Ultimately, differences

in performance across phonetic contrasts may derive less from their phonological status (e.g., consonant versus vowel) and more from the statistical structure of the cues to these contrasts, particularly when we look across multiple relevant selleck kinase inhibitor and irrelevant dimensions. For example, cues like VOT do vary between speakers (Allen, Miller, & de Steno, 2003), but they are largely discriminable without taking this into account; therefore, high variance in speaker cues will quickly reveal the more invariant contrastive VOT cues. However, for vowels, and to a lesser extent, fricatives and liquids, contrastive and noncontrastive acoustic dimensions overlap substantially (vowels: Hillenbrand, Selleck PLX3397 Getty, Clark, & Wheeler, 1995; fricatives: Jongman, Wayland, & Wong, 2000). These contrastive dimensions, such as formant structure, F0, and length, are also cues that vary considerably by speaker. In order to use speaker variation to detect such differences, infants may need more sophisticated ways of dealing with this variability or may simply need to learn more about those things that contribute to variance (Cole, Linebaugh, Munson, & McMurray, 2010) before vowel can be a cue to word identity. As a result, failures

in the switch task at 14 months do not represent a reversal of development, a U-shaped curve, or a discontinuity. We suggest rather that speech perception was never fully developed at 12 months, as is evidenced by studies of older children (Nittrouer, 2002; Ohde & Haley, 1997; Slawinski & Fitzgerald, 1998). Reliance largely on discrimination measures resulted in a failure to consider other factors (like dimensional weighting)

that are revealed by this task. This study hints that dimensional weighting is sensitive to the relative variation along different dimensions. This may in fact represent a general principle of learning. For example, the role of irrelevant variation suggested by this work parallels mechanisms proposed by Gómez (2002) for statistically determined grammatical dependency structures. Adults and infants learned a novel grammar with nonadjacent dependency structure. When intervening elements in the dependency were long and variable, both adults and infants detected the nonadjacent dependencies. When selleck compound intervening elements did not vary, participants were unable to learn the grammatical dependencies. Consequently, learning of grammatical dependencies in Gómez’s experiment requires high variability in those elements that are not criterial for determining the grammar. Yu and Smith’s (2007) work on learning word–object mappings via cross-situational statistics illustrates the same point. In this study, subjects learned a small set of word–object mappings solely by noticing the statistical relationship between the sound and the object: whenever a given word was heard, the referent was consistently present.

05% Tween-20 plus 10% goat serum and incubated for 1 h at 37°C. Plates were then washed and incubated with HRP-conjugated anti-human IgG (Sigma, USA) at 1:3000 dilution. A substrate solution containing

OPD (0.5 mg/mL) in sodium citrate buffer, pH 5.0, and 0.03% H2O2 was used to develop the colorimetric reaction. Reactions were then stopped with 2 M Palbociclib price H2SO4 and the A492 was measured in an ELISA reader (Spectramax, Molecular Devices). Blood from active TB patients (n=11) or PPD-negative (n=6) healthy BCG-vaccinated subjects were collected and PBMC were obtained through Ficoll gradient as previously described 50. PBMC (5×106 cells/mL) were exposed to purified sMTL-13 (10 μg/mL) for 48 h and IFN-γ was measured in culture supernatants by a cytometric bead assay (Bencton, Dickinson and Company, USA) following the manufacturer’s instructions. Non-parametric Mann−Whitney test, Kruskall−Wallis with Dunn’s multiple buy AZD6738 comparison tests or Friedman test were used to the significance of differences between groups. Values of p<0.05 were considered statistically significant. The ROC curve was used for analysis of the accuracy values: area under the ROC curve, sensitivity, and specificity, obtained by using MedCalc Statistical (Version 5.00.020,

