bluuebunny/crossref_metadata_2025 huggingface dataset:
Are VH framework antigenic determinants expressed on both rabbit B and T lymphocytes?
Authors: Wllder Ronald L. , Yuen Catherine C. , Scher Irwin , Mage Rose G.
Published: February 2007

The extent to which VH framework determinants are represented on T cell receptors is unresolved and controversial. We have studied this question in the rabbit using antia (VH framework) allotype antisera and a goat anti‐rabbit VH antiserum. Flow micro‐ fluorometric analysis of spleen lymphocytes from hyperimmune animals (Freund's adjuvant plus picryl chloride) demonstrated closely similar frequencies of cells stained with the anti‐VH framework antisera compared to anti‐light chain antisera. To search for potentially hidden molecules, additional studies were performed with radioiodinated, detergent‐solubilized plasma membranes derived from immune spleen and lymph node cells. The membranes were analyzed by standard immunoprecipitation techniques. Absorption with anti‐Ig constant region immunoabsorbents removed all radioactivity precipitable by specific anti‐VH framework antisera compared to controls, whereas after absorption with control (normal goat globulin) immunosorbents, VH‐bearing surface IgM and putative surface IgD (presumably of B cell origin) were readily demonstrated by immunoprecipitation. Thus, no evidence for a population of cells or a class of molecule(s) bearing VH in the absence of light or heavy chain constant region determinants was obtained. Although these studies do not support the concept of similar VH framework determinants on T and B cell receptors, they do not exclude a much more limited sharing of determinants or a very minor T cell subpopulation which expresses VH framework that would not be detectable by the methods used in these studies.
The detection of membrane‐associated complement components (C 3 and C 4) on circulating human normal and leukemic leukocytes and on cultured cells with monkey erythrocytes
Authors: Burns Gordon F. , Cawley John C.
Published: February 2007

Monkey erythrocyte (Mk) rosette formation is described as an exquisitely sensitive method for the detection of complement (C) components on the membrane of human leukocytes. Blocking of the immune adherence receptor on Mk blocked subsequent rosette formation as did pretreatment of leukocytes with antiserum to the C components C3 and C4. In vitro C deposition by immune complex formation with normal human lymphocytes enhanced Mk rosette formation, and this could be inhibited with antiserum to C3. The use of Mk rosette formation revealed that cells from a wide variety of human lymphoid and myeloid leukemias carry membrane‐bound C. It was also shown that several lymphoblastoid cell lines, including a T cell line, probably synthesize both C3 and C4. Mk rosette formation is not dependent on metabolic activity of the resetting leukocyte, and it is suggested that this technique will be of value in detecting C deposition in a variety of situations.
Isolated hapten‐binding receptors of sensitized lymphocytes: V. Cellular origin of receptor molecules
Authors: Krawinkel Ulrich , Cramer Matthias , Kindred Berenice , Rajewsky Klaus
Published: February 2007

Chimeric mice were constructed by injection of thymus cells into nu/nu mice. The thymus cells carried a different immunoglobulin (Ig) heavy chain linkage group than the cells of the recipients. The chimeric animals were then immunized with the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) on an appropriate carrier, and NP‐binding receptor molecules were isolated from the spleen cells of the animals. Receptor molecules and antibodies were analyzed for the presence of two Ig heavy chain variable region (VH) markers which are specific for the anti‐NP response of mice carrying the Igb allogroup, namely the NPb idiotpye and the heteroclitic fine specificity of hapten binding. Two types of receptor molecules are obtained by our method, those carrying determinants of Ig constant domains (anti‐Ig+ receptors) and others lacking such determinants (anti‐Ig− receptors). The two VH region markers were found on anti‐Ig− receptors but not on anti‐Ig+ receptors and humoral antibodies when the T cells in the chimeric mice carried the Igb allogroup, whereas the B cells were Iga/a. Conversely, anti‐Ig+ receptors and humoral antibodies but not anti‐Ig−receptors, expressed the two markers when the B cells of the chimeras carried the Igband the T cells the Iga allogroup. From these results and previous data showing that anti‐Ig− receptors are enriched together with T lymphocytes and anti‐Ig+ receptors together with B cells, we conclude that the VH‐bearing anti‐Ig− receptors are not only present on T cells, but are indeed synthesized by these cells.
Deficient production of anti‐red cell autoantibodies by mice with an X‐linked B lymphocyte defect
Authors: Marshall‐Clarke Stuart , Cooke Anne , Hutchings Patricia R.
Published: February 2007

The production of anti‐self red cell antibodies has been studied in mice bearing the CBA/N X‐linked B lymphocyte defect and their phenotypically normal littermates. Defective mice produced anti‐self red blood cell (RBC) antibodies at markedly reduced levels after multiple injections of rat RBC. They also failed to show significant numbers of plaque‐forming cells against enzyme‐treated isologous RBC. These findings are discussed in terms of the nature of the CBA/N defect and the acquisition of a complete specificity repertoire.
The presence of Thy‐1 on the surface of rat lymphoid stem cells and colony‐forming units
Authors: Hunt Simon V.
Published: February 2007

