Immune responses induced by a combined vaccination with a recombinant chimera of Mycoplasma hyopneumoniae antigens and capsid virus-like particles of porcine circovirus type 2

Abstract

Background Mycoplasma hyopneumoniae (Mhp) and porcine circovirus type 2 (PCV2) are two important pathogens causing Mycoplasma pneumonia of swine (MPS) and porcine circovirus diseases and porcine circovirus-associated diseases (PCVDs/PCVADs), respectively, and resulted in considerable economic loss to the swine industry worldwide. Currently, vaccination is one of the main measures to control these two diseases; however, there are few combination vaccines that can prevent these two diseases. To determine the effect of combination immunization, we developed capsid-derived (Cap) virus-like particles (VLPs) of PCV2 and a new recombinant chimera composed of the P97R1, P46, and P42 antigens of Mhp. Then we investigated the immune responses induced by the immunization with this combination vaccine in mice and piglets. Results The high level antibodies against three protein antigens (P97R1, P46, and P42 of Mhp) were produced after immunization, up to or higher than 1:400,000; the antibody levels in Pro group continuously increased throughout the 42 days for all the antigens tested. The lymphocyte proliferative response in PCV2 group was stronger than that in PBS, VP, Mhp CV in mice. The antibody levels for Cap remained stable and reached the peak at 35 DAI. The IFN-γ and IL-4 in sera were significantly enhanced in the Pro group than that in the negative control-VP group on Day 14 and 28 post-the first immunization in piglets. Conclusions Above all, the combination immunization could induce humoral and cellular immune responses against all four antigens in mice and piglets. Therefore, our approach is a simple and effective vaccination strategy to protect pigs against MPS and PCVD/PCVAD.

Development of a Multi-Epitope Vaccine for Mycoplasma hyopneumoniae and Evaluation of Its Immune Responses in Mice and Piglets

“…Freund’s adjuvant is an oil adjuvant widely used in animal vaccines, but its ability to stimulate the production of antibodies against recombinant protein is not good, and it often leads to excessive inflammatory responses [ 31 ]. Because of this, we used MontanideTM ISA 206 VG adjuvant in the piglet immunization experiments.…”

“…Although the molecular docking results indicated that MhpMEVC6His could bind to immune-associated receptors, we performed animal immunization to validate our findings and studied the immune response. The design of the animal immunization was based on our previously published papers [ 31 , 66 , 67 ]. All animals (cleanliness of mice: SPF; cleanliness of piglets: free from Mhp and porcine circovirus type 2 infection) were kept in individually ventilated cages.…”

“…The following supporting information can be downloaded at: . References [ 6 , 7 , 8 , 19 , 20 , 21 , 31 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ] are cited in the supplementary materials.…”

“…Supplementary Materials:The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/ijms23147899/s1. References[6][7][8][19][20][21]31,[75][76][77][78][79][80][81][82][83][84][85][86][87][88] are cited in the supplementary materials.…”

Cost‐minimization analysis of DTaP‐IPV‐Hib combination vaccine in China: A nationwide cross‐sectional study

“…Indeed, the development of combination vaccines has gradually become the main trend to adapt to the market's needs. 40 One important barrier for vaccination in countries with low and middle income is the current price of available vaccines. 41 The cost borne by combination vaccine recipients could be sufficient enough to be a hurdle for taking combination vaccines.…”