Bovine anti-Helicobacter pylori antibodies for oral immunotherapy

Therapeutics effects of bovine colostrum applications on gastrointestinal diseases: a systematic review

BACKGROUND

Evidence on the effects of bovine colostrum (BC) supplementation on gastrointestinal (GI) diseases is conflicting.

OBJECTIVES

This systematic review summarized the findings of clinical trials (CTs) on the effects of BC supplementation on GI diseases.

METHODS

A systematic search was conducted in online databases, including PubMed, ISI Web of Science, and Scopus, until March 2021 and updated until December 2023. CTs investigated BC's effect on any measurable symptomatic change in terms of GI health as the primary outcome variable or as one of the outcomes in any population eligible for this systematic review.

RESULTS

Out of 6881 records, 22 CTs (uncontrolled = 4, cross-over = 1, and parallel = 17) with 1427 patients were enrolled in the systematic review. Diarrhea, the most frequently evaluated symptom (20 interventional arms), was decreased in frequency with BC supplementation in 15 of these arms. However, most studies reported no change in its duration. BC supplementation consistently reduced stool frequency across all seven studies. Abdominal pain relief was noted in four interventional arms but showed no improvement in five others. Assessment of other GI symptoms was limited, yielding inconclusive results.

CONCLUSIONS

There is limited evidence on the effects of BC on GI diseases, with mixed findings. More well-designed controlled clinical trials are required to explore its effects.

ABO(H) and Lewis blood group substances and disease treatment

Since the early 20th century, scientists have determined that blood group antigens can be inherited. With more and more studies have been devoted to finding the relationship between blood groups and diseases, the relationship of ABO(H) and Lewis blood groups and the development of human diseases have been summarised. In addition, many studies have shown that blood group substances, such as blood group antigen or related antibody, play an important role in disease prevention and treatment. This review focuses on the advances of ABO(H), Lewis blood group substances in the treatment of diseases, which has important significance for the development of novel therapeutic methods.

Impact of oral immunoglobulins on animal health-A review

Immunoglobulin (Ig) is the one of the main anti-infective components of blood, colostrum and breast milk. It is the unique glycoprotein that defends the body from harmful bacteria, viruses and other environmental pathogens by either binding to them or by forming an encapsulating barrier. The expansion of antimicrobial and immunomodulatory products from natural sources for dietary supplementation in both animals and humans is an ever growing and thriving area of research. Purified Ig from sheep serum (ovine serum Ig) is one such candidate product. Recent work has shown the various biological effects of oral Ig in different animal models including its effect on growth, immunity, intestinal growth and gut barrier function. The objective of this paper is to review the results of recent studies demonstrating the effects of oral Ig in both pathogenic and non-pathogenic animal models and to suggest a possible mechanism of its action. Overall, purified oral Ig improves growth of healthy (and challenged) rats and defends against enteric infection by immunomodulation, mucin protein and/or modification of commensal microbial composition. The findings contribute to knowledge of how orally administered ovine Ig can influence and enhance key indicators of gut function and overall growth performance in an animal model.

