Oral Passive Immunization Research Articles

Protective effect of chicken yolk antibody Y against Campylobacter jejuni induced diarrhea in cats.

Campylobacter jejuni (C. jejuni) is a common pathogen that often causes diarrhea, loss of appetite, and even enteritis in domestic cats, affecting their growth and development, especially in kittens under 6 months of age. Oral passive immunization with chicken yolk antibody Y has been proved effective for the treatment of gastrointestinal pathogen infections due to its high specificity. In this study, C. jejuni was isolated from diarrheal cat feces, and the specific egg yolk antibody Y against C. jejuni was demonstrated to effectively inhibit its proliferation in vitro experiments. To evaluate the effect of anti-C. jejuni IgY, the mouse C. jejuni infection model was established and it was found that IgY could alleviate C. jejuni-induced clinical symptoms. Consistent with these results, the reduction of pro-inflammatory factors and intestinal colonization by C. jejuni in the IgY-treated groups, especially in the high dose group. We then evaluated the protective effect of IgY on young Ragdoll cats infected with C. jejuni. This specific antibody reduced the rate of feline diarrhea, protected the growth of young cats, inhibited systemic inflammatory hyperactivation, and increased fecal short-chain fatty acid concentrations. Notably, IgY may have a protective role by changing intestinal amino acid metabolism and affecting C. jejuni chemotaxis. Collectively, specific IgY is a promising therapeutic strategy for C. jejuni-induced cat diarrhea.

Efficacy of immunoglobulin Y-based oral passive immunization against dental caries

Efficacy of immunoglobulin Y-based oral passive immunization against dental caries

Prevention of Shiga toxin 1-caused colon injury by plant-derived recombinant IgA

Immunoglobulin A (IgA) is a candidate antibody for oral passive immunization against mucosal pathogens like Shiga toxin-producing Escherichia coli (STEC). We previously established a mouse IgG monoclonal antibody (mAb) neutralizing Shiga toxin 1 (Stx1), a bacterial toxin secreted by STEC. We designed cDNA encoding an anti-Stx1 antibody, in which variable regions were from the IgG mAb and all domains of the heavy chain constant region from a mouse IgA mAb. Considering oral administration, we expressed the cDNA in a plant expression system aiming at the production of enough IgA at low cost. The recombinant-IgA expressed in Arabidopsis thaliana formed the dimeric IgA, bound to the B subunit of Stx1, and neutralized Stx1 toxicity to Vero cells. Colon injury was examined by exposing BALB/c mice to Stx1 via the intrarectal route. Epithelial cell death, loss of crypt and goblet cells from the distal colon were observed by electron microscopy. A loss of secretory granules containing MUC2 mucin and activation of caspase-3 were observed by immunohistochemical methods. Pretreatment of Stx1 with the plant-based recombinant IgA completely suppressed caspase-3 activation and loss of secretory granules. The results indicate that a plant-based recombinant IgA prevented colon damage caused by Stx1 in vivo.

Recombinant Human Secretory IgA Induces Salmonella Typhimurium Agglutination and Limits Bacterial Invasion into Gut-Associated Lymphoid Tissues.

As the predominant antibody type in mucosal secretions, human colostrum, and breast milk, secretory IgA (SIgA) plays a central role in safeguarding the intestinal epithelium of newborns from invasive enteric pathogens like the Gram-negative bacterium Salmonella enterica serovar Typhimurium (STm). SIgA is a complex molecule, consisting of an assemblage of two or more IgA monomers, joining (J)-chain, and secretory component (SC), whose exact functions in neutralizing pathogens are only beginning to be elucidated. In this study, we produced and characterized a recombinant human SIgA variant of Sal4, a well-characterized monoclonal antibody (mAb) specific for the O5-antigen of STm lipopolysaccharide (LPS). We demonstrate by flow cytometry, light microscopy, and fluorescence microscopy that Sal4 SIgA promotes the formation of large, densely packed bacterial aggregates in vitro. In a mouse model, passive oral administration of Sal4 SIgA was sufficient to entrap STm within the intestinal lumen and reduce bacterial invasion into gut-associated lymphoid tissues by several orders of magnitude. Bacterial aggregates induced by Sal4 SIgA treatment in the intestinal lumen were recalcitrant to immunohistochemical staining, suggesting the bacteria were encased in a protective capsule. Indeed, a crystal violet staining assay demonstrated that STm secretes an extracellular matrix enriched in cellulose following even short exposures to Sal4 SIgA. Collectively, these results demonstrate that recombinant human SIgA recapitulates key biological activities associated with mucosal immunity and raises the prospect of oral passive immunization to combat enteric diseases.

