bluuebunny/crossref_metadata_2025 huggingface dataset:
Thymus dependence of the antibody response in chickens: Variation with dose of antigen and type of antibody affected
Authors: Droege W. , Malchow D.
Published: February 2007

Neonatal thymectomy reduces the agglutinin response of chickens immunized with Brucella abortus and rabbit erythrocytes at 6 weeks of age. The response to low doses of Brucella antigen is more markedly affected than that to high antigen doses, and 2‐mercaptoethanol resistant antibody is more affected than 2‐mercaptoethanol‐sensitive antibody. Six week old neonatally thymectomized birds have an average body weight 15 ‐ 25% lower than sham operated or untreated control animals. The findings are compared with similar observations in mice.
Renewal and fate in the mammalian thymus: Mechanisms and inferences of thymocytokinetics
Authors: Bryant B. J.
Published: February 2007

Quantitation of cortical thymocyte kinetics in adolescent Swiss Webster mice, using techniques of mitotic counting and [3H]TdR labeling, indicate that proliferating (P) cells and nonproliferating (Q) cells had cycle and compartment transit times of approximately 9 and 72 hours, respectively. The data also suggested that P cells may have existed in numbers greater than needed for Q cell formation, Studies of whole thymus 125I‐DNA regression after [125 I]UdR administration in mice and guinea pigs, in conjunction with the [3H]TdR data, confirmed the cortical P cell excess and indicated that it expressed a P1 to Q to P2 cytodifferentiation pathway not involving cell loss from the thymus before the end of the Q cell maturation compartmentt. Most of the matured Q cell disappeared, probably via intrathymic death. Only 2.5 to 10% of Q cells differentiated to P2 cells, according to preliminary estimation. Whole thymus P2 cell production in adolescent mice was estimated at 50 × 106 cells per day, sufficient to replace blood lymphocytes 5 times daily. However, additional estimates suggest that, if all P2 cells emigrated, less than 2.5% of them contributed to the peripheral long‐lived, thymus‐derived, lymphocyte pool. The functional and homeostatic relationships between these peripheral cells and thymic P2 cells are presently unresolved.
Chemistry and biology of the anaphylatoxin related serum peptide system. II. Purification, crystallization and properties of cocytotaxin, a basic peptide from rat serum
Authors: Wissler J. H.
Published: February 2007

It could be demonstrated that besides classical anaphylatoxin another stable peptide is formed in vitro by the contact reaction of mammalian serum with hydrophilic, insoluble substances of high molecular weight, e.g. dextran, yeast or preformed immune complexes.

This newly detected peptide, called tentatively “cocytotaxin” has been separated from classical anaphylatoxin. It was crystallized in a molecular homogenous state. The basic peptide has a molecular weight of 8500, as determined by gel chromatography, and consists of one peptide unit. Though cocytotaxin is similar in its physicochemical behavior to classical anaphylatoxin, it displays no anaphylatoxin activity. Furthermore, cocytotaxin alone elicites no significant chemotactic activity for neutrophil leucocytes.
Chemistry and biology of the anaphylatoxin related serum peptide system. III. Evaluation of leucotactic activity as a property of a new peptide system with classical anaphylatoxin and cocytotaxin as components
Authors: Wissler J. H. , Stecher Vera J. , Sorkin E.
Published: February 2007

Preparations of crystallized classical anaphylatoxin (CAT) from hog, rat and guinea pig serum display no significant chemotactic activity for neutrophil leucocytes. A newly discovered and crystallized basic peptide from hog, rat and guinea pig serum, tentatively called cocytotaxin (CCT), which is similar in its physicochemical behavior to CAT, displays neither significant CAT activity nor significant chemotactic activity for neutrophil leucocytes.

Recombination of CAT and CCT in different molar ratios leads to chemotactic activity for neutrophil leucocytes in vitro. Such activity was ascribed by previous authors to a molecular property of other anaphylatoxin preparations. Chromatographically it was possible to demonstrate that our “chemotactically active” CAT preparations are paucidisperse systems. Furthermore, evidence is presented that chemotactic activity for neutrophil leucocytes of CAT preparations still containing CCT is not due to formation of a stable complex of the two peptides.

Based on the results presented, it is concluded that chemotactic activity for neutrophil leucocytes is, in this instance, a property of a peptide system for which the name “anaphylatoxin‐related leucotactic peptide system” (ACLsystem) is suggested. Phenomenologically, two types of biological activities are at present known to be elicited by the ACL‐system:

1. anaphylatoxin activity as a property of the CAT molecule.

2. chemotaxis for neutrophil leucocytes as a property of the combined action of CAT and CCT within the ACL‐system.
Protease activity as a possible mechanism of migration inhibitory factor
Authors: Havemann K. , Howat M. , Sodomann C. P. , Havemann Karin , Gürger Sigrid
Published: February 2007

The activity of migration inhibitory factor (MIF), present in the supernatants of specifically and nonspecifically stimulated human lymphocyte cultures, can be blocked by antiproteases of animal and plant origin and by diisopropyl fluorophosphate. MIF, partially purified by column chromatography and zone electrophoresis on polyvinylchloride is blocked in the same way. On the other hand, migration inhibition can be effected by some proteases, especially by cobra venom. These findings are discussed in terms of the probable protease nature of MIF.
Hybrid 7 S immunoglobulin molecules formed in vivo by association of heavy and light chains of different parental origin
Authors: Oriol R. , Barbier Yolaine , Biozzi G.
Published: February 2007

Rabbits were immunized with the purified 7 S immunoglobulins of normal domestic cock (Ga), guinea hen (Nu) and their hybrid, the Numigall (NuGa).

