Science

Mozart is developing CD8 Treg modulators to effectively treat and potentially cure autoimmune diseases.

CD8 Treg Orchestrate a Healthy Immune Surveillance System

Regulatory CD8 T cells (CD8 Treg) are essential for maintaining healthy immune system function. They play a critical role within the complex network of cells that comprise the immune surveillance system, and act early to recognize and kill rogue immune cells—called pathogenic cells—that attack healthy tissue.

Healthy Immune System illustration

CD8 Treg Dysfunction Leads to Autoimmune Disease

In autoimmune disease, CD8 Treg are dysfunctional and fail to kill or otherwise control pathogenic immune cells. Left unchecked, these rogue pathogenic cells initiate a cascade of immunological events, including the production of cytokines (chemical messengers that tell other immune cells how to behave) and self-reactive antibodies. These lead to inflammation and mark healthy tissue for destruction, resulting in reduced self-tolerance, tissue damage, and other hallmarks of autoimmune disease. 

CD8 Treg dysfunction arises when these cells express “KIR” (inhibitory killer immunoglobulin-like receptors), a receptor on their surface that prevents them from becoming activated and killing pathogenic immune cells upon contact. 

CD8 Treg Dysfunction illustration

OUR APPROACH: CD8 Treg Modulators

Current therapies are designed to treat the symptoms of autoimmune disease or target disease-causing (pathogenic) cells or cytokines that emerge downstream in the inflammatory cascade. These approaches often leave patients at increased risk for broad immune suppression. 

CD8 Treg Modulators illustration

Mozart is targeting a fundamental cause of autoimmune disease by developing therapies that selectively target dysfunctional CD8 Treg. Therapeutic modulation of these cells is designed to restore the intrinsic function of CD8 Treg to suppress and eliminate pathogenic immune cells, preventing downstream inflammation and tissue destruction. Restoring healthy immune system function can effectively treat, and potentially cure, autoimmune disease. 

Posters and Publications

Targeting IL-15 to CD8 Treg results in their selective expansion and activation and is a potential therapeutic approach to ameliorate autoimmune disease in patients with deficient CD8 Treg populationsImmunology 2025, May 2025 #P4856

Despite expression of exhaustion markers, CD8 Treg are a cytolytic population that target pathogenic T cells to prevent beta cell destruction by Type 1 Diabetes peripheral blood mononuclear cellsImmunology 2025, May 2025 #P4194

Preclinical Testing of a Bispecific Antibody Targeting Inhibitory KIR and ICOS Designed for the Treatment of Inflammatory Bowel Disease PatientsCrohn’s and Colitis Congress, February 2025 #P129

Preclinical Characterization of MTX-101: A Novel Bispecific CD8 Treg Modulator that Restores CD8 Treg Functions to Suppress Pathogenic T Cells in Autoimmune Diseases | Frontiers in Immunology (doi: 10.3389/fimmu.2024.1452537), November 2024

Characterization of a Reversibly Dysfunctional Regulatory CD8 T Cell Population Responsible for Pathogenic T Cell Elimination in T1D Patients | 20th Immunology of Diabetes Society Congress (IDS 2024), November 2024

Nonclinical Toxicology and Safety Studies of MTX-101, an Inhibitory KIR2DL x CD8 Targeting Bispecific CD8 Treg Modulator, Enabling Clinical Development as Therapeutic for the Treatment of Autoimmune Disease | FOCIS Annual Meeting, June 2024 #W114

MTX-101, a Bispecific CD8 Treg Modulator, Corrects the Dysfunction in Crohn’s Patient CD8 Treg to Restore Immune Balance | 2024 DDW (Digestive Disease Week®), May 2024 #Su1736

Pre-clinical Pharmacology and Tolerability Characterization of a Novel KIR x ICOS Targeting Bispecific CD8 Treg Modulator | AAI Immunology, May 2024 #4471

Nonclinical Assessment of Toxicity and Pharmacology of MTX-101, a Novel KIRxCD8 Targeting Bispecific CD8 Treg Modulator, in Humanized Mouse | Society of Toxicology Meeting, March 2024 #5081

Pre-Clinical Characterization of MTX-101, a Novel Bispecific CD8 Treg Modulator with the Potential to Restore CD8 Treg Functions in Patients with Rheumatological Autoimmune DiseasesAmerican College of Rheumatology (ACR), November 2023

Pre-clinical Pharmacologic and Tolerability Characterization of MTX-101, a Novel KIR x CD8 Targeting Bispecific CD8 Treg Modulator | FOCIS 2023 Annual Meeting, June 2023 #1517124

Pre-clinical Pharmacologic and Tolerability Characterization of a Novel KIR x CD8 Targeting Bispecific CD8 Treg Modulator | American Association of Immunologists (AAI) Annual Meeting, May 2023 #2638

A KIR x CD8 Targeting Bispecific Modulator Enhances Regulatory CD8 T Cell Functions, and Reduces Inflammation in Models of Autoimmune Disease | American Association of Immunologists (AAI) Annual Meeting, May 2023 #2804

A Novel Bispecific CD8 Treg Modulator Targeting Cytolytic CD8 Regulatory T cells Reduces Pathogenic CD4 T cells and Inflammation in Translational Models of Intestinal Autoimmune and Inflammatory Disease | 2023 Crohn’s and Colitis Congress, January 2023 #124

A Newly Discovered Regulatory CD8 T Cell Network Has The Potential To Regulate And Eliminate Pathogenic CD4 T Cells In Autoimmune Mediated Disease Of The Gut​ | 2022 Digestive Disease Week® (DDW) Conference, May 2022, Presentation # sa1117

Bispecific CD8 Treg modulators regulate a novel regulatory CD8 T cell network and eliminate pathogenic CD4 T cells in live cell co-culture system | American Association of Immunologists (AAI) Annual Meeting, May 2022, Abstract # 1090

Demonstration of regulatory CD8 T cell prevalence, phenotype, and functions in autoimmune patients treated with a tolerizing peptide vaccine | American Association of Immunologists (AAI) Annual Meeting, May 2022, Abstract # 889