Autoimmunogenicity of the human sperm protein Sp17 in vasectomized men and identification of linear B cell epitopes

Fertil Steril. 1997 Feb;67(2):355-61. doi: 10.1016/S0015-0282(97)81923-1.


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.

Design: 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.

Setting: University research laboratory.

Patient(s): Fifteen vasectomized or vasovasostomized men.

Main outcome measure(s): Serum antibody reactivity to human Sp17.

Result(s): 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).

Conclusion(s): 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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Surface
  • Autoantibodies / analysis
  • Autoimmunity*
  • B-Lymphocytes / immunology*
  • Calmodulin-Binding Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes*
  • Female
  • Humans
  • Macaca
  • Male
  • Membrane Proteins
  • Papio
  • Recombinant Proteins / immunology
  • Vasectomy*
  • Vasovasostomy


  • Antigens, Surface
  • Autoantibodies
  • Calmodulin-Binding Proteins
  • Carrier Proteins
  • Epitopes
  • Membrane Proteins
  • Recombinant Proteins
  • SPA17 protein, human