Increased Fas ligand expression of peripheral B‐1 cells correlated with CD4+ T‐cell apoptosis in filarial‐infected patients

Cellular hyporesponsiveness observed during helminth infections is attributed to factors such as antigen‐presenting cells (APC) dysfunction, increased interleukin‐10(IL‐10), regulatory T cells and induction of CD4⁺ T (Th)‐cell apoptosis. Increased Fas ligand (FasL) expression on the surface of B‐1 cells and induction of apoptosis of Th cells by FasL‐expressing B‐1 cells due to helminth infection were demonstrated in murine model of helminth infection where as profile of FasL expression, Th‐cell apoptosis and correlation between these two populations of cells in clinical filariasis remain unknown. In this study, we have scored the profile of apoptotic Th‐cell population and FasL‐expressing B‐1 cells in different clinical categories of filariasis. The peripheral apoptotic T‐helper cells were significantly increased in filarial patients compared to endemic controls. Expression of FasL on the surface of peripheral B‐1 cells increased in filarial patients and positively correlated with peripheral apoptotic T‐helper cells indicating FasL‐expressing B‐1 cells may be one of the important mediators of Th‐cell apoptosis and immune anergy during filarial pathology.     

Low percentages of regulatory T cells in common variable immunodeficiency (CVID) patients with autoimmune diseases and its association with increased numbers of CD4+CD45RO+ T and CD21low B cells

BackgroundCommon variable immunodeficiency (CVID) is a heterogeneous group of primary antibody deficiencies defined by marked reductions in serum IgG, IgA and/or IgM levels and recurrent bacterial infections. Some patients are associated with defects in T cells and regulatory T cells (Tregs), resulting in recurrent viral infections and early-onset autoimmune disease.MethodsWe analyzed whether there is an association between Tregs cells (CD4+CD25+CD127^low and CD4+CD25+FoxP3+); memory T cells (CD4+CD45RO+); memory B cells (CD19+CD27-IgD-); and CD21^low B cells (CD19+CD38^lowCD21^low); as well as autoimmune manifestations in 36 patients with CVID (25 women and 11 men, mean age 24 years), all by flow cytometry.ResultsFourteen patients presented with autoimmune diseases (AI) (39%), including 11 with autoimmune thrombocytopenia (ITP) (31%); two with vitiligo (6%); one with systemic lupus erythematosus (LES) (3%); and one with multiple sclerosis (MS) (3%). CVID patients with AI had a reduced proportion of Tregs (both CD4+CD25+CD127^low and FoxP3+ cells) compared with healthy controls. CVID patients with AI had expanded CD21^low B cell populations compared with patients who did not have AI. A correlation between increased CD4+CD45RO T cell populations and reduced Tregs was also observed.ConclusionsOur results showed that 39% of patients with CVID had AI and reduced Tregs populations. Research in this area might provide noteworthy data to better understand immune dysfunction and dysregulation related to CVID.     

Overexpression of T‐bet gene regulates murine autoimmune arthritis

Objective

To clarify the role of T‐bet in the pathogenesis of collagen‐induced arthritis (CIA).

Methods

T‐bet–transgenic (Tg) mice under the control of the CD2 promoter were generated. CIA was induced in T‐bet–Tg mice and wild‐type C57BL/6 (B6) mice. Levels of type II collagen (CII)–reactive T‐bet and retinoic acid receptor–related orphan nuclear receptor γt (RORγt) messenger RNA expression were analyzed by real‐time polymerase chain reaction. Criss‐cross experiments using CD4+ T cells from B6 and T‐bet–Tg mice, as well as CD11c+ splenic dendritic cells (DCs) from B6 and T‐bet–Tg mice with CII were performed, and interleukin‐17 (IL‐17) and interferon‐γ (IFNγ) in the supernatants were measured by enzyme‐linked immunosorbent assay. CD4+ T cells from B6, T‐bet–Tg, or T‐bet–Tg/IFNγ^−/− mice were cultured for Th17 cell differentiation, then the proportions of cells producing IFNγ and IL‐17 were analyzed by fluorescence‐activated cell sorting.

