Immune response induced in mice oral immunization with cowpea severe mosaic virus

Abstract

There is increasing interest in the immune response induced by plant viruses since these could be used as antigen-expressing systems in vaccination procedures. Cowpea severe mosaic virus (CPSMV), as a purified preparation (300 g of leaves, 2 weeks post-inoculation), or crude extract from cowpea (Vigna unguiculata) leaves infected with CPSMV both administered by gavage to Swiss mice induced a humoral immune response. Groups of 10 Swiss mice (2-month-old females) were immunized orally with 10 daily doses of either 50 µg viral capsid protein (boosters of 50 µg at days 21 and 35 after immunization) or 0.6 mg protein of the crude extract (boosters of 0.6 mg at days 21 and 35 after immunization). Anti-CPSMV antibodies were quantified by ELISA in pooled sera diluted at least 1:400 at days 7, 14, 21, 28, 35 and 42 after the 10th dose. IgG and IgA against CPSMV were produced systemically, but IgE was not detected. No synthesis of specific antibodies against the proteins of leaf extracts from V. unguiculata, infected or not with CPSMV, was detected. The use of CPSMV, a plant-infecting virus that apparently does not induce a pathogenic response in animals, induced a humoral and persistent (at least 6 months) immune response through the administration of low antigen doses by gavage. These results raise the possibility of using CPSMV either as a vector for the production of vaccines against animal pathogens or in quick and easy methods to produce specific antisera for viral diagnosis.

Pepper Mild Mottle Virus, a Plant Virus Associated with Specific Immune Responses, Fever, Abdominal Pains, and Pruritus in Humans

“…Beyond these findings, our results, together with previous data, suggest that the relationship between plant viruses and animals may deserve further re-evaluation using modern microbiologic tools (Table 4). The oral administration of Cowpea severe mosaic virus , another plant virus, has been previously shown to induce a durable and systemic immune response in mice without requiring the co-administration of an adjuvant [23], and similar results have been observed in mice using Alfalfa mosaic virus and chimeric plant virus particles [24]–[25]. In addition, some plant viruses can replicate in insect tissues, as illustrated by Tomato spotted wilt virus and Maize rayado fino virus [26]–[28].…”

Biological stability of a strain of Cowpea severe mosaic virus over 20 years

“…The antiserum produced against the CPSMV-MC purified preparation reacted with extracts from CPSMV infected plants without reactions with extracts from health plants and presented a titer of 1:1024 in double immune diffusion tests. The CPSMV immunogenicity was also demonstrated by Swiss mice oral immunization (FLORINDO et al, 2002).…”

Humoral immune response in mice immunised by oral and subcutaneous routes with Isosoy proteins

“…The specific antibodies for soy antigens, obtained from mice immunised with Isosoy † by subcutaneous and oral route, were submitted to the indirect ELISA test modified by Guedes et al (2002). For this test, the plates (96ÁPOLYSORP-NUNC-IMMUNO PLATE BATCH 016181) were sensitised with Isosoy † protein (2 mg of protein/well), CSE (2 mg of protein/well) or purified isoflavone (2 mg of protein/well).…”