Mucosal immunity induced by orally administered transgenic plants

EVANGELINA GÓMEZ, SILVINA CHIMENO ZOTH, ELISA CARRILLO, MARÍA ESTELA ROUX, ANALIA BERINSTEIN

IMMUNOBIOLOGY.

Elsevier

Año: 2008 vol. 213 p. 271 - 275

0171-2985

Oral immunization is an efficient mean to induce protection at the portal entrance for many pathogens. Therefore, the design of efficient edible vaccines through transgenic plants represents a challenging alternative to the traditional injectable ones. We have previously reported the construction of transgenic potato plants expressing the genes coding for the immunogenic proteins of Newcastle Disease Virus (NDV) and its immunogenicity in mice. All mice receiving transgenic plant extracts in incomplete Freund adjuvant produced specific antibodies. Animals fed with transgenic leaves also showed a specific response aganist NDV. The aim of the present study was to continue the evaluation of the mucosal immune response. Adult Balb/c mice were fed with potato leaves during a month and on day 36 mucosal samples were collected. ELISAs performed on intestinal washes showed that transformed plants elicited the synthesis of specific IgG and IgA antibodies. In addition, anti-NDV IgA antibodies were detected in supernatants of cultured small intestine fragments of mice fed with the recombinant immunogens, suggesting the presence of specific IgA secreting plasma cells in the intestinal tissue. Also, indirect immunofluorescences on intestinal tissue were performed. The results showed that IgA+Bcells and T cells subpopulations CD4+ and CD8+ were increased in guts of mice fed with the recombinant plants. The present results suggest that these immunogens, when orally administered, would enhance the increase of IgA+B cells and the citotoxic cellular immune response via CD8+T cells, found in the gut lamina propia that is in concordance with our first findings.