As expected, Western blot analysis showed that levels of HIF-1α protein in nuclear protein extracts of tracheal epithelial cells from OVA-treated mice were increased significantly, as compared with the levels
in tracheal epithelial cells from the control mice (Fig. 2C and D). Treatment with the PI3K-δ inhibitor IC87114 reduced significantly the increased HIF-1α levels in tracheal epithelial cells from OVA-treated mice. Involvement of HIF-1α in VEGF expression was evaluated using their respective inhibitors. Levels of VEGF protein in lung tissues and BALF were 3-MA cell line significantly increased 48 h after the last challenge of OVA, as compared with the levels in the control mice, and administration of 2ME2 (HIF-1α translation inhibitor) or CBO-P11 (VEGF receptor inhibitor) substantially reduced the increased VEGF protein levels in lung tissues (Fig. 3A and B) and BALF (Fig. 3C). In addition, Evans blue dye assay revealed that plasma extravasation was significantly increased 48 h after the last challenge of OVA (Fig. 3D). The increase in plasma extravasation was significantly reduced by administration
of 2ME2 or CBO-P11. To determine whether inhibition of HIF-1α and VEGF suppresses Th2 inflammation in lungs of OVA-treated mice, we measured levels of Th2 cytokines. As shown in Fig. 4, the levels of IL-4, IL-5, and IL-13 in lung tissues and BALF were significantly increased 48 h after the last challenge of OVA, as compared with the selleck chemical Histone demethylase levels in the control mice. The increased IL-4, IL-5, and IL-13 levels after the OVA inhalation were decreased significantly by administration of 2ME2 or CBO-P11. Numbers of total cells, lymphocytes, neutrophils, and eosinophils in BALF were increased significantly 48 h after OVA inhalation, as compared with the numbers in BALF of the control mice (Fig. 5A). The increased numbers
of total cells, lymphocytes, neutrophils, and eosinophils were significantly reduced by administration of 2ME2 or CBO-P11. Effects of the inhibitors of HIF-1α and VEGF receptor on airway responsiveness were evaluated by measuring methacholine-mediated respiratory system resistance (Rrs). As presented in Fig. 5, at dose of 50 mg/mL of methacholine, percent Rrs increased significantly in the OVA-treated mice, as compared with the controls. Administration of 2ME2 or CBO-P11 to OVA-treated mice significantly reduced the levels of Rrs at 50 mg/mL of methacholine inhalation, as compared with the untreated mice. These results suggest that administration of 2ME2 or CBO-P11 reduces OVA-induced airway hyperresponsiveness. Histologic analysis revealed that numerous inflammatory cells as well as eosinophils infiltrated tissue around the bronchioles, the airway epithelium was thickened, and mucus and debris had accumulated in the lumen of bronchioles (Fig. 5D and E), as compared to the control (Fig. 5C). Mice treated with 2ME2 (Fig. 5F) or CBO-P11 (Fig.
