bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble factors in tolerance and contact sensitivity to 2,4‐dinitrofluorobenzene in miceIV. Characterization of migration inhibition factor‐producing lymphocytes and genetic requirements for activation
Authors: Moorhead John W. , Murphy Juneann W. , Harvey Robert P. , Hayes Roberta L. , Fetterhoff Terry J. 
Published: February 2007

AbstractThe production of migration inhibition factor (MIF) in vitro by lymph node cells from mice with contact sensitivity to 2,4‐dinitrofluorobenzene (DNFB) was investigated. MIF activity of cell‐free culture supernatants was measured using a micro, indirect “hanging‐drop” assay system. We found that DNFB‐sensitized lymph node cells are stimulated to produce MIF by co‐culture with DNP‐labeled spleen cells or splenic adherent cells. The stimulation was quantitatively antigen‐specific, as co‐culture with TNP‐spleen cells or TNP‐splenic adherent cells induced only low levels of MIF activity. Pretreating the immune lymph node cells with different antisera plus complement, before addition of DNP‐spleen cells, showed that MIF production is dependent on Ia− T cells. Additional experiments showed that in order for the T cells to be stimulated, homology at the I‐A subregion of the major histocompatibility complex between the T cells and DNP‐spleen cells is required. Collectively, these results correlate with our previous finding that transfer of contact sensitivity is mediated by Ia− T cells and indicate that both tests, i.e., transfer in vivo and MIF production in vitro, are measuring effector functions of the same T cell subset.
Analysis of low natural killer cell activity in 89Sr‐treated mice
Authors: Mellen Paul F. , Lust John A. , Bennett Michael , Kumar Vinay 
Published: February 2007

AbstractTreatment of mice with the long‐lived bone‐seeking radioisotope 89Sr results in the selective irradiation and destruction of the bone marrow. This is accompanied by a marked reduction in natural killer cell activity against YAC‐1 lymphoma [NK(YAC‐1)]. To test for the presence of cellular suppressors of NK(YAC‐1) in 89Sr‐treated mice, in vitro and in vivo cell mixture protocols were used. In vitro, we did not observe any specific inhibitory effect of spleen cells from 89Sr‐treated mice on NK(YAC‐1) activity of normal spleen cells. The NK(YAC‐1) activity of 89Sr‐treated mice, measured in vivo by their ability to clear radiolabeled YAC‐1 cells from the lungs, was impaired. However, spleen cells from 89Sr‐treated mice, when adoptively transferred with normal spleen cells, failed to inhibit the NK(YAC‐1) activity of the latter in the lung clearance assay. Further, when normal spleen cells were injected into 89Sr‐treated mice, the ability of the transferred cells to mediate in vivo activity was not suppressed in the 89Sr‐treated host. These experiments support the suggestion that the low NK(YAC‐1) activity in 89Sr‐treated mice is not mediated by suppressor cells, but may be due to the destruction of the marrow microenvironment which is essential for the generation of functional NK(YAC‐1) cells.
The induction of B cells refractory to antibody‐specific immunoregulation
Authors: Speck Nancy A. , Pierce Susan K. 
Published: February 2007

AbstractSubsequent to primary immunization with a hapten‐carrier conjugate, and concomitant with an initial antibody response to that antigen, a regulatory mechanism is induced that specifically limits the stimulation of hapten‐specific primary B cell responses through the recognition of B cell antibody. Nonimmune B cells are sensitive to this regulation, while secondary B cells are refractory to its suppressive effects. Experiments were conducted to determine the conditions under which refractory B cell populations are generated. B cells from BALBlc and athymic BALB/c nu/nu mice were examined following immunization with the T‐dependent antigen dinitropheny‐lated (DNP) hemocyanin and the T‐independent antigen DNP‐Ficoll to assess the T cell dependence of the generation of refractory B cells. Evidence is presented that this process is not dependent on the presence or participation of T cells during in vivo immunization, since both T‐dependent and T‐independent antigens have the potential to induce a refractory B cell population. However, under certain circumstances, T cells can regulate the induction of refractory B cells during in vivo immunization. In addition, it was determined that the immunoregulatory phenomenon can be induced following immunization with both T‐dependent and T‐independent antigens.
Target‐effector interactions in the rat natural killer cell system. I. The measurement of cytotoxicity at the single Cell level
Authors: Flexman James P. , Shellam Geoffrey R. 
Published: February 2007

