bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytoplasmic levels of IgE(Δ) in human myeloma cells in the different phases of the cell cycle
Authors: Killander D. , Nilsson K. , Lundin Lena , Fabricius H.Å.
Published: February 2007

The cytoplasmic levels of IgE (λ and e chains) of human myeloma cells in vitro in different stages of the cell cycle were determined by cytophotometric techniques. Asynchronously proliferating cells were pulsed with 3H or 14C‐labeled thymidine. After fixation the cells were “stained” with fluorescein‐conjugated anti‐λ or anti‐λ sera. Fluorescence intensities, representing the amounts of λ and ε chains respectively, were determined by microspectrofluorometry. The same individual cells were then analyzed by dry mass and Feulgen DNA determinations using microinterferometry and microspectrophotometry, respectively. S cells were identified by autoradiography. This methodology thus enabled cell cycle analyses without using synchronization procedures.

The amounts of λ and ε chains correlated well indicating a balanced relationship between them during the cell cycle. In 4 out of 7 experiments the IgE concentration ( = amount of IgE in relation to the cellular mass) fluctuated during interphase: it mostly increased during G1 followed by a decrease in S, sometimes with a recovery during G2. In the other 3 experiments no periodicity was found during the cell cycle, i.e. the cytoplasmic IgE accumulated at the same rate as the overall cellular proteins. Thus, previous published assumptions that Ig synthesis is always restricted to certain periods of the cell cycle, could not be confirmed. Instead, our data indicate that the cell cycle expression of IgE(λ) may be variable in a clonal cell population during in vitro conditions. The explanation for this variability has ot been found. Using the same methodology, surface‐bound Ig however, always shows a noncyclic expression.

A nonproliferating fraction of cells (9 %) was found. These cells, predominantly G1 cells, did not differ from proliferating G1 cells with respect to IgE content. Neither was there any relationship between morphology (immature or mature plasma cells) and IgE levels.
Thymocyte subpopulations in youn and adult mice 1. separtion by density tradient and steroid treatment
Authors: Papiernik Martine , Laroche Liliane , Bach J.F.
Published: February 2007

Thymocyte subpopulations obtained after centrifugation on Ficoll density gradients have been studied in youn and 6‐week‐old mice. Whereas the totality of the thymocytes appeared Θpositive, gradient fractionaton showed the existence of a subpopulation of immunoglobulin and Θnegative lymphocytes among the lightest cells. Similar separation was obtained in both age groups in terms of the distribution of such Θnegative cells as well as of phytomitogen responses. However, cell pools with characteristics of cortical cells were less well represented in 2 to 10‐day‐old mice than in adult mice, indicating that post‐ natal thymic development is essentially associated with the appearance of cortical cell. The gradient did not however, provide a clear separation assessed on other parameterws such as Θantigen, concanavalin A and phytohemagglutinin responses and steroid sensitivity. Cellular heterogeneity for a given cell density is discussed in relation to the hypothesis of two separate maturation pathways of thyocytes.
Clones of cytotoxic lymphocytes in culture: the difference in specificity between stimulated and nonstimulated cytotoxic lymphocytes
Authors: Ching Lai‐Ming , Walker Karen Zell , Marbrook J.
Published: February 2007

The specificity of individual clones of cytotoxic lymphocytes (CL) which develop upon stimulation by semi‐allogeneic cells, have been examined and compared with the specificity of CL clones which develop spontaneously when normal spleen cells are cultured without stimulator cells. It was found that the specificity of stimulated clones was different from the specificity of ‘spontaneous’ clones. Specifically stimulated clones from CBA cells cultured with (CBA × DBA)F1 stimulator cells, did not discriminate between the H2d P81 5 and H2d DBA splenic blasts, and lysed both targets. In contrast, spontaneous CL clones from cultures of CBA or (CBA × DBA)Fi spleen cells were found to lyse either P8 15 or DBA blasts, but not both. The results indicated that the spontaneous CL clones were not a representative sample of the total pool of CL.
Spontaneous clones of cytotoxic T cells in culture III. Discriminatory lysis of pairs of syngeneic blasts induced by different mitogens
Authors: Ching Lai‐Ming , Walker Karen Zell , Marbrook J.
Published: February 2007

When normal spleen cells are cultured for 4 days in polyacrylamide vessels, individual clones of cytotoxic lymphocytes (CL) can be detected. The specificity of these ‘spontaneous’ CL was investigated by assaying the cytotoxic activity of cells from individual clones against pairs of different targets. Target cells used were syngeneic blast cells induced by dextran sulfate, lipopolysaccharide (LPS), concanavalin A (ConA) and phytohemagglutinin (PHA). It was found that LPS blasts were lysed by a separate set of CL clones from those which lysed PHA blasts of the same H‐2 haplotype, and the clones of CL which lysed PHA blasts were a subset of all the clones which lysed ConA blasts. When individual clones of spontaneous CL were assayed against LPS and DS blasts, there were clones which lysed both types of blasts as well as clones which were specific for either LPS or DS blasts. These results have been interpreted as demonstrating that spontaneous CL can recognize and kill subsets of cells which are stimulated by different mitogens.
Reconstitution of natural cell‐mediated cytotoxicity with specific antibodies
Authors: Takasugi Julie , Koide Y. , Takasugi M.
Published: February 2007

