Analysis of T regulator cell surface markers and functional properties in multiple sclerosis

Anti-CD20 therapy corrects a CD8 regulatory T cell deficit in multiple sclerosis

OBJECTIVE

To determine the effect of long-term anti-CD20 B-cell-depleting treatment on regulatory T cell immune subsets that are subnormal in untreated MS patients.

METHODS

30 clinically stable MS patients, before and over 38 months of ocrelizumab treatment, were compared to 13 healthy controls, 29 therapy-naïve MS, 9 interferon-β-treated MS, 3 rituximab-treated MS, and 3 rituximab-treated patients with other autoimmune inflammatory diseases. CD8, CD28, CD4, and FOXP3 expression in peripheral blood mononuclear cells was quantitated with flow cytometry.

RESULTS

CD8⁺ CD28^- regulatory cells rose from one-third of healthy control levels before ocrelizumab treatment (2.68% vs 7.98%), normalized by 12 months (13.5%), and rose to 2.4-fold above healthy controls after 18 months of ocrelizumab therapy (19.0%). CD4⁺ FOXP3⁺ regulatory cells were lower in MS than in healthy controls (7.98%) and showed slight long-term decreases with ocrelizumab. CD8⁺ CD28^- and CD4⁺ FOXP3⁺ regulatory T cell percentages in IFN-β-treated MS patients were between those of untreated MS and healthy controls.

INTERPRETATION

Long-term treatment with ocrelizumab markedly enriches CD8⁺ CD28^- regulatory T cells and corrects the low levels seen in MS before treatment, while slightly decreasing CD4⁺ FOXP3+ regulatory T cells. Homeostatic enrichment of regulatory CD8 T cells provides a mechanism, in addition to B cell depletion, for the benefits of anti-CD20 treatment in MS.

Decreased CD8+ T cell response to Epstein-Barr virus infected B cells in multiple sclerosis is not due to decreased HLA class I expression on B cells or monocytes

Background

Patients with multiple sclerosis (MS) have a decreased frequency of CD8⁺ T cells reactive to their own Epstein-Barr virus (EBV) infected B cells. We have proposed that this might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. The decreased CD8⁺ T cell response to EBV results from a general CD8⁺ T cell deficiency and also a decreased proportion of EBV-specific T cells within the total CD8⁺ T cell population. Because decreased HLA class I expression on monocytes and B cells has been reported in MS and could influence the generation and effector function of EBV-specific CD8⁺ T cells, the present study was undertaken to measure the expression of HLA molecules on B cells and monocytes in patients with MS.

Methods

We used flow cytometry to determine the proportions of T cells, natural killer cells, B cells and monocytes in peripheral blood mononuclear cells (PBMC) and to quantify the expression of HLA molecules on T cells, B cells and monocytes of 59 healthy subjects and 62 patients with MS who had not received corticosteroids or immunomodulatory therapy in the previous 3 months.

Results

The levels of HLA class I and class II molecules expressed on T cells, B cells and monocytes were normal in patients with MS, with the exception of two patients with secondary progressive MS with very low class II expression on B cells. In confirmation of previous studies we also found that the percentage of CD8⁺ T cells was significantly decreased whereas the percentage of CD4⁺ T cells and the CD4:CD8 ratio were significantly increased in patients with MS compared to healthy subjects.

Conclusions

The decreased CD8⁺ T cell response to EBV-infected B cells in MS patients is not due to decreased HLA class I expression on monocytes or B cells. In a small proportion of patients decreased HLA class II expression on B cells might impair the CD8⁺ T cell response to EBV by reducing CD4⁺ T cell help.

The essential role of Epstein-Barr virus in the pathogenesis of multiple sclerosis

There is increasing evidence that infection with the Epstein-Barr virus (EBV) plays a role in the development of multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the CNS. This article provides a four-tier hypothesis proposing (1) EBV infection is essential for the development of MS; (2) EBV causes MS in genetically susceptible individuals by infecting autoreactive B cells, which seed the CNS where they produce pathogenic autoantibodies and provide costimulatory survival signals to autoreactive T cells that would otherwise die in the CNS by apoptosis; (3) the susceptibility to develop MS after EBV infection is dependent on a genetically determined quantitative deficiency of the cytotoxic CD8+ T cells that normally keep EBV infection under tight control; and (4) sunlight and vitamin D protect against MS by increasing the number of CD8+ T cells available to control EBV infection. The hypothesis makes predictions that can be tested, including the prevention and successful treatment of MS by controlling EBV infection.

