Route of lymphocyte migration in pigs. II. Migration to the intestinal lamina propria of antigen-specific cells generated in response to intestinal immunization in the pig.

Intestinal lymph-duct cannulae were established in normal and mesenteric lymphadenectomized (MLNx) pigs for the 6-day duration of a local intestinal immune response to a protein antigen (ovalbumin). The daily output of anti-ovalbumin-containing cells (AOCC) in intestinal lymph and the numbers of AOCC in the intestinal lamina propria at the end of the experiment were recorded. Very few AOCC were recovered in the intestinal lymph of normal pigs whereas in MLNx pigs large numbers were recovered reaching a peak output on day 4.

Intestinal immunity following a single intraperitoneal immunisation in lambs.

A single intraperitoneal injection of ovalbumin in oil adjuvant in young lambs has been shown to result in the appearance in the intestinal lamina propria of antibody-containing cells, most of which contained antibody of IgA specificity. Intraperitoneal immunisation of lambs with a Salmonella typhimurium vaccine during the suckling period provided protection against postweaning challenge with live organisms. This response was shown to be associated with specific IgA antibody in intestinal secretion.

Role of gram negative bacteria in ontogeny of gut immunity.

This paper describes an experiment which provides information on the ontogeny of some parameters of the intestinal immune system in normal lambs. It is also demonstrated that oral administration of a gram negative bacterial vaccine to foeta lambs resulted in non-specific amplification of the population of IgA plasma cells in the gut and its associated lymphoid tissue, suggesting involvement of bacterial lipopolysaccharide, a recognised B-lymphocyte mitogen, in ontogeny of gut immunity.

Evaluation of procedures for the diagnosis of Brucella ovis infection in rams.

Procedures for the diagnosis of Br. ovis infection in rams were evaluated by examining 10 rams artificially infected by preputial inoculation. Observations were undertaken at weekly intervals for 1 year to follow changes in clinical, bacteriological and serological findings.

Vaccination of piglets against Escherichia coli enteritis.

An immunisation procedure involving intraperitoneal followed by oral administration of a killed Escherichia coli vaccine was used to reduce losses associated with colibacillosis in young pigs reared under commercial conditions. Mortality was reduced in both the preweaning and postweaning period. The mortality rate among vaccinated piglets was half that of unvaccinated controls and by 3 weeks after weaning the total weight of pigs produced was 33% higher in the vaccinated group than in the control group.

IgA-containing cells in the ruminant intestine following intraperitoneal and local immunization.

Experiments are described which demonstrate that a single intraperitoneal (i.p.) injection of antigen in Freund's complete adjuvant results in the appearance of IgA-specific antibody-containing cells (ACC) in the intestinal lamina propria of sheep and that these cells reach the intestine via the intestinal lymph and blood circulation.

Intestinal response of sheep to intraperitoneal immunization.

The aim of the present study was to develop an immunization procedure which centrally stimulated the IgA system of sheep with the release of antibody-containing cells (ACC) of the IgA class into intestinal lymph. It was found that intraperitoneal injection of ovalbumin resulted in a substantial output of ACC in intestinal lymph. ACC of the IgA class reached a peak 8--9 days after intraperitoneal injection when they comprised 1.

The origin and antigen-dependent distribution of IgA-containing cells in the intestine.

The aims of this paper were to establish the origin of cells producing IgA antibody to cholera toxoid in the lamina propria of the small intestine and to define the role of antigen in their distribution. The use of Thirty-Vella loops made it possible to restrict antigenic challenge to a defined segment of the intestine in rats which had been primed i.p.

An immunisation model for the control of infectious enteritis.

An intestinal immunisation procedure involving systemic priming and oral boosting was investigated in lambs with a view to providing vaccination control of enteritis in young animals. The procedure stimulated the appearance of antibody-containing cells of IgA specificity in the intestine and lambs immunised in this way with a bacterial vaccine were protected against subsequent challenge with live enteropathogenic bacteria. This immunisation regime therefore provides a useful method for the stimulation of IgA immunity in the intestine of ruminants and it is anticipated that it will have general application to a variety of enteric diseases.

The natural history of the cells producing IgA in the gut.

The IgA-secreting cells in the lamina propria of the small intestine are derived from large lymphocytes which enter the blood by way of the thoracic duct and then migrate into the gut where they complete their differentiation into plasma cells. Three aspects of this cellular traffic have been examined in rats. 1.

Immunological events in the popliteal lymph node of sheep following injection of liver or killed Corynebacterium ovis into an afferent popliteal lymphatic duct.

Efferent popliteal lymph and blood were collected daily for three weeks from sheep following injection of live or killed Corynebacterium ovis organisms into an afferent lymphatic duct. The total lymphocyte output, proportion of blast cells and class specificity of immunoglobulin-containing groups of animals and antibody titres and concentrations of IgG1, IgG2, IMg and IgA were measured in both lymph and blood..

Local and systemic immune responses following oral immunization of foetal lambs.

Foetal lambs were immunized orally 6-15 days before birth by introducing horse spleen ferritin into the amniotic fluid. Immunized and non-immunized lambs were killed at birth, usually before they had suckled, blood and intestinal contents were collected and single cell suspensions were prepared from spleen, mesenteric lymph nodes and jejunum. Specific antibody was detected in serum and intestinal contents of all immunized lambs which had not suckled.

The origin of the immunoglobulins in intestinal lymph of sheep.

Various immunoglobulins were labelled with radioactive iodine and their distribution between intestinal lymph and plasma followed in order to determine the origin of the immunoglobulins found in intestinal lymph. By comparing specific activities in plasma and lymph, it was computed that 25 percent of the IgG1 and IgG2 and 90 percent of the IgA in intestinal lymph were locally synthesised. The results suggest that virtually all of the IgA and a proportion of the IgG1 computed to be synthesised locally were derived from plasma cells of corresponding specificity in the lamina propria of the intestine.

Antibody responses to neonatal immunisation in calves.

Antibody responses were measured in colostrum-fed (CF) and colostrum-deprived (CD) calves immunised at ages varying from birth to four months using a variety of antigens with and without adjuvant. In addition immunoglobulin production in CD calves over the same period was compared with that of CF calves. A marked unresponsiveness to antigens injected at birth was observed if maternal antibody specific for the antigen used was present in the circulation.

The effect of glucocorticoid on immunoglobulin secretion into colostrum in cows.

The effect of corticosteroid-induced parturition on transfer of immunoglobulin into mammary secretion of cows has been studied. Seven non-lactating cows in late gestation were injected intramuscularly with a long-acting synthetic glucocorticoid and the concentrations of IgG-1 and IgG-2 were followed in blood serum and mammary secretion which were collected before and after parturition. Within 1 week of injection the udder became distended with secretion identical in appearance to mature milk.