Figure 1.
Detection of hResistin expression in Nb-infected transgenic mice.
(A-B) hResistin expression in the lung and small intestine of naïve or Nb-infected mice was measured by real-time PCR analysis (A) or ELISA (B). (C) Quantification of hResistin expressing cells was performed on immunofluorescent stained lung sections. (D) IF staining for Griffonia simplicifolia lectin (red), hResistin (green), and DAPI (blue) was performed on lung tissue sections. Data (mean ± SEM, n = 4–6 per group) are representative of four separate experiments.
Figure 2.
Monocytes, neutrophils and alveolar macrophages express hResistin in Nb-infected lungs.
(A) Gating strategy for sorted lung cells from Nb-infected mice for CD11b+Ly6C+ monocytes, SiglecF+CD11c− eosinophils, CD11b+Ly6G+ neutrophils, and CD11c+F4/80+ alveolar macrophages and corresponding H&E stained cytospins. (B) Sorted cells were recovered for RNA and analyzed for hRetn by real-time PCR. Data (mean ± SEM, n = 3–4 per group) are representative of three separate experiments.
Figure 3.
Expression of hResistin exacerbates lung inflammation.
(A) hRetnTg− mice or hRetnTg+ mice were infected with Nb and weight loss was measured as a percentage of original weight. (B-C) Lung sections from naïve or Nb-infected mice were stained with H&E (B, scale bar = 200 µm) and pathology at day 7 post-infection was assessed by blind scoring (C). (D-E) At day 7 post infection, total BAL cells were quantified (D) and dissociated lung cells were recovered for flow cytometry analysis of Ly6C+ CD11b+ monocytes (E). Data (mean ± SEM, n = 4–6 per group) are representative of three separate experiments.
Figure 4.
hResistin promotes type 1 inflammation, TLR signaling and chemokines.
(A) Venn diagrams demonstrate infection-induced genes in hRetnTg− and hRetnTg+ mice. (B-C) Enriched biological pathways induced by hRetn were identified by (B) Gene Ontology and (C) KEGG annotations and represented as a graph and heatmap. (D) hRetn-induced TLR signaling and chemokine genes were validated by real-time PCR analysis of lung tissue. (E) Serum TNFα was quantified by ELISA. Data (mean ± SEM, n = 3–4 per group) are representative of two separate experiments.
Figure 5.
hResistin recruits inflammatory monocytes.
(A-B) Naïve BL/6 mice were treated with recombinant human resistin (500 ng) followed by flow cytometry analysis of CD115+ Ly6C+ inflammatory monocytes (A) and real-time PCR analysis of PEC RNA (B). Data (mean ± SEM, n = 3 per group) are representative of two separate experiments.
Figure 6.
Monocytes and neutrophils are the main cellular targets of hResistin during Nb infection.
(A-B) Lung cells from Nb-infected mice were incubated with recombinant hResistin followed by detection with α-hRetn to determine which cells can bind hResistin compared with control PBS (A). Surface expression of the hResistin-bound cells identified monocytes as the main cell-type that bound hResistin (B). (C) Sorted lung cells from Nb-infected hRetnTg− and hRetnTg+ mice were analyzed for proinflammatory gene expression by real-time PCR. Data (mean ± SEM, n = 3–4 per group) are representative of two separate experiments.
Figure 7.
hRetnTg+ mice are more susceptible to Nb infection.
(A-B) hRetnTg+ mice (black bars) and control hRetnTg− mice (white bars) were infected with 500 L3 Nb worms followed by parasitology analysis by fecal egg counts (A) or adult parasite numbers in the intestine at day 9 (B). Data (mean ± SEM, n = 4–6 per group) are representative of three separate experiments. (C) Serum hResistin concentration in hRetnTg+ mice is positively correlated with Nb worms at day 7 post-infection (n = 12).
Figure 8.
Expression of resistin in human patients infected with STH or filarial nematodes.
(A) Serum resistin from uninfected (n = 51) or STH-infected children (n = 49) was measured. (B) The fecal egg burdens in infected children was quantified as A. lumbricoides eggs per gram feces (alepg) and plotted against serum resistin and TNFα. (C) Proinflammatory cytokines were positively correlated with resistin in the serum of STH-infected children. (D) Serum from uninfected endemic normal individuals (n = 17) or patients infected with Wuchereria bancrofti (n = 44) was analyzed by ELISA for resistin. (E) In infected individuals, a positive correlation was observed between the circulating microfilariae and resistin or TNFα. (F) Proinflammatory cytokines were positively correlated with resistin levels in the serum of infected patients.
Table 1.
Many inflammatory factors are positively correlated with resistin in humans infected with soil-transmitted helminths or filarial nematodes.