Short-term administration of Qipian®, a mixed bacterial lysate, inhibits airway inflammation in ovalbumin-induced mouse asthma by modulating cellular, humoral and neurogenic immune responses.

AIMS: Qipian® is a commercialized agent composed of extracts of three genera of commensal bacteria, and its mechanism of action on asthma is unclear. This study aimed to examine the impact of Qipian® on airway inflammation and investigate the underlying mechanisms. MATERIALS AND METHODS: Qipian® or dexamethasone (DEX) was administered before OVA challenge in an ovalbumin-induced asthma mouse model, and then asthmatic symptoms were observed and scored. Samples of lung tissues, blood, and bronchoalveolar lavage fluid (BALF) were collected, and eosinophils (Eos), immunoglobins (Igs), and type 1 T helper (Th1)/Th2 cell cytokines were measured. Mucus production in the lung was assessed by periodic acid-Schiff (PAS) staining. The effects of Qipian® on dendritic and T regulatory (Treg) cells were investigated using flow cytometry. KEY FINDINGS: The short-term administration of Qipian® significantly inhibited the cardinal features of allergic asthma, including an elevated asthmatic behaviour score, airway inflammation and immune response. Histological analysis of the lungs showed that Qipian® attenuated airway inflammatory cell infiltration and mucus hyperproduction. Qipian® restored Th1/Th2 imbalance by decreasing interleukin (IL)-4, IL-5, and IL-13 while increasing interferon (IFN)-γ and IL-10. Further investigation revealed that Qipian® treatment induced the upregulation of CD4+CD25+Foxp3+ Treg cells and CD103+ DCs and downregulation of tachykinins neurokinin A (NKA) and NKB in the lung. SIGNIFICANCE: Our findings suggested that short-term treatment with Qipian® could alleviate inflammation in allergic asthma through restoring the Th1/Th2 balance by recruiting Treg cells to airways and inducing the proliferation of CD103+ DCs, which actually provides a new treatment option for asthma.

CD4+TGFß+ cells infiltrated the bursa of Fabricius following IBDV infection, and correlated with a delayed viral clearance, but did not correlate with disease severity, or immunosuppression.

Introduction: Infectious Bursal Disease Virus (IBDV) causes immunosuppression in chickens. While B-cell destruction is the main cause of humoral immunosuppression, bursal T cells from IBDV-infected birds have been reported to inhibit the mitogenic response of splenocytes, indicating that some T cell subsets in the infected bursa have immunomodulatory activities. CD4+CD25+TGFß+ cells have been recently described in chickens that have immunoregulatory properties and play a role in the pathogenesis of Marek's Disease Virus. Methods: To evaluate if CD4+CD25+TGFß+ cells infiltrated the bursa of Fabricius (BF) following IBDV infection, and influenced the outcome of infection, birds were inoculated at either 2 days or 2 weeks of age with vaccine strain (228E), classic field strain (F52/70), or PBS (mock), and bursal cell populations were quantified by flow cytometry. Results: Both 228E and F52/70 led to atrophy of the BF, a significant reduction of Bu1+-B cells, and a significant increase in CD4+ and CD8α+ T cells in the BF, but only F52/70 caused suppression of immune responses to a test antigen in younger birds, and clinical signs in older birds. Virus was cleared from the BF more rapidly in younger birds than older birds. An infiltration of CD4+CD25+T cells into the BF, and elevated expression of bursal TGFß-1+ mRNA was observed at all time points following infection, irrespective of the strain or age of the birds, but CD4+TGFß+cells and CD4+CD25+TGFß+ cells only appeared in the BF at 28 dpi in younger birds. In older birds, CD4+TGFß+ cells and CD4+CD25+TGFß+ cells were present at earlier time points, from 7dpi following 228E infection, and from 14 and 28 dpi following F52/70 infection, respectively. Discussion: Our data suggest that an earlier infiltration of CD4+TGFß+ cells into the BF correlated with a delayed clearance of virus. However, the influx of CD4+TGFß+ cells and CD4+CD25+TGFß+ into the BF did not correlate with increased pathogenicity, or immunosuppression.

Clinical significance of B7-H3 expression in circulating CD4+CD25high T cells, CD14+ monocytes, and plasma for the progression of HIV infection.

