Brucella abortus antigen-induced lymphocyte reactivity in guinea pigs

A whole blood lymphyocyte transformation (WBLT) assay was used to detect anti-brucella lymphocyte reactivity in guinea pigs. Brucella antigens stimulated an antigen-specific lymphoproliferative response in WBLT assays from $\text{Brucella abortus}$ infected guinea pigs. The response was best detected from 6 to 16 weeks after challenge inoculation with viable $\text{B. abortus}$ 2308. Lymphocytes were not stimulated by unrelated bacterial antigens and control animals did not respond to the Brucella antigens. The responding cell population was characterized as mostly T lymphocytes. The WBLT assay was found to be specific for the detection of anti-brucella lymphocyte reactivity. However, a negative response was not definitive, which indicated a need for repeated testing to establish that a guinea pig did not have anti-brucella lymphocyte sensitization.     

Effects of ionizing radiation on in vitro proliferative responses of porcine peripheral blood lymphocytes

The radiosensitivity of $\text{in vitro}$ proliferative responses of porcine peripheral blood lymphocytes (PBL) was assessed. PBL were stimulated by Con-A, PHA, culture supernates from mitogen-stimulated porcine lymphocytes, or in the case of antigen-primed swine, specific antigens. The resulting levels of proliferation were assessed by a determination of the level of incorporation of tritiated thymidine $\text{in vitro}$, and in some cases by the presence of blast cells in the cultures. Porcine PBL were found to be more radioresistant than either mouse PBL or mouse spleen cells. Irradiation levels of greater than 3000 rads were necessary to arrest Con-A or PHA-induced proliferative responses. Proliferation induced by lymphokines in the form of supernates from mitogen-stimulated lymphocyte cultures was arrested in PBL that had received 3000 rads prior to culture. Antigen-induced proliferative responses in primed porcine PBL populations were the most radiosensitive, in that a previous irradiation with 500 rads was sufficient to completely abolish a secondary $\text{in vitro}$ proliferative response.     

The immune response of goats vaccinated with low and high doses of Brucella melitensis Rev 1

The serological response, lymphocyte reactivity, and dermal hypersensitivity reactions of goats vaccinated with high and low doses of $\text{Brucella melitensis}$ Rev 1 organisms to Brucella antigens were studied. Antibodies to soluble antigen A2 were detectable by immunoelectrophoresis (IE), appeared later than agglutinating antibodies but disappeared faster in most vaccinated animals. Anti-A2 antibodies appeared earlier in goats which received the high dose. Antibodies to polysaccharide B antigen were not detected. Lymphocytes reactive to Brucella antigens in lymphocyte transformation assays appeared at variable times after vaccination. In contrast to the humoral response to antigen A2, the appearance of circulating, reactive lymphocytes was not dependent on vaccine doses. All vaccinated animals demonstrated dermal hypersensitivity reactions to one of the antigenic extracts. Skin reactions peaked at 24 hrs post inoculation. The reactions were elicited when all but one goat had undetectable anti-A2 antibodies and no circulating, reactive lymphocytes as measured in whole blood lymphocyte transformation assay.     

Lack of reactivity of sera from Theileriaparva-infected and recovered cattle against cell membrane antigens of Theileria parva transformed cell lines

Sera from $\text{Theileria}$$\text{parva}$ infected, recovered and rechallenged cattle were tested in complement-dependent cytotoxicity, membrane immunofluorescence and antibody-dependent cellular cytotoxicity assays for the presence of antibodies against cell membrane antigens of $\text{T}$. $\text{parva}$ transformed cell lines.In the complement-dependent antibody-mediated cytotoxicity assay, sera from lethally infected animals were negative. Some recovered cattle showed a positive reaction, but such reactions were also observed when an eland cell line infected with $\text{T}$. $\text{taurotragi}$, and bovine lymphoblastoid cells were used as targets. Reaction was less against Ig-negative peripheral blood lymphocytes.Evidence is presented that these reactions could be evoked by attachment of immune complexes to Fc-receptors. It is concluded that cattle exposed to $\text{T}$. $\text{parva}$ infection do not develop antibodies against specific $\text{T}$. $\text{parva}$ (or $\text{T}$. $\text{parva}$-induced) cell surface antigens.     

Application of indomethacin as a potentiator of lymphocyte blastogenesis in Brucella abortus exposed cattle

Lymphocytes from $\text{Brucella abortus}$ field strain infected, strain 19 vaccinated, non-exposed and field strain infected, but immunologically unresponsive cattle were incubated with $\text{B. abortus}$ antigen and indomethacin. There were significant increases (P < 0.005) in the blastogenic responses, as measured by [³H] thymidine uptake, in cultures with indomethacin as compared to cultures without indomethacin. Lymphocyte blastogenic responses to $\text{B. abortus}$ antigen were potentiated by indomethacin in both $\text{B. abortus}$ exposed and non-exposed cultures. However, potentiation of sensitized lymphocyte blastogenic responses by indomethacin was significantly greater (P < 0.005) than that in non-exposed lymphocytes. Additionally, indomethacin significantly potentiated Brucella-induced lymphocyte blastogenic responses in lymphocytes from anergic cattle.     

