Skin Dendritic Cells Subsets Research Articles

Epicutaneous allergen immunotherapy induces a profound and selective modulation in skin dendritic-cell subsets

Epicutaneous immunotherapy (EPIT) protocols have recently been developed to restore tolerance in patients with food allergy. The mechanisms by which EPIT protocols promote desensitization rely on a profound immune deviation of pathogenic T- and B-cell responses. To date, little is known about the contribution of skin dendritic cells (skDCs) to T-cell remodeling and EPIT efficacy. We capitalized on a preclinical model of food allergy to ovalbumin (OVA) to characterize the phenotype and functions of OVA⁺ skDCs throughout the course of EPIT. Our results showed that both Langerhans cells and dermal conventional cDC1 and cDC2 subsets retained their ability to capture OVA in the skin and to migrate toward the skin-draining lymph nodes during EPIT. However, their activation/maturation status was significantly impaired, as evidenced by the gradual and selective reduction of CD86, CD40, and OVA protein expression in respective subsets. Phenotypic changes during EPIT were also characterized by a progressive diversification of single-cell gene signatures within each DC subset. Interestingly, we observed that OVA⁺ Langerhans cells progressively lost their capacity to prime CD4⁺ T_EFF cells, but gained regulatory T-cell stimulatory properties. In contrast, cDC1 were inefficient in priming CD4⁺ T_EFF cells or in reactivating T_MEM cells invitro, whereas cDC2 retained moderate stimulatory properties, and progressively biased type 2 immunity toward type 1 and type 17 responses. Our results therefore emphasize that the acquisition of distinct phenotypic and functional specializations by skDCs during EPIT is at the cornerstone of the desensitization process.

Laser-assisted epicutaneous immunization to target human skin dendritic cells.

Dendritic cells (DC) are promising targets for immunotherapy of cancer. Clinically, immunization against cancer antigens by means of the most potent antigen-presenting cells, that is DC, remains an important treatment option in combination with the modern immune checkpoint approaches. Instead of adoptively transferring in vitro monocyte-derived DC, they can also be loaded in situ by antibody-mediated targeting of antigen. Conventionally, these vaccines are delivered by classical intradermal injections. Here, we tested an alternative approach, namely laser-assisted epicutaneous immunization. With an infrared laser ("Precise Laser Epidermal System"/P.L.E.A.S.E.® Laser System), we created micropores in human skin and applied monoclonal antibodies (mAbs) against C-type lectins, for example DEC-205/CD205 and Langerin/CD207. Optimal parameters for formation of pores in epidermis and dermis were determined. We could induce pores of defined depths without enhanced apoptosis around them. Antibodies applied epicutaneously to the laser-porated skin could be detected both in Langerhans cells (LC) in situ in the epidermis and in migratory skin DC subsets from short term human skin explant culture, demonstrating uptake and transport of Langerin and DEC-205 mAbs. Efficacy of targeting was similar between the different laser treatments and pore depths. Thus, laser-assisted epicutaneous immunization may be a valuable alternative to intradermal injection, yet the loading efficacy of DC needs to be further improved.

GC-Tfh cell induction by Langerhans cells in steady-state is antigen-dose dependent and IL-6 independent.

Abstract We previously compared the contributions of different skin dendritic cell subsets in the induction of humoral immune responses. We found that antigen delivery without adjuvants to Langerhans cells (LCs) through the c-type lectin receptor Langerin, unlike cDC1, induces germinal center T follicular helper cells (GC-Tfhs), GC B cells, and high antibody titers. We also showed that targeting LCs with higher antigen dose induced significantly lower B cell responses and antibody titers. To better understand the role of antigen dose in this response, we assessed the T cell responses following targeting of LCs with different amounts of antigen. In accordance with the B cell responses, we found that GC-Tfh cell formation was also antigen dose-dependent. Using two-complementary approaches targeting IL-6-deficient LCs and targeting LCs in mice treated with neutralizing anti-IL-6 antibody, we showed that LCs induced GC-Tfh cells’ formation is an IL-6 independent fashion. In summary, this study shows that targeting LCs at steady-state induces the formation of GC-Tfh cells through an antigen-dose dependent and IL-6 independent mechanism.

The role of Langerhans cells in epidermal homeostasis and pathogenesis of psoriasis.

