Intestinal antibody response after vaccination and infection with rotavirus of calves fed colostrum with or without rotavirus antibody

The intestinal and systemic antibody response of calves vaccinated and/or challenged with rotavirus was studied employing isotype-specific ELISAs for the detection of IgG1, IgG2, IgM and IgA antibodies to rotavirus. Monoclonal antibodies to bovine immunoglobulin isotypes of proven specificity were used as conjugated or catching antibody. Five days after oral inoculation (dpi) of a 5-day-old gnotobiotic calf with rotavirus, IgM rotavirus antibodies were excreted in faeces, followed 5 days later by IgA rotavirus antibodies. The increase in IgM rotavirus antibody titre coincided with the inability to detect further rotavirus excretion. Faeces IgM and IgA rotavirus antibody titres fell to low levels within 3 weeks post infection. IgG1 and IgG2 rotavirus antibodies were not detected in faecal samples. In serum, antibodies to rotavirus of all four isotypes were detected, starting with IgM at 5 dpi. Two SPF-calves, which were fed colostrum free of rotavirus antibodies, were vaccinated with a modified live rotavirus vaccine and challenged with virulent rotavirus 6 days later. Upon vaccination, the calves showed an antibody response similar to the response of the infected gnotobiotic calf. Intestinal IgM rotavirus antibodies were excreted before or on the day of challenge and appeared to be associated with protection against challenge infection with virulent virus and rotavirus-induced diarrhoea. In 3 control calves, which were challenged only, the antibody patterns also resembled that of the gnotobiotic calf and again the appearance of IgM rotavirus antibodies coincided with the end of the rotavirus detection period. Two other groups of 3 SPF-calves were treated similarly, but the calves were fed colostrum with rotavirus antibodies during the first 48 h of life. These calves excreted passively acquired IgG1 and IgG2 rotavirus antibodies in their faeces from 2 to 6 days after birth. After vaccination, no IgM or IgA antibody activity in serum or faeces was detectable. Upon challenge, all calves developed diarrhoea and excreted rotavirus. Seven to 10 days after challenge low levels of IgM rotavirus antibody were detected for a short period. These data indicate that the intestinal antibody response of young calves to an enteric viral infection is associated with the excretion of IgM antibodies, immediately followed by IgA antibodies. This response is absent or diminished in calves with passively acquired specific antibodies which may explain the failure to induce a protective intestinal immune response by oral vaccination with modified live rotavirus of calves fed colostrum containing rotavirus antibodies.     

IgA, igG1, IgG2, IgM, and BSA in serum and mammary secretion throughout lactation

Bovine IgG1, IgG2, IgA, and IgM were measured in the serum and lacteal secretions of six cows from 10 days prepartum to 240 days of lactation. Immunoglobulins in lacteal secretions were expressed in units of concentration (mg/ml) as well as in total daily output. All isotypes were selectively accumulated during colostrum formation. The rate of IgG1 accumulation decreased rapidly after calving; this decrease corresponded to a return to normal serum levels of this immunoglobulin. Selective accumulation of IgA > IgM > IgG1 was maintained throughout lactation, but IgG2 showed no selective accumulation beyond 5 days postpartum. In serum, IgA and IgM levels were elevated at parturition and showed a significant decrease postpartum. Increases in serum IgA levels 60 days postpartum corresponded to a rise in lacteal concentration. The concentration of all immunoglobulins increased during late lactation, coincident with a major reduction in milk yield. Six strains of mastitis-causing organisms were cultured during the period of the experiment; however, none resulted in clinical mastitis or showed an effect on immunoglobulin secretion.     

