Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection

Past studies with the live, double-mutant B. abortus (znBAZ) strain resulted in nearly complete protection of mice against pulmonary challenge with wild-type (wt) Brucella via a dominant CD8+ T cell response. To understand the contribution innate immune cells in priming CD8+ T cell responses, mice w...

Full description

Bibliographic Details
Main Authors: Ella Bhagyaraj, Hongbin Wang, Xinghong Yang, Carol Hoffman, Ali Akgul, Zakia I. Goodwin, David W. Pascual
Format: Article
Language:English
Published: Frontiers Media S.A. 2021-07-01
Series:Frontiers in Immunology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fimmu.2021.697953/full
_version_ 1818455577393627136
author Ella Bhagyaraj
Hongbin Wang
Xinghong Yang
Carol Hoffman
Ali Akgul
Zakia I. Goodwin
David W. Pascual
author_facet Ella Bhagyaraj
Hongbin Wang
Xinghong Yang
Carol Hoffman
Ali Akgul
Zakia I. Goodwin
David W. Pascual
author_sort Ella Bhagyaraj
collection DOAJ
description Past studies with the live, double-mutant B. abortus (znBAZ) strain resulted in nearly complete protection of mice against pulmonary challenge with wild-type (wt) Brucella via a dominant CD8+ T cell response. To understand the contribution innate immune cells in priming CD8+ T cell responses, mice were nasally dosed with wt B. abortus, smooth vaccine strain 19 (S19), or znBAZ, and examined for innate immune cell activation. Flow cytometric analysis revealed that znBAZ, but not wt B. abortus nor S19 infection, induces up to a 5-fold increase in the frequency of IFN-γ-producing NK cells in mouse lungs. These NK cells express increased CXCR3 and Ki67, indicating their recruitment and proliferation subsequent to znBAZ infection. Their activation status was augmented noted by the increased NKp46 and granzyme B, but decreased NKG2A expression. Further analysis demonstrated that both lung caspase-1+ inflammatory monocytes and monocyte-derived macrophages secrete chemokines and cytokines responsible for NK cell recruitment and activation. Moreover, neutralizing IL-18, an NK cell-activating cytokine, reduced the znBAZ-induced early NK cell response. NK cell depletion also significantly impaired lung dendritic cell (DC) activation and migration to the lower respiratory lymph nodes (LRLNs). Both lung DC activation and migration to LRLNs were significantly impaired in NK cell-depleted or IFN-γ-/- mice, particularly the CD11b+ and monocytic DC subsets. Furthermore, znBAZ vaccination significantly induced CD8+ T cells, and upon in vivo NK cell depletion, CD8+ T cells were reduced 3-fold compared to isotype-treated mice. In summary, these data show that znBAZ induces lung IFN-γ+ NK cells, which plays a critical role in influencing lung DC activation, migration, and promoting protective CD8+ T cell development.
first_indexed 2024-12-14T22:12:59Z
format Article
id doaj.art-a9226dfbc2354271bb2707727f93517f
institution Directory Open Access Journal
issn 1664-3224
language English
last_indexed 2024-12-14T22:12:59Z
publishDate 2021-07-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Immunology
spelling doaj.art-a9226dfbc2354271bb2707727f93517f2022-12-21T22:45:42ZengFrontiers Media S.A.Frontiers in Immunology1664-32242021-07-011210.3389/fimmu.2021.697953697953Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella InfectionElla BhagyarajHongbin WangXinghong YangCarol HoffmanAli AkgulZakia I. GoodwinDavid W. PascualPast studies with the live, double-mutant B. abortus (znBAZ) strain resulted in nearly complete protection of mice against pulmonary challenge with wild-type (wt) Brucella via a dominant CD8+ T cell response. To understand the contribution innate immune cells in priming CD8+ T cell responses, mice were nasally dosed with wt B. abortus, smooth vaccine strain 19 (S19), or znBAZ, and examined for innate immune cell activation. Flow cytometric analysis revealed that znBAZ, but not wt B. abortus nor S19 infection, induces up to a 5-fold increase in the frequency of IFN-γ-producing NK cells in mouse lungs. These NK cells express increased CXCR3 and Ki67, indicating their recruitment and proliferation subsequent to znBAZ infection. Their activation status was augmented noted by the increased NKp46 and granzyme B, but decreased NKG2A expression. Further analysis demonstrated that both lung caspase-1+ inflammatory monocytes and monocyte-derived macrophages secrete chemokines and cytokines responsible for NK cell recruitment and activation. Moreover, neutralizing IL-18, an NK cell-activating cytokine, reduced the znBAZ-induced early NK cell response. NK cell depletion also significantly impaired lung dendritic cell (DC) activation and migration to the lower respiratory lymph nodes (LRLNs). Both lung DC activation and migration to LRLNs were significantly impaired in NK cell-depleted or IFN-γ-/- mice, particularly the CD11b+ and monocytic DC subsets. Furthermore, znBAZ vaccination significantly induced CD8+ T cells, and upon in vivo NK cell depletion, CD8+ T cells were reduced 3-fold compared to isotype-treated mice. In summary, these data show that znBAZ induces lung IFN-γ+ NK cells, which plays a critical role in influencing lung DC activation, migration, and promoting protective CD8+ T cell development.https://www.frontiersin.org/articles/10.3389/fimmu.2021.697953/fullBrucelladendritic cellsmacrophagesIFN-γchemokinesCD8+ T cells
spellingShingle Ella Bhagyaraj
Hongbin Wang
Xinghong Yang
Carol Hoffman
Ali Akgul
Zakia I. Goodwin
David W. Pascual
Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
Frontiers in Immunology
Brucella
dendritic cells
macrophages
IFN-γ
chemokines
CD8+ T cells
title Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
title_full Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
title_fullStr Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
title_full_unstemmed Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
title_short Mucosal Vaccination Primes NK Cell-Dependent Development of CD8+ T Cells Against Pulmonary Brucella Infection
title_sort mucosal vaccination primes nk cell dependent development of cd8 t cells against pulmonary brucella infection
topic Brucella
dendritic cells
macrophages
IFN-γ
chemokines
CD8+ T cells
url https://www.frontiersin.org/articles/10.3389/fimmu.2021.697953/full
work_keys_str_mv AT ellabhagyaraj mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT hongbinwang mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT xinghongyang mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT carolhoffman mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT aliakgul mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT zakiaigoodwin mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection
AT davidwpascual mucosalvaccinationprimesnkcelldependentdevelopmentofcd8tcellsagainstpulmonarybrucellainfection