bluuebunny/crossref_metadata_2025 huggingface dataset:
The separation of sub‐populations of T and B lymphocytes
Authors: Shortman K. , Cerottini J.‐C. , Brunner K. T.
Published: February 2007

Lymphocytes from mouse spleen and mouse thymus were separated on the basis of buoyant density in continuous gradients of albumin. Density fractions were examined for their content of subclasses of lymphocytes, determined by the presence of specific cell surface antigens. Density distribution profiles were determined for each lymphocyte subclass. The following findings emerged:

A minor subpopulation of thymus cells, characterized by a relatively high level of H‐2 antigen and a low level of Θ antigen on the cell surface, and a relative resistance to corticosteroids, was markedly enriched in the light density regions of the gradient.

The B cell and T cell populations of spleen, determined by a cytotoxic assay with anti‐Θ antiserum, showed substantial density overlap, although limited regions enriched for either B cells or T cells were obtained.

There were substantial differences between mouse strains in the density characteristics of the individual lymphocyte classes.

Each antigenic type of lymphocyte showed pronounced density heterogeneity, with discrete peaks in the distribution profiles.

The density distribution of T cells in the spleen and in the thymus were similar.

The data could be explained by two separate but similar differentiation pathways for the two antigenic types of T cells. One pathway (“High H‐2 ‐ Low Θ”) commences in the thymus, but maturation to a typical dense, small lymphocyte is usually completed after emmigration to the periphery. A second pathway (“Low H‐2 ‐ High Θ”) involves similar differentiation stages, but is restricted to the thymus.
Inheritance of an idiotype associated with the immune response of inbred mice to phosphorylcholine
Authors: Sher A. , Cohn M.
Published: February 2007

Inbred mice immunized with the pneumococcal C carbohydrate produce plaque‐forming cells directed exclusively against the phosphorylcholine determinants of this antigen. The antibody responsible for plaque formation is of restricted heterogeneity with respect to its affinity for phosphorylcholine. Mouse anti‐serum directed against an idiotype shared by certain BALB/c anti‐phosphorylcholine plasmacytoma proteins specifically inhibits the formation of approximately 70% of the plaques induced by the C‐carbohydrate in BALB/c mice. The expression of this idiotype, as revealed by inhibition of plaque formation, occurs in the phosphorylcholine specific immune responses produced by mice of some inbred strains, but not of others, and shows dominant inheritance. By means of a backcross experiment, the inheritance of idiotype was shown to be determined by a gene linked to the chromosome carrying the mouse heavy chain allotype locus. In addition, the backcross data suggested the participation of a second, independently segregating gene in the determination of idiotype. Experiments with congenic mouse strains indicated that this second gene may be H‐2 linked. These observations support the hypothesis, suggested from studies on BALB/c plasmacytoma proteins, that the variable regions of mouse anti‐phosphorylcholine antibodies are specified by germ‐line genes.
Isolation of prekallikrein activator from guinea pig serum or plasma adsorbed to immune precipitates or celite: Possible relationship to Hageman factor
Authors: Treloar M. P. , Pyle H. , Özge‐Anwar A. H. , Takeuchi Y. , Movat H. Z.
Published: February 2007

Immune aggregates of bovine serum albumin (BSA) and rabbit anti‐BSA presumably adsorb Hageman factor (factor XII) and induce its conversion to prekallikrein activator (PKA), which can be eluted from the precipitates and purified by chromatography. No clotting studies could be done with the material desorbed from the immune aggregates incubated with serum, because thrombin was present in the preparations.

When Al(OH)3‐adsorbed plasma (free of prothrombin) was incubated with celite, large quantities of PKA were recovered in the celite eluates, together with activated factor XII (XIIa), activated factor XI (XIa) and kallikrein. These components could be separated by anion exchange chromatography and gel filtration. PKA had a molecular weight of approximately 31 000, 33 000 and 36 000 as determined by sucrose density gradient ultracentrifugation amino acid analysis and gel filtration, respectively; its sedimentation coefficient was 2.7 – 2.9; in fully activated form it migrated as a sharp prealbumin band by disc gel electrophoresis. The isoelectric point of PKA was approximately 4.4. The moderately anionic factor XIIa had an estimated molecular weight of 120 000. The cationic factor XIa and kallikrein were separated by gel filtration, the clot‐promoting substance having a molecular weight of 170 000 – 180 000, while kallikrein was found to be about 96 000. A kinin‐forming, BAEe‐hydrolysing fraction with an elution volume greater than that of egg albumin was recovered and it is assumed that it represents a fragment of kallikrein.

It is concluded that during massive surface adsorption, most of the adsorbed factor XIIa becomes fragmented. This fragment acquires prekallikrein‐activating activity. The fragment retains some of the property of the parent molecule by being able to partially correct the clotting defect of factor XII‐deficient plasma. These findings are in good agreement with those obtained under similar conditions with human plasma.
Induction of immunoglobulin and antibody synthesis in vitro by lipopolysaccharides
Authors: Anderson J. , Sjöberg O. , Moller G.
Published: February 2007

Lipopolysaccharides (LPS) from E. coli bacteria were found to be mitogenic for bone marrowderived (B) lymphocytes, but had no effect on thymusderived (T) lymphocytes. When added to normal spleen cells in culture, LPS selectively stimulated the secretion of 19 S proteins, whereas there was no demonstrable increase of 7 S protein synthesis. Spleen cell cultures treated with various doses of LPS exhibited atypical dose response curve with regard to induction of DNA synthesis, 10 μg/ml being optimal, higher and lower concentrations giving lower responses. When direct antibody producing cells to horse and sheep red cells were studied in normal spleen cell cultures exposed to different concentrations of LPS in vitro, it was found that their number increased in parallel with stimulation of DNA synthesis. In contrast, the number of antibody producing cells to LPS itself did not parallel activation of DNA synthesis. Spleen cells from LPS tolerant animals responded with increased numbers of antibody producing cells to heterologous red cells after treatment with LPS in vitro to the same extent as normal spleen cells.

