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 H 89 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 AZD2014 in vivo “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 CYTH4 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 [46] and the hexameric CpG motifs that optimally stimulate human pDCs differ from those most active in mice (and vice versa) [46]. Similarly, the regulatory regions and splice patterns of genes involved in CpG signaling have diverged between mouse and human [47]. 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.

The ‘instructive’ model hypothesized that all fates could be adopted by every naïve cell. By now, the ‘instructive’ model has been validated by showing that cells that had been partially differentiated towards

the Th2 phenotype could be re-educated to become Th1 cells [91, 106]. Many different signals have been described as being potentially instructive for Th cells, and much study has gone into which signals induce which phenotype. But how does the adaptive immune response choose a correct phenotype? The adaptive immune system of B and T lymphocytes is built on top of the so-called innate immune system composed of intracellular responses, neutrophils, granulocytes and natural killer cells. The members of the innate immune system

detect the presence of pathogens by evolutionary conserved signals that are usually called pathogen-associated molecular patterns (PAMPs) [107]. One important class of cellular Sirolimus receptors that can detect the presence of PAMPs are the Toll-like receptors (TLR), which discriminate between bacterial, viral and several other types of PAMPs [1, 108]. The innate system therefore uses evolutionary conserved information and is probably selected to mount an appropriate immune response C59 wnt research buy to particular pathogens. Because innate cells and infected cells secrete cytokines, these cytokines provide a key to the developing Th0 cells to adopt a particular phenotype [99]. Thus, the local

context of cytokines created by the innate immune Interleukin-2 receptor responses can instruct helper T cells to make an appropriate decision. One notorious example of Th decision-making is the priming with formalin-inactivated and alum-adjuvated RSV vaccine (FI-RSV). In the 1960s, a trial with this vaccine failed because it predisposed for enhanced disease rather than preventing it [109]. This was attributed to the generation of Th2 responses rather than the more appropriate Th1 response. Subsequent mouse studies into RSV have shown that immunization with the RSV fusion protein (F) or the RSV attachment protein (G) induces Th1 or Th2 responses when challenged with RSV [110]. Again the Th2 type response was associated with enhanced disease, including a marked eosinophilia reminiscent of that seen in FI-RSV-primed mice. Induction of these skewed Th2 responses can be abrogated by the insertion of a CD8 epitope derived from the RSV M2 protein into the G protein or by simultaneous priming of mice with G and M2 proteins prior to RSV infection [111]. This demonstrates that the presence or absence of a CD8+ T-cell epitope could play a role in determining the type of immune response against a pathogen. The absence of a CD8+ epitope appears to predispose for the formation of Th2 immunity. Conversely, in the presence of a CD8+ T-cell response, the CD4 T cells adopt a Th1 phenotype.

Comparison of non-parametric data between two groups was performed using the Mann–Whitney U-test. Analysis was performed and data plotted using graphpad prism Version 5 (GraphPad Software, San Diego, CA, USA). As depicted in Table 1, the age and gender distribution of TB patients and EC was comparable. Erythrocyte sedimentation rate (ESR), total leukocyte (TLC) counts and neutrophils were all significantly raised in patients with both Mod-PTB and

Adv-PTB as compared with EC. Lymphocyte counts were reduced in all TB cases as compared with EC, while monocyte counts were comparable between the groups as described previously [30, 36]. We first determined IFN-γ, SOCS1 and SOCS3 mRNA expression levels in PBMCs of TB and EC groups and observed that gene expression of all three targets was comparable between the two groups (Fig. 1A). To determine the cellular source www.selleckchem.com/products/LY294002.html of IFN-γ, SOCS1 and SOCS3 mRNA expression within PBMCs, we determined the concentration Daporinad in vitro of these transcripts in T-cell and non-T-cell populations of TB and EC. mRNA gene expression levels for IFN-γ, SOCS1 and SOCS3 were generally significantly higher (EC, P = 0.0001; TB, P < 0.0001) in T cells as compared with non-T cells in both EC and patients with TB (data not shown). SOCS1 mRNA expression was further

