Resposta imunológica humoral em camundongos imunizados com o "Vírus do Mosaico Severo do Caupi (CPSMV)"

Abstract

The Cowpea Severe Mosaic Severo Virus (CPSMV) belongs to the Comovirus genus that infects plants of the legume, V. unguiculata causing serious shortage in the crop production of grains. The SDS-PAGE analysis of purified CPSMV revealed an electrophorectic profile with 3 protein bands of 42, 23 and 21 kDa. The purified CPSMV was used for subcutaneous immunization of swiss mice in two immunizing doses containing 10 and 100 ug protein (from the viral capside) and synthesis of specific total IgG and IgG1 as detected in the serum. Marcol as well as Al(OR)3 were shown to have adju ant abilities on the synthesis of specific antibodies against CPSMV. ln the synthesis of total IgG and IgG1, marcol had a better adjuvant effect when associated to the low ubcutaneous imunizing dosis of CPSMV (10 ug) and the gel of Al(OH)3 had a better adjuvant role associated to the high dose of CPSMV (100 J.1g). Specific IgE was detected with both subcutaneous immunizing doses in the presence of both adjuvants; A1(OR)3 had a more pronounced adjuvant effect in the synthesis of IgE when associated to the low immunizing dosis (10 ug) of CPSMV while the adjuvant effect of marcol was shown when it was associated to the high dosis of CPSMV (100 J.1g). In the absence of adjuvants, subcutaneous immunization with 10 and 100 ug CPSMV did not induce specific synthesis of IgE. Mice orally immunized either with purified CPSMV or with leaf extract from plants infeeted by CPSMV indueed speeifie produetion of IgG and IgA, anti-CPSMV. Synthesis of speeifie antibodies was not deteeted against the other proteins present in the leaf extract of V. unguiculata. By the fact that CPSMV, by oral route, has been demonstrated to possess selective immunogenie capacity, indueed the synthesis of anti-CPSMV antibodies without indueing synthesis of peeifie antibodies against other proteins of the leaf extract of V. unguiculata plants), such characteristic might justify new viraI eontamination diagnostic procedures, avoiding previous virus exhaustive purifieations. Furthennore, CPSMV, as a good immunogen by oral route, becomes a privileged candidate to express antigens in the produetion of vaeeines against patogens for humans and/or others animais sinee it has no side effeets as other antigen expressing arriers used with the same purpose. On the other hand, the present results contribute with another way of investigating the meehanisms of immunological tolerance established during the immunizations by the oral immunization procedures, rather than the production of specific antibodies.