CD8+ T cell activation correlates with disease activity in clinically isolated syndromes and is regulated by interferon-beta treatment

An increased percentage of blood CD8+ T cells from patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) was found to express CD26 and CD69. The percentage of CD26 or CD69 positive CD8+ T cells was higher in patients with MRI evidence of disease dissemination in space or with active MRI lesions than in the remaining patients. Treatment of MS with interferon (IFN)-beta resulted in a decrease in the percentage of CD26 and CD71 positive CD8+ T cells and an increase in the percentage of CD8+ T cells that expressed interleukin (IL)-10 and IL-13. CD8+ T cell activation in MS may be linked to disease activity already at disease onset, and is regulated by treatment with IFN-beta.

Ingested (Oral) IFN-α Represses TNF-α mRNA in Relapsing-Remitting Multiple Sclerosis

In a phase II trial in relapsing-remitting multiple sclerosis (RRMS), patients ingesting 10,000 IU, but not 30,000 IU, interferon-alpha (IFN-alpha) showed fewer gadolinium enhancements at months 5 and 6, along with decreased proinflammatory tumor necrosis factor-alpha (TNF-alpha) protein secretion. Therefore, we examined MxA mRNA induction and TNF-alpha mRNA repression after 100, 300, 1,000, 3,000, and 10,000 IU doses of ingested IFN-alpha in 24 RRMS patients to determine the optimal dose for future clinical trials in MS. Maximal TNF-alpha repression occurs at 100, 1,000, and 3,000 IU. These data provide new optimal doses for additional clinical studies using ingested IFN-alpha in MS.

Functional activity of immune cells in female MS-patients

Since the well documented immunological disturbances in patients suffering from multiple sclerosis are especially attributed to T-cells we felt it expedient to look also for the functional activity of lymphocytes, monocytes, granulocytes and natural killer cells in the peripheral blood of female MS-patients (n = 17) and healthy controls (n = 17). While MS-patients showed decreased levels of total lymphocytes, CD2(+)- and CD8(+)-cells the percentage of HLA-DR(+)-monocytes was increased, indicating a high activity level of these immune cells, whereas we could find no differences in the functional tests of monocytes, granulocytes and natural killer cells between MS-patients and healthy controls. The percentage of HLA-DR(+)-T-lymphocytes increased with the duration of the illness and support the stronger consideration of clinical staging.

Low serum interleukin-10 levels in multiple sclerosis: further evidence for decreased systemic immunosuppression?

Serum interleukin 10 (IL10) levels were assessed in patients with multiple sclerosis who were either in a stable or active clinical condition. The levels were compared with values in healthy controls. Lower IL10 levels than in controls were seen in multiple sclerosis patients, regardless of clinical disease activity. Low IL10 levels were also seen in patients with systemic lupus erythematosus. No clear-cut relationships emerged between IL10 levels and those of tumour necrosis factor alpha and transforming growth factor beta, or between IL10 and lymphocyte subsets in peripheral blood.

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.

Regulation of myelin basic protein-specific helper T cells in multiple sclerosis: Generation of suppressor T cell lines

Suppressor T cell (Ts) lines specific for myelin basic protein (MBP)-reactive helper T cell (Th) clones were generated from two patients with multiple sclerosis (MS) following a primary culture of peripheral blood mononuclear cells (PBMC) with MBP and cyclosporine A (CsA). These suppressor T cell lines were maintained in culture by alternate stimulation with MBP and antigen-presenting cells (APC). The Ts lines expressed preferentially the CD4 phenotype (5/6 Ts lines tested) and exhibited potent antigen-specific suppressor activity on the proliferation of MBP-specific Th clones and not on the T cell lines with other antigen specificity. For some Ts lines, a Ts-to-Th ratio of 1 was sufficient to inhibit the proliferation of MBP-specific T cells by 90%. The suppressor T cells obtained were weakly responsive to MBP and required the presence of the autologous PBMC for proliferation. Furthermore, proliferation of these suppressor T cell lines was restricted by HLA-DR molecules (for CD4+ Ts lines) and HLA class I (for a CD8+ Ts line). The suppressor T cell lines generated and the techniques described in this study may be helpful in our understanding of the events involved in the immune regulation in MS and other autoimmune diseases.