By labeling Thy‐1‐positive cells of rats with xenoanti‐Thy‐1 or mouse alloanti‐Thy‐1 antibody and separating them from Thy‐1‐negative cells on a fluorescence‐activated cell sorter, it was shown that early lymphopoietic stem cells all carry Thy‐1‐antigen. This was so for both young, adult bone marrow and near‐term fetal liver cells. Two kinds of assay were used: long‐term radiation chimeras employing B and T cell alloantigens to mark cells of donor origin, and in vivo colony‐forming units in the spleens of irradiated recipients (bone marrow only). Thy‐1‐negative cells gave essentially no B or T progeny, even 6 to 12 months after reconstitution of the chimeras. The kinetics of appearance of Thy‐1‐positive cells in rat marrow, which peaked at 6‐8 weeks of age, were also studied. In rats, Thy‐1 is on the surface of pluripotent stem cells and on early progenitors of both B and T lymphocytes.
Production and characterization of cytotoxic Thy‐1 antibody‐secreting hybrid cell lines Detection of T cell subsets
Authors: Lake Phil , Clark Edward A. , Khorshidi Manoocher , Sunshine Geoffrey H.
Published: February 2007

Responses to Thy‐1 were used as a model system to examine parameters which affect the production of antibody‐secreting lines derived from somatic cell hybridization. Experiments with the Thy‐1.1 response revealed that the frequency of clones producing Thy‐1.1 antibodies is a constant of 4 to 6% for each 10000 plaque‐forming cells (PFC) input in the fusion cell mixture, regardless of the maturational stage of the response. Therefore, PFC responses to Thy‐1 were optimized by studying variables in the choice and dose of antigen, the response kinetics and in the fusion procedures. Thus, to produce Thy‐1.1 antibody‐secreting cell lines, we used (a) spleen cells at the peak of the PFC response, (b) xenogeneic (rat) rather than allogeneic donors, (c) secondary rather than primary responses and (d) high ratios of NS‐1 to spleen cells.

For the reproducible production of Thy‐1.2 antibody‐secreting hybridomas, PFC responses to Thy‐1.2 were similarly optimized in AKR mice. Response kinetics and antigen dose were shown to be very critical parameters. By varying the number of cells used for priming, it was revealed that doses only slightly higher than optimal produced a dramatic hyporesponsiveness in the subsequent secondary response. Using the above information, hybrid lines secreting antibody to Thy‐1.2 were obtained reproducibly and one line, F7D 5, which secretes a cytotoxic IgM antibody was characterized in detail since a monoclonal antibody may differ from conventional antisera for immunochemical and genetic reasons.

Serologically, F7D 5 Thy‐1.2 antibody was found to behave as a conventional Thy 1.2 alloantiserum, At high dilutions however, the antibody can be used to discriminate long‐lived T cells (adult thymectomized mice) from newly produced T cells (antilymphocyte antiserum‐treated mice). Functionally, in numerous T cell‐dependent assays both in vivo and in vitro, including helper, suppressor and cytotoxic T cell functions as well as responses to mitogens and antigens, the F7 D 5 antibody behaved as a potent and absolute T cell‐depleting agent. This cell line and some anti‐Thy‐l.1 producing lines are available for research purposes.
Genetic control of the immune response to the terpolymer L‐glutamic acid 60‐L‐alanine 30‐L‐tyrosine10(GAT). III. Restricted heterogeneity of the anti‐GAT response from BALB/c responder mice
Authors: Petit Christine , Joskowicz Mireille , Stanislawski Marc , Thèze Jacques
Published: February 2007

The heterogeneity of the anti‐GAT [terpolymer poly(Glu60, Ala30, Tyr10)] response of GAT responder mice has been analyzed. Purified anti‐GAT antibodies from BALB/c mice belong only to the γ1χ subclass. The isoelectric focusing pattern obtained indicates that the anti‐GAT antibodies are particularly basic and restricted. These results have been confirmed by two‐dimensional polyacrylamide gel electrophoresis; by this technique, we have shown that the γ1 chain and the corresponding χchain of anti‐ GAT antibodies are restricted. All the anti‐GAT antibodies from 10 BALB/c mice bear the cross‐reactive GAT idiotype previously defined (J. Thèze and G. Sommé, Eur. J. Immunol. 1979, 9: 294). The present results indicate that the anti‐GAT repertoire expressed in BALB/c mice is very limited.
Demonstration of a murine cell surface component with affinity for exogenous β2‐microglobulin
Authors: Sege Karin , Östberg Lars , Peterson Per A.
Published: February 2007

Murine and human β2‐microglobulin (β2m) bind to various types of mouse cells. The binding is saturable and displays a single association constant of about 1 × 109 liter/mol. The binding of β2m to splenocytes was not affected by a variety of metabolic inhibitors but was temperature‐dependent. It is suggested that the β2m “receptor” exhibits a temperature‐dependent conformational change since the “receptor”, whether integrated into the membrane or solubilized by the detergent Triton X‐100, binds β2m poorly at low temperatures. Spleen T and B lymphocytes display more binding sites than thymocytes, kidney, liver and brain cells. The relative amounts of the β2m‐binding “receptor” on these cell types are strongly correlated to the relative amounts of H‐2 antigens. This correlation is also obvious for the teratocarcinoma cell line F9, which lacks both β2m “receptor” and H‐2 antigens, but spermatozoa, which express very small amounts of H‐2 antigens, have an appreciable amount of the β2m “receptor”. The latter observation, together with the fact that alloantisera directed against H‐2 K and D antigens do not measurably affect the binding of β2m to the “receptor”, may argue against the notion that the β2m “receptor” represents H‐2 antigens which have lost their endogeneous β2m. Normal mouse serum contains a component which inhibits the binding of β2m to splenocytes. It is likely that this serum protein is identical to a newly discovered H‐2 antigen‐like glycoprotein. The β2m “receptor” appears to be under the control of the major histocompatibility complex as splenocytes of the H‐2f haplotype bind considerably more β2m than splenocytes of other haplotypes.
Analysis of the repertoire of anti‐(4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) antibodies in C 57 BL/6 mice by cell fusion. II. Characterization of idiotopes by monoclonal anti‐idiotope antibodies
Authors: Reth Michael , Imanishi‐Kari Thereza , Rajewsky Klaus
Published: February 2007

