Circulating CD4+ CXCR5+ T cells contribute to proinflammatory responses in multiple ways in coronary artery disease

Coronary artery disease (CAD) is a common subtype of cardiovascular disease. The major contributing event is atherosclerosis, which is a progressive inflammatory condition resulting in the thickening of the arterial wall and the formation of atheromatous plaques. Recent evidence suggests that circulating CD4⁺ CXCR5⁺ T cells can contribute to inflammatory reactions. In this study, the frequency, phenotype, and function of circulating CD4⁺ CXCR5⁺ T cells in CAD patients were examined. Data showed that circulating CD4⁺ CXCR5⁺ T cells in CAD patients were enriched with a PD-1⁺ CCR7⁻ subset, which was previously identified as the most potent in B cell help. The CD4⁺ CXCR5⁺ T cells in CAD patients also secreted significantly higher levels of IFN-γ, IL-17A, and IL-21 than those from healthy controls. Depleting the PD-1⁺ population significantly reduced the cytokine secretion. Interestingly, the CD4⁺ CXCR5⁺ PD-1⁻ T cells significantly upregulated PD-1 following anti-CD3/CD28 or SEB stimulation. CD4⁺ CXCR5⁺ T cells from CAD patients also demonstrated more potent capacity to stimulate B cell inflammation than those from healthy individuals. The phosphorylation of STAT1 and STAT3 were significantly higher in B cells incubated with CD4⁺ CXCR5⁺ T cells from CAD than controls. The IL-6 and IFN-γ expression were also significantly higher in B cells incubated with CD4⁺ CXCR5⁺ T cells from CAD. Together, this study demonstrated that CAD patients presented a highly activated CD4⁺ CXCR5⁺ T cell subset that could contribute to proinflammatory responses in multiple ways. The possibility of using CD4⁺ CXCR5⁺ T cells as a therapeutic target should therefore be examined in CAD patients.     

CXCR5+ CD8+ T cells could induce the death of tumor cells in HBV-related hepatocellular carcinoma

The follicular CXCR5⁺ CD8⁺ T cells have recently emerged as a critical cell type in mediating peripheral tolerance as well as antiviral immune responses during chronic infections. In this study, we investigated the function of CXCR5⁺ CD8⁺ T cells in HBV-related hepatocellular carcinoma patients. Compared to CXCR5⁻ CD8⁺ T cells, CXCR5⁺ CD8⁺ T cells presented elevated PD-1 expression but reduced Tim-3 and CTLA-4 expression. Upon anti-CD3/CD28 stimulation, CXCR5⁺ CD8⁺ T cells demonstrated higher proliferation potency than CXCR5⁻ CD8⁺ T cells, especially after PD-1 blockade. CXCR5⁺ CD8⁺ T cells also demonstrated significantly higher granzyme B synthesis and release, as well as higher level of degranulation. Tumor cells were more readily eliminated by CXCR5⁺ CD8⁺ T cells than by CXCR5⁻ CD8⁺ T cells. Interestingly, we found that B cells were more resistant to CXCR5⁺ CD8⁺ T cell-mediated killing than tumor cells, possibly through IL-10-mediated protection. In addition, the CXCR5⁺ CD8⁺ T cell-mediated cytotoxic effects on tumor cells could be significantly enhanced by PD-L1 blockade. Together, we presented that in patients with in HBV-related hepatocellular carcinoma, CXCR5⁺ CD8⁺ T cells could mediate tumor cell death more potently than the CXCR5⁻ CD8⁺ T cells in vitro while the autologous B cells were protected.     

