FRI0007 MOSPD2: A NOVEL THERAPEUTIC TARGET FOR THE TREATMENT OF RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease with an unknown etiology that affects the joints. B and T lymphocytes are major drivers of arthritis, mediated through their secretion of antibodies against self-antigens and the production of pro-inflammatory cytokines. Nevertheless, innate immune cells play an important role in disease progression, and recruitment of blood monocytes/macrophages was highly correlated with tissue damage in RA patients1,2. Once infiltrated into the joint, monocytes can produce proinflammatory cytokines and chemokines that further escalate the inflammatory process and tissue damage. Consistent with that, genetic and pharmacological intervention targeting CCR2 and CCR5, chemokine receptors which are abundantly expressed on monocytes, was shown to reduce disease severity in multiple preclinical models of RA3. Blocking monocyte migration in RA can be therefore an attractive therapeutic approach, if implied in a manner that can overcome the redundancy of chemokine receptors and ligands.

Motile sperm domain-containing protein 2 (MOSPD2) is a 518 amino acids single-pass membrane protein to which no function was ascribed up until recently. Assessment of MOSPD2 in immune cell subsets showed it is expressed by monocytes and neutrophils. We previously discovered that MOSPD2 regulates human monocyte and neutrophil migration in a chemokine-agnostic manner4.

Objectives:

Using anti MOSPD2 mAbs, the role of MOSPD2 in mouse monocyte migration in-vitro and RA progression in mice was assessed.

Methods:

In-vitro, MCP-1 and SDF-1 chemokines were used to induce migration of mouse splenic monocytes through a trans-well plate in the presence of anti MOSPD2 mAbs. In-vivo, DBA-1 mice were injected with type II collagen on days 0 and 21 to induce arthritis. Mice were then treated twice a week with anti MOSPD2 mAb, anti TNF-α or an isotype control antibody until study end (day 42). Animals were monitored for arthritis score, and upon sacrifice, hind limb joints were examined for pathology.

Results:

Anti MOSPD2 mAbs significantly inhibited migration of mouse monocytes in-vitro. Treatment with anti MOSPD2 mAb after disease was already initiated, limited disease progression and significantly ameliorated clinical manifestation at the climax phase of the disease by more than 50% compared with isotype control and anti TNF-α treatment. Pathological examination revealed that treatment with anti MOSPD2 mAb reduced pannus formation and joint inflammation.

Conclusion:

The results further support the involvement of monocytes in RA pathogenesis and highlight the key role MOSPD2 plays in this disease. Accordingly, targeting of monocyte migration using anti MOSPD2 mAbs may hold promise as a treatment for various chronic inflammatory diseases, including RA.

References:

[1]Tak PP et al., (1997) Analysis of the synovial cell infiltrate in early rheumatoid synovial tissue in relation to local disease activity. Arthritis Rheum 40:217.

[2]Mulherin D et al., (1996) Synovial tissue macrophage populations and articular damage in rheumatoid arthritis. Arthritis Rheum 39:115.

[3]Zhao, Q et al., (2010) Dual targeting of CCR2 and CCR5: therapeutic potential for immunologic and cardiovascular diseases. J. Leukoc. Biol. 88: 41.

[4]Mendel et al., 2017 Identification of Motile Sperm Domain-Containing Protein 2 as Regulator of Human Monocyte Migration. J Immunol. 198: 2125.

Disclosure of Interests:

None declared

MOSPD2 is a therapeutic target for the treatment of CNS inflammation

In multiple sclerosis and experimental autoimmune encephalomyelitis (EAE), myeloid cells comprise a major part of the inflammatory infiltrate in the central nervous system (CNS). We previously described that motile sperm domain‐containing protein 2 (MOSPD2) is expressed on human myeloid cells and regulates monocyte migration in vitro. The role of MOSPD2 in EAE pathogenesis was studied by generating MOSPD2 knock‐out (KO) mice and monoclonal antibodies directed against MOSPD2. We found that EAE development in MOSPD2 KO mice was significantly suppressed. While frequency representation of leukocyte subsets in lymphoid tissues was comparable, the ratio of inflammatory monocytes in the blood was markedly reduced in MOSPD2 KO mice. In addition, T cells from MOSPD2 KO mice displayed reduced secretion of proinflammatory cytokines and increased production of interleukin (IL)‐4. Prophylactic and post‐onset treatment using monoclonal antibodies (mAbs) generated against MOSPD2 abrogated development and reduced EAE severity. These results suggest that MOSPD2 is key in regulating migration of inflammatory monocytes, and that anti‐MOSPD2 mAbs constitute a potential therapy for the treatment of CNS inflammatory diseases.

