S2e) Gal-1, gal-3 and gal-9 were also explored by their effect o

S2e). Gal-1, gal-3 and gal-9 were also explored by their effect on anti-CD3/anti-CD28-induced cytokines in peripheral T lymphocytes. Lymphocytes were stimulated during 24 h

with anti-CD3 and anti-CD28 in the presence or not of gal-1, gal-3 and gal-9 as indicated in Material and methods. Cytokine production was determined using a bead-based immunoassay. Our results showed that the presence of gal-1 during T cell receptor (TCR) stimulation induces a high production of IL-10, P = 0·02 (Fig. 4c). An augmented IL-4 production was also observed in those lymphocytes co-incubated with gal-3 and anti-CD3/anti-CD28; however, this difference was not statistically significant (data not shown). Most published studies on the immunopathogenesis of asthma and other inflammatory diseases focus on proinflammatory mediators. However, in recent years the study of cells and AZD1208 nmr molecules with immunoregulatory activity has buy Ipatasertib begun to gain importance. The data presented here show that airway cells obtained from induced sputum samples of asthma patients express lower levels of gal-1 and gal-9 and higher levels of IL-5 and IL-13 compared with cells from healthy subjects. In addition, we have identified macrophages as the cells from sputum expressing gal-1 and gal-9. A recent study analysed

the presence of galectin-bound proteins in broncoalveolar lavage (BAL) from patients with mild asthma, and a different profile of galectin-bound proteins was observed between patients and healthy subjects. In parallel, authors describe that BAL contains galectins at low concentrations, suggesting that functional interactions with galectins occur at sites where airway cells are present [24]. Numerous studies have highlighted the immunomodulatory

properties of galectins [7]. Phosphoglycerate kinase The anti-inflammatory properties of gal-1 have been evaluated in animal models of chronic inflammation [13, 25-27]. However, the role of gal-1 in asthma has not been explored previously. Published data highlight the ability of gal-1 to counteract Th1 and Th17-mediated responses through a number of anti-inflammatory mechanisms. One reported mechanism is a skewing of the balance from Th1 towards Th2 polarized immune responses, mainly through the induction of Th1 cell apoptosis. The numerous anti-inflammatory effects of gal-1 include induction of IL-10 release [28, 29], down-regulation of the secretion of TNF-α and IFN-γ [30, 31] and inhibition of transendothelial migration as well as chemotaxis of neutrophils [32]. Disruption of all these processes could contribute to exacerbated inflammatory responses in an environment with defective expression of this lectin. In the context of asthma, IL-10 plays a key role in the control of inflammatory process, able to down-modulate the Th2 response [33-35]. Decreased IL-10 expression has been linked recently to the impaired ability of natural regulatory T cells from allergic asthma patients to induce a tolerogenic phenotype in dendritic cells [36].

Very recently, standard chemical transformation methods were appl

Very recently, standard chemical transformation methods were applied to the transfection of moulting L3 B. malayi parasites (92). Previously, biolistic and microinjection techniques have been attempted in these parasites (93,94); however, both techniques are invasive and, in particular, biolistics adversely affected either the viability of the transgenic parasites or the ability of isolated embryos to undergo further development. In contrast, chemical transformation resulted in developmentally competent transfected parasites, and Selleck Erastin the reporter gene used was transcriptionally active throughout all stages of the parasites’ life cycle. However, transgene expression

was significantly reduced compared, for example, to transgenes introduced by biolistics, and hence, alternative chemical or biological methods of delivery into B. malayi are being investigated. It is clear that techniques for the delivery of exogenous genes into parasitic helminths are now considered well established. However, in all examples described thus far, enforced transgene expression has been largely restricted to reporter genes such as GFP and luciferase, unlike with RNAi approaches where many genes involved in diverse cellular pathways have been targeted. Nevertheless, the full potential of transgenesis in parasitic helminths is starting to be realized for the study of parasite protein function. For example,

the role of the protein forkhead transcription factor-1 isoform b (FKTF-1b) in S. stercoralis’

infective larval development was recently Panobinostat molecular weight investigated using GFP-linked proteins, including dominant negative mutants, introduced BCKDHA into adult female parasites via intra-gonadal microinjection (95). Here, the authors showed that recombinant FKTF-1b tagged with GFP localizes to specific tissues remodelled in infective larvae. Furthermore, mutant forms of FKTF-1b designed to interfere with endogenous FKTF-1b function resulted in incomplete development of the infective larval structures and prevented some transgenic larvae from arresting in the infective stage, indicating that FKTF-1b is required for the proper development of S. stercoralis’ infective larvae. Some of the first clear insights into the possibility of achieving heritable transgenesis were made in S. stercoralis and Parastrongyloides trichosuri. Li et al. (96) described the transgenesis of reporter constructs into the syncitial gonads of free-living females by microinjection. The plasmid constructs were found to be transmitted for as many as five generations, but were eventually lost without selection. However, none of the constructs were expressed beyond F2; hence, a stable transgene-expressing line was not generated. Greater success was achieved with P. trichosuri where transgene-expressing worms were established and maintained as transgenic worm lines (97).

