The crosstalk between the innate and adaptive

immune systems is exemplified by responses involving marginal zone (MZ) B cells or invariant NKT (iNKT) cells. Indeed, these lymphocyte subsets mount very early, innate-like adaptive responses after recognizing microbial carbohydrate and glycolipid antigens via both germline-encoded and somatically recombined receptors [[3-5]]. B cells confer immune protection by producing antibody molecules, also known as immunoglobulins (Igs), which can recognize antigen through either low- or high-affinity binding modes. Bone marrow B-cell www.selleckchem.com/products/bay80-6946.html precursors generate Ig recognition diversity by undergoing V(D)J gene recombination, an antigen-independent process that utilizes recombination activating gene (RAG) endonucleases to juxtapose noncontiguous variable (V), diversity (D) and joining (J) gene fragments into functional V(D)J genes encoding the antigen-binding V region of Ig molecules (reviewed in [[6]]). After further maturation events, multiple subsets of mature B cells co-expressing IgM and IgD emerge from buy BAY 73-4506 the

bone marrow and colonize different compartments of secondary lymphoid organs to initiate the antigen-dependent phase of B-cell development. In general, conventional follicular B cells, which are also called B-2 cells, predominantly participate in T-cell-dependent (TD) antibody responses to highly specific determinants usually associated with microbial proteins (reviewed in [[7]]). TD responses unfold in the germinal center of lymphoid follicles and generate high-affinity antibodies through a TD pathway that involves activation of B cells by follicular helper T (TFH) cells. This germinal center-associated

T-cell subset expresses the inducible T-cell costimulator (ICOS) receptor, the chemokine receptor CXCR5, the programmed cell death-1 (PD-1) inhibitory receptor and the transcription factor Bcl6 [[8-15]]. TFH cells provide help to B cells via CD40 ligand (CD40L) and cytokines such as IL-21, IL-4, and IL-10 [[16-19]]. However, recent findings indicate that follicular antibody responses further involve additional T-cell subsets, Selleckchem Fluorouracil including follicular regulatory T (TFR) cells and iNKT cells [[4, 5, 20-22]]. Unlike follicular B cells, certain subsets of extrafollicular B cells such as B-1 cells, splenic MZ B cells (also referred to as IgM memory B cells in humans) and bone marrow perisinusoidal B cells predominantly give rise to rapid T-cell-independent (TI) antibody responses to highly conserved carbohydrate and glycolipid determinants associated with microbes [[3, 23-30]]. TI antibody responses usually unfold at the mucosal interface or in the splenic MZ and generate polyspecific and low-affinity antibodies through a TI pathway involving the interaction of B cells with DCs, macrophages, and granulocytes [[3, 30-34]].

Adjunctive immunotherapy with autophagy-promoting agents could potentially shorten the duration of treatment and improve adherence. It could also enable the use of rifamycin-sparing regimens, which would not affect HIV medications. Given the potent effect of induction of autophagy in promoting the intracellular killing of Mtb in vitro[20], therapy with an inducer

of autophagy may prove valuable as a therapeutic strategy for infection with Mtb. Options would include mTOR inhibitors, including rapamycin (sirolimus) and everolimus, both of which are currently licensed for clinical use to prevent transplant rejection. Aerosolized administration of these drugs, possibly in combination with nanoparticles to enable targeting to macrophages, could maximize efficacy and minimize systemic side effects. Another option would be to target the mTOR-independent, D-myo-inositol-1,4,5-trisphosphate (IP3)-regulated pathway which GSK3 inhibitor induces autophagy. Lithium, carbamazepine and sodium valproate, used to treat mood disorders and epilepsy, activate this pathway [84], and may be amenable to use as adjunctive treatment of tuberculosis [85]. Alternatively, targeted administration of autophagy-promoting cytokines, such as TNF-α

and IFN-γ, could prove effective. Indeed, adjunctive immunotherapy for drug-resistant TB with aerosolized IFN-γ has been trialled with some success [86]. Suppression of IL-10 or the Th2 cytokines IL-4 and IL-13 is Ixazomib clinical trial another potential approach to promoting autophagy. Etofibrate Ghadimi et al. demonstrated that infection of peripheral

