Developmental adaptations of γδ T cells and B cells in blood and intestinal mucosa from birth until weaning in Holstein bull calves

This study aimed to characterize the development of systemic and colon tissue resident B and γδ T cells in newborn calves from birth until weaning. At birth, calves have limited capacity to initiate immune responses, and the immune system gradually matures over time. Gamma delta (γδ) T cells are an important lymphocyte subset in neonatal calves that confer protection and promote immune tolerance. A total of 36 newborn calves were enrolled in a longitudinal study to characterize how systemic and colon tissue resident B and γδ T cells develop from birth until weaning. Blood and colon biopsy samples were collected on d 2, 28, and 42 to determine the proportions of various B and γδ T cell subsets by flow cytometry. We classified γδ T cells into different functional subsets according to the level of expression intensity of the coreceptors WC1.1 (effector function) and WC1.2 (regulatory function). Furthermore, naive B cells were classified based on the expression IgM receptor, and activation state was determined based on expression of CD21 and CD32, 2 receptors with opposing signals involved in B cell activation in early life. Additional colon biopsy samples were used for 16S sequencing, and microbial diversity data are reported. At birth, γδ T cells were the most abundant lymphocyte population in blood, accounting for 58.5% of the lymphocyte pool, after which the proportions of these cells declined to 38.2% after weaning. The proportion of γδ T cells expressing WC1.1 decreased by 50% from d 2 to d 28, whereas no change was observed in the expression of WC1.2. In the colon, there was a 50% increase of γδ T cells after weaning and the proportion of WC1.2+ γδ T cells doubled from d 28 to 42. The proportion of IgM+ B lymphocytes in blood increased from 23.6% at birth to 30% after weaning, were the proportion of B cells expressing CD21 increased by 25%, while the proportion of B cells expressing CD32 decreased by 30%. While no changes were observed for the overall proportion of IgM+ B lymphocytes in the colon, there was a 6-fold increase in the proportion of CD21+ B cells from pre- (d 28) to postweaning (d 42). Microbial diversity increased from d 2 of life to 28 and declined abruptly after weaning. The reduction in microbial diversity during weaning was negatively correlated with the increase in all γδ T cell subsets and CD21+ B cells. These data suggest that developmental adaptations after birth coordinate expansion of γδ T cells to provide early systemic protection, as well as to steer immune tolerance, while B cells mature over time. Additionally, the increase of colonic γδ T cells on d 42 suggests a protective role of these cells during weaning.

Advances in Poultry Vaccines: Leveraging Biotechnology for Improving Vaccine Development, Stability, and Delivery

With the rapidly increasing demand for poultry products and the current challenges facing the poultry industry, the application of biotechnology to enhance poultry production has gained growing significance. Biotechnology encompasses all forms of technology that can be harnessed to improve poultry health and production efficiency. Notably, biotechnology-based approaches have fueled rapid advances in biological research, including (a) genetic manipulation in poultry breeding to improve the growth and egg production traits and disease resistance, (b) rapid identification of infectious agents using DNA-based approaches, (c) inclusion of natural and synthetic feed additives to poultry diets to enhance their nutritional value and maximize feed utilization by birds, and (d) production of biological products such as vaccines and various types of immunostimulants to increase the defensive activity of the immune system against pathogenic infection. Indeed, managing both existing and newly emerging infectious diseases presents a challenge for poultry production. However, recent strides in vaccine technology are demonstrating significant promise for disease prevention and control. This review focuses on the evolving applications of biotechnology aimed at enhancing vaccine immunogenicity, efficacy, stability, and delivery.

Effective behaviour change techniques for family and close friends: A systematic review and meta-analysis across the addictions

This systematic review aimed to determine whether the use of specific behaviour change technique (BCT) groups are associated with greater effectiveness for psychosocial interventions delivered to family and close friends (FCFs) impacted by addiction. A systematic search of peer-reviewed and grey literature published until August 2021 identified 32 studies in 38 articles. An established BCT taxonomy (93 BCTs clustered into 16 groups) was adapted (inclusion of seven additional BCT groups) and applied to 57 interventions. The meta-analyses indicated that some, but not all, FCF outcomes were improved by the exclusion of BCTs within several groups (Reward and Threat, Scheduled Consequences, Confrontation of the Addicted Person to Engage in Treatment, and Goals and Planning) and inclusion of BCTs within the Restoring a Balanced Lifestyle group. Addicted person outcomes were improved by the inclusion of some BCTs within several groups (Repetition and Substitution, Reward and Threat, Scheduled Consequences, and Restoring a Balanced Lifestyle). Relationship functioning outcomes were improved by the inclusion of BCTs within the Confrontation of the Addicted Person to Engage in Treatment group. Future research involving the development and evaluation of numerous interventions or comprehensive multi-component interventions that can address the various needs of FCFs, without counteracting them, is required.

The association of immune response and colostral immunoglobulin G in Canadian and US Holstein-Friesian dairy cows

In cattle, maternal immunoglobulins are transferred through colostrum to provide passive immunity to the neonatal calf once they are absorbed into circulation. Cows can be assessed for antibody- and cell-mediated immune responses (AMIR and CMIR, respectively), and through estimated breeding values (EBV) and genomic parent averages (GPA), cows can be classified as having high, average, or low immune response (IR). The objective of this study was to identify associations of colostral IgG concentrations with IR in dairy cows. High IR dairy cows identified by GPA or EBV were hypothesized to produce higher colostral IgG concentrations than cows with average or low IR. Colostrum was collected from Holstein dairy cows from 3 large commercial herds (n = 590) in the United States and 1 research herd at the Ontario Dairy Research Centre (n = 275) in Canada. For the US herds, IR GPA were available through genotyping. For the Canadian herd, IR EBV were available through phenotyping and pedigree information. Colostral IgG concentrations were measured by radial immunodiffusion and analyzed using general linear models in SAS. Based on a prediction equation, cows in US herds with a CMIR GPA of 1 would have colostral IgG concentrations 6.3 g/L higher on average than cows with a CMIR GPA of 0. High CMIR cows produced statistically greater colostral IgG concentrations (least squares mean ± standard error of the mean, 107.5 ± 7.7 g/L) than low CMIR cows (91.4 ± 7.1 g/L), with intermediate values for average CMIR cows (105.1 ± 5.6 g/L). No differences were found among AMIR categories in US cows. The Canadian herd showed a trend for cows with high CMIR EBV (continuous variable) to produce greater colostral IgG. No differences were observed among high, average, and low AMIR EBV classifications in Canadian cows. The findings suggest that selective breeding of Holstein cows to enhance CMIR could contribute to higher-quality colostrum in succeeding generations.

The effects of timing of high immune response phenotyping in relation to weaning on immune responses of crossbred beef calves

Genetic selection for immune response has the potential to increase the sustainability of the beef industry by breeding cattle that are productive yet with an increased capacity to resist disease. Determining the optimal time to immunophenotype beef cattle is crucial for the accurate prediction of an animal's immune response. The objective of this study was to determine the effect of time of immunophenotyping in relation to weaning on immune responses of beef calves. Antibody- (AMIR) and cell-mediated (CMIR) immune responses were measured on 97 calves on the day of weaning (WEANING, N = 56) or 2 mo post-weaning (POST-WEANING, N = 41). Within each period of immunophenotyping, on day 0, blood was collected, and calves received a 1.0 mL intramuscular injection of type 1 and 2 test antigens. On day 14, blood was collected, and baseline skinfold thickness (SFT) was measured. Calves received an intradermal injection of 0.1 mg of the type 1 antigen suspended in 0.1 mL phosphate buffered saline (PBS) in the right tail fold, and 0.1 mL of PBS in the left. Changes in SFT at 24 h was used to indicate CMIR. To assess AMIR, the titer of type 2 antigen-specific bovine immunoglobulin G in serum from blood collected on day 14 was determined by measuring optical density (OD) using an enzyme-linked immunosorbent assay (ELISA). Among heifers, AMIR was greater for the POST-WEANING group than for the WEANING group (P < 0.01). Among steers, AMIR was not different between the POST-WEANING group and the WEANING group (P = 1.0). Therefore, the AMIR of heifers may be more negatively affected by immunophenotyping at weaning than the AMIR of steers. For steers, CMIR was greater in the POST-WEANING group than the WEANING group (P < 0.001). For heifers, CMIR was not different between the POST-WEANING group and the WEANING group (P = 0.22). The CMIR of steers may be more negatively affected by immunophenotyping at weaning than the CMIR of heifers. Calf age was not associated with AMIR or CMIR for calves phenotyped at weaning or post-weaning. The effect of sire nested within dam age was significant for CMIR for calves in the POST-WEANING group (P < 0.01), but not for calves in the WEANING group (P = 0.67). The results suggest that measuring immunocompetence at weaning may not be representative of a calf's genetic ability to mount an effective immune response, and immunophenotyping should be performed outside the weaning period.

