Immunoproteomic mechanisms of human macrophage resistance to Mycobacterium tuberculosis infection

PROJECT SUMMARY / ABSTRACT
Tuberculosis (TB) is the leading infectious killer worldwide. Upon exposure to Mycobacterium tuberculosis
(Mtb), most people develop asymptomatic latent TB infection (LTBI phenotype). However, Dr. Anterasian's
collaborators identified about 7% of individuals who, despite household exposure to pulmonary TB, do not
convert their tuberculin skin test (TST) or interferon-γ release assay (IGRA), and thus can be classified as
clinically resistant to traditionally defined LTBI (“RSTR” phenotype). Uncovering mechanisms of natural
resistance to Mtb infection may provide unique insights that can inform the development of host-directed
therapeutics (HDTs). Dr. Anterasian has analyzed the first global proteomic dataset of Mtb-infected primary
human macrophages and discovered 46 differentially abundant proteins (DAPs) that define the RSTR vs LTBI
macrophage proteomic response to Mtb. By integrating her data with those of her collaborators, Dr. Anterasian
has identified DAPs that may undergo Mtb-induced post-translational modifications (PTMs) and/or interact with
Mtb bacterial proteins. She has also used bioinformatic network analyses as well as genetic and transcriptomic
data from the same patient cohort to ultimately curate a list of 19 proteins for further mechanistic studies. In
particular, the Rab family of GTPases interact with Mtb bacterial proteins, undergo Mtb-induced ubiquitination,
and are key regulators of membrane trafficking and autophagy, which are pathways Mtb exploits during
infection. The objective of this proposal is to define macrophage pathways and proteins that characterize the
protective RSTR response. Dr. Anterasian hypothesizes that RSTR individuals promote macrophage Mtb
clearance through DAP-mediated pathways modulated by DAP-Mtb protein interactions and differential DAP
ubiquitination. In Aim 1, Dr. Anterasian will investigate Rab-dependent mechanisms of protection against Mtb
in macrophages and how Mtb proteins subvert Rab function. In Aim 2, Dr. Anterasian will identify candidate
proteins associated with control of Mtb infection, their PTMs, and ubiquitin-dependent mechanisms of
resistance. By combining proteomic, bioinformatic, and cellular immunology approaches, Dr. Anterasian is well
poised to identify key pathways in human macrophage resistance to Mtb that can be targeted with HDTs.
Dr. Anterasian is a Pediatric Infectious Disease Fellow in the Division of Infectious Diseases at Seattle
Children's Hospital and the University of Washington. She additionally proposes a comprehensive career
development program that includes: 1) mentored training in proteomics and cellular immunology; 2) formal
didactics in large data set analyses (i.e. proteomics, statistical genetics, systems biology); 3) mentorship in the
design of proteomic studies, human subjects research, and scientific writing; 4) structured opportunities to
present her work to local and international scientific audiences; and 5) Scientific Advisory Committee meetings
that ensure scientific and career development progress. By the conclusion of this award, Dr. Anterasian will
transition to an independently-funded expert in the Mtb host response who will direct her own laboratory.

Grant Number: 5K08AI163381-05
NIH Institute/Center: NIH
Principal Investigator: Christine Anterasian