Establishing Human Lung Organoids and Proximal Differentiation to Generate Mature Airway Organoids

Summary

The protocol presents a method to derive human lung organoids from primary lung tissues, expand the lung organoids and induce proximal differentiation to generate 3D and 2D airway organoids that faithfully phenocopy the human airway epithelium.

Abstract

The lack of a robust in vitro model of the human respiratory epithelium hinders the understanding of the biology and pathology of the respiratory system. We describe a defined protocol to derive human lung organoids from adult stem cells in the lung tissue and induce proximal differentiation to generate mature airway organoids. The lung organoids are then consecutively expanded for over 1 year with high stability, while the differentiated airway organoids are used to morphologically and functionally simulate human airway epithelium to a near-physiological level. Thus, we establish a robust organoid model of the human airway epithelium. The long-term expansion of lung organoids and differentiated airway organoids generates a stable and renewable source, enabling scientists to reconstruct and expand the human airway epithelial cells in culture dishes. The human lung organoid system provides a unique and physiologically active in vitro model for various applications, including studying virus-host interaction, drug testing, and disease modeling.

Introduction

Organoids have become a robust and universal tool for in vitro modeling of organ development and studying biology and disease. When cultured in a growth factor-defined culture medium, adult stem cells (ASC) from a variety of organs can be expanded in 3-dimension (3D) and self-assembled into organ-like cellular clusters composed of multiple cell types, termed organoids. Clevers' laboratory reported the derivation of the first ASC-derived organoid, human intestinal organoid, in 2009^1,2. Afterward, ASC-derived organoids have been established for a variety of human organs and tissues, including prosta....

Protocol

All experimentation using human tissues described herein was approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW13-364 and UW21-695). Informed consent was obtained from patients before tissue collection.

1. Derivation of human lung organoid

1. Preparation of experimental materials
   1. Prepare basal medium by supplementing advanced DMEM/F12 medium with 2 mM glutamine, 10 mM HEPES, 100 U/mL of penicillin, and 100 µg/mL of streptomycin.
   2. Prepare human lung organoid expansion medium by supplementing basal medium with 10% R-spondi....

Results

This protocol enables the derivation of human lung organoids with a high success rate. Fresh human lung tissue is minced into small pieces, and then decomposed with collagenase. The resultant single cells are embedded in the basement matrix and incubated in the lung organoid expansion medium supplemented with a cocktail of niche factors for the outgrowth of epithelial stem cells (step 1.1.2). Figure 1 shows the microphotograph of freshly isolated lung cells embedded in reduced growth factor .......

Discussion

The human airways are lined with the airway epithelium, also known as the pseudostratified ciliated epithelium. The major cell types of the upper airway epithelium are ciliated cells that enable the coordinated movement of their apical cilia to expel mucus and inhaled particles from the airways, goblet cells that produce and secrete mucus, and basal cells that line the basement membrane and are implicated in regeneration. In the small airway such as bronchioles, the cuboidal airway epithelium contains secretory club cell.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Reagents for lung organoid culture
Advanced DMEM/F12	Invitrogen	12634010	-
A8301	Tocris	2939	500nM
B27 supplement	Invitrogen	17504-044	1x
Cultrex Reduced Growth Factor Basement Membrane Matrix, Type 2 (BME 2)	Trevigen	3533-010-0	70-80%
FGF-10	Peprotech	100-26	20 ng/mL
FGF-7	Peprotech	100-19	5 ng/mL
GlutaMAX (glutamine)	Invitrogen	35050061	1x
HEPES 1M	Invitrogen	15630-056	10 mM
Heregulin β-1	Peprotech	100-03	5 nM
N-Acetylcysteine	Sigma-Aldrich	A9165	1.25 mM
Nicotinamide	Sigma-Aldrich	N0636	10 mM
Noggin (conditional medium)	home made	-	10x
Penicillin-Streptomycin (10,000 U/mL)	Invitrogen	15140-122	1x
Primocin	Invivogen	ant-pm-1	100 µg/mL
Rspondin1 (conditional medium)	home made	-	10x
SB202190	Sigma-Aldrich	S7067	1 µM
Y-27632	Tocris	1254	5 µM
Proximal differentiation medium
DAPT	Tocris	2634	10 µM
Heparin Solution	StemCell Technology	7980	4 µg/mL
Hydrocortisone Stock Solution	StemCell Technology	7925	1 µM
PneumaCult-ALI 10X Supplement			air liquid interface supplement
PneumaCult-ALI Basal Medium	StemCell Technology	05001	air liquid interface basal medium
PneumaCult-ALI Maintenance Supplement			air liquid interface maintenance supplement
Y-27632	Tocris	1254	10 µM
Equipment
Biological safety cabinet	Baker	1-800-992-2537
Carl Zeiss LSM 780 or 800	Zeiss		confocal microscope
CO2 Incubator	Thermo Fisher Scientific	42093483
Stereo-microscope	Olympus Corporation	CKX31SF
Centrifuge	Eppendorf	5418BG040397
Serological pipettor	Eppendorf
Micropipette	Eppendorf
ZEN black or ZEN blue software	Zeiss		analysis software
Consumables
12mm Trans-well	StemCell Technology	#38023
12-well cell culture plate	Cellstar	665970
15- and 50 ml conical tubes	Thermo Fisher Scientific	L6BF5Z8118
24-well cell culture plate	Cellstar	662160
6.5mm Trans-well	StemCell Technology	#38024
Medical Syringe Filter Unit, 0.22 µm	Sigma-Aldrich	SLGPR33RB
Microfuge tubes	Eppendorf
Micropipette tips	Thermo Fisher Scientific	TFLR140-200-Q21190531
Pasteur pipette glass	Thermo Fisher Scientific	22-378893
Serological pipettes(5ml, 10ml, 25ml)	Thermo Fisher Scientific	BA08003, 08004, 08005
Antibodies
Goat Anti-Mouse Alexa Fluor 594	Invitrogen	A11005
Goat Anti-Mouse, Alexa Fluor 488	Invitrogen	A11001
Goat Anti-Rabbit Alexa Fluor 488	Invitrogen	A11034
Goat Anti-Rabbit Alexa Fluor 594	Invitrogen	A11037
Goat Anti-Rat Alexa Fluor 594	Invitrogen	A11007
Mouse Anti-Cytokeratin 5	Abcam	ab128190
Mouse Anti-FOX J1	Invitrogen	14-9965-82
Mouse Anti-Mucin 5AC	Abcam	ab3649
Mouse Anti-β-tubulin 4	Sigma	T7941
Rabbit Anti-p63	Abcam	ab124762
Rat Anti-Uteroglobin/CC-10	R&D Systems	MAB4218-SP
Other reagent
TrypLE Select Enzyme (10X)	Thermo Fisher Scientific	A1217701	dissociation enzyme