Transmission of H9N2 Low Pathogenicity Avian Influenza Virus (LPAIV) in a Challenge-Transmission Model

Migratory birds are major reservoirs for avian influenza viruses (AIV), which can be transmitted to poultry and mammals. The H9N2 subtype of AIV has become prevalent in poultry over the last two decades. Despite that, there is a scarcity of detailed information on how this virus can be transmitted. The current study aimed to establish a direct contact model using seeder chickens infected with H9N2 AIV as a source of the virus for transmission to recipient chickens. Seeder chickens were inoculated with two different inoculation routes either directly or via the aerosol route. The results indicate that inoculation via the aerosol route was more effective at establishing infection compared to the direct inoculation route. Shedding was observed to be higher in aerosol-inoculated seeder chickens, with a greater percentage of chickens being infected at each time point. In terms of transmission, the recipient chickens exposed to the aerosol-inoculated seeder chickens had higher oral and cloacal virus shedding compared to the recipient chickens of the directly inoculated group. Furthermore, the aerosol route of infection resulted in enhanced antibody responses in both seeder and recipient chickens compared to the directly inoculated group. Overall, the results confirmed that the aerosol route is a preferred inoculation route for infecting seeder chickens in a direct contact transmission model.

Immuno-phenotyping of Canadian Beef Cattle: Adaptation of the High Immune Response Methodology for Utilization in Beef Cattle

The high immune response (HIR) methodology measures the genetic performance of the adaptive immune system to identify and breed animals with balanced and robust immunity. The HIR methodology has previously been used in dairy and swine to reduce disease but has not been fully investigated in beef cattle. The first objective of the current study was to examine whether the HIR methodology as standardized for use in dairy cattle was appropriate for use in beef cattle. The second objective was to determine the earliest age for immune response phenotyping of beef calves. In this study, beef calves (n = 295) of various ages, as well as mature beef cows (n = 170) of mixed breeds, were immunized using test antigens to assess their antibody- (AMIR) and cell-mediated immune responses (CMIR). Heritability for AMIR and CMIR was estimated at 0.43 and 0.18, respectively. The HIR methodology was appropriate for use in beef cattle; beef calves as young as 2–3 wk of age were capable of mounting AMIR responses comparable with those seen historically in mature Holstein dairy cows. Three-week-old beef calves mounted CMIR responses comparable with those of Holstein cows, but 9-mo-old calves and mature beef cows had significantly higher CMIR responses than Holsteins. The HIR methodology can be used to measure both AMIR and CMIR in beef calves as young as 3 wk of age.

Concentration and heritability of immunoglobulin G and natural antibody immunoglobulin M in dairy and beef colostrum along with serum total protein in their calves

Immunoglobulin (Ig) G and natural antibody (NAb) IgM are passively transferred to the neonatal calf through bovine colostrum. Maternal IgG provides pathogen- or vaccine-specific protection and comprises about 85 percent of colostral Ig. Natural antibody IgM is less abundant but provides broad and non-specific reactivity, potentially contributing to protection against the dissemination of pathogens in the blood (septicemia) in a calf's first days of life. In the dairy and beef industries, failure of passive transfer (FPT) of colostral Ig (serum total protein (STP) <5.2 g/dL) is still a common concern. The objectives of this study were to, i) compare colostral IgG concentrations and NAb-IgM titers between dairy and beef cows; ii) assess the effect of beef breed on colostral IgG; iii) compare passive transfer of colostral Ig in dairy and beef calves; and iv) estimate the heritability of colostral IgG and NAb-IgM. Colostrum was collected from Holstein dairy (n=282) and crossbred beef (n=168) cows at the University of Guelph dairy and beef research centres. Colostral IgG was quantified by radial immunodiffusion and NAb-IgM was quantified by an enzyme-linked immunosorbent assay. In dairy (n=308) and beef (n=169) calves, STP was estimated by digital refractometry. Beef cows had significantly greater colostral IgG (146.5 ± 9.5 SEM g/L) than dairy cows (92.4 ± 5.2 g/L, p <0.01). Beef cows with a higher proportion of Angus ancestry had significantly lower colostral IgG (125.5 ± 5.8 g/L) than cows grouped as "Other" (142.5 ± 4.9 g/L, p= 0.02). Using the FPT cut-off, 13% of dairy and 16% of beef calves had FPT; still, beef calves had a significantly larger proportion with excellent passive transfer (STP ≥6.2 g/dL, p <0.01). The heritability of colostral IgG was 0.04 (± 0.14) in dairy and 0.14 (± 0.32) in beef. Colostral NAb-IgM titers in dairy (12.12 ± 0.22, log2 (reciprocal of titer)) and beef cows (12.03 ± 0.19) did not differ significantly (p=0.71). The range of NAb-IgM titers was 9.18 to 14.60, equivalent to a 42-fold range in antibody concentration. The heritability of colostral NAb was 0.24 (± 0.16) in dairy and 0.11 (± 0.19) in beef cows. This study is the first to compare colostral NAb-IgM between dairy and beef cows. Based on the range in NAb-IgM titers and the heritability, selective breeding may improve colostrum quality and protection for neonatal calves in the early days of life.

Development of innate immunity in chicken embryos and newly hatched chicks: a disease control perspective

Newly hatched chickens are confronted by a wide array of pathogenic microbes because their adaptive immune defences have limited capabilities to control these pathogens. In such circumstances, and within this age group, innate responses provide a degree of protection. Moreover, as the adaptive immune system is relatively naïve to foreign antigens, synergy with innate defences is critical. This review presents knowledge on the ontogeny of innate immunity in chickens pre-hatch and early post-hatch and provides insights into possible interventions to modulate innate responses early in the life of the bird. As in other vertebrate species, the chicken innate immune system which include cellular mediators, cytokine and chemokine repertoires and molecules involved in antigen detection, develop early in life. Comparison of innate immune systems in newly hatched chickens and mature birds has revealed differences in magnitude and quality, but responses in younger chickens can be boosted using innate immune system modulators. Functional expression of pattern recognition receptors and several defence molecules by innate immune system cells of embryos and newly hatched chicks suggests that innate responses can be modulated at this stage of development to combat pathogens. Improved understanding of innate immune system ontogeny and functionality in chickens is critical for the implementation of sound and safe interventions to provide long-term protection against pathogens. Next-generation tools for studying genetic and epigenetic regulation of genes, functional metagenomics and gene knockouts can be used in the future to explore and dissect the contributions of signalling pathways of innate immunity and to devise more efficacious disease control strategies.