Effects of Bovine Immunoglobulins on Immune Function, Allergy, and Infection

This review aims to provide an in depth overview of the current knowledge of the effects of bovine immunoglobulins on the human immune system. The stability and functional effects of orally ingested bovine immunoglobulins in milk products are described and potential mechanisms of action are discussed. Orally ingested bovine IgG (bovine IgG) can be recovered from feces, ranging from very low levels up to 50% of the ingested IgG that has passed through the gastrointestinal tract. In infants the recovered levels are higher than in adults most likely due to differences in stomach and intestinal conditions such as pH. This indicates that bovine IgG can be functionally active throughout the gastrointestinal tract. Indeed, a large number of studies in infants and adults have shown that bovine IgG (or colostrum as a rich source thereof) can prevent gastrointestinal tract infections, upper respiratory tract infections, and LPS-induced inflammation. These studies vary considerably in target group, design, source of bovine IgG, dosage, and endpoints measured making it hard to draw general conclusions on effectiveness of bovine immunoglobulin rich preparations. Typical sources of bovine IgG used in human studies are serum-derived IgG, colostrum, colostrum-derived IgG, or milk-derived immunoglobulins. In addition, many studies have used IgG from vaccinated cows, but studies using IgG from nonimmunized animals have also been reported to be effective. Mechanistically, bovine IgG binds to many human pathogens and allergens, can neutralize experimental infection of human cells, and limits gastrointestinal inflammation. Furthermore, bovine IgG binds to human Fc receptors which, enhances phagocytosis, killing of bacteria and antigen presentation and bovine IgG supports gastrointestinal barrier function in in vitro models. These mechanisms are becoming more and more established and explain why bovine IgG can have immunological effects in vivo. The inclusion of oral bovine immunoglobulins in specialized dairy products and infant nutrition may therefore be a promising approach to support immune function in vulnerable groups such as infants, children, elderly and immunocompromised patients.

Genome sequencing and protein domain annotations of Korean Hanwoo cattle identify Hanwoo-specific immunity-related and other novel genes

Background

Identification of genetic mechanisms and idiosyncrasies at the breed-level can provide valuable information for potential use in evolutionary studies, medical applications, and breeding of selective traits. Here, we analyzed genomic data collected from 136 Korean Native cattle, known as Hanwoo, using advanced statistical methods.

Results

Results revealed Hanwoo-specific protein domains which were largely characterized by immunoglobulin function. Furthermore, domain interactions of novel Hanwoo-specific genes reveal additional links to immunity. Novel Hanwoo-specific genes linked to muscle and other functions were identified, including protein domains with functions related to energy, fat storage, and muscle function that may provide insight into the mechanisms behind Hanwoo cattle’s uniquely high percentage of intramuscular fat and fat marbling.

Conclusion

The identification of Hanwoo-specific genes linked to immunity are potentially useful for future medical research and selective breeding. The significant genomic variations identified here can crucially identify genetic novelties that are arising from useful adaptations. These results will allow future researchers to compare and classify breeds, identify important genetic markers, and develop breeding strategies to further improve significant traits.

Electronic supplementary material

The online version of this article (10.1186/s12863-018-0623-x) contains supplementary material, which is available to authorized users.

Role of Helicobacter pylori infection in gastric carcinogenesis: Current knowledge and future directions

Helicobacter pylori (H. pylori) plays a role in the pathogenesis of gastric cancer. The outcome of the infection depends on environmental factors and bacterial and host characteristics. Gastric carcinogenesis is a multistep process that is reversible in the early phase of mucosal damage, but the exact point of no return has not been identified. Therefore, two main therapeutic strategies could reduce gastric cancer incidence: (1) eradication of the already present infection; and (2) immunization (prior to or during the course of the infection). The success of a gastric cancer prevention strategy depends on timing because the prevention strategy must be introduced before the point of no return in gastric carcinogenesis. Although the exact point of no return has not been identified, infection should be eradicated before severe atrophy of the gastric mucosa develops. Eradication therapy rates remain suboptimal due to increasing H. pylori resistance to antibiotics and patient noncompliance. Vaccination against H. pylori would reduce the cost of eradication therapies and lower gastric cancer incidence. A vaccine against H. pylori is still a research challenge. An effective vaccine should have an adequate route of delivery, appropriate bacterial antigens and effective and safe adjuvants. Future research should focus on the development of rescue eradication therapy protocols until an efficacious vaccine against the bacterium becomes available.

The clearance effect of bovine anti-Helicobacter pylori antibody-containing milk in O blood group Helicobacter pylori-infected patients: a randomized double-blind clinical trial

BACKGROUND

The failure in standard triple therapy has recently increased to high levels in China, primarily because of insufficient patient compliance, antimicrobial resistance, and high costs. Effective prevention and eradication of Helicobacter pylori (H. pylori) by artificial passive immunization with orally administered bovine antibodies in the milk has been demonstrated in many animal studies, but the clinical studies that are available have shown no H. pylori eradication. This study was to evaluate the efficacy and safety of orally administered bovine anti-H. pylori antibodies for the clearance of H. pylori infecting O blood group subpopulations.

