Incubation of Immune Cell Grafts With MAX.16H5 IgG1 Anti-Human CD4 Antibody Prolonged Survival After Hematopoietic Stem Cell Transplantation in a Mouse Model for Fms Like Tyrosine Kinase 3 Positive Acute Myeloid Leukemia.

Despite the constant development of innovative therapeutic options for hematological malignancies, the gold-standard therapy regimen for curative treatment often includes allogeneic hematopoietic stem cell transplantation (HSCT). The graft-vs.-leukemia effect (GVL) is one of the main therapeutic goals that arises from HSCT. On the other hand, graft-vs.-host disease (GVHD) is still one of the main and most serious complications following allogeneic HSCT. In acute myeloid leukemia (AML), HSCT together with high-dose chemotherapy is used as a treatment option. An aggressive progression of the disease, a decreased response to treatment, and a poor prognosis are connected to internal tandem duplication (ITD) mutations in the Fms like tyrosine kinase 3 (FLT3) gene, which affects around 30% of AML patients. In this study, C3H/HeN mice received an allogeneic graft together with 32D-FLT3ITD AML cells to induce acute GVHD and GVL. It was examined if pre-incubation of the graft with the anti-human cluster of differentiation (CD) 4 antibody MAX.16H5 IgG1 prevented the development of GVHD and whether the graft function was impaired. Animals receiving grafts pre-incubated with the antibody together with FLT3ITD AML cells survived significantly longer than mice receiving untreated grafts. The observed prolonged survival due to MAX.16H5 incubation of immune cell grafts prior to transplantation may allow an extended application of additional targeted strategies in the treatment of AML.

Iron supplementation in mouse expands cellular innate defences in spleen and defers lethal malaria infection.

The co-endemicity of malnutrition, erythrocytopathies, transmissible diseases and iron-deficiency contribute to the prevalence of chronic anaemia in many populations of the developing world. Although iron dietary supplementation is applied or recommended in at risk populations, its use is controversial due to undesirable outcomes, particularly regarding the response to infections, including highly prevalent malaria. We hypothesized that a boosted oxidative stress due to iron supplementation have a similar impact on malaria to that of hereditary anaemias, enhancing innate response and conditioning tissues to prevent damage during infection. Thus, we have analysed antioxidant and innate responses against lethal Plasmodium yoelii during the first five days of infection in an iron-supplemented mouse. This murine model showed high iron concentration in plasma with upregulated expression of hemoxygenase-1. The sustained homeostasis after this extrinsic iron conditioning, delayed parasitemia growth that, once installed, developed without anaemia. This protection was not conferred by the intrinsic iron overload of hereditary hemochromatosis. Upon iron-supplementation, a large increase of the macrophages/dendritic cells ratio and the antigen presenting cells was observed in the mouse spleen, independently of malaria infection. Complementary, malaria promoted the splenic B and T CD4 cells activation. Our results show that the iron supplementation in mice prepares host tissues for oxidative-stress and induces unspecific cellular immune responses, which could be seen as an advantage to promote early defences against malaria infection.

Decreased Levels of Spleen Tissue CD4+CD25+Foxp3+ Regulatory T Lymphocytes in Mice Exposed to Berberine.

The effects of isoquinoline alkaloid berberine (BER) on spleen tissue CD4+CD25+Foxp3+ regulatory T (Treg) cells were evaluated in BALB/c mice. Here, BER was administered daily by intraperitoneal injection at doses of 5 mg/kg and 10 mg/kg for 14 days. Following the exposure, mice spleen cellularities, IL-10 production by splenocytes, and spleen Treg/CD4+ cell profiles were studied in all the test groups of animals. The results showed that a high dose of BER (10 mg/kg) could decrease both the absolute and relative percentages of spleen Treg cells as well as decrease the production of IL-10 by splenocytes in the treated mice (p<0.05). BER at 5 mg/kg did not appear to affect any of these parameters. Based on the finding here, it would seem that BER has effective immunostimulatory properties, which contradicts the results from other studies indicating immunosuppressive effects of BER. Depending on the doses of BER used, it might have a broad spectrum from immunosuppressive to stimulatory effects. Further studies, including more doses, are required to better evaluate the effects of this natural product. Mechanistic studies are required, particularly in case of redox state of the immune cells, to elucidate and determine how BER functions to impart the toxicity effects demonstrated here and in other studies.

