Wiltshire, Timothy D.

Abstract Background: Cellular immunotherapy has transformed cancer treatment, but success in solid tumors remains limited by long manufacturing times, high costs, and the need for viral vectors that permanently modify DNA. To address this, we examined electroporation (EP) and mechanoporation (MP) approach to transfect T cells with mRNA to enable the development of a bedside immune cell editing platform. NKG7, natural killer cell granule-7, was previously demonstrated to play key function in activating T-cell cytotoxicity function. mRNA transfection of T cells with NKG-7 can increase these cells’ anti-tumor cell killing. We examine EP and MP methods for NKG7 transfection in primary peripheral blood mononuclear cells (PBMCs) from healthy donors. Method: Synthetic Clean Cap mRNAs encoding NKG7 or NKG7 with membrane-bound cRNA IL-2 were introduced into PBMCs by electroporation (MaxCyte) or mechanoporation (Portal Bio). T cell expression of NKG7 and IL-2 were analyzed by CytoFlex flow and Kaluza. Result: The yield at EP and MP were comparable at 0.615+/-0.09% and 0.597+/-0.16%, respectively. Viability were high at above 80% for 3 days after EP and MP. NKG7 and NKG7+cIL-2 mRNA transfection led to different NKG7 expression kinetics in T-cells and between EP and MP. With EP, CD4 T-cells showed an increase in NKG7 expressions with the highest MFI ratio (NKG7 MFI/ IgG MFI) compared to mock EP at Day 1 for the NKG7 -only EP (1.25 ± 0.38) and at Day 2 for NKG7+cIL-2 EP (1.20 ± 0.27). CD8+ T cells displayed a similar trend, with peak NKG7 expression at Day 1 for NKG7 EP (1.22 ± 0.76) and Day 2 for NKG7+cIL-2 EP (1.21 ± 0.90). However, MP did not enhance NKG7 expression in CD4+ T cells. NKG7 expression peaked at Day 1 for both NKG7 (1.28 ± 0.42) and NKG7 + cIL-2 (1.24 ± 0.20). IL2 expression peaked at Day 1 for both EP and MP: EP, CD4+ T (91.5% ± 4.4), CD8+ T (92.7% ± 12.8); MP, CD4+ T (88.9% ± 31.7), CD8+ T (84.7% ± 9.6). Functional assays for anti-tumor cell killing of these transfected cells are currently ongoing. Conclusions: We report that EP of PBMC can transfect all cell populations. MP may yield comparable yield, viability and NKG7 expression in CD8 T cells compared to EP, but without the need to isolate CD8 T cells from PBMC. EP and MP method can be used for bedside immune cell transfection depending on the target and cell populations of interest. Citation Format: Chen Wu, Christoph Schaefers, Malvika Gupta, Kevin Regan, Zuoyi Shao, Andre De Menezes Silva Corraes, Virginia Van Keulen, Jacob Hirdler, Tobias Peikert, Timothy D. Wiltshire, Haidong Dong, Yi Lin. A non-viral mRNA engineering platform for rapid, same-day immune-cell therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5198.

AbstractTherapeutic antibodies have broad indications across diverse disease states, such as oncology, autoimmune diseases, and infectious diseases. New research continues to identify antibodies with therapeutic potential as well as methods to improve upon endogenous antibodies and to design antibodies de novo. On April 27–30, 2022, experts in antibody research across academia and industry met for the Keystone symposium “Antibodies as Drugs” to present the state‐of‐the‐art in antibody therapeutics, repertoires and deep learning, bispecific antibodies, and engineering.

Abstract The ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants severely limits available effective monoclonal antibody therapies. Effective drugs are also supply limited. COVID-19 convalescent plasma (CCP) qualified for high antibody levels effectively reduces immunocompetent outpatient hospitalization. The Food and Drug Administration currently allows outpatient CCP for the immunosuppressed. Viral-specific antibody levels in CCP can range 10- to 100-fold between donors, unlike the uniform viral-specific monoclonal antibody dosing. Limited data are available on the efficacy of polyclonal CCP to neutralize variants. We examined 108 pre-δ/pre-ο donor units obtained before March 2021, 20 post-δ COVID-19/postvaccination units, and 1 pre-δ/pre-ο hyperimmunoglobulin preparation for variant-specific virus (vaccine-related isolate [WA-1], δ, and ο) neutralization correlated to Euroimmun S1 immunoglobulin G antibody levels. We observed a two- to fourfold and 20- to 40-fold drop in virus neutralization from SARS-CoV-2 WA-1 to δ or ο, respectively. CCP antibody levels in the upper 10% of the 108 donations as well as 100% of the post-δ COVID-19/postvaccination units and the hyperimmunoglobulin effectively neutralized all 3 variants. High-titer CCP neutralizes SARS-CoV-2 variants despite no previous donor exposure to the variants.