METHODS

Two local epidemic H. pylori strains that were prevalent locally were screened and then used to immunize dairy cows. After confirmation of the presence of anti-H. pylori polyclonal antibodies in the milk by enzyme-linked immunosorbent assay, the milk was subsequently defatted and processed into sterile milk by pasteurization. This study was designed as a double-blind placebo-controlled randomized clinical trial. Our 61 H. pylori-infected O blood group subjects were assigned to two groups; 31 subjects were treated with bovine milk containing antibodies and 30 subjects with the placebo. The medication-based study was continued for 28 days. Subjects were followed up for 56 days. The effect was assessed by the C-14 urea breath test (UBT). SPSS 17.0 software for Windows was used to analyze the data.

RESULTS

Of the 61 subjects enrolled, 58 completed the protocol. One volunteer in the antibodies group and two volunteers in the control group dropped out. Of the 30 antibody-treated subjects, 13 became UBT negative, whereas none of the 30 of the placebo-treated subjects became UBT negative after the medication. Of 13 UBT negative patients, 3 became positive again at the end of the follow-up. Both intention to treat and per-protocol analysis indicated a significant difference in the clearance rate of infected patients between the groups treated with bovine antibody-containing milk and the placebo (P = 0.001, P < 0.05) and no significant difference in adverse effects (P > 0.05 all).

CONCLUSIONS

Bovine antibody-based oral immunotherapy appears to be safe and has a significant clearance effect on intragastric H. pylori that infects O blood group adults.

TRIAL REGISTRATION

ChiCTR-TRC-14005212.

Passive Immunization

Whereas active immunity refers to the process of exposing the individual to an antigen to generate an adaptive immune response, passive immunity refers to the transfer of antibodies from one individual to another. Passive immunity provides immediate but short-lived protection, lasting several weeks up to 3 or 4 months. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta or from breast milk to the gut of the infant. It can also be produced artificially, when antibody preparations derived from sera or secretions of immunized donors or, more recently, different antibody producing platforms are transferred via systemic or mucosal route to nonimmune individuals. Passive immunization has recently become an attractive approach because of the emergence of new and drug-resistant microorganisms, diseases that are unresponsive to drug therapy and individuals with an impaired immune system who are unable to respond to conventional vaccines. This chapter addresses the contributions of natural and artificial acquired passive immunity in understanding the concept of passive immunization. We will mainly focus on administration of antibodies for protection against various infectious agents entering through mucosal surfaces.

In vitro bacteriostatic activity of IgY against recombinant Helicobacter pylori FlaA protein

AIM: To evaluate the in vitro antibacterial activity of anti-Helicobacter pylori (H. pylori) FlaA IgY.

METHODS: Recombinant H. pylori FlaA was prepared by prokaryotic expression and used to immunize hens. Anti-FlaA IgY was purified and IgY titer was determined by ELISA. The antibody was then tested to check if there was any cross-reaction with the common intestinal flora like Lacticacid bacteria, Bifidobacterium and Escherichia coli. The antibacterial activity of different concentrations of anti-H. pylori FlaA IgY (0.1, 1 and 5 mg/mL) was finally determined.

RESULTS: The concentration of purified FlaA protein was 2.97 mg/mL, and the titer of anti-FlaA IgY was 1:12800 three weeks after immunization. Anti-FlaA IgY did not react with the common intestinal flora, but reacted well with H. pylori and FlaA protein. In vitro results showed that there were significant differences (P < 0.01) in the H. pylori concentrations between the control group and the groups treated with 0.1, 1, or 5 mg/mL FlaA IgY, indicating that FlaA IgY of various concentrations could inhibit the growth of H. pylori in a certain degree. The antibacterial activity of 0.1 mg/mL FlaA IgY was mainly present between 1 and 6 h, and was mostly lost after 6 h. The growth of H. pylori treated with 1 mg/mL FlaA IgY was relatively slow, and the bacterial concentration of the group treated with 5 mg/mL FlaA IgY did not alter significantly between 1 and 24 h. After 108 CFU/mL H. pylori was treated with three different doses (0.1, 1, 5 mg/mL) of FlaA IgY for 24 h, a significant difference in bacterial concentration was observed between the low dose group and the other two groups (P < 0.01). Anti-FlaA IgY at 5 mg/mL could completely inhibit the growth of H. pylori.