36 A third study provides level IV evidence that weight loss appears to be associated with a fall in total cholesterol in kidney transplant recipients.37 The recommendation that a diet rich in wholegrain, low glycaemic index and high fibre carbohydrates as well as rich sources of vitamin E and monounsaturated fat should be followed by adult kidney transplant recipients with elevated serum total cholesterol, LDL-cholesterol and triglycerides, is based on evidence from the following three studies: Stachowska et al.34
investigated the effect Torin 1 of a modified Mediterranean diet on serum lipid levels in a single-centre, randomized controlled study. Adult kidney transplant recipients with stable graft function were randomized to receive one of two diets for a 6-month period: Treatment: Modified Mediterranean diet (n = 21; 15 males, six females), containing carbohydrates with a low glycaemic index (amylose-poor, cellulose-rich), 30 mL cold-pressed olive oil with only rapeseed oil used Neratinib in cooking, foods rich in alpha-tocopherol (including nuts, grains and linseeds), fresh vegetables with each meal and
daily animal protein of 35–50 g for males and 23–46 g for females. Energy intake was attributed as follows: 47% carbohydrates, 38% fat, 15% protein. Immunosuppressive and antihypertensive regimens were not changed and no antilipemic medications were administered before or during the study Lumacaftor purchase period. Dietary compliance of subjects in both groups was assessed every 4 weeks by means of 24 h food diaries and by monitoring oleic acid content of plasma triglycerides. In the treatment group, total cholesterol dropped from 230 to 210 mg/dL, or 5.9–5.4 mmol/L (P < 0.02) and triglycerides dropped from 194 to 152 mg/dL, or 2.5–1.7 mmol/L (P < 0.0007). Neither total cholesterol nor triglycerides dropped in the control group. There was no significant difference between the groups with respect to weight, body mass index and body fat levels at the
start or the end of the study period. The key limitations of this study are: the small sample size; and The study provides level III-3 evidence that a modified Mediterranean diet can be effective in lowering total cholesterol and triglycerides. The results of this study concur with the findings of studies in non-transplant populations.34 Shen et al.35 conducted a pseudo-randomized controlled study examining the effect of diet on serum lipids. They designed a diet containing less than 500 mg cholesterol, less than 35% calories from fat, less than 50% calories from carbohydrate, polyunsaturated to saturated fat ratio greater than 1, limited alcohol intake. A sodium restriction was made if the transplant recipient had hypertension.
OVA administration had no effect on the CD80, CD86 and I-Ab expression of spleen CD11c+ DCs and the Ulixertinib datasheet number of total CD4+ T cells, with or without IC administration (data not shown). After 5 and 7 days of LPS or CpG ODN administration, IC pretreatment suppressed the increases in total CD4+ T cells in spleen and lymph nodes (Fig. 3A), serum IFN-γ levels (Fig. 3B) and OVA323–339-specific CD4+KJ1.26+ T cells in spleen and lymph nodes (Fig. 3C). To further investigate whether IC-mediated suppression of in vivo T cells response was mediated by FcγRIIb, we performed the experiments described above in FcγRIIb−/− mice. In contrast to WT mice, pretreatment
of FcγRIIb−/− mice with IC did not suppress but instead, increased in vivo T-cell responses in FcγRIIb−/− mice, which was characterized by a significant increase in antigen-specific T cells and serum IFN-γ levels (Fig. 3D and E). Taken together, these data further demonstrate that IC pretreatment could downregulate T-cell responses in vivo to TLR ligands via FcγRIIb. Since IC used in the experiments above was prepared from OVA and anti-OVA mAb, which are not natural IC present in vivo, we isolated natural IC/Ig from MRL/lpr lupus-prone mice and then investigated whether natural IC/Ig also had such inhibitory effects. As Selleckchem Sirolimus expected, IC/Ig derived from MRL/WT and MRL/lpr lupus
mice significantly inhibited LPS or CpG ODN-induced upregulation of I-Ab, CD40, CD80 and CD86 expression on DCs (Fig. 4A), and also inhibited secretion of TNF-α (Fig. 4B). The data show that natural IC/Ig, prepared from mice with PRKACG autoimmune disease, also enhances the resistance of immature DCs to TLR-triggered maturation. Both in vitro and in vivo data above suggest that IC maintains the tolerogenecity of immature DCs in FcγRIIb-dependent manner. Considering that coexpression of activating and inhibitory FcRs
on the same cell will set a threshold for immune cell activation by IC, we tried to overexpress FcγRIIb in immature DCs so as to polarize immature DCs to be dominantly triggered by inhibitory signal once stimulated with IC. Recombinant adenovirus carrying FcγRIIb was constructed and used to transfect immature DCs, and the tolerogenetic properties of DC-FcγRIIb by natural IC/Ig were investigated. Immature DCs transfected with Ad-FcγRIIb at a MOI of 50 or 200 (DC-FcγRIIb) expressed higher levels of FcγRIIb than Ad-LacZ-transfected DCs (DC-LacZ) (Supporting Information Fig. 3). So, an MOI of 50 was used in the following experiments. Natural IC/Ig significantly inhibited DC-FcγRIIb, but not DCs or DC-LacZ, to express I-Ab, CD40, CD80 and CD86 and to secrete TNF-α (Fig. 5A). LPS significantly promoted the three types of DCs to express I-Ab, CD40, CD80 and CD86 and to secrete TNF-α (Fig. 5A and B).
