Particulate Matter Immunomodulatory Effects on Autoantibody Development in New Zealand Mixed Mice

Figures & data

1 Survival of saline (█) (n = 6), acid-washed PM 1648 (▴) (n = 6), PM 1648 (▾) (n = 5) and PM_2.5 (♦) (n = 4) exposed NZM mice. AW PM 1648 = Acid-washed PM 1648.

2 Representative examples of Gomori trichrome staining of (a) saline, (b) acid-washed PM 1648, (c) PM 1648, and (d) PM_2.5 exposed NZM mice 17 weeks following exposure. The PM 1648 and PM_2.5 exposed NZM mice showed increases in fibrosis and collagen deposition represented by the blue staining of collagen. Saline exposed NZM mice had minimal collagen deposition.

3 Representative examples of H&E staining of (a) saline, (b) acid-washed PM 1648, (c) PM 1648, and (d) PM_2.5 exposed NZM mice 17 weeks following exposure. The PM 1648 and PM_2.5 exposed NZM mice showed increases in inflammatory cell infiltration. Saline and AW PM1648 had minimal levels of inflammation. The arrows indicate PM within the lungs 17 weeks following instillation.

Scoring of lung sections for inflammation and fibrosis

	Saline (n = 5)	AW PM1648 (n = 5)	PM1648 (n = 3)	PM2.5 (n = 3)
Inflammation	2.2	2.4	3	3
Fibrosis	1.2	1.8	2.3	2.3

1—none, 2—minimal, 3—moderate, 4—severe.

4 Development of (A) anti-nuclear antigen (ANA) autoantibodies and (B) anti-histone autoantibodies in saline and particulate matter exposed NZM mice measured by ELISA at 16 weeks post-PM instillation. ANA levels were significantly suppressed in the PM 1648 (n = 4) and PM_2.5 (n = 3), but not in acid-washed PM 1648 (n = 6) treated animals compared to the saline group (n = 5). * (p ≤ 0.05). No significant differences were observed in the levels of anti-histone autoantibodies. Values reported are means ± SEM. Single-factor analysis of variance (1-way ANOVA) and post hoc Dunnett test were performed. AW 1648 = Acid-washed PM 1648.

5 IgG serum levels (μ g/ml) of saline (█) (2–14 weeks, n = 6; 16 weeks, n = 5), acid-washed PM 1648 (▴) (n = 6), PM 1648 (▾) (2–10 weeks, n = 5; 12–16 weeks, n = 4) and PM_2.5 (♦) (2–12 weeks, n = 4; 14–16 weeks, n = 3) exposed NZM mice measured by ELISA in NZM mice 2–16 weeks following particulate matter exposure. Serum levels of IgG were significantly increased in the acid-washed PM 1648-instilled mice at 8, weeks following particulate matter instillation as compared to the saline-instilled group. *(p ≤ 0.05). IgG serum levels were significantly decreased in the PM 1648 and PM_2.5 instilled mice at the same time point as compared to the acid-washed PM 1648 instilled group. + < eqid1 > + (p ≤ 0.001) and + (p ≤ 0.05). Values reported are means ± SEM. Single-factor analysis of variance (1-way ANOVA) and post hoc Dunnett and Tukey tests were performed. AW PM 1648 = Acid-washed PM 1648.