The Th1/Th2 balance in autoimmunity

Imbalanced production of cytokines by T cells associates with the activation/exhaustion status of memory T cells in chronic HIV type 1 infection

Chronic HIV-1 infection is characterized by immune cell dysfunctions driven by chronic immune activation. Plasma HIV-1 viral load (VL) is closely correlated with disease progression and the level of immune activation. However, the mechanism by which the persistent presence of HIV-1 damages immune cells is still not fully understood. To evaluate how HIV-1 affects disruption of T cell-mediated immune responses during chronic HIV-1 infection we determined the functional profiles of T cells from subjects with chronic HIV-1 infection. We measured the capacity of peripheral blood mononuclear cells (PBMCs) to produce 25 specific cytokines in response to nonspecific T cell stimulation, and found that the capacity to produce Th-1-related cytokines (MIP-1α, MIP-1β, RANTES, IFN-γ, and MIG), sIL-2R, and IL-17, but not Th-2-related cytokines, was inversely correlated with plasma VL. The capacities to produce these cytokines were interrelated; notably, IL-17 production had a strong direct correlation with production of MIP-1α, MIP-1β, RANTES, and IFN-γ. In both CD4(+) and CD8(+) T cells, dysfunctional production of cytokines was associated with T cell activation (CD38 expression) and exhaustion (PD-1 and/or CTLA-4 expression) status of memory subsets. Although the capacity to produce these cytokines was recovered soon after multiple log(10) reduction of plasma viral levels by antiretroviral therapy, memory CD8(+) T cells remained activated and exhausted after prolonged virus suppression. Our data suggest that HIV-1 levels directly affect the ability of memory T cells to produce specifically Th1- and Th17-related cytokines during chronic HIV-1 infection.

Innate immunity and resistance to tolerogenesis in allotransplantation

The development of immunosuppressive drugs to control adaptive immune responses has led to the success of transplantation as a therapy for end-stage organ failure. However, these agents are largely ineffective in suppressing components of the innate immune system. This distinction has gained in clinical significance as mounting evidence now indicates that innate immune responses play important roles in the acute and chronic rejection of whole organ allografts. For instance, whereas clinical interest in natural killer (NK) cells was once largely confined to the field of bone marrow transplantation, recent findings suggest that these cells can also participate in the acute rejection of cardiac allografts and prevent tolerance induction. Stimulation of Toll-like receptors (TLRs), another important component of innate immunity, by endogenous ligands released in response to ischemia/reperfusion is now known to cause an inflammatory milieu favorable to graft rejection and abrogation of tolerance. Emerging data suggest that activation of complement is linked to acute rejection and interferes with tolerance. In summary, the conventional wisdom that the innate immune system is of little importance in whole organ transplantation is no longer tenable. The addition of strategies that target TLRs, NK cells, complement, and other components of the innate immune system will be necessary to eventually achieve long-term tolerance to human allograft recipients.

Effect of millimeter waves and cyclophosphamide on cytokine regulation

We have reported previously that millimeter waves (MMWs) protect T-cell functions from the toxic side effects of cyclophosphamide (CPA), an anticancer drug. Since the effect of MMWs has been reported to be mediated by endogenous opioids, the present study was undertaken to investigate the role of endogenous opioids in protection of T-cell functions by MMWs. The effect of MMWs (42.2 GHz, incident power density = 38 mW/cm²) was studied on CPA-induced suppression of cytokine release by T cells in the presence of selective opioid receptor antagonists (ORA). Production of cytokines was measured in CD4 T cells isolated from splenocytes. Treatment of mice with CPA suppressed the formation of Th1 cytokines (TNF-α, IFN-γ, and IL-2), shifting the overall balance toward Th2 (IL-4 and IL-5). MMW irradiation of CPA-treated groups up-regulated the production of Th1 cytokines suppressed by CPA. Treatment of the CPA+MMW group with selective kappa (κ) ORA further potentiated this effect of MMWs on Th1 cytokine production, whereas treatment with μ or δ ORA increased the imbalance of cytokine production in the Th2 direction. These results provide further evidence that endogenous opioids are involved in immunomodulation by MMWs.

[Hodgkin disease and autoimmunity in children: 11 case reports]

The association of lymphoma and autoimmune manifestations has been predominantly studied in adults affected by non-Hodgkin lymphoma. Few publications exist in the literature concerning Hodgkin lymphoma, particularly in children and adolescents. The objectives of this study were to define the characteristics of the link between Hodgkin disease and autoimmunity in childhood. The present 25-year retrospective study was conducted in all centers affiliated with the French Society of Paediatric Oncology (SFCE). Eleven children with Hodgkin disease presented manifestations of disimmunity preceding or following their diagnosis. Four patients had thrombocytopenic purpura, the remaining 7 each had a different autoimmune pathology: lupus syndrome, antiphospholipid syndrome with transient ischemic attack, Evans syndrome, leukocytoclastic vasculitis, autoimmune hemolytic anemia, autoimmune thyroiditis, and juvenile idiopathic arthritis. Lymphoma relapse occurred in 3 patients. Two children died, death being directly attributed to the autoimmune disease in 1 case. Our data suggest that development of autoimmunity is related to significant morbidity. Possible pathophysiological mechanisms include lymphocyte proliferation secondary to chronic inflammation, cell-mediated immune deficiency in Hodgkin disease, molecular mimetics, and antineoplastic phenomena are discussed. A study with a larger patient population is needed to identify the group of children at high risk of autoimmunity for whom additional investigations and modified therapy may be indicated.

