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Biology subjects

Malkin, E.

Publications and source records attributed to Malkin, E..

3 recordsLinked to original sources

Sequential vaccination matures VRC01-class HIV-1 neutralizing antibodies in humans

Inducing a broadly neutralizing antibody (bnAb) response is a key goal of HIV-1 vaccine development. Despite significant progress, it is unknown whether vaccine-primed B cells can be reactivated and matured to secrete bona fide bnAbs. In the IAVI C107/C110 single-arm, open-label human trial, VRC01-class memory B cells previously primed by the GT1.1 germline-targeting envelope glycoprotein (Env) trimer were reactivated by a BG505 SOSIP.664 trimer boost. Somatic hypermutation in the activated B cells drove higher antibody affinity for the CD4-binding site on fully glycosylated, heterologous Env trimers. Three VRC01-class monoclonal antibodies derived from independent B cell lineages neutralized 18-31% of 119 viruses in a globally diverse panel. This work advances the HIV-1 germline-targeting vaccination concept from proof-of-priming towards proof-of-breadth and defines a benchmark for bnAb induction.

immunology↗

Adeno-associated viruses escort nanomaterials to specific cells and tissues

The delivery of nanotherapeutics to specific tissues relies on bespoke targeting strategies or invasive surgeries. Conversely, adeno-associated viruses (AAVs) can target specific tissues following intravenous injections. Here we show that cell-targeting properties of AAVs could be broadly conferred to nanomaterials. We develop a strategy to couple AAV capsids to nanoparticles that is invariant of viral serotype or nanomaterial chemistry and permits control over stoichiometry of the AAV-nanoparticle chimeras. The chimeras selectively escort nanoparticles into cell classes governed by AAV serotypes. When applied to magnetic nanoparticles, the AAV-nanoparticle chimeras enable magnetically localized gene delivery. In vivo, we show that leveraging the brain-targeting AAV serotype CAP-B10 achieves nanoparticle delivery to the parenchyma with [~]10% efficiency (% injected dose/g[brain]) while avoiding accumulation in the liver. The enhanced delivery efficiency and tissue specificity highlight the potential of AAV-chimeras as a versatile strategy to escort broad classes of nanotherapeutics to the brain and beyond.

bioengineering↗

Cell type-specific interpretation of noncoding variants using deep learning-based methods

Interpretation of non-coding genomic variants is one of the most important challenges in human genetics. Machine learning methods have emerged recently as a powerful tool to solve this problem. State-of-the-art approaches allow prediction of transcriptional and epigenetic effects caused by non-coding mutations. However, these approaches require specific experimental data for training and can not generalize across cell types where required features were not experimentally measured. We show here that available epigenetic characteristics of human cell types are extremely sparse, limiting those approaches that rely on specific epigenetic input. We propose a new neural network architecture, DeepCT, which can learn complex interconnections of epigenetic features and infer unmeasured data from any available input. Furthermore, we show that DeepCT can learn cell type-specific properties, build biologically meaningful vector representations of cell types and utilize these representations to generate cell type-specific predictions of the effects of non-coding variations in the human genome.

genetics↗