CBA and SJL mice were immunized against the hybrid cell antibody Bl‐8 (μ,λ1) which we have previously isolated from the primary response of C57BL/6 mice against the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) (Eur. J. Immunol. 1978. 8: 393). Cell lines secreting monoclonal antibodies against B1–8 idiotopes were isolated, and the anti‐idiotope antibodies were used to characterize the variable portion of B1–8 and of other anti‐NP antibodies all belonging to an antibody family which carries a major idiotypic marker, namely the NPb idiotype.

Three groups of idiotopes were defined by the monoclonal anti‐idiotope antibodies on the B1–8 protein; a first, in the NP binding site so that the corresponding anti‐ idiotopes compete with the NP hapten for binding to B1–8 (group 1); a second, presumably further apart from the binding site so that there is competition of the corresponding anti‐idiotopes with a polyvalent NP‐protein conjugate but not the free hapten for binding to B1–8 (group 2); and a third (group 3), specific for a determinant constructed by B1–8 μ chains and MOPC 21 χ chains which are still present in the B1–8 preparation as the product of the X63‐Ag8 parent cell line. Group 1 idiotopes were expressed on 1–10% of χ1‐bearing primary anti‐NP antibodies of C57BL/6 origin and group 2 idiotopes on 10–100% of these antibodies. Group 3 idiotopes were not detected in anti‐NP antisera. The analysis of a set of monoclonal hybrid cell anti‐NP antibodies from C57BL/6 confirmed that group 2 idiotopes are more abundantly expressed in the primary anti‐NP response than any given group 1 idiotope. Group 2 idiotopes can thus be expressed independently of group 1 idiotopes. In addition, group 1 idiotopes appear to exhibit a higher degree of diversity than idiotopes of group 2.

The present analysis dissects the NPb idiotype into a large set of idiotopes which can be grouped in terms of localization on the antibody molecule and of variability and which are combined in various ways on a large number of χ chain‐bearing antibody species. At least some of the idiotopes recognized by the monoclonal antibodies are under the control of the heavy chain linkage group, as shown by the idiotope analysis of serum antibodies from Igh‐congenic mice.

In the course of the fusion experiments, also cell lines secreting antibodies of SJL origin with specificity for the constant region of χ1 chains were isolated, and we also describe the preparation of an Fv fragment from B1–8, an IgM antibody.
Age‐dependent changes in tolerizability with rabbit gamma‐globulin in the Biozzi high and low‐responder lines of mice
Authors: Papers Short , Nakano Katsuji , Cinader Bernhard , Sabiston Brian H.
Published: February 2007

The antibody response to rabbit gamma‐globulin (RGG) of high‐responder, but not of low‐responder Biozzi mice decreased with age. Injection with aggregate‐freed RGG reduced the response of high‐responder but not of low‐responder mice to subsequent injections with aggregated RGG. This reduction in the antibody response, formed by high‐responder mice, decreased with increasing age; aggregate‐freed RGG appeared to sensitize 6‐month‐old low‐responder mice to a subsequent injection with aggregated RGG. When animals, not pretreated with aggregate‐freed RGG, were immunized with RGG and lipopolysaccharide (LPS), the immune response was greatly enhanced. The response of both pretreated low and high responders was substantially smaller than that of corresponding animals which were not given aggregate‐freed RGG, prior to immunization. LPS revealed an inhibitory effect on low‐responder mice of aggregate‐freed RGG, which was not detected upon immunization with heat‐aggregated RGG alone. The involvement of nonspecific suppressor cells and of B cell tolerance in low‐responder mice is discussed.
Failure of allogeneic thymocytes to survive in nude mice
Authors: Piguet Pierre‐François , Vassalli Pierre
Published: February 2007

Athymic nude mice or thymectomized mice, irradiated and reconstituted with T‐ depleted bone marrow cells (“B mice”), were injected with allogeneic or syngeneic thymocytes bearing caryotypically distinct chromosomes. The fate of the thymocytes was investigated after various periods of time using two methods: (a) frequency of the cells bearing the Thy‐1 antigen as detected by immunofluorescence with a heteroantiserum among the recipient spleen cells, (b) presence of chromosomally detectable donor cells in phytohemagglutinin‐stimulated spleen cell cultures. These two methods indicate that allogeneic thymocytes disappear after about 7 days, semiallogeneic thymocytes after about 20 days, while syngeneic thymocytes, even when injected in 50 times lower number (106 cells), are detectable for months, thanks to the sensitivity of the caryotypic method. Allogeneic thymocytes induce the production of high titers of alloantibodies, which were shown to react specifically against their own H‐2, a phenomenon interpreted as a “suicidal” allogeneic collaboration. These experiments demonstrate that the failure of allogeneic thymocytes, in contrast to syngeneic thymocytes, to achieve long‐term restoration of the immune responsiveness of T‐depleted mice is due to a rejection of the foreign thymocytes, and not to a failure of T and B cells to collaborate across the histocompatibility barrier.
Stimulation of regulatory T cell circuits by immunoglobulin‐dependent structures on activated B cells
Authors: L'age‐Stehr Johanna , Teichmann Hans , Gershon Richard K. , Cantor Harvey
Published: February 2007