VB-201, an oxidized phospholipid small molecule, inhibits CD14- and Toll-like receptor-2-dependent innate cell activation and constrains atherosclerosis

Atherosclerosis is an inflammatory disease of the vascular wall. Activated monocytes and dendritic cells (DC) in the intima layer of the vasculature promote atherogenesis. Toll-like receptor (TLR)-2 and TLR-4, which are predominantly expressed on these cells and mediate their activation, are essential for atherosclerosis development. In this study we demonstrate that VB-201, an oxidized phospholipid (Ox-PL) small molecule, inhibits TLR signalling restricted to TLR-2 and TLR-4 in human and mouse monocytes and DC. Mechanistically, we show that VB-201 binds directly to TLR-2 and CD14, the TLR-4 co-receptor, to impair downstream cues and cytokine production. In a rabbit model, oral administration of VB-201 constrained atherosclerosis progression. This effect was not due to reduced cholesterol abundance, as hyperlipidaemia was sustained. We suggest that VB-201 may counter inflammation where TLR-2 and/or CD14 complicity is essential, and is therefore beneficial for the treatment of atherosclerosis.

Post-intubation vocal cord paralysis: the viral hypothesis. A case report

After digestive surgery, a 20-year-old man presented dysphonia and fever. Indirect laryngoscopy revealed a left vocal cord paralysis with no structural lesion. IgM and IgG were positive for cytomegalovirus and negative for human immunodeficiency virus, herpes simplex virus, varicella zoster virus and Epstein-Barr virus. The patient recovered spontaneously with a normal voice, and the mobility of vocal cord recovered within 3 months. The aetiology of post-intubation vocal cord paralysis (VCP) remains controversial. Vocal cord paralysis with cytomegalovirus has been reported in two cases associated with acquired immunodeficiency syndrome. Vocal cord paralysis secondary to viral disease has also been described in other circumstances. panied by polyneuritis, especially in immunocompromised patients. We report the case of a patient with transitory unilateral post-intubation vocal cord paralysis which could have been related to a virus infection.

[Evaluation of spontaneous peri-transfusional screening for HVC and HIV at the Rouen University Hospital Center]

INTRODUCTION

Since October 1996, French hospitals have been instructed to introduce screening for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) in all patients before and 3 months after each blood transfusion. The aim of this study was to assess the degree to which this recommendation had been taken into account in a university hospital via a pre- and post transfusion screening comparison.

PATIENTS AND METHODS

A retrospective study on the use or non-use of screening tests for HCV and HIV was carried out in 2 groups of 150 randomly selected patients who had received blood transfusions in 1996 and in 1998.

RESULTS

The coverage by pre-transfusion screening tests for HCV and HIV varied from 23% in 1996 to 20% in 1998 (not significant). The post-transfusion screening tests were performed by the hospital in 6% of the cases in 1996 and in 3% of the cases in 1998 involving blood transfusion.

CONCLUSION

This study suggests that in the majority of patients, screening (particularly post-transfusion screening) for HCV and HIV was not carried out, and that over the 2-year period considered no noticeable improvement was observed. However, these results only concerned one hospital in which no specific screening program had been introduced. It is therefore possible that these findings are not representative of the situation in other hospitals; further studies would be useful in this regard.

The central nervous system-specific myelin oligodendrocytic basic protein (MOBP) is encephalitogenic and a potential target antigen in multiple sclerosis (MS)

Uncovering primary target antigens in multiple sclerosis (MS) is of major significance for understanding the etiology and pathophysiology of the disease, and for designing immunospecific therapy. In this study, a synthetic peptide representing a predicted T cell epitope on myelin oligodendrocytic basic protein (MOBP) was found to be encephalitogenic in C3H.SW mice, inducing experimental autoimmune encephalomyelitis with an abrupt onset. Two separate preliminary studies with MOBP peptides indicated that autoreactivity to MOBP occurs in MS. These data strongly suggest that MOBP is a highly relevant target in MS and further point to the complexity of antigen specificities in MS.