Inhibition of invasive salmonella by orally administered IgA and IgG monoclonal antibodies.

Non-typhoidal Salmonella enterica strains, including serovar Typhimurium (STm), are an emerging cause of invasive disease among children and the immunocompromised, especially in regions of sub-Saharan Africa. STm invades the intestinal mucosa through Peyer’s patch tissues before disseminating systemically. While vaccine development efforts are ongoing, the emergence of multidrug resistant strains of STm affirms the need to seek alternative strategies to protect high-risk individuals from infection. In this report, we investigated the potential of an orally administered O5 serotype-specific IgA monoclonal antibody (mAb), called Sal4, to prevent infection of invasive Salmonella enterica serovar Typhimurium (STm) in mice. Sal4 IgA was delivered to mice prior to or concurrently with STm challenge. Infectivity was measured as bacterial burden in Peyer’s patch tissues one day after challenge. Using this model, we defined the minimal amount of Sal4 IgA required to significantly reduce STm uptake into Peyer’s patches. The relative efficacy of Sal4 in dimeric and secretory IgA (SIgA) forms was compared. To assess the role of isotype in oral passive immunization, we engineered a recombinant IgG1 mAb carrying the Sal4 variable regions and evaluated its ability to block invasion of STm into epithelial cells in vitro and Peyer’s patch tissues. Our results demonstrate the potential of orally administered monoclonal IgA and SIgA, but not IgG, to passively immunize against invasive Salmonella. Nonetheless, the prophylactic window of IgA/SIgA in the mouse was on the order of minutes, underscoring the need to develop formulations to protect mAbs in the gastric environment and to permit sustained release in the small intestine.

Protective effect of chicken egg yolk immunoglobulins (IgY) against enterotoxigenic Escherichia coli K88 adhesion in weaned piglets

BackgroundEnterotoxigenic Escherichia coli K88 (E. coli K88) are considered as a major cause of diarrhea and death in newly weaned piglets. Oral passive immunization with chicken egg yolk immunoglobulins (IgY) have attracted considerable attention for treatment of gastrointestinal infection due to its high specificity. In this study it was estimated the protective effect of anti-K88 fimbriae IgY against E. coli K88 adhesion to piglet intestinal mucus in vitro and to investigate the potential use of IgY for controlling E. coli-induced diarrhea in weaned piglets in vivo.ResultsE. coli K88 was incubated with IgY for 24 h, and the bacterial growth profiles showed that specific IgY with a concentration higher than 5 mg/mL was observed to significantly inhibit the growth of E. coli K88 compared to nonspecific yolk powder in a liquid medium. Moreover, pretreatment with 50 mg/mL of IgY was found to significantly decrease the adhesion ability of E. coli K88 to porcine jejunal and ileal mucus, further supported by the observations from our immunofluorescence microscopic analysis. In vivo, administration of IgY successfully protected piglets from diarrhea caused by E. coli K88 challenge. Additionally, IgY treatment efficiently alleviated E. coli-induced intestinal inflammation in piglets as the gene expression levels of inflammatory cytokines TNF-α, IL-22, IL-6 and IL-1β in IgY-treated piglets remained unchanged after E. coli K88 infection. Furthermore, IgY significantly prevented E. coli K88 adhering to the jejunal and ileal mucosa of piglets with E. coli infection and significantly decreased E. coli and enterotoxin expression in colonic contents.ConclusionOutcome of the study demonstrated that IgY against the fimbrial antigen K88 was able to significantly inhibit the growth of E. coli K88, block the binding of E. coli to small intestinal mucus, and protect piglets from E. coli-induced diarrhea. These results indicate that passive immunization with IgY may be useful to prevent bacterial colonization and to control enteric diseases due to E. coli infection. The study has great clinical implication to provide alternative therapy to antibiotics in E coli induced diarrhea.

Oral Passive Immunization With Plasma-Derived Polyreactive Secretory-Like IgA/M Partially Protects Mice Against Experimental Salmonellosis.

