Influenza was included in the viral antigen mix, as it is known t

Influenza was included in the viral antigen mix, as it is known to initiate the adaptive immune response, provoking a multi-step process with a sudden ‘cytokine storm’ at 48 h [25]. In general, the immune defence of the human body is a multi-step process triggered and executed by different cell Selleckchem RXDX-106 defence lines. The major sources of cell-mediated immune response are leucocytes, whereby B and T cells and their release of cytokines play the most important role. The test presented in this study reflects reactions of both cell types and also of other defence lines as represented, e.g. by macrophages. As the human immune system is a complex organ,

the in-vitro test in this TGF-beta inhibitor study is testing for the overall response. The two important mechanisms are the B cells and their

capacity to produce antibodies, and more importantly the T cell activation followed by the T cell-dependent and -independent B cell activation [26]. Cytokines play a key role in these activation processes. Recent investigations found that the cytokine release is not only limited to T cells but that B cells also have the potency and capacity to produce cytokines [27]. For this reason, the test introduced in this study uses the cytokine responses as a read-out parameter, reflecting both cell lines. Testing for the most suitable and representative read-out parameters to mirror a DTH-like immune response, we focused on three representative cytokines which are involved in T cell-mediated immune responses: IL-2, IFN-γ and TNF-α. IL-2 is one of the key cytokines involved find more in T cell activation and proliferation [28]. After incubation with the different antigens of either a bacterial, viral or fungal nature, the concentrations of IL-2 in the culture supernatants increased significantly at 24 h and even more significantly at 48 h after onset of incubation, reflecting a strong and time-dependent Th1 response. Moreover, IL-2 is known to be a potent inductor of IFN-γ during Th1 and Th2 differentiation [29]. In addition, IFN-γ has been also identified

previously as one of the important cytokines involved in mediating skin DTH reactions [30]. Accordingly, the time kinetic of IFN-γ followed mainly the IL-2 slope, and showed high concentrations at 24 and 48 h. TNF-α secreted by macrophages as well as by T cells is a potent initiator, enhancer and primer of T cell signalling and activation [31] in the inflammatory cascade. It is known to be released very early in the inflammation process [32]. This was confirmed by our findings showing peak levels of TNF-α for bacterial, viral and fungal antigen stimulation as early as after 12 h after onset of incubation. This is in further accordance with previous results from virus-induced TNF-α secretion, which also occurs very early in the inflammatory process [33, 34].

This classification scheme is more acceptable because it takes in

This classification scheme is more acceptable because it takes into consideration the beta-lactamase inhibitors and beta lactam substrates that are clinically relevant (5). Beta-lactamases with carbapenemase activity are a cause for concern and include serine oxacillinase and metallo-beta-lactamase, which are classified as Ambler Class D and Ambler Class B types, respectively. OXA type carbapenemase, which is able to hydrolyze carbapenem and was first studied from a clinical isolate of A. baumannii, has been found to be plasmid encoded and transferable.

It was named blaOXA-23 and is now studied extensively because it contributes to carbapenem resistance in A. baumannii Alpelisib in vivo (6). The blaOXA-23 gene cluster has two other enzymes that are closely related, blaOXA-27 and blaOXA-49. In addition, two more gene clusters contributing to resistance

that include blaOXA-24-like and blaOXA-58-like have been reported. The natural presence of blaOXA-51-like genes has been observed to be intrinsic to A. baumanni and is chromosomally encoded; hence this is used as an identification AG-014699 ic50 marker of this species (7). Rapid acquisition of resistance to meropenem and other carbapenems poses an issue in the treatment of A. baumannii infections. In a report presented in 2007, over 25% of A. baumannii isolates were recorded to be carbapenem resistant (8). In a tertiary care hospital in North India, meropenem resistance was reported in 6.4% of Acinetobacter Protirelin spp. tested (9). In India, several workers have reported metallo-beta-lactamases resulting in resistance in A. baumannii to be prevalent (10, 11). These findings are a pointer to the threat posed by the treatment of carbapenem resistant Acinetobacter in India. The presence of the insertion sequence ISAba1 upstream of the OXA carbapenemase gene has been identified as a key factor affecting over expression of these genes (1). The prevalence of OXA-type genes and their association with ISAba1 in Acinetobacter from India is not well understood. Persistence in the hospital environment is an important characteristic of Acinetobacter spp. It is suspected that the ability to adhere to surfaces

and form biofilm both helps the organism to persist in the environment and also plays a role in its virulence (1, 12). However, there is very little information on the ability of clinical isolates to form biofilm. Though a number of molecular typing methods have been used as epidemiological tools, they have generally been applied to investigate outbreaks (1). Therefore, in this study, non-outbreak associated clinical isolates of Acinetobacter from four hospitals were studied for the presence of OXA-type β-lactamase genes and ISAba1 upstream of these genes, their resistance to meropenem and their biofilm forming ability. Diversity among the strains was assessed by fingerprinting the isolates using RAPD. Sixty two isolates of Acinetobacter spp.

