Current approaches for risk assessment of intestinal transplant patients: A view from the histocompatibility laboratory.

Despite its recent decline in volumes, intestinal transplantation remains an important option for patients with irreversible intestinal failures. The long-term outcome of an intestinal transplant has stagnated. The major cause of graft loss is rejection, resulting from mismatches in human leukocyte antigens (HLA) and the presence of antibodies to mismatched donor-specific HLA antigens (DSA). Literature has reported that DSAs, either preformed before transplantation or developed de novo after transplantation, are harmful to intestinal grafts, especially for those without combined liver grafts. A comprehensive assessment of DSA by the histocompatibility laboratory is critical for successful intestinal transplantation and its long-term survival. This paper briefly reviews the history and current status of different methods for detecting DSA and their clinical applications in intestinal transplantation. The focus is on applying different antibody assays to manage immunologically challenging intestinal transplant patients before and after transplantation. A clinical case is presented to illustrate the complexity of HLA tests and the necessity of multiple assays. The review of risk assessment by the histocompatibility laboratory also highlights the need for close interaction between the laboratory and the intestinal transplant program.

A potential vaccine candidate towards chicken coccidiosis mediated by recombinant Lactobacillus plantarum with surface displayed EtMIC2 protein.

Eimeria tenella (E. tenella) has caused severe economic loss in chicken production, especially after the forbidden use of antibiotics in feed. Considering the drug resistant problem caused by misuse of chemoprophylaxis and live oocyst vaccines can affect the productivity of chickens, also it has the risk to reversion of virulence, the development of efficacious, convenient and safe vaccines is still deeply needed. In this study, the EtMic2 protein of E. tenella was anchored on the surface of Lactobacillus plantarum (L. plantarum) NC8 strain. The newly constructed strain was then used to immunize chickens, followed by E. tenella challenge. The results demonstrated that the recombinant strain could provide efficient protection against E. tenella, shown by increased relative body weight gains, percentages of CD4+ and CD8+ T cells, humoral immune response and inflammatory cytokines. In addition, decreased cecum lesion scores and fecal oocyst shedding were also observed during the experiment. In conclusion, this study proves the possibility to use L. plantarum as a vessel to deliver protective antigen to protect chickens against coccidiosis.

Safety Assessment of Potential Probiotic Lactobacillus fermentum MTCC-5898 in Murine Model after Repetitive Dose for 28 Days (Sub-Acute Exposure).

Safety assessment of probiotic Lactobacillus fermentum MTCC-5898 (LF) with three doses (107, 109, and 1011 cfu/day/animal) was carried on Swiss albino mouse weanlings for 28 days using oral route. Health status of animals was monitored by physical assessment of body weight, organ indices, and histological appearances of liver and intestine along with measurement of hematological parameters (Hb, WBC, RBC count, MCHC, MCV, MCH), biochemical analytes in blood involving glucose, serum enzymes (ALT, AST and LDH), urea, creatinine, and lipid profile (total cholesterol, triglycerides, HDL, VLDL, LDL, and atherogenic index). LF showed no adverse effects on above parameters of general health status after continuous consumption for the experimental period. On the other hand, significant increase (p ≤ 0.05) in TGF-ß (regulatory cytokine) and considerable decrease (p ≤ 0.05) in IFN-γ (pro-inflammatory cytokine) without any major changes in IL-4 and IL-12 in intestinal fluid on consumption of 109 cfu/animal/day confirmed its dose-specific response for immune homeostasis. Further, safety of LF was also confirmed by insignificant changes in release of FITC-dextran (4 kDa) in blood on its consumption than control group where only saline was given orally. Moreover, significantly (p ≤ 0.05) increased mRNA expression of claudin-1 and MUC-2 in intestinal epithelial cells on feeding L. fermentum further supported FITC-dextran permeability data which otherwise showed increased flux of FITC-dextran in blood on consumption of E. coli (109 cfu/animal/day) due to intestinal damage. Thus, in vivo results confirmed that Lactobacillus fermentum MTCC 5898 is safe and non-toxic to weanling mice and may be considered for functional food application after clinical testing.

Allergenicity assessment of Buchanania lanzan protein extract in Balb/c mice.

