Cell-mediated DNA transport between distant inflammatory sites following intradermal DNA immunization in the presence of adjuvant

MUC1 expressing tumor growth was retarded after human mucin 1 (MUC1) plasmid DNA immunization

Introduction

Naked DNA is one of the attractive tools for vaccination studies. We studied naked DNA vaccination against the human tumor antigen, mucin, which is encoded by the MUC1 gene.

Methods

We constructed the pcDNA3.0-MUC1 (pcDNA-MUC1) plasmid expressing an underglycosylated MUC1 protein. BALB/c mice were immunized intradermally thrice at 2-weeks intervals with pcDNA-MUC1. Two weeks after the last immunization, tumor challenge experiments were performed using either the CT26 or TA3HA tumor cell lines, both of which transduce human MUC1.

Results

Immune cell population monitoring from pcDNA-MUC1-immunized animals indicated that immune cell activation was induced by MUC1-specific immunization. Using intracellular fluorescence activated cell sorting and enzyme-linked immunosorbent spot assay, we reported that interferon-γ secreting CD8⁺ T cells were mainly involved in MUC1-specific immunization. In all mice immunized with MUC1 DNA, tumor growth inhibition was observed, whereas control mice developed tumors (p < 0.001).

Conclusion

Our results suggest that intradermal immunization with MUC1 DNA induces MUC1-specific CD8⁺ T cell infiltration into tumors, elicits tumor-specific Th1-type immune response, and inhibits tumor growth.

DNA Vaccination With Hsp70 Protects Against Systemic Lupus Erythematosus in (NZB × NZW)F1 Mice

OBJECTIVE

To address whether a targeted modulation of the abnormal expression of Hsp70 and autoantibodies against this molecule in systemic lupus erythematosus can influence disease.

METHODS

Lupus-prone (NZB × NZW)F1 mice that had been DNA-vaccinated with plasmids encoding Hsp70 and controls were monitored for lupus disease parameters including anti-double stranded DNA (anti-dsDNA) autoantibodies and cytokines using enzyme-linked immunosorbent assay, and for kidney function and pathology. The phenotypic and numerical changes in relevant immune cells were evaluated by flow cytometry, and cell function was assessed.

RESULTS

Mice that had been DNA-vaccinated with Hsp70 displayed marked suppression of anti-dsDNA antibody production, reduced renal disease, and antiinflammatory responses that are associated with a significantly extended survival, compared to controls. These protective effects in Hsp70-vaccinated mice were associated with an induction of tolerogenic immune responses and an expansion of functional Treg cells.

CONCLUSION

DNA vaccination with Hsp70 suppresses murine lupus by inducing tolerogenic immune responses and antiinflammatory immune responses associated with reduced disease manifestations and increased mouse survival.

B lymphocytes as direct antigen-presenting cells for anti-tumor DNA vaccines

In spite of remarkable preclinical efficacy, DNA vaccination has demonstrated low immunogenicity in humans. While efforts have focused on increasing cross-presentation of DNA-encoded antigens, efforts to increase DNA vaccine immunogenicity by targeting direct presentation have remained mostly unexplored. In these studies, we compared the ability of different APCs to present antigen to T cells after simple co-culture with plasmid DNA. We found that human primary peripheral B lymphocytes, and not monocytes or in vitro derived dendritic cells (DCs), were able to efficiently encode antigen mRNA and expand cognate tumor antigen-specific CD8 T cells ex vivo. Similarly, murine B lymphocytes co-cultured with plasmid DNA, and not DCs, were able to prime antigen-specific T cells in vivo. Moreover, B lymphocyte-mediated presentation of plasmid antigen led to greater Th1-biased immunity and was sufficient to elicit an anti-tumor effect in vivo. Surprisingly, increasing plasmid presentation by B cells, and not cross presentation of peptides by DCs, further augmented traditional plasmid vaccination. Together, these data suggest that targeting plasmid DNA to B lymphocytes, for example through transfer of ex vivo plasmidloaded B cells, may be novel means to achieve greater T cell immunity from DNA vaccines.