398 Effects of protein level and supplemental methionine in late-gestation on colostrum quality and passive immunity transfer in beef cattle

The objective of this study was to evaluate the influence of metabolizable protein (MP) level and supplemental rumen-protected methionine (RPM) on colostrum quality and passive immunity transfer from beef cows fed during late-gestation. One hundred and forty-seven pregnant Angus crossbred cows and heifers were randomly assigned to one of six dietary treatments based on a 3 x 2 factorial arrangement. Diets included feeding to 90%, 100% and 110% MP requirements (NRC, 2016), offered with (without) 9 g/d of RPM. Cattle were individually fed a partially mixed ration (60% haylage/40% straw for cows; 70% haylage/30% straw for heifers) with supplements top-dressed daily for approximately 56 d prior to calving. Immediately after calving, a colostrum sample was collected from each dam for analysis of milk components, total protein, and IgG concentrations. Two d post-calving, serum samples were collected from each calf for analysis of total protein and IgG concentrations. A refractometer was used to estimate total protein as a preliminary estimate of the transfer of maternal IgG and total IgG concentrations were later determined using Radial Immunodiffusion (RID). Data were analyzed as a completely randomized block design using Proc GLIMMIX in SAS. Level of MP, RPM, and their interaction did not influence concentrations of fat, protein, BHB or SCC in colostrum (P ≥ 0.12). Supplementation of RPM decreased concentrations of MUN (45.92 vs. 54.51 ±3.17 mg/dl; P = 0.04), but did not change IgG (14.66 vs. 15.90 ±0.87 g/dl; P = 0.29). While MP level during gestation did not affect total protein or IgG concentrations in calf serum (P ≥ 0.64), providing supplemental RPM decreased total protein (5.79 vs. 6.33 ±0.13 g/dl; P = 0.002) and IgG concentrations in calf serum (3.44 vs. 4.30 ±0.25 g/dl; P = 0.01). These results suggest that providing supplemental methionine for beef cows during gestation may alter colostrum quality and decrease serum protein and IgG in offspring.

Gut microbiota-mediated protection against influenza virus subtype H9N2 in chickens is associated with modulation of the innate responses

Commensal gut microbiota plays an important role in health and disease. The current study was designed to assess the role of gut microbiota of chickens in the initiation of antiviral responses against avian influenza virus. Day-old layer chickens received a cocktail of antibiotics for 12 (ABX-D12) or 16 (ABX-D16) days to deplete their gut microbiota, followed by treatment of chickens from ABX-12 with five Lactobacillus species combination (PROB), fecal microbial transplant suspension (FMT) or sham treatment daily for four days. At day 17 of age, chickens were challenged with H9N2 virus. Cloacal virus shedding, and interferon (IFN)-α, IFN-β and interleukin (IL)-22 expression in the trachea, lung, ileum and cecal tonsils was assessed. Higher virus shedding, and compromised type I IFNs and IL-22 expression was observed in ABX-D16 chickens compared to control, while PROB and FMT showed reduced virus shedding and restored IL-22 expression to levels comparable with undepleted chickens. In conclusion, commensal gut microbiota of chickens can modulate innate responses to influenza virus subtype H9N2 infection in chickens, and modulating the composition of the microbiome using probiotics- and/or FMT-based interventions might serve to promote a healthy community that confers protection against influenza virus infection in chickens.

PLGA-encapsulated CpG ODN and Campylobacter jejuni lysate modulate cecal microbiota composition in broiler chickens experimentally challenged with C. jejuni

Campylobacter jejuni is a leading bacterial cause of human gastroenteritis. Reducing Campylobacter numbers in the intestinal tract of chickens will minimize transmission to humans, thereby reducing the incidence of infection. We have previously shown that oral pre-treatment of chickens with C. jejuni lysate and Poly D, L-lactide-co-glycolide polymer nanoparticles (PLGA NPs) containing CpG oligodeoxynucleotide (ODN) can reduce the number of C. jejuni in infected chickens. In the current study, the effects of these pre-treatments on the composition and functional diversity of the cecal microbiota, in chickens experimentally infected with C. jejuni, were investigated using next-generation sequencing. The taxonomic composition analysis revealed a reduction in cecal microbial diversity and considerable changes in the taxonomic profiles of the microbial communities of C. jejuni-challenged chickens. On the other hand, irrespective of the dose, the microbiota of PLGA-encapsulated CpG ODN- and C. jejuni lysate-treated chickens exhibited higher microbial diversity associated with high abundance of members of Firmicutes and Bacteroidetes and lower numbers of Campylobacter than untreated-chickens. These findings suggest that oral administration of encapsulated CpG ODN and C. jejuni lysate can reduce colonization by C. jejuni by enhancing the proliferation of specific microbial groups. The mechanisms that mediate these changes remain, however, to be elucidated.

Oral administration of PLGA-encapsulated CpG ODN and Campylobacter jejuni lysate reduces cecal colonization by Campylobacter jejuni in chickens

Campylobacter jejuni (C. jejuni) is a major cause of bacterial food-borne illness in humans. It is considered a commensal organism of the chicken gut and infected chickens serve as a reservoir and shed bacteria throughout their lifespan. Contaminated poultry products are considered the major source of infection in humans. Therefore, to reduce the risk of human campylobacteriosis, it is essential to reduce the bacterial load in poultry products. The present study aimed to evaluate the protective effects of soluble and PLGA-encapsulated oligodeoxynucleotides (ODN) containing unmethylated CpG motifs (E-CpG ODN) as well as C. jejuni lysate as a multi-antigen vaccine against colonization with C. jejuni. The results revealed that oral administration of a low (5 µg) or high (50 µg) dose of CpG resulted in a significant reduction in cecal C. jejuni colonization by 1.23 and 1.32 log₁₀ (P < .05) in layer chickens, respectively, whereas E-CpG significantly reduced cecal C. jejuni colonization by 1.89 and 1.46 log₁₀ in layer and broiler chickens at day 22 post-infection (slaughter age in broilers), respectively. Similar patterns were observed for C. jejuni lysate; oral administration of C. jejuni lysate reduced the intestinal burden of C. jejuni in layer and broiler chickens by 2.24 and 2.14 log₁₀ at day 22 post-infection, respectively. Moreover, the combination of E-CpG and C. jejuni lysate reduced bacterial counts in cecal contents by 2.42 log₁₀ at day 22 post-infection in broiler chickens. Anti-C. jejuni IgG antibody (Ab) titers were significantly higher for broiler chickens receiving a low or high dose of E-CpG or a low dose of C. jejuni lysate than for chickens receiving the placebo. Furthermore, a positive correlation was observed between serum IgG Ab titers and cecal counts of C. jejuni in these groups. These findings suggest that PLGA-encapsulated CpG or C. jejuni lysate could be a promising strategy for control of C. jejuni in chickens.

Effectiveness of problem gambling interventions in a service setting: a protocol for a pragmatic randomised controlled clinical trial

INTRODUCTION

The primary purpose of this study is to evaluate the relative effectiveness of 2 of the best developed and most promising forms of therapy for problem gambling, namely face-to-face motivational interviewing (MI) combined with a self-instruction booklet (W) and follow-up telephone booster sessions (B; MI+W+B) and face-to-face cognitive-behavioural therapy (CBT).

METHODS AND ANALYSIS

This project is a single-blind pragmatic randomised clinical trial of 2 interventions, with and without the addition of relapse-prevention text messages. Trial assessments take place pretreatment, at 3 and 12 months. A total of 300 participants will be recruited through a community treatment agency that provides services across New Zealand and randomised to up to 10 face-to-face sessions of CBT or 1 face-to-face session of MI+W+up to 5 B. Participants will also be randomised to 9 months of postcare text messaging. Eligibility criteria include a self-perception of having a current gambling problem and a willingness to participate in all components of the study (eg, read workbook). The statistical analysis will use an intent-to-treat approach. Primary outcome measures are days spent gambling and amount of money spent per day gambling in the prior month. Secondary outcome measures include problem gambling severity, gambling urges, gambling cognitions, mood, alcohol, drug use, tobacco, psychological distress, quality of life, health status and direct and indirect costs associated with treatment.

ETHICS AND DISSEMINATION

The research methods to be used in this study have been approved by the Ministry of Health, Health and Disability Ethics Committees (HDEC) 15/CEN/99. The investigators will provide annual reports to the HDEC and report any adverse events to this committee. Amendments will also be submitted to this committee. The results of this trial will be submitted for publication in peer-reviewed journals and as a report to the funding body. Additionally, the results will be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12615000637549.

