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Retnla (relmalpha/fizz1) suppresses helminth-induced Th2-type immunity.

Pesce JT, Ramalingam TR, Wilson MS, Mentink-Kane MM, Thompson RW, Cheever AW, Urban JF, Wynn TA - PLoS Pathog. (2009)

Bottom Line: Retnla (Resistin-like molecule alpha/FIZZ1) is induced during Th2 cytokine immune responses.However, the role of Retnla in Th2-type immunity is unknown.The number of granuloma-associated eosinophils and serum IgE titers were also enhanced.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.

ABSTRACT
Retnla (Resistin-like molecule alpha/FIZZ1) is induced during Th2 cytokine immune responses. However, the role of Retnla in Th2-type immunity is unknown. Here, using Retnla(-/-) mice and three distinct helminth models, we show that Retnla functions as a negative regulator of Th2 responses. Pulmonary granuloma formation induced by the eggs of the helminth parasite Schistosoma mansoni is dependent on IL-4 and IL-13 and associated with marked increases in Retnla expression. We found that both primary and secondary pulmonary granuloma formation were exacerbated in the absence of Retlna. The number of granuloma-associated eosinophils and serum IgE titers were also enhanced. Moreover, when chronically infected with S. mansoni cercariae, Retnla(-/-) mice displayed significant increases in granulomatous inflammation in the liver and the development of fibrosis and progression to hepatosplenic disease was markedly augmented. Finally, Retnla(-/-) mice infected with the gastrointestinal (GI) parasite Nippostrongylus brasiliensis had intensified lung pathology to migrating larvae, reduced fecundity, and accelerated expulsion of adult worms from the intestine, suggesting Th2 immunity was enhanced. When their immune responses were compared, helminth infected Retnla(-/-) mice developed stronger Th2 responses, which could be reversed by exogenous rRelmalpha treatment. Studies with several cytokine knockout mice showed that expression of Retnla was dependent on IL-4 and IL-13 and inhibited by IFN-gamma, while tissue localization and cell isolation experiments indicated that eosinophils and epithelial cells were the primary producers of Retnla in the liver and lung, respectively. Thus, the Th2-inducible gene Retnla suppresses resistance to GI nematode infection, pulmonary granulomatous inflammation, and fibrosis by negatively regulating Th2-dependent responses.

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Retnla is localized to granuloma-associated eosinophils in the liver.Control WT C57BL/6 mice (n = 5) were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 and 12 post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla, Retnlb, Retn, and Retnlg (A). Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Livers from naïve Retnla−/− mice (B) and Retnla−/− mice infected with 30–35 cercariae for 9 (C) and 12 wk (D) were snap frozen and embedded in OCT. In situ Retnla expression was evaluated by LacZ reporter activity (blue precipitate) in frozen tissue sections exposed to β-galactosidase substrate, X-gal. Original magnification ×10 (B, C) and ×20 (D). (E) WT C57BL/6 mice were infected with 35 S. mansoni cercariae and on week 9, eosinophils were purified from perfused livers by positive selection using the Siglec-F antibody. The granuloma-associated leukocytes were separated into nonfractionated, Siglec-F− (eosinophil-negative), and Siglec-F+ (eosinophil-positive) fraction, mRNA was isolated, and then analyzed by real-time PCR analysis for Retnla. The data shown are means±SEM (n = 5/group). (F) WT C57BL/6 mice and IL-5−/− mice were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 (WT n = 9, IL-5−/− n = 10) and 12 (WT n = 6, IL-5−/− n = 8) post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla. Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Similar results were obtained in two repeat experiments.
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ppat-1000393-g004: Retnla is localized to granuloma-associated eosinophils in the liver.Control WT C57BL/6 mice (n = 5) were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 and 12 post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla, Retnlb, Retn, and Retnlg (A). Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Livers from naïve Retnla−/− mice (B) and Retnla−/− mice infected with 30–35 cercariae for 9 (C) and 12 wk (D) were snap frozen and embedded in OCT. In situ Retnla expression was evaluated by LacZ reporter activity (blue precipitate) in frozen tissue sections exposed to β-galactosidase substrate, X-gal. Original magnification ×10 (B, C) and ×20 (D). (E) WT C57BL/6 mice were infected with 35 S. mansoni cercariae and on week 9, eosinophils were purified from perfused livers by positive selection using the Siglec-F antibody. The granuloma-associated leukocytes were separated into nonfractionated, Siglec-F− (eosinophil-negative), and Siglec-F+ (eosinophil-positive) fraction, mRNA was isolated, and then analyzed by real-time PCR analysis for Retnla. The data shown are means±SEM (n = 5/group). (F) WT C57BL/6 mice and IL-5−/− mice were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 (WT n = 9, IL-5−/− n = 10) and 12 (WT n = 6, IL-5−/− n = 8) post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla. Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Similar results were obtained in two repeat experiments.