Toxicology and biodistribution study of CIGB-230, a DNA vaccine against hepatitis C virus

CIGB-230, a mixture of a DNA plasmid expressing hepatitis C virus (HCV) structural antigens and a HCV recombinant capsid protein, has demonstrated to elicit strong immune responses in animals. The present study evaluated the plasmid biodistribution after the administration of CIGB-230 in mice, as well as toxicity of this vaccine candidate in rats. In the biodistribution study, mice received single or repeated intramuscular injections of CIGB-230, 50 μg of plasmid DNA mixed with 5 μg of Co.120 protein. Plasmid presence was assessed in ovaries, kidney, liver, pancreas, mesenteric ganglion, blood, and muscle of the injection site by a qualitative polymerase chain reaction. The toxicology evaluation included treatment groups receiving doses 5, 15, or 50 times higher, according to the body weight, than the expected therapeutic clinical dose. During the first hour after repeated inoculation, a promiscuous distribution was observed. However, 3 months later, plasmid could not be detected in any tissue. There was an absence of detectable adverse effects on key toxicology parameters and no damage evidenced in inspected organs and tissues. These results indicate that CIGB-230 is nontoxic at local and systemic levels and no concerns about persistence are observed, which support clinical testing of this vaccine candidate against HCV.

A pcDNA-Ehcpadh vaccine against Entamoeba histolytica elicits a protective Th1-like response in hamster liver

DNA vaccines are promising tools to fight parasitic diseases, including amoebiasis caused by the protozoan Entamoeba histolytica. Here we studied the immunogenicity and protective efficacy of a DNA vaccine against this parasite composed by the EhCPADH surface complex encoding genes (Ehcp112 and Ehadh112). EhCPADH is formed by an adhesin (EhADH112) and a cysteine proteinase (EhCP112), both involved in the parasite virulence. We evaluated transcription, protein expression, immunological response and protection against hepatic amoebiasis in hamsters intradermally and intramuscularly immunized with a mixture of pcDNA-Ehadh112 and pcDNA-Ehcp112 plasmids. RT-PCR and immunohistochemical assays showed that both antigens were differentially expressed in spleen and liver of immunized animals. No significant antibody immune response was induced by either route. However, intradermally inoculated hamsters presented a robust Th1-like immune response, characterized by high levels of INF-gamma and TNF-alpha cytokines, detected in the liver of animals challenged with virulent trophozoites. Animals showed significant protection against amoebiasis manifested by a higher survival rate and a significant prevention of liver abscess formation. We conclude that a refinement of this DNA vaccine could be a good choice to control hepatic amoebiasis.

Protection against renal disease in (NZB x NZW)F(1) lupus-prone mice after somatic B cell gene vaccination with anti-DNA immunoglobulin consensus peptide

OBJECTIVE

Ig molecules contain epitopes that can induce T cell-mediated immune responses. B cells can process and present such epitopes and activate T cells. The purpose of the present study was to test our hypothesis that T cells that recognize an Ig consensus sequence presented by B cells will modulate lupus-like disease in mice.

METHODS

(NZB x NZW)F(1) (NZB/NZW) lupus mice received somatic B cell gene transfer of a DNA plasmid encoding a consensus sequence of T cell determinants of murine anti-DNA IgG or control plasmids. Treated animals were monitored for the production of antibody, the development of renal disease, and the phenotype, number, and function of T cells.

RESULTS

Treatment of mice with Ig consensus plasmid induced transforming growth factor beta-producing CD8+,CD28- T cells that suppressed the antigen-specific stimulation of CD4+ T cells in a cell-contact-independent manner, reduced antibody production, retarded the development of nephritis, and improved survival. Significantly, adoptive transfer of CD8+,CD28- T cells from protected mice into hypergammaglobulinemic NZB/NZW mice effectively protected the transferred mice from the development of renal disease.

CONCLUSION

Gene expression of anti-DNA Ig consensus sequence induces immunoregulatory T cells that delay the development of lupus nephritis by suppressing hypergammaglobulinemia and renal disease.