The antigen-specific responses among individuals infected with L

The antigen-specific responses among individuals infected with L. braziliensis also

revealed a significant expansion of T cells expressing Vβ12 (Fig. 3). Interestingly, this was the same subpopulation identified by Clarencio et al. in CL caused by L. braziliensis and stimulated by SLA of L. amazonensis[29]. This finding may suggest an existence of common dominant response between different species of Leishmania leading to the expansion of a similar subpopulation of T cells. Frequency differences are only one possible measure of check details the involvement of a specific subpopulation of T cells in an active immune response. It is possible that slight changes or no global change in the frequency of T cell subpopulations will be noted due to a balance between expansion and death of responding T cells. However, by determining the portion of a given subpopulation committed to an activated phenotype, memory phenotype or producing specific cytokines, we can determine

their relative involvement and possible functional role in a protective or pathogenic immune response. Thus, we performed comparative analyses between the different Vβ subpopulations of the proportion of cells expressing either a marker of late T cell activation, the class II molecule, HLA-DR, or a marker associated with many memory T cells, CD45RO. These markers were measured without in vitro antigenic restimulation with the goal of determining their involvement in the host actively infected with Leishmania. Strikingly, CD4+ T cells expressing Vβ BI2536 regions 5·2, 11 and 24 displayed a significantly higher portion of cells expressing CD45RO and HLA-DR (Fig. 4). Thus, these subpopulations demonstrated a phenotype consistent with greater involvement in an ongoing immune response

than the Megestrol Acetate other T cell subpopulations. Importantly, two of these subpopulations (Vβ5·2 and Vβ11 CD4+ T cells) also displayed an expansion after antigen specific stimulation in vitro (Fig. 3). In order to understand more clearly the functional potential of specific subpopulations of CD4+ T cells based on Vβ expression, we went on to measure their relative commitment to production of antigen-specific proinflammatory (IFN-γ and TNF-α) and anti-inflammatory (IL-10) cytokines. Strikingly, the same three Vβ-expressing subpopulations arose as having a disproportionately high percentage of the SLA-stimulated T cells committed to cytokine production compared to the majority of the other Vβ-expressing T cell populations (Fig. 5). Thus, CD4+ T cell subpopulations defined by Vβ 5·2, 11 and 24 in CL patients displayed higher production of IFN-γ, TNF-α and IL-10 compared to several other subpopulations of T cells in CL patients. An important aspect of human leishmaniasis and other infectious diseases is the balance of inflammatory and down-regulatory cytokines.

Only 1 6% of all new patients in Australia were aged 60 or older

Only 1.6% of all new patients in Australia were aged 60 or older in 1970, and this increased to 36% in 1990, and 57% by 2009. However, the incidence rate of older patients has stabilized since 2005, especially among Māori and Indigenous Australian patients (Fig. 3). Numbers of new patients with multiple comorbidities have increased over time, especially for vascular and DN patients DNA Damage inhibitor (Fig. 6). By 2009, 42% of all patients, and 70% of DN patients had two or more comorbidities. Numbers

of older comorbid patients are continuing to increase for DN patients, whereas for other kidney diseases there has only been modest, if any, increase in older comorbid patients since 2005. IR of RRT among Australians 60 years or older was highest in years with low per capita death rates14 (correlation coefficients –0.4 for females and –0.8 for males). Overall, 11% of Indigenous Australian patients were biopsied, compared with 16% for other Australians, giving an adjusted RR of 0.66 (CI 0.61–0.70). Indigenous people were also less likely to receive a pre-emptive transplant than were other Australians (Table 1) (RR = 0.04, CI 0.01–0.14), as were Māori (RR = 0.3, CI 0.1–0.5) and Pacific people (RR = 0.2, CI 0.1–0.3) when compared with other NZ residents, after adjustments for sex, year, age, weight and comorbidities. Indigenous patients were more likely to be referred late than were other Australians (RR = 1.5, CI 1.2–1.8),

