Comparison of adjuvant activities of glucosaminyl-muramyl dipeptide and of the gene coding for granulocyte-macrophage colony-stimulating factor in DNA immunization against herpes simplex virus

Adjuvant activities of granulocyte-macrophage colony-stimulating factor (GM-CSF) and synthetic glucosaminyl-muramyl dipeptide (GMDP) were studied in immunization against type 1 herpes simplex virus (HSV1). Gene encoding the gD HSV1 protein (pDNAgD) was used as an immunogen. Gene encoding GM-CSF in pDNAGM-CSF plasmid, which was developed for eukaryotic expression, and GM-DP were used as immune response modulators. GMDP and plasmid DNA with inserted GM-CSF gene enhanced T-cell immune response to HSV1 after a single injection (pDNAGM-CSF) or 24 h before (GMDP) immunization with the gD HSV1 gene. Both adjuvants increased protective effect of DNA-immunization by a virus gene with 63 up to 100% after injection of two genes and up to 96% after the viral gene was inoculated 24 h after GMDP. These high effects indicate that further investigation of anti-HSV1 DNA-based vaccines used with genetic and peptide adjuvant is prospective.     

Comparison of immune response in sheep immunized with DNA vaccine encoding Toxoplasma gondii GRA7 antigen in different adjuvant formulations

Immunization with plasmid DNA, a relatively novel technique, is a promising vaccination technique. To improve the immune response by DNA vaccination various methods have been used, such as chemical adjuvants or immunomodulatory molecules formulated into microparticles or liposomes. The aim of this research is to evaluate the immune responses of sheep immunized with DNA plasmids encoding Toxoplasma gondii dense granule antigen GRA7 formulated into three different adjuvant formulations. Sixty sheep were injected intramuscularly with the DNA plasmids. Twelve received the liposome-formulated plasmid pVAXIgGRA7, 12 Emulsigen P formulated plasmid pVAXIgGRA7 and 12 Emulsigen D formulated plasmid pVAXIgGRA7. Twelve animals were used as a control and received the vector alone. All the animals were inoculated at week 0, and week 4. Immunization of the sheep with plasmids encoding GRA7, with the different adjuvant formulations, effectively primed the immune response. After the first inoculation, moderate to high antibody responses were observed with the three different adjuvant formulations. A significantly elevated specific IgG2 response was observed in the sheep immunized with liposomes and Emulsigen D as adjuvants. In the group immunized with Emulsigen P as an adjuvant, lower IgG1 and IgG2 antibody levels were developed compared to the other treatment groups. In all the immunized groups, DNA immunization stimulated a IFN-γ response. No antibody or IFN-γ responses were detected in the control group immunized with an empty plasmid or not immunized. These results indicate that intramuscular immunization of sheep with a DNA vaccine with the adjuvants liposomes and Emulsigen D induce a significant immune response against T. gondii.     

Effective DNA vaccination against listeriosis by prime/boost inoculation with the gene gun.

Protective immunity against Listeria monocytogenes strongly depends on CD8+ T lymphocytes, and both IFN-gamma secretion and target cell killing are considered relevant to protection. We analyzed whether we could induce a protective type 1 immune response by DNA vaccination with the gene gun using plasmids encoding for two immunodominant listerial Ags, listeriolysin and p60. To induce a Th1 response, we 1) coprecipitated a plasmid encoding for GM-CSF, 2) employed a prime/boost vaccination schedule with a 45-day interval, and 3) coinjected oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs. DNA immunization of BALB/c mice with plasmids encoding for listeriolysin (pChly) and p60 (pCiap) efficiently induced MHC class I-restricted, Ag-specific CD8+ T cells that produced IFN-gamma. Coinjection of CpG-ODN significantly increased the frequency of specific IFN-gamma-secreting T cells. Although pChly induced specific CD8+ T cells expressing CTL activity, it failed to stimulate CD4+ T cells. Only pCiap induced significant CD4+ T cell and humoral responses, which were predominantly of Th2 type. Vaccination with either plasmid induced protective immunity against listerial challenge, and coinjection of CpG ODN improved vaccine efficacy in some situations. This study demonstrates the feasibility of gene gun administration of plasmid DNA for inducing immunity against an intracellular pathogen for which protection primarily depends on type 1 CD8+ T cells.     