Thus, a B cell mitogen, such as LPS, could activate division in B cells, resulting in an increased number of cells producing antibodies to non‐cross‐reacting antigens, mimicing the effect of specific antigen.
Specificity of antigen recognition by normal thymus cells in nude mice
Authors: Kindred Berenice
Published: February 2007

If injected with normal thymus cells from BALB/c or BALB/c‐Igb, nude mice from a stock which is partially backcrossed to BALB/c make antibodies to many antigens to which untreated nude mice do not respond. Anti‐Igb can be made if the thymus donor is BALB/c, but not if the thymus donor is BALB/c‐Igb. If cells from both donor strains are injected, a response is obtained which shows that the unresponsiveness of recipients of BALB/c‐Igb cells is not due to tolerance of donor antigens.
Thoracic duct lymphocytes from nude mice: Migratory properties and life‐span
Authors: Sprent J. , Miller J. F. A. P.
Published: February 2007

The thoracic duct lymphocyte (TDL) output from nude mice was 5–6 times lower than that from CBA mice during the first 24 h of drainage. Labeled TDL from nude mice (a virtually pure population of B cells) and from CBA mice (containing about 85 % T cells and 15 % B cells) were injected into nude and CBA recipients, respectively, in which thoracic duct fistulas had been established. The recovery of labeled cells in the lymph was 40 – 70 % for CBA TDL was studied and the results suggested that B cells homed predominanlty to the spleen and tended to remain there, whereas those T cells that had a much slower tempo than can T cells. The homing of 51Cr‐labeled nude and CBA TDL was studied and the results suggested that B cells homed predominanlty to the spleen and tended to remain there, whereas those T cells that had initially lodged in the spleen subsequently migrated to the lymph nodes. There was a linear relationship between the appearance of labeled cells in the lymph and the period of time during which tritiated thymidine had been administered thrice daily to nude and to CBA mice. It could be calculated from the curves obtained in these mice that the potential average life‐span of B cells was of the order of 8 weeks and of T cells of 16 weeks.
Antigenic properties of a water soluble fraction of sheep erythrocytes
Authors: Seman M. , Mazié J. C. , Bussard A. E.
Published: February 2007

A technique for preparing soluble extracts of sheep erythrocytes is described. A fraction thereof is fully immunogenic and inhibits antibody formed by spleen cells from only those mice immunized with sheep red blood cells, but not from those which received extracts of horse red blood cells.

The specificity of this fraction varies from one sheep to another.
Structure of the lymphocyte membrane. II. Evidence of two classes of Ig on the surface of rabbit lymphocytes during primary response to sheep red blood cells using inhibition of rosette‐forming cells and combined ultrastructural autoradiographic and peroxydase methods
Authors: Bona C. A. , Trebiciavsky I. , Anteunis Anny , Heuclin C. , Robineaux R.
Published: February 2007

The evolution of immunoglobulin receptors at the surface of spleen rabbit lymphocytes during the primary response to sheep red blood cells (SRBC) was investigated.

Using inhibition of rosette‐forming cells (RFC) by specific anti‐rabbit immunoglobulin sera and a combined ultrastructural autoradiographic and immunocytochemical method, two classes of immunoglobulins have been found on the surface of the same cell during the early phase of primary response to SRBC.

Anti‐immunoglobulin sera did not show any additive effects on inhibition of non‐immunized and 7‐day RFC. Using a combined ultrastructural method, cells never displayed more than one label on their surfaces.
Studies on the mechanism of antigenic competition: Analysis of competition between synthetic polypeptide antigens
Authors: Tassig M. J. , Mozes Edna , Shearer G. M. , Sela M.
Published: February 2007

Antigenic competition has been studied in C3H/HeJ mice between determinants of the multichain synthetic polypeptide antigens, (Phe, G)‐A–L, (T, G)‐Pro–L and (Phe, G)‐Pro–L. Since these mice did not respond detectably to (T, G) and only very weakly to A–L, the relevant immunopotent regions involved were Pro – L and (Phe, G). Thus, these animals generated a good response to the (Phe, G) determinant, when given as (Phe, G)‐A–L, and a good response to Pro – L, when administered either as such or as (T, G)‐Pro–L. However, when the immunogen was (Phe, G)‐Pro–L, the antibody response was mainly towards Pro–L, whereas a very poor response was obtained to the (Phe, G) specificity. This is interpreted as antigenic competition between Pro–L and (Phe, G), with Pro–L the dominant and (Phe, G) the suppressed determinant.

Competition was also demonstrated with mixtures of (T, G)‐Pro–L and (Phe, G)‐A–L. Competition with the mixed antigens was dependent on the relative amounts of the immunogens in the mixtures. Thus, a molar excess of (T, G)‐Pro–L over (Phe, G)‐A–L of 5 to 1 suppressed the response to (Phe, G), but an excess of (Phe, G)‐A–L of 5 to 1 suppressed the of 25 to 1 caused suppression of the anti‐Pro–L response. With equimolar mixtures, an optimal primary response to both (Phe, C) and Pro–L was observed. Where competition had occurred in the primary response, no priming was detected for a secondary response. Under certain conditions immunological memory could be suppressed by competition even though an apparently normal primary response had occurred, suggesting that memory is more susceptible to suppression by competition than is the primary response.