Repeated Vaccination of Cows with HIV Env gp140 during Subsequent Pregnancies Elicits and Sustains an Enduring Strong Env-Binding and Neutralising Antibody Response.

An important feature of a potential vaccine against HIV is the production of broadly neutralising antibodies (BrNAbs) capable of potentially blocking infectivity of a diverse array of HIV strains. BrNAbs naturally arise in some HIV infected individuals after several years of infection and their serum IgG can neutralise various HIV strains across different subtypes. We previously showed that vaccination of cows with HIV gp140 AD8 trimers resulted in a high titre of serum IgG against HIV envelope (Env) that had strong BrNAb activity. These polyclonal BrNAbs concentrated into the colostrum during the late stage of pregnancy and can be harvested in vast quantities immediately after calving. In this study, we investigated the effect of prolonged HIV gp140 vaccination on bovine colostrum IgG HIV Env-binding and BrNAb activity over subsequent pregnancies. Repeated immunisation led to a maintained high titre of HIV Env specific IgG in the colostrum batches, but this did not increase through repeated cycles. Colostrum IgG from all batches also strongly competed with sCD4 binding to gp140 Env trimer and with human-derived monoclonal VRC01 and b12 BrNAbs that bind the CD4 binding site (CD4bs). Furthermore, competition neutralisation assays using RSC3 Env gp120 protein core and a derivative CD4bs mutant, RSC3 Δ371I/P363N, showed that CD4bs neutralising antibodies contribute to the neutralising activity of all batches of purified bovine colostrum IgG. This result indicates that the high IgG titre/avidity of anti-CD4bs antibodies with BrNAb activity was achieved during the first year of vaccination and was sustained throughout the years of repeated vaccinations in the cow tested. Although IgG of subsequent colostrum batches may have a higher avidity towards the CD4bs, the overall breadth in neutralisation was not enhanced. This implies that the boosting vaccinations over 4 years elicited a polyclonal antibody response that maintained the proportion of both neutralising and non-neutralising CD4bs antibodies.

Mechanism of immunoprotective effects of curcumin in DLM-induced thymic apoptosis and altered immune function: an in silico and in vitro study.

Curcumin, a main component of Curcuma Longa Linn, is a plant polyphenol used as an immune-enhancer in the Indian system of traditional medicine. However, its underlying mechanism of immune-protection remains unknown. The present study is designed to delineate the role of curcumin in deltamethrin (DLM)-induced thymocyte apoptosis and altered immune functions. In silico studies revealed that curcumin has a strong binding affinity toward CD4 and CD8 receptors. DLM (25 µM) induces thymocytes apoptosis through oxidative stress and caspase-dependent pathways. Various concentrations of curcumin (1, 10 and 50 µg/ml), when added along with DLM, caused a concentration- and time-related amelioration in apoptogenic signaling pathways induced by DLM. Inhibition of DLM-induced reactive oxygen species production, replenishment of glutathione and suppression of caspase activities by curcumin may thus be responsible for the suppression of downstream cascade of events, i.e. apoptosis, phenotypic changes and altered cytokine release. Thus, this study clearly demonstrates that the mechanism of immunoprotection of curcumin in DLM-induced thymic apoptosis includes inhibition of oxidative stress and caspase-dependent pathways underlying apoptosis.

Effects of cytarabine on activation of human T cells - cytarabine has concentration-dependent effects that are modulated both by valproic acid and all-trans retinoic acid.

