Biology subjects

Craven, H. M.

Publications and source records attributed to Craven, H. M..

3 recordsLinked to original sources

bioRxiv2025

In form for a swarm: programmable neutrophil swarming impacts infection outcome

Many migrating cells pattern signalling molecules to support their accumulation in target tissues. During inflammation, neutrophils achieve rapid swarming at sites of injury or infection by generating spatiotemporal gradients of chemoattractants. Whether these self-generated behaviours can be re-programmed to change disease course is unclear. Here, we show that neutrophil chemoattractant patterning machinery is subject to transcriptional reprogramming after microbial experience, leading to enhanced swarming and control of infection at subsequent wound sites in zebrafish. Through in vitro assays, we demonstrate that "trained swarming phenotypes" are cell-intrinsic and independent of the nature of the microbial target. Furthermore, genetic enhancement of 5-lipoxygenase in neutrophils is sufficient to improve neutrophil swarming and resistance to wound infection. Through mathematical modelling, we demonstrate that neutrophil-intrinsic alterations in chemoattractant release are sufficient to recapitulate trained swarming in infection-experienced animals. Together, these data suggest new routes for reprogramming cell migration in disease settings, via manipulating their ability to shape chemoattractant landscapes.

immunology↗

bioRxiv2025

Viral Diversity Influences T Cell Responses to Enteric Human Adenoviruses F40 and F41

BackgroundHuman enteric species F adenoviruses are a leading cause of diarrhoea-associated paediatric morbidity and mortality worldwide. The cellular immune response (antigen-specific cytotoxic T cells and secreted cytokines) to human adenovirus (HAdV) infection is known to ameliorate symptoms and is critical for viral clearance. We hypothesised that the capsid proteins (hexon and penton) of HAdV-F40 and 41 (F40, F41) are evolving to escape cellular immune responses. Major histocompatibility complex (MHC) binding of viral peptides is a key step in the presentation of peptide-MHC complexes which activate the T cell receptor and the cytotoxic T cell response. MethodsUsing global HAdV genomic data, we predicted MHC-peptide binding within the hexon and penton proteins of F40 and F41. We focused on MHC class I alleles common in the UK and Kenya and identifying predicted CD8+ T cell epitopes. Eight predicted epitope pairs from the F41 hexon were synthesised as 15mer peptides, comparing the wildtype (1970 F41 reference) to the variant (2019-2022) sequences. Cellular IFN{gamma} responses to these epitopes were measured in healthy donors using FluoroSpot assays. ResultsWe identified multiple predicted CD8+ T cell epitopes shared between HAdV-species C and F, but also unique to species F, and epitopes unique to each genotype. We show that IFN{gamma} and IL2 peripheral blood mononuclear cell (PBMC) responses to HAdV-F are ubiquitous among healthy adult donors from Cambridge, UK. Among predicted CD8+ epitopes within the F41 hexon, 11/16 peptides elicited donor positive IFN{gamma} responses from healthy donor PBMC (at least one epitope from seven out of eight peptide pairs). ConclusionsThe hexon and penton proteins of HAdV-F-40 and F41 are predicted to contain a number of genotype-specific, but conserved, CD8+ T cell epitopes which could be used to inform future vaccine design. Using the hexon of F41 as a case study, we show that predicted T cell epitopes in emergent strains are able to elicit an inflammatory cytokine response from healthy donor PBMC. The role of T cell recognition in driving enteric adenovirus evolution deserves further consideration.

microbiology↗

bioRxiv2023

Effects of the G-quadruplex-binding drugs Quarfloxin and CX-5461 on the malaria parasite Plasmodium falciparum

Plasmodium falciparum is the deadliest causative agent of human malaria. This parasite has historically developed resistance to many drugs, including the current frontline treatments, so new therapeutic targets are needed. Our previous work on guanine quadruplexes (G4s) in the parasites DNA and RNA has highlighted their influence on parasite biology, and revealed G4 stabilising compounds as promising candidates for drug repositioning. In particular, quarfloxin, a former anticancer agent, kills blood-stage parasites at all developmental stages, with fast rates of kill and nanomolar potency. Here we explored the molecular mechanism of quarfloxin and its related derivative CX-5461. In vitro, both compounds bound to P. falciparum-encoded G4 sequences. In cellulo, quarfloxin was more potent than CX-5461, and could prevent establishment of blood-stage malaria in vivo in a murine model. CX-5461 showed clear DNA damaging activity, as reported in human cells, while quarfloxin caused weaker signatures of DNA damage. Both compounds caused transcriptional dysregulation in the parasite, but the affected genes were largely different, again suggesting different modes of action. Therefore, CX-5461 may act primarily as a DNA damaging agent in both Plasmodium parasites and mammalian cells, whereas the complete antimalarial mode of action of quarfloxin may be parasite-specific and remains somewhat elusive.

microbiology↗