Kappa: lambda light chain ratio in IgG eluted from rheumatoid arthritis synovium

The light chain ratio in IgG eluted from rheumatoid arthritis synovial membrane was studied using quantitative immunodiffusion. The ratio obtained in synovial IgG was different from that of IgG in peripheral blood. In several instances a marked domination of one type light chain was noted in the eluted IgG, which also showed a limited electrophoretic dispersion on immunoelectrophoresis. This suggests that synovial IgG in rheumatoid arthritis is antibody, and not derived non-specifically from the immunoglobulin pool. Lambda type light chains dominated over kappa type in most eluates, suggesting preferential involvement of cells producing lambda type molecules.     

Kappa opioid binding sites in the dog cerebral cortex and spinal cord

In the dog cerebral cortex and spinal cord, [3H]bremazocine and [3H]U69593 both bound with high affinity to an apparent single population of binding sites under kappa-selective conditions. In the cortex similar Bmax values for both radioligands in the saturation studies and the high affinity of the kappa-selective agents PD117302 and U69593 for both [3H]bremazocine and [3H]U69593 labelled sites in the competition studies suggested a predominance of U69593-sensitive sites previously described as kappa 1 in the guinea-pig and rat brain. The lower slope values for the inhibition curves of PD117302 and U69593 against [3H]bremazocine but not against [3H]U69593 suggested that [3H]bremazocine could also be binding to a relatively minor proportion of additional, possibly kappa 2, sites while [3H]U69593 would appear to be selective for the kappa 1 site. In contrast, in the dog spinal cord, [3H]U69593 appeared to recognize only a proportion (approximately 35%) of the [3H]bremazocine labelled binding site. The significantly lower affinities and slope values of U69593 and PD117302 against [3H]bremazocine were consistent with the additional sites representing the k2 (benzomorphan) sites previously described in guinea-pig and rat spinal cord. Alternatively, the low (micromolar) affinity of the mu-selective ligand, [D-Ala2, MePhe4, Gly-ol5]enkephalin, implied that these additional sites might not be kappa 2 but possibly a low affinity mu site normally expressed under more physiological conditions.     

Kappa and lambda immunoglobulin expression associated with abnormalities of chromosomes #2 and #22 in lymphoma and leukemia

The types of surface immunoglobulins on Burkitt lymphoma (BL) cells correlate with the specific chromosomes that are altered in the tumor. For example, BL with a t(2;8) translocation expresses kappa (kappa) light chains, whereas BL with a t(8;22) translocation expresses lambda (lambda) light immunoglobulin chains; these correspond with the locations of the kappa chain genes on chromosome #2 and the lambda chain genes on chromosome #22, respectively (1-5). In order to explain this close correlation between specific translocations and light chain expression in BL and BL-type acute lymphocytic leukemia (ALL) (L3 type), Hecht et al. [6] proposed the concept of position effect, which is reviewed herein.     

Cyclosporin receptor on mouse lymphocytes.

Specific binding of [3H]-cyclosporin C (3H-CS-C), an immunosuppressive oligopeptide, was characterized on different mouse lymphocytes. The binding was saturable, time-dependent and reversible; and KD of 1.5 x 10(-7) M and maximum binding capacity Bmax of 35 pmol/4 x 10(6) cells was found for thymocytes. A computerized analysis of the data confirmed a single population of high affinity binding sites. Lymphocytes of different organs differed in their Bmax: thymus greater than spleen greater than mesenteric lymph node (pure T cells) greater than mesenteric lymph node (pure B cells). Erythrocytes did not show a specific binding.     

Confirmatory evidence for the existence of two types of receptor sites for Con A on mouse lymphocytes.

Splenic lymphocytes of normal AKR mice (NSL) were sequentially treated with two Con A preparations, each labelled with a different fluorochrome. cells were allowed to cap rhodamine-labelled Con A (TRITC-Con A). They were subsequently incubated with fluorescein-labelled Con A (FITC-Con A). FITC-Con A bound to cell in the region of the cell membrane which was free of the first label after capping. Such mutually exclusive localization of Con A receptors was not observed in the NSL which did not undergo redistribution. This provides direct confirmatory evidence in support of the existence of two behaviourally distinct types of Con A receptors on AKR lymphocytes.     

