Biology subjects

Heegaard, P. M. H.

Publications and source records attributed to Heegaard, P. M. H..

3 recordsLinked to original sources

bioRxiv2025

Dextran-based T-cell expansion nanoparticles for manufacturing CAR T cells with augmented efficacy

Adoptive T cell therapy (ACT) using chimeric antigen receptor (CAR) engineered T cells is currently being explored in multiple cancer types beyond leukemia/lymphoma. A key step in CAR-T cell manufacturing is the activation and expansion of T cells, which facilitates viral transduction, however, may hamper T cell fitness and reduce in vivo persistence. We developed "T-Expand" for T cell activation and expansion, comprising dextran-based nanoparticles (NPs) conjugated with anti-CD3 and anti-CD28 antibodies. The NPs triggered robust polyclonal expansion of human T cells with efficiency in the range of commercial microbeads (Dynabeads). Engineered in presence of T-Expand, CD19 CAR T cells exhibited enhanced proliferative capacity, cytotoxicity and persistence in vitro, and furthermore, showed superior anti-lymphoma activity in mouse models resulting in complete tumor clearance at one fourth of the CAR T cell dose. Importantly, T-Expand is biocompatible with no observed toxicity, circumventing removal steps after T cell expansion compared to DynabeadsTM. As a biocompatible T cell expansion platform, T-Expand simplifies the manufacturing process while enhancing T cell persistence and functionality, thereby holding promise for increasing clinical efficacy of CAR T cell therapy. O_FIG O_LINKSMALLFIG WIDTH=165 HEIGHT=200 SRC="FIGDIR/small/648181v1_ufig1.gif" ALT="Figure 1"> View larger version (74K): org.highwire.dtl.DTLVardef@35337corg.highwire.dtl.DTLVardef@c75199org.highwire.dtl.DTLVardef@1be184forg.highwire.dtl.DTLVardef@12e1683_HPS_FORMAT_FIGEXP M_FIG Graphical abstract/Cover figureIllustration of CAR T cell manufacturing using T-Expands ex vivo. C_FIG

immunology↗

bioRxiv2024

The role of innate immune responses against two strains of PEDV (S INDEL and non-S INDEL) in newborn and weaned piglets inoculated by combined orogastric and intranasal routes

Porcine epidemic diarrhea (PED) is a severe gastrointestinal disease in swine caused by PED virus (PEDV), leading to significant economic losses worldwide. Newborn piglets are especially vulnerable, with nearly 100% mortality, unlike older pigs. Disease severity also varies depending on the PEDV strain, with non-S INDEL strains being more virulent than S INDEL ones. This study examined early pathogenesis and innate immunity in 1-week-old suckling and 5- week-old weaned piglets (n=8 per age group, 4 per strain) inoculated with S INDEL or non-S INDEL PEDV strains via combined orogastric and intranasal route. Age-matched negative controls (n=3 per age group) were included. Body weight, temperature, and clinical signs were monitored for 48 hours post-inoculation (hpi). PEDV RNA levels were assessed in rectal swabs (RS) at 0 and 48 hpi, while pathological analyses and viral RNA loads were measured in jejunal content and intestinal mucosa. Gene expression of 75 selected antiviral and inflammatory genes were measured in laser capture microdissection (LCM)-derived jejunal samples using microfluidic qPCR at 48 hpi. Suckling piglets showed severe clinical signs, while weaned piglets were mostly asymptomatic at 48 hpi. In general, clinical signs and lesions in suckling piglets were similar, regardless of the PEDV strain. Both viral strains produced comparable viral RNA loads in the small intestine and feces, as well as consistent villous atrophy and fusion across age groups. In LCM-derived jejunal samples, weaned piglets had higher expression of antiviral genes (type I/III interferons, ISGs) and Th1/Th17 pro-inflammatory genes, particularly with the non-S INDEL strain. Conversely, the anti-inflammatory cytokine IL-10 was overexpressed in suckling compared to weaned piglets for both strains. Overall, PEDV-induced intestinal damage, viral replication, and excretion were similar regardless of viral strain or piglet age. The reduced clinical severity in weaned piglets may result from their stronger intestinal antiviral and pro-inflammatory response. AUTHOR SUMMARYPorcine epidemic diarrhea virus (PEDV) is the causative agent of a major gastrointestinal disease in piglets worldwide, characterized by severe watery diarrhea. The disease is particularly devastating in newborn piglets, especially when caused by non-S INDEL PEDV strains, while weaned piglets demonstrate resistance regardless of the strain. In this study, during the acute infection phase (48 hpi), both highly virulent non-S INDEL and less virulent S INDEL strains caused comparable intestinal atrophy, viral replication in the intestine, and viral loads in feces in both weaned and suckling piglets. However, weaned piglets mounted a robust antiviral response involving type I and III interferons (IFNs) and the induction of Th1- and Th17-related pro-inflammatory responses in the intestinal mucosa. Additionally, interferon-stimulated genes (ISGs) were broadly upregulated across the intestinal mucosa of weaned piglets in response to both PEDV strains. In contrast, suckling piglets exhibited a weaker innate immune response, coinciding with more severe clinical signs. The observed inverse relationship between disease severity and intestinal innate immune activation highlights the potential role of IFNs, ISGs, and pro-inflammatory cytokines in mitigating PEDV severity and underscores their relevance in developing novel pharmacological prevention strategies.

immunology↗

bioRxiv2023

The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs

The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species this can affect the health of humans as well as livestock. Here we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of Streptococcus suis, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of S. suis is yet to be fully realised.

evolutionary biology↗