# Functional and Mechanistic Studies of the VlsE-mediated Immune Avoidance System in the Lyme Disease Spirochete

> **NIH NIH R21** · WASHINGTON STATE UNIVERSITY · 2021 · $191,250

## Abstract

Project Summary
 A key mechanism for immune evasion and persistent infection by the Lyme disease spirochete, Borrelia
burgdorferi, is antigenic variation of the VlsE surface protein. Despite the presence of a substantial number of
additional proteins residing on the bacterial surface, VlsE is the only antigen that exhibits ongoing variation of
its exposed epitopes. Recent work in our lab has identified a VlsE-mediated immune avoidance system that
allows non-VlsE surface antigens to escape the killing effects of host antibodies. Moreover, we have identified
the Arp lipoprotein as one such surface antigen that benefits from VlsE-mediated immune protection. Despite
this important evidence, certain functional and mechanistic aspects involved in this system are still unknown.
Our long-term goals are to determine the mechanism and overall implications of surface antigen protection
promoted by the VlsE lipoprotein during host infection by B. burgdorferi. The objective of this application is to
decipher the functional details of factors involved in VlsE-mediated immune avoidance, and identify any
additional B. burgdorferi surface antigens that are shielded by VlsE. Based on published studies and
preliminary findings, our central hypothesis is that VlsE exists establishes protein-protein interactions with Arp
and other proteins on the B. burgdorferi cell surface. Additionally, we hypothesize that the presence of VlsE
functions to dampen the antibody response to Arp. The rationale for the proposed research is that identifying
the functional details of this system will provide the knowledge required to design downstream studies targeted
at dissecting the overall mechanism. Together, the proposed research is relevant to NIH’s mission that pertains
to developing fundamental knowledge that will potentially help to reduce the burdens of human illness and
disability.
 Guided by preliminary findings, our hypotheses will be tested by pursuing two specific aims: 1)
Determine whether VlsE directly interacts with Arp and other B. burgdorferi cell surface proteins; and 2)
Determine whether the presence of VlsE modulates the antibody response to Arp. Under the first aim, a
specialized in vivo crosslinking/elution technique will be used to detect protein-protein interactions between
mutant VlsE and Arp, and to identify novel VlsE binding partners. Under the second aim, qRT-PCR will be
utilized to quantitate the relative arp expression levels during host infection by a VlsE-deficient clone compared
to a wild type control, and anti-Arp antibody titers in mice infected with clones expressing or lacking VlsE will
be assessed by ELISA. The proposed work is innovative, because it utilizes a new VlsE/Arp over-expresser
clone to analyze potential VlsE-Arp interactions, and uses the Arp lipoprotein as a readout for VlsE protection
assays. Overall, these studies will significantly advance our knowledge of immune evasion by B. burgdorferi,
and provide more useful strategies to pre...

## Key facts

- **NIH application ID:** 10125672
- **Project number:** 1R21AI148701-01A1
- **Recipient organization:** WASHINGTON STATE UNIVERSITY
- **Principal Investigator:** Troy Michael Bankhead
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $191,250
- **Award type:** 1
- **Project period:** 2021-03-13 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10125672

## Citation

> US National Institutes of Health, RePORTER application 10125672, Functional and Mechanistic Studies of the VlsE-mediated Immune Avoidance System in the Lyme Disease Spirochete (1R21AI148701-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10125672. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*