The apparent nonselective reactions of natural cell‐mediated cytotoxicity (NCMC) are selective when tested by inhibition of cytotoxicity with competitor cells indicating a recognition of specificities by the effector cell. N cells that mediate this NCMC in humans have most of the characteristics of K cells that mediate antibody‐dependent, cell‐mediated cytotoxicity (ADCC) and possess Fc receptors. IgG antibodies attached loosely to N cells through their Fc region, form part of the class of lymphocytes with surface immunoglobulin. We hypothesized that ADCC and NCMS involved similar mechanisms but with the specificity of NCMC directed by the natural IgG antibodies already attached to N cells. Removal of the antibodies with trypsin and reconstitution with specific anti‐HLA antibodies produced specific effector cells supporting the role of antibodies on N cells as directors of specificity in NCMC.
Cellular and genetic control of antibody responses in vitro 1.cellular requirements for the generation of genetically controlled primary IgM responses to soluble antigens
Authors: Hodes R.J. , Singer A.
Published: February 2007

Thrinitropheny1 (TNP)‐specific primary IgM plaque‐forming cell responses were generated in vitro by unprimed spleen cells to the soluble antigens TNP‐keyhole limpet hemocyanin, trinitrophenylated poly‐L(Tyr‐Glu)‐poly‐D,L‐Ala–poly‐L‐Lys[T,G)‐A–L] and poly‐L(His,Glu)‐poly‐D,L‐Ala–poly‐L‐Lys[(H,G)‐A–L].The T cell dependence of these primary lgm responses was esablished by (a) abrogation of responses after pretreatment of cells with a T cell‐specific rabbit anti‐mouse brain serum (RaMB)and C‐treated spleen cells (B cells); and (c) absence of significant responses by spleen cells from congenic nude mice. A requirement for macrophages in these same antibody responses was also demonstrated:(a) responses were abrogated or strongly diminished in spleen cell populations depleted of macrophages by passage over Sephadex G‐10 columns; and (b) these responses were fully reconstituted by the addition of small numbers of adherent, radioresistant, anti‐Thy‐1.2‐treated spleen cells (macrophages) to the Sephadex G‐10‐depleted populations. In addition, H‐2‐linked Ir gene control has been demonstrated for the primary IgM responses to TNP conjugates of (T,G)‐A–L and (H,G)‐A–L. A system has thus been characterized which permits in vitro analysis of the cellular and genetic requirements involved in primary IgM responses to soluble antigens, including those under Ir gene control.
Presence of “la‐like” antigens on human T lymphocytes bearing receptors for IgG
Authors: Samarut Christiane , Gebuhrer Lucette , Brochier J. , Betuel H. , Revillard J.‐P.
Published: February 2007

Human peripheral blood T cells bearing receptors for the Fc portion of immunoglobulins were characterized by the formation of double rosettes with sheep red blood cells and IgG‐coated chicken erythrocytes (EA). Treatment of cells by anti‐“Ia‐like” antisera inhibits the binding of EA. Inhibition appeared to be specific since anti‐HLA‐A and VLA‐B antibodies did not inhibit the formation of EA rosettes, whereas F(ab )2 fragments of anti‐Ia‐like IgC were found to be as potent inhibitors as the whole IgG. This result shows that in humans and in mice, Ia‐like determinants are present, close to Fc7 receptors, on the surface of the T lymphocytes bearing such receptors.
Distinct chemokinetic and chemotactic responses in neutrophil granulocytes
Authors: Keller H. U. , Wissler J. H. , Hess M. W. , Cottier H.
Published: February 2007

Evidence has been presented to show that chemokinesis and chemotaxis of human neutrophil granulocytes can be controlled by distinct cellular mechanisms and by different chemicals. Materials such as human serum albumin or fibrinogen had chemokinetic but no chemotactic properties. Highly purified preparations of serum‐derived peptides containing classical anaphylatoxin had detectable chemotactic activity only. Chemokinetic as well as chemotactic substances were required for the expression of chemotaxis in the form of efficient directional locomotion. The roles of chemokinesis and chemotaxis in the regulation of directional locomotion have been analyzed.

Further experiments showed that the chemotactic response conforms to the law of Weber‐Fechner. The number of cells which had accumulated in response to a chemotactic stimulus was proportional to the logarithm of the concentration of the chemical substance. Readaptation from high to low chemotactic stimulus intensities occurred only to a limited extent.
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‐δ serum
Authors: Scott D. W.
Published: February 2007

Precursor analysis of the function of murine B cells with surface IgD has been accomplished using an alloantiserum directed against a δ allotype and cellular affinity chromatography. Spleen cells from 3‐week‐old C57BL.Ige mice were treated with a TNP‐labeled anti‐δ 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‐δ serum alone produced a partial reduction in the precursor frequency vs. FL with C57BL.Ige spleen cells (which bear the appropriate δ allotype) but not C57BL/6 spleen cells (which are negative for this δ 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‐pi 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.
Effects of retinoic acid on the immune system: Stimulation of T killer cell induction
Authors: Dennert G. , Lotan R.
Published: February 2007