Chemokine-like factor 1 is a functional ligand for CC chemokine receptor 4 (CCR4)

Chemokine-like factor 1 (CKLF1) exhibits chemotactic effects on leukocytes. Its amino acid sequence shares similarity with those of TARC/CCL17 and MDC/CCL22, the cognate ligands for CCR4. The chemotactic effects of CKLF1 for CCR4-transfected cells could be desensitized by TARC/CCL17 and markedly inhibited by PTX. CKLF1 induced a calcium flux in CCR4-transfected cells and fully desensitized a subsequent response to TARC/CCL17, and TARC/CCL17 could partly desensitize the response to CKLF1. CKLF1 caused significant receptor internalization in pCCR4-EGFP transfected cells. Taken together, CKLF1 is a novel functional ligand for CCR4.     

A suppressive oligodeoxynucleotide enhances the efficacy of myelin cocktail/IL-4-tolerizing DNA vaccination and treats autoimmune disease

Targeting pathogenic T cells with Ag-specific tolerizing DNA vaccines encoding autoantigens is a powerful and feasible therapeutic strategy for Th1-mediated autoimmune diseases. However, plasmid DNA contains abundant unmethylated CpG motifs, which induce a strong Th1 immune response. We describe here a novel approach to counteract this undesired side effect of plasmid DNA used for vaccination in Th1-mediated autoimmune diseases. In chronic relapsing experimental autoimmune encephalomyelitis (EAE), combining a myelin cocktail plus IL-4-tolerizing DNA vaccine with a suppressive GpG oligodeoxynucleotide (GpG-ODN) induced a shift of the autoreactive T cell response toward a protective Th2 cytokine pattern. Myelin microarrays demonstrate that tolerizing DNA vaccination plus GpG-ODN further decreased anti-myelin autoantibody epitope spreading and shifted the autoreactive B cell response to a protective IgG1 isotype. Moreover, the addition of GpG-ODN to tolerizing DNA vaccination therapy effectively reduced overall mean disease severity in both the chronic relapsing EAE and chronic progressive EAE mouse models. In conclusion, suppressive GpG-ODN effectively counteracted the undesired CpG-induced inflammatory effect of a tolerizing DNA vaccine in a Th1-mediated autoimmune disease by skewing both the autoaggressive T cell and B cell responses toward a protective Th2 phenotype. These results demonstrate that suppressive GpG-ODN is a simple and highly effective novel therapeutic adjuvant that will boost the efficacy of Ag-specific tolerizing DNA vaccines used for treating Th1-mediated autoimmune diseases.     

Detailed analysis of intrahepatic CD8 T cells in the normal and hepatitis C-infected liver reveals differences in specific populations of memory cells with distinct homing phenotypes

In hepatitis C virus (HCV) infection the immune response is ineffective, leading to chronic hepatitis and liver damage. Primed CD8 T cells are critical for antiviral immunity and subsets of circulating CD8 T cells have been defined in blood but these do not necessarily reflect the clonality or differentiation of cells within tissue. Current models divide primed CD8 T cells into effector and memory cells, further subdivided into central memory (CCR7+, L-selectin+), recirculating through lymphoid tissues and effector memory (CCR7-, L-selectin-) mediating immune response in peripheral organs. We characterized CD8 T cells derived from organ donors and patients with end-stage HCV infection to show that: 1) all liver-infiltrating CD8 T cells express high levels of CD11a, indicating the effective absence of naive CD8 T cells in the liver. 2) The liver contains distinct subsets of primed CD8+ T cells including a population of CCR7+ L-selectin- cells, which does not reflect current paradigms. The expression of CCR7 by these cells may be induced by the hepatic microenvironment to facilitate recirculation. 3) The CCR7 ligands CCL19 and CCL21 are present on lymphatic, vascular, and sinusoidal endothelium in normal liver and in patients with HCV infection. We suggest that the recirculation of CCR7+/L-selectin- intrahepatic CD8 T cells to regional lymphoid tissue will be facilitated by CCL19 and CCL21 on hepatic sinusoids and lymphatics. This centripetal pathway of migration would allow restimulation in lymph nodes, thereby promoting immune surveillance in normal liver and renewal of effector responses in chronic viral infection.     

