The Effect And Mechanism Of Platelet Rich Plasma Combined With Specific Immunotherapy On Murine Asthma Model

Background: Allergen specific immunotherapy(ASIT)is the only curative treatment that can induce long-term clinical tolerance and immune response to Ig E-mediated allergic diseases.It can not only prevent disease progression,but also sustained a long-term clinical effect after treatment.However,there are still several disadvantages in ASIT,which have limited its broad applicability.In order to improve the efficacy and safety of ASIT,it is essential to further investigate new allergy vaccines and regime.Adjuvants are used to induce a quicker,more potent,and longer-lasting ASIT immune response.Seeking for more effective and safer compounds can improve and simplify ASIT,providing more reliable methods for treating allergic disease.In recent years,platelet rich plasma(PRP),as a new type of adjunctive therapy,has been successfully used in clinical trial for some diseases.Autologous PRP is rich in a variety of bioactive substances,studies had been reported that it can enhance immune response of different cells in vitro.PRP may serve as a potent adjuvant for specific immunotherapy based on its safe,biodegradable,non-toxic,cost-effective charateristics.We use PRP co-administered along with the allergen extract and evaluating its effect for murine asthma model.Providing evidences of mechanisms of both ASIT and adjuvants,together with more data on safety and tolerability,will be useful to design new approaches to the management of allergic diseases.Objective: To explore the immunological and clinical changes of PRP co-administered with allergen extract for ASIT in murine asthma model.Methods: We build up a typical ovalbumin allergic asthma murine model and applied with different desensitization treatment.BALB/c mice were assigned to four groups: control group,asthma group,OVA-SIT group and OVA+PRP-SIT group.Immunologic parameters were assessed including serum OVA-specific Ig E levels,bronchoalveolar eosinophilia,cytokine levels and lung tissue.Results: 1.In comparison with the control group,the asthma group showed a significantly increased number of nose-scratching events in 30 min after intranasal ovalbumin instillation.OVA+PRP-SIT group showed fewer nose-scratching events than the asthma animals(P<0.05).2.Sections with H&E staining of lung: asthma group demonstrated inflammatory changes when compared to control group.Various inflammatory cells infiltrated around bronchi and blood vessels,thickening of bronchial wall cavity and submucosal edema were seen in asthma group.Asthma-associated lung inflammation was inhibited in OVA-SIT group and OVA+PRP-SIT group,and OVA+PRP-SIT group showed a better treatment effect.3.There is an obvious contrast between control group and asthma group in the numbers of total cells and EOS in BALF,asthma group showed extremely higher(P<0.01).In comparison with asthma group,the numbers of EOS significantly decreased in OVA-SIT and OVA+PRP-SIT group(P<0.01).4.Compared with asthma group,OVA-SIT and OVA+PRP-SIT group had lower IL-5 levels(P<0.01)and higher IL-10 levels(P<0.05)in BALF.The OVA-specific Ig E in serum levels of OVA-SIT and OVA+PRP-SIT group decreased compared with asthma group but showed no statistic differences.5.Detection results of lung tissue by q PCR: compared to control group,a significantly decreased m RNA expression of T-bet was found in asthma,OVA-SIT and OVA+PRP-SIT group(P<0.01).Foxp3 m RNA expression in OVA-SIT and OVA+PRP-SIT group decreased compared to asthma group(P<0.05).Asthma group showed a little bit increase in GATA-3 and ROR-γt m RNA expression,but with no statistic differences.6.The spleen of mice had varied degrees enlarged in different experimental group.There is a sinigicant different between the control and OVA-SIT group in the spleen weight of mice,OVA-SIT group increased significantly(P<0.01).And contrast with OVA-SIT group,OVA+PRP-SIT group showed a lessen extent in spleen weight(P<0.05).Splenocyte stimulation assay demonstrated that both OVA-SIT group and OVA+PRP-SIT group showed a little decrease in IFN-γ levels,but there were no statistic differences compared with asthma group.And IL-5,IL-10 and IL-17 A levels notably decreased in both OVA-SIT group and OVA+PRP-SIT group(P<0.05).IL-4 levels decreased slightly in OVA-SIT group,but significantly decreased in OVA+PRP-SIT group(P<0.05),compared with asthma group.Conclusions: 1.The characteristics of this asthma murine model mainly included an increase of eosinophils in BALF and serum OVA-specific Ig E expression,significant up-regulation of Th2 immune response.2.Allergic asthma mice treating PRP co-administered with OVA extract for ASIT can enhance the therapeutic effect,reduce airway inflammation,lenssen the nose-scratching symptoms after intranasal instillation and reduce spleen hypertrophy of sensitized mice.3.OVA-SIT and OVA+PRP-SIT can reduce Th2-mediated allergic inflammation and increase anti-inflammatory cytokine IL-10.4.Both OVA-SIT and OVA+PRP-SIT can effectively reduce inflammatory response of splenocytes to allergen.