blood mononuclear cells treated with heat-killed Mtb with lactic acid bacteria (LAB) resulted in decreased secretion of IL-4, IL-13 and IL-10 and increased secretion of IFN-γ, along with increased autophagosome formation [87]. In vivo, oral treatment with lactobacilli may be sufficient to down-regulate the Th2 response, as this has been shown to down-regulate the lung Th2 response in mice [88] and has been found to improve lung immunity in humans [89]. Other approaches to suppressing Th2 cytokines include helminth-derived immunomodulators [90]. Paradoxically, when tuberculosis is treated, patients’ symptoms may worsen, due possibly to increased proinflammatory responses to dead mycobacteria [91,92]. This ‘paradoxical reaction’ can cause serious clinical complications, such as compression of the airways in patients with tuberculosis in neck lymph nodes. The inflammatory response to Mtb is particularly problematic in patients with TB meningitis, and can cause stroke and death. Steroids are used to treat paradoxical reaction and TB meningitis, but are not very effective [93] Autophagy-promoting treatments could potentially limit the production of proinflammatory IL-1β[29] yet promote the clearance of dead mycobacteria, and thereby reduce the overactive inflammatory response.

Smoking cessation would prolong life by a mean of 4 years in a 45-year old man and by 3 years in a diabetic man, whereas

aspirin and antihypertensive treatment would provide approximately 1 year of additional life expectancy.123,124 The following cohort studies summarized in the text below and in Table A15 have included assessment of renal outcomes. Smoking has been found to be an independent risk factor for progression of AER selleck inhibitor in people with type 2 diabetes. In a prospective 9-year follow-up study of 108 people with type 2 diabetes and normal AER after a duration of diabetes of 9 years, there was an over-representation of smokers (55% vs 27%; P = 0.01) in people who progressed to micro- or macroalbuminuria versus those who did not progress.125 A number of prospective cohort studies were identified by the search strategy that have considered smoking in people with type 2 diabetes in relation to kidney function. Relevant details of these studies are summarized in Table A15. All of these studies showed an association between smoking and albuminuria. Only one cohort study was found which included an assessment of smoking as a risk factor for eGFR.126 Of the 7 prospective cohort studies identified only

one small study reported no significant association between smoking and the progress of albuminuria.127 Chuahirun & Wesson128 prospectively sought predictors of renal function decline in 33 people with type 2 diabetes, successfully targeting a mean BP goal of 92 mm Hg (about 125/75 mm Hg) with antihypertensives including ACEi. Initial plasma Methane monooxygenase creatinine was <1.4 mg/dL, follow-up 64.0 ± 1.1 months.

Regression RO4929097 order analysis showed that smoking was the only examined parameter that significantly predicted renal function decline. In the 13 smokers, serum Cr increased from 1.05 +/ to 0.08 mg/dL to 1.78 ± 0.20 mg/dL although MAP was the same. The 20 non-smokers had a lesser Cr rise at 1.08 ± 0.03 mg/dL to 1.32 ± 0.04 mg/dL. The 6 month prospective cohort studies concluded that cigarette smoking exacerbates renal injury despite adequate BP control with ACEi.129 Smoking cessation by those with microalbuminuria was associated with amelioration of the progressive renal injury caused by continual smoking. The smaller but long-term study concluded that smoking and increased UAE are interrelated predictors of nephropathy progression and that smoking increases UAE in patients despite improved BP control and ACE inhibition.130 The prospective cohort study included 6513 people with type 2 diabetes with 5 year follow up period.131 Smoking was identified as an independent risk factor for established microalbuminuria and for the development of microalbuminuria. Similarly the retrospective cohort study,126 used logistic to show that smoking was the most important risk factor for progression of nephropathy. The authors concluded that quitting smoking should be part of the prevention therapy.

Assay was performed as described [17]. Assay was performed as described [39] with some modifications. Anti-Syk immunoprecipitates from pervanadate stimulated RBL-2H3 cells,

used as source of active enzyme, and anti-Hrs immunoprecipitates from unstimulated RBL cells, used as substrate, were washed five times with lysis buffer, once with the kinase buffer (30 mM Hepes, pH 7.4, 5 mM MgCl2, 5 mM MnCl2, and 100 μM Na3VO4), mixed, and resuspended in 40 μL kinase buffer containing 10 μCi of (γ-32P) ATP and 1 μM cold ATP. After 10 min of incubation at 30°C, beads were washed three times with lysis buffer, eluted with SDS-sample buffer and analyzed by SDS-PAGE and autoradiography. Sensitized RBL-2H3 cells (5 × 105) were resuspended in 50 μL of serum-free medium and stimulated with 1 μg/mL DNP-HSA