Characterization of Innate Responses Induced by PLGA Encapsulated- and Soluble TLR Ligands In Vitro and In Vivo in Chickens

Natural or synthetic Toll-like receptor (TLR) ligands trigger innate responses by interacting with distinct TLRs. TLR ligands can thus serve as vaccine adjuvants or stand-alone antimicrobial agents. One of the limitations of TLR ligands for clinical application is their short half-life and rapid clearance from the body. In the current study, encapsulation of selected TLR ligands in biodegradable poly(D,L-lactide-co-glycolide) polymer nanoparticles (PLGA NPs) was examined in vitro and in vivo as a means to prolong innate responses. MQ-NCSU cells (a chicken macrophage cell line) were treated with encapsulated or soluble forms of TLR ligands and the resulting innate responses were evaluated. In most cases, encapsulated forms of TLR ligands (CpG ODN 2007, lipopolysaccharide and Pam3CSK4) induced comparable or higher levels of nitric oxide and cytokine gene expression in macrophages, compared to the soluble forms. Encapsulated CpG ODN, in particular the higher dose, induced significantly higher expression of interferon (IFN)-γ and IFN-β until at least 18 hr post-treatment. Cytokine expression by splenocytes was also examined in chickens receiving encapsulated or soluble forms of lipopolysaccharide (a potent inflammatory cytokine inducer in chickens) by intramuscular injection. Encapsulated LPS induced more sustained innate responses characterized by higher expression of IFN-γ and IL-1β until up to 96 hr. The ability of TLR ligands encapsulated in polymeric nanoparticles to maintain prolonged innate responses indicates that this controlled-release system can extend the use of TLR ligands as vaccine adjuvants or as stand-alone prophylactic agents against pathogens.

Characterization of Immune Responses to an Inactivated Avian Influenza Virus Vaccine Adjuvanted with Nanoparticles Containing CpG ODN

Avian influenza virus (AIV), a mucosal pathogen, gains entry into host chickens through respiratory and gastrointestinal routes. Most commercial AIV vaccines for poultry consist of inactivated, whole virus with adjuvant, delivered by parenteral administration. Recent advances in vaccine development have led to the application of nanoparticle emulsion delivery systems, such as poly (d,l-lactic-co-glycolic acid) (PLGA) nanoparticles to enhance antigen-specific immune responses. In chickens, the Toll-like receptor 21 ligand, CpG oligodeoxynucleotides (ODNs), have been demonstrated to be immunostimulatory. The objective of this study was to compare the adjuvant potential of CpG ODN 2007 encapsulated in PLGA nanoparticles with nonencapsulated CpG ODN 2007 when combined with a formalin-inactivated H9N2 virus, through intramuscular and aerosol delivery routes. Chickens were vaccinated at days 7 and 21 posthatch for the intramuscular route and at days 7, 21, and 35 for the aerosol route. Antibody-mediated responses were evaluated weekly in sera and lacrimal secretions in specific pathogen-free chickens. The results indicate that nonencapsulated CpG ODN 2007 in inactivated AIV vaccines administered by the intramuscular route generated higher antibody responses compared to the encapsulated CpG ODN 2007 formulation by the same route. Additionally, encapsulated CpG ODN 2007 in AIV vaccines administered by the aerosol route elicited higher mucosal responses compared to nonencapsulated CpG ODN 2007. Future studies may be aimed at evaluating protective immune responses induced with PLGA encapsulation of AIV and adjuvants.

Short communication: Variation of total immunoglobulin G and β-lactoglobulin concentrations in colostrum and milk from Canadian Holsteins classified as high, average, or low immune responders

The objective of this study was to evaluate IgG and β-lactoglobulin (β-LG) concentrations in colostrum and milk of Canadian Holsteins (n=108) classified as high (H), average (A), or low (L) for antibody-mediated (AMIR) or cell-mediated immune responses (CMIR) based on estimated breeding values. It was hypothesized that H-AMIR and H-CMIR cows produce colostrum (first milking) and milk (d 5 postcalving) with higher concentrations of IgG and β-LG. Data for IgG and β-LG in colostrum and milk were analyzed independently using mixed linear models. Least squares means were compared using Tukey's test. Cows classified as H-AMIR had higher IgG and β-LG concentrations in colostrum compared with A- and L-AMIR cows; 84% of H-AMIR, 69% of A-AMIR, and 68% of L-AMIR cows had over 5,000 mg/dL IgG in colostrum. No differences in IgG and β-LG concentrations in colostrum were noted among cows ranked on CMIR or in milk of cows ranked on AMIR. β-Lactoglobulin and IgG concentrations were positively correlated in colostrum. Breeding cows for H-AMIR status may reduce failure of passive transfer of IgG in their calves; β-LG may play a role in bovine immune defenses. Colostrum from H-AMIR cows may serve as a more economical feedstock source for manufacturing natural health products.

Lactobacillus and Lactobacillus cell-free culture supernatants modulate chicken macrophage activities

Lactobacilli are commensal microbes that reside in the intestines of several species, including chickens. Structural constituents of lactobacilli are able to stimulate the host immune system. Macrophages are crucial players in both innate and adaptive immune systems. Here, we investigated the effects of Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus salivarius and their cell-free culture supernatants on the pro-inflammatory gene expression profile, nitric oxide (NO) production and phagocytosis by chicken macrophages. Substantial differences were found among Lactobacillus strains in their capacity to induce pro-inflammatory cytokines. L. acidophilus only up-regulated interferon (IFN)-γ, while L. reuteri and L. salivarius up-regulated interleukin (IL)-1β, IL-6, IL-8 and IL-12 expression. Supernatant of L. salivarius up-regulated IL-1β, IL-8 and IFN-γ expression, while the other cell-free supernatants did not induce significant changes. Moreover, L. reuteri and L. salivarius increased macrophage phagocytosis, but all cell-free supernatants increased macrophage NO production and did not change phagocytosis activity.

Systemic immune responses to an inactivated, whole H9N2 avian influenza virus vaccine using class B CpG oligonucleotides in chickens

Commercial vaccines against avian influenza viruses (AIV) in chickens consist mainly of inactivated AIV, requiring parenteral administration and co-delivery of an adjuvant. Limitations in T helper 1 or T helper 2 biased responses generated by these vaccines emphasize the need for alternative, more efficacious adjuvants. The Toll-like receptor (TLR) 21 ligand, CpG oligodeoxynucleotides (ODN), has been established as immunomodulatory in chickens. Therefore, the objective of this study was to investigate the adjuvant potential of high (20μg) and low (2μg) doses of CpG ODN 2007 (CpG 2007) and CpG ODN 1826 (CpG 1826) when administered to chickens with a formalin-inactivated H9N2 AIV. Antibody responses in sera were evaluated in 90 specific pathogen free (SPF) chickens after intramuscular administration of vaccine formulations at 7 and 21 days post-hatch. Antibody responses were assessed based on haemagglutination inhibition (HI) and virus neutralization (VN) assays; virus-specific IgM and IgY antibody responses were evaluated by ELISA. The results suggest that the vaccine formulation containing low dose CpG 2007 was significantly more effective at generating neutralizing (both HI and VN) responses than formulations with high or low doses of CpG 1826 or high dose CpG 2007. Neutralizing responses elicited by low dose CpG 2007 significantly exceeded those generated by a squalene-based adjuvanted vaccine formulation during peak responses. A significantly higher IgM response was elicited by the formulation containing low dose CpG 2007 compared to high and low doses of 1826. Although the low dose of CpG 2007 elicited a higher IgY response than CpG 1826, the difference was not statistically significant. In conclusion, 2μg of CpG 2007 is potentially promising as a vaccine adjuvant when delivered intramuscularly with inactivated H9N2 virus to chickens. Future studies may be directed at determining the mucosal antibody responses to the same vaccine formulations.