BACKGROUND: B7-H3 is an important immune checkpoint molecule that plays a negative role in immune regulation. This study was aimed to explore B7-H3 expression in HIV-infected patients and its clinical significance. METHODS: To explore the expression and clinical significance of B7-H3 in HIV-infected patients, we investigated the B7-H3 expression pattern and the correlation of B7-H3 expression with clinical parameters of HIV-infected patients with different levels of CD4+ T cells. To assess the role of B7-H3 in regulating the function of T cells in HIV infection, we performed a proliferation assay and T cell function test in vitro. RESULTS: B7-H3 expression in HIV-infected patients was significantly higher than that in healthy controls. mB7-H3 expression on CD4+CD25high T cells and CD14+ monocytes increased with disease progression. mB7-H3 expression on CD4+CD25high T cells and monocytes was negatively correlated with lymphocyte count, CD4+T cell count, and positively correlated with HIV viral load in HIV-infected patients. when the number of CD4+ T cells in HIV-infected patients was ≥ 200/µL, sB7-H3 and mB7-H3 expression levels on CD4+CD25high T cells and monocytes were negatively correlated with lymphocyte count, CD4+T cell count. sB7-H3 and mB7-H3 expression on monocytes were positively correlated with HIV viral load. B7-H3 inhibited the proliferation of lymphocytes and the secretion of IFN-γ in vitro, especially the ability of CD8+ T cells to secrete IFN-γ. CONCLUSIONS: B7-H3 played an important negative regulatory role in anti-HIV infection immunity. It could be used as a potential biomarker for the progression of HIV infection and a novel target for the treatment of HIV infection.

Peripheral CD4+CD25hiCD127low regulatory T cells are increased in patients with gastrointestinal cancer.

BACKGROUND: Regulatory T cells (Tregs) play an important role in regulation of immune response and immunologic tolerance in cancer. Gastrointestinal cancer is still a leading cause of cancer-related death in the world. This study aimed to detect Tregs in patients with gastrointestinal cancer. METHODS: In this study, 45 gastric cancer patients, 50 colorectal cancer patients and 50 healthy controls were enrolled. Flow cytometry was used to detect CD4+CD25hiCD127low Tregs, CD4+CD25hi, and CD4+ cells in peripheral blood. Cytokine interleukin-10 (IL-10) and transforming growth factor-ß1 (TGF-ß1) in peripheral blood and in the supernatant of Tregs cultures were measured by enzyme linked immunosorbent assay. RESULTS: Compared with healthy controls, the levels of CD4+CD25hiCD127low Tregs and CD4+CD25hi cells increased significantly in patients with gastrointestinal cancer. Patients with gastrointestinal cancer also showed a significantly increased levels of IL-10 and TGF-ß1 in both peripheral blood and CD4+CD25hiCD127low Tregs culture medium. CONCLUSION: The present study firstly demonstrated that gastrointestinal patients have a compromised immune status where the CD4+CD25hiCD127low Tregs, as well as levels of IL-10 and TGF-ß1 are elevated. The data offered new information for understanding the immunological features of gastrointestinal patients, as well as provided new insights into approaches to develop new immunotherapies for patients with gastrointestinal cancer.

Leptin Deficiency May Influence the Divergence of Cell-Mediated Immunity Between Lepromatous and Tuberculoid Leprosy Patients.

Leprosy is a disease caused by an intracellular bacillus bacterium called Mycobacterium leprae which lives and multiplies in the hosts' macrophages and Schwann cells. Depending on the degree of the host's cell-mediated immunity (CMI) response to the bacilli, the disease manifests itself in five clinical spectra ranging from polar tuberculoid (TT) to polar lepromatous leprosy (LL). A very high level of T helper 1 (Th1) driven bacilli-specific CMI is seen in the TT form, whereas this response is essentially nonexistent in the LL form. As a result, there is very low or absent bacillary load and localized nodular lesions in TT patients. On the contrary, LL patients presented with high bacillary load and generalized lesions due to low CMI response. The mechanism underlying this divergence of CMI response is not clearly elucidated yet. However, mounting evidence links it to an elevated number of Th1 and Th17 suppressing CD4+ CD25+ FOXP3+ T regulatory cells (Treg cells) which are abundantly found in LL than in TT patients. The predominance of these cells in LL patients is partly attributed to a deficiency of leptin, the cytokine-like peptide hormone, in these patients. Becausea normal level of leptin promotes the proliferation and preferential differentiation of effector T cells (Th1 and Th17) while inhibiting the growth and functional responsiveness of the Treg cells. In contrast, leptin deficiency or neutralization was reported to exert the opposite effect on Treg cells and effector T cells. Other smaller subsets of lymphocytes such as gamma delta (γδ) T cells and B regulatory cells are also modulated by leptin level in the pathogenesis of leprosy. Leptin may therefore regulate the divergence of CMI between TT and LL patients by regulating the homeostasis of effector T cells and Treg cells, and this review will examine the underlying mechanism for this.

The proportion and phenotypic changes of CD4+CD25-Foxp3+ T cells in patients with untreated rheumatoid arthritis.