Tree nuts are among "Big Eight" and have been reported globally for causing allergy. Buchanania lanzan (Bl) is one of the major tree nuts consumed by Indian population. However, very little is known about B. lanzan's induced allergic manifestation. Therefore, evaluation of it's allergenic potential was undertaken. Bl-crude protein extract sensitized BALB/c mice sera were used to identify the allergic proteins by it's IgE binding capability. The major IgE binding proteins found with molecular weight of 11, 20, 23, 25, 48, 54, and 65 kDa. Specific IgE, specific IgG1, MCPT-1, PGD2 and histamine were assessed in mice sera. Enormous amount of mast cell infiltration was noted in different organs. The levels of Th1/Th2 transcription factors GATA-3, SOCS3 and STAT-6 were found upregulated, whereas T-bet was downregulated. Furthermore, elevated Th1/Th2 cytokine responses were observed in mice sera. All together, these reactions developed systemic anaphylaxis upon Bl-CPE challenge in sensitized BALB/c mice. In order to confirm the evidences obtained from the studies carried out in BALB/c, the investigation was extended to human subjects as well. Control subjects and allergic patients were subjected to skin prick test (SPT). Later sera collected from those positive to SPT along with controls were used for IgE immunoblotting. The study evaluated the allergic manifestation associated with Bl, and identified it's proteins attributing Bl-mediated allergy. This work may help in managing tree nuts mediated allergies especially due to Buchanania lanzan sensitization.

Assessment of Environmental Enteric Dysfunction in the SHINE Trial: Methods and Challenges.

Environmental enteric dysfunction (EED) is a virtually ubiquitous, but poorly defined, disorder of the small intestine among people living in conditions of poverty, which begins early in infancy and persists. EED is characterized by altered gut structure and function, leading to reduced absorptive surface area and impaired intestinal barrier function. It is hypothesized that recurrent exposure to fecal pathogens and changes in the composition of the intestinal microbiota initiate this process, which leads to a self-perpetuating cycle of pathology. We view EED as a primary gut disorder that drives chronic systemic inflammation, leading to growth hormone resistance and impaired linear growth. There is currently no accepted case definition or gold-standard biomarker of EED, making field studies challenging. The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial in Zimbabwe is evaluating the independent and combined effects of a package of infant feeding and/or water, sanitation, and hygiene interventions on stunting and anemia. SHINE therefore provides an opportunity to longitudinally evaluate EED in a well-characterized cohort of infants, using a panel of biomarkers along the hypothesized causal pathway. Our aims are to describe the evolution of EED during infancy, ascertain its contribution to stunting, and investigate the impact of the randomized interventions on the EED pathway. In this article, we describe current concepts of EED, challenges in defining the condition, and our approach to evaluating EED in the SHINE trial.

Isolation of lactic acid bacteria from kuruma shrimp (Marsupenaeus japonicus) intestine and assessment of immunomodulatory role of a selected strain as probiotic.

Fifty-one lactic acid bacteria (LAB) strains were isolated and identified based on 16S ribosomal DNA sequence from the intestinal tracts of 142 kuruma shrimps (Marsupenaeus japonicus) collected from Kanmon Strait, Fukuoka and Tachibana Bay, Nagasaki, Japan. Cellular immunomodulatory function of 51 isolated LAB strains was assessed by measuring the level of interferon (IFN)-γ induction in mouse spleen cell culture. The strain Lactococcus lactis D1813 exhibited the highest amount of IFN-γ production and also bactericidal activity and was selected for testing its immunomodulatory role as a probiotic in kuruma shrimp. We also assessed the effect of dietary incorporation of this probiotic on resistance to Vibrio penaeicida infection in the kuruma shrimp. Our results demonstrate that probiotic L. lactis D1813-containing diet-fed (105 cfu g⁻¹) shrimps displayed a significant up-regulation of lysozyme gene expressions in the intestine and hepatopancreas. However, insignificantly higher expression of anti-lipopolysaccharide factor, super oxide dismutase, prophenoloxidase, and toll-like receptor 1 was recorded in the intestine of shrimps fed the probiotic diet. Moreover, significantly increased (P < 0.01) resistance to the bacterial pathogen in term of better post-infection survival (61.7 %) was observed in the shrimps fed with the probiotic-incorporated diet compared with the control diet-fed group (28.3 %). The present study indicates the immunomodulatory role of the LAB L. lactis D1813 on the kuruma shrimp immune system and supports its potential use as an effective probiotic in shrimp aquaculture.

Assessment of Cryptosporidium parvum infection in immunocompetent and immunocompromised mice and its role in triggering intestinal dysplasia.