CONCLUSION: High-titer anti-FlaA IgY can specifically react with H. pylori, and has no cross-reaction with the common intestinal flora. Anti-FlaA IgY at 5 mg/mL has a strong inhibitory effect on the growth of H. pylori.

Vaccination of pregnant cows with EspA, EspB, γ-intimin, and Shiga toxin 2 proteins from Escherichia coli O157:H7 induces high levels of specific colostral antibodies that are transferred to newborn calves

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major cause of intestinal disease and hemolytic uremic syndrome, a serious systemic complication that particularly affects children. Cattle are primary reservoirs for EHEC O157:H7 and the main source of infection for humans. Vaccination of cattle with different combinations of bacterial virulence factors has shown efficacy in decreasing EHEC O157:H7 shedding. It is, therefore, important to demonstrate whether vaccination of pregnant cows with EHEC O157:H7 induces high titers of transferable antibodies to avoid early colonization of calves by the bacteria. In this study we evaluated the ability of EspA, EspB, the C-terminal fragment of 280 amino acids of γ-intimin (γ-intimin C₂₈₀) and inactivated Shiga toxin (Stx) 2 proteins to induce specific antibodies in colostrum and their passive transference to colostrum-fed calves. Friesian pregnant cows immunized by the intramuscular route mounted significantly high serum and colostrum IgG responses against EspB and γ-intimin C₂₈₀ that were efficiently transferred to their calves. Antibodies to EspB and γ-intimin C₂₈₀ were detected in milk samples of vaccinated cows at d 40 postparturition. Significant Stx2-neutralizing titers were also observed in colostrum from Stx2-vaccinated cows and sera from colostrum-fed calves. The results presented showed that bovine colostrum with increased levels of antibodies against EHEC O157:H7 may be obtained by systemic immunization of pregnant cows, and that these specific antibodies are efficiently transferred to newborn calves by feeding colostrum. Hyperimmune colostrum and milk may be an alternative to protect calves from early colonization by EHEC O157:H7 and a possible key source of antibodies to block colonization and toxic activity of this bacterium.

Treatment of Helicobacter pylori infection in mice with oral administration of egg yolk-driven anti-UreC immunoglobulin

BACKGROUND

Helicobacter pylori, the causative agent of gastritis and gastric ulcer, plays a crucial role in development of gastric carcinomas. Antibiotic therapy fails in almost 20% of cases due to development of antibiotic resistance. Development of antibodies against specific H. pylori targets could have significant therapeutic effect. In the present research attempts have been made to study the effect of IgY purified from egg yolk of hens immunized with recombinant UreC in treatment of mice infected with H. pylori.

MATERIALS AND METHODS

Purified IgY-HpUc was used in two forms: powdered and PBS dissolved. 10(9) bacteria in BHI were orally administered to C57BL6/j mice three times on alternate day intervals. Eight weeks after the last inoculation, the serum was assayed for infection rate by ELISA. The severity of gastritis was analyzed histopathologically. Infected mice were randomly divided into three groups. Groups one and two were treated with dietary IgY-HpUc and IgY-HpUc dissolved in PBS respectively for 28 days. The untreated group served as control.

RESULTS

Serology and histopathology confirmed the establishment of the infection. Indirect ELISA results in the treated animals showed considerable reduction of H. pylori specific antibodies in their sera. Pathological examination of gastric mucosa of infected mice treated with IgY-HpUc showed considerable reduction of inflammation in the stomach tissues. The bacterial presence on mucosal layer of the stomach was considerably reduced.

