# Tick saliva determinants of Borrelia burgdorferi transmission

> **NIH NIH R21** · TEXAS A&M AGRILIFE RESEARCH · 2020 · $217,959

## Abstract

Project Summary
Lyme disease caused by is the most prevalent human tick-borne disease in the United States. There is strong
evidence that tick transmission of Lyme disease agents is enhanced by tick saliva proteins. Human Lyme
disease is primarily associated with infectious bites of the blacklegged nymph ticks. However, the molecular
identities of Borrelia burgdorferi-infected blacklegged nymph tick salivary proteins and their functional roles in
transmission and promoting the Lyme disease agent infection of the host are not well defined. These data will
be critical to understanding molecular systems that control tick transmission of the Lyme disease agents, which
in turn will be important to developing the highly desired tick-antigen based transmission blocking vaccine to
prevent Lyme disease in humans. Therefore, the broad goals of this application are to utilize to identify and
define functions of tick saliva proteins that are associated with transmission of the Lyme disease agent. The
rationale for this approach is to identify tick saliva proteins that are induced or are differentially enhanced in
response to infection of nymphs. We plan to identify Borrelia burgdorferi infection responsive tick saliva
proteins over the 12-72 h feeding period when the Lyme disease agent is expected to be transmitted. The
novelty of our data is that we will determine both molecular identities and the timelines at which Bb infection
associated TSPs are injected into the host during the critical 12-72 h tick feeding period. We will juxtapose
these data against published tick feeding timelines of Borrelia burgdorferi transmission to identify early stage
tick feeding tick saliva proteins that precede major Borrelia burgdorferi transmission events, and middle/late
stage tick feeding tick saliva proteins that coincide with major transmission events. In the short-term, we will
undertake systematic RNAi silencing analysis to determine which of the two clusters of tick saliva proteins are
important to transmission and Borrelia burgdorferi infection. Data from this application will serve as the
foundation for our long-term goals to develop tick-antigen based Lyme disease agent transmission blocking
vaccines. We will test the hypothesis that Bb infection of the I. scapularis nymph tick will induce expression of
tick saliva proteins that promote transmission and Borrelia burgdorferi infection of the host, which if disrupted
will protect the host against Lyme disease. The goals of this research will be accomplished in two specific
aims: (i) to identify tick saliva proteins associated with transmission of Borrelia burgdorferi by Ixodes scapularis
nymph ticks, and (ii) to validate roles of Borrelia burgdorferi infection associated tick saliva proteins in Borrelia
burgdorferi transmission by ticks.

## Key facts

- **NIH application ID:** 9830582
- **Project number:** 5R21AI138129-02
- **Recipient organization:** TEXAS A&M AGRILIFE RESEARCH
- **Principal Investigator:** ALBERT MULENGA
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $217,959
- **Award type:** 5
- **Project period:** 2018-12-01 → 2022-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9830582

## Citation

> US National Institutes of Health, RePORTER application 9830582, Tick saliva determinants of Borrelia burgdorferi transmission (5R21AI138129-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9830582. Licensed CC0.

---

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