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Figure 1. NK cells appear early during the allergic inflammatory
response and correlate with eosinophils. Subjects (n=20) suffering from
confirmed seasonal grass pollen rhinitis were challenged intranasally
with a single threshold dose of a grass pollen extract or diluent.(A) Representative dot plots for flow cytometric sequential
gating of leukocyte populations in nasal lavage. (B) Time
course of neutrophils, eosinophils, NK cells, lymphoid cells, T
lymphocytes and monocytes following allergen nasal challenge or diluent.
Data are displayed as mean ± SEM; *P < 0.05; **P <
0.01; ***P < 0.001; 2-way ANOVA with Sidaks’s multiple
comparison test was used to compare allergen vs diluent at various time
points. (C) Correlation between total NK cells and eosinophils
1, 6 and 24h after the allergen challenge (Pearson correlation rvalue and significance are noted).
Figure 2. LXA4 is produced in the nasal mucosa
after nasal allergen and is essential to inhibit NK cells triggered
eosinophil superoxide release in vitro. (A)LXA4 concentrations in nasal lavage samples; *P< 0.05 compared to diluent, $P<
0.05 compared to baseline levels; allergen vs diluent: 2-way
ANOVA with Sidaks’s multiple comparison test, levels vs baseline
levels: 2-way ANOVA with Tukey’s multiple comparison test. (B)Correlation of LXA4 levels and neutrophil and monocyte
counts after allergen challenge; Pearson correlation r value and
significance are noted). (C) Superoxide release by different
leukocyte population at rest (vehicle) and when activated by phorbol
myristate acetate (PMA), n = 5 healthy donors, *P <
0.05, at rest (vehicle) when cells are compared to each other; **P
< 0.05, after PMA when cells are compared to each other;£P < 0.05, when cells are compared between
rest (vehicle) and PMA; multiple t -tests with Bonferroni
correction. (D) Superoxide release from eosinophils
co-incubated with NK cells, n = 7 healthy donors,
*p<0.05, paired Student’s t test. (E)Superoxide release from eosinophils pre-treated with increasing doses of
LXA4 and stimulated with PMA; n = 6 healthy
donors; *p<0.05 compared to vehicle;£p<0.05 compared to 1 nM; one-way ANOVA with
Tukey’s multiple comparison test. (F) , Superoxide release from
eosinophils pre-treated with LXA4 and co-incubated with
NK cells, n = 3 healthy donors; *P < 0.05; multiplet -tests with Bonferroni correction. Results are expressed as
means ± SEM.