bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic marker in the variable region of kappa chains of mouse anti‐phosphorylcholine antibodies
Authors: Claflin J. L.
Published: February 2007

A newly discovered genetic marker in the kappa light chains of mouse immunoglobulins is described. This marker, designated K‐PC8, is located in the L chains of those anti‐phosphorylcholine (PC) antibodies which show the same functional and idiotypic characteristics as a PC‐binding myeloma protein, HOPC 8 (H8). Analytical isoelectric focusing of these L chains revealed two phenotypes whose strain distribution pattern suggested a genetic association with genes that determine the T lymphocyte surface antigen(s) Ly‐2/Ly‐3. In four strains, AKR/J, C58/J, RF/J and PL/J (AKR‐type, A) the H8‐like L chains have a slightly lower isoelectric point than those of C57L/J and 12 other strains (C57L‐type, B). Breeding experiments showed that the K‐PC8‐A phenotype is preferentially expressed. The most probable location of the marker is the variable region since other idiotypically related K‐chains in CS7L/J and AKR/J do not show differences in their electrophoretic mobility.
Regulation of the immune response. I. Suppression of delayed‐type hypersensitivity by T cells from mice expressing humoral immunity
Authors: Ramshaw I. A. , Bretscher P. A. , Parish C. R.
Published: February 2007

The ability of horse red blood cell (HRBC)‐specific T cells from mice expressing humoral immunity to suppress the induction of HRBC‐specific delayed‐type hypersensitivity (DTH) was investigated. The transfer of Ig‐negative spleen cells, from mice injected 4 days previously with HRBC, completely suppressed the development of DTH in mice treated with cyclo‐phosphamide and sensitized with HRBC. The suppressor cell was found to be lysed by treatment with anti‐theta serum and complement. Furthermore, hemocyanin‐specific immune T cells were able to suppress the DTH induced to HRBC, provided these two antigens were coupled together.

These studies suggest that T cells present under conditions where humoral immunity is induced can suppress DTH and that such cells play an important role in the regulation of the immune response.
Development of sheep thymus in relation to in utero thymectomy experiments
Authors: Jordan R. K.
Published: February 2007

The developing thymus of sheep embryos has been examined from 20 days of gestation onwards. The initial relationships of the thymus to the parathyroid III and the pericardium are maintained so that the thymus develops as an extensive and complex structure consisting of paired cords of tissues on either side of the neck continuous with a single, fused structure in the anterior mediastinum. Histological examination of the developing thymus revealed that thymic lymphopoiesis commences at 36 days of gestation (term = 150 days).

The results indicate that conclusions drawn from sheep thymectomy, usually performed after 60 days of gestation, must be interpreted with caution.
Production of osteoclast‐activating factor by normal human peripheral blood rosetting and nonrosetting lymphocytes
Authors: Chen Priscilla , Trummel C. , Horton J. , Baker J. J. , Oppenheim J. J.
Published: February 2007

This study has tested the ability of human mononuclear cells and the subpopulations of lymphocytes that rosette (E‐RFC) or do not rosette (non‐E‐RFC) with sheep red blood cells to synthesize DNA and to produce a mediator with bone resorbing activity (osteoclast‐activating factor, OAF) in response to stimulation with phytohemagglutinin (PHA). Mononuclear cells were stimulated by PHA both to synthesize DNA and to produce a factor that caused bone resorption. E‐RFC enriched for T lymphocytes and depleted of macrophages synthesized considerable DNA in response to stimulation with PHA, but were unable to produce significant bone resorbing activity in tissue culture unless macrophages were re‐added to the E‐RFC. In contrast, mononuclear cells depleted of E‐RFC (non‐E‐RFC enriched for B cells) did not synthesize DNA in response to stimulation with PHA, but did produce a mediator that caused significant bone resorption in tissue culture. In most of the experiments, unstimulated non‐E‐RFC produced as much OAF as the PHA‐stimulated non‐E‐RFC. These results suggest that both activated T lymphocytes (E‐RFC) and B lymphocytes (non‐E‐ RFC) can produce OAF.
Investigations of red cell glyoxalase in recombinant families
Authors: Pretorius Aletta M. G. , Scholz S. , Kuntz Barbara , Albert E. D.
Published: February 2007

The polymorphism of the red cell glyoxalase (GLO), which has recently been found to be linked with the major histocompatibility complex (HLA) in man, was investigated in a number of selected families showing various recombinations between HLA‐A, HLA‐B and the third locus of the phosphoglucomutase (PGM3). In two families with a recombination between HLA‐A and HLA‐B, the GLO allele travels with the HLA‐B locus fragment of the chromosome, indicating that GLO is located on the side of the HLA‐B locus. In other families, recombinations occurred between HLA‐A and B on one side and GLO and PGM3 on the other side, demonstrating that GLO and PGM3 are located on the same side of HLA. Other recombinations separated PGM3 from GLO so that it can be assumed that GLO is located between HLA‐B and PGM3. Thus the immunogenetic linkage group on human chromosome C6 has been increased by yet another outside marker gene to include now the following genes in this order: HLA‐A–HLAC–HLA‐B–Bf–HLA‐D‐CLO–PGM3.
“Early T cells” and “late T cells”; suggestive evidence for two T cell lineages with separate developmental pathways
Authors: Droege W.
Published: February 2007

Peripheral lymphocytes from mice have been analyzed by a combination of cell electrophoresis and size distribution analysis and the data have been processed with a computer into two‐dimensional distribution patterns (fingerprints). The fingerprints of lymph node cells revealed the existence of at least three major classes of small lymphocytes. Cells with similar physical properties were found in the spleen and thoracic duct lymph. The data also allowed calculation of the quantitative ratios of the three cell types. In the normal mouse, the two electrophoretically faster cell classes represent essentially two subclasses of T cells. The quantitative ratios are here always in agreement with the known percentages of B and T cells.

