quillaja-saponins and Tick-Infestations

Sheep and cattle were immunized with soluble and membrane midgut antigens of the cattle tick, Boophilus microplus in association with various adjuvants, and antibody levels to soluble and membrane midgut extracts were measured by enzyme-linked immunosorbent assay (ELISA). The adjuvants used were Quil A, Freund's incomplete adjuvant (FIA) and aluminium hydroxide (A1(OH)3). Significant antibody levels to midgut membrane antigen (GM) were not detected in the sera of sheep immunized with GM plus A1(OH)3. However, membrane and soluble midgut antigens combined with Quil A generated significantly higher levels of antibodies in sheep than these antigens emulsified in FIA (P < 0.05). In cattle, although soluble midgut antigen (GS) plus Quil A induced significantly higher levels of antibodies compared with GS in FIA (P < 0.05), neither preparation provided significant protective immunity against challenge with B. microplus (46% and 22%, respectively). A soluble form of membrane midgut antigen extracted by low ionic strength buffer (LI-GM) when combined with Quil A provided 83% and 87% protection against challenge with B. microplus in two separate experiments. Quil A was clearly superior to FIA and A1(OH)3 as an adjuvant for these tick antigens.

Topics: Adjuvants, Immunologic; Aluminum Hydroxide; Animals; Antibodies; Antigens; Cattle; Cattle Diseases; Female; Freund's Adjuvant; Immunity, Active; Male; Quillaja Saponins; Saponins; Sheep; Sheep Diseases; Solubility; Tick Infestations; Ticks; Vaccination

Quil A used with Boophilus microplus gut membrane antigen (GM) had a significant effect on antibody levels induced in sheep (P < 0.05) since GM alone did not induce a significant level of antibodies. Injection of a vaccine containing GM and Quil A, either subcutaneously or intramuscularly, induced similar levels of antibodies in sheep. However, Quil A injected subcutaneously induced acute inflammatory reaction. The amount of Quil A for use with GM was determined to be 1000 micrograms/ml. Immunostimulating complexes (ISCOMs) incorporating detergent-solubilized membrane midgut antigens (TX-GM) failed to induce an immune response in cattle without the addition of Quil A. The addition of Quil A to the ISCOMs containing TX-GM did not stimulate antibody responses greater than those stimulated by TX-GM plus Quil A, and protection in vaccinated cattle was 86% and 74%, respectively.

Topics: Adjuvants, Immunologic; Animals; Antibody Formation; Antigens, Surface; Cattle; Cattle Diseases; Centrifugation, Density Gradient; Enzyme-Linked Immunosorbent Assay; Female; Inflammation; ISCOMs; Male; Quillaja Saponins; Saponins; Sheep; Sheep Diseases; Tick Infestations; Ticks; Vaccines