Strategies for induction of protective immunity to bovine herpesvirus-1 in newborn calves with maternal antibodies

The objective of this study was to evaluate Th1 promoting strategies for vaccination of neonates against bovine herpesvirus-1 (BHV-1). A plasmid encoding a secreted truncated version of glycoprotein D (tgD) and tgD protein formulated with CpG oligodeoxynucleotide (ODN) effectively primed the immune system of newborn lambs, whereas without CpG ODN the tgD protein was less effective. Furthermore, a heterologous DNA prime-protein/CpG boost induced stronger and more balanced immune responses than either the DNA vaccine or a protein/CpG prime-DNA boost. Three of these strategies were compared as an approach to induce protective immunity in newborn calves with BHV-1-specific maternal antibodies. Whereas the DNA vaccine induced minimal protection, the DNA prime-protein boost resulted in reduced temperature response, weight loss and virus shedding in comparison to the placebo group. Close to complete protection against BHV-1 challenge was elicited in the calves immunized with the protein/CpG formulation, as these animals lost very little weight, had only slightly elevated temperatures and shed almost no virus.

The attainment of life goals by adult survivors of childhood cancer

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Background: Adult survivors of childhood cancer are at risk for disease- and therapy-related morbidity, which can adversely affect marriage and employment status, ability to obtain health insurance and access to care. Our aim was to identify factors associated with survivors’ ability to achieve these goals. Methods: We surveyed 1,437 survivors of different types of childhood cancer who were >18 years of age and >10 years from diagnosis. We compared our cohort's data to normative data in the Medical Expenditure Panel Survey and the Current Population Surveys of the U.S. Census Bureau. Survivors were categorized into 3 groups (hematological malignancy, solid tumors, or central nervous system tumors) and whether they had received radiation therapy. Results: The majority of respondents (response rate 65%) were survivors of hematological malignancies (71%), white (91%), and working full-time (62%); (43%) were married. When compared to age- and gender-adjusted national averages, only survivors of hematological malignancy who received radiation therapy were significantly less likely to be married than the general population (44% vs. 52%). Full-time employment among survivors was lower than national norms, except for survivors of hematological malignancy who had not received radiation therapy. The prevalence of having any health insurance, especially public insurance, was higher in all diagnostic groups than in the general population. Difficulty obtaining care was reported by 11% of all survivors; 12% reported not receiving needed health care. Additionally, 26.9% reported having been denied insurance. Current unemployment and lack of insurance were significantly associated with difficulty in obtaining care (p=0.049 and p<0.001, respectively). CNS tumor survivors reported greater difficulty in obtaining needed care (p=0.030). Current employment and solid tumor diagnosis were associated with lower rates of denial of insurance (p=0.018 and p=0.003, respectively). Conclusion: Subgroups of adult childhood cancer survivors are at risk of problems with attaining life goals, including access to care. This has serious implications given the known long-term secondary medical complications in this at- risk population.

No significant financial relationships to disclose.

Induction of protective immunity in pigs after immunisation with CpG oligodeoxynucleotides formulated in a lipid-based delivery system (Biphasix)

A large number of studies demonstrated the immunostimulatory effects of CpG oligonucleotides (ODN), particularly in mice. In the present study, we evaluated the ability of lipid-based delivery systems to enhance the adjuvant effect of CpG-ODN and protect against infection in a porcine pleuropneumonia model. Increased levels of OmlA-specific antibody were detected in animals immunised with OmlA and CpG-ODN formulated in the delivery system Biphasix-vaccine targeting adjuvant (VTA), compared to pigs immunised with VTA without CpG-ODN or CpG-ODN alone. In addition, the responses induced by VTA/CpG formulation were similar to those induced by the commercial adjuvant VSA; however, VTA formulations caused significantly less tissue damage than VSA.