The antisera rendered specific for Ga and Nu immunoglobulins by appropriate absorptions were used to study the antigenic structure of the NuGa 7 S immunoglobulins.

Nine to twenty percent of the NuGa molecules showed only Ga antigenic determinants, and six to twelve percent only Nu antigenic determinants. More than half of the NuGa immunoglobulins presented both Nu and Ga antigenic determinants on the same molecule.

The heavy and light chains of the 7 S immunoglobulins of the three species were isolated and studied with the same rabbit antisera.

The isolated chains of the NuGa immunoglobulins showed either the antigenic structure of Nu or Ga. No hybrid chains could be demonstrated.

A model of in vivo chain assembly of heavy and light chains from different parental origin is proposed to explain the presence of hybrid molecules in the NuGa 7 S immunoglobulins.
Similarity of cellular recognition structures for histocompatibility antigens and of combining sites of corresponding alloan tibodies
Authors: Ramseier H. , Lindenmann J.
Published: February 2007

Theoretical considerations on a possible similarity between recognition structures (RS) on immunocompetent cells and the antigen‐binding sites of alloantibodies aimed at the same target have been tested experimentally in the PAR assay with the aid of antisera directed against recognition structures (anti‐RS sera). It was found that the activity of an alloantiserum could be neutralized specifically by a corresponding anti‐RS serum. Conversely, the activity of an anti‐RS serum could be blocked specifically by a corresponding alloantiserum. The term “aliotype” is proposed for antigenic determinants residing on the combining region of alloantibodies and on corresponding recognition structures of lymphoid cells.
Studies on antigenic competition III. Is there a competitive step in tolerance induction?
Authors: Taussig M. J.
Published: February 2007

The induction of tolerance to mixtures of antigens has been studied in mice. The mixtures used were rabbit Fab′ and rabbit Fab′, a synthetic polypeptide(T,G)‐Pro‐L and rabbit Fab′, and (T,G)‐Pro‐L and rabbit IgG. It was established that these antigens would compete with each other for antibody production if administered in adjuvant. However, in no case was the threshold of tolerance induction of an antigen affected by the simultaneous induction of tolerance to any other antigen in the mixture. Other competitive systems confirmed this result. Thus, there is apparently no competititve step intolerance induction. Moreover, antigenic competition for antibody production did not occur in animals rendered tolerant to the dominant antigen. The relevance of these findings to the mechanisms of competition and tolerance is discussed.
Subclasses of porcine immunoglobulins G. Production of subclass specific antisera with S‐sulfonated gamma chains
Authors: Metzger J.‐J. , Houdayer Monique
Published: February 2007

Using antisera made against porcine S‐sulfonated heavy chains two subclasses of porcine IgG could be distinguished on the basis of antigenic determinants located on the Fc fragment. The antisera prepared against the porcine gamma chains reacted with other mammalian IgG proteins, but not with avian, amphibian or fish immunoglobulins. Antigenic determinants responsible for cross‐reactivity are further localized on the Fc′ fragment of the porcine IgG molecule. Comparable antisera, specific for porcine light chains, did not cross‐react with IgG from any of the other species tested. Porcine IgG and F(ab′)2 fragment reacted with both the anti‐heavy and anti‐light chain sera, while the Fab fragment reacted only with the anti‐light chain sera. Important antigenic determinants are thus located on the light chains and the Fc portion of the heavy chain of the porcine IgG molecule.
Induction of immunity and tolerancein vitroby hapten protein conjugates. II. Carrier independence of the response to dinitrophenylated polymerized flagellin
Authors: Feldmann Marc
Published: February 2007

The response to dinitrophenylated polymeric flagellin (DNP POL)in vitro, unlike that to DNP monomeric flagellin (DNP MON) or erythrocyte antigens does not require the presence of T cells. It was thus proposed that antigens with repeating determinants, like DNP POL, may immunize B cells without the cooperation of the usual helper cells. Since carrier specificity in secondary anti‐hapten responses is based upon the cooperation of carrier‐reactive T cells and hapten‐reactive cells, the requirement for carrier‐reactive cells in the response to “thymus‐independent” DNP POL and “thymus‐dependent” DNP MON was investigated. Using flagellin‐primed spleen, the anti‐DNP response to DNP MON was enhanced, but not that caused by DNP POL. Furthermore, there was no carrier specificity in the anti‐DNP responses with DNP POL, which elicited similar responses in spleen cells primed with various DNP proteins, whereas DNP MON only immunized spleen cells which were primed with that carrier. Carrier‐hapten cooperation has also been demonstrated by the suppressive effect of unconjugated carrier on the anti‐hapten response to carrier hapten conjugates. Neither the induction of tolerance to flagellin, the carrier, nor the presence of free flagellinin vitrosuppressed the anti‐DNP response to DNP POL. In contrast, both these manoeuvres suppressed the anti‐flagellin response to DNP POL, and both the anti‐DNP and anti‐flagellin responses elicited by DNP MON. Thus, by several criteria, there was no cooperation between carrier‐reactive and hapten‐sensitive cells in the genesis of the response to DNP POL.