Human CD8+ T cell clone regulates autologous CD4+ myelin basic protein specific T cells

Normal human CD8+ T cell clones were co-isolated from the same culture wells as CD4+ T effector cell clones specific for myelin basic protein (MBP). Microcultures from which the CD8+ clones were isolated initially proliferated weakly to whole MBP and to an MBP peptide spanning residues 90-170. This pattern of response was similar to strongly proliferating wells that yielded CD4+ T cell clones specific for the 90-170 peptide. After repeated stimulation, however, no response to MBP or MBP 90-170 was detected, even though the number of cells increased after stimulation. Phenotyping and TCR analyses revealed the presence of two CD8+, CD4-, IL-2R+ T cell isolates that expressed a single V beta gene (V beta 17) that differed from the CD4+ isolates that uniformly expressed V beta 14. One of these CD8+ clones (C9) inhibited the antigen-driven proliferation of an autologous MBP 90-170 reactive clone but not an autologous clone specific for Herpes simplex virus (HSV), without affecting MHC non-restricted mitogen responses of the same clones. Moreover, C9 did not inhibit heterologous CD4+ T cell clones specific for MBP 1-38 or 90-170. A culture supernatant of the CD8+ clone showed the same pattern but lower levels of inhibition. C9 had mild cytolytic activity when incubated at high ratios with an autologous MBP-specific CD4+ clone. Lysis was blocked completely by anti-MHC class I antibodies, but not by anti-MHC II antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4+, CD8+, and CD4- CD8- T cells in CSF and blood of patients with multiple sclerosis and tension headache

Two-colour flow cytometric analysis was performed on paired samples of peripheral blood (PB) and cerebrospinal fluid (CSF) of patients with untreated multiple sclerosis (MS) and, for reference, subjects with muscular tension headache (TH) using anti-CD3, anti-CD4, anti-CD8, and anti-HLA-DR monoclonal antibodies in different combinations. CD4+/CD8+ T-cell ratio was increased in CSF compared to PB in both MS patients and TH subjects to a similar extent. This was mainly due to higher CD4+ T-cell levels in the CSF compartment. The proportion of HLA-DR+ T cells was higher in CSF than PB in both MS and TH; this increase of DR+ T cells in CSF was more prominent in MS. The level of CD4+ CD8+ T cells, which represent a subset of activated T cells, was not different between CSF and PB, either in MS or in TH. The proportion of CD4- CD8- T cells, which were found generally not to be blast cells, was lower in CSF compared to PB in both patient groups. However, their CSF level was higher and their PB level lower in MS compared to TH. Results point to an accumulation of activated T-helper cells in the CSF of both MS patients and healthy subjects. Fetal-type CD4- CD8- T cells bearing the unusual T-cell receptor gamma/delta seem to be selectively recruited to the CSF of MS patients.

Suppressor cell regulation of encephalitogenic T cell lines: generation of suppressor macrophages with cyclosporin A and myelin basic protein

Chronic relapsing experimental allergic encephalomyelitis (CR-EAE) can be adoptively transferred using myelin basic protein (BP)-specific helper T cell lines, and suppressor cells may be important in recovery from EAE. In order to generate suppressor cells, spleen cells obtained from BP-complete Freund's adjuvant (CFA) inoculated SJL/J mice and from normal mice were cultured for 7 days with medium, with cyclosporin A (CsA), or with CsA and antigen (BP or purified protein derivative of mycobacterium (PPD)). Cultured spleen cells were assayed for suppressor activity in vitro by coculture with BP-specific and PPD-specific helper T cell lines derived from SJL/J mice. Immunized donor spleen cells cultured with cyclosporin A (CsA) and BP were potent inhibitors of T cell line proliferation, and suppressor activity was increased 17-fold compared with control splenocytes. The number of suppressor cells required to suppress PPD-specific line proliferation by 50% (I50) was significantly higher than the number required to suppress BP-specific line proliferation, suggesting an antigen-specific component to the suppression. The major effector cell required for suppression was a large granular Mac-1+ cell with the functional characteristics of a macrophage. Suppressor activity persisted after depletion of Thy 1.2+ cells, but suppression was no longer antigen-specific, suggesting that culture of spleen cells with CsA and BP may generate suppressor macrophages which are antigen-nonspecific and Thy 1.2+ suppressor cells which are antigen-specific. These suppressor cells may be important in the regulation of CR-EAE and the techniques described for their generation may prove useful for treatment and prevention of disease.