CONCLUSIONS

UreC-induced IgY is specifically successful in inhibition of H. pylori infection and could be an alternative to antibiotic treatment.

Bovine antibody-based oral immunotherapy for reduction of intragastric Helicobacter pylori colonization: a randomized clinical trial

BACKGROUND

Antibiotic-based regimens are frequently used for the treatment of Helicobacter pylori infection. These regimens fail to eradicate H pylori in 15% to 40% of patients, primarily due to antimicrobial resistance and insufficient patient compliance. Effective prevention and eradication of H pylori by passive immunization with orally administered bovine antibodies has been demonstrated in animal studies, and may serve as an alternative therapy in humans.

OBJECTIVE

To study the efficacy and safety of orally administered bovine anti-H pylori antibodies for the reduction of intragastric bacterial load and eradication of H pylori in humans.

METHODS

Dairy cows were immunized against H pylori. After confirmation of the presence of anti-H pylori antibodies in the milk, the milk was subsequently processed into a whey protein concentrate (WPC). In a prospective, double-blind, placebo-controlled randomized clinical trial, H pylori-infected subjects were randomly assigned to treatment with the WPC preparation or placebo. Study medication was continued for 28 days; subjects were followed-up for 56 days.

RESULTS

Of the 30 subjects included, 27 completed the protocol. Of these 27 evaluable subjects, 14 were treated with WPC and 13 with placebo. There was no significant difference in urea breath test decrease between the WPC- and placebo-treated group (P=0.75). H pylori-associated gastritis and density were not significantly reduced in either group after treatment (P>0.05 for all).

CONCLUSION

Bovine antibody-based oral immunotherapy appears to be safe, but does not significantly reduce intragastric density in humans. Further studies are needed to determine whether WPC treatment has additional value to conventional antibiotic treatment for H pylori.

Novel combination therapy for the eradication of Helicobacter pylori infection in a mouse model

OBJECTIVE

To investigate the combination therapy, consisting of hyperimmune bovine colostrum, N-acetyl cysteine, zinc and amoxicillin on the eradication of Helicobacter pylori in a mouse model.

MATERIAL AND METHODS

C57BL/6 female mice (6 weeks of age) were inoculated with 0.1 ml of 1×10(9) H. pylori via a single oro-gastric gavage and were left infected for 4 weeks. Mice (n=9/group) were randomly allocated to receive by oral gavage (0.1 ml) HNZ (hyperimmune bovine colostrum+N-acetyl cysteine+zinc), HNZA (HNZ+amoxicillin; A), HNZA2 (2× amoxicillin; A2), HNZA5 (5× amoxicillin; A5), triple therapy (TT) or saline twice daily for 10 days. Bacterial load was assessed by culture. Gastric emptying was assessed by 13C-octanoic acid breath test.

RESULTS

Mice receiving HNZ, HNZA, and HNZA2 have a 22%, 44% and 67% eradication rate, respectively. Eradication rate was 100% with HNZA5, TT and those animals receiving A5 alone. In H. pylori infected mice there was an increased gastric emptying time by 7.9, 3.7, 10.1 and 7.7 min for the TT, HNZ, HNZA2, and HNZA5, respectively, compared to saline.

CONCLUSIONS

HNZ with the addition of a high dose of amoxicillin is effective at eradicating H. pylori in vivo as HNZA1 and HNZA2 did not give raise to eradication. The potency of the novel anti-H. pylori combination therapy may be due to the delayed gastric emptying.

Protective efficacy of recombinant urease B and aluminum hydroxide against Helicobacter pylori infection in a mouse model

Efforts are underway for the development of an effective vaccine against Helicobacter pylori infection. We prepared recombinant full-length (568 aa) H. pylori recombinant urease B (rUreB) protein and tested it for immunogenicity and protection. BALB/c mice received either rUreB (40 μg) plus CpG (10 μg) intranasally, rUreB (50 μg) plus 3% aluminum hydroxide (50 μL) intramuscularly or rUreB (25 μg) plus Freund's adjuvant (25 μL) subcutaneously, three times (weeks 0, 2 and 6). Intranasal rUreB plus CpG was neither immunogenic nor protective; intramuscular rUreB plus aluminum hydroxide was immunogenic and modestly protective, and subcutaneous rUreB plus Freund's adjuvant was immunogenic and highly protective. The fact that protection was improved with Freund's adjuvant indicates that rUreB is a good antigen for a vaccine but that it needs a stronger adjuvant than aluminum hydroxide.