A higher frequency of CD4+ CXCR5+ T follicular helper cells in patients with newly diagnosed Henoch–Schönlein purpura nephritis

T follicular helper (TFH) cells play an important role in the humoral immune responses. The aim of this study was to examine the frequency of different subsets of CD4⁺ CXCR5⁺ TFH cells and B cells in patients with new-onset Henoch–Schönlein purpura nephritis (HSPN). The numbers of different subsets of CD4⁺ CXCR5⁺ TFH cells, B cells and the constituents of serum cytokines were detected in a total of 25 patients with newly diagnosed HSPN before and after treatment, and in 14 healthy controls (HC). The potential connection of these cells with the clinical characteristics in HSPN patients was analyzed. The numbers of circulating CD4⁺ CXCR5⁺, CD4⁺ CXCR5⁺ ICOS⁺ and CD4⁺ CXCR5⁺ PD-1⁺ TFH cells, CD86⁺ CD19⁺, CD38⁺ CD19⁺ B cells and serum IL-2, IL-4, IL-17A, IL-21 and IFN-γ were significantly higher in HSPN patients (p < 0.05) than in HC. Before and after treatment the numbers of CD4⁺ CXCR5⁺ TFH cells were negatively correlated with the values of eGFR (r = − 0.7162, p < 0.05; r = − 0.732, p < 0.05, respectively). Similarly the numbers of CD4⁺ CXCR5⁺ PD-1⁺ TFH cells were negatively correlated with 24-h urinary proteins (r = − 0.4013, p < 0.05; r = − 0.7857, p < 0.05, respectively), and the numbers of CD4⁺ CXCR5⁺ ICOS⁺ TFH cells were positively correlated with the levels of serum IL-21 (r = 0.5186, p < 0.05; r = 0.8503, p < 0.05, respectively) and 24-h urinary protein (r = 0.6045, p < 0.05; r = 0.833, p < 0.05, respectively) in these patients, regardless of treatment. Following treatment the numbers of CD4⁺ CXCR5⁺, CD4⁺ CXCR5⁺ PD-1⁺, and CD4⁺ CXCR5⁺ ICOS⁺ TFH cells, as well as serum levels of IL-21 were significantly reduced, however IL-4 levels were noticeably increased (p < 0.05). A higher frequency of circulating CD4⁺ CXCR5⁺ TFH cells existed in patients with HSPN and may be a viable therapeutic target.     

CXCR5+ CD8+ T cells present elevated capacity in mediating cytotoxicity toward autologous tumor cells through interleukin 10 in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a common and aggressive subtype of non-Hodgkin's lymphomas, with limited treatment options in refractory and relapsed patients. Growing evidence supports the notion that CD8⁺ T cell immunity could be utilized to eliminate B cell lymphomas. CXCR5⁺ CD8⁺ T cell is a novel cell subtype and share CXCR5 expression with CD19⁺ tumor cells. In this study, we investigated the frequency and function of existing CXCR5⁺ CD8⁺ T cells in DLBCL patients. We found that DLBCL patients as a group demonstrated significantly higher level of CXCR5⁺ CD8⁺ T cells than healthy individuals, with huge variability in each patient. Using anti-CD3/CD28-stimulated CD8⁺ T cells as effector (E) cells and autologous CD19⁺ tumor cells as target (T) cells, at high E:T ratio, no difference between the intensities of CXCR5⁺ CD8⁺ T cell- and CXCR5⁻ CD8⁺ T cell-mediated cytotoxicity were observed. However, at intermediate and low E:T ratios, the CXCR5⁺ CD8⁺ T cells presented stronger cytotoxicity than CXCR5⁻ CD8⁺ T cells. The expressions of granzyme A, granzyme B, and perforin were significantly higher in CXCR5⁺ CD8⁺ T cells than in CXCR5⁻ CD8⁺ T cells, with no significant difference in the level of degranulation. Tumor cells in DLBCL were known to secrete high level of interleukin 10 (IL-10). We therefore blocked the IL-10/IL-10R pathway, and found that the expressions of granzyme A, granzyme B, and perforin by CXCR5⁺ CD8⁺ T cells were significantly elevated. Together, these results suggest that CXCR5⁺ CD8⁺ T cells are potential candidates of CD8⁺ T cell-based immunotherapies, could mediate elimination of autologous tumor cells in DLBCL patients, but are also susceptible to IL-10-mediated suppression.     

