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Multidecadal trends in the terminus position of outlet glaciers along the margin of the East Antarctic ice sheet reveal three epochal patterns of glacier retreat or advance consistent with a rapid and coherent response to air temperature and sea-ice trends. East Antarctic ice sensitive to climate variation It is widely known that glaciers in West Antarctica and Greenland have been discharging ice into the oceans in response to warming in recent years, and that sea levels have risen as a result. By contrast, we hear little about the much larger East Antarctic ice sheet, which has been viewed as being less vulnerable to climate change owing to its location in an extremely cold climate. Chris Stokes and colleagues have used satellite imagery to map a large sample of glaciers along the Pacific coast of East Antarctica and show that in fact, they are responding to decadal climate variability. In concert with climate, glaciers retreated in the 1970s and 1980s, advanced in the 1990s, and approximately split between advance and retreat since the 2000s. The authors conclude that parts of the world's largest ice sheet may be more responsive to external forcing than previously recognized. Observations of ocean-terminating outlet glaciers in Greenland and West Antarctica.sup.1,2,3,4,5,6 indicate that their contribution to sea level is accelerating as a result of increased velocity, thinning and retreat.sup.7,8,9,10,11. Thinning has also been reported along the margin of the much larger East Antarctic ice sheet.sup.1, but whether glaciers are advancing or retreating there is largely unknown, and there has been no attempt to place such changes in the context of localized mass loss.sup.7,9 or climatic or oceanic forcing. Here we present multidecadal trends in the terminus position of 175 ocean-terminating outlet glaciers along 5,400 kilometres of the margin of the East Antarctic ice sheet, and reveal widespread and synchronous changes. Despite large fluctuations between glaciers--linked to their size--three epochal patterns emerged: 63 per cent of glaciers retreated from 1974 to 1990, 72 per cent advanced from 1990 to 2000, and 58 per cent advanced from 2000 to 2010. These trends were most pronounced along the warmer western South Pacific coast, whereas glaciers along the cooler Ross Sea coast experienced no significant changes. We find that glacier change along the Pacific coast is consistent with a rapid and coherent response to air temperature and sea-ice trends, linked through the dominant mode of atmospheric variability (the Southern Annular Mode). We conclude that parts of the world's largest ice sheet may be more vulnerable to external forcing than recognized previously., Author(s): B. W. J. Miles [sup.1] , C. R. Stokes [sup.1] , A. Vieli [sup.1] [sup.2] , N. J. Cox [sup.1] Author Affiliations: (1) Department of Geography, Durham University, Science [...]

Here we present a glacial and periglacial geomorphological map of a ~6800 km² region of central Troms and Finnmark county, Arctic Norway. The map is presented at a 1:115,000 scale with the aim of characterising the spatial distribution of glacial and periglacial landforms and facilitating the reconstruction of the glacial history of the region during the latter stages of deglaciation from the Last Glacial Maximum and into the Holocene. Mapping was conducted predominantly by manual digitisation of landforms using a combination of Sentinel-2A/2B satellite imagery (10 m pixel resolution), vertical aerial photographs (<1 m pixel resolution), and Digital Elevation Models (10 and 2 m pixel resolution). Over 20,000 individual features have been mapped and include moraines (subdivided into major and minor moraines), ridges within areas of discrete debris accumulations (DDAs), flutings, eskers, irregular mounded terrain, lineations, glacially streamlined bedrock, possible glacially streamlined terrain, pronival ramparts, rock glaciers (subdivided into valley wall and valley floor, and rock glacierised moraines), lithalsas, contemporary glaciers and lakes. The map records several noteworthy large moraine assemblages within individual valleys, forming inset sequences from pre-Younger Dryas limits up to the 2018/19 ice margins and represents a valuable dataset for reconstructing Holocene glacial and periglacial activity. [ABSTRACT FROM AUTHOR]