OBJECTIVE: CD4+CD25+Foxp3+ regulatory T (Treg) cell-mediated immunosuppression is an essential mechanism of rheumatoid arthritis (RA). However, little is known regarding the specific role of CD4+CD25-Foxp3+ Treg cells in RA. This study aimed to investigate the frequency of circulating CD4+CD25-Foxp3+ Treg cells and their role in RA. METHODS: Sixty-one untreated RA patients and 40 healthy controls (HCs) were enrolled in this study. The proportion of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs; the levels of CTLA4, GITR, Helios, and ICOS; and the production of IL-17A, IFN-γ, and IL-10 were assessed by flow cytometry. The correlation of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs with the clinical indicators was conducted by Spearman correlation analysis. RESULTS: The proportion of CD4+CD25-Foxp3+ T cells was elevated in RA and positively correlated with disease activity. CD4+CD25-Foxp3+ T cells expressed less Helios and produced more IFN-γ than conventional Tregs in RA. Additionally, the proportion of CD4+CD25-Foxp3+ T cells was positively correlated with DAS28 score, IgG titer, and anti-CCP titer. CONCLUSIONS: These data indicate that CD4+CD25-Foxp3+ T cells in RA exhibit several different functional properties from conventional Tregs and are correlated with RA disease activity.

Therapeutic effects of Hirudo medicinalis extract antigens on modulation of CD4+CD25+Foxp3 T cell activity in murine eimeriosis.

Eimeriosis is a common parasitic disease in the chicken industry. The aim of this study was to assess the protective role of Hirudo extract antigens (HEA) against murine eimeriosis induced by Eimeria papillate. The oocyst output, developmental stages, goblet cells and oxidative stress, were investigated. Immunohistochemistry was used to detect anti-apoptotic Bcl2 marker and the number of both CD4+ and CD25+ cells in jejunal tissue, while ELISA was used to quantify TGF-ß, IL-10 and IL-22 in jejunal tissue homogenate. Real-time PCR was also used to detect mRNA expression of mucin 2 (MUC2), inducible nitric oxide synthase (iNOS), IL-1ß, IFN-γ, TNF-α, IL-6, and FoxP3. The most effective dose (5 µg/mice) reduced the oocyst output by 82.95 ± 1.02% (P ˂ 0.001). Similarly, the same dose reduced the jejunal developmental stages by 66.67 ± 0.49% (P ˂ 0.001). Furthermore, HEA therapy increased the number of jejunal goblet cells by 12.8 ± 1 (P ˂ 0.001) and the expression of MUC2 by 0.83 ± 0.06 (P ˂ 0.001). In contrast, TNF-α, IFN-γ, IL-6, iNOS, and IL-1ß expression as well as apoptosis were reduced. The number of CD4+ and CD25+ in the jejunal tissue was increased (14.6 ± 1.2 (P ˂ 0.001), 6.84 ± 1 (P ˂ 0.01), respectively) after HEA therapy. The molecular analysis showed an increased expression of intestinal Foxp3 (3.2 ± 0.13 (P ˂ 0.001), while IL-22 was reduced (124 ± 10 (P ˂ 0.001)) versus an increase in TGF-ß (250 ± 17 (P ˂ 0.01)) and IL-10 (236 ± 16 (P ˂ 0.001)) after HEA treatment in comparison to the non-treated infected group. With respect to the infected group, HEA reduced lipid peroxidation (LPO) (15.7 ± 1.12 (P ˂ 0.001)) and nitric oxide (NO) (13 ± 1.3 (P ˂ 0.001)) but increased reduced glutathione (GSH) (3.7 ± 0.26 (P ˂ 0.001)). In conclusion, HEA therapy protected against intestinal tissue damage by activation of CD4+CD25+Foxp3 cells which showed anti-inflammatory action. Hence, HEA can be recommended as a therapeutic treatment for eimeriosis.

Elevated apoptosis and abnormal apoptosis signaling of regulatory T cells in patients with systemic lupus erythematosus.

In systemic lupus erythematosus (SLE), immune tolerance is influenced by defects in naturally occurring T cells (Tregs). To investigate the apoptosis rate of Tregs and their suppressive activity in patients with SLE and then to recognize the genes and signaling pathways that cause Treg apoptosis. FACS was used to assess the frequency and apoptosis rates of Tregs in 48 SLE patients and 28 normal controls (NCs). Coculture of Tregs with CD4+CD25-CD127dim/- T cells was used to assess the suppressive activity of Tregs. Microarray analysis was used to generate unstimulated Tregs gene expression profiles from very high activity patients with SLE and NCs. Real-time PCR was used to confirm differential gene expression. In patients with SLE, the frequency of Tregs was substantially reduced compared to Tregs from NCs. Furthermore, Tregs from SLE patients had an elevated rate of apoptosis and a lower suppressing ability than Tregs from NCs. Tregs apoptosis was negatively associated with the total count of Tregs and positively related to disease activity. Unstimulated Tregs gene expression profiles from patients with recent-onset SLE revealed a biological response that can cause apoptosis, partially triggered by stress, DNA damage, and cytokine stimulation. The discovery of pathway-specific expression signatures is a significant step forward in understanding how Tregs defects contribute to the pathogenesis of SLE. Our findings may contribute to the development of new strategies for treating SLE based on abnormal Tregs apoptosis and restoring immune homeostasis in patients with SLE.

