TGFb signaling instructs a conserved fibrosis-associated cell state marked by LRRC15

J Justin A. Shyer (Genentech Research and Early Development, Genentech, Inc.) F Fabien Wehbe (Roche Informatics, F. Hoffmann-La Roche Ltd.) C Christopher D. Davidson (Genentech Research and Early Development, Genentech, Inc.) H Hannah S. Bender (Genentech Research and Early Development, Genentech, Inc.) M Minh Thai (Genentech Research and Early Development, Genentech, Inc.) C Christian Cox (Genentech Research and Early Development, Genentech, Inc.) A Alsu Missarova (Genentech Research and Early Development, Genentech, Inc.) A Alexander Arlantico (Genentech Research and Early Development, Genentech, Inc.) B Ben Hall (Genentech Research and Early Development, Genentech, Inc.) R Ruoyu Zhang D David Kim (Genentech Research and Early Development, Genentech, Inc.) A Anthony Altieri (Department of Immunology, University of Toronto) S Shakir Hasan (Department of Immunology, University of Toronto) A Afshin Namdar (Department of Immunology, University of Toronto) T Tina Chen (Hospital for Sick Children Research Institute) S Shaheed W. Hakim (St. Joseph’s Health Centre, Unity Health Toronto) C Cynthia Guidos (Hospital for Sick Children Research Institute) H Hans D. Brightbill (Genentech Research and Early Development, Genentech, Inc.) T Tony Kuo (Roche Informatics, F. Hoffmann-La Roche Ltd.) G Graham Heimberg (Genentech Research and Early Development, Genentech, Inc.) H Héctor Corrada Bravo (Genentech Research and Early Development, Genentech, Inc.) R Rojo A. Ratsimandresy (Genentech Research and Early Development, Genentech, Inc.) S Salil Uttarwar (Genentech Research and Early Development, Genentech, Inc.) G Grace Teng (Genentech Research and Early Development, Genentech, Inc.) O Omar Salem (Genentech Research and Early Development, Genentech, Inc.) M Mehrdad Arjomandi (Department of Medicine, University of California San Francisco) M Mark S. Wilson (Genentech Research and Early Development, Genentech, Inc.) S Spyros Darmanis J James Ziai (Genentech Research and Early Development, Genentech, Inc.) A Alexis Scherl (Pathology, Genentech) Z Zora Modrusan P Paul J. Wolters (Department of Medicine, University of California San Francisco) M Matthew B. Buechler (University of Toronto, Department of Immunology, Toronto, ON, Canada.) J Jason A. Vander Heiden (Genentech Research and Early Development, Genentech, Inc.) S Shannon J. Turley (Genentech Research and Early Development, Genentech, Inc.)

Abstract

Fibroblasts are key potentiators of chronic disease pathophysiology. Despite their established roles in promoting pathological inflammation and tissue remodeling, activated myofibroblasts are generally characterized as a single, homogeneous cell population, obscuring critical functional distinctions. Defining the cell states, their molecular regulators, and restricted markers is critical to developing effective therapies for the treatment of fibrosis. Here, using a human lung stromal cell atlas of idiopathic pulmonary fibrosis, we identify two myofibroblast transcriptional states associated with distinct predicted biological function, regulation, and cell surface marker expression. We identify fibroblast-specific TGFb signaling as the key regulator of the mechanistic switch from a wound healing–associated and proliferative to a profibrotic myofibroblast. Further, we elucidate conserved TGFb-dependent and suppressed gene expression programs that define these states. Our findings reveal that LRRC15 is highly restricted to myofibroblasts that primarily express an extracellular matrix-remodeling gene program and illuminate that this key cell state can differentiate in the absence of an obligate inflammatory precursor intermediate. Last, we apply machine learning using a human single-cell foundation model to demonstrate broad applicability of the biology described herein to human chronic disease.

Article Details

Volume / Issue Vol. 123, Issue 21
Published May 26, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (35)

J

Justin A. Shyer

Genentech Research and Early Development, Genentech, Inc.

F

Fabien Wehbe

Roche Informatics, F. Hoffmann-La Roche Ltd.

C

Christopher D. Davidson

Genentech Research and Early Development, Genentech, Inc.

H

Hannah S. Bender

Genentech Research and Early Development, Genentech, Inc.

M

Minh Thai

Genentech Research and Early Development, Genentech, Inc.

C

Christian Cox

Genentech Research and Early Development, Genentech, Inc.

A

Alsu Missarova

Genentech Research and Early Development, Genentech, Inc.

A

Alexander Arlantico

Genentech Research and Early Development, Genentech, Inc.

B

Ben Hall

Genentech Research and Early Development, Genentech, Inc.

R

Ruoyu Zhang

D

David Kim

Genentech Research and Early Development, Genentech, Inc.

A

Anthony Altieri

Department of Immunology, University of Toronto

S

Shakir Hasan

Department of Immunology, University of Toronto

A

Afshin Namdar

Department of Immunology, University of Toronto

T

Tina Chen

Hospital for Sick Children Research Institute

S

Shaheed W. Hakim

St. Joseph’s Health Centre, Unity Health Toronto

C

Cynthia Guidos

Hospital for Sick Children Research Institute

H

Hans D. Brightbill

Genentech Research and Early Development, Genentech, Inc.

T

Tony Kuo

Roche Informatics, F. Hoffmann-La Roche Ltd.

G

Graham Heimberg

Genentech Research and Early Development, Genentech, Inc.

H

Héctor Corrada Bravo

Genentech Research and Early Development, Genentech, Inc.

R

Rojo A. Ratsimandresy

Genentech Research and Early Development, Genentech, Inc.

S

Salil Uttarwar

Genentech Research and Early Development, Genentech, Inc.

G

Grace Teng

Genentech Research and Early Development, Genentech, Inc.

O

Omar Salem

Genentech Research and Early Development, Genentech, Inc.

M

Mehrdad Arjomandi

Department of Medicine, University of California San Francisco

M

Mark S. Wilson

Genentech Research and Early Development, Genentech, Inc.

S

Spyros Darmanis

J

James Ziai

Genentech Research and Early Development, Genentech, Inc.

A

Alexis Scherl

Pathology, Genentech

Z

Zora Modrusan

P

Paul J. Wolters

Department of Medicine, University of California San Francisco

M

Matthew B. Buechler

University of Toronto, Department of Immunology, Toronto, ON, Canada.

J

Jason A. Vander Heiden

Genentech Research and Early Development, Genentech, Inc.

S

Shannon J. Turley

Genentech Research and Early Development, Genentech, Inc.