A receptor for ''self'' on lymphocytes.

A large population of lymphocytes is able to form rosettes with syngeneic, allogeneic or closely related xenogeneic erythrocytes. Similar results were found with spleen cells from mice, rats and rabbits. The highest numbers were found in mice where up to 30% of lymphocytes bound autologous erythrocytes. Rosette formation is probably due to stereospecific cell surface receptors since erythrocytes of distant xenogeneic origin were not recognized. Rosette forming cells do not seem to be restricted to the B-cell or T-cell compartment since mouse thymus cells as well as spleen cells from congenitally athymic (nude) mice bound erythrocytes to a similar degree.     

Anti-kappa/lambda immunobead for detection of human B lymphocytes.

Several methods were compared for quantitating the B lymphocytes in human peripheral blood. RBC rosette assays including sheep and bovine red blood cells, and immunobead rosette assays including beads coated with anti-kappalambda and trivalent anti-GAM antibodies respectively were investigated. The anti-kappalambda bead assay proved to be simpler, faster, higher in reproducibility, and appeared to be more accurate than any of the other assays.     

Kappa/lambda ratios in IgG, IgA and IgM of cerebrospinal fluid and of sera in patients with multiple sclerosis

Kappa/lambda (kappa/lambda) ratios of each immunoglobulin, i.e. IgG, IgA and IgM in cerebrospinal fluid (CSF) and in sera of patients with multiple sclerosis (MS) were analysed by sandwich enzyme linked immunosorbent assay. In CSF kappa/lambda ratios of IgG of MS patients were significantly (p less than 0.05) higher than those of normal controls, whereas the values of IgA and IgM did not differ significantly from those of normal controls. In sera kappa/lambda ratios of IgG, IgA and IgM did not differ significantly from those of normal controls. Our results suggest that in MS patients abnormal kappa/lambda ratios are also restricted to IgG components in CSF, as oligoclonal IgG bands are.     

Are umami taste receptor sites structurally related to glutamate CNS receptor sites?

Umami tasting substances, MSG (monosodium glutamate), HG (glutamic acid), LGDE (1-glutamic acid diethyl ester), DLHCA (dl-homocysteic acid), DLAAA (dl-aminoadipic acid) and 5'GMP, were tested on the hamster and the human. Ten mM MSG was routinely used in the hamster as it elicited strong chorda tympani responses. Similar response amplitudes were found for MSG, HG, LGDE, DLAAA 10 mM, DLHCA 8 mM and sucrose 100 mM. A 5 microM concentration of 5'GMP eventually was an efficient stimulus on a few preparations. Such a low concentration is very seldom efficient as a taste stimulus in rodents, indicating a higher specificity of receptor mechanisms than what is usually found for sweet taste, for example. The synergy between MSG and 5'GMP was found in the hamster CT only for concentrations lower than those of the literature, i.e., a mixture of 12 microM 5'GMP and 2.5 mM MSG showed a reinforcement of 50% in response amplitude equivalent to a 100% increase in concentration. We take this as an evidence of an umami component in the hamster CT response to glutamate; in accordance with literature data, we could not find reinforcement for higher concentrations which were in fact near saturation. Responses to MSG, HG, LGDE, DLAAA and DLHCA, among 38 other organic stimuli, were studied in 42 hamster chorda tympani. Responses to HG, LGDE and 5'GMP, among chemoreception of these compounds used as umami tasting stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)     

Kappa opioid receptor inhibition of glutamatergic transmission in the nucleus accumbens shell