Abstract Many somatic mutations have been detected in pancreatic ductal adenocarcinoma (PDAC), leading to the identification of some key drivers of disease progression, but the involvement of large genomic rearrangements has often been overlooked. In this study, we performed mate pair sequencing (MPseq) on genomic DNA from 24 PDAC tumors, including 15 laser-captured microdissected PDAC and 9 patient-derived xenografts, to identify genome-wide rearrangements. Large genomic rearrangements with intragenic breakpoints altering key regulatory genes involved in PDAC progression were detected in all tumors. SMAD4, ZNF521, and FHIT were among the most frequently hit genes. Conversely, commonly reported genes with copy number gains, including MYC and GATA6, were frequently observed in the absence of direct intragenic breakpoints, suggesting a requirement for sustaining oncogenic function during PDAC progression. Integration of data from MPseq, exome sequencing, and transcriptome analysis of primary PDAC cases identified limited overlap in genes affected by both rearrangements and point mutations. However, significant overlap was observed in major PDAC-associated signaling pathways, with all PDAC exhibiting reduced SMAD4 expression, reduced SMAD-dependent TGFβ signaling, and increased WNT and Hedgehog signaling. The frequent loss of SMAD4 and FHIT due to genomic rearrangements strongly implicates these genes as key drivers of PDAC, thus highlighting the strengths of an integrated genomic and transcriptomic approach for identifying mechanisms underlying disease initiation and progression. Cancer Res; 76(3); 749–61. ©2015 AACR.

Tyr142, the C-terminal amino acid of histone variant H2A.X is phosphorylated by WSTF (Williams-Beuren syndrome transcription factor), a component of the WICH complex (WSTF-ISWI chromatin-remodeling complex), under basal conditions in the cell. In response to DNA double-strand breaks (DSBs), H2A.X is instantaneously phosphorylated at Ser139 by the kinases ATM and ATR and is progressively dephosphorylated at Tyr142 by the Eya1 and Eya3 tyrosine phosphatases, resulting in a temporal switch from a postulated diphosphorylated (pSer139, pTyr142) to monophosphorylated (pSer139) H2A.X state. How mediator proteins interpret these two signals remains a question of fundamental interest. We provide structural, biochemical, and cellular evidence that Microcephalin (MCPH1), an early DNA damage response protein, can read both modifications via its tandem BRCA1 C-terminal (BRCT) domains, thereby emerging as a versatile sensor of H2A.X phosphorylation marks. We show that MCPH1 recruitment to sites of DNA damage is linked to both states of H2A.X.

Abstract Microcephalin (MCPH1), the first gene identified as causative for primary recessive autosomal microcephaly, is aberrantly expressed in autism-like disorders and human malignancy of breast and ovarian origin. MCPH1, the encoded protein product, has been implicated in various cellular processes including the DNA damage checkpoint, DNA repair and transcription. While our understanding of the cellular context in which MCPH1 operates continues to develop, a structural understanding of the C-terminal tandem BRCT domains of MCPH1 remains unexplored. Here, we identify Cdc27, a component of the anaphase-promoting complex (APC/C), as a novel interacting partner of MCPH1. We provide in vitro and in vivo evidence that the C-terminal tandem BRCT domains of MCPH1 (C-BRCTs) bind Cdc27 in a phosphorylation-dependent manner. To further characterize this interaction, we determined the structure of MCPH1 C-BRCTs in complex with a phosphorylated Cdc27 peptide (pCdc27) using X-ray crystallography. Based on this structure, we identified single amino acid mutations targeted at the binding interface that disrupted the MCPH1-pCdc27 interaction. Collectively, our data defines the biochemical, structural and cellular determinants of the novel interaction between MCPH1 and Cdc27 and suggests that this interaction may occur within the larger context of MCPH1-APC/C. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2133. doi:1538-7445.AM2012-2133