Evaluation of a polysaccharide conjugate vaccine to reduce colonization by Campylobacter jejuni in broiler chickens

Background

Campylobacter jejuni is a leading bacterial cause of food-borne illness in humans. Symptoms range from mild gastroenteritis to dysentery. Contaminated chicken meat is the most common cause of infection. Broiler chickens become colonized with high numbers of C. jejuni in the intestinal tract, but do not become clinically ill. Vaccination of broiler chicks to control colonization by C. jejuni is challenging because immune function is limited in the first 2 weeks post-hatch and immune suppressive maternal antibodies are common. In addition, there is little time for induction of immunity, since broilers reach slaughter weight by 5–6 weeks of age. In the current study the immunogenicity of a C. jejuni capsular polysaccharide—diphtheria toxoid conjugated vaccine (CPSconj), administered subcutaneously with various adjuvants was assessed and the efficacy of vaccination for reducing cecal colonization after experimental challenge was evaluated by determining colony-forming units (CFU) of C. jejuni in cecal contents.

Results

The CPSconj vaccine was immunogenic when administered as three doses at 3, 4 and 5 weeks of age to specific pathogen free chicks lacking maternal antibodies (seroconversion rates up to 75%). Commercial broiler chicks (having maternal antibodies) receiving two doses of CPSconj vaccine at 7 and 21 days of age did not seroconvert before oral challenge at 29 days, but 33% seroconverted post challenge; none of the placebo-injected, challenged birds seroconverted. Vaccinated birds had significantly lower numbers of C. jejuni in cecal contents than control birds at necropsy (38 days of age). CFU of C. jejuni did not differ significantly among groups of birds receiving CPSconj vaccine with different adjuvants. In two trials, the mean reduction in CFU associated with vaccination was 0.64 log₁₀ units.

Conclusions

The CPSconj vaccine was immunogenic in chicks lacking maternal antibodies, vaccinated beginning at 3 weeks of age. In commercial broiler birds (possessing maternal antibodies) vaccinated at 7 and 21 days of age, 33% of birds seroconverted by 9 days after challenge, and there was a modest, but significant, reduction in cecal counts of C. jejuni. Further studies are needed to optimize adjuvant, route of delivery and scheduling of administration of this vaccine.

Investigation of a commercial ELISA for the detection of canine procalcitonin

Background

Rapid identification of sepsis enables prompt administration of antibiotics and is essential to improve patient survival. Procalcitonin (PCT) is a biomarker used to diagnose sepsis in people. Commercial assays to measure canine PCT peptide have not been validated.

Objective

To investigate the validity of a commercially available enzyme‐linked immunosorbent assay (ELISA) marketed for the measurement of canine PCT.

Animals

Three dogs with sepsis, 1 healthy dog, 1 dog with thyroid carcinoma.

Methods

Experimental study. The ELISA's ability to detect recombinant and native canine PCT was investigated and intra‐assay and interassay coefficients of variability were calculated. Assay validation including mass spectrometry of the kit standard solution was performed.

Results

The ELISA did not consistently detect recombinant canine PCT. Thyroid lysate yielded a positive ELISA signal. Intra‐assay variability ranged from 18.9 to 77.4%, while interassay variability ranged from 56.1 to 79.5%. Mass spectrometry of the standard solution provided with the evaluated ELISA kit did not indicate presence of PCT.

Conclusions and Clinical Importance

The results of this investigation do not support the use of this ELISA for the detection of PCT in dogs.

Factors associated with morbidity, mortality, and growth of dairy heifer calves up to 3 months of age

Calfhood disease is an important problem on many dairy operations that can have substantial effects on heifer survival and productivity, and has economic and welfare impacts. Neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) are the most common causes of morbidity and mortality in young dairy cattle. The objective of this observational study was to investigate factors associated with the risks of morbidity and mortality, and with growth, in commercial dairy heifers calves. A total of 2874 heifer calves from 19 commercial dairy farms in Minnesota and Ontario were enrolled at 1-7 days of age and followed for approximately 3 months. Using cut-points of serum total protein of 5.2 and 5.7 g/dl, the incidences of failure of transfer of passive immunity (FTPI) were 11 and 32%, respectively. A cut-point of 5.7 g/dl was the most predictive of BRD before 5 weeks of age (sensitivity=40%, specificity=69%). The positive predictive value was poor (PPV=18%), but the negative predictive value was good (NPV=87%). A cut-point of 5.2g/dl was most predictive of death before 5 weeks of age (sensitivity=27%, specificity=89%, PPV=5%, NPV=98%). Serum total protein during the first week of life was a poor predictor of NCD. Over 23% of calves were treated for diarrhea. Risk factors were weight at enrollment, other diseases before 2 weeks of age, and an interaction between season of birth and herd-level incidence of NCD. Almost 22% of calves were treated at least once for BRD. Factors associated with an increased risk of BRD included herd-level incidence of BRD, season of birth, navel dipping, other diseases before 2 weeks of age, failure of transfer of passive immunity, and manual control of temperature in pre-weaning housing. Administration of supplemental antibody products at birth was associated with a reduced incidence of BRD. Overall mortality was 3.5%. Risk of mortality was increased by treatment for BRD and other diseases. The mean average weight gain was 0.95 kg/day (range: 0.11-1.62 kg/day; SD=0.2). Twinning status, FTP, treatment for NCD or other diseases, and month of birth influenced body weight. This study illustrated relationships among various diseases, mortality, and growth. Furthermore, it demonstrated the importance of colostrum for protection against BRD and improved growth performance, while bringing into question the optimal method of determining failure of transfer of passive immunity.

Induction of chicken cytokine responses in vivo and in vitro by lipooligosaccharide of Campylobacter jejuni HS:10

Campylobacter jejuni is a pathogen of the gastrointestinal tract of humans, but colonizes chickens for prolonged periods without causing disease. It is unclear what host and bacterial mechanisms maintain a non-inflammatory state in chickens. The present work was undertaken to characterize cytokine responses of chickens to purified lipooligosaccharide (LOS) of C. jejuni HS:10. Chickens were injected with purified LOS, and expression of interleukin (IL)-1β (pro-inflammatory cytokine), IL-8 (pro-inflammatory chemokine), interferon (IFN)γ (Th1-like cytokine), IL-10 (immune regulatory/anti-inflammatory cytokine) and IL-13 (Th2-like cytokine) was evaluated in spleen using quantitative RT-PCR, up to 24h post-injection. In an in vitro study, splenocytes were incubated with LOS, and cytokine expression followed up to 18 h. Chickens injected with LOS had increased expression of IL-1β up to 24h later. Expression of IL-8 was significantly increased at 2h but then declined below baseline. Expression of IFNγ and IL-10 was increased significantly at 2h, but declined thereafter. Splenocytes incubated with LOS had increased expression of IL-1β and IL-8 up to 18 h of incubation. Expression of IFNγ was increased at 6 and 18 h, IL-10 was increased at 2h, but expression of IL-13 did not differ significantly up to 18h. It is concluded that LOS of C. jejuni can induce expression of pro-inflammatory IL-1β and IL-8, as well as IFNγ and IL-10 in chickens. More extensive studies with more prolonged exposure to LOS are needed to further clarify the interaction between C. jejuni and the chicken host.

Expression of complement receptors 1 (CR1/CD35) and 2 (CR2/CD21), and co-signaling molecule CD19 in cattle

C3d is a sub-fragment of the C3 component of the complement system. Covalent binding of multiple C3ds to antigen reduces the activation threshold of cognate B lymphocytes by one thousand fold through co-ligation of the B cell antigen receptor (BCR) and complement receptor 2 (CR2/CD21). Reverse transcriptase polymerase chain reaction (RT-PCR) revealed that, in cattle, four distinct complement receptors are produced from the Cr2 gene by alternative splicing. Cattle express two major variants of the Cr2 gene representing homologues of murine CR1 and CR2, each of which is expressed in both a long and a short form. Expression of CR1 and CR2 was detected in IgM(+) cells from both the spleen and peripheral blood. Additionally, the coding sequence of CD19, the CR2 co-signaling molecule, was determined. CD19 was confirmed to be expressed by IgM(+) cells from the spleen and peripheral blood.