Genetic co-transfer of CCR7 ligands enhances immunity and prolongs survival against virulent challenge of pseudorabies virus

The CC chemokine receptor 7 (CCR7) and cognate CCR7 ligands, CCL19 and CCL21, help establish microenvironments in lymphoid tissue that can facilitate encounters between naive T cells and mature dendritic cells (DCs). This study was conducted to determine if CCR7 ligands can augment the immunogenicity of a DNA vaccine that expresses glycoprotein B (gB) of the pseudorabies virus (PrV). The genetic co-transfer of CCR7 ligands along with a PrV DNA vaccine increased the levels of serum PrV-specific immunoglobulin (Ig) G by 2- to 2.5-fold. In addition, the level of PrV-specific IgG2a isotype was significantly enhanced by co-injection of CCR7 ligand DNA, which indicates that CCR7 ligand biases the humoral immunity toward the Th1-type pattern. The co-injection of CCR7 ligand DNA consistently enhanced the level of Th1-type cytokines (IL-2 and IFN-gamma) produced by stimulated immune cells when compared with a group that was vaccinated with the PrV DNA vaccine. Also, the genetic co-transfer of CCR7 ligand DNAs with PrV DNA vaccine provided prolonged survival against a virulent challenge by PrV. Moreover, the co-administration of CCR7 ligand DNA increased the number of mature DCs into the secondary lymphoid tissues, which appeared to enhance the proliferation of PrV-immune CD4(+) T cells. Taken together, these findings indicate that CCR7 ligands are an attractive adjuvant for a PrV DNA vaccine that can offer protective immunity against the PrV.     

Role of CC chemokine receptor 1 and two of its ligands in human dengue infection. Three approaches under the Cuban situation

Any of the four dengue serotypes can cause a severe disease, partly due to systemic inflammation orchestrated by mediators like cytokines and chemokines. We addressed the role of CCR1 and its ligands CCL3/MIP-1α and CCL5/RANTES in dengue infection using three different approaches: an ex vivo model exploring memory immune response in subjects with a well characterized dengue immune background, an in vivo study in patients with primary or secondary dengue infection, and an approach in fatal dengue. CCR1 and CCL3/MIP-1α gene expression showed differences after homotypic and heterotypic challenge according to dengue immune background of subjects, in correspondence with previous observations in Cuban dengue outbreaks. CCL5/RANTES gene expression was higher after homotypic challenge. CCR1 and CCL3/MIP-1α gene expression was higher in patients with secondary infection during critical days of the dengue disease, while the increase in RANTES expression started earlier than the observed for CCR1 and CCL3/MIP-1α. CCR1 and CCL3/MIP-1α gene expression was as high in brain as in spleen tissue from necropsy. Our results confirm the strong influence of previous immunity in subsequent dengue infections, and confer a possible pathogenic role to CCR1 and CCL3/MIP-1α in dengue disease and a possible protective role for CCL5/RANTES, probably through CCR5 interaction.     