The effects of alcoholism pharmacotherapy on immune responses in alcohol-dependent patients

Chronic alcohol use has profound modulatory effects on the immune system. Both the innate and the acquired immunity are compromised. The use of pharmacotherapy is increasingly applied to enhance the percentage of success in maintaining alcoholic patients in remission. Disulfiram, naltrexone and gamma hydroxybutiric acid are the drugs used for this purpose in Italian Addiction Services. In this study we analyze the effect of pharmacotherapy of alcohol dependence on immune responses in alcoholics. Six groups were studied. Group A included 10 patients who were still using alcohol. Group B consisted of 10 patients abstinent from alcohol in treatment only with group therapy. Groups C, D and E were composed of 10 patients each, treated for at least 6 months with oral doses of gamma hydroxybutiric acid, naltrexone or disulfiram respectively. Ten age- and sex-matched healthy volunteers who never misused alcohol were included as a control group. Lymphoproliferation and peripheral mononuclear cell production of the Th1 cytokines IL-2 and IFN-gamma, the Th2 cytokine IL-4, and of the pro-inflammatory cytokines IL-1 and TNF-alpha were evaluated in all the patients and controls. The level of activity of the hypothalamus pituitary adrenal axis was assessed. Both ACTH and cortisol levels in plasma were elevated in alcoholic patients with no treatment. In this group a significant alteration of cytokine production was observed. TNF and IFN-gamma were lower than controls, while the Th2 cytokine IL-4 was increased. These altered levels state for a Th1/Th2 unbalance characterized by decreased Th1 response in the presence of Th2 predominance. In patients undergoing pharmacological treatment, none of the immune parameters were different from those observed in healthy controls, independently of the type of drug administered. These data indicate that pharmacotherapy more than group therapy treatment is able to ameliorate the immune system functioning in alcoholic patients.

Decoy receptor 3 protects non-obese diabetic mice from autoimmune diabetes by regulating dendritic cell maturation and function

Decoy receptor 3 (DcR3), a member of the tumor necrosis factor receptor superfamily, regulates immune responses through competing with receptors of Fas ligand (FasL), LIGHT and TNF-like molecule 1A (TL1A). We have previously demonstrated that transgenic expression of DcR3 in a β cell-specific manner significantly protects non-obese diabetic (NOD) mice from autoimmune diabetes. In this study, we further investigated the systemic effect of DcR3 in regulating lymphocytes and dendritic cells in NOD mice. Our results demonstrated that both DcR3 plasmid and protein treatments significantly inhibited insulitis and diabetes. Lymphocytes from DcR3.Fc-treated mice revealed less proliferative potential and transferred ameliorated diabetes. By administration of DcR3.Fc in T1 and T2 double transgenic NOD mice expressing human Thy1 or murine Thy1.1 surface marker under IFN-γ or IL-4 promoter control respectively, we observed a remarkable reduction of Th1 and an increase of Th2 immune responses in vivo. Strikingly, in vitro polarization experiments exhibited that not only Th1 but also Th17 cell differentiation was significantly inhibited in splenocytes treated with DcR3.Fc protein. However, this phenomenon was only observed in splenocytes, not in purified CD4(+) T cells, suggesting that DcR3-mediated inhibition of Th1 and Th17 differentiation is not T cell-autonomous and maybe through other cell types such as dendritic cells. Finally, our results demonstrated that DcR3 directly modulates the differentiation and maturation of dendritic cells and subsequently regulates the differentiation and effector function of T cells.

Repeated gamma irradiation attenuates collagen-induced arthritis via up-regulation of regulatory T cells but not by damaging lymphocytes directly

We recently reported that repeated 0.5-Gy gamma irradiation attenuates the pathology of collagen-induced arthritis. In this study, to investigate the mechanism further, we focused on changes in Treg/Th17 cells and changes in the production of antibody against an external antigen in response to gamma irradiation as well as on the radiosensitivity of Treg cells. DBA/1J mice were immunized with type II collagen to induce arthritis and exposed to low-dose gamma rays (0.5 Gy/week for 5 weeks). Production of IL6 and IL17 as well as autoantibody was suppressed by irradiation in the early phase of collagen-induced arthritis. The percentage of Treg cells was significantly increased by irradiation at 4, 6 and 8 weeks after the immunization. We also investigated the effect of repeated gamma radiation on the production of antibodies against an external antigen in ovalbumin-immunized BALB/c mice. We found that repeated 0.5-Gy gamma irradiation enhanced antibody production, accompanied by an increase of the antibody-producing plasma cell population and increased Th2-type cytokine secretion. We also found that the radiosensitivity of Treg cells did not differ from that of other T cells. These results suggest that a major mechanism of attenuation of the pathology of collagen-induced arthritis by repeated 0.5-Gy gamma irradiation is up-regulation of Treg cells concomitantly with suppression of IL6 and IL17 production.

The effect of magnetic nanoparticles of Fe(3)O(4) on immune function in normal ICR mice

We investigated the effect of magnetic nanoparticles of Fe₃O₄ (Fe₃O₄-MNPs) on the mice immune system. Imprinting control region (ICR) mice were assigned randomly into four groups and treated with normal saline or low, medium, or high doses of Fe₃O₄-MNPs, respectively. After intravenous administration of Fe₃O₄-MNPs for 72 hours, the peripheral T cells and the induction of primary immune responses in mice were investigated by flow cytometry and determined using enzyme-linked immunosorbent assay, respectively. The results showed that the ratio of spleen to body weight was not different between the experimental groups and control group (P > 0.05). The lymphocyte transformation rates in the suspension of spleen were higher in low-dose group than those in the control group (P < 0.05), while the proliferation of splenocytes was low in the medium and high groups when compared to the control group (P < 0.05). In peripheral blood, both the proportions of subset CD4⁺ and CD8⁺ T lymphocytes in the low-dose group were higher than those in the control group, whereas there was no difference in the number of CD4⁺ T cells between the medium- and low-dose groups. Interestingly, the Fe₃O₄-MNPs enhanced the production of interleukin-2 (IL-2), interferon-γ, and IL-10 but did not affect the production of IL-4 in peripheral blood. It is concluded that Fe₃O₄-MNPs could influence immune functions of normal ICR mice in a dose-dependent manner.

SATB1 dictates expression of multiple genes including IL-5 involved in human T helper cell differentiation

Special AT-rich binding protein 1 (SATB1) is a global chromatin organizer and a transcription factor regulated by interleukin-4 (IL-4) during the early T helper 2 (Th2) cell differentiation. Here we show that SATB1 controls multiple IL-4 target genes involved in human Th cell polarization or function. Among the genes regulated by SATB1 is that encoding the cytokine IL-5, which is predominantly produced by Th2 cells and plays a key role in the development of eosinophilia in asthma. We demonstrate that, during the early Th2 cell differentiation, IL-5 expression is repressed through direct binding of SATB1 to the IL-5 promoter. Furthermore, SATB1 knockdown-induced up-regulation of IL-5 is partly counteracted by down-regulating GATA3 expression using RNAi in polarizing Th2 cells. Our results suggest that a competitive mechanism involving SATB1 and GATA3 regulates IL-5 transcription, and provide new mechanistic insights into the stringent regulation of IL-5 expression during human Th2 cell differentiation.

