R01AI154138

Exploring Siglec-Glycan Ligand Interactions Using Chemoenzymatic Approaches - Project Summary/Abstract

Regulation of the immune system is substantially influenced by glycosylation. Cell-surface glycans tune ligand-receptor binding and set a threshold for initiating the downstream signaling for immune cell activation. Siglecs (sialic acid-binding immunoglobulin-type lectins) are a family of regulatory receptors involved in these processes. A Siglec can bind to both cis and trans sialylated glycan ligands that are expressed on the same or interacting cells, respectively.

The binding of Siglecs with their ligands can either segregate Siglecs from activation receptors or move them closer. The ability of inhibitory Siglecs to modulate activation receptors is regulated by spatial proximity: recruiting Siglecs to the immune synapse in the proximity of activation receptors would trigger inhibitory signaling to suppress immune system activation, whereas moving Siglecs away from activation receptors would enable optimal signaling through activation receptors. For the above reasons, recently, Siglecs have been described as glyco-immune checkpoints.

Through their interaction with sialylated glycans aberrantly expressed on tumor cells, innate immune cell-associated Siglecs trigger signaling cascades to inhibit immune system activation. Likewise, Siglecs upregulated on tumor cells interact with yet-to-be identified T-cell membrane glycoproteins to suppress T cell anti-tumor functions. On the positive side, however, inhibitory signaling through Siglecs curbs inflammation during cell death induced by viral infection. Despite these intriguing observations, the mechanisms underlying the above processes are just starting to be elucidated.

The overarching goal of this project is to use a combination of chemoenzymatic, biochemical, and genetic tools to explore Siglec-glycan ligand interactions and their therapeutic implications.

In Aim 1, we will design Siglec-based chimeric switch receptors and convert inhibitory Siglecs into activation receptors.

In Aim 2, we will use a cell-based glycan array platform to screen for high-affinity and specific ligands of Siglecs. Once identified, we will explore their utilities to suppress or harness the inhibitory Siglec signaling for therapeutic applications.

Finally, we will use our chemoenzymatic tools to investigate how the Siglec-cis ligand interaction is involved in mediating the Siglec-trans ligand interaction and accordingly immune cell activation (Aim 3).

Scripps Research Institute

TO ASSIST PUBLIC AND PRIVATE NONPROFIT INSTITUTIONS AND INDIVIDUALS TO ESTABLISH, EXPAND AND IMPROVE BIOMEDICAL RESEARCH AND RESEARCH TRAINING IN INFECTIOUS DISEASES AND RELATED AREAS, TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS. TO ASSIST PUBLIC, PRIVATE AND COMMERCIAL INSTITUTIONS TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS, TO PROVIDE RESEARCH SERVICES AS REQUIRED BY THE AGENCY FOR PROGRAMS IN INFECTIOUS DISEASES, AND CONTROLLING DISEASE CAUSED BY INFECTIOUS OR PARASITIC AGENTS, ALLERGIC AND IMMUNOLOGIC DISEASES AND RELATED AREAS. PROJECTS RANGE FROM STUDIES OF MICROBIAL PHYSIOLOGY AND ANTIGENIC STRUCTURE TO COLLABORATIVE TRIALS OF EXPERIMENTAL DRUGS AND VACCINES, MECHANISMS OF RESISTANCE TO ANTIBIOTICS AS WELL AS RESEARCH DEALING WITH EPIDEMIOLOGICAL OBSERVATIONS IN HOSPITALIZED PATIENTS OR COMMUNITY POPULATIONS AND PROGRESS IN ALLERGIC AND IMMUNOLOGIC DISEASES. BECAUSE OF THIS DUAL FOCUS, THE PROGRAM ENCOMPASSES BOTH BASIC RESEARCH AND CLINICAL RESEARCH. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM EXPANDS AND IMPROVES PRIVATE SECTOR PARTICIPATION IN BIOMEDICAL RESEARCH. THE SBIR PROGRAM INTENDS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM STIMULATES AND FOSTERS SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. RESEARCH CAREER DEVELOPMENT AWARDS SUPPORT THE DEVELOPMENT OF SCIENTISTS DURING THE FORMATIVE STAGES OF THEIR CAREERS. INDIVIDUAL NATIONAL RESEARCH SERVICE AWARDS (NRSAS) ARE MADE DIRECTLY TO APPROVE APPLICANTS FOR RESEARCH TRAINING IN SPECIFIED BIOMEDICAL SHORTAGE AREAS. IN ADDITION, INSTITUTIONAL NATIONAL RESEARCH SERVICE AWARDS ARE MADE TO ENABLE INSTITUTIONS TO SELECT AND MAKE AWARDS TO INDIVIDUALS TO RECEIVE TRAINING UNDER THE AEGIS OF THEIR INSTITUTIONAL PROGRAM.

93.855 - Allergy and Infectious Diseases Research

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

La Jolla, California 920371000 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 397% from $815,317 to $4,052,733.