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Mucosal-Associated Invariant T Cells in the Human Gastric Mucosa and Blood: Role in Helicobacter pylori Infection.

Booth JS, Salerno-Goncalves R, Blanchard TG, Patil SA, Kader HA, Safta AM, Morningstar LM, Czinn SJ, Greenwald BD, Sztein MB - Front Immunol (2015)

Bottom Line: We found that CD8(+) and CD4(-)CD8(-) (double negative) MAIT cell subsets respond to H. pylori-infected macrophages stimulation in a MR-1 restrictive manner by producing cytokines (IFN-γ, TNF-α, IL-17A) and exhibiting cytotoxic activity.Interestingly, we observed that blood MAIT cell frequency in Hp(+ve) individuals was significantly lower than in Hp(-ve) individuals.However, gastric MAIT cell frequency was not significantly different between Hp(+ve) and Hp(-ve) individuals, demonstrating a dichotomy between blood and gastric tissues.

View Article: PubMed Central - PubMed

Affiliation: Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA ; Department of Pediatrics, University of Maryland School of Medicine , Baltimore, MD , USA.

ABSTRACT
Mucosal-associated invariant T (MAIT) cells represent a class of antimicrobial innate-like T cells that have been characterized in human blood, liver, lungs, and intestine. Here, we investigated, for the first time, the presence of MAIT cells in the stomach of children, adults, and the elderly undergoing routine endoscopy and assessed their reactivity to Helicobacter pylori (H. pylori - Hp), a major gastric pathogen. We observed that MAIT cells are present in the lamina propria compartment of the stomach and display a similar memory phenotype to blood MAIT cells. We then demonstrated that gastric and blood MAIT cells are able to recognize H. pylori. We found that CD8(+) and CD4(-)CD8(-) (double negative) MAIT cell subsets respond to H. pylori-infected macrophages stimulation in a MR-1 restrictive manner by producing cytokines (IFN-γ, TNF-α, IL-17A) and exhibiting cytotoxic activity. Interestingly, we observed that blood MAIT cell frequency in Hp(+ve) individuals was significantly lower than in Hp(-ve) individuals. However, gastric MAIT cell frequency was not significantly different between Hp(+ve) and Hp(-ve) individuals, demonstrating a dichotomy between blood and gastric tissues. Further, we observed that the majority of gastric MAIT cells (>80%) expressed tissue-resident markers (CD69(+) CD103(+)), which were only marginally present on PBMC MAIT cells (<3%), suggesting that gastric MAIT cells are readily available to respond quickly to pathogens. These results contribute important new information to the understanding of MAIT cells function on peripheral and mucosal tissues and its possible implications in the host response to H. pylori.

No MeSH data available.


MR1 restriction of responses by blood MAIT CD8+ and CD4−CD8− DN subsets from healthy adults to H. pylori-infected primary autologous macrophages. Representative volunteer showing the induction of cytokine production (IFN-γ and TNF-α) and up-regulation of CD107a expression in (A) CD8+ and (B) DN MAIT cell subsets following stimulation with non-infected primary autologous macrophages (Mϕ); H. pylori-infected primary autologous Mϕ (E:T 5:1 ratio); H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + α-MR1 (26.5 monoclonal ab) (10 μg/ml); or H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + isotype control (10 μg/ml). Cumulative data (n = 5) showing MR1-restricted production of IFN-γ, TNF-α, and expression of CD107a by (C) CD8+ and (D) DN MAIT cells following stimulation with the four treatments described above. The % of responses compared to media control (% of media control) was calculated as (cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary autologous macrophages containing either α-MR1 or IC)/(cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary macrophages) × 100. Horizontal black lines in (B,D) represent medians. Significant differences are denoted by asterisks (*P < 0.05; **P < 0.005).
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Figure 6: MR1 restriction of responses by blood MAIT CD8+ and CD4−CD8− DN subsets from healthy adults to H. pylori-infected primary autologous macrophages. Representative volunteer showing the induction of cytokine production (IFN-γ and TNF-α) and up-regulation of CD107a expression in (A) CD8+ and (B) DN MAIT cell subsets following stimulation with non-infected primary autologous macrophages (Mϕ); H. pylori-infected primary autologous Mϕ (E:T 5:1 ratio); H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + α-MR1 (26.5 monoclonal ab) (10 μg/ml); or H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + isotype control (10 μg/ml). Cumulative data (n = 5) showing MR1-restricted production of IFN-γ, TNF-α, and expression of CD107a by (C) CD8+ and (D) DN MAIT cells following stimulation with the four treatments described above. The % of responses compared to media control (% of media control) was calculated as (cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary autologous macrophages containing either α-MR1 or IC)/(cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary macrophages) × 100. Horizontal black lines in (B,D) represent medians. Significant differences are denoted by asterisks (*P < 0.05; **P < 0.005).