Retinoic acid (RA), a vitamin A derivative with anti‐tumor activity, was assayed for its effects on the immune system in mice. High doses of this compound (1000 μg/mouse/day) have toxic effects and cause depletion of the peripheral lymphoid organs (spleen, thymus) while leaving the bone marrow cells unaffected. Both the in vivo and in vitro induction of cell‐mediated cytotoxicity (CMC) to allogeneic tumor cells is stimulated at least tenfold by low doses (25–300 μg/mouse/day) of RA while high doses suppress CMC induction. RA is shown to be a specific adjuvant for the induction of cytotoxic thymus‐derived lymphocytes (T cells) and not a general T cell mitogen or adjuvant. It does not enhance the proliferative response in the mixed lymphocyte culture nor does it stimulate lymphocyte proliferation in response to the mitogens concanavalin A and phytohemagglutinin. The induction of cooperating T cells and the delayed‐type hypersensitivity reaction are also not stimulated by RA. In contrast to the reported stimulatory effects of retinyl palmitate and retinyl acetate, RA does not stimulate the humoral response to erythrocytes. The strong adjuvant effects that RA has on the induction of CMC at low doses may be responsible for its anti‐tumor activity.
Sequential interaction of macrophages, initiator T lymphocytes and recruited T lymphocytes in a cell‐mediated immune response to soluble antigen
Authors: Steinman L. , Tzehoval Esther , Cohen I. R. , Segal Shraga , Glickman Eva
Published: February 2007

We have investigated the sequential interaction of macrophages, initiator T lymphocytes (ITL) and recruited T lymphocytes (RTL) in the development of a T cell‐mediated response to soluble antigens. Macrophages were pulsed with soluble antigens and used to sensitize ITL in vitro. The ITL were irradiated to prevent their proliferation and then injected into the footpads of syngeneic mice. Sensitized ITL were found to recruit immunospecific RTL in the draining lymph nodes, as determined by a thymidine uptake assay of the lymph node cells in vitro. The richest source of lymphocytes with ITL activity was the thymus, and progressively less activity was detectable among spleen or lymph node lymphocytes. The magnitude of the subsequent RTL response could be modified by genetic differences between the ITL and the antigen‐pulsed macrophages that were used to sensitize them. Thus, ITL conveyed an immunogenic signal to RTL whose magnitude reflected the genotype of the macrophages, but whose specificity was directed by determinants of the soluble antigen.
Initiator and recruited T lymphocytes are distinct subclasses of T lymphocytes
Authors: Cohen I. R. , Livnat S. , Waksal S. D.
Published: February 2007

In previous studies we found that the generation of a cell‐mediated immune reaction required interaction between sensitized initiator T lymphocytes (ITL) and syngeneic recruited T lymphocytes (RTL). ITL were sensitized in vitro against allogeneic mouse fibroblasts and injected into a footpad of syngeneic recipient mice. ITL were observed to migrate from the connective tissues of the footpad to the draining popliteal lymph node (PLN). Sensitized ITL recruited RTL from the blood circulation into the PLN. This recruitment led to the generation of immunospecific effector and memory lymphocytes.

In the present study we investigated the cellular characteristics of ITL and RTL. We found that both ITL and RTL were positive for Thy‐1 antigen, and were absent from B mice. However, ITL and RTL differed in their response to various treatments. ITL were sensitive to adult thymectomy and resistant to antithymocyte serum (ATS). RTL were resistant to adult thymectomy and sensitive to ATS. Sensitized ITL were adherent to nylon wool or histamine‐rabbit serum albumin‐Sepharose, while RTL were not retained on such columns.

ITL and RTL also differed in their relative distributions in various lymphoid organs and migratory pathways. The thymus demonstrated ITL but not RTL activity. In contrast, lymph node lymphocytes were a rich source of RTL, but had no detectable ITL activity. Both ITL and RTL could be demonstrated in the spleen. Thus, ITL and RTL functions are mediated by distinct subclasses of T lymphocytes which reside in particular compartments of the immune system.
Genetic and functional characterization of an antiserum to the lipid A‐specific triggering receptor on murine B lymphocytes
Authors: Coutinho A. , Forni Luciana , Watanabe T.
Published: February 2007

The inheritance of responsiveness to lipopolysaccharide (LPS), and of a marker recognized in LPS‐reactive cells by a heterologous antiserum, was studied in crosses between C3H/HeJ (nonresponder) and C3H/Tif (high responder) mice. F1 hybrid mice show codominant expression of these traits: (a) LPS‐reactive cells are only half as frequent in the hybrids as in the high responder parent; (b) the serologically defined marker is expressed in half as many cells in the hybrids as in the high responder parent. In backcross generations, both LPS responsiveness and this serological marker segregated into high, intermediate, and nonresponders.

LPS or free lipid A, but not two other B cell mitogens (lipoprotein, and purified protein derivative of tuberculin), compete with the antiserum for binding to the B cell surface membrane, and are capable of completely inhibiting such binding without interfering with the binding of anti‐Ig antibodies or complexes to Fc receptors. The addition of an IgG fraction of the antiserum to B cell cultures results in exponential growth of the cells and in maturation to antibody secretion. This mitogenic activity is dose‐dependent and absorbable on spleen cells from LPS high responder mice.

Taken together, these observations suggest that this antiserum contains antibodies to the lipid A‐specific triggering receptor on B lymphocytes.
Specificity of helper T cells for different antigens
Authors: Kindred Berenice , Corley R. B.
Published: February 2007

BALB/c nude mice have been injected with 106 congenic thymus cells, a number which allows some, but not all mice to respond to any particular T‐dependent antigen. These mice have been tested for their ability to respond to three bacteriophages, T4, T7 and ΦX, sheep and horse erythrocytes, and alloantigens of C3H and C57BL/6 mice. The number of mice able to respond to each of these antigens was of the same order of magnitude. Sheep and horse erythrocytes showed cross‐reactivitty at the T cell level, i.e. the responses to these two antigens were not independent. The same was observed for C3H and C57BL/6. Otherwise, the responses were independent showing that the antigens are recognize by different populations of specific helper T cells.
Cell membrane‐mediated cytolysis by membranes from noncytolytic cells
Authors: Kahn‐Perles Brigitte , Golstein P.
Published: February 2007