as were Māori (RR = 1.9, CI 1.2–3.0) and Pacific (RR = 1.8, CI 1.2–2.4) DN when compared SCH 900776 with other NZ patients. Racial discrepancies in late referrals are decreasing over time for Indigenous Fossariinae Australians (P = 0.004 for time : race interaction). Over time, patients have been commencing RRT with lower serum creatinine (higher eGFR), i.e. earlier in the progression of kidney disease (Fig. 7). Mean eGFR at commencement of RRT

increased by 0.22 mL/min per 1.73 m2 per year (adjusted) or 0.23 mL/min per 1.73 m2 (unadjusted) per year. DN patients started RRT at higher values of eGFR (P < 0.001), but the difference between DN and other patients is decreasing over time (P < 0.001 for the diabetes :time interaction) (Fig. 7). The number of new RRT patients in Australia and NZ has been increasing since RRT first became available. Much of this increase since 1990 is due to DN. These increases have not been equal among all demographic groups and continue to evolve. Although Indigenous Australians are considerably more at risk of commencing RRT due to DN than are non-indigenous Australians, this relative difference is decreasing over time. Similar trends are seen among Māori and Pacific people in NZ. These changes reflect a number of contributors. For example, changes in DN will be influenced by the prevalence of diabetes, rates of progression to DN among diabetics, changing competing risks of mortality, and the propensity to treat older and comorbid ESKD patients with RRT.

In addition, studies that did not specify women’s HIV infection s

In addition, studies that did not specify women’s HIV infection status and only mentioned investigating STIs in general as outcomes of interest in the abstract were excluded. In addition to the limitations of the review itself, there are important methodological limitations within the studies included in this review, which may have affected

their findings. Most studies utilised a cross-sectional design, which severely limits their ability to make causal inferences. None of the studies Selleckchem U0126 provided strong longitudinal, prospective information on the relationship between early sexual debut and women’s increased HIV risk, because a few cohort studies included in this review had short follow-up times or only included women in their sample who were already sexually active. In addition, asking women retrospectively about their age at their first sexual intercourse is prone to result in potential recall or response bias, especially given the potential sensitivity of the topic being explored, especially if first sexual debut was with a non-marital sexual

partner.[36] There may also potentially be variations in the quality of the research being presented, with a potential for bias being enhanced if surveys have not met standards of intensive interviewer 3-Methyladenine mw training, careful translation into local languages of terms such as sexual intercourse and sexual partners.[30] Only a few studies included in this review reported implementing strategies or measures to reduce recall and social desirability biases when asking women about their age at their sexual debut.[14] In the review, we were also not able to ensure comparability in the definitions of early sexual debut selleck chemical across studies and instead had to compile evidence from studies that used differing definitions. In practice, the majority of studies reviewed compared rates of HIV infection among women who had started having

sex before the age of 15 to rates among women who had their first sex after the age of 15. However, a few studies also used other age cut-offs, and a number of studies used multiple age categories, which made the comparisons and interpretations difficult. For example, they compared early sexual debut before the age of 15 with first sex after the age of 20 or even 25, while the majority of women in most studies had their first sex between the ages of 16–20. Existing evidence on the developmental stages of adolescents[37] seems to suggest that an age cut-off for early first sex before the age of 15 is the most sensible; however, this should be determined according to the cultural background, as first sex may often coincide with cultural norms or legal marriage age. Whichever cut-off point is chosen, it should be accompanied by a justification, which was rarely given in the reviewed studies.

The role of FcRn includes the maintenance of serum IgG and albumi

The role of FcRn includes the maintenance of serum IgG and albumin levels and the delivery of antigen in the form of immune complexes to degradative compartments within cells. The FcRn–IgG interaction is strictly pH-dependent, with a maximum at pH 6, and becomes undetectable as near neutral pH is approached, a feature that is essential for efficient transport. IgG transport between the blood and