Salivary and serum immunoglobulin levels in cats with chronic gingivostomatitis

The salivary and serum concentrations of immunoglobulins G, M and A (IgG, IgM and IgA), and the salivary concentrations of albumin were measured by ELISA in 30 cats with chronic gingivostomatitis and 32 healthy cats. The cats with chronic gingivostomatitis had significantly higher salivary concentrations of IgG, IgM and albumin, and higher serum concentrations of IgG, IgM and IgA, but significantly lower salivary concentrations of IgA than the healthy cats. The cats with chronic gingivostomatitis were treated with either methylprednisolone, sodium aurothiomalate, metronidazole and spiramycin, or oral hygiene products. After three months of treatment, the cats receiving methylprednisolone had a significant reduction in serum IgG levels compared to the cats treated with sodium aurothiomalate or metronidazole and spiramycin, but after six months of treatment there were no significant differences between the groups. Before the treatments, the levels of oral inflammation were not correlated significantly with any of the serum or salivary immunoglobulin levels. However, the changes in oral inflammation were correlated significantly with the changes in the salivary IgM concentration after three and six months of treatment, and with the change in the salivary IgA concentration after six months of treatment.     

Antibody response in bovine pharyngeal fluid following foot-and-mouth disease vaccination and, or, exposure to live virus

Samples of pharyngeal fluid and serum were collected from cattle after exposure to live foot-and-mouth disease (FMD) virus (with or without prior vaccination) or after subcutaneous vaccination with inactivated virus. The pharyngeal fluid samples were examined for FMD neutralising activity and specific anti-FMD IgG, IgM and IgA antibodies. The neutralising activity of the serum was also monitored. A peak of neutralising activity which occurred in the pharyngeal fluid of unvaccinated cattle seven days after virus exposure corresponded to a rise in specific IgM and IgA antibodies. This peak appeared to be due to serum and tissue fluid escaping from the damaged mucosa during the acute inflammatory phase of infection. At later stages (20 to 60 days after virus exposure) the pharyngeal fluid neutralising activity corresponded to a rise in specific IgA antibodies, suggesting that active local antibody production was taking place. The pharyngeal fluid neutralising activity detected after revaccination with oil emulsion or aqueous vaccines, without exposure to live virus, corresponded to a rise in specific IgG and IgM antibody levels and this may have been due to serum transudation.     

Proteinuria and immunoglobulinuria in neonatal dogs

Samples of urine and serum from 45 newborn rottweiler puppies from six litters, and milk from their mothers, were taken 24, 48 and 72 hours and seven and 14 days after birth. Urine total protein and creatinine concentrations were determined and the ratios calculated. The immunoglobulin (Ig) concentrations of IgG, IgM and IgA in urine, serum and milk were determined with a commercially available elisa kit. The concentration of total protein in urine decreased from 1.64 to 0.29 mg/ml, and it and the ratio of total protein to creatinine in the urine of the neonatal puppies exceeded the normal values for adult dogs, but all the puppies developed normally. The average concentration of IgG in urine decreased from 0.0035 to 0.0003 mg/ml, that of IgA from 0.0035 to 0.0002 mg/ml and that of IgM from 0.0006 mg/ml to undetectable levels after two weeks. After two weeks, 47 per cent of the puppies had measurable levels of IgA and 70.6 per cent had measurable levels of IgG, but none of them had measurable levels of IgM.     

Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm

The objective of the present study was to determine the pattern of Hepatitis E virus (HEV) infection in a naturally infected, farrow-to-finish herd. For that purpose, a prospective study was conducted in randomly selected 19 sows and 45 piglets. Blood samples were collected from sows at 1 week post-farrowing and from piglets at 1, 3, 6, 9, 12, 15, 18 and 22 weeks of age. Furthermore 3 or 5 animals were necropsied at each bleeding day (but at 1 week of age), and serum, bile, liver, mesenteric lymph nodes and faeces taken. HEV IgG, IgM and IgA antibodies were determined in serum and viral RNA was analysed in all collected samples by semi-nested RT-PCR. Histopathological examination of mesenteric lymph nodes and liver was also conducted. From 13 analysed sows, 10 (76.9%) were positive to IgG, one to IgA (7.7%) and two to IgM (15.4%) antibodies specific to HEV. In piglets, IgG and IgA maternal antibodies lasted until 9 and 3 weeks of age, respectively. IgG seroconversion occurred by 15 weeks of age while IgM and IgA at 12. On individual basis, IgG was detectable until the end of the study while IgM and IgA antibody duration was of 4-7 weeks. HEV RNA was detected in serum at all analysed ages with the highest prevalence at 15 weeks of age. HEV was detected in faeces and lymph nodes for the first time at 9 weeks of age and peaked at 12 and 15 weeks of age. This peak coincided with the occurrence of hepatitis as well as with HEV detection in bile, liver, mesenteric lymph nodes and faeces, and also with highest IgG and IgM OD values at 15 weeks. Finally, different HEV sequences from this farm were obtained, which they clustered within 3 different groups, together with other Spanish sequences, all of them of genotype 3. Moreover, the present study also indicates that the same pig can be infected with at least two different strains of HEV during its productive life. This is the first study characterizing HEV infection in naturally infected pigs with chronological virus detection and its relationship with tissue lesions throughout the productive life of the animals.     

