Stimulation of mucosal immune response following oral administration of enterotoxigenic Escherichia coli fimbriae (CFA/I) entrapped in liposomes in conjunction with inactivated whole-cell Vibrio cholerae vaccine.
In this study, we have searched for an effective mucosal vaccine. An oral enterotoxigenic E. coli vaccine containing colonization factor antigen (CFA/I) associated with inactivated whole-cell V. cholerae vaccine (WCV) has been tested for safety and immunogenicity in animals. Five groups of animals were used. The results showed the following: (a) vaccine containing CFA/I antigen entrapped in liposomes and associated with WCV (batch C) had increased titers of specific antibodies to CFA/I antigen in 15 to 18 (83.3%) animals; (b) specific Peyer's patches (PP), lymph nodes (LN) and spleen (SPL) lymphocytes proliferation was detected following in vitro restimulation with CFA/I antigen or WCV. This response gradually increased to the highest value by the 35th postimmunization day. Moreover, lower PP, LN and spleen (SPL) proliferation was observed in rabbits receiving soluble CFA/I antigen (S-CFA/I) or free liposomes (F-L) alone; (c) adhesion of E. coli H10407 strain labelled with 3H-leucine in immunized and control animals revealed the following local effects: (i) protection of rabbit intestinal mucosa against virulent E. coli cells; (ii) inhibition of adhesion of ETEC bacteria to intestinal mucosa and (iii) significantly faster release of E. coli H 10407 strain labelled with 3H-leucine from the intestinal tract of immunized animals. The histopathological and electron microscope findings confirmed the above results. The experimental results point out an efficient protection against infection with E. coli strains (ETEC), after mucosal vaccination with CFA/I antigen entrapped in liposomes associated with inactivated whole-cell Vibrio cholerae as immunological adjuvant.
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Cantacuzino Institute, Victor Babeş Institute, Bucharest, Romania.
Ionescu
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Palade
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Balotescu
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C
Becheanu
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G
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S V
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D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000276:immunology*; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology; D004927:Escherichia coli Infections / Q000517:prevention & control*; D022361:Escherichia coli Vaccines / Q000008:administration & dosage / Q000276:immunology*; D036781:Fimbriae Proteins; D018928:Immunity, Mucosal; D007114:Immunization; D007413:Intestinal Mucosa / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008081:Liposomes / Q000008:administration & dosage / Q000276:immunology*; D008213:Lymphocyte Activation; D011817:Rabbits; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014734:Vibrio cholerae / Q000166:cytology / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D022121:Cholera Vaccines; D022361:Escherichia coli Vaccines; D008081:Liposomes; D017778:Vaccines, Combined; D015164:Vaccines, Inactivated; C022924:colonization factor antigens; D036781:Fimbriae Proteins