Mucosal immunization confers long-term protection against intragastrically established Neospora caninum infection.
Neospora caninum is an obligate intracellular protozoan parasite responsible for heavy economic losses in dairy and beef cattle farms worldwide. Although vaccination is widely regarded as the preferable strategy to prevent neosporosis no commercial vaccine is currently available. We have previously shown that intranasal immunization with an N. caninum antigen extract enriched in hydrophobic proteins plus CpG adjuvant protected mice against intragastrically established neosporosis. Nevertheless, the antigen specificity as well as the long-term protective effect of this immunization strategy were not determined. Here, we show that the protective effect of this intranasal immunization procedure lasted for at least 20weeks. Protection was accompanied by long-lasting elevated levels of parasite-specific serum IgG and intestinal IgA. Moreover, spleen and mesenteric lymph node cells obtained from non-infected long-term immunized mice responded by producing interferon-γ following in vitro parasite-antigen recall. Analysis of serum IgG and intestinal IgA antibody reactivity in immunized mice identified dense granule antigen 7 (NcGRA7) and microneme associated protein 1 (NcMIC1) as immunodominant antigens respectively recognized by those antibody fractions. In summary, this work shows that a previously reported mucosal immunization strategy against N. caninum infection established through the gastrointestinal tract is effective in the long term.
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
Pedro
P
Ferreirinha
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
Alexandra
A
Correia
IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
Maria
M
Teixeira-Coelho
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IPATIMUP - Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal; FMUP - Faculdade de Medicina da Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
Hugo
H
Osório
ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 228, 4050-313 Porto, Portugal; UMIB - Unidade Multidisciplinar de Investigação Biomédica, Universidade do Porto, Portugal.
Luzia
L
Teixeira
ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 228, 4050-313 Porto, Portugal.
António
A
Rocha
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 228, 4050-313 Porto, Portugal. Electronic address: vilanova@icbas.up.pt.
Manuel
M
Vilanova
D000281:Administration, Intranasal; D058956:Administration, Mucosal; D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D002417:Cattle; D003048:Coccidiosis / Q000469:parasitology / Q000517:prevention & control*; D005260:Female; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D007422:Intestines / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D008810:Mice, Inbred C57BL; D018688:Neospora / Q000276:immunology*; D016052:Protozoan Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D044967:Serum / Q000276:immunology; D013154:Spleen / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D016052:Protozoan Vaccines; D007371:Interferon-gamma
Dense granule antigen 7; Long-term protection; Microneme associated protein 1; Mucosal immunization; Neospora caninum