BACKGROUND: Cytarabine is used in the treatment of acute myeloid leukemia (AML). Low-dose cytarabine can be combined with valproic acid and all-trans retinoic acid (ATRA) as AML-stabilizing treatment. We have investigated the possible risk of immunotoxicity by this combination. We examined the effects of cytarabine combined with valproic acid and ATRA on in vitro activated human T cells, and we tested cytarabine at concentrations reached during in vivo treatment with high doses, conventional doses and low doses. METHODS: T cells derived from blood donors were activated in vitro in cell culture medium alone or supplemented with ATRA (1 µM), valproic acid (500 or 1000 µM) or cytarabine (0.01-44 µM). Cell characteristics were assessed by flow cytometry. Supernatants were analyzed for cytokines by ELISA or Luminex. Effects on primary human AML cell viability and proliferation of low-dose cytarabine (0.01-0.5 µM) were also assessed. Statistical tests include ANOVA and Cluster analyses. RESULTS: Only cytarabine 44 µM had both antiproliferative and proapoptotic effects. Additionally, this concentration increased the CD4:CD8 T cell ratio, prolonged the expression of the CD69 activation marker, inhibited CD95L and heat shock protein (HSP) 90 release, and decreased the release of several cytokines. In contrast, the lowest concentrations (0.35 and 0.01 µM) did not have or showed minor antiproliferative or cytotoxic effects, did not alter activation marker expression (CD38, CD69) or the release of CD95L and HSP90, but inhibited the release of certain T cell cytokines. Even when these lower cytarabine concentrations were combined with ATRA and/or valproic acid there was still no or minor effects on T cell viability. However, these combinations had strong antiproliferative effects, the expression of both CD38 and CD69 was altered and there was a stronger inhibition of the release of FasL, HSP90 as well as several cytokines. Cytarabine (0.01-0.05 µM) showed a dose-dependent antiproliferative effect on AML cells, and in contrast to the T cells this effect reached statistical significance even at 0.01 µM. CONCLUSIONS: Even low levels of cytarabine, and especially when combined with ATRA and valproic acid, can decrease T cell viability, alter activation-induced membrane-molecule expression and decrease the cytokine release.

Immunomodulatory effects of selenium and vitamin E on alterations in T lymphocyte subsets induced by T-2 toxin.

UNLABELLED: Abstract Context: T-2 toxin, a potent mycotoxin, has serious effects on immune system. OBJECTIVE: Here, the effects of a sublethal dose of this toxin on T lymphocyte sub-population levels and the potential protective effects from treatment with selenium or vitamin E were studied. MATERIALS AND METHODS: After having determined the sublethal dose of the T-2 toxin in Balb/c mice hosts, the post-injection kinetics of changes in T lymphocyte sub-population (CD3(+), CD4(+) and CD8(+) cells) profiles were analyzed via flow cytometry. For these studies, the selenium and vitamin E were either provided to the mice before or concurrent with the toxin. RESULTS: The results show that after a sublethal dose of T-2 alone, the number of CD8(+) T-lymphocytes was significantly decreased at 12 h and normalized at 48 h. In contrast, level of CD3(+) and CD4(+) T-lymphocytes were significantly increased at 24 h and returned to normal after 48 h. When selenium was injected into the mice 24 h before or concurrent with the T-2, the effects on CD8(+) cells were mitigated. Oddly, only when the selenium was given with the toxin could the effects on the CD3(+) and CD4(+) cells be altered. Vitamin E, when injected 24 h before or concurrent with the T-2 toxin, was only able to impact upon the CD8(+) lymphocyte alterations induced by the toxin. CONCLUSIONS: Compared with vitamin E, it seems that selenium could assert an important effect against the immunotoxic effects of T-2 toxin against T lymphocytes.

Regulation of CD4(+)NKG2D(+) Th1 cells in patients with metastatic melanoma treated with sorafenib: role of IL-15Rα and NKG2D triggering.

