Interleukin-17-secreting T cells in neuromyelitis optica and multiple sclerosis during relapse

Growing evidence suggests that interleukin (IL)-17 and IL-17-secreting CD4⁺T (Th17) cells are involved in the pathogenic mechanisms of multiple sclerosis (MS). IL-17-secreting CD8⁺T cells were recently identified as a novel subset of CD8⁺T cells. We aimed to analyze the role of Th17 and IL-17 secreting CD8⁺T cells in the pathogenesis of neuromyelitis optica (NMO) as well as MS. Fourteen patients with NMO, 20 with MS and 16 control participants (CTL) were enrolled between November 2008 and December 2009. The proportion of Th17 cells and IL-17 secreting CD8⁺T cells were counted using flow cytometry, and serum levels of IL-6, IL-17, IL-21, IL-23, and transforming growth factor-beta (TGF-β) were measured by enzyme-linked immunosorbent assay. Patients with NMO had a larger proportion of Th17 cells than patients with MS (3.72% versus [vs.] 2.58%, p = 0.02) and CTL (3.72% vs. 1.36%, p < 0.001). The proportion of Th17 cells in patients with MS was also markedly higher than in the CTL (2.58% vs. 1.36%, p < 0.001). IL-17-secreting CD8⁺T cell counts in NMO patients were markedly higher than in MS patients (1.61% vs. 1.09%, p = 0.036) and CTLs (1.61% vs. 0.58%, p < 0.001). The proportion of IL-17-secreting CD8⁺T cells in MS patients was also higher than in CTLs (1.09% vs. 0.58%, p = 0.002). Serum IL-17 and IL-23 levels were increased in patients with NMO and MS, while serum IL-21 concentration was higher only in NMO patients compared to CTL. We concluded that Th17 cells were highly activated in patients with NMO. IL-17-secreting CD8⁺T cells were increased in patients with NMO and MS during relapse and have an important role in the pathological mechanism of NMO and MS.     

Presence of pluripotent CD133+ cells correlates with malignancy of gliomas

BackgroundPresence of CD133⁺ cancer stem cells has been demonstrated within glioblastoma multiforme (GBM), the most malignant phenotype of gliomas (WHO grade IV). Since GBM frequently develops from low grade gliomas (WHO grade II) we assessed a possible qualitative or quantitative correlation of CD133⁺ cells and glioma grade to get new insights in gliomagenesis.ResultsThe amount of CD133⁺ cells within the bulk tumor mass, analyzed by immunostaining and Western blotting, showed a clear quantitative correlation with glioma grade (WHO° II, III and IV). Most of CD133⁺ cells were arranged in clusters frequently associated to tumor vessels. Protein analysis revealed high cellular coexpression of CD133 with Musashi-I but not CD34 indicating a neural, i.e. local origin of these cells. In vitro, no differences in stem cell properties concerning self-renewal and multi-lineage differentiation have been found for CD133⁺ cells isolated from gliomas of different grades.ConclusionsThese findings indicate a solely quantitative correlation of glioma grade with the presence of neural CD133⁺ cells within tumors supporting the concept of a CD133⁺ stem cell dependent gliomagenesis.     

Brain CD8+ and cytotoxic T lymphocytes are associated with, and may be specific for, human immunodeficiency virus type 1 encephalitis in patients with acquired immunodeficiency syndrome

