The In Vitro Anti-pathogenic Activity of Immunoglobulin Concentrates Extracted from Ovine Blood

Abstract

An immunoglobulin-rich fraction has been prepared from ovine blood in our laboratory. We have investigated its antibacterial activity and binding activity to pathogenic whole cell antigens, lipopolysaccharide (LPS) and staphylococcal enterotoxin B. Ovine immunoglobulin concentrate (OIC) comprised about 73 +/- 2% of IgG and 11 +/- 1% of IgM on a protein basis. It inhibited the growth of all 13 strains of pathogens tested, but the inhibitory activity varied according to bacterial strain. The inhibitory activity of OIC was attributed to the high contents of undenatured immunoglobulin present because its inhibitory activity was destroyed by pepsin digestion and heat treatment (65 degrees C for 30 min). OIC bound to all the Gram-positive and Gram-negative pathogens, regardless of cell wall structure. The highest magnitude of crossreactivity to whole cell antigens was against Staphylococcus epidermidis and Shigella soneii strains (p < 0.001). The binding activity of OIC to LPS obtained from Escherichia coli O111:B4 and Salmonella enterica serotype typhimurium was assessed by enzyme-linked immunosorbent assay and lymphoblast K-562 proliferation assay. OIC bound to LPS with a binding activity that was dependent on OIC concentration and saturable, showing typical hyperbolic curves. For toxin-binding activity, an OIC concentration-dependent trend like that for LPS-binding activity was also observed. This preliminary evidence suggests that the OIC used in this study could be a promising supplement for protecting against pathogenic bacteria.

Ovine Serum Immunoglobulin Has Immunomodulatory Effects in Growing Rats Gavaged with Salmonella enteritidis1

“…Recently, Han et al (11) in an in vitro experiment demonstrated the antipathogenic effect of an ovine Ig concentrate. They reported that it was able to bind to the cell walls of 13 strains of bacteria (both Gram-positive and Gram-negative).…”

“…Han et al (11), using an in vitro approach, reported an inhibitory activity of ovine Ig concentrate against 13 strains of pathogenic bacteria, including Salmonella species. Previously, our group reported that feeding freeze-dried ovine Ig (FDOI) (Ig extracted from lamb blood) to normal growing rats improved growth performance, increased the weight of some organs, and improved gut architecture, such as increased villus height, surface area, and crypt depth (12).…”

Orally administered ovine serum immunoglobulins modulate the intestinal levels of Lactobacillus and enterobacteria in the growing rat1

“…It is well known that animal semm contains antibodies that are effective against a variefy of pathogens like E. coli. Salmonella, Listeria, C. difficile, rotavirus, and many more (Eibl et al, 1988;Hammarström et al, 1993;Bogstedt et al, 1996;Pérez-Bosque et al, 2008;Han et al, 2009;Balan, 2011;. Therefore, semm Ig may provide passive antimicrobial proteetion (and proteetion fi^om subelinieal infection) by exclusion of opportunistic pathogens.…”

“…We therefore hypothesize that oral administration of purified, polyspecific, pooled ovine serum immunoglobulin may positively modulate gut microbiota, potentially via immunoglobulin-mediated binding of potential pathogenic bacteria (preventing attachment; Han et al, 2009) or by supporting the development of beneficial bacteria in the gut.…”

Dietary supplementation with ovine serum immunoglobulin modulates correlations between mucin, microbiota and immunity proteins in the growing rat

“…Ig prepared from ovine serum (from New Zealand lamb) was tested for apparent antimicrobial effects using an in vitro study (Han, Boland, Singh, & Moughan, ). Han et al () reported that ovine serum Ig exerted inhibitory and binding activity to Gram‐positive and Gram‐negative microbial pathogens, as well as their lipopolysaccharide and enterotoxin. Following which, a series of peer‐reviewed publications are found in the literature suggesting the various positive biological effects of ovine Ig preparation in different challenged and unchallenged animal models.…”