Conjugation of HPV16 E7 to cholera toxin enhances the HPV-specific T-cell recall responses to pulsed dendritic cells in vitro in women with cervical dysplasia.

We have evaluated whether cholera toxin (CT) as a carrier/adjuvant can enhance human T-cell responses to a viral oncoprotein in vitro using dendritic cells (DCs) as antigen-presenting cells. Monocyte-derived DCs obtained from women with cervical dysplasia were pulsed with the HPV16 oncoprotein E7, either alone or conjugated to CT, and tested for their ability to induce antigen-specific activation of autologous T cells in vitro. CT-conjugation of E7 significantly improved the capacity of pulsed DCs to activate antigen-specific CD4+ T-cell proliferation and IFN-gamma secretion. The CT-E7-pulsed DCs also produced significantly more of the Th1-inducing cytokine IL-12 compared to DCs pulsed with E7 or CT alone. Furthermore, DCs pulsed with CT-conjugated HPV16 E7 caused a response in T cells from women with advanced disease (CIN III) as well as in T cells from women that were currently not infected with HPV16. These data show the potential of using CT-conjugated viral oncoproteins for DC-induced T-cell activation in humans.

Oncostatin M-induced genes in human astrocytomas.

Oncostatin M (OSM) is a member of the interleukin-6 (IL-6) cytokine family and known to be induced in the nervous system as a result of cell stress. OSM is expressed in most human brain tumors, but the effects on tumor cells are unclear. The cytokine is known to activate the JAK/STAT signaling pathway by binding to its receptors gp130/OSMbeta or gp130/LIFRbeta and thereby initiating activation or suppression of a number of STAT target genes. The objective of the study was to identify OSM-regulated genes that could help in understanding the function of OSM in glioma cells. The glioma cell line, U1242MG was stimulated by OSM and the gene expression patterns were analyzed by microarray. In total, nineteen differentially expressed genes were selected due to high intensity, level of up/down-regulation and biological functions. The differentially expressed genes were verified using quantitative PCR. Additional validation of the confirmed OSM-induced proteins was performed in human astrocytoma tissues by immunohistochemistry. Among the up-regulated genes were CHI3L1, PLAU, MT2A and EPAS1. These genes are known to be involved in cell matrix remodeling, migration, proliferation control and angiogenesis. The results suggest that OSM induces genes that might contribute to the development and progression of astrocytomas.

Therapeutic dendritic cell vaccination with Ag coupled to cholera toxin in combination with intratumoural CpG injection leads to complete tumour eradication in mice bearing HPV 16 expressing tumours.

We have evaluated whether cholera toxin (CT) can enhance the efficiency of therapeutic dendritic cell (DC) vaccination in mice bearing a human papilloma virus (HPV) 16 antigen (Ag) expressing tumour. Mice were therefore injected with the TC-1 cancer cell line expressing E6 and E7, which are the major oncogenic proteins produced in HPV-induced cervical cancer, and they were then vaccinated with Ag pulsed DCs. While vaccination with E7 pulsed DCs had no impact on tumour growth, DCs pulsed with CT conjugated E7 (CT-E7) significantly reduced tumour size. However, this treatment was only able to eradicate the tumour in 11% of the affected animals. For complete tumour eradication, combinational therapy with CT-E7 pulsed DCs and local treatment of the tumour with CpG oligodeoxynucleotides (CpG) was required. Combinational therapy was associated with increased expression of MHC I and MHC II and increased levels of chemokine production in the tumour. These results suggest that combined treatment with CT-Ag pulsed DCs and local CpG administration offers an efficient strategy to eradicate an already existing HPV-E7 expressing tumour in mice.

CpG oligodeoxynucleotide augments HSV-2 glycoprotein D DNA vaccine efficacy to generate T helper 1 response and subsequent protection against primary genital herpes infection in mice.

The present study was undertaken to evaluate the efficacy of a combined use of DNA vaccine of HSV-2 glycoprotein D (gD DNA) and CpG oligodeoxynucleotide (ODN) in comparison to gD DNA vaccine alone in inducing immunity against genital HSV-2 infection. Intramuscular vaccination of C57Bl/6 mice with gD DNA followed 48 h later by CpG ODN administration conferred a strong immunity against genital herpes infection. This was concomitant with development of a robust specific IgG2c (an indicator of Th1-type response in C57Bl/6 mice) antibody response as well as IFN-gamma production by genital lymph node and spleen cells in vitro. Administration of CpG ODN prior to gD DNA immunization, on the other hand, was inferior to immunization with gD DNA alone in providing protection against macroscopic signs of the disease. Consistent with the in vivo protection data, mice immunized with CpG ODN followed by gD DNA vaccine showed decreased specific lymphoproliferative and IFN-gamma responses compared to gD DNA vaccinated mice. In conclusion, these results indicate that timely administration of CpG ODN augments the immunity elicited by gD DNA vaccine, resulting in augmented Th1-type immunity against genital herpes infection in mice. These findings emphasize the value of using CpG ODN in a DNA vaccination scheme against genital herpes and merit also further evaluation in genetic vaccination approaches against other sexually transmitted infections.