Therapeutic vaccination of koalas harbouring endogenous koala retrovirus (KoRV) improves antibody responses and reduces circulating viral load

The long-term survival of the koala is under serious threat from multiple factors, including infectious disease agents such as Chlamydia and koala retrovirus (KoRV). KoRV is present in both exogenous and endogenous forms, depending on the geographical location of the population. In the northern half of Australia, it is present as an endogenous infection in all koalas, making a case for an urgent need to develop a therapeutic vaccine that might prevent KoRV-associated pathologies in these koalas. To this end, we determined the therapeutic effects of vaccinating koalas harbouring endogenous KoRV with a recombinant KoRV Env protein combined with a Tri-adjuvant. We found that vaccination led to a significant increase in circulating anti-KoRV IgG levels, as well as increase in neutralising antibodies. Our study also showed that post-vaccination antibodies were able to recognize epitopes on the Env protein that were unrecognised pre-vaccination, as well as resulting in an increase in the recognition of the previously recognised epitopes. The vaccine also induced antibodies that were cross-reactive against multiple KoRV-subtypes. Finally, we found a complete clearance of KoRV-A in plasma from koalas that had detectable levels of KoRV-A pre-vaccination. Similarly, there was a significant reduction in the expression of KoRV-B viral RNA levels post-vaccination. Collectively, this study showed that koalas harbouring endogenous KoRV can benefit from prophylactic vaccination against KoRV using a recombinant KoRV-A Env protein and that the mechanism of this protection might be through the boosting of natural anti-KoRV antibodies and expanding the breadth of the recognised epitopes.Olusola Olagoke, Bonnie L. Quigley, Farhid Hemmatzadeh, Galit Tzipori, and Peter Timm

A non-contacting thermal wave technique for NDT of coatings and other applications in the CEGB Current status (July 1987)

SIGLEAvailable from British Library Document Supply Centre- DSC:7761.062(TPRD/M--1684/RR88) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A non-contacting thermal wave technique for NDT of coatings and other applications in the CEGB Current status (July 1987)

SIGLEAvailable from British Library Document Supply Centre- DSC:7761.062(TPRD/M--1684/RR88) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Colostral immunoglobulins absorption in Canchim and Nelore calves Absorção de imunoglobulinas do colostro em bezerros das raças Canchim e Nelore

The efficiency of absorption of colostral immunoglobulins was evaluated in five Canchim and seven Nelore calves. They received colostrum pools with concentration of 70.20 ± 6.14 mg/mL through esofageal feeder at 2, 12, 24 and 36 hours after birth. The immunoglobulins concentrations of the pools were estimated through specific gravity and measured by radial immunodifusion. In the blood collection at birth and during the first 70 days of life, the total protein was assayed by biuret method and the immunoglobulins were assayed by radial immunodifusion. Data were analysed as a randomized split-plot statistical model. The highest concentrations of serum immunoglobulins and total protein were observed at 24 hours of age. No significant differences (P>0.5484) were observed for immunoglobulins concentration at 24 hours, with concentrations of 28.80 ± 7.24 mg/mL for Canchim and 27.32 ± 9.54 mg/mL for Nelore. The efficiency for immunoglobulins absorption was not significantly different (P>0.8715) between breeds, 64.04 ± 7.74% for Canchim and 62.30 ± 6.93% for Nelore. The lack of statistical significance persisted until the fourtieth day of life, period of maternal immunoglobulin predominance in the calves blood circulation. In the following period, from 40 to 70 days of age, phase of establishment of the endogenous production of immunoglobulin, differences in the IgG concentrations between the two groups were detected refflecting a possible breed effect difference. The process of colostral IgG absorption by the newborn calves was not affected by breed. The differences between breeds in the calves serum IgG were related to the phase of endogenous production of antibodies.<br>A eficiência de absorção de imunoglobulinas do colostro foi avaliada em cinco bezerros da raça Canchim e sete bezerros da raça Nelore. Os bezerros receberam colostro de "pools" com concentração média de 70,20 ± 6,14 mg/mL, por sonda esofagiana, às 2, 12, 24 e 36 horas após o nascimento. As concentrações de imunoglobulinas dos "pools" foram estimadas por gravidade específica e quantificadas por imunodifusão radial. No sangue obtido ao nascimento e durante os primeiros 70 dias de idade, a proteína total foi analisada pelo método do biureto e as imunoglobulinas séricas, quantificadas por imunodifusão radial. O delineamento experimental foi inteiramente casualizado em parcelas subdivididas no tempo. As concentrações máximas de imunoglobulinas séricas e de proteína total foram observada às 24 horas de idade. Não foi observada diferença significativa quanto à concentração de imunoglobulinas às 24 horas (P>0,5484), com valores médios de 28,80 ± 7,24 mg/mL para Canchim e de 27,32 ± 9,54 mg/mL para Nelore. A eficiência de absorção das imunoglobulinas não diferiu significativamente (P> 0,8715) entre as raças, sendo 64,04 ± 7,74% para Canchim e 62,30 ± 6,93% para Nelore. A ausência de diferença significativa estendeu-se até o 40º dia, período de predominância de anticorpos maternos na corrente sangüínea do bezerro. No período seguinte, dos 40 aos 70 dias de idade, fase de estabelecimento da produção endógena de anticorpos, verificaram-se diferenças na concentração de IgG entre os dois grupos de animais, refletindo provavelmente o comportamento diferenciado das raças. O processo de absorção das imunoglobulinas provenientes do colostro pelos bezerros recém-nascidos não foi afetado pela raça. As diferenças entre raças na concentração sérica de IgG foram relacionadas à fase endógena de produção de anticorpos