Evolving conditions at the terminus of Thwaites Glacier will be important in determining the rate of its future sea-level contribution over the coming decades. Here, we use remote-sensing observations to investigate recent changes (2000–2018) in the structure and velocity of Thwaites Glacier and its floating tongue. We show that the main trunk of Thwaites Glacier has accelerated by 38% over this period, while its previously intact floating tongue has transitioned to a weaker mélange of fractured icebergs bounded by sea ice. However, the rate of structural weakening and acceleration was not uniform across the observational period and we identify two periods of rapid acceleration and structural weakening (2006–2012; 2016–2018), separated by a period of deceleration and re-advance of the structurally-intact shear margin boundary (2012–2015). The timing of these accelerations/decelerations strongly suggests a link to variable ocean forcing. The weakened tongue now has some dependency on landfast sea ice for structural integrity and is vulnerable to changes in landfast ice persistency. Future reductions in landfast sea ice could manifest from changes in climate and/or the imminent removal of the B-22A iceberg from the Thwaites embayment. Such changes could have important implications for the integrity of the ice tongue and future glacier discharge. [ABSTRACT FROM AUTHOR]

Glaciers are important indicators of climate change, and recent observations worldwide document increasing rates of mountain glacier recession. Here we present approximately 200 years of change in mountain glacier extent in northern Troms and western Finnmark, northern Norway. This was achieved through (1) mapping and lichenometric dating of major moraine systems within a subset of the main study area (the Rotsund Valley) and (2) mapping recent (post-1980s) changes in ice extent from remotely sensed data. Lichenometric dating reveals that the Little Ice Age (LIA) maximum occurred approximately 1814 (±41 years), which is before the early twentieth-century LIA maximum proposed on the nearby Lyngen Peninsula but younger than LIA maximum limits in southern and central Norway (mid-eighteenth century). Between LIA maximum and 1989, a small sample of measured glaciers (n = 15) shrank a total of 3.9 km2 (39 percent), and those that shrank by more than 50 percent are fronted by proglacial lakes. Between 1989 and 2018, the total area of glaciers within the study area (n = 219 in 1989) shrank by approximately 35 km2. Very small glaciers (<0.5 km2) show the highest relative rates of shrinkage, and 90 percent of mapped glaciers within the study area were less than 0.5 km2 in 2018. [ABSTRACT FROM AUTHOR]

Small mountain glaciers are an important part of the cryosphere and tend to respond rapidly to climate warming. Historically, mapping very small glaciers (generally considered to be <0.5 km2) using satellite imagery has often been subjective due to the difficulty in differentiating them from perennial snowpatches. For this reason, most scientists implement minimum size-thresholds (typically 0.01–0.05 km2). Here, we compare the ability of different remote-sensing approaches to identify and map very small glaciers on imagery of varying spatial resolutions (30–0.25 m) and investigate how operator subjectivity influences the results. Based on this analysis, we support the use of a minimum size-threshold of 0.01 km2 for imagery with coarse to medium spatial resolution (30–10 m). However, when mapping on high-resolution imagery (<1 m) with minimal seasonal snow cover, glaciers <0.05 km2 and even <0.01 km2 are readily identifiable and using a minimum threshold may be inappropriate. For these cases, we develop a set of criteria to enable the identification of very small glaciers and classify them as certain , probable or possible. This should facilitate a more consistent approach to identifying and mapping very small glaciers on high-resolution imagery, helping to produce more comprehensive and accurate glacier inventories. [ABSTRACT FROM AUTHOR]

ABSTRACT: This paper systematically reviews the glacial geomorphological evidence of the Loch Lomond Stadial (LLS; Younger Dryas) glaciation in Britain (12.9–11.7 ka). The geomorphology of sub‐regions within Scotland, England and Wales is assessed, providing the most comprehensive synthesis of this evidence to date. The contrasting nature of the evidence at the local scale is reviewed and conceptual themes common to multiple sub‐regions are examined. Advancements in glaciological theory, mapping technologies, numerical modelling and dating have been applied unevenly to localities across Britain, inhibiting a holistic understanding of the extent and dynamics of the LLS glaciation at a regional scale. The quantity and quality of evidence is highly uneven, leading to uncertainties regarding the extent of glaciation and inhibiting detailed analysis of ice dynamics and chronology. Robust dates are relatively scarce, making it difficult to confidently identify the limits of LLS glaciers and assess their synchroneity. Numerical models have allowed the glacier–climate relationships of the LLS to be assessed but have, thus far, been unable to incorporate local conditions which influenced glaciation. Recommendations for future research are made that will allow refined reconstructions of the LLS in Britain and contribute to a more comprehensive understanding of glacier–climate interactions during the Younger Dryas. [ABSTRACT FROM AUTHOR]