Brussels, Belgium). The authors thank Mr. Jorge Tolentino and Dr. Bruno Bezerril (Fiocruz/BA) for technical support and Prof. Mario Steindel for critical reading of this manuscript. They also thank Marcos L’Hotellier and the staff of the DRD-CPHC/JF

for helping with the TB patients. They are indebted to Drs. Luciana Leite and Ivan Nascimento (I. Butantan) as well as Profa. Maria Luiza Bazzo (UFSC) for providing the M. bovis BCG CFP and non-tuberculous mycobacteria strains, respectively. L.N. received CAPES/CNPq fellowship. A.B. received funding from CNPq (472477/2007-2 and 565496/2008-5), CAPES (210/2007), FAPESC (04524/2008-1) and WHO/TDR (2008-8734-0). C.D.S., B.S.C., H.C.T., S.C.O., M.B.N., and A.B. are CNPq investigators. Conflict of interest: The authors declare no financial or commercial conflict of interest. “
“Division of Immunoregulation, National Niclosamide Institute for Medical Research, London, UK Administration of peptides i.n. induces peripheral tolerance in Tg4 myelin basic protein-specific TCR-Tg mice. This is characterized by the generation of anergic, IL-10-secreting CD4+ T cells with regulatory function (IL-10 Treg). Myelin basic protein Ac1–9 peptide analogs, displaying a hierarchy of affinities for H-2 Au (Ac1–9[4K]<<[4A]<[4Y]), were used to investigate the mechanisms of tolerance induction, focusing on IL-10 Treg generation. Repeated i.n. administration of the highest affinity peptide, Ac1–9[4Y], provided complete protection against EAE, while i.n. Ac1–9[4A] and Ac1–9[4K] treatment resulted in only partial protection. Ac1–9[4Y] was also the most potent stimulus for IL-10 Treg generation. Although i.n.

Vα2+, Vα12+ and Vα2Vα12-double positive cells were identified in gated CD4+CD25highCD127lowFOXP3+ Treg and in CD4+CD25−/lowCD127+FOXP3− Tconv, and used to calculate the frequencies of %dual TCR cells

as described elsewhere 21 (Fig. 1C). To determine surface expression levels of TSLPR on MDCs, PBMCs were stained with mAbs specific for CD11c, CD123, HLA-DR, TSLPR, and the lineage cocktail (Lin, mAbs specific for CD3 (T cells), CD14 (monocytes), CD16, CD56 (natural killer cells), and CD19, CD20 (B cells). Labeled PBMCs were first gated for HLA-DR+Lin−, and further analyzed for expression of CD11c and CD123 to identify CD11c+CD123− MDC. Finally, TSLPR-MFIs were determined on gated MDC; Fig. 1D. PBMCs were isolated from 10–50 mL of peripheral blood by density gradient centrifugation with Ficoll-Hypaque (Biochrom AG, Berlin,

buy Z-VAD-FMK Germany). Ixazomib Total Treg and Tconv were immunomagnetically separated as described previously 2, 37, 38. IL-7 levels in serum samples were measured using a highly sensitive enzyme-linked immunosorbent assay (Quantikine-HS, Human IL-7 Immunoassay; R&D, Abingdon, UK), according to the manufacturer’s instructions. Samples were assayed in duplicate. For quantitation of sIL-7Rα in serum samples an in-house two-step ELISA was established, according to the protocol described by Rose et al. 39. In short, a microtiter plate was coated with a mouse anti-human IL-7Rα mAb (clone 40131), and – after blocking with PBS/0.05% Tween 20 – incubated with 200 μL undiluted serum overnight at room temperature. A biotinylated goat anti-human

