Passive Transfer Of Immunoglobulins Research Articles

Importance of the colostrum period in the infectious diseases’ prophylaxis in newborn calves

An important period in the development of immunity and effective protection against calf diseases is the colostrum period, when the transfer of passive immunity from cow to calf occurs. Diseases of calves can be prevented from the first hours of life, by absorbing as much immunoglobulin as possible from the colostrum. This study examines the role played by calf health management during the first three days post calving in its susceptibility to infection and the effect on future production performance. Studies and scientific communications were reviewed in order to collect information on the prevention of calf pathology by passive transfer of immunoglobulins from colostrum in the first hours after calving. The amount of colostrum at the first meal, the Brix value of the colostrum, and the time when the newborn calves received the first colostrum influence the transfer of passive immunity, the incidence/severity of the pathology developed, and the productive performance of the farm (reduction of slaughter rate, reduction of age at first calving, increasing milk production performance). All dairy farms must implement a colostrum management protocol to ensure that the newborn calf has assimilated sufficient antibodies during the colostrum period. This study is based on research carried out within the DISARM project which received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 817591.

SARS-CoV-2 ferritin nanoparticle vaccines elicit broad SARS coronavirus immunogenicity.

The need for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) next-generation vaccines has been highlighted by the rise of variants of concern (VoCs) and the long-term threat of emerging coronaviruses. Here, we design and characterize four categories of engineered nanoparticle immunogens that recapitulate the structural and antigenic properties of the prefusion SARS-CoV-2 spike (S), S1, and receptor-binding domain (RBD). These immunogens induce robust S binding, ACE2 inhibition, and authentic and pseudovirus neutralizing antibodies against SARS-CoV-2. A spike-ferritin nanoparticle (SpFN) vaccine elicits neutralizing titers (ID50 > 10,000) following a single immunization, whereas RBD-ferritin nanoparticle (RFN) immunogens elicit similar responses after two immunizations and also show durable and potent neutralization against circulating VoCs. Passive transfer of immunoglobulin G (IgG) purified from SpFN- or RFN-immunized mice protects K18-hACE2 transgenic mice from a lethal SARS-CoV-2 challenge. Furthermore, S-domain nanoparticle immunization elicits ACE2-blocking activity and ID50 neutralizing antibody titers >2,000 against SARS-CoV-1, highlighting the broad response elicited by these immunogens.

Effect of milk replacer allowance on calf faecal bacterial community profiles and fermentation

BackgroundThe nutrition of calves from birth until weaning is predominantly from liquid (milk or milk-based) feeds. Liquid feed allowances are often restricted during artificial rearing to accelerate the development of the rumen by promoting solid feed intake. Liquid feeds bypass the rumen and are digested in the lower digestive tract, however, the influence of different types of milk feeds, and their allowances, on the calf hindgut microbiota is not well understood. In this study, faecal samples from 199 calves raised on three different allowances of milk replacer: 10% of initial bodyweight (LA), 20% of initial bodyweight (HA), and ad libitum (ADLIB), were collected just prior to weaning. Bacterial community structures and fermentation products were analysed, and their relationships with calf growth and health parameters were examined to identify potential interactions between diet, gut microbiota and calf performance.ResultsDifferences in the total concentrations of short-chain fatty acids were not observed, but higher milk replacer allowances increased the concentrations of branched short-chain fatty acids and decreased acetate to propionate ratios. The bacterial communities were dominated by Ruminococcaceae, Lachnospiraceae and Bacteroides, and the bacterial diversity of the ADLIB diet group was greater than that of the other diet groups. Faecalibacterium was over three times more abundant in the ADLIB compared to the LA group, and its abundance correlated strongly with girth and body weight gains. Milk replacer intake correlated strongly with Peptococcus and Blautia, which also correlated with body weight gain. Bifidobacterium averaged less than 1% abundance, however its levels, and those of Clostridium sensu stricto 1, correlated strongly with initial serum protein levels, which are an indicator of colostrum intake and passive transfer of immunoglobulins in early life.ConclusionsHigher milk replacer intakes in calves increased hindgut bacterial diversity and resulted in bacterial communities and short chain fatty acid profiles associated with greater protein fermentation. Increased abundances of beneficial bacteria such as Faecalibacterium, were also observed, which may contribute to development and growth. Moreover, correlations between microbial taxa and initial serum protein levels suggest that colostrum intake in the first days of life may influence microbiota composition at pre-weaning.

