Mapping and validation of a major QTL affecting resistance to pancreas disease (salmonid alphavirus) in Atlantic salmon (Salmo salar)

Pancreas disease (PD), caused by a salmonid alphavirus (SAV), has a large negative economic and animal welfare impact on Atlantic salmon aquaculture. Evidence for genetic variation in host resistance to this disease has been reported, suggesting that selective breeding may potentially form an important component of disease control. The aim of this study was to explore the genetic architecture of resistance to PD, using survival data collected from two unrelated populations of Atlantic salmon; one challenged with SAV as fry in freshwater (POP 1) and one challenged with SAV as post-smolts in sea water (POP 2). Analyses of the binary survival data revealed a moderate-to-high heritability for host resistance to PD in both populations (fry POP 1 h²~0.5; post-smolt POP 2 h²~0.4). Subsets of both populations were genotyped for single nucleotide polymorphism markers, and six putative resistance quantitative trait loci (QTL) were identified. One of these QTL was mapped to the same location on chromosome 3 in both populations, reaching chromosome-wide significance in both the sire- and dam-based analyses in POP 1, and genome-wide significance in a combined analysis in POP 2. This independently verified QTL explains a significant proportion of host genetic variation in resistance to PD in both populations, suggesting a common underlying mechanism for genetic resistance across lifecycle stages. Markers associated with this QTL are being incorporated into selective breeding programs to improve PD resistance.

Antibodies recognizing both IgM isotypes in Atlantic salmon

Identification and characterization of subpopulations of cells involved in immunological reactions against invading organisms are essential for understanding defense mechanisms against disease. In lower vertebrates like teleost fish, as opposed to mammals, immune cell subsets are still poorly defined, mostly due to the lack of appropriate working tools like antibodies and functional assays. Membrane bound molecules like immunoglobulins (Ig) serve as cell surface markers for specific cell subsets and the identification of cells relies upon the production of specific antibodies towards these molecules. The present study aimed at identifying tools to separate IgM positive (IgM(+)) B cells from IgM negative (IgM(-)) non-B cell populations using flow cytometry. Several monoclonal antibodies (mAbs), and one polyclonal antibody (pAb) to both rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) IgM, either commercially available or locally produced were tested for their recognition of Atlantic salmon IgM(+) cells. Leukocytes were isolated from peripheral blood (PB), spleen (S) and head kidney (HK) and stained with all mAbs and the pAb, to possibly verify the approximate number of IgM(+) cells in the respective tissues in salmon. To our surprise, this seemingly simple task did not reveal similar staining patterns for all antibodies as expected, but rather large differences in the number of positively stained cells were discovered. In short, positively stained cells by each antibody ranged from below 5% to above 80% with similar ratios between the antibodies in each tissue. The three most used mAbs, 4c10, N2 and 1.14; originally produced towards rainbow trout IgM, recognize only a fraction of salmon B cells as previously shown for the 4c10 mAb binding exclusively to the IgM-A isotype. In comparison, our three novel mAbs, IgF1-3, -18 and -19, bind to both IgM-A and -B isotypes as shown using intracellular staining of 293T cells transfected with both IgM-A and -B constructs. Based on binding percentages, one of three commercially available Abs, IgH FITC from Cedarlane, may also identify both isotypes. The three new IgF1-3, -18 and -19 mAbs and potentially IgH FITC from Cedarlane, provide us with great tools enabling complete depletion or enrichment of IgM(+) B cells and/or IgM(-) T cells in Atlantic salmon.

Oral spray immunization may be an alternative to intranasal vaccine delivery to induce systemic antibodies but not nasal mucosal or cellular immunity

Sixty-five healthy adult volunteers were immunized four times at 1-week intervals with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1) without adjuvant. The vaccine was administered as nasal spray with a newly developed device to secure intranasal delivery (OptiMist, OptiNose AS, Oslo, Norway), as regular nasal spray, nasal drops or as an oral spray. Significant IgA-antibody responses in nasal secretions were induced in volunteers immunized intranasally but not after oral spray immunization. In saliva, IgA antibodies were only marginally amplified even after oral spray immunizations. At least 73% of the volunteers belonging to any group of vaccine delivery reached serum haemagglutination inhibition titres of 40 or higher, considered protective against influenza, after only two vaccine doses. Those who had the vaccine delivered intranasally also showed evidence from in vitro secretion of granzyme B that cytotoxic T cells had been stimulated. Although immunization with the breath-actuated OptiMist device and nasal drops were superior with respect to both mucosal and systemic immune responses, oral spray immunization might still be considered for studies of mucosal adjuvants that are not yet acceptable for intranasal use.

Immunoglobulin-A antibodies in upper airway secretions may inhibit intranasal influenza virus replication in mice but not protect against clinical illness

Mice immunized intranasally with a formalin-inactivated A/PR/8/34 (H1N1) influenza whole virus vaccine adjuvanted with cholera toxin, outer membrane vesicles from group B meningococci or formalin-inactivated whole cell Bordetella pertussis were protected against replication of the homologous virus in the nasal cavity. Only some mice were protected against clinical illness measured as weight loss and lowered body temperature. All mice immunized subcutaneously with one-tenth the intranasal vaccine dose without adjuvant were protected against clinical illness but not against local mucosal viral replication. Replicating virus was primarily found in animals with low concentrations of immunoglobulin (Ig)-A antibodies in saliva regardless of concentrations of IgG antibodies in serum. Clinical illness was seen only in those with low serum antibodies regardless of antibody levels in saliva. Nonreplicating nasal vaccines may not be sufficiently protective unless they also have a substantial influence on systemic immunity.