Results

Unlike the B6 mice, the T‐bet–Tg mice did not develop CIA. T‐bet–Tg mice showed overexpression of Tbx21 and down‐regulation of Rorc in CII‐reactive T cells. Criss‐cross experiments with CD4+ T cells and splenic DCs showed a significant reduction in IL‐17 production by CII‐reactive CD4+ T cells in T‐bet–Tg mice, even upon coculture with DCs from B6 mice, indicating dysfunction of IL‐17–producing CD4+ T cells. Inhibition of Th17 cell differentiation under an in vitro condition favoring Th17 cell differentiation was observed in both T‐bet–Tg mice and T‐bet–Tg/IFNγ^−/− mice.

Conclusion

Overexpression of T‐bet in T cells suppressed the development of autoimmune arthritis. The regulatory mechanism of arthritis might involve dysfunction of CII‐reactive Th17 cell differentiation by overexpression of T‐bet via IFNγ‐independent pathways.

     

Cytokine Profiles Contribute to Understanding the Pathogenic Difference Between Good Syndrome and Oral Lichen Planus: Two Case Reports and Literature Review

We described and analyzed the pathogenic difference between Good syndrome (GS) and oral lichen planus (OLP) in oral mucosa.Good syndrome (GS) is a rare disease characterized by B and T cell immunodeficiency associated with hypogammaglobulinemia and thymoma. GS patients frequently develop oral lichenoid lesions with lymphocytic infiltration beneath the basal layer. Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa characterized by destruction of basal cells by Langerhans cells, macrophages, and T lymphocytes. Although the histological features of the lesions of both diseases are very similar, the pathogenesis of GS in the oral mucosa remains unknown. In this study, we thus investigated the expression of infiltrating lymphocyte subsets (CD3, CD20, CD4, and CD8) and T helper (Th) cytokines including interferon (IFN)-γ (Th1 type), interleukin (IL)-4 (Th2 type), IL-17 (Th17 type), and IL-10 (regulatory T cell type) by immunohistochemistry in buccal mucosa specimens from 2 GS patients compared with 15 OLP patients. All patients showed a predominance of CD3⁺ T cells over CD20⁺ B cells, and CD4⁺ Th cells over CD8⁺ cytotoxic T cells. This polarization was especially prominent in GS. IFN-γ and IL-10 were strongly detected in the infiltrating lymphocytes of all patients. However, IL-4 and IL-17 were detected in OLP patients only.These results suggest that the pathogenesis of GS is different from that of OLP. GS is a unique inflammatory disorder characterized by dysfunction of Th2 and Th17 immune reactions via abnormal T–B cell interaction.     

Reduced expression of decay‐accelerating factor 1 on CD4+ T cells in murine systemic autoimmune disease

Objective

Deficiency of decay‐accelerating factor 1 (termed Daf1 in mice) has been shown to exacerbate autoimmunity, and recent studies have suggested that this may be explained by Daf1 acting as a regulator of T cell immunity. The aim of this study was to determine whether Daf1 expression on T cells is modulated during development of autoimmunity in mice.

Methods

To test this hypothesis, we examined Daf1 levels in NZB, DBA/2, and B10.S mice before and after induction of murine mercury‐induced autoimmunity (mHgIA). Daf1 was measured by real‐time polymerase chain reaction and flow cytometry, and levels of Daf1 were correlated with markers of lymphocyte activation and cytokine production.

Results

Autoimmune‐prone NZB mice had low endogenous levels of Daf1 irrespective of the induction of mHgIA. Induction of autoimmunity reduced Daf1 expression in mHgIA‐sensitive B10.S mice, particularly on activated/memory (CD44^high) CD4+ T cells that accumulate as a result of exposure to mercury. Murine mercury‐induced autoimmunity–resistant DBA/2 mice, which fail to accumulate CD44^high T cells, showed no change in Daf1 expression. Modulation of Daf1 expression was found to require CD4+ T cell costimulation, since B10.S mice deficient in CD28 were unable to down‐regulate Daf1 or accumulate activated/memory CD4+ T cells. In B10.S mice exposed to mercury, the production of interleukin‐4 (IL‐4), but not that of IL‐2 or interferon‐γ, in the spleen was associated with CD44^high,Daf1^low,CD4+ T cells.