Hepatitis C virus genotypes in France: relationship with epidemiology, pathogenicity and response to interferon therapy. The GEMHEP

The aim of this study was to investigate the following in a large population of French patients with chronic hepatitis C: the geographical distribution of hepatitis C virus (HCV) genotypes; the relationship between HCV genotypes and epidemiological characteristics; severity of the disease; and response to interferon (IFN) therapy. Data from 14 tertiary referral centres, corresponding to 1872 patients with chronic hepatitis C, were prospectively collected from 1989 to 1997. HCV genotyping was performed using the line probe assay (LiPA). HCV genotypes 1b, 3, 1a, 2, 4 and a mixed infection were found in 41%, 22%, 16%, 11%, 4% and 4% of our population, respectively. HCV genotype distribution was homogeneous, except for genotype 2 that was found more frequently in the southwest than in the other regions (21% vs 9.2%) (P=0.001). HCV distribution was associated with gender, age, and source and duration of infection. In multivariate analysis, these correlations were related to the source of infection, which was the only independent factor significantly associated with genotype (P=0.001). Genotype 1b was significantly more common in patients with cirrhosis, but in multivariate analysis cirrhosis was independently related to older age at exposure and longer duration of infection (P=0.001). A sustained response to IFN therapy was observed in 11% of patients infected with genotypes 1a or 1b vs 32% of those infected with genotypes 2 or 3 (P=0.001). This study shows that HCV genotype is mainly related to the source infection, but not to the intrinsic pathogenicity of HCV, and is a strong predictor of sustained response to therapy.

Effect of the bm12 class II mutation on proliferative and cytokine responses of encephalitogenic T cells in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis

The bm12 mutation in the class II I-A(b)molecule can profoundly influence experimental autoimmune disease, enhancing the development of systemic lupus erythematosus-like syndromes in NZB.H-2(bm12)mice or, conversely, abolishing the susceptibility of C57BL/6J (H-2(b)) mice to the induction of experimental autoimmune myasthenia gravis. We have studied the effect of this mutation on experimental autoimmune encephalomyelitis (EAE), induced in H-2(b)mice by myelin oligodendrocyte glycoprotein (MOG), and recently showed that MOG 35-55 peptide (pMOG 35-55), which represents the immunodominant encephalitogenic region for H-2(b)mice, is also a strong encephalitogen for H-2(bm12)mice. Nevertheless, although the differences in fine epitope specificity and TCR-Vbeta gene usage between encephalitogenic pMOG 35-55-specific T cells from H-2(b)and H-2(bm12)mice were subtle, H-2(bm12)and H-2(b)antigen presenting cells failed to effectively cross-present pMOG 35-55 non-syngeneically to I-A(b)/pMOG 33-55- and I-A(bm12)/pMOG 35-55-specific T cells, respectively. In the present study, we show that the abrogation of the response to pMOG 35-55 by the Th1 encephalitogenic pMOG 35-55-specific T cells upon non-syngeneic cross-presentation is neither due to a cytokine shift to a Th2 pattern, nor a result of anergy induction. Therefore, we suggest that presentation of pMOG 35-55 to I-A(b)/pMOG 35-55-specific T cells via the bm12 class II MHC molecule resulted in ineffective stimulation, similar to a weak agonistic effect.

Experimental autoimmune encephalomyelitis induced in B6.C-H-2bm12 mice by myelin oligodendrocyte glycoprotein: effect of MHC class II mutation on immunodominant epitope selection and fine epitope specificity of encephalitogenic T cells

The effect of the bm12 mutation on susceptibility to MOG-induced EAE, TCR repertoire and fine epitope specificity of the encephalitogenic T-cells, was assessed. prMOG35-55 was encephalitogenic for H-2bm12 and H-2b mice. Despite only minor differences in TCRVbeta expression and fine epitope specificity, H-2bm12/ and H-2b/prMOG35-55-specific T-cells failed to recognize Ab/prMOG35-55 and Abm12/prMOG35-55, respectively. rhMOG-induced EAE was milder in H-2bm12 mice, possibly as a result of co-dominant responses to prMOG35-55 and to the non-encephalitogenic pMOG94-116, rather than a single dominant response to prMOG35-55 in H-2b mice.

Detection of adenovirus in the waters of the Seine River estuary by nested-PCR

Several systems for isolating viruses from environmental samples have been tested. The most promising method is based on genomic amplification. The authors attempted to detect adenovirus in nucleic-acid extracts from the Seine River estuary by a two-step amplification of a 220-bp segment of the conserved coding region of type 2 adenovirus hexon protein L3. The primers used in this study detected the most prevalent adenovirus serotypes in human disease in France, but not other virus strains or bacteria. The sensitivity of the nested polymerase chain reaction (PCR) amplification was estimated to be 10(2) copies of the adenovirus target sequence per ml of Seine River water. Nucleic-acid extracts from Seine River estuary waters were analysed and some tested positive for the presence of adenoviruses.