An immunoregulatory circuit is described in which B cell blasts activate syngeneic Ly‐1+2−3− T cells to (a) start a reaction which is indistinguishable from a graft‐vs.‐ host reaction (syngeneic GvH) and (b) induce suppressor cell activity which abrogates the syngeneic GvH. Since capping the surface immunoglobulin (Ig) on B cell blasts blocks their ability to activate this circuit, it is likely that the relevant cell surface structure “seen” on the B cell by the Ly‐1 T cell is either Ig itself or another molecule in association with Ig.
Prolonged exposure to antigen induces specific unresponsiveness of mixed leukocyte culture‐activated cells
Authors: Sagman Julius Gordon Uri , Rode Harold
Published: February 2007

One‐way mixed leukocyte cultures, supplemented by the daily addition of small numbers of fresh stimulating cells between days 5 and 15 of incubation, failed to give a secondary proliferative or cell‐mediated lyrnpholytic response upon challenge with activating concentrations of the same stimulating cells. However, these cultures could be fully activated by blastogenic factor (BF). The unresponsiveness induced was immunologically specific: when reponding cells were primed simultaneously with stimulating cells from two donors and one stimulator was added daily, the cultures were unresponsive to challenge with cells of the stimulator which were added daily, but good secondary responses were elicited both by cells of the other stimulator used in priming and by BF. The induced unresponsiveness may be a consequence of specific inactivation of helper cells.
Subpopulations of T lymphocytes from human blood differing in density and stage of maturation
Authors: van de Griend René J. , Astaldi Giulia C. B. , van den Ende Abraham , Loos Johannes A. , Roos Dirk
Published: February 2007

Previous investigations have shown that peripheral lymphocytes with a low specific gravity are much more active than are heavy lymphocytes in the proliferative response towards mitogens, antigens and allogeneic lymphocytes. We have now studied the biological significance of this difference in human peripheral T lymphocytes with two independent parameters generally regarded as maturation criteria.

Heavy human T lymphocytes contain about one‐third of the amount of cyclic AMP found in light T cells, but the increase in cyclic AMP produced by isoproterenol or prostaglandin E1 is much higher in the heavy T cells. The lactate dehydrogenase isoenzyme pattern of heavy human T lymphocytes is intermediate between that of human thymocytes and light T lymphocytes, the latter showing the most mature pattern. A high correlation was found between these two parameters, the cell density and the reactivity towards phytohemagglutinin.

We conclude that human peripheral T lymphocytes are heterogeneous in maturation level: heavy, nonreactive T lymphocytes are less mature than light T lymphocytes.
Suppression of the immune response to altered self induced by immunogenic and nonimmunogenic altered self structures
Authors: Ramos Teresa , Möller Erna , Möller Göran
Published: February 2007

Fluorescein (FITC)‐haptenated mouse spleen cells are capable of inducing a B cell immune response characterized by the production of antibodies directed against hapten‐altered self structures. The induction of this response is thymus‐independent and strictly dependent on the hapten concentration used for labeling the cells.

Pretreatment of mice with immunogenic, labeled spleen cells strongly suppressed the plaque‐forming cell response to a subsequent challenge with FITC‐labeled spleen cells, sheep (SRC) or horse (HRC) red cells labeled with the same hapten and native FITC‐dextran.

Mice primed with lightly haptenated (nonimmunogenic) cells 7 days before challenge were completely unresponsive to the immunogenic dose of labeled cells and displayed a significantly reduced response to FITC‐SRC or FITC‐HRC. However, the response to FITC‐dextran was enhanced, as compared to unprimed animals.

The concept of immunogenic vs. nonimmunogenic requirements of an antigen to induce unresponsiveness, and the specificity of the B cell clones affected by suppression is discussed.
Correlated expression of VH framework and VHidiotypic determinants on T helper cells and on functionally undefined T cells binding group A streptococcal carbohydrate
Authors: Eichmann Klaus , Ben‐Neriah Yinon , Hetzelberger Doris , Polke Christine , Givol David , Lonai Peter
Published: February 2007

Antibodies to framework determinants of the VH and Vλ. fragments of MOPC 315 and antisera to the VH idiotype determinants of the A 5 A antibody were used to analyze the antigen receptors of mouse T (and B) cells. This was done by using the antibodies as inhibitors in (a) an assay in which the binding of radiolabeled streptococcal carbohydrate (A‐CHO) antigen by primed and unprimed T and B cells is determined and (b) an assay in which the helper activity of group A streptococcal vaccine‐primed T cells is determined. The results suggest that the major proportion of primed and unprimed T cells binding A‐CHO (70–9076) exhibit VH framework and VH idiotypic determinants. This population appears to include the helper T cells. A minor proportion of T cells (10–3076) express Vλ‐related framework determinants and lack VHframework and VH idiotypic determinants. This population does not include T helper cells. Taken together, the data suggest that a subpopulation of T cells, including the helper cells, uses entire Ig VH regions as part of their antigen receptor system.
Microsequence analysis of Ia antigens from three strains of rats
Authors: Cecka J. Michael , Blankenhorn Elizabeth P. , Götze Dietrich , Hood Leroy
Published: February 2007

