Autoimmunogenicity of the human sperm protein Sp17 in vasectomized men and identification of linear B cell epitopes.
OBJECTIVE
To assess whether human sera positive for antisperm antibodies have detectable levels of Sp17 autoantibodies and to determine the linear B cell epitopes to which these are raised for both native and recombinant Sp17.


METHODS
Enzyme-linked immunoaborbent assays were performed against recombinant HSp17 on 15 serum samples from prevasovasostomy and postvasovasostomy patients. Positive sera then were used in mimotope analyses to determine HSp17 immunodominant linear B cell epitopes. These were compared with the linear B cell epitopes of recombinant HSp17.


METHODS
University research laboratory.


METHODS
Fifteen vasectomized or vasovasostomized men.


METHODS
Serum antibody reactivity to human Sp17.


RESULTS
Sera from vasectomized and vasovasostomized men exhibit Sp17 antibodies raised predominantly to two immunodominant linear B cell epitopes (amino acids 4 to 19 and amino acids 118 to 127), which differed from those of recombinant HSp17 (amino acids 52 to 79 and amino acids 124 to 136).


CONCLUSIONS
The results show that Sp17 is an antigen to which vasectomized men raise autoantibodies. Two linear B cell epitopes predominate in native Sp17 and these differ from (but overlap with) those of the bacterially expressed recombinant protein.
Lea
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IA
Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599, USA.
Adoyo
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P
O'Rand
M G
MG
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface; D001323:Autoantibodies / Q000032:analysis; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology*; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D008251:Macaca; D008297:Male; D008565:Membrane Proteins; D010215:Papio; D011994:Recombinant Proteins / Q000276:immunology; D014659:Vasectomy; D014669:Vasovasostomy
D000954:Antigens, Surface; D001323:Autoantibodies; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D000939:Epitopes; D008565:Membrane Proteins; D011994:Recombinant Proteins; C090172:SPA17 protein, human