Cytolysis was obtained with plasma membrane fractions prepared not only from cytolytic T cells, but also from nonimmune lymphoid cells and, moreover, from cell lines of nonlymphoid origin displaying no lytic ability. Furthermore, no relationship exists between the genetic specificity of T cell‐mediated cytolysis and the activity of membrane preparations. If anything, it appears that certain cell types may be unusually sensitive to membrane‐mediated cytolysis. Our observations argue against a mechanistic relationship between T cell‐mediated and membrane‐mediated cytolysis.
Role of adherent cells in immune responses to phytohemagglutinin and concanavalin A
Authors: Arala‐Chaves M. P. , Hope L. , Korn J. H. , Fudenberg H.
Published: February 2007

The roles of adherent and nonadherent T cells in the responses to phytohemagglutinin (PHA) and concanavalin A (Con A) were studied. [3H]thymidine uptake by mononuclear cells from human thymus and peripheral blood was used to measure the relative influence of monocytes and B cells on the responses to these mitogens. The response to Con A was dependent on two populations of T cells, one adherent to cotton or nylon and the other nonadherent. The first population appeared to potentiate the latter. In contrast, the response to PHA was dependent only on the nonadherent T cell subpopulation. The responses to PHA and to Con A were both dependent on monocytes to approximately the same extent, but the response to Con A, unlike the response to PHA, was also slightly dependent on B cells.
Modification and fate of J chain in myeloma cells in the presence and absence of polymeric immunoglobulin secretion
Authors: Mosmann T. R. , Gravel Y. , Williamson A. R. , Baumal R.
Published: February 2007

Processing of J chain in various mouse myeloma cell lines was examined by incorporation of radioactive cystine, followed by analysis of proteins by immune precipitation and gel electrophoresis. J chain was synthesized by all myeloma‐derived cell lines examined, but not by nonmyeloma cell lines, even of B lymphocyte lineage. Secretion of J chain occurred only from cells secreting IgA or IgM. The J chain synthesized in other myeloma cell lines, was altered to a form that did not migrate at the rate of J chain during electrophoresis and was not recognized by the anti‐J chain antiserum. This alteration, probably due to degradation, occurred at a similar rate to the secretion of J chain by cell lines producing IgA or IgM. Some degradation of J chain may also occur in cell lines secreting J chain.

Although the J chains from several cell lines were indistinguishable by gel electrophoresis when first synthesized, secreted J chains from three cell lines all showed slight differences in mobility both from one another and from intracellular J chain. The change in mobility occurred at or near the time of secretion of immunoglobulin, and was consistent with the addition of different amounts of carbohydrate to J chain in the three different myelomas.
Correlations between the genetic control of natural and oxazolone‐induced antibody production
Authors: Andó I. , Erdei J. , Mäkelä O. , Fachet J.
Published: February 2007

Nonimmune sera of inbred and H‐2‐congenic mouse strains contain natural antibodies of the IgM type reacting with 4‐(ethoxymethylene)‐2‐phenyl‐oxazolin‐5‐one (oxazolone). The genetic regulation of the level of natural and induced antibodies to oxazolone was compared. High natural antibody‐producing ability was inherited recessively, while high oxazolone‐induced IgM antibody formation was dominant in F1 animals. Studies on nude mice demonstrated that T cells do not affect the natural antibody level, but were required for induced antibody production. Breeding studies and linkage analysis revealed multigenic control and a significant role of allotype‐linked genes in both cases. Furthermore, the influence of H‐2‐linked genes on induced primary IgM antibody production was demonstrated.
Antigen‐induced proliferation assay for mouse T lymphocytes. Response to a monovalent antigen
Authors: Alkan Ş. Ş.
Published: February 2007

This report describes an antigen‐specific proliferative assay which makes use of lymph node cells obtained from mice injected subcutaneously at the base of the tail one week previously. When lymphocytes from only the draining lymph nodes of mice immunized with a variety of different antigens, were stimulated in flat‐bottomed microculture plates with the immunizing antigen, a substantial degree of proliferation was observed, measured as incorporation of [3H]thymidine. Monovalent immunogen p‐azobenzenearsonate‐L‐tyrosine, (ABA‐Tyr, 500 daltons) which induces T cell responses in guinea pigs without antibody production, was studied in detail. In a typical experiment, ABA‐Tyr gave ∼ 17000 cpm while control cultures without antigen showed ∼ 1600 cpm. The response is antigen‐specific and seems to be mediated by T cells, since (a) it can be abolished by pretreatment of these cells with anti‐Thy‐1.2 serum and complement, (b) cells from nu/nu mice primed with ABA‐Tyr do not show any antigen‐induced proliferation, in contrast to the response observed in nu/+ and BALB/c controls, and (c) purified T cells require macrophages to proliferate, but neither macrophages nor B cells appear to divide in culture. Thus, this rapid and easy technique should prove useful for the in vitro study of murine T lymphocytes.
Subpopulations of mouse T lymphocytes. II. Suppression of graft‐vs.‐host reactions by naturally proliferating splenic T cells
Authors: Moorhead J. W.
Published: February 2007

