Immunomodulatory Effects Of Taishan Pinus Massoniana Pollen Polysaccharide And Propolis On Immunosuppressed Chickens

Immunesuppresseddiseases caused by virus primary infection in chicken flocks resut indirectlydeath. They also can cause lower immunity levels than normal in chicken flocks,which is the so-called immunosuppression. Immunosuppression makes chickens more sensitive to pathogens because of thedamage of the immune system, which leads to low antibody levels, and vaccination failure. What’s more, immunosuppression induced by immunosuppressive viruses has caused increasing economic consequences and bring a lot of potential hazards. Both avian leueosis viruses subgroup J(ALV-J)and reticuloendotheliosis viruses( REV) belong to Retroviridae, and they could causedifferentdegrees of immunosuppression. In addition, these two viruses co-infection are very common in practice.However, these immunosuppressive viruses are difficult to control because they usually exist via latent infection. Moreover, the inactivated REV or ALV-J vaccine cannot induce enough protection against the viral infection, and the attenuated vaccines always pose high risks for reactivation and infection. In this study, we used SPF chickens as the experimental object to study the relationship in REV and ALV-J co-infection effect. At the same time, the Taishan Pinus massoniana pollen polysaccharide(TPPPS) and propolis(PP) mixture, as well as single TPPPS or PP, was then applied to investigate the immune modulatory functions in immunosuppressed chickens by evaluating the immune organdevelopment, lymphocyte transformation, T-lymphocyte count, cytokine secretion, antibody production, and viral loads in spleen.The immunosuppressed model was established by chickens who were infected with ALV-J and REV. Four randomly assigned groups of these SPF chickens were successively administered with ALV-J, REV, mixture of ALV-J and REV, or phosphate-buffered saline(PBS). At different points, the indices of immune organ weight, lymphocyte transformation rates, CD4+and CD8+T-lymphocyte counts in peripheral blood, IL-2 and IFN- γ secretions weredetermined. The result in this study showed that chickens infected with viruses alone or combined could reduce the indices of immune organ weight, lymphocyte transformation rates,CD4+ and CD8+ T-lymphocyte counts in peripheral blood, IL-2 and IFN-γ secretions, serum antibody titers of ND vaccine. The viruses co-infection displayed synergistic effects in immunosuppression.Taishan Pinus massoniana pollen polysaccharide(TPPPS) and propolis(PP) have been proven to possess immune modulatory effects and improve the immune effects of vaccines. This study aimed to investigate the immune modulatory ability of TPPPS and PP on chickens co-infected with immunosuppressive viruses. Prior to the study, chickens were artificially established as REV and ALV-J co-infection models. Four randomly assigned groups of these immunosuppressed chickens were successively administered with TPPPS, PP,mixture of TPPPS and PP(TPPPS-PP), or phosphate-buffered saline(PBS)for three days.At nine days old, the four immunosuppressed groups, as well as one normal group, were inoculated with the attenuated Newcastle disease(ND) vaccine.during the monitoring period, the indices of immune organ weight, lymphocyte transformation rates, CD4+ and CD8+T-lymphocyte counts in peripheral blood, IL-2 and IFN-γ secretions, serum antibody titers of ND vaccine, and viral loads in spleens weredetermined. The results showed that chickens administered with TPPPS, PP, or TPPPS-PP could significantly enhance the levels of the above immune parameters compared to chickens in the PBS group. We observed the strongest immunity in the TPPPS-PP group, which indicates that the combination of TPPPS and PP versus TPPPS or PP alone, could generate better effects on improving the immune system effectiveness of immunosuppressed chickens.