The ability of an excess of (Phe, G)‐A–L to suppress the response to Pro–L could be reproduced completely with A–L alone. Thus, a molecule that is very poorly immunogenic, but which functions as a carrier for haptens, can be successful in competition.
The detection of Θ antigen on cells by immunofluorescence: Failure to detect Θ antigen on rosette‐forming cells
Authors: Russell S. M. , Ferrarini M. , Munro A. , Lachmann P. J.
Published: February 2007

A technique is described which is capable of detecting Θ antigen on the surface of lymphoid cells. It utilizes the fixation of C6 deficient rabbit complement, the fixed C3 being detected by means of anti‐C3 serum conjugated with fluorochrome.

In an attempt to demonstrate antigen‐binding cells of thymic origin, the technique has been combined with the suspension‐centrifugation technique for rosette formation. This system gives no evidence for the existence of thymusderived rosette‐forming cells.
The effect of thymectomy and anti‐thymocyte serum on the immunological competence of adult mice
Authors: Ströbel G.
Published: February 2007

The immune response of normal mice, adult thymectomized mice, micetreated with anti‐thymocyte serum and ice which were treated with antithymocyte serum (ATS) after hymectomy were studied for their response to tobacco mosaic virus (TMV) as antigen, 52, 84 and 316 days after the beginning of treatment. Adult mice, treated after thymectomy with ATS, failed to produce detectable antibodies to TMV. The role of the thymus in the adult mouse in the immune response to a thymus‐dependent antigen is discussed.
The restriction of the release of migration inhibitory factor to certain phases of the cell cycle of murine leukemia, L1210
Authors: Thomas D. B.
Published: February 2007

Migration inhibitory factor (MIF) activity has been detected in the culture media of the murine cell lines L1210 and P815Y. Cell cultures were synchronized by excess thymidine in order to study the relationship between MIF production and DNA synthesis. Inhibitory activity could be detected only in synchronous cultures of L 12 10 cells; the release of MlF was restricted to a discrete phase of the cell cycle.

The presence of surface immunoglobulin and absence of the Θ‐isoantigen on L1210 cells suggest that this cell line is derived from a “B” lymphocyte precursor.
Amplification of B cell clones forming antibody to the 2,4‐dinitrophenyl group
Authors: Askonas Brigitte A. , Cunningham A. J. , Kreth H. W. , Roelants G. E. , Williamson A. R.
Published: February 2007

The selection of several single cell clones forming anti‐2,4‐dinitrophenyl (DNP) antibody in mice enabled us to study the life span of B memory cells, and to estimate the number of DNP‐binding cells belonging to a single clone, as well as their amplification into anti‐DNP plaque‐forming cells.

B memory cells belonging to clone E9 were found to survive for several weeks in the absence of antigen. Memory cells for this clone were transferred into recipient mice; antigen challenge after 2 or 4 weeks led to E9 anti‐DNP formation at the same or half the level resulting from immediate antigen challenge.

DNP‐binding cells were labeled with 125I‐DNP on a heterologous carrier protein (Maia Squinudo hemocyanin); for 3 different DNP‐clones the incidence of DNP‐binding cells in spleen (2nd transfer generation, 8 weeks after cell transfer) was 1000 – 1900 per 106 cells. This compares with 900/106 spleen cells in a multiclonal mouse primed with DNP‐ovalbumin; a proportion of these cells may represent T cells with specificity for DNP.

Anti‐DNP‐forming cells in spleens of irradiated mice, receiving clonal memory cells and antigen, appeared after a lag of 4 – 5 days, reached a peak of 12000 – 18000 PFC between day 8 and 11 and then declined rapidly despite continued high levels of antibody production in recipient mice; this suggests antibody formation at sites other than spleen. The data are consistent with around 1 % effective homing of B precursor cells in spleen.
Antisera against recognition sites. Lack of effect on the mixed leukocyte culture interaction
Authors: Lindahl Kinten Fischer
Published: February 2007

Antisera against receptors for histocompatibility antigens, known to block antigenic recognition in the product of antigenic recognition‐(PAR) assay described by Ramseier, have been tested in mixed leukocyte culture (MLC). The MLC response was not affected, indicating that the T cell receptor is not blocked by such sera.
The lipid A immunity system. I. Induction of heterophile antibodies by enterobacterial lipopolysaccharides and their lipid A component
Authors: Rank W.‐R. , Dipauli R. , Flügge‐Rank U.
Published: February 2007

Mice were immunized either with lipopolysaccharides (LPS) or with the respective lipid A components. After four days an increase in the number of direct plaque‐forming cells with complement‐dependent antibody against sheep red cells was seen. Cross‐reactions were observed with red cells of cattle, goats, horses and rabbits. All LPS investigated, of Shigella, Escherichia coli, and S and R form Salmonella, as well as the lipid A component evoked this immune response. We therefore conclude that all enterobacterial LPS induce an antibody which cross‐reacts with SRC and that the lipid A component is responsible for this reaction. Evidence is presented that these effects, such as toxicity, fever, pyrogen tolerance, leucopenia/leucocytosis, nonspecific immunity, and tumor inhibition are mediated by lipid A‐induced antibodies.
The immune response to phage fd in normal and thymus‐deprived animals of a low responding inbred strain and in genetically thymusless mice
Authors: Kölsch E. , Davies A. J. S. , Leuchars Elizabeth
Published: February 2007

Thymus‐deprived and normal DBA/2 mice show no difference in the immune response to bacteriophage fd, an antigen for which these mice are low responders. Thymectomy in high responders reduces the response 100–1000‐fold. The immune response to SRBC in the deprived and normal DBA/2 has also been tested. The drastically reduced response in deprived mice shows that these animals indeed lack thymic influence.

