Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice.

INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice

Abstract INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection.

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Serological status of mares in parturition and the levels of antibodies (IgG) against protozoan family Sarcocystidae from their pre colostral foals.

Protozoa from the family Sarcocystidae are agents of reproductive and neurological disorders in horses. The transmission of these protozoa may occur via horizontal or vertical means, and the frequency and potential of the later is not fully elucidated in horses. Thus, the aim of study was to correlation levels of antibodies in mares with pre colostral foals seropositive and assess the level and distribution of antibodies against Neospora spp., Sarcocystis neurona and Toxoplasma gondii, in mares and pre colostral foals at the parturition. The blood samples were collected from mares immediately after parturition and from newborns before the ingestion of colostrum, and sera were analyzed for the presence of IgG by ELISA. It was found that 21.5%, 33.7% and 27.6% of mares were seropositive for Neospora spp., S. neurona and T. gondii, respectively; foals had antibodies at a rate of 8.3%, 6.6% and 6.6% for Neospora spp., S. neurona and T. gondii, respectively. Additionally, paired samples from mares and pre-colostral foals revealed an overall negative correlation between the serum reactivity against these three parasites and suggested that seronegative mares, or those with low to intermediate antibody levels, have a higher risk of giving birth to seropositive foals.

Neonatal tolerance under breastfeeding influence: the presence of allergen and transforming growth factor-beta in breast milk protects the progeny from allergic asthma.

Once the umbilical cord has been cut, immunologists have often looked at the neonate as an entity that develops on its own. For years, breast milk was considered mainly as a source of nutrients for the developing child. The extensive observations that breastfeeding affords protection toward infectious diseases and could reduce by more than the half the mortality rate because of common infections have added another key role to breastfeeding. This protection relies in great part on the passive transfer through breast milk of high amounts of microbe-specific immunoglobulins that compensate for the deficiency of immunoglobulins synthesis during the first year of life. Here, we will present and discuss our data showing how breast milk can actively shape the immune response of the progeny, particularly in the context of allergic disease. Indeed, our data obtained in a mouse model suggest that the protection attributed to breastfeeding toward asthma development might rely on immune tolerance induction. For this to occur, the mother mice needed to be exposed to the allergen by aerosol or oral route during the lactation period, which resulted into the transfer of the allergen to breast milk. The presence of the allergen together with transforming growth factor-beta in breast milk was necessary and sufficient to induce the development of regulatory T lymphocytes in the progeny and their protection from asthma development. If confirmed in human beings, this study may suggest new strategies for asthma prevention such as deliberate exposure of mother to allergens during breastfeeding and qualitative modification of artificial milks.

Brucella spp. lumazine synthase as a bovine rotavirus antigen delivery system.

Brucella spp. lumazine synthase (BLS) is a highly immunogenic decameric protein. It has been previously evaluated as a carrier to increase the immunogenicity of peptides fused to its N-termini. VP8 is a sialic acid binding domain of rotavirus external capsid protein VP4, which is involved in virus adhesion to host cells. In this work, the C486 bovine rotavirus (BRV) VP8 core protein (VP8d) was fused to the structure of BLS with the aim to produce an enhancement of the immune response against BRV VP8 and to evaluate the possible use of this antigen for vaccine development. The feasibility of using BLS as an antigen delivery system of polypeptides larger in size than those previously tested was also evaluated. Groups of female mice were immunized with BLS-VP8d fusion protein, VP8d or an equimolar mixture of purified VP8d and BLS (BLS+VP8d). Dams immunized with BLS-VP8 induced 97.5-100% protection against homologous challenge with C486 BRV; while pups born to dams immunized either with VP8d or BLS+VP8d presented a significant lower level of protection. The neutralizing antibody pattern was also significantly different among these experimental groups, and in concordance with challenge experiment. Overall, these results demonstrate that the BLS-VP8d chimeric protein is properly folded and stable, and that the BLS scaffold is a potent antigen delivery system that enhances the antibody response against BRV and elicits complete homotypic passive protection in a suckling mouse model.