IL-7Rα mAb, streptavidin-HRP and TMB substrate were used for detection and visualization of sIL-7Rα with a detection limit of 0.5 ng/mL. Serial dilutions of recombinant human IL-7Rα-Fc chimera protein served as positive PLEK2 control and were used for creation of a standard curve. All antibodies and reagents were purchased from R&D. Genomic DNA was extracted from 105–106 PBMC cells using a QIAamp DNA Blood Mini Kit (Qiagen, Düsseldorf, Germany) according to the manufactures’ protocol. Screening for the MS-associated rs6897932 SNP within the IL-7RA gene was performed by using a TaqMan® predesigned SNP genotyping assay (Applied Biosystems, Foster City, CA, USA). PCR reactions were performed and analyzed as described by the manufacturer utilizing an Applied Biosystems 7500 Real-Time PCR System. In vitro proliferation assays were performed as previously described 2, 37. In brief, 105 freshly isolated Tconv were incubated alone or in co-culture with 2.5×104 total Treg (Tconv/Treg ratio 4:1) and polyclonally activated by addition of soluble anti-CD3 (1 μg/mL) and anti-CD28 mAbs (1 μg/mL). After 4 days, cells were pulsed for 16 h with 1 μCi of 3[H]-thymidine per well. After harvesting T-cell proliferation was measured with a scintillation counter.

The finding that AMPs were upregulated in colonic ECs in pIgR KO mice suggests that epithelial sensing of bacteria through microbe-associated molecular patterns are increased in mice lacking Metformin SIgs compared with WT animals, perhaps because live bacteria or microbe-associated molecular patterns can more readily reach the epithelium. This is in agreement with the observation of enhanced epithelial invasion by Salmonella typhimurium in naïve pIgR KO mice [30]. Alternatively, the altered composition of

the intestinal microbiota in pIgR KO mice could provide qualitatively different signals to the epithelium. We found 208 genes that were differentially regulated in colonic ECs of pIgR KO and WT mice when both strains had conventional intestinal microbiota. However, when

both genotypes were treated with antibiotics, this number was reduced to 27, suggesting that most of the observed CH5424802 in vivo differences in untreated mice were driven by the endogenous microbiota. Furthermore, we identified 296 genes with more than twofold differential expression between antibiotic-treated and untreated pIgR KO mice (Fig. 1). The same comparison in WT mice revealed a substantially fewer 106 genes altered [17]. Thus, a considerably higher number of genes were regulated by the commensal microbiota in pIgR KO mice than in WT mice, suggesting that the commensals drive epithelial activation in the absence of SIg. This finding is in agreement with a recent study of jejunal responses in B cell and IgA-deficient mice as well as immunocompromised humans [31]. In the absence of B cells or IgA, ECs mounted a commensal microbiota-driven immune response at the cost of reduced metabolic function. We

observed a similar microbiota-driven enhancement of epithelial immune responses in the colon of pIgR KO mice. However, there was little overlap of genes differentially expressed in jejunum of B-cell KO mice compared with WT mice [31] with genes differentially expressed in colonic epithelium of untreated pIgR KO mice compared with WT PLEKHM2 mice (this study). These differences are probably due to differences in anatomy and physiological function of the two intestinal sites. We found that several xenobiotic-metabolizing enzymes were downregulated in pIgR KO mice, in agreement with published reports that these enzymes are downregulated by the presence of intestinal bacteria [32]. We conclude that although the biological principle of enhanced epithelial defense in the absence of IgA is conserved between small and large intestine, the host expressed molecules mediating this defense differ. The fine-tuned balance between beneficial intestinal bacteria and the host is important for maintaining a healthy gut [33, 34]. Underlying causes of a perturbed host–microbiota relationship are complex.

After calculations, the number of eggs eliminated by each infected mouse was expressed as eggs/g of faeces. Given the fact that S. venezuelensis filiform larvae develop only into female worms in the small intestine of the host, fecundity rate was estimated by dividing number of eggs per number of worms recovered from the intestine of each animal. The eosinophil peroxidase (EPO) assay was used to measure eosinophil activity in the skin and lung as previously described by Strath et al.(28) and modified by Silveira et al.(16).