Lethally irradiated mice that have been reconstituted with syngeneic bone marrow or fetal liver cells often lack one of the T cell subclasses. This has two important implications. 1) It indicates that the widely used syngeneic or allogeneic bone marrow chimeras may be incomplete in respect to their T cell repertoire and that experiments with these models should be interpreted with caution. 2) The deficiency was found to correlate strictly with a deficiency in a physically defined subset of small cortical thymocytes that has been described previously. This correlation suggests strongly that the fast peripheral T cells and the “early small cortical thymocytes” represent two developmental stages of a distinct cell lineage (“early T cell lineage”), while the thymic pool of “late small cortical thymocytes” gives rise to electrophoretically slow peripheral T cells, which may be called “late T cells”. The possibility that both T cell lineages are derived from different classes of prethymic stem cells in the reconstituting stem cell preparation is discussed. The proportion of “early T cells” in the lymph nodes decreases with age. The ratio of “late” and “early T cells” is similar in the spleen and in the lymph nodes, and both cell classes contain a significant proportion of cells that are not affected by the early effects of adult thymectomy. Thus, they do not correspond to T1 and T2 cells.
Comparison of the cytophilic activities of guinea pig IgG1 and IgG2 antibodies
Authors: Leslie R. G. Q. , Cohen S.
Published: February 2007

Monomeric guinea pig IgG1 binds to homologous peritoneal macrophages, though less effectively than IgG2. It binds to the cells with a lower association constant (Ka = 0.61 ± 0.22 × 106 L/M at 20 °C) than IgG2 (Ka = 1.44 ± 0.16 × 106 L/M), and the number of IgG1 receptor sites per cell (1.3 ± 0.18 × 106) is about one‐half that for IgG2 (2.65 ± 0.45 × 106). Enhanced IgG1 binding is observed on immune complex formation, though the increase in avidity of the complexes is dependent on their size. Marked enhancement of avidity with increase in complex size occurs only with small complexes (containing less than seven antibody molecules): with larger complexes a plateau in avidity appears to be reached. Immune complex binding is inhibited by monomeric IgG1. Comparative studies with IgG1 and IgG2 demonstrate that IgG1 is bound to the same cell type as IgG2 (primarily, the macrophage) by a nonidentical, though related, receptor.
Regulation of T cell‐mediated cytotoxic allograft responses. I. Evidence for antigen‐specific suppressor T cells
Authors: Wagner H. , Starzinski‐Powitz A. , Pfizenmaier K. , Röllinghoff M.
Published: February 2007

Murine lymph node cells draining a local lymphoid cell allograft (LNd) exhibited weak cytolytic activity when tested immediately after surgical removal, However, upon mere in vitro cultivation, high cytotoxic activity developed. The in vitro generation of cytotoxic activity could be inhibited by treatment of the cells with mitomycin C. Upon transfer into a primary mixed lymphocyte culture, mitomycin C‐treated LNd cells effectively suppressed the induction of cytotoxic T lymphocytes (CTL). Using the velocity sedimentation technique at 1 × g the suppressor cells could be confined to the blast cells within LNd cells, the sensitized prekiller T cells being nonsuppressive. Results derived from independent experimental approaches suggested that the in vivo sensitized blast suppressor cells exhibited an immunological specific suppression, i.e. they selectively suppressed the in vitro induction of CTL reactive towards those H‐2 transplantation antigens against which the suppressor cells had been immunized. Thus, antigen‐specific suppressor cells (which were Thy‐1.2 positive) appeared to be specifically activated during the in vivo sensitization procedure.
Expression on a human cell line (Daudi) lacking both HLA and β2 ‐microglobulin of HLA‐D products and cell‐mediated lympholysis targets
Authors: Charmot D. , Kamoun M. , Crosier P. , Sasportes M. , Fellous M. , Mawas C.
Published: February 2007

The Daudi cell line which originated from a Burkitt lymphoma has recently been found lacking in HLA and β2‐microglobulin (β2 m), but carrying surface antigens, coded for by the human major histocompatibility complex, which are expressed on B cell‐enriched normal human peripheral blood lymphocytes. This report demonstrates that the stimulating property of the Daudi cell line in a mixed lymphocyte culture is indeed related to the expression of HLA‐D for which this cell line has been typed by the primed lymphocyte test; furthermore, this cell line was found to be an excellent target in the cell‐mediated lympholysis (CML) test for cytotoxic effector cells generated either against Daudi cells or against normal lymphocytes. Preliminary serological data obtained with the Daudi cell line suggest a correlation with CML data. Therefore β2m is probably not necessary for the expression of HLA‐D products nor is HLA a prerequisite for CML recognition and lysis.
Suppression of generation of human cytotoxic effectors by lectins or lectin‐activated peripheral blood lymphocytes
Authors: Mawas C. , Charmot D. , Comoy A. , Sasportes M.
Published: February 2007

The lectins phytohemagglutinin, pokeweed mitogen and concanavalin A used at their optimal mitogenic concentration, or human lymphocytes activated by the same mitogens, were found to suppress thein vitrogeneration of cytotoxic effectors when added to a cell‐mediated lympholysis (CML) mixture during the first 48 h of culture. The data suggest that the suppressive mechanism is mediated to a greater extent by an allogeneic interaction between lectin‐activated cells and the allogeneic cells present in the CML mixture than by suppressor cells induced by the lectin. Since partial suppression was observed with supernatants of activated lymphocytes cultured for 18 h with allogeneic stimulating cells (but not activated lymphocytes alone), a soluble mediator may be involved in the suppressive mechanism. The mechanism of suppression therefore may be identical to the preemption phenomenon recently described in primary and secondary CML.
Studies on the lymphocytes of sheep. Destination of lymph‐borne immunoblasts in relation to their tissue of origin
Authors: Hall J. G. , Hopkins J. , Orlans E.
Published: February 2007

Lymph‐borne immunoblasts were labeled in vitro with 125I[ ] iodo‐deoxy‐uridine, washed and returned by intravenous injection to the sheep from which they had been collected. Twenty h later the sheep were killed and the distribution of the immunoblasts was determined by assaying the radioactivity in various organs.