Spleen cell suspensions deprived of their content of phagocytes responded normally to DNP POL. Thus, since T cells, carrier‐reactive cells and phagocytes are not needed for the induction of a response to DNP POL, this antigen immunizes B cells directly. The use of this simple system should facilitate our understanding of the mechanism of binding of antigen molecules to the surface of B cells in the process of immunization.
Antibody response in rats to the synthetic polypeptide (T,G)‐A‐ genetically linked to the major histocompatibility system
Authors: Günther E , Rüde E. , Štark O.
Published: February 2007

Various inbred strains of rats were immunized with the synthetic polypeptide (T,G)‐A–L and showed considerable differences in their antibody response to this polymer. Further investigations using congenic strains, which differ at the major histocompatibility locus (H‐1, Ag‐B), and F1 and F2 hybrids of high and low responding strains demonstrated that the ability to respond to (T, G)‐A–L is under the control of a dominant factor genetically linked to the H‐1 locus.
Cellular heterogeneity in the thymus. I. Electrophoretic analysis of lymphoid cell populations from chickens
Authors: Droege W. , Malchow D. , Strminger J. L.
Published: February 2007

Micro‐cell‐electrophoresis has been applied to demonstrate differences and heterogeneities in various lymphocyte populations. The lymphocytes from the blood, spleen, bursa and thymus of young chickens differ significantly in their electrophoretic mobility (EM) pattern. The blood and spleen lymphocytes appear to be homogeneous by this criteria; bursa cells show slight heterogeneity, and thymus lymphocytes contain two clearly distinct subpopulations.

One of the two thymocyte subpopulations is absent in neonatally bursectomized and irradiated animals. This bursa‐dependent cellular component in the thymus has about the same EM as bursa cells themselves, which may suggest that these cells are, as such, derived from the bursa. The possible role of the bursa‐dependent subpopulation is discussed. Within the first months of life, there is a dramatic shift from the predominance of the electrophoretically slower population to its virtually complete disappearence and the subsequent dominance of the other cellular component.

Bursectomy plus irradiation provided pure preparations of one of the thymus subpopulations. The other subpopulation could be highly enriched by differential centrifugation in chicken plasma. Both subpopulations are thus separately available for direct immunological tests.

The reduction of the EM by neuraminidase show that sialic acid is a major charged component in the cell surface of all lymphocyte preparations tested. The data indicate also that the different EM of the two thymocyte subpopulations is not due to different amounts of neuraminidase labile groups on the cell surface. The high EM of blood lymphocytes, on the other hand, is probably to be explained by a high content of neuraminidase‐labile groups, as well as some ribonuclease sensitive material. A substantial reduction of the EM by ribonuclease was observed on blood lymphocytes, but not on lymphocytes from other organs.
Anaphylatoxin formation by contact activation of plasma III. Fixation of two different anaphylatoxin‐forming complexes on zymosan
Authors: Brade V. , Schmidt Gisa , Vogt W.
Published: February 2007

During incubation of zymosan with human or guinea pig serum, a complex is fixed on the polysaccharide which, after washing, releases anaphylatoxin from C5 when incubated with an anaphylatoxinogen preparation from rat serum containing C3 and C5. In order to form this complex, properdin and an unknown serum factor (UF), as well as high serum concentrations (not less than 1:4), are needed. No anti‐zymosan antibodies need be added. The complexes consume little C2 from serum and are active in anaphylatoxin (AT) liberation in small amounts (3 mg zymosan complex/ml substrate). After spontaneous decay of the AT‐forming activity, regeneration is affected by addition of UF, not by C2.

Zymosan‐R3g.p., i.e. guinea pig serum lacking properdin and UF because of pretreatment with zymosan, does not coat fresh zymosan with an active AT‐liberating complex, although it contains C1, C4, and C2. However, it does coat zymosan to which large amounts of rabbit anti‐zymosan antibodies have already been fixed. The resulting complement complex ZAC 142 forms at serum (R3) dilutions of 1:10 also. It effectively releases AT from substrate only when present in high amounts (20 mg/ml substrate); it largely consumes C2 from serum, and it is less active as an AT‐forming system than the zymosan properdin complex. Thus, two different AT‐forming systems can be activated by and fixed to zymosan, both derived from serum factors.

No evidence for activation or fixation of the properdin system by sheep red cells was found. Red cells appear to release AT only via the complex of early complement factors. It is probably the special polysaccharide surface which enables zymosan and possibly other (lipo)polysaccharides to fix the properdin system.
The dynamic state of the lymphocyte membrane. Factors affecting the distribution and turnover of surface immunoglobulins
Authors: Loor F. , Forni Luciana , Pernis B.
Published: February 2007

The immunoglobulins which are present on the membrane of B lymphocytes of different species are mobile in the plane of the membrane itself.

This mobility results in the formation of spots of immunoglobulins when the cells are treated with divalent antibodies against immunoglobulins; the spots then combine into polar caps.

The process of spot formation is not inhibited by different substances that inhibit cell metabolism, but is markedly inhibited in the cold.