Gene therapy and wound healing

Wound repair involves the sequential interaction of various cell types, extracellular matrix molecules, and soluble mediators. During the past 10 years, much new information on signals controlling wound cell behavior has emerged. This knowledge has led to a number of novel therapeutic strategies. In particular, the local delivery of pluripotent growth factor molecules to the injured tissue has been intensively investigated over the past decade. Limited success of clinical trails indicates that a crucial aspect of the growth factor wound healing strategy is the effective delivery of these polypeptides to the wound site. A molecular approach in which genetically modified cells synthesize and deliver the desired growth factor in regulated fashion has been used to overcome the limitations associated with the (topical) application of recombinant growth factor proteins. We have summarized the molecular and cellular basis of repair mechanisms and their failure, and we give an overview of techniques and studies applied to gene transfer in tissue repair.

Nonviral delivery of cancer genetic vaccines

The potential use of genetic vaccines to address numerous diseases including cancer is promising, but currently unrealized. Here, we review advances in the nonviral delivery of antigen-encoded plasmid DNA for the purpose of treating cancer through the human immune system, as this disease has drawn the most attention in this field to date. Brief overviews of dendritic cell immunobiology and the mechanism of immune activation through genetic vaccines set the stage for the desirability of delivery technology. Several promising nonviral delivery techniques are discussed along with a mention of targeting strategies aimed at improving the potency of vaccine formulations. Implications for the future of genetic vaccines are also presented.

Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system.

Gene transfer in tissue repair: status, challenges and future directions

Wound repair involves a complex interaction of various cell types, extracellular matrix molecules and soluble mediators. Details on signals controlling wound cell activities are beginning to emerge. In recent years this knowledge has been applied to a number of therapeutic strategies in soft tissue repair. Key challenges include re-adjusting the adult repair process in order to augment diseased healing processes, and providing the basis for a regenerative rather than a reparative wound environment. In particular, the local delivery of pluripotent growth factor molecules to the injured tissue has been intensively investigated over the past decade. Limited success of clinical trials indicates that an important aspect of the growth factor wound-healing paradigm is the effective delivery of these polypeptides to the wound site. A molecular genetic approach in which genetically modified cells synthesise and deliver the desired growth factor in a time-regulated manner is a powerful means to overcome the limitations associated with the (topical) application of recombinant growth factor proteins. This article summarises repair mechanisms and their failure, and gives an overview of techniques and studies applied to gene transfer in tissue repair. It also provides perspectives on potential targets for gene transfer technology.

Biodistribution and general safety of a naked DNA plasmid, GTU®-MultiHIV, in a rat, using a quantitative PCR method

We studied the general safety, biodistribution and persistence of a naked DNA plasmid in a rat model using intramuscular, intradermal and intravenous routes of administration. Clinical signs were followed up throughout the study and at the necropsy. Tissue samples were collected at the necropsy at 2, 14 and 28 days after injection of 200 microg of plasmid DNA and analysed with validated quantitative polymerase chain reaction (QPCR). The plasmid (GTU-MultiHIV) was shown to be well tolerated and no clinical observations related to the vaccine were found. Within 2 days after the intramuscular and intradermal injections, the plasmid could be detected in the lymph nodes and also at 14 days in a few test animals. The quantitative PCR analysis indicated that in positive lymph nodes one of 15-213 dendritic cells could be carrying the plasmid. No plasmid was detected in gonads or brain samples in any of the study groups. In intramuscular and intradermal administration, low amounts of the plasmid DNA persisted at the injection site 28 days after the injection, whereas a complete clearance with intravenous route was observed already at 14 days. The results show that the GTU-MultiHIV plasmid is safe and suitable for human clinical trials.

Immune modulation of collagen-induced arthritis by intranasal cytokine gene delivery: A model for the therapy of rheumatoid arthritis

OBJECTIVE

To develop a passively targeted, patient-compliant, intranasal interleukin-10 (IL-10) gene therapy delivery system and to investigate its therapeutic benefit in experimental collagen-induced arthritis, a model of rheumatoid arthritis.