Immunoblasts from the efferent lymph of peripheral somatic lymph nodes (PSLN) went mainly t o the spleen, lungs and other PSLN, while immunoblasts from intestinal lymph went mainly to the small gut. This ability of intestinal immunoblasts t o home t o the gut was demonstrated also in the sterile environment of fetuses in utero; apparently the migratory behavior of immunoblasts, like that of small lymphocytes, is not primarily “antigen‐driven”.

A technique was devised for the collection of peripheral (i.e. afferent to the mesenteric node) intestinal lymph which was found to contain 10–20 times the numbers of small lymphocytes that occur in the peripheral lymph from other tissues. Immunoblasts from peripheral intestinal lymph also homed to the gut.

The immunoglobulin content of immunoblasts was studied by making detergent extracts of lymph cells, by applying immuno‐peroxidase techniques t o cell films and by investigating the incorporation of 14C‐labeled amino acids into immunoglobulins by immunoblasts in vitro. Immunoblasts from both somatic and intestinal lymph contained and made IgG and IgM, but many intestinal immunoblasts contained and made IgA. It is not known whether this immunoglobulin mediates the extravasation of immunoblasts into the gut. Nonetheless, there is compelling evidence that there are two major migratory pathways for lymphoid cells; one through the gut‐associated lymphoid tissue and the other through the somatic‐splenic lymphoid tissues.
Radioimmunoassay of the phagocytosis‐stimulating peptide tuftsin in normal and splenectomized subjects
Authors: Spirer Z. , Zakuth Vera , Bogair N. , Fridkin M.
Published: February 2007

A radioimmunoassay was developed for the phagocytosis‐stimulating peptide tuftsin, H‐Thr‐Lys‐Pro‐Arg‐OH, and preliminary results of its use in evaluating tuftsin levels in human blood are presented.

Synthetic tuftsin was rendered antigenic through coupling of p‐diazonium phenylacetyl‐tuftsin to bovine serum albumin (BSA). Using the BSA‐tuftsin conjugate to immunize rabbits, antisera were obtained that bound 125I‐labeled p‐aminophenylacetyl‐tuftsin at dilutions up to 1:1500 (maximal binding 25–3 0 %). Binding of the radiolabeled peptide was inhibited by tuftsin and some of its synthetic N‐terminal analogs but was not affected by various unrelated natural and synthetic peptides. The amino acid sequence Lys‐Pro‐Arg‐OH appears to be the antigenic determinant recognized by the rabbit antibodies.

Using the radioimmunoassay, quantitative determination of material immuno‐chemically related to tuftsin was performed in the sera of intact and splenectomized subjects after treatment of the sera with trypsin. Sera from normal patients (21 cases) were found to contain an average ± standard error of 278.47 ± 13.49 ng/ml, whereas those of patients who underwent traumatic (5 cases) and elective (6 cases) splenectomy contained 239.0 ± 47.68 ng/ml and 94.71 ± 22.5 ng/ml, respectively. No correlation was found between levels of IgG in serum and that of tuftsin‐like material.

Analysis of purified IgG fragments, Fab from man and from rabbit and Fc from rabbit, clearly demonstrated that tuftsin is located or bound to the latter polypeptide. It was, of course, also found to be present in the intact purified IgG from humans.
Interferon‐induced antibody suppression: a selective effect on high density, late responding precursor cells
Authors: Finlay G.J. , Marbrook J. , Booth R. J.
Published: February 2007

Mouse spleen cells have been fractionated into three subpopulations by density gradient centrifugation and the effect of interferon on the ability of each fraction to generate an antibody response in vitro has been examined. The results show that only the antibody‐forming cell precursors (AFCP) of the high density, late responding fraction are suppressed by interferon. The presence of interferon had no effect on either the number or the mean size of clones of antibody‐forming cells in cultures of the low and medium density fractions. Interferon‐mediated suppression of the response of high density precursors was due to a decrease in the number but not the size of responding clones. These results suggest that interferon suppresses antibody responses by affecting the degree to which high density AFCP can becoming activated rather than the degree to which precursors proliferate.
Down regulation in B lymphocytes: low dose signals
Authors: Baltz Marilyn , Rittenberg M.B.
Published: February 2007

Picogram quantities of dinitrophenylated (DNP) dextran, a thymus‐inde‐pendent antigen or lipopolysaccharide, a B cell mitogen, signal down B lymphocytes to unresponsiveness. Down signals were detected by a decision test in which signaled lymphocytes were allowed one hour to react to an immunogenic pulse of DNP‐dextran. Depletion of T cells or macrophages did not interfere with the generation of down signals. The signaling can proceed entirely at 4 °C and its negative effect is transitory. Down signals which could be detected after 15 min at 37°C were reversed by 60 min. It is suggested that down regulation by low dose antigenic signals provides a means of distinguishing background noise from true antigenic stimuli.
Antigen recognition by T cells activated in the mixed lymphocyte reaction: specific binding of allogeneic cell material after removal of surface‐bound antigen by trypsin
Authors: Elliott B. E. , Nagy Z. , Nabholz M. , Pernis B.
Published: February 2007

