caa a22 4500 606236910 CHVBK 20210128101250.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s11010-015-2332-3 doi (NATIONALLICENCE)springer-10.1007/s11010-015-2332-3 Immunopathology of desialylation: human plasma lipoprotein(a) and circulating anti-carbohydrate antibodies form immune complexes that recognize host cells [Elektronische Daten] [P. Sabarinath, P. Appukuttan] Human plasma lipoprotein(a) [Lp(a)], the dominant lipoprotein in atherosclerotic plaques, contains an apo(a) subunit of variable size linked to the apoB subunit of a low-density lipoprotein (LDL) molecule. Circulating lipoprotein immune complexes (ICs) assayed by ELISA using microplate-coated anti-apo(a) or anti-apoB antibody for capture and peroxidase-labelled anti-human immunoglobulins as probe consisted mostly of Lp(a) despite several-fold excess of LDL over Lp(a) in plasma. Microplate coating of plasma lipoprotein IC and probing with antibodies to apo(a) and apoB also revealed negligible presence of LDL compared to Lp(a). Peanut agglutinin specific to desialylated O-glycans bound significantly more to Lp(a) recovered after urea dissociation of IC than to free Lp(a). Plasma lipoproteins separated by ultracentrifugation and desialylated by neuraminidase formed IC with naturally occurring antibodies in normal plasma. These de novo ICs agglutinated desialylated but not normal human RBC in proportion to the polyagglutinin antibody titre of plasma used, suggesting availability of multipleunoccupied binding sites on the participating antibodies even after IC formation. Agglutination was inhibitable by galactosidesanddecreased 4-8 fold if precursor lipoprotein was selectively depleted ofLp(a), showing agglutinatingICs werecontributed mainlyby desialylated Lp(a) and galactose-specific antibodies. IC was 2 fold more agglutinating if lipoproteins used contained smaller rather than larger Lp(a) molecules of the same number. Small size/high plasma concentration Lp(a) phenotype and neuraminidase-releasing diseases including diabetes are risk factors for vascular disorders. Results suggest a possible route ofLp(a) attachment to vascular cells that offer terminal galactose on surface glycans following desialylation. Springer Science+Business Media New York, 2015 Atherosclerosis nationallicence Lipoprotein(a) nationallicence Immune complex nationallicence Desialylation nationallicence Lactose-binding immunoglobulin nationallicence Anti-T nationallicence Sabarinath P. Department of Biochemistry, Sree Chitra Tirunal Institute for Medical Sciences and Technology, 695011, Thiruvananthapuram, India aut Appukuttan P. Department of Biochemistry, Sree Chitra Tirunal Institute for Medical Sciences and Technology, 695011, Thiruvananthapuram, India aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 403/1-2(2015-05-01), 13-23 0300-8177 403:1-2<13 2015 403 11010 https://doi.org/10.1007/s11010-015-2332-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-015-2332-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sabarinath P. Department of Biochemistry, Sree Chitra Tirunal Institute for Medical Sciences and Technology, 695011, Thiruvananthapuram, India aut NATIONALLICENCE 700 1- Appukuttan P. Department of Biochemistry, Sree Chitra Tirunal Institute for Medical Sciences and Technology, 695011, Thiruvananthapuram, India aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 403/1-2(2015-05-01), 13-23 0300-8177 403:1-2<13 2015 403 11010