It can be speculated that the elevation of the RDW is due to the

It can be speculated that the elevation of the RDW is due to the inflammation in the prostate already leading to an enlargement of the gland. Thus, the RDW to IPSS relationship is lost after the prostate volume enlargement. In this study, patients treated with surgery also had higher RDW values than patients preferring medical therapy. Before the RDW can be incorporated into clinical practice, it must be confirmed in multiple datasets evaluating broad populations FK506 mouse with BPH to definitively establish validity and generalizability. Future studies that carefully evaluate the RDW in the context of a more complete evaluation of iron metabolism and markers

of inflammation in BPH patients may provide further insight into the mechanisms of

the interaction between the hematologic system PCI-32765 research buy and BPH. A limitation of the present study is that only a few types of parameters were assessed; therefore, the mechanisms that underlie the association of the RDW with BPH remain to be determined by a large-scale study. Another significant limitation of this study is its single-centered character, which makes extrapolation of the results difficult. These limitations notwithstanding, this analysis has several strengths. None of the patients had hematologic pathology or a disorder that may affect the RDW and all of the patients had normal ferritin and vitamin B12. The adjustment for important confounding factors, such as hemoglobin and age, ensured an unbiased estimate for the relationship between the RDW and BPH. The finding of a strong, graded association of the RDW with elevated prostate volume may have important clinical implications. The increase in the RDW may be a consequence of various underlying pathologic processes, for example, inflammatory stress, and may contribute to disease progression in prostate enlargement. Prostate specific antigen and RDW were the significant predictors of treatment type. In this study,

RDW had a stronger association with surgical treatment than PSA. Elucidating how and why an elevated RDW is associated with the risk of surgery better than Epothilone B (EPO906, Patupilone) PSA (Table 4) in BPH treatment may provide an increased understanding of the pathophysiology and improve the targeting of therapies. If confirmed by future studies, the association between the easy, inexpensive RDW and inflammatory markers may, in fact, provide a rational basis to include the RDW in algorithms for surgery risk prediction. This study should prompt further investigation into the association between the RDW and BPH to improve the understanding of pathophysiology. The authors have no actual or potential conflict of interest in relation to this article. “
“Clinical diagnosis of overactive bladder (OAB) syndrome has great variation and usually can only be based on subjective symptoms.

On the other hand, the binding of integrin extracelluar domains t

On the other hand, the binding of integrin extracelluar domains to ligands or other agonists (stimulatory antibody, PMA, Mg2+ or Mn2+), and physiological force exerted on the bond, could initiate conformational change of the integrin, which then sends biochemical and mechanical signalling into the cell to regulate multiple cellular functions; this is termed ‘outside-in’ signalling.12,13 In T cells, integrin bidirectional signals lead to the formation of the immunological synapse, stabilization of T-cell–APC contact to facilitate T-cell activation, proliferation and cytokine secretion (e.g. interleukin-2, interferon-γ).19–21 In macrophages, integrin activation induces cytoskeletal rearrangement during the

process of phagocytosis, cytokine mRNA stabilization (e.g. interleukin-1β) and cell differentiation.22 Integrin signalling also enhances neutrophil

degranulation and activation of NADPH oxidase, leading to production of reactive oxygen species,23 or induces DNA Synthesis inhibitor polarization of cytolytic granules in natural killer cells or cytolytic T lymphocytes.24 In the following discussion, we will describe those key effectors involved in integrin bidirectional signalling pathways, with particular attention to the signalling molecules in T lymphocytes. After the TCR/CD3 complex is engaged with the MHC–peptide complex, Src kinase (lymphocyte-specific protein tyrosine kinase; LCK) is phosphorylated and activated, leading to phosphorylation selleck compound of immunoreceptor tyrosine-based activation motifs on the TCRξ/CD3 chains. Kinase ζ-associated protein of molecular weight 70 000 (ZAP-70) is recruited to the TCR/CD3 complex Celecoxib and is phosphorylated by LCK. Activated ZAP-70 then phosphorylates a number of downstream adaptors, including linker for activation of T cells (LAT) and Src homology

