William Penhale

In the event of a novel influenza A virus pandemic, prophylaxis mediated by antibodies provides an adjunct control option to vaccines and antivirals. This strategy is particularly pertinent to unvaccinated populations at risk during the lag time to produce and distribute an effective vaccine. Therefore, development of effective prophylactic therapies is of high importance. Although previous approaches have used systemic delivery of monoclonal antibodies or convalescent sera, available supply is a serious limitation. Here, we have investigated intranasal delivery of influenza-specific ovine polyclonal IgG antibodies for their efficacy against homologous influenza virus challenge in a mouse model. Both influenza-specific IgG and F(ab’)2 reduced clinical scores, body weight loss and lung viral loads in mice treated 1 hour before virus exposure. Full protection from disease was also observed when antibody was delivered up to 3 days prior to virus infection. Furthermore, effective prophylaxis was independent of a strong innate immune response. This strategy presents a further option for prophylactic intervention against influenza A virus using ruminants to generate a bulk supply that could potentially be used in a pandemic setting, to slow virus transmission and reduce morbidity associated with a high cytokine phenotype.

Influenza is a perennial problem affecting millions of people annually with the everpresent threat of devastating pandemics. Active prophylaxis by vaccination against influenza virus is currently the main countermeasure supplemented with antivirals. However, disadvantages of this strategy include the impact of antigenic drift, necessitating constant updating of vaccine strain composition, and emerging antiviral drug resistance. The development of other options for influenza prophylaxis, particularly with broad acting agents able to provide protection in the period between the onset of a pandemic and the development of a strain specific vaccine, is of great interest. Exploitation of broad-spectrum mediators could provide barricade protection in the early critical phase of influenza virus outbreaks. Passive immunity has the potential to provide immediate antiviral effects, inhibiting virus replication, reducing virus shedding, and thereby protecting vulnerable populations in the event of an impending influenza pandemic. Here, we review passive broad-spectrum influenza prophylaxis options with a focus on harnessing natural host defenses, including interferons and antibodies.

The development of a simple, convenient, and reliable polypropylene screw-capped skin chamber, which can be inserted into mice, is described. All implanted chambers of normal immuno-competent mice (n ≤ 10), or immuno-suppressed mice (n ≤ 10) remained in-situ for 15 days. Wound infection was established by a clinical isolate of Pseudomonas aeruginosa in immuno-competent mice (n ≤ 10) 1 day after chamber implantation and chambers remained in-situ for 10 days. Similar infections of wounds among mice immuno-suppressed with cyclophosphamide resulted in the mouse becoming moribund due to systemic invasion by the bacterium. The authors conclude that this mouse skin chamber will be of potential value for studying wound healing during the inflammatory and early proliferative phases, and the influence of infection and treatments on these processes in immuno-suppressed and immuno-competent mice.

Nucleotide polymorphisms of the C4 genes were investigated by direct sequencing of seven different homozygous typing cells from the 10IHW panels. Two novel sequences were identified within the C4d region of the C4 genes. Our sequencing analyses extend previous findings suggesting that a recombination hot spot is likely to have occurred between codon positions 1157 and 1186 within the C4d region. The classification of electrophoretically defined C4A and C4B alleles can be further subtyped by sequencing. Because the central major histocompatibility complex region that carries various copies of the C4 gene has been associated with a range of disorders; further analysis at the sequence level within the C4 locus may provide informative genetic markers for the investigation of disease-associated polymorphisms.

In order to examine the relationship between corneodesmosin (CDSN) and psoriasis we have determined the presence of CDSN polymorphisms by DNA sequencing in (a) nine B-LCL cell lines of major histocompatibility complex ancestral haplotypes known to be associated with psoriasis vulgaris including 13.1AH, 46.1AH, 46.2 and 57.1AH, and in (b) a group of 267 unrelated individuals comprising Japanese psoriasis patients (n = 101) and Japanese subjects without the disease (n = 166). Three novel CDSN gene sequences were identified. In addition, we have classified the 18 alleles into seven main groups based on phylogeny of non-synonymous substitutions. However, we have found no statistically significant differences between the patients and the unaffected individuals in any of these groups. These findings indicate that CDSN is not a major psoriasis susceptibility gene.

Jembrana disease virus (JDV) is a newly recognised bovine lentivirus causing an acute disease syndrome in Bali cattle (Bos javanicus) in Indonesia. We evaluated the effect of JDV infection on the antibody response to chicken ovalbumin (cOVA) and Brucella abortus Strain 19 in Bali cattle. In infected cattle the IgG and IgM response to cOVA was suppressed and delayed and the IgG response to B. abortus Strain 19 was delayed. The results indicate that the humoral immune response is suppressed and delayed in JDV infected cattle.