Ponatinib concentration interstitial compartments may proceed by convection through paracellular pores in the vascular endothelium, or via FcRn-mediated transcytosis across vascular endosomal cells. Because of the redundancy of the transport systems, high-dose IVIG may help to block FcRn resulting in the enhanced clearance of pathogenic autoantibodies, but will never be able to block it completely, as

indicated in several experimental studies to date [42]. Although improving the binding of IgG to FcRn in vitro generally translates to an improved serum IgG half-life in vivo, this is not always the case. Recombinant therapeutics genetically engineered to contain IgG fragments with the CH2–CH3 domain that binds to FcRn can have significantly prolonged half-life due to protection of catabolism through FcRn binding. However, increased binding affinity to the FcRn does not appear to be proportional to the half-life extension. For example, when comparing variants of Herceptin antibody (an ERBB2-specific human IgG1 against mammary tumour cells) with a threefold LDE225 nmr increase in FcRn binding at acidic pH and another variant with a 12-fold increased binding at acidic pH and also enhanced binding at more neutral pH,

both antibodies exhibited similar half-lives when tested in a humanized FcRn transgenic mouse model [43]. Increased binding may enhance degradation of IgG under neutral Exoribonuclease conditions. Clearly, there is an obvious need to have a better understanding of FcRn in the exact regulation of IgG-mediated responses and half-life in vivo. Research in immunoglobulin therapy with IVIG or SCIG has shown that therapy targets and treatment options evolve in parallel. Achieving good clinical outcomes to enable a state of health as found in immunocompetent individuals is achievable with the use of 0·4–0·6 g/kg/month for many patients with PI, although some patients may require higher doses. For patients with autoimmune neuropathies, an empirically derived starting dose of 2 g/kg is used frequently in the acute setting as in Guillain–Barré syndrome. For maintenance treatment, evidence from a recent randomized placebo-controlled trial in chronic inflammatory demyelinating neuropathy suggests that a dose of 1 g/kg every 3 weeks is sufficient to maintain strength [44]. Indications for review of immunoglobulin doses in patients with PI and autoimmune neuropathies are summarized in Table 5.


the anti-αMβ2 reagent, clone 44, promoted a modest


the anti-αMβ2 reagent, clone 44, promoted a modest release of IL-8 and MIP-1β in the THP-1 cell line model, but was without significant stimulatory effect in the U937 system (Fig. 3a,b). The MEM48 pan anti-β2 reagent did not stimulate cytokine release. Clone 3.9, an anti-αXβ2 heterodimer antibody (Fig. 3a,b), stimulated significant release of IL-8, MIP-1β and, to a lesser extent, RANTES from the immature THP-1 cells but, with the exception of a small effect on IL-8 release, did not promote cytokine release this website from U937 cells. The difference in cytokine response between cell lines could not be attributed to differences in integrin expression levels as THP1 and U937 cells expressed similar levels of both the αV and β2 integrin heterodimers studied (Fig. S2). The data in Fig. 3(a,b) are based on cell line models and it is important to validate the data from such systems in primary tissue. To

this end, bone marrow monocyte precursors and PBMC were assessed Ceritinib supplier for their patterns of responsiveness to ligation with anti-integrin mAbs (Fig. 3c). Bone marrow monocytes and PBMC showed striking differences in expression of the sCD23-binding integrins (Fig. 3c). Bone marrow monocytes expressed αXβ2 and αVβ3 in moderate amounts and were weakly positive for αMβ2; the cells were negative for αVβ5. The PBMC expressed all four integrins, with greatly increased levels of αXβ2 and αVβ3, clear positivity for αMβ2 and robust expression of αVβ5 (Fig. 3c). Bone marrow monocytes were treated with different anti-integrin mAbs and the patterns of cytokine release were determined. None of the stimuli used, including LPS, promoted IL-8 release (data not shown), but there was a clear and robust effect on release of MIP-1β, RANTES and TNF-α. Antibodies

Teicoplanin directed to αXβ2 and to αVβ3 promoted significant release of all three cytokines, whereas antibodies directed to αMβ2 (ICO-GMI) or αVβ5 (P1F6) failed to induce cytokine release (Fig. 3c). Ligation of αXβ2 on PBMC with clone 3.9 mAb promoted cytokine release, albeit to lower levels than noted with bone marrow monocytic cells, but treatment with anti-αVβ3 mAbs did not drive TNF-α release. Cross-linking of αMβ2 stimulated TNF-α release from PBMCs (Fig. 3c). However, none of the anti-integrin mAbs could provoke IL-8 (data not shown) or RANTES secretion from PBMC (Fig. 3c), a result that is consistent with the observations from cell lines representative of immature and mature monocytes. Finally, THP1 cells were treated with db-cAMP to induce differentiation and the effects on integrin expression and responsiveness were assessed (Fig. 3d). The db-cAMP caused a minor increase in expression of αMβ2 and αVβ5 in THP-1 cells and a more pronounced elevation in levels of αXβ2; αVβ3 levels were unchanged (Fig. 3d).

