Membrane immunoglobulins and antigen receptors on B and T lymphocytes

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.

The influence of embryonal bursectomy on benzpyrene-induced sarcoma of the chicken

160 chickens hormonally bursectomized before hatching, and 160 controls were twice given a dose of 10 mg 3,4-benzo(a)pyrene 2 weeks and 6 weeks after hatching. After 24 weeks the controls had developed muscle sarcomas at a significantly higher rate than the bursectomized animals (49.6--32.1%). The tumors were identified as malignant polymorphocellular rhabdomyosarcomas in light and electron microscopy. When the experiment was stopped after 27 weeks, the controls showed more tumors than the bursectomized chickens (65.1% versus 58.9%). The effect of bursectomy lies in a prolongation fo tumor latency. The frequency of metastases is equally decreased to a significant degree (41.7% versus 21.7%). These results are interpreted as an illustration of the disturbed equilibrium between the T and B cell responses.

The lymphoid system. Its normal architecture and the potential for understanding the system through the study of lymphoproliferative diseases

This article presents a view of lymphoid tissue architecture as defined by the traffic of defined lymphoid cell classes. The compartmentalization of lymphocytes is discussed in reference to specific cell-cell interactions that occur in antigen-driven immune responses. Finally, the distribution of normal and neoplastic lymphocytes in humans is defined and compared with animal model systems.

The detection of human B lymphocytes by both light and electron microscopy utilizing colloidal gold labeled anti-immunoglobulin

Colloidal gold was used to label rabbit anti-goat IgG for the indirect detection of goat anti-human IgD and IgM. Utilizing this technique, surface immunoglobulin was visualized on human blood B lymphocytes at both the light and electron microscopic levels of resolution. By this technique, percentages of lymphocytes were found to closely correlate with those of the standard immunofluorescent procedure. The ease of the procedure along with the clarity of the marker in both light and electron microscopy suggest wide applicability in clinical and research studies of lymphocyte membrane markers.

Allotypes of IgM and IgD receptors in the mouse: a probe for lymphocyte differentiation

Antibodies to IgD and IgM are present in many mouse alloantisera made against lymphocytes. Antibodies to IgM are also present in a small minority of conventional antiallotype sera made against pertussis/anti-pertussis complexes. These antibodies reflect different allelic forms of IgD and IgM in different mouse strains, and allowed the mapping of the delta- and mu-chain genes (Ig-5 and Ig-6, respectively) to the heavy-chain complex. The variable portions of IgM and IgD receptors on individual cells bearing both chains are similar or identical. Both receptors show allelic exclusion and come from the same chromosome on individual cells (haplotype exclusion). It is suggested that very early in B lymphocyte differentiation there is a commitment to a given chromosome, and translocation of one copy of a given variable region gene to each heavy-chain gene. Subsequent switches of immunoglobulin class then involve differential gene activation. Immature B cells possess IgM receptors only and mature into cells bearing both IgM and IgD receptors. After activation with antigen, IgD is probably lost. These findings are discussed within the framework of the clonal abortion theory of B-lymphocyte tolerance.

Role of IgD in the immune response and tolerance. II. Precursor analysis of murine B cells separated on the basis of surface IgD or treated with an anti-delta serum

Precursor analysis of the function of murine B cells with surface IgD has been accomplished using an alloantiserum directed against a delta allotype and cellular affinity chromatography. Spleen cells from 3-week-old C57BL.Ige mice were treated with a TNP-labeled anti-delta allotype serum, washed and passed through an anti-TNP affinity column. The cells passing such a column were depleted of IgD-bearing lymphocytes by immunofluorescence and also showed a greatly reduced ability to develop into specific antibody-forming cell clones vs. the fluorescein (FL) hapten in a limiting dilution microculture system in vitro. In contrast, the IgD-bearing cells eluted from such columns were slightly enriched in precursor activity compared to the original population. Moreover, brief treatment with anti-delta serum alone produced a partial reduction in the precursor frequency vs. FL with C57BL.Ige spleen cells (which bear the appropriate delta allotype) but not C57BL/6 spleen cells (which are negative for this delta allotype). This effect varied with the age of the spleen donor, but was most dramatic with splenocytes from 2 to 3-week-old mice. This contrasts with the effect of anti-mu pretreatment, which only inhibited neonatal precursors. The results are interpreted in terms of the maturation of murine B cells and the function of IgD and IgM receptors in triggering an immune response.