Th9 cells promote antitumor immunity via IL-9 and IL-21 and demonstrate atypical cytokine expression in breast cancer

Breast cancer is a major cause of cancer-related death in women. Antitumor T cell responses play critical therapeutic roles, including direct cytotoxicity mediated by CD8⁺ T cells and immunomodulatory roles mediated by CD4⁺ T cells. The IL-9-expressing Th9 cells are recently found to present antitumor immunity in melanoma and lung adenocarcinoma. In this study, we found that IL-9 expression in the serum and in circulating CD4⁺ T cells were significantly upregulated in breast cancer patients compared to healthy controls. The IL-9-expressing Th9 cells were enriched in the CCR4⁻ CCR6⁻ CXCR3⁻ subset. Upon TCR stimulation, this subset also presented potent IL-10 and IL-21 expression in addition to IL-9 expression. CCR4⁻ CCR6⁻ CXCR3⁻ CD4⁺ T cells also assisted in the killing of autologous tumor cells by CD8⁺ T cells, but did not initiate cytotoxicity by themselves. This enhancement in CD8⁺ T cell-mediated cytotoxicity was dependent on IL-9 as well as on IL-21. Interestingly, the tumor-infiltrating Th9 cells presented comparable IL-9, reduced IL-10, and elevated IL-21 expression compared with their counterparts in the peripheral blood. Together, these results demonstrated that IL-9-expressing Th9 cells were upregulated in breast cancer patients and potentially possessed antitumor roles by enhancing CD8⁺ T cell-mediated cytotoxicity.     

CD4+ B220+ TCRγδ+ T cells produce IL-17 in lupus-prone MRL/lpr mice

Systemic lupus erythematosus is an autoimmune disease with comprehensive immune cell disorders. Recent studies suggested that pro-inflammatory cytokine IL-17 plays important role in lupus, leaving the cellular sources and their pathogenic and physiologic characters largely unknown. In the current study, by using lupus-prone MRL/lpr mice, we demonstrated that Th17 response prevails in lupus disease regarding significantly accumulated serum IL-17, increased IL-17-producing splenocytes, and elevated phospho-STAT3 in CD4⁺ T cells. Intracellular staining revealed that unusual CD4⁺ B220⁺ T cells are major IL-17-producing cells, whereas conventional CD4⁺ B220⁻ T cells are major IFN-γ-producing cells. Subsequent studies showed that CD4⁺ B220⁺ cells contains both αβ and γδ T cells in the spleen and thymus of MRL/lpr mice. Further study showed that around 60% of γδ T cells in MRL/lpr mice co-express both B220 and CD4 on their surface, and are the major RORγt⁺ cells in MRL/lpr mice. Finally, CD4⁺ B220⁺ T cells alone do not proliferate, but could enhance the proliferation and IFN-γ-production of conventional CD4⁺ B220⁻ T cells. Our findings suggest the pathogenic role of unusual CD4⁺ B220⁺ T cells in lupus disease in MRL/lpr mice according to their IL-17-producing ability and stimulatory function for conventional CD4⁺ B220⁻ T cells.     