2 (SH2) domain-containing leucocyte protein of molecular weight 76 000 (SLP-76) (Fig. 1). Elevated levels of LCK in cloned cytolytic T cells markedly increase cytolytic activity and enhance LFA-1 expression levels with increased cell binding to the ligand intercellular adhesion molecule 1 (ICAM-1).25 In LCK-deficient Jurkat cells (i.e. JCaM1.6 cells) or in Src kinase inhibitor PP2-treated Jurkat cells, CD3 ligation-induced adhesion to ICAM-1 is dramatically reduced.26 These studies suggest that LCK is a positive regulator for integrin activation. Similarly, ZAP-70-deficient Jurkat cells fail in TCR-induced integrin β1-mediated adhesion and the kinase activity of ZAP-70 required for LAT phosphorylation is crucial for integrin activation.27 This fits with the defective integrin activation and adhesion in LAT-deficient Jurkat cells. Further, LAT is associated directly or indirectly with a number of key signalling proteins, including phosphatidylinositol 3-kinase, the inducible T-cell kinase (ITK), SLP-76, and phospholipase C-γ1 (Fig. 1). These kinases, adaptors or enzymes have been implicated to play critical roles in TCR-induced ‘inside-out’ signalling for integrin activation.

However, it must be noted that TD and TI responses are not rigidl

However, it must be noted that TD and TI responses are not rigidly compartmentalized within the B-2 and MZ/B-1 cell subsets. Pexidartinib chemical structure For instance,

MZ B cells also participate in TD antibody production owing to their ability to shuttle to the follicle and present antigen to T cells [[40, 41]]. Conversely, B-2 cells can initiate TI antibody responses in the intestine [[42]]. Here, we discuss recent advances in our understanding of the mechanisms by which adaptive and innate immune cells provide help to B cells. Protein antigens initiate protective antibody responses in the follicles of secondary lymphoid organs, a microenvironment that favors the interaction of B and T cells with each other as well as with antigen presenting DCs and

antigen exposing follicular dendritic cells (FDCs) (reviewed in [[7]]). After interacting with antigen through the B-cell receptor (BCR), which includes IgM and IgD (Fig. 1), naive B cells migrate Pembrolizumab cost to the boundary between the follicle and the outer T-cell zone [[43]]. At this location, B cells form dynamic conjugates with TFH cells, which deliver cognate B-cell help through a mechanism involving the tumor necrosis factor (TNF) family member CD40L and cytokines such as interferon-γ (IFN-γ, a cytokine also expressed by TH1 cells) and interleukin-4 (IL-4, a cytokine also expressed by TH2 cells) [[13, 14, 43, 44]]. B cells thereafter differentiate

along one of the two pathways. The follicular pathway generates Bcl6-positive germinal center B cells that further differentiate into long-lived memory B cells and plasma cells producing high-affinity antibodies, whereas the extrafollicular pathway generates Bcl6-negative blasts that further differentiate into short-lived plasma cells secreting low-affinity antibodies [[14, 45]]. After receiving activating signals from TFH cells at the border of the follicle with the T-cell zone, B cells upregulate the expression of the DNA-editing enzyme activation-induced cytidine deaminase (AID) and initiate somatic hypermutation (SHM) and class switch recombination (CSR), two Ig gene diversifying processes highly dependent on AID [[46-49]]. SHM introduces point mutations within V(D)J genes, thereby providing the structural find more correlate for selection of high-affinity Ig mutants by antigen (reviewed in [[50]]). By replacing constant (C) μ, and Cδ genes, which encode IgM and IgD, respectively, with Cγ, C, or C genes, which encode IgG, IgA, or IgE, respectively, CSR provides antibodies with novel effector functions without changing antigen specificity (reviewed in [[51]]). In humans, a noncanonical form of CSR from Cμ to Cδ has also been documented in lymphoid structures associated with the upper respiratory tract and generates B cells specialized in IgD production [[52]].

