bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface molecules of cultured human lymphoid cells
Authors: Trowbridge I. S. , Hyman R. , Mazauskas Catherine 
Published: February 2007

AbstractCell surface molecules of cultured human lymphoid cells were selectively labeled by lactoperoxidase‐catalyzed iodination and examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Two major iodinated species with apparent mol. wts. of 27 000 and 35 000 daltons were detected on autoradiographs of the labeled proteins of human lymphoid cell lines believed to be of thymus‐independent (B) cell origin. Neither molecule was detected on putative thymus‐dependent (T) lymphoid cell lines. Metabolic labeling studies showed that both molecules are glycoproteins. Rabbit antisera against cultured B lymphoid cells made specific by absorption for B cells reacted with several labeled species from iodinated B cells including the 27 000 and 35 000 mol. wt. glycoproteins. These molecules were also detected on tonsillar lymphocytes but not on peripheral blood lymphocytes. Reciprocal absorption with B cells of rabbit antisera against cultured T cells gave antisera specifically cytotoxic for T cells. However, these sera did not precipitate iodinated proteins from Nonidet P‐40 lysates of T cells.
Studies on the relationships between the immunogenicity and catabolism of antigens and their binding to the surface of macrophages
Authors: Gallily Ruth , Bar‐Eli M. 
Published: February 2007

AbstractThe relationship between immunogenicity of Shigella paradysenteriae, the branched synthetic polypeptide poly‐L (Tyr, Glu)‐polyLPro‐polyLLys [(T, G)‐Pro–L] and human serum albumin (HSA) interacting with macrophages and the kinetics of antigen degradation and degree of binding to the cell surface was studied. Following thioglycollate inoculation into C57BL/6 mice, the peritoneal‐stimulated macrophages had higher levels of hydrolases as compared to unstimulated cells. The lysates of the stimulated macrophages catabolized the three labeled antigens faster than did the lysates of unstimulated cells. However, when degradation of labeled antigens by macrophage cells was assessed, no direct correlation could be demonstrated between the level of cell hydrolases and rate of (T, G)‐Pro–L or HSA catabolism.The immunogenicity of the antigens following their uptake by unstimulated and stimulated macrophages was determined by transfer of the antigen‐bearing cells into irradiated and nonirradiated syngeneic recipients. No correlation was apparent between the rate of antigen degradation and the capacity to evoke a humoral response. Similarly, no correlation could be demonstrated between the amount of antigen bound to the macrophage cell surface and the immunogenicity of the antigen.It is suggested that neither the rate of antigen catabolism by macrophages nor the amount of antigen bound to the macrophage membrane is the sole factor which determines the immunogenicity of antigens interacting with macrophages.
In vivo sensitization of T cells to hapten‐conjugated syngeneic structures of major histocompatibility complex. I. Effect of in vitro culture upon generation of cytotoxic T lymphocytes
Authors: Starzinski‐Powitz A. , Pfizenmaier K. , Röllinghoff M. , Wagner H. 
Published: February 2007

AbstractMurine T cells were sensitized in vitro towards fluorescein isothiocyanate (FITC)‐conjugated syngeneic spleen cells. The lytic activity of the effector cells generated was restricted to FITC‐conjugated, H‐2‐compatible target cells. 2,4,6‐Trinitrophenyl (TNP)‐conjugated syngeneic targets were not lysed.A method is described for the in vivo sensitization of murine T cells towards TNP (or FITC)‐conjugated syngeneic spleen cells. The procedure is based on the observation that a local graft of hapten‐conjugated syngeneic spleen cells results in the development of sensitized prekiller T cells within the draining lymph node (LN). By mere in vitro incubation of such LN cells immunological specific anti TNP (or anti‐FITC)‐reactive cytotoxic T lymphocytes (CTL) are generated. The in vitro differentiation of CTL requires 48‐72 h; it is dependent on cell proliferation and is abolished by treatment of the LN cells with mitomycin C. Thus there is a separation between the sensitization of CTL precursors (which effectively takes place in vivo) and the phase of cell differentiation into CTL (which effectively takes place only in vitro). Similar to in vitro‐sensitized CTL, the specificity of in vivo‐sensitized CTL is dictated by the hapten used for the induction of the immune response and is restricted to hapten‐conjugated syngeneic target cells.
Active heterologous chain recombinants of monoclonal antibodies raised in related rabbits
Authors: Braun D. G. , Riesen W. F. , Huser H. 
Published: February 2007