The immunological role of a naturally proliferating subpopulation of splenic T cells was investigated using the graft‐vs.‐host (GvH) reaction in the mouse. Normal parental spleen cells, purified splenic T cells or lymph node cells were pulse‐treated for one hour in vitro with tritiated thymidine of high specific activity ([3H]dThd, “thymidine suicide”). The treatment specifically and selectively kills proliferating cells which are actively synthesizing DNA, i.e. cells in S phase. Following treatment, the cells were transferred to F1 recipients and the GvH reaction measured by the splenomegaly assay. The results showed that the GvH effector cells in the donor spleen and lymph node are nonproliferating T cells. Furthermore, donor spleen cells treated with [3H]‐dThd consistently had enhanced GvH reactivity when compared to the controls, while the phytohemagglutinin response of these same treated cell suspensions was significantly inhibited. When purified splenic T cells were used, treatment with [3H]dThd also caused an increase in the GvH reaction, showing that a T cell population was being affected by the cycleactive agent. These results indicated that some naturally proliferating T cells have suppressor functions, and their specific inactivation allows nonproliferating effector T cells to mount a more vigorous GvH reaction.
Regulation of the immune response. I. Regulatory cell equilibrium in the “virgin” state
Authors: Kelsoe G. , Cerny J.
Published: February 2007

Spleen cells from pairs of inbred mice (age‐ and sex‐matched) were challenged in vitro with a T‐independent antigen. The specific plaque‐forming cell(PFC) response in cultures containing cells from both donors was not intermediate to the responses of independently cultured donor spleen cells. Instead, a pattern of significant suppression (67 % of pairs tested) or enhancement (22 % of pairs tested) was observed. The suppression or enhancement was antigen‐specific and did not represent a general phenomenon within the mixed cultures. A suppressive outcome in mixed cell cultures seems to be associated with cells from the donor with the higher individual PFC response. The converse is true for enhancement.

The nonadditive nature of the PFC response in mixed cultures and the frequency of suppression to enhancement (3:1) imply that (a) specific, ongoing immunoregulation occurs even in the naive individual, and (b) this regulation is characterized by regular cycles of specific suppression and enhancement.
Murine heavy chain disease
Authors: Morrison Sherie L.
Published: February 2007

Using cultured mouse myeloma cells, it has been possible to derive cells which are now synthesizing products similar to human heavy chain disease proteins. An initial mutant was isolated which synthesized a heavy chain with an internal deletion and a normal light chain. In a subsequent step, a variant was identified in which the synthesis of the heavy chain with the deletion persisted in the absence of light chain synthesis. These experiments also demonstrate that in the MPC‐11‐derived cultured cell line, the continued synthesis of heavy chain does not require the synthesis of light chain.
Genetic control of allogeneic interactions in the guinea pig. I. Evidence from mixed leukocyte culture and normal lymphocyte transfer reactions
Authors: Geczy Carolyn L. , Geczy A. F.
Published: February 2007

The role of gene products of the B region of the guinea pig major hist ocompatibility complex (MHC) in the production of mixed leukocyte culture mitogenic factor (MLC‐MF) has been investigated. Lymphoid cells of partially inbred and outbred guinea pigs which bear the serologically defined B.2 alloantigen, respond poorly or not at all in the guinea pig MLC. Since MLC culture supernatants from B.2+ cells do not stimulate B.2− third party lymphoid cells, it is possible that either B.2+ lymphoid cells do not elaborate MLC‐MF or they produce a suppressor factor. Genetic studies have demonstrated that genes closely linked to or identical with the gene(s) coding for the B.2 alloantigen, regulate “MLC unresponsiveness”. By contrast to their unresponsiveness in the MLC, B.2+ lymphoid cells produce migration inhibition factor at least as well as cells bearing the B.1 and B.3 specificities, and they respond in vitro to antigens which are under the control of specific immune response genes.

The genetic restrictions for responsiveness in the MLC are supported by in vivo studies which strongly suggest that the degree of interaction between allogeneic lymphoid cells (normal lymphocyte transfer, immune lymphocyte transfer and direct reactions) are also under the control of genes which map in or near the B region of the guinea pig MHC. Preliminary evidence suggests that the B.2+ donor cells rather than B.2+ host cells are responsible for initiating the unresponsiveness associated with the normal lymphocyte transfer reaction. These studies should provide a basis for the reproducible production of MLC‐MF and a system for the study of some molecular aspects of allogeneic interactions in vitro and in vivo.
Antibody against rabbit immunoglobulin VH and L chain allotype determinants in heterologous anti‐lg antisera
Authors: Jensenius J. C. , Mole L. E.
Published: February 2007

Heterologous anti‐rabbit IgG antisera have been examined by radioimmunoassay for the occurrence of anti‐VH antibody. Most of the sera contained antibody specific for VH allotype determinants (Aa1). The antisera contained as much or more anti‐al antibody as estimated in conventional alloantisera. It has further been shown that the anti‐L chain antibody in all these sera was specific for L chain allotype determinants. Antibody against H chain‐dependent L chain conformational determinants or cross‐reacting determinants in CHlγ and CHlα could not be demonstrated.
Antibodies to ganglioside GM1 induce mitogenic stimulation and cap formation in rat thymocytes
Authors: Sela B.‐A. , Raz A. , Geiger B.
Published: February 2007

Antibodies towards the ganglioside GM1[galactosyl‐N‐acetylgalactosaminyl‐(N‐acetylneuraminyl)‐galactosylglucosyl ceramide] stimulated DNA synthesis in rat thymocytes. No mitogenic stimulation was observed with the monomeric Fab fragment of anti‐GM1, suggesting that cross‐linking of the gangliosides or associated components was required for activation by these antibodies.