CD8+ T cells infiltrate brains with human immunodeficiency virus type-1 (HIV-1) encephalitis (HIVE) and related animal models; their perineuronal localization suggests cytotoxic T cell (CTL)-mediated neuronal killing. Because CTLs have not been identified in acquired immunodeficiency syndrome (AIDS) brains, the authors identified their cytotoxic granules in autopsy AIDS brains with HIVE and without HIVE (HIVnE) plus controls (7 to 13 cases/group) and determined gene expression profiles of CTL-associated genes in a separate series of cases. CD3+ and CD8+ T cells were significantly increased (P < .01) in perivascular spaces and inflammatory nodules in HIVE but were rare or absent in brain parenchyma in HIVnE and control brains. Eight HIVE brains contained granzyme B+ T cells and five contained perforin+ T cells. Their T-cell origin was confirmed by colocalization of CD8 and granzyme B in the same cell and the absence of CD56+ natural killer cells. The CTLs directly contacted with neurons, as the authors showed previously for CD3+ and CD8+ T cells. CTLs were rare or absent in HIV nonencephalitis (HIVnE) and controls. Granzyme B and H precursor gene expression was up-regulated and interleukin (IL)-12A precursor, a maturation factor for natural killer cells and CTLs, was down-regulated in HIVE versus HIVnE brain. This study demonstrates, for the first time, CTLs in HIVE and shows that parenchymal T cells and CTLs are sensitive biomarkers for HIVE. Consequently, CD8+ T cells and CTLs could mediate brain injury in HIVE and may represent an important biomarker for productive brain infection by HIV-1.     

Human CD8 TCR-αβ and TCR-γδ cells modulate autologous autoreactive neuroantigen-specific CD4 T-cells by different mechanisms

To investigate the regulatory interactions among autologous T-cells during the course of multiple sclerosis (MS), proteolipid protein peptide-specific CD4⁺ T-cell clones (TCCs) were irradiated and used as immunogens to stimulate purified populations of autologous CD8⁺ TCR-αβ⁺ and TCR-γδ⁺ T-cells isolated from the peripheral blood of MS patients, patients with other non-inflammatory neurological diseases, and healthy blood donors. The resulting blasts were expanded in the presence of hIL-2 and then cloned by limiting dilution. Two different groups of CD8⁺ TCCs were revealed. A first group of CD8⁺ TCCs recognized autologous CD4⁺ T-cells based in their TCRVβ structures (anti-idiotypic responsiveness). A second group of CD8⁺ TCCs recognized Ag activated autologous CD4⁺ TCCs irrespective of their Ag specificity or TCRVβ expression (anti-ergotypic responsiveness). Both groups showed MHC class I restricted cytotoxicity against CD4⁺ T-cells and were able to secrete IFN-γ, TNFα/β and TGF-β. TCR-γδ⁺ TCCs isolated in response to stimulation with autologous peptide-specific CD4⁺ TCCs showed only anti-ergotypic cytotoxicity, which was not inhibited by anti-MHC class Ia monoclonal antibodies. Moreover, they were able to secrete IFN-γ and TNFα/β, but not TGF-β. These data demonstrate that regulatory mechanisms among human autologous T-cells can be mediated by cytolytic interactions or by the release of specific cytokines. Furthermore, they provide evidence that CD8⁺ TCR-αβ⁺ and TCR-γδ⁺ cells differ in their patterns of recognition and in their abilities to modulate the immune response mediated by autologous autoreactive CD4⁺ T-cells.     

Circulating CD4+CD8+ cells in myasthenia gravis: supplementary immunological parameter for long-term prognosis

Summary Twenty patients with myasthenia gravis (MG) were studied prospectively for up to 5 years after thymectomy, in order to clarify the relationships between disease severity, anti-acetylcholine receptor antibody (anti-AChR) titres, proportions of circulating CD4⁺CD8⁺ cells (CD4⁺CD8⁺ cell level) and major lymphocyte subsets. The CD4⁺CD8⁺ cell levels were closely related to the clinical change within 1 year after surgery in 8 patients who showed a preoperative elevation in the cell levels. This group of patients consisted of six thymomatous and two non-thymomatous patients; the latter were both negative for anti-AChR. The anti-AChR titres generally changed in parallel with the clinical state in 9 of the 16 patients who were followed up for more than a year after thymectomy, and the CD4⁺CD8⁺ cell levels were useful in predicting the clinical course in 6 of the above 9 patients and 3 other patients, including antibody-negative cases. The present study suggests that the CD4⁺CD8⁺ cell levels may serve as an indicator for long-term prognosis of MG.     