Homologues of Ia antigens of the mouse are identified in three rat strains by partial N‐terminal amino acid sequence analysis. Ia antigens of the rat were isolated by indirect immune precipitation using specific rat alloantisera. Rat Ia antigens consist of two components, α and β, which have respective mol. wts. of approximately 35000 and 28 000. Partial N‐terminal sequence analysis of each of the αa components of the H‐la, H‐1l and H‐1n haplotypes yields a single, apparently homogeneous sequence which is identical among the three haplotypes and is strikingly homologous to the a polypeptides of the I‐E subregion of mouse and to the human polypeptide, p34. Partial N‐terminal sequence analysis of the β components shows that a mixture of polypeptides is present for each haplotype. There are differences in the β sequences among the three haplotypes and potential homologies between the rat β sequences and the sequences of the β polypeptides of the I‐A and I‐E subregions of mouse. These observations imply that the rat has at least two distinct groups of Ia molecules. The organization of genes encoding the Ia polypeptides in the major histocompatibility complex of the rat is discussed.
Fc receptors on rabbit lymphocytes Existence of receptors for IgG antibody complexed with antigen; conditions for its detection
Authors: Bast Bert J. E. G. , Manten‐Slingerland Ria , Roholl Paul , Meyling Frits Gmelig , Ballieux Rudy E.
Published: February 2007

The presence of Fc receptors (FcR) on rabbit peripheral blood leukocytes is demonstrated using rosette formation with an ox erythrocyte‐antibody (EoxA) complex. The receptor is specific for the Fc fragment of IgG (neither IgM nor F (ab′)2anti‐Eox mediates rosette formation) that is antigen‐bound (aggregated rabbit IgG inhibits the rosette formation only transiently). The receptor is species‐specific: guinea pig IgG/ Eox, goat IgG/Eox and sheep IgG/Eox complexes do not show rosette formation, and goat IgG aggregates do not inhibit rosette formation.

The origin of the target erythrocytes is of importance. Sheep erythrocytes are not useful, and within Eox large differences between donors were found. Rosette formation was only inhibited by pretreatment of the rosette‐forming cells with homologous immune complexes, whereas the size of the antigen greatly influenced the degree of inhibition. The rabbit FcR is pronase‐resistant, unlike the human and murine FcR. The interaction of IgG and the FcR is not inhibited by isolated Cγ 3 domains. Further evidence for the requirement of the whole Fc region was obtained in experiments where inhibition of the rosette formation was observed using antisera directed to the Cγ3 and the Cγ2 domain, respectively. Anti‐Fab antiserum did not inhibit rosette formation. Results are discussed in relation to the mechanism of allotypic suppression.
Fc receptors on rabbit lymphocytes. Identification and organ distribution of rosette‐forming cells; cocapping with surface immunoglobulin
Authors: Bast Bert J. E. G. , Manten‐Slingerland Ria , Roholl Paul , van Graft Marja , Ballieux Rudy E.
Published: February 2007

Fc receptor (FcR)‐bearing cells were demonstrated using ox erythrocytes coated with homologous IgG‐type antibodies (EAY) in rabbit peripheral blood leukocytes (PBL) and in various lymphoid organs.

Discrimination of the rosette‐forming cells (RFC) is carried out after prior ingestion of tetramethylrhodamine isothiocyanate‐labeled latex particles and in transmission electron microscopic studies. Most of the nonlymphoid cells (5‐10%) in PBL and spleen cell suspensions expose FcR. These nonlymphoid cells are almost absent in other lymphoid organs, except in bone marrow. The average percentage of cells rosetting with IgG‐sensitized erythrocytes (EAγRFC) in lymphoid cell preparations of the various tissues was as follows: PBL 25%, bone marrow 65%, appendix 37%, spleen 40%, Peyer's patches 44%, thymus 2% and peripheral lymph node 27%.

The nature of FcR‐bearing PBL was further studied using F(ab′)2 anti‐IgM, anti‐IgA or anti‐T cell conjugates. About half of the population of B cells, bearing IgM or IgA, express FcR. Moreover, about 80% of the RFC are found within the B cell population. Only a few T cells were found rosetting with EAγ suggesting that most of the non‐B lymphoid RFC are “null” cells. In different lymphoid organs, the percentages of EAγRFC and B cells are comparable but not identical. A greater part of the EAγRFC also expresses the receptor for the third component of complement. After capping of membrane IgM determinants, FcR is located in the same cap on the majority (60%) of the FcR‐positive IgM‐capped cells.
Thymus cell migration: Quantitative aspects of cellular traffic from the thymus to the periphery in mice
Authors: Scollay Roland G. , Butcher Eugene C. , Weissman Irving L.
Published: February 2007

We have used intrathymic injection of fluorescein isothiocyanate to label thymocytes in situ. The method gives random labeling of the thymocyte population and so can be used to quantitate the extent of migration of cells from the thymus to the periphery. Migrant cells can be visualized in frozen sections or cell suspensions of peripheral organs by their fluorescence.

