TY - JOUR
T1 - Anionization of an antigen promotes glomerular binding and immune complex formation
AU - Barnes, J. L.
AU - Reznicek, M. J.
AU - Radnik, R. A.
AU - Venkatachalam, M. A.
N1 - Funding Information:
This investigation was supported by research grants AM 17387 and AM 30393 from the National Institutes of Health. The authors acknowledge the technical assistance of Ron Reif and Greg Potter, and the typing of the manuscript by Laura Gantt.
PY - 1988
Y1 - 1988
N2 - Bovine serum albumin (BSA, pl 4.9) was maleylated to yield highly anionic MBSA (pl 3.0). Maleylation of BSA lead to an expansion of molecular size of native BSA from an effective molecular radius (EMR) of 37 Å to 57 Å for MBSA as assessed by gel filtration chromatography. MBSA, but not BSA, bound to peripheral capillary wall (PCW) and mesangium in vitro in frozen sections, and in vivo following i.v. injection (0.006 mg/g body wt), examined by immunofluorescence. When similarly injected rats or controls were given antibodies to either MBSA or BSA following injection of antigen, immune complexes were observed in glomeruli by immunofluorescence and EM only in MBSA injected rats. Deposits occurred in the mesangium and subendothelium in the PCW. In frozen sections, bound MBSA could be partially removed from tissue sections by high ionic strength buffer. Also, binding of MBSA was diminished by prior treatment of sections with synthetic polyanions. Maleylated bovine gamma-globulin and succinylated BSA showed identical binding patterns as described for MBSA, indicating that binding was not unique to the modified BSA molecule nor to the form of anionization. These results indicate that charge interactions between circulating highly anionic macromolecules and cationic domains within glomerular structures, are responsible, in part, for MBSA binding and subsequent localization of immune complexes. Furthermore, it is inferred that the selective binding of MBSA to glomeruli and formation of immune complexes occurred by a mechanism not related to difference in size between MBSA and BSA. These findings are different from conventionally understood charge interactions in glomerular immune complex formation.
AB - Bovine serum albumin (BSA, pl 4.9) was maleylated to yield highly anionic MBSA (pl 3.0). Maleylation of BSA lead to an expansion of molecular size of native BSA from an effective molecular radius (EMR) of 37 Å to 57 Å for MBSA as assessed by gel filtration chromatography. MBSA, but not BSA, bound to peripheral capillary wall (PCW) and mesangium in vitro in frozen sections, and in vivo following i.v. injection (0.006 mg/g body wt), examined by immunofluorescence. When similarly injected rats or controls were given antibodies to either MBSA or BSA following injection of antigen, immune complexes were observed in glomeruli by immunofluorescence and EM only in MBSA injected rats. Deposits occurred in the mesangium and subendothelium in the PCW. In frozen sections, bound MBSA could be partially removed from tissue sections by high ionic strength buffer. Also, binding of MBSA was diminished by prior treatment of sections with synthetic polyanions. Maleylated bovine gamma-globulin and succinylated BSA showed identical binding patterns as described for MBSA, indicating that binding was not unique to the modified BSA molecule nor to the form of anionization. These results indicate that charge interactions between circulating highly anionic macromolecules and cationic domains within glomerular structures, are responsible, in part, for MBSA binding and subsequent localization of immune complexes. Furthermore, it is inferred that the selective binding of MBSA to glomeruli and formation of immune complexes occurred by a mechanism not related to difference in size between MBSA and BSA. These findings are different from conventionally understood charge interactions in glomerular immune complex formation.
UR - http://www.scopus.com/inward/record.url?scp=0023680196&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023680196&partnerID=8YFLogxK
U2 - 10.1038/ki.1988.161
DO - 10.1038/ki.1988.161
M3 - Article
C2 - 2460660
AN - SCOPUS:0023680196
VL - 34
SP - 156
EP - 163
JO - Kidney International
JF - Kidney International
SN - 0085-2538
IS - 2
ER -