[Multiple sclerosis management system 3D. Moving from documentation towards management of patients]. / Multiple-Sklerose-Dokumentationssystem 3D. Von der Dokumentation zum Patientenmanagement.

BACKGROUND: The increasing therapeutic options for relapsing-remitting multiple sclerosis require a specific treatment and risk management to recognize the individual response as well as potential side effects. To switch from pure MS documentation to MS management by implementing a new multiple sclerosis management and documentation tool may be of importance. METHOD: This article presents the novel computer-based patient management system "multiple sclerosis management system 3D" (MSDS 3D). RESULTS: MSDS 3D allows documentation and visualization of visit schedules and mandatory examinations via defined study modules by integration of data input from patients, attending physicians and MS nurses. It provides forms for the documentation of patient visits as well as clinical and diagnostic findings. Information is collected via interactive touch screens. A specific module which is part of MSDS 3D's current version allows the monthly monitoring of patients under treatment with natalizumab. A checklist covering clinical signs of progressive multifocal leukoencephalopathy (PML) and a detailed questionnaire about the handling of natalizumab in practice have additionally been added. DISCUSSION: The MS patient management system MSDS 3D has successfully been implemented and is currently being evaluated in a multi-centre setting. Advanced assessment of patient data may allow improvements in clinical practice and research work. The addition of a checklist and a questionnaire into the natalizumab module may support the recognition of PML during its early, treatable course.

[MS registry in Germany--design and first results of the pilot phase]. / MS-Register in Deutschland -- Design und erste Ergebnisse der Pilotphase.

In the summer of 2001, a nationwide epidemiological multiple sclerosis (MS) register was initiated under the auspices of the German MS Society (DMSG). This project aimed at collecting epidemiological data on the number of patients with MS, course of the disease, and their social situation in Germany. During the 2-year pilot phase, five MS centers with various regional differences and treatment methods participated, leading to a representative selection of patients. In December 2003, standardised data sets of 3,458 MS patients were available for evaluation. After examining the quality of the data, 3,223 sets remained for further analysis. The demographics were similar to those obtained from other epidemiological studies: 72% of the patients were female, mean age was 42.9+/-11.2 years, mean disease duration 12.6+/-8.7 years, and 64% suffered from the relapsing-remitting form of the disease. The median EDSS was 3.0, and 69% of patients had an EDSS

[The Multiple Sclerosis Documentation System MSDS. Discussion of a documentation standard for multiple sclerosis]. / Das Multiple-Sklerose-Dokumentationssystem MSDS. Diskussionsgrundlage für einen Dokumentationsstandard Multiple Sklerose?

The MSDS (multiple sclerosis documentation system) has been developed at the Department of Neurology, Technical University of Dresden, Germany, during the last 4 years. The first version of this database application has been in use since October 2000. The MSDS manages information on MS patients, their treating physicians, patient history (symptoms, other diseases, biographical history, family history, habits, medication), clinical signs, results of laboratory examinations (blood chemistry, autoantibodies, borrelia serology, evoked potentials, cranial and spinal cord magnetic resonance imaging), clinical scores relevant for MS, and biosamples. In principle, MSDS allows online data input and semiautomatically generates reports to all general practitioners and neurologists treating the respective patient. Patient information sheets and internal treatment guidelines are part of the system. During a 3-month evaluation, the first version of MSDS was tested at eight university multiple sclerosis ambulatory care units and one general neurology hospital. The overall judgement was favorable. Suggestions for changes and improvements, as well as practical experiences, were considered when developing MSDS 2.0, which will be available by the end of 2001.

Chronic myelogenous leukemia blast cell proliferation is inhibited by peptides that disrupt Grb2-SoS complexes.

Chronic myelogenous leukemia (CML) is commonly characterized by the presence of the p210(Bcr-Abl) oncoprotein. Many downstream effectors of Bcr-Abl have been described, including activation of the Grb2-SoS-Ras-MAP kinase (Erk) pathway. The precise contributions of these signal-transduction proteins in CML blast cells in human patients are not yet well defined. To gain further insight into the importance of Grb2 for CML, peptides that disrupt Grb2-SoS complexes were tested. These high-affinity Grb2-binding peptides (HAGBPs) can autonomously shuttle into cells and function by binding to the N-terminal SH3 domain of Grb2. The HAGBPs were analyzed for their effects on Bcr-Abl-expressing cell lines and freshly isolated CML blast cells from patients. They induced a dramatic decrease in the proliferation of CML cell lines. This was not observed with point-mutated control peptides with abolished Grb2SH3(N) binding. As expected, Grb2-SoS complexes were greatly diminished in the HAGBP-treated cells, and MAP kinase activity was significantly reduced as determined by an activation-specific phospho-MAPK antibody. Furthermore, cell fractions that are enriched for blast cells from CML patients with active disease were also incubated with the Grb2 blocker peptides. The HAGBPs led to a significant proliferation reduction of these cells in the majority of the isolates, but not in all patients' cells. These results show that, in addition to the direct targeting of Bcr-Abl, selective inhibition of Grb2 protein complexes may be a therapeutic option for a significant number of CML patients.