T cell blasts activated in the mixed lymphocyte reaction (MLR) carry on their surface stimulator alloantigens which can be removed by treatment of the blasts with trypsin. After overnight incubation in trypsin‐free medium, the treated cells exhibit specific alloantigen binding ability: they bind much more effectively cellular material, either obtained from the corresponding MLR supernatant or released by nitrogen cavitation from fresh cells from the stimulating strain, than that from an unrelated H‐2 different strain. Trypsin‐treated cells which have been incubated in the presence of low concentrations of puromycin are unable to bind stimulator cell fragments.
Induction of specific transplantation tolerance with blood serum in newborn and adult rats
Authors: Chutná Jitka , Hašek M. , Holáň V. , Sládeček M.
Published: February 2007

Histocompatibility (H) antigens present in the serum of rats induce a relatively high degree of neonatal transplantation tolerance in the absence of cellular chimerism. With the non‐H‐1 difference, which is relatively strong in the rat strain combination used, skin grafts survive permanently in some animals. With the H‐l plus non‐H‐1 difference, only some animals show a slight prolongation of skin graft survival, but cytotoxic antibody production is inhibited for long periods of time. In adult animals, at least with the non‐H‐1 difference, allograft survival is very significantly prolonged after treatment with serum alone, or in combination with hydrocortisone. The nonspecific component(s) of the serum also contributes to a prolongation of graft survival. The data suggest that blood serum is a good source of H antigens which seem to be present in a tolerogenic active form.
Characterization of a carcinogen‐induced murine B lymphocyte cell line of C3H/eB origin
Authors: Bergman Yehudit , Haimovich J.
Published: February 2007

A carcinogen‐induced lymphoid tumor, denoted 38C‐13, obtained in a T cell‐depleted mouse of C3H/eB strain, was adapted to continuous culture in vitro and characterized with respect to its cell surface components. The cells possess IgM class immunoglobulins on their surface but do not secrete it. This membrane IgM is composed of μ and L‐chains that are similar in apparent molecular weight to those of an IgM myeloma protein. It is also homogeneous as revealed by isoelectric focusing. The cells possess Fc receptors but lack complement receptors as well as Thy‐1 and Ia alloantigens. These characteristics indicate that 38C‐13 cells are transformed counterparts of small B lymphocytes at an early stage of differentiation.
Detection of bursa and thymus‐specific alloantigens in the chicken
Authors: Galton Jane , Ivanyi J.
Published: February 2007

CH strain chickens selected from the F2 progeny of a cross between CH (B10/10) and B14B (B14/14) strains camed bursa (BA) and thymus (TA)‐specific alloantigens of B14B parental origin. The BA marker was present on 95 % of bursal cells but only on 10 % of splenic and blood B lymphocytes. The TA marker was expressed by 80 % of thymus cells and weakly by 45 % of splenic and 70 % of blood T lymphocytes. The adopted immunolo‐gical and genetic protocol offers a feasible approach towards detection of differentiation antigens in major histocompatibility complex‐homozygous but ‘minor’ alloantigen‐segregating populations.
B lymphocyte development in fetal liver
Authors: Melchers F.
Published: February 2007

Single cell cultures of fetal liver cells (FLC) from day 13 of gestation onwards until birth develop lipopolysaccharide (LPS)‐reactive B cells which can be stimulated by LPS to IgM‐secreting plaque‐forming cells (PFC). When the cell concentration of FLC is lowered from 4 × 106 cells/ml to 4 × 10s cells/ml and below, the “in vitro” development to IgM‐secreting PFC is lost. Less and less FLC initiate growth to IgM‐secreting PFC as the cell concentration is lowered. Addition of 3 × 106 thymus cells/ml from either syngeneic mice or from xenogeneic Lewis rats dramatically increases the efficiency with which FLC develop into LPS‐reactive cells and initiate, after stimulation by LPS, clonal growth and maturation to IgM‐secreting PFC. Thus, day 13 FLC can be diluted to 1 × 106 cells/culture, day 16 FLC to 1 × 104 cells/culture and day 19 FLC to 3 × 101 cells/culture before the responding cells become limiting. The frequencies of precursor B cells developing to LPS reactivity and then to IgM‐secreting PFC in culture have been determined by limiting dilution analyses of FLC from day 13 to 19 (birth) of gestation and of liver cells at days 2, 4 and 7 after birth in cultures containing thymus cells and LPS. They are 1 precursor B cell in ∼ 1 × 106 FLC at day 13 of gestation, 1 in ∼ 1 × 10s at day 14, 1 in ∼ 3 × 104 at day 15, 1 in ∼ 1 × 104 at day 16, 1 in ∼ 2 × 103 at day 17, 1 in ∼ 1 × 102 at day 18 and 1 in ∼ 3 × 101 at day 19 of gestation. After birth, these frequencies decline rapidly to 1 in ∼ 3 × 102 at day 2, 1 in 3 × 103 at day 4 and 1 in less than 10s liver cells at day 7 after birth.
Evidence for suppressor cells in Lewis rats' experimental allergic encephalomyelitis
Authors: Adda D.‐H. , Beraud Evelyne , Depieds R.
Published: February 2007

In this work we demonstrate a suppressive activity on the induction of experimental allergic encephalomyelitis (EAE) in Lewis rats, transferable to syngeneic animals, challenged with encephalitogenic mixture (myelin basic protein, complete Freund's adjuvant plus Bordetella pertussis organisms) 24 h later. This activity is probably effected by T cells and not by (an) inhibitory serum factor(s). The induction of this specific protection could be due to the penetration of the myelin basic protein antigen into the thymus where we first found suppressive cells. From the thymus, suppressor cells could then emigrate to spleen (on day 15) and to nondraining lymph nodes (on day 17). In the course of normal EAE in Lewis rats and especially at the time of self cure, this suppression is not demonstrated, but possible.
Characterization of syngeneic anti‐idiotypic antibody against the idiotype of BALB/c myeloma protein J558
Authors: Schuler W. , Weiler E. , Kolb H.
Published: February 2007