Mentions: To determine whether Retnla is expressed during chronic Th2-dominated responses, we infected mice percutaneously with S. mansoni cercariae and analyzed their pathological reactions at both acute (9 wk, 3–4 wk after egg laying commences) and chronic time points (≥12 wk) following infection. As observed in the pulmonary granuloma studies, there was a marked upregulation of Retnla, Retnlb, and Retnlg mRNA expression in the livers of infected C57BL/6 mice, with peak expression for all three genes peaking at 12 wk after infection (Fig. 4A). In contrast to the other Relm family members, Retn was not induced in the liver during S. mansoni infection. In addition, as predicted from the mRNA results, there was little to no positive Retnla protein expressed (β-galactosidase staining) in the livers of naïve mice (Fig. 4B). Following infection, however, the Retnla reporter mice showed significant β-gal activity in the liver at both 9 (Fig. 4C) and 12 wk (Fig. 4D). In contrast to the lung granuloma studies where β-gal activity was localized to the lung parenchyma in areas outside the granulomas (Fig. 2C), staining in infected livers was concentrated in the egg-induced lesions where inflammatory cells were located (Fig. 4C and 4D).


Retnla (relmalpha/fizz1) suppresses helminth-induced Th2-type immunity.

Pesce JT, Ramalingam TR, Wilson MS, Mentink-Kane MM, Thompson RW, Cheever AW, Urban JF, Wynn TA - PLoS Pathog. (2009)

Retnla is localized to granuloma-associated eosinophils in the liver.Control WT C57BL/6 mice (n = 5) were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 and 12 post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla, Retnlb, Retn, and Retnlg (A). Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Livers from naïve Retnla−/− mice (B) and Retnla−/− mice infected with 30–35 cercariae for 9 (C) and 12 wk (D) were snap frozen and embedded in OCT. In situ Retnla expression was evaluated by LacZ reporter activity (blue precipitate) in frozen tissue sections exposed to β-galactosidase substrate, X-gal. Original magnification ×10 (B, C) and ×20 (D). (E) WT C57BL/6 mice were infected with 35 S. mansoni cercariae and on week 9, eosinophils were purified from perfused livers by positive selection using the Siglec-F antibody. The granuloma-associated leukocytes were separated into nonfractionated, Siglec-F− (eosinophil-negative), and Siglec-F+ (eosinophil-positive) fraction, mRNA was isolated, and then analyzed by real-time PCR analysis for Retnla. The data shown are means±SEM (n = 5/group). (F) WT C57BL/6 mice and IL-5−/− mice were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 (WT n = 9, IL-5−/− n = 10) and 12 (WT n = 6, IL-5−/− n = 8) post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla. Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Similar results were obtained in two repeat experiments.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2663845&req=5