Chemical typing of amyloid protein contained in formalin-fixed paraffin-embedded biopsy specimens.

The human amyloidoses represent a heterogeneous group of disorders characterized by the deposition of fibrillar protein in vital organs. Given the fact that at least 20 different molecules can form fibrils, the unambiguous identification of the type of amyloid deposited is critical to the correct diagnosis and treatment of patients with these disorders. Heretofore, this information has been inferred from particular clinical features of the disease, ancillary laboratory tests, and results of immunohistochemical analyses. However, to establish unequivocally the kind of protein that is deposited as amyloid, it is necessary to determine its chemical composition through amino acid sequencing or mass spectroscopy of material extracted from fibrillar deposits. We have developed a micromethod whereby such studies can be performed readily using sections of formalin-fixed, paraffin-embedded biopsy specimens. The ability to identify precisely the nature of the tissue deposits has diagnostic, therapeutic, and prognostic implications for patients with amyloid-associated disorders.

Codeposition of apolipoprotein A-IV and transthyretin in senile systemic (ATTR) amyloidosis.

Protein material was extracted from amyloid-rich sections of formalin-fixed and paraffin-embedded heart tissue from an individual with senile systemic amyloidosis, known to contain wild-type transthyretin as major amyloid fibril protein. Amino acid sequence analysis of tryptic peptides of this material revealed in addition to transthyretin sequences, also amino acid sequence corresponding to an N-terminal fragment of apolipoprotein A-IV. In immunohistochemistry, an antiserum to a synthetic apolipoprotein A-IV peptide labeled amyloid specifically. This peptide formed spontaneously amyloid-like fibrils in vitro and enhanced fibril formation from wild-type transthyretin. We conclude that several apolipoproteins, including apolipoprotein A-IV, may be important minor amyloid constituents, promoting fibril formation.

The C-terminal SH3 domain of the adapter protein Grb2 binds with high affinity to sequences in Gab1 and SLP-76 which lack the SH3-typical P-x-x-P core motif.

The adapter Grb2 is an important mediator of normal cell proliferation and oncogenic signal transduction events. It consists of a central SH2 domain flanked by two SH3 domains. While the binding specificities of the Grb2 SH2 and N-terminal SH3 domain [Grb2 SH3(N)] have been studied in detail, binding properties of the Grb2 SH3(C) domain remained poorly defined. Gab1, a receptor tyrosine kinase substrate which associates with Grb2 and the c-Met receptor, was previously shown to bind Grb2 via a region which lacks a Grb2 SH3(N)-typical motif (P-x-x-P-x-R). Precipitation experiments with the domains of Grb2 show now that Gab1 can bind stably to the Grb2 SH3(C) domain. For further analyses, Gab1 mutants were generated by PCR to test in vivo residues thought to be crucial for Grb2 SH3(C) binding. The Grb2 SH3(C) binding region of Gab1 has significant homology to a region of the adapter protein SLP-76. Peptides corresponding to epitopes SLP-76, Gab1, SoS and other proteins with related sequences, as well as mutant peptides were synthesized and analysed by tryptophan-fluorescence spectrometry and by in vitro competition experiments. These experiments define a 13 amino acid sequence with the unusual consensus motif P-x-x-x-R-x-x-K-P as required for a stable binding to the SH3(C) domain of Grb2. Additional analyses point to a distinct binding specificity of the Grb2-homologous adapter protein Mona (Gads), indicating that the proteins of the Grb2 adapter family may have partially overlapping, yet distinct protein binding properties.

The Raf-1 kinase associates with vimentin kinases and regulates the structure of vimentin filaments.