Immune surveillance of the normal human CNS takes place in dependence of the locoregional blood–brain barrier configuration and is mainly performed by CD3+/CD8+ lymphocytes

Despite the blood–brain barrier (BBB) the human CNS is continuously screened by blood‐derived immunological cells. In certain brain areas the local BBB configuration grants passage of large molecules, whereas others are better shielded. We investigated whether these regional BBB compositions are paralleled by differences in the degree of cellular immunosurveillance by investigating tissue from 23 normal human brains for several CD markers, FoxP3, granzyme B, and perforin. Our results provide evidence that immunosurveillance is associated with locoregional BBB configuration and is mainly performed by CD3⁺/CD8⁺/granzyme B^‐/perforin^‐ lymphocytes.     

CD8+/perforin+/granzyme B+ effector cells infiltrating cerebellum and inferior olives in gluten ataxia

Up to 8% of patients with gluten sensitivity (GS) develop neurological symptoms such as ataxia, dementia, seizures or peripheral neuropathy. The underlying immunological mechanisms still remain to be elucidated. We here report the case of a 68‐year‐old male patient suffering from progressive ataxia and dementia associated with chronic diarrhea and both elevated IgG and IgA antigliadin‐antibodies. At autopsy, frequent argyrophilic glial and neuronal inclusions within the basal nucleus of Meynert were considered as the structural correlative for the cognitive decline. Significant neuronal loss in the cerebellar cortex and the inferior olives was accompanied by infiltrating CD8⁺/perforin⁺/granzyme B⁺ cells as well as reactive astrogliosis and microglial activation. These CD8⁺ cytotoxic T and NK cells are likely to act as effector cells responsible for neuronal cell death in patients with gluten sensitivity and neurological disease and might therefore at least partly be responsible for cerebellar symptoms in gluten ataxia. In conclusion, our results, showing an absence of B‐ or plasma cells but multiple CD8⁺ as well as granzyme B and perforin expressing cells in ataxia‐associated brain areas, suggest that there are also prominent cytotoxic effects in neuropathogenesis of GS.     

Increased Fas-mediated cytotoxicity of CD4-positive T cells in patients with human T-lymphotropic virus type I-associated myelopathy

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release assay, we investigated Fas-mediated cytotoxicity of peripheral blood CD4⁺ T cells of patients with human T-lymphotropic virus type-I (HTLV-I)-associated myelopathy (HAM) against T98G, a glioblastoma cell line which expresses Fas. Cytotoxic activity of CD4⁺ T cells against T98G was significantly higher in HAM patients than in controls. Moreover, when CD4⁺ T cells of HAM patients were preincubated with a monoclonal antibody to human Fas ligand (FasL), cytotoxic activity against T98G was significantly suppressed. These results suggest that damage to nervous tissues by the Fas/FasL system is involved in the pathogenesis of HAM.     

T lymphocyte subset abnormalities in peripheral blood from patients with the Guillain-Barré syndrome

T lymphocytes are probably of pathogenic importance in many autoimmune diseases. Recently, deviations of circulating T-helper (CD4⁺) subpopulations have been noticed. Blood samples from 12 patients with Guillain-Barré syndrome (GBS) were studied with flow cytometry during their disease to define circulating T cell populations. The proportion of T-helper cells (CD4⁺) was decreased (mean value 41±15%, P = 0.01) and the proportion of T cytotoxic/suppressor cells (CD8⁺) was increased (35±18%, P = 0.0006) as compared to the control group of healthy blood donors (47±8% and 26±7% respectively). The CD4⁺ population is divided into the helper/inducer (CD4⁺ CD29⁺) and suppressor/inducer (CD4⁺ CD45RA⁺) subsets. which normally are equally distributed (mean values in our control group were 45±15% and 44±15%, respectively). In patients with GBS, the helper/inducer (CD4⁺ CD29⁺) subset was increased (54±10%, P = 0.05) and the suppressor/inducer (CD4⁺ CD45RA⁺) subset was decreased (31±9, P = 0.005) compared to the controls. The proportion of activated HLA-DR-expressing T cells was increased (7±8%, P = 0.005) as compared to control (3±3%). The total proportions of T cells (CD2⁺), B cells (CD19⁺) and natural killer (NK) cells (CD56⁺) were similar in pateints and controls. The CD4⁺ and CD8⁺ populations, as well as the activated HLA-DR⁺ T cells, normalized during the disease course. The derivations within the CD4⁺ population also tended to normalize, but even at follow up after 6–33 (mean 23) months, some abnormalities remained. In conclusion, we confirm previous reports of T cell activation in peripheral blood from patients with GBS. A new finding is the derivation of T helper subpopulations with an increased helper/inducer (CD4⁺ CD29⁺) subset and a decreased suppressor/inducer (CD4⁺ CD45RA⁺) subset, which indicates a possible autoimmune character of GBS.     