for 30 min at 37°C. Endocytosis was www.selleckchem.com/autophagy.html stopped by addition of 0.1% NaN3 in cold PBS for 5 min. Samples were labeled with FITC-conjugated anti-mouse IgE and the cytofluorimetric analysis was performed with a FACSCalibur flow check details cytometer (Becton Dickinson Immunocytometry Systems). Cells (120 × 103/well) were grown on glass coverslips coated with 2% gelatin, incubated with anti-DNP IgE (0.3 μg/well) overnight and stimulated with 500 or 50 ng/mL DNP-HSA for the indicated lengths of time to induce receptor internalization. Cells were then fixed, permeabilized, and stained with FITC-conjugated anti-IgE, as previously described [11]. To identify late

endosomes and lysosomes, cells were incubated with 300 nM Lyso-Tracker Red for the last 30 min during stimulation. buy Enzalutamide Images were acquired at room temperature using an ApoTome Observer Z.1 microscope (Carl Zeiss, Jena, Germany) with a Plan-Neofluar objective x40/0.75 and an Axiocam MRm camera (all from Carl Zeiss). ApoTome Zeiss system provides an optical slice view reconstructed from fluorescent samples using a series of “grid projection” acquisitions, as reported [11]. Imaging stacks in the axial direction were acquired using AxioVision 4.6.3 software (Carl Zeiss), and all images shown are from a representative axial plane. Colocalization of the fluorescence signal was analyzed with AxioVision 4.6.3 software (Carl Zeiss). Images were processed with Photoshop 7 (Adobe, San Jose, CA, USA). The bands from immunoblot were quantified by densitometric analysis performed using Image J statistical software (National Institutes of Health, Bethesda, MD, USA). Data are presented as mean ± SD and compared using one-way analysis of variance followed by Student’s t-test. A p-value less than 0.05 was considered as statistically significant. We thank G. Benigni for isolating mouse bone marrow cells, G. Bernardini and A. Kettner for technical advises for BMMC culture, P. Birarelli and B. Milana for technical assistance, and P. Di Russo for secretarial assistance.

Immunized ER-β−/− and WT donors

LNC were sorted for CD11b/CD11c+ DC and CD11b/CD11c− (non-DC) fractions. The DC fractions were from ER-β−/− or WT mice, whereas non-DC fractions were all from WT mice. Cells from various ER-β−/− and WT donors were mixed with the ratios of DC (3%) and non-DC (97%) based on the immune cell composition selleck chemical of non-manipulated immunized donor LNC, then stimulated with autoantigen before adoptive transfer into ER-β ligand- or vehicle-treated recipient mice (Fig. 5A). As shown in Fig. 5B, ER-β ligand-treated mice adoptively transferred with WT DC (green) had reduced EAE disease severity compared with ER-β ligand-treated mice that were adoptively transferred ER-β−/− DC (orange). These results demonstrated that ER-β ligand treatment during the effector phase of EAE acts at least in part on ER-β-expressing DC. Previously, our lab showed that ER-β ligand treatment was neuroprotective in active EAE without altering cytokine production of autoantigen-specific MG-132 concentration immune cells in the periphery and without reducing the level of CNS inflammation. Specifically, ER-β ligand treatment preserved axon densities and myelin staining late in disease despite persistent inflammation in the CNS 16. However, it remained unknown whether qualitative differences might exist in the inflammatory

infiltrates of ER-β ligand-treated EAE mice. Therefore, in the present study, we examined immune cells in the CNS of EAE mice treated with ER-β ligand. We found that ER-β ligand treatment conferred clinical protection in the effector phase of adoptive EAE and reduced the percentage of DC in the target organ. DC isolated from the CNS of ER-β ligand-treated EAE mice exhibited decreased TNF-α production. Finally, we showed that ER-β ligand treatment in EAE conferred disease protection through ER-β expressed