Briefly, 100 mg of tissue (skin or lung) was homogenized in 1·9 mL of PBS using a tissue homogenizer (Power Gen 125; Fisher Scientific, Pittsburgh, PA, USA). The homogenate was centrifuged (3000g for 10 min), red blood cells in the pellet underwent hypotonic lysis (1·5 mL of 0·2% NaCl) and the molarity was restored

with 1·5 mL of 1·6% NaCl solution containing 5% glucose. After a further centrifugation PI3K inhibitor (3000g selleck chemicals for 10 min), the pellet was resuspended in PBS (pH 7·4) containing 0·5% hexadecyltrimethylammonium bromide (PBS-HTAB). The cell solution was homogenized again and the homogenates were then freeze-thawed three times in liquid nitrogen, centrifuged for 15 min at 3000 g and the supernatant was used to measure EPO activity. For this assay, 75 μL of each experimental sample obtained from different tissues was incubated with 75 μL of substrate [1·5 mm o-phenylenediamine (OPD) in 0·075 mm Tris–HCl buffer, pH 8·0, containing 6·6 mm

of hydrogen peroxide] for 30 min at room temperature (RT) in the dark. Reaction was stopped by adding 50 μL of 1 m H2SO4. Reaction intensity was read at 492 nm on a micro-plate reader (Emax; Molecular Devices, Sunnyvale, CA, USA) and results are shown as absorbance units. The extent of neutrophil activity was indirectly estimated by myeloperoxidase (MPO) assay as previously described by Ivey et al. (29) and modified by Matos et al. (30). Tissue samples (100 mg of skin this website and lung) were homogenized in extraction buffer (0·1 m NaCl, 0·02 m NaPO4, 0·015 m NaEDTA; pH 4·7) and the pellet underwent hypotonic/hypertonic lysis as described in EPO assay. After further centrifugation (3000g for 10 min), the pellet was resuspended and rehomogenized in 0·05 m NaPO4 buffer, pH 5·4, containing 0·5% HTAB, followed by three freeze-thaw cycles using liquid nitrogen. The resulting solution was centrifuged for 15 min at 10 000g and the supernatant was used for the colorimetric assay. For this, 75 μL of supernatant was incubated with 75 μL of substrate (1·6 mm tetramethylbenzidine and 0·5 mm H2O2 in 0·05 m NaPO4 buffer, pH 5·4) for 30 min at room temperature in the dark. Reaction was stopped by adding 50 μL of 1 m H2SO4. Myeloperoxidase activity present in the sample was measured at 450 nm on a micro-plate reader (Emax; Molecular Devices).

To confirm that nitric oxide was the active agent limiting the specific subset of activated CD4+ T cells in M. avium infected mice, we delivered a specific inhibitor of nitric oxide synthase activity to infected mice and monitored the development of specific T-cell subsets. In these experiments, we treated

mice early in infection, as we wanted to be able to detect the CD69loT-bet+ CD4+ T-cell population in the WT mice. Mice were infected and either left untreated or treated Selleck JQ1 with aminoguanidine [36] from day 0 to day 30 or day 20 to day 30 and the phenotype of the activated CD4+ T-cell population in the infected organs determined by flow cytometry. We found that both CD69hiT-bet+ and CD69loT-bet+ CD4+ T cells could be detected in the organs of untreated infected mice (Fig. 6A) and that the frequency of CD69hiT-bet+ CD4+ T cells was either unaffected (spleen) or modestly reduced by aminoguanidine treatment (lung and liver) (Fig. 6A, top panels). In contrast, the frequency of CD69loT-bethi CD4+ T cells significantly increased in the organs of all treated mice (Fig. 6A, lower panels). These data indicate that BIBW2992 supplier the presence of nitric oxide influences the expression of CD69 in activated CD4+ T cells in all infected organs. Based on the array data (Fig. 5B), we also wanted to determine the impact of nitric oxide on the expression of the