Expression of FcR2/CD23 and p55 IL-2R/CD25 on peripheral blood macrophages/monocytes in multiple sclerosis

Macrophages have been found histologically to be activated in multiple sclerosis. We analyzed the expression of CD23 and CD25 on monocytes/macrophages in peripheral blood obtained from patients with multiple sclerosis (MS) to investigate their role in the demyelinating process. Peripheral blood mononuclear cells were obtained from 30 patients with MS including for Baló's diseases (24 with acute relapsing type disease, six with chronic progressive type disease) and 12 healthy controls. The percentage of CD14⁺ CD23⁺ monocytes/macrophages and CD14⁺ CD25⁺ monocytes/macrophages were determined by two-color flow cytometry. The percentage of CD14⁺ CD23⁺ monocytes was significantly higher in patients with MS in the active phase as compared with controls (P < 0.01). Six patients with acute relapsing MS, who had received no therapy, had higher CD14⁺ CD23⁺ cells than did controls (P < 0.0001). CD14⁺ CD25⁺ monocytes/macrophages were not detected in peripheral blood monocytes/macrophages of patients with MS except Baló's concentric sclerosis. The four patients with Baló's concentric sclerosis had markedly elevated levels of CD14⁺ CD25⁺ monocytes/macrophages. Our findings suggest that monocytes/macrophages are activated during an exacerbatiion of MS. and that they may play an important role in the process of demyelination.     

The renal v-ATPase a4 subunit is expressed in specific subtypes of human gliomas

Vacuolar H⁺-ATPases (v-ATPases) are multimeric proton pumps which acidify various intra-cellular organelles and may participate in pHe and pHi regulation in cancer cell lines. The ATP6V0A4 gene encodes the a4 subunit which is expressed in kidney and epididymis. Because we found a4 mRNA highly expressed in C6Bu1 glioma cell line, we measured it in 205 glioma biopsies and 11 brain biopsies from epileptic patients. a4 was absent in epileptic brain biopsies, but was expressed by 34% (11/32) of grade III oligodendrogliomas, independently of the chromosome 1p19q codeletion. a4 expression in grade III oligodendrogliomas and oligoastrocytomas without the 1p19q codeletion tended to be associated with a shorter overall survival of patients. We also observed a4 expression in biopsies of pilocytic astrocytomas (68%; 19/28) and gangliogliomas (37%; 6/16). In pilocytic astrocytomas a4 expression was associated with a tandem duplication of the 7q34 chromosome region, distant 0.5 Mb to the ATP6V0A4 gene locus. In conclusion, a4 expression identifies subtypes of oligodendrogliomas, pilocytic astrocytomas and gangliogliomas and may contribute to refine characterization of these tumors. © 2012 Wiley Periodicals, Inc.     