Secretory immunoglobulins have a critical role in defense of the gastrointestinal tract and are known to act by preventing bacterial acquisition. A stringent murine model of bacterial infection with Salmonella enterica Typhimurium was used to examine protection mediated by oral passive immunization with human plasma-derived polyreactive IgA and IgM antibodies (Abs) reconstituted as secretory-like immunoglobulins (SCIgA/M). This reagent has been shown to trigger Salmonella agglutination and to limit the entry of bacterium into intestinal Peyer's patches via immune exclusion. We now demonstrate that upon administration into ligated intestinal loops, SCIgA/M properly anchors in the mucus and is protected from degradation to a better extent that IgA/M or IgG. Moreover, prophylactic oral administration of SCIgA/M before intragastric infection of mice with a virulent strain of S. enterica Typhimurium allows to protect infected animals, as reflected by reduced colonization of both mucosal and systemic compartments, and conserved integrity of intestinal tissues. In comparison with IgA/M or IgG administration, SCIgA/M provided the highest degree of protection. Moreover, such protective efficacy is also observed after therapeutic oral delivery of SCIgA/M. Either prophylactic or therapeutic treatment with passively delivered SCIgA/M ensured survival of up to 50% of infected mice, while untreated animals all died. Our findings unravel the potential of oral passive immunization with plasma-derived polyreactive SCIgA/M Abs to fight gastrointestinal infections.

Biomanufacturing of protective antibodies and other therapeutics in edible plant tissues for oral applications.

SummaryAlthough plant expression systems used for production of therapeutic proteins have the advantage of being scalable at a low price, the downstream processing necessary to obtain pure therapeutic molecules is as expensive as for the traditional Chinese hamster ovary (CHO) platforms. However, when edible plant tissues (EPTs) are used, there is no need for exhaustive purification, because they can be delivered orally as partially purified formulations that are safe for consumption. This economic benefit is especially interesting when high doses of recombinant proteins are required throughout the treatment/prophylaxis period, as is the case for antibodies used for oral passive immunization (OPI). The secretory IgA (SIgA) antibodies, which are highly abundant in the digestive tract and mucosal secretions, and thus the first choice for OPI, have only been successfully produced in plant expression systems. Here, we cover most of the up‐to‐date examples of EPT‐produced pharmaceuticals, including two examples of SIgA aimed at oral delivery. We describe the benefits and drawbacks of delivering partially purified formulations and discuss a number of practical considerations and criteria to take into account when using plant expression systems, such as subcellular targeting, protein degradation, glycosylation patterns and downstream strategies, all crucial for improved yield, high quality and low cost of the final product.

Effects of oral passive immunization against somatostatin-14 on growth performance, body composition and IgY delivery in rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio)

Egg-yolk antibodies (IgY) against somatostatin-14 (anti-SST-14) were evaluated as orally administered, growth promotants in gastric rainbow trout (Oncorhynchus mykiss) and agastric common carp (Cyprinus carpio) in an 8-week feeding trial. Feeding groups were compared with fish which did not receive anti-SST-14 IgY. Growth responses and IgY plasma contents of the blood were assessed. In contrast to rainbow trout, oral anti-SST-14 addition to carp significantly improved protein efficiency ratio (PER, 1.02 ± 0.04) and protein productive value (PPV, 26.7 ± 0.91) after 56 days (P < 0.05) compared to the negative control (PER = 0.91 ± 0.02; PPV = 22.9 ± 0.66). IgY was undetectable in plasma of rainbow trout after oral administration, indicating that gastric degradation of the fed IgY makes this application route for growth promotion in gastric trout challenging.

Immunoprophylactic effect of chicken egg yolk antibody (IgY) against a recombinant S1 domain of the porcine epidemic diarrhea virus spike protein in piglets.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric pathogen of swine causing high mortality rates in piglets. PEDV outbreaks have occurred continuously in most swine-producing Asian countries and have recently emerged in the United States, leading to large economic losses for both the Asian and US pig industries. The spike (S) protein of PEDV consists of the S1 and S2 domains, responsible for virus binding and fusion, respectively. The involvement of the S1 domain in specific high-affinity interactions with the cellular receptor and induction of neutralizing antibodies in the natural host makes it a logical target for the development of effective vaccines and therapeutics against PEDV. Passive immunization by oral administration of egg yolk antibodies (IgY) obtained from immunized chickens provides an alternative source of specific antibodies for the prevention and treatment of PEDV in newborn piglets. In this study, we produced an IgY against the PEDV S1 protein and investigated its immunoprophylactic effect in neonatal piglets. A codon-optimized PEDV S1 gene consisting of amino acid residues 25–749 was synthesized and used to establish a stable porcine cell line constitutively expressing a recombinant PEDV S1 protein containing the chicken immunoglobulin Fc fragment at its C-terminus. The purified recombinant S1 protein was found to mediate potent immune responses in immunized hens. We next tested the ability of oral passive immunization with anti-PEDV S1 IgY to protect piglets against PEDV. Specific chicken IgY against the S1 protein was orally administered to neonatal piglets, and their responses subsequent to a virulent PEDV challenge were monitored. The results showed that oral administration of anti-PEDV S1 IgY efficiently protects neonatal piglets against PEDV, suggesting its potential as a prophylactic or therapeutic agent against acute PEDV infection.

