# MR1-dependent presentation of Mycobacterium tuberculosis: a unique role for calcium signaling

> **NIH NIH K08** · OREGON HEALTH & SCIENCE UNIVERSITY · 2022 · $185,544

## Abstract

Project Summary
The fundamental role of the immune system is to detect self from non-self. The detection and elimination of
microbial infection is critical for human survival. One challenge to the immune system is infection from an
intracellular microbe because the microbe masks its presence in a host cell. One strategy of the immune
system to detect microbes is the sampling of different kinds of antigens, such as peptides, lipids and
glycolipids, by antigen presenting molecules. A fundamentally unique arm of the immune system is MR1, which
is an antigen presenting molecule that is intracellular, ubiquitously expressed across tissues, and detects small
molecules derived from microbial metabolism. These features suggest that MR1 is poised to detect intracellular
microbes. MR1 presents antigens to MR1-restricted T cells. These T cells are highly prevalent in the lungs and
have the ability to kill infected cells. Because MR1 presents small molecule antigens and adopts an
intracellular distribution, the mechanisms governing MR1 sampling of the intracellular environment are distinct
from other antigen presenting molecules. Our hypothesis is that endosomal recycling and endosomal calcium
signaling are key for MR1-dependent antigen presentation, and that these features distinguish MR1 from MHC-
Ia antigen presentation. We use Mycobacterium tuberculosis (Mtb) as a model for intracellular infection and
have identified calcium-sensitive trafficking proteins and calcium channels important for MR1 antigen
presentation. In Aim 1, we will define the role of the endosomal trafficking protein Syntaxin 16 in MR1-
dependent antigen presentation. In Aim 2, we will define the role of calcium sensitive Synaptotagmins in MR1-
dependent antigen presentation. In Aim 3, we will identify the important calcium channels involved in this
process and examined the role of Two-pore channels. This research plan is part of a detailed training and
career development plan for the applicant. In addition to hands-on basic science research with an emphasis on
techniques such as measurement of intracellular calcium and live-cell fluorescence microscopy, the applicant
will complete coursework in scientific writing and biostatistics to expand scientific knowledge and will attend
scientific conferences to develop collaborations. Acquisition of all of these skills will lead to expertise in defining
intracellular signaling cascades in antigen presenting cells, with the goal of obtaining an R01 by the end of the
K08 award. The primary mentor has a long track record of training scientists and a Mentoring Committee will
track the applicant's progress and contribute to the applicant's development as a scientist. Finally, the
sponsoring institution, Oregon Health & Science University, has all the facilities and support necessary to
support the proposal.

## Key facts

- **NIH application ID:** 10415103
- **Project number:** 5K08AI153359-03
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** Elham Karamooz
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $185,544
- **Award type:** 5
- **Project period:** 2020-06-01 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10415103

## Citation

> US National Institutes of Health, RePORTER application 10415103, MR1-dependent presentation of Mycobacterium tuberculosis: a unique role for calcium signaling (5K08AI153359-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10415103. Licensed CC0.

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