Beyond cancer-cell intrinsic factors, the immune status of the host has a prognostic impact on patients with cancer and influences the effects of conventional chemotherapies. Metastatic melanoma is intrinsically immunogenic, thereby facilitating the search for immune biomarkers of clinical responses to cytotoxic agents. Here, we show that a multi-tyrosine kinase inhibitor, sorafenib, upregulates interleukin (IL)-15Rα in vitro and in vivo in patients with melanoma, and in conjunction with natural killer (NK) group 2D (NKG2D) ligands, contributes to the Th1 polarization and accumulation of peripheral CD4(+)NKG2D(+) T cells. Hence, the increase of blood CD4(+)NKG2D(+) T cells after two cycles of sorafenib (combined with temozolomide) was associated with prolonged survival in a prospective phase I/II trial enrolling 63 patients with metastatic melanoma who did not receive vemurafenib nor immune checkpoint-blocking antibodies. In contrast, in metastatic melanoma patients treated with classical treatment modalities, this CD4(+)NKG2D(+) subset failed to correlate with prognosis. These findings indicate that sorafenib may be used as an "adjuvant" molecule capable of inducing or restoring IL-15Rα/IL-15 in tumors expressing MHC class I-related chain A/B (MICA/B) and on circulating monocytes of responding patients, hereby contributing to the bioactivity of NKG2D(+) Th1 cells.

Effect of narrow band-ultraviolet B on CD4(+) CD25(high) FoxP3(+) T-lymphocytes in the peripheral blood of vitiligo patients.

BACKGROUND: It is widely believed that an imbalance between activated CD8(+) T cells and regulatory T cells (Tregs) exists in patients with vitiligo. Although there is evidence that narrow band ultraviolet (NB-UVB) irradiation can induce Tregs' number and activity, but up to our knowledge, none of the published studies involved the possible effect of NB-UVB on Tregs in vitiligo. OBJECTIVE: To evaluate the effect of NB-UVB on circulating CD4(+) CD25(high) FoxP3(+) regulatory T cells (FoxP3(+) Tregs) in vitiligo. METHODS: This prospective analytic study included 20 patients with active non-segmental vitiligo and 20 healthy controls. The patients were exposed to NB-UVB therapy three times per week for 30 sessions. Blood sampling before and after NB-UVB phototherapy was done to evaluate circulating CD4(+) CD25(high) Tregs and Foxp3(+) Tregs. RESULTS: The CD4(+) CD25(high) Tregs% and FoxP3(+) Tregs% were significantly higher in vitiligo patients compared with controls. NB-UVB therapy decreased both of them in patients, but they did not reach those of controls. Each of circulating CD4(+) CD25(high) Tregs% and FoxP3(+) Tregs% didn't correlate with either extent or activity of vitiligo before or after NB-UVB. CONCLUSION: Tregs functional defect is probably having an impact on NSV. NB-UVB may improve the function of Tregs. Understanding the mechanisms through which NB-UVB exert its effect on reducing the number of circulating Tregs would help open up the paths for future therapeutic options.

Adjuvant facilitates tolerance induction to factor VIII in hemophilic mice through a Foxp3-independent mechanism that relies on IL-10.

Current treatment of hemophilia consists of the administration of recombinant clotting factors, such as factor VIII (FVIII). However, patients with severe hemophilia can mount immune responses targeting therapeutically administered FVIII through inhibitory immunoglobulins that limit treatment efficacy. Induction of immune tolerance to FVIII in hemophilia has been extensively studied but remains an unmet need. We found that nondepleting anti-CD4 monoclonal antibodies (mAbs) are effective in inducing long-term tolerance to FVIII in different strains of hemophilic mice. Tolerance induction was facilitated when anti-CD4 mAbs were administered together with FVIII adsorbed in an adjuvant (alum). The observed state of tolerance was antigen specific, with mice remaining immune competent to respond to different antigens. Importantly, we found that following immunization with FVIII, the primed cells remained susceptible to tolerance induction. Studies with Foxp3-deficient and interleukin 10 (IL-10)-deficient mice demonstrated that the underlying tolerance mechanism is Foxp3 independent but requires IL-10. Our data show that an adjuvant, when administered together with a tolerizing agent such as nondepleting anti-CD4, can facilitate the induction of long-term tolerance to recombinant proteins, possibly not only in hemophilia but also in other diseases that are treated with potentially immunogenic therapeutics.