Immunoregulatory properties of T-cell lines derived from the systemic and intrathecal compartments: a phenotypic and functional study

To determine whether immune regulation can differ within the intrathecal and systemic compartments, we compared phenotypic markers and functional properties of in vitro anti-CD3 monoclonal antibody-stimulated, interleukin 2-expanded lymphoid cell lines simultaneously derived from peripheral blood and cerebrospinal fluid of individual donors (n = 9). We found that the proportions of total CD8+ T cells and of the putative CD8+ suppressor effector subset (CD28-) were lower in the cell lines derived from cerebrospinal fluid compared with cultures derived from peripheral blood (p less than 0.025 and p less than 0.005, respectively; paired t test), whereas the total CD4+ T-cell proportion was higher (p less than 0.025). For a donor subgroup with "normal" peripheral blood cell-mediated activated suppressor function (63 +/- 2%), mean suppressor cell function mediated by unfractionated or CD8(+)-enriched cells derived from cerebrospinal fluid was significantly lower (38 +/- 7%; p less than 0.01, paired t test). For a donor subgroup with "low" peripheral blood cell-mediated suppression (-1 +/- 10%), suppression mediated by cerebrospinal fluid cells was also "low" (9 +/- 12%). Our results support the postulate that the immune response may be differentially regulated between the central nervous system and peripheral blood compartments.

Cell count and ratio of helper/inducer to suppressor/cytotoxic T-cells in the cerebrospinal fluid of patients with multiple sclerosis

The cell count and the helper/inducer to suppressor/cytotoxic T-cell ratio (T4:T8) in cerebrospinal fluid (CSF) were compared in patients with multiple sclerosis (MS) and other neurological diseases. The T4:T8 ratio was higher in patients with MS than in patients with other neurological diseases. A low or normal CSF cell count was associated with a more significant increase in the T4:T8 ratio in patients with MS. These findings imply that the increased T4:T8 ratio found in MS is masked by an inflammatory pleocytosis or that the shift appears only when pleocytosis is absent.

Absence of a correlation between T lymphocyte subsets and clinical activity in relapsing-remitting multiple sclerosis

Cytofluorographic analysis of CD3+, Tac+, HLA-DR+ peripheral blood lymphocytes and CD4/CD8 ratio was performed monthly, over a 10-month period, in a group of 16 patients with multiple sclerosis (MS). No correlation was found between clinical relapses and fluctuations in the lymphocyte subsets, although patients who were in remission throughout the study showed a number of CD3+ cells and a CD4/CD8 ratio significantly lower than those in normal controls. We concluded that changes in peripheral blood lymphocyte subsets are not related to the disease process and their measurement is not helpful in monitoring the illness.

Correlation of immunological studies and disease progression in chronic progressive multiple sclerosis

Thirty untreated patients with clinically definite chronic progressive multiple sclerosis were matched with 10 patients with clinically stable definite multiple sclerosis and 16 patients with other neurological diseases. A group of 12 normal control (NC) volunteers was matched to these groups. All patients with chronic progressive multiple sclerosis and normal control subjects were analyzed for the concanavalin A suppressor assay, mitogen stimulation, and phenotyping of peripheral blood mononuclear cells. In addition, serum was analyzed for interleukin-2 levels. Results of mitogen stimulation studies did not distinguish the groups. Concanavalin A-induced suppression was significantly decreased in the patients with chronic progressive multiple sclerosis (p less than 0.01). Phenotyping of fresh cells showed an elevated CD4: CD8 ratio in the patients with chronic progressive multiple sclerosis. Neither phenotyping nor concanavalin A-induced suppression correlated with or predicted the degree of disability, but the serum levels of interleukin-2 correlated inversely with disability (p less than 0.01) and directly with a poor prognosis after 18 months of observation (p less than 0.05). Serum levels of interleukin-2 decreased as the disease progressed.

T-cell subsets in the cerebrospinal fluid and blood of patients with multiple sclerosis

The absolute numbers and ratios of helper/inducer (T4) and cytotoxic/suppressor (T8) T-cells were determined in cerebrospinal fluid (CSF) and blood of patients with multiple sclerosis (MS) and various other neurologic diseases (OND). In patients with MS, the T4:T8 ratio was higher in both blood and CSF, and the increase was significantly greater in CSF than in blood. These findings were due to an increased proportion of T4-lymphocytes in the CSF and to a decreased proportion of T8-cells in blood. These results indicate the need for additional studies of CSF lymphocytes in patients with MS.