Chronic Exposure to the Combination of Cigarette Smoke and Morphine Decreases CD4+ Regulatory T Cell Numbers by Reprogramming the Treg Cell Transcriptome.

There is a high incidence of tobacco use among intravenous opioid drug users. It is well established that opioids and tobacco smoke induce a degree of immune activation, and recent work suggests that the combination of these drugs promotes further activation of the immune system. Our approach involved the treatment of wild-type mice with cigarette smoke (SM) for a period of eight weeks, and the chronic continuous administration of morphine (M) via mini-pumps for the final four weeks. In an effort to examine the responses of CD4+CD25highCD127low regulatory T (Treg) cells, the major immune suppressive cell type, to the combined chronic administration of SM and M, we determined the frequency of these cells in the spleen, lymph nodes and lungs. Flow cytometric analyses showed that SM and M individually, and the combination (SM + M) have differential effects on the numbers of Treg in the spleen, lymph node, and lung. Either SM or M alone increased Treg cell numbers in the spleen, but SM+M did not. Furthermore, SM + M decreased Treg cell numbers in the lymph node and lung. We then performed RNA-Seq on Treg cells from mice treated with SM, M, or SM + M, and we found that the S + M induced a number of significant changes in the transcriptome, that were not as apparent following treatment with either SM or M alone. This included an activation of TWEAK, PI3K/AKT and OXPHOS pathways and a shift to Th17 immunity. Our results have provided novel insights on tissue Treg cell changes, which we suggest are the result of transcriptomic reprogramming induced by SM, M, and SM + M, respectively. We believe these results may lead to the identification of novel therapeutic targets for suppressing smoke and opioid induced Treg cell impairment.

Progesterone modulates CD4+ CD25+ FoxP3+ regulatory T Cells and TGF-ß1 in the maternal-fetal interface of the late pregnant mouse.

OBJECTIVE: Progesterone supplementation is recommended to prevent spontaneous preterm birth (sPTB) in clinical practice. However, the exact mechanism is still unclear. This study aims to better understand the mechanisms that progesterone can prevent PTB. METHODS: Late pregnant mice were given various doses of progesterone receptor antagonist mifepristone, and pregnancy outcomes were observed. Then, non-pregnant and pregnant mice were given a subcutaneous injection of 40 mg/kg progesterone and 5 mg/kg mifepristone, respectively. CD4+ CD25+ FoxP3+ Treg cells in peripheral blood and decidua basalis were detected by FACS. Expressions of FoxP3 and TGF-ß1 in the decidua basalis were detected. RESULTS: Mifepristone induced preterm birth, and an obvious dose-response was found. Proportions of CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of non-pregnant mice increased significantly after progesterone injection. CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of pregnant mice increased significantly compared with those of non-pregnant mice. In pregnant mice, mifepristone significantly decreased the proportions of CD4+ CD25+ FoxP3+ Treg cells in peripheral blood, and reduced proportions of Treg cells at the maternal-fetal interface and expressions of FoxP3 and TGF-ß1 in the maternal-fetal interface. Total 40 mg/kg of progesterone did not increase CD4+ CD25+ FoxP3+ Treg in the peripheral blood of pregnant mice, but increased proportions of Treg cells at the maternal-fetal interface and up-regulated FoxP3 and TGF-ß1 expressions in the maternal-fetal interface. CONCLUSION: Progesterone promotes pregnancy immune homeostasis by up-regulating Treg cells and TGF-ß1 expression in the maternal-fetal interface. It may be one of the mechanisms of progesterone in preventing sPTB.

Short- and long-term effects of antiretroviral therapy on peripheral regulatory CD4+/CD25hi/CD127low T lymphocytes in people living with HIV/AIDS

ABSTRACT The effect of antiretroviral therapy (ART) on CD4+/CD25hi/CD127low T lymphocyte changes in people living with HIV/AIDS (PLWHA) is still a matter of debate. From October 2015 to December 2019, peripheral blood from 70 cases of PLWHA were collected for the detection of CD4+/CD25hi/CD127low T lymphocytes by flow cytometry. Statistical analysis was performed to detect changes of CD4+/CD25hi/CD127low T lymphocytes in patients with different duration of ART and different treatment effects. We found that the number of CD4+/CD25hi/CD127low T lymphocytes in ART-naive PLWHA were lower than those in healthy volunteers (10.3±٦.٠ cells/uL vs 31.7±8.0 cells/uL, P < 0.05). CD4+/CD25hi/CD127low T lymphocyte counts increased to 17.8±٤.٠ cells/uL 6 months post-ART and 25.0±١١.٩ cells/uL 9 months post-ART, respectively (P < 0.05). There was no significant difference in CD4+/CD25hi/CD127low T lymphocyte counts between PLWHA who reached a complete immune reconstruction after ART and healthy volunteers. The growth of CD4+/CD25hi/CD127low T lymphocyte counts in patients who had baseline CD4 > 200 cells/uL was greater than those who had baseline CD4 ≤ 200 cells/uL (12.6±٤.٦ cells/uL vs 5.6±٥.٠ cells/uL, P = 0.027). CD4+/CD25hi/CD127low T lymphocyte counts were positively correlated with CD4+ T lymphocyte counts (r = 0.923, P < 0.001) and CD4+/CD8+ ratio (r = 0.741, P < 0.001), but were negatively correlated with HIV-VL (r = −0.648, P = 0.000). In conclusion, the results of the present study showed that changes in CD4+/CD25hi/CD127low T lymphocyte counts can be used to assess the effect of ART in PLWHA.

