A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis

Abstract

BackgroundExtracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin) is an inducer of the expression of several matrix metalloproteinases (MMPs). We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE).MethodsTo improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies.ResultsOf these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9) production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control.ConclusionsWe have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

An epitope-specific novel anti-EMMPRIN polyclonal antibody inhibits tumor progression

“…In support of this conclusion is the study that elicited a novel anti-EMMPRIN antibody directed against the epitope TCSLNDSATEVTGHRW (including only four amino acids of our epitope), which inhibited T cell proliferation and reduced MMP-9 production, reduced T cell cytotoxicity to neurons and successfully reduced the clinical score in an EAE mouse model. 19 However, in contrast to these findings, another study found that the sequence AAGTVFTT-VEDLGSKILLTCSLNDSATEV (positions 22-50 in the human EMMRIN sequence), which does not include our epitope at all, was responsible for the EMMPRIN MMP induction activity and association with tumor invasion. 20 We suggest that because we used an antibody to target a specific epitope of 11 amino acids, we could use a shorter sequence than the two previous studies that used peptides to directly generate a steric hindrance or to compete with the homophilic binding to EMMPRIN.…”

Impact of Minocycline on Extracellular Matrix Metalloproteinase Inducer, a Factor Implicated in Multiple Sclerosis Immunopathogenesis

“…In support, inflammatory perivascular cuffs in the CNS of EAE and MS specimens have highly elevated EMMPRIN expression in many leukocyte subsets (11), and mice treated with anti-EMMPRIN Abs have reduced EAE clinical severity (12,20). To further ascribe importance to EMMPRIN in MS, we evaluated whether established or emerging therapies in MS affect EMMPRIN expression in leukocytes.…”

“…Although it is unclear how all these mechanisms connect, it is supported by the identification of several EMMPRIN-interacting proteins that correspond to these functions such as monocarboxylate transporters (MCTs) (14,15), integrins (16), CD98 (17), cyclophilins (18), and EMMPRIN itself (1,19). Treatment with anti-EMMPRIN Abs reduced EAE clinical severity, the number of perivascular cuffs, and MMP activity (12,20). Perivascular cuffs, which are aggregates of immune cells in the perivascular space of postcapillary venules prior to their entry into the CNS parenchyma, were shown to be enriched for EMMPRIN expression that colocalized with T cells, B cells, and macrophages, and with manifestation of MMP activity (11).…”

“…MS is an immune-mediated disorder of the CNS characterized by the generation of myelin-reactive T cells, demyelination, and axonal degeneration. Accumulating evidence supports functional roles for EMMPRIN during T cell activation and proliferation (5-7), migration (8,9), adhesion (10,11), and invasion (12,13), all steps important in the pathogenesis of MS as well as other immunological diseases (1). Although it is unclear how all these mechanisms connect, it is supported by the identification of several EMMPRIN-interacting proteins that correspond to these functions such as monocarboxylate transporters (MCTs) (14,15), integrins (16), CD98 (17), cyclophilins (18), and EMMPRIN itself (1,19).…”

“…Perivascular cuffs, which are aggregates of immune cells in the perivascular space of postcapillary venules prior to their entry into the CNS parenchyma, were shown to be enriched for EMMPRIN expression that colocalized with T cells, B cells, and macrophages, and with manifestation of MMP activity (11). In vitro, treatments with an anti-EMMPRIN Ab reduced the adhesion and migration of leukocytes across blood-brain barrier endothelial cells (11), as well as T cell neurotoxicity (12). Thus, therapies that dampen down EMMPRIN levels would likely be beneficial in hindering various T cell activities in MS.…”