Antigen-specific B-cell responses by neonatal calves after early vaccination

Field trial of antibody response to inactivated bacterial vaccine in young Holstein calves: influence of animal health status

Introduction

Bovine respiratory disease (BRD) is one of the primary causes of death in young calves. Vaccination against infection by the common bacteria causing BRD is possible; however, the physical condition of the young calves that enables antibody production when stimulated by early immunisation remains to be elucidated.

Material and Methods

Healthy young female Holstein calves on a commercial dairy farm were fed a colostrum replacer and administered primary and booster immunisations with an inactivated vaccine against the bacterial pneumonia agents Histophilus somni, Pasteurella multocida and Mannheimia haemolytica. At each immunisation, the body weight and height at the withers were measured and the body mass index (BMI) was calculated. Blood was sampled immediately before immunisation and 3 weeks following the booster. The calves were divided into positive and negative groups based on the antibody titre at the final blood sampling. Maternal antibody titres at the primary immunisation and BMI, nutritional status and oxidative stress at both immunisations were compared between the two groups.

Results

Antibody titre at the primary and BMI at both immunisations were significantly higher in the positive than in the negative group (P < 0.05). Additionally, serum gamma globulin was significantly higher in the positive group (P < 0.05), indicating a strong correlation between maternal antibody and serum gamma globulin levels.

Conclusion

Elevated maternal antibody titre and higher BMI are positive factors for successful early immunisation, for which suitable colostrum may also be fundamental in young calves administered inactivated vaccines.

Hydrolyzed Yeast Supplementation in Calf Starter Promotes Innate Immune Responses in Holstein Calves under Weaning Stress Condition

Simple Summary

New-born Holstein calves are vulnerable to infectious diseases owing to incomplete immune system development. This study aimed to evaluate the effects of six weeks of hydrolyzed yeast supplementation in Holstein calf starter on stress and immune responses after weaning. Hydrolyzed yeast supplementation facilitated the innate immune response after weaning, with a limited stress response. Therefore, the supplementation of hydrolyzed yeast in calf starters may help weaned calves adapt to diet-induced stresses. These results suggest that hydrolyzed yeast may be an effective feed additive for modulating stress-related immune responses.

Abstract

Weaned calves are susceptible to infectious diseases because of the stress and malnutrition that occurs during weaning. Therefore, the dairy industry requires effective feed additives to ameliorate stress responses and promote immunity. This study aimed to investigate the effects of hydrolyzed yeast (HY) supplementation on the growth performance, immune and stress parameters, and health status of calves after weaning. Eighteen Holstein calves were randomly assigned to two groups, either receiving a control calf starter or 0.2% HY calf starter from one week of age. All calves were weaned at six weeks of age as a stress challenge. The HY-fed calves had a significantly-higher body weight gain during the post-weaning period (kg/week) compared to the control. Cortisol levels at three days post-weaning (DPW) were significantly lower in the HY group than the control group. Calves fed HY had significantly-higher serum levels of tumor necrosis factor-α and interleukin-1β at one DPW. The HY-fed calves also had higher concentrations of the acute-phase proteins, haptoglobin, serum amyloid A, and transferrin at one DPW. In addition, the diarrhea severity in HY-fed calves was milder after weaning compared to the control group. Our results indicate that HY supplementation reduces stress responses and may promote innate immunity in newly-weaned calves.

Field Trial of Primary and Booster Dose of Inactivated Vaccine Against Bovine Respiratory Bacteria in Young Holstein Calves

Introduction

The objective of this research was to evaluate the antibody response to multiple doses of an inactivated mixed vaccine against Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica, and to investigate the influence of age at time of vaccination in the field.

Material and Methods

Healthy female Holstein calves received the vaccine at the age of 5–12 days and 2, 3, or 4 weeks later in the first experiment or at 1, 2, or 3 weeks of age and 4 weeks later in the second. Blood samples were collected at each vaccination and 3 weeks after the booster dose. Based on the antibody titres after the vaccinations, calves were divided into positive and negative groups for each of the bacteria. Calves in the control group were vaccinated only once at the age of 19–26 days.

Results

Antibody titres against H. somni and P. multocida were significantly increased by the booster. After the second vaccinations, the titres against each bacterium were higher than those of the control group, and the M. haemolytica-positive percentage in calves with high maternal antibody levels (MAL) exceeded that in calves with low MAL. In the first experiment, a majority of the M. haemolytica-positive calves tended to have received the primary dose at seven days of age or older.

Conclusion

A booster dose of the inactivated bacterial vaccine in young Holstein calves increased antibody production and overcame the maternal antibodies. Calves should be vaccinated first at seven days of age or older.