The imbalance in CSF T cell subsets in active multiple sclerosis

We determined the percentage of each lymphocyte subpopulation in the cerebrospinal fluid (CSF) and the peripheral blood of 7 patients with active multiple sclerosis (MS), 7 with inactive MS, 5 with other inflammatory diseases in the central nervous system, and 12 with non-inflammatory neurological diseases, using fluorescein-labelled monoclonal antibodies (anti-Leu7, anti-HLA-DR, and those that recognize such surface antigens as CD3, CD4, CD8, and CD19), and by laser flow cytometry to clarify the clinical usefulness of their measurement in the assessment of disease activity in MS. In CSF, a significant increase in the percentage of CD4+ cells and a significant decrease in the percentage of CD8+ cells were observed in the active MS group compared with the other 3 groups, while none of the percentages of the 6 subsets studied in the peripheral blood were significantly different among these groups. Our preliminary study indicated that evaluation of the percentages of CD4+ and CD8+ cells in CSF by flow cytometry could be a useful indicator of disease activity in MS.

Líquido cefalorraqueano e neurocisticercose: aspectos evolutivos da resposta inflamatória celular

Foram estudadas 357 amostras de LCR de 40 pacientes com neurocisticercose, submetidos a tratamento medicamentoso com praziquantel associado a dexametasona. No sentido de avaliar aspectos evolutivos do componente celular da resposta inflamatória, foram programadas, para cada paciente, avaliações do exame de LCR em 13 oportunidades: por ocasião do dagnóstico; durante o tratamento; e posteriormente, a intervalos prefixados até completar dois anos de evolução. Foi utilizada metodologia adequada ao estudo citológico e citomorfológico, bem como à quantificação de linfócitos B e T. Para determinação de subpopulações T-ativa, T-sensibilizada e T-ávidas foram utilizados, como marcadores de superfície, receptores para hemácias de carneiro. O grupo controle é constituído de 50 pacientes com cefaléia crônica e que não apresentavam alterações ao exame físico e ao exame neurológico. Em todos, o exame de LCR estava dentro dos limites normais. Linfócitos B e T não apresentavam alterações no exame inicial de LCR; não houve modificações no seu comportamento durante toda a evolução. Os elementos da resposta inflamatória celular capazes de fornecer informações significativas acerca do perfil evolutivo em estudo foram: o número de células, a presença e o número de polimorfonucleares neutrófilos e de células eosinófilas e a quantificação de subpopulações T-ativa e T-sensibilizada. A presença de polimorfonucleares neutrófilos embora influenciada pela ação dos corticosteróides e pela presença de sistema de derivação do trânsito do LCR, pode constituir-se em elemento qualitativo sugestivo de atividade inflamatória. Os valores percentuais para linfócitos T-ativos, diminuídos na primeira amostra, e T-sensibilizados, aumentados na primeira amostra, podem ser indicadores quantitativos e qualitativos adequados a reconhecer a vigência de atividade inflamatória local no sistema LCR; estas subpopulações linfocitárias, com alterações significativas em 63,2% dos pacientes no exame inicial, não são influenciadas significativamente pelo uso de corticosteróides. Os valores de eosinófilos e de linfócitos T-sensibilizados estão significativamente aumentados em pacientes que apresentaram complicações clínicas durante o período de acompanhamento após o tratamento; subpopulação de linfócitos T-ativos estava significativamente diminuída nestes casos. O número de células e a presença de eosinófilos são os elementos da resposta inflamatória celular relacionáveis a tipos de alterações detectadas pela tomografia computadorizada do crânio. Os elementos da resposta inflamatória celular estudados não apresentam correlação significativa entre si, podendo traduzir cada um deles aspectos particulares da reação inflamatória celular no SNC em pacientes com neurocisticercose.

