bluuebunny/crossref_metadata_2025 huggingface dataset:
Target cell‐dependent T cell‐mediated lysis of vaccinia virus‐infected cells
Authors: Koszinowski U. , Thomssen R.
Published: February 2007

Vaccinia virus specific cytotoxicity against infected target cells was observed in vitro. Spleen lymphocytes from normal and immunized mice of the inbred strains C3H and DBA/2 were incubated with vaccinia virus‐infected and non‐infected 51Cr‐labeled mastocytoma P‐815‐X2 cells and L‐929 fibroblasts, which were used as targets. Cytotoxic lymphocytes could be isolated from the mice as early as 2 days after infection with vaccinia virus. The highest cytotoxic effect was obtained with lymphocytes taken 6 days after infection. The degree of lysi was correlated with the ratio of immune lymphocytes to target cells. Specific blocking of target cell lysis resulted after addition of anti‐vaccinia antibody from different sources. The effector cells could be characterized as T cells by elimination of macrophages and B cells. Target cell killing was only possible in a syngeneic system; allogeneic infected target cells were not lysed significantly.
Early detection of potentially lethal events in T cell‐mediated cytolysis
Authors: MacDonald H. R.
Published: February 2007

The short‐term kinetics of the interaction between mouse cytolytic T lymphocytes (CTL) and 51Cr‐labeled target cells was investigated. It was found that addition of EDTA to mixtures of CTL and target cells instantaneously blocked de novo lytic interactions, but did not inhibit the release of 51Cr from already damaged target cells. Using this information, a modified cytolytic assay was developed. By applying this assay to highly active CTL populations generated in secondary mixed leukocyte cultures, it was possible to detect appreciable target cell damage as early as 30 seconds after exposure to CTL. Quantitative studies demonstrated linear relationships between cytolysis and time and between rate of cytolysis and cell number under these assay conditions.
Antigens on mouse and rat lymphocytes recognized by rabbit antiserum against rat brain: The quantitative analysis of a xenogeneic antiserum
Authors: Morris R. J. , Williams A. F.
Published: February 2007

Quantitative assays for measuring the binding of xenogeneic antiserum to dispersed cell suspensions are described. Cells were incubated with unlabeled xenogeneic antiserum and the antibody bound measured indirectly by a second binding step with 125I‐labeled anti‐immunoglobulin antibody. This indirect radioactive binding assay was calibrated by measuring, with a radioimmunoassay, the true amount of antibody bound in the first step. With these methods one can measure the strength of antisera, quantitate the number of antigenic sites, and partially differentiate determinants being recognized on cell surfaces.

The binding of rabbit anti‐rat brain antiserum to rat and mouse lymphocytes was analyzed in detail. After absorption of the antiserum with rat liver, the antibody remaining recognized lymphocyte antigens that were distributed among various rat and mouse tissues in quantities identical to Thy‐1.1 antigen. Thus, at saturation, 670 000 Ig molecules from liver‐absorbed rabbit antiserum were bound per rat thymocyte, and the antiserum bound to 90 %, 21 %, 4 % and 2 % of rat thymocytes, spleen, lymph node and thoracic duct lymphocytes, respectively. With mouse tissues, 90 %, 24 %, and 50 % of thymocytes, spleen and lymph node cells, respectively, were labeled. In rat brain the concentration of xenoantigen increased with age, while in thymocytes the full adult amount was present at birth.

Three antigenic determinants could be defined with the liver absorbed rabbit antiserum: the Thy‐1. 1 antigen, a rat specific antigen and an antigen cross‐reacting between rat and mouse tissues. All 3 may be on the Thy‐1 molecule. The anti‐brain antiserum contained about 0.05 mg/ml of antibody specific to these xenoantigens.
H‐2‐linked genetic control of antibody response to soluble calf skin collagen in mice
Authors: Hahn E. , Nowack H. , Götze D. , Timpl R.
Published: February 2007

An autosomal dominant immune response gene could be demonstrated in congenic resistant strains of mice which is linked to the H‐2 locus and controls the antibody response to soluble calf collagen. High responsiveness was associated with the H‐2 alleles, b and f, low responsiveness with the H‐2 alleles, d, k, m and r. Studies with calf procollagen, which contains an additional carrier moiety, indicated that these genetic differences might be expressed at the level of T cells.
Comparative studies of sheep immunoglobulins IgG1 and IgG2: Amino acid sequence of carboxy‐terminal cyanogen bromide fragments from their heavy chains
Authors: Conde F. P. , Deverson E. V. , Milstein Celia P.
Published: February 2007

Sheep immunoglobulin IgG1 and immunoglobulin IgG2 heavy chains were treated with cyanogen bromide. The fractions from the C‐terminal end of the heavy chains were isolated and purified, and the amino acid sequences of these fractions were determined. The C‐terminal octadecapeptides from γ1 and γ2 heavy chains had the identical sequence: Met‐His‐Glx‐Ala‐Leu‐His‐Asx‐His‐Tyr‐Thr‐Glx‐Lys‐Ser‐Ile‐Ser‐Lys‐Pro‐Pro‐Gly.

Comparison with the C‐terminal peptides of other species, reported in the literature, suggests that the subclasses are the results of recent evolutionary processes. Residues at position 4 from the C‐terminus may be phylogenetically related.
Fine specificity of the H‐2 linked immune response gene for the gallinaceous lysozymes
Authors: Hill Sharon W. , Sercarz E. E.
Published: February 2007

An immune response (Ir) gene is described which controls the abilityof mice to respond to seven very closely related gallinaceous egg white lysozymes (GEL This Ir‐GEL gene locus is linked to the major histocompatibility locus of the mouse and operates at the level of the T cell. Responsiveness to the nonimmunogenic prototype hen egg white lysozyme(HEL) is dominant and is unrelated to age or sex of the animals, or to dose of protein administered.