OBJECTIVES: There is an association between chronic inflammation and cancer, including colon cancer. Cryptosporidium parvum is a protozoan parasite that infects the gastrointestinal epithelial cells causing several parasitological and pathological changes. It is incriminated in the development of colorectal cancer in immunosuppressed individuals. Cyclin D1 expression is essential for cell cycle progression and its overexpression has been reported in colorectal cancer. This work aimed to study the gastrointestinal changes, including parasitological and pathological changes, induced by C. parvum infection in both immunocompetent and in chemically immunosuppressed mice, together with immunohistochemical assessment of cyclin D1 expression in infected tissues. In addition, the effectiveness of nitazoxanide (NTZ) in the treatment of cryptosporidiosis was evaluated. METHODS: This study included six groups of mice: group I, infected; group II, infected and immunosuppressed; group III, infected and treated with NTZ; group IV, infected, immunosuppressed, and treated with NTZ; and groups V and VI representing non-infected controls. Mice were subjected to stool examination for oocyst counts and were later sacrificed for intestinal dissection and routine histopathological examination of pathological changes; the endogenous developmental stages of the parasite were counted and immunohistochemical staining was carried out for the determination of cyclin D1. RESULTS: Group II showed the highest numbers of oocysts shed and endogenous developmental stages compared to the other groups. Intestinal dysplastic changes were seen only in groups I and II, where these changes were in favor of group II compared to group I. High-grade dysplasia was seen in four out of 20 mice in group II and was significantly associated with the number of endogenous developmental stages of C. parvum. NTZ was effective in the treatment of Cryptosporidium infection, with a greater effect in group III than in group IV. CONCLUSIONS: C. parvum is one of the infectious agents that may induce intestinal dysplasia, including the high-grade category, which occurs particularly in the presence of immune suppression states and elevated endogenous parasite loads. Cyclin D1 is a good and useful marker for the detection of intestinal dysplasia. The effectiveness of NTZ is dependent on the immune status of the infected host.

In vitro assessment of the immunomodulatory effects of multispecies probiotic formulations for management of allergic diseases.

Modulation of the composition of the intestinal microbiota with probiotics could possibly offer a way of prevention or management of allergic diseases. The objective of this study was to determine the immunomodulating effects of various multispecies probiotic combinations in vitro, as preamble to application in vivo. Multispecies probiotic combinations were formulated and tested for their effects on in vitro cytokine production by human mononuclear cells and were compared to products that already have shown beneficial effects in vivo. All 4 tested combinations of probiotics showed a 40-71% decrease of Th2 cytokine production (IL-4, IL-5, and IL-13) and a variable increase of Th1 (IFN-γ) and Treg cytokine (IL-10) production compared to the medium. A specific probiotic mixture that contained Bifidobacterium breve W25, Bifidobacterium lactis ATCC SD 5219, B. lactis ATCC SD 5220, Lactobacillus plantarum W62, Lactobacillus salivarius W57 and Lactococcus lactis W19 was superior in its stimulating effect on IL-10 production (significant better than the other tested combinations; P=0.001). Modulation of in vitro cytokine production profiles can be used to differentiate between selected probiotic formulations for their immunomodulatory properties. In the future it should be demonstrated whether the immunomodulatory capacities from the multispecies probiotic formulation with the desired profile will be effective in vivo (in adolescents, followed by application in children).

[The influence assessment of probiotic fermented milk products on intestinal microflora, hematological indices and cellular immunity in rats (report 1)].

Influence of probiotic fermented milk products on the intestinal flora, hematological parameters and immune status of the experiment in vivo at rats is studied. Entering in digestive tract of probiotic strains of Lactobacillus acidophilus NK-1 and Bifidobacterium bifidum 791 at the level of hundreds of millions CFU in a day (from 1,7 x 10(8) to 9 x 10(8) CFU) in composition fermented milk products renders on the whole positive, but not significant statistically influence on the indexes of colon microflora and immune status of rats, and it must be extended for the achievement of reliable effect.

Safety assessment of probiotics for human use.

The safety of probiotics is tied to their intended use, which includes consideration of potential vulnerability of the consumer or patient, dose and duration of consumption, and both the manner and frequency of administration. Unique to probiotics is that they are alive when administered, and unlike other food or drug ingredients, possess the potential for infectivity or in situ toxin production. Since numerous types of microbes are used as probiotics, safety is also intricately tied to the nature of the specific microbe being used. The presence of transferable antibiotic resistance genes, which comprises a theoretical risk of transfer to a less innocuous member of the gut microbial community, must also be considered. Genetic stability of the probiotic over time, deleterious metabolic activities, and the potential for pathogenicity or toxicogenicity must be assessed depending on the characteristics of the genus and species of the microbe being used. Immunological effects must be considered, especially in certain vulnerable populations, including infants with undeveloped immune function. A few reports about negative probiotic effects have surfaced, the significance of which would be better understood with more complete understanding of the mechanisms of probiotic interaction with the host and colonizing microbes. Use of readily available and low cost genomic sequencing technologies to assure the absence of genes of concern is advisable for candidate probiotic strains. The field of probiotic safety is characterized by the scarcity of studies specifically designed to assess safety contrasted with the long history of safe use of many of these microbes in foods.