Similarly, 2 × 106 CD19+ B cells were added to equal numbers of i

Similarly, 2 × 106 CD19+ B cells were added to equal numbers of iDC in the presence or absence selleck chemicals of the pan-RAR selective antagonist ER50891 (Tocris Biosciences, Minneapolis, MN, USA) at a final concentration of 1 μM for 72 h. The B cells and/or DC were subsequently isolated by magnet assistance for further analysis. Statistically relevant differences among means (Student’s t-test, analysis of variance: anova) and medians (paired Wilcoxon’s test) were ascertained using GraphPad Prism version 4 software (GraphPad, La Jolla, CA, USA). In all statistical analyses, a P-value < 0·05 was considered to represent

statistically significant differences. We have shown previously that T1D patients treated with cDC or iDC exhibit an increase in the frequency of B220+CD11c– cells in the peripheral blood [31]. Flow cytometry of these cells [31] suggested that they represented a late transitional B cell population that shared some cell surface proteins (CD5+CD10+CD24+CD38intermediate) with at least one population of human Bregs recently reported and characterized [23, 32, 33]). Thus, we hypothesized that the increase in the frequency of B220+CD11c– cells in DC recipients was

a consequence see more of, and reflected an increase in, the number of constituent suppressive immunoregulatory B cell populations that express B220 on the surface, even though B220 on its own does not define B cells [29, 30]. We discovered subsequently that a population of CD19+B220+CD11c– IL-10+ cells accounted for an average of 48% of the B220+CD11c– cells (V. D. C., B. P. and N. G., unpublished data) and, more importantly, that the CD19+B220+CD11c– IL-10+ population was immunosuppressive in Buspirone HCl vitro [31]. To date, two human B cell populations with immunosuppressive ability in vitro have been characterized, mainly by cell

surface markers [23, 25, 26, 32, 40]. Although both populations produce IL-10, their surface phenotypes are different. ‘B10’ Bregs express the CD1d and CD5 markers [25, 26], whereas the other suppressive cells are characterized specifically as CD19+CD24+/intermediateCD38+/intermediate [23, 32, 40]. We first asked if the suppressive properties of the CD19+B220+CD11c– IL-10+ B cells shown in [31] were concentrated in either or both of the currently characterized Bregs (CD19+CD1d+CD5+ or CD19+CD24+CD27+CD38+ B cells [23, 25, 26, 32, 40]), or if other novel CD19+ cell populations inside the parental CD19+B220+CD11c– IL-10+ cell population possessed suppressive ability. Using flow cytometry (Supplementary Fig. S1 shows the approach), we determined that CD19+CD24+CD27+CD38+ cells accounted for 19·85% (median) of FACS-sorted CD11c–B220+CD19+ IL-10+ cells from freshly acquired PBMC (Fig. 1a; n = 6 healthy unrelated adult individuals). We did not detect any B10 Bregs (CD19+CD1d+CD5+ IL-10+ cells) [25] inside the CD11c–B220+CD19+ IL-10+ population (not shown).

Furthermore, the doxycycline-induced proliferative expansion of p

Furthermore, the doxycycline-induced proliferative expansion of pre-B- and immature B-cell pools is reversible upon termination of Pim1/Myc overexpression. To test whether Pim1/Myc overexpression could also induce propagation of mature B cells

after in vivo maturation, 5×106 Pim1/Myc double-transgenic pre-BI cells were transplanted into sublethally irradiated Rag1−/− mice. After 2–4 weeks, expression of Pim1 and Myc was switched on in these matured cells by feeding doxycycline. Two and four weeks after the start of doxycycline Epacadostat mw treatment, mice were sacrificed and B-lineage cells of the BM (1 femur, 1 tibia), spleen and peritoneal cavity were analyzed by FACS (see Fig. 4A for an outline of the experiment). As shown in Fig. 4B, total B-cell numbers did not increase in BM, spleen or peritoneum when overexpression of Pim1 and Myc in B cells was induced 2 weeks after transplantation. Furthermore, there was no change in the percentage of immature, CD93+ cells versus mature, CD93−IgM+ cells in the spleen (Fig. 4C) and peritoneum. Transplantation of Pim1/Myc transgenic pre-B cells into sublethally irradiated Rag1−/− mice in the absence of doxycycline allows the development of CD93+IgM+ immature and of CD93−IgM+ mature B cells in the spleen of the transplanted mice. Thus, four weeks after maturation of these

transplanted cells, IgM+ cells were prepared from the spleens of these mice by magnetic MACS beads Z-VAD-FMK mouse (see Fig. 5A for an outline of the experiment). The cells, which had a purity of ∼97%, were induced for 18 h with doxycycline or left in medium alone. Then, RNA was prepared, transcribed into cDNA, and cDNA levels of Pim1, Myc and Gapdh were analyzed by semiquantitative PCR (Fig. 5B). The results of the RT-PCR analyses show that doxycycline successfully induced the overexpression of transgenic Pim1 and Myc in IgM+ sorted splenic B cells ex vivo. However, in spite of the induced overexpression of both oncogenes, there were no significant changes in the survival and proliferation of IgM+ or CD19+ splenic B cells (Fig. 5C). CFSE labeling of splenic CD19+ B