Secretion of Salmonella-specific antibodies in the oviducts of hens experimentally infected with Salmonella enteritidis

The production and secretion of Salmonella enteritidis whole cell antigen-specific antibodies in the oviducts and in the serum of laying hens experimentally infected with Salmonella enteritidis, was analyzed by ELISA. The dynamics of the antibody levels in the oviducts were identical to that in the serum. Subclasses of antibodies (IgA, IgG, and IgM) in the infected hens were found to increase significantly (p < 0.01) compared to those in the control uninfected hens throughout the experiment. IgG and IgM levels in both oviducts and in sera reached to a peak by 14 days post-inoculation, and remained elevated throughout. The secretion of IgA seemed to be transient since the IgA levels increased to a peak 7 days after both primary and secondary inoculations, and declined rapidly. The elevated levels of antibodies were followed by partial clearance of Salmonella organisms from the oviducts. The present results indicate a significant local immune reaction against the Salmonella infection and suggest an association of the local antibodies with the clearance of Salmonella from the oviducts at least partially.     

Bile and serum immunoglobulin levels during primary and secondary infections with Eimeria tenella in chickens

Using a radial immunodiffusion assay, total bile and serum IgG, IgM and IgA were measured following primary and secondary exposures to Eimeria tenella. Neither IgG nor IgM could be detected consistently in bile. Biliary IgA peaked at Days 6 and 10 following a primary infection of either 5000 or 10,000 oocysts and remained elevated following a subsequent 10,000-oocyst challenge at Day 10. Serum IgG and IgM levels were not influenced by parasitism and measurable concentrations of serum IgA were not detected.     

Change of antibody levels to ferritin in the sera of foals after birth: Possible passive transfer of maternal anti‐ferritin autoantibody via colostrum and age‐related anti‐ferritin autoantibody production

Antibody (immunoglobulin G (IgG), IgM or IgA) levels relative to ferritin in six foal sera (three male and three female) after birth (day 0 and 2, 6, 10, 20, 28, 36, 40, 52 and 56 weeks of age) were semi‐quantitatively measured with normalization with antibody activity to ferritin in one adult horse serum. After addition of horse spleen ferritin to the serum sample, the complex formed between antibodies to ferritin in the serum and ferritin was co‐immunoprecipitated using antibody to horse spleen ferritin. Antibody classes of the co‐immnoprecipitate were detected with antibodies specific for horse IgG, IgM or IgA heavy chain. Six adult horse serum samples were found to have ferritin‐binding activities in all immunoglobulin classes examined. Although ferritin antibody activities (IgG, IgM and IgA) were scant in the foal sera before sucking colostrum (day 0), their activities increased at 2 weeks of age. IgG antibodies showed a biphasic response and IgM antibody activity increased up to 40 weeks of age. Antibody (IgG, IgM and IgA) activities to ferritin in three colostrum samples were significantly higher than in adult horse serum samples. These results demonstrate that antibody to ferritin in foal serum is derived from colostrum after birth and is produced thereafter.     