Impaired activation of IFN-gamma+CD4+ T cells in peripheral blood of patients with dilated cardiomyopathy

Viral persistence and autoantibodies are pathogenic components in patients with idiopathic dilated cardiomyopathy (DCM). The aim was to evaluate T-cell function in DCM using different flow cytometry based detection techniques. Following stimulation, the frequency of IFN-gamma-producing CD4+ T cells was significantly lower in patients compared with controls. In contrast, the frequency of IL-4 producing CD4+ T cells was no different. In supernatants of cultured PBMC, IFN-gamma and IL-10 were significantly lower in patients. In addition, lymphocyte proliferation was significantly lower in patients compared with controls, whereas major lymphocyte subsets were not different. IFN-gamma and IL-10 are key cytokines in the ability to mount protective immune responses and to maintain self-tolerance. A reduced activation of T-helper 1 (IFN-gamma producing) cells and a decreased capacity to produce IL-10, found in the present study, could explain parts of the autoimmune features seen in patients with DCM.

Cytokine-dependent modification of IL-12p70 and IL-23 balance in dendritic cells by ligand activation of Valpha24 invariant NKT cells

CD1d-restricted invariant NKT (iNKT) cells play crucial roles in various types of immune responses, including autoimmune diseases, infectious diseases and tumor surveillance. The mechanisms underlying their adjuvant functions are well understood. Nevertheless, although IL-4 and IL-10 production characterize iNKT cells able to prevent or ameliorate some autoimmune diseases and inflammatory conditions, the precise mechanisms by which iNKT cells exert immune regulatory function remain elusive. This study demonstrates that the activation of human iNKT cells by their specific ligand alpha-galactosylceramide enhances IL-12p70 while inhibiting the IL-23 production by monocyte-derived dendritic cells, and in turn down-regulating the IL-17 production by memory CD4(+) Th cells. The ability of the iNKT cells to regulate the differential production of IL-12p70/IL-23 is mainly mediated by a remarkable hallmark of their function to produce both Th1 and Th2 cytokines. In particular, the down-regulation of IL-23 is markedly associated with a production of IL-4 and IL-10 from iNKT cells. Moreover, Th2 cytokines, such as IL-4 and IL-13 play a crucial role in defining the biased production of IL-12p70/IL-23 by enhancement of IL-12p70 in synergy with IFN-gamma, whereas inhibition of the IFN-gamma-promoted IL-23 production. Collectively, the results suggest that iNKT cells modify the IL-12p70/IL-23 balance to enhance the IL-12p70-induced cell-mediated immunity and suppress the IL-23-dependent inflammatory pathologies. These results may account for the long-appreciated contrasting beneficial and adverse consequence of ligand activation of iNKT cells.

Cytotoxic T-lymphocyte antigen 4 gene polymorphisms are associated with latent autoimmune diabetes in adults

BACKGROUND

Cytotoxic T lymphocyte antigen-4 (CTLA-4) molecule is an important regulator of T cell activation involved in the down-regulation of immune response. Polymorphisms within the CTLA-4 gene have been suggested to confer susceptibility to autoimmune endocrine disorders.

METHODS

In order to evaluate the impact of allelic variants of the CTLA-4 gene in latent autoimmune diabetes in adults (LADA), the CT60 A/G SNP and the CTBC217_1 C/T SNP were studied in a population of Estonian origin, including 61 LADA patients and 230 controls.

RESULTS

It was found that the CT60 GG genotype (p=0.004) and the CTBC217_1 TT genotype (p=0.007) were significant associated with LADA.

CONCLUSIONS

Our investigation revealed that not only type 1 diabetes but also LADA is associated with CTLA-4 gene polymorphisms. The role of CTLA-4 gene in the pathogenesis of LADA is open and needs further investigations.

Quantitative analysis of inflammatory cytokines expression in peripheral blood mononuclear cells of the ferret (Mustela putorius furo) using real-time PCR

This study describes the expression pattern of cytokines, interferon-gamma (IFN-gamma), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and IL-10, produced by LPS stimulation in peripheral blood mononuclear cells (PBMCs) of the ferret (Mustela putorius furo). Real-time PCR was used with TaqMan probes, which were modified by dual-labeled probes (TAMRA/FAM), quantitative analysis of cytokine mRNA comparing the cytokine with the housekeeping gene, ferret GAPDH, as the relative C(t) value. Expression peaks of IFN-gamma, TNF-alpha, IL-6 mRNA occurred 2 h after LPS stimulation, whereas the IL-10 peak was 8 h post-LPS. In the present study, peak cytokine expression was detected within 8 h, similar to several other mammalian studies. This current study provides baseline information on inflammatory cytokines of ferret PBMCs.

The prokineticin receptor agonist Bv8 decreases IL-10 and IL-4 production in mice splenocytes by activating prokineticin receptor-1

Background

Bv8, prokineticin-1, or endocrine gland-vascular endothelial growth factor, and prokineticin-2 are recently isolated peptide agonists of two G protein-coupled receptors, prokineticin receptor-1 (PROKR 1) and PROKR 2, and have been described as affecting a number of myeloid cell functions. We evaluated the impact of Bv8 on lymphoid cells by investigating its ability to modulate T cell cytokine balance in mouse.

Results

The production of T-helper1 cytokines (IL-2, IFN-γ and IL-1β), the T-helper 2 cytokine IL-4, and the anti-inflammatory cytokine IL-10 by mouse splenocytes was evaluated after polyclonal stimulation or immunisation with the keyhole limpet hemocyanin protein antigen by measuring cytokine levels. When added in vitro to Con-A-stimulated splenocytes, Bv8 significantly increased IL-1β and decreased IL-4 and IL-10; IL-2 and IFN-γ were not affected. Similar results were obtained when Bv8 was administered in vivo. In KLH-immunised mice, splenocytes restimulated in vitro with KLH and Bv8 produced significantly smaller amounts of IL-4 and IL-10. KLH-induced IL-10 and IL-4 production was also significantly blunted in animals administered Bv8 in vivo at the time of KLH immunisation or two weeks later. The Bv8-induced effects were lost in mice lacking the PROKR 1 gene, thus indicating that PROKR 1 is the receptor involved in the modulation of cytokines.

Conclusion

These findings indicate that Bv8/prokineticin-1 is a novel modulator of lymphoid functions, and may be a suitable target for new immunopharmacological strategies.