Using immobilized GST-Raf-1 as bait, we have isolated the intermediate filament protein vimentin as a Raf-1-associated protein. Vimentin coimmunoprecipitated and colocalized with Raf-1 in fibroblasts. Vimentin was not a Raf-1 substrate, but was phosphorylated by Raf-1-associated vimentin kinases. We provide evidence for at least two Raf-1-associated vimentin kinases and identified one as casein kinase 2. They are regulated by Raf-1, since the activation status of Raf-1 correlated with the phosphorylation of vimentin. Vimentin phosphorylation by Raf-1 preparations interfered with its polymerization in vitro. A subset of tryptic vimentin phosphopeptides induced by Raf-1 in vitro matched the vimentin phosphopeptides isolated from v-raf-transfected cells labeled with orthophosphoric acid, indicating that Raf-1 also induces vimentin phosphorylation in intact cells. In NIH 3T3 fibroblasts, the selective activation of an estrogen-regulated Raf-1 mutant induced a rearrangement and depolymerization of the reticular vimentin scaffold similar to the changes elicited by serum treatment. The rearrangement of the vimentin network occurred independently of the MEK/ERK pathway. These data identify a new branch point in Raf-1 signaling, which links Raf-1 to changes in the cytoskeletal architecture.

Identification of the smooth muscle-specific protein, sm22, as a novel protein kinase C substrate using two-dimensional gel electrophoresis and mass spectrometry.

We report a novel method to identify protein kinase C (PKC) substrates. Tissue lysates were fractionated by ion exchange chromatography and used as substrates in in vitro kinase reactions. The phosphorylated proteins were separated using two-dimensional gel electrophoresis. Spots that contained isolated phosphoproteins were excised and digested with trypsin. The tryptic peptides were analyzed using mass spectrometry. While several of the proteins identified using this technique represent known PKC substrates, we identified a new PKC substrate in the initial screen. This protein, sm22, is expressed in smooth muscle cells and served well as a substrate for PKC in vitro. Sm22 is predominantly associated with the actin cytoskeleton. Upon activation of PKC in vivo, sm22 dissociates from the actin cytoskeleton and is distributed diffusely in the cytoplasm. Our data strongly suggest that phosphorylation by PKC controls the intracellular localization of sm22. This demonstrates that our approach, using a complex mixture of proteins as in vitro kinase substrates and subsequently identifying the newly phosphorylated proteins by mass spectrometry, is a powerful method to identify new kinase substrates.

Cell-penetrating SH3 domain blocker peptides inhibit proliferation of primary blast cells from CML patients.

Bcr-Abl contributes prominently to the development of most chronic myeloid leukemias (CMLs). Prior work has identified the adapter protein CRKL as a major substrate of the Bcr-Abl tyrosine kinase. CRKL can also bind via its first SH3 domain [SH3(1)] to specific sequences in Bcr-Abl. Cell-penetrating peptides were developed that bind with high affinity and selectivity to the SH3(1) domain of CRKL. They disrupt Bcr-Abl-CRKL complexes and strongly reduce the proliferation of primary CML blast cells and cell lines established from Bcr-Abl-positive patients. Activation-specific antibodies against phosphorylated MAP kinase (MAPK) showed that MAPK activity is down-regulated in blast cells treated with the CRKLSH3(1) blocker peptides. We conclude that the Bcr-Abl-CRKL complexes are largely dependent on the CRKLSH3(1) domain, that the central mitogenic cascade is down-regulated as a consequence of the disruption of CRKLSH3(1) interactions, and that CRKL therefore contributes to the proliferation of CML blast cells.

Consequences of antigen self-presentation by tumor-specific cytotoxic T cells.

CD8-positive cytotoxic T cells (CTL) recognize antigenic peptides in combination with major histocompatibility complex (MHC) class I molecules on the surface of syngeneic antigen presenting cells (APC). In the present paper we show that cells from tumor antigen-specific CTL clones present their cognate antigenic peptide to other CTL from the same clone. Inter-CTL peptide presentation resulted in activation of the cells of one CTL clone to MHC-unrestricted lysis of bystander cells. In contrast to the behaviour of this clone, another CTL clone did not lyse bystander cells after incubation with the cognate peptide, but was activated to self-destruction. The human herpes virus Epstein-Barr virus is involved in the pathogenesis of a broad spectrum of human neoplasias. Using freshly established non-clonal T cells with specificity for a peptide derived from an Epstein-Barr virus encoded antigen we found again lysis of MHC mismatched bystander cells as a consequence of inter-CTL peptide presentation, indicating that bystander lysis following antigen self-presentation is not a phenomenon restricted to long-term in vitro cultured T cell clones. The potential implications for immunosurveillance against cancer and for tumor escape mechanisms are discussed.