Diacetyl Vapor Inhalation Induces Mixed, Granulocytic Lung Inflammation with Increased CD4+CD25+ T Cells in the Rat.

Diacetyl (DA) is a highly reactive alpha diketone associated with flavoring-related lung disease. In rodents, acute DA vapor exposure can initiate an airway-centric, inflammatory response. However, this immune response has yet to be fully characterized in the context of flavoring-related lung disease progression. The following studies were designed to characterize the different T cell populations within the lung following repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor for 5 consecutive days × 6 h/day. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for changes in histology by H&E and Trichrome stain, T cell markers by flow cytometry, total BALF cell counts and differentials, BALF IL17a and total protein immediately, 1 and 2 weeks post-exposure. Lung histology and BALF cell composition demonstrated mixed, granulocytic lung inflammation with bronchial lymphoid aggregates at all time points in DA-exposed lungs compared to air controls. While no significant change was seen in percent lung CD3+, CD4+, or CD8+ T cells, a significant increase in lung CD4+CD25+ T cells developed at 1 week that persisted at 2 weeks post-exposure. Further characterization of this CD4+CD25+ T cell population identified Foxp3+ T cells at 1 week that failed to persist at 2 weeks. Conversely, BALF IL-17a increased significantly at 2 weeks in DA-exposed rats compared to air controls. Lung CD4+CD25+ T cells and BALF IL17a correlated directly with BALF total protein and inversely with rat oxygen saturations. Repetitive DA vapor exposure at occupationally relevant concentrations induced mixed, granulocytic lung inflammation with increased CD4+CD25+ T cells in the rat lung.

Mesenchymal Stem Cell Induced Foxp3(+) Tregs Suppress Effector T Cells and Protect against Retinal Ischemic Injury.

Mesenchymal stem/stromal cells (MSC) are well known for immunomodulation; however, the mechanisms involved in their benefits in the ischemic retina are unknown. This study tested the hypothesis that MSC induces upregulation of transcription factor forkhead box protein P3 (Foxp3) in T cells to elicit immune modulation, and thus, protect against retinal damage. Induced MSCs (iMSCs) were generated by differentiating the induced pluripotent stem cells (iPSC) derived from urinary epithelial cells through a noninsertional reprogramming approach. In in-vitro cultures, iMSC transferred mitochondria to immune cells via F-actin nanotubes significantly increased oxygen consumption rate (OCR) for basal respiration and ATP production, suppressed effector T cells, and promoted differentiation of CD4+CD25+ T regulatory cells (Tregs) in coculture with mouse splenocytes. In in-vivo studies, iMSCs transplanted in ischemia-reperfusion (I/R) injured eye significantly increased Foxp3+ Tregs in the retina compared to that of saline-injected I/R eyes. Furthermore, iMSC injected I/R eyes significantly decreased retinal inflammation as evidenced by reduced gene expression of IL1ß, VCAM1, LAMA5, and CCL2 and improved b-wave amplitudes compared to that of saline-injected I/R eyes. Our study demonstrates that iMSCs can transfer mitochondria to immune cells to suppress the effector T cell population. Additionally, our current data indicate that iMSC can enhance differentiation of T cells into Foxp3 Tregs in vitro and therapeutically improve the retina's immune function by upregulation of Tregs to decrease inflammation and reduce I/R injury-induced retinal degeneration in vivo.

The Association of Circulating CD14++CD16+ Monocytes, Natural Killer Cells and Regulatory T Cells Subpopulations With Phenotypes of Cardiovascular Disease in a Cohort of Peritoneal Dialysis Patients.