Role of secretory immunoglobulin A and secretory component in the protection of mucosal surfaces

The contribution of secretory immunoglobulin A (SIgA) antibodies in the defense of mucosal epithelia plays an important role in preventing pathogen adhesion to host cells, therefore blocking dissemination and further infection. This mechanism, referred to as immune exclusion, represents the dominant mode of action of the antibody. However, SIgA antibodies combine multiple facets, which together confer properties extending from intracellular and serosal neutralization of antigens, activation of non-inflammatory pathways and homeostatic control of the endogenous microbiota. The sum of these features suggests that future opportunities for translational application from research-based knowledge to clinics include the mucosal delivery of bioactive antibodies capable of preserving immunoreactivity in the lung, gastrointestinal tract, the genito-urinary tract for the treatment of infections. This article covers topics dealing with the structure of SIgA, the dissection of its mode of action in epithelia lining different mucosal surfaces and its potential in immunotherapy against infectious pathogens.

Immunogenicity of Recombinant Helicobacter pylori Urease B Administered by Various Routes and with Different Adjuvants

Because of the high prevalence of Helicobacter pylori infection and the morbidity and mortality associated to the disease, development of a preventive vaccine has become a priority. To this goal, we produced recombinant H. pylori urease B (rUreB) and tested its immunogenicity in BALB/c mice when administered as 3 doses (week 0, 4 and 6) by either parenteral (intramuscular) or mucosal routes (intragastric, intranasal, intrarectal) and with the use of various adjuvants (none, CpG, alum or Freund's). The intramuscular route was more immunogenic than any mucosal route; of the mucosas, only intranasal induced modest levels of serum IgG. All adjuvants improved the seroresponse to plain rUreB and, of them, Freund's and alum were equally good and better than CpG ODN 1826. Stool IgA was barely detected by any immunization strategy.

Bovine milk immunoglobulins against microbial human diseases

Immunoglobulins (Igs), also called antibodies, are present in milk and colostrum of all lactating species. Igs are divided into classes having different physico-chemical structures and biological activities. The major Ig classes in bovine and human milk are IgA, IgG and IgM. Bovine colostral Igs provide the newborn calf with passive immune protection against microbial infections until the calf’s own immune system matures. Colostral Ig preparations designed for farm animals have been commercially available for many years. Potential health benefits attributed to bovine colostrum have increased manufacture and marketing of colostral Ig-based dietary supplements also for human use. Furthermore, specific anti-microbial antibodies can be produced into colostrum by immunizing cows with vaccines made of pathogenic microorganisms. These antibodies can be concentrated and used to formulate so-called immune milk preparations. Such preparations have proven effective in prevention of animal and human infections caused, e.g. by rotavirus, Shigella flexneri, Escherichia coli, Clostridium difficile, Streptococcus mutans, Cryptosporidium parvum and Helicobacter pylori. Their therapeutic efficacy, however, seems limited. A few immune milk products have been commercialized and more can be expected in the future for use, e.g. as a supportive means in antibiotic treatments and for prevention of hospital infections.

