Objective: To investigate the role of TIM4 (T cell immunoglobulin and mucin domain molecule 4) in the pathogenesis of allergic rhinitis (AR) in mice, and to identify a novel therapeutic target for the treatment of AR.
Methods: Twenty-one male BALB/C mice of clean grade were divided into three groups randomly (n = 7 per group) including control, AR and anti-TIM4 antibody treatment groups. In order to induce upper airway allergic inflammation, the mice from AR and anti-TIM4 antibody treatment groups were sensitized by intraperitoneal injection followed by intranasal challenge with ovalbumin. Before the ovalbumin challenge, a group of mice was treated with anti-TIM4 antibody. To assess the AR model, behavioral observation with immunological assessments and HE staining of nasal tissues were performed. The TIM4 expression in nasal tissues in different groups of mice were assessed by immunofluorescence and RT-PCR.SPSS18.0 software was used to analyze the data.
Results: The AR model in mice was successfully established as shown by behavioral observation and immunological evaluation. RT-PCR assays showed the relative expression of TIM4 mRNA in nasal mucosa of AR, control and anti-TIM4 antibody treatment mice was 16.29 ± 3.80, 0.51 ± 0.60, 1.64 ± 0.98, respectively. There was statistically significant differences mong three group (F = 46.56, P < 0.05). The expression of TIM4 in AR group was significantly higher than those in control group (t = 8.650, P < 0.05) and anti-TIM4 group (t = 8.027, P < 0.05). The expression of TIM4 was significantly reduced in the anti-TIM4 antibody group, as well as control group (t = -0.623, P > 0.05). More expression of TIM4 was detected in local nasal tissues of AR mice, mainly located below the pseudostratified ciliated columnar epithelium.
Conclusions: TIM4 plays a crucial role in the pathogenesis of AR. Effective inhibition of TIM4 expression can partially reverse the pathological changes of AR.