Low responder DBA/2 mice have a weak primary and secondary response to the phage fd. They largely produce IgM, but in spite of that, they are able to build up an immunological memory. The data suggest that the inability of DBA/2 mice to respond well to fd is a thymus deficiency. This observation is supported by the finding that polyacrylic acid converts low responder DBA/2 mice to high responders. Genetically thymusless (nude) C57BL/6‐nu/nu mice are low responders, but, in contrast to DBA/2, are unable to form an immunological memory. The secondary response is identical in height and rate with a primary response.
Cooperation of antigenic determinants in intact mice and interference by antigenic competition
Authors: Taussig M. J. , Mozes Edna , Shearer G. M. , Sela M.
Published: February 2007

Cooperation between two immunopotent regions (Phe, G) and Pro‐L, of a synthetic polypeptide, multichain (Phe, G)‐Pro‐L, in a secondary response in intact mice 1s described. (Phe, C) behaves as a haptenic group for which the multichain polypeptides, Pro‐L and A‐L, act as carriers. When C3H/HeJ mice were primed with (Phe, G)‐A‐L and challenged with (Phe, G)‐Pro‐L, a strong carrier effect could be demonstrated, 2.e. the response to (Phe, G) was very poor compared with that obtained upon secondary challenge with (Phe, G)‐A‐L. Since (Phe, G) is larger than the known size of an antibody combining site, this result argues against a local environment contribution to the carrier effect. Mice received, primary inoculation with mixtures of (Phe, G)‐A‐L and (T, G)‐Pro‐L in various molar ratios and then were boosted with (Phe, G)‐Pro‐L. Cooperation in the secondary response was obtained in some cases, as judged by the enhanced anti‐(Phe, G) titers, compared with mice primed with (Phe, G)‐A‐L alone, after challenge with (Phe, G)‐Pro‐L. However, the molar ratio of (T, G)‐Pro‐L/(Phe, C)‐A‐L in the primary immunization was found to be a critical factor, a priming ratio of 1/5 being optimal. With other priming ratios, no cooperation could be demonstrated in the secondary response. This was shown to be due to antigenic competition between (Phe, G) and Pro–L in the primary response, which reduced the degree of priming or memory for the secondary response to either the haptenic or carrier determinants, Thus, antigenic competition may be an important factor to be considered in the design of experiments to investigate cooperation of antigenic determinants.
A new method to measure the specific cellular component of a delayed hypersensitivity response in the ear of the mouse
Authors: Sabolovic D. , Beugnot Marie‐Chantal , Dumont F. , Bujadoux Madeleine
Published: February 2007

We here describe a simple method of measuring a pure cellular reaction in the mouse.

Mice were challenged at the ear pinna to detect a cell population labeled in vivo with [3 H]thymidine. The reaction was found to be specific, radiosensitive and thymus‐dependent.
The immune response against hapten‐autologous protein conjugates in the mouse. I. Specificity of antibodies produced during the primary response against dinitrophenylated mouse serum albumin
Authors: Rubin B.
Published: February 2007

The primary immune response to dinitrophenylated mouse serum albumin (DNP8MSA, DNP32MSA) and dinitrophenylated bovine γ‐globulin (DNP12BGG) was investigated in different mouse strains. It was found that DNP12BGG elicits specific antibodies against 1) DNP, 2) new antigenic determinants (NAD) introduced by the hapten coupling reaction and 3) BGG. DNP8MSA induces specific antibodies against 1) DNP and 2) NAD, and DNP32MSA induces anti‐DNP antibodies only. Further evidence for regarding the haptenic groups and the NAD as distinct antigenic specificities was obtained in mice high or low responders to the haptens. These mice respond equally well to the NAD.

The amount, class distribution and avidity of antibodies produced against DNP8MSA, DNP32MSA and DNP12BGG were studied and the results will be discussed in relation to the cooperation hypothesis.
Nature of anti‐hapten antibodies arising after immune suppression of a set of cross‐reactive idiotypic specificities
Authors: Hart D. A. , Pawlak Laura L. , Nisonoff A.
Published: February 2007

Anti‐p‐azophenylarsonate (anti‐Ar) antibodies arising in strain A mice immunized with keyhole limpet hemocyanin‐Ar have previously been shown to exhibit strong idiotypic cross‐reactions. The appearance of the cross‐reacting idiotype is suppressed by prior administration of antiidiotypic antibody, but a high titer of anti‐Ar antibodies lacking the idiotype is produced in response to the antigen. The present studies indicate that these antibodies do not share idiotype with anti‐Ar antibodies arising in other suppressed or nonsuppressed mice of the same strain. Strain A mice therefore produce at least 2 populations of anti‐Ar antibodies, one showing intrastrain cross‐reactions and the other being unique to each mouse. The results emphasize the great diversity of anti‐hapten antibodies produced within an inbred strain.