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At birth the piglet's immune system is immature and it is dependent upon passive maternal protection until weaning. The piglet's mucosal immune system develops over the first few weeks but has not reached maturity at weaning ages which are common on commercial farms. At weaning piglets are presented with a vast and diverse range of microbial and dietary/environmental antigens. Their ability to distinguish between antigens and mount a protective response to potential pathogens and to develop tolerance to dietary antigens is critical to their survival and failure to do so is reflected in the high incidence of morbidity and mortality in the post-weaning period. A growing recognition that the widespread use of antibiotics to control infection during this critical period should be controlled has led to detailed studies of those factors which drive the development of the mucosal immune system, the role of gut microbiota in driving this process, the origin of the bacteria that colonise the young piglet's intestine and the impact of rearing environment. This review briefly describes how the mucosal immune system is equipped to respond "appropriately" to antigenic challenge and the programmed sequence by which it develops. The results of studies on the critical interplay between the host immune system and gut microbiota are discussed along with the effects of rearing environment. By comparing these with results from human studies on the development of allergies in children, an approach to promote an earlier maturation of the piglet immune system to resist the challenges of weaning are outlined. [ABSTRACT FROM AUTHOR]

The Loch Lomond Stadial (LLS) was an abrupt period of renewed cooling between 12.9 and 11.7 ka and has long been associated with the regrowth of glaciers in much of upland Britain. Mapping the glacial landforms associated with this period has been undertaken for over a century, but in a non-systematic nature and at specific locations. In this paper, glacial geomorphology associated with the LLS in Britain has been compiled from the published literature into a glacial map and accompanying geographical information system database that is available electronically as supplementary information. A variety of scales have been used to best represent the evidence in the database. Map A is at 1:310 000; B, C, D, E, F, J, L, M and O are at 1:175 000; K, N, P are at 1:100 000 and G, H and I are at 1:50,000. The database contains over 95,000 individual features, which are organised into thematic layers and each attributed to its original citation. The evidence includes moraines, drift and boulder limits, drift benches, periglacial trimlines, meltwater channels, eskers, striations and roches moutonneés, protalus ramparts and ice-dammed lakes. Creation of this database overcomes the drawbacks posed by the non-systematic nature of previous mapping output from studies of LLS glaciation. It is intended to be a catalyst for future research in this area, with especial significance for regional palaeoglaciological and palaeoclimatic reconstructions of the Younger Dryas and numerical modelling. [ABSTRACT FROM AUTHOR]

Discharge from marine-terminating outlet glaciers accounts for up to half the recent mass loss from the Greenland ice sheet, yet the causal factors are not fully understood. Here we assess the factors controlling the behaviour of Humboldt Glacier (HG), allowing us to evaluate the influence of basal topography on outlet glacier response to external forcing since part of HG's terminus occupies a large overdeepening. HG's retreat accelerated dramatically after 1999, coinciding with summer atmospheric warming of up to 0.19°C a-1 and sea-ice decline. Retreat was an order of magnitude greater in the northern section of the terminus, underlain by a major basal trough, than in the southern section, where the bedrock is comparatively shallow. Velocity change following retreat was spatially non-uniform, potentially due to a pinning point near HG's northern lateral margin. Consistent with observations, numerical modelling demonstrates an order-of-magnitude greater sensitivity to sea-ice buttressing and crevasse depth (used as a proxy for atmospheric warming) in the northern section. The trough extends up to 72km inland, so it is likely to facilitate sustained retreat and ice loss from HG during the 21st century. [ABSTRACT FROM AUTHOR]