Effect of late-gestation heat stress in nulliparous heifers on postnatal growth, passive transfer of immunoglobulin G, and thermoregulation of their calves

Youngstock such as nulliparous pregnant dairy heifers are not typically considered for active cooling, as they are thought to be more heat tolerant than mature cows. Recently, the benefits of heat stress abatement in pregnant heifers were studied, but the effect of in utero hyperthermia on the calf is still unknown. Herein, we aimed to investigate the effects of late-gestation heat stress in nulliparous heifers on the growth, immune, and thermoregulatory responses of their calves. Pregnant nulliparous dams were randomly selected for either active cooling (CL; fans and soakers; n = 15) or heat stress (HT; n = 16) 60 d before expected calving. After birth, respiration rate, rectal temperature, skin temperature, and sweating rate were obtained from their heifer calves at 24 h and on d 14, 28, 42, and 56. Blood samples and body weights were both collected for measurement of total protein and hematocrit and calculation of average daily gains, respectively. Gestation length was shorter in HT heifers (272 vs. 276 ± 1.28 d) relative to CL heifers. Birth weights, weaning weights, body weights up to d 56, and average daily gain from birth to weaning were not different between in utero HT (IUHT; n = 13) and in utero CL (IUCL; n = 12) calves. Apparent efficiency of absorption of immunoglobulin G tended to be lower in IUHT calves (26.3 vs. 42.7 ± 9.0%), and serum IgG concentrations from birth to d 56 were significantly lower in IUHT calves relative to IUCL calves (22.0 vs. 32.4 ± 4.47 g/L). Postnatal respiration rate, rectal temperature, sweating rate, total protein, and hematocrit were not different between in utero treatments. There was a tendency for IUHT calves to have lower skin temperature at 24 h (34.9 vs. 36.9 ± 1.05°C), and skin temperature tended to be elevated in IUHT calves at d 56 (29.6 vs. 27.9 ± 1.05°C). In summary, the lack of heat stress abatement during late gestation reduces gestation length of nulliparous heifers. Additionally, providing active cooling to nulliparous heifers during the prepartum period confers immune benefits to their offspring, although it does not translate to growth improvements.

Equine immunoglobulin F(ab′)2 fragments protect mice from Rift Valley fever virus infection

BackgroundRift Valley fever virus (RVFV) is an emerging arbovirus in Africa and the Arabian Peninsula, in which infection with RVFV poses a serious threat to humans and livestock globally. Approved treatments for RVFV infection, especially for use in humans, have not yet been developed. There is an urgent need for effective drugs to prevent RVFV disease. MethodsIn previous study, we developed RVFV virus like particles (VLPs) expressing the surface glycoproteins Gn and Gc. The morphology was shown to be similar to live RVFV under electron microscopy. In this study, we immunized horses with RVFV VLPs, prepared the immunoglobulin F(ab′)2 fragments, and characterized its in vitro neutralization and in vivo efficacy in mice. ResultsF(ab′)2 was found to potently neutralize RVFV in VeroE6 cells, and passive transfer of immunoglobulin F(ab′)2 fragments resulting in reduced mortality in RVFV infected mice. ConclusionOur results show that passive immunotherapy with equine immunoglobulin F(ab′)2 fragments is a promising strategy to treat RVFV infections.

Relationship between selected perinatal paratuberculosis management interventions and passive transfer of immunity in dairy calves

The objective of this cohort study was to assess the relationship between perinatal calf management practices relevant to the control of paratuberculosis and passive transfer of immunoglobulin in calves born...

Hemagglutinin-stem nanoparticles generate heterosubtypic influenza protection.