Suppression persisted when 9 weeks were permitted to elapse between administration of antiidiotypic antibody and the first challenge with antigen. This gives further evidence that suppression takes place at a central level and not through simple neutralization by antiidiotypic antibody of anti‐Ar antibodies bearing the cross‐reactive idiotype. Suppression of idiotype is maintained for a total of at least 5 months.
Studies on antibody affinity in mice
Authors: Huchet R. , Feldman Marc
Published: February 2007

The plaque inhibition method of measuring the affinity of single antibody‐forming cells (AFC) developed by Andersson has been modified for use with haptens. Using this method, it was possible to make simultaneous determinations of the relative affinities of IgG and IgM plaques during the primary and secondary responses.

It was shown that there was no maturation of the affinity of antibody‐released IgM AFC in the primary response in mice. There was an increase in affinity of the antibody released from IgG AFC, which was antigen dose‐ and time‐dependent, confirming results obtained by others. Furthermore, at any time during the course of the primary response, the affinity of the IgM antibody released by AFC was always lower than that of IgG plaque‐forming cells. This difference averaged about 10‐fold.

The same factors were shown to influence the affinity changes of IgG AFC observed during the secondary response. In addition the booster, or secondary dose of antigen used, was important. Highest affinity antibody was produced in response to intermediate antigen doses. The maturation of affinity affects the generation of memory cells to the same degree as the antibody‐secreting cells during the primary response, since similar affinity changes occurred in the absence of detectable primary responses.

Finally, when the period between primary stimulation and challenge is 5 months, there is a decrease of between 2 and 2.6 log10 in the concentrations of DNP lysine needed to inhibit 50 % of the IgG antibody‐forming cells depending on the doses used for priming. The variation of affinity of IgM antibody was much less obvious, with a 6‐fold difference at the maximum, which was independent of the doses of antigen used for priming or boosting, and of the time elapsed between the two antigenic stimuli.
Macrophage cytotoxicity factor. A product of in vitro sensitized thymus‐dependent cells
Authors: Lohmann‐Matthes Marie‐Luise , Ziegler F. G. , Fischer H.
Published: February 2007

Peritoneal mouse macrophages are rendered specifically cytotoxic to allogeneic target cells by a cell‐free filtered supernatant from in vivo sensitized spleen cells. Pretreatment of sensitized spleen cells with anti‐θ serum and complement completely abolishes secretion of the supernatant factor. The factor can also be induced by in vitro sensitization of mouse spleen cells to alloantigens. Furthermore, a cortisone‐resistant population of pure thymocytes can be sensitized in vitro and induced to liberate the factor. The macrophage cytotoxicity factor is only effective if bound to macrophages and can be transferred to iso‐ and allogeneic macrophages without loss of activity.
The occurrence of spontaneous rosette‐forming cells in the chicken bursa of Fabricius and spleen
Authors: Bäck R. , Alm G. V.
Published: February 2007

The bursa of Fabricius of non‐immunized chickens contained a significant number of cells forming rosettes (RFC) with sheep red blood cells. A considerably smaller number was found in the spleen. Spontaneous RFC may develop in the bursa and emigrate to peripheral lymphoid tissue.
Allotype‐specific anti‐autoantibody activity in tetraparental NZB mice
Authors: Barnes R. D. , Tuffrey Maureen
Published: February 2007

Evidence has favored graft‐versus‐host activity in hitherto assumed tolerant tetraparental NZB ↔ CFW chimeras. The events in this situation appear to be twofold. A primary NZB autoantibody occurs and is followed by secondary CFW allotype anti‐NZB autoantibody activity. Adherence and phagocytosis of Combs'‐coated red cells by primitive lympho‐monocytoid cells in these chimeras has been considered secondary and to reflect this anti‐autoantibody activity. Furthermore, phagocytosis of plasma cells suggest that this receptor determinant reaction might also be responsible for the “normal” elimination of aberrant autoimmune clones.
Characterization of thymus‐derived and bone marrow‐derived rosette‐forming lymphocytes
Authors: Elliott B. E. , Haskill J. S.
Published: February 2007

An improved technique has been developed to accurately quantitate lymphoid rosette‐forming cells (RFC) and to assess the morphology and antigen‐binding ability of each RFC. Two essential features were involved. First, rosettes were fixed with glutaraldehyde (a concentration of 0.6 % minimized the formation of artefacts). This fixation prevented dissociation of rosettes; RFC of weak antigen‐binding ability could therefore consistently be preserved. Second, rosette preparations were stained, thus permitting morphological classification of RFC and the elimination of false rosettes. The antigen‐binding ability of each RFC was determined by the number of sheep red blood cells (SRBC) bound. By this technique, thymus‐derived (T) RFC were found to bind fewer erythrocytes than bone marrow‐derived (B) RFC. Pretreatment of the SRBC with neuraminidase increased the SRBC‐binding ability of B RFC, thus making the latter readily distinguishable from T RFC. Functionally different subpopulations of T and B RFC were suggested.
Immunodeviation by passive antibody, an expression of selective immunodepression. I. Action of guinea pig IgG1 and IgG2 anti‐hapten antibodies
Authors: Vuagnat P. , Neveu Thérèse , Voisin G. A.
Published: February 2007

The effect of passively administered anti‐2,4‐dinitrophenyl (DNP) IgG1 and IgG2 antibodies on their own production has been studied.

Guinea pigs were immunized with immune complexes emulsified in complete Freund's adjuvant. These complexes were made at 4 times equivalence with IgG1 and/or IgG2 anti‐DNP antibodies having the same affinity. Humoral IgG1 and IgG2 anti‐DNP antibody contents were assayed at weekly intervals, and 4 and 10 days after a booster injection of antigen in saline given on the 12th week.