AbstractHeterologous chain recombinants of homogeneous anti‐streptococcal group A‐variant polysaccharide antibodies produced by pedigreed rabbits regain in certain pairs the same antigen‐binding capacity as the homologous pairs. In contrast, chain recombinants with antibodies from nonrelated rabbits are much less active. This data suggests random pairing of immunoglobulin heavy and light chains coded for in the germ line and subsequent selection.
Binding of immune complexes of guinea pig IgG2 to homologous peritoneal exudate cells
Authors: Leslie R. G. Q. , Alexander M. D. , Cohen S. 
Published: February 2007

AbstractA quantitative study has been performed to correlate the macrophage‐binding activity of immune complexes of guinea pig IgG2 with the antigen‐antibody composition and size of the immune complex. Binding, measured as (a) uptake at a single IgG concentration, (b) resistance to IgG2 monomer inhibition and (c) mean binding avidity of the complex, was maximum at the antigen‐antibody ratio optimum for immune precipitation. All three parameters declined in value with increasing proportions of antigen in the complex. Gel filtration of immune complexes revealed that complex size and binding avidity declined with increase in antigen excess. The relationship of binding activity to complex size and the similar inhibitory patterns of IgG2 and its fragments for binding of monomer and complexed IgG2 suggest that binding enhancement results from the cooperative action of multiple Fc sites in the immune oligomer, rather than from conformational change.
The helper cell function of primed T cells. I. Marked amplification of antibody formation by antigen‐educated T cells carrying surface Ig 6 h after priming
Authors: Paraskevas F. , Lee S. T. 
Published: February 2007

AbstractThese experiments deal with a subpopulation of T cells bearing adsorbed Ig, thus considered to be Fc‐receptor positive. Such cells were collected from spleens of lethally irradiated mice reconstituted with thymocytes 6 h after priming with heterologous erythrocytes (sheep or horse red blood cells). The helper cell function of such cells was examined upon transfer to secondary hosts with normal bone marrow cells. Such educated thymocytes upon challenge generated a 2–3‐fold increase of 19 S plaque‐forming cells (PFC) and a 6–7‐fold increase of 7 S PFC above the level given by unprimed thymocytes. Such amplification of antibody formation is highly specific. No helper cell function was detected in cells obtained similarly from nonreconstituted animals or from mice reconstituted with bone marrow cells. Carrier‐primed thymocytes collected 6 h after priming are also able to enhance the primary 7 S anti‐hapten response but only when the hapten is provided on the same carrier used for priming. The helper cell function of 6 h primed thymocytes was compared to that of more conventionally educated thymocytes collected 5 days after priming. Although both cell preparations induced similar enhancements of 19 S PFC, the 6 h primed cells gave more than twice the number of 7 S PFC as compared to 5 day primed cells. This difference is statistically highly significant (p < 0.001).Since the 6 h primed thymocytes contain a subpopulation which has acquired surface Ig, as shown by our previous work, their role in the mechanism of the enhancement of the helper cell function is discussed.
Characterization of suppressor cells involved in regulation of experimental allergic encephalomyelitis
Authors: Welch A. M. , Swanborg R. H. 
Published: February 2007

AbstractThis report describes studies carried out in an effort to identify the suppressor cells involved in the regulation of experimental allergic encephalomyelitis (EAE) in the Lewis rat. Viable lymph node cells (LNC) from donors rendered tolerant to clinical EAE by pretreatment with myelin basic protein antigen in nonencephalitogenic form are capable of transferring unresponsiveness to syngeneic recipients. Adoptive transfer of unresponsiveness was abrogated if LNC were treated in vitro with anti‐thymocyte serum and complement.In further experiments, it was shown that suppressor cells are among the LNC subpopulations that do not adhere to glass wool. These findings suggest that the immunoregulatory cells in EAE are suppressor T lymphocytes.
Tolerance in differentiating B lymphocytes
Authors: Elson C. J. 
Published: February 2007