Serum igG, blood profiles, growth and survival in goat kids supplemented with artificial colostrum on the first day of life.

The objective of this study was to compare serum IgG concentrations, blood metabolites indicative of nutritional status, weight gain and mortality rate in goat kids fed a commercial colostral supplement containing immunoglobulins against several pathogen microorganisms, prior to the ingestion of the mother colostrum, and goat kids ingesting natural colostrum only. There was no difference in serum IgG concentrations between 27 kids fed a colostrum supplement (20 g, derived from cow lacteal secretions) prior to the kids' first meal (658+/-703 mg dl(-1)) and 21 kids ingesting maternal colostrum freely (1011+/-1140 mg dl(-1)) at 24 hours of birth. Hematocrit values, serum glucose and urea concentrations at 24 hours and 5 days of age were unaffected by treatment. Serum total proteins were 14% higher (P<0.05) in the unsuplemented group than in the supplemented group at 5 d of age. There was no significant difference between the supplemented and unsupplemented kids in daily weight gain from birth to 70 days of age (92+/-4.8 vs 102+/-5.1 g day(-1)). Mortality was 4% for kids receiving the colostrum supplement as compared with 0.0% for kids ingesting maternal colostrum only. Results suggest that, in intensively managed non-dairy goats with kiddings in summer, the supplementation of this commercial colostrum derived from cow lacteal secretions and containing antibodies against diverse pathogens organisms did not enhanced growth, survival or immunity under the farming conditions of this study.

Long-term effect of early protein malnutrition on growth curve, hematological parameters and macrophage function of rats.

To evaluate the long-term effect of mild-early maternal protein malnutrition on weight gain, hematological parameters and macrophage function in rats at adult age, we compared rats whose dams were fed diets containing either 9.5% (low protein-LPD) or 23% protein (normal-NPD) for the first 12 d of lactation. At 80 d of age, the functions of spreading, phagocytosis and killing Candida albicans were determined in resident peritoneal macrophages, whereas leukocytes and red blood cells were counted in peripheral blood. The number of resident peritoneal macrophages from LPD was the same as from NPD, but the ability of spreading and phagocytosing opsonised yeast was impaired. Besides, they were not able to block the germ tube formation or kill C. albicans to the same extent as in the control group. The low protein diet produced a significant reduction in the pups' growth and in hematological parameters although no difference was found in leukocyte counts. Taken together the data suggest that protein malnutrition during early lactation induces permanent alterations in macrophage function, body composition and hematological status, which are not restored completely even after a normal protein diet is supplied.

Resistance of Santa Inês and Ile de France suckling lambs to gastrointestinal nematode infections.

A trial was carried out to determine the resistance to natural infection by gastrointestinal nematodes in 12 Santa Inês and nine Ile de France lambs before weaning. Faecal samples were obtained for faecal nematode egg counts (FEC). Blood samples were collected to determine packed cell volume (PCV), total plasma protein levels and peripheral eosinophil counts. Most Ile de France lambs (77.8%) were treated with an anthelmintic at 43 days of age, while 50% off Santa Inês lambs were treated at weaning, 57 days of age. The mean PCV values were normal in Santa Inês lambs, while in Ile de France lambs showed lower values reaching 22.3% at 43 days of age. The lowest mean plasma protein values were observed in Ile de France lambs (4.13 g/dl) at 43 days of age and in Santa Inês lambs (5.0 g/dl) at 57 days of age. Before weaning, Santa Inês lambs were susceptible to natural infections by gastrointestinal nematodes but with a greater capacity to stand the adverse effects of parasitism compared to Ile de France lambs.

Immunoglobulin M serum levels in females and pups of southern elephant seal (Mirounga leonina) during the suckling period.