The antibody response to influenza is primarily focused on the head region of the hemagglutinin (HA) glycoprotein, which in turn undergoes antigenic drift, thus necessitating annual updates of influenza vaccines. In contrast, the immunogenically subdominant stem region of HA is highly conserved and recognized by antibodies capable of binding multiple HA subtypes. Here we report the structure-based development of an H1 HA stem-only immunogen that confers heterosubtypic protection in mice and ferrets. Six iterative cycles of structure-based design (Gen1-Gen6) yielded successive H1 HA stabilized-stem (HA-SS) immunogens that lack the immunodominant head domain. Antigenic characterization, determination of two HA-SS crystal structures in complex with stem-specific monoclonal antibodies and cryo-electron microscopy analysis of HA-SS on ferritin nanoparticles (H1-SS-np) confirmed the preservation of key structural elements. Vaccination of mice and ferrets with H1-SS-np elicited broadly cross-reactive antibodies that completely protected mice and partially protected ferrets against lethal heterosubtypic H5N1 influenza virus challenge despite the absence of detectable H5N1 neutralizing activity in vitro. Passive transfer of immunoglobulin from H1-SS-np-immunized mice to naive mice conferred protection against H5N1 challenge, indicating that vaccine-elicited HA stem-specific antibodies can protect against diverse group 1 influenza strains.

The effect of birth weight and age at tail docking and ear notching on the behavioral and physiological responses of piglets1

Selection for high prolificacy has resulted in litters comprising a large number of low-birth-weight (LBW) piglets. Given their presence in over 75% of litters and increased mortality rate, it is clear that a greater understanding of LBW piglet management is required for both animal welfare and productivity. In this study, we compared the effects of tail docking and ear notching LBW and average-birth-weight (ABW) piglets at 1 or 3 d of age on suckling, behavior, passive transfer of immunoglobulins, and growth. Six piglets per litter from 20 litters (n = 120 piglets) were used in a 2 × 2 complete block design. Piglets were weighed at birth and designated as LBW (0.6 to 1.0 kg) or ABW (≥ 1.2 kg) and "processed" (tail docked and ear notched) at either 1 or 3 d of age. Vocalizations were recorded during the procedures. The acute behavioral responses were observed for 10 min after the procedure. Piglets were observed for 6 h after birth and after the procedure to determine their presence at nursing bouts. On d 5, blood samples were collected to determine concentrations of serum immunoglobulins (IgA and IgG) and IGF-I. Piglet weights were recorded at birth and on d 5, 14, and 21. During the procedures, LBW piglets produced fewer (P = 0.03) calls than ABW piglets. Piglets from either birth weight category produced a similar number (calls/s; P = 0.29) of high-frequency calls (≥ 1,000 Hz), which are indicative of pain and distress, although the average frequency (Hz) of these calls was greatest (P = 0.05) for ABW piglets processed on d 3. Immediately following the procedures, LBW piglets spent more (P = 0.005) time dog-sitting and less (P = 0.005) time lying than ABW piglets. When observed with the sow, LBW males spent more (P = 0.001) time alone and had the lowest (P = 0.007) attendance at nursing bouts compared with LBW females and all ABW piglets. Concentrations of serum IgA (P = 0.06) and IgG (P = 0.04) and plasma IGF-I (P = 0.003) were lower for LBW than ABW piglets regardless of age of processing although the magnitude of these differences was likely not of biological significance. Average-birth-weight piglets may be less reactive to the acute effects of the procedures on d 1 than on d 3. Given the decreased likelihood of a LBW piglet surviving to weaning (P = 0.001), delaying processing until 3 d of age for LBW piglets may eliminate unnecessary procedures.

Effect of adding gut active carbohydrates to colostrum replacer on passive transfer of immunoglobulin G in Holstein dairy calves

Early feeding of a sufficient quantity of high-quality colostrum is the key to good colostrum management and obtaining sufficient passive transfer of immunity in newborn calves. Various products have been added to colostrum to evaluate their potential for improving passive transfer of colostral immunoglobulins (lg). Research findings suggest that maternal colostrum supplemented with gut-active carbohydrates (GAC) or mannan-oligosaccharides resulted in higher serum IgG concentrations in young mammals. The aim of this study was to investigate the effects of supplementing a commercial colostrum replacer (CR) with GAC on the serum IgG concentration and preweaning performance of dairy calves in a commercial farm setting.