Presence of T-cell subset abnormalities in newly diagnosed cases of multiple sclerosis and relationship with short-term clinical activity

Abnormalities of T-cell subsets in patients with multiple sclerosis are well known; in order to assess whether immunological abnormalities are relevant in the pathogenesis of the disease after its clinical onset, peripheral blood lymphocyte subsets (CD3⁺, CD4⁺, CD4⁺ CD45RA⁺, CD4⁺CD45RA^–, CD8⁺, CD8⁺CD57⁺, CD57⁺, CD25⁺) were analysed serially in 25 patients at the first clinical episode suggestive of inflammatory demyelinating disease and in an equal number of age- and sex-matched controls. During the follow-up period (12–18 months, mean 14) 6 of 25 patients presented new relapses: in this subgroup of patients, significant changes in CD4⁺ ratio (% CD4⁺CD45RA^–/%CD4⁺CD45RA^–) were detected in comparison both with healthy controls and with clinically stable patients. Patients clinically stable at follow-up did not display immunological abnormalities, regardless of the presence or absence of cerebrospinal fluid and/or magnetic resonance imaging alterations consistent with multiple sclerosis. These findings suggest a possible prognostic role of early T-cell subset imbalance in multiple sclerosis.     

Clinical significance of Tim3-positive T cell subsets in patients with multiple sclerosis

The present study evaluated associations between the percentages of T cell immunoglobulin and mucin domain 3 (Tim3)-positive T cells and related cytokines and multiple sclerosis (MS). We collected peripheral blood samples from 30 MS patients and 30 healthy controls. Flow cytometry was used to determine the proportions of CD3⁺Tim3⁺, CD4⁺Tim3⁺, and CD4⁺CD25⁺Tim3⁺ in peripheral blood mononuclear cells (PBMCs) and related cell subsets. The serum concentrations of galectin-9, IL-17, and IFN-γ also were determined using enzyme-linked immunosorbent assays (ELISA). The percentages of Tim3-positive T cells in CD4⁺ and CD4⁺CD25⁺ T cell subsets were significantly lower among MS patients than among controls. This difference was particularly evident in the CD4⁺CD25(high) T cell subset. The proportions of CD4⁺Tim3⁺ and CD4⁺CD25⁺Tim3⁺ cells in PBMCs were significantly lower in the MS group than in the control group, whereas no significant differences were detected regarding the percentages of CD3⁺Tim3⁺ in PBMCs and T cell subsets. The serum concentrations of galectin-9, IL-17, and IFN-γ all were increased in MS patients compared with healthy controls. Our results support that Tim3 and related cytokines may be involved in the onset of MS.     

Role of perforin secretion from CD8+ T-cells in neuronal cytotoxicity in multiple sclerosis

Objectives: Multiple sclerosis (MS) is the most prevalent autoimmune disease of the central nervous system, and is characterized by inflammation and myelin damage. The immune system initiates the autoimmune response, although the mechanisms of neuronal damage have not been elucidated. The purpose of the present study was to investigate autoreactive CD4+ and CD8⁺ T lymphocytes, in conjunction with other inflammatory cells and cytokines in active MS lesions.

Methods: EAE animal models was established by plantar injections of MBP (200 μg per rat). Purified CD4+ or CD8+ T-cells were isolated from heparinized peripheral blood (EAE animals and control animals) via negative selection. To examine effects of presence of autoreactive CD4+ and CD8+ T lymphocytes, we carried out ELISA, Western blot analysis and TUNEL. In addition, we examined the direct effects of various factors on neuronal cell death using MTT assay.

Results: The data revealed that CD8+ T-cells were more toxic to neurons compared to CD4+ T-cells, in both the MBP and EAE conditions. Bax was greater increased when neurons were co-cultured with CD8+ T-cells in the MBP group. There is a significant increase in IL-17 secretion by CD4+ T-cells in both the MBP group and EAE group. Neuronal viability were affected by Perforin (1.5 μg/mL).

Conclusion: The present study extends previous research by demonstrating the role of CD8+ T-cells in MS and supports perforin secretion by CD8+ T-cells as a potential therapeutic factor. Furthermore, we determined that CD4⁺ T-cells can enhance CD8⁺ T-cell neuronal cytotoxicity via induction of intense inflammation.     