BALB/c mice were immunized against the idiotype of BALB/c myeloma J558. Syngeneic, specific anti‐idiotypic antibodies against this germ line idiotype were shown by the isoelectric focusing technique to be markedly heterogeneous. In fact, the heterogeneity of isogeneic anti‐idiotypic sera appeared to be comparable to those of allogeneic anti‐JSS8 sera, raised in A/J and CB20 mice. As a rule, individual mice exhibit different clonal spectra. By spleen cell transfer experiments, each individual spectrum of clones could be expanded in order to arrive at an estimate of the size of anti‐idiotypic repertoires. These were found to be of the order of 7–16 different anti‐idiotypic clones for an individual BALB/c mouse. From the infrequency of clonal repetition we conclude that the repertoire of the BALB/c strain must be well in excess of one hundred anti‐idiotypic molecular species.
Analysis of the alloimmune properties of a recombinant genotype in the major histocompatibility complex of the chicken
Authors: Vilhelmová Miloslava , Miggiano V.C. , Pink J.R.L. , Hála K. , Hart‐manová Jana
Published: February 2007

In a population of (CB x CC)F1 x WB hybrids, a chicken was found with a presumably recombinant haplotype, BR1, whose antigenic products detectable by hemagglutination contained determinants derived from both parental haplotypes, i.e. B1 (from CB) and B2 (from CC). This recombinant bird and its progeny from different crosses were tested by skin grafting, graft‐vs .‐host (GVH) and mixed lymphocyte reactions (MLR). The results define two regions of the B system, the B‐F and the B–G. The B–F region determined serologically defined antigens, histocompatibility antigens, and controlled the GVH and MLR reactions, while the B–G region was responsible only for synthesis of serologically detectable antigens.
Rabbits possess conventional T lymphocytes
Authors: Bell Clara , Wigzell H.
Published: February 2007

Rabbit lymphocytes have been analyzed as to surface Ig markers in relation to the function of the cells. A battery of specific anti‐Ig reagents as well as supposed B and T cell‐specific mitogens were used, and DNA synthesis as well as high‐rate Ig synthesis in vitro were recorded.

Using cells from spleen, lymph node or blood, surface Ig‐negative lymphocytes expressed the expected behavior of T lymphocytes. No evidence was found of significant expression of allotypic markers on the surface of such nonactivated rabbit T lymphocytes.

Lymphoid cells from bone marrow constituted an exception to the rule in the sense that they contained a high proportion of cells being surface Ig‐negative at the time of anti‐Ig column fractionation. They did, however, rapidly express surface Ig molecules as well as B cell markers as judged by B cell mitogenic stimulation shortly after in vitro explantation.

In conclusion, we failed to find any constant region Ig markers on rabbit lymphocytes, which in every sense behave like conventional T lymphocytes.
Ly and la phenotype of suppressor T cells induced by graft‐vs. ‐host reaction
Authors: Shand F.L.
Published: February 2007

Suppressor T cells were generated in (CBA x C57BL)F1 mice undergoing graf t‐vs. ‐host (GvH) reaction and treated with anti‐Ly and anti‐Ia antisera to determine their membrane antigen phenotype. Pretreatment of CBA‐induced GvH suppressor T cells with anti‐Ly‐1.1, anti‐Ly‐2.1 or anti‐Iak anti‐sera plus complement abrogated their suppressive properties when tested against primed F1 spleen cells in vitro. In contrast, concanavalin A (Con A)‐induced suppressor T cells were insensitive to anti‐Ly‐1.1 serum. It is concluded that GvH‐induced suppressor T cells are Ly‐1+,2+,3+,Ia+, and thus distinct from Con A or antigen‐induced suppressor T cells.
Secondary IgG responses to type 3 pneumococcal polysaccharide III. T cell requirement for development of B memory
Authors: Braley‐Mullen Helen
Published: February 2007

Mice primed with a thymus‐dependent form of Type 3 pneumococcal polysaccharide (S3), i.e. S3 coupled to erythrocytes (S3‐RBC) produce S3‐specific IgG antibody after secondary challenge with S3‐RBC. When mice are depleted of T cells by treatment with anti‐lymphocyte serum (ALS) at the time of priming, no IgG antibody is produced after secondary challenge. In order to determine the cellular basis for this phenomenon, various combinations of T and/or B cells from ALS‐treated or normal primed mice were transferred to irradiated recipients prior to secondary challenge with S3‐RBC. The results indicated that T cells were required at the time of priming with S3‐RBC in order to (a) prevent the induction of tolerance in S3‐specific B cells in mice primed with high doses of S3‐RBC, and (b) induce differentiation of IgG‐producing B cell precursors to Bλ memory cells in mice primed with low doses of antigen.
In rat bone marrow Thy‐1 antigen is present on cells with membrane immunoglobulin and on precursors of peripheral B lymphocytes
Authors: Hunt S.V. , Mason D.W. , Williams A.F.
Published: February 2007

Rat bone marrow cells carrying Thy‐1 antigen were studied morphologically, and tested for their independence of the thymus and their relationship to the B lymphocyte lineage.