Induction of immune responses in newborn lambs following enteric immunization with a human adenovirus vaccine vector

We investigated the antigen-specific mucosal and systemic immune responses of newborn lambs following enteric immunization, targeting jejunal Peyer's patches with a human adenovirus vector that expressed the glycoprotein D (gD) of bovine herpesvirus-1. Both humoral and cell-mediated gD-specific mucosal immune responses were detected in newborn lambs (1-4 days old) after a single immunization and these responses were qualitatively and quantitatively similar to those detected in 5-6-week-old lambs. Passively transferred gD-specific maternal antibody did not significantly alter either mucosal or systemic gD-specific immune responses. Furthermore, enteric immunization of newborn lambs primed mucosal immune responses in the lungs. These observations confirmed that gut-associated lymphoid tissue of a newborn ruminant is immune competent and that enteric immunization may be an effective approach for the induction of both mucosal and systemic immune responses in the neonate.

Post-transcriptional regulation of the arginine transporter Cat-1 by amino acid availability

The regulation of the high affinity cationic amino acid transporter (Cat-1) by amino acid availability has been studied. In C6 glioma and NRK kidney cells, cat-1 mRNA levels increased 3.8-18-fold following 2 h of amino acid starvation. The transcription rate of the cat-1 gene remained unchanged during amino acid starvation, suggesting a post-transcriptional mechanism of regulation. This mechanism was investigated by expressing a cat-1 mRNA from a tetracycline-regulated promoter. The cat-1 mRNA contained 1.9 kilobase pairs (kb) of coding sequence, 4.5 kb of 3'-untranslated region, and 80 base pairs of 5'-untranslated region. The full-length (7.9 kb) mRNA increased 5-fold in amino acid-depleted cells. However, a 3.4-kb species that results from the usage of an alternative polyadenylation site was not induced, suggesting that the cat-1 mRNA was stabilized by cis-acting RNA sequences within the 3'-UTR. Transcription and protein synthesis were required for the increase in full-length cat-1 mRNA level. Because omission of amino acids from the cell culture medium leads to a substantial decrease in protein synthesis, the translation of the increased cat-1 mRNA was assessed in amino acid-depleted cells. Western blot analysis demonstrated that cat-1 mRNA and protein levels changed in parallel. The increase in protein level was significantly lower than the increase in mRNA level, supporting the conclusion that cat-1 mRNA is inefficiently translated when the supply of amino acids is limited, relative to amino acid-fed cells. Finally, y(+)-mediated transport of arginine in amino acid-fed and -starved cells paralleled Cat-1 protein levels. We conclude that the cat-1 gene is subject to adaptive regulation by amino acid availability. Amino acid depletion initiates molecular events that lead to increased cat-1 mRNA stability. This causes an increase in Cat-1 protein, and y(+) transport once amino acids become available.

Induction of mucosal immune responses by administration of liposome-antigen formulations and interleukin-12

We examined the effect of interleukin-12 (IL-12) on the induction of mucosal immune responses following intranasal immunization with liposome-antigen formulations. We assessed the immune response to two recombinant glycoproteins (gD and gB) from bovine herpesvirus type 1 (BHV-1). Positively charged liposomes induced significantly higher gD-specific IgA titers than did immunization with antigen alone. This liposome formulation was selected to further assess the ability of IL-12 to influence mucosal immune responses. Intranasal immunization with IL-12 gD-liposome formulations did not alter the induction of mucosal immune responses. However, a significant increase in anti-gD antibody responses was induced in serum after intranasal immunization with IL-12 gD-liposome when compared with animals immunized with gD-liposomes. Mucosal antibody responses induced by a subcutaneous priming followed by an intranasal boost were significantly higher than those induced by two intranasal immunizations with the same IL-12 liposome-gD formulations. Furthermore, this immunization protocol resulted in the induction of high levels of interferon-gamma (IFN-gamma) in the lungs of subcutaneously primed mice. These findings indicate that the immunomodulatory effects of IL-12 influenced immune responses to a vaccine antigen when delivered intranasally and that these responses can be further enhanced by subcutaneous priming.