CD4+ CD25+ T cells regulate vaccine-generated primary and memory CD8+ T-cell responses against herpes simplex virus type 1

It has become evident that naturally occurring CD25(+) regulatory T cells (T(reg) cells) not only influence self-antigen specific immune response but also dampen foreign antigen specific immunity. This report extends our previous findings by demonstrating that immunity to certain herpes simplex virus (HSV) vaccines is significantly elevated and more effective if T(reg) cell response is curtailed during either primary or recall immunization. The data presented here show that removal of CD25(+) T(reg) cells prior to SSIEFARL-CpG or gB-DNA immunization significantly enhanced the resultant CD8(+) T-cell response to the immunodominant SSIEFARL peptide. The enhanced CD8(+) T-cell reactivity in T(reg) cell-depleted animals was between two- and threefold and evident in both acute and memory stages. Interestingly, removal of CD25(+) T(reg) cells during the memory recall response to plasmid immunization resulted in a twofold increase in CD8(+) T-cell memory pool. Moreover, in the challenge experiments, memory CD8(+) T cells generated with plasmid DNA in the absence of T(reg) cells cleared the virus more effectively compared with control groups. We conclude that CD25(+) T(reg) cells quantitatively as well as qualitatively affect the memory CD8(+) T-cell response generated by gB-DNA vaccination against HSV. However, it remains to be seen if all types of vaccines against HSV are similarly affected by CD25(+) T(reg) cells and if it is possible to devise means of limiting T(reg) cell activity to enhance vaccine efficacy.     

Comparison of the Adjuvant Activity for the Glucosaminyl-Muramyl Dipeptide and the Granulocyte-Macrophage Colony-Stimulating Factor Gene in Gene Immunization against the Herpes Simplex Virus

The adjuvant activity in DNA immunization against herpes simplex virus type 1 (HSV1) was studied for the granulocyte-macrophage colony-stimulating factor (GM-CSF) synthesized from an eukaryotic expression plasmid (pDNAGM-CSF) and for the synthetic glucosaminyl-muramyl dipeptide (GMDP). A plasmid containing the HSV gD gene (pDNAgD) was used as an immunogen. GMDP and pDNAGM-CSF each enhanced the T-cell immune response to DNA immunization. The protective effect of DNA immunization increased from 63 to 100% when the two plasmids were injected simultaneously and to 96% when pDNAgD was injected one day after injecting GMDP. The results showed that DNA vaccines combined with genetic or peptide adjuvants are promising for DNA immunization against HSV.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 3, 2005, pp. 504–512.Original Russian Text Copyright © 2005 by Kozlov, Klimova, Shingarova, Boldyreva, Nekrasova, Guryanova, Andronova, Novikov, Kushch.     

靶向CCL21/CCR7轴治疗肿瘤转移的研究进展

转移是肿瘤患者死亡最常见的原因,而淋巴转移是大多数肿瘤转移的主要途径之一。近年来,CC趋化因子配体21 (CC chemokine ligand 21,CCL21) 及其受体CC趋化因子受体7型 (CC chemokine receptor type 7,CCR7) 在淋巴转移中的作用逐渐受到关注。CCL21主要由淋巴内皮细胞产生,其与树突状细胞 (Dendritic cells,DCs) 和T细胞等表面CCR7的相互作用是免疫细胞淋巴迁移及淋巴结归巢的主要决定因素。然而,表达CCR7的肿瘤细胞也可以利用类似的机制进入淋巴管进行淋巴转移。如何靶向CCL21/CCR7轴,既能抑制淋巴转移,又不影响抗肿瘤免疫反应已成为肿瘤免疫治疗研究的重要议题。文中将对CCL21/CCR7轴在淋巴转移中的作用及其作为靶点治疗肿瘤转移的临床前和临床试验研究进行综述,为靶向CCL21/CCR7信号轴治疗肿瘤转移的相关研究提供参考。     

CCR7 and its ligands: balancing immunity and tolerance

A key feature of the immune system is its ability to induce protective immunity against pathogens while maintaining tolerance towards self and innocuous environmental antigens. Recent evidence suggests that by guiding cells to and within lymphoid organs, CC-chemokine receptor 7 (CCR7) essentially contributes to both immunity and tolerance. This receptor is involved in organizing thymic architecture and function, lymph-node homing of naive and regulatory T cells via high endothelial venules, as well as steady state and inflammation-induced lymph-node-bound migration of dendritic cells via afferent lymphatics. Here, we focus on the cellular and molecular mechanisms that enable CCR7 and its two ligands, CCL19 and CCL21, to balance immunity and tolerance.     