Induction and effector functions of T(H)17 cells

T helper (T(H)) cells constitute an important arm of the adaptive immune system because they coordinate defence against specific pathogens, and their unique cytokines and effector functions mediate different types of tissue inflammation. The recently discovered T(H)17 cells, the third subset of effector T helper cells, have been the subject of intense research aimed at understanding their role in immunity and disease. Here we review emerging data suggesting that T(H)17 cells have an important role in host defence against specific pathogens and are potent inducers of autoimmunity and tissue inflammation. In addition, the differentiation factors responsible for their generation have revealed an interesting reciprocal relationship with regulatory T (T(reg)) cells, which prevent tissue inflammation and mediate self-tolerance.

Buprenorphine and methadone maintenance treatment of heroin addicts preserves immune function

Opiate addiction influences many physiological functions including immune responses. The objective of this study was to investigate the immune system function in heroin addicted patients submitted to methadone or buprenorphine maintenance treatment compared to untreated heroin addicts and healthy controls. Four groups were studied: group A included nine heroin addicted subjects, who were still injecting heroin; groups B and C were composed of 12 patients previously addicted to heroin, being treated with methadone (mean dosage 58+/-12.7 mg/day) or buprenorphine (mean dose 9.3+/-2.3mg/day) since at least 6 months; group D was composed of 15 sex and age matched healthy controls. Lymphoproliferation and peripheral mononuclear cell cultures production of the Th1 cytokines IL-2 and IFN-gamma, the Th2 cytokine IL-4, and of the pro-inflammatory cytokine TNF-alpha were evaluated in all the patients and controls. PHA-lymphoproliferation was lower in untreated heroin addicts than in controls, while it was normal in methadone and buprenorphine treated patients. An altered Th1/Th2 balance, characterized by reduced IL-4, IFN-gamma and TNF-alpha but normal IL-2 levels, was present in untreated heroin addicted subjects, while the Th1/Th2 balance was well conserved in the methadone and buprenorphine groups. These findings suggest that the immune system abnormalities in heroin addicted patients can be restored to almost normal values by controlled treatment with methadone and buprenorphine.

Pathogenesis of myocarditis and dilated cardiomyopathy

Myocarditis is a disease with a variable clinical presentation, ranging from asymptomatic to a fatal outcome. Among the recognized causes of myocarditis are mutations in multiple genes; infection by bacterial, rickettsial, mycotic, protozoan, and viral agents; and exposure to drugs, toxins, and alcohol. Some subtypes of myocarditis, such as giant cell myocarditis or eosinophilic necrotizing myocarditis, are suspected to be caused by an autoimmune inflammation. Several lines of evidence support the involvement of autoimmunity in myocarditis. These include the production of antibodies against relevant self-antigens, the fact that myocarditis symptoms can be relieved by immunosuppressive therapy in some patients, and a co-occurrence of myocarditis with other autoimmune diseases. Most of the evidence that myocarditis is an autoimmune disease comes from animal models. In this chapter, we discuss coxsackievirus B3-induced myocarditis and myosin-induced myocarditis as models of both viral and autoimmune inflammation in the heart. The latest advances in the study of autoimmunity have been concentrated on T helper cells, particularly the newly discovered subset, Th17 cells. Experimental autoimmune myocarditis (EAM), a mouse model of myocarditis induced by cardiac myosin, is partly an IL-17-driven disease. However, we have shown recently in IL-13 knockout mice that the disease can be driven through other pathways, and that the Th1 helper cells also lead to severe heart inflammation. Most importantly, IL-17A knockout mice are not fully protected against EAM and still develop mild myocarditis. The most abundant cells in heart infiltrate in human giant cell myocarditis or EAM are monocyte/macrophages, and there is now evidence that macrophages play a decisive role in the course of EAM.

Expression of IL-27 p28 by Theiler's virus-infected macrophages depends on TLR3 and TLR7 activation of JNK-MAP-kinases

Theiler's murine encephalomyelitis virus (TMEV) causes a demyelinating disease (DD) due to infection of macrophages, stimulation of macrophage Toll-like receptor (TLR)3 and TLR7 pathways, activation of Mitogen-activated protein kinases (MAPK)s, and production of macrophages cytokines. Because expression of IL-27, a macrophage cytokine composed of p28 and EBI3 subunits, has been implicated in DD, we examined IL-27 subunit mRNA expression during TMEV infection of RAW264.7 cells, a macrophage cell line. TMEV infection of RAW264.7 cells did not affect cell viability, resulted in viral RNA replication, as well as p28 and EBI3 expression. Expression of p28 in TMEV-infected RAW264.7 cells depended on TLR3 and TLR7, as well as JNK but not p38 or ERK MAPKs. Since TMEV causes DD in SJL/J but not B10.S mice we determined the difference in expression of IL-27 subunit mRNA in SJL/J compared to B10.S macrophages. SJL/J macrophages expressed significantly more p28 mRNA after TMEV infection and after stimulation with TLR3 and TLR7 agonists compared with B10.S macrophages. Therefore, macrophages expression of IL-27 p28 mRNA in response to TMEV is due to activation of TLR3, TLR7, and JNK MAPKs pathways.

The envelope protein of a human endogenous retrovirus-W family activates innate immunity through CD14/TLR4 and promotes Th1-like responses

Multiple sclerosis-associated retroviral element (MSRV) is a retroviral element, the sequence of which served to define the W family of human endogenous retroviruses. MSRV viral particles display proinflammatory activities both in vitro in human mononuclear cell cultures and in vivo in a humanized SCID mice model. To understand the molecular basis of such properties, we have investigated the inflammatory potential of the surface unit of the MSRV envelope protein (ENV-SU), the fraction that is poised to naturally interact with host cells. We report in this study that MSRV ENV-SU induces, in a specific manner, human monocytes to produce major proinflammatory cytokines through engagement of CD14 and TLR4, which are pattern recognition receptors of primary importance in innate immunity. ENV-SU could also trigger a maturation process in human dendritic cells. Finally, ENV-SU endowed dendritic cells with the capacity to support a Th1-like type of Th cell differentiation. The data are discussed in the context of immune responses and chronic proinflammatory disorders.