The skin is the main barrier between the human body and the outside world, which not only plays the role of a physical barrier but also functions as the first line of defence of immunology. Langerhans cells (LCs), as dendritic cells (DC) that play an important role in the immune system, are mainly distributed in the epidermis. This review focuses on the role of these epidermal LCs in regulating skin threats (such as microorganisms, ultraviolet radiation and allergens), especially psoriasis. Since human and mouse skin DC subsets share common ontogenetic characteristics, we can further explore the role of LCs in psoriatic inflammation.

Lipo-Based Vaccines as an Approach to Target Dendritic Cells for Induction of T- and iNKT Cell Responses.

In this study we developed a liposome-based vaccine containing palmitoylated synthetic long peptides (SLP) and alpha galactosylceramide (αGC) to specifically target dendritic cells (DC) for activation of both innate (invariant natural killer T-cells [iNKT]) and adaptive (CD8+ T-cells) players of the immune system. Combination of model tumor specific antigens (gp100/MART-1) formulated as a SLP and αGC in one liposome results in strong activation of CD8+ and iNKT, as measured by IFNγ secretion. Moreover, addition of lipo-Lewis Y (LeY) to the liposomes for C-type lectin targeting increased not only uptake by monocyte-derived dendritic cells (moDC), dermal dendritic cells and Langerhans cells but also enhanced gp100-specific CD8+ T- and iNKT cell activation by human skin-emigrated antigen presenting cells in an ex vivo explant model. Loading of moDC with liposomes containing LeY also showed priming of MART-126−35L specific CD8+ T-cells. In conclusion, chemically linking a lipid tail to a glycan-based targeting moiety and SLP combined with αGC in one liposome allows for easy generation of vaccine formulations that target multiple skin DC subsets and induce tumor antigen specific CD8+ T- and iNKT cells. These liposomes present a new vaccination strategy against tumors.

Transcutaneous Cancer Vaccine Using a Reverse Micellar Antigen Carrier.

Skin dendritic cells (DCs) such as Langerhans cells and dermal dendritic cells have a pivotal role in inducing antigen-specific immunity; therefore, transcutaneous cancer vaccines are a promising strategy to prophylactically prevent the onset of a variety of diseases, including cancers. The largest obstacle to delivering antigen to these skin DC subsets is the barrier function of the stratum corneum. Although reverse micellar carriers are commonly used to enhance skin permeability to hydrophilic drugs, the transcutaneous delivery of antigen, proteins, or peptides has not been achieved to date because of the large molecular weight of drugs. To achieve effective antigen delivery to skin DCs, we developed a novel strategy using a surfactant as a skin permeation enhancer in a reverse micellar carrier. In this study, glyceryl monooleate (MO) was chosen as a skin permeation enhancer, and the MO-based reverse micellar carrier enabled the successful delivery of antigen to Langerhans cells and dermal dendritic cells. Moreover, transcutaneous vaccination with the MO-based reverse micellar carrier significantly inhibited tumor growth, indicating that it is a promising vaccine platform against tumors.

Glyco-Dendrimers as Intradermal Anti-Tumor Vaccine Targeting Multiple Skin DC Subsets.

The human skin is an attractive anti-tumor vaccination site due to the vast network of dendritic cell (DC) subsets that carry antigens to the draining lymph nodes and stimulate tumor specific CD4+ and CD8+ T cells in. Specific vaccine delivery to skin DC can be accomplished by targeting glycan coated antigens to C-type lectin receptors (CLRs) such as DC-SIGN expressed by human dermal DCs and Langerin expressed by Langerhans cells (LCs), which facilitate endocytosis and processing for antigen presentation and T cell activation. Although there are multiple human skin DC subsets, targeting individual DC subsets and receptors has been a focus in the past. However, the simultaneous targeting of multiple human skin DC subsets that mobilize the majority of the skin antigen presenting cells (APC) is preferred to accomplish more robust and efficient T cell stimulation. Dual CLR targeting using a single tumor vaccine has been difficult, as we previously showed Langerin to favor binding and uptake of monovalent glyco-peptides whereas DC-SIGN favors binding of larger multivalent glyco-particles such as glyco-liposomes.Methods: We used branched polyamidoamine (PAMAM) dendrimers as scaffold for melanoma specific gp100 synthetic long peptides and the common DC-SIGN and Langerin ligand Lewis Y (LeY), to create multivalent glyco-dendrimers with varying molecular weights for investigating dual DC-SIGN and Langerin targeting. Using DC-SIGN+ monocyte derived DC (moDC) and Langerin+ primary LC we investigated glyco-dendrimer CLR targeting properties and subsequent gp100 specific CD8+ T cell activation in vitro. In situ targeting ability to human dermal DC and LC through intradermal injection in a human skin explant model was elucidated.Results: Dual DC-SIGN and Langerin binding was achieved using glyco-dendrimers of approximately 100kD, thereby fulfilling our criteria to simultaneously target LCs and CD1a+ and CD14+ dermal DC in situ. Both DC-SIGN and Langerin targeting by glyco-dendrimers resulted in enhanced internalization and gp100 specific CD8+ T cell activation.Conclusion: We designed the first glyco-vaccine with dual CLR targeting properties, thereby reaching multiple human skin DC subsets in situ for improved anti-tumor CD8+ T cell responses.