AbstractOptimal conditions have been developed for measuring interactions at the single cell level between effector cells and target cells in the rat NK cell system. Conjugates were formed between splenic leukocytes and target cells to determine the percentage of target binding cells, and after immobilization of the conjugates in agar, single lytic interactions were measured by the uptake of trypan blue by dead target cells. Cytotoxic effector cells were expressed as a percentage of target binding cells. Factors which influenced conjugate formation were the ratio of effector to target cells, temperature, centrifugation and the conditions of culture of the target cells. When comparing a number of rat and mouse strains with various levels of natural killer cell activity, there was found to be a good correlation between the number of target binding cells and cytotoxicity in the standard 51Cr‐release assay in rats, but in mice the removal of nylon‐adherent cells was required to achieve a reasonable correlation. However, 60–70% of the cytotoxicity was lost on nylon fractionation, making this approach of doubtful value. The target‐binding cell and cytotoxic effector cell assays were used in conjunction with the 51Cr‐release assay to study the specificity, rat strain variation and ontogeny of natural killer cells. During ontogeny target binding cells reached adult levels sooner than did cytotoxic effector cells. The greatest development of natural killer cells occurred during the first 3 weeks of life; the number of cytotoxic cells per spleen increased 138‐fold up to 21 days of age, compared with an 11‐fold increase between 21 days and 9 weeks of age.
A comparison of two anti‐neuraminidase monoclonal antibodies by complement activation
Authors: Holmes Kerry T. , Hampson Alan W. , Raison Robert L. , Webster Robert G. , O'Sullivan William J. , Mountford Carolyn E. 
Published: February 2007

AbstractThe specificities of two anti‐neuraminidase monoclonal antibodies have been compared by their ability to fix complement. They were found to differ to some extent in their reactivity with a range of N2 influenza viruses. Thus, as in the case of anti‐hemagglutinin antibodies, anti‐neuraminidase monoclonal antibodies are able to detect subtle structural changes in the viral antigen. Although both monoclonal antibodies fixed complement with intact virus, neither one fixed complement when complexed with isolated neuraminidase “heads”.
Are Tγ cells of myelomonocytic lineage?
Authors: Astaldi Alberto , Van De Griend René J. , Schellekens Peter Th. A. , Vossen Jaak M. 
Published: February 2007

AbstractTo evaluate the cell lineage from which Tγ cells derive by means other than cell membrane markers, the rare situation of human chimerism was studied. In patients with severe combined immunodeficiency who have been successfully treated by bone marrow transplantation, the occurrence of split take has been well documented: whereas myelomonocytic hemopoietic cell lines remain of host origin, the T lymphoid compartment is of donor origin, and the B lymphoid compartment may be either of host or of donor origin. We have studied the Tγ cells of two patients successfully treated by bone marrow transplantation from donors of the opposite sex with respect to the sex chromosome pattern, the binding of OKM1 and OKT3 monoclonal antibody and the killer (K) and natural killer (NK) cell activities. All Tγ cells of both patients were found to be of donor origin. These Tγ cells contained two serologically distinct subpopulations, one OKM1+, OKT3+, the other OKM1+, OKT3−, as was also found in normal persons. However, the ratio between these two subpopulations is < 1, whereas the ratio in these patients was > 1. Furthermore, the patients' Tγ cells displayed strongly reduced K and NK activities (< 5% of normal). It was concluded that at least part of the OKM1+, OKT3− and the OKM1+, OKT3− Tγ cells are derived from other than the myelomonocytic lineage, presumably from the lymphocytic lineage. The origin of the K‐ and NK‐active Tγ cells, however, cannot be conclusively determined from these experiments. The findings also imply that the antigen detected by OKM1 should no longer be regarded as exclusively present on myelomonocytic cells.
Migrant μ+δ+ and static μ+δ− B lymphocyte subsets
Authors: Gray David , MacLennan Ian C. M. , Bazin Hervé , Khan Mahmood 
Published: February 2007

