Immunoregulation by breast milk cells

Importance of nutrition in inflammatory bowel disease

Inflammatory bowel disease (IBD) results from the interaction between an individual's immune response and precipitant environmental factors, which generate an anomalous chronic inflammatory response in those who are genetically predisposed. Various feeding practices have been implicated in the origin of IBD based on epidemiological observations in developed countries, but we do not have solid evidence for the etiological role played by specific food types. IBD is associated with frequent nutritional deficiencies, the pattern and severity of which depends on the extent, duration and activity of the inflammation. Nutritional support allows these deficiencies in calories, macro- and micro-nutrients to be rectified. Enteral nutrition is also a primary therapy for IBD, especially for Crohn's disease, as it allows the inflammatory activity to be controlled, kept in remission, and prevents or delays the need for surgery. Nutritional support is especially important in childhood IBD as an alternative to pharmacological treatment. This report discusses the complex relationship between diet and IBD.

Importance of nutrition in inflammatory bowel disease

Inflammatory bowel disease (IBD) results from the interaction between an individual’s immune response and precipitant environmental factors, which generate an anomalous chronic inflammatory response in those who are genetically predisposed. Various feeding practices have been implicated in the origin of IBD based on epidemiological observations in developed countries, but we do not have solid evidence for the etiological role played by specific food types. IBD is associated with frequent nutritional deficiencies, the pattern and severity of which depends on the extent, duration and activity of the inflammation. Nutritional support allows these deficiencies in calories, macro- and micro-nutrients to be rectified. Enteral nutrition is also a primary therapy for IBD, especially for Crohn’s disease, as it allows the inflammatory activity to be controlled, kept in remission, and prevents or delays the need for surgery. Nutritional support is especially important in childhood IBD as an alternative to pharmacological treatment. This report discusses the complex relationship between diet and IBD.

Effects of transforming growth factor-beta and formula feeding on systemic immune responses to dietary beta-lactoglobulin in allergy-prone rats

Early nutritional events have the potential to affect health outcomes in later life including the development of allergy. Food allergy is usually the first manifestation of allergy. Breast-feeding has been associated with a protective effect against the development of allergy, but the evidence is contradictory and the mechanisms involved are not clear. We hypothesize that milk cytokines, such as transforming growth factor beta (TGF-beta), play a role in regulating immune responses to dietary antigens. Using a rat pup model of gastrostomy feeding, the immune response profile, at weaning and post-weaning, of allergy-prone Brown Norway rats fed formula supplementation with TGF-beta was assessed. We show that feeding formula to allergy-prone rat pups results in increased total IgE immunoglobulin, beta-lactoglobulin (BLG) IgG1 antibody, and mucosal mast cell activation, as measured by serum rat mast cell protease II (RMCPII) levels in the gut. Supplementation of formula with physiological levels of TGF-beta down-regulated the BLG IgG1 response as well as total IgE and mucosal mast cell activation. Supplementation of formula also resulted in an increase in Th1 cytokines, interleukin (IL)-18, IL-12p40, IL-12p35, and interferon gamma (IFN-gamma) and an increase in IL-10. In conclusion, TGF-beta supplementation of formula moved the immune response profile of allergy prone (Th2 type) rat pups toward a Th1 profile in the suckling period. Importantly, this immune profile persisted after weaning when TGF-beta was no longer present in the diet.

Is nutrition an aetiological factor for inflammatory bowel disease?

Inflammatory bowel disease (IBD) is a chronic inflammatory process, the aetiology of which is complex and probably multi-factorial. Nutrition has been proposed to be an important aetiological factor for IBD. The present review critically examines the relationship between components of the diet (such as sugar, fat, fibre, fruit and vegetables, and protein) and IBD, including ulcerative colitis and Crohn's disease. In addition, it investigates the possible role of infant feeding practices in the development of IBD.

Neonatal IgA and IgE levels among infants with paternal heredity for atopic disease

Serum IgA and IgE levels were studied in the postnatal period in 21 infants having a paternal heredity of atopic disease. Three different sampling techniques were used, aspirated cord blood (CB), gravity-collected cord blood, and capillary collected blood at 4-5 days of age. Significant differences among the three sampling techniques were recorded for IgA (P < 0.01), but not for IgE. The IgA levels decreased from birth to 4-5 days of age in 90% (19/21 of infants (P < 0.01). The corresponding decrease in IgE levels was 20%. This postnatal difference in the frequency of decreasing/increasing IgA and IgE levels was significant (P < 0.05). An analysis of CB IgA to detect maternal contamination of CB was found to be of questionable value, since only 50% (2/4) of the cases with an elevated CB-IgA level could be considered contaminated. The results of this study further emphasize that aspiration of CB and capillary collection of blood at 4-5 days of age are the best sampling techniques to avoid contamination. The general finding that paternal heredity had no significant influence on infant IgE contrasts with the strong influence of maternal heredity. Further studies will show whether the explanation lies in genetic or transplacental factors, or in both kinds of factors.