Activating KIR show much greater variation in their presence/absence in different populations. For example KIR2DS1 has four populations with greater than 80% frequency (Australia Aborigines, Brazil Amazon, Brazil Rodonia Province Karitiana and Papua New Guinea Nasioi) but three African populations with < 10%; Central Africa Republic Bagandu Biaka, Ghana and Nigeria Enugu Ibo. Similarly, KIR2DS2 has high frequencies (> 70%) in nine populations (e.g. Australia Aborigines, South Africa San and Xhosa and populations from India) but very low frequencies in Japan
(8·5–16·0%), South Korea (16·9%) and China (17·3%). In some of the South American Amerindian populations KIR2DS3 is absent – Argentina Salta Wichis, Mexico Tarahumaras, Venezuela Bari CHIR-99021 mw and Venezuela Yucpa.53,54 The frequency of this gene is also low Selleck LY294002 in Japan and China. The KIR2DS4 gene is present in seven populations at 100% – either from Africa or African Americans in USA. However, it has also low frequencies – Costa Rica (31%), Australia Aborigines (52%), Taiwan (59·4%). Selection against having KIR3DS1 has been reported
in African populations25 with KIR3DS1 present in San (2·2%), Xhosa (4·0%), Nigeria (3·4% and 6·3%), Senegal (4·0%), Kenya (0·7%), Ghana (4·9%), Central Africa Republic Bagandu Biaka (2·9%). Global phenotype frequencies of KIR3DS1 are shown as an example of how the data can be represented (Fig. 6). Obviously there is a close inverted correspondence between the frequencies of KIR3DL1 and KIR3DS1 in an individual population. A very small percentage of individuals (0·34%) are negative for both KIR3DL1 and KIR3DS1. Such extensive diversity between modern populations may indicate that geographically distinct diseases have exerted recent, or perhaps ongoing, selection on KIR
repertoires. The differences in frequencies therefore make the choice of controls for disease studies very important for all populations. We linked the published data by analysing all populations submitted to the website that had data for 13 KIR genes (excluding KIR2DP1 and KIR3DP1).55 ID-8 The 56 populations analysed, using neighbour-joining dendrograms and correspondence analysis, grouped with a few exceptions according to a geographical gradient. Subsequently, we selected 38 of the 56 populations that we considered to be well defined in the anthropological sense. We found that based on KIR haplotype B genes (i.e. genes mainly encoding activating KIR) the populations were related to geography like a good anthropological marker such as HLA or Y chromosome. However, the results based on the KIR haplotype A (i.e. genes mainly encoding inhibitory KIR) did not show such a correlation.56 There has been an increase in the number of known alleles from 87 in the first KIR nomenclature report in 2002 to 335 in the latest release on the IPD-KIR database, where the sequence of all KIR alleles is kept.