AbstractImmunoglobulin isotype expression in isolated lymph node (LN), spleen and blood lymphocyte suspensions was assessed in rats. The proportion of μ+δ− B cells in spleen (34%) was approximately twice that in blood and LN. Immunohistological examination of spleens showed the cells of the marginal zones to be predominantly μ+δ−. On the other hand, μ+δ+ B cells were mainly confined to the follicles in both spleen and LN. These follicles had a minor μ+δ− component.The migratory properties of B cells with these two phenotypes were assessed by depleting lymphocytes migrating through the white pulp of rat spleen. This was achieved by placing a 32P‐impregnated β‐emitting polythene strip over one half of the spleen. Examination of the nonirradiated half of the spleen, LN and peripheral blood after 12 days irradiation showed selective loss of δ+ B cells. The μ+δ− cells of the splenic marginal zone were numerically unaltered. There was also a substantial residual μ+δ− B cell presence in the small lymphocyte compartment of follicles of LN and spleen in depleted animals. In addition, the blood selectively retained a μ+δ− B cell component. This was not derived from the spleen, as μ+δ− blood B cell numbers were sustained even where both halves of the spleen were irradiated. It is concluded that: (a) the major static B cell component of spleen and LN is μ+δ−, (b) that most if not all δ+ B cells repeatedly migrate through the spleen and (c) there is a blood‐born μ+δ− component which is resistant to depletion by splenic irradiation.
Natural killer cell activity in the rat. Analysis of effector cell morphology and effects of interferon on natural killer cell function in the athymic (nude) rat
Authors: Reynolds Craig W. , Timonen Tuomo T. , Holden Howard T. , Hansen Carl T. , Herberman Ronald B. 
Published: February 2007

AbstractAthymic (nude) rats were found to have increased levels of natural killer (NK) activity, 3− to 5−fold higher than in euthymic rats. Studies were performed to determine the nature of the NK cells in these animals and the basis for their increased cytotoxic reactivity. Large granular lymphocytes (LGL), which were previously shown to be the NK cells in euthymic rats, were increased 2‐ to 7‐fold in the peripheral blood and spleen of nude rats. The LGL, enriched by centrifugation on discontinous Percoll density gradients, were shown to have augmented NK activity similar to that seen with LGL‐enriched fractions from euthymic rats. These results indicate that the NK cells in euthymic and athymic rats are morphologically and functionally similar, and that the higher NK activity in nude rats appears to be mainly attributable to an increased proportion of effector cells. In a single‐cell cytotoxicity assay, interferon pretreatment of LGL was shown to increase: (a) the percentage of LGL which form conjugates with target cells; (b) the percentage of conjugate‐forming cells which kill; and (c) the kinetics of lysis. Different effects were seen depending on the target cell tested.
surface markers of mono‐and multi‐functional mixed leukocyte culture‐derived T cell clones in man
Authors: Pawelec Graham , Kahle Paul , Wernet Peter 
Published: February 2007