Attenuation of murine graft-versus-host disease by a tea polyphenol.

Since donor T-cells' allorecognition of host antigens is a prerequisite for the onset of graft-versus-host disease (GVHD), blocking their cellular signaling pathways can decrease the severity of GVHD. We hypothesized that epigallocatechin-3-gallate (EGCG), due to its strong affinity to macromolecules, would adhere to surface molecules of donor T cells, inhibit their allorecognition, and attenuate GVHD in the recipient. We tested the hypothesis by treating donor splenocytes with EGCG in both in vitro and in vivo murine GVHD models. EGCG treatment decreased the proliferation of donor cells in MLR cultures and secretion of IL-2 and INF-γ. It also reduced the epitope detection of CD3ɛ, CD4, and CD28 but did not downregulate the protein expression of these molecules, suggesting blockage of cell surface stimulatory signals. Similarly, EGCG treatment did not decrease mRNA expression for some of these molecules but decreased mitogen-induced cell proliferation, indicating that EGCG did not interfere the transcription of these genes but affected cell proliferation pathways. Furthermore, EGCG-treated donor splenocytes, when transplanted into immunocompromized recipient mice, decreased of proliferation, and the treatment extended the recipients' survival at least during the early stage of GVHD. These results strongly suggest that EGCG attenuates GVHD by both blocking specific cell surface molecules and affecting the donor T-cell proliferation pathways.

Total alkaloids of Sophora alopecuroides increases the expression of CD4+ CD25+ Tregs and IL-10 in rats with experimental colitis.

Previous studies have demonstrated that the total alkaloids of Sophora alopecuroides (TASA), which contains many different ingredients like sophocarpine, matrine, oxymatrine, sophoridine, sophoramine, aloperine and cytosine, were able to protect colon against ulcers caused by 2,4,6-trinitrobenze sulphonic acid (TNBS)/ethanol treated models. In order to elucidate the mechanisms by which TASA exerts its effect of anti-inflammation and immunoregulation on rats with colitis, DAI (disease activity index) and histological grading of colitis were evaluated in the animal model. Moreover, the expression of CD4(+)CD25(+) regulatory T cells (Tregs) and IL-10 in rats with experimental colitis were observed by FCM, ELISA and RT-PCR in this study. Results showed that TASA (15, 30 or 60 mg/kg/day) significantly up-regulated CD4(+)CD25(+)Tregs (P = 0.02, P = 0.02, P = 0.03) and IL-10 levels (ELISA: P = 0.03, P = 0.02, P = 0.00; RT-PCR: P = 0.04, P = 0.02, P = 0.01) respectively and decreased the DAI and histological grading of colitis in the peripheral blood (PB) and colon of rat colitis models (3.44 +/- 1.53, 4.25 +/- 1.27, 4.42 +/- 1.24 and 3.50 +/- 1.42, 4.05 +/- 1.32, 4.51 +/- 1.55 vs. 7.18 +/- 1.32 and 7.38 +/- 1.52, P < 0.05, P < 0.01, respectively). Most interestingly, a negative correlation was demonstrated between the expression of CD4(+)CD25(+) Tregs and DAI (Pearson r(PB) = -0.677, P < 0.01; Pearson r(COLON) = -0.663, P < 0.01, n = 60), or histological grading of colitis (Pearson r(PB) = -0.725, P < 0.01; Pearson r(COLON) = -0.623, P < 0.01, n = 60). Simultaneously, a positive correlation existed between CD4(+)CD25(+) Tregs and IL-10 cytokine (IL-10 mRNA) in the colon and PB of rats (Pearson r(PB) = 0.789, P < 0.01, n = 60; Pearson r(COLON) = 0.678, P < 0.01, n = 60). These results may explain to some extent the mechanisms of TASA on treating rats with experimental colitis.