METHODS

Arthritis was induced in DBA/1 mice and monitored following intranasal administration of an IL-10 plasmid (pG-IL-10) or the empty vector 2 days (days -2 and 19) prior to collagen injection (prophylactic group, as a single dose after collagen boost on day 21 (early therapy group, or as a single dose upon acquisition of a disease score of 3 (late therapy group. IL-10-induced alterations in cytokine secretion and proliferation by spleen and lymph node cells were assessed on days 31 and 65 and correlated with histologic changes and bone erosions assessed on day 65.

RESULTS

Intranasal delivery of pG-IL-10 significantly delayed arthritis onset and reduced disease severity in the prophylactic group and early therapy group, reduced cellular infiltration and bone loss in the early therapy group, and reduced T cell proliferation in response to collagen on days 31 and 65 in these two groups, with a significant reduction in tumor necrosis factor alpha production on day 65. Within the late therapy group, disease progression was arrested for the rest of the study. The intranasally administered pG-IL-10 targeted monocytes and macrophages and showed dissemination to inflamed joints and draining lymph nodes in vivo. Importantly, systemic levels of IL-10 (in serum) were transient (peaking on day 2) and undetectable by day 4.

CONCLUSION

Intranasal IL-10 gene delivery significantly reduces bone destruction, shows evidence of reducing joint inflammation, and may be mediated by high local levels of IL-10 produced by transfected monocytes trafficking to inflamed joints and draining lymph nodes.

Soluble cytokines can act as effective adjuvants in plasmid DNA vaccines targeting self tumor antigens

There are few vaccination strategies available for the reproducible generation of a cytotoxic T cell (CTL) response, particularly in the setting of immunizing against a tumor antigen. Plasmid-based DNA vaccination offers several advantages as compared to MHC class I peptide-based vaccines or DNA immunization using viral vectors. Plasmid-based DNA vaccines are easily produced, can potentially elicit both an MHC class I and class II response, and have little infectious potential. Plasmid-based vaccines, however, have been poorly immunogenic. The systemic immune response generated after plasmid vaccination relies on in vivo transfection of local antigen presenting cells (APC) and both direct presentation and "cross priming" of antigen by professional and non-professional APC. Therefore, methods to enhance the function of APC, such as simultaneous inoculation with plasmids encoding cytokine genes, has resulted in an enhancement of detectable immunity after vaccination. We questioned whether local application of soluble cytokines would be effective in enhancing the systemic immune response elicited after DNA vaccination. Using a self-tumor antigen model, we vaccinated rats with a plasmid-based rat neu intracellular domain (ICD) DNA construct and either no adjuvant, soluble GM-CSF, or IL-12. We demonstrate that the addition of soluble GM-CSF or IL-12 to rat neu ICD DNA vaccination elicits detectable neu specific T cell immunity; specifically the generation of CTL. Antibodies directed against rat neu were not elicited with this approach, indicating that the neu specific T cell immune response elicited with plasmid DNA was skewed towards cell-mediated rather than humoral immunity.

B-lymphocytes in bone marrow or lymph nodes can take up plasmid DNA after intramuscular delivery

Nucleic acid vaccines are an attractive alternative to conventional protein vaccines because of their ability to induce de novo production of antigens in a given tissue after DNA delivery. Although DNA vaccines are highly effective in inducing both cell-mediated and humoral immunity, little is known about the many cell types involved in plasmid DNA uptake in vivo. Here we demonstrate, for the first time, that plasmid DNA can be taken up by both bone marrow and lymph node B cells after intramuscular immunization. Plasmid DNA was also detected in CD11b+ and CD11c+ cells. This phenomenon was not restricted to plasmid DNA encoding mycobacterial 65-kd heat shock protein (pcDNA3-hsp65) because we observed similar results with plasmid-encoding green fluorescent protein (GFP-pEGFP-2C). In addition to plasmid DNA uptake, B cells also express the encoded protein, suggesting that B cells play a role in the immune response after DNA immunization. The biodistribution of plasmid DNA in B cells opens a new perspective in B-cell gene therapy for the in vivo use of plasmid DNA.