Sex differences in proinflammatory cytokine profiles of progressive patients in multiple sclerosis

The objective of this article is to evaluate the presence of sex differences in expression of cytokines in both CD4+ and CD8+ T cells derived from peripheral blood of untreated multiple sclerosis (MS) patients. The predominance of females in MS and other autoimmune diseases may be related to their differential responses in many immunological settings. Recent data show beneficial effect of sex hormones on proinflammatory cytokine levels and on magnetic resonance imaging in MS. Better understanding of gender differences is warranted. In this study 124 MS subjects (M:F; 56:68) and 34 healthy controls (M:F; 12:22) were included. Stimulated peripheral blood-derived CD4+ and CD8+ T cells were analysed for interferon-gamma, interleukin (IL)-2, tumour necrosis factor alpha, IL-4, IL- 10 and IL- 13 production. There were no significant differences for these cytokines between male and female MS subjects in the whole group. Compared to males, female patients had higher proinflammatory cytokine levels in the progressive phase of the disease. In conclusion, the data presented indicate that cytokine production and sex differences in cytokine production might differ between disease phases, probably related to underlying disease mechanisms.

Role of IL-27-producing dendritic [corrected] cells in Th1-immunity polarization in Lewis rats

Lewis and Brown Norway rats are entirely different with respect to the polarization of their immune responses (Th1 and Th2, respectively). We found that naive Lewis rat splenocytes treated in vitro with heat-killed Mycobacterium tuberculosis (Mtb) upregulate the expression of both subunits of IL-27 (IL-27p28 and EBI3). Mtb treatment caused naive Lewis rat splenocytes to express 4.6-fold more IL-27p28 than Mtb-treated Brown Norway rat splenocytes 6h after the treatment. Although WSX-1, the IL-27 receptor, was not induced by Mtb treatment in splenocytes from either rat strain, Lewis rats expressed significantly higher levels of the IL-27 signal transducers T-bet and IL-12Rbeta2 than Brown Norway rats. Flow cytometric analysis of dendritic cells from bone marrow cells revealed Lewis rats had more IL-27p28-positive cells. Thus, early in the immune response, Lewis rats appear to produce higher levels of IL-27 than Brown Norway rats, resulting in polarization towards Th1-immunity.

Expression of cytokine mRNA and protein in joints and lymphoid organs during the course of rat antigen-induced arthritis

Cytokine expression was assessed during antigen-induced arthritis (AIA) in synovial membrane (SM), inguinal lymph node (LN), and spleen using competitive RT-PCR and sandwich ELISA. In the SM, early elevations of IL-1β and IL-6 mRNA (by 6 hours; 450- and 200-fold, respectively) correlated with the joint swelling; a 6-fold increase in tumor necrosis factor α (TNFα) was not significant. Not only IL-2 and IFN-γ (which increased 10,000-fold and 200-fold, respectively), but also IL-5 and IL-10, increased acutely (6 hours – day 1; 3-fold and 35-fold, respectively) in the SM. In general, the protein levels in the SM for IL-1β, IL-6, TNFα, IFN-γ, IL-4, and IL-10 (increase from 4-fold to 15-fold) matched the course of mRNA expression. In the inguinal LN, there were early mRNA elevations of IL-6 (a 2.5-fold increase by 6 hours, which correlated positively with the joint swelling) and IL-2 (4-fold by 6 hours), as well as later rises of IL-4 and IL-5 (2.5- and 4-fold, respectively, by day 3). No significant elevations of the corresponding proteins in this tissue were observed, except for IL-1β (by day 6) and IL-10 (by day 1). In the spleen, there were significant mRNA elevations at 6 hours of IL-1β (1.5-fold), IL-6 (4-fold; positively correlated with the joint swelling), IFN-γ (3-fold), and IL-2 (7- to 10-fold). IL-5 and IL-10 (2- and 3-fold, respectively) peaked from 6 hours to day 3 in the spleen. Increases of the corresponding proteins were significant in comparison with day 0 only in the case of IL-2 (day 6). By day 6 (transition to the chronic phase), the mRNA for cytokines declined to or below prearthritis levels in all the tissues studied except for IL-1β in the SM and IL-6 in the spleen. AIA is thus characterized by four phenomena: early synovial activation of macrophages, T helper (Th)1-like, and Th2-like cells; late, well-segregated Th2-like responses in the inguinal LN; late, overlapping Th1-like/Th2-like peaks in the spleen; and chronic elevation of synovial IL-1β mRNA and spleen IL-6 mRNA.

An integrated view of suppressor T cell subsets in immunoregulation

The immune system evolved to protect organisms from a virtually infinite variety of disease-causing agents but to avoid harmful responses to self. Because immune protective mechanisms include the elaboration of potent inflammatory molecules, antibodies, and killer cell activation--which together can not only destroy invading microorganisms, pathogenic autoreactive cells, and tumors, but also mortally injure normal cells--the immune system is inherently a "double-edged sword" and must be tightly regulated. Immune response regulation includes homeostatic mechanisms intrinsic to the activation and differentiation of antigen-triggered immunocompetent cells and extrinsic mechanisms mediated by suppressor cells. This review series will focus on recent advances indicating that distinct subsets of regulatory CD4+ and CD8+ T cells as well as NK T cells control the outgrowth of potentially pathogenic antigen-reactive T cells and will highlight the evidence that these suppressor T cells may play potentially important clinical roles in preventing and treating immune-mediated disease. Here we provide a historical overview of suppressor cells and the experimental basis for the existence of functionally and phenotypically distinct suppressor subsets. Finally, we will speculate on how the distinct suppressor cell subsets may function in concert to regulate immune responses.

Impaired type I IFN-induced Jak/STAT signaling in FA-C cells and abnormal CD4+ Th cell subsets in Fancc-/- mice

The Fanconi anemia (FA) group C protein, FANCC, interacts with STAT1 following stimulation with IFN-gamma and is required for proper docking of STAT1 at the IFN-gamma receptor alpha-chain (IFN-gammaRalpha, IFN-gammaR1). Consequently, loss of a functional FANCC results in decreased activation of STAT1 following IFN-gamma stimulation. Because type I IFN receptors influence the function of type II receptors, and vice versa, we conducted experiments designed to determine whether type I IFN-induced activation of other STAT proteins is compromised in FA-C cells and found that activation of STAT 1, 3, and 5 is diminished in type I IFN-stimulated cells bearing Fancc-inactivating mutations. We also determined that the reduced activation of STATs was accompanied by significant reduction of type I IFN-induced tyrosine kinase 2 and Jak1 phosphorylation. Because tyrosine kinase 2 plays a role in differentiation of Th cells, we quantified cytokine secretion from CD4+ cells and in vitro generated CD4+ Th cell subsets from splenocytes of Fancc null mice to that of heterozygous mice and discovered reduced CD4+ IFN-gamma secretion in the Fancc-/- mouse, indicating impaired Th1 differentiation. We suggest that Fancc mutations result in a subtle immunological defect owing to the failure of FANCC to normally support Jak/STAT signaling.