Our data show that in young adults, about 1% of thymocytes leave the thymus per day. Since the bulk of thymocytes turn over every 5 to 7 days, this indicates that the vast majority (95%) of thyrnocytes die within the thymus. Cells that do leave the thymus, go mainly to the T areas of lymph nodes, spleen and Peyer's patches. Migrants are extremely rare in bone marrow, gut and liver. Migration is about the same in neonates as in adults relative to the size of the thymus, but is considerably lower in older animals where it is only about 0.1% of thymocytes per day at the age of six months.
Dissociation between interferon production induced by phytohemagglutinin and concanavalin A in spleen cell cultures of nude mice
Authors: Kirchner Holger , Fenkl Herbert , Zawatzky Rainer , Engier Helmut , Becker Hans
Published: February 2007

Spleen cells of homozygous nude mice did not react with lymphoproliferation to both phytohemagglutinin (PHA) and concanavalin A (Con A), and there was no detectable interferon production in response to Con A. However, PHA‐induced interferon production was equal in spleen cells of nuinu mice and nu/+ mice. One possible explanation for these findings is that a subset of T cells responds to PHA with interferon production different from that responding to Con A with interferon production.
Presence of receptors for IgA on human T and non‐T lymphocytes
Authors: Sjöberg Olof
Published: February 2007

Latex particles coated with human IgA were used to detect the presence in human blood of lymphocytes capable of binding IgA. It was necessary to culture the lymphocytes in medium without IgA before the assay. A small percentage of both T and non‐T cells had IgA receptors. The receptors were distinct from those binding to IgG or IgM.
Antibodies to immunoglobulin heavy chain variable regions protect helper cells from specific suicide by radiolabeled antigen
Authors: Puri Joseph , Ben‐Neriah Yinon , Givol David , Lonai Peter
Published: February 2007

The antigen‐binding receptor of helper T cells was studied by radioactive antigen‐ caused suicide in vitro. Purified antibodies to immunoglobulin variable regions, obtained from sera of rabbits immunized with isolated VH and VL fragments of mouse myeloma proteins (MOPC 315, XRPC 25), were used to inhibit the binding of radiotoxic antigen. Anti‐VH, but not anti‐Vγ, or anti‐Vχ, inhibited suicide of carrier‐ primed cells.
The binding of soluble immune complexes of guinea pig IgG2 to homologous peritoneal macrophages Determination of the avidity constants at 4 °C.
Authors: Leslie Robert G. Q.
Published: February 2007

Soluble immune complexes of guinea pig IgG2 anti‐DNP (2,4‐dinitrophenyl) antibodies and DNP19BSA (bovine serum albumin) were prepared at a variety of antibody‐to‐antigen ratios. The mean sizes of the complexes were determined by gel filtration, and equilibrium binding of the complexes to homologous peritoneal macrophages was measured at 4°C. Scatchard plots of the binding data were linear indicating that the complexes were binding to a uniform population of functionally independent membrane receptors.

The avidity constants for complex binding to macrophages increased from 15.4 × 107 M−1 for complexes containing an average of two antibody molecules to 59.0 × 107 M−1 for complexes containing an average of four, compared with an association constant for monomeric IgG2 of 0.21 × 107 M−1. Calculation of the molar‐free energy changes accompanying monomer and immune complex binding revealed not only that the intrinsic binding activity of mononer was sufficient to account for the complex binding activities by simple cooperation of linked antibodies, but also that the cross‐ linking of antibodies with antigen imposed a strain on the antibody‐receptor interaction, resulting in complex binding energies that were lower than the values expected from a simple cooperative mechanism.

Complex inhibition by monomeric IgG2 of unrelated antibody specificity was studied, and it was observed that high concentrations of monomer led to an increase in macrophage discrimination between complexes of different size. The relevance of this finding to the in vivo clearance of circulating complexes is discussed.
Active and passive re‐expression of Fcγ receptors on human lymphocytes
Authors: Samarut Christiane , Revillard Jean‐Pierre
Published: February 2007

Modulation of receptors for IgG (FcγR) on human lymphocytes was induced by the interaction with erythrocyte‐IgG antibody (EAG) complexes followed by incubation at 37°C. The re‐expression of FcγR could be achieved by two independent processes, (a) Active synthesis, susceptible to inhibition by puromycin or cycloheximide was shown to peak 4 to 6 h after removal of EAG complexes; it required addition of at least 2% fetal calf serum. (b) Insertion of soluble FcγR into the membrane of modulated lymphocytes was shown to occur within 20 min of contact between cells and FcγR‐containing supernatants; it was not altered by protein synthesis inhibitors. FcγR‐like material, spontaneously released by unstimulated peripheral blood lymphocytes or by polymorphonuclear cells, was taken up by modulated lymphocytes. This soluble material was fully absorbed on polymerized human IgG; it was non‐ dialyzable, thermolabile (56 °C, 30 min) and partially destroyed by freezing and thawing; it was recovered as two broad peaks from chromatography on polyacrylamide gel; it was shown to bind to both T and non‐T FcγR‐bearing lymphocytes capable of forming EAG rosettes before modulation; and it could be inserted into allogeneic lymphocytes. These results demonstrate that the FcγR structure bears two active sites, one binding to the Fcγ and the other to the surface of EAG rosette‐forming cells. Rapid release of soluble FcγR from the cells and their possible insertion into the membrane may have important implications with respect to the biological functions associated with these receptors.
Multiple H‐2 and non‐H‐2 genes controlling the anti‐lysozyme response: Alternative gene constellations can lead to responsiveness
Authors: Hill Sharon W. , Kipp Dale E. , Melchers Inga , Frelinger Jeffrey A. , Sercarz Eli E.
Published: February 2007

