Immune Cell Imaging
Loïc Dupré, Immune Cell Imaging
Area of research: lymphocyte biology in health and disease
We study the biology of human immune cells in the context of health and rare diseases via the angle of innovative quantitative cell imaging modalities. We focus particularly on the role played by the actin cytoskeleton in sustaining key functions of lymphocytes: adhesion, migration, and cytotoxic activity. We combine super-resolution microscopy and live cell imaging to study the structural organization of primary human lymphocytes. The gained knowledge is then applied to pathological settings such as rare inborn errors of immunity and skin pathologies related to immune dysfunction. We also develop automated high-content cell imaging approaches to systematically monitor morphology, signaling events, and function of lymphocytes from multiple patients.
Key findings: revealing faulty leukocyte responses
Among the vast number of rare genetic diseases affecting immune system integrity, a growing subset is related to impairments in the molecular machinery controlling actin cytoskeleton remodeling. This reflects the pivotal role of the actin cytoskeleton to drive crucial activities of immune cells such as migration, antigen scanning, and pathogen uptake. Application of advanced microscopy approaches to study immune cells from patients with actin-related pathologies recently allowed us to reveal connection between aberrant morphology and defective function of lymphocytes and myeloid cells (Pfajfer et al., 2017 ; Houmadi et al., 2018 ; Pfajfer et al., 2018 ; Thian et al., 2020).
Confocal microscopy images showing morphological aberrations in leukocytes
isolated from the peripheral blood of a patient carrying homozygous mutations
in the gene encoding the actin regulator WDR1. The composite image shows
a representative neutrophil with nuclear herniation, a monocyte assembling
dense actin foci upon LPS stimulation, a T cell with accumulation of actin at the
center of the anti-CD3 evoked synapse and a B cell emitting extended filopodia
upon BCR/TLR stimulation. F-actin is shown in white and DAPI (for the neutrophil)
Credit: Laurène Pfajfer, Javier Rey-Barroso & Loïc Dupré
Related publication: http://dx.doi.org/10.1016/j.jaci.2018.04.023
Current research activities
Our group is focused on two major topics:
- To study the function of the actin cytoskeleton in fundamental immune processes
- To turn high-content cell imaging into a supportive approach for diagnostics and drug testing
1 – Function of the actin cytoskeleton in fundamental immune processes
In order to deepen our understanding of how actin cytoskeleton regulates and controls fundamental functions of human lymphocytes, we implement various advanced microscopy modalities, such as super-resolution, 3D confocal and TIRF live microscopy to assess assembly and stability of the immunological synapse, polarization of the cytolytic machinery, control of cell shape remodeling following integrin or chemokine stimulation.
2 – Improvement of current diagnostics and therapy via high-content cell imaging
We are developing high-content cell imaging to systematically analyze the morphology and function of blood-derived immune cell populations. This approach allows for the comparative analysis of immune cell populations from multiple patients and healthy individuals in parallel, thereby helping to characterize defects in novel patients. This approach is also amenable to testing drug arrays for correction of defects on patient cells. We are confident that our findings in this area will greatly accelerate current research in personalized medicine and help to widen patent-care options.
We interact closely with multiple groups from the LBI-RUD and our partners, the Medical University of Vienna (in particular the Department of Dermatology), the St. Anna Children’s Cancer Research Institute (CCRI), and the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences. In addition, our group is tightly linked to the INSERM Center for Physiopathology of Toulouse Purpan, France, where Loïc Dupré holds a dual appointment.