Alloantigen specific T regulatory cells in transplant tolerance

CD4⁺CD25⁺Foxp3⁺T cells are regulatory/suppressor cells (Treg) that include non-antigen(Ag)-specific as well as Ag-specific Tregs. How non-Ag-specific naïve CD4⁺CD25⁺Treg develop into specific Tregs is unknown. We have studied DA rats tolerant to fully allogeneic PVG cardiac grafts that survived with out immunosuppression for over 100 days and identified the cellular basis of alloantigen specific tolerance. Key observations from our studies will be reviewed including how CD4⁺CD25⁺Tregs were first identified and the cytokine dependence of CD4⁺T cells that transfer alloantigen specific transplant tolerance which died in culture unless stimulated with both cytokine rich ConA supernatant and specific donor alloantigen. Both the tolerant CD4⁺CD25⁺ and CD4⁺CD25⁻ T cell populations are required to transfer tolerance, yet alone the CD4⁺CD25⁻ T cell effect rejection. Tolerance transfer occurs with a low ratio of CD4⁺CD25⁺T cells (< 1:10), whereas to induce tolerance with naive CD4⁺CD25⁺T cells requires both a ratio of > 1:1 and is not alloantigen specific.Recent findings on how naïve CD4⁺CD25⁺T cells developed into two separated pathways of alloantigen specific Tregs, by culturing them with alloAg with either IL-2 or IL-4 and donor alloantigen are described. IL-2 enhances IFN-γR and IL-5 mRNA while IL-4 induced a reciprocal profile with de novo IL-5Rα and increased IFN-γ mRNA expression. Both IL-2 and IL-4 alloactivated CD4⁺CD25⁺Tregs within 3–4 days of culture can induce alloantigen specific tolerance at ratios of 1:10. Long term, CD4⁺CD25⁺T cells from tolerant hosts given IL-2 cultured cells have increased IL-5 and IFN-γR mRNA; whereas hosts given IL-4 cultured cells had enhanced IL-5Rα mRNA expression and IL-5 enhanced their proliferation to donor but not third party alloAg.These findings suggest that Th1 and Th2 responses activate two pathways of alloantigen specific Tregs that can mediate transplant tolerance but are dependent upon cytokines produced by ongoing Th1 and/or Th2 immune responses.     

Compact bone-derived mesenchymal stem cells attenuate nonalcoholic steatohepatitis in a mouse model by modulation of CD4 cells differentiation

Increasing evidence has accrued which indicates that mesenchymal stem cells (MSCs) have a potential clinical value in the treatment of certain diseases. Globally, nonalcoholic steatohepatitis (NASH) is a widespread disorder. In the present study, MSCs were isolated successfully from compact bone and a mouse model of NASH was established as achieved with use of a methionine-choline deficient (MCD) diet. Compact bone-derived MSCs transplantation reduced MCD diet-induced weight loss, hepatic lipid peroxidation, steatosis, ballooning, lobular inflammation and fibrogenesis. It was shown that MSCs treatment hampered MCD diet-induced proliferation of CD4⁺ IFN-γ⁺ and CD4⁺ IL-6⁺ T spleen cells. In addition, CD4⁺ IL-17⁺ lymphocytes that associated with anti-inflammation show little change in MCD as well as in MCD + MSCs splenocytes. We conclude that MSCs may have a potential clinical value upon NASH, through their capacity to suppress activation of CD4⁺ IFN-γ⁺ and CD4⁺ IL-6⁺ lymphocytes.     

Erythropoietin exerts direct immunomodulatory effects on the cytokine production by activated human T-lymphocytes

The effect of erythropoietin-β (Epo-β) on the functional profile of activated human T-lymphocytes remains largely unknown, which hinders clinical application of Epo as an immunomodulatory agent. We studied the direct impact of Epo on the activation status of human T lymphocytes following activation by particles loaded with antibodies (Abs) against human CD2, CD3, and CD28. T cell activation was assessed by the surface expression of CD38 activation marker. Epo did not significantly affect activation status of both CD4⁺ and CD4⁻ T cells, as well as of naive (CD45RA⁺ CD197⁺), central memory (CD45RA⁻ CD197⁺), effector memory (CD45RA⁻ CD197⁻), and terminally-differentiated (CD45RA⁺ CD197⁻) T cells. However, Epo markedly augmented production of IL-2, IL-4 and IL10 by activated T cells with concomitant reduction in IFN-γ secretion. Taken together, our data showed that Epo could directly down-regulate pro-inflammatory T cell responses without affecting T cell activation status.     

