Light-Harvesting Complex II (LHCII) is responsible for light absorption and excitation energy transfer in plants and photosynthetic algae, while in high light it undergoes conformational changes by which it quenches excitations to prevent photodamage.

Promotor: A.H. Meijer, Co-promotor: B.E. Snaar-Jagalska

Multicellular giant algae Chara species have been widely used in physiological studies for decades.

Dendritic cells (DC) play a prominent role in the priming of CD8(+) T cells. Vaccination is a promising treatment to boost tumor-specific CD8(+) T cells which is crucially dependent on adequate delivery of the vaccine to DC.

The lipid matrix of the skin's stratum corneum plays a key role in the barrier function, which protects the body from desiccation. The lipids that make up this matrix consist of ceramides, cholesterol, and free fatty acids, and can form two coexisting crystalline lamellar phases: the long periodicity…

Cells in our body are constantly performing small tasks, such as repairing wounds. They exert force by changing shape. But how do cells translate their shape into exerting a force in a specific direction? Experimental and theoretical Leiden physicists have now found a clue to answer this question. Cells’…

Research aims: Identification of key genes involved in programming the cellular architecture of A. niger & Genetic engineering of A. niger in order to improve its secretory capacities and rheological behavior under industrial fermentation conditions.

This thesis describes the antimicrobial discovery strategy developed in our group, the den Hertog Group at the Hubrecht Institute. It includes a cultivation-based screening approach for novel antimicrobial agents from the source of fungi, and a bacterial time-lapse imaging approach for antimicrobial…

We aim to develop A. niger strains that produce more starch degrading enzymes even in the absence of starch.

Carbohydrates are present on the surface of bacteria making them suitable antigen candidates for vaccine development. This thesis deals with the synthesis of two carbohydrate-based components; the capsular polisaccharide of S. aureus type 5 and teichoic acids from staphilococci and enterococci speci…

The aim of this work was to study the applicability of antigen-coated pH-sensitive microneedle arrays for effective vaccination strategies. Therefore, a model antigen (ovalbumin) was coated onto pH-sensitive (pyridine-modified) microneedle arrays to test pH-triggered antigen release by applying the…

Poly(lactic-co-glycolic acid) (PLGA) particles have been extensively studied as biodegradable delivery system to improve the potency and safety of protein-based vaccines. In this study we analyzed how the size of PLGA particles, and hence their ability to be engulfed by dendritic cells (DC), affects…

For effective cancer immunotherapy by vaccination, co-delivery of tumour antigens and adjuvants to dendritic cells and subsequent activation of antigen-specific cytotoxic T cells (CTLs) is crucial. In this study, a synthetic long peptide (SLP) harbouring the model CTL epitope SIINFEKL was encapsulated…

How does an embryonic stem cell decide if it becomes a heart cell or a kidney cell? That’s the question computational biologist Maria Mircea studied for her PhD research. She looked at the inside of individual cells to analyse how they change. This is what she discovered.

Thread-like bacteria make cells that no longer have a cell wall under the influence of osmotic stress. A remarkable discovery, since the cell wall serves as a protection barrier for bacteria. It could also help to explain how pathogenic bacteria can hide in our body from our immune system. A team of…

Promotor: G.A. van der Marel, Co-promotor: J.D.C. Codée

When you think of physics, do you think only of complicated formulas? You’re not the only one. Therefore, every year, the Leiden Insitute of Physics organises the LION Image Award to show another side of physics: beautiful images about intriguing science. The winner of the 2022 photo competition captured…

The Leiden University Medical Center (LUMC), the Danstem Institute from the University of Copenhagen and the Murdoch Children’s Research Institute in Melbourne have received 300m euros from the Novo Nordisk foundation. The aim of this new international consortium is to bring stem-cell based therapies…

Kidney failure is a serious issue because kidneys cannot regenerate themselves after injury. A possible solution consists of artificially growing healthy kidney tissue. To achieve that, scientists first need to understand kidney development during the earliest stages, in the fetus. Leiden researchers…

A new mathematical model may explain how body cells get their shapes and what makes them move within a tissue. The model provides fundamental knowledge for applications in tissue engineering, amongst other things. Publication in open-access journal iScience.

Zebrafish-human communication shows that cancer cells lacking a signaling protein are less able to develop aggressive metastatic properties. This discovery has been made by molecular cell biologist Claudia Tulotta. PhD defence 14 June.

The life of a fibroblast is heavy, but PhD student Julia Eckert makes it 19.5 times heavier, using the Large Diameter Centrifuge at the ESTEC space research centre in Noordwijk.

Promotor: Prof.dr. P. Hooykaas, Co-promotor: Dr. R. Offringa

The main aim of this thesis was to unravel the signaling and regulatory networks that drive tumor cell migration during breast cancer metastasis.

This dissertation contains four works during my PhD. Different biomaterials have been designed based on coiled-coil peptides. These biomaterials have a range of applications, inclusing drug delivery, cell sorting to cell-cell fusion.

Chemist Roxanne Kieltyka has received an ERC Starting Grant of 2 million euros. In her lab, she creates gels that mimic the instructive material that supports cells in our body. With the grant, she aims to make these gels stiff and tough, and to create a bio-printed miniature heart ventricle.

Viral hemorrhagic fever (VHF) is a group of acute diseases caused by highly infectious viruses including Ebola, Lassa, Dengue viruses. Its high mortality rate poses high risk to public health, however, studies on VHF have been hampered due to the non-availability of proper models and incomplete knowledge…

Biophysicist Rolf Harkes has developed a microscope to optically localize individual molecules in living cells. It improves monitoring of diseases like cancer and Parkinson’s at the cellular level. Defende PhD thesis on t13 January 2016.

Prison staff are working under high pressure. The current proposal for cell sharing is the final straw. Associate Professor Esther van Ginneken appeared on Dutch news programme ‘Nieuwsuur’: ‘Serious incidents have occurred, including the murder of a cellmate.’

Embryonic stem cells have the remarkable ability to develop into any type of cell. On their way to become for example a liver or a heart cell, they must repeatedly decide between alternative developmental paths. How they make these decisions is largely unknown. An international team of biophysicists…

Promotor: Prof.dr. J. Kuiper, Co-promotor: Saskia C.A. de Jager

Leiden molecular cell biologists in the research group of Annemarie Meijer have discovered novel early macrophage-specific genes in zebrafish, including a signal transducer pivotal for the migration of macrophages in the innate immune response to bacterial infection. Their findings were published on…

Leiden chemists, together with colleagues at the University of York (UK) and Technion (Israel) have discovered a small, sugar-like molecule that maintains the integrity of tissue around a tumour during cancer. This molecule prevents tumour cells from spreading from the primary cancer site to colonise…

Leiden physicists are helping Wageningen plant researchers to study unpredictable plant embryos. For this, they are using a novel two-photon fluorescence microscope, aided by a 30 thousand euro ZonMW grant.

An international group of scientists has discovered that certain cells of our immune system – the so-called T cells – communicate with each other and work together as a team. To fight an infection they stimulate each other’s growth, but at the same time, they inhibit each other when there is a surplus…

With the necessary measures, researchers restart their work in various laboratories. The Leiden Cell Observatory is one of the places where scientists resume their lab work.

Many teachers in secondary education take differences between pupils into account . PhD research by Saskia Stollman (ICLON) shows that they need room to experiment and the support of the school management

When the immune system attacks cancer, the tumour modifies itself to escape the immune reaction. Researchers at LUMC published on this subject in Nature on 28 June.