AbstractThese experiments demonstrate that the response of B lymphocytes to particulate antigen in vivo can depend on their stage of differentiation: B lymphocytes differentiating from stem cells were rendered tolerant, while mature B lymphocytes were primed under the same conditions. Lethally irradiated mice of one allotype were repopulated with 13–15 day fetal liver cells from congenic mice bearing another allotype and the effect of antigen on the emergence of responsive B cells determined. B cells, descended from the fetal liver inoculum (identified by their allotype) produced an antibody response to antigen in the presence of additional T cells, 15 days after transfer. Such a response could be prevented by injecting the recipient with alum‐precipitated antigen (but not with deaggregated antigen) shortly after irradiation and reconstitution. This unresponsive state was specific and independent of afferent suppressor mechanisms. Mature B cells, on the other hand, were shown to be primed by alum precipitated antigen in irradiated reconstituted hosts. It was concluded that a fundamental difference exists between the responsiveness of mature and differentiating B lymphocytes. Tolerance in differentiating B lymphocytes is discussed in relation to the acquisition of self‐tolerance.
Evidence for quasi‐silent germline genes coding for phylogenetically ancient determinants of the rabbit a locus allotypes
Authors: Van Der Loo W. , De Baetseliei P. , Hamers‐Casterman Cécile , Hamers R. 
Published: February 2007

AbstractAnti‐a 2 sera raised in a3 rabbits are shown to detect determinants on a2 molecules which are different from those detected by anti‐a 2 sera raised in al animals.The former determinants are occasionally observed at a low level in rabbits of the al allotype and at a high level in sera of Leporidae of different genera. The two types of anti‐a 2 sera are shown to compete for the same sterical region of the a2 molecules. All homogeneous a2 molecules which have been tested show both types of determinants.
The expression and relation of HLA, β2 ‐microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells
Authors: Fellous M. , Wiels J. , Hors M. C. , Rebourcet R. , Finaz C. , Weil D. , Heuertz S. , Mahouy G. , Fridman W. H. 
Published: February 2007

AbstractThe expression of HLA, human and mouse β2‐microglobulin (β2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human β2m and where redistribution experiments demonstrate that HLA is associated with mouse β2m. Synteny between HLA and the receptor for MaRBC can be a useful tool to select HLA‐positive hybrid clones.
Inhibition of human mixed lymphocyte culture stimulation by anti‐HLA‐D ‐associated antisera: studies with primed responding cells
Authors: Hirschberg H. , Albrechtsen D. , Solheim B. G. , Thorsby E. 
Published: February 2007

AbstractThe inhibitory effects of HLA‐D ‐associated antisera on stimulating lymphocytes when cultured together with allogeneic primed responding lymphocytes were investigated. The responding lymphocytes were primed for either the HLA‐Dw2 or Dw3 determinants. The presence of HLA‐D ‐associated (la‐like) antibodies during the culture period specifically inhibited the stimulatory capability of lymphocytes possessing the HLA‐D determinants with which the antisera were apparently reacting, as long as the stimulating cells carried the determinant for which the responding cells were primed. HLA‐D ‐associated antisera of other specificities caused no decrease in the stimulatory capability. These antisera, therefore, apparently contain antibodies which are reactive with determinants closely associated or identical to the HLA‐D determinants and may be human analogues to the mouse Ia antigens.
Responses of alloantigen‐primed lymphocytes in vitro Quantitative analysis of the relative frequency of reactive lymphocytes in primed populations which respond to allogeneic stimulating cells
Authors: Corley R. B. 
Published: February 2007

AbstractPopulations of lymphocytes primed to alloantigens in vitro are stimulated by allogeneic cells which are unrelated to the specific stimulator cells used for priming. The number of lymphocytes in the primed population which responded to unrelated stimulators could be estimated in relation to the number of primed lymphocytes responding to the specific stimulator. This was done by measuring the responses of decreasing numbers of primed lymphocytes to various stimulator cell populations. Similar estimates were obtained on several occasions using the same combination of lymphocytes which were primed and retested at different times.There was a close correlation between the estimated frequency of lymphocytes in a primed population which responded to unrelated stimulators and the number of responder lymphocytes required to obtain a measurable response. Stimulators which activated a high frequency of primed cells required fewer responder lymphocytes than those which activated lower frequencies of primed cells. The specific stimulator was capable of initiating a response using fewer responder lymphocytes than were most unrelated stimulator cells. This confirms that primed populations are predominantly enriched for lymphocytes responding to the specific stimulator.At least some lymphocytes in a primed population responded to both the specific stimulator and unrelated stimulator cells. This was demonstrated in two types of experiments. In the first, it was possible to enrich lymphocytes in a primed population which responded to unrelated stimulator cells without depleting lymphocytes which also responded to the specific stimulator. In the second, primed lymphocytes from donor A, which showed strong reactivity to stimulators from donor D after priming with B stimulator cells, also showed significant reactivity to B stimulators after priming with D cells. These results strongly suggest that primed populations contain several subpopulations (clones) of lymphocytes whose specificities differ as exhibited by their responsiveness to unrelated stimulator cells.
Estimation by radioimmunoassay of VH determinants (Aa1) associated with rabbit T lymphocytes
Authors: Jensenius J. C. , Williams A. F. , Mole L. E. 
Published: February 2007