Astilbin inhibits Th17 cell differentiation and ameliorates imiquimod-induced psoriasis-like skin lesions in BALB/c mice via Jak3/Stat3 signaling pathway

The flavonoid astilbin is the major active component extracted from the rhizome of Smilax glabra, which has been widely used in China to treat inflammatory and autoimmune diseases, Psoriasis is a common chronic inflammatory disease in which T helper 17 (Th17) cells play an important role, provoking inflammation. We employed an imiquimod (IMQ)-induced psoriasis-like mouse model to investigate the effect of astilbin in inflammation. Mice were administered 25 to 50 mg/kg astilbin. Inflammation of psoriasis-like lesions was assessed by histology, circulating levels of T cells were assessed by flow cytometry and cytokines by bead-based immunoassay. Jak/Stat3 in isolated T cells was assessed by Western blotting and RORγt expression was assessed by RT-PCR. Administration of astilbin ameliorated IMQ-induced keratinocyte proliferation, infiltration of CD3 + cells to psoriatic lesions and ameliorated elevations in circulating CD4 + and CD8 + T cells and inflammatory cytokines (IL-17A, TNF-α, IL-6, IFN-γ and IL-2). In vitro, astilbin inhibited Th17 cell differentiation and IL-17 secretion of isolated T cells, and inhibited Jak/Stat3 signaling in Th17 cells, while up-regulating Stat3 inhibitor SCOSE3 expression in psoriatic lesions. Thus, astilbin likely alleviates psoriasis-like skin lesions by inhibiting Th17 related inflammation. Astilbin represents as an interesting candidate drug for immunoregulation of psoriasis.     

APL-1, an altered peptide ligand derived from human heat-shock protein 60, selectively induces apoptosis in activated CD4 + CD25 + T cells from peripheral blood of rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a chronic T-cell mediated autoimmune disease that affects primarily the joints. The induction of immune tolerance through antigen-specific therapies for the blockade of pathogenic CD4 + T cells constitutes a current focus of research. In this focus it is attempted to simultaneously activate multiple regulatory mechanisms, such as: apoptosis and regulatory T cells (Tregs). APL-1 is an altered peptide ligand derived from a novel CD4 + T-cell epitope of human heat-shock protein of 60 kDa, an autoantigen involved in the pathogenesis of RA. Previously, we have reported that APL-1 induces CD4 + CD25^highFoxp3 + Tregs in several systems. Here, we investigated the ability of APL-1 in inducing apoptosis in PBMCs from RA patients, who were classified as active or inactive according to their DAS28 score. APL-1 decreased the viability of PBMCs from active but not from inactive patients. DNA fragmentation assays and typical morphological features clearly demonstrated that APL-1 induced apoptosis in these cells. Activated CD4 + CD25 + T cells but not resting CD4 + CD25 − T cells were identified as targets of APL-1. Furthermore, CD4 + T-cell responses to APL-1 were found to be dependent on antigen presentation via the HLA-DR molecule. Thus, APL-1 is a regulatory CD4 + T cell epitope which might modulate inflammatory immune responses in PBMCs from RA patients by inducing CD4 + CD25^highFoxp3 + Tregs and apoptosis in activated CD4 + T cells. These results support further investigation of this candidate drug for the treatment of RA.     

P-glycoprotein function in peripheral T lymphocyte subsets of myasthenia gravis patients: Clinical implications and influence of glucocorticoid administration

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder with a chronic clinical course that requires long-term glucocorticoid (GC) therapy. A drug efflux pump, P-glycoprotein (P-gp), actively transports GC out of target cells, thereby reducing its efficacy. We evaluated the P-gp function of peripheral-blood mononuclear cells in 59 MG patients. P-gp function was estimated from a decrease in fluorescent P-gp substrate Rhodamine 123 and its inhibition by the conformation-sensitive UIC2 monoclonal antibody. P-gp function on CD8⁺ T cells in 21 MG patients having experienced GC therapy was higher than that in 19 MG patients having no history of GC therapy (p = 0.026). There was a significant correlation between P-gp function in CD3⁺ (r = 0.55, p = 0.014) or CD4⁺ (r = 0.48, p = 0.034) T cells and the total dose of prednisolone for treatment. P-gp function on CD4⁺ T cells in MG patients who showed low responses to prednisolone therapy (n = 8) was higher than that in patients who showed relatively high responses to prednisolone therapy (n = 10) (p = 0.045). These results suggest that higher P-glycoprotein activity on CD3⁺ or CD4⁺ cells necessitated treatment with higher steroid doses in order to achieve a clinical response. The measurement of P-gp function on CD4⁺ T cells is useful in the assessment of clinical response to GC therapy.     