Lipoarabinomannan in Active and Passive Protection Against Tuberculosis

Glycolipids of the cell wall of Mycobacterium tuberculosis (Mtb) are important immunomodulators in tuberculosis. In particular, lipoarabinomannan (LAM) has a profound effect on the innate immune response. LAM and its structural variants can be recognized by and activate human CD1b-restricted T cells, and emerging evidence indicates that B cells and antibodies against LAM can modulate the immune response to Mtb. Anti-LAM antibodies are induced during Mtb infection and after bacille Calmette-Guerin (BCG) vaccination, and monoclonal antibodies against LAM have been shown to confer protection by passive administration in mice and guinea pigs. In this review, we describe the immune response against LAM and the potential use of the mannose-capped arabinan moiety of LAM in the construction of vaccine candidates against tuberculosis.

Immune cells transferred by colostrum do not influence the immune responses to foot-and-mouth disease primary vaccination

Little is known about the influence of maternal antibodies and immune cells transferred through colostrum on the immune responses of calves to the currently used foot-and-mouth disease (FMD) vaccines. Here we evaluated the humoral and cellular immune responses induced by vaccination of colostrum-deprived calves and calves that received equivalent amounts of colostrum preparations that differed in the presence or absence of maternal immune cells but contained the same quantity and quality of anti-foot-and-mouth disease virus (FMDV) antibodies. Three groups of 32-d-old calves (n = 3 per group) were deprived of colostrum and fed either whole immune colostrum or a cell-free colostrum preparation containing only anti-FMDV antibodies. All groups were immunized with 1 dose of an oil-adjuvanted commercial vaccine. Blood samples were collected periodically before vaccination and weekly after vaccination. Immune responses specific to FMDV were assessed based on T-cell proliferation, IFN-γ production, total and neutralizing serum antibodies, and isotype profile. All vaccinated calves developed IFN-γ and lymphoproliferative responses, irrespective of the colostrum received. Colostrum-deprived animals responded to vaccination with a primary IgM response followed by an increase of IgG₁ titers. Conversely, antibody titers decreased in all colostrum-fed calves after vaccination. This study demonstrates for the first time that maternal immune cells transferred to the calves through colostrum do not modify immune responses to FMD vaccine, and it confirms the interference of maternal antibodies in the induction of humoral but not cell-mediated immune responses.

Mannose-capped lipoarabinomannan in Mycobacterium tuberculosis pathogenesis

Mannose-capped lipoarabinomannan (ManLAM), present in all members of the Mycobacterium tuberculosis complex and in other pathogenic Mycobacterium spp, is a high molecular mass amphipathic lipoglycan with a defined critical role in mycobacterial survival during infection. In particular, ManLAM is well-characterized for its importance in providing M. tuberculosis a safe portal of entry to phagocytes, regulating the intracellular trafficking network, as well as immune responses of infected host cells. These ManLAM immunological characteristics are thought to be linked to the subtle but unique and well-defined structural characteristics of this molecule, including but not limited to the degree of acylation, the length of the D-mannan and D-arabinan cores, the length of the mannose caps, as well as the presence of other acidic constituents such as succinates, lactates and/or malates, and also the presence of 5-methylthioxylosyl. The impact of all these structural features on ManLAM spatial conformation and biological functions during M. tuberculosis infection is still uncertain. In this review, we dissect the relationship between ManLAM structure and biological function addressing how this relationship determines M. tuberculosis interactions with host cells, and how it aids this exceptional pathogen during the course of infection.

Influence of vaccine potency and booster administration of foot-and-mouth disease vaccines on the antibody response in calves with maternal antibodies

Foot-and-mouth disease is one of the most important viral diseases of cloven-hoofed animals. Mass vaccination is an effective method to control the disease and is frequently utilized in endemic regions. Sufficient protection of young animals is important in mass vaccination campaigns. Maternal antibodies negatively affect the success of vaccination. Hence, determination of the optimal vaccination age is crucial for the uninterrupted protection of young animals. This study was performed to identify the effect of vaccine potency and booster administration on serum neutralizing antibody titers of calves with different levels of maternal antibodies. Calves (n = 111) on a state farm were used in this study. Oil adjuvant foot-and-mouth disease vaccines with 3 PD50 and 6 PD50 potencies were used with or without booster administration. Serum samples were collected each month up to day 120 postvaccination. Virus neutralization tests were used to measure the serum neutralizing antibody titers and estimate the protection period by using pre-determined cut-off values for protection. The results revealed that a vaccination with a 6 PD50 potency vaccine, preferably followed by a booster dose, should be used to overcome maternal immunity for incessant protection.

