Human Immunoglobulin Lambda Light Chain Research Articles

Measles virus expressed Helicobacter pylori neutrophil-activating protein significantly enhances the immunogenicity of poor immunogens

Helicobacter pylori neutrophil-activating protein (NAP) is a toll-like receptor 2 (TLR2) agonist and potent immunomodulator inducing Th1-type immune response. Here we present data about characterization of the humoral immune response against NAP-tagged antigens, encoded by attenuated measles virus (MV) vector platform, in MV infection susceptible type I interferon receptor knockout and human CD46 transgenic (Ifnarko-CD46Ge) mice. Immunogenicity of MV expressing a full-length human immunoglobulin lambda light chain (MV-lambda) was compared to that of MV expressing lambda-NAP chimeric protein (MV-lambda-NAP). MV-lambda-NAP immunized Ifnarko-CD46Ge mice developed significantly higher (6–20-fold) anti-lambda ELISA titers as compared to the MV-lambda-immunized control animal group, indicating that covalently-linked NAP co-expression significantly enhanced lambda immunogenicity. In contrast, ELISA titers against MV antigens were not significantly different between the animals vaccinated with MV-lambda or MV-lambda-NAP. NAP-tagged antigen expression did not affect development of protective anti-measles immunity. Both MV-lambda and MV-lambda-NAP-immunized groups showed strong virus neutralization serum titers in plaque reduction microneutralization test. These results demonstrated that MV-encoded lambda-NAP is highly immunogenic as compared to the unmodified full-length lambda chain. Boost of immune response to poor immunogens using live vectors expressing NAP-tagged chimeric antigens is an attractive approach with potential application in immunoprophylaxis of infectious diseases and cancer immunotherapy.

Nephrotoxicity of Bence-Jones proteins: interference in renal epithelial cell acidification.

The aim of the present study was to evaluate the acidification of the endosome-lysosome system of renal epithelial cells after endocytosis of two human immunoglobulin lambda light chains (Bence-Jones proteins, BJP) obtained from patients with multiple myeloma. Renal epithelial cell handling of two BJP (neutral and acidic BJP) was evaluated by rhodamine fluorescence. Renal cells (MDCK) were maintained in culture and, when confluent, were incubated with rhodamine-labeled BJP for different periods of time. Photos were obtained with a fluorescence microscope (Axiolab-Zeiss). Labeling density was determined on slides with a densitometer (Shimadzu Dual-Wavelength Flying-Spot Scanner CS9000). Endocytosis of neutral and acidic BJP was correlated with acidic intracellular compartment distribution using acridine orange labeling. We compared the pattern of distribution after incubation of native neutral and acidic BJP and after complete deglycosylation of BJP by periodate oxidation. The subsequent alteration of pI converted neutral BJP to acidic BJP. There was a significant accumulation of neutral BJP in endocytic structures, reduced lysosomal acidification, and a diffuse pattern of acidification. This pattern was reversed after total deglycosylation and subsequent alteration of the pI to an acidic BJP. We conclude that the physicochemical characteristics of BJP interfere with intracellular acidification, possibly explaining the strong nephrotoxicity of neutral BJP. Lysosomal acidification is fundamental for adequate protein processing and catabolism.

Molecular, cellular and functional characterizations of a novel ICAM-like molecule of the immunoglobulin superfamily from Leishmania mexicana amazonensis

A molecule with two immunoglobulin (Ig) domains cloned from Leishmania mexicana amazonensis was characterized to have a sequence homology to the Ig domains of an ICAM-like molecule telencephalin, cloned from the brain of mammals, as well as to the variable domains of human immunoglobulin lambda light chain. The molecule therefore appears to be an ICAM-like molecule as well as a member of the immunoglobulin superfamily. We thus named it ICAM-L for Leishmania ICAM. The gene was coamplified with the ribonucleotide reductase M 2 subunit gene responsible for hydroxyurea resistance from hydroxyurea (Hu)-resistant Leishmania variants. As expected, an increase of the ICAM-L protein as well as an increase of the specific ICAM-L transcript of 2.1 kb was detected in the Hu-resistant variants with increasing doses of the drug used for resistance selection. Structurally, ICAM-L is more similar to the secretory adhesive molecules, such as 1Bgp and the link protein of the immunoglobulin superfamily, in that it lacks a transmembrane region and a GPI anchor sequence. Although ICAM-L was mainly localized in the nucleus of the parasite by confocal microscopy, however, detailed studies by electron microscopy and FACS analysis indicated that the protein was also localized on the surface of the parasite. The surface localization of the protein was furthered strengthened by the observations that anti-ICAM-L or ICAM-L itself can significantly block the binding of the parasite to macrophages. The blocking of the attachment of parasite to macrophages may indicate that ICAM-L functions as an intercellular adhesive molecule.