Mentions: Given that MAIT cells detect bacterially derived antigens presented by the MHC-like molecule MR-1, we next investigated whether responses to H. pylori-infected human primary autologous macrophages by CD8+ and DN MAIT cell subsets were MR-1 restricted. To address this question, H. pylori-infected primary autologous macrophages were incubated with neutralizing anti-human MR-1 antibodies or matched isotype controls to block the cytokine responses (IFN-γ and TNF-α) and/or expression of CD107a elicited in MAIT cells subsets. We observed that blocking of MR-1 using a mouse anti-human monoclonal antibody (clone 26.5; Figure 6A) resulted in significantly decreased production of cytokines (IFN-γ and TNF-α) and expression of CD107a by CD8+ (Figure 6A) and DN MAIT cell subsets (Figure 6B) when compared to cultures with H. pylori-infected autologous targets only. In contrast, the addition of a matched isotype (IC) control failed to significantly decrease the production of cytokines and expression of CD107 by CD8+ (Figure 6A) or DN (CD4−CD8−) (Figure 6B) MAIT cells recorded in cultures exposed to H. pylori-infected autologous targets. Cumulative data (n = 5) showed significant suppression in the production of cytokines (IFN-γ and TNF-α) and expression of CD107 by both MAIT cells subsets (CD8+ and DN) following blocking with MR-1 antibody but not with a matched isotype control (Figures 6C,D). These results indicate that both MAIT cell subsets detect and respond to H. pylori-infected primary autologous macrophages and that this effect is MR-1 restricted.


Mucosal-Associated Invariant T Cells in the Human Gastric Mucosa and Blood: Role in Helicobacter pylori Infection.

Booth JS, Salerno-Goncalves R, Blanchard TG, Patil SA, Kader HA, Safta AM, Morningstar LM, Czinn SJ, Greenwald BD, Sztein MB - Front Immunol (2015)