Improved protective efficacy of a species-specific DNA vaccine encoding mycolyl-transferase Ag85A from Mycobacterium ulcerans by homologous protein boosting

Vaccination with plasmid DNA encoding Ag85A from M. bovis BCG can partially protect C57BL/6 mice against a subsequent footpad challenge with M. ulcerans. Unfortunately, this cross-reactive protection is insufficient to completely control the infection. Although genes encoding Ag85A from M. bovis BCG (identical to genes from M. tuberculosis) and from M. ulcerans are highly conserved, minor sequence differences exist, and use of the specific gene of M. ulcerans could possibly result in a more potent vaccine. Here we report on a comparison of immunogenicity and protective efficacy in C57BL/6 mice of Ag85A from M. tuberculosis and M. ulcerans, administered as a plasmid DNA vaccine, as a recombinant protein vaccine in adjuvant or as a combined DNA prime-protein boost vaccine. All three vaccination formulations induced cross-reactive humoral and cell-mediated immune responses, although species-specific Th1 type T cell epitopes could be identified in both the NH2-terminal region and the COOH-terminal region of the antigens. This partial species-specificity was reflected in a higher--albeit not sustained--protective efficacy of the M. ulcerans than of the M. tuberculosis vaccine, particularly when administered using the DNA prime-protein boost protocol.     

CCR5-deficient mice control Mycobacterium tuberculosis infection despite increased pulmonary lymphocytic infiltration

The control of Mycobacterium tuberculosis infection is dependent on the development of an adaptive immune response, which is mediated by granulomas. The granuloma is a dynamic structure that forms in the lung and consists primarily of macrophages and lymphocytes. For this structure to be effective in containment of the bacillus, it must develop in an organized and timely manner. The formation of the granuloma is dependent on recruitment of activated cells through adhesion molecules and chemokines. M. tuberculosis infection causes an increase in the expression of beta-chemokines CCL3, CCL4, and CCL5, and their receptor CCR5, in the lungs. In this study, we demonstrate that CCR5-transgenic knockout mice were capable of recruiting immune cells to the lung to form granulomas. CCR5(-/-) mice successfully induced a Th1 response and controlled infection. Unexpectedly, M. tuberculosis infection in these mice resulted in greater numbers of lymphocytes migrating to the lung and higher levels of many inflammatory cytokines, compared with wild-type mice, without apparent long-term detrimental effects. In the absence of CCR5, there were more dendritic cells in the lung-draining lymph nodes and more primed T lymphocytes in these mice. Bacterial numbers in the lymph nodes were also higher in CCR5(-/-) mice. Therefore, CCR5 may play a role in the migration of dendritic cells to and from the lymph nodes during M. tuberculosis infection.     

Enhanced potency of individual and bivalent DNA replicon vaccines or conventional DNA vaccines by formulation with aluminum phosphate

DNA vaccines against botulinum neurotoxin (BoNTs) induce protective humoral immune responses in mouse model, but when compared with conventional vaccines such as toxoid and protein vaccines, DNA vaccines often induce lower antibody level and protective efficacy and are still necessary to increase their potency. In this study we evaluated the potency of aluminum phosphate as an adjuvant of DNA vaccines to enhance antibody responses and protective efficacy against botulinum neurotoxin serotypes A and B in Balb/c mice. The administration of these individual and bivalent plasmid DNA replicon vaccines against botulinum neurotoxin serotypes A and B in the presence of aluminum phosphate improved both antibody responses and protective efficacy. Furthermore, formulation of conventional plasmid DNA vaccines encoding the same Hc domains of botulinum neurotoxin serotypes A and B with aluminum phosphate adjuvant increased both antibody responses and protective efficacy. These results indicate aluminum phosphate is an effective adjuvant for these two types of DNA vaccines (i.e., plasmid DNA replicon vaccines and conventional plasmid DNA vaccines), and the vaccine formulation described here may be an excellent candidate for further vaccine development against botulinum neurotoxins.     

