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Biology subjects

Gaglione, S. A.

Publications and source records attributed to Gaglione, S. A..

4 recordsLinked to original sources

Activation-dependent lentiviruses enable antigen-specific T cell expansion and transduction

Cancer immunotherapies rely on tumor-specific T cells, which arise endogenously in most patients with cancer, but can be low frequency and poorly functional. Methods to specifically identify, expand, and manipulate tumor-specific T cells at the rare frequencies found in peripheral blood would enable new immunotherapeutic strategies. Here, we demonstrate an approach to virally transduce polyclonal tumor-reactive T cells across any MHC haplotype and in the absence of knowing the cognate antigen. By generating lentiviral vectors that selectively transduce cells expressing 4-1BB (CD137), a marker of T cell activation, we can transduce antigen-specific T cells with user-defined genetic cargoes that can selectively expand and track individual clonotypes via single-cell sequencing. Anti-4-1BB lentiviruses (4-1BB LVs) encoding therapeutic cargoes can also enhance antigen-specific T cells to extend survival in a xenograft model of human melanoma and transduce tumor-infiltrating T cells from patients with ovarian cancer. Overall, the 4-1BB LV platform targets antigen-specific T cells in a manner agnostic to both the antigen and presenting MHC, with potential applications in adoptive cell therapy manufacturing and TCR identification. One Sentence SummaryEngineered lentiviral vectors targeting 4-1BB selectively activate, expand, and transduce antigen-specific T cells with immunomodulatory cargo.

immunology↗

Interrogating antiviral antibody responses with multiplexed, high-throughput serum assays

The COVID-19 pandemic underscored the importance of rapidly analyzing antibody responses against emerging viruses. Existing techniques, however, are limited in their ability to probe antibodies recognition of multiple native-conformation antigens simultaneously. To increase the throughput and multiplexability of antibody profiling, we developed Antibody Reactivity Characterization by Antibody-Dependent Enhancement (ARCADE). This assay employs an antigen-agnostic Fc receptor-expressing cell line and a library of antigen-displaying, genetically barcoded lentiviruses that, when mixed with serum, infect cells and integrate their barcodes at rates reflecting the relative abundances and affinities of the antigen-specific antibodies present. Verified using sera from COVID-19-convalescent and - vaccinated donors, ARCADE delivers insights that align with and expand upon those offered by established immunoassays, highlighting, for example, how an mRNA-based vaccine elicits broader and stronger antibody responses than an adenovirus vector-based vaccine. ARCADE can comprehensively assess how infection and vaccination impact antiviral antibody repertoires over time and across patient populations.

immunology↗

Deep mapping of the TCR-antigen interface using pMHC-pseudotyped viruses and yeast display

T cell receptor (TCR) specificity is central to the efficacy of T cell therapies, yet scalable methods to map how TCR sequences shape antigen recognition remain limited. To address this, we introduce VelociRAPTR, a library-on-library approach that combines yeast-displayed TCR libraries with pMHC-displaying virus-like particles (pMHC-VLPs) to rapidly screen millions of TCR-antigen interactions. We show that pMHC-VLPs efficiently bind TCRs on yeast and generate equivalent data to recombinantly produced pMHC protein. We then apply VelociRAPTR to screen 47 million variants of the A6 and 868 TCRs against 92 pMHCs simultaneously, mutating both the CDR3 loops and cognate peptides. The resulting CDR3-pMHC maps reveal biased recognition patterns, where mutations to CDR3 loops can selectively constrain or broaden specificity to peptide analogs. These insights provide a foundation for engineering TCRs with defined pMHC binding profiles and improving models that predict TCR-antigen interactions, including the prediction of off-target recognition. By coupling the scale of yeast display with the modularity of VLPs, VelociRAPTR offers a generalizable strategy for generating deep, high-throughput protein- protein interaction data.

immunology↗

Peptide-MHC-targeted retroviruses enable in vivo expansion and gene delivery to tumor-specific T cells

Tumor-infiltrating-lymphocyte (TIL) therapy has demonstrated that endogenous T cells can be harnessed to initiate an effective anti-tumor response. Despite clinical promise, current TIL production protocols involve weeks-long ex vivo expansions which can affect treatment efficacy. Therefore, additional tools are needed to engineer endogenous tumor-specific T cells to have increased potency while mitigating challenges of manufacturing. Here, we present a strategy for pseudotyping retroviral vectors with peptide-major histocompatibility complexes (pMHC) for antigen-specific gene delivery to CD8 T cells and examine the efficacy of these transduced cells in immunocompetent mouse models. We demonstrate that pMHC-targeted viruses are able to specifically deliver function-enhancing cargoes while simultaneously activating and expanding anti-tumor T cells. The specificity of these viral vectors enables in vivo engineering of tumor-specific T cells, circumventing ex vivo manufacturing processes and improving overall survival in B16F10-bearing mice. Altogether, we have established that pMHC-targeted viruses are efficient vectors for reprogramming and expanding tumor-specific populations of T cells directly in vivo, with the potential to substantially streamline engineered cell therapy production for a variety of applications.

immunology↗