Analysis of E-cadherin in diffuse-type gastric cancer using a mutation-specific monoclonal antibody.

In-frame deletions from the E-cadherin mRNA, coding for a homophilic cell adhesion molecule, are characteristic for diffuse-type gastric carcinomas. Using immunohistochemical analysis the mutant form cannot be distinguished from normal E-cadherin, making results difficult to interpret. In this study, a rat monoclonal antibody, designated E-cad delta 9-1, was generated against a peptide spanning the fusion junction region between exons 8 and 10. This new epitope is present in an E-cadherin variant that lacks exon 9 from the mRNA due to different splice-site gene mutations. Using Western blotting and immunohistochemistry of E-cadherin-transfected cells, we demonstrate that E-cad delta 9-1 specifically reacts with E-cadherin lacking exon 9 but not with the wild-type protein. No immunoreactivity was observed in 31 nontumorous and embryonal tissues analyzed. In gastric carcinoma specimens known to express mutant E-cadherin mRNA lacking exon 9, E-cad delta 9-1 targets exclusively tumor cells in routine formalin-fixed and paraffin-embedded material from biopsies, primary tumors, and lymph node metastases. In a retrospective series of 172 diffuse-type gastric carcinomas expressing E-cadherin, E-cad delta 9-1 reacted with 22 tumors (13%). This new tumor marker-monoclonal antibody system could open novel avenues for selective diagnosis and specific therapy of a subgroup of diffuse-type gastric cancer patients.

[Novel mutation-specific monoclonal E-cadherin antibodies make possible allele differentiation at the protein level in tumors]. / Neue mutationsspezifische monoklonale E-Cadherin Antikörper ermöglichen eine Alleldifferenzierung auf Proteinebene in Tumoren.

Somatic deletion mutations in the cell adhesion molecule E-cadherin are present in almost 50% of diffuse type gastric cancer. We recently generated monoclonal antibodies against an in-frame deletion of exon 9. The aim of this study was to generate and characterize monoclonal antibodies against the second mutational hot spot, in-frame deletions of exon 8. Lou/C rats were immunized using a KLH-coupled peptide that represents a unique sequence generated by fusion of exon 7 and exon 9 from an E-cadherin deletion mutation lacking exon 8. Hybridoma supernatants were tested in a solid-phase immunoassay using BSA-coupled peptide. Positive reacting hybridomas were confirmed by Western Blots, FACS analysis, and immunohistochemistry of E-cadherin negative carcinoma cells that had been transfected with mutant and wild-type E-cadherin cDNA, respectively. In addition, routine formalin fixed and paraffin embedded tissues from gastric cancer patients were analyzed using both mutation-specific and commercial monoclonal antibodies against E-cadherin, including HECD-1 and AEC. Two hybridoma supernatants, termed E-cad delta 8-1, were selected that reacted with the mutant peptide used for immunization and gave strong signals in Western Blot and FACS analysis with cells expressing mutant E-cadherin lacking exon 8. Wild-type protein expressing cells only reacted with the commercial antibodies but not with the two selected hybridoma supernatants. In contrast to AEC, monoclonal antibody HECD-1 did not react with exon 8 deleted E-cadherin, suggesting that the previously unknown epitope for this often used monoclonal antibody is located at least in part within exon 8. Four gastric cancer specimens known to express mutated E-cadherin mRNA strongly reacted with both mutation-specific supernatants and with AEC monoclonal antibody but not with HECD-1. Taken together, we succeeded in generating monoclonal antibodies reacting with mutant E-cadherin protein lacking exon 8. Furthermore, using both HECD-1 and the new mutation-specific antibodies E-cadherin immunoreactivity can for the first time be evaluated in an allele-specific manner in archival tissues.

Influence of mutation of the amino-terminal signal anchor sequence of cytochrome P450 2B4 on the enzyme structure and electron transfer processes.