, Viropharma and Cubist. “
“Extrathymically induced Foxp3+ regulatory T (Treg) cells contribute to the pool of Treg cells and are implicated in the maintenance of immune tolerance at selleck chemicals environmental interfaces. The impact of T-cell senescence on their generation and function is, however, poorly characterized. We report here that
steady-state induction of Foxp3 is impaired in aged T cells in vivo. In vitro assays further revealed that this defective generation of Treg cells was independent from the strength of TCR stimulation and arose before T-cell proliferation. Importantly, they also revealed that this impairment of Foxp3 induction is unrelated to known age-related T-cell defects, such as IL-2 secretion impairment, accumulation of activated T-cell populations, or narrowing of the T-cell repertoire. Finally, a loss of extrathymic induction of Foxp3 www.selleckchem.com/products/poziotinib-hm781-36b.html and tolerance
to minor-mismatched skin graft were observed in aged mice treated by nondepleting anti-CD4 antibody. The T-cell intrinsic impairment of Treg-cell generation revealed here highlights age as a key factor to be considered in immune tolerance induction. Foxp3+ regulatory T (Treg) cells are required for the control of autoimmune responses and maintenance of immune homeostasis [1, 2]. Depending on their site of generation, two populations have been distinguished: tTreg cells generated in the thymus and pTreg induced in the periphery from mature conventional T (Tconv) cells. A key role of pTreg cells has been established in models of oral tolerance , colitis , transplantation
[5, 6], and in pregnancy [7, 8] in which pTreg cells allow the development of a suppressive T-cell repertoire adapted to evolving antigens encountered in the periphery. Aging is associated with altered immune responses to vaccination, infection, cancer, and dysregulation of inflammatory responses [9, 10]. In addition to a decrease in naïve T-cell numbers due to thymus involution [11, 12], functional impairment of T cells is a major component of the defective immune response in the elderly . In particular, an early and transient IL-2 secretion defect in aged T cells leads to impaired proliferation and differentiation in fully functional Th1 and Th2 cells [14, 15]. We characteri-zed here the effect of T-cell senescence on pTreg-cell generation and report that T-cell intrinsic defects oppose the induction of Foxp3 in aged Tconv not cells both at the steady state and during induction of transplantation tolerance. To explore whether T-cell senescence affects pTreg production, we first compared in vivo Foxp3 induction at the steady state in Tconv populations isolated from either young (5–20 weeks) or old (60–65 weeks) Foxp3-eGFP mice. Highly purified CD4+eGFP− T cells (>99.99%) from young Foxp3-eGFP mice (Fig. 1A) were transferred into C57Bl/6 CD45.1+ congenic hosts, and 4 weeks after transfer, 0.4% of eGFP+ cells was detected in the donor T-cell population (Fig. 1B). In contrast, a 1.
P.Ncf1*/*.MBQ mice ROS production by macrophages modulate T-cell reactivity to CII. The influence of NOX2-derived ROS on several Th-polarized subsets 7, 43, 44, on tolerization 44–46, activation 7 and, as
we show here, on priming, suggest a role for ROS in increasing the threshold of activation of T cells and modulating the phenotype at different moments of activation. The anti-inflammatory Ipatasertib effect of ROS on T cells is likely to be highly regulated and operating compartmentally, i.e. in the immunological synapse, making it plausible that excessive production of ROS has pro-inflammatory or balancing effects in other situations. Increased ROS production in the joints is observed in both the animal models 1 and in human RA 47–51. This has been suggested to increase inflammation and damage in rheumatoid arthritis 47–51 although our data show that ROS in fact protect against disease in the animal models. In CIA it is well known that B cells are crucial and antibodies are a major pathogenic factor. In the B10.P.MBQ mouse no enhanced B-cell activation or anti-CII antibody production as compared with the arthritis resistant B10.P controls has been observed. Importantly however, the Ap molecule can present CII peptides,
and the B10.P mice do produce small amounts of anti-CII antibodies, possibly reflecting a low level of T-cell activation. Apparently, these low levels of antibodies did not result in arthritis. To exclude the possibility that a small subset of EGFR assay B cells was expressing low levels of Aq and were thereby able to accept T-cell help resulting in increased anti-CII antibody levels and disease, the epitope specificity of the anti-CII response was determined. If a few B cells were responsible for the observed effects, one would expect skewing of the antibody response toward a specific epitope. No difference in levels of Ab reactive with the U1, J1, C1 or B/T-cell epitopes on CII 20 or Ig isotypes (IgM, IgG1, IgG2a, IgG2b and IgG3) (data not shown) were observed. In conclusion, we have shown PIK3C2G that macrophages are
important cells not only in the inflammatory phase but are also able to prime an autoimmune response when ROS production is impaired. Importantly, the priming of T-cell responses occurred when the macrophage lacked the possibility to suppress activation via antigen presentation because of ROS producing capacity. These data indicate that the Ncf1-controlled ROS production is critical in inhibiting macrophages from priming autoimmune responses. All mice used were genetically controlled and shared the C57Bl/10 background. The C57/Bl10.P/rhd and C57/Bl10.Q/rhd strains originate from the Jan Klein mouse colony (Tübingen, Germany). C57/Bl10.P/rhd (B10.P) mice express MHC class II H2-Ap encoded by a congenic fragment from the P/J strain on chromosome 17 that is approximately spanning from 17.8 to 47.8 Mbp. The MHC class II congenic C57/Bl10.Q/rhd (B10.
