IMMUNE RESPONSE INDUCED BY NEW ADJUVANT STRATEGY TO PRODUCE CROTALIC ANTI-PLA2

LUCIANO FUSCO,; ANDREA VAN DE VELDE; DAVID HERNÁNDEZ; SANTIAGO PALMA; BELKYS MALETO,; GABRIEL MORON; LAURA LEIVA

Buenos Aires

Congreso; 0th World Congress of the International Society on Toxinology "Toxinology in the 21st century: Public health impact from basic, translational and clinical sciences"; 2019

IST

Snakeenvenomation is a serious medical problem and antivenoms are the maintreatment. Antisera are produced by immunization of horses with snakevenom using complete Freund?s adjuvant and incomplete (booster) butit causes severe local reactions. A new adjuvant strategy is hereproposed to increase efficiency in antisera production under muchless morbilty to immunized animals. Previous works showed thatCpG-ODN formulated with a 6-O-ascorbyl palmitate nanostructure(Coa-ASC16) was more efficient as adjuvant than CpG-ODN alone usingovalbumin (OVA) as an antigen model. Here, we evaluated the immuneresponse induced by this adjuvant strategy using crotalicPLA2enzymeas antigen. Balb/c mice were subcutaneously immunizated on days 0, 15and 30 with PLA2/CpG-ODN/Coa-ASC16or PLA2/Freund?sAdyuvant (complete first and incomplete-booster) (dose/mice: crotalicPLA2:10-15μg,CpG-ODN: 30 μg).On day 50, mice were sacrificed. In both immunized group mice, theantibody titers in plasma were high (dilution1/24800), with a similarIgG1/IgG2a ratio. The IgG antibodies were then purified by affinitySepharose-proteinG column. Indirect hemolytic activity neutralizationof the PLA2(2.5μg) with specific antibodies (1.7-4.5 μgrange; IgG anti-PLA2)were made by radial hemolisis. The evaluation did not show differenceneutralizing capacity of the antibodies produced by CpG-ODN/Coa-ASC16or Freund?s Adyuvant. Macroscopic and microscopic analysis at thesite of injection of mice inoculated with Freund?s adjuvant showedlocal damage (with non-infectious abscesses) and hypertrophy ofinguinal lymph nodes, whereas mice injected with CpG-ODN/Coa-ASC16did not.Our results show that CpG-ODN/Coa-ASC16producesa humoral response as strong and specific as Freund´sadjuvant, withminor or null local deleterious effect, So, this complex emerge as anew adjuvant, a very attractive alternative for  anticrotalicsera production.p { margin-bottom: 0.25cm; direction: ltr; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }