Maxadilan-simile expression in Nyssomyia neivai, a sandfly vector in an endemic region of Brazil, and its immunogenicity in patients with American tegumentary leishmaniasis.
BACKGROUND
Maxadilan (Max) is a salivary component in the sandfly Lutzomyia longipalpis (Lutz & Neiva 1912), a vector of visceral leishmaniasis. Max has a powerful vasodilatory effect and is a candidate vaccine that has been tested in experimental leishmaniasis. Nyssomyia neivai (Pinto 1926) is a vector of the pathogen responsible for American tegumentary leishmaniasis (ATL) in Brazil.


OBJECTIVE
We searched for Max expression in Ny. neivai and for antibodies against Max in ATL patients.


METHODS
cDNA and protein were extracted from the cephalic segment, including salivary glands, of Ny. neivai and analysed by polymerase chain reaction, DNA sequencing, and blotting assays. The results were compared with data obtained from Lu. longipalpis samples. We quantified antibodies against Max in serum samples from 41 patients with ATL (31 and 10 with the cutaneous and mucocutaneous forms, respectively) and 63 controls from the endemic northeastern region of São Paulo state, using enzyme-linked immunosorbent assay.


RESULTS
Recognition of a Max-simile peptide by specific antibodies confirmed expression of a Max sequence in Ny. neivai (GenBank EF601123.1). Compared to controls, patients with ATL presented higher levels of antibodies against Max (p = 0.004); 24.4% of the patients with ATL and 3.2% of the controls presented anti-Max levels above the cutoff index (p = 0.014). The anti-Max levels were not associated with the specific clinical form of ATL, leishmanin skin test response, absence or presence of amastigotes in histopathologic exam, results of indirect immunofluorescence testing for leishmaniasis, or duration of cutaneous form disease.


CONCLUSIONS
High serum anti-Max levels did not protect patients against ATL, but confirmed previous natural exposure to Ny. neivai bites in this ATL endemic region.
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Divisão de Dermatologia, Ribeirão Preto, SP, Brasil.
Juliana
J
Aires
Secretaria de Estado da Saúde, Superintendência de Controle de Endemias, Mogi Guaçu, SP, Brasil.
Claudio
C
Casanova
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Divisão de Dermatologia, Ribeirão Preto, SP, Brasil.
Sebastian
S
Vernal
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Laboratório de Sorologia, Hospital das Clínicas, Ribeirão Preto, SP, Brasil.
Margarida
M
Nascimento
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Laboratório de Biologia Molecular, Ribeirão Preto, SP, Brasil.
Sandra
S
Rodrigues
Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Ethan A
EA
Lerner
Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Divisão de Dermatologia, Ribeirão Preto, SP, Brasil.|Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Clínica Médica, Laboratório de Biologia Molecular, Ribeirão Preto, SP, Brasil.
Ana Maria
AM
Roselino
D000818:Animals; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D001938:Brazil; D016022:Case-Control Studies; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015151:Immunoblotting; D019476:Insect Proteins / Q000032:analysis* / Q000276:immunology; D007303:Insect Vectors / Q000737:chemistry* / Q000145:classification; D016773:Leishmaniasis, Cutaneous / Q000097:blood* / Q000276:immunology; D008297:Male; D016133:Polymerase Chain Reaction; D011576:Psychodidae / Q000737:chemistry* / Q000145:classification; D011817:Rabbits; D017422:Sequence Analysis, DNA
D000906:Antibodies; D019476:Insect Proteins; C069147:maxadilan protein, insect