Disordered gambling among higher-frequency gamblers: who is at risk?

BACKGROUND

When gambling opportunities are made available to the public in a given jurisdiction, some individuals participate occasionally and others more frequently. Among frequent gamblers, some individuals develop problematic involvement and some do not. This study addresses the association among demographic and social risk factors, frequency of gambling and gambling disorders.

METHOD

Data from an adult community sample (n=1372) were used to identify risk factors for higher-frequency gambling and disordered gambling involvement.

RESULTS

Individuals with higher intelligence, older individuals and more religious individuals were less frequent gamblers. Males, single individuals and those exposed to gambling environments (friends and family who gamble) and those who started to gamble at a younger age were more frequent gamblers. Excitement-seeking personality traits were also higher among more frequent gamblers. A different set of risk factors was associated with the likelihood of gambling disorder among these higher-frequency gamblers. These variables included mental health indicators, childhood maltreatment and parental gambling involvement. Among higher-frequency gamblers, individuals who smoke cigarettes, those with a diagnosis of alcohol or drug dependence or obsessive-compulsive disorder, those with higher anxiety or depression and those with higher impulsivity and antisocial personality traits were more likely to report gambling-related problems. These individuals were also more likely to report gambling on electronic gambling machines (e.g. slot machines).

CONCLUSIONS

These data suggest a model in which higher-frequency gambling, particularly with electronic gambling machines, when combined with any type of emotional vulnerability increased the likelihood of gambling disorder.

Serum IgG response in calves to the putative pneumonic virulence factor Gs60 of Mannheimia haemolytica A1

Bovine pneumonic pasteurellosis vaccines incorporate various antigens of Mannheimia haemolytica, including the acknowledged virulence factor leukotoxin (Lkt), and Gs60, a surface lipoprotein. To examine the role of antibodies to Gs60 in protection, an enzyme-linked immunosorbent assay (ELISA) was developed for retrospective analysis of serum samples from previous trials in which vaccines containing native or recombinant Gs60 were administered parenterally. The analysis revealed a positive correlation between the titer of antibodies to Gs60 and protection against experimental challenge in both vaccinates and naturally exposed controls. There was a strong correlation between production of IgG antibodies to Gs60 and Lkt neutralizing antibodies. Analysis of the relationship between the serum antibody titers and resistance to experimental challenge using linear statistical models revealed a significant association between prechallenge titers of serum antibodies to Lkt and protection. Further analysis suggested that antibodies against Gs60 were beneficial when Lkt neutralizing antibody titers were low.

Variation in expression of membrane IgM, CD21 (CR2) and CD32 (Fcgamma RIIB) on bovine lymphocytes with age: a longitudinal study

Typically, neonatal calves have poor active antibody responses to vaccination, attributed to immaturity of the neonatal immune system and suppressive effects of maternal (colostral) antibodies. Responses of naïve B cells are regulated by ligation of opposing activating (CD21, membrane IgM [mIgM]) and inhibitory (CD32) receptors. Expression of these receptors on blood lymphocytes of 15 calves, from birth to 6 months of age, was investigated by three-colour flow cytometry. Although the absolute number of mIgM(+) B lymphocytes was low in calves under 6 weeks, the intensity of mIgM expression per cell was significantly higher than for adults and >90% expressed both CD21 and CD32. The intensity of CD21 expression in calves did not differ significantly from adults, whereas CD32 expression was lower. Paradoxically, these findings suggest that responses of neonates should bias toward activation at the B cell level, warranting further investigation to reveal strategies for development of vaccines that are efficacious at an early age.

Porcine reproductive and respiratory syndrome virus as a vector: immunogenicity of green fluorescent protein and porcine circovirus type 2 capsid expressed from dedicated subgenomic RNAs

Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of PRRS, which is characterized by late-term abortions in sows and respiratory disease in young pigs. Using an infectious cDNA clone of North American PRRSV strain P129, the viral genome was engineered to transcribe an additional subgenomic RNA initiating between non-structural and structural genes. Two unique restriction sites and a copy of the transcription regulatory sequence for ORF6 (TRS6) were inserted between ORFs 1b and 2a, yielding a general purpose expression vector. The enhanced green fluorescent protein (GFP) gene was cloned between the unique sites such that the inserted gene was transcribed from TRS2 which was located upstream within ORF1b, while the copy of TRS6 drives ORF2a/b transcription. Upon transfection of cells with this plasmid, PRRSV infection was initiated and progeny virus "P129-GFP" was obtained. Cells infected with P129-GFP showed fluorescence and the inserted gene was phenotypically stable for at least 37 serial in vitro passages. Subsequently, a capsid (C) protein gene was cloned from porcine circovirus type 2 (PCV2) recovered from an outbreak of porcine multisystemic wasting syndrome (PMWS) and inserted into the PRRSV infectious clone vector, generating virus "P129-PCV". To determine the immunogenicity of the recombinant viruses, pigs were immunized intramuscularly with P129-WT (wild-type), P129-GFP, or P129-PCV2. By 5 weeks post-infection, specific antibody responses to GFP and PCV2 capsid were elicited. This is the first report of foreign gene expression using PRRSV from dedicated subgenomic RNAs and demonstrates the potential use of PRRSV as a vaccine vector for swine pathogens.

Challenges in mucosal vaccination of cattle

Recognition of the mucosal portal of entry for many infectious diseases and of the relevance of mucosal immune response to protection has encouraged the development of vaccines administered by mucosal routes, principally oral and intranasal, for stimulation of intestinal and nasopharyngeal lymphoid tissues respectively. The oral route is problematic in cattle and other ruminants where antigen degradation in the rumen is likely, prior to transit to the intestine. On the other hand, rumination can be exploited for exposure of nasopharyngeal tissues during cudding if vaccine antigen is expressed by a fibrous feed like alfalfa. An increase in anti-leukotoxin (Lkt) IgA was demonstrated in nasal secretions of calves following feeding of alfalfa expressing a truncated Lkt50 from Mannheimia haemolytica, and there is evidence suggesting that such vaccination may protect against experimentally induced pneumonia. Intranasal vaccination is an alternative approach for use in pre-ruminating calves. Intranasal administration of ISCOMs carrying soluble antigens of M. haemolytica, including native Lkt, induced Lkt specific IgA in nasal secretions after vaccination at 4 and 6 weeks of age. Subcutaneous (s.c.) administration of the same vaccine induced Lkt specific IgG in both serum and nasal secretions, whereas s.c. administration of a commercial M. haemolytica vaccine did not. Regardless of the vaccination strategy employed it is difficult to assess the immunogenicity of mucosally administered vaccines because production of secreted antibodies tends to be transient, and they do not persist on the mucosal surface in the absence of ongoing antigenic stimulation. An additional challenge is demonstration of vaccine efficacy in response to experimental infection. Protection of the mucosally vaccinated animal will most probably result from recall response, which may not amplify sufficiently to counter the effects of experimental pulmonary delivery of a large bolus of virulent bacteria, even though the response would suffice over the more prolonged and gradual infection that occurs in natural induction of pneumonia.

Functional mapping of the porcine reproductive and respiratory syndrome virus capsid protein nuclear localization signal and its pathogenic association

PRRSV (porcine reproductive and respiratory syndrome virus) nucleocapsid (N) protein is the most abundant structural protein of the virus. During infection, the N protein is specifically localized to the nucleus and nucleolus in addition to its normal cytoplasmic distribution. Previously, a nuclear localization signal (NLS, 41-PGKK(N/S)KKKN)-null mutant virus (41-PGGGNKKKN) showed reduced viremia and increased production of neutralizing antibodies in infected pigs. However, the mutagenized NLS underwent strong selection pressure in the pig that resulted in partial or complete reversion and reacquisition of NLS function, and thus the biological effect of the NLS-null mutation needed further investigation. In the present study, a total of 9 "reversion resistant" mutants were generated by amino acid deletions and substitutions using an infectious cDNA clone. Two mutant clones (PG--SKKKS and PG--S-KKS) that produced progeny viruses were genetically stable for at least 20 passages in cell culture. Infection of pigs with those mutants induced neutralizing antibodies to higher titers than with wild-type virus. Both mutant viruses induced viremia of lower titer and of shorter duration than wild-type virus. RT-PCR from tonsils showed that both mutants persisted at a reduced level. Virus transmission to contact pigs was also lower in the mutant virus infected groups. No reversion to functional NLS was detected in either mutant from any pig. These data demonstrate that N protein nuclear localization is indeed associated with viral pathogenesis and host response to PRRS.