Mice carrying the H‐Zb and H‐2s haplotypes are genetically nonresponsive to hen egg‐white lysozyme (HEL). Analysis of the anti‐HEL response patterns of F1, F2 and backcross progeny showed that responsiveness was dominant and H‐2‐linked. From plaque‐forming cell and serum assays in intra‐H‐2 recombinant mice, it was established that two I loci were implicated, the possession of either leading to responsiveness to HEL. One of the I genes maps in I‐A, and the second in I‐C, S or G. While the nonresponse phenotype was determined by the H‐2 haplotype, there were codominant non‐H‐2 genes which contributed to a severe reduction in the level of antibody produced in responder strains. A model is presented attributing the outcome of an encounter with HEL to the regulatory balance of helper and suppressor T cells, which have been activated by different subregions of the major histocompatibility complex.
Enhancement of the primary antibody response by 2‐mercaptoethanol is mediated by its action on glutathione in the serum
Authors: Hoffeld J. Terrell , Oppenheim Joost J.
Published: February 2007

2‐Mercaptoethanol (2‐ME) is widely used in rodent lymphoid cell cultures as an enhancer of multiple cellular functions. We have confirmed that the action of 2‐ME must be on a serum component(s), rather than a direct action on the cells. The serum component(s) is contained within the dialyzable fraction of fetal calf serum (FCS) since: (a) dialysis of FCS diminished the ability of FCS to support an antibody response even in the presence of 2‐ME; and (b) FCS dialysate, pulsed with 2‐ME, restored the ability of dialyzed FCS to support an antibody response. Diminution of the reduced glutathione content of FCS by heating reduced the capacity of FCS to support an antibody response, whereas addition of 2‐ME‐pulsed glutathione restored the supportive capacity of heated FCS. Conversely, oxidized glutathione inhibited the antibody response in the absence of 2‐ME, but that inhibition was not seen in the presence of 2‐ME. We have concluded that reduced glutathione is an essential component in FCS in order for 2‐ME to produce its enhancing effect. The most plausible explanation for the enhancement of antibody responses, in vitro, by 2‐ME is the concomitant reversal of the inhibitory effect of oxidized glutathione and the increased availability of reduced glutathione which can scavenge oxygen‐derived radicals, thus protecting macrophages and lymphocytes from the deleterious effects of oxygen‐derived free radicals.
Identification and partial characterization of surface antigens specific for human normal and leukemic T cells
Authors: Gross Nicole , Bron Claude
Published: February 2007

Rabbit antisera to membrane preparations of human thymocytes (anti‐HTLA), T lymphocytes of the MOLT 4 cell line or B lymphocytes of the LIK cell line, have been serologically characterized and used for the identification of surface membrane antigens specifically expressed by human lymphocyte subpopulations. By immunoprecipitation of surface 125I‐ or NaB (3H)4‐labeled protein followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis of the precipitates, the anti‐HTLA antiserum was shown to detect on thymocytes three glycoproteins of apparent molecular weights 160000, 110000 and 45000. The first two only appeared to be sialylated. A similar pattern of antigens could be detected on cultured T lymphocytes, except for the 45 kDalton glycoprotein which could not be detected on the surface of these cells. None of these proteins were detected on 125I‐labeled Raji cells. The serological specificity of the anti‐MOLT 4 antiserum for T lymphocytes was more restricted since it only precipitated the 160 kDalton antigen. In addition, the 45 kDalton protein was shown to be sensitive to trypsin treatment as was the sheep red blood cell (SRBC) receptor. The results shown suggest a possible activity as SRBC receptor for this particular protein. In contrast, the anti‐LIK antiserum which behaves as an anti‐HLA‐DR reagent in cytotoxicity testing, only precipitates from cultured B lymphocyte lysates the typical Ia‐like 28 and 33 kDalton polypeptides.
Studies on the mechanisms of macrophage activation. III. Investigations on the interaction of macrophage‐activating factor with the macrophage membrane
Authors: Buchmüller Yolande , Mauël Jacques
Published: February 2007

A macrophage‐activating factor (MAF), produced by concanavalin (Con A)‐stimulated spleen lymphocytes, was tested by its capacity to induce mouse peritoneal exudate macrophages to destroy the intracellular parasite Leishmania enriettii. MAF could be removed from active media by adsorption on macrophages at 37°C and 4°C; the adsorption was not specific, as cells from various origins could similarly be used to deplete supernatants of their activity. Treatment of macrophages with trypsin resulted in loss of response to MAF, presumably due to inactivation of a membrane receptor for the lymphokine. In addition, trypsin treatment of macrophages, following a 6‐h pulse, but not a 9‐h‐pulse, of MAF‐rich medium, inhibited activation suggesting that triggering of the biochemical processes of activation required interaction between macrophages and the lymphokine of sufficient duration, and that once these processes were initiated, parasite destruction could proceed to completion in the absence of further exogenous lymphokine. MAF activity was enhanced by treatment of macrophages with al‐antitrypsin suggesting a role for membrane‐associated serine esterases in modulating the cell response to the lymphokine. High concentrations of Con A also impaired MAF‐induced activation, presumably through binding of the lymphokine by the lectin.
Immunoglobulin M mutants
Authors: Köhler Georges , Shulman Marc J.
Published: February 2007

Mutants of a hybridoma line secreting IgM with anti‐trinitrophenyl specificity were enriched by coupling the hapten to the cell surface and incubating the cells in the presence of complement. In this way, cells secreting wild‐type Ig commit suicide, whereas cells secreting IgM with reduced lytic activity preferentially survive. Mutants have been isolated which showed no or reduced synthesis of either the heavy or the light chain of the IgM molecule, mutants with internal and carboxy‐terminal deletions of the μ chain, and a mutant with an electrophoretically silent change of the μ chain that reduces the affinity of the antibody for the hapten tenfold. The frequency of mutants in the original population was estimated to be about 10−4 to 10−5. All mutants were stable with reversion frequencies of about 10−5 or less.
Activation of complement, the induction of antibodies to the surface of nematodes and the effect of these factors and cells on worm survival in vitro
Authors: Mackenzie Charles D. , Jungery Michele , Taylor Patricia M. , Ogilvie Bridget M.
Published: February 2007