Intradermal immunization with a bovine herpesvirus-1 DNA vaccine induces protective immunity in cattle

Although intramuscular (i.m.) injection of DNA encoding glycoprotein D (gD) of bovine herpesvirus-1 (BHV-1) induces immune responses in cattle, this route of delivery is inefficient. Here we assessed three parameters that may enhance the efficacy of a gD DNA vaccine in cattle. First, the immune response generated by i.m. injected plasmid expressing a secreted form of gD (tgD) was determined and found to be very similar in magnitude to the response induced by gD-expressing plasmid. Secondly, gD- and tgD-expressing plasmids were administered by intradermal (i.d.) immunization, which resulted in a superior immune response to the secreted form, but no improvement in the response to the membrane-associated form. However, the form of gD used for immunization did not influence the immunoglobulin subtype, the ratio of antigen-specific IgG1 to IgG2 being approximately 4:1. Finally, the effect of promoter strength was assessed by replacing the Rous sarcoma virus (RSV) promoter, which was used in the original experiments, with the human cytomegalovirus immediate early promoter and first intron A (HCMV/IA). Although upon transfection in vitro the HCMV/IA promoter appeared to be stronger than the RSV promoter, there was only a 2-fold higher antibody response in vivo upon i.d. injection of cattle. Protection against virus challenge was obtained in the calves immunized i.d. with tgD-encoding plasmid, as shown by a significant reduction in weight loss, virus excretion, temperature response and clinical disease. No significant protection was observed in the animals vaccinated i.d. with the gD-expressing plasmid, which correlates with the lower level of immunity pre-challenge.

Effect of IL-4 and IL-12 liposomal formulations on the induction of immune response to bovine herpesvirus type-1 glycoprotein D

Activation of different T-helper (Th) responses following immunisation has profound and specific influences on the development of the immune response and on the ability of a vaccine to confer protection. Since cytokines are capable of influencing the stimulation of distinct T-cell responses, their encapsulation in vaccines should modulate antigen-specific immune responses. Unfortunately, the use of cytokines in vivo is hampered by their rapid clearance and inactivation. One possible solution to this problem is the use of liposomes to entrap both cytokines and antigen. This approach will not only protect the cytokine but will also deliver the two components simultaneously to the same site. The authors examined, therefore, the immune responses elicited by systemic immunisation of mice with liposome formulations containing a truncated form of bovine herpesvirus type-1 glycoprotein D (tgD) together with IL-4 or IL-12. Subcutaneous immunisation with liposomes containing tgD and IL-12 significantly enhanced the induction of antigen-specific cellular and humoral immune responses. These responses were characterised by an increase in IFN-gamma secreting cells and the induction of tgD-specific IgG2a antibodies. In contrast, encapsulation of IL-4 into tgD-liposomes did not enhance the humoral immune response to gD but significantly influenced the development of antigen-specific IL-4 secreting cells. Our results indicated that encapsulation of IL-12 into the liposomes was necessary for the systemic adjuvant effect and demonstrated the feasibility of using liposome technology and cytokines to manipulate the development of different antigen-specific Th subsets in vivo.

Immunogenicity of bovine herpesvirus 1 glycoprotein D in mice: effect of antigen form on the induction of cellular and humoral immune responses

For the development of veterinary subunit vaccines, modifications to the antigen may be needed to make the production of these vaccines cost effective. To investigate the effect of antigen modifications on immune response, we used glycoprotein D, one of the major glycoproteins of bovine herpesvirus-1 (BHV-1), as a model antigen. We developed a mouse model to assess the immune response elicited by immunization with either a recombinant truncated (tgD) or the authentic full-length (gD) form of BHV-1 gD in VSA3, a novel water-in-oil adjuvant. Both forms of BHV-1 gD antigen induced good levels of cell-mediated immunity, as evaluated by antigen-specific proliferative response and cytokine (IFN-gamma and IL-4) production. Following primary immunization, the humoral immune response induced by gD was superior to that elicited by vaccination with tgD. However, after a secondary immunization, a strong and similar antibody response to BHV-1 gD was induced by both forms of the antigen. The difference in immunogenicity between gD and tgD after primary immunization was not due to the loss of immunogenic epitopes in the truncated antigen or the ability to associate with the adjuvant VSA3. Our results indicate that both gD and tgD are capable of efficiently inducing a cell-mediated immune response, and although recombinant tgD is less efficient in inducing a primary humoral immune response when compared to the full-length gD, tgD effectively primed for a secondary antibody response.