VLA-4 marker in CD4+ T cells by measuring the expression of the inducible subunit CD49d in the infected and aminoguanidine-treated mice. Using flow cytometry, we found that infection resulted in increased expression of VLA-4 on T-bet+ CD4+ T cells and that inhibition of nitric oxide generation resulted in further increased expression of this marker (Fig. 6B, upper panels). There was also an increased frequency of VLA-4+Tbet+ cells in the aminoguanidine-treated mice (Fig. 6B, bottom panels). These data demonstrate that nitric oxide limits the expression of VLA-4 on the activated Gefitinib research buy CD4+ T cells in mycobacterially infected mice. In the low dose model of infection, M. avium strain 25291 generates

highly necrotic lesions resembling those induced by M. tuberculosis in humans and the development of necrosis is entirely dependent upon IFN-γ, IL-12p40, and CD4+ T cells [32, 37]. In high-dose infection models, this strain of M. avium results in loss of CD4+ T cells [38] and phagocyte-dominated lesions that do not become necrotic [32]. We wanted to determine whether the impact of nitric oxide on the granulomatous response to M. avium 25291 was related to the impact of nitric oxide on CD4+ Th1 cells. The data show that in the absence of Nos2, the inflammatory site in the liver of M. avium 25291 infected mice is indeed altered. The WT lesion is characterized by the accumulation of F4/80+, p22-phox+ monocytic phagocytes.

Millipore HA cellulose ester (MAHAS4510) was used for IgA ELISpot

assays and Immobilon P (MAIPS4510) membrane-bottom plates were used for IFN-γ ELISpot assays. For IgA ELISpots, the antigens used were recombinant nucleoprotein, recombinant listeriolysin, and sonicated WT listerial antigen. Antibodies in cultured lymphocyte supernatants were also harvested for soluble vaccine-specific immunoglobulins by ELISA, as previously described (25), an assay also known as the ALS assay (30). For IFN-γ ELISpots, control wells included phytohemagglutinin (PHA) and “CEF”, a commercially available standard peptide pool including 32 CMV, EBV and influenza virus peptides, 8–12 buy FK228 amino acids in length (AnaSpec, San Jose, CA, USA). Test peptides included the same three influenza peptide pools and the listeriolysin O (LLO) (25) peptide pool described above. The complex whole listerial antigen was also used in IFN-γ ELISpot studies. Spots were counted by an automated reader (Immunospot; CTL, Shaker

Heights, OH, USA). Low level spot counts in unstimulated medium-only control wells were subtracted from the test wells. The IFN-γ ELISpot results are presented as mean values of duplicate wells per condition as spot-forming DMXAA nmr cells (SFC)/106 PBMC. A positive response for an individual was defined as more than two-fold greater than baseline results for that antigen and over 100 SFC/106 PBMC (31, 32). Because IFN-γ responses did not appear related to the oral dose given, results were also analyzed as a whole by organism given, comparing pre-immune with peak values. Serum samples were studied by ELISA to quantify IgG and IgA directed against sonicated listerial antigens, recombinant his-tagged listeriolysin and Influenza A nucleoprotein over time. Antigens were suspended in PBS and used to coat Nunc-Immuno Maxisorp 96-well plates (Nalge Nunc International, Roskilde, Denmark). Assays were performed as described (9) and read on a Vmax kinetic microplate reader (Molecular Devices, Sunnyvale, CA, USA).

Endpoint dilutions are reported as the highest dilution at which a serum sample was ≥0.14 OD units at 405 nm, an arbitrarily chosen cutoff value. Four-fold or greater increases in endpoint titer were considered a positive result. The differences in geometric means between groups were compared statistically with the Mann–Whitney (-)-p-Bromotetramisole Oxalate test. Both vaccine strains were demonstrated by sequencing to contain the expected deletions and heterologous fusion antigen. The introduction of the attenuating mutations ΔactA/plcB and ΔactA/inlB did not significantly alter growth kinetics in TSB broth as measured by optical density, nor did the incorporation of the “empty” integration vector, pPL2. Introduction of the foreign antigen fusion cassette did moderately alter growth kinetics; both the rate of growth and the final density of growth were slightly depressed (OD600nm∼1.5 to 2.0 vs. ∼2.3 to 2.7).