The influence of colostral leukocytes on the course of an experimental Escherichia coli infection and serum antibodies in neonatal calves

Three hours post natum, 20 calves were orally infected with 10(9) colony forming units of an enteropathogenic E. coli. Immediately after infection and on 2 days subsequent, ten of the calves (COL-) received cell-deprived pooled colostrum and the other ten (COL+) pooled colostrum supplemented with colostral cells. The COL+ calves excreted significantly less bacteria of the infectious strain with their faeces in the first week after infection and reached the lower limit of detectability earlier than the COL- calves. Colostral leukocytes obtained from cows which developed clinical mastitis (n = 2), showed a marked reduction in the number of shed bacteria. The concentration of IgA and IgM specific antibodies against E. coli in the serum of the COL+ calves was significantly higher in the early postnatal period than in the serum of the COL- calves and remained at a slightly higher level throughout the whole investigative period. In addition to humoral substances of the colostrum, colostral leukocytes obviously contribute to the passive immunity and resistance of the newborn calf. The quality and quantity of the leukocytes seem to be of crucial importance to their efficiency.

Interleukin-4 fails to inhibit interferon-gamma-induced activation of human colostral macrophages

IL-4 abrogates the IFN-gamma-mediated activation of peripheral blood monocytes (M. Lehn, W. Y. Weiser, S. E. Engelhorn, S. Gillis, and H. G. Remold, 1989, J. Immunol. 143, 3020). In contrast, in colostral macrophages IL-4 fails to inhibit IFN-gamma-induced increase of H2O2 production and of antileishmanial activity. Flow cytometric analysis shows that the number of IL-4 receptors (IL-4R) is 2.4 times higher on colostral macrophages than on peripheral blood monocytes and that 23% of the colostral macrophages have detectable IL-4R in contrast to 2% of the blood monocytes. Thus, colostral macrophages are functionally different from peripheral blood monocytes in their response to IL-4 and in the numbers of IL-4R. This difference could reflect specific requirements for their protective performance in the neonatal intestine.

Mucosal immunity: the immunology of breast milk

The mammary glands represent one part of the mucosal immune system, a definable, subunit of humoral and cellular immune functions in man that appears to have developed particular qualities well suited to guard our interface with the environment. As our understanding of secretory immunoglobulins and lymphocyte migration patterns continues to develop, the immunologic components found in breast milk appear increasingly likely to play a specific immunologic role in the protection of the nursing infant. The biologic basis for the observed protective effect of breast-feeding is reviewed with an emphasis on the mechanisms involved in the development and maintenance of mucosal immunity in general.

Presence of IgE suppressor factors in human colostrum

In spite of intensive investigations, the ability of breast feeding to delay and to attenuate atopic diseases in children remains debatable. This study documents a mechanism whereby breast feeding might interfere with the synthesis of IgE by breast-fed infants. Indeed, we show that colostrum contains IgE-binding factors (IgE-BF) capable of suppressing the in vitro synthesis of human IgE. Colostrum obtained from 15 donors was successively depleted of lipids and casein, filtered through Amicon XM50 membrane (mol. mass cut-off 50 kDa) and lyophilized. IgE-BF was demonstrated in such preparations by two different approaches, i.e. a classical rosette inhibition assay and Western blot analysis. In the first instance, lyophilized preparations of colostrum inhibited the binding of IgE-coated bovine erythrocytes to IgE recovered on the surface of RPMI 8866 lymphoblastoid cells. The rosette-inhibiting activity could be absorbed on IgE- but not on IgG-Sepharose 4B and it could be recovered in the eluate of IgE-Sepharose 4B. The molecular mass of IgE-BF was comprised between 10 to 20 kDa as estimated by gel filtration through a calibrated Sephadex G-75 column. After fractionation on 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transfer to nitrocellulose membrane, colostrum displayed one band of 14 kDa and reacted with radiolabeled IgE but not with IgG nor IgM. This 14-kDa band could be removed by absorbing colostrum with IgE- but not with IgG-Sepharose 4B. Most importantly, the colostrum IgE-BF suppressed the spontaneous in vitro synthesis of IgE by B lymphocytes derived from allergic donors without altering the production of IgM.

Oxidative metabolic response and microbicidal activity of human milk macrophages: effect of lipopolysaccharide and muramyl dipeptide

Mouse macrophages can be primed by exposure in vitro to the bacterial products lipopolysaccharide and muramyl dipeptide (MDP) or in vivo by injection of MDP, so that they produce more of the bactericidal agent superoxide anion (O2-) when stimulated by phagocytosis or by contact with phorbol myristate acetate (PMA). Because little is known about the physiology of human tissue macrophages, we examined release of O2- by milk macrophages obtained from 45 normal women for the ability to undergo priming for greater O2- release. In samples from the same individuals, PMA-stimulated O2- release was similar from colostrum (0 to 3 days postpartum) or from transitional milk (5 to 8 days). Release of O2- by milk macrophages was almost identical to that by blood monocytes from the same women. Milk macrophages phagocytized and killed Candida albicans relatively effectively. Incubation with lipopolysaccharide activated the macrophages in that they were primed for greater PMA-stimulated O2- release. Incubation with the adjuvant MDP or its analog 6-O-(2-tetradecylhexadecanoyl)-MDP did not prime, but incubation with a second analog, 6-O-(stearoyl)-MDP, primed the macrophage for greater O2- release. These results indicated that human tissue macrophages can be primed for greater oxidative response by exposure to bacterial products. Potential exists for the therapeutic use of such immunomodulating agents in the enhancement of host defense.

Immunoglobulin synthesis by cord blood lymphocytes

The IgG, IgA and IgM synthesis by adult peripheral blood and cord blood lymphocytes incubated alone and with pokeweed mitogen was quantitated. The cord blood lymphocytes produced no immunoglobulin even with mitogen stimulation while the adult peripheral blood lymphocytes responded to the mitogen with a significant (p less than 0.04) increase in immunoglobulin production.