Anion-exchange chromatography of normal and monoclonal serum immunoglobulins

Oxidation of alpha1-proteinase inhibitor by the myeloperoxidase-hydrogen peroxidase system promotes binding to immunoglobulin A

We have demonstrated previously that patients with rheumatoid arthritis (RA) show an increase in serum and synovial fluid levels of complexes between alpha1-proteinase inhibitor (alpha1PI) and IgA. These are believed to form through disulfide binding between the Cys232 residue on alpha1PI and the penultimate cysteine residue (Cys471) of the IgA alpha chain. The mechanism for this has not been elucidated. We show here that alpha1PI oxidized by the myeloperoxidase-hydrogen peroxide (MPO-H2O2) system promotes the formation of IgA-alpha1PI complexes when incubated with IgA and that such complexes have no inhibitory activity against porcine pancreatic elastase (PPE). The activity of alpha1PI was considerably reduced also in IgA-alpha1PI complexes isolated from serum of an RA patient. We suggest that formation of IgA-alpha1PI complexes in inflammation may involve oxidation of alpha1PI, and as a consequence the alpha1PI in such complexes has reduced elastase inhibitory activity.

Intrathecal synthesis of anti-Borrelia burgdorferi antibodies in neuroborreliosis: a study with special emphasis on oligoclonal IgM antibody bands

Pre- and post-treatment (up to 3-26 months after antibiotic therapy) humoral immune responses were investigated in five neuroborreliosis patients. Anti-Borrelia (B.) burgdorferi IgG and IgM antibodies in CSF and serum were quantitated by capture ELISA. Agarose gel isoelectric focusing (AIF) and protein blotting were used to detect oligoclonal IgG and IgM bands as well as oligoclonal anti-B. burgdorferi IgG and IgM antibodies. These latter components were visualized by transfer to antigen-coated membranes (immunoblot) and immunoenzymatic staining. By ELISA, intrathecal anti-B. burgdorferi IgG and IgM antibody synthesis was detected in all initial specimens and continued 3-26 months after antibiotic therapy in four and three cases, respectively. AIF with protein blotting showed oligoclonal bands of total IgG as well as total IgM in the initial CSF specimens of all patients and persistence of such components occurred in four and five cases, respectively. By AIF and immunoblot, oligoclonal anti-B. burgdorferi IgG and IgM antibody bands could be detected in the CSF of every patient. IgG antibody bands were present in all initial CSF samples. The first specimen of one patient was negative for IgM antibody bands but such components appeared 3 weeks later. Oligoclonal CSF anti-B. burgdorferi IgG antibody components persisted over the entire follow-up periods in all but one case where they disappeared 6 weeks after treatment. The oligoclonal IgM antibodies in CSF vanished in two cases (after being present up to 4 and 11 months after antibiotic therapy) while they persisted over the entire (3-6 months after antibiotic therapy) follow-up periods in three cases. The specificity of the IgM antibody immunoblot technique was corroborated by control experiments, including antibody absorption studies and use of 41 kDa flagellar antigen.

Production and isolation of guinea pig IgE antibody

Immunoglobulins of the IgE and IgG classes have been causally associated with hypersensitivity reactions in man and in numerous animal species including mice, rats and guinea pigs. The use of the guinea pig as an animal model for both pulmonary and dermal hypersensitivity reactions, and the recent recognition of the importance of IgE antibodies in both early- and late-onset hypersensitivity responses, has heightened interest in production, separation, and isolation of this immunoglobulin class from the guinea pig. IgE antibodies were produced by treatment of strain 13 guinea pigs with cyclophosphamide followed by injection with S. aureus enterotoxin. Serum was obtained and the globulin fraction isolated by addition of caprylic acid then ammonium sulfate. Immunoglobulins were separated into classes using fast protein liquid chromatography (FPLC) employing a Mono Q column and a linear gradient of 0.01-0.3 M Na,K phosphate buffer, pH 7.5 (buffer B). IgG eluted in two major peaks. IgG2 was not retained on the column and emerged with the starting buffer; IgG1 was eluted with 15-20% buffer B. IgE, detected as heat labile homocytotropic antibody, was found in the fraction eluting with 30-35% buffer B. The elution profile of the guinea pig immunoglobulins was predicted from the pattern obtained with immunoglobulin classes from other species. This chromatographic procedure enabled rapid isolation of immunoglobulin classes from guinea pig sera and effectively separated IgG1 from IgE, the two classes associated with hypersensitivity reactions.

Immunoglobulin light chain patterns in the cerebrospinal fluid. A study with special reference to the occurrence of free light chains in cerebrospinal fluid with and without oligoclonal immunoglobulin G

The immunoglobulin light chain patterns were studied in paired cerebrospinal fluid (CSF) and serum samples from 30 controls, 70 multiple sclerosis (MS) patients, 18 subjects with other inflammatory neurological diseases and 17 patients with other non-inflammatory neurological disorders. In MS, all CSF samples examined by two-dimensional gel electrophoresis exhibited clonally restricted light chain components. Isoelectric focusing and immunoblotting detected free light chains in around 90% of CSF samples from patients with MS or other inflammatory diseases. These components were clonally restricted, appeared in both mono- and dimeric forms and occurred in CSF samples with as well as without oligoclonal immunoglobulin G bands. Generally, the positive CSF samples contained kappa as well as lambda free lights chains. Such components were not detected in the sera, nor in the CSF samples from controls or patients with non-inflammatory diseases.

Comparison of mono Q, superose-6, and ABx fast protein liquid chromatography for the purification of IgM monoclonal antibodies

Nine immunoglobulin M (IgM) monoclonal antibodies (MAbs) produced in ascites fluids or in cell culture supernatants, have been purified on a fast protein liquid chromatography (FPLC) system using anion-exchange, size-exclusion, or mixed-mode chromatography matrices. The use of a mixed-mode ABx column provided an IgM that had a purity of greater than 99% after a single purification step. Anion-exchange chromatography using a Mono Q column, provided a partial purification of the IgM which could subsequently be purified to a product of ca. 90% purity (determined from sodium dodecyl sulfate polyacrylamide gel electrophoresis) by size-exclusion chromatography on a Superose-6 column. Alternatively, the ascites containing the IgM was ammonium sulfate precipitated and chromatographed on the Superose-6 column under normal- as well as high-ionic strength conditions, which also yielded a product of ca. 90% purity. The purification of IgM from concentrated cell culture supernatants was evaluated using the Superose-6 or the ABx column. IgM purified from this source was greater than 99% pure when chromatographed on the mixed-mode column and ca. 60% pure on the size-exclusion column. MAbs from each of the procedures retained their immunoreactivity, as shown by indirect immunofluorescence staining of fixed cell preparations. A comparison of these methods revealed that mixed mode chromatography was simple, efficient, and yielded a product of high purity. The optimization of these methods facilitates the large-scale purification of mouse IgM MAbs and provides practical procedures for generating IgMs for use as diagnostic and therapeutic reagents.