470
Autoantibodies and Autoimmunity
(b)
(a)
(d)
(e)
(f)
(c)
Fig. 4
Immunofluorescence patterns produced
by autoantibodies recognizing intracellular
structures other than the nucleus. (a) Antimitotic
spindle apparatus antibodies identify spindle
poles and spindle Fbers during cell division.
(b) Antimidbody antibodies react with the
bridgelike midbody that connects daughter cells
following chromosome segregation but before
cell separation. (c) Anti-Golgi complex
antibodies decorate the Golgi apparatus, which
in most cells is shown as an accumulation of
fluorescence in a discrete cytoplasmic region.
(d) Antimitochondrial antibodies demonstrate
the presence of mitochondria throughout the
cytoplasm; the discrete nuclear dots represent
an additional autoantibody speciFcity in this
serum unrelated to mitochondria.
(e) Antiribosome antibodies produce a diffuse
cytoplasmic staining pattern that spares the
nucleus but may show some weak nucleolar
fluorescence. (f) Anticytoskeletal antibodies
react with a variety of cytoskeletal components;
in this case, the antibody reacts with nonmuscle
myosin. (magniFcation: a, 700
×
; b–f, 350
×
).
protein they have found most use in
the cloning and characterization of the
primary structure of numerous human
cellular proteins. This diversity of targets
that can be exploited by this approach is
clearly illustrated in Tables 1 and 2.
Elucidation
of
the
structure
of
the
autoantigens that are the targets of au-
toantibodies from systemic autoimmune
diseases has revealed that many are func-
tional macromolecular complexes involved
in nucleic acid and protein synthesis and
processing (Table 3). A distinguishing fea-
ture of many of these complexes of nucleic
acids and/or proteins is that autoantibod-
ies do not recognize all the components
of the complex. An extreme, but use-
ful, example is the ribosome, which in
eukaryotes may contain more than 70
proteins. However, only the P-proteins
(P
0
,P
1
,andP
2
), S10, and L12 are rec-
ognized by autoantibodies. Nonetheless,
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