Ninety percent of C57BL/6 mice are absolute nonresponders to thenonimmun genic lysozymes in complete Freund's adjuvant. The remaining mice exhibit severely restricted responses, with different anti‐HEL clonotypes appearing in individual mice.

The fine specificity of the Ir‐GEL locus is evident in the discrimination of as few as two amino acid differences in a single region of the lysozyme molecule. This very precise distinction determines whether there will, or will not, be any response to the multideterminant molecule.
Regulation of the immune response by subclasses of T lymphocytes. II. The effect of adult thymectomy upon humoral and cellular responses in mice
Authors: Simpson Elizabeth , Cantor H.
Published: February 2007

The immunologic consequences resulting from thymectomy in adult lifewere investigated. Primary humoral responses were not diminished shortlyafter adult thymectomy, as judged by responses of intact thymetomized mice as well as by the ability of spleen cells from such mice to transfer primary responses. However, secondary humoral responses were substantially reduced in irradiated recipients of spleen cells from primed adult‐thymectomized mice, suggesting that the thymus is required in adultlife to maintain a population of cells important in the generation of immunologic helper memory. By contrast, small doses of anti‐ thymocyte serum, which primarily affect recirculating T cells, abrogated the printary humoral response, but allowed the subsequent development of immune memory.

Using a technique permitting in vitro sensitization of purified T cells to alloantigens, it was shown that adult thymectomy increasesthe ability of T cells to generate primary cytotoxic responses, but had little effect upon the development of cytotoxic T memory activity. Theseexperiments suggest that in adult life the thymus maintains a regulatorypopulation of T cells in peripheral tissues which suppress early T cell differentiation to cytotoxic effector cells and potentiates the development of immune memory.
Antibody response to phosphorylcholine in vitro. I. Studies on the frequency of precursor cells, average clone size and cellular cooperation
Authors: Cosenza H , Quintáns J , Lefkovits I
Published: February 2007

The anti‐phosphorylcholine (PC) antibodies synthesized by BALB/c spleen cells in microcultures upon immunization with heat‐killed vaccine of Pneucocci R36A (Pn) are directed exclusively to the PC epitope. These antibod are of very restricted avidity and 88 % of the responding clones express the idiotype characteristic of the TEPC‐15 PC‐binding myeloma. This idiotypi restriction appears to be due to the absence of clones capable of expressins other idiotypes, rather than to “clonal dominance”.

The estimated frequency of precursor cells for the PC epitope is 1 × 10− to 2.5 × 10−5. These precursors give rise to clones with an average size of 9 plaque‐forming cells. When the logarithm of the numberof negative wells was plottedagainst the number of spleen cells/well, the fraction of nonresing cultures decreased exponentially as the number of spleen cells was increased. This indicated that only one cell type was limiting in our assay, presumable B cell. Furthermore, treatment of spleen cells with AKR anti‐Θ serum completelyabolished the response to sheep red cells without affecting the response to. It is concluded that PC is a T cell‐independent antigen. Of interest was the finding that PC requires adherent (A) cells and this is a particular character of PC, since most T cell‐independent antigens have been found not torequire A cells. Reasons for the possible homogeneity of the response to PC are a discussed.
Binding of (T,G)‐A—L by normal sera
Authors: Krouwels J. M. , Bruning J. W.
Published: February 2007

The synthetic polypeptide poly‐L‐(Tyr, Glu)‐poly‐DL‐Ala—poly‐L‐Lys [(T,G)‐A—L] was found to be bound not only by mouse immune serum, but also by nonimmune sera from several species. A combination of immunoelectrophoresis and autoradiography showed that albumin, β‐globulins and immunoglobulins in these sera maybind the antigen. This binding pattern is different, however, for the various species investigated.
A new method of radioiodine labeling of polyanionic macromolecules for radiommunoassay
Authors: Little J. R. , Blanke T. J. , Little Katharine D.
Published: February 2007

A method is described for radiolabeling polyanionic macromolecules by the formation of an electrostatic complex with a radioiodinated tyramine conjugated DEAE‐dextran. Data is presented on the use of this technique for the detection and quantitation of immunospecific binding of polynitrophenylated proteins, deoxyribonucleic acids, and cell surfaceantigens.
Immunoglobulin turnover in B lymphocyte subpopulations
Authors: Melchers F , Cone R. E. , von Boehmer H , Sprent J
Published: February 2007

“In vitro” turnover of turnover of leucine‐labeled and of radioiodinated IgM has been studied with cells from various lymphoid organs of nude mice, i.e. lymph nodes, thoracic duct, spleen and bone marrow, as well as with subpopulations of B cells fromspleen and bone marrow separated by free flow electrophoresis.

Three types of IgM‐producing lymphocytes could be distinguished by their turnover rates of IgM, by the size of the released IgM and by the capacity of the IgM molecules to be labeled by the lactoperoxidase‐catalyzed radioiodination reaction and/or by incorporation of radioactive leucine. Type I cells release 7—8 S IgM rapidly (t1/2 = 1—3 h); the released IgM is leucine‐labeled and radioiodinated. Type II cells release 7—8S IgM slowly (t1/2 = 10—30); the released IgM is leucine labeled and radioiodinated. Type III cells release 19 S IgM rapidly (t1/2 = 2—4 h);the released IgM is leucine labeled, but not radioiodinated. Lymph nodesand thoracic duct contain predominantly type II cells, bone marrow contains type I and II cells, spleen contains type I, II and III cells. It is suggested that type III cells areIg‐secreting, plaque‐forming plasma cells, type II cells are small, resting “memory” B cells, and type I cells may be newly formed antigen‐inexperienced B cells.
Immunologic induction of reticulum cell sarcoma: donor‐type lymhomas in the graft‐versus‐host model
Authors: Gleichmann E , Peters K , Lattmann Evelyn , Gleichmann Helga
Published: February 2007