Suppressor and cytolytic cell function in multiple sclerosis. Effects of cyclosporine A and interleukin 2

Patients with progressive multiple sclerosis (MS) demonstrated persistent reductions in levels of concanavalin A (Con A)-induced suppressor activity and heightened levels of in vitro pokeweed mitogen (PWM)-induced IgG secretion. The reduced Con A suppressor activity could not be reversed by addition of interleukin 2 (IL-2). Cyclosporine A (CsA) treatment did not alter the defect in Con A-induced suppressor activity, but did markedly inhibit T8+ cell-mediated alloantigen directed cytolytic activity; this latter defect was reversible by in vitro addition of IL-2. CsA-treated patients did not differ from placebo-treated patients with regard to levels of PWM-induced IgG secretion or proliferative responses of their mononuclear cells to Con A. The results indicate that CsA treatment of MS patients reduces cytolytic function from baseline normal values, but does not alter aberrant suppressor cell function.

Peripheral blood T lymphocyte changes in multiple sclerosis: a marker of disease progression rather than of relapse?

A serial study of peripheral blood T lymphocytes in 27 patients with clinically definite multiple sclerosis and 11 healthy controls was carried out over a 12 month period. This showed that contrary to many previous reports, relapses were not consistently associated with reduced numbers of peripheral blood suppressor T lymphocytes or any other T cells. Persistently low T cells numbers, including both the helper and suppressor T cell subsets, were, however, associated with disease activity as measured by the development of increased disability during the course of the study. This was true both for the patients with relapsing/remitting disease and those with progressive disease. The importance of carrying out a serial study was emphasised by the consistent and significant differences that were detected between individuals in both the control and the patient groups. A serial study is the most reliable means by which clinical events can clearly be correlated with laboratory estimations. The association in this study between the development of increased disability and persistently low levels of peripheral blood T lymphocytes suggest that both may be related to the underlying disease process in multiple sclerosis.

Immunohistochemical analysis of the cellular infiltrate in multiple sclerosis lesions

Immunohistochemical staining of 16 brains post mortem from patients with progressive multiple sclerosis and of two biopsy specimens from patients with acute demyelinating disease was performed using a panel of monoclonal antibodies reactive with T cells and T-cell subsets, B cells, and Ia (HLA-DR) antigens. Lymphocytic perivascular cuffs were most prominent at the edge of active plaques and were occasionally seen in areas with no evidence of demyelination or macrophage infiltration. Perivascular cuffs consisted predominantly of T cells and Ia+ cells, with many T8+ cells and variable numbers of T4+ cells. T8/T4 ratios in cuffs varied between 1:1 and 50:1. In normal-appearing white matter, cuffs were sparse and were predominantly T8+. The distribution of T cells in the parenchyma resembled that seen in perivascular cuffs, namely, predominantly T8+ cells and variable numbers of T4+ cells. Many Ia+ cells were present in active lesions, and the majority of these cells appeared, by histological criteria, to be macrophages. Tissue macrophages were also stained lightly by the anti-T4 antibody. No brain had more T4+ than T8+ cells, determined using both T4 and Leu3a monoclonal antibodies. B1+ cells were rare. These results suggest that the cellular infiltrate in multiple sclerosis consists predominantly of T cells and macrophages and that there is an overrepresentation of T8+ cells compared with T4+ cells.

Multiple sclerosis: neuroimmunologic puzzle

Multiple sclerosis (MS), a chronic disease with a relapsing and remitting course, is the most common neuroimmunologic condition in the United States. The hallmarks of the disease are focal demyelination and inflammation within the central nervous system (CNS). Because histopathologic changes can be identified only at autopsy, attention has been directed at formulating standardized clinical and laboratory procedures to aid in MS diagnosis. Currently, there are no MS-specific clinical or laboratory tests, but detection of abnormality in cerebrospinal fluid (CSF) IgG is important in supporting clinical evidence of disease. A number of other immunologic abnormalities have been recognized in MS, including the presence of T- and B-lymphocytes within the CNS and alterations in circulating suppressor T-lymphocytes. These findings have been interpreted as indicating disturbed immunoregulation associated with a chronic autoimmune response within the CNS. Evidence implicates viral infection in the pathogenesis of MS but the cause of the disease remains unknown.