raised in T cells from patients with TB as compared with EC (P = 0.02, Fig. 1B), while IFN-γ and SOCS3 mRNA levels in T cells were comparable in these groups. To investigate whether the differential activation of SOCS1 could have affected T-cell differentiation, we determined the gene expression of Th1 marker (T-bet) and Th2 marker (GATA-3) in T cells of TB and EC. However, no differences were observed between T-bet and GATA-3 mRNA expression in these groups (Fig. 1C). We measured IFN-γ, IL6, IL10 and TNFα in supernatants of PBMCs as these cytokines are important for regulating T cell and innate immunity in TB. Levels of IL6 (P = 0.018) and IL10 (P = 0.013) were found to be increased in TB as compared with EC (Fig. 2A,B). However, IFN-γ and TNFα levels were comparable Ketotifen between TB and EC (data not shown). We next investigated the

association of IFN-γ, SOCS1 and SOCS3 mRNA expression with severity of TB infections by studying mRNA transcripts in PBMCs from patients with Mod-PTB and far advanced disease (Adv-PTB). IFN-γ and SOCS3 mRNA expression levels were found to be comparable between Mod-PTB and Adv-PTB groups (Fig. 3A,C). However, SOCS1 mRNA levels were significantly higher in Adv-PTB as compared with Mod-PTB (P = 0.008, Fig. 3B). This study provides results to support an association of SOCS1 with severity of pulmonary TB disease. SOCS1 mRNA expression was predominantly found in T cells from patients with TB as well as EC. Hence, while SOCS1 mRNA expression levels were comparable in peripheral blood cells from TB and EC, SOCS1 was raised in T cells from patients with TB as compared to EC.

A similar approach was undertaken in an MHC-mismatched model although in this case the CD4+ T cells were initially primed in vitro before parking in syngeneic RAG−/− hosts. Upon re-isolation and transfer to secondary allogeneic recipients, the CD4+ TEM cell population was again unable to induce GVHD. This was despite Palbociclib mouse the fact that the TEM cell population contained increased frequencies of alloreactive

cells as documented in vitro. Furthermore, and in dramatic contrast to the failure of the CD4+ TEM cells to induce GVHD, transfer of the same population to RAG−/− mice enabled rapid rejection of allogeneic skin grafts. These data argue strongly against the concept that the failure of CD4+ TMP cells to induce GVHD can simply be explained by a relative deficiency of alloreactive precursors in the TMP, as compared with the TN, cell population. Indeed, although a separate study by Samuel Strober and colleagues indicated that repertoire may be of importance under certain experimental conditions, they also showed that CD4+ TEM cells were less able to Lorlatinib purchase induce GVHD than TN cells 13.

This indicates that other fundamental differences must exist between the populations that are independent of the repertoire. Thus, a third concept to explain the failure of unprimed CD4+ TMP or primed TEM cells to induce GVHD is that in the process of transitioning to memory, CD4+ T cells lose certain elements that are critical for the full range of effector functions upon recall (Fig. 1C). The extent to which this loss occurs at a population or on a per-cell level requires dissection in experiments that permit the tracking of specific populations, for example by MHC

class II tetramers, or transfer of clonal CD4+ T cells that are transgenic for host antigen-specific TCR. Indeed, Mark and Warren Shlomchik and colleagues have recently published a further article Tolmetin in which they studied the properties of naïve and memory CD4+ T-cell populations bearing a transgenic TCR specific for a model antigen, influenza hemagglutinin, that was expressed ubiquitously in recipient mice 21. Again, CD4+ T cells were primed in vitro before resting in antigen-free RAG−/− mice to generate TEM cell populations. Similar to their findings with polyclonal populations 4, the transgenic TEM cell population induced only transient GVHD as compared with that induced by TN cells 21. These data demonstrate that intrinsic defects in TEM cells are relevant to their failure to induce GVHD. Although TEM cells engrafted and initially increased in numbers to the same extent as TN cells, their proliferation was not maintained fully in the spleen or colon beyond 2–3 wk.

