Development and characterization of mouse hybridomas

Generation of Monoclonal Antibodies against Defined Oligosaccharide Antigens

Unique carbohydrate antigens are expressed on the surface of various pathogens, including bacteria, parasites, and viruses, and aberrant glycosylation is a frequent feature of cancer cells. Antibodies recognizing such carbohydrate antigens may be used for the specific detection of potentially harmful cells, immunohistochemistry, and diagnostic and therapeutic applications. The generation of specific and strongly binding antibodies against defined carbohydrate epitopes is challenging, since isolated carbohydrates often suffer from low purity, usually have limited immunogenicity, and induce antibodies of low affinity. We describe a protocol to generate highly affine monoclonal antibodies (mAbs) against pure and defined synthetic carbohydrate antigens. First, an oligosaccharide is covalently coupled to an immunogenic carrier protein to obtain a glycoconjugate. This glycoconjugate is used to raise oligosaccharide-specific antibodies in mice, and splenocytes are fused with myeloma cells to form hybridomas. Hybridoma clones producing oligosaccharide-specific mAbs are selected by glycan microarray screening. Selected clones are expanded and mAbs are purified from the cell culture supernatant. This protocol is suitable to procure carbohydrate-specific mAbs of high specificity, selectivity, and affinity that may be useful for a variety of biochemical and medical applications.

Monoclonal antibodies and recombinant immunoglobulins for the treatment of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory and degenerative disease leading to demyelination and axonal damage in the CNS. Autoimmunity plays a central role in MS pathogenesis. Per definition, monoclonal antibodies are recombinant biological compounds with a well defined target, thus carrying the promise of targeting pathogenic cells or molecules with high specificity, avoiding undesired off-target effects. Natalizumab was the first monoclonal antibody to be approved for the treatment of MS. Several other monoclonal antibodies are in development and have demonstrated promising efficacy in phase II studies. They can be categorized according to their mode of action into compounds targeting (i) leukocyte migration into the CNS (natalizumab); (ii) cytolytic antibodies (rituximab, ocrelizumab, ofatumumab, alemtuzumab); or (iii) antibodies and recombinant proteins targeting cytokines and chemokines and their receptors (daclizumab, ustekinumab, atacicept, tabalumab [Ly-2127399], secukinumab [AIN457]). In this review, we discuss the specific molecular targets, clinical efficacy and safety of these compounds and discuss criteria to anticipate the position of monoclonal antibodies in the diversifying armamentarium of MS therapy in the coming years.

Expression and immunoaffinity purification of recombinant dengue virus 2 NS1 protein as a cleavable SUMOstar fusion

Dengue virus (DENV) encoded nonstructural one (NS1) is a 352 amino acid protein that exists in multiple oligomeric states and is conserved within the flavivirus family. Although NS1 has been heavily researched for its diagnostic utility, there is a gap in the understanding of its role in a range of viral processes, including replication and development of clinical pathologies such as vascular leakage. Many of these functions involve unknown interactions with viral and host proteins. This study describes the generation of a mouse monoclonal antibody (mAb 56.2) that reacts with NS1 from DENV1 and 2, and the expression of recombinant SUMOstar-tagged DENV2 NS1 (DENV2 S∗-NS1) in baculovirus. This is the first time dengue NS1 has been produced as a SUMOstar fusion with the S∗-tag increasing protein solubility and secretion compared with a non-S∗-tagged NS1 construct. The protein was readily purified using a mAb 56.2 immunoaffinity column and untagged NS1 was obtained by treatment with tobacco etch virus protease to remove the S∗-tag. Size exclusion chromatography and glycosylation assays showed that both secreted S∗-NS1, and cleaved NS1, are hexameric and glycosylated, and will be useful tools in elucidating dengue NS1 protein interactions and functions.

Monoclonal antibodies in the therapy of multiple sclerosis: an overview

With the generation of monoclonal antibodies (mAbs), a new therapeutical concept has gained importance. MAbs aim against selective antigens and so have changed our treatment strategies from non-specific to specific. Four therapeuticals have gained importance in the therapy of multiple sclerosis (MS): One has already been approved for therapy (natalizumab), whereas the other three are either in clinical trials or are about to enter phase III studies. Currently, two phase III studies that evaluate the efficacy of alemtuzumab have begun with recruitment (MS CARE I and II). Another mAb (daclizumab) under study is directed to the interleukin-2alpha chain (CD25). Results of clinical trials are promising by reporting reduction of relapses and progression in relapsing remitting and secondary progressive MS accompanied by reduction of new lesions in magnetic resonance imaging. A multicenter randomized controlled trial of daclizumab in MS is going to be initiated. Trials with a humanised antibody directed against the cell surface molecule CD20 are under development. Although the future will emphasise this trend to mAbs, the risks should not be ignored as has been shown in recent news. Still, mAbs have the possibility to revolutionise therapeutical concepts in the treatment of immune-mediated diseases, and will therefore be a useful addition to current therapeutic concepts.