Welcome

We bring together expertise in novel cell culture methodologies to accelerate progress in 3D cell and tissue models. Our aim is to establish a cross-disciplinary working group to galvanise collaborations and provide a focal point for those planning to move into 3-D cell culture modelling and training of PhD students.

At Southampton General Hospital as researchers we are privileged to have access to clinical samples directly from patients. Once collected, the samples are either sent to a biorepository such as a tissue bank, or they get processed for integrated multiomic analysis. This approach answers research hypothesis and creates new ones: either way you need a lab with expertise in advanced cell culture platforms.

These modelling platforms are also a tool to identify new interventions, new drugs leading to innovative trial designs. Under the NIHR Southampton Biomedical Research Centre (BRC) respiratory theme, we have an “Advanced cell culture” programme, and the first action has been to set up SoCRATES.

Ex vivo nasal or bronchial samples, obtained by brushing or biopsy, in addition to human pluripotent stem cells and immortalised epithelial cell lines, provide human airway epithelial cells for in vitro two-dimensional (2D) culture models as submerged monocultures. Air–liquid interface (ALI) cultures are three-dimensional (3D) epithelial culture systems where basal cells are able to differentiate in a pseudo-stratified epithelium resembling the area of the lung they originate from.

The model can be enriched in co-culture systems where the epithelium differentiates in the presence of pathogens and immune cells such as macrophages. Further complexity is achieved by the addition of fibroblasts and mesenchymal cells to mimic epithelial–mesenchymal cross-talk. To recapitulate the extracellular matrix (ECM) present in the lung interstitium, natural or synthetic macromolecules can be added to the cultures to promote the self-assembly of a mature 3D ECM.

Similarly, 3D cultures made out of cells encapsulated in macromolecule-enriched media support the growth of organoids. To investigate pathophysiological questions and in particular inflammatory processes, one example is tuberculosis granulomas, which can be developed using collagen–alginate microspheres generated by bioelectrospray methodology incorporating Mycobacterium tuberculosis-infected peripheral blood mononuclear cells.

Among other cell types, alveolar cells can be isolated from healthy surgically resected lung tissue that together with lung fibroblasts support 3D cultures mimicking the lung parenchyma. Availability of lung tissue may be exploited in ex vivo lung tissue models using small lung sections preserving its complex native architecture. Whole lung or tissue derived from pneumonectomies allows the development of human ex vivo whole-lung perfusion models or provides precision-cut lung slices (PCLSs), both preserving native structural features. Human embryonic/fetal lung explant models support lung development studies. Fetal tissue is collected 7–21 weeks post-conception, and the mixed cell population is cultured as monolayers, organoids and other 3D cultures.

In vitro and ex vivo human lung models

Miniaturised models such as lung-on-a-chip combine microfluidics, engineering and cell biology to recreate certain aspects of organ physiology in vitro, and are a promising alternative to conventional models. Specific devices allow mimicking normal breathing patterns and enable microscopic tissue evaluation post-stretching. Other micro-physiological systems permit relevant cells of the respiratory tree to be cultured within a biopolymer or tissue-derived matrix within microfluidic devices incorporating flow. These systems can have integrated sensors to maintain cultures and monitor responses.

PNEC: pulmonary neuroendocrine cell; Th1: T-helper 1; Treg: T regulatory; NK: natural killer; DC: dendritic cell. Figure partially created with BioRender.com.