Methods for the identification of human B lymphocytes

Complement-receptor lymphocytes and monocytes were identified by a rosette method using trypsin treated sheep erythrocytes (Et), sensitized with affinity column purified IgM (19S) antibodies against sheep erythrocytes (E) and mouse complement deficient in C5. Fc receptor mononuclear cells were identified by a rosette method using Et and IgG (7S) antibodies against E. Identification of the cell-type rosetting was facilitated by myeloperoxidase staining of dry mounted rosetted preparations. Comparison of lymphocytes with receptors for activated mouse complement and lymphocytes with stable surface immunoglobulin detected by immunofluorescent assay, strongly suggests that these cells constitute the same population in the peripheral blood of healthy humans.

Characterization of a carcinogen-induced murine B lymphocyte cell line of C3H/eB origin

A carcinogen-induced lymphoid tumor, denoted 38C-13, obtained in a T cell-depleted mouse of C3H/eB strain, was adapted to continuous culture in vitro and characterized with respect to its cell surface components. The cells possess IgM class immunoglobulins on their surface but do not secrete it. This membrane IgM is composed of mu and L-chains that are similar in apparent molecular weight to those of an IgM myeloma protein. It is also homogeneous as revealed by isoelectric focusing. The cells possess Fc receptors but lack complement receptors as well as Thy-1 and Ia alloantigens. These characteristics indicate that 38C-13 cells are transformed counterparts of small B lymphocytes at an early stage of differentiation.

Determination of B lymphocyte population using antibody-coated polyacrylamide beads

The present study describes a method for the determination of the human B cell population by the use of polyacrylamide beads which are coated with antibody specific for each of the immunoglobulin classes. This method provides a simpler determination of the B cell count than the EA or EAC rosette tests. The antibodycoated beads also have the potential of being used to quantify the subpopulations of B cells bearing specific classes of immunoglobulins.

Purine nucleoside phosphorylase, a possible histochemical marker for T-cells in man

A procedure is described for the histochemical detection of purine nucleoside phosphorylase (PNP) activity in circulating lymphocytes of man. The number of PNP-positive cells, as evaluated on smears of Ficoll--Hypaque purified cells, correlated well with the number of E-rosette-forming cells of the same blood samples of healthy and diseased people with normal or abnormal numbers of E-rosettes. In healthy people, the number of PNP-positive cells was within the range of 70-80% of the total lymphocyte population, whilst the corresponding E-rosette-forming cells were scored between 60-75%. Patients with unusually low or high E-rosettes had equally low or high numbers of PNP-reactive cells. More substantial evidence for the presence of PNP activity in T-cells and not in B cells was gathered from experiments in which PNP activity and surface membrane immunoglobulins (SMIg) were simultaneously demonstrated on the same preparation. These results showed, on the one hand, that the bulk of lymphocytes that are reactive for PNP do not reveal SMIg and, on the other hand, that most Ig-bearing cells were unreactive for PNP.

Functional specificity of thymus- dependent lymphocytes

Thymus-dependent lymphocytes display a restricted range of specificity when compared to thymus-independent (B) lymphocytes. They react particularly to thymus-dependent protein and cell surface antigens and to products of genes encoded in the MHC. In addition, T lymphocytes have important functions in regulating the immune response and in discriminating of self from nonself. Recent work indicates that individual T lymphocytes possess receptors that interact with both thymus-dependent antigens and MHC gene products, either independently or as associated structures. We attempt to relate this complex specificity pattern to the regulatory and surveillance functions of T lymphocytes.

Peripheral blood lymphocyte populations in influenza patients

The peripheral blood lymphocyte populations were determined in 10 patients during the acute phase of influenza and 6-8 weeks after recovery. The percentage of T-lymphocytes, demonstrated by their binding sheep erythrocytes non-specifically (E-rosette forming cells), was decreased during influenza. A relative and absolute increase of non-T-lymphocytes could be shown by the determination on these cells of receptors for activiated C'3 (EAC-rosette forming cells).

Density differences between membrane and secreted immunoglobins of murine splenocytes

The buoyant densities of mouse immunoglobulins were determined by isopycnic centrifugation in phosphate-buffered cesium chloride using beta-galactosidase as marker. The buoyant densities of IgG, TEPC 15 IgA, secreted IgM, and MOPC 104E IgM were consistent with their carbohydrate contents both in the presence and the absence of the nonionic detergent, Nonidet P-40. Intracellular IgM from spleen cell lysates had a buoyant density corresponding to a carbohydrate content of 6%. Membrane IgM from detergent lysates of spleen cells was less dense than either intracellular or secreted IgM in the presence of detergent. The IgD-like membrane molecules were more dense than membrane IgM.