Effects of some cholinergic agonists on neocortical slow wave activity in rats with basal forebrain lesions

Chronic rats, prepared with unilateral injections of kainic acid in the left basal forebrain, displayed prominent large amplitude slow wave activity in the neocortex ipsilateral to the injection. Oxotremorine and pilocarpine, given systemically following pretreatment with methyl scopolamine to block peripheral muscarinic effects, restored low voltage fast activity (LVFA) in a dose-related manner. Oxotremorine was more potent than pilocarpine. Arecoline was not consistently effective. Tetrahydroaminoacridine abolished abnormal 4-6 Hz rhythmical slow waves in the left neocortex but had little effect on large amplitude irregular slow waves. Direct-acting cholinergic agonists can restore near-normal neocortical activity after extensive cholinergic deafferentation of the neocortex.

Physiological and morphological changes in bovine mammary glands following intramammary infusion of recombinant interferon-gamma

Eleven lactating dairy cows were used to evaluate the response of bovine mammary glands to increasing doses of recombinant bovine interferon (rBoIFN)-gamma. Right front and rear quarters were intramammarily infused with eight different doses (10(2) U to 2 x 10(8) U/quarter) of rBoIFN-gamma; each dose was tested in at least two quarters. Left udder halves served as within animal controls in which quarters were injected with a saline placebo or were not infused at all. Milk secretion samples for compositional analysis were collected from each quarter prior to infusion and at 6, 24, 36 and 48 h following infusion. Animals were slaughtered immediately following the 48 h sampling period and mammary tissue was obtained for morphometric analyses. Milk composition was similar between control quarters and those quarters infused with up to 10(5) U of rBo-IFN-gamma during the entire sampling period. Quarters infused with 10(6) U and 10(7) U of rBoIFN-gamma had higher milk somatic cell counts (SCC) following treatment compared with preinfusion values. Changes in the composition of mammary secretion were most dramatic in quarters infused with greater than or equal to 10(8) U of rBoIFN-gamma as indicated by the significant increase in SCC and milk pH with a concomitant decrease in lactose concentration when compared with pre-infusion values or with control quarters. Morphometric analysis of tissue demonstrated an increase in stroma, a decrease in luminal area, and a marked increase in the number of infiltrating leukocytes in those quarters infused with the higher doses of rBoIFN-gamma.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathological changes in bovine mammary glands following intramammary infusion of recombinant interleukin-2

Eighteen lactating dairy cows were used to evaluate the physiological response of mammary glands to increasing doses of recombinant bovine interleukin-2. Right front and rear quarters were intramammarily infused with five different doses (.1 to 100 micrograms per quarter) of interleukin-2 as either a single or multiple treatment. Left front and rear quarters were intramammarily infused with a saline placebo and served as within-animal controls. Milk secretion samples for compositional analysis were collected from each quarter prior to infusion and at 12, 24, 36, and 48 h following infusion. Animals were slaughtered by exsanguination immediately following the 48-h sampling period, and mammary gland tissue was obtained for morphometric analysis. No changes in milk composition were observed between control quarters and those infused with up to 10 micrograms of interleukin-2 per quarter, administered as either a single or multiple treatment. Quarters infused with a single 100-micrograms dose of interleukin-2 or three consecutive doses of 25 and 100 micrograms of interleukin-2 had significantly lower lactose concentrations; there was a concomitant increase in bovine serum albumin, pH, and SCC compared with preinfusion concentrations or with control quarters. Morphometric analysis of tissue demonstrated an increase in stroma, a decrease in lumenal area, and a marked increase in the number of infiltrating leukocytes in those quarters infused with the higher doses of interleukin-2. Results suggest that interleukin-2 can be intrammammarily infused at doses as high as 10 micrograms per quarter without adversely affecting milk quality or normal mammary gland function.