Meningococcal outer membrane vesicle vaccine given intranasally can induce immunological memory and booster responses without evidence of tolerance

We have studied the ability of outer membrane vesicle (OMV) vaccines from Neisseria meningitidis serogroup B to induce vaccine-specific antibody and spleen cell proliferative responses in mice after being administered intranasally (i.n.) and/or subcutaneously (s.c.). A series of four weekly i.n. doses (25 microg) without adjuvant or a single s.c. dose (2.5 microg) with aluminum hydroxide was followed 2 months later by secondary i.n. or s.c. immunizations. After i.n. priming, both immunoglobulin G (IgG) antibody responses in serum, measured by enzyme-linked immunosorbent assay, and IgA antibodies in saliva and extracts of feces were significantly boosted by later i.n. immunizations. The IgG antibody responses in serum were also significantly augmented by secondary s.c. immunization after i.n. as well as s.c. priming. Sera from mice immunized i.n. reached the same level of bactericidal activity as after s.c. immunizations. The s.c. immunizations alone, however, had no effect on mucosal IgA antibody responses, but could prime for booster antibody responses in secretions to later i.n. immunizations. The i.n. immunizations also led to marked OMV-specific spleen cell proliferation in vitro. Both serum antibody responses and spleen cell proliferation were higher after i.n. priming and later s.c. immunizations than after s.c. immunizations alone. There was thus no evidence that i.n. priming had induced immunological tolerance within the B- or T-cell system. Our results indicate that a nonproliferating meningococcal OMV vaccine given i.n. can induce immunological memory and that it may be favorably combined with similar vaccines for injections.

Influence of urological morbidity on quality of life in patients with prostate cancer

OBJECTIVE

To evaluate the prevalence of urological morbidity in patients with prostate cancer and its influence on global quality of life (QL).

METHODS

379 patients with prostate cancer completed several questionnaires (EORTC QLQ-C33, I-PSS, PAIS [sexuality]) and were grouped according to the type of treatment they had undergone: observation only (n = 57), androgen deprivation (n = 112), radiotherapy (n = 114) and radical prostatectomy (n = 96). A group of 86 urologists also completed the questionnaires, imagining that they had stable prostate cancer and had been undergoing androgen deprivation for at least 1 year. Their responses were compared with those from patients who had undergone androgen deprivation.

RESULTS

In all patient groups urinary symptoms were mostly mild to moderate but 12% of patients who had undergone radiotherapy and 11% of hormonally treated patients described severe symptoms. Severe urinary leakage occurred in 16% of patients who had undergone radical prostatectomy. 22% of all patients were impotent before treatment; after treatment sexual life was considerably disturbed in all patients except those who had undergone observation only. Fatigue was a general problem in all patients. In the logistic regression analysis fatigue and lower urinary tract symptoms (LUTS), but not disturbance of sexual life or urinary leakage, were correlated with global QL. In the doctor-patient comparison, doctors underestimated the disturbance of sexual life in patients who had undergone androgen deprivation therapy but overestimated the impairment of QL and psychological distress experienced by these patients.

CONCLUSIONS

LUTS and fatigue are independent predictive factors for global QL after initial treatment in patients with prostate cancer. Radiotherapy of the prostate leads to more significant morbidity than was generally anticipated by doctors. The disagreement between doctors' and patients' assessments of QL following treatment indicates the necessity for further systematic QL evaluation in these patients.

Relationships between teat characteristics and udder health. A field survey

A field survey in 13 Norwegian dairy herds showed a marked increase in teat size and degree of teat canal eversion during a period of six months while most of the cows were still in the same lactation period. There was a statistically significant relationship between the following variables: teat location (front/rear) and teat length, teat shape and teat size, teat end shape and mastitis prevalence, teat end shape and canal eversion, severe teat canal eversion and mastitis prevalence, teat canal eversion and rough/cracked teat canal, teat canal eversion and teat end oedema, teat end oedema and mastitis prevalence. Many young cows had a normal teat orifice or mild teat canal eversions, but also a greater proportion of young cows had distinct or severe teat canal eversions compared with older cows.

Effect of teatcup liner design on teat characteristics and udder health

A 6-month field experiment was carried out to test effects of liner design on teats and udder health. 13 herds with 138 cows participated. The liners tested had mouthpiece and barrel diameters of 24/24 mm (A) and 20/21 mm (B), both were Alfa Laval products. Teat length and diameter measured on unstimulated teats between milkings, were significantly affected by the liner used. Liner A gave 2.6 mm longer and 1.4 mm wider teats than liner B at the end of the experiment. The choice of liner had no effect on the severity of teat canal eversions. CMT-score increased over the period, but no difference between liners was observed when data for all cows were included. For first lactating cows there was a different response in the liner groups, with lowest CMT-scores at the end of the experiment for the narrowest liner (B). Laboratory diagnoses of quarter milk samples revealed no effect of liner when all cows were included. The first calvers, however, had significant lower mastitis prevalence rate in the liner B group at the end of the experiment. A tendency towards lower new infection rate, and fewer clinical mastitis cases was also observed for the narrowest liner (B).

5alpha-androstenone in fat from boars selected for rate of gain and thickness of back fat, and from boars used in artificial insemination service

Large variations in the level of 5α-androstenone in fat from different boars have been found. No significant difference in the level of 5α-androstenone was detected in fat from boars selected for high rate of gain and low back fat (HP-line), low rate of gain and high degree of fatness (LP-line) and a control group maintained without deliberate selection (GL-line). In boars used in artificial insemination service relatively high levels of 5α-androstenone in fat were observed, and in these animals a significant (P < 0.05) positive regression of 5α-androstenone level on age was found. Positive but non-significant regression coefficients were found between number of services which the boars had performed and level of 5α-androstenone in fat from the same animals.