Ezh2 Controls Skin Tolerance through Distinct Mechanisms in Different Subsets of Skin Dendritic Cells

SummaryEzh2, a well-established epigenetic repressor, can down-regulate leukocyte inflammatory responses, but its role in cutaneous health remains elusive. Here we demonstrate that Ezh2 controls cutaneous tolerance by regulating Langerhans cell (LC) transmigration across the epidermal basement membrane directly via Talin1 methylation. Ezh2 deficiency impaired disassembly of adhesion structures in LCs, leading to their defective integrin-dependent emigration from the epidermis and failure in tolerance induction. Moreover, mobilization of Ezh2-deficient Langerin– dermal dendritic cells (dDCs) via high-dose treatment with a weak allergen restored tolerance, which is associated with an increased tolerogenic potential of Langerin– dDCs likely due to epigenetic de-repression of Aldh in the absence of Ezh2. Our data reveal novel roles for Ezh2 in governing LC- and dDC-mediated host protection against cutaneous allergen via distinct mechanisms.

High-Dimensional Phenotypic Mapping of Human Dendritic Cells Reveals Interindividual Variation and Tissue Specialization

Given the limited efficacy of clinical approaches that rely on exvivo generated dendritic cells (DCs), it is imperative to design strategies that harness specialized DC subsets in situ. This requires delineating the expression of surface markers by DC subsets among individuals and tissues. Here, we performed a multiparametric phenotypic characterization and unbiased analysis of human DC subsets in blood, tonsil, spleen, and skin. We uncovered previously unreported phenotypic heterogeneity of human cDC2s among individuals, including variable expression of functional receptors such as CD172a. We found marked differences in DC subsets localized in blood and lymphoid tissues versus skin, and a striking absence of the newly discovered Axl+ DCs in the skin. Finally, we evaluated the capacity of anti-receptor monoclonal antibodies to deliver vaccine components to skin DC subsets. These results offer a promising path for developing DC subset-specific immunotherapies that cannot be provided by transcriptomic analysis alone.

347 Regulated expression of CD73 by subsets of dendritic cells in skin is crucial for modulating contact hypersensitivity reactions in mice

The ecto-5'-nucleotidase CD73 converts extracellular adenosine monophosphate, which is a product of ATP degradation by CD39, to adenosine (ADO). Because ADO has well established anti-inflammatory effects, expression of CD73 by different types of skin cells may be crucial for the outcome of contact hypersensitivity (CHS) reactions. At first we analysed expression of CD39 and CD73, respectively, by different subsets of skin dendritic cells (DCs) and found ubiquitous expression of CD39 on all defined DC subsets. In contrast, CD73 was expressed by only 3%-8% of CD207+ Langerhans cells (LC) and other dermal DCs, respectively. Similar expression patterns were observed in skin migrating (sm) DCs in the lymph node under steady state conditions. However, application of the hapten TNCB induced surface-expression of CD73 in all cells, resulting in 20%-30% CD73+ DC and LC, respectively. This increased expression of CD73 was persistent, as it was also detectable in smDC 24h-48h after sensitization. Next, CD73 deficient (CD73KO) mice were subjected to a classical TNCB-induced CHS protocol and we found increased ear swelling reactions as compared to wild type mice, indicating rather down-modulatory functions of CD73 in CHS reactions. To accurately assess the tolerogenic functions of CD73 expression by smDC in CHS reactions, we established a tolerance model whereby application of DNTB renders animals tolerant to subsequent sensitization with DNFB. Here we show that both, the tolerogen DNTB as well as the sensitizer DNFB induced migration of similar DC subsets from skin to lymph nodes. But after DNTB application substantially higher expression levels of CD73 was observed in particular in CD11b+ as well as in CD207+CD103+ smDC. Of note, CD73KO animals were resistant to tolerization by DNTB. Thus, these data indicate a substantial role of CD73+ skin DC in regulating tolerance to haptens.

