Amplified antigen-specific immune responses in HIV-1 infected individuals in a double blind DNA immunization and therapy interruption trial.

Immunotherapy in patients with HIV-1 infection aims to restore and broaden immunological competence, reduce viral load and thereby permit longer periods without combined antiretroviral treatment (cART). Twelve HIV-1-infected patients on cART were immunized on the skin with DNA plasmids containing genes of several HIV-1 subtypes with or without the addition of hydroxyurea (HU), or with placebo. The mean net gain of HIV-specific CD8+ T cell responses were higher and broader in the HIV DNA vaccine groups compared to non-vaccinated individuals (p<0.05). The vaccine-induced immune responses per se had no direct effect on viral replication. In all patients combined, including placebo, the viral set point after a final structured therapy interruption (STI) was lower than prior to initiation of cART (p=0.003). Nadir CD4 levels appeared to strongly influence the post-STI viral titers. After the sixth immunization or placebo, patients could stay off cART for a median time of 15 months. The study shows that HIV DNA immunization induces broader and higher magnitudes of HIV-specific immune responses compared to structured therapy interruptions alone. Although compromised by small numbers of patients, the study also demonstrates that well-monitored STI may safely function as an immunological read out of HIV vaccine efficacy.

Enhancement of epitope-specific cellular immune responses by immunization with HIV-1 peptides genetically conjugated to the B-subunit of recombinant cholera toxin.

As more HIV-1 infected patients receive anti-retroviral drug treatment, the occurrence of drug-resistant variants of the virus is increasing. We have previously shown that mutated HIV peptide sequences represent mutations induced by antiretroviral drugs are equally good and often better immunogens than wild type peptides. The non-toxic B subunit of cholera toxin (CTB) is an active substance in the oral cholera vaccine, and has been shown to bind ganglioside receptors and activate mucosal cells. By fusing mutant epitopes deriving from HIV-1 enzymes with the B subunit of cholera toxin, we aim is to induce cellular responses against virus harboring drug-induced mutations. We successfully created conjugates of HIV peptide sequences fused to rCTB. The immune response against the different peptides was strongly enhanced by the fusion to the toxin. Moreover, immunization with sequence containing drug-induced mutation triggered a cross-reactive immune response against the wild type epitope. Long-term follow-up of immunized animals revealed a persistence of cellular immune response for over 4 months, which could readily be boosted with an additional late immunization. By linking HIV-peptides to the B subunit of cholera toxin it is thus possible to stimulate a strong and long-lasting immune response, significantly better than that evoked by the peptide alone.

Pre-clinical evaluation of a CEA DNA prime/protein boost vaccination strategy against colorectal cancer.

In preparation for a clinical trial in patients diagnosed with colorectal cancer, a vaccination strategy targeting the carcinoembryonic antigen (CEA) was evaluated in mice using a GMP-produced plasmid DNA vaccine, CEA66, encoding a truncated form of the tumour-associated antigen, CEA. The GMP-produced CEA DNA vaccine was also evaluated for toxicity. Repeated intradermal administration of the GMP-produced vaccine using a novel needle-free jet injection device (Biojector) induced robust CD4 and CD8 T-cell responses in mice, and did not result in any vaccine-related toxicity. In a heterologous DNA prime/protein boost setting, cellular immune responses were of higher magnitude in animals primed with CEA66 DNA than in animals receiving repeated doses of recombinant CEA protein. These responses were further enhanced if recombinant murine granulocyte-macrophage colony-stimulating factor was given as an adjuvant prior to vaccination. In contrast to repeated administration of recombinant CEA protein as a single modality vaccine, the heterologous CEA66 DNA prime/rCEA boost vaccination strategy resulted in a qualitatively broader immune response, and supports clinical testing of this vaccination regimen in humans.

The rationale behind a vaccine based on multiple HIV antigens.

The viral diversity of HIV-1 is likely to require a vaccine strategy that induces broad cellular and humoral anti-HIV-1 immunity. Our strategy is based on multiple HIV-1 DNA immunogens together with adjuvant recombinant granulocyte-macrophage stimulating factor. This article describes pre-clinical and clinical work preceding the initiation of clinical HIV-1 phase I/II trials.

Evaluating the usefulness in neuro-ophthalmology of visual field examinations peripheral to 30 degrees.

The value of the information obtained from Goldmann manual kinetic perimetry beyond 30 degrees was examined. Of 229 randomly selected patients in a University eye clinic who had visual fields performed for reasons other than glaucoma or ocular hypertension only 3 patients had abnormalities confined to the PVF of one or both eyes. In none of these three patients was the PVF necessary to detect disease (Graves' disease, 2 cases; retinoschisis, 1 case). The PVF was useful in determining the localization of the disorder and/or the therapeutic management in 14 patients of whom 4 of these had retinitis pigmentosa and 5 had other disorders where the PVF showed the extent of the retinal damage. For ergo-ophthalmologic purposes the PVF was useful in 45 patients; most frequently because the extent of abnormality provided a basis for warning the patient. In some cases the PVF was considered to be useful for economic disability determination or to exclude significant PVF defects in a patient with only one visually useful eye. In 77 patients the PVF of each eye was abnormal but not of ergo-ophthalmologic significance. If these data can be extrapolated to automated static perimetry, there will be a very great incremental cost for any clinically useful information obtained from the examination of the PVF. Because the cost-effectiveness of the examination must be compared with competing methods of obtaining information, it is proposed that the PVF be examined (1) whenever indicated for ergo-ophthalmologic reasons, or (2) when the CVF examination does not resolve a clinical problem for which there is a reasonably high probability that (a) additional clinically useful information will be obtained by examination of the PVF after the results of the CVF examination have been analyzed, or (b) the eye is likely to have a condition that can be detected or followed best by PVF examination.

Influence of thyroid surgery on voice function and laryngeal symptoms.

A comprehensive examination of voice function and laryngeal symptoms was applied systematically to 20 patients undergoing thyroid surgery. Patients were excluded from the series if there had been previous neck surgery or if postoperative indirect laryngoscopy showed abnormal cord mobility. Examination before operation showed that patients with sporadic non-toxic goitre or medically pre-treated toxic goitre had impaired voice function based on stroboscopy, electro-glottography, phono-oscillometry and determination of voice range, phonation time, pitch, and peak flow. Three months after thyroid surgery the voice function was significantly improved although not normal in non-toxic goitre patients, whereas the voice function in patients with thyrotoxicosis was unchanged. The number of laryngeal symptoms was significantly reduced in non-toxic goitres following surgery and unaltered in the group with thyrotoxicosis.

Late voice function after surgical injury to the recurrent nerve.

In the period 1960 to 1970, a total of 213 patients underwent subtotal thyroidectomy for benign cervical toxic goitre. Postoperatively, immobile vocal cord indicating paralysis of the recurrent nerve was found in 17 patients. In 8 patients, immobility of the vocal cord was permanent. Seven of the 17 patients received voice training which was initiated within 3 weeks after operation. After a period of 5-10 years, on an average 8 years, the 17 patients had a clinical and a comprehensive objective examination of the voice function comprising stroboscopy, electroglottography, phono-oscillometry, voice range, phonation time, peak-flow and pitch. Only a few complaints were ciliated whereas the objective examination of the voice function revealed abnormal findings in all but one patient. The findings were less abnormal in patients who had received early voice training. It is concluded that despite abnormal objective findings, all 17 patients found their voice function satisfactory. Moreover, early voice training seemed to offer a fair chance of minimizing late voice problems, whether the paralysis was permanent or transitory.