[105] In support of this, both sKl and mKl were reduced 3 hours post reperfusion[102] and the administration of exogenous klotho reduced renal injury especially when given within 60 minutes of reperfusion.[102] Further transgenic overexpression of klotho conferred more resistance to ischaemia reperfusion injury compared with wild-type.[102] Therefore klotho deficiency as an early event in AKI and its potential role as apathogenic factor that exacerbates acute

kidney damage may make this renal-derived protein a highly promising candidate for both an early biomarker and therapeutic agent for AKI. Progression from AKI to CKD or end-stage kidney disease inevitably follows a common pathway, selleck chemicals llc characterized www.selleckchem.com/products/ABT-263.html by progressive interstitial fibrosis.[111] Transforming growth factor-β1 (TGF-β1) is a key player in mesenchymal transition and has an important role in fibrosis.[109] In the UUO model TGF-β1 is elevated and correlates with the severity

of fibrosis following injury.[110] Administration of recombinant klotho was observed to inhibit TGF-β1 signalling by directly binding to its receptor, thereby inhibiting the binding of TGF-β1 and ultimately alleviating renal fibrosis.[109] In a murine model of folic acid nephropathy and with cell culture, Moreno et al. demonstrated klotho downregulation by inflammation through the tumour necrosis factor (TNF) family of cytokines in a nuclear factor-kappa B (NFκB)-dependent manner.[104] This reduced gene expression was demonstrated to be a result of histone deacetylation, with inhibition of Sirolimus supplier this mechanism resulting in reversal of the effects of TNFα,[104] arguing again for a possible therapeutic role using sKl, not only as a novel AKI biomarker but as potential therapy in kidney injury. Angiotensin-II (AngII) is a well-recognized potent pro-inflammatory, pro-oxidant and pro-fibrotic

agent traditionally considered exclusively involved in blood pressure and electrolyte control that is upregulated in a variety of renal pathology.[112, 113] AngII blockade using angiotensin-converting enzyme inhibitors (ACE-i) and angiotensin (type-1) receptor blockers (ARB) have not only demonstrated the pleiotropic effects of AngII but blockade confers cardio-renal protection beyond that of blood pressure control.[113-115] In examining these mechanisms, Zhou et al. studied rat renal tubular epithelial cells (NRK-52E) treated with AngII, ACE-i and ARB, alone and in combination.[116] The authors determined that several markers of fibrosis and inflammation including TGF-β1, were upregulated as a result of treatment with AngII and downregulated when treated in combination with ACE-i and/or ARB. Concurrently, klotho mRNA and protein levels in the cells showed relative inverse regulation, suggesting potential mechanistic pathways of AngII-induced kidney damage and klotho protection.

Tullis et al. performed a cross-sectional analysis of the effect of usage vs non-usage of different

classes of antihypertensive medication on blood pressure control in a population of 139 hypertensive patients with atherosclerotic renal artery stenosis demonstrated by renal artery duplex ultrasonography (Table 2).24 The study found ACE inhibitor usage vs non-usage was associated with significantly lower systolic (157 ± 27 vs 169 ± 22 mmHg; P = 0.03) and diastolic (79 ± 9 vs 85 ± 9 mmHg; P = 0.001) blood pressure. In contrast, usage vs non-usage selleck of beta-blockers or calcium channel blockers did not have any significant effect on blood pressure. Blood pressure was actually slightly higher in users of diuretics compared with non-users. The observed beneficial effect of ACE inhibitor use on blood pressure was confined to those patients with at least one high-grade (>60%) renal artery stenosis lesion Talazoparib supplier and was more pronounced in those with unilateral rather than bilateral high-grade disease. A multiple regression analysis model predicted an 11.2 mmHg reduction in mean arterial pressure in patients with high-grade unilateral renal artery stenosis who were taking an ACE inhibitor, compared with those who were not. In summary, this study supports the concept that using medications