The mechanisms, by which neutrophil migration into the SF is induced in RA are not well understood; animal models of RA indicate the involvement of an IL-23/IL-17 axis in neutrophil recruitment that may be mediated by prostaglandin [7, 8] whilst a role for G-CSF in the

Mac-1-integrin dependent trafficking of neutrophils has been implicated in a model of inflammatory arthritis [9]. Neutrophils are thought to participate in both the initiation and progression of RA [3], as they have the capacity to persist for much longer periods of time following inflammatory activation [10] and www.selleckchem.com/products/Vorinostat-saha.html also synthesize numerous inflammatory proteins, including the cytokines IL-8 and tumour necrosis factor-α (TNF-α), contributing to the chronic inflammatory state [11]. Furthermore, as the primary function of neutrophils is to destroy pathogens, prolonged neutrophil responses can contribute to local tissue destruction due to the production and generation of reactive oxygen species and proteolytic enzymes [12]. Current pharmacological approaches for the treatment of RA include medications that suppress inflammation, such as the Omipalisib nonsteroidal antiinflamatory drugs (NSAIDs) and glucocorticoids and disease-modifying anti-rheumatic drugs (DMARDs), including methotrexate (MTX), hydroxychloroquine, sulfasalazine and leflunomide

[1]. The newest class of RA drugs constitutes the biological-response modifiers that target the inflammatory mediators of tissue damage in RA; drugs include infliximab, etanercept and adalimumab, all of which are inhibitors of TNF-α function [13]. TNF-α plays a key role in the pathogenesis of RA and, as neutrophils are known targets for the biological activity of this molecule, such therapies may alter the function and gene expression of this class of leucocyte [14]. To date, the exact mechanism responsible for the accumulation of cells, particularly neutrophils, in rheumatoid joints is not well understood. This

study aimed to compare the adhesive and chemotactic functions of neutrophils, as well as levels of circulating neutrophilic chemokines, in RA patients in activity Bumetanide and not in activity. In addition, the effects of different treatment approaches on these characteristics were observed in these patients. Reagents.  Fibronectin (FN) was purchased from Sigma-Aldrich (St Louis, MO, USA) and IL-8 was from Biosource (Camarillo, CA, USA) or R&D Systems (Minneapolis, MN, USA). Phycoerythrin (PE)-conjugated mouse anti-human CD62L and Alexa Fluor 488-conjugated mouse anti-human CD11b (Mac-1) were purchased from BD Biosciences (San Jose, CA, USA). Phycoerythrin (PE)-conjugated mouse anti-human CD11a (LFA-1) was from AbD Serotec (Raleigh, NC, USA). All other reagents were from Sigma Chemical (St Louis, MO, USA), unless otherwise stated. Patients.

At the end of the study period (April 2012), all but one patient survived and all flaps remained viable. One patient expired due to local recurrence of angiosarcoma, 4 months after chemotherapy and radiotherapy. Table 1 is a summary of

all nine patients’ data. In July 2008, a 40-year-old male patient with a history of epilepsy presented with rupture of an intracranial arterio-venous malformation in the temporoparietal lobe, for which an emergent decompression find more craniectomy was performed. Four months later, the patient underwent cranioplasty using prosthesis for cranial vault resurfacing and a local advancement scalp flap for coverage. Prosthesis exposure developed subsequently and this problem persisted despite another two advancement procedures in the following year (Fig. 1). The patient was then referred for scalp reconstruction, for which a free ALT flap was used for the final defect, measuring 15 × 6 cm2 (Fig. 2). Microvascular end-to-end anastomosis was performed to the right superficial temporal artery and vena comitants using 9-0 nylon, while the thigh donor-site was closed primarily. At 1-month follow-up, the flap healed uneventfully, and the patient was discharged without complications (Fig. 3). This 36-year-old male was involved in multiple traumas and suffered from head

injury 10 years ago, during which he underwent craniectomy followed by cranioplasty using Selleck Doxorubicin prostheses. He presented in December of 2011 with an exposed and infected prosthesis at the left temporoparietal area. Following excisional debridement and removal of the prosthesis, a scalp defect measuring 30 × 7 cm2 was noted (Fig. 4). A free ALT flap was performed via end-to-end anastomosis to the left facial artery and vein. The ever left thigh donor site was closed primarily.