The aim of this study was to investigate malignant lymphomas of donor origin induced in F1 mice undergoing a chronic graft‐versus‐host reaction (GVHR) after injection of parental strain spleen cells. A total of 3 × 108 or 4 × 108 C57BL/10 spleen cells were administered to 7—8‐week‐old H‐2 incompaltible (C57BL/10 × HTG)F1 hybrids either as single or fractionated i.p. injections. Recipients were killed at intervals ranging from 1 month to 1 year after the first injection and their lymphoid cells typed for host‐derived and donor‐derived histocompatibility antigens. In 49 % of the 88 GVH F1 mice, cells failed to be killed by a hyperimmune serum against HTG (H‐2g) but reacted normally with antisera to C57BL/10(H‐2b) and, in the 9 cases tested, to theta‐C3H. The conclusion that the lymphoid cells of these mice were derived from donor cells was supported by the finding that these amimals lacked immunoglobulins bearing host‐derived Iga allotype in their serum.

Forty‐three percent of the GVH F1 mice developed reticulum cell sarcomas (RCS), 32 % revealed hyperplasticlymphoreticular tissue, and 25 % showed no grossly abnormal changes. Mice with donor‐typelymphoid tissues were found in all three groups; 50 % of the 38 RCS detected were donor‐type neoplasms. The induction of donor‐type RCS during the GVHR strengthens the concept of lymphomagenesis through persistent stimulation with antigen(s).
The amino‐terminal sequence of the VHIII subgroup ofpooled porcine IgG
Authors: Franěk F. , Wasserman R. L. , Novotn J , Kehoe J. M.
Published: February 2007

Pig γ‐chains contain a significant fraction of the unblocked VHIII variable region subgroup. The amino terminal sequence (30 residues) was found to be uniform and more than 90 % homologous with the prototype sequence of the human VHIII subgroup. An additional VHIII phylogenetically associated residue, glutamic acidin position 2 was identified in these porcine heavy chains.
Immunological effects of IgT synthesized by thetapositive cell lines
Authors: Feldmann Marc , Boylston A , Hogg Nancy M.
Published: February 2007

The effects of immunologlobulin (Ig) purified by affinity chromatography from two cultured T cell lines on in vitro immune responses was studied. IgT purified from both EL‐4 and WEHI‐22 suppressed the thymus‐dependent IgM response, but had no effect on thethymus‐independent IgM response. In contrast, the IgG responses to both thymus‐dependent and independent antigens were augmented at optimal concentrations of IgT. Ig of B cell origin — serum Ig, myeloma Ig, B cell surface Ig — did not have any of these effects. Because of the similarity of the effects of IgT purified from the lymphomas with the effects of T cells and their IgT, it seems likely that the IgT obtained from EL‐4 and WEHI‐22 cell lines are analogues of normal IgT and thus should be useful in elucidating some of the chemicaland biological properties of IgT.
Cell‐free media of mixed lymphocyte cultures augmenting sensitization in vitro of mouse T lymphocytes against allogeneic fibroblasts
Authors: Altman A. , Cohen I. R.
Published: February 2007

Using an in vitro mouse lymphocyte anti‐fibroblast reaction (AFR), we recently reported that the addition of allogeneic stimulator lymphocytes to the sensitization phase of the AFR enhanced sensitization to fibroblast antigens as evidenced by a marked increase in the cytolytic activity of the sensitized lymphocyte population. In the present report we studied the mechanism of this helper effect by testing the capacity of cell‐free media derived from 48‐h mixed spleen cultures to enhance anti‐fibroblast sensitization. We found that such cell‐free media could produce a marked helper effect when applied to the sensitization phase of the AFR, but not when added to the cytolytic effector phase. The stimulator cells in the mixed lymphocyte culture (MLC) did not have to be syngeneic with the sensitizing fibroblasts in the AFR in order for the helper effect to be demonstrated. Lymphocytes sensitized to fibroblast antigens in the presence of MLC medium retained their specificity of the effector phase. Our data suggest that the MLC medium acts by enhancing differentiation processes of antigen‐triggered lymphocytes. Generation of helper activity by the MLC was abolished by 1000 r irradiation of the responder cells. By using nu/nu and normal spleens, both from two different strains, as cell sources for the MLC, we found that the generation of helper activity depended on T cells capable of proliferation. Furthermore, stimulator lymphocytes differing from responder lymphocytes by non‐H‐2 alloantigens as well as by point mutation within the H‐2 complex were capable of eliciting helper factor(s). Thus, soluble factor(s) produced in a MLC, which are dependent on T lymphocyte proliferation, have the capacity to enhance the sensitization of mouse lymphocytes against antigens present on allogeneic fibroblasts.
Ontogeny of the antibody‐forming cell line in mice. I. Kinetics of appearance of mature B cells
Authors: Rosenberg Yvonne J. , Cunningham A. J.
Published: February 2007

The development of functionally mature B cells in the liver and spleen of fetal and neonatal CBA mice has been followed. A mature B cell is defined as one giving rise to antibody‐producing progeny within 2 days in culture. Very few such B cells are found during fetal life. After birth there is a rapid rise in the numbers reaching 1/3 of adult levels in the 7‐day‐old spleen.
Independent expression of the two HL‐A antigen polypeptide chains
Authors: Ostberg L. , Rask L. , Nilsson K. , Peterson P. A.
Published: February 2007