As a result of the European ban of in-feed growth-promoting antibiotics, new strategies are being developed to increase the resistance to disease in farm animals. In pig production, this is of particular importance during the weaning transition when piglets are subjected to major stressful events, making them highly sensitive to digestive disorders. At this time, the development of both innate and adaptive immunity at the mucosal surface is critical in preventing the potential harmful effects of intestinal pathogenic agents. Strategies aiming at stimulating natural host defences through the use of substances able to modulate immune functions have gained increasing interest in animal research, and different bioactive components a priori sharing those properties have been the subject of in vivo nutritional investigations in pig. Among these, yeast derivates (b-glucans and mannans) are able to interact with immune cells, particularly phagocytic cells. However, studies where they have been fed to pigs have shown inconsistent results, suggesting that their ability to target the sensitive immune cells through the oral route is questionable. The plant extracts, which would benefit from a positive image in the public opinion, have also been tested. However, due to a lack of data on the bioactive components of particular plants and the large diversity of species, it has proved difficult to prepare extracts of equivalent potency and thus, the literature on their influence on pig immunity remains inconclusive. In considering piglet immunity and health benefits, the most promising results to date have been obtained with spray-dried animal plasma, whose positive effects would be provided by specific antibodies and nonspecific competition of some plasma components with bacteria for intestinal receptors. The major positive effect of spray-dried animal plasma is in reducing the infiltration of gut-associated lymphoid tissue by immune cells, which is likely to be the result of a decreased colonisation by potentially harmful bacteria. This review also highlights the limitations of some of the published in vivo studies on the immunomodulatory activity of certain feed additives. Among those, the lack of standardisation of extracts and the heterogeneity of piglet-rearing conditions (e.g. exposure to pathogens) are likely the most limiting. [ABSTRACT FROM AUTHOR]

Proposes a hypothesis for the formation of giant glacial grooves detected on Landsat Enhanced Thematic Mapper Plus imagery. Use of Multi-Spectral Scanner imagery to map a distinctive convergent flow pattern; Genesis of giant glacial grooves.

Discusses the implications of identifying and mapping palaeo-ice stream geomorphology from satellite imagery for ice stream functioning and ice sheet dynamics. Description of an ice stream; Interactions with the ocean and climate system; Characteristics of contemporary ice streams.

In human disease and rodent models, immune responses in the intestinal mucosa can be damaging. Damage is characterised by villus atrophy, crypt hyperplasia and reduced ability to digest and absorb nutrients. In normal individuals active responses to harmless environmental antigens associated with food and commensal bacteria are controlled by the development of immunological tolerance. Similar pathological changes occur in piglets weaned early from their mothers. Active immune responses to food antigens are observed in these piglets, and we and others have hypothesised that the changes occur as a result of transient allergic immune responses to novel food or bacteria antigens. The normal mechanism for producing tolerance to food antigens may operate at induction (Peyer's patches and mesenteric lymph nodes) or at the effector stage (intestinal lamina propria). In our piglet studies immunological tolerance occurs despite the initial active response. Together with evidence from rodents, this observation suggests that active responses are likely to be controlled at the effector stage, within the intestinal lamina propria. Support for this mechanism comes from the observation that human and pig intestinal T-cells are susceptible to apoptosis, and that this process is accelerated by antigen. We suggest that the role of the normal mature intestinal lamina propria is a balance between immunological effector and regulatory function. In neonatal animals this balance develops slowly and is dependant on contact with antigen. Immunological insults such as weaning may tip the balance of the developing mucosal immune system into excessive effector or regulatory function resulting in transient or chronic allergy or disease susceptibility. [ABSTRACT FROM AUTHOR]

The effect of feeding ovalbumin was studied in CBA, C3H, SWR/J and A inbred strains of mice. In non-immune animals differences were observed in their abilities to absorb intact antigen and eliminate it from their circulation. Following oral immunization, C3H mice were able to absorb significantly less ovalbumin than controls, however no evidence for immune exclusion was found in the other strains. Oral tolerance could be induced in all strains tested but in CBA and SWR/J mice oral immunization had to be continual, via the drinking rather than a single daily gastric intubation. The results suggest that genetic differences exist in the handling of antigen by the gut. If similar differences exist in man they may underly differences in susceptibility to food allergy. [ABSTRACT FROM AUTHOR]

