Biology subjects

Shemer, A.

Publications and source records attributed to Shemer, A..

5 recordsLinked to original sources

bioRxiv2026

Dual Immune Checkpoint and Cytokine Receptor Modulation by an Engineered Human CTLA-4/IL-10 Bispecific Fusion Protein

Bispecific fusion proteins represent a unique strategy for developing precision therapeutics. By linking functional domains from distinct proteins, these biomolecules can engage multiple targets, enhancing both therapeutic efficacy and safety. Unlike bispecific antibodies, low-molecular-weight fusion proteins offer distinct advantages, including reduced immunogenicity and superior tissue penetration due to their relatively compact size and structure. Such a profile is particularly valuable in managing complex inflammatory diseases, where modulating multiple pathways is required to impart an effective anti-inflammatory effect. Among the various regulators of immune signaling, the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and interleukin-10 (IL-10) play imperative roles in immune suppression through their interactions with CD80/86 and IL-10R, respectively. While Fc-fused CTLA-4 is a clinically approved drug (e.g., Abatacept), the clinical development of IL-10 has been hampered by unpredictable immunostimulatory side effects. Here, we engineered a bispecific fusion protein linking the extracellular domain of CTLA-4 to IL-10. We successfully expressed the protein in E. coli as an N-terminal GST-tagged variant and refolded it from the inclusion bodies. Additionally, we achieved soluble expression of an Fc-tagged variant in mammalian CHO cells. Both origins demonstrated binding to their cognate receptors, CD80 and IL-10R. Finally, the fusion protein demonstrated a T cell-inhibitory effect by reducing Interferon-{gamma} (IFN{gamma}) secretion levels in an in vitro human Virus-Specific T cells (VSTs) model. This innovative protein engineering offers a promising strategy for addressing unmet clinical needs in autoimmune and inflammatory diseases.

bioengineering↗

bioRxiv2019

An enhancer:involucrin regulatory module impacts human skin barrier adaptation out-of-Africa and modifies atopic dermatitis risk

The genetic modules that contribute to human evolution are poorly understood. We identified positive selection for two independent involucrin (IVL) haplotypes in European (CEU) and Asian (JPT/CHB) populations for skin epidermis. CEU IVL associated with increased IVL and a known epidermal-specific enhancer underwent a recent selective sweep out-of-Africa correlating with increased northern latitude. CRISPR/Cas9 deletion of the mouse enhancer revealed enhancer-mediated cis regulation for Ivl expression with human population-specific enhancer reporter assays confirming the additive effect. Furthermore, IVL enhancer eQTLs associated with decreased IVL together with filaggrin loss-of-function variants are enriched in atopic dermatitis cases vs. controls. Together, our enhancer-IVL cis regulatory module findings reveal an emerging paradigm for recently evolved traits to impact skin disease risk in contemporary populations.

genetics↗

bioRxiv2019

Comparative analysis of CreER transgenic mice for the study of brain macrophages - a case study

Conditional mutagenesis and fate mapping have contributed considerably to our understanding of physiology and pathology. Specifically, Cre recombinase-based approaches allow the definition of cell type-specific contributions to disease development and inter-cellular communication circuits in respective animals models. Here we compared Cx3cr1CreER and Sall1CreER transgenic mice and their use to decipher the brain macrophage compartment as a showcase to discuss recent technological advances. Specifically, we highlight the need to define the accuracy of Cre recombinase expression, as well as strengths and pitfalls of these particular systems that should be taken into consideration when applying these models.

immunology↗

bioRxiv2019

Defining Monocyte Differentiation into Colonic and Ileal Macrophages

Monocytes are circulating short-lived macrophage precursors that are recruited on demand from the blood to sites of inflammation and challenge. In steady state, classical monocytes give rise to vasculature-resident cells that patrol the luminal side of the endothelium. In addition, classical monocytes feed macrophage compartments of selected organs, including barrier tissues, such as the skin and intestine, as well as the heart. Monocyte differentiation under conditions of inflammation has been studied in considerable detail. In contrast, monocyte differentiation under non-inflammatory conditions remains less well understood. Here we took advantage of a combination of cell ablation and precursor engraftment to investigate the generation of gut macrophages from monocytes. Collectively, we identify factors associated with the gradual adaptation of monocytes to tissue residency. Moreover, comparison of monocyte differentiation into the colon and ileum-resident macrophages revealed the graduated acquisition of gut segment-specific gene expression signatures.

immunology↗

bioRxiv2018

Engrafted parenchymal brain macrophages differ from host microglia in transcriptome, epigenome and responsiveness to challenge

Microglia are yolk sac-derived macrophages residing in the parenchyma of brain and spinal cord, where they interact with neurons and other glial cells by constantly probing their surroundings with dynamic extensions. Following different conditioning paradigms and bone marrow (BM) / hematopoietic stem cell (HSC) transplantation, graft-derived cells seed the brain and persistently contribute to the parenchymal brain macrophage compartment. Here we establish that these cells acquire over time microglia characteristics, including ramified morphology, longevity, radio-resistance and clonal expansion. However, even following prolonged CNS residence, transcriptomes and epigenomes of engrafted HSC-derived macrophages remain distinct from yolk sac-derived host microglia. Furthermore, BM graft-derived cells display discrete responses to peripheral endotoxin challenge, as compared to host microglia. Also in human HSC transplant recipients, engrafted cells remain distinct from host microglia, extending our finding to clinical settings. Collectively, our data emphasize the molecular and functional heterogeneity of parenchymal brain macrophages and highlight potential clinical implications for patients treated by HSC gene therapy.

immunology↗