Interleukin-6 functions in autoimmune encephalomyelitis: a study in gene-targeted mice

The encephalitogenic peptide pMOG 35-55 from the myelin oligodendrocyte glycoprotein was used to induce experimental autoimmune encephalomyelitis (EAE) in H-2b mice with the interleukin-6 (IL-6) gene intact or disrupted. The IL-6+/+ mice developed a chronic form of EAE ascending paralysis, whereas the IL-6-/- mice were resistant to the disease. Injections of recombinant IL-6 following pMOG immunization induced severe disease in the IL-6-/- mice. Histological examination of brain and spinal cord sections showed that the perivascular infiltration of inflammatory cells evident in IL-6+/+ mice was absent in the IL-6-/- animals and could be restored by exogenous IL-6 administration. Anti-MOG antibody levels were much lower in the IL-6-/- mice, but were not restored to high levels by IL-6 injections which elicited the development of pMOG 35-55-induced EAE. T lymphocytes reactive to the pMOG antigen were recovered from lymph nodes of both types of mice and Tcell lines could be established from both. Adoptive transfer of Tcell lines from IL-6+/+ mice induced EAE in the mice with the intact IL-6 gene but less in the IL-6-deficient mice, indicating that the resistant phenotype cannot be explained solely by lack of encephalitogenic Tcells. The absence of cell infiltrates in the brain and spinal cords of IL-6-/- mice upon adoptive transfer of the pathogenic Tcells from IL-6+/+ mice is consistent with a function of IL-6 in the local perivascular inflammatory process.

Enterovirus-associated haemophagocytic syndrome in a neonate

A 3-d-old neonate presented with fever, hepatosplenomegaly, coagulopathy, thrombopenia and anaemia. Secondary haemophagocytic lymphohistiocytosis was suspected, as persistent cytopenias were associated with hypofibrinogenaemia, haemophagocytosis in bone marrow and decreased NK cell. There was no positive family lymphohistiocytosis history or parental consanguinity. Bacterial investigation proved negative. The diagnosis of enterovirus maternofoetal infection was carried out. The infant's condition improved with symptomatic therapy from day 7. Follow up at 1 y was normal without relapse. This is the first report of a neonatal enteroviral infection that was responsible for excessive macrophage activation.

Predominance of the autoimmune response to myelin oligodendrocyte glycoprotein (MOG) in multiple sclerosis: reactivity to the extracellular domain of MOG is directed against three main regions

Our previous analysis of the T cell reactivity to myelin antigens in a group of 24 patients with multiple sclerosis (MS) and 16 control individuals revealed that the autoimmune response to myelin oligodendrocyte glycoprotein (MOG) predominates in MS over that to myelin basic protein (MBP), proteolipid protein or myelin-associated glycoprotein, suggesting a prevalent role for the autoimmune response to MOG in the pathogenesis of MS. Using a recombinant human MOG (rhMOG) preparation corresponding to the extracellular immunoglobulin-like domain of the MOG molecule, we have now analyzed another group of 52 MS patients and 49 control individuals for reactivity of their peripheral blood lymphocytes (PBL) to rhMOG and to MBP concomitantly. Of the 52 MS patients tested 24 responded to MOG and 10 out of 49 responded to MBP, whereas only 5 MOG-reactive and 4 MBP-reactive control individuals were detected out of the 49 tested. These results are therefore highly confirmatory of the predominant reactivity to MOG in MS. The analysis of the primary proliferative response to 11 synthetic overlapping peptides (phMOG) spanning the extracellular domain of human MOG by PBL from 9 MS patients and 15 control individuals (9 healthy controls and 6 patients with neurological diseases other than MS) further supports a prevalent role for the autoimmune response to MOG in MS, as only 1 of the 15 controls tested showed reactivity to any of the phMOG, whilst 5 out of the 9 patients studied reacted to at least 1 of the phMOG. PBL from 10 MS patients, and from 4 controls, were selected in vitro with each of the phMOG. Of the 10 patients studied 7 reacted to at least 1 phMOG upon secondary stimulation and the reactivity was mostly directed to epitopes localized within three main regions (amino acids 1-22, 34-56 and 64-96), as was observed for the primary response of PBL. The predominant response to MOG of PBL from MS patients as demonstrated in two separate studies using native MOG and rhMOG as antigens, and the high incidence of reactivity of these PBL compared to the lack of response to phMOG by control PBL, emphasize the relevance of MOG in MS pathogenesis and support a primary role for the autoimmune T cell response to MOG in disease development.