Functional defects in peripheral blood T cells of multiple sclerosis patients: Diminished in vitro responsiveness in accessory cell dependent activation systems

Function and phenotype of peripheral blood (PB) T cells in multiple sclerosis (MS) patients were analyzed. In whole blood cultures, T cell proliferation of multiple sclerosis (MS) patients, using soluble CD3 mAB and CD2 mAb as stimulants, was reduced in comparison to healthy controls. A similar difference was seen when isolated PBMC were tested after stimulation with soluble CD3 mAb. However, in accessory cell-independent activation systems, i.e. after stimulation of PBMC with immobilized CD3 mAb or after co-stimulation with CD28 mAb, both patients and controls responded equally well. Phenotypical analysis of the circulating T cell population showed that there were no differences in the percentage of CD26⁺, ‘memory’ (CD45R0⁺) or ‘effector’ (CD4⁺CD45R0⁺CD27⁻) cells between MS patients and healthy controls. Finally, although MS patients did show an enhanced proportion of ‘naive’ (CD4⁺CD45RA⁺) T cells, this did not correlate with the observed functional defects.     

Alterations of cerebromicrovascular Na, K-ATPase activity due to fatty acids and acute hypertension

Acute hypertension, induced in rats by intravenous injection of angiotensin II, previously has been shown to increase cerebrovascular permeability to macromolecules. The purpose of this study was to examine the effect of acute hypertension on Na⁺, K⁺-ATPase, the enzyme responsible for controlling ionic permeability of the cerebromicrovascular endothelium. The K⁺-dependent p-nitrophenylphosphatase activity of the cerebromicrovascular Na⁺, K⁺-ATPase was determined using microvessels prepared from hypertensive and normotensive rats. When compared to controls, a 70% decrease (P < 0.02) in the maximum rate (V_max) of the Na⁺, K⁺-ATPase from hypertensive rats was evident with no change in the Michaelis constant (K_M). In contrast, γ-glutamyltranspeptidase, a marker enzyme for cerebral endothelic cells, was not significantly affected. Sodium arachidonate (1–100 μM) inhibited the phosphatase activity of the Na⁺, K⁺-ATPase in microvessels isolated from both normotensive and hypertensive rats in a dose-dependent manner. Furthermore, poly-unsaturated fatty acids (sodium linoleate and arachidonate) evoked the greatest inhibition of the enzyme, while sodium oleate and sodium palmitate inhibited the Na⁺, K⁺-ATPase to lesser extents. This regulation of enzyme activity by fatty acids was comparable in control and hypertensive groups. In summary, the data indicate that the cerebromicrovascular Na⁺, K⁺-ATPase was altered as a consequence of acute hypertension and that poly-unsaturated fatty acids can modulate this enzyme in microvessels derived from hypertensive or control rats     

Virus-activated T cells regulate expression of adhesion molecules on endothelial cells in sites of infection

To study the role of cell adhesion molecules in the fatal CD8⁺ T-cell mediated meningitis which is induced by intracerebral infection with lymphocytic choriomenmgitis virus, the expression of relevant molecules on inflammatory cells and local endothelium was analyzed immunohistochemically. Most inflammatory cells were strongly positive for LFA-1, VLA-4, Pgp-1 and ICAM-1. Expression of ICAM-1 and VCAM-1 was upregulated on the endothelial cells in immunocompetent mice, but hot in T-cell deficient nude mice. analysis of mice deficient in either CD4⁺ or CD8⁺ T cells, revealed that not only was the inflammatory reaction dependent on the presence of CD8⁺ cells, but these cells also appeared to be required for maximal upregulation of ICAM-1 and VCAM-1 on the endothelial cells. These results indicate that virus-specific CD8⁺ T cells are crucially involved in regulating the inflammatory reaction through effects on endothelial expression of adhesion molecules.     

Pathology for severe inflammatory PML with PD1/PD-L1 expression of favorable prognosis: What's a prognostic factor for PML-IRIS?