Microinjection of kappa-opioid receptor agonists into the nucleus accumbens produces conditioned place aversion. While attention has focused primarily on the inhibition of dopamine release by kappa-receptor agonists as the synaptic mechanism underlying this effect, recent anatomical studies have raised the possibility that regulation of noncatecholaminergic transmission also contribute. We have investigated the effects of kappa-receptor activation on fast excitatory synaptic transmission in an in vitro slice preparation using whole cell voltage-clamp or extracellular field recordings in the shell region of the nucleus accumbens. The kappa-receptor agonist U69593 produces a pronounced, dose-dependent inhibition of glutamatergic excitatory postsynaptic currents (EPSCs) that can be reversed by 100 nM nor-BNI. Furthermore, U69593 causes an increase in the paired-pulse ratio as well as a decrease in the frequency of spontaneous miniature events, suggesting a presynaptic site of action. Despite anatomical evidence for kappa-receptor localization on dendritic spines of nucleus accumbens neurons, no electrophysiological evidence of a postsynaptic effect was found. This presynaptic inhibition of excitatory synaptic transmission in the nucleus accumbens shell provides a novel mechanism that may contribute to the kappa-receptor-mediated aversion observed in intact animals.     

LambdaattB-attP, a lambda derivative containing both sites involved in integrative recombination

A phage genome has been isolated which contains both attB and attP, the bacterial and phage sites which are recombined in the process of formation of stable lysogens. The derivative was created by an illegitimate recombination during mixed vegetative growth of two phage strains which contained attB and attP separately. The attachment sites on the double site derivative can undergo site-specific recombination to to yield a recombinant deleted for about 15% of the parental DNA. This recombination is dependent on the product of the int gene and demonstrates a great preference for recombination between two sites located on the same molecule. The int gene product used for recombination of λattB-attP may be provided either from the int gene residing either on λattB-attP or on another phage genome. In both cases, ochre suppression of amber mutations of the int gene results in extremely depressed levels of integrative recombination.     

Fragile sites limited to lymphocytes: molecular recombination and malignancy

Fragile sites on chromosomes are points at which rearrangements tend to occur nonrandomly. Because translocations between chromosomes #7 and #14 occur nonrandomly in normal cultured lymphocytes, we analyzed chromosomes #7 and #14 in 53,580 cultured lymphocytes and 109,300 other human cells. We found one rearrangement per 1,218 lymphocytes. These rearrangements were not restricted to translocations but included inversions and hitherto undetected duplications and deletions. In lymphocytes cultured for only 48 hours, rearrangements were seen indicating their presence in vivo. The breakpoints were exclusively in chromosome bands 7p13, 7q35, 14q11, and 14q32. The predisposition to form these rearrangements appeared nonrandom and inherited. These four bands act as if they contain fragile sites limited to lymphocytes. Fragility was not observed in these bands in cells from amniotic fluid, bone marrow, skin, or chorionic villi. Bands 7p13, 7q35, and 14q11 contain T-cell receptor (TCR) genes, whereas, band 14q32 contains the immunoglobulin heavy (IgH) chain locus. Rearrangements of these bands may result from molecular recombination between TCR or between TCR and IgH genes forming TCR/TCR and TCR/IgH chimeric genes important to understanding lymphocyte development and neoplasia. TCR/IgH chimeric genes have been found in T- and B-cell malignancy.     

Bacteriophage Mu sites and functions involved in the inhibition of lambda::mini-Mu growth

To better understand the nature of the mini-Mu-directed process which results in inhibition of lambda::mini-Mu growth we characterized spontaneous deletion mutants of the lambda::mini-Mu phage. On the basis of analysis of the deletion endpoints, mini-Mu replication functions, and integration and inhibition properties, the lambda::mini-Mu deletion mutants were divided into five classes which define the Mu sites and functions involved in lambda::mini-Mu growth inhibition. Class 1 mutants, which still exhibit lambda::mini-Mu growth inhibition, collectively delete all the Mu late functions encoded by the mini-Mu. Class 2 and 5 mutants, which show cis-dominant defects in inhibition and integration, delete the right and left mini-Mu attachment sites, respectively. Phages of Classes 3 and 4, which delete the Mu B or A and B genes, respectively, show recessive defects in growth inhibition. The properties of these mutants define the Mu replication functions, A and B, and the Mu attachment sites as essential for the inhibition of lambda::mini-Mu growth. The observation that the sites and functions essential for Mu replication also have requisite roles in the inhibition of lambda::mini-Mu growth suggests that inhibition results from mini-Mu-promoted replicative interference of lambda::mini-Mu development.     