English

Avian eggs present an ideal alternative antibody source to mammals as the immunoglobulin (IgY) in the chicken&rsquo;s blood is transported to the egg and accumulates in the egg yolk in large quantities. The existence of an immunoglobulin G (IgG)-like molecule in avian eggs, referred to as IgY, has been well documented, and extensive research has been carried out on its characterization, production and purification.&nbsp;Although it is the functional equivalent of mammalian IgG, the major serum antibody found in mammals IgY is structurally different, and has been found to exhibit several important differences when compared to mammalian antibodies, including its physicochemical properties and immunological capabilities. Recently, considerable research has focus seldom use of IgY as an alternative to mammalian antibodies for several applications, including immunotherapeutic applications, especially for the oral passive immunization against various bacteria and viruses. Much research has also been carried out on the use of IgY as a replacement for IgG in various immunodiagnostic and immunoaffinity purification purposes. The use of IgY offers several advantages over polyclonal antibodies produced in mammals, including providing a much more hygienic, cost efficient, convenient, humane and plentiful source of antigen-specific antibodies. &nbsp; Key&nbsp;words:&nbsp;Avian,&nbsp;egg&nbsp;yolk&nbsp;antibody,&nbsp;immunodiagnostic,&nbsp;immunotherapeutic, IgY.

Polyclonal Antibody Therapies for Clostridium difficile Infection

Clostridium difficile infection has emerged as a growing worldwide health problem. The colitis of Clostridium difficile infection results from the synergistic action of C. difficile secreted toxins A and B upon the colon mucosa. A human monoclonal IgG anti-toxin has demonstrated the ability in combination therapy to reduce mortality in C. difficile challenged hamsters. This antibody is currently in a clinical trial for the treatment of human Clostridium difficile infection. More than one group of investigators has considered using polyclonal bovine colostral antibodies to toxins A and B as an oral passive immunization. A significant proportion of the healthy human population possesses polyclonal antibodies to the Clostridium difficile toxins. We have demonstrated that polyclonal IgA derived from the pooled plasma of healthy donors possesses specificity to toxins A and B and can neutralize these toxins in a cell-based assay. This suggests that secretory IgA prepared from such pooled plasma IgA may be able to be used as an oral treatment for Clostridium difficile infection.

Effect of chicken egg yolk antibodies (IgY) against diarrhea in domesticated animals: a systematic review and meta-analysis.

BackgroundIgY antibodies are serum immunoglobulin in birds, reptiles and amphibians, and are transferred from serum to egg yolk to confer passive immunity to their embryos and offspring. Currently, the oral passive immunization using chicken IgY has been focused as an alternative to antibiotics for the treatment and control of diarrhea in animals and humans. This systematic review was focused to determine the effect of IgY in controlling and preventing diarrhea in domesticated animals including Piglets, Mice, Poultry and Calves.Methods and ResultsPrevious research reports focused on treatment effect of Chicken IgY against diarrhea were retrieved from different electronic data bases (MEDLINE, EMBASE, SPRINGER-LINK, WILEY, AGRICOLA, MEDWELL Journals, Scientific Publish, Chinese articles from Core periodicals in 2012). A total of 61 studies in 4 different animal classes met the inclusion criteria. Data on study characteristics and outcome measures were extracted. The pooled relative risk (RR) of 49 studies of different animals [Piglets – 22; Mice – 14; Poultry – 7 and Calves – 6] in meta-analyses revealed that, IgY significantly reduced the risk of diarrhea in treatment group when compare to the placebo. However, the 95% confidence intervals of the majority of studies in animal class piglets and calves embrace RR of one. The same results were obtained in sub group analyses (treatment regiment – prophylactic or therapeutic; pathogen type – bacterial or viral). Perhaps, this inconsistency in the effect of IgY at the individual study level and overall effect measures could be influenced by the methodological heterogeneity.ConclusionThe present systematic review (SR) and meta-analysis demonstrated the beneficial effect of IgY. This supports the opinion that IgY is useful for prophylaxis and treatment. However, more intensive studies using the gold standard animal experiments with the focus to use IgY alone or in combination with other alternative strategies are indispensable.