39 α-lipoic selleck products acid (α-LA) is also found naturally in mitochondria and acts as a critical coenzyme for the mitochondria enzymes pyruvate dehydrogenase and α—ketoglutarate dehydrogenase.40 Its reduced form, dihydrolipoic acid (DHLA), and other metabolites have strong antioxidant effects as ROS scavengers and act as chelators of transition metals.41 In a PBOO study, CoQ10 plus α-LA treatment significantly
increased bladder contractility in vitro, decreased bladder wall protein carbonylation and nitration, increased mitochondrial function, prevented intramural nerve degeneration and diminished detrusor smooth muscle hypertrophy in rabbit bladder.26 Specifically, bladder voiding contraction can be separated into two phases: an initial peak phase and a second tonic phase.42 The initial peak response p38 MAP Kinase pathway was supported energetically by extant cellular ATP stores, whereas the tonic phase required active mitochondrial oxidation of substrates to generate energy. Ability of the bladder to sustain contraction is directly related to the availability of energy produced by mitochondrial electron transport and oxidative phosphorylation.42 Decompensation of bladder from extended obstruction may
be mediated by breakdown of mitochondrial function. Both CoQ10 and α-LA are essential mitochondrial components in respiratory chain and pyruvate-dehydrogenase complex. Combination therapy may target several common pathways in mitochondrial dysfunctions. Following 4 weeks PBOO, both choline acetyl-transferase activity (an indicator of cholinergic function) and neurofilament amounts decreased significantly and diminished further after 7 weeks of obstruction. PBOO also significantly increased both protein nitration and carbonylation following obstruction, especially after 7 weeks obstruction. CoQ10 and α-LA are both strong antioxidant reagents in nature. Treatment with CoQ10 plus α-LA significantly attenuated protein carbonylation Mannose-binding protein-associated serine protease and nitration, indicating that these medications
may work through an antioxidative effect. The antioxidative function of CoQ10 is likely to occur by providing hydrogen equivalents to reduce peroxyl and/or generation of alkoxylradicals.39α-LA has also been proven to reduce lipid peroxidation by enhancing the activity of glutathione peroxidase and SOD, which improves the efficiency of the endogenous antioxidant systems.43 A combination of these two strong antioxidants thus prevents free radical induced tissue damages subjected to PBOO. Ischemia/reperfusion injury is also involved in bladder overdistention injury. It has been known for a long time that bladder overdistention reduces blood perfusion of the bladder.44 Blood flow is resumed following emptying and decompressing the urinary bladder. Reperfusion of the overdistended and ischemic urinary bladder might induce reperfusion injury. In a rabbit overdistention model, Lin et al.