Active anti‐DNP IgG2 antibody production is strongly inhibited by passive IgG2, IgG1 and F(ab')2 antibody fragments.

Active anti‐DNP IgG1 antibody production of the same animals is inhibited by passive IgG2 and F(ab')2, to an extent similar to active IgG2 antibody inhibition, but the response after boosting is normal. On the other hand, passive IgG1 antibodies lead to a delayed enhanced active IgG1 antibody response.

The effect of a 1 : 1 mixture of both passive antibody classes is intermediate to what is observed with either class alone.

These differential effects according to the class (i.e. the Fc fragment) of the passive antibodies used show the importance of immune complexes in not only the quantitative, but also the qualitative, regulation of the immune response.
Synthesis of DNA by the spleens of germ‐free mice during the primary response to sheep red cells
Authors: Harris G. , Pelc S. R. , Blackmore D. K.
Published: February 2007

The mitotic activity of the spleens of non‐immunized germ‐free (GF) mice was less than in similar specific pathogen‐free (SPF) animals. No evidence of germinal center activity was noted in these GF mouse spleens before challenge with sheep erythrocytes (SRC). These centers only began to develop 4 days after immunization and were not fully developed before 8 days. In control SPF mice, the spleens showed very few germinal centers which were small in size, but they showed the same pattern of evolution as in similarly immunized GF mice.

The changes in the red pulp, characterized by the development of clusters of nuclei labeled with [3H]thymidine, followed closely the development of plaqueforming cells (PFC). The numbers of direct PFC reached the same peak level in GF and SPF mice on day 4 of the response to SRC, but were not so well sustained in the former animals after this time. Indirect PFC were much lower in the spleens of GF mice than in SPF animals.

The pattern and degree of increase of DNA synthesis in the spleen of GF and SPF mice following immunization with SRC differed from and was less than that of mice reared in less clean conditions. Increased DNA synthesis occurred very soon after injection of SRC (6 to 24 h) and the increase was sustained for 4 days without further significant rise and then declined.

Autoradiographs of the spleen of immunized GF mice given [3H]thymidine showed that the first increase of labeled nuclei in the white pulp occurred around the central arterioles as early as 6 h after SRC. This was followed by increased labeling in the mantle layer of the white pulp and the characteristic pattern of germinal center labeling developed after 4 days. Increased labeling of nuclei developed in the red pulp as early as in the white pulp, while the subcapsular and trabecular areas showed high labeling indices even in the spleens of non‐immunized controls.

The ratio of labeling index/mitotic index which is governed by the respective durations of DNA synthesis and mitosis in those cells in division cycle, varied between 10 and 280 in different areas of the spleen. This indicated a vast excess of cells synthesising DNA in relation to the numbers of dividing cells actually present in the spleens of these mice.
Direct cell contact is required in the syngeneic mixed lymphocyte reaction
Authors: Von Boehmer H.
Published: February 2007

A positive syngeneic mixed lymphocyte reaction can be observed by culturing neonatal thymus cells with syngeneic Mitomycin C‐treated spleen cells. Evidence that direct cell contact between the reacting thymus cells and the stimulating spleen cells is required was obtained by the following experiments. Supernatants from spleen cells prepared after different times of culture failed completely to stimulate syngeneic thymus cells. Stimulation was not transmitted in a double chamber system where thymus cells and spleen cells were separated by a nucleopore membrane (pore size 0.22 μ).

Fetal calf serum was not required in the culture medium to obtain a positive syngeneic and allogeneic mixed lymphocyte reaction, indicating that foreign protein does not influence the reaction.
The appearance of migration inhibition factor and a mitogen in lymph draining tuberculin reactions
Authors: Hay J. B. , Lachmann P. J. , Trnka Z.
Published: February 2007

The tuberculin reaction in the skin of sheep was accompanied by greatly increased traffic of mononuclear cells through both the lesion and through regional lymph nodes, as well as the appearance of basophilic cells in the lymph. Changes in vascular permeability were also evident and two, apparently distinct, biologically active materials appeared in the lymph plasma. The first of these materials inhibited the migration of guinea pig macrophages in a conventional migration inhibition factor (MIF) test. This material was evident within a few hours; the strongest activity appeared at about 24 h. Normal lymph and serum or lymph and serum from BCG‐sensitive sheep did not contain this material in detectable amounts. The second material that appeared in the lymph increased the DNA synthesis of normal lymphocyte cultures.
Influence of antigenic stimulation on lymphoid cell traffic in the chicken
Authors: Bäck R. , Linna T. J.
Published: February 2007

The influence of one intravenous injection of human serum albumin (HSA) on the pattern of cell migration from the bursa of Fabricius was studied in six‐week old chickens. The bursa was labeled in situ with ['Hlthymidine 24 h after either HSA o r saline administration. Forty‐eight hours following local labeling of the bursa, the chickens were killed and the transport of label to other lymphoid organs studied with a radiochemical method, based on measurements of tritium in DNA of the different organs, and with autoradiography. The radiochemical method revealed a significantly increased proportion of bursa‐derived label in the spleen of the immunized chickens. This was associated with an increased number of heavily labeled bursa‐derived cells in the autoradiograms from the same organ. The majority of the bursa emigrant cells in the spleen were localized in the red pulp, particularly in clusters of pyroninophilic cells. Their topographical distribution was not apparently influenced by the immunization. It is suggested that the increased homing of bursa‐derived cells to the spleen may reflect a recruitment of antibody‐forming cell precursors.
Fine structure of receptors for H‐2 antigenic specificities as measured in the PAR assay
Authors: Ramseier H.
Published: February 2007

