Biology subjects

Elsaesser, H.

Publications and source records attributed to Elsaesser, H..

4 recordsLinked to original sources

bioRxiv2026

Sequential infection reprograms the immune landscape to shape future responses

Mouse models have been instrumental in defining immune mechanisms but often fail to capture the complexity of human immunity, limiting clinical translation. A major limitation is the immunological immaturity of specific pathogen-free (SPF) mice relative to pathogen-experienced adult humans. Here, we use a sequential infection (SI) model that recapitulates cumulative pathogen exposure and define its impact on immune composition and function. Beyond the previously reported expansion of memory T cells, SI induced durable, system-wide remodeling across lymphoid and non-lymphoid tissues, reshaping innate and adaptive immune populations, tissue-resident immunity, and hematopoietic output. Single-cell transcriptomic analyses revealed inflammatory imprinting of naive CD4 and CD8 T cells, whereas memory T cells acquired enhanced effector programs coupled with reduced biosynthetic activity, transcriptional states that more closely resemble those of pathogen-experienced adult humans. Functionally, SI mice recapitulated the human response to anti-CD28 super-agonist and exhibited altered magnitude and differentiation of acute and chronic antiviral T cell responses, demonstrating that cumulative pathogen exposure reshapes both existing immunity and the generation of future immune responses. Thus, cumulative pathogen exposure coordinately remodels hematopoiesis and naive and memory lymphocyte states, establishing a durable inflammation-experienced immune landscape that reshapes both immune memory and future immune responses, with broad implications for the translational fidelity of preclinical mouse models.

immunology↗

bioRxiv2026

Functional Type I and Type II interferon crosstalk restricts progenitor exhausted CD8 T cells through spatial exclusion and checkpoint enforcement

Type I interferon (IFN-I) and interferon-{gamma} (IFN{gamma}) are central regulators of antiviral immunity, yet how they cooperatively govern CD8 T cell fate during chronic infection remains unresolved. Here, we uncover a previously unrecognized, spatially encoded interferon circuit that actively constrains progenitor exhausted CD8 T cells (Tpex) during chronic LCMV infection. Persistent IFN-I signaling indirectly restricts Tpex expansion by enforcing their sequestration within PDL1-rich B cell niches of lymphoid tissue and by suppressing T cell-derived IFN{gamma}. Blockade of IFN-I signaling enables Tpex migration into T cell zones of splenic follicles driving IFN{gamma} production, which in turn sustains PDL1 expression on myeloid cells to re-impose local inhibitory pressure. Combined IFN-I and IFN{gamma} blockade disrupts this feedback, promoting coordinated niche redistribution of Tpex and checkpoint remodeling that drives robust Tpex expansion. Single-cell transcriptomics reveal that this layered IFN-I-IFN{gamma} interplay establishes a regulatory balance that constrains Tpex proliferation while preserving effector-like transcriptional programs in their progeny effector CD8 T cells, ultimately preventing premature terminal differentiation. Thus, interferons orchestrate the coordinated T cell-myeloid regulatory circuit that integrates tissue organization, cytokine feedback, and checkpoint control to regulate CD8 T cell exhaustion during chronic infection.

immunology↗

bioRxiv2024

A Unified Atlas of T cell Glycophysiology

Glycans are emerging as important regulators of T cell function but remain poorly characterized across the functionally distinct populations that exist in vivo. Here, we couple single-cell analysis technologies with soluble lectins and chemical probes to interrogate glycosylation patterns on major T cell populations across multiple mouse and human tissues. Our analysis focused on terminal glycan epitopes with immunomodulatory functions, including sialoglycan ligands for Siglecs. We demonstrate that glycosylation patterns are diverse across the resting murine T cell repertoire and dynamically remodelled in response to antigen-specific stimulation. Surprisingly, we find that human T cell populations do not share the same glycoprofiles or glycan remodelling dynamics as their murine counterparts. We show that these differences can be explained by divergent regulation of glycan biosynthesis pathways between the species. These results highlight fundamental glycophysiological differences between mouse and human T cells and reveal features that are critical to consider for glycan-targeted therapies.

immunology↗

bioRxiv2023

Molecular, metabolic and functional CD4 T cell paralysis impedes tumor control

CD4 T cells are important effectors of anti-tumor immunity, yet the regulation of CD4 tumor-specific T (TTS) cells during cancer development is still unclear. We demonstrate that CD4 TTS cells are initially primed in the tumor draining lymph node and begin to divide following tumor initiation. Distinct from CD8 TTS cells and previously defined exhaustion programs, CD4 TTS cell proliferation is rapidly frozen in place and differentiation stunted by a functional interplay of T regulatory cells and both intrinsic and extrinsic CTLA4 signaling. Together these mechanisms paralyze CD4 TTS cell differentiation, redirecting metabolic and cytokine production circuits, and reducing CD4 TTS cell accumulation in the tumor. Paralysis is actively maintained throughout cancer progression and CD4 TTS cells rapidly resume proliferation and functional differentiation when both suppressive reactions are alleviated. Strikingly, Treg depletion alone reciprocally induced CD4 TTS cells to themselves become tumor-specific Tregs, whereas CTLA4 blockade alone failed to promote T helper differentiation. Overcoming their paralysis established long-term tumor control, demonstrating a novel immune evasion mechanism that specifically cripples CD4 TTS cells to favor tumor progression.

cancer biology↗