Local antibody responses in the bile and faeces of sheep infected with Fasciola hepatica

The effect of infection with the liver fluke Fasciola hepatica on serum, bile and faecal immunoglobulin and antibody levels was studied in Scottish Blackface sheep. In the serum the immunoglobulins showing the most marked increase were IgG1 and IgG2 and their maximal values were reached at 16 weeks after infection. In the bile IgG2 rose to peak values at two weeks and IgG1, IgA and IgM were maximal at four weeks after infection. The levels of faecal IgG and IgA were low after primary infection but after reinfection a rapid increase in IgA concentration was observed within one to two weeks. Haemagglutinating antibody levels against egg antigens, juvenile and adult excretory-secretory antigens and adult fluke somatic antigens were evaluated. In the sera high titres were observed starting from two to four weeks after infection and persisting until 14 to 16 weeks. Bile haemagglutinating antibodies against excretory-secretory antigens showed the highest level at two and four weeks after infection while antibodies against adult somatic antigens reached maximal titres between four and eight weeks. Faecal antibody levels after primary infection were low but increased rapidly within two weeks after reinfection, coinciding with the elevation in faecal IgA concentration. However, there was no reduction in the number of flukes established in reinfected animals.     

Analysis of the kinetics, isotype and specificity of serum and coproantibody in lambs infected with Cryptosporidium parvum

Enteric cryptosporidiosis was studied in colostrum-deprived lambs each infected at five days old with 10(6) oocysts. The prepatent period was three to five days and faecal oocyst concentration fell below detectable levels by day 16 after infection. Specific IgA, the only isotype detected by immunofluorescent assay in faecal extracts from infected lambs, was first evident on day 10 and titres continued to rise until day 16 of infection in association with declining oocyst output. Specific IgM and IgG antibodies were first detected in serum seven days after infection. No specific antibody was detected in uninfected control lambs. Immunoblotting methods showed that serum antibody and faecal IgA had similar profiles of antigen recognition. Antigens with approximate molecular weights of 180,000, 23,000 and 15,000 were consistent features on immunoblots performed with convalescent sera and faecal extracts. The results suggest that specific IgA in intestinal secretions has an important role in immunity to cryptosporidiosis.     

Maternal-neonatal immunoregulation in swine. II. Influence of multiparity on de novo immunoglobulin synthesis by piglets

In the first-litter sows lower serum levels were found for all three Ig classes as compared to multiparous sows. The same was true for IgA in lacteal secretions and in piglet serum during the first days of life, while no differences were found for IgG levels. In contrast to these findings, IgM levels were found to be higher in lacteal secretions of first-litter sows and in piglet serum during the first days of life as compared to their counterparts. From three weeks after birth Igs found in piglet serum mainly originate from de novo synthesis. In this period piglets of first litter sows showed a higher IgA level up to the 6th week of life and higher IgG and IgM levels up to the end of the investigation period. Results are discussed in terms of maternal-neonatal immune regulation, focussing on the apparent suppressive role of maternally-derived IgG on total de novo Ig synthesis by suckling piglets.     

Transfer of maternal antibody against group A rotavirus from sows to piglets and serological responses following natural infection

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of antirotaviral antibody in sera and faeces from pigs and used to study the dynamics of antirotaviral antibody responses in three cohorts of pigs. Piglets acquired antirotaviral antibody by sucking their dams soon after birth. Antirotaviral antibodies of IgA and IgG classes were detected in both colostrum and milk of all sows tested but IgM class antibodies were not. The antibody levels in colostrum were eight to 32 times higher than those in milk which was collected 18 days post partum. The levels of antibody in piglets' sera were comparable to those in colostrum but declined quickly to low levels by one month old. Maternal antibody was also detected in the faeces of piglets up to 18 days old. Natural rotavirus infection occurred in each of these cohorts when the geometric mean ELISA titres of maternal antibody in their sera declined to 1/1600 (by days 21, 25 and 30 for cohorts 1, 2 and 3, respectively). However, a positive correlation was not obtained between the levels of antirotaviral antibody and protection in individual litters within each of the cohort groups. In each of the cohorts, rotavirus infection usually occurred in one or two piglets first and then spread to other piglets in the same cohort. It is therefore suggested that maternally derived antibody is protective against rotavirus infection in piglets only for the first one or two weeks. Following natural infection with rotavirus, increases in serum antibodies were detected in two of the three cohorts by 20 to 30 days after the average time of onset of faecal shedding of virus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antibody dynamics in BRSV-infected Danish dairy herds as determined by isotype-specific immunoglobulins

Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection.Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The IgM titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection.In two closed herds, repeated blood samplings were performed on young stock to analyse maternal immunity. The passively transferred antibodies were mainly of the IgG1 isotype and the half-life of IgG1 to BRSV was estimated to be 26.6 days. One of the herds had an outbreak of enzootic pneumonia, diagnosed to be caused by BRSV. Furthermore, another herd with acute BRSV was followed by weekly blood samples in six calves; in both herds IgM and IgG1 was detected shortly after the appearance of clinical signs. Serum samples from 50 Danish dairy herds (453 samples) were tested for immunoglobulins of the isotypes IgG1, IgG2 and IgM. The presence of antibodies to BRSV was widespread and more than 54% of the samples had BRSV antibodies of both the IgG1 and IgG2 isotypes indicating a high herd prevalence to BRSV. Test samples from two herds out of 50 were free from all isotypes to BRSV.     

雏鸡感染毒害艾美耳球虫后血清免疫球蛋白含量的动态变化

采用间接ELISA法检测雏鸡初次及二次感染毒害艾美耳球虫(Eimerianecatrix)后血清免疫球蛋白含量的动态变化。结果表明,雏鸡初次感染E.necatrix 后10 d~ 14 d血清IgG, IgM, IgA 含量开始增加,16 d~18 d达到峰值;雏鸡二次攻击性感染E.necatrix 后2 d~7 d,其血清的上述3种免疫球蛋白含量均不同程度低于初次感染雏鸡,随后开始回升,至10 d~14 d明显高于相应对照及初次感染雏鸡。血清抗体,特别是IgG介导的体液免疫,在雏鸡抵抗E.necatrix初次及二次感染中发挥了重要作用。     

Serum antibody response to soluble extract of the third-larval stage of Ostertagia ostertagi in cattle

Serum IgG, IgM, and IgA antibody responses against L₃ antigens of Ostertagia ostertagi were monitored by enzyme-linked immunosorbent assay (ELISA) after one, two or multiple sequential inoculations of this nematode in calves. Following the first infection, antibody levels did not change. After a second inoculation, IgG increased significantly (P < 0.05) after 2 months. IgG was not significantly increased 1 month after challenge inoculation. IgM and IgA antibody levels did not change following the first or second inoculations of L₃. IgG antibody levels rose only slightly following multiple sequential inoculations with infectious L₃.

Results indicate that calves with ostertagiasis have very weak serum antibody responses to L₃, and these appear to be of little value in detection of the infection in these animals.     

Isotype- and subclass-specific responses to infection and reinfection with parainfluenza-3 virus: comparison of the diagnostic potential of ELISAs detecting seroconversion and specific IgM and IgA.

Isotype- and subclass-specific indirect enzyme-linked immunosorbent assays were developed to detect parainfluenza-3 virus-specific IgG1, IgG2, IgM, and IgA responses. Sera were treated with protein G-agarose prior to testing for specific IgM and IgA to eliminate the possibility of false-positive results due to IgM-rheumatoid factor and to remove interisotypic competition due to specific IgG. IgM and IgA absorbance values were expressed as a percentage of the absorbance values of positive reference sera included on each plate (S/P%), and respective positive/negative threshold values of 15.0% and 28.0% were determined. The mean interval between experimental infection of 3 calves and initial detection of specific IgG1 and IgG2 responses was 8.0 and 9.3 days respectively, rising rapidly to an initial plateau 13.7 and 11.0 days postinfection (dpi). Reinfection of these calves at 30 dpi resulted in further rapid increases, with higher plateau values reached 13.0 (IgG1) and 13.7 (IgG2) days later. The mean interval between infection and the first positive IgM and IgA responses was 6.7 and 12.3 days, respectively. IgM S/P% values peaked at 13.0 dpi, with all 3 calves showing a secondary anamnestic response to reinfection, peaking 4.7 days later. The IgA response to initial infection was weak, with only 2 calves showing an obvious peak response at 15.0 dpi. A strong anamnestic IgA response to reinfection occurred in 2 calves, with a peak response 9.5 days later. Apparent biphasic and triphasic IgM and IgA responses were evident in some calves. Acute and convalescent serum samples from 80 calves involved in 17 outbreaks of respiratory disease were tested for specific IgM and IgA. Positive IgM results were detected in 15 outbreaks, with 71 sera from 44 calves testing positive. Although IgA-positive results were detected in the same 15 outbreaks, only 42 sera from 31 calves were positive. In a previous study, seroconversion was detected in 21 of these calves from 10 outbreaks. Thus the diagnostic potential of the assays was in the order IgM > IgA > seroconversion. The correlations between IgM and IgA, IgM and seroconversion, and IgA and seroconversion results for each calf were 73.8%, 58.8% and 62.5%, respectively.     