The formation of caps is followed by the disappearance of immunoglobulins from the cell membrane but, if the cells are not left in contact with the anti‐immunoglobulin antiserum, there is a rapid resynthesis of new membrane immunoglobulins. It appears that the percentage of lymphocytes that resynthesize immunoglobulins is identical to that of cells originally carrying immunoglobulins, but the amount of surface immunoglobulins of each cell is increased after antiserum treatment. Many other membrane antigens behave in a similar way after treatment with the corresponding antisera; the possible role of the mobility of membrane proteins for the immunological functions of lymphocytes is discussed.
Metabolic characteristics of lymphocyte surface immunoglobulins
Authors: Wilson J. D. , Nossal G. J. V. , Lewis Heather
Published: February 2007

Rabbit anti‐mouse globulin reagents at low concentration were attached to the surface of living mouse lymphocytes in the cold. After appropriate washing, the cells were incubated under tissue culture conditions but without C02 gassing and the rate of disappearance of the antiglobulin from the cell surface was monitored. Two methods were used, namely, direct labeling with 125I‐labeled antiglobulin, and sandwich labeling in which the amount of residual antiglobulin at the surface was measured by assessing the degree of binding of a 1251‐labeled sheep anti‐rabbit globulin reagent. Binding of radioactivity to cells was measured both by scintillation counting of washed cell suspensions and by quantitative radioautography.

Elution of polyvalent antiglobulin, anti‐k or anti‐μ sera from spleen cells was surprisingly rapid. There was an initial phase of very fast elution and some 30% of counts were lost within 30 min or so, but control experiments showed that this phase was irrelevant to the main experiments. Subsequently, counts were lost more slowly and a reasonable first approximation to the half‐life of Ig receptors on B cells was 2 h. In contrast, lymphocyte surface H‐2 antigen and the receptors to which anti‐lymphocyte globulins attach were much more stable. A number of control experiments suggested that anti‐Ig reagents were shed from the cell surface by true metabolic turnover of B cell receptors, and not by antigen‐ antibody uncoupling or anti‐receptor‐induced extrusion. It was strongly suggested that some pinocytosis of attached antiglobulin occurred, but that this was not the major source of anti‐receptor loss. Shed receptors were continually regenerated, and the process of shedding was shown to be dependent on lymphocyte metabolic activity.

Thymus lymphocyte surface Ig also turned over, but at a rate considerably less than that for spleen cells.

A continuous, gentle leakage of Ig from the B lymphocyte surface was deemed to have important theoretical implications. These included a logical source of much natural antibody, increased emphasis on the multi‐hit nature of both immune induction and tolerance induction, a plausible explanation for the necessity of multi‐point binding of antigens to B cells in activation and a rationale for the fact that many adoptive immune responses require active immunization of the host animal.
Responses of athymic (“nude”) mice to sheep red blood cells
Authors: Pantelouris E. M. , Flisch P. A.
Published: February 2007

“Nude” (thymusless) mice immunized with sheep red cells gave rise to indirect PFC in numbers (per million spleen cells) that were comparable to those of normal animals for days 2 ‐ 4, but declined sharply thereafter. Hemolysin and hemagglutinin titers follow essentially the pattern of the direct PFC response.

About two‐thirds of nude animals also formed some indirect hemolytic plaques which are interpreted as due to 7 S (IgG) globulins rather than to low efficiency 19 S (IgM) globulins.

In the secondary response, nude mice failed to exceed their primary performance in any of the four parameters measured: direct PFC, indirect PFC, hemolysin titers and hemagglutinin titers, thus demonstrating the thymus dependence of immunological memory.

The initial spurt of immunological reactions by nude animals, followed by premature decline suggest a failure of proliferation or recruitment of immunologically responding cell population in the absence of a thymus.
Cell transfer studies in a genetically controlled immune response
Authors: Chesebro B. W. , Mitchell G. F. , Grumet F. C. , Herzenberg L. A. , McDevitt H. O. , Wegmann T. G.
Published: February 2007

Fetal liver cells from 14‐17‐day old mouse embryos of inbred strains which are genetic responders (C57BL/ 10) or nonresponders (CBA) to a branched synthetic polypeptide [(T, G)‐A‐L] were injected into reciprocal (nonresponder or responder) strain, lethally irradiated adult mice. These radiation chimeras were then tested for: (a) their ability to respond to (T, G)‐A‐L; (b) the allotype for specific anti‐(T, G)‐A‐L antibody produced; and (c) the degree of tolerance for CBA (nonresponder) histocompatibility antigens of C57BL/10 (responder) cells taken from high responder chimeras.

Eleven high responder radiation chimeras had specific anti‐(T, G)‐A‐L antibody, which appeared to be exclusively responder (C57BL/10) allotype. However, since all the high responder chimeras were predominantly C57BL/10 in total serum immunoglobulin allotype and lymphoid cell type, this result is not conclusive.

Six high responder chimeras had C57BL/10 spleen cells which were tolerant of CBA (nonresponder) histocompatibility antigens in the Simonsen discriminant spleen assay.
Antibody‐induced redistribution of HL‐A antigens at the cell surface
Authors: Kourilsky F. M. , Silvestre D. , Neauport‐Sautes C. , Loosfelt Y. , Dausset J.
Published: February 2007

The in vitro binding of anti‐HL‐A antibodies to the membrane of human lymphocytes induces important changes in the distribution of HL‐A antigens on the cell surface. Following either direct or indirect immunofluorescence staining at 0 °C, cell‐bound anti‐HL‐A antibodies are dispersed all over the cell surface. When the washed, stained lymphocytes are warmed and incubated at 37 °C, fluorescent antibodies cluster progressively at the cell surface. They form large spots of fluorescence, and sometimes single caps at one pole of the cell, outside which HL‐A antigens are no longer detectable, but other antigens can still be found. Similar findings were made in electron microscopy, following indirect labeling of HL‐A antigens on human lymphocytes, with ferritin or plant virus as the markers.