Solid-phase enzyme immunoassay of bovine antibody responses following immunization against and natural infection with Pasteurella haemolytica

A solid-phase enzyme immunoassay (EIA) was developed in order to monitor bovine antibody responses following immunization against and natural infection with $\text{Pasteurella haemolytica}$ serotype A:1. Non-ionic surfactants, used in many antibody EIAs to reduce non-specific immunoglobulin binding, had to be avoided because they inhibited specific binding of bovine antibodies to $\text{P. haemolytica}$ antigens. Calves were immunized with a KSCN extract of $\text{P. haemolytica}$. Subcutaneously immunized animals developed a significantly higher humoral antibody response than did intranasally vaccinated animals. Intranasally immunized calves developed a slightly, but not significantly higher nasal antibody response than did calves vaccinated subcutaneously. Field study results based on bacterial isolation and EIA detection of antibodies to $\text{P. haemolytica}$ indicate that cattle can generate carrier states where bacteria are present in the upper respiratory tract, yet no humoral antibody response is induced. The converse was also found where cattle were free from $\text{P. haemolytica}$ in the upper respiratory tract, yet possessed a good humoral antibody response to $\text{P. haemolytica}$.     

The use of a cathodic antigen in the immunoelectrophoretic serodiagnosis of Echinococcus granulosus in sheep

An antigen was prepared from purified sheep hydatid-cyst fluid by gelfiltration on Sephadex G-200 followed by chromatography on DEAE-cellulose. In each case the first-peak material was used. This antigen, which migrated cathodically, was concentrated and used in immunoelectrophoretic analyses of 4X concentrated sera from sheep experimentally and naturally infected with $\text{Echinococcus granulosus}$ and from uninfected sheep. Of 34 sheep with $\text{E. granulosus}$ infection 31 were positive with the cathodic antigen while of 85 sheep without $\text{E. granulosus}$ 8 were (falsely) positive. Many false positives appeared to be associated with heavy infections of $\text{Taenia ovis}$ or $\text{T. hydatigena}$ larvae. The “arc 5” immunoelectrophoresis test, which is the most specific immuno-diagnostic test for echinococcus infection in humans, was not able to specifically identify $\text{E. granulosus}$ infections in sheep.     

Bovine babesiosis: The immunization of cattle with fractions of erythrocytes infected with Babesia bovis (syn B. argentina)

Soluble antigen which protected susceptible cattle against challenge with $\text{Babesia bovis}$ was extracted from $\text{B. bovis}$-infected erythrocytes by sonic disintegration and separation of the soluble from the insoluble matter by ultracentrifugation. The material was then fractionated by the precipitation of fibrinogen-like proteins. The precipitate contained the babesial antigens that were located on the stroma of the infected erythrocytes. Antigen originally located on the parasite remained in solution. Both fractions conferred protection on splenectomized calves against challenge with $\text{B. bovis}$. However, the fraction containing the parasite antigens appeared to have more potential for development as a killed vaccine because it was not heavily contaminated with antigenic material from bovine erythrocytes.     

The role of serum and biliary antibodies and cell-mediated immunity in the clearance of S. typhimurium from chickens

The development of three parameters of immunity in response to a non-lethal infection of $\text{Salmonella typhimurium}$ in adult chickens has been examined. Intravenous inoculation of 1 × 10⁶ organisms established infection in the liver, spleen and intestinal tract of all birds; the organism persisted in these sites until day 9 of the infection, after which it was cleared rapidly from all sites. High levels of agglutinating and haemagglutinating antibodies were found in serum and bile 5 days after infection; they peaked at days 7 to 10, and detectable antibody was still present in both fluids 6 weeks after infection. The presence of this antibody did not appear to cause a significant reduction in organism numbers in any of the sites examined. Cell mediated immunity was detected at day 14. It is suggested that cell mediated immunity is responsible for clearance of the organisms from the tissues.     

mRNA from porcine colostral and milk cells coding for specific antibodies in response to orally administered Escherichia coli strains

The effect of feeding live $\text{Escherichia coli}$ bacteria to sows on the lymphocyte populations in colostrum and milk was studied by $\text{in ovo}$ translation of the mRNA of these cells (Kortbeek-Jacobs and van der Donk, 1978). Four $\text{E. coli}$ strains were tested: one wild type K88 producing strain, two conjugated K12 strains producing K88 antigen and one wild type K12 strain. Only after feeding the wild type K88 bacteria, colostral lymphocytes contained mRNA coding for anti-K88 antibodies, predominantly of the IgA and IgM isotypes. Milk lymphocytes of the sows receiving one of the other strains were capable of producing more anti-K88 antibodies than the sows that were fed the wild type K88 strain. Antibodies were predominantly of the IgM class. The reactivity of the milk lymphocytes is ascribed to the strain with which the piglets were challenged. The results support the phenomenon of sensitized gut lymphocytes that home to the mammary gland.     