Conclusion

These findings demonstrate that reduction of Daf1 expression is closely associated with CD4+ T cell activation and the accumulation of CD44^high(activated/memory),CD4+ T cells in both spontaneous and induced systemic autoimmune disease.

     

原发性肝癌和乙型肝炎肝硬化患者外周血淋巴细胞凋亡率、T细胞亚群和NK细胞的水平变化和临床意义

目的通过检测乙型肝炎肝硬化和合并乙型肝炎病毒感染的原发性肝细胞癌患者的外周血的粒细胞、单核细胞、NK细胞、T细胞及其亚群和淋巴细胞及其凋亡率,探讨两者在细胞免疫方面的差异.方法用Ficoll Hypaque离心法分离外周血单个核细胞(PBMNC),流式细胞仪检测外周血T细胞及其亚群、NK细胞和淋巴细胞、单核细胞和粒细胞,AnnexinV/FITCKit检测凋亡细胞.结果乙型肝炎肝硬化患者的外周血单核细胞、粒细胞、淋巴细胞、CD3-CD16 CD56 NK细胞、CD3 T细胞、CD3 CD4 T细胞、CD3 CD4 T细胞和CD4 CD8 T细胞比值,均与正常对照组无显著性差异(P＞0.05);但淋巴细胞凋亡率明显低于对照组(P＜0.01).原发性肝癌外周血CD3-CD16 CD56 NK细胞、单核细胞和CD4 /CD8 T细胞比值与肝硬化组和正常对照组比较,均无显著性差异(P＞0.05),而粒细胞明显升高(P＜0.05);CD3 T细胞、CD3 CD4 T细胞和CD3 CD8 T细胞均较另两组明显减少(P＜0.05),淋巴细胞及其凋亡率均明显低于另两组(P＜0.01).结论乙型肝炎肝硬化患者的外周血细胞免疫只发生不显著的变化,但淋巴细胞的凋亡率明显降低.原发性肝癌外周血的细胞免疫和淋巴细胞凋亡率均明显低下.     

Chronic hepatitis B: The interplay between intrahepatic lymphocyte population and viral antigens in relation to liver damage

In Chronic hepatitis B (CHB) infection, virus and immune response interplay is thought to be responsible for pathogenesis. Yet, the impact of each immune cell population and viral protein expression in liver damage is still unknown. Our aim was to study the interplay between intrahepatic immune response and viral activity in relation to CHB liver damage. Immunostaining was performed in 29 liver biopsies from untreated CHB patients to characterize liver infiltrate [Th (CD4+), CTL (CD8+), Treg (FoxP3+), Th17 (IL‐17A+) and Th1 (T‐bet+)] and viral antigen expression (HBsAg and HBcAg). Inflammatory activity and fibrosis were assessed using the HAI and METAVIR scoring system. All studied populations were identified in the portal‐periportal (P‐P) areas with a CD4+ lymphocyte predominance, while only CD8+ and FoxP3+ cells were observed in the intralobular area. Both P‐P CD4+ and intralobular CD8+ cell frequencies were increased among severe hepatitis cases. Concerning HBsAg and HBcAg expression, a mutually exclusive pattern was observed. HBcAg was mainly detected among HBeAg‐positive patients and was associated with hepatitis severity and higher frequency of P‐P FoxP3+, intralobular CD8+ and FoxP3+ cells. HBsAg was identified among HBeAg‐negative cases with less severe hepatitis grade and lower frequency of P‐P CD4+ and intralobular FoxP3+ lymphocytes. In conclusion, the HBV antigen profile expression seen during CHB infection may be reflecting different stages of viral replication which impacts the host immune response and liver damage process. While HBcAg might be an inducer of a regulatory microenvironment, the intralobular CTL population seemed to have a key role in hepatitis severity.     

