Immunization with Bin1b decreases sperm motility with compromised fertility in rats.
ABSTRACT To evaluate the contraceptive ability of a synthetic Bin1b peptide in vivo in the rat.
University laboratory animal service center.
A peptide-based immunization model was developed; rats were injected with the Bin1b specific peptide.
A synthetic peptide segment, MCRSGERKGDICSDP-conjugated with KLH (Bin1b), was used to immunize male wistar rats. Freund's complete adjuvant was used as a control.
Anti-Bin1b levels in sera were evaluated by enzyme-linked immunosorbent assay (ELISA). Anti-Bin1b and control antisera were used to evaluate sperm function inhibition in vitro. The fertility of immunized rats was determined by mating experiment. The testis and epididymides were analyzed by histology.
Histological studies showed no evidence of orchitis or epididymitis in Bin1b-immunized animals. ELISA results revealed that the titers of anti-Bin1b antibodies in serum increased with the immunization process in immunized rats. Sperm recovered from the corpus epididymidis of the Bin1b-immunized animals exhibited a significant decrease in motility. Immunization of Bin1b also caused a reduction (25%) in fertility after the mating experiment.
The present study has demonstrated that immunization with Bin1b peptide specifically interferes with sperm motility, resulting in a compromised fertilizing capacity of sperm.
Article: Antimicrobial peptide defensin: identification of novel isoforms and the characterization of their physiological roles and their significance in the pathogenesis of diseases.[show abstract] [hide abstract]
ABSTRACT: Defensins comprise a family of cationic antimicrobial peptides containing a specific six-cysteine motif. Their contribution to the host defense against microbial invasion and the control of normal flora have been previously described. Some of the β-defensin isoforms are predominantly expressed in the epididymis and showed a region-specific expression pattern in the epididymis, which thus suggested that these isoforms may possess epididymis-specific functions in addition to antimicrobial activities. A sequence variant of the β-defensin 126 gene has been shown to be associated with reductions in the human sperm function, thus supporting this hypothesis. Furthermore, defensins have the capacity to chemoattract immune cells and induce the secretion of inflammatory cytokines. Mice expressing human neutrophil α-defensin showed more severe lung injuries after the aspiration of acidic contents than did control mice. Recent investigations regarding copy number variations of human defensin genes also suggest the significance of defensin in the pathogenesis or the worsening of chronic obstructive pulmonary diseases, sepsis and psoriasis.Proceedings of the Japan Academy Ser B Physical and Biological Sciences 01/2012; 88(4):152-66. · 2.77 Impact Factor