Changes in serum immunoglobulin values in kittens after ingestion of colostrum.

Immunoglobulin values were determined in fetal and kitten sera. In the fetal and precolostral kitten sera, only IgG was detected, except in 1 case in which IgM was detected. The IgG, IgA, and IgM were transferred to the kittens through colostrum ingestion with some selectivity. Concentration of the transferred IgG, IgA, and IgM decreased significantly with half-lives of 4.15 +/- 1.29 days, 2.03 +/- 0.33 days, and 2.2 +/- 1.2 days, respectively. As a result of this decrease and increase of de novo immunoglobulin synthesis, IgG, IgA, and IgM were at their lowest values when kittens were 20 to 25 days, 14 to 20 days, and 8 to 10 days old, respectively. After their nadir was reached, IgG values increased gradually, IgA slowly, and IgM rapidly, as a result of de novo immunoglobulin synthesis. When the kittens were 90 days old, their immunoglobulin values were 80% (IgG), 7% (IgA), and 100% (IgM), compared with those of adult cats. These findings suggest that kittens that receive inadequate colostrum from their mothers will be particularly susceptible to infection after they are 5 weeks old.     

Antibody response of pigs to foot-and-mouth disease oil emulsion vaccine: the antibody classes involved

Groups of three pigs were vaccinated with water-in-oil emulsion vaccine and revaccinated either 21 and 148 or 106 days later. Sera were taken periodically for six months and fractionated into heavy and light elements on sucrose density gradients. The heavier fraction contained IgM and the lighter fraction IgG and IgA. Neutralising antibodies were first detectable eight days after initial vaccination (dpiv), rose to a peak between 14 and 21 dpiv and persisted at relatively high titres until the time of revaccination. Neutralising antibody at eight dpiv was attributed to IgM but by 10 to 14 dpiv both IgM and IgG were involved. Thirty-five days (and later) after a single vaccination all the neutralising activity in the sera was due to IgG. The revaccinations produced an increment in the whole serum neutralising titres and in each case both IgM and IgG class antibodies were involved.     

Colostral and serum IgG, IgA, and IgM concentrations in Standardbred mares and their foals at parturition

Immunoglobulin G, IgM, and IgA concentrations were measured in serum collected from 36 Standardbred mares within 12 hours of foaling, in colostrum collected within 6 hours of foaling, and in serum collected from foals 24 to 48 hours after birth. In serum collected from mares after parturition, mean concentrations of IgG, IgM, and IgA were 2,463.9 +/- 1,337.3 mg/dl, 136.4 +/- 218 mg/dl, and 305.2 +/- 237.5 mg/dl, respectively. In serum from foals, mean concentrations of IgG, IgM, and IgA were 1,953.3 +/- 1,635 mg/dl, 33.8 +/- 30.4 mg/dl, and 58.4 +/- 42.2 mg/dl, respectively. In colostrum, mean concentrations of IgG, IgM, and IgA were 8,911.9 +/- 6,282.2 mg/dl, 957 +/- 1088.1 mg/dl, and 122.9 +/- 77.3 mg/dl, respectively. The IgG concentrations in foal serum were poorly correlated with IgG concentrations in colostrum (r = 0.462, P less than 0.01). Correlations of IgM or IgA concentrations in serum from foals with IgM or IgA concentrations in colostrum and correlations of IgG concentrations in serum from mares with those in colostrum were not significant (P less than 0.01). Of 36 foals, 1 (2.8%) had a serum IgG concentration less than 400 mg/dl. Of 36 foals monitored for 4 months, 6 developed infectious respiratory tract disease requiring antimicrobial therapy at ages varying from 55 to 113 days; these infections were probably not related to failure or partial failure of passive transfer of antibody.