on DC. This is the first study elucidating an in vivo immunomodulatory role for ER-β during autoimmune demyelinating disease. DC are emerging as critical mediators of inflammation in a variety of organ-specific autoimmune diseases such as rheumatoid arthritis, psoriasis, and EAE due to their efficient antigen-presenting ability 20, 26, 28–31. CNS DC are critical to EAE many pathogenesis, as DC infiltrates in the CNS during EAE preferentially localize with effector TC at sites of inflammation and they alone can activate infiltrating naïve TC to differentiate and perpetuate inflammation 20, 28. Our finding of quantitative and qualitative effects of ER-β ligand treatment on CNS DC, which occurred in a setting of improved clinical and neuropathologic disease corroborates other studies showing that CNS DC play a critical role in EAE disease severity 32–34. Further, ER-β ligand treatment can now be considered as a novel treatment strategy targeting DC in the CNS. DC are excellent targets for organ-specific autoimmune diseases for several reasons.

21,88 The transplanted trophoblasts undergo autonomous terminal differentiation in ectopic sites independent of the physiological state of pregnancy. They stimulate maternal antibody responses and attract T cells to the sites of transplantation and yet evade immediate destruction by the immune system of the recipients. The trophoblasts also maintain their endocrine capacity

and produce eCG.88 In addition to the characteristics that make the horse unique as a species in the study of pregnancy immunology, many advantages offered by commonly used animal models apply. The MHC of the horse has been well characterized using functional and genetic studies.89–94 Crizotinib supplier Horses have been selectively bred for homozygosity at the MHC region, enabling the establishment of MHC-compatible and MHC-incompatible pregnancies to investigate the role of paternal antigens in maternal immune recognition.21 Advanced assisted reproductive techniques, such as artificial insemination and embryo transfer, are routinely used in horse breeding. Notably, embryo transfer is performed in thousands of horses

every year worldwide with high success rates,95 suggesting that the insemination-induced tolerance that plays a role in pregnancy in some species96 may be less important in others. Other more advanced techniques such selleck inhibitor as oocyte transfer, intracytoplasmic sperm injection, and nuclear transfer (cloning) are also successfully used in horse reproduction.97 These techniques are primarily used to generate genetically desirable offspring, but they can also be useful tools in understanding early reproductive events such as fertilization and conception. Recent advances in equine genomics and immunology have expanded opportunities for the study click here of pregnancy immunology at the mechanistic level. A 6.8X sequence of the equine genome has been determined

and extensively annotated.98 Multiple horse-specific expression microarrays have been developed and validated, allowing researchers to investigate the expression of thousands of genes simultaneously.99–102 Molecular advances have also facilitated the development of new horse-specific monoclonal antibodies103–106 and immune assay technologies.107 Our understanding of the mare’s immune responses during pregnancy has progressed substantially, but several critical questions still remain. Firstly, why do the chorionic girdle trophoblasts express such high levels of paternal MHC class I while invading the maternal endometrium? The horse is not unique in this respect – MHC class I expression can be observed in trophoblast populations of other species at various stages of placentation. However, the horse demonstrates the clearest evidence for maternal immune recognition of paternal alloantigens expressed by trophoblast. A proposed role for the expression of HLA molecules by human invasive extravillous trophoblasts is to confer protection from cytotoxic natural killer (NK) cells.

Phagosome maturation of the professional phagocytes after ingestion of microbial pathogens, characterized by phagosomal acidification and phagosome/lysosome fusion, is a critical step in the killing and degradation of the internalized mTOR inhibitor pathogens and thus plays a key role in innate immunity against microbial infection [23-25]. We first measured phasosomal pH in infant macrophages and observed a substantially delayed and reduced phagosomal acidification in infant macrophages compared with adult macrophages after ingestion of either S. aureus or S. typhimurium. Consistent with

the defective phagosomal acidification, infant macrophages also exhibited severely impaired phagolysosome fusion in response

to both gram-positive and C59 wnt in vivo gram-negative bacterial challenges, as revealed by the impaired colocalization of either S. aureus-FITC or E. coli-FITC with LysoTraker red-labeled lysosomes in infant macrophages compared with adult macrophages. These data indicate that infant macrophages exhibit a defect in phagosome maturation into the late lysosomal stage. Collectively, our results reveal the deficiency of infant mice in their innate phagocyte-associated antimicrobial functions in response to bacterial infection, which is characterized by diminished PMN in vitro chemotaxis and in Interleukin-2 receptor vivo recruitment into the infections site, and impaired macrophage phagosome maturation and bactericidal activity. These defective innate immunity-mediated antimicrobial responses render infant mice more susceptible to microbial