ppat-1000393-g004: Retnla is localized to granuloma-associated eosinophils in the liver.Control WT C57BL/6 mice (n = 5) were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 and 12 post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla, Retnlb, Retn, and Retnlg (A). Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Livers from naïve Retnla−/− mice (B) and Retnla−/− mice infected with 30–35 cercariae for 9 (C) and 12 wk (D) were snap frozen and embedded in OCT. In situ Retnla expression was evaluated by LacZ reporter activity (blue precipitate) in frozen tissue sections exposed to β-galactosidase substrate, X-gal. Original magnification ×10 (B, C) and ×20 (D). (E) WT C57BL/6 mice were infected with 35 S. mansoni cercariae and on week 9, eosinophils were purified from perfused livers by positive selection using the Siglec-F antibody. The granuloma-associated leukocytes were separated into nonfractionated, Siglec-F− (eosinophil-negative), and Siglec-F+ (eosinophil-positive) fraction, mRNA was isolated, and then analyzed by real-time PCR analysis for Retnla. The data shown are means±SEM (n = 5/group). (F) WT C57BL/6 mice and IL-5−/− mice were infected with 30–35 S. mansoni cercariae percutaneously. Mice were sacrificed at weeks 9 (WT n = 9, IL-5−/− n = 10) and 12 (WT n = 6, IL-5−/− n = 8) post infection and liver RNA specimens were prepared individually for real-time PCR analysis of Retnla. Gene expression (mean±SEM) is expressed as the fold-increase over naïve WT controls after normalization to HPRT. Similar results were obtained in two repeat experiments.
Mentions: To determine whether Retnla is expressed during chronic Th2-dominated responses, we infected mice percutaneously with S. mansoni cercariae and analyzed their pathological reactions at both acute (9 wk, 3–4 wk after egg laying commences) and chronic time points (≥12 wk) following infection. As observed in the pulmonary granuloma studies, there was a marked upregulation of Retnla, Retnlb, and Retnlg mRNA expression in the livers of infected C57BL/6 mice, with peak expression for all three genes peaking at 12 wk after infection (Fig. 4A). In contrast to the other Relm family members, Retn was not induced in the liver during S. mansoni infection. In addition, as predicted from the mRNA results, there was little to no positive Retnla protein expressed (β-galactosidase staining) in the livers of naïve mice (Fig. 4B). Following infection, however, the Retnla reporter mice showed significant β-gal activity in the liver at both 9 (Fig. 4C) and 12 wk (Fig. 4D). In contrast to the lung granuloma studies where β-gal activity was localized to the lung parenchyma in areas outside the granulomas (Fig. 2C), staining in infected livers was concentrated in the egg-induced lesions where inflammatory cells were located (Fig. 4C and 4D).

Bottom Line: Retnla (Resistin-like molecule alpha/FIZZ1) is induced during Th2 cytokine immune responses.However, the role of Retnla in Th2-type immunity is unknown.The number of granuloma-associated eosinophils and serum IgE titers were also enhanced.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.

ABSTRACT
Retnla (Resistin-like molecule alpha/FIZZ1) is induced during Th2 cytokine immune responses. However, the role of Retnla in Th2-type immunity is unknown. Here, using Retnla(-/-) mice and three distinct helminth models, we show that Retnla functions as a negative regulator of Th2 responses. Pulmonary granuloma formation induced by the eggs of the helminth parasite Schistosoma mansoni is dependent on IL-4 and IL-13 and associated with marked increases in Retnla expression. We found that both primary and secondary pulmonary granuloma formation were exacerbated in the absence of Retlna. The number of granuloma-associated eosinophils and serum IgE titers were also enhanced. Moreover, when chronically infected with S. mansoni cercariae, Retnla(-/-) mice displayed significant increases in granulomatous inflammation in the liver and the development of fibrosis and progression to hepatosplenic disease was markedly augmented. Finally, Retnla(-/-) mice infected with the gastrointestinal (GI) parasite Nippostrongylus brasiliensis had intensified lung pathology to migrating larvae, reduced fecundity, and accelerated expulsion of adult worms from the intestine, suggesting Th2 immunity was enhanced. When their immune responses were compared, helminth infected Retnla(-/-) mice developed stronger Th2 responses, which could be reversed by exogenous rRelmalpha treatment. Studies with several cytokine knockout mice showed that expression of Retnla was dependent on IL-4 and IL-13 and inhibited by IFN-gamma, while tissue localization and cell isolation experiments indicated that eosinophils and epithelial cells were the primary producers of Retnla in the liver and lung, respectively. Thus, the Th2-inducible gene Retnla suppresses resistance to GI nematode infection, pulmonary granulomatous inflammation, and fibrosis by negatively regulating Th2-dependent responses.

Show MeSH
Related in: MedlinePlus