Extrapolation to humans from experimental radioimmunotherapy in nude mouse xenograft models is confounded by large relative tumour size and small volume of distribution in mice allowing tumour uptake of radiolabelled antibodies unattainable in patients. Our large animal model of human tumours in cyclosporin-immunosuppressed sheep demonstrated tumour uptake of targeted radiolabelled monoclonal antibodies comparable with uptakes reported in clinical trials. Sheep immunosuppression with daily intravenous cyclosporin augmented by oral ketoconazole maintained trough blood levels of cyclosporin within the range 1000-1500 ng ml(-1). Human tumour cells were transplanted orthotopically by inoculation of 10(7) cells: SKMEL melanoma subcutaneously; LS174T and HT29 colon carcinoma into bowel, peritoneum and liver; and JAM ovarian carcinoma into ovary and peritoneum. Tumour xenografts grew at all sites within 3 weeks of inoculation, preserving characteristic morphology without evidence of necrosis or host rejection. Lymphatic metastasis was demonstrated in regional nodes draining xenografts of melanoma and ovarian carcinoma. Colonic LS1 74T xenografts produced mucin and carcinoembryonic antigen (CEA). The anti-CEA IgG1 monoclonal antibody A5B7 was radiolabelled with iodine-131 and administered intravenously to sheep. Peak uptake at 5 days in orthotopic human tumour transplants in gut was 0.027% DI g(-1) (percentage of injected dose per gram) and 0.034% DI g(-1) in hepatic metastases with tumour to blood ratios of 2-2.5. Non-specific tumour uptake in melanoma was 0.003% DI g(-1). Uptake of radiolabelled monoclonal antibody in human tumours in our large animal model is comparable with that observed in patients and may be more realistic than nude mice xenografts for prediction of clinical efficacy of radioimmunotherapy.

The purpose of this study was to prepare specific sera for use in the rapid detection and identification of the intestinal spirochaete Serpulina pilosicoli. In Western blot analysis, with pig antiserum which was raised against whole cells of S. pilosicoli and absorbed with outer envelope protein extracts from S. hyodysenteriae and S. innocens, a prominent protein with Mr of c. 72 kDa was consistently identified in outer envelope preparations of S. pilosicoli strains. Immunogold labelling demonstrated that this was located on the outer surface of intact S. pilosicoli cells. Two monoclonal antibodies (MAbs), designated C12 and M96, were raised against the protein. Although C12 reacted with a protein band of c. 72 kDa, this was also present in preparations from strains of other Serpulina spp. examined. MAb M96 reacted with an 80-kDa protein which was present only in preparations made from strains of S. pilosicoli. This was used in Western blot analysis and in an immunodot-blot assay with outer envelope extracts to specifically identify S. pilosicoli strains isolated from man, pigs, dogs and poultry. An indirect immunofluorescence test with MAb M96 also was used to detect and identify whole S. pilosicoli cells. Therefore, both the cross-absorbed antiserum and MAb M96 are potentially useful reagents for the detection and identification of S. pilosicoli.

The effect of oral administration of ovalbumin (OVA) or recombinant house dust mite allergen (Der p I) to dogs upon specific IgG and IgE reactions to subcutaneous immunization with these antigens was studied. Daily feeding of 10 x 10 g of OVA resulted in a non-responsiveness to subsequent parenteral immunization with OVA in two young dogs. The same two dogs were also immunized parenterally with Der p I and showed a pronounced IgG response against native Der p I, confirming that the non-responsiveness to OVA was antigen-specific. Thus, it has been demonstrated that it is possible to induce oral tolerance in dogs. Two other dogs of the same litter that received 2 x 10 mg of recombinant Der p I in a crude yeast lysate per os reacted to immunization with OVA with pronounced IgG and IgE production against OVA, further confirming the antigen-specificity of the OVA tolerance. However, tolerance to Der p I was not induced, as evidenced by a strong IgG response to immunization after per os application of the antigen, possibly because the oral dose was too small.

Local and systemic lymphocyte proliferation and antibody production were tested in five dogs 35 days after primary experimental infection with Echinococcus granulosus. A significant cell proliferation was demonstrated by [3H] thymidine incorporation in mesenteric, popliteal and/or Peyer's patches (PPs) cells in response to E. granulosus protoscolex or adult worm antigen in three of five infected dogs, but not in five control animals. In contrast, blood mononuclear cells responded very weakly in only two of the infected dogs to parasite antigens. Elevated levels (compared with preinfection status) of protoscolex- and adult worm antigen-specific serum IgG were detected (ELISA) in four of the five dogs 35 days after infection. Furthermore, slightly elevated levels of parasite-specific IgE and IgA were observed in the sera of three and four infected dogs, respectively. Specific serum IgM was not significantly higher 35 days after infection than before infection. Local antibody production was studied in vitro using PPs, mesenteric and popliteal cells isolated from three infected and three uninfected dogs by ELISA using adult worm antigen. In two of three cultures of unstimulated PPs cells of infected dogs, parasite-specific IgG was detectable. Parasite-specific IgA and IgM were detected in one of the unstimulated PPs cell culture derived from an infected dog. Following in vitro stimulation with parasite antigen, PPs cells from two infected dogs showed increased parasite-specific IgG and PPs cells of all three infected dogs produced parasite-specific IgA. PPs cells from uninfected dogs did not produce significant quantities of parasite-specific antibodies and cells from mesenteric and popliteal lymph nodes of infected or uninfected dogs neither produced antibodies whilst in in vitro cultures.