Cross-dressing and antigen transfer after DC targeting induce robust T cell response

Abstract Cutaneous dendritic cells (DC) are critical in protecting host from environmental insults as well as maintaining skin homeostasis. Using mouse models that are lack certain subset of cutaneous DC, studies have showed the distinct function of different subsets of skin DC, However, the interaction between skin DC subsets is less known. By targeting antigen to Langerhans cells (LC), we showed that endogenous CD4+ T cell response is independent of MHC II expression on LC. We also showed that LC handed over antigen to CD11b+ dDC and DN dDC. At the same time, MHC II deficient LC acquired MHC-II in the lymph node through cross-dressing. We demonstrated unexpected collaboration between cutaneous DC subsets, and provided insight on DC targeted vaccine design.

Functional Specialization of Skin Dendritic Cell Subsets in Regulating T Cell Responses.

Dendritic cells (DC) are a heterogeneous family of professional antigen-presenting cells classically recognized as most potent inducers of adaptive immune responses. In this respect, Langerhans cells have long been considered to be prototypic immunogenic DC in the skin. More recently this view has considerably changed. The generation of in vivo cell ablation and lineage tracing models revealed the complexity of the skin DC network and, in particular, established the existence of a number of phenotypically distinct Langerin+ and negative DC populations in the dermis. Moreover, by now we appreciate that DC also exert important regulatory functions and are required for the maintenance of tolerance toward harmless foreign and self-antigens. This review summarizes our current understanding of the skin-resident DC system in the mouse and discusses emerging concepts on the functional specialization of the different skin DC subsets in regulating T cell responses. Special consideration is given to antigen cross-presentation as well as immune reactions toward contact sensitizers, cutaneous pathogens, and tumors. These studies form the basis for the manipulation of the human counterparts of the murine DC subsets to promote immunity or tolerance for the treatment of human disease.

Mushrooming Insights into Skin Dendritic Cell Physiology

Mechanisms responsible for protective immunity against epicutaneous Candida infections are incompletely characterized. In this issue of Immunity, Kashem et al. demonstrate that different Candida life forms engage selected skin dendritic cell subsets in distinct compartments, resulting in qualitatively different immune responses.

Human skin dendritic cells can be targeted in situ by intradermal injection of antibodies against lectin receptors.

Skin dendritic cells (DC) express C-type lectin receptors for the recognition of pathogens. Langerhans cells (LC) express the receptor Langerin/CD207, whereas DEC-205/CD205 is mainly expressed by dermal DC, but can also be detected at low levels on LC. In this study, we tested an ex vivo approach for targeting DC in situ with monoclonal antibodies (mAb) against Langerin and DEC-205. The targeting mAb was injected intradermally into human skin biopsies or added to the medium during skin explant culture. Corresponding to the expression patterns of these lectin receptors on skin DC, Langerin mAb was detected merely in LC in the epidermis and DEC-205 mainly in dermal DC in human skin explants, regardless of the application route. Migratory skin DC bound and carried targeting mAb from skin explants according to their lectin receptor expression profiles. In contrast to the very selective transport of Langerin mAb by LC, DEC-205 mAb was more widely distributed on all CD1a+ skin DC subsets but almost absent in CD14+ dermal DC. As effective vaccination requires the addition of adjuvant, we co-administered the toll-like receptor (TLR)-3 ligand poly I:C with the mAb. This adjuvant enhanced binding of DEC-205 mAb to all skin DC subsets, whereas Langerin targeting efficacy remained unchanged. Our findings demonstrate that LC can be preferentially targeted by Langerin mAb. In contrast, DEC-205 mAb can be bound by all CD1a+ skin DC subsets. The efficacy of DEC-205 mAb targeting strategy can be boosted by addition of poly I:C underlining the potential of this combination for immunotherapeutical interventions.

Transcriptional fingerprints of antigen-presenting cell subsets in the human vaginal mucosa and skin reflect tissue-specific immune microenvironments.