Effect of feeding colostrum that was heat-treated with the Perfect Udder® System on passive transfer of immunoglobulin G in neonatal Jersey calves

Heat-treating colostrum by the use of batch pasteurizers is an effective method to reduce bacterial contamination while protecting immunoglobulins and enhancing passive transfer and health in calves. The Perfect Udder® bag (Dairy Tech Inc., Windsor, CO) is designed to heat-treat 1 gallon (~4 L) of colostrum at a time prior to storage and feeding; however, this system has not been validated. The objective of this study was to compare passive transfer of IgG in neonatal calves that were fed colostrum that was heat-treated with the Perfect Udder® system, heat-treated with a batch pasteurizer (positive control), or fresh-refrigerated or fresh-frozen (negative controls).

Effect of adding gut-active carbohydrates to fresh colostrum on passive transfer of immunoglobulin G in Holstein dairy calves

Lower concentrations of coliform bacteria in maternal colostrum (MC) have been associated with enhanced IgG absorption in calves. Mannan-oligosaccharide, a gut active carbohydrate (GAC) derived from yeast cell walls, can adsorb pathogens expressing type-1-fimbriae, which reduces their ability to colonize the gastrointestinal tract. Results of preliminary research suggest that feeding GAC in colostrum enhanced serum IgG concentration in calves. The purpose of this study was to investigate whether addition of a GAC (Bio-MOS®. Alltech, Inc.) to colostrum would increase IgG absorption in newborn calves.

Hantavirus infections by Puumala or Dobrava-Belgrade virus in pregnant women

BackgroundHantavirus infection in humans usually occurs via inhalation of infectious aerosolized excreta of rodents. Horizontal human-to-human transmission was reported only for the highly virulent Andes virus. The likelihood of vertical transmission and the clinical outcome of hantavirus infections in pregnancy is still unpredictable. ObjectivesVery few data were published about the impact of hantaviruses in pregnancy. Here we present four cases of pregnant women infected by European hantaviruses. The risk of vertical virus transmission was investigated. Study designFour pregnant women with clinical signs of acute hantavirus disease were investigated for hantavirus IgM and IgG after onset of clinical symptoms. Furthermore, the newborns were tested for presence of viral RNA and antibodies in cord blood and, if any parameter was found positive, 8–12 months after delivery. ResultsFour women suffered from a hantavirus infection, two of them due to infection by Puumala virus and two by Dobrava-Belgrade virus. Three women delivered healthy babies by vaginal route and one woman by Caesarean section (week 28). In no case hantavirus RNA was detected in cord blood after delivery or in the 8–12 month old babies. Hantavirus IgG was detectable in the cord blood of 3 babies (but not in the preterm child); these antibodies disappeared after 8–12 months indicating a passive transfer of immunoglobulins. No child had any clinical sign of hantavirus infection. ConclusionsIn this study, the absence of vertical hantavirus transmission was demonstrated for pregnant women with onset of hantavirus disease between gestation weeks 14 and 28.

The passive transfer of immunoglobulin G serum antibodies from patients with longstanding Complex Regional Pain Syndrome

Background The aetiology of Complex Regional Pain Syndrome (CRPS) is unknown. Recent evidence suggests that there may be autoantibodies directed against peripheral nerves, but it is unclear whether such autoantibodies are merely biomarkers or whether they cause or contribute to the underlying pathology. The transfer of disease after injection of a patient’s serum or IgG fraction into mice (‘passive transfer’) is the classic way to demonstrate a functional role of autoantibodies. Aims Based on previous preliminary results, we wished to investigate whether the transfer of IgG antibodies affected mouse behaviour or produced signs of CRPS. Methods We injected purified serum-IgG from 12 patients and 12 controls into groups of 6–10 mice (∼17 mg/mouse intraperitoneally) on 2 consecutive days and looked for any evidence for altered behaviour or signs of CRPS. The observer, blinded as to test or control group, measured behaviour in the open field, stimulus-evoked pain and motor coordination, and inspected limbs for autonomic CRPS signs. Results Stimulus-evoked pain and autonomic signs were not detected, but CRPS-IgG induced significant depression of rearing behaviour (17.9 rears/3 min ( n = 84) vs. 22.1 rears/3 min ( n = 83), p = 0.0004), confirming previous observations in a single case study. Moreover, motor impairment, one of the four cardinal signs of CRPS, was evident in the three CRPS-IgG injected groups tested with a sensitive rota-rod protocol ( p < 0.0001 vs. control-IgG injected groups). Conclusions These results lend support to a pathophysiological role for IgG autoantibodies in CRPS.