The effects of long-term administration of recombinant alpha-2 interferon on lymphocyte subsets, proliferation, and suppressor cell function in multiple sclerosis

The immunological effects of long-term treatment with recombinant alpha-2 interferon (rIFN-alpha 2) were investigated in multiple sclerosis (MS) patients treated with 2 X 10(6) units of IFN or a placebo three times per week for one year. A mild lymphopenia was observed in IFN patients who also showed a decrease in the absolute number of total T cells in the blood (OKT3 binding cells); however, the percentage of cells reacting with OKT3, OKT4, and OKT8 antibodies did not change significantly during the study. The percentage of cells reacting with the Leu-7 antibody, which recognizes NK cells, was unchanged. During MS exacerbations, placebo patients showed a tendency for decreased levels of OKT3 and OKT8 cells. In contrast, IFN patients did not demonstrate a decrease in either OKT3 or OKT8 cells during disease attacks. Concanavalin A (ConA)-induced suppressor cell activity was depressed in both IFN and placebo-treated patients during attacks. Lymphoproliferative responses to phytohemagglutinin, pokeweed mitogen, and ConA were unchanged. These studies demonstrate that long-term treatment with rIFN-alpha 2 induces a generalized T-cell lymphopenia, but at this dose does not significantly affect the profiles of T-cell subsets and suppressor cell function in MS patients.

Myelin basic protein and demyelinating diseases

Myelin basic protein (MBP) is a major protein component of myelin sheath. Primarily because of its ability to induce experimental allergic encephalomyelitis (EAE) in animals, this protein has been considered to play an important role in the pathogenesis of multiple sclerosis (MS), which is one of the most common demyelinating diseases. Its precise measurement in the cerebrospinal fluid (CSF) has been uncommonly difficult, mainly due to immunoheterogeneity of MBP or MBP-like material. More recently, highly sensitive radioimmunoassay techniques utilizing well-characterized antisera have been developed that facilitated its use in the management of MS. The clinical course of MS is highly variable, and the disease is characterized by periods of remission and relapses. Many studies have demonstrated the release of MBP during relapses and elevated levels of MBP in the CSF can be detected if lumbar puncture is performed within 7 days of the onset of neurologic symptoms suggestive of MS. However, the presence of MBP is not an absolute indicator of MS, as elevated MBP levels are also frequently observed in other demyelinating diseases.

Phenotypic and functional analysis of T cells cloned directly from the blood and cerebrospinal fluid of patients with multiple sclerosis

A single-cell cloning technique was used to analyze both phenotype and function of individual T cells in patients with multiple sclerosis (MS). Blood and cerebrospinal fluid (CSF) lymphocytes were plated at 1 cell per well, stimulated with phytohemagglutinin followed by interleukin 2, and expanded to 3 X 10(6) cells per "clone." More than 90% of the T8 clones generated from patients with MS and controls in both blood and CSF were cytotoxic precursors. There was also a slight decrease in cytotoxic T4 clones in the blood of patients with MS. The cytotoxic precursor frequencies of T cells in the CSF generally reflected those in the blood. In separate experiments, antigen reactivity was examined in lines established from blood or CSF. No reactivity to myelin basic protein or white matter was found in patients with MS or controls. Myelin basic protein-reactive clones could, however, be generated after first stimulating lymphocytes with antigen before cloning. These results suggest that changes in the T8 population from the blood of patients with MS involve cytotoxic as well as suppressor cells. Sequestration of myelin basic protein- or white matter-reactive T cells was not seen in the CSF of patients with MS, unlike reports of viral meningoencephalitis, in which large numbers of antigen-specific cells were found in the CSF. Direct single-cell clonal analysis of the CSF should provide a more sophisticated approach to the study of T cell abnormalities in patients with MS.

T8 antigen density on peripheral blood lymphocytes remains unchanged during exacerbations of multiple sclerosis

Fluorescence-activated cell sorter (FACS) analysis was used to quantitate the antigen density of the lymphocyte markers T3, T4, T8, and Leu 7 on the surface of peripheral blood mononuclear cells (MNC) from exacerbating/remitting multiple sclerosis (MS) patients. Serial studies showed that the mean fluoresce intensity for all the markers studied did not change significantly during exacerbations. There was a tendency for a generalized decline in T-cells, evidenced by a drop in both T8+- and T4+-cells; however, these changes were not statistically significant. It appears, therefore, that the lymphocyte markers studied here are not useful as markers of disease activity in exacerbating/remitting MS.

Effect of lymphocytapheresis plus cyclophosphamide on the course of a chronic progressive form of multiple sclerosis

We report a case of a 16 year old boy with a chronic progressive form of Multiple Sclerosis treated with lymphocytapheresis and a low dose regimen of cyclophosphamide. A progressive improvement in the disability index and slowing of the clinical course were obtained. No side effects were observed. Depletion of lymphocytes and their pharmacological suppression point to their possible role in the induction of an immunoregulation of the disease process.