Homology between cattle bull sperm and bacterial antigenic proteins viz a viz possible role in immunological infertility

Abstract

This study was carried out to investigate the possible presence of identical sperm and bacterial antigens which may cause similar antisperm antibody production leading to lower fertility. Cross-reactive antigens of cattle bull spermatozoa and different bacteria including Escherichia coli (E. coli), Bacillus sp., and Staphylococcus sp. were characterized by immunoblotting and mass fingerprinting. Significant cross-reactivity was obtained for 75, 72, 44, 40, 33, 30, 25, 18, 14 kDa proteins with purified IgG of calves, heifers and cows between spermatozoa and the studied bacteria. Significantly (p < 0.05) matched cross-reactive 40/33/30 kDa sperm, 33 kDa Staphylococcus sp/Bacillus sp and 40/25 kDa E. coli proteins were analyzed. Mass fingerprinting of 40/33/30 kDa (spermatozoa); 40/25 kDa (E. coli) and 33 kDa (Bacillus/Staphylococcus) proteins revealed their matching with vitellogenin-1-like/mitochondrial malate dehydrogenase 2, NAD/acrosin-binding protein isoform XI; outer membrane insertion signal domain/spore coat protein and glyceraldehyde-3-phosphate dehydrogenase, respectively. Acrosin-binding protein isoform X1 and mitochondrial malate dehydrogenase 2, NAD contributes to the capacitation of spermatozoa. Spore coat protein; glyceraldehyde-3-phosphate dehydrogenase of E. coli; Bacillus/Staphylococcus are 37.6% and 39.01% identical to acrosin-binding protein isoform X1; mitochondrial malate dehydrogenase 2, NAD of cattle bull spermatozoa. It can be interpreted from these observations that cross-reacting antibodies developed against 33/30 kDa sperm proteins and 25, 33 kDa bacterial proteins in cows may affect the functional activity of spermatozoa leading to delayed fertility in heifers and cows.

Pathogenesis of Autoimmune Male Infertility: Juxtacrine, Paracrine, and Endocrine Dysregulation

“…For example, a specific immune response to Chlamydia trachomatis , the causative agent of the most common sexually transmitted infection, can lead to inflammation and impaired fertility by DNA fragmentation and also by activating immune responses to an epitope of a heat shock protein, shared by Chlamydia and human sperm cells, which is accompanied by high levels of ASAs [ 21 , 29 , 124 , 126 ]. The epitopes shared with sperm cell antigens have been found in many microbial antigens from Escherichia coli , Bacillus sp ., Staphylococcus aureus , Streptococcus pyogenes , Streptococcus agalactiae , and many viruses [ 7 , 29 , 125 , 126 , 130 ]. Helicobacter pylori is also considered as a possible initiator of autoimmunity against spermatozoa, as since spermatozoa are the only human cells possessing flagella, the possibility of their homology with bacterial flagella cannot be ignored [ 126 ].…”

Pathogenesis of Autoimmune Male Infertility: Juxtacrine, Paracrine and Endocrine Deregulation

“…For example, a specific immune response to Chlamydia trachomatis, the causative agent of the most common sexually transmitted infection, can lead to inflammation and impaired fertility by DNA fragmentation and also by activating immune responses to an epitope of a heat shock protein, shared by Chlamydia and human sperm cells, which is accompanied by high levels of ASAs [21,29,125,127]. The epitopes shared with sperm cell antigens have been found in many microbial antigens from: Escherichia coli, Bacillus sp., Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae and many viruses [7,29,126,127,131]. Helicobacter pylori is also considered as a possible initiator of autoimmunity to spermatozoa, since spermatozoa are the only human cells possessing with flagella, the possibility of their homology with bacterial flagella cannot be ignored [127].…”