With the indirect immunofluorescence technique, anti‐human thymocyte antibodies and anti‐mouse H‐2 antibodies were found to induce a similar redistribution of the corresponding antigens.

The mechanism and the interpretation of this displacement of surface antigens by antibodies are still unclear and are discussed in terms of membrane structure and immunological significance.
Localization of antigenic determinants on bovine encephalitogenic protein Studies in rabbits with the blood leukocyte transformation test
Authors: Bergstrand H.
Published: February 2007

Bovine encephalitogenic protein and different fragments of it have been used to show that the protein contains at least three antigenic determinants capable of stimulating the transformation of peripheral blood leukocytes from sensitized rabbits. The determinants were tentatively localized on regions 1 ‐ 43, 44 ‐ 116 and 117 ‐ 170, respectively. There was no evidence that the tryptophan‐containing region carries an antigenic determinant when tested with leukocyte transformation in rabbits.
Recognition of conjugated and native peptide determinants. II. Enhancement of antibodies with sequential specificity in anti‐TMV sera by preimmunization with conjugated peptide antigens
Authors: Anderer F. A. , Ströbel G.
Published: February 2007

Rabbits which were preimmunized with the C‐terminal peptides of TMV protein conjugated to cross‐linked bovine serum albumin were stimulated with native TMV. All animals responded with a striking titer increase of antibodies with sequential specificity versus the C‐terminal peptides of TMV compared with animals which had not been preimmunized with the conjugated peptide antigens. The same degree of antibody enhancement with sequential specificity was obtained when the animals were stimulated with TMV for a second time after an interval of 255 days. The class distribution of 19 S and 7 S antibodies with sequential, as well as with conformational specificity, versus TMV was determined.
Antibody response to bacteriophage ϕX 174 in vitro: Demonstration of immunological memory in terms of IgM and IgG responses
Authors: Tao T. W.
Published: February 2007

The initiation of a primary‐type antibody response to bacteriophage ϕX 174 has been studied in organ cultures of lymph nodes from normal rabbits. Lymph nodes are also removed for culture at various times following a primary injection of ϕX in the rabbits and their responsiveness to a second anti‐genic stimulus investigated. All the cultures are maintained for 2 to 4 weeks and the antibody responses followed throughout. The following points are shown.

The ability of non‐primed lymph node fragments to initiate a primary type response in responding to ϕX stimulation in vitro declines rapidly during the first 2 ‐ 3 days and is lost after 3 days of culture.

An apparent failure to develop a primary IgG response is shown in cultures of non‐immunized lymph nodes even when the antigen was given for 1 to 6 days continuously or given twice, once on day 0 to 1 and another time on day 2, 3, 4, or 5.

Following antigenic stimulation in vitro, cultures of lymph nodes from rabbits immunized one (to two) days previously produce an antibody response of primarly IgM antibodies with a geometric mean significantly smaller than that produced by non‐primed lymph node cultures.

Cultures of primed lymph nodes without a secondary antigenic stimulation in vitro produce antibodies only of the type present in the animal at the time of the tissue removal.

Cultures of lymph nodes from rabbits immunized more than 4 days previously exhibit IgM and IgG memories. The secondary response initiated in vitro exhibits predominantly IgM memory when cultures are of nodes primed in vivo 4 days previously, but exhibits primarily IgG memory when cultures are of nodes primed in vivo 14 days previously. Intermediate proportions of IgM and IgG are seen at intermediate time intervals.

The ability of primed lymph nodes to show the phenomenon of memory appears to be positively correlated in time with the ability to develop IgG antibodies.

IgM memory is transient in the sense that it is exhibited only in lymph nodes primed in vivo less than 2 weeks previously, whereas IgG memory lasts as long as the life of the animal.
Conversion of Hageman factor (Factor XII) of the guinea pig to prekallikrein activator and inhibition of the formed kallikrein by a natural plasma inhibitor
Authors: Takeuchi Y. , Movat H. Z.
Published: February 2007

Aluminum hydroxide adsorbed guinea pig plasma was fractionated by QAE Sephadex A‐50. Fractions correcting the clotting defect in Factor XII‐deficient plasma (without having an effect on Factor XI‐deficient plasma) were pooled and rechromatographed twice through Sephadex G‐200. By gel filtration Factor XII had an approximate molecular weight of 130 000 – 140 000. Its approximate isoelectric point was 5.2. The partially purified Factor XII had no effect on prekallikrein, but upon trypsinization or adsorption to and desorption from celite, generation of prekallikrein activator was induced. Prekallikrein activator added to prekallikrein activated this pre‐enzyme, which then hydrolyzed BAEe and liberated kinin from heated plasma.