that block the renin–angiotensin system provides superior control of blood pressure than do alternative agents in patients with renovascular hypertension. This study is limited, however, by its cross-sectional observational design and its lack of data regarding either renal function or clinical outcomes. Several open label studies have found that ACE inhibitors can successfully control blood pressure in a high proportion (82–96%) of patients with

renovascular triclocarban hypertension (Table 3). This is a contrast to the era before ACE inhibitors were available, when renovascular hypertension was commonly refractory to the available medical therapies.25 In addition, in a review of 269 patients with documented renovascular hypertension treated with captopril in worldwide hypertension trials, Hollenberg reported that control of hypertension (diastolic pressure  < 95 mmHg) was achieved in 74% of patients.25 Renal failure necessitating cessation of captopril only occurred in 5% of these patients. The response of renovascular hypertension to captopril has also been reported to be predictive of the effectiveness of surgical revascularization in improving blood pressure.26,27 Hodsman et al. treated 20 patients with renovascular hypertension with enalapril and was able to successfully lower blood pressure in all 20 patients with no significant adverse effects.28 Jackson et al. also reported that enalapril (±a diuretic) was able to achieve a satisfactory reduction in blood pressure in a high proportion (75%) of patients with proven renovascular hypertension.

Viral, bacterial or parasite infections

strongly induce KLRG1 expression in NK cells and T cells and most T cells with effector or effector-memory phenotypes are KLRG1+8–11. T cells expressing KLRG1 have normal effector functions but the proliferative capacity of these cells is impaired 7, 11–14. In addition, KLRG1 was shown to serve as a marker for short-lived effector CD8+ T cells during viral infection 15, 16. Within the NK-cell population, KLRG1 is predominantly found in the most mature CD11b+CD27− NK-cell subset in mice 17–19 and in CD56dim NK cells in humans 7. Of interest, NK cells from MHC-class-I-deficient mice express lower levels of KLRG1 20. Moreover, KLRG1 expression by NK cells after murine cytomegalovirus (MCMV) FDA approval PARP inhibitor infection has been demonstrated to inversely correlate with the ability to produce IFN-γ 21. Thus, similar to T cells, KLRG1 is also a marker for NK cells that are approaching the end PS-341 mouse of their differentiation stage. Members of the classical cadherin family have been identified

as ligands for both human and mouse KLRG1 22–25. In addition, inhibition of T and NK-cell function by interaction of KLRG1 with E-cadherin has been demonstrated in some but not all experimental settings 22–24, 26. These findings suggested a role for KLRG1 in dampening KLRG1+ lymphocytes in tissues expressing cadherins in order to prevent immunopathology 27. The crystal structure of KLRG1 in complex with E-cadherin has recently been solved 28. It shows that KLRG1 binds to a highly conserved site on cadherins that overlaps with the site involved in homophilic trans interaction but is distinct from the αEβ7 (CD103) binding site. An exceptionally weak affinity

of KLRG1 to cadherins has further been noted substantiating the notion that KLRG1–cadherin interaction occurs through multivalent binding and involves the formation of multimeric receptor/ligand complexes 26. Despite KLRG1 being widely Ribonucleotide reductase used as a lymphocyte differentiation marker, and the substantial progress made in structural and functional characterization of KLRG1, the role of KLRG1 in vivo is still poorly defined. To address this issue, we generated KLRG1-deficient mice by homologous recombination. The characterization of these mice indicates that KLRG1 is dispensable for normal CD8+ T-cell differentiation and memory cell formation after viral infections. In addition, KLRG1 deficiency did not affect development and function of NK cells in the various assays used in this study. KLRG1-deficient mice were generated by homologous recombination using a targeting construct that carries a lacZ reporter gene and a neo cassette inserted into the third exon of the mouse Klrg1 gene (Fig. 1A). This exon encodes the neck region and the proximal half of the C-type lectin domain of KLRG1 2. A homologous recombinant HM1 ES cell clone (M31) was injected into B6 blastocysts and resulting 129/B6 chimeric mice were crossed with B6 mice to attain germ line transmission.