This report describes the effect on various stages in the life cycle of the nematodes T. spiralis and N. brasiliensis of complement, antibodies from rats infected with these parasites and several different cell types. The cuticle of the infective larvae and adult worms of both nematode species activates complement via the alternative pathway, but the cuticle of newborn T. spiralis lacks this property initially. As newborn larvae grow, however, the newly formed cuticle in the midregion of their body is able to activate complement. Rats infected with either nematode species produce antibodies to the cuticle of all life cycle stages which show marked specificity to each stage in the life cycle. Whereas the cuticle of T. spiralis reacts evenly over the entire surface both to complement and to antibodies, the reaction of the cuticle of N. brasiliensis to either reagent is patchy. Infective larvae of N. brasiliensis were killed in vitro in the presence of complement, by neutral red‐positive peritoneal macrophages which were nonadherent to plastic. The infective and newborn larvae of T. spiralis were killed by eosinophil‐enriched cell populations and antibodies. The speed of eosinophil killing of the T. spiralis larvae was enhanced when the serum was freshly collected and when the eosinophil suspension also contained neutral red‐positive nonadherent macrophages. Newborn larvae of T. spiralis and infective larvae of N. brasiliensis assumed a rigid appearance at death. Infective larvae of T. spiralis burst, extruding their internal organs through their cuticle weakened by antibodies and the cells.
Lymphoid stem cell homing to the early thymic primordium of the avian embryo
Authors: Jotereau Francine V. , Houssaint Elisabeth , Le Douarin Nicole M.
Published: February 2007

The quail‐chick marker system was used to investigate the mechanism of lymphoid precursor cells (LPC) homing to the early thymic rudiment during development of the avian embryo. Migration of LPC was demonstrated in vivo and in vitro from the yolk sac, spleen and bone marrow to the thymus rudiment at a definite period of the latter's ontogeny. Before and after this period, the thymic rudiment is nonreceptive for LPC. The onset of stem cell seeding depends on a stage‐dependent maturation of the thymic primordium while its arrest is regulated by the number of cells which have invaded the organ. An in vitro transfilter culture technique is described which permits LPC to be attracted to a thymic rudiment. The thymus at its physiological receptive period and several other organs were associated with LPC donors. The capacity of these various organs to induce LPC traffic was compared. It appeared that the “receptive” thymus is a much better “attractant” than the liver, the mesonephros or the already colonized thymic rudiment. The hypothesis of the production of a chemotactic factor responsible for LPC attraction by the thymus rudiment is proposed which accounts for experimental data reported in this article, as well as for the events of thymus ontogeny previously established.
Opposite effects of the synthetic adjuvant N‐acetyl‐muramyl‐L‐alanyl‐D‐isoglutamine on the immune response in mice depending on experimental conditions
Authors: Souvannavong Vongthip , Adam Arlette
Published: February 2007

The influence of N‐acetyl‐muramyl‐L‐alanyl‐D‐isoglutamine (muramyl dipeptide, MDP) on the plaque‐forming cell (PFC) response of mice to sheep red blood cells (SRBC) was studied. The effect of MDP depends on the relative doses of antigen and adjuvant and on the timing of adjuvant addition. For a given concentration of antigen, when SRBC and MDP were simultaneously injected in the i.v. route, MDP led to an enhancement of the response; in contrast, when antigen was injected i.p., a depression of the PFC response was observed. In vitro, the same duality of effect was obtained, for the same spleen cell concentration; addition of MDP led to a stimulation of the response when cultures were set in petri dishes and to an important decrease in the response when cultures were set up in plastic tubes. This inhibitory effect of MDP did not appear when it was added one night after the initiation of the cultures. These contrasting results confirm the adjuvant properties of MDP, but they show that under certain conditions, MDP can stimulate suppressive processes.
Regulation of the T15 idiotype‐positive, T‐independent immune response to Streptococcus pneumoniae R36 a(Pn). I. Specific suppressor T cells induced by Pn in vitro are antigen‐specific and idiotype‐positive
Authors: Cerny Jan , Caulfield Michael J. , Siat Maureen
Published: February 2007

Normal BALB/c spleen cells incubated for 2 days with Streptococcus pneumoniae R 36 a (Pn) vaccine in vitro acquired the specific ability to inhibit the T‐independent anti‐Pn response of fresh lymphocytes. The activated suppressor cells were susceptible to cytotoxic treatment with mouse anti‐theta serum plus complement, and they inhibited the anti‐Pn response of B lymphocytes deprived of T cells. The suppressive effect was eliminated by adsorbtion of cells on dishes coated with the C polysac‐charide from Pn, and treatment of the suppressor cells with a rabbit antibody specific for TEPC‐15 myeloma protein, in the presence of complement, abolished the suppressive effect. The results indicate that stimulation of lymphocytes with a T‐independent antigen in vitro activates suppressor T cells bearing a specific antigen receptor that may express the idiotype(s) characteristic of anti‐Pn antibody, and that these cells inhibit the Pn‐reactive B cells directly.