The role of the NH2-terminal hydrophobic patch of cytochrome P4502B4 (CYP2B4) in interactions with NADPH-cytochrome P450 reductase (P450R) and cytochrome b5 (b5) was assessed using a variant lacking the signal anchor sequence (Delta2-27). CD, second-derivative, and fluorescence emission spectra indicated that the structure of the deletion mutant slightly differed from that of the native CYP2B4. Fitting of the initial-velocity patterns for P450R- and b5-directed electron transfer to the ferric CYP2B4 forms to Michaelis-Menten kinetics revealed an approximately 2.3-fold decrease in the affinity of the two electron donors for the engineered enzyme, while the reductive efficiency remained unaffected. Circumstantial analysis suggested that impaired association of the redox proteins with P4502B4(Delta2-27) accounted for this phenomenon. Interestingly, spectral docking of P450R to the truncated pigment was not hampered, while the binding of b5 was blocked. The rates of substrate-triggered aerobic NADPH consumption in systems containing CYP2B4(Delta2-27) and P450R were 16 to 56% those obtained with the unchanged hemoprotein. Decelerated cofactor oxidation did not arise on defective substrate binding or perturbed utilization of the substrate-bound oxy complex. Experiments with b5 as the ultimate electron donor hinted at some damage to second-electron transfer to the truncated enzyme. The results are consistent with the proposal that the NH2-terminal hydrophobic region of CYP2B4 might be of importance in preservation of the catalytic competence of the enzyme.

Negative regulation of Raf-1 by phosphorylation of serine 621.

The elevation of cyclic AMP (cAMP) levels in the cell downregulates the activity of the Raf-1 kinase. It has been suggested that this effect is due to the activation of cAMP-dependent protein kinase (PKA), which can directly phosphorylate Raf-1 in vitro. In this study, we confirmed this hypothesis by coexpressing Raf-1 with the constitutively active catalytic subunit of PKA, which could fully reproduce the inhibition previously achieved by cAMP. PKA-phosphorylated Raf-1 exhibits a reduced affinity for GTP-loaded Ras as well as impaired catalytic activity. As the binding to GTP-loaded Ras induces Raf-1 activation in the cell, we examined which mechanism is required for PKA-mediated Raf-1 inhibition in vivo. A Raf-1 point mutant (RafR89L), which is unable to bind Ras, as well as the isolated Raf-1 kinase domain were still fully susceptible to inhibition by PKA, demonstrating that the phosphorylation of the Raf-1 kinase suffices for inhibition. By the use of mass spectroscopy and point mutants, PKA phosphorylation site was mapped to a single site in the Raf-1 kinase domain, serine 621. Replacement of serine 621 by alanine or cysteine or destruction of the PKA consensus motif by changing arginine 618 resulted in the loss of catalytic activity. Notably, a mutation of serine 619 to alanine did not significantly affect kinase activity or regulation by activators or PKA. Changing serine 621 to aspartic acid yielded a Raf-1 protein which, when expressed to high levels in Sf-9 insect cells, retained a very low inducible kinase activity that was resistant to PKA downregulation. The purified Raf-1 kinase domain displayed slow autophosphorylation of serine 621, which correlated with a decrease in catalytic function. The Raf-1 kinase domain activated by tyrosine phosphorylation could be downregulated by PKA. Specific removal of the phosphate residue at serine 621 reactivated the catalytic activity. These results are most consistent with a dual role of serine 621. On the one hand, serine 621 appears essential for catalytic activity; on the other hand, it serves as a phosphorylation site which confers negative regulation.

Histidine residues in rabbit liver microsomal cytochrome P-450 2B4 control electron transfer from NADPH-cytochrome P-450 reductase and cytochrome b5.

Treatment of cytochrome P-450 2B4 (P-450 2B4) with diethylpyrocarbonate to introduce 10-11 equivalents of acylating agent per polypeptide chain resulted in the selective derivatization of histidine residues characterized by differential susceptibility toward the modifier. Second-derivative spectral analysis as well as fluorescence measurements disproved gross alterations in P-450 2B4 structure as a consequence of labelling. The modified haemoprotein retained its ability to bind hexobarbital and catalyse cumene hydroperoxide-sustained N-demethylation of the barbiturate. However, there was a steady attenuation of NAD(P)H-driven electron flux with increasing extent of P-450 2B4 carbethoxylation in reconstituted systems fortified with either NADPH-cytochrome P-450 reductase or NADH-cytochrome b5 reductase/cytochrome b5 as the redox partners, with 50% inhibition occurring when 6-7 histidines were blocked. Hampered P-450 2B4 reductase activities recovered to differing degrees upon treatment of the acylated mono-oxygenase with neutral hydroxylamine. Spectral data indicated that docking of the redox components to derivatized P-450 2B4 was not perturbed, so that disruption of the electron flows most likely resulted from some injury of the electron-transfer mechanisms.

Characterization of IkappaB kinases. IkappaB-alpha is not phosphorylated by Raf-1 or protein kinase C isozymes, but is a casein kinase II substrate.

