Development and partial evaluation of a recombinant vaccine against Anaplasma marginale.

M. SARLI; M. B. NOVOA; M. MAZZUCO; C.S. THOMPSON; S. T DE ECHAIDE; M E. PRIMO,

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Anaplasma marginale is an intraerythrocytic bacteria that cause bovine anaplasmosis, disease characterized by high lethality in adults. The disease is in expansion and has become a serious threat to cattle industry. The drawbacks of the currently used A. centrale live vaccine, produced in splenectomized calves, boosted the search of safer, more efficient and cost-effective immunogens. The aim of this preliminary work was to evaluate the humoral and cellular immune responses generated by the inoculation of the recombinant form of five subdominant and surface exposed A. marginale proteins, members of the type IV secretion system. VirB9.1, VirB9.2, VirB10, VirB11 and Et-Tu proteins were cloned and expressed in Escherichia coli. Twenty Holstein steers, two years old, were randomly clustered into four groups (G) of five steers each. GA and GB were immunized with a cocktail of 50 µg of each recombinant protein (rP) in Quil-A® or Montanide® adjuvants, respectively. GC and GD (controls) were inoculated with Quil-A or Montanide adjuvants, respectively. Steers received four inoculations within three-week interval. An indirect ELISA, and a lymphocyte proliferation assay (LPA) was standardized to evaluate the humoral and cellular immune response against the five rP. The production of rVirB9.1/9.2 was higher (25 mg/L) than that produced by the remaining three rP (