Recognition of a distinct antigenic specificity, H‐2 transplantation antigen 32, could be demonstrated in a congenic strain of mice, using the PAR test. In another congenic strain of mice, recognition of a group of 15 such H‐2 specificities was demonstrated. Both recognition processes could be blocked either by treating target cells, representing the appropriate antigens, with corresponding alloantisera or by treating aggressor cells, carrying receptors for these antigens, with the appropriate anti‐receptor (anti‐RS) antibodies. Antigens recognized in the two strain combinations were of different H‐2 specificities. No cross‐reactivity of inhibitory antisera was found. This indicates that lymphoid cells possess highly specialized receptors which enable competent cells to recognize individual antigenic specificities.
Graft‐versus‐host response induced in vitro by mouse yolk sac cells
Authors: Hofman Florence , Globerson Amiela
Published: February 2007

Mouse yolk sac cells at the 9th day of gestation were found capable of eliciting, in vitro, a graft‐versus‐host response manifested in splenomegaly. Reactivity of 5 x 104 and 1 x 105 yolk sac cells was greater than that of adult spleen cells tested at the same concentrations. It seems that the immune potential of yolk sac cells at this stage of development is higher than that of the adult spleens.
J‐chain determinants in polymeric immunoglobulins
Authors: Kobayashi K. , Vaerman J.‐P. , Heremans J. F.
Published: February 2007

An antiserum was raised against purified J‐chain from S‐sulfonated human secretory IgA and was tested for its reactivity with secretory IgA, polymeric myeloma proteins of IgA1 and IgA2 subclasses and a Waldenström IgM macroglobulin. The antiserum, which was absorbed with normal human IgG and L‐chains, developed a single precipitin line with the following S‐sulfonated proteins: purified J‐chain, secretory IgA, polymeric IgA1, and IgA2, and IgM. The antiserum also reacted with the same proteins after complete reduction and alkylation. The antiserum did not precipitate the same polymeric immunoglobulins in their native states. At high concentrations, however, native polymeric serum IgA and IgM inhibited the precipitin reaction between the purified J‐chain and its antibodies. In contrast, native secretory IgA displayed no inhibition in this system. After treatment of these immunoglobulins with 8 M urea, 5 M guanidine, or 1 M propionic acid, the J‐chain determinants became accessible and were precipitated with the anti‐J‐chain antiserum, with the exception of IgM which displayed very weak reactivity only after exposure to 5 M guanidine. In conclusion, J‐chain determinants are accessible only to a very limited extent in native serum polymeric IgA and IgM, and none are detectable in the native secretory IgA. Most of the determinants become easily available by mere denaturation of these immunoglobulins with exposure to several kinds of dissociating agents.
Allotypic determinants on the surface of rosette‐forming cells in the rabbit
Authors: Ferrarini M. , Kent S. P. , Munro A. , Kelus A. S. , Catty D. , Coombs R. R. A.
Published: February 2007

Antigen‐binding cells to sheep erythrocytes from non‐injected rabbits and from rabbits after a single injection of sheep red blood cells (SRBC) have been detected by the immunocyto‐adherence technique (rosette formation). The expression of immunoglobulin allotypic determinants on these antigen‐binding cells has been investigated by inhibition of rosette formation with anti‐allotype antisera.

The results indicate that a and b locus allotypes are expressed by the great majority of rosette‐forming cells (RFC) in the lymph nodes of injected and non‐injected rabbits. Ms3 allotype is expressed by practically all RFC from non‐injected rabbits, while, after injection of SRBC, a population of RFC appears, which does not express this allotype. An antiserum to d 11 consistently failed to inhibit RFC.

Pretreatment of lymphocytes from rabbits heterozygous at the b locus with antiserum to only one allelic product produced an inhibition of rosette formation which was approximately half that obtained when antiglobulin reagents to both allelic products were added. The results suggest that in heterozygous animals, the two allelic markers are expressed on two different populations of antigen‐binding cells.

Electron microscopy studies on the morphology of RFC showed that the majority of the RFC were formed around small lymphocytes.
Ontogeny of the murine immune system: development of antigen recognition and immune responsiveness
Authors: Yung Lily L. L. , Cheryl Wyn‐Evans T. , Diener E.
Published: February 2007

The grafting of a single spleen colony obtained from irradiated mice protected with 12‐day fetal liver will reconstitute the lymphopoietic and erythropoietic system of irradiation‐deprived syngeneic recipients. Using this experimental model, the early events during the ontogenic development of the immune system were studied in CBA mice. Cells capable of binding radio‐iodine labeled S. adelaide polymerized flagellin were first detectable after 18 to 20 days of lymphopoiesis starting from presumably a single stem cell. However, antibody‐forming cell production after immunization against the same antigen was not demonstrable until days 19 to 26. The same sequential development of antigen recognition (by rosette formation) followed by immune reactivity was observed for sheep red cell antigens, both events occurring later than those for POL. Our observed requirement for the ontogeny of an antigen‐recognition spectrum is compatible with Jerne's theory on the generation of antibody diversity.
Biosynthesis and assembly of IgM. Free thiol groups present on the intracellular subunits
Authors: Stott D. I. , Feinstein A.
Published: February 2007