Regulation of Mycobacterium-specific mononuclear cell responses by 25-hydroxyvitamin D3

The active vitamin D metabolite, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), has been shown to be an important regulator of innate and adaptive immune function. In addition, synthesis of 1,25(OH)(2)D(3) from 25-hydroxyvitamin D(3) (25(OH)D(3)) by the enzyme 1α-hydroxylase in monocytes upon activation by TLR signaling has been found to regulate innate immune responses of monocytes in an intracrine fashion. In this study we wanted to determine what cells expressed 1α-hydroxylase in stimulated peripheral blood mononuclear cell (PBMC) cultures and if conversion of 25(OH)D(3) to 1,25(OH)(2)D(3) in PBMC cultures regulated antigen-specific immune responses. Initially, we found that stimulation of PBMCs from animals vaccinated with Mycobacterium bovis (M. bovis) BCG with purified protein derivative of M. bovis (M. bovis PPD) induced 1α-hydroxylase gene expression and that treatment with a physiological concentration of 25(OH)D(3) down-regulated IFN-γ and IL-17F gene expression. Next, we stimulated PBMCs from M. bovis BCG-vaccinated and non-vaccinated cattle with M. bovis PPD and sorted them by FACS according to surface markers for monocytes/macrophages (CD14), B cells (IgM), and T cells (CD3). Sorting the PBMCs revealed that 1α-hydroxylase expression was induced in the monocytes and B cells, but not in the T cells. Furthermore, treatment of stimulated PBMCs with 25(OH)D(3) down-regulated antigen-specific IFN-γ and IL-17F responses in the T cells, even though 1α-hydroxylase expression was not induced in the T cells. Based on evidence of no T cell 1α-hydroxylase we hypothesize that activated monocytes and B cells synthesize 1,25(OH)(2)D(3) and that 1,25(OH)(2)D(3) down-regulates antigen-specific expression of IFN-γ and IL-17F in T cells in a paracrine fashion.

Induction of B cell responses upon experimental infection of neonatal calves with Mycobacterium avium subsp. paratuberculosis

The objective of this study was to determine if experimental infection of neonatal calves with Mycobacterium avium subsp. paratuberculosis would invoke changes in the percentages of total B cells in the peripheral blood mononuclear cell population and of subpopulations of B cells as determined by CD5, CD25, and CD45RO markers during a 12-month period. Experimental infection groups included control (noninfected), oral (infected with M. avium subsp. paratuberculosis strain K-10), oral/DXM (pretreatment with dexamethasone before oral inoculation), i.p. (intraperitoneal inoculation), and oral/M (oral inoculation with mucosal scrapings from a cow with clinical disease) groups. Over the course of the study, the percentages of total B cells in nonstimulated and antigen-stimulated cell cultures increased for oral and i.p. group calves, with the highest percentages noted at 3 and 6 months. Oral/M group calves had increased percentages of activated B cells, as determined by CD5(dim) and CD5(bright) markers, at 9 and 12 months. Experimental infection by all methods resulted in increased expression of CD25(+) and CD45RO(+) B cells early in the study, but the most significant results were observed at 12 months for oral/DXM and oral/M group calves. Immunoblot analyses with a whole-cell sonicate of M. avium subsp. paratuberculosis demonstrated the most reactivity with sera from i.p. group calves and the least reactivity with sera from oral group calves. Further evidence of M. avium subsp. paratuberculosis-specific antibody responses in the i.p. group calves was demonstrated using the ethanol vortex enzyme-linked immunosorbent assay (EvELISA) method. In summary, an induction of B cell responses was noted after experimental infection with M. avium subsp. paratuberculosis, with differences in responses noted according to the method of experimental inoculation.

Effects of fermented soybean meal on growth performance, diarrheal incidence and immune-response of neonatal calves

The effects of partial substitution of fermented soybean meal (FSBM) for soybean meal (SBM) on immune-physiological parameters, growth performance and diarrheal incidence in neonatal calves after microbial infection were investigated. Holstein calves (n = 12) were randomly assigned to two dietary treatments: the SBM and the FSBM group. The latter group received a calf starter containing 5% FSBM instead of SBM. In order to evaluate the immunocompetence against microbial infection, all calves were challenged with porcine live vaccine by intramuscular injection at 21 days of age. The incidence and severity of diarrhea were significantly less (P < 0.05) in the FSBM group compared to those in the SBM group at 21 and 42 days of age. Feeding FSBM starter resulted in a higher (P < 0.05) relative amount of bacterial-specific IgA than those on SBM at days 5 and 14 post-microbial infection (DPMI). Viral-specific IgA also increased (P < 0.05) at 5 DPMI in the FSBM group when compared to the SBM group. The average concentration of haptoglobin of calves fed FSBM was generally higher at 3 DPMI. Our results indicate that FSBM plays a role in the alleviation of diarrhea and in the production of immune-related effector cells such as IgA and haptoglobin in calves.