1 Another ligand of alpha(M)beta(
2),
C3bi, which is known to use the same segments of the alp
2 (IgG)- and complement protein fragment
3bi (
C3bi)-opsonized zymosan similarly induced rapid phosphor
3 Ser138 to Ala in the beta2 subunit
abolished C3bi binding and cell adhesion but did not affect NIF bi
4 us counterparts in integrin alpha2
abrogated C3bi binding, whereas substitution of eight other segmen
5 etely abrogated adhesion while not
affecting C3bi and NIF binding.
6 the conformation of the beta(2)I-domain
and C3bi binding activity of alpha(M)beta(2) were dependent
7 mal or even stronger interaction with Fg
and C3bi, as reported in our previous study.
8 s(309)) that are critical for fibrinogen
and C3bi binding to alpha(M)beta(2).
9 ides interacted directly with fibrinogen
and C3bi.
10 results, Abl-deficient Ms are inefficient
at C3bi-opsonized promastigote uptake, and Arg-deficient Ms
11 s process depends on the interaction
between C3bi, a degradation product derived from activation of t
12 structurally very similar but does not
bind C3bi.
13 es within the W4 blade significantly
blocked C3bi binding by wild-type alpha M beta 2.
14 glial fibrillary acidic protein,
complement C3bi receptor, and myelin basic protein.
15 fibrillary acidic protein or the
complement C3bi receptor was used to determine if glia/macrophages
16 enhanced immunoexpression of the
complement C3bi receptor, both of which are indicators of cerebella
17 fibrillary acidic protein or the
complement C3bi receptor.
18 hrocytes opsonized with complement
component C3bi were bound to macrophages at 37degrees C, a conditi
19 Decreased C3bi and C5b-9 deposition on RBCs and neutrophils was do
20 The residues necessary to
engage C3bi reside on or adjacent to the cation binding MIDAS s
21 es (PMN) to surfaces coated with
fibrinogen,
C3bi, ICAM-1, and other ligands.
22 main, which has a low intrinsic affinity
for C3bi, acquired high affinity for the ligand when the imp
23 , P257 were identified as being critical
for C3bi binding.
24 sence of serum, the macrophage receptors
for C3bi, CR3 (CD11b/CD18) and CR4 (CD11c/CD18), were signif
25 us studies have mapped critical residues
for C3bi binding to the I-domains of the alpha M and the bet
26 48) is more critical for fibrinogen than
for C3bi binding.
27 immunoglobulin G or the complement
fragment C3bi.
28 2) These five mutants defective
in C3bi binding supported strong alpha M beta 2-mediated an
29 s with the complex midsegment, Q204-I215,
in C3bi recognition.
30 The amino acids involved
in C3bi binding are distinct from those involved in interac
31 sp398 to Thr451) is involved specifically
in C3bi but not fibrinogen binding to alpha M beta 2.
32 ent, K245 plays a critical role in
mediating C3bi binding to alpha M beta 2.
33 ncluding neutrophil inhibitory factor (
NIF),
C3bi, and certain immobilized protein substrates, repres
34 Thus, the contact sites for
NIF,
C3bi, and adhesive proteins, represented by denatured ov
35 dertaken to establish the molecular basis
of C3bi recognition by alpha M beta 2.
36 within the alpha M subunit in the binding
of C3bi, as well as many other alpha M beta 2 ligands.
37 We report that the binding
of C3bi-opsonized sheep red blood cells (RBCs) to alphaMbet
38 d that binds CR3 and competes the binding
of C3bi.
39 (3) Blocking
of C3bi binding to alpha M beta 2 by monoclonal antibodies
40 3), in macrophages, allowing phagocytosis
of C3bi-opsonized targets.
41 decreased in Arg-deficient Ms, while that
of C3bi-coated beads is unaffected.
42 Conversely, uptake
of C3bi-coated beads is decreased in Abl-deficient Ms, but
43 n mononuclear phagocytes through the
opsonin C3bi.
44 surface and the C3 cleavage products, C3b
or C3bi.
45 G (IgG)-opsonized C. neoformans and IgG-
or C3bi-opsonized sheep erythrocytes was performed using a
46 ition, i.e., C3b (opsonization and lysis)
or C3bi (opsonization only) fragment deposition, is central
47 s between the complement degradation
product C3bi and leukocyte integrin alpha M beta 2 are critical
48 s between the complement degradation
product C3bi and leukocyte integrin alpha(M)beta(2) are critical
49 ates the phagocytosis of complement
protein (
C3bi)-coated particles.
50 immunoreactivity (IR) to complement
receptor C3bi (monoclonal antibody OX-42) and major histocompatib
51 utation of K245 to Ala significantly
reduced C3bi binding but had no effect on binding of another alp
52 We report three major findings: (1)
The C3bi binding pocket is composed of three regions, P147-R
53 interacts with C3bi, detailed mapping of
the C3bi binding site was undertaken.
54 ether and contribute to the formation of
the C3bi-binding site.
55 fect was at least partially mediated
through C3bi-CD11b/CD18 interaction.
56 on, rapid conversion of surface-bound C3b
to C3bi, and the presence of LPS O Ag.
57 targeted to the IAM, where it was cleaved
to C3bi.
58 the persistent presence of C3b compared
with C3bi, which indicates that C3b inactivation results in s
59 24-Gly440 within W4 interacted directly
with C3bi.
60 ha(M)I-domain of the integrin interacts
with C3bi, detailed mapping of the C3bi binding site was unde
61 d in coating the apoptotic cell surface
with C3bi.