Decrease in hepatic CD56(+) T cells and V alpha 24(+) natural killer T cells in chronic hepatitis C viral infection

BACKGROUND/AIMS: The intrahepatic immune system is likely to play a key role in determining the outcome of hepatitis C virus (HCV) infection. The hepatic lymphocyte repertoire is characterised by high CD8/CD4 T cell ratios and large numbers of gamma delta T cells, natural killer (NK) cells, NK T cells and NK receptor-positive T cells. It is not known which of these populations contribute to immunity against HCV or immune pathology. METHODS: To explore the relative contributions of lymphocyte subpopulations, we have compared the intrahepatic lymphocyte repertoires and cytokine expression in 13 patients with mild chronic hepatitis C infection, 14 with end-stage hepatitis C cirrhosis and five histologically normal livers by flow cytometry and immunohistochemistry. RESULTS: CD4(+) T cells bearing alpha beta T cell receptors (TCR) were significantly expanded in livers with chronic HCV infection while CD56(+) alpha beta T cells and V alpha 24 TCR-positive T cells were significantly depleted. Expanded CD4(+)T cells were predominantly Th1 cells, producing interferon-gamma but not interleukin-4. CONCLUSIONS: Failure to resolve HCV infection may be due to deficient innate and/or memory immune responses, while Th1 cells may mediate immune pathology.     

Peripheral lymphocyte subsets vary with stage of hepatitis C virus-associated liver disease

BACKGROUND/AIMS: Hepatitis C virus induces various clinical features in a host depending on duration of the viral infection. METHODOLOGY: We investigated peripheral lymphocyte subsets in patients with three different stages of hepatitis C virus infection: 5 patients with acute hepatitis, 10 with chronic hepatitis unassociated with cirrhosis, and 10 with cirrhosis. Peripheral lymphocytes were double-stained with multiple fluorescent antibody combinations: anti-CD3 plus anti-gammasigmaT cell receptor; anti-CD19 plus anti-CD5; anti-CD4 plus anti-CD45RA; or anti-CD8 plus anti-CD11b. Triple staining was performed with fluorescent antibodies against CD4, interferon gamma, and interleukin-4. Both staining protocols were followed by flow cytometric analysis. RESULTS: Acute hepatitis patients had a high proportion of CD3+ T cells with increased CD4+CD45RA-T helper and CD8+CD11b- cytotoxic T cells. Compared to this group, chronic hepatitis patients showed a decrease in CD4+ cells and an increase in CD19+ B cells and interleukin-4-producing Th2 cells. Cirrhotic patients showed decreased circulating lymphocytes and a low proportion of CD8+ cells accompanied by a decrease in cytotoxic T cells. Furthermore, their lymphocyte profiles showed decreases in primordial lymphocyte subpopulations (T cells with gammasigmaT cell receptors and B cells with CD5). CONCLUSIONS: Although the same pathogenic agent was involved, immune dynamics differed greatly according to duration of viral infection.     

Antigenic fractions of Leishmania (Viannia) braziliensis: the immune response characterization of patients at the initial phase of disease

American cutaneous leishmaniasis (ACL) has different clinical manifestations and these manifestations are dependent on the immunological status of the host. As CD4⁺ and CD8⁺ T cells and their mediators play a fundamental role in the host response to Leishmania and there is also a search for antigenic molecules to be used as future vaccines and tools for prognostic tests, this study characterized ACL patients’ immune response after stimulation with soluble and insoluble fractions of L. (V.) braziliensis. We demonstrated a prevailing production of the Th2 cytokines, IL‐4 and IL‐10 and a specific production of IFN‐γ and TNF‐α in patients before treatment. There was also a predominance of CD4⁺ T cells and a small percentage CD8⁺ T cells. The insoluble antigenic fraction primarily stimulated CD4⁺ T cells, while the soluble antigenic fraction showed a mixed profile, with CD4⁺ T cells being the main responsible for Th2 cytokines and CD8⁺ T cells for Th1 cytokines. Therefore, our results showed that a down‐modulation of the Th1 type of response occurs in the initial phase of L. braziliensis disease, being the antigenic fractions capable of stimulating a specific immune response.     