AbstractA radioimmunoassay with specificity for the al allotype determinant of rabbit immunoglobulin (Ig) heavy chains was used for the quantitation of VH in detergent extracts of lymph node cells from a1a1/b4b4 rabbits. B cell‐derived Ig in the same extracts was estimated with a radioimmunoassay specific for L‐chain. About 2 × 105 molecules/cell was found by both assays when assuming a molecular weight of 1.5 × 105 dalton. Extracts prepared from lymphocytes depleted of B cells (surface Ig+ cells) were also found to contain corresponding amounts of a1 and L‐chain, with values varying from about 103 to 104 molecules/cell. The estimates were not influenced by the presence of inhibitors of proteolytic enzymes. Supernatants, obtained after keeping the lymphocytes in culture for 16 h, were analyzed by the same methods. Again, matching amounts of a1 and L‐chain were found in supernatants from nonfractionated as well as from B cell‐depleted populations.The results obtained indicate that T cells do not carry or produce an excess of a1 compared to L‐chain, as would have been expected if the T cell antigen receptor carried the same variable region as the Ig heavy chain while being otherwise composed of nonimmunoglobulin‐like structures.
Peptide mapping of the λ‐like chains of the BASILEA rabbits
Authors: Jaton J.‐C. , Kelus A. S. 
Published: February 2007

AbstractThe recently established mutant strain of rabbits, named BASILEA, lacks the K polypeptide L‐chain which is replaced by a λ‐like type (bas). This is evident from the amino acid composition and peptide maps of the bas L‐chain when compared to the L‐chains of the rabbits suppressed for the expression of the b locus allotypes.
Decidual extracts suppress antibody response in vitro
Authors: Globerson Amiela , Bauminger S. , Abel L. , Peleg S. 
Published: February 2007

AbstractExtracts of decidual tissue produced in pseudopregnant rats were found to suppress in vitro antibody response to α‐2,4‐d initrophenyl‐polylysine. The peak levels of both the total antibody response and the 2‐m ercaptoethanol‐resistant fraction were reduced. Extracts prepared in a similar manner from uteri of normal untreated or pseudopregnant rats did not exert such an effect.
Spontaneous, augmentable cell‐mediated cytotoxicity with limited target cell specificity in human blood
Authors: Saksela Eero , Lmir Turgut , Mäkelä O. 
Published: February 2007

AbstractNonadherent and nonphagocytic lymphoid cells from human peripheral blood became strongly cytotoxic against 51Cr‐labeled chicken red blood cells and cells from an established human myeloma cell line when subjected to repeated cycles of washing in phosphate buffered saline or treated with trypsin or lecithinase. Prior to augmentation the effector cells pass nylon wool columns that remove practically all surface IgG‐positive cells, but after augmentation they are retained in such columns. Augmentation docs not make them phagocytic or adherent to plastic surfaces. Incubation at 37°C of augmented cells prior to addition on the target cells restores the original nonaggressive state. Morphologically the cells making contact with the target cells are small or intermediate‐sized mononuclear cells.
Separation and properties of EA‐rosette‐forming lymphocytes in humans
Authors: Van Oers M.H.J. , Zeijlemaker W.P. , Schellekens P. T. H. A. 
Published: February 2007