Effect of Feeding Bovamine® Probiotic on Passive Transfer of Immunoglobulin G in Newborn Calves

Early studies have suggested that bacteria in colostrum may interfere with passive absorption of immunoglobulins (lg) in newborn calves (James et al, 1981), and recent studies reported that calves fed pasteurized colostrum had improved passive transfer of IgG versus calves fed fresh colostrum (Johnson et al, 2007; Heinrichs et al, 2009a). However, a recent study reported that colostrum bacteria counts were not associated with IgG absorption (Heinrichs et al, 2009b). Do pathogenic or non-pathogenic bacteria, living or dead, truly interfere with lg absorption? Bovamine® (Nutrition Physiology Company, LLC, Overland Park, KS) is a direct-fed microbial (DFM or probiotic) containing a patented combination of living Lactobacillus acidophilus ( 1 x 109 cfu/1 g dose) and Propionibacterium freudenreichii (2 x 109 cfu/1 g dose). The study objective was to describe the effect of supplementing colostrum with living or dead DFM on serum total protein (STP) and IgG levels, and apparent efficiency of absorption of IgG (AEA %).

Natural Antibody Contributes to Host Defense against an Attenuated Brucella abortus virB Mutant

Brucella abortus is an intracellular pathogen that persists within phagocytic cells of the reticuloendothelial system. To identify in vivo interactions between B. abortus and the host that lead to persistent infection, we studied the persistence of B. abortus and an isogenic virB mutant deficient in the VirB type IV secretion system (T4SS) in knockout mice. In contrast to control mice, mice lacking B cells (Igh6(-/-)) were permissive for infection with the attenuated virB mutant. To determine the basis for this phenotype, we characterized immune functions of Igh6(-/-) mice in the context of B. abortus infection. Igh6(-/-) mice had greater numbers of extracellular bacteria in the spleen and increased early expression of proinflammatory cytokines during B. abortus infection. Further, a virB mutant, despite its wild-type level of survival, failed to elicit microgranuloma formation in the spleens of Igh6(-/-) mice, suggesting a requirement for the T4SS to elicit this pathological change. Passive transfer of immunoglobulin G from naïve mice restored the ability of Igh6(-/-) mice to control the persistence of the virB mutant by a complement-independent mechanism. Further, adoptive transfer of CD11b(+) cells from C57BL/6 mice to Igh6(-/-) mice restored the ability of the knockout mice to limit the replication of the virB mutant in the spleen, suggesting that the Igh6(-)(/)(-) mutation affects phagocyte function and that phagocyte function can be restored by natural antibody.

Effect of age on the behavioral and physiological responses of piglets to tail docking and ear notching1

Neonatal piglets are often subject to potentially painful processing procedures such as tail docking and ear notching during the first few days after birth. However, these procedures may influence the development of suckling behavior and passive transfer of immunoglobulins, especially if done within the first day postpartum. The objective of this experiment was to compare the effects of processing piglets during the first 24 h versus at 3 d of age on suckling and pain-related behavior, the passive transfer of immunoglobulins, and growth. Six piglets per litter from 20 litters (n = 120 piglets) were used in a 3 x 2 complete block design. Piglets were weighed at birth and assigned to 1 of 3 treatments (balanced by birth weight): control (unmanipulated), sham processed (manually manipulated), and processed (tail docked and ear notched) at 1 of 2 ages (1 or 3 d of age). Vocalizations were recorded during the procedures, and piglets were observed after the procedures for pain-related behavior. Suckling behavior was observed for 6 h on each of d 1 to 4. Colostrum samples were collected after the birth of all piglets (before first suck), and blood samples were collected on d 5 to examine concentrations of immunoglobulins (IgA and IgG) and IGF-I. Body weights were measured at birth and on d 5 and 14. During the procedures, processed piglets, regardless of age, vocalized at a greater frequency (P < 0.001) and produced more high frequency calls (P = 0.016) than sham-processed piglets. All piglets on d 1 produced more high frequency calls than all piglets on d 3 (P = 0.047). Immediately after the procedures, sham-processed and processed piglets spent less time lying and more time standing than control piglets (P < 0.001), whereas processed piglets jammed their tail between their legs more than sham-processed or control piglets (P < 0.001). Lying, standing and tail posture were not influenced by age, nor were there age by treatment interactions. Piglets on d 1 trembled more than piglets on d 3 (P < 0.001), and this tended to be exacerbated by processing (P = 0.076). There was no effect of treatment or age of treatment on suckling behavior. Processed piglets had decreased IgG serum concentrations compared with sham-processed and control piglets (P = 0.029), although there was no interaction between treatment and age of treatment (P = 0.67). Whereas tail docking and ear notching do appear to result in short-term pain and modulated immune status, processing on d 1 appears neither better nor worse than processing on d 3.