Using a fluorescence‐activated cell sorter to separate Thy‐1+ and Thy‐1‐ fractions, it has been confirmed that up to 50 % of all nucleated bone marrow cells are Thy‐1+, most of which have the morphology of small lymphocytes. Thy‐1‐cells were mainly neutrophils and erythroid. Thy‐1+ cells were found also in the marrow of B rats (rats thymectomized as adults, irradiated and reconstituted with syngeneic bone marrow from thymectomized donors drained of recirculating lymphocytes), though at a lower frequency (roughly half) than of normal rats. In both normal and B rats about 1/4 of the Thy‐1+ cells also bore lymphocyte surface immunoglobulin (sIg), and these doubly labeled cells accounted for the majority (∼ 2/3) of marrow cells carrying large amounts of sIg. Therefore, unlike mice, Thy‐1 is not a marker of thymus‐dependent lymphocytes in rats.

The B precursor activity of marrow fractions was measured in a long‐term re‐constitution assay counting sIg+ cells in the thoracic duct of lethally irradiated recipients. Virtually all the precursors were in the Thy‐1+ or sIg‐ fractions, and were barely detectable among Thy‐1‐ or sIg+ cells. Thus, in the rat peripheral B lymphocytes descend from precursors bearing Thy‐1 antigen but lacking sIg.
Effect of a human serum thymic factor on hydrocortisone‐treated thymocytes
Authors: Astaldi Giulia C.B. , Astaldi A. , Groenewoud Marjorie , Wijermans P. , Schellekens P.Th.A. , Eijsvoogel V.P.
Published: February 2007

A human serum thymic factor (SF) stimulated cyclic adenosine‐3′,5′‐mono‐phosphate (cAMP) synthesis in normal mouse thymocytes. Such stimulation was no longer observed when thymocytes were depleted of hydrocortisone (HC)‐sensitive cells. It was concluded that SF selectively stimulates cAMP in HC‐sensitive cells. Furthermore, incubation of thymocytes with SF enlarged the population of HC‐resistant thymocytes.

These results suggest that SF might act on HC‐sensitive thymocytes increasing their cellular cAMP level and inducing their transformation in HC‐resistant cells.
Presence of common idiotypes on antibodies induced by glutamic acid‐lysine‐containing terpolymers in responder and nonresponder mice with the lg‐1b heavy chain allotype
Authors: Kipps T.J. , Benacerraf B. , Dorf M.E.
Published: February 2007

A B10.A(5R) responder mouse to the random linear terpolymer, poly‐L‐(Glu, Lys, Phe), GLΦ, can produce immunoglobulins which bind poly‐L (Glu, Lys), GL, that share idiotypic determinants with GL‐ binding antibodies produced by other members of the same strain. Expression of these common idiotypic determinants, termed BGL, is independent of the H‐2 haplotype and closely linked to the Ig‐1b heavy chain allotype. Moreover, nonresponder mice with the Ig‐1b heavy chain allotype, when immunized with GLΦ that has been chemically coupled to an immunogenic carrier, chicken IgG, can produce GL‐binding antibodies that share BGL idiotypic specificities with anti‐GLΦ antibodies produced by responder animals. Also, the responses to other GL‐containing polymers, such as poly‐L (Glu, Lys, Ala) and poly‐L (Glu, Lys, Pro), which are under the control of distinct Ir genes, can stimulate the production of GL‐binding antibodies that share common BGL idiotypic determinants with antibodies induced with GLΦ. These findings are discussed with respect to their implications concerning the mechanism(s) of Ir gene control.
Activation of human B and T lymphocytes by protein A of Staphylococcus aureus
Authors: Ringdén O. , Rynnel‐Dagöö Britta
Published: February 2007

Protein A from Staphylococcus aureus, in soluble form or coupled to Sepharose beads, acts as a polyclonal B cell activator (PBA) for human lymphocytes in blood and spleen.

PBA activity was demonstrated in spleen cells by the ability of protein A to induce the formation of intracellular immunoglobulin synthesis and to activate polyclonal antibody secretion demonstrated against fluorescein isothiocyanatecoupled sheep erythrocytes in a modified hemolysis in gel assay. More plaqueforming cells (PFC) were seen in unseparated cells than in purified B cells. In blood lymphocytes, only few PFC were activated by soluble protein A.

Protein A increased DNA synthesis in blood and spleen cells. At a concentration of 100 μg/ml the peak response was on day 4 or 5, but at 1 μg/ml the peak response occurred later. On day 4 of culture, high mitogenic activity was seen in unseparated lymphocytes or mixtures of separated B and T cells, whereas in enriched B and T cell suspensions activity was low. On day 7, however, DNA synthesis in both the enriched B and T cells was higher than in mixtures of B and T cells. Protein A stimulated DNA synthesis in thymus cells with a peak response on day 6. It is concluded that protein A alone or as an IgG complex can activate both B and T cells, though the mechanism of activation is not known and may be different for B and T cells.
Immunoglobulin production by lymphocyte hybridomas
Authors: Köhler G. , Hengartner H. , Shulman M. J.
Published: February 2007

We have investigated immunoglobulin production by cloned hybrid cells. γ2b heavy chains, but not γ1 or γ2a, exist in two forms, differing in molecular weight, galactose labeling and charge. Hybrid molecules containing γ2b and γ1 heavy chains were secreted by hybridoma cells synthesizing Ig molecules of both subclasses. However, cells synthesizing both IgM and IgG chains did not secrete μ‐γ hybrid molecules. We have surveyed many new hybridomas derived from different mouse strains: 10 % of those secreting IgM produce a μ chain which is about 5000 daltons larger than normal μ. Two IgM‐secreting lines were studied in detail and were found to bear μ but not δ in their membrane. Intra‐ and extracellular μ differ in molecular size; pentameric IgM‐containing molecules of both sizes were observed in the membrane fraction.
The number of antibody‐producing clones as revealed by the distribution of allelic variants of immunoglobulin light chains
Authors: Rokhlin O. V. , Livshits M. A.
Published: February 2007

