concanavalin-a and Foot-and-Mouth-Disease

Previous investigations demonstrated that saponins isolated from the root of Panax ginseng C. A. Meyer (i.e., ginseng root saponin [GS-R]) had adjuvant activity. In the present study, the combined effects of rapeseed oil (RO) and GS-R on the immune responses elicited by foot-and-mouth disease (FMD) vaccine were investigated by measuring FMD virus (FMDV)-specific antibody levels, cytokine levels, lymphocyte proliferation, and long-lived IgG-secreting plasma cells from bone marrow in a mouse model. The results indicated that RO in combination with GS-R significantly enhanced serum IgG and isotype concentrations, gamma interferon (IFN-γ) and interleukin 5 (IL-5) levels, splenocyte proliferative responses to stimulations with concanavalin A (ConA), lipopolysaccharide (LPS), and FMDV antigen, and the numbers of IgG-secreting plasma cells in the bone marrow, suggesting that RO/GS-R enhanced both Th1 and Th2 immune responses. In addition, no significant difference was found between RO/GS-R and the commercial adjuvant oil ISA 206 in the promotion of FMD vaccine-induced immune responses. Considering the vegetable origin of RO and GS-R and the potent adjuvant activity, RO/GS-R should be studied further for the development of veterinary vaccines, especially for use in food animals in order to promote food safety.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Viral; Antigens, Viral; Cell Proliferation; Concanavalin A; Fatty Acids, Monounsaturated; Female; Foot-and-Mouth Disease; Foot-and-Mouth Disease Virus; Immunoglobulin G; Interferon-gamma; Interleukin-5; Lipopolysaccharides; Lymphocyte Activation; Mice; Mice, Inbred ICR; Panax; Plant Oils; Rapeseed Oil; Saponins; Spleen; Th1 Cells; Th2 Cells; Viral Vaccines

Despite their potential role in the spread of foot-and-mouth disease (FMD), the immune response and viral persistence in FMD virus (FMDV)-infected Indian buffaloes (Bubalus bubalis) have been unexplored. We found similar kinetics of neutralizing antibody responses in the sera and secretory fluids of buffaloes following experimental FMDV Asia 1 infection, but the lymphocyte-proliferative response in infected buffaloes was of low magnitude. Despite inducing a significant systemic and secretory immune response, viral persistence seems to be a common outcome in buffaloes following FMDV Asia 1 infection, which is associated with a weak cellular immune response.

Topics: Animals; Antibodies, Neutralizing; Body Fluids; Buffaloes; Concanavalin A; Foot-and-Mouth Disease; Foot-and-Mouth Disease Virus; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Leukocytes, Mononuclear; Mitogens

Foot and mouth disease virus (FMDV) is a picornavirus that causes an acute vesicular disease of cloven-hoofed animals. This virus continues to be a threat to livestock worldwide with outbreaks causing severe economic losses. The present study shows an analysis of immune system phenotype and function during the acute phase of FMDV infection in swine. In the first days of infection, a significant lymphopenia is observed that involves all T cell subsets, CD4(+), CD8(+), and CD4(+)/CD8(+). This marked lymphopenia is not a result of active infection of PBMC with the virus. Further, the response of residual peripheral blood T cells to the mitogen, Concanavalin A (ConA) is significantly reduced and occasionally eliminated. Animals usually resolve clinical signs of disease and develop antigen specific T cell responses to the virus and recover ConA reactivity. These characteristics of acute phase infection likely play an important role in viral pathogenesis, propagation and shedding of viral particles and may be targeted as a way of improving vaccine formulations.

Topics: Animals; Blood Cell Count; Concanavalin A; Flow Cytometry; Foot-and-Mouth Disease; Foot-and-Mouth Disease Virus; Lymphocyte Activation; Lymphocyte Subsets; Lymphopenia; Swine; Swine Diseases; T-Lymphocytes; Viremia