It is now well established that β2‐microglobulin constitutes one of the two HL‐A antigen subunits. In this study support was obtained for the previous notion that the human lymphoma Daudi does not produce β2‐microglobulin (β2m). Papain‐solubilized as well as nonidet P‐40‐solubilized Daudi HL‐A antigens do not contain any β2m or any detectable structural analogue of this protein. The chemical and physico‐chemical characteristics of highly purified HL‐A antigens derived from Daudi cells are indistinguishable from those of the HL‐A antigen‐carrying polypeptide chain isolated from the P3HRIK cell line. Like P3HRIK‐derived HL‐A antigens, the HL‐A antigens derived from Daudi cells are composed of two identical, heavy, alloantigenic polypeptide chains with a molecular weight of about 50000 each, which are held together by disulfide bridge(s). The HL‐A antigens of P3HRIK cells contain, in contrast to Daudi HL‐A antigens, two molecules of β2m. Although no evidence was obtained suggesting any β2m synthesis in Daudi cells it was apparent that these cells express the HL‐A alloantigenic polypeptide chain in amounts similar to those of other cell lines which produce β2m

The present data suggest [1] that β2m and the alloantigenic HL‐A polypeptide chain are under separate genetic regulation [2], that the cell surface integration of the HL‐A antigen‐carrying polypeptide chain is independent of the presence of β2m and [3] that β2m does not constitute a membrane component absolutely necessary to the integrity of the cell membrane.
Studies on the generation of B lymphocytes in the mouse embryo
Authors: Owen J. J. T. , Raff M. C. , Cooper M. D.
Published: February 2007

Using an organ culture technique, the development of B lymphocytes has been studied in a number of isolated embryonic hemopoietic tissues. Developing B lymphocytes were identified by cytoplasmic and surface immunofluorescence using purified class‐specific antibodies and a Fab antiimmunoglobulin reagent. In fetal liver cultures these cells were further characterized for Fc and complement receptors and for the presence of mousespecific B lymphocyte antigen. The results indicate that B lymphocytes develop independently in fetal liver and in fetal spleen; they do not develop in cultures of yolk sac and thymus. In conclusion, it is likely that B lymphocyte maturation in mammals is multifocal and is not dependent upon gastrointestinal influences as suggested previously.
Characteristics of the effector cells mediating cytotoxicity against antibody‐coated target cells. II. The mouse nonadherent K cell
Authors: Greenberg A. H. , Shen L. , Walker L. , Arnaiz‐Villena A. , Roitt I. M.
Published: February 2007

A cell of lymphoid morphology capable of killing antibody‐coated chicken erythrocytes was isolated from nonimmune mouse spleen using a combination of carbonyl iron treatment and glass bead column passage. This nonphagocytic effector cell, which is referred to as the nonadherent K (killer) cell, is distinguished from the non‐phagocytic myeloid K cell described earlier (Greenberg, A.H., Shen, L. and Roitt, I.M., Clin. Exp. Immunol. 1973. 15: 251) by its relatively weak surface adherence properties and low concentration within the mouse spleen. The cell is further characterized by its relatively large size, lack of theta or immunoglobulin determinants, the presence of Mg++‐independent complement receptors, affinity for aggregated IgG2 myeloma proteins, inhibition by cytochalasin B and good survival in cell culture. The possible lineage of the cell is discussed.
Persisting T cells in rats tolerant of human serum albumin. The significance of tolerant and nonimmune T cells which preferentially restrict high affinity antibody synthesis
Authors: Bell E. B. , Shand F. L.
Published: February 2007

The adoptive response of primed rat thoracic duct lymphocytes (′TDL) following specific antigen challenge (soluble human serum albumin, s‐HSA) was restricted when cells were transferred into syngeneic, adult (AS2 × AS) F1 hybrid recipients in comparison with irradiated hosts. This adoptive memory response was also inhibited in irradiated recipients by transferring nonimmune TDL along with ′TDL. Recirculating B cells (B‐TDL) did not inhibit the ′TDL response, indicating that the adoptive secondary response was regulated by T cells. Antibody synthesis was preferentially restricted in the high affinity memory cell precursor population, demonstrating a role for T cells in regulating the maturation of antibody affinity. The adoptive memory response was liberated from this T regulatory effect in adult recipients when hosts were challenged with the alum‐precipitated adjuvant form (HSA‐adj) rather than the soluble form of HSA.

Since the adoptive memory response was sensitive to the presence or absence of T cells, this experimental model was used to determine whether or not T cells were eliminated from HSA‐tolerant rats. Antibody synthesis by ′TDL was reduced approximatel 10‐fold compared with controls when transferred into tolerant recipients and challenged with either s‐HSA or HSA‐adj; a similar reduction was not observed by substituting bovine serum albumin (BSA) ′TDL and challenging with s‐BSA. The tolerance‐induced inhibition of HSA ′TDL was destroyed by irradiation and TDL from HSA‐tolerant donors were more effective than normal nonimmune TDL in reducing the adoptive HSA ′TDL response. HSA‐tolerant TDL did not inhibit the BSA ′TDL response significantly.