A myriad of functions and complex regulation of the CCR7/CCL19/CCL21 chemokine axis in the adaptive immune system

The chemokine receptor CCR7 and its ligands CCL19 and CCL21 control a diverse array of migratory events in adaptive immune function. Most prominently, CCR7 promotes homing of T cells and DCs to T cell areas of lymphoid tissues where T cell priming occurs. However, CCR7 and its ligands also contribute to a multitude of adaptive immune functions including thymocyte development, secondary lymphoid organogenesis, high affinity antibody responses, regulatory and memory T cell function, and lymphocyte egress from tissues. In this survey, we summarise the role of CCR7 in adaptive immunity and describe recent progress in understanding how this axis is regulated. In particular we highlight CCX-CKR, which scavenges both CCR7 ligands, and discuss its emerging significance in the immune system.     

The 'co-delivery' approach to liposomal vaccines: application to the development of influenza-A and hepatitis-B vaccine candidates

DNA vaccination with mammalian-expressible plasmid DNA encoding protein antigens is known to be an effective means to elicit cell-mediated immunity, sometimes in the absence of a significant antibody response. This may be contrasted with protein vaccination, which gives rise to antibody responses with little evidence of cell-mediated immunity. This has led to considerable interest in DNA vaccination as a means to elicit cell-mediated immune responses against conserved viral antigens or intracellular cancer antigens, for the purpose of therapeutic vaccination. However, almost all current vaccines are used prophylactically and work by producing antibodies rather than cell mediated immune responses. In the present study we have therefore explored the combination of DNA and protein forms of an antigen using two exemplary prophylactic vaccine antigens, namely inactivated influenza virion and hepatitis-B surface antigen. We studied the effects of various combinations of DNA and protein on the antibody response. Co-administration of soluble forms of DNA and protein representations of the same antigen gave rise to the same level of antibody response as if protein were administered alone. In contrast, we found that when these antigens are entrapped in the same liposomal compartment, that there was a strong synergistic effect on the immune response, which was much greater than when either antigen was administered alone, or in various other modes of combination (e.g. co-administration as free entities, also pooled liposomal formulations where the two materials were contained in separate liposomal vehicles in the same suspension). The synergistic effect of liposomally co-entrapped DNA and protein exceeded, markedly, the well known adjuvant effects of plasmid DNA and liposomes. We have termed this new approach to vaccination 'co-delivery' and suggest that it may derive from the simultaneous presentation of antigen via MHC class-I (DNA) and MHC class-II (protein) pathways to CD8+ and CD4+ cells at the same antigen presenting cell--a mode of presentation that would commonly occur with live viral pathogens. We conclude that co-delivery is a very effective means to generate protective antibody responses against viral pathogens.     

C-Terminal Domain Deletion Enhances the Protective Activity of cpa/cpb Loaded Solid Lipid Nanoparticles against Leishmania major in BALB/c Mice

Background

We have demonstrated that vaccination with pDNA encoding cysteine proteinase Type II (CPA) and Type I (CPB) with its unusual C-terminal extension (CTE) can partially protect BALB/c mice against cutaneous leishmanial infection. Unfortunately, this protection is insufficient to completely control infection without booster injection. Furthermore, in developing vaccines for leishmaniasis, it is necessary to consider a proper adjuvant and/or delivery system to promote an antigen specific immune response. Solid lipid nanoparticles have found their way in drug delivery system development against intracellular infections and cancer, but not Leishmania DNA vaccination. Therefore, undefined effect of cationic solid lipid nanoparticles (cSLN) as an adjuvant in enhancing the immune response toward leishmanial antigens led us to refocus our vaccine development projects.