An incidental finding was the recovery of an inhibitor of kallikrein. It eluted immediately after the excluded peak by anion exchange chromatography. It was passed twice through Sephadex G‐200 and had an approximate molecular weight of 100 000. The kallikrein inhibitor had a pl of 4.7–5.3. It was found to be heat‐resistant up to 80°C and resistant to acidification (pH 1.4). Under the conditions obtained the inhibitor also inactivated plasmin, trypsin and thrombin.
Induction of antibody‐forming cell clones in microcultures
Authors: Lefkovits I.
Published: February 2007

When microcultures containing 2 × 105 mouse spleen cells are stimulated with heterologous red cells and the response is measured by the production of plaque‐forming cells or antibodies, some microcultures respond, some do not. Microcultures which do not respond to a given antigen are still capable of responding to another antigen. The response marks the presence of at least one precursor cell, probably a B cell. Most of the responding cultures would receive only one such precursor cell, and hence contain single clones of antibody‐forming cells. The frequency of these precursor cells is calculated to be 5.5 × 10−6. Methods for handling and assaying large numbers of cultures in very small volumes (10 μl) are given in detail.
Direct evidence for immunoglobulins on the surface of thymus lymphocytes of amphibian larvae
Authors: Du Pasquier L. , Weiss N. , Loor F.
Published: February 2007

Immunoglobulins associated with the membrane of amphibian lymphocytes are easily detectable by immunofluorescence and behave very much like membrane immunoglobulins on mammalian lymphocytes. Ontogenic studies of the thymus and spleen in larvae show a sharp increase (from less than 1 % to 80 %) in the level of lymphocytes carrying immunoglobulins in the thymus at very early stages of their development. This level remains constant during the entire larval and early adult life, and is significantly higher than that in the thymus of older adults (9 %). Splenic lymphocytes having immunoglobulins on their membrane remain at a constant level (40–60 %).
The effect of embryonic bursectomy on the rosette‐forming cells in the chicken
Authors: Hemmingsson E. J. , Alm G. V.
Published: February 2007

Surgical bursectomy in 17‐day old chicken embryos drastically impaired both the rosette‐forming cell and plaque‐forming cell responses later in life. Thus, both these responses are primarily bursa‐dependent.
The effect of antigen and mode of immunization on the allotypic distribution of enhanceable plaque‐forming antibody
Authors: Chou C.‐T. , Cinader B. , Dubiski S.
Published: February 2007

The relation between the genotypic control and phenotypic expression of antibody formation and between gene dose and product concentration depends on and is modified by antigen‐mediated selection and by antigen‐induced cell division. This dependence was studied in terms of allotypic specificities of rabbit light chain as markers and with different antigens and. regimens of immunization. The number of enhanceable plaque‐forming cells of the same allotype was measured in the spleens of rabbits, homozygous and heterozygous at the Ab locus. A significant departure from a simple gene‐dose relationship was observed. The regular preponderance of one allotype over another (“pecking order”: A4>A6>A5>A9) was confirmed. The preponderance in A4/A5 animals was found to persist whether the allotype ratio of enhanceable plaques was tested after one, two or ten injections with SRBC, after immunization with chemically modified SRBC or with DNP‐HGG. There was no significant difference in the cross‐reactivity of A4 and AS plaque‐forming SRBC antibody. The distribution of allotype ratios of responding A4/A5 animals changed with prolonged immunization from trimodal to bimodal and finally approached unimodality. After two injections with SRBC, the incidence of individual heterozygotes, making a monoallotypic enhanceable plaque response, was greatest among animals with allotypes from the extremes of the pecking order (i.e. A4/A9).

We can account for our observations and for the distribution of allotype ratios in the response to strong and to weak antigen on the basis of the following assumptions:

a small number of receptor‐carrying precursors of antibody‐forming cells is involved in the response to one cr two injections with antigen;

the specificity spectrum for antigens which evoke a heterogeneous response is the same for plaque‐forming antibodies of different allotypic specificity (A4 or A5);

in heterozygotes, the ratio of receptors with different allotypic specificities is different from 1 and is related to the distance in the pecking order; the greater the distance, the greater the difference from 1;

there is continuous recruitment from precursor cells during prolonged immunization.
Dose‐ and time‐dependent changes in the binding capacity of IgM antibody
Authors: Wu C.‐Y. , Cinader B.
Published: February 2007

Past experiments have revealed antigen dose‐dependent changes in IgG but not in IgM affinity. This is of importance to the general validity of the receptor concept and led us to investigate IgM affinity as a function of antigen dose and of time after antigen administration.

Rabbits were immunized with proteins conjugated with p‐azobenzene arsonate and the hapten response was assessed by plaque formation. Dose‐ and time‐dependent changes in binding properties of IgM were determined by inhibition with hapten. The quantity of hapten which led to inhibition of 50% of the plaques, I50, was independent of the amount of hapten antibody in the system. All direct plaques could be inhibited by antibody directed against μ chains, but were not inhibited by antibody against γ chains. The amount of antibody against μ chain which inhibited 50 % of the plaques was the same in the early as in the late plaque‐forming response.

In the initial stages of antibody response, there was no change in I50, over a considerable range of immunizing doses, including doses sufficient to trigger a plaque‐forming response, but insufficient to maintain it. Dose related changes in IgM affinity were observed fifteen days after antigen injection. In general, the avidity of IgM plaque‐forming antibody increased with time. However, at a very high dose of antigen, there were no changes in average affinity. After a second administration of antigen, plaque‐forming cells were detected earlier than in the primary response, though not in greater numbers. The first plaque forming antibody to be detected was of relatively high affinity; antibody detected subsequently was of the same affinity as the antibody formed in the primary response.