Allelic polymorphisms and RFLP in the human immunoglobulin lambda light chain locus.

The organization of the human immunoglobulin lambda light chain locus (IGL) was recently described. This locus has been entirely sequenced. To evaluate the extent of the genomic variability existing inside that locus, we compiled all the available sequences of germline IGLV genes to find variants of Vlambda sequences. We also looked for RFLP polymorphisms in a reputedly highly polymorphic human population from eastern Senegal, and compiled all RFLP data previously published. Analysis of these data indicates that IGLV alleles are frequent and increase the diversity of the lambda light chain repertoire in the human population. In contrast, RFLP and polymorphism by insertion and/or deletion are limited in that locus. This observation reinforces our hypothesis that the human IGL locus has undergone less evolutionary shuffling than the human kappa or heavy-chain loci.

Vλ and Jλ‐Cλ gene segments of the human immunoglobulin λ light chain locus are separated by 14 kb and rearrange by a deletion mechanism

We have cloned a region of 124 kb of the human immunoglobulin lambda light chain locus on chromosome 22 encompassing seven V lambda and seven J-C lambda gene segments. No further C lambda gene segment was found in a region of 35 kb downstream of C lambda 7, which encodes the Ke+Oz- isotype. The C lambda proximal V lambda gene segment V lambda III. 1 is located 14.5 kb upstream of C lambda 1. The five sequenced V lambda genes have the same transcriptional orientation as the J-C lambda gene segments which is likely to be true for the majority of the V lambda gene segments in the human lambda locus and which suggests a deletion mechanism for DNA rearrangement. This is supported by hybridization of V lambda gene probes to germ-line and rearranged DNA from lambda light chain-producing cell lines. Sequences of 23 cDNA clones allow to establish a V lambda subgroup classification based on nucleic acid sequence data and an estimate of the J-C lambda usage.

The IGLVA gene as a STS in the human immunoglobulin lambda light chain variable gene locus (located at 22q11)

The IGLVA gene as a STS in the human immunoglobulin lambda light chain variable gene locus (located at 22q11)

The IGLYA gene as a STS in the human immunoglobulin lambda light chain variable gene locus (located at 22qll)

The authors wish to point out that the 7.0 Kb hybridizing band displayed in the figure accompanying this article is from an EcoRl digest.

The IGLJ6 joining segment as a STS in the human immunoglobulin lambda light chain constant region gene locus (located at 22q11)

The IGLJ6 joining segment as a STS in the human immunoglobulin lambda light chain constant region gene locus (located at 22q11)

Purification and NH2-terminal amino acid sequencing of the beta subunit of a human T-cell antigen receptor.

To obtain information about the structural basis for T-cell antigen recognition, a T3-associated Ti receptor molecule was isolated from crude membranes of the REX human thymic tumor line and purified by affinity chromatography with an anti- clonotypic monoclonal antibody in conjunction with preparative gel electrophoresis. NH2-terminal amino acid sequencing of the beta subunit unambiguously identified the amino acids in positions 2-12. Comparative protein sequence analysis by computer search demonstrated that this Ti beta sequence bore weak, but definite, homology to the first framework of the variable region of human lambda light chain. Anti-sera to a synthetic peptide corresponding to positions 2-11 precipitated the denatured Ti beta subunit from REX, thus confirming the above sequence. This information suggests that the Ti beta subunit is distantly related to human immunoglobulin lambda light chain and, moreover, should be of use in the molecular cloning of the Ti beta gene.

Regional mapping of the human immunoglobulin lambda light chain to the Philadelphia chromosome in chronic myeloid leukaemia

The lambda light chain immunoglobulin constant region (Cλ) locus was mapped on human chromosome 22. A DNA probe containing part of the Cλ locus was isolated from a human chromosome 22 genomic library, and a series of rodent × human somatic cell hybrids (each of which contained different translocated parts of chromosome 22) were constructed and characterized. The hybridization of the Cλ probe to DNA from these cell hybrids was then studied by Southern blot analysis. The results demonstrates that the Cλ locus is situated very close to the translocation breakpoint on human chromosome 22 which is characteristic of chronic myeloid leukaemia, and at least part if not at all of the locus is situated on the Philadelphia chromosome.