Interleukin-23 promotes Th17 differentiation by inhibiting T-bet and FoxP3 and is required for elevation of interleukin-22, but not interleukin-21, in autoimmune experimental arthritis.

OBJECTIVE: To examine the role of interleukin-23 (IL-23) in subgroup polarization of IL-17A-positive and/or interferon-gamma (IFNgamma)-positive T cells in autoimmune disease-prone DBA/1 mice with and without collagen-induced arthritis. METHODS: A magnetic-activated cell sorting system was used to isolate CD4+ T cells from the spleen of naive and type II collagen (CII)-immunized DBA/1 mice. These CD4+ T cells were stimulated in vitro under Th0, Th1, or different Th17 culture conditions. Intracellular staining for IL-17A and IFNgamma was evaluated by flow cytometry. In addition, Th17 cytokines and T helper-specific transcription factors were analyzed by enzyme-linked immunosorbent assay and/or quantitative polymerase chain reaction. RESULTS: In CD4+ T cells from naive DBA/1 mice, IL-23 alone hardly induced retinoic acid-related orphan receptor gammat (RORgammat), Th17 polarization, and Th17 cytokines, but it inhibited T-bet expression. In contrast, transforming growth factor beta1 (TGFbeta1)/IL-6 was a potent inducer of RORgammat, RORalpha, IL-17A, IL-17F, IL-21, and FoxP3 in these cells. In contrast to TGFbeta1/IL-6, IL-23 was critical for the induction of IL-22 in CD4+ T cells from both naive and CII-immunized DBA/1 mice. Consistent with these findings, IL-23 showed a more pronounced induction of the IL-17A+IFNgamma- subset in CD4+ T cells from CII-immunized mice. However, in CD4+ T cells from naive mice, IL-23 significantly increased the TGFbeta1/IL-6-induced Th17 polarization, including elevated levels of IL-17A and IL-17F and decreased expression of T-bet and FoxP3. Of note, the IL-23-induced increase in IL-17A and IL-17F levels was prevented in T-bet-deficient mice. CONCLUSION: IL-23 promotes Th17 differentiation by inhibiting T-bet and FoxP3 and is required for elevation of IL-22, but not IL-21, levels in autoimmune arthritis. These data indicate different mechanisms for IL-23 and TGFbeta1/IL-6 at the transcription factor level during Th17 differentiation in autoimmune experimental arthritis.

Sesquiterpenes as immunosuppressants.

BACKGROUND: The search for new immunosuppressive drugs is a high priority. Sesquiterpenes constitute a family of compounds with a great variety of biological activities due to their reactive moieties. METHODS: Human tumor cell lines and murine primary cells and human peripheral blood mononuclear cells or primary CD4+ cells from healthy individuals were stimulated in the presence of sesquiterpenes. Cell division was analyzed by 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester, cell cycle progression by Hoecht, and cell death by Anexin-V and propidium iodine staining. Cytokine secretion was analyzed by means of a bioplex assay. RESULTS: Two sesquiterpene derivatives of the 18 previously shown to inhibit vegetal cell growth are shown to block cell division and cell cycle progression in human and murine cell lines and primary cells. Cytokine secretion is also impaired on stimulation in the presence of sesquiterpenes. CONCLUSIONS: Here, we show that sesquiterpenes heliannuols constitute a novel family of molecules with potential use as immunosuppressants. Moreover, we show that an assay based on the allelopathic effect of plant leads can be used as a cost-effective screening previous to studies in mammalian cells.