sepsis. Two- and eight-week-old infant and adult C57BL/6 mice were purchased from Harlan (Oxon, U.K.) and maintained in the University Biological Services Unit, University College Cork / National University of Ireland. Mice were housed in barrier cages under controlled environmental conditions (12/12 h of light/dark cycle, 55% ± 5% humidity, 23°C) and had free access to standard laboratory chow and water. Animals were fasted 12 h before experiments and allowed water ad libitum. All animal procedures were carried out in the University Biological Services Unit under a license from the Department of Health (Republic of Ireland). All animal studies were conducted with ethical approval granted from the University College Cork Ethics Committee. Gram-positive S. aureus and gram-negative S. typhimurium were obtained from American Type Culture Collection (ATCC, Manassas, VA, USA) and the National University of Ireland Culture Collection, respectively. Bacteria were cultured at 37°C in trypticase soy broth (Merck, Darmstadt, Germany), harvested at the mid-logarithmic growth phase, washed twice, and resuspended in PBS for in vitro and in vivo use.

This implies that thymically derived natural Treg cells may also play a role in controlling the overall size of the GC response, or upon systemic TGF-β neutralization, other factors or cytokines may partially compensate leading to nominal induction of iTreg cells. The potential role of IL-10 was also examined by repeated administration of a blocking anti-IL-10R mAb. Mice were injected i.p. on day 0 with 1 mg of anti-IL-10R (1B1.3a) mAb or control rat IgG. Starting selleck chemicals in the second week, 500 μg of anti-IL-10R mAb

or rat IgG was injected twice weekly and continued until the mice were killed. The SRBC were given i.p. on day 0. Similar to anti-TGF-β-treated mice, blockade of the IL-10R resulted in an inability to control the balance of IgM+ to switched GC B cells in the spleen. Although not evident at days 8 and 12, this imbalance became marked at days 18 and 24 and reflected a significant increase in both the frequency and MK-2206 solubility dmso total number of IgM− GC B cells (Fig. 9b). Examination of the frequency and number of total B220+ PNAhi B cells showed little difference between anti-IL-10R mAb and control-treated mice, except at day 24 (Fig. 9a). This is again similar to the result observed after TGF-β neutralization, and may likewise reflect the activity of natural Treg cells or the ability of other cytokines to partially compensate.

Finally, to ensure that anti-IL-10R mAb treatment did not directly modulate responding B cells, the GC population was tested for expression of IL-10R. As shown in the Supplementary material, Fig. S3, no expression above background was detected. A large number of studies have documented the role of Treg cells in controlling antibody responses.16–46 Using either in vivo disruption (anti-GITR mAb) or depletion (anti-CD25 mAb) protocols, investigators have shown that loss of Treg-cell activity results in enhanced humoral

responses to experimental antigens,16–22 pathogens23,24 and auto-antigens.17,25–29 In all of these reports, antibody levels directed against the specific Methocarbamol antigen or infectious agent were significantly elevated, including IgG,16–27,29 IgA18,25 and even IgE.19,26 Additional studies examined whether adoptive transfer of polyclonal21,30–32,35,37–40 or TCR transgenic33,34,36,41 Treg cells could dampen antibody responses to defined allo-antigens or auto-antigens. In all cases, the transfer of Treg cells significantly lowered or even eliminated serum antibodies directed against these antigens. As GCs serve as the basis for T-cell-driven humoral responses, the current study examined the behaviour of primary splenic GC reactions induced to a number of antigens in mice treated with an anti-GITR mAb (Figs 1–4). After disruption of Treg-cell activity, total SRBC-induced GC B-cell numbers were increased at all time-points examined (days 8–24). A higher proportion of IgM− switched B cells within the GC compartment largely accounted for this increase.

