The Associations And Regulatory Mechanism Between Chicken Monocytes/macrophages Phagocytosis And Immunity,Production Performance

Monocytes/macrophages phagocytosis has key roles in innate immunity and inflammatory responses.In this study,we comprehensively investigate the associations and regulatory mechanism between monocytes/macrophages phagocytosis and disease resistance,production performance.In this study,we applied the HCT-8-MTT method to detect monocytes/macrophages phagocytosis product(PP)of dwarf chickens at 12 weeks of age.Based on PP in 990 dwarf chickens(890 hens and 100 cocks),chickens were divided into high phagocytosis product group(HPPG)and low phagocytosis product group(LPPG).To study the relationship between phagocytosis product and immune response,the morbidity of HPPG ♀ and LPPG ♀were analyzed.Chickens in HPPG ♀ and LPPG ♀(100 per group)were inoculated with inactivated vaccines of avian influenza virus H9 at 58 wk.The serum antibody titers were investigated by hemagglutination inhibition tests.The results showed that the morbidity of HPPG ♀ was 44%of LPPG during 40 weeks of age(P<0.05).Chickens with higher PP levels showed higher antibody titers for the avian influenza virus H9 inactivated vaccine at 14 and 28 d post-vaccination(P<0.01).The growth and production performance in HPPG ♀ and LPPG ♀ were detected.There were no differences between HPPG ♀ and LPPG ♀ in body weight(0 d,6 wk,and 18 wk)and shank length(6 wk and 18 wk)(P>0.05),Chickens in LPPG ♀ have higher laying rate at 24 wk and 71 wk and higher average egg weight at 23 wk and 24 wk than in HPPG ♀(P<0.05).The levels of follicle-stimulating hormone(FSH)and luteinizing hormone(LH)in LPPG ♀ were 0.63 and 0.22 times higher than HPPG ♀at 58 wk,respectively(P<0.01).In an analysis of the semen quality of cocks,the two mating combinations(HPPG ♀×HPPG(?)and LPPG(?)× LPPG(?))were evaluated,and then,the reproductive performance was investigated.There were no differences in semen quality between groups(P>0.05).The fertilization rate(45,49,53,77,and 82 wk)and hatchability(45,49,and 77 wk)in LPPG ♀ was higher than that in HPPG ♀(P<0.05).Transcriptional levels of related genes in uterus,isthmus,ovary,and follicle were detected.In LPPG ♀,the mRNA expression levels of FSHR and CD9 in the follicle were 1.01 and 1.00 times higher than HPPG ♀(P<0.05).Interferonry(IFN-γ)is critical against viral and bacterial infection.Some studies have reported that IFN-y has the effect on the phagocytosis of macrophages and pituitary function.The present study analyzed the impact of recombinant chicken IFN-y on monocytes/macrophages phagocytosis,production performance,and pituitary function in vivo and in vitro.In vitro,monocytes/macrophages phagocytosis product was decreased by IFN-y treatment in a dose-dependent manner(P<0.05).In the in vivo experiment,IFN-γ was injected into chickens in HPPG ♀ through a vein,the levels of IFN-γ(7,14,and 21 d post-injection;P<0.05)and FSH(1,3,7,and 14 d post-injection;P<0.01)were increased in the treatment group.Monocytes/macrophages PP was lower in the treatment group than the control group(1,3,7,10,14 and 21 d post-injection;P<0.01).The laying rate was higher in the treatment group than in the control group at 2 and 3 weeks post-injection(P<0.05).In the in vitro experiment,the pituitary tissues were supplemented with IFN-γ,the mRNA expression levels of IFNGRI and IFNGR2 in the treatment group were up-regulated(P<0.05).Increased expression levels of FSH-β and FSH secretions at transcription and protein level were observed in the treatment group(P<0.05).Sum up,monocytes/macrophages PP was positively associated with humoral immunity and negatively related to production and reproductive performance.IFN-γ inhibited monocytes/macrophages phagocytosis and improved the laying rate via enhanced the secretion of FSH.IFN-y might be an important regulator in the trade-off between the immune effect and production performance in dwarf chickens.This study can provide a theoretical basis for selective breeding in the poultry industry.