Lymphocyte surface immunoglobulins: detection, characterization, and occurrence in disease of the lymphoid system

Surface immunoglobulins (Igs) of lymphocytes are of considerable interest because these molecules probably function as receptors for antigen, and knowledge of their molecular properties should provide information on the mechanisms of immune differentiation. The density and types of surface Ig on a cell provide markers useful in indicating the class of a lymphocyte and its stage of maturity. Moreover, knowledge of the specificities of the surface Ig of neoplastic lymphocytes might suggest the nature of agents involved in the generation of the disease. Two broad classes of lymphocytes, bone marrow-derived lymphocytes (B cells) active in antibody secretion, and thymus-derived lymphocytes (T cells) which mediate cellular immune reactions, and their subpopulations must be considered with reference to the nature, origin, and function of their surface immunoglobulin. This article analyzes direct and indirect methods for the demonstration of surface Igs and describes certain physicochemical properties of isolated surface Ig molecules. Roles of these surface molecules in recognition of antigen, initiation of all differentiation, and cooperation among lymphocytes and accessory cells are discussed.

Differentiation antigens of the lymphocyte cell surface

Many alloantigens and xenoantigens of lymphocytes are not found generally on other tissues, and this suggests that much of the lymphocyte cell surface is differentiated in comparison with other cell membranes. These differentiation antigens are probably molecules that mediate lymphocyte-specific functions, and are also of interest in that they provide markers for different lymphoid cell types and may be important as target antigens for immunosuppressive anti-(lymphocyte) sera. The purification of differentiation antigens will be important in allowing their molecular properties to be discovered, and will also lead to the production of strong, specific antisera that can be used in functional studies. Radioimmunoassays have been developed for the analysis of anti-(lymphocyte) sera, and these assays provide advantages in purification studies over other techniques. The features of these assays are discussed, and studies of differentiation antigens of rat lymphocytes are described. These include the purification and characterization of the rat Thy-1 antigen, and preliminary studies on two other rat lymphocyte differentiation antigens.

Ligand-induced redistribution and augmentation of surface-bound myeloma protein on MOPC 315 plasmacytoma cells

The dinitrophenyl (DNP)- and trinitrophenyl (TNP)-binding IgA(lambda2) myeloma protein M315, bound on the surface of MOPC315 mouse plasmacytoma cells, was redistributed into spots, patches, and, more rarely, into caps by TNP14-BSA and by divalent but not monovalent anti-M315 antibodies. Antiserum to the L-chain of M315 (L315) induced similar redistribution of L315 bound on the surface of variant cells that only produced L315. The spots were much larger and more brilliant when the cells were incubated with the ligands at 37 degrees C than at 4 degrees C. Redistribution of M315 also occurred on M315-producing cells in peritoneal diffusion chambers incubated in BALB/c mice producing antibodies against the M315 idiotype. The clearance of immune aggregates and the regeneration of new surface-bound M315 in diffusion chambers were much slower for MOPC315 cells than that reported for B lymphocytes. The total pool of M315 was 1.9 pg per cell (about 8 x 10(6) 7S molecules), but only an average of 6 x 10(3) [125I]TNP-BSA molecules were bound on the surface of each MOPC cell at 4 degrees C. The amount of surface-bound TNP-BSA increased eightfold when the cells were preincubated at 37 degrees C with rabbit anti-mouse IgA; at 4 degrees C the increase was only twofold. The data indicate that multivalent ligands specific for M315 induce an accumulation of M315 on the cell surface that correlates with secretion; the immediate precursors of secreted myeloma protein may be arrested in their transit through the membrane by the ligands.

Lymphocyte markers in newborn infants

Purified peripheral blood lymphocytes from 20 newborn infants and 12 adults have been studied for the presence of surface markers. Adults and infants did not differ in the percentage of sheep RBC-binding cells (means 58-65%) or in Ig-bearing cells measured by the mixed antiglobulin reaction (means 7.2-11.6%). However, newborn infants had a significantly lower percentage of lymphocytes binding Fc of IgG (mean 10.4%) as compared to adults (mean 17.2%). No overall correlation between plasma Ig levels and Ig-bearing lymphocytes was found but a single infant with increased plasma IgA also showed the highest level of Ig-bearing lymphocytes among all infants.