The results indicate that T cells are not eliminated by tolerance induction in this model and after interaction with tolerogen may exert an activ (or competitive) role in restricting antibody synthesis by high affinity B memory cell prcursors. However, the fact that tolerant T cells are not able to prevent a primary response suggests that unresponsiveness to HSA in the T compartment represents a functional deficiency and not an active suppression at this level. Nevertheless, the presence of these tolerant cells probably accounts for the failure of antibody affinity to mature in partially tolerant rats.
Immune response to phosphorylcholine. I. Characterization of the epitope‐specific antibody
Authors: Kluskens L. , Lee W. , Köhler H.
Published: February 2007

The antibodies to phosphorylcholine induced in BALB/c mice were isolated and studied with a variety of biochemical and immunochemical methods. Analysis of the idiotype and the hapten‐binding specificities showed no differences to the phosphorylcholine‐binding myeloma protein TEPC 15, indicating a high degree of homogeneity. However, disc electrophoresis, isoelectric focusing and amino acid composition data indicated large differences in the structure of anti‐phosphorylcholine antibody and TEPC 15. By these criteria the anti‐phosphorylcholine anti‐bodies from BALB/c mice are of oligoclonal origin.
Close linkage between genes coding for allotypic markers on chicken IgG and IgM
Authors: Pink J. R. L. , Ivanyi J.
Published: February 2007

The allotypic markers Gla and Gld (present on chicken IgG molecules) and Mla and Mlc (present on IgM) have previously been defined. The inheritance of these markers was studied in the F2 progeny of a cross between birds of the inbred lines CB (Gla+,d−, Mla+, c−) and WA (Gla−, d+, Mla‐, c+). The results suggest that antigens Gla and Gld, and Mla and Mlc, are genetically controlled by alleles at two loci (Gl and Ml, respectively) and also show that these loci are closely linked.
Correlation of “sneaking through” of tumor cells with specific immunological impairment of the host
Authors: Mengersen R. , Schick R. , Kölsch E.
Published: February 2007

The preferential take of tumors after small‐size inocula of transplantable tumor cells has been described for many systems. The phenomenon has been named “sneaking through” or “dilution escape”. Using a BALB/c mastocytoma, we have analyzed the immunological parameters accompanying sneaking through that can be observed upon injection of 101 to 103 living cells. Mice can also be conditioned by injection of low, subimmunogenic numbers of irradiated cells to show increased tumor incidences upon injection of living cells in doses two orders of magnitude above the sneaking through dose. The general immune reactivity of the animals is not impaired under these conditions. However, determinant‐specific unresponsiveness is found which can be transferred by spleen cells and therefore seems to be actively maintained. It is concluded that sneaking through of tumor cells is the result of specific immunological impairment of the host's immune system by subimmunogenic small‐size inocula of tumor cells.
Role of epitope density in the induction of immunity and tolerance with thymus‐independent antigens. II. Studies with 2,4‐dinitrophenyl conjugates in vivo
Authors: Desaymard Catherine , Howard J. G.
Published: February 2007

The immunogenicity and tolerogenicity of 2,4‐dinitrophenyl (DNP) conjugates of levan, type 3 pneumococcal polysaccharide (SIII), dextran B512 and dextran B 1299 with different levels of substitution were assessed in vivo. It was confirmed that, as in vitro, conjugates with low epitope density are solely immunogenic for Bμ cells, whereas higher density conjugates are both immunogenic and tolerogenic according to dosage. The maximal anti‐DNP plaque‐forming cell responses attainable varied by 2 log10 according to the carrier, being greatest with dextrans and least with SIII. The effect of the carrier on immunogenicity was not attributable to B cells responding to it, as concurrent tolerization by either free polysaccharide or the conjugate itself was without effect. Optimal immunization was succeeded by varying degrees of responsiveness (“exhaustion”) which was greatest with the more immunogenic conjugates. In contrast, reduction of tolerizing dose by cyclophosphamide suppression was only a feature of more highly substituted conjugates.
T cell proliferation in the mixed lymphocyte culture does not necessarily result in the generation of cytotoxic T effector cells
Authors: Röllinghoff M. , Pfizenmeier K. , Trostmann H. , Wagner H.
Published: February 2007

It was tested whether T lymphocytes, when stimulated in vitro by M locus‐coded lymphocyte activating determinants (LAD), are able to mediate cytotoxic effector functions. The assay for cytotoxicity included both the use of purified appropriate target cells (i.e. purified lipopolysaccharide blasts) as well as the use of phytohemagglutinin dependent cytolysis as a model for detecting cytotoxic T lymphocytes (CTL). Although strong proliferative responses were obtained in the mixed lymphocyte culture, the T cell blast generated did not display any detectable cytotoxic effector function. Thus, it is concluded that LAD, at least in the M locus‐dependenet system, do have the capacity to induce T cell proliferation but do not induce CTL.
I‐region‐associated determinants: expression on mitogen‐stimulated lymphocytes and detection by cytotoxic T cells
Authors: Nabholz M. , Young H. , Rynbeek A. , Boccardo R. , David C. S. , Meo T. , Miggiano V. , Shreffler D. C.
Published: February 2007

We have studied the expression of Ia‐antigens, controlled by genes in the I‐region of the H‐2 complex, on phytohemagglutinin (PHA)‐stimulated lymph node cells and on lipopolysaccharide (LPS)‐stimulated spleen cells, and have compared these two types of cell populations as targets for killer cells in the cell mediated lympholysis (CML) assay. PHA targets are almost completely insensitive to complement‐mediated lysis by anti‐Ia sera while the majority of LPS targets are killed. T cell‐mediated lysis against I‐region determinants was also detected, and these determinants, in contrast to H‐2K and H‐2D CML determinants, seem to be much more strongly expressed on LPS‐stimulated cells. No differences in the kinetics of the response to K‐or I‐region CML determinants were observed. Lysis by killer cells can also be obtained against incompatibilities which do not give rise to strong skin graft rejection and against determinants which are most probably controlled by genes outside the K‐D interval.
Inhibition of mixed leukocyte culture by anti‐idiotypic antibodies
Authors: Binz H. , Askonas Brigitte A.
Published: February 2007

(CBA × C57BL/6)F1 antisera prepared by injecting F1 mice with CBA T lymphocytes or CBA anti‐C57BL/6 alloantibodies were tested for their ability to inhibit the mixed leukocyte culture (MLC) response. Presence of antiserum throughout the culture period in the absence of complement did not have any effect on the MLC response. Treatment of CBA responder cells with F1 antiserum and complement prior to the culture specifically inhibited the MLC response. Specificity of the suppression was ascertained; absorption of the F1 sera with F1 or C57BL/6 spleen cells did not remove the suppressive factor, whereas absorption with CBA spleen cells did so. F1 antiserum treatment left intact the response to third party alloantigens (DBA/2).