This paper reports Immunoglobulin M (IgM) levels in serum samples from eight female-pup pairs of southern elephant seals (Mirounga leonina), at King George Island, Antarctica. IgM levels were determined on sera obtained from sequential sampling throughout the suckling period (approximately 23 days). The IgM concentration in southern elephant seal serum was measured by single radial immunodiffusion on agarose plates. Female IgM levels (123.5-613.0 mg/dL, n = 8) were significantly higher than pup levels (5.9-123.6 mg/dL, n = 8). Both groups showed an increasing trend throughout the entire suckling period, with significant differences in relation to stages of lactation. Pup IgM levels on the first day of life (mean +/- SD, 7.6 +/- 2.9 mg/dL, n = 3) suggest that endogenous synthesis takes place before birth.

Reversible effects on B and T cells of the gut-associated lymphoid tissues in rats malnourished during suckling: impaired induction of the immune response to intra-Peyer patches immunization with cholera toxin.

To define the alterations provoked by malnutrition during suckling (20 pups/dam) in the gut-associated lymphoid tissues of rats, Peyer patch (PP) and mesenteric lymph node (MLN) cells were studied by flow cytometry. After weaning (21 days of age), rats malnourished during suckling (MNR) showed an increase in the CD4+ CD45RC+ subset together with a decrease in the CD4+ CD45RC- subset (P < 0.01). These alterations remained even after 3 weeks of refeeding with stock diet. The CD4+CD8+ subset was not increased in the MNR, indicating that a release of cortical thymocytes did not occur. At weaning the percentage of CD4+Thy1+ cells was decreased in the MNR, indicating a low number of cells released from the thymus. When the B cell lineage was studied, we found a decreased percentage of precursors in the bone marrow and a decreased percentage of mature B cells in the periphery. When the MNR were immunized intra-PP with cholera toxin (CT) after 1 week of refeeding, the specific IgG and IgA and IgM antibody-forming cells (measured by ELISPOT) were diminished in the PP, MLN, and spleen when compared to the age-matched controls (P < 0.001). These results were coincident with the ELISA titers obtained in the sera and in the intestinal fluids. When CT was administered after 2 weeks of refeeding, the number of IgM anti-toxin AFC approached control values, but the number of IgA and IgG AFC continued to be low. When 3 weeks of refeeding was allowed before the CT delivery, the immune response in the MNR approached control values. These results indicate that malnutrition during suckling provokes alterations in B and T lymphocytes and produces a lack in the induction of the primary and secondary immune responses in the GALT which reversed after 3 weeks of refeeding.

Long-lasting functional unresponsiveness induced by a milk-transmitted Mls-1a-like superantigen.

We have recently shown (Piazzon et al. (1994) J. Immunol. 153, 1553) that foster-nursing of BALB/c mice on F1 Mls-1bxa mothers induce the progressive deletion of V beta 6+ and 8.1+ T cells in 50% of the mice. Preceding clonal deletion, a state of functional inactivation of CD4+ T cells to Mls-1a and anti-V beta 6 antibodies was detected in young mice. In the present paper we show that foster-nursing of BALB/c mice on (BALB/cxAKR)FI mothers is able to induce alterations in T cell reactivity in the non-deletor mice. Lymph node cells from foster-nursed mice show a decreased proliferative level against anti-V beta 6 antibodies and a diminished response in MLR and in CTL assays. The proliferative responses to either OVA or Con-A are also reduced. This state of functional inactivation is detected even in 6-month-old foster-nursed mice. Thus, the transmission through milk of the Mls-1a-like superantigen correlates in the non-deletor mice with a long-lasting state of functional inactivation and a decreased immune reactivity.

Deficient induction of the immune response to oral immunization with cholera toxin in malnourished rats during suckling.