Incubation of thymocytes with anti‐GM1 and fluorescein‐labeled anti‐rabbit IgG at 0°C resulted in uniform ring‐like or patchy staining that developed into a pronounced cap upon elevation of temperature. The cap had a characteristic uropod form, enriched with intracellular organelles. Sodium azide and cytochalasin B completely inhibited cap formation, while colchicine was without effect.

These results imply a possible direct or indirect association between surface gangliosides and submembraneous cytoskeletal assemblies that control modulation of these surface components and may transmit stimuli to the interior of the cell.
Fc IgM receptors on human lymphoblastoid B cell lines
Authors: Pichler W. J. , Broder S. , Muul Linda , Magrath I. , Waldmann T. A.
Published: February 2007

Five human lymphoblastoid cell lines have been investigated for their ability to secrete immunoglobulins (IgG, IgA, IgM) and for the presence of different cell surface markers, with special emphasis on the Fc IgM receptor, using a rosette technique with IgM‐coated bovine red blood cells (EA‐IgM).

Four cell lines (Hu, 8432, SB, PA3) were characterized as having as cell origin due to the presence of surface immunoglobulins, complement receptors, mouse red blood cell rosette formation, low avidity Fc IgG receptors and absence of sheep red blood cell rosette formation. Two of these B cell lines (Hu and PA3) secreted IgM, two cell lines (8432 and SB) secreted IgG, while the human T cell line Molt 4 did not secrete Ig.

All four B cell lines exhibited Fc IgM receptors (17–35%) while the T cell line Molt 4 had no detectable Fc IgM receptor. The receptor was specific for IgM. Neither aggregated IgG, soluble IgG immune complexes nor EDTA could abrogate the rosette formation, IgM immune complexes, pure human IgM, as well as normal human serum had an inhibitory effect on EA‐IgM rosette formation. The receptor was trypsin‐sensitive and required protein synthesis for expression.

There was no correlation between the expression of Fc IgM receptors and secretion of any given Ig class, indicating that B cells may express Fc IgM receptors independently of their commitment to produce IgM or IgG.
In vitro induction of experimental autoimmune orchitis Characterization of a primary T lymphocyte response against testicular self antigens
Authors: Wekerle H. , Begemann M.
Published: February 2007

Lymphocytes from normal, young adult rats were autosensitized in vitro against trypsin‐dissociated autologous testis cells. The autoimmune response had been assayed both by determination of the lymphocyte proliferation, using a [3H]thymidine incorporation test, as well as by determination of their specific cytostatic activity against monolayer‐forming testis cells which was measured in a terminal 51Cr uptake assay. The actively responding cells in this system are T lymphocytes. Non‐T cells can exert additional, nonspecific cytostasis. The immune specificity of the in vitro experimental autoimmune orchitis (EAO) has been demonstrated on two levels. First, the responding T lymphocytes were found to specifically adhere around cells from one particular test is subpopulation which morphologically resemble Sertoli cells. The rosetting lymphocytes respond only to testicular self antigen, but not to allogeneic lymphocytes. Second, specificity to the effector T lymphocytes was revealed in transfer experiments. Autosensitized EAO effector T cells cytostatically affected only major histocompatibility gene complex (MHC)‐compatible testis cells. Their reactivity against MHC‐different testis cells or MHC‐compatible nontesticular fibroblasts was significantly decreased which suggests both tissue as well as MHC specificity of the EAO response.
Mechanism of T cell‐mediated cytolysis: the differential impact of cytochalasins at the recognition and lethal hit stages
Authors: Golstein P. , Foa C. , Maclennan I. C. M.
Published: February 2007

We have investigated the impact of a range of cytochalasins of various classes, not only on T cell‐mediated cytolysis as a whole, but also at each stage of this process using the analytical Ca++ pulse method. We compared the results thus obtained with the effect of some of these drugs on microfilaments (assessed by electron microscopy) and on glucose metabolism. All cytochalasins blocked the recognition stage of T cell‐mediated cytolysis, none blocked the target cell disintegration stage, and all cytochalasins but cytochalasin A blocked Ca++‐dependent events of the lethal hit stage. Cytochalasin A, which did not block lethal hit, clearly affected microfilaments. Cytochalasin B blocked both the lethal hit and glucose catabolism while cytochalasin A inhibited neither. The following pattern is therefore suggested. The recognition stage can be blocked by both cytochalasin A and cytochalasin B, presumably through a common effect of these drugs on microfilamental structures. The lethal hit stage can be blocked by cytochalasin B but not by cytochalasin A, presumably through the impact of the former on cell membrane permeability to glucose. These results are discussed both in terms of their practical interest relative to the use of Ca++ and cytochalasin A to probe lytic events, and in terms of the information they provide about metabolic steps and cell structures which could be involved in the lethal hit.
The anti‐delta suppressed mouse
Authors: Layton Judith E. , Johnson G. R. , Scott D. W. , Nossal G. J. V.
Published: February 2007

The ontogeny of IgD was examined in neonatal to adult mice by immunofluorescence. The first δ‐positive cells appeared in the spleen at about 3 days of age, while lymph nodes from 4 to 5‐day‐old mice already contained 10–20% δ‐positive B cells.