We have studied the biosynthesis of IgM and its subunits, and the role played by the thiol groups of these subunits in the assembly of the IgM molecule using mouse plasma cell tumor MOPC 104E. In addition to 19 S IgM and light chain, the tumor secretes a small amount of 7 S IgM (IgMs), whereas the cells contain light chain, an HL subunit, IgMs and only a small amount of 19 S IgM. Although the light chain monomers excreted in the urine have blocked thiol groups, the light chain monomers inside the cell and freshly secreted from it have one free thiol group per polypeptide chain. Both the intracellular IgMs and HL subunits also carry free thiol groups, the evidence indicating that there are four per intracellular IgMs subunit. Since there is some evidence that the cysteine residues involved in the formation of the intersubunit bridges may not be free, the polymerization of IgMs to 19 S IgM may be initiated by a rearrangement of thiol groups.
Original antigenic sin at the cellular level. II. Specificity of the antibodies produced by individual cells
Authors: Deutsch Sylvia , Vinit Marie‐Antoinette , Bussard A. E.
Published: February 2007

Original antigenic sin has been studied at the cell level with mice given a primary injection of meta‐aminobenzoic acid (mB) (coupled to human IgG) and a secondary injection of meta‐sulfanilic acid (mS) (coupled to human IgG), or the reverse. Spleen cell activity against red cells coupled to these haptens was measured by the local hemolysis technique. In order to distinguish between mB specific cells, mS specific cells and cells forming antibodies to both, two procedures were developed:

mB was added in the test medium in order to compete with anti‐mB antibodies and inhibit mB plaques.

Two different types of red cells, pigeon and sheep red blood cells, were coated either with mB or with mS, providing a means of distinguishing three types of plaques: anti‐mS only, anti‐mB only and anti‐mS‐anti‐mB. Both procedures showed that cells specific for the primary hapten only are stimulated by the heterologous booster in the two reciprocal situations. These results are discussed in relation to the specificity of receptors and antibodies and to their affinities towards haptens.
Urinary IgE: a reappraisal
Authors: Stokes C. R. , Hosking C. S. , Turner M. W. , Johansson S. G. O.
Published: February 2007

Evidence is presented that previously reported values for urinary IgE were overestimations. This probably arose from nonspecific inhibition in the radioimmunoassay procedure. Gel filtration chromatography suggests that IgE occurs in normal urine as an intact molecule, but at a considerably lower concentration than previously thought.
In vitro primary response in microcultures containing less than fifty thousand lymphoid cells
Authors: Jonard J. , Panijel J.
Published: February 2007

A microculture system which permits the survival of very small numbers of active lymphoid cells is here described. These cultures are phage stimulated and are capable of neutralizing the phage by producing specific IgM antibodies. The smaller the number of active cells in the microcultures the greater the percentage of negative microcultures. Positive microcultures are considered to contain at least one “response unit”, the frequency of which is calculated to be 3 per 105 mouse spleen cells. Theoretical implications of these results are also discussed.
Antibody‐induced changes in expression of an immunoglobulin surface antigen
Authors: Knopf P. M. , Destree Antonia , Hyman R.
Published: February 2007

An IgG1‐secreting myeloma possesses Ig‐related surface antigen, Ig‐mem, detected both by a cytotoxic and a 125I‐labeled anti‐Ig binding assay. The properties of Ig‐mem were studied by examining the fate of 125I‐labeled rabbit anti‐Ig and the complement sensitivity of cells sensitized by the binding of labeled antibody at 0 °C. Shifting the temperature to 24 °C or 37 °C leads to a rapid loss of sensitivity to lysis by complement, as well as a loss in the capacity to detect the rabbit antibody on the cell surface. These reactions occur without any appreciable loss of radioactivity from cells at 24 °C. The 125I‐labeled antibody is subsequently degraded to amino acids (detected as iodotyrosine) more rapidly at 37 °C than at 24 °C.

We interpret these results as an antibody‐induced interiorization of the IG‐mem, together with its bound antibody. The interiorization reaction does not occur if 125I‐labeled, univalent Fab fragment of the rabbit antibody is used. Instead, most of this reagent remains bound to cells for at least an hour at 24 °C or 37 °C. These latter findings suggest that the bulk of Ig‐mem may not be an immediate precursor of the secreted IgG1, in transit through the plasma membrane.
In vitro activation of mouse lymphocytes in serum‐free medium: effect of T and B cell mitogens on proliferation and antibody synthesis
Authors: Coutinho A. , Möller G. , Andersson J. , Bullock W. W.
Published: February 2007

Mouse spleen cells were successfully activated by mitogens in serum‐free medium. The T cell mitogen, concanavalin A (ConA), was found to activate DNA synthesis in the presence or absence of serum to the same extent, although the dose response curve was shifted. Thus, concentrations ten times lower were optimally stimulating in serum‐free medium. The strain differences existing with regard to Con A activation were the same whether serum was present or not. B cell mitogens, such as lipopolysaccharide (LPS) and purified protein derivative (PPD) of tuberculin, were equally active in the presence or absence of serum with regard to dose response curves and kinetics for the induction of DNA synthesis.

When added to normal spleen cells in culture in the absence of serum, Con A also activated antibody synthesis against a variety of antigens and haptens. It had no such effect on spleen cells from nude animals, indicating that it exerted its B cell‐activating effect via T cells. It was also effective when DNA synthesis in the lymphocytes had been suppressed with mitomycin.

LPS and PPD activated antibody synthesis to haptens in normal and nude spleen cells, the response in nude animals being markedly stronger.

Since there is virtually no background antibody synthesis in unstimulated cultures in the absence of serum, but a substantial background in serum, it follows that the factor of activation caused by T and B cell mitogens is more pronounced in the absence of serum.