[Stress-mast cell axis and regulation of gut mucosal inflammation: from intestinal health to an irritable bowel]. / Eje estrés-mastocito y regulación de la inflamación en la mucosa intestinal: desde la salud intestinal hasta el intestino irritable.

The functional gastrointestinal disorders and the irritable bowel syndrome, in particular, represent one of the commonest causes of medical consultation and the most frequent diagnosis raised by the gastroenterologists. Despite their high prevalence, the aetiology and pathophysiology of these functional digestive disorders remains unclear and specific diagnostic markers and clearly effective therapeutic options are lacking as well. These factors generate an important impairment in the quality of life in these patients and a growing sanitary burden. Recent studies showing the presence of low grade intestinal mucosal inflammation along with mast cell hyperplasia may contribute to the development and perpetuation of visceral hypersensitivity and dismotility patterns and epithelial barrier abnormalities, characteristic of the irritable bowel syndrome. In this article we will review the role of the stress-mast cell axis in the modulation of the gut mucosal inflammation and in the pathophysiology of the irritable bowel syndrome.

PASSCLAIM--gut health and immunity.

BACKGROUND: The gut and immune system form a complex integrated structure that has evolved to provide effective digestion and defence against ingested toxins and pathogenic bacteria. However, great variation exists in what is considered normal healthy gut and immune function. Thus, whilst it is possible to measure many aspects of digestion and immunity, it is more difficult to interpret the benefits to individuals of variation within what is considered to be a normal range. Nevertheless, it is important to set standards for optimal function for use both by the consumer, industry and those concerned with the public health. The digestive tract is most frequently the object of functional and health claims and a large market already exists for gut-functional foods worldwide. AIM: To define normal function of the gut and immune system and describe available methods of measuring it. RESULTS: We have defined normal bowel habit and transit time, identified their role as risk factors for disease and how they may be measured. Similarly, we have tried to define what is a healthy gut flora in terms of the dominant genera and their metabolism and listed the many, varied and novel methods for determining these parameters. It has proved less easy to provide boundaries for what constitutes optimal or improved gastric emptying, gut motility, nutrient and water absorption and the function of organs such as the liver, gallbladder and pancreas. The many tests of these functions are described. We have discussed gastrointestinal well being. Sensations arising from the gut can be both pleasant and unpleasant. However, the characteristics of well being are ill defined and merge imperceptibly from acceptable to unacceptable, a state that is subjective. Nevertheless, we feel this is an important area for future work and method development. The immune system is even more difficult to make quantitative judgements about. When it is defective, then clinical problems ensure, but this is an uncommon state. The innate and adaptive immune systems work synergistically together and comprise many cellular and humoral factors. The adaptive system is extremely sophisticated and between the two arms of immunity there is great redundancy, which provides robust defences. New aspects of immune function are discovered regularly. It is not clear whether immune function can be "improved". Measuring aspects of immune function is possible but there is no one test that will define either the status or functional capacity of the immune system. Human studies are often limited by the ability to sample only blood or secretions such as saliva but it should be remembered that only 2% of lymphocytes circulate at any given time, which limits interpretation of data. We recommend assessing the functional capacity of the immune system by: measuring specific cell functions ex vivo. measuring in vivo responses to challenge, e. g. change in antibody in blood or response to antigens. determining the incidence and severity of infection in target populations during naturally occurring episodes or in response to attenuated pathogens.

Assessment of intestinal permeability and orocecal transit time in patients with systemic sclerosis: analysis of relationships with epidemiologic and clinical parameters.