Oral Passive Immunization of Carp Cyprinus carpio with Anti-CyHV-3 Chicken Egg Yolk Immunoglobulin (IgY)

Oral Passive Immunization of Carp Cyprinus carpio with Anti-CyHV-3 Chicken Egg Yolk Immunoglobulin (IgY)

Orally fed seeds producing designer IgAs protect weaned piglets against enterotoxigenicEscherichia coliinfection

Oral feed-based passive immunization can be a promising strategy to prolong maternal lactogenic immunity against postweaning infections. Enterotoxigenic Escherichia coli (ETEC)-caused postweaning diarrhea in piglets is one such infection that may be prevented by oral passive immunization and might avert recurrent economic losses to the pig farming industry. As a proof of principle, we designed anti-ETEC antibodies by fusing variable domains of llama heavy chain-only antibodies (VHHs) against ETEC to the Fc part of a porcine immunoglobulin (IgG or IgA) and expressed them in Arabidopsis thaliana seeds. In this way, four VHH-IgG and four VHH-IgA antibodies were produced to levels of about 3% and 0.2% of seed weight, respectively. Cotransformation of VHH-IgA with the porcine joining chain and secretory component led to the production of light-chain devoid, assembled multivalent dimeric, and secretory IgA-like antibodies. In vitro analysis of all of the antibody-producing seed extracts showed inhibition of bacterial binding to porcine gut villous enterocytes. However, in the piglet feed-challenge experiment, only the piglets receiving feed containing the VHH-IgA-based antibodies (dose 20 mg/d per pig) were protected. Piglets receiving the VHH-IgA-based antibodies in the feed showed a progressive decline in shedding of bacteria, significantly lower immune responses corroborating reduced exposure to the ETEC pathogen, and a significantly higher weight gain compared with the piglets receiving VHH-IgG producing (dose 80 mg/d per pig) or wild-type seeds. These results stress the importance of the antibody format in oral passive immunization and encourage future expression of these antibodies in crop seeds.

Role of plant expression systems in antibody production for passive immunization

Passive immunization is a method to achieve immediate protection against infectious agents by administering pathogen-specific antibodies. It has proven to be lifesaving for many acute infections, and it is now also used for cancer treatment. Passive immunization therapies, however, are extremely expensive because they require large amounts of specific antibodies that are produced predominantly in mammalian expression systems. The cost for manufacturing plant-made antibodies is estimated to be comparatively low since plant production systems require relatively less capital investments. In addition, they are not prone to mammalian pathogens, which also eases downstream processing along with making it a safe expression system. Moreover, some of the recent developments in transient expression have enabled rapid, cGMP (current Good Manufacturing Practices) compliant manufacturing of antibodies. Whether lower production costs will be reflected in a lower market price for purified antibodies will be known when more plant-produced antibodies come to the market. Promisingly, the current molecular techniques in the field of in planta expression have enabled high-level production of a variety of antibodies in different plant organs, like roots/tubers/fruits, leaves and seeds, of a variety of plants, like potato, tobacco, maize, rice, tomato and pea, providing a very wide range of possible plant-based passive immunization therapies. For instance, the production of antibodies in edible tissues would allow for a unique, convenient, needle-less, oral passive immunization at the gastric mucosal surface. The technological advances, together with the innate capacity of plant tissues to assemble complex antibodies, will enable carving a niche in the antibody market. This non-exhaustive review aims to shed light on the role of plants as a flexible expression system for passive immunotherapy, which we envisage to progress alongside the conventional production platforms to manufacture specialized antibodies.