AbstractAlloactivated human lymphocytes have been cloned by limiting dilution followed by expansion of clonal progeny using interleukin 2. Their differing functional specificities were analyzed in terms of reactivity in primed lymphocyte typing (PLT), cell‐mediated cytotoxicity to normal peripheral blood mononuclear cells or to cell line targets susceptible to lysis by natural killer cells, and finally, suppressive capacity in mixed leukocyte cultures. T lymphocyte clones mediating exclusively PLT, CML or suppression were isolated. In contrast, all clones with natural killer‐like activity were found to be multifunctional, in that they strongly suppressed mixed leukocyte cultures, as well as having variable, although generally weak, activity in PLT and CML. From a total of 148 clones initially screened, about half manifested PLT reactivity. Of these, 60% were restimulated exclusively by determinants associated with the HLA‐D type of the original priming cells, whereas the remainder were restimulated by a variety of different HLA‐D as well as HLA non‐D products. Similar heterogeneity of responses at the clonal level was observed among the populations active in CML. Using monoclonal antibodies, surface marker phenotyping of functionally distinct clones was undertaken in an attempt to correlate surface marker profiles with particular functions. It was found that all clones tested were mature, activated T cells (Lyt‐3+, T28+, OKT3+, HLA‐DR+, HTA1‐1, OKT6−). Many of the clones described here, whether functional in PLT CML, having natural killer‐like or suppressor cell activity, expressed putative “helper/inducer” T cell markers defined by OKT4. The putative “suppressor/cytotoxic” marker OKT8 appeared on some natural killer‐functional clones, but not on CML or suppressor cell clones. Clones with natural killer‐like function were identifiable by their additional unique expression of the antigen detected by the rat monoclonal antibody YD1/48.HLK, whereas the monoclonal antibody M522 reacted selectively with clones having natural killer or CML function, but not with those with PLT or suppressor cell function. These results show that cloned T cells with PLT, CML, natural killer or suppressor activities, derived from MLC, can act as valuable tools in the elucidation of T cell function in vitro. To this end, the correlation of defined function with analysis of cell surface markers using monoclonal antibodies will be of value in dissecting components of human immune responses and determining the functional relevance, if any, of structures detected by such antibodies.
Age‐related alterations of the lymphocyte population in the thymus of (NZB × SJL)F1 mice: Analysis by flow cytofluorometry
Authors: Dumont Francis , Habbersett Robert C. 
Published: February 2007

Abstract(NZB × SJL)F1 (NS) female mice develop a marked hypertrophy of the thymus in the course of aging. The age‐dependent evolution of the intrathymic lymphocyte population of these mice was monitored in comparison with that of the immunologically normal BALB/c and C57BL/6 strains. The expression of several lymphocyte markers on the surface of the thymic cells was quantitated using single‐ and two‐color flow cytofluorometry analysis. Two main cell types could thus be identified in the thymus of 3‐month‐old mice: a major subset of bright Thy‐1+, Lyt‐1+2−, bright peanut agglutinin (PNA)+ lymphocytes and a minor subset of dull Thy‐1+, Lyt‐1+2−, dull PNA+ lymphocytes. In BALB/c and C57BL/6 mice, the frequencies of these cell types did not significantly vary between 3 and 18 months of age, despite a drop of thymic cellularity. In contrast, in NS female mice the proportion as well as the absolute number of dull Thy‐1+, Lyt‐1+2−, dull PNA+ cells increased while those of bright Thy‐1+, Lyt−1+2−, bright PNA+ cells diminished during the same period. The emergence of new cell types could also be noted in the thymus of aging NS female mice. Thus, in addition to the appearance of dull PNA+, Lyt‐2+ cells and of bright PNA+ cells devoid of T cell markers, there was a high frequency of non‐T cells bearing surface immunogloublin, Ia antigen and receptors for Fc. These data indicate that the thymic hypertrophy of NS female mice reflects the intrathymic accumulation of large numbers of phenotypically mature T and B cells. Such alterations were not detectable in NS male mice.
Ontogenic development of B cell reactivities to cooperative cell signals: Dissociation between proliferation and antibody secretion
Authors: Pettersson Svea , Pobor Grgur , Coutinho Antonio 
Published: February 2007

