Mucosal immune responses induced by oral administration recombinant Bacillus subtilis expressing the COE antigen of PEDV in newborn piglets.
Porcine epidemic diarrhea (PED) is a highly contagious disease in newborn piglets and causes substantial economic losses in the world. PED virus (PEDV) spreads by fecal-oral contact and can be prevented by oral immunization. Therefore, it is necessary to develop an effective oral vaccine against PEDV infection. Currently, Bacillus subtilis as recombinant vaccine carrier has been used for antigen delivery and proved well in immune effect and safety. The present study evaluated the immunogenicity of recombinant Bacillus subtilis (B. subtilis-RC) in piglets via oral administration. After oral immunization in piglets, B. subtilis-RC significantly increased the local mucosal immune responses. Oral administration with B. subtilis-RC significantly improved the level of specific mucosal immunoglobulin A (IgA) antibodies against PEDV infection, through enlarging the area of Peyer's patches (PPs) and increasing the number of ileum IgA+ secreting (SIgA) cells. In the meantime, B. subtilis-RC remarkably increased the number of intraepithelial lymphocytes (IELs). We also observed that oral administration of B. subtilis-RC significantly increased CD3+T lymphocytes' numbers and up-regulated the ratio of CD4+/CD8+ T cells. Furthermore, high titers of specific serum immunoglobulin G (IgG) revealed satisfactory systemic immune response against PEDV infection. In summary, our study demonstrated that oral administration of B. subtilis-RC could trigger a high level of local and systemic immune responses and would be a promising candidate vaccine against PEDV infection in piglets.
['Wang|Jialu|J|', 'Huang|Lulu|L|', 'Mou|Chunxiao|C|', 'Zhang|En|E|', 'Wang|Yongheng|Y|', 'Cao|Yanan|Y|', 'Yang|Qian|Q|']
D000284:Administration, Oral D000818:Animals D000831:Animals, Newborn D000914:Antibodies, Viral D000956:Antigens, Viral D001412:Bacillus subtilis D016516:CD4-CD8 Ratio D018352:Coronavirus Infections D006801:Humans D018928:Immunity, Mucosal D007070:Immunoglobulin A D053485:Porcine epidemic diarrhea virus D013552:Swine D013553:Swine Diseases D013601:T-Lymphocytes
mucosal immunity recombinant Bacillus subtilis piglets vaccines Porcine epidemic diarrhea virus