Passive Transfer of Immunoglobulin G and Preweaning Health in Holstein Calves Fed a Commercial Colostrum Replacer

The objective of this study was to describe passive transfer of IgG and preweaning health in newborn calves fed a commercially available plasma-derived colostrum replacement (CR) product or maternal colostrum (MC). Twelve commercial Holstein dairy farms enrolled singleton newborn heifer calves to be fed fresh MC (n=239 calves) or one dose of CR containing 125g of Ig (n=218 calves) as the first colostrum feeding. For 7 of these farms that routinely provided a second feeding of 1.9L of MC to their calves 8 to 12h after the first colostrum feeding, calves assigned to the CR treatment group were offered a second feeding consisting of 1.9L of commercial milk replacer supplemented with one dose of a commercially available plasma-derived colostrum supplement, containing 45g of Ig per dose, 8 to 12h after the first colostrum feeding. A blood sample was collected from all calves between 1 to 8 d of age for serum IgG and total protein (TP) determination, and records of all treatment and mortality events were collected until weaning. Serum IgG and TP concentrations were significantly higher in calves fed MC (IgG=14.8±7.0mg/mL; TP=5.5±0.7g/dL) compared with calves fed CR (IgG=5.8±3.2mg/mL; TP=4.6±0.5g/dL). The proportion of calves with failure of passive transfer (serum IgG <10.0mg/mL) was 28.0 and 93.1% in the MC and CR treatment groups, respectively. Though a trend was present, the proportion of calves treated for illness was not statistically different for calves fed MC (51.9%) vs. CR (59.6%). Total number of days treated per calf (MC=1.7; CR=2.0), treatment costs per calf (MC=$10.84; CR=$11.88), and proportion of calves dying (MC=10.0%; CR=12.4%) was not different between the 2 colostrum treatment groups. The mean serum total protein concentration predictive of successful passive transfer (serum IgG=10mg/mL) was 5.0g/dL in calves fed MC or CR. Long-term follow-up of these calves (to maturity) is ongoing to describe the effects of feeding CR on longevity, productivity, risk for Johne's disease, and economics.

Immune response and serum immunoglobulin G concentrations in beef calves suckling cows of differing body condition score at parturition and supplemented with high-linoleate or high-oleate safflower seeds1

Two experiments were conducted to determine the effect of maternal lipid supplementation on the immune response to antigenic challenge in suckling calves. In Exp. 1, beginning 1 d postpartum, 18 primiparous crossbred beef cows were fed Foxtail millet hay and a low-fat (control) supplement or a supplement containing cracked, high-linoleate safflower seed in individual feeding stanchions until d 40 of lactation. The diets were formulated to provide similar quantities of N and TDN, and the linoleate diet was formulated to contain 5% of DMI as fat. Calves were injected s.c. with 15 mg of antigen (ovalbumin) at d 21 and again at d 35 of age. To measure the total serum antibody production in response to the antigen, blood samples were collected from the calves every 7 d via jugular venipuncture from d 14 to 42. Calves from linoleate-supplemented cows had a decrease (P = 0.04) in total antibody production in response to ovalbumin and appeared to have a delayed response to antigen challenge. Total antibody production increased (P < 0.001) after secondary exposure to ovalbumin. In Exp. 2, 36 Angus x Gelbvieh beef cows that were nutritionally managed to achieve a BCS of 4 or 6 at parturition were used to determine the effects of prepartum energy balance and postpartum lipid supplementation on the passive transfer of immunoglobulins and the immune response to antigenic challenge in their calves. Beginning at 3 d postpartum and continuing until d 60 of lactation, cows were fed hay and a low-fat control supplement or supplements consisting of either cracked, high-linoleate or high-oleate safflower seeds. Safflower seed supplements were formulated to provide 5% of DMI as fat. Calves were injected s.c. with 15 mg of ovalbumin at 21 d of age and again at 48 d of age. The antibody responses were determined in serum; cell-mediated immunity was assessed by intradermal antigen injection at 60 d of age. A trend was noted (P = 0.10) for calves suckling control-supplemented cows to have a greater response to antigen compared with calves from linoleate- and oleate-supplemented cows; however, no difference was observed among treatments (P = 0.86) in cell-mediated immune response. Postpartum oilseed supplementation in beef cows appears to decrease antibody production in response to antigenic challenge in suckling calves. However, BCS at parturition did not influence passive transfer of immunoglobulins in neonatal calves.