The altered expression of immune cells including monocyte subsets, natural killer (NK) cells and CD4+CD25+ regulatory T cells (Tregs) in end-stage kidney disease, affect the modulation of inflammation and immunity with significant clinical implications. The aim of this study was to investigate the profile of specific immune cells subpopulations and their correlations with phenotypes of established cardiovascular disease (CVD), including coronary artery disease (CAD) and heart failure (HF) in peritoneal dialysis (PD) patients. Materials and Methods: 29 stable PD patients and 13 healthy volunteers were enrolled. Demographic, laboratory, bioimpedance measurements, lung ultrasound and echocardiography data were collected. The peripheral blood immune cell subsets analysis was performed using flow cytometry. Results: PD patients compared to normal controls had lower total lymphocytes (22.3 ± 6.28 vs. 31.3 ± 5.54%, p = <0.001) and B-lymphocytes (6.39 ± 3.75 vs. 9.72 ± 3.63%, p = 0.01) as well as higher CD14++CD16+ monocytes numbers (9.28 ± 6.36 vs. 4.75 ± 2.75%, p = 0.0002). PD patients with prevalent CAD had NK cells levels elevated above median values (85.7 vs. 40.9%, p = 0.04) and lower B cells counts (3.85 ± 2.46 vs. 7.2 ± 3.77%, p = 0.03). Patients with increased NK cells (>15.4%) had 3.8 times higher risk of CAD comparing with patients with lower NK cell levels (95% CI, 1.86 - 77.87; p = 0.034). B cells were inversely associated with the presence of CAD (increase of B-lymphocyte by 1% was associated with 30% less risk for presence of CAD (95% CI, -0.71 - 0.01; p = 0.05). Overhydrated patients had lower lymphocytes counts (18.3 ± 4.29% vs. 24.7 ± 6.18%, p = 0.006) and increased NK cells [20.5% (14.3, 23.6) vs. 13.21% (6.23, 19.2), p = 0.04)]. In multiple logistic regression analysis the CRP (OR 1.43; 95% CI, 1.00 - 2.05; p = 0.04)] and lymphocytes counts (OR 0.79; 95% CI, 0.63-0.99; p = 0.04)] were associated with the presence of lung comets. Patients with higher NK cells (>15.4%, n = 15) were more likely to be rapid transporters (D/P creatinine 0.76 ± 0.1 vs. 0.69 ± 0.08, p = 0.04). Patients displaying higher Tregs (>1.79%) were older (70.8 ± 10.7 years vs. 57.7 ± 14.7years, p = 0.011) and had higher nPCR (0.83 ± 0.14 vs. 0.91 ± 0.17, p = 0.09). Conclusion: Future research is required to evaluate the role of immune cells subsets as potential tools to identify patients at the highest risk for complications and guide interventions.

Microglia/Macrophages and CD4+CD25+ T Cells Enhance the Ability of Injury-Activated Lymphocytes to Reduce Traumatic Optic Neuropathy In Vitro.

Inflammation after acute CNS injury plays a dual role. The interplay between immune cells and inflammatory mediators is critical to the outcome of injured neurons. Microglia/macrophages are the first sensors and regulators of the immune response. We previously found that the enhancement of macrophages on neuron survival does not persist in thymectomized rats. How T lymphocytes and macrophages interact and benefit neuron survival is not fully elucidated. To this point, we introduce and characterize a cell-retina co-culture model that mimics the recruitment of peripheral lymphocytes at the injury site. Three-day post-optic nerve transection (ONT) in Fischer 344 rats, transected retinas were co-cultured with either peripheral lymph node-derived lymphocytes (injury-activated) or from intact rats as the control. The injury-activated lymphocytes preserved retinal ganglion cells (RGCs) and caused extensive retina microglial/macrophage infiltration. CD4+CD25+ T cells were upregulated in the injury-activated lymphocytes and increased RGC survival, suggesting that CD4+CD25+ T cells suppressed the cytotoxicity of control lymphocytes. When microglia/macrophages were depleted by clodronate, neuron loss was more extensive, the cytotoxicity of control lymphocytes on RGCs was alleviated, and the neuroprotective effect of injury-activated lymphocytes remain unchanged Cytokine detection showed an increase in IL-6 and TNF-α levels that were reduced with microglia/macrophage depletion. Our results suggest that microglial/macrophage infiltration into axotomized retinas promotes RGC survival by secreting cytokines to induce CD4+CD25+ T cells and suppress T cell-mediated RGC toxicity. These findings reveal a specific role for microglia/macrophage and CD4+CD25+ T cells in inflammation after CNS injury, thereby adding to the mechanistic basis for the development of microglial/macrophage modulation therapy for traumatic CNS injury.

High-frequency and activation of CD4+CD25+ T cells maintain persistent immunotolerance induced by congenital ALV-J infection.