Anti-A?: The good, the bad, and the unforeseen

Alzheimer's disease (AD) is characterized in part by the deposition of amyloid beta protein (Abeta) in compact fibrillar plaques. These structures can induce an innate immune response in the brain, which triggers progressive inflammation, neuronal loss, and further acceleration of Abeta plaque formation. Compared with the case in normal individuals, the T and B lymphocytes in AD patients and murine models are hyporesponsive to Abeta. However, depending on the route of delivery, tolerance can be overcome by vaccination, with the induction of an anti-Abeta-mediated immune response. Through mechanisms that are incompletely understood, immunized APP transgenic animals show markedly reduced Abeta deposition, preservation of normal neuronal architecture, and improved performance in memory and spatial learning tasks. In human trials, Abeta vaccination stabilized cognition and slowed the progression of dementia. Neuropathologic examination of a vaccinated subject showed reduced cortical Abeta without changes in other AD-associated pathology. However, in some patients, vaccination induced severe meningoencephalitis, causing the trial to be terminated. Thus, vaccination appears to activate both beneficial and deleterious anti-Abeta immunity, suggesting that the vaccine can have potent clinical utility if an appropriate immunologic response can be generated.

Comparison of adjuvant efficacy of herpes simplex virus type 1 recombinant viruses expressing TH1 and TH2 cytokine genes

The adjuvant effects of cytokines in humoral and cell-mediated immunity to herpes simplex virus type 1 (HSV-1) have been examined in mice using HSV-1 recombinant viruses expressing murine interleukin-2 (IL-2), IL-4, or gamma interferon (IFN-gamma) gene. Groups of naive BALB/c mice were immunized intraperitoneally with one or three doses of the HSV-1 recombinant viruses expressing IL-2, IL-4, or IFN-gamma or with parental control virus. Despite similar replication kinetics, these three recombinant viruses elicited different immune responses to HSV-1 on immunization. Immunization with the recombinant virus expressing IL-4 elicited a humoral response of greater magnitude than immunization with the recombinant viruses expressing IL-2 or IFN-gamma or with parental virus. In contrast, immunization with recombinant virus expressing IL-2 elicited a higher cytotoxic T-cell response than immunization with viruses expressing IL-4 or IFN-gamma. Stimulation in vitro of splenocytes obtained from the mice immunized with UV-inactivated HSV-1 McKrae resulted in a T(H)1 pattern of cytokine expression irrespective of the recombinant virus used in the immunization. As observed for the parental virus, both CD4(+) and CD8(+) T cells contributed equally to the production of IL-2 by the splenocytes of mice immunized with any of the three recombinant viruses. However, the pattern of IFN-gamma production by CD4(+) and CD8(+) T cells differed according to the recombinant virus used. After lethal ocular challenge, all immunized mice were protected completely against death and manifestations of eye disease caused by HSV-1, which are typical responses in unimmunized mice. Mice immunized with IL-4-expressing virus cleared the virus from their eyes more rapidly than mice immunized with IL-2- or IFN-gamma-expressing virus. Taken together, our results suggest that, in contrast to IFN-gamma which did not exhibit an adjuvant effect, both IL-4 and IL-2 act as adjuvants in immunization with HSV, with IL-4 showing greater efficacy.

Genetic background determines sensitivity to the inhibitory function of NO on T cell proliferation and the amounts of NO production mediated through IFN-gamma

Abstract: Nitric oxide (NO) inhibits T cell proliferation. We demonstrate that the action of NO on T cell proliferation is different for Lewis and Brown Norway (BN) rats. Splenocytes from Lewis rats consistently showed higher proliferation against concanavalin A than splenocytes from BN rats did. In contrast, NO production was higher in BN rats than in Lewis rats. A depletion of adherent cells increased proliferation in BN rats to a level similar to that in Lewis rats. Thus NO produced by adherent splenocytes could be considered to inhibit proliferation. The addition of NG-monomethyl-L-arginine, a potent inhibitor of NO production, increased proliferation in Lewis rats, but much less so in BN rats. Similar results were obtained by the addition of anti-interferon (IFN)-gamma. It is surprising that, low doses of sodium nitroprusside, an NO donor, increased proliferation in BN rats but not in Lewis rats. To investigate the mechanism of differential NO production between the two strains, splenocytes were stimulated with IFN-gamma. The early signaling event evaluated by the phosphorylation of Stat-1 was similar in both strains, whereas inducible NO synthase (iNOS) mRNA expression seemed more sustained in BN rats. Thus the differential production of NO might be related to the differential transcriptional regulation of iNOS. Altogether, genetic background might be involved in sensitivity to the inhibitory function of NO for T cell proliferation and NO production.

Enhanced clearance of herpes simplex virus type 1 and reduced herpetic eye disease in STAT6 knockout mice is associated with increased IL-2

STAT6 (signal transducers and activators of transcription 6)-deficient (STAT6-/-) mice have defects in IL-4- and IL-13-mediated functions and thus have a reduced T(H)2-mediated immune response. Conversely, they have elevated levels of IL-2 and thus an increased T(H)1-mediated immune response. To assess the relative impact of reduced T(H)2- and elevated T(H)1-dependent immune responses on HSV-1 infection, vaccinated and mock-vaccinated STAT6-/- mice were challenged ocularly with HSV-1. Mock-vaccinated STAT6-/- mice were as susceptible to lethal HSV-1 infection as parental BALB/c mice. Mock-vaccinated STAT6-/- mice had reduced HSV-1 titers in their eyes compared to BALB/c mice. Furthermore, mock-vaccinated STAT6-/- mice had significantly less corneal scarring than their BALB/c counterparts. Vaccination induced significantly higher serum-neutralizing antibody titers in STAT6-/- mice compared to BALB/c mice, while completely protecting both types of mice against HSV-1-induced death and corneal scarring. Vaccinated STAT6-/- mice had reduced HSV-1 titers in their eyes compared to BALB/c mice. Lymphocytes from both vaccinated and mock-vaccinated STAT6-/- mice secreted higher amounts of IL-2 than lymphocytes from BALB/c mice, in the presence or absence of stimulation with UV-inactivated HSV-1. Finally, depletion of IL-2 increased ocular virus replication in STAT6-/- mice to levels similar to that measured in BALB/c mice. Our results suggest that in the absence of the STAT6 pathway, IL-2-mediated immune responses are up-regulated. This, in turn, leads to faster viral clearance and, consequently, lower levels of eye disease.