Immunabsorbent columns with alloantibody of corresponding specificity removed the suppressive factor from anti‐T cell sera as well as from antisera to alloantibody. The data suggest that the circulating alloantibody population contains molecules which share idiotypic determinants with surface receptors on T cells recognizing the same alloantigens.
Separation of antigen‐specific lymphocytes. A new general method of releasing cells bound to nylon mesh
Authors: Kiefer H.
Published: February 2007

Inserting a disulfide bridge between nylon and hapten or antigen allows the release of fiber bound cells by cleaving the disulfide bond with 10−4 M 2‐mercaptoethanol at 4°C. Four to 12‐fold enrichments in specific precursor cells could be obtained. The method is compared with the thermal release previously used. The T and B cell content of the specific fraction was determined.

It is suggested that the low enrichment in plaque‐forming cells of the hapten‐specific fraction found after stimulation with antigen in vitro might be due to the fact that there is also enrichment for suppressor cells in the specific fraction.
Permissiveness of athymic (“nude”) mice towards congenic memory cells
Authors: Kobow Ursula , Weiler E.
Published: February 2007

Spleen cells from BALB/c or BALB‐Igb mice immunized against the determinant oligo‐D‐alanine were transferred to the following recipients: normal BALB/c; lethally irradiated BALB/c; and congenitally athymic BALB/c‐nu. Irradiated as well as nude recipients permitted the development of a strong adoptive antibody response, while the response in normal BALB/c recipients was very low (“isogeneic barrier”). Using allotypically marked spleen cells from BALB‐Igb donors it was shown that the antibodies in irradiated as well as in nude recipients were produced by donor cells. The same conclusion was drawn by assessing isoelectric focusing spectra, which in each transfer displayed the individually characteristic pattern of the donor. In addition to specific antibodies, the donor cells produced considerable levels of IgG, as characterized by allotype, but again only in nude and in irradiated recipients.

The ready permissiveness of nude recipients towards congenic memory cells could be abolished when prospective recipients were restored, some time prior to transfer, by BALB/c thymus or BABL/c spleen cells.

The results are interpreted to suggest that the isogeneic barrier in normal recipients is due to a thymus‐dependent suppression or rejection of memory cells by the recipients.
Energy requirements of the binding and lytic steps of T lymphocyte‐mediated cytolysis of leukemic cells in vitro
Authors: Berke G. , Gabison D.
Published: February 2007

The process of T lymphocyte‐mediated destruction of target cells in vitro is temperature dependent and is suppressed by inhibitors of energy metabolism, but the energy requirements for the conjugation and lytic steps of the process are different. The conjugation step of lymphocytes and target cells is prevented by metabolic inhibitors and is dependent on temperature, increasing in the range from 2°C to 22°C. However, after lymphocyte‐target cell conjugates are formed, they are stable at low temperatures (0°C) and in the presence of metabolic inhibitors. Thus, the formation but not the maintenance of lymphocyte‐target cell conjugates is an energy‐dependent process. In contrast to the conjugation step, which is influenced both by metabolic inhibitors and by temperature, the lytic step, which occurs only between 22°C and 37°C, is not affected by inhibitors of energy metabolism. The sigmoidal behavior of lysis as a function of temperature, showing a sharp inflection around 20°C, can be explamed in terms of the alteration of the viscosity of the membrane matrix of the target cells rather than as a general metabolic effect on the killer and target cells.
Specific B lymphocyte suppression by infectious bursal agent (Gumboro disease virus) in chickens
Authors: Hudson L. , Pattison M. , Thantrey N.
Published: February 2007

Chickens infected experimentally with infectious bursal agent (IBA) during embryonation or early after hatching show a severe depression of bursa‐dependent lymphoid components, and associated immune functions. Data presented here and elsewhere show that the degree of B cell suppression correlates with the time of infection. This would be compatible with a virus‐induced block in B lymphocyte differentation. Accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) B lymphocytes or, more likely, the virus inactivates those non‐lymphoid bursal cells mediating lymphocyte differentiation.
B cell tolerance induced by polymeric antigens. III. Dissociation of antibody formation and memory generation in tolerant mice
Authors: Klaus G. G. B. , Willcox H. N. A.
Published: February 2007

Hapten (2,4‐dinitrophenyl (DNP))‐substituted type 3 pneumococcal polysaccharide (DNP‐lys‐S3) effectively suppresses both primary and secondary anti‐DNP antibody responses to DNP‐proteins. The present experiments show that tolerizing doses of DNP‐lys‐S3 have much less effect on B cell memory (re)generation in three distinct situations: (i) in serial transfers of DNP‐protein‐primed cells, (ii) in virgin mice tolerized before priming with DNP‐hemocyanin, and (iii) in tolerized, hemocyanin‐primed mice boosted with DNP‐hemocyanin. Under some conditions tolerized mice developed 10–50% of normal memory in the absence of significant antibody formation.

Isoelectric focusing analyses revealed that many B cell clones proliferate in tolerant mice, but produce very little antibody until transferred to further hosts. Clones that escape suppression in partially tolerant mice do not appear to be resistant to DNP‐lys‐S3, when retested.