Hepatosplenic gamma/delta T-cell lymphoma: a report of two cases in immunocompromised patients, associated with isochromosome 7q

Two cases of peripheral T-cell lymphoma, characterized by hepatosplenic presentation and gamma/delta T-cell receptor phenotype on malignant cells, are reported. Little is known about the chromosomal changes in these peculiar lymphomas. We report the cytogenetic analysis of these two patients. Isochromosome 7q and trisomy 8 were observed. These abnormalities were reported previously in five cases of gamma/delta T-cell lymphoma. These two patients had lymphomatous infiltration of the spleen, liver, bone marrow, and (in one case) lymph nodes. These abnormalities occurred in immunocompromised patients (i.e., immunosuppressive therapy for kidney transplantation and chemotherapy for Hodgkin's disease), without Epstein-Barr virus infection stigmata in tumor cells.

Detection and genotyping of the hepatitis C RNA in tear fluid from patients with chronic hepatitis C

Tear fluid from 51 patients with chronic hepatitis C virus (HCV) infection was analyzed for the presence of the hepatitis C RNA to assess the potential role of this fluid in virus transmission. HCV sequences were amplified from sera and tear fluids by nested polymerase chain reaction using primers from the 5' non coding region of the virus genome. Positive samples were genotyped by the LiPA procedures. HCV RNA was detected in 76.5% (39/51) of the sera and in 9.8% (5/51%) of the tear fluid samples. The presence of the RNA in the tear fluid was independent of the severity of the hepatitis and of the viral load as measured by the branched DNA assay. The genotypes of the tears and serum isolates were different for two patients. For another patient, the HCV RNA was positive in the tear sample but negative in the serum sample. These findings suggest that tear fluid may transmit HCV but the source of HCV RNA in this fluid needs to be better understood.

Immunomodulation of murine experimental autoimmune encephalomyelitis by pertussis toxin: the protective activity, but not the disease-enhancing activity, can be attributed to the nontoxic B-oligomer

Bordetella pertussis and its major virulence component, pertussis toxin (PT), have been used routinely to promote the development of such murine experimental autoimmune diseases as experimental autoimmune encephalomyelitis (EAE). Recently, we reported that B. pertussis also can protect against EAE. The protective activity was assigned to PT, a complex holomer composed of an A-promoter, the toxic S1 subunit, and a B-oligomer comprised of subunits S2, S3, S4, and S5. Although some data are available to explain how PT can enhance the development of EAE, nothing is known about the mechanism by which it protects against the disease. Toward understanding how PT can have such conflicting effects on EAE, we investigated the immunomodulatory activity of the various components of PT. Herein we show that the enhancing and protective activities reside within different regions of the PT holomer. Thus, though S1 appeared essential in imparting enhancing activity to PT, it played no role of importance in disease protection, and the protective effects of PT could be assigned fully to the B-oligomer. Further investigation with gel-purified PT subunits revealed that B-oligomer subunits protected against EAE to varying extent, with S3 being the most protective. These data suggest a potential therapeutic application for the B-oligomer or some of its subunits, which appear to be potent protective agents, without the toxicity or disease-promoting activity associated with PT.

The autoimmune reactivity to myelin oligodendrocyte glycoprotein (MOG) in multiple sclerosis is potentially pathogenic: effect of copolymer 1 on MOG-induced disease

Multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) characterized by primary demyelination, is believed to result from an autoimmune attack against myelin components. In view of their ability to induce experimental autoimmune encephalomyelitis (EAE), an animal model for MS, the quantitatively major malign proteins--myelin basic protein (MBP) and proteolipid protein (PLP)--have been extensively studied as the relevant primary antigens in MS, and therapeutic approaches have been targeted to counteract autoimmune reactivity to MBP and PLP. Accordingly, copolymer 1, a random synthetic amino acid copolymer crossreactive with MBP and highly protective against the induction of EAE with MBP or PLP, is not being extensively tested in clinical studies as a therapeutic agent for MS. However, increasing evidence suggests that autoimmune reactivity against other CNS-specific myelin proteins could also be involved in the pathogenesis of MS. In this context, we have demonstrated that peripheral blood lymphocytes from patients with MS respond predominantly to myelin oligodendrocyte glycoprotein (MOG) rather than to MBP or PLP, suggesting an important role for cell reactivity against MOG in the pathogenesis of MS. We have demonstrated that T-cell reactivity in MOG can also be pathogenic by inducing neurological disease in H-2u and H-2b mice with the same peptide of MOG, pMOG 35-55. Most interestingly, the expression of the disease differed with the different MHC backgrounds. Induction of a differentially expressed disease in different strains of mice with the same myelin antigen makes this new model particularly relevant to MS, where different expression of the disease is seen in different patients. Therefore, notwithstanding the importance of the autoimmune reactivity to MBP and PLP in MS, the potentially pathogenic autoimmune reactivity to MOG must now also be taken into consideration in therapeutic approaches to MS. In this context, we have investigated the possible effect of copolymer 1 treatment on autoimmune reactivity to MOG and on the development of EAE induced by MOG. Copolymer 1 was found to inhibit the binding of MOG peptides to MHC molecules, as well as the proliferation of MOG-reactive T cells, in a dose-dependent manner. In parallel, injection of copolymer 1 concomitantly with the encephalitogenic MOG peptide exerted a strong protective effect against the development of EAE. These preliminary data on the effect of copolymer 1 on the autoimmune response to MOG in mice indicate that copolymer 1 may also be effective in cases of MS where the autoimmune response to MOG prevails, and should therefore be further investigated in this context.

Hepatitis C virus infection in an HIV-positive population in Normandy: antibodies, HCV RNA and genotype prevalence

The prevalence and the characteristics of hepatitis C virus infection (HCV) in 161 HIV-positive patients were studied. HCV seroprevalence was determined by enzyme immunoassay and recombinant immunoblot assay (RIBA). Two different reverse transcriptase polymerase chain reaction (RT-PCR) methods were also used to test the HCV-seropositive samples and 50 EIA-negative sera used as controls. The RNA HCV-positive sera were genotyped by the LiPA procedure. Associations of HCV status with demographic characteristics and risk factors were assessed by chi 2 and Fisher's exact tests. The seroprevalence of HCV was 34.2% with a significant difference between blood and sexual exposure risk groups (60.6% vs. 13.6%, respectively; P < 0.0001). Thirty-six of the 55 anti-HCV-positive sera were also positive for HCV RNA, and PCR detected HCV RNA in 8 HCV-seronegative patients. Various RIBA profiles were found and all sera were positive for antibodies to the c33 protein. A proportion of sera had elevated levels of transaminase activity (37.2%), and abnormal liver function as associated with HCV infection. Forty-two samples were genotyped and five genotypes and subtypes of the HCV virus were detected. Genotype 1a was the most frequent in this cohort, although genotype 1b is generally more common in France. The majority (94.1%) of the patients with genotype 1a had a history of blood exposure, which may account for the difference.

A myelin oligodendrocyte glycoprotein peptide induces typical chronic experimental autoimmune encephalomyelitis in H-2b mice: fine specificity and T cell receptor V beta expression of encephalitogenic T cells

A predominant response to myelin oligodendrocyte glycoprotein (MOG) was recently observed in patients with multiple sclerosis (MS). To study the possible pathogenic role of T cell response to MOG in MS, we have investigated the encephalitogenic potential of MOG. Synthetic MOG peptides, pMOG 1-21, 35-55, 67-87, 104-117 and 202-218, representing predicted T cell epitopes, were injected into C57BL/6J and C3H.SW (H-2b) mice. The mice developed significant specific T cell responses to pMOG 1-21, pMOG 35-55 and pMOG 104-117. However, pMOG 35-55 was the only MOG peptide which could induce neurological impairment. The highly reproducible disease was chronic, with ascending paralysis and neuropathology comparable with those observed in experimental autoimmune encephalomyelitis (EAE) induced by myelin basic protein or proteolipid protein, except that in H-2b mice the disease was consistently non-remitting. These features differ markedly from those which we recently observed in PL (H-2u) mice with pMOG 35-55-induced disease. In PL mice, pMOG 35-55-induces atypical chronic relapsing EAE, the expression and progression of which are unpredictable. Hence, in different mouse strains, the same MOG peptide can induce typical EAE characterized by ascending paralysis, or atypical EAE with unpredictable clinical signs. pMOG 35-55-specific T cells from H-2b mice recognized an epitope within amino acids 40-55 of the MOG molecule, and pMOG 40-55-reactive T cell lines were encephalitogenic upon transfer into syngeneic recipients. The encephalitogenic pMOG 35-55-reactive C57BL/6J T cell lines expressed V beta 1, V beta 6, V beta 8, V beta 14 and V beta 15 gene segments, and the pMOG 35-55-reactive C3H.SW T cell lines expressed V beta 1, V beta 2, V beta 6, V beta 8, V beta 10, V beta 14, and V beta 15 gene segments. However, in both mouse strains, the utilization of the V beta 8 gene product was predominant (40-43%). The highly reproducible encephalitogenic activity of pMOG 35-55 strongly suggests a pathogenic role for T cell reactivity to MOG in MS and supports the possibility that MOG may also be a primary target antigen in the disease.

