title: Immunomodulatory response of mice splenocytes induced by RcaL, a lectin isolated from cobia fish (Rachycentron canadum) serum.
abstract: This work reports the isolation of a serum lectin from cobia fish (Rachycentron canadum) named RcaL. Immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production were also performed. RcaL was obtained through precipitation with ammonium sulphate and affinity chromatography on a Concanavalin A-Sepharose 4B column. The ammonium sulphate fraction F3 showed the highest specific hemagglutinating activity and was applied to affinity chromatography. The lectin was eluted with methyl-α-D-mannopyranoside. RcaL showed highest affinity for methyl-α-D-mannopyranoside and D-mannose; eluted fractions of RcaL agglutinated rabbit erythrocytes (titre, 128(-1)) retained 66 % of chromatographed lectin activity, and the obtained purification factor was 1.14. Under reducing conditions, a polypeptide band of 19.2 kDa was revealed in sodium dodecyl sulphate polyacrylamide gel electrophoresis (PAGE). PAGE confirmed RcaL as an acidic protein revealed in a single band. Cytotoxic and immunomodulatory assays with RcaL in mice splenocyte cultures showed that the lectin was not cytotoxic and induced higher interferon gamma and nitric oxide production in splenocyte cultures. Purified RcaL induced preferential Th1 response, suggesting that it acts as an immunomodulatory compound.
authors.affiliation: Departamento de Bioquímica, Laboratório de Glicoproteínas, Universidade Federal de Pernambuco/UFPE, Av. Prof. Moraes Rego s/n, Cidade Universitária, CEP: 50670-420, Recife, Pernambuco, Brazil.
authors.forename: Marília Cavalcanti
authors.initials: MC
authors.lastname: Coriolano
authors.forename: Cynarha Daysy Cardoso da
authors.initials: CD
authors.lastname: Silva
authors.forename: Cristiane Moutinho Lagos de
authors.initials: CM
authors.lastname: Melo
authors.forename: Ranilson de Souza
authors.initials: Rde S
authors.lastname: Bezerra
authors.forename: Athiê Jorge Guerra
authors.initials: AJ
authors.lastname: Santos
authors.forename: Valéria Rêgo Alves
authors.initials: VR
authors.lastname: Pereira
authors.forename: Luana Cassandra Breitenbach Barroso
authors.initials: LC
authors.lastname: Coelho
mesh_terms: D000818:Animals; D002845:Chromatography; D005399:Fishes / Q000097:blood*; D006388:Hemagglutinins / Q000737:chemistry; D007155:Immunologic Factors / Q000097:blood / Q000737:chemistry / Q000494:pharmacology; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D037102:Lectins / Q000097:blood / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology*; D008358:Mannose / Q000737:chemistry; D051379:Mice; D008970:Molecular Weight; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D006388:Hemagglutinins; D007155:Immunologic Factors; D037102:Lectins; D007371:Interferon-gamma; D008358:Mannose