Triptolide promotes generation of FoxP3+ T regulatory cells in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Triptolide (TPT), a component of the Chinese herb Triptergium wilfordii, has potent immunosuppressive and anti-inflammatory activity and is used clinically in recipients of kidney transplantation. AIM OF THE STUDY: This work aimed to investigate the effect of TPT on the differentiation of regulatory T lymphocytes (Tregs) from CD4+ cells in rats. MATERIALS AND METHODS: MACS-purified rat CD4+ cells were costimulated with anti-CD3 and anti-CD28 in the presence of TGF-beta to induce the expression of FoxP3, which was detected by flow cytometry. TPT and cyclosporine A (CsA) were separately added into the cultures to observe the effect on the expression of FoxP3. Kidney transplantation was performed in rats that either received no treatment or were treated with TPT after transplantation. RESULTS: TPT treatment enhanced the expression of FoxP3 in CD4+ cells, whereas CsA inhibited the FoxP3 expression. In the rat kidney transplantation model, the recipient rats treated with TPT survived longer than the control rats (18-19.83 vs 6.83 days, P<0.05). Meanwhile, the FoxP3+ T cells in the spleens of treated rats were higher than those from the untreated rats (12.4% vs 4.7%, P<0.05). CONCLUSIONS: These data suggest that TPT may promote the differentiation of CD4+ cells to FoxP3+ Tregs. This would be at least one of the pathways responsible for the immunosuppressive activity of TPT.

Effect of Bifidobacterium bifidum DSM 20082 cytoplasmic fraction on human immune cells.

The objective of the present study was to determine the effect of the soluble cytoplasmic fraction from Bifidobacterium bifidum DSM 20082 (Bb) lysate on peripheral blood T cells. In peripheral blood mononuclear cells of healthy subjects, cytotoxic activity, proliferation, apoptosis, and up-regulation of CD8 or CD4 molecules in T cells were examined. When peripheral blood mononuclear cells were stimulated with Bb lysate, the main effect was observed in CD8+ cells as a significant increase of CD8 molecules in a dose-dependent manner, and this behavior was observed at 24, 48, and 72 h after stimulation; in contrast, stimulation with Bb lysate showed no effect on the up-regulation of CD4 molecules in T helper cells. Further Bb lysate did not induce proliferation activity in either CD8+ or CD4+ cells. Bb lysate induced activation of CD8+ cytotoxic activity against autologous monocytes. Around 80% of the cells stimulated with Bb lysate were positive to peanut agglutinin (PNA), suggesting that the stimulated CD8+ cells corresponded to activated/effector cellular populations. When apoptosis was determined, there were no differences between stimulated and non-stimulated cells. Our results indicate that Bb lysate is able to increase cytotoxic activity of peripheral CD8+ cells, without affecting lymphocyte survival.

Calreticulin from the intestinal nematode Heligmosomoides polygyrus is a Th2-skewing protein and interacts with murine scavenger receptor-A.

Helminth infections are commonly associated with a Th2 immune response, yet only a few parasite molecules involved in triggering such immune responses have been identified. Here, we describe the Th2-skewing property of calreticulin of Heligmosomoides polygyrus (HpCRT). HpCRT is a secreted protein most abundantly expressed by tissue invasive larvae (L4). Native HpCRT purified from adult worm extract (nHpCRT) stimulated robust IL-4 release from CD4(+) T cells of H. polygyrus infected mice. Interestingly, CD4(+) T cells also produced significant amounts of IL-10 while IFN-gamma was not detectable. Likewise, immunization with recombinant HpCRT (rHpCRT) without extrinsic adjuvant led predominantly to a specific IL-4 production implying the innate ability of HpCRT to drive Th2 responses. The triggering of a Th2-skewed immune response to rHpCRT is corroborated by the induction of HpCRT-specific IgG1 and IgE antibodies. Furthermore, rHpCRT bound to scavenger receptor type A (SR-A) on dendritic cells, and interaction of HpCRT with SR-A led to internalization of HpCRT that could be partially blocked by competition with SR-A ligands as well as with an anti-SR-A monoclonal antibody. Hence, our data imply that nematode calreticulin interacts with a mammalian scavenger receptor and at the same time induces a Th2 response.

Protosappanin a, an immunosuppressive constituent from a Chinese herb, prolongs graft survival and attenuates acute rejection in rat heart allografts.