Preferential induction of IL-10 in APC correlates with a switch from Th1 to Th2 response following infection with a low pathogenic variant of Theiler's virus

Theiler's murine encephalomyelitis virus induces immune-mediated demyelination in susceptible mice after intracerebral inoculation. A naturally occurring, low pathogenic Theiler's murine encephalomyelitis virus variant showed a single amino acid change within a predominant Th epitope from lysine to arginine at position 244 of VP1. This substitution is the only one present in the entire viral capsid proteins. In this paper, we demonstrate that the majority of T cells specific for VP1(233-250) and VP2(74-86) from wild-type virus-infected mice are Th1 type and these VP1-specific cells poorly recognize the variant VP1 epitope (VP1(K244R)) containing the substituted arginine. In contrast, the Th2-type T cell population specific for these epitopes predominates in variant virus-infected mice. Immunization with UV-inactivated virus or VP1 epitope peptides could not duplicate the preferential Th1/Th2 responses following viral infection. Interestingly, the major APC populations, such as dendritic cells and macrophages, produce IL-12 on exposure to the pathogenic wild-type virus, whereas they preferentially produce IL-10 in response to the low pathogenic variant virus. Thus, such a spontaneous mutant virus may have a profoundly different capability to induce Th-type responses via selective production of cytokines involved in T cell differentiation and the consequent pathogenicity of virally induced immune-mediated inflammatory diseases.

Unique therapeutic effects of the Japanese-Chinese herbal medicine, Sairei-to, on Th1/Th2 cytokines balance of the autoimmunity of MRL/lpr mice

Sairei-to, one of the Japanese-Chinese herbal medicines has been used for the treatment of various diseases, especially collagen disease and edema in nephrotic syndrome. However, the mechanism of the therapeutic effects remains uncertain. Therefore, we investigated the immunological changes of skin, kidney, spleen cells and serum in autoimmune-prone MRL/lpr, MRL/n and C57BL/6J mice treated with Sairei-to. In MRL/lpr mice treated with Sairei-to, the improvement of proteinuria, reduction in the number of hematoxylin bodies in kidney, and reduced serum levels of blood urea nitrogen were observed. These results indicate that Sairei-to can improve or inhibit the progression of lupus nephritis. The proportion of CD19 and the serum levels of IgG1, which is one of the pathogenesis of lupus dermatoses and lupus nephritis, were significantly reduced in Sairei-to-treated MRL/lpr mice. Therefore, it is suspected that the B cell function was suppressed by Sairei-to. In addition, CD4/8 ratio in spleen cells and the degree of lymphoproliferation in MRL/lpr mice also decreased. Interestingly, IL-4 producing spleen cells were increased significantly by ELISPOT assay, and IFN-gamma mRNA expressions were reduced in Sairei-to-treated MRL/lpr mice. Regarding the Th balance, an imbalance towards Th1 predominance may play a significant role in MRL/lpr mice, and the Th1 axis was suppressed and the Th2 axis became predominant in Sairei-to-treated MRL/lpr mice. On the other hand, Th2 cell type immunoglobulins (IgG1) were suppressed. These results suggested that Sairei-to is potential for impairing shifted Th1/Th2 balance and hypergammaglobulinemia resulting in therapeutic effects.

From farm to table to brain: foodborne pathogen infection and the potential role of the neuro-immune-endocrine system in neurotoxic sequelae

The American diet is among the safest in the world; however, diseases transmitted by foodborne pathogens (FBPs) still pose a public health hazard. FBPs are the second most frequent cause of all infectious illnesses in the United States. Numerous anecdotal and clinical reports have demonstrated that central nervous system inflammation, infection, and adverse neurological effects occur as complications of foodborne gastroenteritis. Only a few well-controlled clinical or experimental studies, however, have investigated the neuropathogenesis. The full nature and extent of neurological involvement in foodborne illness is therefore unclear. To our knowledge, this review and commentary is the first effort to comprehensively discuss the issue of FBP induced neurotoxicity. We suggest that much of this information supports the role of a theoretical model, the neuro-immune-endocrine system, in organizing and helping to explain the complex pathogenesis of FBP neurotoxicity.

Th1 and Th2 responses in pathogenesis and regulation of experimental autoimmune uveoretinitis

Experimental autoimmune uveoretinitis (EAU) in animals can be induced by immunization with retinal antigens or their fragments and represents human uveitis of putative autoimmune origin. The pathogenesis of EAU, and likely also of human uveitis, involves cell-mediated destruction of retinal tissues that is dependent on retinal antigen-specific T cells. Because in most cases a Th1-type response has been implicated in pathogenesis, the prevailing consensus has been that immunoregulatory manipulations designed to enhance the Th2 response at the expense of the Th1 response will be beneficial in clinical treatment of uveitis. This assumption may not always be correct. The present review will summarize the evidence that, despite a central role for Th1 response in uveitis, an unopposed Th2-like response can be equally or more destructive to the retinal tissues. Furthermore, the Th1 response itself triggers regulatory circuits that feed back and dampen further recruitment of antigen-specific T cells into the Th1 effector pool. Thus, although the Th1 effector response can and does result in retinal pathology, immunoregulatory strategies must take into account that immune deviation therapies designed to replace the Th1 with a Th2 response might result in exchanging one type of pathology for another rather than in achieving the desired therapeutic effect.