Optimization of DNA-based vaccination in cows using green fluorescent protein and protein A as a prelude to immunization against staphylococcal mastitis

Staphylococcus aureus is a contagious pathogen that often results in chronic intramammary infections in dairy cows. Current vaccine formulations are ineffective in preventing this infection. The objective of this study was to stimulate an immune response in dairy cows through injection of plasmid DNA designed to express staphylococcal Protein A in transfected cells. Intramuscular and intradermal vaccination sites were evaluated using a plasmid containing the human cytomegalovirus (CMV) promoter/enhancer directing expression of green fluorescent protein (pcDNA3/GFP). DNA was delivered by needle and syringe, or by high-, intermediate-, or low-pressure jet injections (Ped-o-Jet and LectraJet). Five cows per treatment were injected with 0.5 mg of plasmid DNA at 6, 4, and 2 wk prepartum. Serum antibody levels determined by ELISA indicated that intradermal high-pressure jet injection elicited a greater immune response compared to needle and syringe injection. Differences in antibody production among low-pressure and needle and syringe treatment groups were not significant. An expression plasmid containing the CMV promoter/enhancer driving expression of the Fc-binding domain of S. aureus Protein A was coinjected into cows by vulvamucosal vaccination using the high-pressure Ped-o-Jet. Beginning 6 wk prepartum, groups of cows (n = 5) were injected three times at 2-wk intervals with DNA in saline, DNA in aluminum phosphate adjuvant, or served as noninjected controls. A cellular immune response to Protein A was detected in 4 of 10 animals, while cellular responses to GFP were not detected. Humoral responses to Protein A were observed in 6 of 10 animals and to GFP in 2 of 10 animals. Aluminum phosphate adjuvant appeared to enhance antibody production in response to Protein A. In experiment 3, a protein boost injection of Protein A was given to six animals approximately 5 mo postpartum. Three animals were nonvaccinated controls, and three were among those stimulated to produce antibody in response to the DNA-based vaccine. These results showed that Protein A specific antibodies remained elevated as compared to nonvaccinated controls and were stimulated in response to the protein boost. However, the magnitude of the response in animals previously vaccinated with DNA was not different than that observed in the nonvaccinated controls. We have shown that a humoral and cellular immune response to abbreviated Protein A can be raised in dairy cows using intravulvamucosal jet injection of a DNA-based vaccine.

Vaccination of mice with MUC1 cDNA suppresses the development of lung metastases

C57BL/6 mice were immunized intradermally with various doses of purified pCEP4 plasmid DNA containing full-length MUC1 cDNA (22 tandem repeats). Mice immunized with MUC1 DNA three times at weekly intervals had serum antibodies to a synthetic peptide corresponding to the tandem repeats of MUC1. The antibody titer correlated with the plasmid DNA dose. After the third immunization mice were injected intravenously with 5 x 10(5) 16-F10 melanoma cells that had been stably transfected with MUC1 cDNA (F10-MUC1-C8 clone cells). The number of lung metastatic nodules three weeks after inoculation of F10-MUC1-C8 cells was significantly lower in mice immunized with MUC1 plasmid DNA than in mice immunized with the vector DNA alone. Thus, the suppression of lung metastasis was antigen-specific. In vivo depletion of lymphocyte subpopulations by specific antibodies revealed that natural killer cells are the major effector cells responsible for the suppression of lung metastasis. CD4+ cells and CD8+ cells apparently played some roles too.