At 1 week, the distal flap tip developed necrosis and required debridement of a 2.5 cm segment, followed by a small Z-plasty to close the defect. Subsequent healing proceeded uneventfully at 1-year follow-up (Fig. 5). For uncomplicated small- to moderate-sized defects, local flap coverage is the best option for reconstruction, typically involving a single or multiple transposition procedures depending on the defect size and location.[23, 24] However, local and regional flaps reach their limit when defects extend beyond 200 cm2, especially when compounded by complications such as infection, radiation therapy, multiple prior surgeries and composite tissue and bone loss. Although tissue expansion has been proven to be successful for resurfacing large scalp defects, its role is limited due to the requirement of prior planning, patient compliance, and absence of infection. In complex cases, only well-vascularized free-tissue transfer can meet both structural and protective requirements, albeit resulting in a hairless reconstruction.

Strips were rinsed briefly with 25% 1.5 M pH 8.0 Tris before SDS–PAGE was performed using Criterion 12.5% Tris-HCl Precast gels (Bio-Rad), run at 200 V for approximately 45 min. For each sample, two gels were run simultaneously, one for silver staining and another for

immunoblotting. Gels for silver staining were fixed individually in 0.1 L fixing solution [50% (v/v) methanol, 10% (v/v) acetic acid] for Selleckchem MI-503 a minimum of 1 h, and were subsequently stained using a sensitive ammoniacal silver method based on silver nitrate. Gel images were acquired using the UMAX Powerlook 1000 flat-bed scanner. Proteins from unstained gels were transferred electrophoretically onto polyvinylidene fluoride (PVDF) membranes using the Trans-blot cell transfer system (Bio-Rad Laboratories). ABT-888 clinical trial To visualize total proteins, membranes were stained with a Sypro Ruby blot stain (Bio-Rad

Laboratories). To detect immunoreactive proteins, membranes were destained and subsequently probed according to the Immun-Star™ WesternC™ kit protocol (Bio-Rad Laboratories). Membranes were immunolabeled with patients’ sera at a 1 : 250 dilution, and goat anti-human IgG antibodies coupled to HRP (1 : 2000; Bio-Rad) were used as a secondary antibody. The immunoreactive protein spots matched using both the Sypro Ruby stained membrane and the silver-stained gels were identified by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Briefly, spots were washed twice for 10 min in 200 μL of 100 mM NH4HCO3, reduced at 37 °C for 1 h with 50 μL of 10 mM DTT, alkylated for 1 h in 50 μL of 10 mM iodoacetamide, washed for 10 min with 200 μL of 10 mM NH4HCO3, dehydrated in acetonitrile, and trypsin-digested with 10 ng μL−1 of trypsin (Promega, Annandale, NSW, Australia). After digestion for 14 h at 37 °C, peptides were extracted by washing the gel slice for 15 min with 25 μL 1% formic acid, followed by dehydration in acetonitrile. Digests were then dried in vacuo, resuspended in 10 μL 1% formic acid and submitted for

a Quadrupole-TOF analysis on a Micromass instrument which generated collision-induced dissociation. Results were analyzed using the Mascot MS/MS ion search (Matrix Science, Boston, MA), and searches were performed on the National Centre for Biotechnology Galeterone Information non-redundant (NCBI nr) database (specifically against the available genome sequence of C. concisus BAA-1457). This study was approved by the Research Ethics Committees of the University of New South Wales and the South East Sydney Area Health Service-Eastern Section, Sydney (Ethics No.: 03/163, 03/165 and 06/164). Recently, an association between the presence of C. concisus DNA and newly diagnosed CD was reported in two case–control studies using intestinal biopsies and fecal samples (Zhang et al., 2009; Man et al., 2010c). In addition, significantly higher levels of C. concisus-specific IgG antibodies were detected in children with CD as compared with controls (Zhang et al.