Effect of specific colostral antibodies and selected lactobacilli on the adhesion of Helicobacter pylori on AGS cells and the Helicobacter-induced IL-8 production

Helicobacter pylori infection is the most common cause of gastritis, gastric ulcer and adenocarcinoma. It has proven difficult to cure because of its capability to develop strains resistant to antibiotics. The effect of three strains of lactic acid bacteria (LAB) and bovine colostral preparations on the adhesion of H. pylori NCTC 11637 on gastric adenocarcinoma (AGS) cells and on the interleukin (IL)-8 production was studied. Before infection, H. pylori were pretreated with Lactobacillus plantarum MLBPL1, Lactobacillus rhamnosus GG, Lactococcus lactis, or with a colostral preparation with or without specific H. pylori antibodies. The relative number of H. pylori adhered on AGS cells was determined by urease test. IL-8 produced by the cells was studied by enzyme-linked immunosorbent assay. Colostral preparations with and without specific antibodies reduced the adhesion of H. pylori on AGS cells in a dose-dependent manner. Live LAB at a concentration of 10(10) CFU/ml reduced the adhesion by approximately 50% (P < 0.05). After the infection of AGS cells by H. pylori, the IL-8 level rose up to about 10-fold (5500 +/- 1600 pg/ml). Pretreatment of H. pylori with colostral preparations or high concentrations of LAB prevented this IL-8 rise. Similar effect was seen with live and heat-killed LAB, the live LAB being more effective. Heat-killed LAB at a concentration of 10(10) CFU/ml rose the IL-8 level of non-infected cells significantly. Suppression of IL-8 production by LAB or colostral products could have a suppressive effect on inflammation in Helicobacter infection.

Engineered lactobody-producing lactobacilli: a novel form of therapy against rotavirus infection

Rotavirus infections remain a major cause of morbidity and mortality worldwide, accounting for an estimated 600,000 deaths each year. New vaccines have been released recently but the lag time between vaccine administration and induction of an immune response can be critical in epidemic situations. A model system has been developed in which Lactobacillus, a ‘Generally Regarded As Safe’ microorganism, can be transformed with antibody fragment-encoding vectors. This allows in situ production of functional variable domains of llama heavy chain antibodies (VHH antibody fragments) against rotavirus in the intestinal tract. The modified bacteria were shown to be protective in a mouse pup model. Our approach represents a novel system for the induction of passive immunity that can be rapidly applied to populations at risk, for example through drinking water, rehydrating solutions or as a food supplement.

Milk immunoglobulins for health promotion

The biological function of bovine colostral immunoglobulins is to provide the newborn calf with adequate passive immune protection against microbial infections. Immunoglobulin preparations designed for farm animals are commercially available, and some colostrum-based products are marketed also for humans as dietary supplements. The concentration of specific antibodies against a certain pathogenic microorganism can be raised in colostrum and milk by immunizing cows with this pathogen or its antigen. Advances in bioseparation and chromatographic techniques have made it possible to fractionate and enrich these antibodies and formulate so-called hyperimmune colostral or milk preparations. Their efficacy in prevention and treatment of various microbial infections has been evaluated in numerous studies. Immune milk preparations have proven effective in prophylaxis against infections caused by a variety of gastrointestinal pathogens. Their therapeutic efficacy, however, seems more limited. A few commercial immune milk products are already on market and more applications can be expected in the coming years. This article reviews the recent progress made in isolation techniques of bovine immunoglobulins and the application of colostral and immune milk preparations in fighting various microbial infectious diseases in humans.

In vitro inhibition ofHelicobacter pyloribyEnterococcus faeciumGM-1

A strain of Enterococcus faecium that exhibits antibacterial activity against Helicobacter pylori was isolated from the feces of newborn babies. This strain was selected for its ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions, such as acidic pH and high bile concentration. Biochemical tests and 16S rRNA sequencing specific for Enterococcus faecium GM-1 were used to identify the isolated bacterial strain. In vitro studies were used to investigate the inhibitory effects of E. faecium GM-1 on H. pylori. These results showed that the culture supernatant of E. faecium GM-1 significantly decreased the viability and urease activity of H. pylori. This inhibitory activity remained after adjustment of pH of culture supernatant to neutral. However, treatment with proteolytic enzymes reduced the anti-H. pylori activity of GM-1. Therefore, some substance(s) of E. faecium GM-1 other than pH and lactic acid might be associated with this inhibitory activity. Analysis by electron microscopy also demonstrated that the addition of GM-1 destroyed the cell structure of H. pylori. Additional studies suggested that the binding of H. pylori to human colonial cells decreased in the presence of GM-1.Key words: Enterococcus faecium, Helicobacter pylori, inhibition, human fecal strain, proteinaceous substance(s).