The NF-kappaB transcription factor is activated by a wide variety of stimuli, including phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate. In its inactive state, NF-kappaB is sequestered in the cytoplasm tethered to an inhibitor protein, IkappaB. Activation comprises the rapid phosphorylation of IkappaB-alpha at N-terminal sites, which presumably marks IkappaB-alpha for proteolytic degradation and leads to release of NF-kappaB into the nucleus. In addition, IkappaB-alpha is constitutively phosphorylated at the C terminus, which may be a prerequisite for proper IkappaB function. Protein kinase C (PKC) is activated by 12-O-tetradecanoylphorbol-13-acetate and has been previously reported to phosphorylate IkappaB-alpha in vitro. As PKC has turned out to constitute a multigene family encoding isozymes with different biological functions, we have reinvestigated IkappaB-alpha phosphorylation by PKC using recombinant PKC isozymes expressed in insect cells. While crude PKC preparations were efficient IkappaB-alpha kinases, highly purified PKC isozymes completely failed to phosphorylate IkappaB-alpha. Biochemical separation of porcine spleen yielded at least two fractions with IkappaB-alpha kinase activity, both of which were devoid of detectable PKC isozymes. One peak contained both Raf-1 and casein kinase II (CKII). Purified Raf-1 does not phosphorylate IkappaB-alpha directly, but associates with CKII, which efficiently phosphorylates the C terminus of IkappaB-alpha. Two-dimensional phosphopeptide mapping and high pressure liquid chromatography-mass spectroscopy analysis showed that all IkappaB-alpha kinases induced phosphorylation at the same prominent sites in the C terminus. Our results clearly indicate that PKC isozymes alpha, beta, gamma, delta, epsilon, eta, and zeta as well as Raf-1 are not IkappaB-alpha kinases. They furthermore demonstrate that IkappaB-alpha is targeted by several kinases, one of which appears to be CKII.

Distinctive serologic, chemical, and molecular properties of human lambda IV light chains.

Through extensive serologic, chemical, and molecular studies involving monoclonal Ig proteins and B cell-related populations, we provide definitive evidence that the V lambda IV subgroup of human light (L) chains is separate and distinct from V lambda III and all other known V lambda gene families. lambda IV and lambda III L chains were differentiated immunochemically using well-characterized polyclonal and monoclonal anti-V lambda subgroup-specific Abs. Prototypic L chains, originally classified as lambda IV on the basis of distinctive framework region 1 residues, were distinguished serologically from lambda IIIa, lambda IIIb, and lambda IIIc proteins and also from lambda I, lambda II, lambda VI, and lambda VIII L chains. Furthermore, by using anti-lambda IV reagents, we identified eight additional monoclonal V lambda IV-related populations, including three IgM rheumatoid factor-producing cell lines. The percentage of homology among the lambda IV proteins ranged from 83 to 100, vs 53 to 72 when compared with lambda III components. Moreover, lambda IV proteins shared particular subgroup-associated FR and complementarity-determining region residues. At the molecular level, the nucleotide sequences encoding two of the IgM lambda IV rheumatoid factors were identical to that found for the genomic counterpart, as well as to the previously reported IGLV3S1 and Humlv418 germ-line genes. Two other lambda IV cDNAs contained additional non-germ-line-encoded nucleotides at the V-J joint. The single or pauci-gene nature of the V lambda IV family was evidenced from Southern blotting and from the extensive sequence homology among lambda IV components. Our studies have provided further evidence for the prevalence of lambda IV L chains among Ig lambda autoantibodies, thus implying a functional significance for the V lambda IV subgroup.

Rat monoclonal antibodies differentiating between the Epstein-Barr virus nuclear antigens 2A (EBNA2A) and 2B (EBNA2B).

Rat monoclonal antibodies were produced against the C-terminus of Epstein-Barr virus nuclear antigens 2A (EBNA2A) and 2B (EBNA2B) expressed as bacterial trpE fusion proteins. The initial screening was performed using a soluble bacterial extract containing the fusion proteins. Positive hybridomas were confirmed by immunofluorescence on SF158 (Spodoptera frugiperda) insect cells infected with recombinant baculovirus (Autographa californica nuclear polyhedrosis virus) and expressing the complete EBNA2A or EBNA2B genes. We selected a panel of antibodies which reacted either with both antigens or specifically with EBNA2A or with EBNA2B. The antibodies were extensively characterized using immunoprecipitation, Western blotting, epitope mapping on synthesized peptide segments of EBNA2A, immunocytology, and immunohistology on both cryostat sections and paraffin sections of AIDS-associated primary central nervous system lymphomas.