Submicroscopic infections that are highly prevalent in all malaria endemic settings [31] appeared to provide sufficiently high levels of antigen exposure to maintain

Selleck Crizotinib antibody titres. Our findings confirm observations in Kenyan children where antibody boosting was observed in the absence of patent malaria infections and provide evidence in support of their hypothesis that this could be explained by submicroscopic infections [32]. Our data also offer support for the hypothesis that circulating antimalarial antibodies in children derive mainly from short-lived plasma cells [33] but that long-lived plasma cells may be the major source of antibodies in older individuals [34]. Finally, the very rapid decline – in all age groups – in titres of antibodies to mosquito salivary gland antigens indicates that these antigens fail to induce long-lived plasma cells, suggesting that the antibodies may emanate from ‘innate’ or ‘natural’ B1 cells or that the antigens activate B cells in a T-cell

independent manner (35). We are grateful to the Apac district’s inhabitants for their participation to the study; we also thank CAL 101 Sam Edweo and Dorcus Akello for their contribution during the field work. This study was supported by the FIGHTMAL project, receiving funding from the European Community’s Seventh Framework Programme [FP7/2007-2013] under grant agreement PIAP-GA-2008-218164. “
“In certain infection sites or tumor tissues, the disruption of homeostasis can give rise to a hypoxic microenvironment, which, in turn, can alter

the function of different immune cell types and favor the progression of the disease. Natural killer (NK) cells are directly involved in the elimination of virus-infected or transformed cells, however it is unknown whether their function is affected by hypoxia or not. In this study, we show that NK cells adapt to a hypoxic this website environment by upregulating the hypoxia-inducible factor 1α. However, NK cells lose their ability to upregulate the surface expression of the major activating NK-cell receptors (NKp46, NKp30, NKp44, and NKG2D) in response to IL-2 (or other activating cytokines, including IL-15, IL-12, and IL-21). These altered phenotypic features correlate with reduced responses to triggering signals resulting in impaired capability of killing infected or tumor target cells. Remarkably, hypoxia does not significantly alter the surface density and the triggering function of the Fc-γ receptor CD16, thus allowing NK cells to maintain their capability of killing target cells via antibody-dependent cellular cytotoxicity. This finding offers an important clue for exploitation of NK cell in antibody-based immunotherapy of cancer. As a component of innate immunity, natural killer (NK) cells play an important role in the control of virus infections and in cancer immune surveillance [1-5].

Furthermore, IgG3 binds with high affinity to Fc receptors on macrophages, and thus may be important in antibody-mediated Selleckchem JQ1 phagocytosis [2]. These factors may explain why patients with isolated IgG3 deficiency present with recurrent upper respiratory tract infections. However, the propensity for infections in these patients may not be attributed solely to IgG3 deficiency. There have been reports of patients with complete absence of IgG3 due to gene deletion in the heavy chain constant

regions, but these patients have had no infectious complications [3]. Therefore, other immune dysfunctions might exist in those patients with isolated IgG3 deficiency and recurrent infections. A more detailed analysis of immune function in IgG3-deficient patients is needed. The majority of reported studies for IgG subclass deficiency have been in children [4–6], and very few studies have reported detailed clinical and immunological features of adult patients with IgG3 deficiency [7–8]. In some of these reports, IgG3 subclass deficiency was associated with either IgA deficiency or another subclass deficiency, and therefore may not be considered selective IgG3 deficiency. BGB324 datasheet Moreover, none of these studies reported immunological data. Finally, there is a lack of information about the use of intravenous

immunoglobulin for treatment of IgG3 subclass deficiency. In this study, we present detailed information regarding immune functions of patients with recurrent infections and isolated IgG3 deficiency, and their response to intravenous Ig therapy (IVIG). We reviewed the charts of patients with recurrent infections referred to one of us (S. G.) at Immunology Clinic, University of California, Irvine (UCI) from 1998 to 2007. We identified 17 adult patients with a diagnosis of selective IgG3 deficiency. The diagnosis was made according to published guidelines [9]. Patients

were 16 years of age or older at the time of diagnosis, suffered from recurrent Selleckchem Gemcitabine infections, had an IgG3 level that was greater than 2 standard deviations below the mean on at least two separate occasions and had normal levels of IgA, IgM, IgG, IgG1, IgG2 and IgG4. The charts of these 17 patients were reviewed for immunological data, the type and frequency of infections and response to IVIG treatment. This study was approved by the UCI Institutional Review Board, and the patients signed informed consent. Fluorescein isothiocyanate (FITC)- and phycoerythrin (PE)-conjugated monoclonal antibodies to CD3, CD4, CD8, CD19, CD16, CD56, CD14, Toll-like receptor-4 (TLR-4) and isotype controls were obtained from Becton Dickinson (San Jose, CA, USA). Tritiated thymidine [3H] for lymphocyte transformation assays was obtained from New England Nuclear (Boston, MA, USA).