Congenital avian leukosis virus subgroup J (ALV-J) infection can induce persistent immunotolerance in chicken, however, the underlying mechanism remains unclear. Here, we demonstrate that congenital ALV-J infection induces the production of high-frequency and activated CD4+CD25+ Tregs that maintain persistent immunotolerance. A model of congenital infection by ALV-J was established in fertilized eggs, and hatched chicks showed persistent immunotolerance characterized by persistent viremia, immune organ dysplasia, severe imbalance of the ratio of CD4+/CD8+ T cells in blood and immune organs, and significant decrease in CD3+ T cells and Bu-1+ B cells in the spleen. Concurrently, the mRNA levels of IL-2, IL-10, and IFN-γ showed significant fluctuations in immune organs. Moreover, the frequency of CD4+CD25+ Tregs in blood and immune organs significantly increased, and the frequency of CD4+CD25+ Tregs was positively correlated with changes in ALV-J load in immune organs. Interestingly, CD4+CD25+ Tregs increased in the marginal zone of splenic nodules in ALV-J-infected chickens and dispersed to the germinal center. In addition, the proliferation and activation of B cells in splenic nodules was inhibited, and the number of IgM+ and IgG+ cells in the marginal zone significantly decreased. We further found that the mRNA levels of TGF- ß and CTLA-4 in CD4+CD25+ Tregs of ALV-J-infected chickens significantly increased. Together, high-frequency and activated CD4+CD25+ Tregs inhibited B cells functions by expressing the inhibitory cytokine TGF-ß and inhibitory surface receptor CTLA-4, thereby maintaining persistent immunotolerance in congenital ALV-J-infected chickens.

Impaired T helper cell responses in human immunodeficiency virus-exposed uninfected newborns.

INTRODUCTION: HIV-exposed uninfected (HEU) newborns suffer from higher risks of opportunistic infections during the first months of life compared to HIV-unexposed uninfected (HUU) newborns. Alterations in thymic mass, amounts of T helper (Th) cells, T-cell receptor diversity, and activation markers have been found in HEU newborns, suggesting alterations in T cell ontogeny and differentiation. However, little is known about the ability of these cells to produce specialized Th responses from CD4+ T cells. METHOD: To characterize the Th cell profile, we evaluated the frequency of Th1 (CD183+ CD194- CD196- /CXCR3+ CCR4- CCR6- ), Th2 (CD183- CD194+ CD196- /CXCR3- CCR4+ CCR6- ), Th17 (CD183- CD194+ CD196+ /CXCR3- CCR4+ CCR6+ ), and CD4+ CD25++ blood T-cell phenotypes in 50 HEU and 25 HUU newborns. Early activation markers on CD4+ T cells and the Th cytokine profile produced from mononuclear cells under polyclonal T cell stimulation were also studied. Additionally, we probed the ability of CD4+ T cells to differentiate into interferon (IFN)-γ-producing Th1 CD4+ T cells in vitro. RESULTS: Lower percentages of differentiated Th1 , Th2 , Th17, and CD4+ CD25++ T cells were found in blood from HEU newborns than in blood from HUU newborns. However, polyclonally stimulated Th cells showed a similar ability to express CD69 and CD279 but produced less secreted interleukin (IL)-2 and IL-4. Interestingly, under Th1 differentiation conditions, the percentages of CD4+ IFN-γ+ T cells and soluble IFN-γ were higher in HEU newborns than in HUU newborns. CONCLUSION: HEU neonates are born with reduced proportions of differentiated Th1 /Th2 /Th17 and CD4+ CD25++ T cells, but the intrinsic abilities of CD4+ T cells to acquire a Th1 profile are not affected by the adverse maternal milieu during development.

Extracellular vesicles of Echinococcus granulosus have therapeutic effects in allergic airway inflammation.

BACKGROUND: Previous studies have shown that Echinococcus granulosus cystic fluid can alleviate Th2 allergic airway inflammatory responses by increasing the number of CD4+ CD25+ Foxp3+ T (regulatory T; Treg) cells. Parasite-derived extracellular vesicles (EV) are known to not only promote parasite infection by communicating between parasites but also regulate the inflammatory response by acting as an immunomodulatory agent in the host. METHODS: To evaluate the effect of EV extracted from the cystic fluid of E. granulosus on allergic airway inflammation, gene expression was investigated after administering EV to mouse lung epithelial cells (MLE-12) following 2 h of pretreatment with Aspergillus proteins. An allergic airway inflammation animal model was used to investigate the regulation of the inflammatory response by EV and induced with ovalbumin. RESULTS: EV treatment significantly reduced airway resistance and the number of eosinophils and other immune cells in the bronchoalveolar lavage fluid and Th2- and Th17-related cytokine levels. EV pretreatment decreased the number of IL-4+ CD4+ T cells and increased the number of Treg cells in the lung-draining lymph nodes and spleen. CONCLUSIONS: Echinococcus granulosus cystic fluid derived EV ameliorated Th2 allergic airway inflammatory through Treg cells, similar to whole cystic fluid treatment. Thus, EV may be important immunomodulatory molecules in cystic fluid.

Taurine promotes the production of CD4+CD25+FOXP3+ Treg cells through regulating IL-35/STAT1 pathway in a mouse allergic rhinitis model.