Effects of Lyophilized Colostrum and Different Colostrum Feeding Regimens on Passive Transfer of Immunoglobulin G in Majorera Goat Kids

Three experiments were conducted including 180 Majorera kids. In the first experiment, the effect of use of lyophilized colostrum vs. frozen colostrum on immunoglobulin G (IgG) blood serum concentration was evaluated. Kids (n=40) received the same management and IgG mass [3368mg/kg of body weight (BW)] during the colostrum feeding period. The IgG in blood serum of kids from the lyophilized colostrum group was greater than that for kids that received frozen colostrum. The second experiment evaluated the effect of total IgG ingested by kids (n=60) on IgG in blood serum during the colostrum feeding period. Three groups of animals received 3368, 1684, and 842mg of IgG/kg of BW in 4 feedings for 2 d [high IgG concentration (H-IgG), medium IgG concentration (M-IgG), and low-IgG concentration (L-IgG), respectively]. The IgG blood serum in the kids that received H-IgG was greater than in the other 2 treatment groups, and no statistical differences were found for IgG in blood serum of kids that received either M-IgG or L-IgG. The third experiment evaluated the effect of timing of lyophilized colostrum meals on IgG blood serum concentration. Four groups of kids (n=80) were used. Two groups received 1684mg of IgG/kg of BW (higher level-1 d and higher level-2 d) and the other 2 groups received 842mg of IgG/kg of BW (lower level-1 d and lower level-2 d). Two groups received 2 feedings in 1 d, and the other 2 groups received 4 feedings over a 2-d period, as denoted. Higher level-1 d kids had greater IgG blood serum concentration than the higher level-2 d kids, and no statistical differences were found between lower level-1 d and lower level-2 d kids.

Antineutrophil cytoplasm antibodies directed against myeloperoxidase augment leukocyte-microvascular interactions in vivo

AbstractSystemic small vessel vasculitis is associated with antineutrophil cytoplasm antibodies (ANCAs). While there is mounting in vitro evidence to suggest that ANCAs are capable of enhancing leukocyte-endothelial interactions, no in vivo evidence for this has been provided. In this study a novel rat model of ANCA-associated experimental autoimmune vasculitis (EAV), induced by immunization with human myeloperoxidase (MPO), was used to analyze directly the potential effect of ANCAs on leukocyte-venular wall interactions in vivo as observed by intravital microscopy. These rats developed anti-MPO antibodies directed against rat leukocytes, showed pathologic evidence of small vessel vasculitis, and had enhanced leukocyte adhesion and transmigration in response to the chemokine Groα (CXCL1 [CXC ligand 1]). Passive transfer of immunoglobulin from rats with EAV to naive rats conferred enhanced adhesion and transmigration responses in the recipients. Furthermore, rats with EAV and recipients of ANCA-positive immunoglobulin developed extensive microvascular injury, as manifested by mesenteric hemorrhage, in response to CXCL1. This study provides the first direct in vivo evidence for the ability of ANCAs to enhance leukocyteendothelial interactions and cause microvascular hemorrhage, thereby providing a mechanism by which ANCAs could exert pathogenic effects in systemic vasculitis. (Blood. 2005;106:2050-2058)