TY - JOUR
T1 - Evolutionary conservation of mannan-binding lectin (MBL) in bony fish
T2 - identification, characterization and expression analysis of three bona fide collectin homologues of MBL in the rainbow trout (Onchorhynchus mykiss)
AU - Kania, Per Walter
AU - Sørensen, Rasmus Reng
AU - Koch, Claus
AU - Brandt, Jette
AU - Kliem, Anette
AU - Vitved, Lars
AU - Hansen, Søren
AU - Skjødt, Karsten
PY - 2010/12
Y1 - 2010/12
N2 - The complement system of fish is generally as complex as in mammals, and in addition Teleost fish often possess several genes encoding different subtypes of a given complement component, such as C3-1, C3-3 and C3-4. Initiators of both the classical (C1) and alternative pathway (factor B) have been characterized in the rainbow trout but so far no molecules of the lectin pathway have been identified. Based on the generally accepted idea of complement evolution, which predicts that the alternative pathway predates the two other pathways, and that the lectin pathway developed before the classical, we set out to characterize members of the lectin pathway in fish. We identified and characterized three homologues of mannan-binding lectin (MBL) with a bona fide collectin structure. By means of RT-PCR and immunohistochemistry using monoclonal antibodies we found that they were synthesized in the spleen, the anterior intestine and the liver. In the liver, we saw co-expression with mannan-binding lectin associated serine protease (MASP). The MBL homologues 2 and 3 (MBL-H2,3) were also found in the vascular system of the rainbow trout. By means of gel size exclusion chromatography of serum we found that MBL-H2,3 oligomerized heterogeneously from monomers to tetramers of a trimeric collagenous subunit. Sequence comparison and phylogenetic studies showed that the homologues were more related with MBL than any other collectins, and that two previously characterized trout proteins, designated MBL1 and MBL2, should be reconsidered as MBL candidates.
AB - The complement system of fish is generally as complex as in mammals, and in addition Teleost fish often possess several genes encoding different subtypes of a given complement component, such as C3-1, C3-3 and C3-4. Initiators of both the classical (C1) and alternative pathway (factor B) have been characterized in the rainbow trout but so far no molecules of the lectin pathway have been identified. Based on the generally accepted idea of complement evolution, which predicts that the alternative pathway predates the two other pathways, and that the lectin pathway developed before the classical, we set out to characterize members of the lectin pathway in fish. We identified and characterized three homologues of mannan-binding lectin (MBL) with a bona fide collectin structure. By means of RT-PCR and immunohistochemistry using monoclonal antibodies we found that they were synthesized in the spleen, the anterior intestine and the liver. In the liver, we saw co-expression with mannan-binding lectin associated serine protease (MASP). The MBL homologues 2 and 3 (MBL-H2,3) were also found in the vascular system of the rainbow trout. By means of gel size exclusion chromatography of serum we found that MBL-H2,3 oligomerized heterogeneously from monomers to tetramers of a trimeric collagenous subunit. Sequence comparison and phylogenetic studies showed that the homologues were more related with MBL than any other collectins, and that two previously characterized trout proteins, designated MBL1 and MBL2, should be reconsidered as MBL candidates.
KW - Former LIFE faculty
KW - Mannan-binding lectin (MBL)
KW - Mannan-binding lectin associated serine protease (MASP)
KW - Collectin
KW - Complement
KW - Innate immunity
U2 - 10.1016/j.fsi.2010.07.020
DO - 10.1016/j.fsi.2010.07.020
M3 - Journal article
SN - 1050-4648
VL - 29
SP - 910
EP - 920
JO - Fish and Shellfish Immunology
JF - Fish and Shellfish Immunology
IS - 6
ER -