Nagarkatti et al. demonstrated that CD44-deficiency triggers a Th2-biased
Th development using OVA immunization with a Th1-skewing adjuvant CFA without airway antigen challenge 12. In the present study, we used Th2-skewing adjuvant aluminum hydroxide for Derf-immunization. Before antigen challenge, the levels of Th2 cytokines, Der-specific IgE, and IgG1 in the serum of CD44KO mice were similar to those in WT mice, while IFN-γ was not detected in the serum of both CD44KO and WT mice, and the serum level of Der-specific IgG2c was similar between CD44KO and WT mice. These data suggested that the lack of CD44 did not influence the Th1- or Th2-biased Th development in the sensitization Buparlisib supplier phase of this model. After antigen challenge, the
number of Th2 cells and the levels of Th2 cytokines in the BALF of CD44KO mice were lower than those in WT mice, while the levels of Th2 chemokine (TARC) in the BALF of CD44KO mice were similar to those in WT mice. Finally, we demonstrated that anti-CD44 mAb inhibited the infiltration of OVA-specific in vitro-differentiated Th2, but not Th1, cells into the airway after antigen challenge. These data suggested that CD44 plays a critical role in the infiltration of Th2 cells into the airway induced by antigen challenge, in large part, as an adhesion molecule. Anti-CD44 mAb significantly reduced airway accumulation of eosinophils and the concentration of eotaxin in the BALF in murine models of pulmonary eosinophilia 17, 18. Consistently, the number of eosinophil
in the BALF of CD44KO mice was marginally lower than those in WT mice, although the level of eotaxin in the BALF of CD44KO mice was selleck products similar to that of WT mice in Derf-sensitized and challenged mouse asthmatic model in this study. Even though exact reason for such discrepancy is unclear at present, it may be caused by differences of antigen, mouse strain, and the way of antigen administration. Increased levels of both Th1 and Th2 cytokines in the serum were observed after antigen challenge. Increased levels of Th2 cytokines in the BALF reflect the elevated levels Metalloexopeptidase of Th2 cytokines in the serum of WT mice after antigen challenge. Higher levels of IFN-γ in the BALF and serum in CD44KO mice might be caused by lower levels of Th2 cytokines in the BALF and serum in CD44KO mice compared with WT mice after antigen challenge, because IFN-γ was not detected in the serum of both CD44KO and WT mice, while the serum levels of Th2 cytokines were similar between CD44KO and WT mice before the antigen challenge. Higher levels of IFN-γ might contribute to the higher levels of Derf-specific IgG2c in serum of CD44KO mice after antigen challenge. The number of macrophages in the BALF was not significantly different between CD44KO and WT mice at baseline, as previously described 27. In this Derf-induced asthmatic model, CD44KO mice had significantly fewer macrophages compared with WT mice 24 h after antigen challenge.
6B). The serum concentration of self-DNA
in patients with DNA-related autoimmune diseases is higher than that in healthy subjects 7–9. In addition, circulating CpG DNA has been reported to be a pathogenic factor of SLE 23, 24. However, it is unclear whether the augmented self-DNA in serum affects the immune response to CpG DNA in autoimmune diseases. In the present study, we clearly demonstrated that DNase I-treated DNA, but not intact DNA, increases the CpG motif- and TLR9-dependent cytokine production in murine macrophages. As shown in Fig. 3B, it was found that only the DNase I-treated DNA, but not DNase II-treated one, has an ability to increase CpG DNA-induced cytokine production. Both DNase I and DNase II are endonucleases and cleave the PO bond in DNA, which yields polynucleotides with a 5′-mono-phosphate and 3′-mono-phosphate, respectively 13, 25. Taking into HTS assay consideration these results, an oligonucleotide