Since there is independent evidence that the generation of B memory cells is less T cell‐dependent than the development of antibody‐forming cells, these data are best explained by assuming that DNP‐lys‐S3 blocks lymphocyte cooperation. This would be expected to preferentially suppress antibody formation, and to spare memory generation.
Surface immunoglobulins on the lymphocytes of the skate Raja naevus
Authors: Ellis A. E. , Parkhouse R. M. E.
Published: February 2007

Living lymphocytes of the Elasmobranch fish, Raja naevus, have been examined for surface immunoglobulin (Ig) by treatment with a fluorescent anti‐Ig system. Large numbers of Ig‐positive cells (60–80%) were found in peripheral blood, spleen and thymus. Following modulation of the surface Ig with anti‐Ig, resynthesis occurred, showing that the surface Ig is a product of the individual lymphocytes rather than material passively absorbed from the serum. Formation of caps was independent of temperature, occurring as readily at 4°C as at 20°C, a finding which presumably reflects the environmental conditions normally experienced by the skate. The presence of Ig‐bearing lymphocytes in the adult skate thymus suggests a similarity to the amphibian larval thymus, which may be a primary lymphoid organ for the production of both T and B lymphocyte analogues.
Genetics of mouse antibodies. I. Linkage of the dextran response locus, VH‐DEX, to allotype
Authors: Riblet R. , Blomberg Bonnie , Weigert M. , Lieberman Rose , Taylor B. A. , Potter M.
Published: February 2007

The antibody response of mice to α‐1,3 linked dextran is shown to be controlled by a heavy chain variable region gene, VH‐DEX. The map distance between this gene and the heavy chain allotype locus is estimated to be 0.3 recombination units.
Genetics of mouse antibodies. II. Recombination between VH genes and allotype
Authors: Riblet R. , Weigert M. , Mäkelä O.
Published: February 2007

The BAB/14 (BALB/c.C57BL/Ka‐Ig‐1b/Hz) congenic mouse strain was found to respond to (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)‐chicken globulin immunization with nonheteroclitic anti‐NP antibodies as does the BALB/c inbred partner strain. This is in contrast to the heteroclitic anti‐NP response of the C57BL/Ka allotype donor strain and indicates that the allotype linked VH‐NP gene was inherited with the VH‐DEX gene from BALB/c rather than with the allotype genes from C57BL/Ka. This verifies the interpretation of BAB/14 as an immunoglobulin gene recombinant.

Two recombinants between VH‐DEX and Ig‐1 allotype genes have been found among 554 chromosomes tested yielding a recombination frequency of 0.4%. Analysis of the BAB/14 recombinant showed that this crossover occurred between VH genes implying that VH genes and CH genes are not organized in separate clusters separated by a large spacer region but are contiguous. Analysis of the recombination frequencies indicates that the total number of VH genes must be at least 50.
A primary immune response of Bufo marinus spleen cells in vitro
Authors: Azzolina L. S.
Published: February 2007

Single‐cell suspensions of Bufo marinus spleen have been induced to produce a primary immune response to a soluble purified protein. Using polymerized flagellin from Salmonella adelaide as antigen and culture conditions commonly available in most laboratories but new for amphibian cells, it has been found that in vitro at 37°C, toad spleen cells produce an antibody‐forming cell response optimal at day 6. The response depends on the number of cultured cells and dose of antigen, and parallels that obtained in vivo. The optimal immune response is preceded at day 4 by the peak uptake of tritiated thymidine. The antibody‐forming cell response is suppressed in the presence of allogeneic serum.
Control mechanisms of lymphocyte traffic. Modification of the traffic of 51 Cr‐Labeled mouse lymph node cells by treatment with plant lectins in intact and splenectomized hosts
Authors: Freitas A. A. , de Sousa Maria
Published: February 2007

The results of a study of the effect of treatment of purified or mixed lymphocyte populations with concanavalin A (Con A), chymotrypsinized Con A and phytohemagglutinin on their distribution in syngeneic intact and splenectomized hosts after i. v. injection are reported. The currently held view that lymphocyte traffic is controlled by a specific interaction between the sugars on the surface of the lymphocytes and the post‐capillary venule in the lymph nodes is questioned and an alternative explanation offered for the demonstrable decrease in lymph node entry in intact recipients of lymphocytes pretreated with plant lectins.
Secondary cytotoxic allograft response in vitro. I. Antigenic requirements
Authors: Röllinghoff M. , Wagner H.
Published: February 2007

The antigenic requirementsfor in vitro induction of secondary murine cytotoxic allograft responses were tested. The proliferative responses were assayed by the [3H]thymidine uptake technique; the generation of cytotoxic T lymphocytes (CTL) was tested in a 51Cr‐cytotoxicity assay. Spleen cells from normal or alloantigen preimmunized CBA mice (H‐2k) were used as responder cells. Allogeneic x‐irradiated splenic lymphocytes (normal stimulator cells) were UV light treated, heat treated or glutaradehyde fixed and subsequently tested for their capacity to induce CTL in a primary or secondary mixed lymphocyte culture (MLC). In addition allogeneic fibroblasts were tested as stimulator cells. The results obtained suggest that although they fail to trigger significant proliferative and cytotoxic T cell responses, in a primary MLC certain allogeneic stimulator cells, are able to induce strong cytotoxic T cell activity in a secondary MLC. The generation of these secondary CTL is preceded by only marginal cell proliferation.
H‐2 and non‐H‐2 determinants in the genetic control of cell‐mediated lympholysis
Authors: Schendel Dolores J. , Bach F. H.
Published: February 2007