Oral immunization with 25 mg/day of ovalbumin resulted in a number of changes in non-specific immune responsiveness, including increases in antibody produced to T-dependent but not T-independent antigens and the abrogation of tolerance induced by both oral and intravenous routes. The effect was transient, sex- and strain-dependent. Evidence suggests that it is a consequence of cell-mediated immunity to the oral immunogen. [ABSTRACT FROM AUTHOR]

We report a girl with severe combined immunodeficiency with functional impairměnt of both humoral and cellular immunity despite normal numbers of B and T lymphocytes. Immunologic studies revealed hypergammaglobulinaemia, absent migratory response by polymorphonuclear leucocytes to chemoattractants, and diminished lymphocyte proliferative responses to mitogens, antigens and allogeneic leucocytes. However, stimulation of the patient's mononuclear leucocytes with the calcium ionophore, A23187, resulted in a normal proliferative response. We therefore postulate a membrane defect as the basis for immunologic dysfunction in this child. [ABSTRACT FROM AUTHOR]

The introduction of 25 mg of a new protein antigen into the diets of mice produced transient increases in PVP clearance which reached a maximum 60 hr after the change of diet and had disappeared by 4 days. At the same time the immune responsiveness to unrelated antigens given parenterally was also raised transiently, reaching a peak 5 days following the change and disappearing by 7 days. In contrast the responsiveness to the fed antigen was diminished. [ABSTRACT FROM AUTHOR]

We have examined the morphology and functional characteristics of porcine intraepithelial lymphocytes (IEL). A subpopulation of IEL contains granules as seen in other species, and their ultrastructure was also similar. They were capable of producing T-cell growth factor and interferon on in vitro stimulation. IEL killed P815 cells in the presence of PHA, but did not kill K562 cells. [ABSTRACT FROM AUTHOR]

Intraepithelial lymphocytes (IEL) were isolated from the small intestine of pigs. They showed a strong blastogenic response to the T-cell mitogens phytohaemagglutinin A (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM); in contrast, mouse IEL responded weakly to these mitogens. The response of pig IEL was age-dependent, reaching adult levels by 9 weeks of age. Early weaning of pigs delayed the onset of this response. The effects of inflammatory mediators on the response of mouse IEL were also examined. [ABSTRACT FROM AUTHOR]

An enzyme-linked immunosorbent assay (ELISA) was adapted for the horse to investigate the production of antibody in response to subcutaneous, intrauterine or intravaginal immunization with dinitro-phenylated human serum albumin. An 1gM response was not detected, but antibodies of the IgGab, IgGc, IgGT and IgA isotypes were measured in serum, uterine and vaginal secretions. Local immunization produced antibody titres in serum and secretions, with evidence of significant local production. [ABSTRACT FROM AUTHOR]

The effect of feeding the B-cell mitogens Escherichia coli lipopolysaccharide and dextran sulphate on the development of orally induced tolerance to the contact sensitizing agent picryl chloride was studied in mice. Feeding either agent throughout the experiment or during tolerization, increased the tolerizing effect of a single feed of picryl chloride. [ABSTRACT FROM AUTHOR]

Passively transferred MOPC 315 IgA myeloma protein accelerated the elimination of DNP-ovalbumin, to which the myeloma protein bound with antibody-like affinity, from the circulation and increased the subsequent antibody response to hapten and to carrier, when injected with or without adjuvant. [ABSTRACT FROM AUTHOR]

The secretory and systemic antibody responses to oral dead Escherichia coli were examined in A strain mice. The best responses were obtained in mice dosed with 1 x 1010 bacteria. Orally immunized animals showed an enhanced response to subsequent parenteral immunization with somatic antigens. This effect could be passively transferred with serum In contrast, the response to the capsular antigen K88 was reduced in the same animals. [ABSTRACT FROM AUTHOR]