Defining origin of positive slope in hypercapnic ventilatory response curve

The sensitivity to CO2 as a respiratory stimulant has traditionally been studied by exposing organisms to progressively increasing levels of inspired CO2 while measuring the corresponding increase in minute ventilation (V). Plots of V as a function of end-tidal CO2 concentration reveal a complex function with a "dogleg" shape. Only the positive slope of the V function is taken as an index of chemosensitivity, but the starting points for such analyses are often chosen arbitrarily. This paper examined the hypotheses that the range of CO2 concentrations over which V slopes are compared may be mathematically defined and that arbitrary choices of this analytic range may influence conclusions about the hypercapnic ventilatory response (HCVR). Three mathematical models attempted to define the origin of the positive slope for the HCVR curve using empirically derived data. The results revealed good agreement that the origin of the positive HCVR slope may be reliably defined by a point that joins the horizontal and positive slope of the HCVR curve. In addition to identifying the "joint-point" statistic, the results suggest that arbitrarily defining the range of CO2 values over which V is analyzed can be replaced by quantitative approaches for identifying the origin of the ventilatory response to hypercapnia.

Molecular mimicry: a herpes virus glycoprotein antigenically related to a cell-surface glycoprotein expressed by macrophages, polymorphonuclear leucocytes, and platelets

Bovine herpes virus type 1 (BHV-1) gIII is a major virion glycoprotein with homology to the immunoglobulin superfamily. We have investigated the possibility that gIII is related to host molecules and have identified a gIII-specific monoclonal antibody (mAb) that cross-reacts with normal bovine cells. The cross-reactive entity was expressed mainly on monocyte/macrophages (M phi), polymorphonuclear leucocytes (PMN) and platelets, and was identified as a 43,000-63,000 molecular weight (MW) cell-surface glycoprotein. For M phi, the glycoprotein appears to be a general lineage marker, rather than a maturation or activation marker, and may be a functional receptor, as evidenced by its endocytosis via coated pits and its involvement in proliferation of mononuclear cells in vitro. This novel leucocyte marker was also detected on subsets of human, ovine and canine M phi. Competitive binding assays with sera from cattle immunized with BHV-1 or gIII revealed apparent low responsiveness to the cross-reactive epitope. The results suggest that BHV-1 gIII is antigenically related to a novel host leucocyte receptor and that evasion and/or interference with leucocyte function may be a consequence of this molecular mimicry relationship.

Effect of chronic administration of recombinant bovine tumor necrosis factor to cattle

Cachectin/tumor necrosis factor-alpha (TNF), a protein produced by macrophages upon stimulation, has been implicated as an important mediator of inflammatory processes and of clinical manifestations in chronic infectious diseases. In order to study further the potential role of TNF in infectious diseases, a homologous system was employed in which recombinant Escherichia coli (E. coli) derived bovine TNF (rBoTNF) was injected in cattle, either as a single bolus or in a repetitive treatment-regime. No clinical signs were observed, although changes occurred in hematologic and immunologic parameters when less than 0.5 mg of TNF/100 kg body weight was administered twice daily for 18 days. Prolonged treatment with 0.05-0.5 mg/100 kg induced histologic but no gross changes in the kidneys and liver. When doses were increased above 0.5 mg/100 kg, depression, anorexia, cachexia, and diarrhea appeared rapidly. Pathologic changes were apparent in various tissues including liver, kidneys, and lymphoid organs; body fat depots were depleted. Most of these changes appeared to be reversible; return to normal tissue-morphology occurred within 3 weeks of withdrawal of rBoTNF. The clinical and pathologic changes induced by prolonged rBoTNF administration resembled those observed in some chronic parasitic and viral infections of cattle in which macrophage-activation characteristically occur. Our finding may be relevant to the elucidation of the pathogenesis of these and other chronic infections.

Hepatoma secretory proteins migrate from rough endoplasmic reticulum to Golgi at characteristic rates

In eukaryotic cells, secretory proteins and glycoproteins migrate from the rough endoplasmic reticulum, their site of synthesis, through Golgi vesicles before being released from the cell. Cellular and viral integral plasma membrane glycoproteins are co-translationally inserted into the rough endoplasmic reticulum membrane and follow a similar pathway to the cell surface. Previous studies using endoglycosidase H (Endo H) suggested that in rat hepatoma cells the vesicular stomatitis virus (VSV) G protein, albumin and transferrin migrate from the rough endoplasmic reticulum to the Golgi apparatus at different rates. Here we show directly that in human hepatoma HepG2 cells, five secreted proteins mature from the rough endoplasmic reticulum to Golgi vesicles at characteristic rates which differ at least threefold. The results are incompatible with bulk-phase movement of the luminal contents of the endoplasmic reticulum, and suggest that there is a membrane-bound receptor that selectively mediates the transport of secretory proteins from the rough endoplasmic reticulum to the Golgi.