A new method of evaluation of the number of clonal precursors of antibody‐producing cells based on the phenomenon of allelic exclusion is proposed. The distribution of the allotypes of specific antibodies in the population of heterozygous F1 hybrids depends on the number of clonal precursor cells. The smaller the number of precursors, the larger the variance of the distribution. The frequency of clones producing antibodies to the azobenzoate hapten (∼ 10−8 after first and ∼ 10−9 after second and third immunizations) in (MSU × August)F1 rats calculated in the present work is in reasonable agreement with the data obtained (for other haptens) by limiting dilution cloning assays. The difference in the numbers of anti‐hapten and anti‐carrier clones is discussed. The numbers of IgM and IgG‐synthesizing clones are calculated from the distributions of the allelic variants of corresponding rat antibodies to lactoside. The data suggest the existence of distinct IgG precursors which contradicts the hypothesis of IgM‐IgG switch within the clones only.
Tumor‐induced changes in T cell mitogen responses in rats: Suppression of spleen and blood lymphocyte responses and enhancement of thymocyte responses
Authors: Kruisbeek Ada M. , Zijlstra Jelly , Zurcher C.
Published: February 2007

Concanavalin A (Con A) and phytohemagglutinin (PHA) responses of spleen and blood lymphocytes from tumor‐bearing (TB) rats were found to be markedly depressed in 4 different models employing tumors of spontaneous origin. Removal of phagocytic cells from both spleen and blood lymphocyte suspensions led to a complete restoration of the responses, indicating that the decreased responses were not due to intrinsic defects in the lymphocytes. The reduction was shown to be due to the inhibitory effect of an increase in the percentage of phagocytic cells.

In addition, TB induced an atrophy of the thymus and a decrease in the number of thymic lymphocytes, mainly due to severe lymphocyte depletion in the cortex. The cells that remained in the thymus exhibited increased responsiveness to PHA and Con A as compared to thymus cells from normal rats. Similar results were found in hydrocortisone acetate‐treated rats, suggesting that TB leads to a decrease in nonresponsive, cortical corticosteroid‐sensitive thymocytes.
Identification of T cell subpopulations binding phytohemagglutinin: functional characteristics
Authors: Callard R. E. , Basten A.
Published: February 2007

Lymphocytes binding 125I‐labeled phytohemagglutinin (125I‐PHA) were directly quantitated by autoradiography. The distribution of grain counts proved to be trimodal indicating the presence of three distinct subpopulations of PHA‐binding cells. Low intensity binders (median grain count of 8–12 grains/cell) predominated in spleen and lymph node, included B and T cells, and responded to the mitogen, lipopolysaccharide (LPS). High intensity binders (median grain count greater than 60 grains/cell) occurred at low frequency in every lymphoid organ, were T cells, and included mixed lymphocyte culture (MLC)‐reactive but not PHA‐reactive cells as judged by preferential sensitivity to suicide with 125I‐PHA. Medium intensity binders (median grain count of 40–45 grains/cell) predominated in the thymus, formed a subpopulation in the spleen and lymph nodes of normal mice, but were absent from bone marrow of normal mice and the spleen of nude mice. In addition, their numbers were markedly reduced following adult thymectomy and cortisone treatment indicating that they were most likely T cells of recent thymic origin.

PHA‐reactive cells were considered to belong to the medium intensity PHA‐binding subpopulation. This conclusion was based on the following: first, medium intensity binders, like PHA‐reactive cells, were T cells; second, they were contained in the same subpopulation of T cells as PHA‐reactive cells. That is, they were of recent thymic origin (T1 cells) according to studies of tissue distribution, cortisone sensitivity and effect of adult thymectomy; third, “suicide” of the response to PHA as well as to allogeneic cells but not LPS was achieved by prior incubation of cells with high doses of soluble 125I‐PHA, whereas lower doses resulted only in abrogation of the MLC response. In other words, PHA‐reactive cells resided in the medium, rather than high intensity subpopulation of binding cells. By analogy with suicide of antigen‐binding cells, this observation implies that PHA binds preferentially to those cells responding to it, and confirms the validity of using mitogen activation as a model for antigen‐induced triggering. On the other hand, binding of PHA to a subpopulation of T cells casts doubt on the value of the PHA response as a measure of overall T Cell function. Support for this conclusion came from the failure of PHA suicide to abrogate effector T cell activities such as help and suppression.
Enhancement by IgM rheumatoid factor of in vitro ingestion by macrophages and in vivo clearance of aggregated IgG or antigen‐antibody complexes
Authors: Van Snick J. L. , Van Roost E. , Markowetz B. , Cambiaso C. L. , Masson P. L.
Published: February 2007

Polyclonal as well as monoclonal IgM rheumatoid factors (RF) markedly enhanced both the attachment and ingestion of heat‐aggregated human IgG (HAG) by mouse alveolar macrophages, mouse peritoneal macrophages and human peripheral monocytes. This effect depended upon the integrity of the Fc fragment of the HAG as shown by the experiments performed with reduced and alkylated HAG. Marked differences in the stimulation index were observed between the five tested RF.

When we compared the effect of complement (C) and/or RF on the total amounts of HAG cleared from the medium, i.e. the sum of the HAG associated with the cells and the digestion products released in the medium, the addition of C alone resulted in a 10‐fold increase, the addition of RF alone in a 20‐fold increase, and the addition of both RF and C in a 10‐fold increase. Apparently, the effect of RF was mainly on the binding of HAG to macrophages, whereas C mainly induced ingestion as indicated by the increased release of degradation products.