Results were discussed in terms of cooperation between receptor binding sites and in terms of interference with this cooperation when antigen antibody complexes trigger antibody formation.
The long‐term distribution of antibody‐forming cells
Authors: Anderson H. R. , Dresser D. W.
Published: February 2007

Previous experiments suggested that the spleen might not be the chief source of serum antibody synthesized several months after the immunization of mice by sheep erythrocytes; this has been confirmed for classes other than γM. The anatomical location of the cells making the antibody is not the same for each class. The thymus contains a relatively greater number of non‐γM antibody‐producing cells late in the response than it does in the first three weeks after immunization.
Position of a locus determining mixed lymphocyte reaction distinct from the known HL‐A loci
Authors: Eijsvoogel V. P. , Van Rood J. J. , Du Toit E. D. , Schellekens P. T. H. A.
Published: February 2007

Bilateral and unilateral mixed lymphocyte culture (MLC) tests were performed in five families, each containing one sibling in which recombination between the genes determining the antigens of the LA and Four segregant series of IIL‐A had occurred. The results confirm the very weak or non‐stimulatory effect of antigens of the LA segregant series, bringing to seven the total number of alleles for which this has been shown so far. Further anomalies in one of the families, however, indicate that the antigens of the Four segregant series are not fully responsible for MLC activation either. Of a group of three HL‐A identical siblings, one proved to be MLC‐positive with the other two, but MLC‐negative with another group of two HL‐A identical siblings, which group displayed a one‐allelic difference for HL‐A with the former group. Furthermore, the child showing this unexpected MLC reaction pattern proved also to be MLC‐negative with the earlier mentioned sibling who had the serologically demonstrable recombination between the LA and Four series, notwithstanding a difference for three HL‐A antigens.

These findings are interpreted as strong evidence for the occurrence of a recombination between the HL‐A loci and a MLC determining locus, which can thus be localize outside the previously recognized HL‐A region close to the Four locus. The relationships between HL‐A, MLC, skin graft rejection and organ transplantation are reexamined in the light of this concept.
The synthesis of radioactively labeled sulfanyl‐N‐chloracetyl tyrosine and its use for determinations of quantities and affinities of anti‐p‐azobenzenesulfonate antibodies
Authors: Schirrmacher V.
Published: February 2007

35S‐labeled sulfany l‐N‐chloracetyl‐L‐tyrosine is presented as a valuable hapten for binding studies on anti‐p‐azo‐benzenesulfonate antibodies. The capacities of individual rabbit anti‐sulf antisera to bind this hapten were correlated with their 7 S passive hemagglutination titers. Affinities of anti‐sulf antibodies to the hapten were determined by two methods, a) by directly measuring the binding constants and b) by calculating the ratios of the hapten‐binding capacities of the sera determined at two different hapten concentrations. The values obtained by the latter, much simpler method, were correlated with the binding constants determined for the same sera.
The rosette cell response of several mouse strains to immunization with both sheep and pigeon erythrocytes; magnitude of errors caused by cytophilic antibody
Authors: Kapp Judith , Benacerraf B.
Published: February 2007

Immunization of mice with two non‐cross‐reacting red cells, sheep and pigeon, gave rise to rosette‐forming spleen cells (RFC) capable of binding both types of erythrocytes. These double rosettes occurred in random bred mice and ininbred strains. The double RFC response vaned from strain to strain, from 6‐32% of the total RFC response. Serum taken from mice during the peak response was able to passively sensitize normal mice, resulting in a considerable number of RFC and double RFC recovered in their spleens. Strain differences in the number of double KFC determined following immunization were found to be related to the ability of individual strains to be passively sensitized with cytophilic antibody. The transfer could be performed in vivo or in vitro. It has also been shown that this cytophilic antibody can belong to the IgM or IgC class. This data indicates that cytophilic antibodies are responsible for all double RFC and for a significant varying number of the RFC in actively immunized mice depending upon the strain.
Serum immunoglobulin levels in nude mice
Authors: Luzzati Alma L. , Jacobson Ethel B.
Published: February 2007

A quantitative evaluation of Ig classes in the serum of “nude” mice(nu/nu) in comparison with nu/+ and +/+ animals is reported. IgA and IgG classes are shown to be reduced in “nude” mice, the reduction being particularly severe in the case of IgG1. On the other hand these animals have normal IgM levels.
Anti‐hapten antibodies in normal sera. II. Species difference in amounts and characteristics
Authors: Jormalainen Seija
Published: February 2007

The relationship between anti‐NIP (4‐hydroxy‐3‐iodo‐5‐nitrophenacetyl) and anti‐DNP (2,4‐dinitrophenyl) antibodies was studied in 158 sera of seven species. Evidence was found suggesting that anti‐NIP and anti‐DNP antibodies are generally different populations of molecules. It was shown that some species had higher average levels of natural antibodies than other species and some individuals of a species had a generally higher level of natural antibodies than other individuals of the same species.

Fine specificity of natural antibodies was studied by using the related haptens NIP, NNP (4‐hydroxy‐3, Sdinitrophenacetyl) and NP (4‐hydroxy‐3‐nitrophenacetyl). A positive correlation was found between anti‐NIP and anti‐NP titers in individual sera as well as between the mean titers within the species. By using hapten inhibition and immunoadsorbents the antibody populations which inactivated NIP‐ and NP‐phages were shown to be represented in a different way in rabbits, pigs and rainbow trout. Rabbits appeared to have distinct NP‐specific antibodies, whereas pigs and rainbow trout did not.
Factors affecting the propagation of a B Cell Clone forming antibody to the 2,4‐dinitrophenyl group
Authors: Askonas Brigitte A. , Williamson A. R.
Published: February 2007

We have studied the factors controlling the propagation and sequential transfer of B cell clone, E9, forming IgGI antibody to DNP in syngeneic CBA/H mice. The history of this clone is documented here in detail. E9 antibody was recognized by its isoelectric spectrum, detected by binding of 131‐DNP hapten after isoelectric focusing.