Malnourished rats during suckling were orally immunized with cholera toxin (CT) after different periods of refeeding. Intestinal fluids, sera, and supernatant fluids from cultured mesenteric lymph node (MLN) cells were obtained after rats were given three doses of CT and analyzed by enzyme-linked immunosorbent assay (ELISA) to evaluate the specific antibody response. Serum-specific immunoglobulin G (IgG), IgA, and IgM were severely diminished in malnourished rats immunized with three doses of CT after 1 week of refeeding when compared with those of controls. Also, a decreased IgA ELISA titer of the intestinal fluids and abrogation of the capacity to neutralize the CT in the intestinal ligated loop test were found. When a booster was given at 113 days of age, the immune response continued to be affected in the serum and the intestinal fluid. The results from the analysis of the supernatant fluids from cultured MLN cells were coincident with those mentioned above. When one dose of CT was administered into Peyer's patches (PP) after 1 week of refeeding, an impaired immune response was found in the intestinal fluid of malnourished rats during suckling compared with that of controls. This result together with the analysis of supernatant from MLN and PP cell cultures suggests that antigen triggering in the PP was affected. When the refeeding period was extended to 30 days and then the first dose of CT was administered, the antibody immune responses in intestinal fluid serum and supernatant fluid approached control values. These observations reinforce the fact that the gut-associated lymphoid tissue immaturity of the rats when they received the first CT dose (at 28 days old) was the main reason for the decreased immune response observed in the experimental group.

Impairment of B and T cell maturation in gut associated lymphoid tissues due to malnutrition during lactation.

Previously we found that malnutrition during lactation in rats produces an impairment in the immune response to cholera toxin. In this report we found that malnutrition during lactation provokes in 28-day-old rats an increase of Thy1+ c mu+ cells in gut associated lymphoid tissues concomitantly with a decrease of sIgA+ B cells. No differences were found in the percentages of the IgM+ B cell populations. Furthermore, no differences were found in the Peyer's patch (PP) and mesenteric lymph node (MLN) T cell subsets in weaning rats when compared to controls. However, after 1 week of refeeding a higher percentage of the Thy1+ c mu- subset together with a lower percentage of CD5+, CD4+, and CD8+ T cells, were found in malnourished rats when compared to controls. The above results may indicate that B-cell maturation is delayed in malnourished rats at two stages of differentiation: (a) in the passage of pre-B cells (Thy1+ c mu+) to immature B cells (s mu+), and (b) in the switch from s mu+ B cells to s alpha+ B cells. The decrease of CD5+, CD4+, and CD8+ T cells together with an increase of the Thy1+ c mu- subset in gut-associated lymphoid tissues (GALT) may indicate that T-cell maturation is also delayed. Results obtained at weaning may be due to an engraftment by maternal milk-derived lymphocytes in the pups.

Transmission of an Mls-1a-like superantigen to BALB/c mice by foster-nursing on F1 Mls-1bxa mothers. Sex-influenced onset of clonal deletion.

Foster nursing of BALB/c (Mls-1b) mice on (BALB/cxAKR/J)F1 and (BALB/cxDBA/2)F1 (Mls-1bxa), but not on (BALB/cxC57Bl/6)F1 or (BALB/cxC3H/He)F1 (Mls-1bxb mothers, induced the progressive deletion of V beta 6+ and V beta 8.1+ T cells in 50% of the litter. The onset of this Mls-1a-like clonal deletion was markedly sex-influenced, being earlier in females (8-10 wk of age) than in males (32 wk). In both sexes, CD4+ V beta 6+ cells were more affected than CD8+ V beta 6+ cells. Decreases in the percentage of V beta 6+ cells were detected simultaneously in the thymus, lymph nodes, and peripheral blood. Preceding clonal deletion, functional unresponsiveness of CD4+ T cells to Mls-1 a Ags and to anti-V beta 6 Abs could be detected in most young male and female mice. The transmission of the Mls-1a-like superantigen through foster-nursing on (BALB/cxAKR/J)F1 mice correlated with the presence in milk of the mouse mammary tumor virus envelope protein gp52.

Regulation of parental alloreactivity by reciprocal F1 hybrids. The role of lactation.

Adult reciprocal F1 hybrids differ in their susceptibility to parental graft versus host (GvH) reactions. These reactions were lower when the donor strain was syngeneic with the maternal one. Splenocytes from the member of the reciprocal pair in which the GvH reactions were lower also induced a decreased response of parental cells in cytotoxicity assays and in mixed lymphocyte reactions (MLR). The treatment with anti-CD8 plus complement was able to abrogate the different stimulatory ability of the reciprocal F1 spleen populations. Foster-nursing of F1 hybrids on mothers from the paternal strain was able to induce permanent alterations in the ability of their splenocytes to induce both parental anti-F1 MLR and CTL. The stimulatory ability was indistinguishable from that observed in the reciprocal F1 combination nursed on its own mother. Moreover, lactation was able to alter the ability of CD8+ spleen cells to regulate CTL and parental anti-F1 MLR. The results reported herein show the existence of a maternal effect acting though milk capable of altering the regulation of parental alloreactive T reactions towards self histocompatibility antigens.

