Pathogenic natural antibodies recognizing annexin IV are required to develop intestinal ischemia-reperfusion injury.
Intestinal ischemia-reperfusion (IR) injury is initiated when natural IgM Abs recognize neo-epitopes that are revealed on ischemic cells. The target molecules and mechanisms whereby these neo-epitopes become accessible to recognition are not well understood. Proposing that isolated intestinal epithelial cells (IEC) may carry IR-related neo-epitopes, we used in vitro IEC binding assays to screen hybridomas created from B cells of unmanipulated wild-type C57BL/6 mice. We identified a novel IgM mAb (mAb B4) that reacted with the surface of IEC by flow cytometric analysis and was alone capable of causing complement activation, neutrophil recruitment and intestinal injury in otherwise IR-resistant Rag1(-/-) mice. mAb B4 was found to specifically recognize mouse annexin IV. Preinjection of recombinant annexin IV blocked IR injury in wild-type C57BL/6 mice, demonstrating the requirement for recognition of this protein to develop IR injury in the context of a complex natural Ab repertoire. Humans were also found to exhibit IgM natural Abs that recognize annexin IV. These data in toto identify annexin IV as a key ischemia-related target Ag that is recognized by natural Abs in a pathologic process required in vivo to develop intestinal IR injury.
Kulik
Liudmila
L
Department of Medicine, University of Colorado Denver School of Medicine, Denver, CO 80045, USA.
Fleming
Sherry D
SD
Moratz
Chantal
C
Reuter
Jason W
JW
Novikov
Aleksey
A
Chen
Kuan
K
Andrews
Kathy A
KA
Markaryan
Adam
A
Quigg
Richard J
RJ
Silverman
Gregg J
GJ
Tsokos
George C
GC
Holers
V Michael
VM
D000595:Amino Acid Sequence; D000818:Animals; D017314:Annexin A4 / Q000008:administration & dosage / Q000276:immunology* / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000009:adverse effects / Q000096:biosynthesis / Q000378:metabolism* / Q000502:physiology; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000276:immunology* / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D017464:Receptors, Complement 3d / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D015427:Reperfusion Injury / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
D017314:Annexin A4; D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D017464:Receptors, Complement 3d