Some immunopathological aspects of aged Praomys (Mastomys) natalensis

$\text{Praomys (Mastomys) natalensis}$ develops a wide variety of autoantibody specificities with age; of these only those to thyroid colloid were associated with a histopathological lesion e.g. thyroiditis. An inverse relationship was found between the mean number of autoantibodies and the occurrence of lymphoreticular tumors. It appears that $\text{Mastomys}$ is a better model for studies on the general mechanisms of autoimmunity than for investigating specific autoimmune diseases per se.     

Coccidiosis: T-lymphocyte-dependent effects of infection with Eimeria nieschulzi in rats

The intestinal pathology caused by infection with $\text{Eimeria nieschulzi}$ was investigated and comparisons were made between the effects in athymic nude (rnu/rnu) rats and their heterozygous (rnu/+) litter-mates. Most of the changes noted, i.e. increase in gut weight, partial villous atrophy and increased numbers of mast, goblet and pyroninophilic cells were shown to be largely or wholely thymus dependent. The numbers of intraepithelial lymphocytes were decreased in both groups during the period of study. The peripheral blood leucocyte response was similar in both groups of rats during a primary infection but differed after a challenge inoculum, indicating that the secondary type of response which occurred in the rnu/+ rats was thymus dependent, as is resistance to reinfection.     

Thymus atrophy during early pregnancy and its effect on a Trichinella spiralis infection in mice,including intestinal pathology and blood eosinophilia

The effects of pregnancy on the course of a $\text{Trichinella spiralis}$ infection and associated histopathological changes in thymus and small intestine were studied in outbred Swiss mice. For this purpose pregnant mice were orally infected with $\text{T. spiralis}$ on various days (1 to 8) $\text{post coitum}$. Virgin, age-matched infected and non-infected mice served as controls.Pregnancy induced a severe but reversible thymus atrophy, which was even more marked during a $\text{T. spiralis}$ infection. Thymus atrophy was most dramatic during mid and late pregnancy. During the involution phase a distinct increase in mast cells was observed.In animals infected during early pregnancy a not statistically significant inhibitory effect on worm expulsion was observed, whereas no effect was seen on the yield of muscle larvae, small intestine pathology (numbers of eosinophils, intestinal mast cells and globule leucocytes), blood eosinophilia and antibody production.Infection given during mid-pregnancy exerted an inhibitory effect on blood eosinophilia.On the basis of these results, it is concluded that although a severe atrophy of the thymus occurs during mid and late pregnancy, no effect on worm expulsion and intestinal pathology was observed when the infectious agent was given before thymus depletion started.     

Nippostrongylus brasiliensis infection in the rat: 1. Production of bile lgA and serum lgG antibodies by adult rats

Bile lgA and serum lgG antibody responses were assayed by a micro ELISA technique. Antibodies of both classes were produced by 14 days after infection against whole worm antigens and worm metabolic product antigens, by adult rats infected once with $\text{Nippostrongylus brasiliensis}$. Rats were reinfected on day 28 and titres of both classes of antibody against both antigens were greater 7 and 14 days after reinfection than after the initial infection. Bile lgA antibodies were produced against phosphorylcholine after a single infection with the parasite but no increased response occurred after reinfection. The possible significance of lgA and lgG antibody responses in relation to immunity to intestinal nematode infections is discussed.     

An ELISA test to detect antibody to Bordetella bronchiseptica

An enzyme-linked immunosorbant assay (ELISA) was developed to measure antibody to $\text{Bordetella bronchiseptica}$ in dogs. The ELISA test was more rapid and sensitive and required 50 to 150 times less antigen than the amount of antigen required for the conventional tube agglutination test. A survey of 50 canine serum samples using ELISA suggested that 8% of all sera had titers greater than 1:64, 56% had titers of 1:8 to 1:64, and 36% had titers of less than 1:8. The mean titer of survey sera was 1:46 and the median titer was 1:16. Serum antibody responses in dogs inoculated with a commercially available bacterin were compared with responses in dogs inoculated with experimental endotoxin depleted bacterin.     