with a phosphate group selleck chemicals at the 5′-terminal is required for increased cytokine production from macrophages. In addition, the results showing that dNMPs and dNTPs but not deoxynucleosides increased the TNF-α release by CpG DNA at the comparable level (Fig. 3A), support the importance of the presence of a phosphate at the 5′-end of DNA. Moreover, the results in Fig. 3A indicate that this activity of DNA with 5′-phosphate to increase CpG DNA-induced cytokine production is dependent on the type of base, because TMP and TTP were much less effective than other dNMP or dNTP. It is still unknown how short the DNA is when DNA is fully cleaved by DNase I. However, the present study has demonstrated that mononucleotides are sufficient to increase the CpG DNA-dependent cytokine release from macrophages. TNF-α production in RAW264.7 cells was not proportional to the concentration of ODN1668; a 3-fold increase in the concentration of ODN1668 resulted in a 18-fold increase in TNF-α
check production (Fig. 1A). ODN1668 at a concentration of 1 μM or lower was hardly effective for cytokine production (data not shown). In addition, CpG DNA was often used at the equal concentration to this study in multiple reports of immune responses to DNA 26, 27. Therefore, the concentrations of ODN1668 used in the present study (1 and 3 μM for RAW264.7 cells and splenic macrophages, respectively) were similar levels to those used in literatures 26, 27, even though they were higher than the concentration of DNA in the serum of active SLE patients (about 3.2±1.1 μg/mL) 28. It was excluded that increased cellular uptake or stabilization is involved in the DNase I-treated DNA-mediated increase in cytokine production (Fig. 5). Zwiorek et al.
6D and E). Similar results were obtained in immunofluorescence studies of freshly isolated human pDCs. Consistent with results from CAL-1 cells, the nuclear localization of both proteins increased significantly after stimulation with “K” ODN (Fig. 7A and B). Limited IRF-5 and p50 co-localization
was observed in freshly isolated pDCs, presumably reflecting cell activation in vivo or during the purification process. The level of co-localization increased nearly threefold after CpG stimulation (average 8.5 ± 0.9 versus 23.6 ± 1.2 μm2, p < 0.0001, Fig. 7A and B). These findings support the conclusion that “K”-driven pDC stimulation involves the nuclear co-localization of IRF-5 with p50. pDCs make a critical contribution to both the innate and adaptive arms of the immune response. Activated pDCs excel in antigen presentation selleck chemicals llc and produce IFNs and other pro-inflammatory cytokines required for host defense [13, 41]. Human pDCs utilize TLR9 to sense the unmethylated CpG motifs present in microbial DNA. “K” ODN have been evaluated in phase I–III clinical trials as immunotherapeutics for the treatment of cancer, allergy, and infectious diseases [4, 42-44]. Understanding the signaling cascades and patterns of gene expression triggered by the recognition of selleck screening library “K” ODN by human pDCs is thus of both fundamental and
therapeutic relevance. We and others recently established that “K” ODN induced human pDCs to upregulate the expression Quisqualic acid of two functionally defined groups of genes: those involved in antiviral responses (exemplified by IFN-β) and those involved in pro-inflammatory responses (exemplified by IL-6) [8, 12]. Current studies clarify the regulatory pathways underlying the
activation of those genes by studying CAL-1 cells. Efforts to resolve this issue solely by studying resting human pDCs were impeded by the rarity of such cells (they typically constitute less than 0.5% of PBMCs) and their propensity to activate during the purification process [6, 7]. The use of CAL-1 cells also facilitated analysis of the behavior of intracellular proteins. Unlike previous studies that relied upon protein overexpression models [15, 38, 45], both the level of expression and interaction between cellular proteins could be studied under physiologic conditions in CAL-1 cells. The effect of CpG ODN on murine DCs has been examined extensively. However, human and murine TLR9 molecules differ by 24% at the amino acid level  and the hexameric CpG motifs that optimally stimulate human pDCs differ from those most active in mice (and vice versa) . Similarly, the regulatory regions and splice patterns of genes involved in CpG signaling have diverged between mouse and human . Thus, the relevance of results from earlier studies examining mixed populations of murine mDCs and pDCs (both of which respond to CpG stimulation) to human pDCs is unclear.