A 72-year-old woman with dermatomyositis (DM) developed neurological manifestation, and magnetic resonance imaging (MRI) revealed multiple T2/fluid-attenuated inversion recovery (FLAIR)-hyperintense lesions predominantly in the deep white matter of the cerebral hemisphere. Punctate or linear contrast enhancement was observed surrounding the T1-hypointense area. Multiple T2/FLAIR-hyperintense lesions were aligned along with the corona radiata. Malignant lymphoma was first suspected, and a brain biopsy was performed. Pathological investigation suggested the provisional diagnosis of “suspicious of malignant lymphoma.” Owing to emergent clinical conditions, high-dose methotrexate (MTX) therapy was conducted, and then T2/FLAIR-hyperintense lesions were dramatically reduced. However, the diagnosis of malignant lymphoma was concerning since multiplex PCR demonstrated clonal restriction of the Ig H gene for B cells and TCR beta genes for T cells. Histopathology revealed the infiltration of both CD4⁺ and CD8⁺ T cells, and the CD4⁺/CD8⁺ ratio was 4.0. Moreover, prominent plasma cells were observed, in addition to CD20⁺ B cells. Atypical cells with enlarged nuclei were present, and they were not hematopoietic but found as glial cells. JC virus (JCV) infection was verified with both immunohistochemistry and in situ hybridization; the final diagnosis was progressive multifocal leukoencephalopathy (PML). The patient was treated with mefloquine and discharged. This case is informative in understanding the host anti-viral response. Variable inflammatory cells were observed, including CD4⁺ and CD8⁺ T cells, plasma cells, and a small amount of perivascular CD20⁺ B cells. PD-1 and PD-L1 expression was observed in lymphoid cells and macrophages, respectively. PML with inflammatory reactions was thought fatal, and autopsy cases of PML with immune reconstitution inflammatory syndrome (IRIS) demonstrated excessive infiltration of only CD8⁺ T cells. However, this case revealed infiltration of variable inflammatory cells, and a favorable prognosis would be expected under PD-1/PD-L1 immune-checkpoint regulation.     

Long-term immunological changes in azathioprine-treated MS patients

The long-term immunological effects of azathioprine treatment have been investigated in 8 multiple sclerosis patients with different course of disease, chronic progressive (CP) or relapsing progressive (RP). We studied fluctuations in peripheral blood mononuclear cell subsets, IgG, IgM and soluble vascular cell adhesion molecule-1 (sVCAM-1), before and after 2 (T24) and 3 (T36) years of therapy. We observed a significant decrease in CD8⁺ cells over time and a trend to lower percentage of CD3⁻CD56⁺ cells at T24 and T36. CD4⁺CD45RA⁺ cells in MS patients were lower than in healthy controls before therapy and reached values similar to those of healthy controls at T24 and T36. The remaining immunological parameters did not show any significant fluctuations. Received: 24 November 1999 / Accepted in revised form: 8 February 2000     

Evidence for a missed signal to the CD8+ cells in CSF of Multiple Sclerosis patients

Peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocyte subpopulations, defined by various T-cell specific monoclonal antibodies and flow cytometry, were analysed in 44 relapsing remitting multiple sclerosis (RRMS) patients (including 21 subjects in the acute phase and 23 in the stable phase), 40 chronic-progressive multiple sclerosis (CPMS) patients, and 24 patients with other neurological diseases (OND), in order to verify the presence of any abnormality in the lymphocyte subset pattern. A significant increase in the total number of T-lymphocytes and the CD4+ subpopulation was found in the PB of the MS patients in comparison with the OND group. Moreover, a not statistically significant increase in CD4⁺ cells was observed in the CSF of MS patients. A statistically significant increase was also found in the CD4⁺ Leu 8⁺ (suppressor inducer) cells in the CSF of all of the MS groups. Finally, the CD8⁺ (suppressor/cytotoxic) cell levels, were significantly lower in the CSF of CPMS and stable RMS patients than in the CSF of the OND patients. As a whole, our data suggest that the immunosuppressive deficit that seems to be a constant finding in MS is not due to a decrease in suppressor inducer cell levels, as previously suggested, but may be caused by a missed or altered signal from the suppressor inducer to CD8⁺ suppressor cells.This Work was partially supported by an IRCCS Current Research Grant 1994.