Abstract
Immunohistochemical studies have shown that a unique immunoreactive molecule is present near the apical region of human biliary epithelial (BE) cells in patients with primary biliary cirrhosis (PBC). This can be visualized by confocal microscopy in PBC livers using a number of unique monoclonal antibodies to the E2 component of pyruvate dehydrogenase complex (PDC-E2), the autoantigen most commonly recognized by antimitochondrial antibodies (AMA). One such antibody, the murine mAb C355.1 was used to identify peptide mimotopes of PDC-E2 by screening a random dodecapeptide phage library ON 159.2 to identify the possible biochemical nature of this apical staining molecule. Out of 36 independent clones, 29 showed a common sequence and seven other sequences were singly represented. Three common amino acid motifs (SYP, TYVS and VRH) were found among these eight sequences. Similar to C355.1, the human combinatorial antibodies derived from a patient with PBC, SP1 and SP4, recognize the inner lipoyl domain of PDC-E2. However, when these antibodies are used to stain PBC BE cells, SP4 stains the apical region of PBC BE cells with high intensity whereas SP1 produces only cytoplasmic staining. Competitive inhibition of immunohistochemical staining using PDC-E2 specific human combinatorial antibodies SP1 and SP4 was performed using five of the above dodecapeptides. Interestingly, the peptides selected with C355.1 differentially inhibited the binding of SP1 and SP4 to PBC BE cells. Finally, rabbit sera raised against one such peptide (WMSYPDRTLRTS) stained BE cells from patients with PBC with a higher intensity than controls. Comparable data was obtained with immunoelectron-microscopy. These data suggest that a molecular mimic of PDC-E2 is present at the external aspect of PBC BE cells.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 785-793 |
| Number of pages | 9 |
| Journal | Journal of Autoimmunity |
| Volume | 9 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 1996 |
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Keywords
- bile duct epithelials
- molecular mimicry
- monoclonal antibodies
- primary biliary cirrhosis
- random peptide library
- selective inhibition
ASJC Scopus subject areas
- Immunology
- Immunology and Allergy
Cite this
Inhibition of PDC-E2 human combinatorial autoantibodies by peptide mimotopes. / Leung, Patrick S; Cha, Sanghoon; Joplin, Ruth E.; Galperin, Claudio; Van de Water, Judith A; Ansari, Aftab A.; Coppel, Ross L.; Schatz, Peter J.; Cwirla, Steve; Fabris, Luca E.; Neuberger, James M.; Gershwin, M. Eric.
In: Journal of Autoimmunity, Vol. 9, No. 6, 12.1996, p. 785-793.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Inhibition of PDC-E2 human combinatorial autoantibodies by peptide mimotopes
AU - Leung, Patrick S
AU - Cha, Sanghoon
AU - Joplin, Ruth E.
AU - Galperin, Claudio
AU - Van de Water, Judith A
AU - Ansari, Aftab A.
AU - Coppel, Ross L.
AU - Schatz, Peter J.
AU - Cwirla, Steve
AU - Fabris, Luca E.
AU - Neuberger, James M.
AU - Gershwin, M. Eric
PY - 1996/12
Y1 - 1996/12
N2 - Immunohistochemical studies have shown that a unique immunoreactive molecule is present near the apical region of human biliary epithelial (BE) cells in patients with primary biliary cirrhosis (PBC). This can be visualized by confocal microscopy in PBC livers using a number of unique monoclonal antibodies to the E2 component of pyruvate dehydrogenase complex (PDC-E2), the autoantigen most commonly recognized by antimitochondrial antibodies (AMA). One such antibody, the murine mAb C355.1 was used to identify peptide mimotopes of PDC-E2 by screening a random dodecapeptide phage library ON 159.2 to identify the possible biochemical nature of this apical staining molecule. Out of 36 independent clones, 29 showed a common sequence and seven other sequences were singly represented. Three common amino acid motifs (SYP, TYVS and VRH) were found among these eight sequences. Similar to C355.1, the human combinatorial antibodies derived from a patient with PBC, SP1 and SP4, recognize the inner lipoyl domain of PDC-E2. However, when these antibodies are used to stain PBC BE cells, SP4 stains the apical region of PBC BE cells with high intensity whereas SP1 produces only cytoplasmic staining. Competitive inhibition of immunohistochemical staining using PDC-E2 specific human combinatorial antibodies SP1 and SP4 was performed using five of the above dodecapeptides. Interestingly, the peptides selected with C355.1 differentially inhibited the binding of SP1 and SP4 to PBC BE cells. Finally, rabbit sera raised against one such peptide (WMSYPDRTLRTS) stained BE cells from patients with PBC with a higher intensity than controls. Comparable data was obtained with immunoelectron-microscopy. These data suggest that a molecular mimic of PDC-E2 is present at the external aspect of PBC BE cells.
AB - Immunohistochemical studies have shown that a unique immunoreactive molecule is present near the apical region of human biliary epithelial (BE) cells in patients with primary biliary cirrhosis (PBC). This can be visualized by confocal microscopy in PBC livers using a number of unique monoclonal antibodies to the E2 component of pyruvate dehydrogenase complex (PDC-E2), the autoantigen most commonly recognized by antimitochondrial antibodies (AMA). One such antibody, the murine mAb C355.1 was used to identify peptide mimotopes of PDC-E2 by screening a random dodecapeptide phage library ON 159.2 to identify the possible biochemical nature of this apical staining molecule. Out of 36 independent clones, 29 showed a common sequence and seven other sequences were singly represented. Three common amino acid motifs (SYP, TYVS and VRH) were found among these eight sequences. Similar to C355.1, the human combinatorial antibodies derived from a patient with PBC, SP1 and SP4, recognize the inner lipoyl domain of PDC-E2. However, when these antibodies are used to stain PBC BE cells, SP4 stains the apical region of PBC BE cells with high intensity whereas SP1 produces only cytoplasmic staining. Competitive inhibition of immunohistochemical staining using PDC-E2 specific human combinatorial antibodies SP1 and SP4 was performed using five of the above dodecapeptides. Interestingly, the peptides selected with C355.1 differentially inhibited the binding of SP1 and SP4 to PBC BE cells. Finally, rabbit sera raised against one such peptide (WMSYPDRTLRTS) stained BE cells from patients with PBC with a higher intensity than controls. Comparable data was obtained with immunoelectron-microscopy. These data suggest that a molecular mimic of PDC-E2 is present at the external aspect of PBC BE cells.
KW - bile duct epithelials
KW - molecular mimicry
KW - monoclonal antibodies
KW - primary biliary cirrhosis
KW - random peptide library
KW - selective inhibition
UR - http://www.scopus.com/inward/record.url?scp=0030462423&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030462423&partnerID=8YFLogxK
U2 - 10.1006/jaut.1996.0101
DO - 10.1006/jaut.1996.0101
M3 - Article
C2 - 9115581
AN - SCOPUS:0030462423
VL - 9
SP - 785
EP - 793
JO - Journal of Autoimmunity
JF - Journal of Autoimmunity
SN - 0896-8411
IS - 6
ER -