Histocompatibility loci of the H‐2 complex in mouse have been divided into two genetically and functionally distinct components: the lymphocyte defined (LD) and serologically defined (SD) systems. Generation in mixed leukocyte cultures of cytotoxic lymphocytes which mediate 51Cr release from appropriate targets in cell‐mediated lympholysis (CML) tests involves an interaction between the responses to the H‐2 LD and SD differences. Data presented here show that genetic differences for the Mls locus can substitute for H‐2 LD in the generation of cytotoxic lymphocytes; relataively low level but significant CML is associated with H‐2 LD.
Secondary cytotoxic allograft responses in vitro. II. Differentiation Of memory T Cells into cytotoxic T lymphocytes in the absence of cell proliferation
Authors: Wagner H. , Röllinghoff M.
Published: February 2007

Murine cytotoxic T lymphocytes (CTL) were induced in “one‐way” mixed lymphocyte cultures and their physical characteristics investigated by velocity sedimentation at 1 × g. The in vitro differentiation of progenitors of CTL into primary and secondary CTL was paralleled by characteristic changes in the size of the responder cells. Fractionated cells enriched for primary blast CTL reverted into clonally restricted “nonlytic” secondary T lymphocytes. Upon antigenic reexposure, these lymphocytes differentiated into secondary CTL within 18–32 h. This took place in the absence of cell proliferation and could be triggered by UV light irradiated allogeneic stimulator cells. It is suggested that the different characteristics for the induction of either a primary or secondary cytotoxic T cell response reflect qualitative differences between unprimed T cells and memory T lymphocytes.
The expression of human beta2 microglobulin on human spermatozoa
Authors: Fellous M. , Colle A. , Tonnelle C.
Published: February 2007

The expression of human β2‐microglobulin was detected on human spermatozoa from 7 donors using a cytotoxicity assay and indirect immunofluorescence. Inhibition experiments using purified β2‐microglobulin demonstrated the specificities of these reactions. We were able to localize β2‐microglobulin on human spermatozoa on the post‐acrosomal region at a similar location to those described for HL‐A antigen and for early embryonic antigen +t12, but also at the end of the intermediary piece and the beginning of the tail.
Rapid recovery of antigen‐binding receptors on chicken B cells following anti‐lg serum treatment
Authors: Ivanyi J. , Fuensalida E. , Lydyard P. M.
Published: February 2007

Rosette‐forming cells (RFC) from the peripheral blood of sheep red blood cell (SRBC)‐immunized chickens were characterized as B cells which manifest antigen‐binding receptors but no antibody secretion. Lymphocytes were pretreated at 0 °C with anti‐Ig serum, washed, incubated further at various temperatures and harvested for the rosette‐forming cells (RFC) assay. Anti‐Ig treatment blocked all RFC formation and providing that the cells were maintained at less than 10 °C regeneration did not occur up to 6 h. Complete recovery of RFC formation occurred within 10 min at 37 °C following treatment with low but not with high concentrations of anti‐Ig serum. However, recovery from inhibition by high‐dose anti‐Ig treatment was achieved by including chicken IgG in the incubation medium. The recovery of receptors was reduced following “sandwich” treatment of lymphocytes. When cells were treated with anti‐Ig antibody, washed and exposed to various drug inhibitors of “capping” the regeneration of RFC was prevented; in contrast, inhibitors of protein synthesis were ineffective. The results were interpreted in terms of dissociation of anti‐Ig antibodies from the Ig receptor at an early stage of the ligand‐induced receptor redistribution process.
Immunological enhancement of a murine tumor allograft by passive alloantibody IgG and F(ab′)2
Authors: Kaliss N. , Sinclair N. R. Stc. , Cantrell J. L.
Published: February 2007

The F(ab′)2 fraction of an anti‐tumor IgG alloantiserum induced passive enhancement of tumor allografts in inbred mice about as well as did intact IgG; i.e. apparently the Fc fragment is not required for suppressing cellular immunity. Passive F(ab′)2, however, was somewhat less efficient than intact IgG or whole alloantiserum in depressing the allohemagglutinin response. The latter finding is in accord with previous observations on the relative inefficiency of F(ab′)2 in feedback inhibition of the humoral response of mice to a heteroantigen.
Requirement for accessory cells in the antibody response to T cell‐independent antigens in vitro
Authors: Lee K.‐C. , Shiozawa C. , Shaw A. , Diener E.
Published: February 2007

The antibody responses of mouse spleen cells in vitro to three thymus‐independent (TI) antigens namely, polymeric flagellin (POL) of Salmonella adelaide, DNP‐Ficoll and “soluble” sheep erythrocyte (SRBC) antigen, were found to be dependent on adherent accessory cells (A cells) but to a lesser degree than the response to intact SRBC. Evidence for this comes from selective depletion of A cells from spleen cells and reconstitution with A cell‐rich populations. Thus, depletion of A cells by adherence on glass resulted in abolition of the response to SRBC leaving the response to POL intact. More thorough removal of A cells by treatment with carbonyl iron powder was required for appreciable reduction of the responses to POL, DNP‐Ficoll and “soluble” SRBC. This reduction in responsiveness was not due to poor cell survival after A cell depletion or to the loss of immunocompetent cells since 1) the recoveries of viable cells in all cultures were similar; 2) the contents of Θ‐ and Ig‐bearing cells and tritium‐labeled POL‐binding cells were unaltered after carbonyl iron treatment, and 3) responsiveness was fully restored by the addition of irradiated and anti‐Θ‐treated A cells from the peritoneal cavity or the spleen. Hence, the hitherto A cell independence of TI antigens on which some theories of B cell activation are based is a result of inadequate depletion procedures, and the minimal model for B cell activation must take into account two cell types: B cells and A cells.