In order to study the function of IgD, we developed a system in which the appearance of δ‐positive cells was suppressed by treatment of mice from birth with an anti‐δ allotype serum. Immunofluorescence studies showed that very few δ‐positive cells could be found in the spleen and lymph nodes of such suppressed mice, and also that the percentage of μ‐positive cells was reduced by about 50%. The recovery from suppression was rapid, indicating that potential δ‐positive cells were modulated rather than killed. Studies of the immune response of suppressed mice in vitro and in vivo showed that suppression had little effect on the IgM response but caused a definite reduction in the IgG response.
Analysis of the diversity of murine antibodies to dextran B1355. III. Idiotypic and spectrotypic correlations
Authors: Hansburg D. , Perlmutter R. M. , Briles D. E. , Davie J. M.
Published: February 2007

Examination of 19 S and 7 S anti‐α(1→3) dextran (Dex) antibodies by serological assays and isoelectric focusing (IEF) has revealed substantial variation of idiotypic and spectrotypic expression between individuals of the same genotype. 7 S antibodies appeared to be more heterogeneous than 19 S by both methods. A strong, but complex, association was found between the IEF patterns of 19 S and 7 S anti‐Dex antibodies and their expression of the idiotypic determinant(s) common to both the M104 and J558 dextran‐binding myeloma proteins. However, no such relationship was found between the IEF pattern and the expression of idiotypic determinant(s) unique to the M104 myeloma protein. Rather, indistinguishable spectrotypes from different individuals have widely differing levels of expression of the determinant. In addition, this determinant(s) may be present on different spectrotypes of the same isotype. Both the M104 and J558‐specific idiotypes were found on antibodies of the IgG3 subclass as well as in pools containing predominantly the IgG2a subclass. These data confirm and extend the picture of substantial structural variation among the antibodies comprising a response of restricted heterogeneity.
Monoclonal IgM cryoglobulinemia associated with gamma‐3 heavy chain disease: immunochemical and biochemical studies
Authors: Wang A.‐C. , Arnaud P. , Fudenberg H. H. , Creyssel R.
Published: February 2007

A patient (Mia) with a monoclonal IgM(k) cryoglobulin (cryo IgM) developed additional heavy chain disease proteins of the γ3 subclass 8 years later. Biochemical studies of the cryo IgM indicated that the heavy chain was VHI, but the NH2‐terminal amino acid sequence of the light chain did not permit a definite assignment of its VK subgroup. Two major fragments of the γ3 chain were distinguishable by electrophoresis in sodium dodecyl sulfate polyacryl‐amide gel. The smaller component (designated Mia F) had a molecular weight of approximately 30 000 and the larger component (designated Mia S) 35 000. Both fragments had G3m(21) and G3m(27) allotypic determinants. These data and the NH2‐terminal amino acid sequence of the γ chain fragments suggested that Mia S consists of the major part of the γ3 hinge region plus the CH2 and CH3 domains of the γ3 chain, whereas Mia F may be derived from the former as a result of postsynthetic cleavage. The partial amino acid sequence of the Mia S fragment is homologous to the hinge region amino acid sequence of human γ3 chains reported in the literature, with only one amino acid difference out of the 11 residues compared. This difference may represent an allotypic difference within the γ3 subclass. Alternatively, the production of Mia S may have resulted from the accidental derepression of a “silent” constant region gene not expressed in normal individuals.
H‐2 control of the magnitude and heterogeneity of the immune response
Authors: Kipps T. J. , Benacerraf B. , Dorf M. E.
Published: February 2007

The antibody responses to the random linear terpolymer poly(LLyu54, LLys36, LAla10), and its 2,4 dinitrophenyl conjugate, DNP‐GLA, were analyzed. Dominant immune response genes (Ir genes) mapping to the I region of the murine major histocompatibility complex control the magnitude of the anti‐GLA and DNP‐GLA antibody responses. Mice of the H‐2f haplotype were found to be high responders. These animals produce significantly higher titers of anti‐GLA antibody to GLA than intermediate H‐2‐congenic responder mice of the H‐2b,a,d,k,s,u,v or z haplotypes. In contrast, animals with H‐2 haplotypes j,n,p,q or r were found to be nonresponders to GLA. The relative magnitude of each strain's response to GLA was also reflected in the relative magnitude of its anti‐DNP antibody response to DNP‐GLA. High, intermediate and nonresponder mice could be further distinguished by the number of antigen‐specific plaque‐forming cells generated in the response to GLA, and in the relative amounts of IgM, IgG1 and IgG2 anti‐GLA antibodies produced in both primary and secondary anti‐GLA responses. Both intermediate and nonresponder strains of mice, however, could respond to GLA that was chemically coupled with an immunogenic carrier, chicken gamma globulin, to generate antigen‐specific plaque‐forming responses that were similar in magnitude to that produced by high responder strains to GLA.

Isoelectric focusing studies revealed that GLA intermediate responder mice generated anti‐DNP antibody responses to DNP‐GLA of very restricted heterogeneity. H‐2‐congenic high responder animals, however, produced anti‐DNP antibody responses upon DNP‐GLA immunization that were significantly more heterogeneous than these restricted anti‐DNP‐GLA responses of intermediate responder animals. Thus, genes located within the major histocompatibility complex can influence the degree of heterogeneity of the anti‐DNP antibody response to DNP‐GLA. The potential mechanisms responsible for the Ir gene‐controlled differences in the magnitude or heterogeneity of the immune response to GLA or to its DNP conjugate, DNP‐GLA, are discussed.
The relationship of membrane antigens on 141 (NZB) and EL4 (C57BL) lymphoma cells as demonstrated by antibodyinduced resistance to complement‐mediated cytotoxicity
Authors: Ran Maya , Yaakubowicz Margalith , Talal N. , Witz I. P.
Published: February 2007

We have studied the ability of various antisera to induce resistance to complement‐dependent lysis (CdL) (lysostripping) of surface antigens of B and T lymphoma cells. Alloantisera, xenoantisera, as well as anti‐Rauscher‐leukemia virus (RLV) antisera, were used. Whereas all antisera could induce resistance to CdL mediated by the same serum that served for lysostripping (autolysostrip), only some of the tested antisera could induce resistance to CdL by other antisera (co‐lysostrip). In some combinations co‐lysostrip was unidirectional, i.e. in a pair of antisera, one induced autolysostrip as well as co‐lysostrip, whereas the other antiserum induced autolysostrip only. In other combinations co‐lysostrip was reciprocal.