Chronic relapsing experimental autoimmune encephalomyelitis with a delayed onset and an atypical clinical course, induced in PL/J mice by myelin oligodendrocyte glycoprotein (MOG)-derived peptide: preliminary analysis of MOG T cell epitopes

Myelin basic protein (MBP) and proteolipid protein (PLP), the most abundant proteins of central nervous system (CNS) myelin, have been extensively studied as possible primary target antigens in multiple sclerosis (MS), a primary demyelinating autoimmune disease of the CNS. However, there is increasing evidence to suggest that autoimmune reactivity against the quantitatively minor myelin component, myelin oligodendrocyte glycoprotein (MOG), can also play a role in the pathogenicity of MS. We recently demonstrated a predominant response to MOG by peripheral blood lymphocytes from patients with MS tested for their reactivity against various myelin antigens, including MBP and PLP. To ascertain whether or not T cell reactivity to MOG in MS is a potentially pathogenic response, we have tested the ability of synthetic MOG peptides (pMOG) representing potential T cell epitopes, to induce neurological disease in mice. Both strains of mice tested (SJL/J and PL/J mice) were able to mount a primary T cell response to some of the five MOG peptides synthesized, pMOG 1-21, 35-55, 67-87, 104-117 and 202-218. T cell lines could be raised in both strains to pMOG 35-55 and 67-87, but epitope definition revealed that each strain recognized a different minimal epitope within these two peptides. T cell lines to pMOG 1-21 and 202-218 could also be raised in SJL/J and PL/J mice, respectively. T cell reactivity to pMOG 104-117 was not observed in either mouse strain. None of the peptides tested induced detectable clinical signs in SJL/J mice. In contrast, an MS-like chronic relapsing-remitting disease could be induced in PL/J mice with pMOG 35-55. The disease presented with a delayed onset and with clinical signs which differed significantly in their progression and expression from the typical ascending paralysis of experimental autoimmune encephalomyelitis induced with other myelin components, such as MBP and PLP. Histological examination of CNS tissue from mice injected with pMOG 35-55 revealed only mild neuropathological signs with few inflammatory foci in brain and spinal cord. Some myelin splitting and edema were detected upon electron microscopic examination in the spinal cord and cerebellum. Transfer of pMOG 35-55 reactive T cells into naive PL/J mice resulted in pathological changes characterized by inflammatory foci in the brain and spinal cord. This passively induced disease was clinically silent, as was also reported for Lewis rats injected with T cells specific for the same MOG peptide.(ABSTRACT TRUNCATED AT 400 WORDS)

A 12-kDa protein of Mycobacterium tuberculosis protects mice against experimental autoimmune encephalomyelitis. Protection in the absence of shared T cell epitopes with encephalitogenic proteins

Mycobacterium tuberculosis (Mt), routinely used to promote the induction of autoimmune diseases, can also protect against their development. Recently, we demonstrated that purified protein derivative (PPD) is the major fraction of Mt that protects mice against the induction of experimental autoimmune encephalomyelitis (EAE). We have now ascribed the protective activity to a 12-kDa protein purified from PPD. Sequence identity between the first 17 amino acids of the 12-kDa PPD protein and the 10-kDa BCG-a protein of Mt suggested that these proteins are identical or closely related. However, in contrast to the 12-kDa PPD protein, the 10-kDa BCG-a protein did not protect against EAE, nor did it stimulate PPD-specific T cells, suggesting that the 12-kDa PPD protein and the 10-kDa BCG-a protein share some homology but are not identical. The protective activity of the 12-kDa PPD protein correlated with its ability to stimulate PPD-specific T cells. The significance of this correlation is not clear and the mechanism of protection was not fully elucidated. However, N-terminal sequence identity between the 12-kDa PPD protein and the 10-kDa BCG-a protein, which shares 43% homology with GroES stress protein, suggested that the 12-kDa PPD protein may also belong to the bacterial heat-shock protein (hsp) family. Thus, by analogy with protection against arthritis or diabetes by hsp65, the mechanism of protection could be based on shared T cell epitopes with the target self Ag. However, the 12-kDa PPD protein did not stimulate encephalitogenic T lymphocytes. Effective protection against EAE by the 12-kDa PPD protein, in the absence of a stimulatory effect on encephalitogenic T lymphocytes, suggests a potential use for this protein in the therapy of autoimmune diseases.