PD-1 regulates CXCR5+ CD4 T cell-mediated proinflammatory functions in non-small cell lung cancer patients

PD-1 inhibitors have been used to revive exhausted T cell responses in non-small cell lung cancer (NSCLC) and other malignancies. CXCR5⁺ T follicular helper (Tfh) cells are characterized by constitutive high PD-1 expression and have been associated with the formation of tertiary lymphoid structures and implicated in antitumor immunity. In this study, we investigated the effect of PD-1 and PD-1 inhibition on CXCR5⁺ CD4 T cells. Data showed that CXCR5⁺ CD4 T cells in both healthy subjects and NSCLC patients presented markedly higher PD-1 expression than CXCR5⁻ CD4 T cells. Both CXCR5⁻ and CXCR5⁺ CD4 T cells from NSCLC patients presented higher PD-1 expression than their counterparts in healthy subjects. PD-1⁺ CXCR5⁺ CD4 T cells were functional, could express IL-21, IL-10, and CXCL13 upon stimulation, demonstrated auxiliary effects toward CD8 T cell-mediated IFN-γ production and proliferation, and promoted IgM and IgG production. However, the potency of PD-1⁺ CXCR5⁺ CD4 T cells was lower than the potency of PD-1⁻ CXCR5⁺ CD4 T cells. PD-1 blocking could significantly enhance the effector functions of PD-1⁺ CXCR5⁺ CD4 T cells. Overall, this study demonstrated that PD-1⁺ CXCR5⁺ CD4 T cells could promote CD8 T cell and B cell inflammation and could be modulated by PD-1 inhibition.     

Reversing the polarization of tumor-associated macrophages inhibits tumor metastasis

ObjectiveThe M2 phenotype is dominant in tumor associated macrophages (TAM), and plays a key role in promoting tumor growth, invasion and metastasis. Converting TAM polarization from M2 to M1 may contribute to eliciting anti-tumor-specific immune responses and inhibiting tumor metastasis. In this study, the effect of reversing the polarization of TAM on tumor metastasis was investigated.MethodsPeritoneal macrophages were obtained from BABL/c mice, and M2 polarization was induced by IL-4. In an in vivo experiment, BABL/c mice were transplanted with 4 T1 tumor cells. In vitro and in vivo experimental studies, M2 macrophage polarization was reversed with CpG-DNA or CpG-DNA combined with anti-IL-10R Ab. CD68, MHCII and FRβ molecular expression in macrophages were examined with immunofluorescence staining. The mRNA expression of IL-2, IL-6, IL-13, VEGF and MMP-9 were detected with RT-PCR. VEGF and MMP-9 protein expression of tumors in situ was measured by western blot assay. Lung-metastasis of the tumor was observed and assessed by micro-CT.ResultsCpG-DNA and CpG-DNA combined with anti-IL-10R Ab could promote MHCII, IL-2, IL-6 and IL-13 molecular expression, and suppress the expression of FRβ, MMP-9 and VEGF, in both freshly isolated peritoneal macrophages and M2 macrophages. In the CpG-DNA combined with anti-IL-10R Ab injecting group, the percentage of CD68⁺ MHCII⁺ cells were significantly higher than that of CD68⁺ FRβ⁺ cells (P < 0.05). This was distinct from the result of the control group, which CD68⁺ FRβ⁺ was higher than CD68⁺ MHCII⁺ cells (P < 0.01). Furthermore, VEGF-A and MMP-9 level in primary tumor tissues in the experimental group was significantly lower (P < 0.01), compared to the control group. Moreover, the number of detectable lung-metastasis foci was significantly lower in the experimental group than in the control group (P < 0.05).ConclusionReversing the polarization of TAM from M2 to M1 phenotype can inhibit tumor metastasis.     

