Organoids: a promising new in vitro platform in livestock and veterinary research

Abstract

Organoids are self-organizing, self-renewing three-dimensional cellular structures that resemble organs in structure and function. They can be derived from adult stem cells, embryonic stem cells, or induced pluripotent stem cells. They contain most of the relevant cell types with a topology and cell-to-cell interactions resembling that of the in vivo tissue. The widespread and increasing adoption of organoid-based technologies in human biomedical research is testament to their enormous potential in basic, translational- and applied-research. In a similar fashion there appear to be ample possibilities for research applications of organoids from livestock and companion animals. Furthermore, organoids as in vitro models offer a great possibility to reduce the use of experimental animals. Here, we provide an overview of studies on organoids in livestock and companion animal species, with focus on the methods developed for organoids from a variety of tissues/organs from various animal species and on the applications in veterinary research. Current limitations, and ongoing research to address these limitations, are discussed. Further, we elaborate on a number of fields of research in animal nutrition, host-microbe interactions, animal breeding and genomics, and animal biotechnology, in which organoids may have great potential as an in vitro research tool.

Keywords: Animal breeding and genomics; Animal health; Animal nutrition; Host-microbe interaction; In vitro model; Organoids; Stem cell research; Veterinary research.

Figure 1

Application opportunities of organoids in livestock and veterinary research.

Figure 2

Current organoid culture techniques. Organoids can be derived from tissue samples containing adult stem cells (ASCs). Here, intestinal crypts are shown as example, but methods for other tissues (see main text) are similar. Organoids can also be derived from embryonic stem cells (ESCs), or induced pluripotent stem cells (iPSCs). Under appropriate conditions, using various growth factors and an extracellular matrix, such as matrigel (MG), the stem cells can proliferate while their daughter cells can differentiate to multiple cell types that self-organize into functional three dimensional (3D) structures. Different tissues require different (combinations of) growth factors. The 3D organoids can be dissociated, and plated onto membrane supports coated with MG or collagen, to form 2D monolayer organoid models. This is particularly useful of intestinal organoids as it allows access to the apical side, for instance to study interaction with microbes, or transport of nutrients.