Suppression of cutaneous inflammation by intradermal gene delivery

Biological effects of in vivo transfection of a potential anti-inflammatory gene, designated Sm16, cloned from the human parasite Schistosoma mansoni were analyzed in these studies. A single intradermal injection of a full-length cDNA of Sm16 resulted in the expression of Sm16 in the epidermis, dermis, skin migratory cells and skin-draining lymph nodes of mice for up to 7 days. Subsequently the anti-inflammatory effect of this gene expression was evaluated by inducing an inflammatory response in the skin of mice. These studies showed that Sm16 gene delivery resulted in a significant suppression of cutaneous inflammation as shown by a reduction in cutaneous edema, decrease in neutrophil infiltration, suppression of pro-inflammatory cytokine expression and down-regulation of ICAM-1 expression in the skin inflammatory site. Cells collected from the skin-draining lymph nodes showed reduced proliferation to mitogen. Multiple intradermal injection of Sm16 cDNA failed to induce any antibody response in mice for up to 8 weeks after initial injection. These findings suggest a potential for developing Sm16 gene delivery as a therapeutic agent for treating inflammatory skin disorders.

Topical application of the cornea post-infection with plasmid DNA encoding interferon-alpha1 but not recombinant interferon-alphaA reduces herpes simplex virus type 1-induced mortality in mice

A study was undertaken to compare the efficacy of recombinant interferon (rIFN)-alphaA to plasmid DNA encoding IFN-alpha1 against ocular herpes simplex virus type 1 (HSV-1) infection. The topical application of rIFN-alphaA (100-300 units/eye) onto the cornea of mice subsequently infected 24 h later with HSV-1 antagonized viral-induced mortality. The enhancement in cumulative survival in the rIFN-alphaA-treated mice correlated with a reduction of viral titers recovered in the eye and trigeminal ganglion (TG) at 3 and 6 days post-infection. The protective effect was site-specific such that when rIFN-alphaA was administered orally or intranasally, no efficacy against HSV-1 was observed. However, the protective effect was time-dependent. Specifically, when the rIFN-alphaA (100-1000 units/eye) was administered at 24 h post-infection, no protective effect was observed against HSV-1 compared to the vehicle-treated group. In contrast, plasmid DNA (100 microg/eye) containing the IFN-alpha1 transgene showed significant protection when topically applied 24 h post-infection. Although the transgene was found to traffic distal from the site of application (eye), including the trigeminal ganglion and the spleen where CD11b(+) and CD11c(+) cells express the transgene, the migration of the transgene did not correlate with efficacy. Collectively, the results suggest that naked DNA encoding type I IFN applied post-infection provides a greater degree of protection against ocular HSV-1 infection in comparison with recombinant protein effectively antagonizing viral replication and spread.

Antigen-independent suppression of the allergic immune response to bee venom phospholipase A(2) by DNA vaccination in CBA/J mice

Phospholipase A(2) (PLA(2)) is one of the major honey bee venom allergens for humans. To assess the long-term prevention of allergic reactions by DNA vaccination, a PLA(2)-CBA/J mouse model was employed using empty or PLA(2) sequence-carrying DNA plasmids. Early skin application of either DNA construct before (prophylactic approach) or after (therapeutic approach) sensitization with PLA(2)/alum led to reduced PLA(2)-specific IgE and IgG1 titers at 7 mo, with concomitant rise in IgG2a and IgG3. Splenocytes recovered at 5-6 mo after the last DNA administration exhibited a sustained IFN-gamma and IL-10 secretion and reduced IL-4 production. Recall challenge with PLA(2) boosted IFN-gamma and IL-10 secretion, suggesting the reactivation of quiescent memory Th1 lymphocytes. Mice from the prophylactic groups were fully protected against anaphylaxis, whereas 65% of the animals recovered in the therapeutic groups. Th1-polarized immune responses were also active in mice vaccinated with an empty plasmid 32 wk before sensitization with another Ag (OVA). This is the first demonstration that the Ag-coding sequence in DNA vaccine is not necessary to promote immune modulation in naive and sensitized animals for a prolonged period, and has relevance for the understanding of the innate and induced mechanisms underlying gene immunotherapy in long-term treatment of allergy.