BackgroundDendritic cells localize throughout the body, where they can sense and capture invading pathogens to induce protective immunity. Hence, harnessing the biology of tissue-resident dendritic cells is fundamental for the rational design of vaccines against pathogens.MethodsHerein, we characterized the transcriptomes of four antigen-presenting cell subsets from the human vagina (Langerhans cells, CD14- and CD14+ dendritic cells, macrophages) by microarray, at both the transcript and network level, and compared them to those of three skin dendritic cell subsets and blood myeloid dendritic cells.ResultsWe found that genomic fingerprints of antigen-presenting cells are significantly influenced by the tissue of origin as well as by individual subsets. Nonetheless, CD14+ populations from both vagina and skin are geared towards innate immunity and pro-inflammatory responses, whereas CD14- populations, particularly skin and vaginal Langerhans cells, and vaginal CD14- dendritic cells, display both Th2-inducing and regulatory phenotypes. We also identified new phenotypic and functional biomarkers of vaginal antigen-presenting cell subsets.ConclusionsWe provide a transcriptional database of 87 microarray samples spanning eight antigen-presenting cell populations in the human vagina, skin and blood. Altogether, these data provide molecular information that will further help characterize human tissue antigen-presenting cell lineages and their functions. Data from this study can guide the design of mucosal vaccines against sexually transmitted pathogens.Electronic supplementary materialThe online version of this article (doi:10.1186/s13073-014-0098-y) contains supplementary material, which is available to authorized users.

Langerin+ Dermal DC, but Not Langerhans Cells, Are Required for Effective CD8-Mediated Immune Responses after Skin Scarification with Vaccinia Virus

Skin scarification (s.s.) with Vaccinia virus (VACV) is essential for generation of an optimal protective T cell memory immune response. Dendritic Cells (DC), which are professional antigen presenting cells, are required for naïve T cell priming and activation. At least three subsets of skin resident DC have been identified: Langerhans Cells (LC), Dermal Langerin+ DC (Lang+dDC) and Dermal Langerin− DC (Lang−dDC). Using Langerin-diphtheria toxin receptor mice and established mouse model of VACV delivered by s.s., we demonstrated that Lang+dDC, but not LC, are absolutely required for the induction of a rapid and robust antigen-specific CD8+ T cell response after s.s. with VACV. The depletion of Lang+dDC led to a significant delay in the priming and proliferation of antigen-specific CD8+ T cells. Moreover CD8+ T cells generated after VACV s.s. in the absence of Lang+dDC lacked effector cytotoxic functions both in vitro and in vivo. While s.s.-immunized WT and LC depleted mice controlled the progression of OVA257–264 expressing T cell lymphoma EG7 (injected intradermally), the depletion of Lang+dDC led to rapid lymphoma progression and mortality. These data indicate that of all skin DC subsets, Lang+dDC the most critical for the generation of robust CD8+ T cell immunity after s.s. with VACV.

Tumor-promoting role of TGFβ1 signaling in ultraviolet B-induced skin carcinogenesis is associated with cutaneous inflammation and lymph node migration of dermal dendritic cells

Transforming growth factor beta 1 (TGFβ1) is a pleiotropic cytokine in the skin that can function both as a tumor promoter and suppressor in chemically induced skin carcinogenesis, but the function in ultraviolet B (UVB) carcinogenesis is not well understood. Treatment of SKH1 hairless mice with the activin-like kinase 5 (ALK5) inhibitor SB431542 to block UVB-induced activation of cutaneous TGFβ1 signaling suppressed skin tumor formation but did not alter tumor size or tumor cell proliferation. Tumors that arose in SB-treated mice after 30 weeks had significantly reduced percentage of IFNγ(+) tumor-infiltrating lymphocytes compared with control mice. SB431542 blocked acute and chronic UVB-induced skin inflammation and T-cell activation in the skin-draining lymph node (SDLN) and skin but did not alter UVB-induced epidermal proliferation. We tested the effect of SB431542 on migration of skin dendritic cell (DC) populations because DCs are critical mediators of T-cell activation and cutaneous inflammation. SB431542 blocked (i) UVB-induced Smad2 phosphorylation in dermal DC (dDC) and (ii) SDLN and ear explant migration of CD103(+) CD207(+) and CD207(-) skin DC subsets but did not affect basal or UV-induced migration of Langerhans cells. Mice expressing a dominant-negative TGFβ type II receptor in CD11c(+) cells had reduced basal and UVB-induced SDLN migration of CD103(+) CD207(+) and CD207(-) DC subsets and a reduced percentage of CD86(high) dDC following UVB irradiation. Together, these suggest that TGFβ1 signaling has a tumor-promoting role in UVB-induced skin carcinogenesis and this is mediated in part through its role in UVB-induced migration of dDC and cutaneous inflammation.