cells cultured for 4 days Thiamine-diphosphate kinase in the absence of mitogens revealed that overexpression of Pim1 and Myc did not induce cell cycle entry in these cells (Fig. 5D). Next, we tested these resting, mature B cells for their capacities to proliferate in response to polyclonal B-cell activators. Hence, the sorted IgM+ splenic B cells were cultured either in the absence or in the presence of polyclonal B-cell activators such as CD40-specific mAbs, IL-4, IL-5, IgM-specific mAbs, LPS, or combinations thereof. To rule out the possibility that the purification step with anti-IgM antibodies had an anergizing or otherwise detrimental effect on the sorted B cells, the experiment was repeated with CD19+ MACS-sorted B cells and erythrocyte-depleted total splenic cells. Data in Fig.

This might indicate a central role for Smads in AD pathology wher

This might indicate a central role for Smads in AD pathology where they show a substantial deficiency and disturbed subcellular distribution in neurones. Still, the mechanisms driving relocation and decrease of neuronal Smad in AD are not well understood. However, Pin1, a peptidyl-prolyl-cis/trans-isomerase, which allows isomerization of tau protein, was recently identified also controlling the fate of Smads. Here we analyse a possible role of Pin1 for Smad disturbances in AD. Multiple immunofluorescence labelling and confocal laser-scanning microscopy were performed to examine the localization of Smad and Pin1 in human control and AD hippocampi. Ectopic Pin1 expression

in neuronal cell cultures combined with Western blot analysis and immunoprecipitation allowed studying Smad level and subcellular distribution. Luciferase reporter assays, electromobility shift, RNAi-technique and qRT-PCR revealed a potential transcriptional impact of Smad on Pin1 promoter. We report on a colocalization of phosphorylated Smad in AD with Pin1. Pin1 does not only affect Smad phosphorylation and stability but also regulates subcellular localization of Smad2 and supports its binding to

phosphorylated tau protein. Smads, in turn, exert a negative feed-back regulation on Pin1. Our data suggest both Smad proteins and Pin1 to be elements of a vicious circle with potential pathogenetic significance in AD. “
“Primary lateral sclerosis (PLS) is clinically defined as Rapamycin supplier a disorder selectively affecting the upper motor neuron (UMN) system. However, recently it has also been considered that PLS is heterogeneous in its clinical presentation. To elucidate the association of PLS, or disorders mimicking PLS, with 43-kDa TAR Docetaxel in vivo DNA-binding protein (TDP-43) abnormality, we examined two adult patients with motor neuron disease, which clinically was limited almost entirely to the UMN system, and was followed by progressive frontotemporal atrophy. In the present study, the distribution and severity, and

biochemical profile of phosphorylated TDP-43 (pTDP-43) in the brains and spinal cords were examined immunohistochemically and biochemically. Pathologically, in both cases, frontotemporal lobar degeneration with ubiquitin inclusions (FTLD-U) was evident, with the most severe degeneration in the motor cortex. An important feature in both cases was the presence of Bunina bodies and/or ubiquitin inclusions, albeit very rarely, in the well preserved lower motor neurons. The amygdala and neostriatum were also affected. pTDP-43 immunohistochemistry revealed the presence of many positively stained neuronal cytoplamic inclusions (NCIs) and dystrophic neurites/neuropil threads in the affected frontotemporal cortex and subcortical gray matter. By contrast, such pTDP-43 lesions, including NCIs, were observed in only a few lower motor neurons.

Sustained suppression of the B cell compartment can lead to impai

Sustained suppression of the B cell compartment can lead to impairment of T cell responses, resulting in a prolonged immunosuppressive

state with an increased risk of vertical transmission of cytomegalovirus (CMV) infection from mother to fetus [112]. Pan-specific depletion of B cells can deplete autoantibodies as well as protective natural antibodies and regulatory B cell subsets [5]. Therefore, it is clear that carefully planned clinical trials are needed to evaluate selleck the full benefits and harms of rituximab in pregnancy before it can be recommended for wider use in pregnancy. The evidence presented in this review has clearly highlighted the important role of B cells in shaping pregnancy outcomes that have implications for long-term MAPK Inhibitor Library human health. Despite this, there are still limited data detailing the changes in the human B cell compartment, and the role of B cell subsets in pregnancy outcomes is poorly studied. This is due to the limited