The role of IFN-gamma in systemic lupus erythematosus: a challenge to the Th1/Th2 paradigm in autoimmunity

The classification of T helper cells into type 1 (Th1) and type 2 (Th2) led to the hypothesis that Th1 cells and their cytokines (interleukin [IL]-2, interferon [IFN]-gamma) are involved in cell-mediated autoimmune diseases, and that Th2 cells and their cytokines (IL-4, IL-5, IL-10, IL-13) are involved in autoantibody(humoral)-mediated autoimmune diseases. However, this paradigm has been refuted by recent studies in several induced and spontaneous mouse models of systemic lupus erythematosus, which showed that IFN-gamma is a major effector molecule in this disease. These and additional findings, reviewed here, suggest that these two cross-talking classes of cytokines can exert autoimmune disease-promoting or disease-inhibiting effects without predictability or strict adherence to the Th1-versus-Th2 dualism.

The application of a plasmid DNA encoding IFN-alpha 1 postinfection enhances cumulative survival of herpes simplex virus type 2 vaginally infected mice

Using a hormonally induced susceptibility mouse model to investigate vaginal HSV type 2 (HSV-2) infection, a study was undertaken to determine the efficacy of a plasmid DNA encoding IFN-alpha1 introduced into the vaginal lumen postinfection (PI). Mice infected with HSV-2 intravaginally and treated intravaginally 24 h later with 100 microg DNA encoding IFN-alpha1 showed enhanced survival (10/15) in comparison to mice treated with 100 microg plasmid DNA vector alone (3/10) or vehicle (4/27). In contrast, mice receiving recombinant IFN-alphaA (5-500 U/vagina) 24 h PI showed no significant survival in comparison to the vehicle (saline)-treated group. The protective effect was time dependent in that mice receiving the IFN-alpha1 transgene 48 h PI succumbed at a rate similar to the plasmid DNA vector-treated group. The increase in cumulative survival elicited by the transgene corresponded with a reduction in viral replication and Ag expressed in the vaginal epithelium early (i.e., 3 days PI) during acute infection and replicating virus recovered in the spinal cord day 7 PI. By day 7 PI, HSV-2 glycoprotein B transcript expression was no longer detectable in vaginal tissue from the IFN-alpha1 transgene-treated group (0/8) compared with levels expressed in plasmid vector-treated controls (4/6 mice surveyed were positive). Collectively, these results suggest the application of DNA encoding type I IFN is an effective and alternative approach to currently prescribed therapies in controlling vaginal HSV-2 infection by antagonizing viral replication.

Treatment of murine lupus with cDNA encoding IFN-gammaR/Fc

IFN-gamma, a pleiotropic cytokine, is a key effector molecule in the pathogenesis of several autoimmune diseases, including lupus. Importantly, deletion of IFN-gamma or IFN-gammaR in several lupus-predisposed mouse strains resulted in significant disease reduction, suggesting the potential for therapeutic intervention. We evaluated whether intramuscular injections of plasmids with cDNA encoding IFN-gammaR/Fc can retard lupus development and progression in MRL-Fas(lpr) mice. Therapy significantly reduced serum levels of IFN-gamma, as well as disease manifestations (autoantibodies, lymphoid hyperplasia, glomerulonephritis, mortality), when treatment was initiated at the predisease stage, particularly when IFN-gammaR/Fc expression was enhanced by electroporation at the injection site. Remarkably, disease was arrested and even ameliorated when this treatment was initiated at an advanced stage. This therapy represents a rare example of disease reversal and makes application of this nonviral gene therapy in humans with lupus (and perhaps other autoimmune/inflammatory conditions) highly promising.

Genetic immunization for the recovery and purification of recombinant proteins

A system that uses genetic immunization for recombinant protein recovery and purification is described. The genetic sequence encoding a target protein is subcloned into both a eukaryotic and a prokaryotic vector. With the eukaryotic construct, a rabbit is genetically immunized and specific polyclonal antibodies to the encoded protein raised. The prokaryotic construct is used for bacterial transformation and expression of recombinant protein. Recovery and purification of target recombinant protein are obtained by passing the lysate of expressing bacteria through an immunoaffinity column prepared with the polyclonal antibodies raised in the genetically immunized animal. This method allows purification of recombinant protein without fusion tails and can be applied to purify any protein whose encoding genetic sequence is known.