Methodology/Principal Findings

Three pDNAs encoding L. major cysteine proteinase type I and II (with or without CTE) were formulated by cSLN. BALB/c mice were immunized twice by 3-week interval, with cSLN-pcDNA-cpa/b, pcDNA-cpa/b, cSLN-pcDNA-cpa/b^-CTE, pcDNA-cpa/b^-CTE, cSLN, cSLN-pcDNA and PBS. Mice vaccinated with cSLN-pcDNA-cpa/b^-CTE showed significantly higher levels of parasite inhibition related to protection with specific Th1 immune response development, compared to other groups. Parasite inhibition was determined by different techniques currently available in exploration vacciation efficacy, i.e., flowcytometry on footpad and lymph node, footpad caliper based measurements and imaging as well as lymph node microtitration assay. Among these techniques, lymph node flowcytometry was found to be the most rapid, sensitive and easily reproducible method for discrimination between the efficacy of vaccination strategies.

Conclusions/Significance

This report demonstrates cSLN''s ability to boost immune response magnitude of cpa/cpb^-CTE cocktail vaccination against leishmaniasis so that the average parasite inhibition percent could be increased significantly. Hence, cSLNs can be considered as suitable adjuvant and/or delivery systems for designing third generation cocktail vaccines.     

Chemokines and chemokine receptors expression in the lesions of patients with American cutaneous leishmaniasis

American cutaneous leishmaniasis (ACL) presents distinct active clinical forms with different grades of severity, known as localised (LCL), intermediate (ICL) and diffuse (DCL) cutaneous leishmaniasis. LCL and DCL are associated with a polarised T-helper (Th)1 and Th2 immune response, respectively, whereas ICL, or chronic cutaneous leishmaniasis, is associated with an exacerbated immune response and a mixed cytokine expression profile. Chemokines and chemokine receptors are involved in cellular migration and are critical in the inflammatory response. Therefore, we evaluated the expression of the chemokines CXCL10, CCL4, CCL8, CCL11 and CXCL8 and the chemokine receptors CCR3, CXCR3, CCR5 and CCR7 in the lesions of patients with different clinical forms of ACL using immunohistochemistry. LCL patients exhibited a high density of CXCL10+, CCL4+ and CCL8+ cells, indicating an important role for these chemokines in the local Th1 immune response and the migration of CXCR3+ cells. LCL patients showed a higher density of CCR7+ cells than ICL or DCL patients, suggesting major dendritic cell (DC) migration to lymph nodes. Furthermore, DCL was associated with low expression levels of Th1-associated chemokines and CCL11+ epidermal DCs, which contribute to the recruitment of CCR3+ cells. Our findings also suggest an important role for epidermal cells in the induction of skin immune responses through the production of chemokines, such as CXCL10, by keratinocytes.     

DNA vaccination strategies against infectious diseases

DNA immunisation represents a novel approach to vaccine and immunotherapeutic development. Injection of plasmid DNA encoding a foreign gene of interest can result in the subsequent expression of the foreign gene products and the induction of an immune response within a host. This is relevant to prophylactic and therapeutic vaccination strategies when the foreign gene represents a protective epitope from a pathogen. The recent demonstration by a number of laboratories that these immune responses evoke protective immunity against some infectious diseases and cancers provides support for the use of this approach. In this article, we attempt to present an informative and unbiased representation of the field of DNA immunisation. The focus is on studies that impart information on the development of vaccination strategies against a number of human and animal pathogens. Investigations that describe the mechanism(s) of protective immunity induced by DNA immunisation highlight the advantages and disadvantages of this approach to developing vaccines within a given system. A variety of systems in which DNA vaccination has resulted in the induction of protective immunity, as well as the correlates associated with these protective immune responses, will be described. Particular attention will focus on systems involving parasitic diseases. Finally, the potential of DNA immunisation is discussed as it relates to veterinary medicine and its role as a possible vaccine strategy against animal coccidioses.