in V1b firing, that began after learning was complete and persisted for days. This upward firing rate plasticity was gradual, occurred selectively during wake states, and in L2/3 was driven by a TNF-dependent increase in excitatory synapses and excitatory synaptic charge onto pyramidal neurons - all features of homeostatic forms of plasticity within V1. Finally, TNF inhibition administered after learning was complete diminished this increase in excitability and impaired the retention of hunting skills. Taken together, these data suggest that naturalistic learning in juvenile animals co-opts homeostatic forms of plasticity to reset firing rate setpoints within V1b, in a process that facilitates skill consolidation.

neuroscience↗

Cell-free expression and SMA copolymer encapsulation of a functional receptor tyrosine kinase disease variant, FGFR3-TACC3

Despite their high clinical relevance, obtaining structural and biophysical data on transmembrane proteins has been hindered by challenges involved in their expression and extraction in a homogeneous, functionally-active form. The inherent enzymatic activity of receptor tyrosine kinases (RTKs) presents additional challenges. Oncogenic fusions of RTKs with heterologous partners represent a particularly difficult-to-express protein subtype due to their high flexibility, aggregation propensity and the lack of a known method for extraction within the native lipid environment. One such protein is the fibroblast growth factor receptor 3 fused with transforming acidic coiled-coil-containing protein 3 (FGFR3-TACC3), which has failed to express to sufficient quality or functionality in traditional expression systems. Cell-free protein expression (CFPE) is a burgeoning arm of synthetic biology, enabling the rapid and efficient generation of recombinant proteins. This platform is characterised by utilising an optimised solution of cellular machinery to facilitate protein synthesis in vitro. In doing so, CFPE can act as a surrogate system for a range of proteins that are otherwise difficult to express through traditional host cell-based approaches. Here, functional FGFR3-TACC3 was expressed through a novel cell-free expression system in under 48 hours. The resultant protein was reconstituted using SMA copolymers with a specific yield of 300 {micro}g/mL of lysate. Functionally, the protein demonstrated significant kinase domain phosphorylation (t<0.0001). Currently, there is no published, high-resolution structure of any full-length RTK. These findings form a promising foundation for future research on oncogenic RTKs and the application of cell-free systems for synthesising functional membrane proteins.

biochemistry↗

Mechanical and molecular activation lead to structurally analogous MscL states

The MscL channel gates in response to membrane tension changes to allow the exchange of molecules through its pore. Lipid removal from transmembrane pockets leads to a MscL response. However, it is unknown whether there is correlation between the tension mediated state and the state derived by pocket delipidation in the absence of tension. Transitions between MscL states may follow a similar pathway to cover the available conformational space but may not necessarily sample the same discrete intermediates. Here, we combined pulsed-EPR and HDX-MS measurements on MscL, coupled with molecular dynamics under membrane tension, to investigate the changes associated with the distinctively derived states. Whether it is tension or pocket delipidation, we find that MscL samples a similar expanded state, which is the final step of the delipidation pathway but only an intermediate stop of the tension mediated path. Our findings hint at synergistic modes of regulation in mechanosensitive channels.

biophysics↗

Dopamine maintains network synchrony via direct modulation of gap junctions in the crustacean cardiac ganglion

Abstract The Large Cell (LC) motor neurons of the crab (C. borealis) cardiac ganglion have variable membrane conductance magnitudes even within the same individual, yet produce identical synchronized activity in the intact network. In our previous study (Lane et al., 2016) we blocked a subset of K+ conductances across LCs, resulting in loss of synchronous activity. In this study, we hypothesized that this same variability of conductances could make LCs vulnerable to desynchronization during neuromodulation. We exposed the LCs to serotonin (5HT) and dopamine (DA) while recording simultaneously from multiple LCs. Both amines had distinct excitatory effects on LC output, but only 5HT caused desynchronized output. We further determined that DA rapidly increased gap junctional conductance. Co-application of both amines induced 5HT-like output, but waveforms remained synchronized. Furthermore, DA prevented desynchronization induced by the K+ channel blocker tetraethylammonium (TEA), suggesting that dopaminergic modulation of electrical coupling plays a protective role in maintaining network synchrony.

neuroscience↗