Optimal strategies in immunology. I. B-cell differentiation and proliferation

The optimal strategy available to the immune system for responding to a non-replicating thymus-independent antigen is examined. By applying Pontryagin's maximum principle to a set of mathematical models of lymphocyte populations and their antibody production, it is found that the optimal strategy of bang-bang control appears robust. In a variety of structurely related biological models, similar behaviour is observed. The models that we consider assume that antigen triggers a population of B-lymphocytes. These triggered lymphocytes can either proliferate and secrete modest amounts of antibody or differentiate into nondividing plasma cells which secrete large amounts of antibody. For biologically reasonable parameter values it is found that for low doses of antigen, immediate differentiation into plasma cells is optimal, while for high antigen doses a proliferative state followed by differentiation is the best strategy.

B-lymphocyte heterogeneity: ontogenetic development and organ distribution of B-lymphocyte populations defined by their density of surface immunoglobulin

The density of total Ig and of IgM, IgG1, IgG2, and IgA on the surface of adult murine splenic B lymphocytes was measured using the technique of rapid flow microfluorometry. In addition, the density of total surface Ig and of IgM on B lymphocytes derived from adult bone marrow, lymph nodes, and Peyer's patches, and from neonatal spleen was determined. Adult spleen and lymph node B lymphocytes are characterized by the presence of a large population of cells with a low-to-intermediate density of total surface Ig, which is seen as a peak in the fluorescence profiles when these cells are labeled with fluorescein-conjugated (F1) anti-Ig. This peak is not detected when neonatal spleen or adult bone marrow are examined; the development of this peak among spleen cells occurs during the first 4 wk of life. Although the characteristic fluorescence intensity peak is not seen when adult spleen cells are labeled with Fl anti-mu, changes in the density of surface IgM do occur during the first few weeks of life and are detected as a decrease in the frequency of cells which have relatively large amounts of surface IgM. The differences seen in the fluorescence patterns of adult spleen cells labeled with Fl anti-Ig and Fl anti-mu may be due to the appearance of IgD on the surface of mature splenic B lymphocytes. This is supported by the similarity of the fluorescence profiles of adult bone marrow cells stained with Fl anti-Ig and Fl anti-mu, as the latter population of cells is reported to lack surface IgD.

Conformation of immunoglobulin M. I. Characterization of anti-epsilon-1-dimethylamino-5-naphthalenesulfonyl-L-lysine immunoglobulin M antibodies from horse, pig, and shark

IgM antibodies specific for the fluorophore epsiolon-1-dimethylamino-5-naphthalenesulfonyl-L-lysine(DNS-lysine) were elicited in the horse and nurse shark by immunization with a DNS-lysine streptococcal conjugate; the antibodies were purified by specific adsorption with an immunoadsorbent followed by gel filtration to select the IgM class (molecular weight 900 000). About 90% of the equine anti-DNS was IgM.DNS-Lysine, when bound in the combining sites of a population of these anti-DNS IgM antigodies from horse and nurse shark, as well as from pig, exhibited a marked fluorescence enhancement and shift of the emission spectrum to shorter wavelengths compared with emission in aqueous solution; these results indicate that the environments of the anti-DNS combining sites of this population were relatively hydrophovic. Approximately one-third of the ten possible combining sites in each of these anti-DNS IgM species bound DNS-lysine in this manner with an average intrinsic association constant (Ko) of greater than 10(6) M-1. Small differences were noted in binding behavior among the three species of antibodies. The enzymatic susceptibility of equine IgM was similar to that of human IgM. (Fab')2mu, Fab'mu, and Fabmu fragments were prepared following digestion with pepsin. These fragments could be clearly differentiated on the basis of molecular size. They bound DNS-lysine with the same affinity as intact IgM and the DNS-lysine-fragment complexes exhibited the same spectral properties as the parent IgM. It was concluded that the anti-dNs IgM antibodies from all three species, as well as the enzymatic fragments, were suitable for nanosecond depolarization studies which are reported in the accompanying paper Holowka, D.A., and Cathou, R.E. (1976), Biochemistry, the following papter in this issue.

Phylogenetic origins of immune recognition: lymphocyte surface immunoglobulins in the goldfish, Carassius auratus

Membrane immunoglobulin (Ig) of splenocytes and thymocytes of the goldfish, Carassius auratus, was demonstrated by indirect fluorescent-antibody techniques. Observations on shedding and resynthesis indicated that the thymocyte Ig was endogenously produced. The lymphocyte surface proteins were radioiodinated using the lactoperoxidase-catalyzed reaction, and the labeled Ig molecules were isolated by specific precipitation and analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The IgM-like membrane Igs of splenocytes and thymocytes were shown to differ in their ease of solubilization with nonionic detergent, and in the sodium dodecyl sulfate/electrophoretic mobility of their heavy chains. The significance of these observations for the evolution of T-cell recognition is discussed.