Publications
A complete up-to-date list of publications of Robert can be found on Google Scholar and full-texts might be available from the Warwick Research Active Portal (WRAP).
The circadian clock in mammalian cells modulates bacterial entry
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An endogenous biological clock, the circadian clock, coordinates life with the 24-hour day/night cycle of the environment. The unit of this circadian clock is the cell but in multicellular organisms, such as mammals, a circadian timing system (CTS) with a central pacemaker orchestrates peripheral clocks and the overall finely tuned temporal order. For example, the CTS changes immune responses to infections depending on time-of-day, however, its role in controlling bacterial infections at a cellular level is not understood. In this study, we investigated the role of the host cellular clock during infection by Staphylococcus aureus, a highly drug-resistant, facultatively intracellular human pathogen. Our findings revealed that S. aureus invasion into epithelial cells is dependent on the cellular circadian phase. Interestingly, in BMAL1, an essential clock protein, deficient cells bacterial uptake was significantly higher compared to parental A549 cells. RNA sequencing of BMAL1 knockdown (KD) cells showed a significant upregulation of GP340, coding for the receptor of SraP, an S. aureus adhesin. An S. aureus mutant lacking SraP did not exhibit a circadian rhythm of uptake into A549 cells nor an increased uptake into BMAL1 KD compared to the parental A549 cells. Of note, bacterial mutants for other adhesins continued to show a rhythmic and higher uptake in BMAL1 KD cells. Hence, we report that S. aureus invasion of epithelial cells is clock-modulated and mediated through S. aureus SraP, suggesting potential for host clock-directed therapy against this pathogen. |
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Targeting intracellular mycobacteria using novel antibiotic-loaded nanoparticles
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Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge. Currently treatment of drug-sensitive TB, involves a six-month regimen consisting of a combination of four anti-TB drugs, with drug-resistant TB requiring over two years of treatment and additional drugs. As toxicity of anti-TB drugs often leads to poor compliance, disease relapse and the emergence of drug-resistant strains, new strategies to reduce drug toxicity and shorten treatment duration are critical. We report nanocarrier-based drug delivery systems targeting macrophages, which primarily support replication and survival of Mtb. We demonstrate that antibiotic-containing nanocarriers efficiently accumulated in macrophages without causing toxicity. Encapsulated RIF showed enhanced efficacy against both BCG and Mtb in primary macrophages. Biodistribution studies in mice revealed that the nanoparticles have extended circulation time and do not induce toxicity. In addition, the encapsulated RIF showed better targeting of mycobacteria when compared to free RIF in a murine model of mycobacterial infection. Such an enhanced bacterial killing using mannose-functionalised nanocarriers loaded with the key anti-TB drug rifampicin offers excellent potential for TB therapy. |
Good clocks in breast tumours are bad news for patients
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Vadim's magnum opus now online as a preprint. 7 years after the initial preprint, 2 PhD students working on it. A coolaboration with David Rand and also including input Francis Lévi and with data from George Bjarnasson and Tami Martino. We show in over 1200 patients that TimeTeller predicted functional tumour clocks have a negative effect on 10-year survival in breast cancer patients. Also, the tumour clocks are "off" compared to wall clock time, which we speculate might be a feature of tumour evading detection by the patients immune system. |
In Situ Lipid Interactions of an Anticancer Metal Complex
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Ed Lant's paper on cool molecular helicopters that also fluoresc entitled: "In Situ Lipid Interactions of an Anticancer Metal Complex". A big collaboration with Peter Sadler's lab and collaborators from Diamond (Maria Harkiolaki) and others. In this paper, Ed uses an integrated multimodal imaging workflow of cryogenic super-resolution fluorescence microscopy and soft X-ray tomography, Orbitrap secondary ion mass spectrometry, and inductively coupled mass spectrometry to reveal unexpected targeting of a half-sandwich cyclopentadienyl Rh(III) phenylazopyridine anticancer complex to cellular lipid membranes and lipid droplets. The complex accumulates in plasma membranes with a surprisingly intense switch-on luminescence in living cancer cells, drives remodelling of lipid droplet architecture, and penetrates deeply into lipid-rich tissue environments. DFT modelling shows strong supramolecular interactions between the complex and glycerophosphorylcholine lipids. |
How to safeguard against the low hanging fruit being rotten?
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Recent clinical results suggest that early immunotherapy is more efficacious than late immunotherapy. In a commentary lead by Seline Ismail-Sutton, we argue that "Personalising chronotherapy of immune checkpoint blockade" is important. Chronotype as a factor should be looked at in pragmatic chrono-immunotherapy trials. |