Roles for both CD+ and CD8+ T cells in protective immunity against Onchocerca lienalis microfilariae in the mouse

Mice inoculated with microfilariae of the filarial nematode Onchocerca lienalis clear their parasites from the skin over a period of 3 to 4 months and are highly resistant to a challenge infection. The adoptive transfer of spleen cells at various time points following primary and secondary infections of mice shows that exposures of 50 days or greater are required for the generation of lymphocytes capable of transferring protection to naive recipients. This adoptive transfer of protection with spleen cells from infection-primed mice partitions with the T lymphocyte population. In contrast, the passive transfer of protection with spleen-derived B cells, or sera taken at various time points following infection was not achieved. Moreover, there was no detectable synergistic effect when B and T cells were co-administered to recipient animals. Depletion of CD4+ and CD8+ T cells with monoclonal antibodies shows that CD8 + T cells have some regulatory effect on parasite establishment early in primary infection, but this is later superseded by CD4+ T cell reactivity that is predominant both when primary infection microfilariae are cleared and also during resistance to reinfection. Measurement of cytokines in the sera of mice undergoing primary and secondary infections support a microfilariae-induced Th2 activity, with high levels of IL-5 that are sustained upon reinfection, and low levels oflFN-γ that are negligible at the time when mice are most strongly immune.     

T‐cell clones in human trichinellosis: Evidence for a mixed Th1/Th2 response

In humans, studies on the cellular immune response against Trichinella are scarce. Aim of this study was to characterize the cytokine profile of T cells specific for Trichinella britovi in trichinellosis patients. Peripheral blood mononuclear cells (PBMC) were obtained from five patients involved in a trichinellosis outbreak caused by T. britovi, which occurred in 2013 in Tuscany (Italy). All the patients resulted positive for Trichinella‐specific IgG, IgE and presented eosinophilia. T cells were investigated for their proliferation to excretory/secretory antigens from Trichinella spiralis muscle larvae (TsES) and for their cytokine profile. A total of 284 CD4+ and 42 CD8+ T‐cell clones were obtained from the TsES‐specific T‐cell lines from PBMC. All T‐cell clones proliferated in response to mitogen. Of the 284 CD4+ T‐cell clones generated from TsES‐specific T‐cell lines, 135 (47%) proliferated significantly to TsES; 26% CD8+ T‐cell clones showed proliferation to TsES. In the series of the 135 TsES‐specific CD4+ clones, 51% expressed a Th2 profile, 30% a Th0 and 19% Th1. In the series of the 11 TsES‐specific CD8+ T‐cell clones, 18% were Tc2, 45% Tc0 and 36% Tc1. In human trichinellosis, the cellular immune response is, during the chronic phase, mixed Th1/Th2.     

B- and T-cell memory elicited by a seasonal live attenuated reassortant influenza vaccine: assessment of local antibody avidity and virus-specific memory T-cells using trogocytosis-based method

Please cite this paper as: Petukhova et al. (2011) B‐ and T‐cell memory elicited by a seasonal live attenuated reassortant influenza vaccine: assessment of local antibody avidity and virus‐specific memory T‐cells using trogocytosis‐based method. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2011.00279.x. Purpose The main purpose of vaccination is to generate immunological memory providing enhanced immune responses against infectious pathogens. The standard and most commonly used assay for influenza vaccine immunogenicity evaluation is a hemagglutination inhibition assay (HAI). It is clear now that HAI assay is unable to properly assess the proven protective immunity elicited by live attenuated influenza vaccines (LAIV). New methods need to be developed for more accurate LAIV immunogenicity assessment and prediction of vaccine efficacy among target populations. Objective Randomized placebo‐controlled study of memory B‐ and T‐cell responses to intranasal LAIV in young adults. Methods A total of 56 healthy young adults 18–20 years old received seasonal monovalent LAIV. Mucosal memory B‐cell responses were measured by IgA avidity assessment in nasal swabs. CD4 memory T cells in peripheral blood were examined by the expression of CD45RO marker and in functional test by the ability of virus‐specific T cells to maintain the trogocytosis with antigen‐loaded target cells. Results Intranasal LAIV immunization enhances mucosal IgA avidity even without reliable increases in antibody titers. At the day 21 after vaccination, up to 40% of subjects demonstrated significant increases in both total and virus‐specific CD4 memory T cells that were observed regardless of seroconversion rate measured by HAI assay. Conclusion The data suggest that immunogenicity of LAIV vaccines should be evaluated on the mucosal and cellular immunity basis. The assays applied could be used to support influenza clinical trials through preliminary screening of volunteers and subsequent measurement of anti‐influenza in immunity.     