OBJECTIVE: The aim of this study was to assess intestinal permeability (IP) in patients with systemic sclerosis (SSc) and to relate the results with general disease activity and gastrointestinal involvement. METHODS: Twenty-eight females and four males were studied. Patients with severe gastrointestinal involvement were excluded. Thirty-three healthy volunteers served as controls. Intestinal permeability was assessed by means of the orally administered cellobiose/mannitol sugar (Ce/Ma) test. Intestinal transit time (ITT) was investigated with the H2-lactulose breath test. RESULTS: The mean value of IP in 32 SSc patients was significantly higher than in 33 controls ( P<0.05), although it fell within the normal range. Eleven patients showed abnormally high individual IP values (>0.028) that significantly correlated to disease duration ( r=0.73). Altered IP was associated with the higher but not statistically relevant presence of anti-Scl70 antibodies (9/11) and to more severe gastrointestinal involvement. More than half of the SSc patients showed slower orocecal transit times on the H2 breath test. In particular, delayed ITT was observed in 60% of patients with increased IP and in all patients with moderate gastrointestinal involvement according to the scleroderma severity scale. CONCLUSION: Intestinal permeability was altered in 11/32 SSc patients. Correlations between increased IP and duration of disease and degree of gastrointestinal involvement appear to support the hypothesis of secondary involvement of the intestinal barrier, and the presence of anti-Scl70 antibodies in 82% of the patients with higher IP clearly reinforces the hypothesis of an altered immune response in these subjects.

Intestinal inflammation in adhesion molecule-deficient mice: an assessment of P-selectin alone and in combination with ICAM-1 or E-selectin.

Biopsy specimens from patients with inflammatory bowel disease have demonstrated an up-regulation of P-selectin, suggesting a role for P-selectin in intestinal inflammation. We examined the role of P-selectin in experimental intestinal inflammation using mice deficient in P-selectin alone or in combination with either ICAM-1 or E-selectin. Colitis was induced using acetic acid or trinitrobenzene sulfonic acid (TNBS). Damage scores and neutrophil infiltration 24 h post acetic acid were not different between wild-type and P-selectin- or P-selectin/ICAM-1-deficient mice, whereas P/E-selectin-deficient mice had enhanced leukocyte recruitment and damage. At 72 h an attenuation in damage scores and a slight decrease in neutrophil infiltration was observed in the P- and P/ICAM-deficient animals. The P/E-selectin-deficient mice maintained enhanced leukocyte recruitment and damage. In wild-type mice P-selectin expression was elevated 48 and 72 h post acetic acid-induced inflammation. Surprisingly, P-selectin or P-selectin/ICAM-1 deficiency did not improve the inflammation induced by TNBS over 7 days. In fact, increased mortality was observed. Anti-adhesion therapy may play only a limited, beneficial role and often a detrimental role in intestinal inflammation.

An alternative approach to the assessment of gamma delta T-cell clonality in celiac disease intestinal lesions through cDNA heteroduplex analysis of T-cell receptor VJ junctions.

We have investigated the clonality of the gamma delta T lymphocytes infiltrating the intestinal mucosa of CD patients and control subjects by means of a simple and powerful method based on the heteroduplex analysis of the TCR VJ junctions. Each V-specific TCR chain, amplified either from fresh biopsy material or intestinal T-cell-line cDNA, is denatured and renatured to allow the random reshuffling of the various strands carrying different junctional sequences, coamplified in the same reaction. The mismatched chains (heteroduplexes) are separated from the matched ones (homoduplexes) through polyacrylamide gel electrophoresis, and whenever one or more T-cell clones are emerging over the polyclonal background, discrete bands are visible by ethidium-bromide staining. Through this method, we have estimated the diversity of the V delta 1-3 chains and a newly described V gene (V delta 8) whose homologue in mice is abundantly expressed in gamma delta iLs. We demonstrate that the well-documented expansion of V gamma 1+ gamma delta lymphocytes in the jejunum of CD patients is polyclonal. Overall, the heteroduplex analysis on fresh intestinal and peripheral blood lymphocytes from both healthy and affected subjects shows a polyclonal pattern of all the V delta+ subsets. In contrast, most intestinal T-cell lines produce oligoclonal patterns, suggesting a dramatic in vitro selection effect. The cell expansion in culture is generally not required for the TCR heteroduplex analysis, which can therefore be applied to rapidly monitor the T-cell response in a variety of physiologic and autoimmune reactions, substituting the standard approach of TCR cloning and multiple VJ sequencing.

Extravasation assay for the assessment of intestinal reactions to orally presented compounds.

Adverse reactions characteristic of food intolerance are claimed to occur in susceptible individuals following exposure to various chemical additives used to colour, flavour or preserve food. The objective of the present study was to develop a method suitable for investigating the nature and mechanism of these reactions in an animal model. Our results demonstrate that intestinal responses, elicited either specifically following oral challenge by antigen or non-specifically by the direct action of a chemical, can be quantified by evaluating the intestinal extravasation (IEV) of intravenously administered 125I-labelled rat albumin.