1a). Using these boundaries and the level of CD127 expression by CD4+ lymphocytes, CD4+ CD25inter CD127low/− and CD4+ CD25high CD127low/− Treg cells and CD4+ CD25− CD127−/+ and CD4+ CD25+ CD127+ effector T cells were identified and isolated (Fig. 1b), with the prevalence of Treg cells expressed as a percentage of the total CD4+ population (mean ± SEM). Foxp3 expression on the two Treg cell populations (CD4+ CD25inter CD127low/− and CD4+ CD25high CD127low/−) was assessed following fixation and permeabilization of

the cells, as directed (Human Foxp3 Buffer Set; BD Biosciences), before incubation with a mouse anti-human Foxp3-Alexa Fluor 488 antibody (clone 259D/C7; BD learn more Biosciences) or its corresponding isotype control (BD Biosciences) for 30 min protected from light. The labelled cells were washed, re-suspended and the same gating strategy as detailed above was applied during the acquisition of the samples. The suppressive activity of isolated Treg cells on the proliferation of autologous effector T cells was determined by a co-culture carboxyfluorescein diacetate succinimidyl ester (CFSE) assay. Effector T-cell populations (CD4+ CD25− CD127−/+ or CD4+ CD25+ CD127+) were incubated with 5 μm of CFSE (Sigma, Poole, UK) for 10 min Selleck Palbociclib at 37°C. The labelling

was quenched by the addition of 2·5 ml of ice cold culture medium [X-VIVO 20 medium (Lonza, Slough, UK) supplemented with 5% volume/volume heat-inactivated AB serum (Invitrogen) and penicillin/streptomycin (final concentration:

0·1 U/ml and 0·1 mg/ml, respectively; PAA)] before the cell suspension was incubated on ice for 5 min. Following three washes with pre-warmed medium the labelled effector T cells were co-cultured with Treg cells (CD4+ CD25inter CD127low/− and CD4+ CD25high CD127low/−) in 200 μl of culture medium at various ratios (Treg : effector; 0 : 1, 1 : 1, 1 : 2, 1 : 5 and 1 : 10). Depending on the number of Treg cells available; the 1 : 1 ratio was always prepared. Where possible MRIP the CFSE assay was run with 5 × 104 effector cells cultured in each well of a 96-well round-bottomed plate, however, when insufficient cells were isolated the number of effector cells plated was successfully scaled down to 1 × 104/well. Lymphocyte stimulation was provided by Human T-Activator CD3/CD28 Dynabeads (Invitrogen) at a cell : bead ratio of 1 : 3 and 100 U/ml recombinant human IL-2 (AbD Serotec, Kidlington, UK). Following 4 days of co-culture, the cells were harvested and the proliferation of the CFSE-labelled effector T cells was determined using flow cytometry.

Because of the timing of serum EMA and NFR antibodies, circulating ANA were evaluated at three time-points: during EMA-positive results, under EMA disappearance/NFR-positive results and after NFR disappearance. At all time-points, serum ANA were positive in two of 20 CD EPZ-6438 solubility dmso patients in group 1. In both cases, an ANA-S antibody pattern (subpattern: fine speckled) was visible. None of the 15 subjects in group

3 presented serum EMA-positive results, while two showed an NFR-like pattern on monkey oesophagus sections. The latter two subjects were put on a GFD for 12 months. Serum EMA and NFR antibodies were evaluated each month, showing no changes in the NFR-like pattern. The characterization of this NFR-like pattern showed that it belonged simultaneously to IgA1 and IgA2 subclasses, and that it was localized in the nucleus. The results of the present study demonstrate that serum IgA from CD patients are able to react with two nuclear antigens determining the appearance of a nuclear fluorescence GDC-0973 datasheet reactivity (NFR) antibody pattern on monkey oesophagus sections used routinely for EMA detection. Moreover, as NFR antibodies are detectable

in serum as long as the CD patients consume gluten and disappear after gluten withdrawal from the diet, they are gluten-dependent and related strictly to CD. The autoimmune nature of CD is understood clearly [5–7], and the main autoantigen is well known to be tTG [11]. However, tTG is not the only CD-related autoantigen, as other tissue components have been shown to be a target of coeliac autoimmunity [12–15]. In serum of active CD patients, antibodies against thyroid and pancreas structures, cytoskeleton molecules and central nervous