These investigations do not support the possibility that viral components and alloantigenic determinants are associated on mouse lymphoma cells.
Antibody diversity in amphibians: inheritance of isoelectric focusing antibody patterns in isogenic frogs
Authors: Du Pasquier L. , Wabl M. R.
Published: February 2007

Anti‐sheep red cell, anti‐dinitrophenyl, anti‐phosphorylcholine antibody responses have been followed in isogenic frogs of the genus Xenopus. Isoelectric focusing antibody patterns show a high degree of overlap for all antigens studied, and a heterogeneity that is lower than in mammals for the same antigens. Inheritance of antibody isoelectric focusing spectrotypes was demonstrated for sheep red cells and dinitrophenyl in two clones of isogenic animals.

Outbred frogs show a higher frequency of spectrotype sharing than outbred mammals. It is therefore suggested that antibody diversity is lower in frogs than in mammals.
Generation and release of eosinophil chemotactic factor from human polymorphonuclear neutrophils by arachidonic acid
Authors: König W. , Tesch H. , Frickhofen N.
Published: February 2007

This study describes the generation and release of an eosinophil chemotactic factor from human polymorphonuclear neutrophils, rat basophilic leukemia cells, and from a lymphocyte monocyte basophil suspension by arachidonic acid (AA). The eosinophil chemotactic factor (ECF) is highly specific for eosinophils and resembles the ECF activity obtained from human polymorpho‐nuclear neutrophils after stimulation with the Ca ionophore or during phagocytosis. In this regard, AA‐induced ECF represents a biological activity distinct from oxidized AA and its conversion products. AA may therefore have a dual function: it represents an important mechanism of cell activation; as AA is converted into prostaglandins, it appears likely that they exert a modulatory and a suppressive role on biological functions, such as chemotaxis and phagocytosis.
Selection of antigen‐specific cells by adherence to allogeneic cell monolayers: cytolytic activity, graft‐vs.‐host activity and numbers of adherent and nonadherent cells
Authors: Chisholm Patricia M. , Ford W. L.
Published: February 2007

Rat lymph node cells taken at the peak of cytolytic activity following a skin allograft were separated into adherent and nonadherent fractions by incubation on monolayers of thoracic duct lymphocytes either of the same strain as the graft donor or of an Ag‐B different strain. In the face of a 3‐fold enrichment of cytolytic activity in the adherent cells and a 3‐fold depletion in the nonadherent cells there was no detectible partition of graft‐vs.‐host (GVH) activity. Supplementary experiments supported the simplest interpretation of this finding, namely that the antigen receptors on GVH‐reactive cells did not influence their adherence in this system. Similarly, there was no partition of the GVH activity of nonimmune lymph node cells by adherence. Labeling lymph node cells with either radioactive uridine or thymidine in vitro, suggested that about 20% of DNA‐synthesizing cells in the immune population adhered because of antigen recognition.
T‐independent responses in B cell‐defective CBA/N mice to Brucella abortus and to trinitrophenyl (TNP) conjugates of Brucella abortus
Authors: Mond J. J. , Scher I. , Mosier D. E. , Baese M. , Paul W. E.
Published: February 2007

CBA/N mice have an X‐linked immune defect in B lymphocyte function which leads to their inability to respond to several thymus‐independent antigens. We report here that these mice and immunologically defective F1 male (CBA/N × DBA/2N) mice can respond to Brucella abortus and to 2,4,6‐trinitrophenyl derivatives of Brucella abortus (TNP‐BA). These responses can be obtained in vivo and in vitro and are thymus‐independent by the criteria that (a) they can be transferred to irradiated recipients by bone marrow cells and anti‐Thy‐1.2 and complement‐treated spleen cells; (b) that nu/nu BALB/c spleen cells respond to TNP‐BA in vitro; and (c) that anti‐Thy‐1.2 and complement‐treated (CBA/N × DBA/2N)F1 male spleen cells respond to TNP‐BA in vitro. B. abortus and TNP‐BA are poor polyclonal B cell activators (PBA) and poor B cell mitogens, unlike lipopolysaccharide which is both a powerful PBA and B cell mitogen. These results therefore indicate that mice with the CBA/N B cell defect can respond to some thymus‐independent antigens, namely TNP‐BA, and as shown previously, TNP‐LPS, although not to other thymus‐independent antigens. This, in turn, suggests that thymus‐independent antigens may be subdivided on the basis of their ability or inability to stimulate responses by CBA/N B lymphocytes.
Possible occurrence and meaning of lymphocytes bearing autoanti‐idiotypic receptors during the immune response
Authors: Tasiaux N. , Leuwenkroon R. , Bruyns C. , Urbain J.
Published: February 2007

During an immune response, the increase in binding affinity of antibodies is followed by a fall. Lymphocytes bearing autoanti‐idiotypic receptors were detected during a normal immune response. The kinetics of appearance and disappearance of such lymphocytes led us to propose a network model to explain the changes occurring in antibody properties during an immune response.