MR1 restriction of responses by blood MAIT CD8+ and CD4−CD8− DN subsets from healthy adults to H. pylori-infected primary autologous macrophages. Representative volunteer showing the induction of cytokine production (IFN-γ and TNF-α) and up-regulation of CD107a expression in (A) CD8+ and (B) DN MAIT cell subsets following stimulation with non-infected primary autologous macrophages (Mϕ); H. pylori-infected primary autologous Mϕ (E:T 5:1 ratio); H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + α-MR1 (26.5 monoclonal ab) (10 μg/ml); or H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + isotype control (10 μg/ml). Cumulative data (n = 5) showing MR1-restricted production of IFN-γ, TNF-α, and expression of CD107a by (C) CD8+ and (D) DN MAIT cells following stimulation with the four treatments described above. The % of responses compared to media control (% of media control) was calculated as (cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary autologous macrophages containing either α-MR1 or IC)/(cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary macrophages) × 100. Horizontal black lines in (B,D) represent medians. Significant differences are denoted by asterisks (*P < 0.05; **P < 0.005).
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Figure 6: MR1 restriction of responses by blood MAIT CD8+ and CD4−CD8− DN subsets from healthy adults to H. pylori-infected primary autologous macrophages. Representative volunteer showing the induction of cytokine production (IFN-γ and TNF-α) and up-regulation of CD107a expression in (A) CD8+ and (B) DN MAIT cell subsets following stimulation with non-infected primary autologous macrophages (Mϕ); H. pylori-infected primary autologous Mϕ (E:T 5:1 ratio); H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + α-MR1 (26.5 monoclonal ab) (10 μg/ml); or H. pylori-infected primary autologous Mϕ (E:T – 5:1 ratio) + isotype control (10 μg/ml). Cumulative data (n = 5) showing MR1-restricted production of IFN-γ, TNF-α, and expression of CD107a by (C) CD8+ and (D) DN MAIT cells following stimulation with the four treatments described above. The % of responses compared to media control (% of media control) was calculated as (cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary autologous macrophages containing either α-MR1 or IC)/(cytokine production/CD107 expression in cells stimulated with H. pylori-infected primary macrophages) × 100. Horizontal black lines in (B,D) represent medians. Significant differences are denoted by asterisks (*P < 0.05; **P < 0.005).
Mentions: Given that MAIT cells detect bacterially derived antigens presented by the MHC-like molecule MR-1, we next investigated whether responses to H. pylori-infected human primary autologous macrophages by CD8+ and DN MAIT cell subsets were MR-1 restricted. To address this question, H. pylori-infected primary autologous macrophages were incubated with neutralizing anti-human MR-1 antibodies or matched isotype controls to block the cytokine responses (IFN-γ and TNF-α) and/or expression of CD107a elicited in MAIT cells subsets. We observed that blocking of MR-1 using a mouse anti-human monoclonal antibody (clone 26.5; Figure 6A) resulted in significantly decreased production of cytokines (IFN-γ and TNF-α) and expression of CD107a by CD8+ (Figure 6A) and DN MAIT cell subsets (Figure 6B) when compared to cultures with H. pylori-infected autologous targets only. In contrast, the addition of a matched isotype (IC) control failed to significantly decrease the production of cytokines and expression of CD107 by CD8+ (Figure 6A) or DN (CD4−CD8−) (Figure 6B) MAIT cells recorded in cultures exposed to H. pylori-infected autologous targets. Cumulative data (n = 5) showed significant suppression in the production of cytokines (IFN-γ and TNF-α) and expression of CD107 by both MAIT cells subsets (CD8+ and DN) following blocking with MR-1 antibody but not with a matched isotype control (Figures 6C,D). These results indicate that both MAIT cell subsets detect and respond to H. pylori-infected primary autologous macrophages and that this effect is MR-1 restricted.

Bottom Line: We found that CD8(+) and CD4(-)CD8(-) (double negative) MAIT cell subsets respond to H. pylori-infected macrophages stimulation in a MR-1 restrictive manner by producing cytokines (IFN-γ, TNF-α, IL-17A) and exhibiting cytotoxic activity.Interestingly, we observed that blood MAIT cell frequency in Hp(+ve) individuals was significantly lower than in Hp(-ve) individuals.However, gastric MAIT cell frequency was not significantly different between Hp(+ve) and Hp(-ve) individuals, demonstrating a dichotomy between blood and gastric tissues.

View Article: PubMed Central - PubMed

Affiliation: Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA ; Department of Pediatrics, University of Maryland School of Medicine , Baltimore, MD , USA.

ABSTRACT
Mucosal-associated invariant T (MAIT) cells represent a class of antimicrobial innate-like T cells that have been characterized in human blood, liver, lungs, and intestine. Here, we investigated, for the first time, the presence of MAIT cells in the stomach of children, adults, and the elderly undergoing routine endoscopy and assessed their reactivity to Helicobacter pylori (H. pylori - Hp), a major gastric pathogen. We observed that MAIT cells are present in the lamina propria compartment of the stomach and display a similar memory phenotype to blood MAIT cells. We then demonstrated that gastric and blood MAIT cells are able to recognize H. pylori. We found that CD8(+) and CD4(-)CD8(-) (double negative) MAIT cell subsets respond to H. pylori-infected macrophages stimulation in a MR-1 restrictive manner by producing cytokines (IFN-γ, TNF-α, IL-17A) and exhibiting cytotoxic activity. Interestingly, we observed that blood MAIT cell frequency in Hp(+ve) individuals was significantly lower than in Hp(-ve) individuals. However, gastric MAIT cell frequency was not significantly different between Hp(+ve) and Hp(-ve) individuals, demonstrating a dichotomy between blood and gastric tissues. Further, we observed that the majority of gastric MAIT cells (>80%) expressed tissue-resident markers (CD69(+) CD103(+)), which were only marginally present on PBMC MAIT cells (<3%), suggesting that gastric MAIT cells are readily available to respond quickly to pathogens. These results contribute important new information to the understanding of MAIT cells function on peripheral and mucosal tissues and its possible implications in the host response to H. pylori.

No MeSH data available.