Autoradiographic detection and characterization of a Chinese hamster ovary cell mutant deficient in fucoproteins

Autoradiography of colony replicas immobilized on filter paper was used to isolate a Chinese hamster ovary cell line deficient in incorporation of radiolabeled fucose into a trichloroacetic acid-insoluble fraction. This cell line, called 62.1, has the same growth rate at 37 degrees C as wild-type cells, but incorporates five times less fucose into acid-insoluble radioactivity. Chemical analysis of fucose bound to macromolecules also showed a fivefold reduction in the mutant. The fucoproteins of the mutant cell line differ qualitatively from those of wild-type cells as visualized by SDS gel electrophoresis fluorography; no differences were detected between total proteins as visualized by coomassie blue staining. The macromolecular sialic acid content of the mutant was somewhat higher than the wild type (20%). Studies of the synthesis of the glycoprotein of vesicular stomatitis virus in mutant and wild-type cells showed that the mutant is unable to synthesize complex-type N-linked oligosaccharides. Enzyme assays show that ths defect in the mutant is due to reduction in UDP-N-acetylglucosamine-glycoprotein N-acetyl-glucosaminyltransferase, a key enzyme in the assembly of complex glycopeptides. Hybridization studies have shown that mutant 62.1 has common mutations belonging to the same complementation group as mutant PhaR1-1. This latter mutant was previously isolated using lectin resistance by Stanley et al. (1975) and was also deficient in the above N-acetyl-glucosaminyltransferase.

Week long partial pulmonary bypass with an artificial lung pumped by the right ventricle

Extracorporeal pumping PA-LA perfusions were carried out for 24 hrs in 5 awake, alert lambs by cannulating the main PA and the LA with large bore polyurethane cannulae. A mean of 42% of the basal cardiac was pumped through the membrane lung. When the PA occluder cuff was progressively inflated, up to 80% of the basal cardiac output was diverted to the extracorporeal circuit for short periods. Hemothorax remained a significant problem. Three lambs were electively perfused 12 hrs, 36 hrs, and 8 days without a roller pump, using a low resistance spiral coil membrane lung pumped by the RV. By inflating the occluder cuff, a mean of 55% of basal cardiac output was pumped by the RV through the membrane lung. The 8 day bypass lamb remained healthy and active without any bleeding or gross pathology. We did not observe air emboli, thromboemboli or gross infections in either group. We believe that such a mode of cannulation will eventually allow long-term perfusion of a low resistance membrane oxygenator driven directly by the RV.

Myocardial ischemia due to infrarenal aortic cross-clamping during aortic surgery in patients with severe coronary artery disease

Hemodynamic measurements were performed and ECG recorded before and shortly after infrarenal aortic cross-clamping during operation for abdominal aortic aneurysm in five patients without evidence of heart disease (group I) and in ten patients with severe coronary artery disease (group II). All patients sustained an increase in systemic arterial pressure. Group I demonstrated a decrease in pulmonary artery, pulmonary capillary wedge (PCW), and central venous pressures when the aorta was clamped, whereas group II demonstrated an increase. The difference in response of the groups is significant (P less than 0.05). All three patients who responded to cross-clamping with increases of 7 mm Hg or greater in PCW demonstrated myocardial ischemia during cross-clamping. None of the values measured prior to cross-clamping predicted with certainty the response to cross-clamping. Sodium nitroprusside reversed the elevation of left ventricular filling pressure in all three patients, and in two patients, relieved evidence of myocardial ischemia concurrently. In the third patient, ventricular irritability was abolished by lidocaine and did not recur. We conclude that infrarenal aortic cross-clamping may cause myocardial ischemia in patients with severe coronary artery disease. This ischemia may be predicted by a rise in PCW at the time of cross-clamping, and vasodilator therapy is indicated in such patients.