During the life of this clone, induction of anti‐DNP depended on the presence of antigen (1 – 10 μg provided an optimum dose) and on cooperation with T‐derived cells recognizing carrier molecules. T cells contribute no information towards antibody formed by the B cells.

During the first three transfer generations the clone produced high levels of E9 anti‐DNP (2 – 3 mg/ml serum) and the reliability of clonal transfer was high; 53/54 recipient mice formed large amounts of E9 antibody. As the proliferative capacity of the clone decreased, transfer became less reliable.

The optimum interval between consecutive spleen cell transfers was 3 – 5 weeks, although successful transfer of memory cells could still be accomplished 65 days after last contact with antigen.

The pI spectrum of E9 anti‐DNP remained constant throughout the life span of the clone, covering a period of one year and eight transfer generations and passage into 300 mice. We have therefore no evidence for any change or improvement in antibody produced by a single clone due to selective pressure.

In other experimental series, limiting numbers (0.5 × 106 ‐ 2 × 106) of spleen cells primed with DNP‐BGG were distributed into irradiated syngeneic CBA/H mice. The incidence of single anti‐DNP‐forming clones sufficiently expanded for reliable sequential transfer is low; in 300 irradiated recipients we found 9 clones which produced high levels (0.3 ‐ 3 mg/ml) of anti‐DNP; some of these have been propagated by serial transfer. The high protein production appears to reflect overall expansion of the clone and to be a useful indicator of large numbers of memory cells. In general, low producing clones are not sufficiently expanded for effective propagation of the clone by serial spleen cell transfer.
Identification and genetic control of allotypic specificites on two variable region subgroups of rabbit immunoglobulin heavy chains
Authors: Kim B. S. , Dray S.
Published: February 2007

After absorption with selected individual rabbit sera, allo‐antibodies directed against the a‐negative IgG from homozygous a2‐suppressed rabbit resulted in the separation of three distinct antibody populations which are designated anti‐A31, anti‐x32 and anti‐y33. The mating studies indicated that the x32 and y33 allotypic specificities are not controlled by allelic alternatives. The inheritance of the x32 and y33 allotypes was found to be closely linked to that of the al, a2 or a3 allotypes. Five allogroups were identified: a1, x−,y−;a1,x−,y33;a1,x32,y33;a2x32,y33; and a3,x32,y−. As was found for the a1, a2 and a3 allotypic specificities, the x32 and y33 allotypic specificities are present on IgA and IgM as well as on IgG suggesting that the x32 and y33 allotypic specificities are located on the variable region of immunoglobulin heavy chains. Our results indicate that three closely linked VH genes code for the variable regions of rabbit Ig heavy chain subgroups.
“Spontaneous” B cell activation due to loss of normal mouse serum suppressor
Authors: Bullock W. W. , Möller Erna
Published: February 2007

Normal mouse spleen cells initiate synthesis of immunoglobulins in vitro in the presence of fetal calf serum and in the absence of specific antigen following the removal of regulatory suppressor(s) present in normal syngeneic mouse serum.
Sulfanilic acid as surface antigen on mouse lymphoid cells. I. Properties of hapten‐labeled cells and effects of antihapten antiserum in vitro and in vivo
Authors: Seiler H.
Published: February 2007

The conventional hapten sulfanilic acid (sulf) was coupled covalently to mouse spleen cells via an azobridge. Survival and functional behavior of the coupled cells were assayed by determining their capacity to exclude trypan blue, to secrete antibody and to produce a secondary immune response in an adoptive transfer system. Conditions have been found under which the cells were not affected by the coupling procedure but could be specifically lysed or inactivated in vitro and in vivo by anti‐sulf antiserum. Inactivation in vivo appeared to require complement, since F(ab')2 fragments of anti‐sulf antibody did not inactivate coupled cells. The effects of antibody and complement were shown to depend strongly on the amount of hapten coupled to the cells.

The potential of this method is twofold. The hapten can serve as a surface marker, which can be detected by the effect of antiserum in vitro and in vivo. In addition the coupled hapten may be used as an artificial histocompatibility antigen, which can be manipulated to a certain extent for experimental analysis of its function.
Leucocyte mobilizing factor: A new biological activity derived from the third component of complement
Authors: Rother K.
Published: February 2007

A simple method is described to assay for factors that mobilize leucocytes in the bone marrow. Guinea pig or rat femura were slowly perfused with Medium 199 and the cell concentration in the effluent was determined. Leucocyte mobilizing factor (LMF) was recognized by an increase in the effluent cell concentration following addition of the material to the perfusion medium.

By reaction with C 142, the rabbit C3 molecule was cleaved, releasing a fragment with LMF activity. A purification procedure is described. The factor was devoid of chemotactic activity. It was negatively charged at pH 8.6.

LMF may be involved in the pathogenesis of the leucocytosis associated with C dependent immune reactions in vivo.