The role of regulatory B cells (Bregs) in the Tregs-amplifying effect of Sirolimus

Sirolimus can significantly amplify regulatory T cells (Tregs) in vivo and in vitro, but the specific mechanism of this has not been well documented. The role of regulatory B cells (Bregs) in the Tregs-amplifying effect of Sirolimus was investigated in peripheral blood mononuclear cells (PBMCs) in vitro in this study. The results showed that the percentages of both CD19 + CD24 + CD38 + TGF-β1 + Bregs and CD19 + CD24 + CD38 + IL-10 + Bregs to B cells were elevated by Sirolimus in PBMCs including B cells. Sirolimus significantly enhances the cytokine production of transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) in PBMCs with B cells, and the enhancement significantly decreased in PBMCs without B cells. The percentage of CD4 + CD25 + Foxp3 + Tregs to T cells was also elevated by Sirolimus in PBMCs including B cells. The elevation of Tregs percentage decreased in PBMCs without B cells and recovered when additional TGF-β1 and IL-10 were added. The amplification of Tregs by Sirolimus was partially inhibited when either TGF-β1 or IL-10 was neutralized, and it even disappeared when these two cytokines were both neutralized. These results indicate that Sirolimus can amplify Bregs and Tregs in PBMCs in vitro, and Bregs may be the why Sirolimus amplifies Tregs.     

Chicken egg yolk antibodies (IgY) modulate the intestinal mucosal immune response in a mouse model of Salmonella typhimurium infection

This study determined the effects of chicken egg yolk antibodies (IgY) on immune responses in the intestinal mucosal of mice infected with Salmonella typhimurium. Sixty, 28-day-old mice were divided into 4 groups and treated with streptomycin or sterile water for 2 days followed by 1 day without treatment. The control group was unchallenged whereas the mice in the other three groups were treated twice with 10⁹ CFU mL^− 1 S. typhimurium. For the next 3 days, control mice continued to receive no treatment whereas the mice in the remaining three groups were orally administered with 20 mg mL^− 1 of specific IgY, 20 mg mL^− 1 of nonspecific IgY or PBS. S. typhimurium activated gut-associated lymphoid tissue, increasing the release of IFN-γ and TNF-α in the mucosa and increased the number of activated T-lymphocytes and cytotoxic T-γδ. Specific IgY attenuated the increase in IFN-γ and TNF-α and the decrease in IL-10. S. typhimurium induced mobilization of CD8⁺ and CD8⁺ TCRγδ T cells in the epithelium and CD4⁺ and CD8⁺ T cells in the lamina propria reflecting an inflammatory process that was attenuated by IgY. These results suggest that specific IgY modulates intestinal mucosal immune responses during a S. typhimurium infection.     

Direct effects of interleukin-8 on growth and functional activity of T lymphocytes

CD3⁺ T-lymphocytes were isolated from the normal donors by positive magnetic separation. Activation of the T cells with particles conjugated with antibodies to CD3, СD28 and СD2 molecules led to a marked increase in T-cell production of interleukine-8 (IL-8). We present evidence that IL-8 receptor α-chain (CXCR1, CD181) is expressed on the cell surface of 13.3% T cells. Activation of T-lymphocytes resulted in significant enhancement of CD181⁺ cells both in naive CD4⁺ T cell and terminally differentiated effector CD4⁺ T cell compartments with concomitant reduction of CD181⁺ cells in effector memory CD4⁺ T cell subset. The level of T cell activation was assessed judging from the surface expression of CD25 (IL-2 receptor α-chain). We demonstrate that IL-8 treatment (0.01–10.0 ng/ml concentration range) reduced the activation status of both CD4⁻ and CD4⁺ effector memory T cells, as well as terminally differentiated effector T cells, without significantly affecting the activation of naive T cells or central memory T cells. In addition, IL-8 up-regulated IL-2 and down-regulated IL-10 production by activated T cells, with no effect on interferon-gamma (IFN-γ) and IL-4 production. Data obtained suggests the importance of IL-8 in the direct regulation of adaptive T cell reactivity.     

