Immune responses to a GnRH-based anti-fertility immunogen, induced by different adjuvants and subsequent effect on vaccine efficacy

Vaccination with Recombinant Leishmania donovani Gamma-Glutamylcysteine Synthetase Fusion Protein Protects Against L. donovani Infection

“…However, the vesicular formulation gave a similar level of protection as immunization with LdcGCS alone. In previous studies, we have shown that immunization with modified gonadotrophin hormone-NIV formulation to induce castration of male rats (4 doses, 10 mg/dose) induced a predominant Th2 response (Ferro et al, 2004), whereas in the present study immunization with LdcGCS induced a mixed Th1/Th2 response. The difference in results could be due to the different species, antigen used, or dosing regimen.…”

“…Therefore, in the present study the ability of L. donovani cGCS (LdcGCS) to protect against infection was assessed. Adjuvants have been used to improve the efficacy of protein vaccines (O'Hagan and De Gregorio, 2009); therefore, in the present study, the ability of the non-ionic surfactant vesicles (NIV), which have adjuvant capabilities (Ferro et al, 2004), to increase the efficacy of LdcGCS vaccination was also evaluated.…”

Early postnatal immunisation against gonadotrophin-releasing hormone induces a high but differential immune response in heifer calves

“…Although it is not possible to extrapolate antibody biological function in vivo from in vitro binding activity in these experiments (Finnerty et al, 1994;Meloen, 1995), it is interesting to note that antibody titres similar to those measured in the HT heifers (>30% binding at 1:1000 dilution) have previously been shown to block endogenous GnRH signalling and inhibit reproduction in cattle (Adams and Adams, 1990). Additionally, the variability in the immune response in early postnatal calves may be explained by factors such as immaturity of the immune system, interference of maternal antibodies, individual genetic variation (Chappuis, 1998;Chase et al, 2008;Morein et al, 2007;Siegrist, 2007) and/ or vaccine formulation (Chase et al, 2008;Ferro et al, 2004;Geary et al, 2006;Johnson et al, 1988). Despite this variability and the fact that thirty-four weeks after primary vaccination antibody titres had fallen (<5% binding at 1:1000 dilution), immunised heifer calves still had significantly higher titres than control animals at the end of the study.…”

“…This implies that if an appropriate GnRH construct and/or formulation are used as an immunogen, it is possible to stimulate the immune system of postnatal calves to generate a specific immune response to this peptide hormone. Because of its small size and its recognition by the immune system as ''self'', GnRH is unable to function as an immunogen under normal conditions (Ferro et al, 2004;Thompson, 2000). However, it is possible to induce an adaptive immune response to GnRH by coupling this molecule to a protein carrier molecule in admixture with an appropriate adjuvant preparation (Ferro et al, 2004;Thompson, 2000).…”

Carrier mediated protein and peptide stabilization

“…The encapsulation of pharmaceutical materials in niosomes can decrease drug toxicity, increase drug absorption, stability or activity, and retard removal of drug from the circulation due to slow drug release. Some proteins and peptides such as α-interferon (Niemiec et al, 1995), bovine serum albumin (Brewer & Alexander, 1992;Murdan et al, 1999), cyclosporine A (Niemiec et al, 1995;Waranuch et al, 1998), 9-desglycinamide-8-arginine vasopressin [DGAVP] (Yoshida et al, 1992), GnRH-based anti-fertility immunogen (Ferro et al, 2004), hemagglutinin (Murdan et al, 1999), influenza viral antigens (Chattaraj & Das, 2003), insulin (Khaksa et al, 2000;Varshosaz et al, 2003), luteinizing hormone releasing hormone [LHRH] (Arunothayanun et al, 1999), ovalbumin (Brewer et al, 1998;Rentel et al, 1999), and recombinant human granulocyte-macrophage colony stimulating factor [rhGM-CSF] (Memisoglu et al, 1997) have been successfully encapsulated in niosomes.…”