Antigen‐antibody (AgAb) complexes were prepared with 125I‐labeled human transferrin as antigen and mouse anti‐transferrin serum at various Ag/Ab ratios. Without RF, a significant uptake occurred up to a 3‐fold Ag excess. RF caused a 3‐fold increase of the uptake of complexes prepared at equivalence, but an 80‐fold increase of the uptake of the complexes prepared in 10‐fold Ag excess.

Gradient ultracentrifugation of the AgAb complexes showed that the enhancement of the uptake due to RF was related to the increase of the sedimentation rate of the complexes. However, an excess of RF decreased its enhancing effect on endocytosis.

One hour after the intraperitoneal injection of complexes in 10‐fold Ag excess, the radioactivity of the peritoneal cells was 14 times higher when the complexes were pre‐incubated with RF than with complexes not preincubated with RF. Similar complexes were also injected intravenously. The 13 S fraction which was visible on the ultracentrifugation profile in the absence of RF was eliminated very slowly, whereas the “heavy” fraction (> 30 S) which appeared after addition of RF, was cleared from the plasma in 25 sec.
Transformation capacity of human blood lymphocytes in relation to their specific gravity; another heterogeneity of lymphocyte reactivity
Authors: Th. Schut Bep. J. , Loos H. A. , Roos Marijke Th. L. , Pinkster Tinie , Zeijlemaker W. P. , Schellekens P. Th. A.
Published: February 2007

By separation of human blood lymphocyte suspensions on isotonic linear density gradients, fractions were obtained which differed in their response in vitro towards mitogens, antigens and allogeneic lymphocytes, as tested by incorporation of radioactive thymidine. Next, light (ρ < 1.067 g/cm3) and heavy (ρ > 1.067 g/cm3) lymphocytes were separated on discontinuous density, gradients and their reactivity tested to phytohemagglutinin, pokeweed mitogen, concanavalin A, purified protein derivative of tuberculin, a cocktail of antigens, and in the mixed lymphocyte culture (MLC). The light lymphocytes responded 1.6 to 6 times more strongly than the heavy lymphocytes (p < 0.0005) to all stimuli tested. The spontaneous thymidine incorporation of the light lymphocytes was 16 times as high as that of the heavy lymphocytes. In controls, the recombined light and heavy lymphocytes showed the same reactivity as the unseparated cell suspension. Furthermore, the stimulatory capacity in the MLC was significantly higher in the light lymphocyte fraction than in the heavy lymphocytes. Finally, the capacity to recruit and to be recruited in the lymphocyte reaction on antigens was also highest in the light lymphocytes.

The light and heavy lymphocytes showed a similar dose response curve as well as time courses in the response to all stimuli tested. Addition of purified monocytes to the heavy lymphocytes to the same level as was found in the light lymphocyte fraction did not restore the level of reactivity to that of the light lymphocytes. The heavy and light lymphocytes contained identical proportions of T (E rosettes), B (IgG‐bearing cells) and C3 receptor‐bearing lymphocytes (EAC rosettes). The two fractions had similar cytotoxic capacity in antibody‐dependent cytotoxicity.

It is concluded that the reactivity differences are an intrinsic property of the heavy and light lymphocyte subsets.
Induction of immunological tolerance to the penicilloyl antigenic determinant. I. Evaluation of penicilloylated amino acid polymers and copolymers in mice
Authors: Otz Ursula , Schneider C. H. , De Weck A. L. , Gruden Elsbeth , Gill T. J.
Published: February 2007

Antibody responses to the penicilloyl (BPO) group, the major antigenic determinant of penicillin allergy induced in C3H mice by penicilloylated bovine gamma globulin in complete Freund's adjuvant, were reduced or abolished by various amino acid polymers and copolymers of different composition and size carrying BPO groups. Tolerogenic treatment was effective before or after primary immunization and also during anamnestic responses. The unresponsive state was of long duration and persisted even after several booster injections when efficient tolerogens were used. Among the most promising tolerogens are fully penicilloylated oligolysines with a molecular weight below 10 000.
Immunoglobulins with hapten‐binding activity: structure‐function correlations and genetic implications
Authors: Barstad P. , Hubert J. , Hunkapiller M. , Goetze A. , Schilling J. , Black B. , Eaton Barbara , Richards J. , Weigert M. , Hood L.
Published: February 2007

The N‐terminal amino acid sequences of light and heavy chains from mouse myeloma immunoglobulins binding a variety of simple haptens are compared through the first hypervariable region with available sequences from the literature. These comparisons suggest that (a) the heavy chain sequences correlate closely with their respective hapten‐binding specificity, and (b) light chain sequences correlate closely in the case of some specificities (e.g., carbohydrate moieties) but fall into several distinct sets with others (e.g., phosphorylcholine and 2,4‐dinitrophenyl), We suggest that carbohydrate moieties may bind to the antibody combining site by multiple weak noncovalent interactions that require precise complementarity over an extended portion of the combining site. Accordingly, both the light and heavy chains are highly conserved. In contrast, the phosphorylcholine and 2,4‐dinitrophenyl moieties are small and have many possibilities for ionic or charge transfer interactions, but presumably occupy only a small portion of the active site crevice. Hence, a variety of light chain sequences are compatible with active sites that bind these haptens. Even in the case of a small hapten such as phosphorylcholine, however, the light chain sequences place important constraints on the interactions between hapten and immunoglobulin. Heavy/light chain recombination studies reported in this paper reveal the importance of specific heavy/light chain pairing for generation of the antibody specificity to phosphorylcholine. These chain recombination and sequence data also impose important constraints on certain theories of antibody diversity which are discussed.