Habib, S and El Andaloussi, A and Hisham, A and Ismail, N
(2016)
NK cell-mediated regulation of protective memory responses against intracellular ehrlichial pathogens.
PLoS ONE, 11 (4).
Abstract
Ehrlichiae are gram-negative obligate intracellular bacteria that cause potentially fatal human monocytic ehrlichiosis. We previously showed that natural killer (NK) cells play a critical role in host defense against Ehrlichia during primary infection. However, the contribution of NK cells to the memory response against Ehrlichia remains elusive. Primary infection of C57BL/6 mice with Ehrlichia muris provides long-term protection against a second challenge with the highly virulent Ixodes ovatus Ehrlichia (IOE), which ordinarily causes fatal disease in naïve mice. Here, we show that the depletion of NK cells in E. muris-primed mice abrogates the protective memory response against IOE. Approximately, 80% of NK cell-depleted E. muris-primed mice succumbed to lethal IOE infection on days 8-10 after IOE infection, similar to naïve mice infected with the same dose of IOE. The lack of a recall response in NK cell-depleted mice correlated with an increased bacterial burden, extensive liver injury, decreased frequency of Ehrlichia-specific IFN-γ-producing memory CD4+ and CD8+ T-cells, and a low titer of Ehrlichia-specific antibodies. Intraperitoneal infection of mice with E. muris resulted in the production of IL-15, IL-12, and IFN-γ as well as an expansion of activated NKG2D+ NK cells. The adoptive transfer of purified E. muris-primed hepatic and splenic NK cells into Rag2-/-Il2rg-/-recipient mice provided protective immunity against challenge with E. muris. Together, these data suggest that E. muris-induced memory-like NK cells, which contribute to the protective, recall response against Ehrlichia.
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Item Type: |
Article
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Status: |
Published |
Creators/Authors: |
Creators | Email | Pitt Username | ORCID  |
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Habib, S | | | | El Andaloussi, A | | | | Hisham, A | | | | Ismail, N | nai13@pitt.edu | NAI13 | |
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Contributors: |
Contribution | Contributors Name | Email | Pitt Username | ORCID  |
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Editor | Ganta, Roman R. | UNSPECIFIED | UNSPECIFIED | UNSPECIFIED |
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Date: |
1 April 2016 |
Date Type: |
Publication |
Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
Journal or Publication Title: |
PLoS ONE |
Volume: |
11 |
Number: |
4 |
DOI or Unique Handle: |
10.1371/journal.pone.0153223 |
Institution: |
University of Pittsburgh |
Schools and Programs: |
School of Medicine > Pathology |
Refereed: |
Yes |
Date Deposited: |
31 Aug 2016 17:31 |
Last Modified: |
22 Jun 2021 11:55 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/28268 |
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