Summary Mast cells in the equine respiratory mucosa were studied at both light - and transmission electron - microscope levels. Mast cells were identified at all levels of the tract, with the greatest cell density in the nasopharynx. The majority (57 to 94 per cent) of this cell population were located within the connective tissue of the lamina propria. Up to 20 per cent of these cells were associated with the mucosal glandular tissue, whilst small numbers were present within the surface epithelium and in association with nodular lymphoid tissue. In the peripheral lung tissue 20 per cent of the mast cell population was associated with the small airways, 25 per cent with the pleura, and 32 per cent with blood vessels. The fine and ultrastructural features of these mast cells resemble those described in other species, and their granules consist of two types which resemble human mast cells. [ABSTRACT FROM AUTHOR]

Autoantigens in canine autoimmune haemolytic anaemia (AIH A) were identified by immunoprecipitation using autoantibody eluted from the erythrocytes of affected dogs. At least three patterns of precipitated antigen were identified in six cases of AIHA. The most commonly precipitated antigen pattern was a combination of 42-kD and 29-kD peptides. associated with up to three other membrane components. These autoantigens may be canine glycophorins. which are of similar molecular mass, or may possibly represent an equivalent of the human Rhesus complex. An autoantigen identical in molecular mass to band 3. the erythrocyte anion channel protein, was precipitated in one case of AIHA, and unknown peptides of 37kD and l00kD were isolated by autoantibody from another dog. In one case, no antigens were precipitated by the eluted antibody, indicating that the autoantibody may have bound a non-protein membrane component such as phospholipid. Overall it is considered that the different patterns observed may reflect differences in the aetiology of the condition. In other studies, sera from dogs with AIHA failed lo immunoprecipitate autoantigens, but were shown by immunoblotting to contain autoantibodies to proteins of the erythrocyte cytoskeleton. Such autoantibodies were also demonstrated in normal canine sera and it is suggested that they are unlikely to play a role in the pathogenesis of AIHA., but may be part of a normal clearance mechanism for damaged red blood cells. [ABSTRACT FROM AUTHOR]

The presumed HLA haplotype Al: B8 was more frequent and the combination of A3 and B7 was less frequent in allergic subjects presenting with eczema, than in those presenting with hayfever. Al : B8 was most frequent (36%) in eczema complicated by asthma and/or hay fever, and least frequent (5%) in hay fever alone, considerably above and below the frequency in the general population (17%). [ABSTRACT FROM AUTHOR]

FIV is a lentivirus infection of cats which induces an immunodeficiency syndrome associated with early qualitative defects in antigen-specific T cell function and with late quantitative defects in CD4+ T lymphocytes. We have observed that peripheral blood mononuclear cells (PBMC) from FIV-infected cats have impaired survival in culture. The mechanism of this in vitro dysfunction and depletion is not known. We have proposed that inappropriate induction of programmed cell death (apoptosis) could account for these In vitro defects. Here, we report that PBMC from FIV-infected cats, with impaired T cell blastogenesis and impaired survival in vitro, undergo an active cell death upon culture, which has the morphological and biochemical characteristics of programmed cell death (PCD), Apoptosis occurred in all six asymptomatic FIV-infected cats, and in none of the nine uninfected cats, which were studied. Changes in cell morphology under both light and electron microscopy, and fragmentation of genomic DNA were characteristic for apoptosing cells. Ceil death was spontaneous and occurred in the absence of any stimuli, and culture with the T cell mitogen, concanavalin A (Con A), did not significantly enhance cell death. Activation-induced cell death was inhibited, in a dose-dependent manner, by addition to the incubation medium of zinc, which has been shown to inhibit the action of endonuclease responsible for the characteristic fragmentation of DNA. Since apoptosis has recently been implicated in AIDS pathoiiencsis, FIV infection may prove useful to study this aspect of retroviral, in particular HIV, infection. [ABSTRACT FROM AUTHOR]

