PD-1 And Its Ligands Regulate Immune Balance In Allergic Rhinitis

Objective To explore the expression and significance in regulating immune balance of programmed cell death protein 1(PD-1)and its ligands PD-L1,PD-L2 in allergic rhinitis(AR).Methods Eighty-two cases of Department of Otorhinolaryngology Head and Neck Surgery of Renmin Hospital of Wuhan University from May 2018 to May 2019 who received outpatient treatment due to high nasal reaction symptoms or were hospitalized due to nasal septum deviation and underwent nasal septum correction surgery were enrolled,including 42 males and 40 females,with the age ranging from14 to 38 years old.Blood,inferior turbinate nasal mucosal tissue and relevant clinical data were collected.Patients were divided into AR group and control group due to clinical manifestation,skin prick test and detection of specific Ig E(s Ig E)in serum.Flow cytometry was used to detect the proportions of PD-1+CD4+T cells,PD-L1+DC cells,PD-L2+DC cells and Th2 cells in peripheral blood of the two groups.The expression levels of total Ig E,s PD-1,s PD-L1 and s PD-L2 in serum of the two groups were detected by ELISA.Immunohistochemistry was used to detect the expression of PD-1 and its ligands in nasal mucosa of the two groups.The measurement data of normal distribution or normal distribution after the logarithm conversion to Ln were compared by t test.Pearson correlation or Spearman correlation was used to analyze the correlation among the indicators.P<0.05 was considered statistically significant.Results The ratio of PD-1+CD4+T cells,PD-L1+DC cells and Th2 cells in peripheral blood of AR group was significantly higher than that of the control group((15.24±6.45)% vs(8.71±5.33)%,(8.79±2.01)% vs(5.74±2.90)%,(7.89±1.95)% vs(2.52±1.34)%,all P<0.05).There was no significant difference in the ratio of PD-L2+DC cells between the two groups.Correlation analysis found that the proportion of PD-1+CD4+T cells was positively correlated with the visual analogue scale(VAS)score of AR,total Ig E concentration and the serum s Ig E concentration(r value was 0.501,0.541,0.608,respectively,all P<0.05).The proportion of PD-L1+DC cells was positively correlated with the VAS score of AR and the serum s Ig E concentration(r value was 0.604,0.563,respectively,all P<0.05).The proportion of Th2 cells in peripheral blood is positively correlated with the proportion of PD-L1+DC cells and PD-1+CD4+T cells(r value was 0.538,0.623,respectively,all P<0.05).Serum total Ig E,s PD-1and s PD-L1 in the AR group were significantly higher than those in the control group((6.34±1.38)vs(4.89±1.10)(Ln,ng/ml),(4.40±1.01)vs(3.79±1.21)(Ln,pg/ml),(3.88±0.25)vs(3.57±0.23)(Ln,pg/ml),all P<0.05),and s PD-L2 levels had no significant difference.Correlation analysis showed that s PD-L1 was positively correlated with total Ig E and s Ig E concentration(r values was 0.32,0.45,respectively,all P<0.05).The expression of PD-1 and its ligands on the surface of immune cells in the nasal mucosa of the AR group was significantly higher than that of the control group(P<0.05).Conclusions PD-1 and PD-L1 are highly expressed on the surface of immune cells in peripheral blood and nasal mucosa of AR patients,and s PD-1 and s PD-L1 expression levels in peripheral blood of AR patients are increased.The PD-1 / PD-L1 signaling pathway promote AR inflammatory response by inducing Th2 type immune response.