BACKGROUND: Allergic rhinitis (AR) is one of the most widespread immune conditions worldwide. However, common treatments often present with significant side effects or are cost-prohibitive for much of the population. A plethora of treatments have been used for the treatment of AR including antihistamines, steroids, and immune modulators. Among the treatments which have shown potential for efficacy in treating AR with a minimum of side effects but remains understudied is the conditionally essential amino acid taurine. Taurine has been previously shown to reduce AR symptoms. Here, we examine the role of taurine in modulating T regulatory cells, modulating the cytokine response in AR, and restoring healthy nasal mucosa. METHODS: Blood samples from 20 healthy donors and 20 AR patients were compared for CD4+CD25+FoxP3+ T regulatory (Treg) cell population percentage, cytokine release, and STAT1 signaling with and without taurine treatment or IL-35 neutralization. An OVA-induced AR mouse model was administered vehicle, taurine, or taurine plus an IL-35 neutralizing antibody and assayed for sneezing frequency, inflammatory cytokine response, nasal mucosa goblet cell density, and T regulatory cell percentage. CD4+ cells were further examined for cytokine release, STAT1 phosphorylation, and response to an anti-IL-35 antibody with and without a STAT1 inhibitor. RESULTS: Comparison of blood from normal donors and AR patients showed a reduction in CD4+CD25+FoxP3+ Treg cells in AR patients and a strong correlation between Treg percentage and IL-35 release. A similar pattern of Treg suppression was found in untreated AR mice when compared to normal control mice wherein there was a reduction in Treg percentage and a corresponding decrease in IL-35 release. AR mice also demonstrated increased sneezing frequency, an infiltration of goblet cell in nasal mucosa, and a reduction in IL-35 release from CD4+ cells. Conversely, IL-4, IL-5, and IL-13 secretion from CD4+ cells were increased in AR model mice, as was STAT1 phosphorylation. When AR mice were treated with taurine, sneezing frequency and nasal mucosa goblet cell content were reduced while Treg abundance was increased to that of normal mice. Accordingly, IL-35 release was restored, while IL-4, IL-5, and IL-13 secretion from CD4+ cells were suppressed. Likewise, STAT1 phosphorylation was inhibited with taurine treatment. Taurine-treated mice also given an IL-35 neutralizing antibody exhibited AR pathology including frequent sneezing and high nasal goblet cell content while retaining a restoration of Tregs. Furthermore, murine AR model CD4+ cells exposed to recombinant IL-35 responded with a reduction in inflammatory cytokine release and a decrease in STAT1 phosphorylation, mimicking the effect of taurine treatment. CONCLUSIONS: Taurine induces release of IL-35 in AR; IL-35 promotes the production of CD4+CD25+FoxP3+ Treg cells via a STAT1-dependent pathway. The restoration of Treg populations by taurine normalizes the inflammatory response, reduces AR symptomology, and reduces histopathologic signs of AR.

Temporal and spatial characterization of negative regulatory T cells in HIV-infected/AIDS patients raises new diagnostic markers and therapeutic strategies.

BACKGROUND: Negative regulatory T cells (Tregs) not only deplete effector T cells but also inhibit the clearance of HIV during infection, which may allow Tregs to be used as informative diagnostic markers. To facilitate both diagnosis and treatment, a thorough understanding of these regulators by characterizing them on temporal and spatial scales is strongly required. METHODS: Hundred HIV-infected/AIDS patients, including 87 males, with an average age of 35.8 years, as well as 20 healthy controls, were enrolled. Flow cytometry was used to analyze CD3+T cells, CD4+T cells, and CD8+T cells to evaluate the immune status of the participants. Then, a group of representative negative regulatory T cells, including CD4+PD-1+T cells, CD4+PD-1high T cells, CD8+PD-1+T cells, and CD4+CD25high Tregs was also analyzed to explore their effects on disease progression and intercorrelation. RESULTS: The percentages of CD4+ PD-1+ T cells and CD4+ CD25high Tregs increased in patients with the same ultrahigh significance. Temporally, the patients with both intermediate-stage and late-stage disease had higher percentages of CD4+ PD-1+ T cells; however, the percentage of CD4+ CD25high Tregs only increased in the patients with late-stage disease. In addition, CD4+ PD-1+ T cells but not CD4+ CD25high Tregs were negatively correlated with the absolute CD4+ T cell count. Spatially, no correlations between CD4+ PD-1+ T cells and CD4+ CD25high Tregs were observed, which suggests these Tregs function differently during immunosuppression. CONCLUSIONS: This study characterized negative regulatory T cells in HIV-infected/AIDS patients at both temporal and spatial scales and found that CD4+ CD25+ Tregs and CD4+ PD-1+ T cells could be used as potential diagnostic markers for identifying different disease stages and monitoring disease progression.