Inosine Acedoben Dimepranol promotes an early and sustained increase in the natural killer cell component of circulating lymphocytes: A clinical trial supporting anti-viral indications

Inosine Acedoben Dimepranol (IAD), licensed for the treatment of cell-mediated immune deficiencies associated with viral infections, has been reported to impact a variety of immune parameters both in vitro and in vivo. Here we report the results from a clinical trial where multiple lymphocyte subsets – CD19 + B cells, CD3 + T cells, CD4 + T-helper cells, FoxP3^hi/CD25^hi/CD127^lo regulatory T cells (Tregs), CD3 −/CD56 + NK cells, and CD3 +/CD56 + NKT cells – were, together with serum immunoglobulins and IgG subclasses, followed during 14 days of IAD administration to ten healthy volunteers; these selected from 27 individuals pre-screened in vitro for their capacity to respond to IAD as gauged by increases in the percentage of Treg and/or NKT cells arising in PHA-stimulated cultures. While a transient spike and dip in Treg and T-helper fractions, respectively, was noted, the outstanding consequence of IAD administration (1 g po, qds) was an early and durable rise in NK cells. For half the cohort, NK cells increased as a percentage of total peripheral blood lymphocytes within 1.5 h of receiving drug. By Day 5, all but one of the volunteers displayed higher NK cell percentages, such elevation – effectively a doubling or greater – being maintained at termination of study. The IAD-induced populations were as replete in Granzyme A and Perforin as basal NK cells. The novel finding of IAD boosting phenotypically competent NK numbers in healthy individuals supports the drug's indicated benefit in conditions associated with viral infection and reinforces the potential for uplift where immune performance may be compromised.     

Effects of taurocholic acid on immunoregulation in mice

ContextCurrently, there is a dramatically growing interest in Chinese traditional medicines, especially in the therapy of inflammatory diseases. Taurocholic acid (TCA), as a kind of natural bioactive substance of animal bile acid, has medicinal applications to treat a wide range of inflammatory diseases.ObjectiveThe study was designed to evaluate the effects of TCA on cytokine secretion, such as TNF-α and IL-1β and on the ratio of CD4⁺/CD8⁺, which is beneficial for understanding the mechanism of TCA on immunoregulation preliminarily, and also will benefit our further research.Materials and methodsThe gene and protein expressions of TNF-α and IL-1β were measured by real time RT-PCR and ELISA in serum, spleen and lymphocytes respectively. The ratio of CD4⁺/CD8⁺ in peripheral blood and lymphocytes was measured by flow cytometry.ResultsOur present study has shown that lipopolysaccharide (LPS) and cyclosporin A (CsA) could increase or decrease the gene and protein expressions of TNF-α and IL-1β respectively. TCA (0.25 g/kg, 0.125 g/kg) could recover the suppressed expressions of TNF-α and IL-1β and increase the ratio of CD4⁺/CD8⁺. In vitro, TCA (15 μg/mL) could inhibit the increased production of TNF-α and IL-1β; TCA (0.15 μg/mL–15 μg/mL) could inhibit the increased gene expressions of IL-1β and TNF-α. TCA (0.15 μg/mL) could recover the suppressed expressions of TNF-α and IL-1β.ConclusionThe function of immunoregulation of TCA may be accomplished through modulating the gene and protein expressions of TNF-α and IL-1β and elevating CD4⁺/CD8⁺ T-cell ratio.