Expression of a modified Mannheimia haemolytica GS60 outer membrane lipoprotein in transgenic alfalfa for the development of an edible vaccine against bovine pneumonic pasteurellosis

The GS60 antigen is one of the protective antigens of Mannheimia haemolytica A1. GS60 contains conserved domains belonging to the LppC family of bacterial outer membrane lipoproteins. A high antibody titer to GS60 has been shown to be significantly correlated with resistance to pneumonic pasteurellosis. Calves vaccinated with a commercial vaccine (Presponse) and demonstrating protection against M. haemolytica A1 produced antibodies directed against GS60. Alfalfa was chosen as the platform for an edible vaccine. Agrobacterium tumefaciens was used to mediate the transformation of alfalfa with sequences encoding a slightly shortened derivative of the GS60 antigen (GS60(54)). Stable transgenic alfalfa lines were recovered and production of GS60(54) was examined by Western immunoblot analysis. The antigen is stable in dried transgenic plant material stored at ambient temperature for more than a year. The plant-produced GS60(54) protein was shown to be immunogenic when injected into rabbits. Feeding of the dried transgenic alfalfa expressing the GS60(54) to rabbits is capable of inducing seroconversion, suggesting that GS60(54) could be an effective oral antigen for stimulating mucosal immune responses.

Cloning of a gene fragment encoding bovine complement component C3d with expression and characterization of derived fusion proteins

The gene fragment coding for bovine C3d gene (boC3d) was cloned and expressed as a component of fusion proteins destined for use in vaccine studies in cattle, and for in vitro experiments. This fragment of complement protein C3 (C3d) has been shown to enhance B cell responses when complexed with antigen. Three potential vaccine constructs were engineered to contain one, two or three boC3d units linked to a fragment of the leukotoxin of Mannheimia haemolytica A1, an economically important pathogen of cattle that causes a fibrinous pneumonia in calves. A recombinant biotinylated boC3d protein (for use in in vitro studies) was generated by endogenous biotinylation in Escherichia coli by means of the BirA holoenzyme synthetase. All recombinant proteins incorporated polyhistidine tags and were purified by nickel-agarose chromatography, then analyzed by SDS-PAGE and Western immunoblot. The identity of boC3d was confirmed by mass spectrometry, since monoclonal antibodies to boC3d were not available. To date, published research into the adjuvant activities of C3d has been limited to experiments in mice and rabbits, using antigens unrelated to diseases occurring naturally in these species. The boC3d fusion proteins expressed in this study will provide the basis for immunization trials in cattle and studies of receptor binding and cell activation of bovine lymphocytes.

Passive and active components of neonatal innate immune defenses

Innate immune defenses are crucial for survival in the first days and weeks of life. At birth, newborns are confronted with a vast array of potentially pathogenic microorganisms that were not encountered in utero. At this age, cellular components of the adaptive immune system are in a naive state and are slow to respond. Antibodies received from the dam are essential for defense, but represent a finite and dwindling resource. Innate components of the immune system detect pathogen-associated molecular patterns (PAMPs) on microorganisms (and their products) by means of pattern-recognition receptors (PRRs). Soluble mediators of the innate system such as complement proteins, pentraxins, collectins, ficolins, defensins, lactoferrin, lysozyme etc. can bind to structures on pathogens, leading to agglutination, interference with receptor binding, opsonization, neutralization, direct membrane damage and recruitment of additional soluble and cellular elements through inflammation. Cell-associated receptors such as the Toll-like receptors (TLRs) can activate cells and coordinate responses (both innate and adaptive). In this paper, accumulated knowledge of the receptors, soluble and cellular elements that contribute to innate defenses of young animals is reviewed. Research interest in this area has been intermittent, and the literature varies in quantity and quality. It is hoped that documentation of the limitations of our knowledge base will lead to more extensive and enlightening studies.

Homotypic and Heterotypic Serum Isotype–Specific Antibody Responses to Rotavirus Nonstructural Protein 4 and Viral Protein (VP) 4, VP6, and VP7 in Infants Who Received Selected Live Oral Rotavirus Vaccines

Homotypic and heterotypic serum isotype-specific antibody responses to rotavirus enterotoxin nonstructural protein (NSP)-4, independent neutralization antigens viral protein (VP)-4 and VP7, and group A rotavirus common antigen VP6 were analyzed by an immunocytochemistry assay in infants who received 1 of several live oral rotavirus vaccines. Significant serum immunoglobulin (Ig) A and IgG antibody responses to homotypic and/or heterotypic NSP4s of genotype [A], [B], or [C] were detected after vaccination. The magnitude of antibody responses to homotypic and heterotypic NSP4s was not significantly different, irrespective of the NSP4 genotype of the administered vaccine strain. In addition, there were no significant differences between IgA antibody responses to homotypic and heterotypic VP7s. In contrast, IgA antibody responses to VP4 were predominantly homotypic. IgA antibody responses to VP7 were lower in magnitude than those to VP4 but were comparable to those to NSP4. Antibody titers to homotypic and/or heterotypic NSP4s were positively correlated with those to VP6 before and after vaccination.

Efficacy of recombinant sialoglycoprotease in protection of cattle against pneumonic challenge with Mannheimia (Pasteurella) haemolytica A1

Secreted recombinant sialoglycoprotease fusion protein (Gcp-F) of Mannheimia (Pasteurella) haemolytica A1 was examined for its ability to protect cattle from experimental challenge with M. haemolytica A1. Five M. haemolytica vaccines were compared including Gcp-F, logarithmic phase culture supernate (Presponse) and Presponse enriched with Gcp-F, recombinant leukotoxin (rLkt) or both. All calves receiving Gcp-F had significant serum antibody responses to this antigen, measured by ELISA, prior to challenge. Those vaccinated with Gcp-F alone had significantly lower percent pneumonic tissue than unvaccinated controls and a trend (P=0.085, one-tailed test) to lower clinical scores. Calves receiving Presponse with Gcp-F and rLkt had lower percent pneumonic tissue than those receiving Presponse alone, and calves receiving Presponse enriched with Gcp-F and/or rLkt had lower mean clinical scores, but the differences were not significant. This trial demonstrates the protective capacity of sialoglycoprotease. While, remarkably, recombinant Gcp-F provided some protection alone the results support its practical potential as a component of a multiple antigen vaccine.

Influence of depression and gender on smoking expectancies and temptations in alcoholics in early recovery

PURPOSE

Rates of smoking are much higher among persons with alcohol problems and a history of depressive illness than persons without those disorders. Drug use in general may be motivated by outcome expectancies such as negative affective reduction and relaxation. Persons with a history of depression may smoke as a means of mood management. The role of outcome expectancies and major depression in maintaining smoking behavior in a high-risk group of smokers, such as recovering alcoholics, has not been thoroughly examined.

METHODS

Using a cross-sectional design, 161 abstinent alcohol-dependent men and women who smoked were administered the Inventory to Diagnose Depression (IDD), a self-report instrument for assessing current and lifetime depression according to DSM-IV criteria, and measures of alcohol dependence, nicotine dependence, smoking motives, and situation-defined temptations to smoke.

RESULTS

As expected, smoking motives and temptations were moderated by history of depression. Alcoholics with a history of depression were more likely to smoke with the expectancy of negative affect reduction than those with no prior major depression. Using multiple regression, negative affective reduction, addiction, and severity of past depression were the strongest predictors of current temptations to smoke.