Ultra pure LPS from E coli 0111:B4, Pam3CSK4 and IFN-γ were purc

Ultra pure LPS from E. coli 0111:B4, Pam3CSK4 and IFN-γ were purchased from InvivoGen (San Diego, USA), pertussis toxin, polymixin B and 8Br-cAMP (B7880) from Sigma Dorset, UK and QCL-1000® Endpoint Chromogenic LAL Assay from Lonza Group, Basel, Switzerland. Mouse

CD40L was kindly provided by Dr. David Gray (University of Edinburgh). hBD3 (GIINTLQKYYCRVRGGRCAVLSCLPKEEQIGKCSTRGRKCCRRKK) and hBD2 (GIGDPVTCLKSGAICHPVFCPRRYKQIGTCGLPGTKCCKKP) were purchased from Peptides International Louisville, USA and are oxidised so the disulfide connectivities are of the canonical β-defensin arrangement 32. Defb14 (FLPKTLRKFFCRIRGGRCAVLNCLGKEEQIGIRCSNSGRKCCRKKK) and LL37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) AP24534 in vitro were synthesized as previously described Selleckchem AZD5363 20, 33. RAW264.7 cells were maintained in DMEM (GIBCO Paisley, UK) and THP-1 cells in RPMI containing 10% FBS, essential amino acids and antibiotics. Balb/c, CBA and C57 Black/6 mice were obtained from

Charles River (UK) and Mc1r e/e and Mc3r KO mutants were bred in-house. C3H/HeJ OlaHsd-Tlr4 mutants and C3H/HeN controls were obtained from Harlan Laboratories, UK. Primary Mϕ were generated from femur BM and grown in DMEM containing 10% FBS and 20 ng/mL M-CSF (R&D Systems, Abingdon, UK) for 7 days. Cells were seeded at 1.25×105 into 48-well plates and grown without growth factor for 24 h prior to treatment. Replicate experiments were done with separate Mϕ preparations from at least three mice for each experiment. Human venous blood was collected according to Lothian Research Ethics Committee approvals ♯08/S1103/38, using sodium citrate anticoagulant (Phoenix

Pharma, Gloucester, UK), and cells were separated by Dextran sedimentation, followed by discontinuous, isotonic Percoll gradient centrifugation as previously described 33. PBMC were incubated at 4×106/mL in IMDM (PAA Laboratories, Somerset, UK) at 37°C, 5% CO2, for 1 h. Non-adherent Terminal deoxynucleotidyl transferase cells were removed and adherent monocytes cultured for 6 days in IMDM with 10% autologous serum to generate monocyte-derived Mϕ. Cells were treated with LPS (50 ng/mL), Pam3CSK4 (100 ng/mL), CD40L (3 μg/mL) IFN-γ (5 ng/mL), hBD3, Defb14, LL-37, 8Br-cAMP (at concentrations shown) or combinations of these as described, in serum free media then incubated at 37°C, 5% CO2 for 18 h. Supernatants were collected and centrifuged to remove particulate debris. Levels of TNF-α, IL-6 and IL-10 in the supernatants were measured using human or mouse DuoSet ELISA (R&D Systems) according to the manufacturer’s instructions. Cell viability was measured using TACS™ MTT assay (R&D Systems). Balb/c male mice (5–8 wk) were injected with 16 mg/kg of LPS (approx. 200 μg/mouse) with or without 10 μg of hBD3 in 200 μL of PBS. After 1 h mice were killed by cervical dislocation, exsanguinated and serum TNF-α levels measured by ELISA.

A free flap transfer combined

A free flap transfer combined GDC-0973 in vitro with an autologous vein graft can cover large tissue defects and simultaneously improve distal perfusion even in patients with arterial occlusive disease. We are presenting a case of bypass-free radial forearm flap used to cover a foot defect in an old diabetic

patient with peripheral arterial disease. The flap perfusion deteriorated significantly during the early postoperative period. The patient was brought back to the operating room with acute thrombosis of the popliteal-radial venous graft and the arterial pedicle of the flap. The flap was salvaged by thrombectomy and creation of an additional arteriovenous fistula at the distal arterial pedicle. The procedure improved the flap perfusion and decreased the high internal resistance that was noticed in the flap when trying to flush the radial artery during the revision surgery and was evident by continuous wave -Doppler sonography. The successful salvage of the flap in the presented case and the convenient long-term follow up suggest that this technique may be safe and helpful as a last effort to salvage a bypass-free flap with a suspected high internal resistance. © 2013 Wiley Periodicals, Inc. Microsurgery 33:391–395, selleck inhibitor 2013. “
“Although ischemia-reperfusion (I/R) strongly influences muscle flap survival in reconstructive