OBJECTIVE: Caesalpinia sappan L., which has been used in oriental medicine as an analgesic and antiinflammatory agent, has shown immunosuppressive activity on acute rejection on rat heart allografts. The present study was designed to investigate the potency of protosappanin A, one major ingredient of C. sappan L., in rat heart transplantation. MATERIALS AND METHODS: Protosappanin A isolated from an ethanol extract of C. sappan L. was identified by wave spectrum. All groups consisted of Wistar donors into Sprague-Dawley (SD) recipients, including large (25 mg/kg) or small (5 mg/kg) doses of protosappanin A plus cyclosporine (10 mg/kg). A control group was used. Animals were given the drugs on postoperative day 2. We observed graft survival and pathologic conditions of the hearts. Blood samples were obtained on postoperative day 7 to measure the CD4+/CD8+ T-cell ratio. Graft perforin and granzyme B mRNA expression levels were examined with reverse transcription-polymerase chain reaction (RT-PCR) methods. RESULTS: Protosappanin A or cyclosporine significantly prolonged heart allograft survival (P < .01), alleviated myocardial pathologic damages (P < .01), decreased the CD4+/CD8+ ratio (P < .05), and inhibited perforin and granzyme B mRNA expressions in the graft (P < .05). CONCLUSIONS: These findings demonstrated that protosappanin A prolonged heart allograft survival by significantly attenuating acute rejection.

[Effects and mechanism of CD4+ CD25+ regulatory T cells in mouse experimental colitis treated by CLYSTER No. 1].

OBJECTIVE: To explore the effects and mechanism of CD4+ CD25+ regulatory T cells (Tregs) in mouse experimental colitis treated by CLYSTER No. 1. METHOD: The mouse model of experimental colitis was established by dinitrochlorobenzene (DNCB)-acetic acid (AA) in mice DNCB and AA. Adult KM mouse were randomly divided into four groups: normal control group, experimental colitis model group, SASP and Chinese medicine therapeutic groups. Proportion of CD4 CD25+ Tregs in peripheral blood (PB) and mesenteric lymph node (MLN) was estimated by flow cytometry at the end of one or two week after treating with SASP and CLYSTER No. 1. RESULT: The model of experimental colitis in mouse was successfully established. Compared with normal control group, the proportion of CD4 CD25 Tregs was markedly decreased in PB and MLN of model control group of experimental colitis. But it was significantly increased in therapeutic groups of SASP and CLYSTER No. 1, and their CD4+ CD25+ Tregs in PB and MLN were much more than the model control group at the end of one or two weeks after treating with SASP and CLYSTER No. 1. CONCLUSION: CD4+ CD25+ Tregs with strong immune suppression could play a central role in the initiation and development of mouse experiment colitis, and the CLYSTER No. 1 might exert its therapeutic effects on UC by the regulation of number and function of CD4+ CD25+ Tregs.

Gender differences in inflammatory proteins and pathways in seasonal allergic rhinitis.

In model organisms, thousands of genes differ in expression between females and males. It is not known if differences on a similar scale are found in humans nor how this relates to disease. However, in allergic disease gender differences in the levels of both inflammatory cells and proteins have been shown. In this study, we found lower nasal fluid allergen-specific IgE in women than men with seasonal allergic rhinitis (SAR). This led to genome-wide analyses of gene expression in allergen-challenged CD4(+) cells from patients with SAR before and after treatment with cortisone. Before treatment, 975 genes differed in expression between women and men: 337 were higher in women. After treatment only 428 genes and one pathway differed in expression. The genes that differed in expression between women and men were over-represented in 10 pathways. Five of the pathways regulated chemotaxis. All five were less active in women. One of the pathways was induced by the eosinophilic chemokine CCL4. Analysis of nasal fluid CCL4 protein confirmed lower levels in women with seasonal allergic rhinitis, before and during the pollen season. By contrast, nasal fluid CCL3 levels did not differ between the genders. In summary, this study shows gender differences in specific inflammatory pathways and proteins in patients with seasonal allergic rhinitis. Further studies are warranted to examine if such differences have diagnostic and therapeutic implications in allergic diseases.