Serodiagnosis of Metastrongylus apri infection of pigs by immunofluorescence

The lyophilised first stage larvae of Metastrongylus apri were used as antigen in the indirect fluorescent antibody test for the diagnosis of the infection of pigs. The larvae were recovered from the embryonated eggs discharged by the gravid females of the nematode in vitro. Ten pigs were used in the test. Serial serum samples were taken of seven pigs, experimentally infected with varying doses of M. apri larvae, all of which were found to discharge eggs of the nematode in their faeces after infection was established. The other three pigs were uninfected and used as controls.Positive cuticular fluorescence of the larvae was first detected with the serum samples obtained between 14 and 33 days post-infection. This fluorescence persisted with subsequent serum samples up to 85 days post-infection. Pronounced and uniform cuticular fluorescence was generally observed with the serum dilutions of up to $\text{1}\text{10}$. Earlier post-infection serum samples either exhibited no cuticular fluorescence or gave non-brilliant fluorescence. The pre-infection serum of these pigs and also serum samples obtained from the three uninfected control pigs did not give cuticular fluorescence even at the initial serum dilution of $\text{1}\text{5}$.     

Intestinal mast cell response in thymectomised and normal mice infected with Trichinella spiralis.

In NIH mice, expulsion of $\text{Trichinella spiralis}$ from the small intestine and increase in intestinal mast cells were each dependent on the presence of T-lymphocytes. Both changes were deficient in thymectomised mice but could be largely restored by reconstitution of thymectomised mice with syngeneic mesenteric lymph node cells. In both NIH and BALB/C mice the majority of the increased number of mast cells occurred within the intestinal epithelium. In NIH mice increase in the number of intestinal mast cells coincided roughly with expulsion of the parasites.In BALB/C mice increase in the numbers of intestinal mast cells did not appear to be connected with the location or expulsion of parasites and it is concluded that mast cell proliferation, accumulation and discharge $\text{per se}$ do not result in or from worm expulsion.     

Antibodies to Brucella abortus in sera from strain 19 vaccinated and non-vaccinated cows as determined by enzyme linked immunosorbent assay and conventional serologic methods

The sensitivity of an enzyme linked immunosorbent assay was compared with 4 other serologic methods for detecting antibodies in $\text{B. abortus}$ vaccinated and non-vaccinated cows. Antibodies were detected by ELISA in sera from more than 93% of the culture positive cows, however, less than 55% of the infected animals were identified by any other serologic method. Similarly, antibodies were detected in 82% of the culture negative cows by the ELISA method.     

The early phase of the immune response to live and killed Staphylococcus aureus vaccines in sheep — Cellular and immunoglobulin parameters

Various cellular and protein parameters in efferent lymph were monitored during early stages of immune responses in the draining popliteal lymph nodes of sheep following injection with either live or killed $\text{Staphylococcus aureus}$ vaccines. Significantly higher outputs of leucocytes and lymphoblasts were measured in lymph from animals injected with the live vaccine (Group 1) compared with animals given the killed vaccine (Group 2) and non-immunised controls (Group 3). At 48 h post-injection the mean output of leucocytes in lymph for Group 1 was 9.5 × 10⁷ cells/h, and for Groups 2 and 3 comparable mean outputs were 5.2 × 10⁷ and 2.2 × 10⁷ respectively.There was a marked increase in IgM-containing cells in Group 1 animals, significant differences between Group 1 and 2 occurring 96 h post-injection. A difference was observed between the two immunised groups in the kinetics of output of cells containing antibody to a staphylococcal antigen extract. There was a slower increase in antibody-containing cells for Group 1 than for Group 2 animals. The mean proportion of antibody-containing cells reached 0.09% (of total leucocytes) at 72 h post-injection for Group 2 and 0.10% at 120 h post-injection for Group 1.Rapid increases in flow rate of lymph were recorded in animals in Group 1. These results were in contrast to lower corresponding values observed in sheep in Groups 2 and 3. There was a twofold increase in the lymph: serum (L:S) concentration ratio for IgG2 in animals in Group 1 and the evidence suggested that this was due to local synthesis of IgG2 by lymphoid cells in the abscess at the site of injection and/or in the draining popliteal lymph node. This change in L:S ratio for IgG2 was not recorded for sheep in Groups 2 and 3.     

Nippostrongylus brasiliensis infection in the rat: 2. A comparison of production of antibodies in bile and serum by baby rats,lactating rats and adult rats

Production of bile lgA and serum lgG antibody responses against whole worm antigens and worm metabolic product antigens occurred by 7 to 14 days after a single infection with $\text{N. brasiliensis}$ and was similar in adult rats, lactating rats and baby rats. Production of bile lgA antibodies against phosphorylcholine was greater in adult rats, 7 days after infection, than in baby rats or lactating rats. lgA antibody production by baby rats may be affected by immaturity of the intestinal lgA system, and diversion to the mammary gland of lgA-plasma cell precursors may occur in lactating rats. Such effects may be involved in the failure of baby rats and lactating rats to expel parasites by day 21 at which time in adult rats expulsion was complete.