surgery, there is limited knowledge about its relation to hemorheological parameters and oxidative stress markers in flaps. In the present study we investigated these changes during I/R of latissimus dorsi muscle (LDM) flaps in beagle dogs. In four animals LDM flaps were prepared bilaterally. The right side served as control, while the left side’s vascular pedicle was clamped for 60 minutes, and a 60-minute reperfusion was allowed afterward. Blood samples (0.5 ml each) were taken from the pedicle’s vein bilaterally before and after the ischemia,

and at the 5th, 15th, Astemizole 30th, 45th, and 60th minutes of the reperfusion, for hematological and erythrocyte aggregation tests. In muscle biopsies, taken before and after I/R, histological investigations and tests for measuring gluthation-peroxidase (GSH-PX) activity, glutathione (GSH) and carbonyl concentrations, and thiobarbituric acid reactive substances (TBARS) content were carried out. In I/R side leukocyte count increased during the reperfusion with a peak at the 30th minute. Hematocrit continuously increased from the 15th minute. In the first 5 minutes of the reperfusion, erythrocyte aggregation increased, than tented to be normalized. In muscle homogenates GSH-PX activity did not change markedly, GSH content slightly decreased, carbonyl and TBARS content increased during reperfusion. A 1-hour ischemia and reperfusion of LDM flaps caused local changes of leukocyte distribution and erythrocyte aggregation, supposedly due to the metabolic and inflammatory reactions.

burgdorferi might involve TLR-2, keeping in mind that the intact

burgdorferi might involve TLR-2, keeping in mind that the intact bacterium can activate immune responses by TLR-independent mechanisms 31. For example, MyD88 deletion in mice affects immune-mediated pathogen selleck chemicals clearance, while allowing many inflammatory processes to proceed 32, 33. We pre-treated monocytes with a neutralizing monoclonal antibody against TLR-2 (T2.5) and pulsed them with borrelial lipids, leaving blocking antibody

in culture 34. As noted previously in cytokine-activated monocytes 12, the range of CD1a expression on borrelia-activated cells is broad and the histogram is bimodal in nature. T.2.5 reduces the number and mean level of CD1a expression as compared to isotype-matched antibody-treated controls, but some cells retain detectable staining (Fig. 2B and D). For CD1c, the histogram of activated cells shows a single population with a normal Gaussian distribution,

and treatment with anti-TLR-2 blocked expression to levels seen in unactivated cells (Fig. 2D). Thus, live B. burgdorferi and its hydrophobic components selectively increased group 1 but not CD1d protein expression using TLR-2. CD1 cell surface expression might be induced through the NF-κB signaling pathway within a single cell that expresses both TLR-2 and CD1. Alternatively, RO4929097 cell line CD1 might appear through a multi-cell mechanism in which the TLR-2 expressing cells secrete transferable factors. The single cell model is plausible because we found that TLR-2 and group 1 CD1 are co-expressed on myeloid cells (data not shown). On the other hand, a prior study of cellular infection showed that CD1 appeared on individual myeloid cells harboring fluorescent mycobacteria as well as uninfected bystander cells 13. The natural TLR-2 agonists in B. burgdorferi are chemically diverse, but mechanistic studies could more reliably be carried out using a single compound of defined molecular structure. Therefore, we used a synthetic lipopeptide

(triacyl-CSK4) 34. Validation of this TLR-2 agonist showed its ability 3-mercaptopyruvate sulfurtransferase to stimulate group 1 CD1 protein expression on monocytes in a dose-dependent manner (data not shown). Because this and other preliminary studies found concordant upregulation of CD1a, CD1b and CD1c by TLR agonists 13, 17, we measured CD1a as a surrogate for group 1 CD1 proteins 4. Kinetic studies showed that CD1a expression was transiently detected at high densities after 48–72 h after stimulation (Fig. 3A). When triacyl-CSK4 was pulsed onto cells and then washed off, there was a delay of more than 2 days before CD1a proteins appeared at the surface, even though only 10–60 min of exposure to the initial stimulus was sufficient to trigger CD1a expression (Fig. 3B and data not shown). Prior studies have shown that the proximal signaling events involving MyD88, IRAK4, IRAK1, TRAF6, TAK1, IKK and IκB leading to activation are complete within hours 35–40.