Skin Dendritic Cell Targeting via Microneedle Arrays Laden with Antigen-Encapsulated Poly-d,l-lactide-co-Glycolide Nanoparticles Induces Efficient Antitumor and Antiviral Immune Responses

The efficacious delivery of antigens to antigen-presenting cells (APCs), in particular, to dendritic cells (DCs), and their subsequent activation remains a significant challenge in the development of effective vaccines. This study highlights the potential of dissolving microneedle (MN) arrays laden with nanoencapsulated antigen to increase vaccine immunogenicity by targeting antigen specifically to contiguous DC networks within the skin. Following in situ uptake, skin-resident DCs were able to deliver antigen-encapsulated poly-d,l-lactide-co-glycolide (PGLA) nanoparticles to cutaneous draining lymph nodes where they subsequently induced significant expansion of antigen-specific T cells. Moreover, we show that antigen-encapsulated nanoparticle vaccination via microneedles generated robust antigen-specific cellular immune responses in mice. This approach provided complete protection in vivo against both the development of antigen-expressing B16 melanoma tumors and a murine model of para-influenza, through the activation of antigen-specific cytotoxic CD8+ T cells that resulted in efficient clearance of tumors and virus, respectively. In addition, we show promising findings that nanoencapsulation facilitates antigen retention into skin layers and provides antigen stability in microneedles. Therefore, the use of biodegradable polymeric nanoparticles for selective targeting of antigen to skin DC subsets through dissolvable MNs provides a promising technology for improved vaccination efficacy, compliance, and coverage.

Intradermal application of vitamin D3 increases migration of CD14+ dermal dendritic cells and promotes the development of Foxp3+ regulatory T cells

The active form of vitamin D3 (VitD) is a potent immunosuppressive drug. Its effects are mediated in part through dendritic cells (DCs) that promote the development of regulatory T cells (Tregs). However, it remains elusive how VitD would influence the different human skin DC subsets, e.g., CD1a+/langerin+ Langerhans cells, CD14+ DDCs and CD1a+ DDCs upon administration through the skin route in their natural environment. We addressed this issue by intradermal (ID) administration of VitD in a human skin explant system that closely resembles physiological conditions. ID injection of VitD selectively enhanced the migration of CD14+ DDCs, a subset known for the induction of tolerance. Moreover, ID injection of VitD repressed the LPS-induced T cell stimulatory capacity of migrating DCs. These migrating DCs collectively induced T cells with suppressive activity and abolished IFN-γ productivity. Those induced T cells were characterized by the expression of Foxp3. Thus, we report the novel finding that ID injection of VitD not only modifies skin DC migration, but also programs these DCs in their natural milieu to promote the development of Foxp3+ Tregs.

Canine Recombinant Adenovirus Vector Induces an Immunogenicity-Related Gene Expression Profile in Skin-Migrated CD11b+ -Type DCs

Gene expression profiling of the blood cell response induced early after vaccination has previously been demonstrated to predict the immunogenicity of vaccines. In this study, we evaluated whether the analysis of the gene expression profile of skin-migrated dendritic cells (DCs) could be informative for the in vitro prediction of immunogenicity of vaccine, using canine adenovirus serotype 2 (CAV2) as vaccine vector. CAV2 has been shown to induce immunity to transgenes in several species including sheep and is an interesting alternative to human adenovirus-based vectors, based on the safety records of the parental strain in dogs and the lack of pre-existing immunity in non-host species. Skin-migrated DCs were collected from pseudo-afferent lymph in sheep. Both the CD11b+ -type and CD103+ -type skin-migrated DCs were transduced by CAV2. An analysis of the global gene response to CAV2 in the two skin DC subsets showed that the gene response in CD11b+ -type DCs was far higher and broader than in the CD103+ -type DCs. A newly released integrative analytic tool from Ingenuity systems revealed that the CAV2-modulated genes in the CD11b+ -type DCs clustered in several activated immunogenicity-related functions, such as immune response, immune cell trafficking and inflammation. Thus gene profiling in skin-migrated DC in vitro indicates that the CD11b+ DC type is more responsive to CAV2 than the CD103+ DC type, and provides valuable information to help in evaluating and possibly improving viral vector vaccine effectiveness.