As in HIV infection of humans, eats infected with FIV are particularly susceptible to secondary infection by opportunistic pathogens, suggesting an impaired ability to elicit an effective immune response against foreign intigens. In order to investigate the development of immunity in Fly- infected cats. we have used an autologous culture system to directly measure priming of naive CD4+ T cells to soluble protein antigen. in rum. Using this assay. we showed previously that cats infected with Fly For several months had significantly reduced primary proliferative responses. We have now examined cats before infection, and at varying times after infection with FIV. to determine how soon alter infection this defect in T cell priming was evident, compared with other quantitative and qualitative measurements of lymphocyte function. Our results showed a progressive decline in immune function in asymptomatic cats during the acute stage of infection with FIV. Primary T cells responses were most sensitive and a significant reduction in proliferation of naive T cells to foreign antigen occurred 5 weeks after infection, despite normal blastogenesis to T cell mitogens and normal CD4+/CD8+ ratios at these times. Whilst lymphocyte proliferation to T cell mitogens was unaffected throughout, a significant reduction in proliferation to a B cell mitogen occurred from week 8 onwards. CD4+/CDK+ ratios fell significantly from week 13 onwards, and proliferation of the memory T cell population to a recall antigen was significantly impaired later. from week 19 onwards. The defect in the priming of naive T cells to foreign antigen early after infection may be important in determining susceptibility to secondary infections. [ABSTRACT FROM AUTHOR]

Sows were Ted ovalbumin (OvA) as a novel protein antigen either throughout gestation and lactation (G + L) or during lactation only (L). This resulted in a significant uptake of OvA into blood, colostrum and milk along with a specific IgG response. In piglets from the G + L group. OvA and antibodies to OvA were detected in serum after ingestion of colostrum. In a large proportion of these piglets OvA was still detected at 3 weeks of age. In the L group a significant proportion of the piglets responded to OvA whilst still stickling their mother. At 3 weeks of age all piglets were weaned onto an egg-based diet. A similar uptake of OvA was .seen in all piglets but there was no response to OvA in the G + L piglets. In piglets from sows fed only during lactation, however, a rapid IgG anti-OvA response and signs of diarrhoea were seen. The results suggest that factors of immunological importance are passed over from mother to offspring and it is proposed that immunological experience of dietary antigens by the mother is important for a 'safe' tolerance induction in her offspring. [ABSTRACT FROM AUTHOR]

We examined the effect of orally administered cholera toxin (CT) on the immune response to keyhole limpet haemocyanin (KLH) and ovalhumin (OVA) in high C57B1;6H2b) medium (CBAHM2k), and low (BALB/c H2d) responder I-A haplotypes to CF. Mice were fed OVA or KLH on three occasions at 10-day intervals and the effect of simultaneous feeding of CT determined, isotype-specific antibody levels were assayed in serum samples collected 7 days after the last immunization, Antibody was also measured in the supernatant of gut explant cultures incubated at either 4 or 37° C. Increased antibody levels in cultures kept at 37° C indicated release of local intracellular antibody Cholera toxin exerted an adjuvant effect on the mucosal response of all three strains to KLH and OVA. Overall, the responses to CT and the second protein were not correlated: we interpret these findings to indicate that while CT had an cited on the mucosal immune system which enhanets the immune response to itself and other protein antigens, the final outcome of the response to the second antigen is dependent on differences in the ability of the strains to process, recognize and respond to a particular antigen. [ABSTRACT FROM AUTHOR]

Oral immunization of the lactating sow with live Escherichia coli (O8:K88) stimulated an IgA anti-K88 antibody response in mammary secretions und significantly enhanced the capacity of whey to inhibit adhesion of the inoculum E. coli strain to isolated pig enterocytes. An increase in agglutinating unti-O8 activity was also evident in milk and was associated with both the IgA and IgM immunoglobulin classes. These results are consistent with the concept of a gut mammary link, although measurement of specific antibody in the intestinal secretions of these animals suggested that there may he a difference in response duration at the two secretory sites. Prolonged oral administration of heat-killed organisms also stimulated specific antibody synthesis within the mammary gland, although the response, particularly to the O antigen, was both reduced und delayed in its appearance. [ABSTRACT FROM AUTHOR]

Antigenic proteins may be absorbed intact. We report here results from in vivo experiments in mice showing that the prior feeding of protein antigen may reduce the subsequent absorption of that antigen without altering its elimination from the circulation. This may be a function of local immunity. We have also shown that the same feeding regime can paradoxically induce a state of systemic tolerance and suggest that the two phenomena contribute to the safe handling of these antigens. [ABSTRACT FROM PUBLISHER]