number of B cell markers used in earlier studies to describe changes in B cell subsets during pregnancy. Recent advances in B cell biology indicate clearly that these markers alone are not adequate in describing their full functions in human pregnancy. Further efforts should be dedicated to delineate the contribution of these B cell subsets in the maintenance of a healthy pregnancy as well as their roles in pregnancy complications. In light of the potential benefits of rituximab in depleting autoreactive B cells and the emerging safety profile of rituximab in pregnancy, it is anticipated that B cell depletion therapies will eventually be trialled in obstetric complications that involve autoantibodies such as APS, SLE or ITP. It is reasonable to expect that rituximab will make some advances in the treatment of refractory conditions in pregnancy and provide a viable option that spares the use of high doses of chemotherapeutics

and steroids in high-risk pregnancy to reduce risk of fetal toxicity [115], and thereby allows the pregnancy a better chance to develop to full term. Future pilot studies into the Avelestat (AZD9668) safety and efficacy of rituximab in pregnant patient cohorts are needed to provide a rational basis for larger studies. Although B cell depletion has demonstrated clinical benefits for maternal conditions in high-risk pregnancies, its potential benefits and risks for neonatal outcomes have not yet been investigated fully. It remains to be determined whether or not B cell depletion can improve neonatal outcomes on preterm birth, low birth weights, congenital malformations and their associated long-term health consequences.

e CD25+ cells) were depleted before activation (Fig  2a; compare

e. CD25+ cells) were depleted before activation (Fig. 2a; compare whole versus CD25-depleted populations on day 0). In contrast to control PBMC, depletion of CD25+ cells resulted in loss of CD4+ FoxP3HI cells at day 3 post-activation (Fig. 2a; DAPT solubility dmso compare whole versus CD25-depleted populations on day 3). Moreover, if carboxyfluorescein succinimidyl ester (CFSE)-labelled CD25Neg cells were reintroduced

into these polyclonally activated PBMC, there was significantly greater Teff proliferation in PBMC depleted of Tregs (Fig. 2b). Together, these data provide evidence to support the conclusion that aTregs derive from a starting pool of rTregs within PBMC. To study the effect of IFN-I on the generation of aTregs, freshly isolated PBMC were stimulated with anti-CD3 in the absence or presence of human leucocyte IFN (predominantly IFN-α) at 100 or 1000 U/ml or purified recombinant human IFN-β. Then, the total number of CD4 T cells and the generation of aTregs (CD4+ FoxP3HI IFN-γNeg)

and aTeffs (CD4+ FoxP3Low/Neg IFN-γPos) were analysed for separate normal donors after 3 days of polyclonal activation without or with added IFN-α (Fig. 3) or IFN-β (Fig. S1). While there was no consistent inhibitory p38 MAPK inhibitor review or stimulatory effect of IFN-α on total CD4 cell numbers (Fig. 3a,b), there was an average of 42% (P = 0·03) and 50% (P = 0·005) inhibition of aTreg generation in the presence of 100 and 1000 U/ml of IFN-α, respectively (Fig. 3c,d). In contrast, the presence of IFN-α tended

to increased the number of aTeff cells with an average of 53% increase in the number of aTeff cells using 1000 Units IFN-α (P = 0·06) (Fig. 3e,f). In contrast, although IFN-β significantly suppressed Treg activation, this cytokine also tended to decrease Teff activation at the higher concentration (Fig. S1). Although the number of donor PBMC tested with IFN-β was limited, the results may suggest that IFNs α and β may exert distinct effects on lymphocyte homeostasis during cell activation. As a result of the opposite effects of IFN-α on aTreg and aTeff, there was an alteration in the balance Flavopiridol (Alvocidib) between regulatory and effector cells as represented by the aTreg:aTeff ratio. Across all seven donors, this balance tended to favour aTregs in the absence of IFN-α (average aTreg:aTeff ratio = 1·4). However, the substantial suppression of aTreg generation induced by IFN-α caused a statistically significant shift in the mean aTreg:aTeff ratio for all seven donors [ratio = 0·7 for 100 U IFN-α (P = 0·05) and 0·5 for 1000 U IFN-α (P = 0·01)] such that aTeffs outnumbered aTregs on average by 2:1. Together, these data suggest that IFN-α significantly suppresses generation of activated Tregs in polyclonally activated PBMC, and at the same time promotes an increase in IFNγ-producing aTeffs.