IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Modification of antibody specifity by cytokines inhibition
Autor/es:
JOSÉ L. APARICIO; MACARENA A. OTTOBRE SABORIDO
Lugar:
Buenos Aires
Reunión:
Congreso; IV International Congress in Translational Medicine; 2018
Institución organizadora:
IMBS
Resumen:
Introduction: Lactate DehydrogenaseElevating Virus (LDV) is a single stranded positive sense RNA envelopedarterivirus, is persistent, non pathogenic and induces NK, macrophages and B-cell activation in mice. It was found that LDV- infection modified Abspecificity to different antigens, depending on the genetic background of thehost.Objectives: The purpose ofthis work was to study, through of anti-cytokine auto-vaccination and monoclonalantibody (MAb) treatment, the effect in the change of specificity of antibodiesto an model antigen (OVA).   Methods: i) C57BL/6mice wereinfected with 2×107 50% infectious doses of LDV in saline.Subsequently, the animals were inoculated in the footpads, four times at 2-wkintervals, with 2μg of IL-17/OVA complex emulsified in Gerbu adjuvant. Ten daysafter the last inoculation the animals were bled. ii) C57BL/6 mice wereinoculated subcutaneously with 25 μg of OVA emulsified in phosphate-bufferedsaline (PBS) and Complete Freund?s Adjuvant. At day 15, the mice were boostedwith the Ag in Incomplete Freund?s Adjuvant. At days 4, 7 and 11, half of theanimals were inoculated intraperitoneally with 150 µg of anti-IL-17A MAb(MM17F3) in 200 µl of PBS. Another mouse group were treated as before but infectedwith 2×107 50% infectious doses of LDV in saline at day -1. Bleeding was performed at days 8, 21, and 30.IL-17 concentration was measured by Sandwich ELISA. The titer of Abanti-OVA was determinated by Indirect ELISA whereas the proportionof Ab directed to native OVA epitopes was calculated by ELISA competitionassays.Results: Vaccination withIL-17/OVA decreased titers of anti-OVA Ab LDV-infected (1/290,000 ± 6,000) andnon-infected animals (1/280,000 ± 17,000), respect to control mince only inoculatedwith OVA (790,000 ± 70,000, P<0.001). The proportion of nativeanti-OVA Ab in control C57BL/6 micevaccinated with IL-17/OVA developed low titers of anti native OVA epitopes (38%) thatincreased to 71%, in LDV-infected animals. Furthermore, vaccination withIL-17/OVA augmented plasmatic IL-17 levels in LDV-infected animals incomparison with control (150±12 pg/ml and 24±6 pg/ml P<0.001, respectively).Whereas that in the MAb to IL-17A treatment titers of anti-OVA Ab inLDV-infected animals decreased by MAb treatment (1/167,000 ± 1/13,000 to1/68000±1/5,000, for control and MAb treated mice, respectively, P<0.001).Besides, percent of native anti-OVA Ab in non-infected mice increased bytreatment with the MAb (48 to 61%, respectively). Same effect was shown in LDV-infected mice (65 to 87%, for control and treated animals, respectively)Conclusions: This work suggests that inhibition of a cytokine (IL-17A) induce a modification inthe specificity of antibodies against conformational determinants to a givenantigen.