High intravenous doses of human immune globulin suppress neonatal group B streptococcal immunity in rats.

We evaluated the effect of intravenously administered immune globulin (IVIG) on neonatal group B streptococcal (GBS) infection in vivo and in vitro. A suckling rat model was used to compare the impact of penicillin (150 mg/kg) with albumin control, high-dose IVIG (2.7 gm/kg), or low-dose IVIG (0.68 gm/kg) on survival and bacteremia. Three lots of IVIG (two standard and one hyperimmune) with varying titers of GBS type III activity were used. An opsonophagocytic assay was then employed to evaluate in vitro the effect of concentrations of penicillin (none to 2.4 micrograms/ml), IVIG (none to 20 mg/ml), organism-specific (GBS type III-specific) activity (none to 1280(-1], and quantity of organisms (10(4) to 10(6] on the killing of several strains of GBS type III. Low doses of IVIG enhanced suckling rat survival (p less than 0.0025) and bacterial clearance (p less than 0.01). High doses of IVIG did not improve survival and in fact delayed bacterial clearance (p less than 0.05) when compared with low doses. Survival and bacterial clearance increased as the GBS type III activity of the IVIG lot increased. GBS opsonophagocytosis was suppressed at all penicillin concentrations (p less than 0.01) by high levels of IVIG (20 mg/ml). High-dose IVIG suppression of GBS opsonophagocytosis decreased as type III activity of the lot increased. We speculate that high doses of nonspecific IVIG may cause blockade of neutrophil or bacterial receptors necessary for GBS immunity in neonates.

[Humoral immune response in cattle vaccinated against aphthovirus. Study of the kinetics of protective and neutralizing antibodies]. / Respuesta inmune humoral en bovinos vacunados contra aftovirus. Estudio de la cinética de anticuerpos protectores y neutralizantes.

The sera of three groups (I, II and III) of cattle vaccinated every three months with trivalent hydroxysaponinated commercial vaccine against aphthovirus were studied. The only difference between groups I and II was that the former received a revaccination on day 17 after the initial immunization. Groups I and II included sera from animals three months old born from vaccinated mothers. Group III consisted of the sera of adult animals (the mothers of animals in groups I and II). The animals from the three groups were bled monthly during one year. The studies were performed with pooled sera from each group. The presence of protective and neutralizing antibodies was investigated in the gammaglobulin fractions which were then separated into subclasses, by chromatography on DE-cellulose columns, in order to study their biological activity. The immunization of cattle 3 months old with commercial vaccine against aphthovirus resulted in weak primary humoral response; neutralizing antibodies could not be detected. When the animals were restimulated three weeks after the first immunization, neutralizing antibodies appeared although the response did not persist. Nevertheless, five months after the experiment was started both groups I and II showed neutralizing antibodies. (Fig. 1, 2, 3). Persistent immunity to the three virus subtypes was acquired by animals of groups I and II but not before nine months. The kinetics of protective antibodies was similar to that of neutralizing antibodies, but with higher titers. Some bleedings that did not show neutralizing activity, did show significant protective activity (Figs. 4, 5). The investigation of the neutralizing activity of the gammaglobulin subclasses obtained by chromatography revealed that there was not one single subclass responsible for this activity, but that several subclasses were involved. The gammaglobulin subclasses were analyzed by immunoelectrophoresis; proteins with alpha 2 mobility appeared, coincident with early bleedings of high neutralizing titers, although these proteins did not present neutralizing activity (Tables 1, 2). The protective and neutralizing activity was not correlated with the protein concentration of the fractions so that the increase observed may be due to a qualitative change in the antibodies.