Differential expression of binding sites for chemokine RANTES on human T lymphocytes

The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3+ T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6–15 h incubation at 37°C, the binding of RANTES, but not of macrophage inflammatory protein-1α (MIP-1α) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RANTES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4⁺ T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-1α, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-1α.     

The presence of a receptor for complement on T lymphocytes. Restriction of the complement receptor to Fc-receptor-bearing T lymphocytes

Using rhodaminated guinea pig anti-ovalbumin:ovalbumin:complement complexes, a fluoresceinated monoclonal anti-Thy 1 antibody and a FACS-II equipped with dual fluorescence detection channels, we find that 25–30 % of Thy 1⁺ splenocytes express a receptor for complement. That a receptor for complement is involved in binding the guinea-pig AgAb:C' complexes is supported by the observations that: a) guinea-pig complexes, which were not treated with a serum source of complement or which were treated with either fresh serum in the presence of EDTA or with heat-inactivated serum, do not bind to the T lymphocytes, and b) heat-aggregated human gamma globulin, which effectively inhibits binding of mouse AgAb complexes to the aFcRγ, has no effect on the binding of guinea-pig AgAb:C' complexes to the T lymphocytes. By analyzing cell subpopulations isolated by cell sorting, it is demonstrated that the C'R-positive T lymphocyte clearly delineates a major subpopulation of aFcRγ-positive T lymphocytes, whereas no cells are found bearing a C'R, while lacking the aFcRγ. The implications of the presence of a C'R in immunoregulation are discussed.     

Collagen receptor on T lymphocytes and the control of lymphocyte motility

Human lymphocytes, freshly isolated from blood, were allowed to settle on surfaces coated by collagen type 1, fibronectin, laminin, IgG or albumin at different concentrations. In separate cultures the lymphocytes were also exposed to these proteins in soluble form. The lymphocytes, predominantly T cells, attached to two-dimensional collagen substrata both in the presence and absence of serum but did not adhere or adhered poorly to substrata coated with fibronectin, laminin, IgG and albumin. In contrast, T blasts induced in a mixed lymphocyte culture adhered to fibronectin-coated substratum. During contact with substratum-bound collagen for a 24-h period, 47 +/- 15% of the freshly purified lymphocytes from separate individuals developed motile behavior whereas 16 +/- 4% of the cells became motile on fibronectin. Gelatin (denatured collagen) also mediated attachment of lymphocytes to surfaces but only at comparatively high concentrations (40 mg/ml). Collagen and gelatin in solution also caused agglutination and motility of the vast majority of freshly isolated T lymphocytes whereas fibronectin and other proteins, when presented in soluble form, did not. Cell agglutination was maximal at moderate (10 or 20 mg/ml) and cell motility at low gelatin concentrations (1 to 10 mg/ml). High gelatin concentrations (20 and 40 mg/ml) did not induce motile behavior. Cytochalasin B augmented the proportion of adherent cells on gelatin-coated substrata. In the presence of cytochalasin B gelatin mediated substrate-adhesion at concentrations below those which normally induced adhesion indicating that motile behavior counteracted persistent lymphocyte adhesion to the substratum. Noteworthy, gelatin/collagen is unique among ligands (e.g. plasma fibronectin and other serum proteins) in its capacity to induce motility in the vast majority of resting lymphocytes freshly isolated from blood within a relatively short period. Taken together these results indicate that circulating lymphocytes have a collagen/gelatin-binding plasma membrane component. Cross-linking of this component is a likely explanation for the selective inducing effect of gelatin and collagen on lymphocyte motility. The present results showed that the lymphocyte plasma membrane contains collagen-binding components with a relative molecular mass of 130 and 55 kDa. The 55-kDa component also reacted with an anti-fibronectin antibody. Thus, interactions with the extracellular matrix may control lymphocyte locomotor capacity.