A 12-kDa protein of Mycobacterium tuberculosis protects mice against experimental autoimmune encephalomyelitis. Protection in the absence of shared T cell epitopes with encephalitogenic proteins

Mycobacterium tuberculosis (Mt), routinely used to promote the induction of autoimmune diseases, can also protect against their development. Recently, we demonstrated that purified protein derivative (PPD) is the major fraction of Mt that protects mice against the induction of experimental autoimmune encephalomyelitis (EAE). We have now ascribed the protective activity to a 12-kDa protein purified from PPD. Sequence identity between the first 17 amino acids of the 12-kDa PPD protein and the 10-kDa BCG-a protein of Mt suggested that these proteins are identical or closely related. However, in contrast to the 12-kDa PPD protein, the 10-kDa BCG-a protein did not protect against EAE, nor did it stimulate PPD-specific T cells, suggesting that the 12-kDa PPD protein and the 10-kDa BCG-a protein share some homology but are not identical. The protective activity of the 12-kDa PPD protein correlated with its ability to stimulate PPD-specific T cells. The significance of this correlation is not clear and the mechanism of protection was not fully elucidated. However, N-terminal sequence identity between the 12-kDa PPD protein and the 10-kDa BCG-a protein, which shares 43% homology with GroES stress protein, suggested that the 12-kDa PPD protein may also belong to the bacterial heat-shock protein (hsp) family. Thus, by analogy with protection against arthritis or diabetes by hsp65, the mechanism of protection could be based on shared T cell epitopes with the target self Ag. However, the 12-kDa PPD protein did not stimulate encephalitogenic T lymphocytes. Effective protection against EAE by the 12-kDa PPD protein, in the absence of a stimulatory effect on encephalitogenic T lymphocytes, suggests a potential use for this protein in the therapy of autoimmune diseases.

[Multicenter study of the in vitro sensitivity of genital mycoplasmas to antibiotics]

The in vitro susceptibility of Ureaplasma urealyticum (Uu) and Mycoplasma hominis (Mh) was evaluated in a multicentric study performed in seven hospitals from different geographic areas in France. During a three month period, 324 Uu and 72 Mh clinical isolates were tested using a system ready for use, SIR Mycoplasma (Sanofi Diagnostics Pasteur). For Uu, the percentage of strains intermediate (I) or resistant (R) was as follows: doxycycline (3), minocycline (2.5), lymecycline (6.7), erythromycin (72, most I), josamycin (0.9), clindamycin (88), pristinamycin (0.3), ofloxacin (34, most I). For Mh, the percentage of strains I or R was respectively: doxycycline (2.7), minocycline (5.5), lymecycline (15.2), erythromycin (100), clindamycin (1.4), ofloxacin (2.7), josamycin (0) and pristinamycin (0). Comparable results were observed in the different geographic areas. The frequency of acquired resistances does not justify modifications in the usual treatment of genital mycoplasma infections but leads to monitor their susceptibility to antibiotics.

Prepapillary metastatic abscess in a case of subacute bacterial endocarditis

The case of a 49-year-old woman is described in which the presenting symptom of subacute bacterial endocarditis was the rare condition of a prepapillary abscess. There was a rapid decrease in visual acuity in the patient's left eye 10 days after the onset of an influenza-like episode, and ophthalmological examination revealed a pus-containing formation covering the optic disc, star-figure exudates in the macula, and some retinal hemorrhages with white centers. These findings in a patient known to have old valvular stenosis indicated a diagnosis of subacute bacterial endocarditis which was confirmed by further investigation. Both forms of endogenous primary retinitis were present in the same eye, i.e. (1) acute suppurative metastatic retinitis in the form of a prepapillary abscess and (2) subacute focal retinitis with the characteristic Roth's spots. Intensive antibiotic treatment was instituted, and within one month the prepapillary abscess was resorbed, with a parallel improvement in the general condition of the patient.