IMPLICATIONS

These results suggest that individuals with a combined history of alcoholism and major depression are at a high risk to use smoking as a means of mood enhancement.

Antibody-secreting cell responses to rotavirus proteins in gnotobiotic pigs inoculated with attenuated or virulent human rotavirus

Because of their similarities to infants in mucosal immune responses and their susceptibility to human rotavirus (HRV) diarrhea, gnotobiotic pigs provide a useful model for rotaviral disease. In this study, we performed quantitative enzyme-linked immunospot (ELISPOT) assays to measure local and systemic isotype-specific antibody-secreting cell (ASC) responses to individual structural (VP4, VP6, and VP7) and nonstructural (NSP3 and NSP4) proteins of Wa HRV. The Spodoptera frugiperda cells expressing each recombinant baculovirus HRV protein were formalin fixed and used as antigen for ELISPOT assays. Neonatal gnotobiotic pigs were orally inoculated once with virulent Wa (WaV) or three times with attenuated Wa (WaA) HRV or mock inoculated (Mock) and then were challenged with virulent Wa (WaV/PC) 28 days after the first inoculation. The ASCs from intestinal and systemic lymphoid tissues of pigs from each group were quantitated by ELISPOT assay at the day of challenge, at postinoculation day 28 (WaV, WaA, and Mock) or at postchallenge day (PCD) 7 (WaV+WaV/PC, WaA+WaV/PC, and Mock+WaV/PC). In all virus-inoculated pigs, regardless of the inoculum, lymphoid tissue, or isotype, VP6 induced the highest numbers of ASCs, followed by VP4; ASCs specific for VP7, NSP3, and NSP4 were less numerous. At challenge, total HRV- and HRV protein-specific immunoglobulin A (IgA) and IgG ASCs in intestinal lymphoid tissues were significantly greater in WaV- than in WaA-inoculated pigs, and WaV pigs were fully protected against diarrhea postchallenge, whereas the WaA pigs were partially protected. At PCD 7, there were no significant differences in ASC numbers for any HRV proteins between the WaV+WaV/PC and WaA+WaV/PC groups.

Motivational enhancement and self-help treatments for problem gambling

Two brief treatments for problem gambling were compared with a waiting-list control in a randomized trial. Eighty-four percent of participants (N = 102) reported a significant reduction in gambling over a 12-month follow-up period. Participants who received a motivational enhancement telephone intervention and a self-help workbook in the mail, but not those who received the workbook only, had better outcomes than participants in a 1-month waiting-list control. Participants who received the motivational interview and workbook showed better outcomes than those receiving the workbook only at 3- and 6-month follow-ups. At the 12-month follow-up, the advantage of the motivational interview and workbook condition was found only for participants with less severe gambling problems. Overall, these results support the effectiveness of a brief telephone and mail-based treatment for problem gambling.

The reliability and validity of the inventory to diagnose depression in alcohol-dependent men and women

PURPOSE

This study examined the reliability and validity of the Inventory to Diagnose Depression (IDD) in alcohol-dependent men and women. The IDD is a self-report instrument that provides a continuous score reflecting depression severity and a DSM-IV major depression diagnosis (MDD).

METHODS

Participants (N = 57) were administered the IDD, Beck Depression Inventory (BDI), and the mood module of the Structured Clinical Interview for the DSM (SCID).

RESULTS

Internal reliability and item-total correlations were generally good and the IDD severity score correlated highly with the BDI. The diagnostic performance of the IDD using the DSM-IV scoring algorithm was good overall but excellent for currently abstinent participants and fair for participants who had recently consumed alcohol. The IDD cut-off score for identifying cases of depression appears stringent compared to the BDI and SCID.

IMPLICATIONS

The present investigation provides some support for the use of the IDD with abstinent alcoholic outpatient samples when a self-report diagnostic instrument is desirable. For a current drinker, a positive IDD does not distinguish between an alcohol-induced depression and MDD.

Motivational enhancement and self-help treatments for problem gambling

Two brief treatments for problem gambling were compared with a waiting-list control in a randomized trial. Eighty-four percent of participants (N = 102) reported a significant reduction in gambling over a 12-month follow-up period. Participants who received a motivational enhancement telephone intervention and a self-help workbook in the mail, but not those who received the workbook only, had better outcomes than participants in a 1-month waiting-list control. Participants who received the motivational interview and workbook showed better outcomes than those receiving the workbook only at 3- and 6-month follow-ups. At the 12-month follow-up, the advantage of the motivational interview and workbook condition was found only for participants with less severe gambling problems. Overall, these results support the effectiveness of a brief telephone and mail-based treatment for problem gambling.

Processes of changing gambling behavior

Recovered problem gamblers (N = 37) described the processes used in overcoming their gambling problem using a modified version of the Processes of Change Questionnaire (J. O. Prochaska, W. F. Velicer, C. C. DiClemente, & J. S. Fava, 1988). The most frequently used processes were cognitive-experiential in nature and included self-reevaluation, environmental reevaluation, dramatic relief, and self-liberation. The least-used processes were reinforcement management and social liberation. Individuals who had sought gambling treatment reported greater use of most processes, in particular cognitive-experiential ones, compared with self-changers. The processes reported by participants were similar to those elicited through open-ended questions, but the results for problem gamblers differ from results of studies of other types of behavior change.

Intranasal administration of 2/6-rotavirus-like particles with mutant Escherichia coli heat-labile toxin (LT-R192G) induces antibody-secreting cell responses but not protective immunity in gnotobiotic pigs

We investigated the immunogenicity of recombinant double-layered rotavirus-like particle (2/6-VLPs) vaccines derived from simian SA11 or human (VP6) Wa and bovine RF (VP2) rotavirus strains. The 2/6-VLPs were administered to gnotobiotic pigs intranasally (i.n.) with a mutant Escherichia coli heat-labile toxin, LT-R192G (mLT), as mucosal adjuvant. Pigs were challenged with virulent Wa (P1A[8],G1) human rotavirus at postinoculation day (PID) 21 (two-dose VLP regimen) or 28 (three-dose VLP regimen). In vivo antigen-activated antibody-secreting cells (ASC) (effector B cells) and in vitro antigen-reactivated ASC (derived from memory B cells) from intestinal and systemic lymphoid tissues (duodenum, ileum, mesenteric lymph nodes [MLN], spleen, peripheral blood lymphocytes [PBL], and bone marrow lymphocytes) collected at selected times were quantitated by enzyme-linked immunospot assays. Rotavirus-specific immunoglobulin M (IgM), IgA, and IgG ASC and memory B-cell responses were detected by PID 21 or 28 in intestinal and systemic lymphoid tissues after i.n. inoculation with two or three doses of 2/6-VLPs with or without mLT. Greater mean numbers of virus-specific ASC and memory B cells in all tissues prechallenge were induced in pigs inoculated with two doses of SA11 2/6-VLPs plus mLT compared to SA11 2/6-VLPs without mLT. After challenge, anamnestic IgA and IgG ASC and memory B-cell responses were detected in intestinal lymphoid tissues of all VLP-inoculated groups, but serum virus-neutralizing antibody titers were not significantly enhanced compared to the challenged controls. Pigs inoculated with Wa-RF 2/6-VLPs (with or without mLT) developed higher anamnestic IgA and IgG ASC responses in ileum after challenge compared to pigs inoculated with SA11 2/6-VLPs (with or without mLT). Three doses of SA 11 2/6-VLP plus mLT induced the highest mean numbers of IgG memory B cells in MLN, spleen, and PBL among all groups postchallenge. However, no significant protection against diarrhea or virus shedding was evident in any of the 2/6-VLP (with or without mLT)-inoculated pigs after challenge with virulent Wa human rotavirus. These results indicate that 2/6-VLP vaccines are immunogenic in gnotobiotic pigs when inoculated i.n. and that the adjuvant mLT enhanced their immunogenicity. However, i.n. inoculation of gnotobiotic pigs with 2/6-VLPs did not confer protection against human rotavirus challenge.