Rumen microbial diversity under influence of a polyclonal antibody preparation against lactate-producing and proteolytic bacteria in cows fed different energy sources

Nine ruminally cannulated cows fed different energy sources were used to evaluate an avianderived polyclonal antibody preparation against specific ruminal bacteria and monensin on microbial community diversity. The experimental design was three Latin squares 3 x 3 distinguished by the main energy source in the diet [dry-ground corn grain, high moisture corn silage or citrus pulp]. Inside each Latin square, animals received one of the feed additives per period [control, monensin or polyclonal antibody preparation]. Each period lasted 21 days where 20 were used for treatments adaptation and the last one for sampling collection. Microbial diversity was evaluated by protozoa counts and denaturing gradient gel electrophoresis. Polyclonal antibodies plus citrus pulp (CiPu) addition in the diet resulted in an increase of relative counting of Isotricha protozoa that indicates a possible effect on this ruminal ciliate population. In general lines, in the present experiment, it was not possible to assign that there was a pattern in the structures of amplification of Bacteria and Archaea communities of the ruminal content. Oral passive immunization is a technology that arises as an effective alternative for feed additive production. Further research is still necessary to better understand its mechanisms of action.

Efficacy of Passive Immunization with IgY Antibodies to a 58-kDa H. pylori Antigen on Severe Gastritis in BALB/c Mouse Model

Consecutive triple doses of 1 × 108 CFU/mL of a pathogenic H. pylori strain isolated from stomach of Egyptian patients with severe gastritis were used to establish infection in BALB/c mice model. White Leghorn hens were immunized with H. pylori whole cell lysate (HpLysate) antigen and with a highly reactive 58-kDa H. pylori (Hp58) antigen. Two months later, IgY antibodies (IgY-HpLysate & IgY-Hp58) were purified from egg yolk and its efficacy was evaluated in the adopted model. Microbiological culture and immunohistochemical staining revealed that H. pylori infection was inhibited 1 week after oral passive immunization in 70% of infected BALB/c mice with a significant decrease (p < 0.05) in the degrees of gastritis. In conclusion, we have adapted BALB/c mice model for human H. pylori pathogenic strain and oral passive immunization with specific IgY antibodies to the 58-kDa antigen inhibited active H. pylori infection and decreased gastritis.

Secretory immunoglobulin A obtained from pooled human colostrum and milk for oral passive immunization

Passive immunization is useful in cases of immunodeficiencies or infectious diseases, but usually seric gammaglobulin or hyperimmune sera are administered parenterally, providing good systemic immunization, though with low protection of the mucosal surfaces. The oral administration of secretory antibodies, especially surface immunoglobulin (SIg)A, which is perfectly adapted to the mucosal environment, would therefore, be preferable. The aim of the present study was to obtain a SIgA preparation from pooled human colostrum and milk, which should maintain the essential properties of the antibodies suitable for clinical oral administration. IgA preparations were obtained from colostrum and milk pools by salt precipitation. The final products were evaluated in terms of yield and purity, as well as antibody activity to bacterial antigens and toxins and inhibitory activity of bacterial adhesion to epithelial cells. The best yield and purity were achieved when the colostrum pool was used as a source of IgA; the final product showed very few bands of protein contamination. The IgA preparations preserved the antibody reactivity against various microbial antigens, well comparable with the reactivity exhibited by the original milk and colostrum pools. SIgA preparations were able to inhibit greatly the adhesion of enteropathogenic Escherichia coli to Hep-2 cells and the invasion of enteroinvasive E. coli. These promising results show the feasibility of obtaining SIgA suitable for oral use, which may in future be administered to immunodeficient patients with gastrointestinal manifestations, from human colostrum and milk.

Passive Immunization Through Avian Egg Antibodies

Oral administration of specific antibodies is an attractive approach to establish passive immunization against various pathogens in humans and animals. Egg yolk contains over 100 mg of IgY per egg and is considered to be a more hygienic and economical source of antibodies, than antibodies from mammalian sera. Recently, considerable research has focussed on the use of IgY as an alternative to mammalian antibodies for several applications, most notably for oral passive immunization against various bacteria and viruses. Oral administration of IgY has proven to be successful for the treatment of a variety of gastrointestinal (GI) pathogens such as bovine and human rotaviruses, bovine coronavirus, Yersinia ruckeri, enterotoxigenic Escherichia coli, Salmonella spp., Edwardsiella, Staphylococcus, and Pseudomonas. Recent advances in hybridoma technology, for the production of monoclonal IgY, also present many benefits for its universal application. IgY technology has significant future opportunities for the design of strategies for the prevention and treatment of infectious gastrointestinal diseases in humans and animals.