Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Binding and release of C3 from Leishmania donovani promastigotes during incubation in normal human serum
AU - Puentes, S M
AU - Dwyer, D M
AU - Bates, P A
AU - Joiner, K A
PY - 1989/12
Y1 - 1989/12
N2 - We have examined the nature and extent of C3 deposition on Leishmania donovani, strain 1S, clone 2D, promastigotes. Total molecules of C3 bound/parasite after 60 min was similar for parasites incubated in normal human serum, normal human serum adsorbed to remove natural antibody, or either serum source chelated with Mg-EGTA to limit activation to the alternative pathway. A comparison of parasites grown to early, mid, late-log or stationary phases revealed no difference in the extent and kinetics of C3 binding. C3 bound covalently to the parasite primarily through a hydroxylamine resistant (putatively amide) linkage. Of the bound C3, 75% was present as hemolytically inactive iC3b. Nearly 50% of the bound C3 was spontaneously released within 30 min at 37 degrees C. This spontaneous release was due to an unusual proteolytic cleavage event that released C3 from the C3 acceptor on the parasite surface. These results define and characterize the unusual features of C3 binding to L. donovani promastigotes during incubation in serum.
AB - We have examined the nature and extent of C3 deposition on Leishmania donovani, strain 1S, clone 2D, promastigotes. Total molecules of C3 bound/parasite after 60 min was similar for parasites incubated in normal human serum, normal human serum adsorbed to remove natural antibody, or either serum source chelated with Mg-EGTA to limit activation to the alternative pathway. A comparison of parasites grown to early, mid, late-log or stationary phases revealed no difference in the extent and kinetics of C3 binding. C3 bound covalently to the parasite primarily through a hydroxylamine resistant (putatively amide) linkage. Of the bound C3, 75% was present as hemolytically inactive iC3b. Nearly 50% of the bound C3 was spontaneously released within 30 min at 37 degrees C. This spontaneous release was due to an unusual proteolytic cleavage event that released C3 from the C3 acceptor on the parasite surface. These results define and characterize the unusual features of C3 binding to L. donovani promastigotes during incubation in serum.
M3 - Journal article
C2 - 2584716
VL - 143
SP - 3743
EP - 3749
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 11
ER -