Oral antigen exposure in newborn piglets circumvents induction of oral tolerance in response to intraperitoneal vaccination in later life.

Background: We previously determined that newborn piglets orally gavaged with Ovalbumin (OVA) responded to systemic OVA re-exposure with tolerance; if adjuvants were included in oral vaccine, piglets responded with antibody-mediated immunity (Vet Immunol Immunopathol 161(3-4):211-21, 2014). Here, we will investigate whether newborn piglets gavaged with a vaccine comprised of OVA plus unmethylated CpG oligodeoxynucleotides (CpG; soluble component; OVA/CpG) combined with OVA plus CpG encapsulated within polyphosphazene microparticles (MP; particulate component) responded with systemic and mucosal immunity. To monitor the response to systemic antigen re-exposure, piglets were i.

Oral antigen exposure in extreme early life in lambs influences the magnitude of the immune response which can be generated in later life.

Background: Previous investigations in newborn lambs determined that adenovirus-mediated expression of antigen to a localized region of the gut induced antigen-specific mucosal and systemic immunity. These experiments were limited in that the localized region of the gut to which antigen was introduced was sterile and the influence of colostrum on the antigen was not assessed but they do suggest that mucosal vaccines may be an effective vaccination strategy to protect neonatal lambs. We propose that persistent oral antigen exposure introduced in extreme early life can induce immunity in lambs, despite the presence of commensal bacteria and colostrum.

Innate immune cocktail partially protects broilers against cellulitis and septicemia.

Antimicrobial/host defense peptides (A/HDP) are natural compounds that are found in leucocyte cells and on the skin and bodily fluids of birds, reptiles, and mammals. Not only do they possess antibacterial, antiviral, and antiparasitic characteristics but they also stimulate the host immune system to combat infectious diseases and may play a role in the promotion of wound repair. Gamma-amino butyric acid (GABA) is an amino acid-based inhibitory neurotransmitter in the brain that has also been shown to promote wound healing on skin.

Low dose antigen exposure for a finite period in newborn rats prevents induction of mucosal tolerance.

Background: In adult rats, initial exposure to antigens by a mucosal route triggers tolerance such that any subsequent re-exposure, even by a systemic route, results in suppression of immunity. The newborn's gut is semi-permeable for a finite period to allow maternal antibodies to enter the newborn's circulation. We propose that antigens introduced in extreme early life can readily traverse the gut wall and therefore circumvent induction of mucosal tolerance.

Milk-derived antimicrobial peptides to protect against Neonatal Diarrheal Disease: An alternative to antibiotics.

Neonatal Diarrheal Disease is responsible for significant economic losses to the livestock industries in Canada and around the world. Microbes responsible are diverse and include , Salmonella, Rotavirus, Coronavirus and Cryptosporidia. While the use of antibiotics as a treatment for bacterial infections and as a prophylactic additive in feed has dramatically improved cattle production in recent decades, the increasing pressure to reduce or eliminate use of antibiotics in animals has caused the livestock industry to seek appropriate alternatives.

B-cell activating factor (BAFF) promotes CpG ODN-induced B cell activation and proliferation.

It is controversial whether naïve B cells are directly activated in response to TLR9 ligand, CpG ODN. Although bovine blood-derived CD21(+) B cells express TLR9 and proliferate in response to CpG in mixed-cell populations, purified bovine B cells do not proliferate significantly in response to CpG ODN, even when the B cell receptor is engaged. When co-cultured with CD14(+) myeloid cells and/or B-cell activating factor (BAFF), a cytokine produced by activated myeloid cells, there was a significant increase in CpG-specific B cell proliferation, and the number of large B cells in general or positive for CD25, all of which are markers for B cell activation.

Maternal immunity provides protection against pertussis in newborn piglets.

Pertussis continues to be a significant cause of morbidity and mortality in infants and young children worldwide. Methods to control the disease are based on vaccination with either whole-cell or acellular vaccines or treatment with antibiotics. However, despite worldwide vaccination infants are still at the highest risk for the disease.

The host defense peptide beta-defensin 1 confers protection against Bordetella pertussis in newborn piglets.

Innate immunity plays an important role in protection against respiratory infections in humans and animals. Host defense peptides such as beta-defensins represent major components of innate immunity. We recently developed a novel porcine model of pertussis, an important respiratory disease of young children and infants worldwide.