Effect of dietary anti-urease immunoglobulin Y on Helicobacter pylori infection in Mongolian gerbils

BACKGROUND AND AIM

Helicobacter pylori is known to be a major pathogenic factor in the development of gastritis, peptic ulcer disease and gastric cancer. Recently, chicken egg yolk immunoglobulin Y (IgY) has been recognized as an inexpensive antibody source for passive immunization against gastrointestinal infections. The present study was designed to investigate the effect of anti-urease IgY on H. pylori infection in Mongolian gerbils.

METHODS

H. pylori-infected Mongolian gerbils were administered a diet containing anti-urease IgY, with or without famotidine (F). After 10 weeks, bacterial culture and measurement of the gastric mucosal myeloperoxidase (MPO) activity were performed. In a second experiment, another group of gerbils was started on a diet containing F + IgY a week prior to H. pylori inoculation. After 9 weeks, these animals were examined.

RESULTS

In the H. pylori-infected gerbils, there were no significant differences in the level of H. pylori colonization among the different dietary and control groups. However, the MPO activity was significantly decreased in the H. pylori group administered the F + IgY diet compared with that in the H. pylori group administered the IgY, F, or control diet. Furthermore, in the gerbils administered the F + IgY diet prior to the bacterial inoculation, inhibition of H. pylori colonization and suppression of the elevated gastric mucosal MPO activity were observed.

CONCLUSIONS

Oral administration of urease-specific IgY not only inhibited H. pylori disease activity in H. pylori-infected gerbils, but also prevented H. pylori colonization in those not yet infected. These encouraging results may pave the way for a novel therapeutic and prophylactic approach in the management of H. pylori-associated gastroduodenal disease.

Physical mapping of the bovine immunoglobulin heavy chain constant region gene locus

Bovine antibodies have recently attracted increasing attention, as they have been shown to exhibit prophylactic and therapeutic properties in selected infectious diseases in humans. In the present study, we have isolated bacterial artificial chromosomes and cosmid clones containing the bovine JH, mu, delta, gamma 1, gamma 2, gamma 3, epsilon, and alpha genes, which allowed us to make a contig of the genes within the bovine IGHC locus. The genes are arranged in a 5'-JH-7 kb-mu-5 kb-delta-33 kb-gamma 3-20 kb-gamma 1-34 kb-gamma 2-20 kb-epsilon- 13 kb-alpha-3' order, spanning approximately 150 kb DNA. Examination of the bovine germline JH locus revealed six JH segments, two of which, JH1 and JH2, were shown to be functional although there was a strong preference for expression of the former. Sequence alignment of the bovine 5' E mu enhancer core region with those of other mammals, demonstrated an absence of the mu E3 motif and a shortened spacer between the mu A and mu B sites within the bovine E mu enhancer core region. Furthermore, the essential sequence element for class switching, switch mu, spanning approximately 3-kb repetitive sequence and abundant in the switch region motifs CTGGG (187 repeats) and CTGAG (127 repeats), was identified immediately upstream of the mu gene. A further sequence comparison revealed that the bovine IGHC genes display an extensive polymorphism leading to expression of multiple antibody allotypes.

Helicobacter pylori- inflammation, immunity and vaccines

The mechanisms by which Helicobacter pylori escape the host immune response remains an important topic. Regulatory T cells appear to play a role in the persistence of the infection and the control of tissue damage. In the thought that the host genetic background influences the cross-talk between pathogens and hosts, the impact of cytokine polymorphisms on the outcome of H. pylori has been further delineated in the review period. On the other hand, several additional genes of H. pylori have been shown to participate in the pro-inflammatory cytokine and chemokine response to the infection. Finally, progress has been achieved in vaccine development, with new vaccine delivery systems and routes of immunization tested in animal models and human volunteers.