Immunologic dysfunction contributes to the otitis prone condition

Acute Otitis Media (AOM) is a multifactorial disease occurring mostly in young children who are immunologically naïve to AOM pathogens. This review focuses on work from Rochester NY, USA over the past 12 years among young children who had AOM infections microbiologically-confirmed by tympanocentesis, so called “stringently-defined”. Among stringently-defined otitis prone children deficiencies in fundamental immune defense mechanisms have been identified that contribute to the propensity of young children to experience recurrent AOM. Dysfunction in innate immune responses that cause an immunopathological impact in the nasopharynx have been discovered including inadequate proinflammatory cytokine response and poor epithelial cell repair. Adaptive immunity defects in B cell function and immunologic memory resulting in low levels of antibody to otopathogen-specific antigens allows repeated infections. CD4+ and CD8+ T cell function and memory defects significantly contribute. The immune profile of an otitis prone child resembles that of a neonate through the first year of life. Immunologic deficits in otitis prone children cause them to be unusually vulnerable to viral upper respiratory infections and respond inadequately to routine pediatric vaccines.     

CD4+ T cells mediate mucosal and systemic immune responses to experimental hookworm infection

Hookworm infection is associated with anaemia and malnutrition in many resource‐limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen‐mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4⁺ T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4⁺ for up to 9 days following intraperitoneal injection (200 μg) of a murine anti‐mouse CD4 monoclonal IgG (clone GK1·5). CD4⁺ T‐cell‐depleted hamsters infected with the hookworm Ancylostoma ceylanicum exhibited a threefold higher mean intestinal worm burden and more severe anaemia than animals that received isotype control IgG. In addition, depletion of CD4⁺ T cells was associated with impaired cellular and humoral (serum and mucosal) immune responses to hookworm antigens. These data demonstrate an effector role for CD4⁺ T cells in hookworm immunity and disease pathogenesis. Ultimately, these studies may yield important insights into the relationship between intestinal nematode infections and diseases that are associated with CD4⁺ T‐cell depletion, including HIV.     

Immune formulation-assisted conventional therapy on anti-infective effectness of multidrug-resistant Mycobacterium tuberculosis infection mice

Objective:To study the effect of immune formulation-assisted conventional therapy on antiinfective ability of multidrug-resistant Mycobacterium tuberculous infection mice.Methods:BALB/c mice were used as experimental animals,multidrug-resistant Mycobacterium tuberculosis infection models were built,randomly divided into model group,moxifloxacin group,thymopentin group and combined treatment group and given corresponding drug intervention,and then colony numbers in the spleen and lung,T lymphocyte subset contents and programmed death-1(PD-1) expression levels in peripheral blood were detected.Results:Colony numbers in lung and spleen of moxifloxacin group and thymopentin group were significantly lower than those of model group and colony numbers in lung and spleen of combined treatment group were significantly lower than those of moxifloxacin group and thymopentin group:contents of CD3~+CD4~+T cells,Thl and Thl7 in peripheral blood of moxifloxacin group and thymopentin group were higher than dtose of model group,and contents of CD3~+CD8~+T cells.Th2 and Treg were lower than those of model group;contents of CD3~+CD4~+T cells.Th 1 and Th 17 in peripheral blood of combined treatment group were higher than those of moxifloxacin group and thymopentin group,and contents of CD3~+CD8~+T cells.Th2 and Treg were lower than those of moxifloxacin group and thymopentin group:PD-I expression levels on T lymphocyte,B lymphocyte and monocyte surface in peripheral blood of moxifloxacin group and thymopentin group were lower than those of model group,and PD-I expression levels on T lymphocyte.B lymphocyte and monocyte surface in peripheral blood of combined treatment group were lower than those of moxifloxacin group and thymopentin group.Conclusions:Immune formulation thymopentin can enhance the anti-infective ability of multidrug-resistant Mycobacterium tuberculosis infection mice,decrease bacterial load in lung and spleen,and enhance immune function.