Phospholipase D1 system-related antigens have been found previously [14]. The present study adds a new antigen type to the list, as we found that serum IgA from untreated CD patients react with two NFR-related nuclear antigens of 65 and 49 kDa. The identity of NFR-related autoantigens is as yet unknown, but based on the different distribution of EMA and NFR reaction sites on monkey oesophagus sections it is reasonable to hypothesize that these reactivities are due to distinct antigenic specificity. Indeed, EMA and NFR antibody patterns are never observable simultaneously during total IgA EMA detection but, using secondary mAbs against IgA subclasses (IgA1 and IgA2) coupled with different fluorochromes (FITC and TRITC), the presence of two different and not overlapping fluorescence signals becomes evident. That the main endomysial antigen, known to be tTG [11], has a different molecular weight with respect to the newly identified autoantigens (85 versus 65 and 49 kDa), further confirms the hypothesis that EMA and NFR are two distinct antibodies.

This observation strongly argued in favour of a general regulation of immune response by corticoid hormones during H. polygyrus infection [12, 28]. In the present study, we identified that H. polygyrus

products are potent to inhibit apoptosis provoked by DEX in MLN cell populations. The most sensitive subpopulation was CD4+CD25hi cells. Significantly, more CD4+CD25hi cells than other subpopulation of T cells underwent apoptosis 12 days after infection; it might be that activated via TCR, CD4+CD25hi cells expressed a high level of glucocorticoid-induced TNF receptor, FK506 mouse GITR and therefore this subpopulation was more sensitive to glucocorticoid-induced apoptosis, which was previously reported [29, 30]. The inhibition of apoptosis induced via TCR receptor in MLN cells exposed to H. polygyrus antigen in vitro is confirmed by the elevated expression of FLIP, which is an inhibitor of death receptor-mediated apoptosis via caspase cascade. FLIP is expressed Venetoclax solubility dmso during the early stage of T-cell activation, but disappears when T cells become susceptible to Fas ligand-mediated apoptosis [31, 32]. High expression of FLIP protein was present both in naïve and restimulated cells and was distinctly regulated by H. polygyrus antigenic fractions. Heligmosomoides polygyrus infection

and the nematode protein fractions activated FLIP in MLN cells. The studies of different populations of lymphocytes revealed significant differences in the percentage of apoptotic cells between control and infected mice. The antigenic fractions added to the culture supported survival of cells preferentially from infected mice. As the level of apoptosis was different and FLIP expression

did not correlate with the infection, it is likely that FLIP would not be considered as a specific marker of inhibited apoptosis during H. polygyrus infection. Naïve cells which expressed FLIP were also sensitive to DEX-induced apoptosis in spite of exposure to H. polygyrus antigens in cell culture. It seems that signals other than only FLIP were required to keep cells alive. DEX induces apoptosis via the intrinsic mitochondrial pathway [33]; therefore, H. polygyrus related factors were probably able to induce those signals which produce Bcl-2, but only after restimulation. This was also reflected in the higher percentage of Bcl-2-positive CD4+ Astemizole T cells, which were evoked by factors present in all examined antigen fractions. The nematode infection induces expansion of CD8+ T regulatory cells [34]. We indicated that survival of CD8+ T-cell population was regulated differently than of CD4+ T cells; both infection and restimulation with H. polygyrus antigen strongly reduced the percentage of Bcl-2-positive cells among T-cell subpopulations [12]. The percentage of CD4+ T cells which expressed Bcl-2 protein increased but the percentage of CD8+ T cells was strongly reduced. This might suggest that H.