Expression of cyclooxygenase-2 in intestinal goblet cells of pre-diabetic NOD mice

Cyclooxygenase, the rate-limiting enzyme in prostaglandin synthesis, is expressed in constitutive (COX-1) and inducible (COX-2) isoforms. The COX-2 has been proposed to be involved in development of autoimmune type 1 diabetes (T1D). We examined COX-2 expression in the gut-associated lymphoid tissue (GALT), and found COX-2 was strongly expressed in goblet cells of non-obese diabetic (NOD) mice at the apical villi at the age of 2.5 weeks, clearly before the onset of insulitis, while the expression in the control BALB/c mice was weak or absent at all ages (P < 0.001). Lipopolysaccharide (LPS) given intraperitoneally slightly increased COX-2 expression in the goblet cells and epithelium of both NOD and BALB/c mice. High-resolution confocal microscopy showed that the surroundings of the goblet cells contained no COX-2, implying that the enzyme is synthesized by the goblet cells. The COX-2 is secreted from goblet cells into the intestinal lumen along with mucins. The COX-2 concentration in the goblet cell of BALB/c and especially of NOD mice was markedly higher than that in the intraepithelial lymphocytes or lamina propria macrophages. High mucin COX-2 from goblet cells may increase luminal prostaglandin synthesis, alter epithelial permeability, modulate intestinal immune responses and modify functional properties of the lymphocytes in the GALT, which all may be important for the initiation of the autoimmune phenomenon in the NOD mice.

Mechanism for maintenance of dominant T helper 1 immune responses in Lewis rats

Lewis rats are prone to T helper (Th) 1 immune responses, whereas Brown Norway (BN) rats are susceptible to Th2 immune responses. Yet, the precise mechanism of induction of the different outcome between these two strains remained elusive. We investigated the expression levels of some cytokines, their receptors and accessory molecules responsible for the polarization of antigen-specific immune response into a predominant Th1 or Th2 profile in Lewis and BN rats. Lymph node (LN) cells collected from rats immunized with short ragweed (RW) were used directly or after stimulation in vitro with RW for 3 days. Expression of cytokines, their receptors and accessory molecules in these LN cells were tested by reverse transcriptase-PCR. Culture supernatant was used for ELISA to detect IL-12 protein. We observed clear differences between these strains in the expression of IL-12p40, which was high in LN cells of Lewis rats even before stimulation in vitro. In addition, a higher amount of IL-12 was present in the culture supernatant in Lewis rats. Upregulation of the expression of IL-12 receptor beta1, beta2, IFN-gamma receptor alpha and beta genes were more prominent in Lewis rats rather than BN rats. Furthermore, attenuated expression of CD40 and CD40 ligand by stimulation in vitro was noted only in BN rats. Changes in expression of these molecules by stimulation as well as higher basal level of IL-12p40 might have led to the activation of Th1 cells in Lewis rats.

Opposing effects of anti-activation-inducible lymphocyte-immunomodulatory molecule/inducible costimulator antibody on the development of acute versus chronic graft-versus-host disease

The functional role of inducible costimulator (ICOS)-mediated costimulation was examined in an in vivo model of alloantigen-driven Th1 or Th2 cytokine responses, the parent-into-F(1) model of acute or chronic graft-vs-host disease (GVHD), respectively. When the Ab specific for mouse ICOS was injected into chronic GVHD-induced mice, activation of B cells, production of autoantibody, and development of glomerulonephritis were strongly suppressed. In contrast, the same treatment enhanced donor T cell chimerism and host B cell depletion in acute GVHD induced host mice. Blocking of B7-CD28 interaction by injection of anti-B7-1 and anti-B7-2 Abs inhibited both acute and chronic GVHD. These observations clearly indicate that the costimulatory signal mediated by CD28 caused the initial allorecognition resulting in the clonal expansion of alloreactive T cells, whereas the costimulatory signal mediated by ICOS played a critical role in the functional differentiation and manifestation of alloreactive T cells. Furthermore, treatment with anti-ICOS Ab selectively suppresses Th2-dominant autoimmune disease.

Analysis of mercury-induced immune activation in nonobese diabetic (NOD) mice

In susceptible mice, the heavy metal ion mercury is able to induce a strong immune activation, which resembles a T helper 2 (Th2) type of immune response and is characterized by a polyclonal B cell activation, formation of high levels of IgG1 and IgE antibodies, production of autoantibodies of different specificities and development of renal IgG deposits. In the present study, we analysed the in vivo effects of mercury in nonobese diabetic (NOD) mice, which is believed to develop a spontaneous Th1 cell-mediated autoimmune diabetes similar to type 1 diabetes in humans. Three weeks of treatment with mercury induced a strong Th2 like immune/autoimmune response in NOD mice. This response was characterized by an intensive increase in splenic IgG1 antibody secreting cells, a marked elevation in serum IgE levels, a substantial increase in splenic IL-4 mRNA, but a significant decrease in splenic IFN-gamma mRNA. Mercury-induced IgG1 antibodies were mainly against ssDNA, TNP and thyroglobulin, but not against nucleolar antigen. Moreover, mercury-injected NOD mice developed high titres of IgG1 deposits in the kidney glomeruli. We further tested if the generated Th2 response could interfere with the development of insulitis and diabetes in NOD mice. We found that three weeks of treatment with mercury was also able to significantly suppress the development of insulitis and postpone the onset of diabetes in these mice. Thus, mercury-induced immune activation can counter-regulate the Th1 cell-mediated autoimmune responses and confer a partial protection against autoimmune diabetes in NOD mice.

Intracellular cytokine profile in T-cell subsets of multiple sclerosis patients: different features in primary progressive disease

OBJECTIVE

To evaluate the expression of cytokines in both CD4+ and CD8+ T cells derived from peripheral blood of untreated multiple sclerosis (MS) patients with either relapsing-remitting (RR), secondary progressive (SP) or primary progressive (PP) MS and healthy controls (HC).

BACKGROUND

MS is an immune-mediated disease and cytokines hove been hypothesized to contribute significantly to disease progression. Compared to the relapse-onset (RR, SP) form of the disease, PPMS patients have different clinical, immunological and pathological features. Surprisingly, the ability of their circulating T cells to produce immunoregulatory cytokines has not been extensively studied so far.

METHODS

Seventy-two MS patients (24 RR, 26 SP, 22 PP) and 34 HC were studied. Stimulated peripheral blood derived CD4+ and CD8+ T MS patients express significantly more CD4+ and CD8+ T cells were analyzed for IFN-gamma, IL-2, TNF-alpha, IL-4, IL-10 and IL-13 production.

RESULTS

cells producing IFN-gamma compared to HC. Compared to the other forms of the disease, PPMS patients display a significant decrease in CD4+ T cells producing IL-2, IL-13 and TNF-alpha and a significant increase in CD8+ T cells producing IL-4 and IL-10.

CONCLUSIONS

The data presented here demonstrate that patients with PPMS express less pro- and more anti-inflammatory cytokine producing T cells compared to the relapse-onset form of the disease, confirming the view on PPMS as a distinct disease entity.