Wendland, M. | Search bioRxiv

bioRxiv2024

TNF signaling mediates cellular immune function and promotes malaria parasite killing in the mosquito Anopheles gambiae

Tumor Necrosis Factor- (TNF-) is a proinflammatory cytokine and a master regulator of immune cell function in vertebrates. While previous studies have implicated TNF signaling in invertebrate immunity, the roles of TNF in mosquito innate immunity and vector competence have yet to be explored. Herein, we confirm the identification of a conserved TNF- pathway in Anopheles gambiae consisting of the TNF- ligand, Eiger, and its cognate receptors Wengen and Grindelwald. Through gene expression analysis, RNAi, and in vivo injection of recombinant TNF-, we provide direct evidence for the requirement of TNF signaling in regulating mosquito immune cell function by promoting granulocyte midgut attachment, increased granulocyte abundance, and oenocytoid rupture. Moreover, our data demonstrate that TNF signaling is an integral component of anti-Plasmodium immunity that limits malaria parasite survival. Together, our data support the existence of a highly conserved TNF signaling pathway in mosquitoes that mediates cellular immunity and influences Plasmodium infection outcomes, offering potential new approaches to interfere with malaria transmission by targeting the mosquito host.

immunology↗

bioRxiv2022

Quantitative imaging of gene therapy delivery vehicles using CEST-NMR/MRI

PurposeGene therapy employing AAV vector-mediated gene delivery has undergone substantial growth in recent years with promising results in both preclinical and clinical studies, as well as emerging regulatory approval. However, the lack of methods for quantifying the efficacy of gene therapy from cellular delivery of gene editing technology to specific functional outcomes remains an obstacle for the efficient development of gene therapy treatments. Building upon prior works that utilized a genetically encoded Lysine Rich Protein as a chemical exchange saturation transfer (CEST) reporter, we hypothesized that AAV viral capsids may generate endogenous CEST contrast from the large number of surface lysine residues. MethodsWater-suppressed NMR and NMR-CEST experiments were performed on isolated solutions of AAV serotypes 1-9 on a Bruker 800MHz vertical scanner. A series of in vitro experiments were performed for thorough testing of NMR-CEST contrast of AAV2 capsids under varying pH, density, biological transduction stage, and later across multiple serotypes and mixed biological media. Reverse transcriptase (RT)-polymerase chain reaction (PCR) was used to quantify virus concentration. Subsequent experiments determined the pH-dependent exchange rate and optimized CEST saturation schemes for AAV contrast detection at 7 T. ResultsNMR-CEST experiments revealed CEST contrast up to 52% for AAV2 viral capsids between 0.6-0.8 ppm. Evaluation of CEST contrast generated by AAV2 demonstrates high levels of CEST contrast across a variety of chemical environments, concentrations, and saturation schemes. AAV2 CEST contrast displayed significant positive correlations with capsid density (R2>0.99, P<0.001), pH (R2=0.97, P=0.01), and viral titer per cell count (R2=0.92, P<0.001). Transition to a preclinical field strength yielded up to 11.8% CEST contrast following optimization of saturation parameters. ConclusionAAV2 viral capsids exhibit strong capacity as an endogenous CEST contrast agent and can potentially be used for monitoring and evaluation of AAV vector-mediated gene therapy protocols.

bioengineering↗