AbstractHuman peripheral blood lymphocytes were separated into subpopulations enriched or depleted with respect to B lymphocytes (Ig‐bearing cells), T lymphocytes, (cells forming rosettes with sheep erythrocytes: E‐RFC) and Fc receptor‐bearing lymphocytes (EA‐RFC).From the distributions and recoveries of the various cell types it could be concluded that there was very little overlap between Ig‐bearing lymphocytes and EA‐RFC. The latter cells partly belonged to “null” (non‐T, non‐B) cells; it was however demonstrated that 30 % of the EA‐RFC were T cells (E‐RFC).The lytic capacity in antibody‐dependent lymphocytotoxicity (ADL) was shown to correspond with the proportions of EA‐RFC in the various fractions. Non‐T cells showed enhanced ADL activity when compared to the unseparated cells. Purified T cell populations also displayed ADL activity. Since the latter could not be due to contaminating non‐T cells, this activity was ascribed to Fc receptor‐bearing T lymphocytes.
Surface immunoglobulins of lipopolysaccharide‐stimulated spleen cells The behaviour of IgM, IgD and IgG
Authors: Bourgois A. , Kitajima K. , Hunter I.R. , Askonas Brigitte A. 
Published: February 2007

AbstractThe nature of Ig receptors carried by lipopolysaccharide (LPS)‐stimulated mouse spleen B cells was analyzed by surface iodination, direct antiserum precipitation and polyacrylamide gel electrophoresis. LPS activation led to a rapid decrease of surface IgD to 20 % and 80 % of the original level on days three and five of culture, respectively. Efficiency of iodination of cells doubled after culture but the proportional radioactivity in IgM remained constant.We could definitively identify γ‐chains on the surface of cells, but only in small amounts (1 % of total surface Ig) and this expression of IgG remained constant during 5 days of culture.
Control of immunity in parental and F1, hybrid mouse strains to a spontaneously arising parental tumor I. Correlation between in vitro and in vivo anti‐tumor reactivity in responsive and unresponsive animals
Authors: Levy R.B. , Waksal S.D. , Shearer Gene M. 
Published: February 2007

AbstractThis study has investigated the in vivo and in vitro cellular immunity of the AKR/J, (AKR/J × C57BL/6)F1, and (AKR/J × DBA/2)F1 mouse strains to a spontaneously arising AKR/J tumor. The study concludes that: 1) there is an excellent correlation between the growth of the tumor in vivo, and the ability of spleen cells from the respective strains to generate both primary and secondary cell‐mediated cytotoxic responses in vitro; and 2) one F1 host can be considered a responder against this tumor, whereas the other F1 strain studied appears to be genetically nonresponsive. Possible mechanisms relating to the observed patterns of response are discussed.
Hapten‐bearing cell in carrier‐determined tolerance
Authors: Aldo‐Benson Marlene , Borel Y. 
Published: February 2007

AbstractThe relationship between tolerance to the 2,4‐dinitrophenyl (DNP) hapten and cells bearing this hapten on their surface, was investigated using autoradiography. Animals injected with nontolerogenic conjugates of DNP‐ε‐lysine‐IgG, DNP‐azo‐IgG, and DNP‐mustard‐IgG (J. Immunol. 1975. 115: 1409) did not have splenic lymphocytes bearing DNP on their surface 5 days after their last injection, while those injected with tolerogenic conjugates of DNP‐ε‐lysine‐IgG did have splenic hapten‐bearing cells. Control studies showed that I25I‐labeled anti‐DNP used to reveal hapten‐bearing cells did react with the nontolerogenic conjugates on the cell surface. There was no difference in the numbers of hapten‐bearing cells in animals receiving either 100 μg or 1000 μg of tolerogenic DNP‐IgG 5 days after the injection. Animals injected with 1000μg of tolerogen remained tolerant for 6 months. These tolerant animals still had hapten‐bearing cells in their spleens 6 weeks after injection. In contrast, animals which had lost tolerance 3 months after 200 μg of tolerogen injection did not have hapten‐bearing cells.These experiments confirm that the hapten DNP remains on the surface of hapten‐binding cells in tolerance only. It is unlikely that the carrier alone, either nonspecifically or specifically via Fc binding, accounts for the presence of the tolerogen on lymphoid cells because it would be observed with nontolerogenic as well as tolerogenic DNP‐IgG conjugates. A direct relationship between tolerance and hapten‐bearing cells exists. The significance of this correlation to the mechanism of tolerance is discussed.