AbstractCloned helper T cell lines, with specificity for “minor” antigens expressed on all B lymphocyte (and macrophage) surfaces were used to study the postnatal development of B cell reactivity to helper T cell cooperative signals. Such helper T cell populations, upon physiologic interactions with “target” B lymphocytes, activate them polyclon‐ally, allowing for the analysis of functional ontogeny independent of V gene repertoires. Due to the high frequency of responding cells, these methods also offer a high level of sensitivity and permit measurement of B cell proliferation in the absence of antibody production.The results demonstrate that neonatal spleen cells are fully competent to stimulate adult helper T cell responses and that neonatal and adult B cells are comparable in their proliferative responses to cooperative cell interactions. In contrast, a marked deficiency in the ability of neonatal cells to mature to immunoglobulin secretion was observed in the same responses. Since the presence of suppressive activities in neonatal spleen cells could not be demonstrated, it was concluded that “early” B lymphocytes are intrinsically defective in their ability to secrete immunoglobulin upon cooperative induction, whereas they show full competence to expand clonally.
Tumor‐specific T helper activity can be abrogated by two distinct suppressor cell mechanisms
Authors: Howie Sarah , McBride William H. 
Published: February 2007

AbstractTumor‐specific helper T cell activity was detected in the spleens of tumor‐bearing mice using a sensitive, simple and reproducible in vitro assay based on those previously described for soluble hapten‐carrier antigens. Helper activity disappears when the tumor is large. This is coincident with the appearance of two distinct types of suppressor cells: (a) T cells which suppress tumor‐specific T helper responses and (b) non‐T cells which are nonspecific in their action.
Secretion of human immunoglobulins by mouse myeloma × Daudi somatic cell hybrids
Authors: Erikson Jan , Croce Carlo M. 
Published: February 2007

AbstractSomatic cell hybrids between nonproducer mouse myeloma cells and Burkitt lymphoma‐derived Daudi cells that do not secrete human immunoglobulin chains secrete human IgM. The 33 000 dalton protein (P33) is also secreted by the hybrids as part of the IgM molecule. Since P33 and x chains cosegregate in all primary hybrid clones and subclones, it is concluded that they are coded for by the same human chromosome 2. The fact that both P33 and x' chains are immunoprecipitated by specific anti‐human x chain antisera, and that both P33 and x' bands disappear and a single band immuno‐precipitable by an anti‐human x chain antiserum appears in tunicamycin‐treated hybrid cells, suggest that they are differently glycosylated forms of the same polypeptide.
Immunosuppression caused by antigen feeding. I. Evidence for the activation of a feedback suppressor pathway in the spleens of antigen‐fed mice
Authors: Macdonald Thomas Thornton 
Published: February 2007

AbstractSheep red blood cells (SRBC) administered by the oral route to normal mice elicited no detectable splenic anti‐SRBC plaque‐forming cell (PFC) response until 8 weeks of antigen feeding. At this time a splenic IgA anti‐SRBC PFC response was detected. On the other hand, spleen cells taken from mice given oral SRBC for 1‐5 weeks showed striking changes in their in vitro anti‐SRBC responsiveness as compared to spleen cells from normal mice. This was evidenced by enhanced early (days 3‐4) in vitro responses, followed by suppressed late (day 5‐6) in vitro responses. Both early enhancement and late suppression were T cell‐mediated. Early enhancement appeared to be mediated by helper T cells of the Lyt‐1+2.3− phenotype. Late suppression was also mediated by Lyt‐1+2.3− cells, but Lyt‐2‐bearing cells had to be present in culture for suppression to occur. Lyt‐2‐bearing cells could be replaced with normal T cells. Furthermore, elimination of cells bearing I‐J‐encoded determinants from the T cell population isolated from the spleens of antigen‐fed mice also partially relieved suppression. Thus, antigen feeding appears to activate a feedback suppressor pathway in which Lyt‐1+2.3−, I‐J subregion determinant‐bearing T cells can suppress immune responses by causing normal T cells to become suppressor effectors. No evidence was found to show that antigen feeding induced Lyt‐1−2.3+ suppressor cells in the spleen, nor were any serum suppressor factors detected.
Effects of 15‐hydroperoxyeicosatetraenoic acid on human lymphocyte sheep erythrocyte rosette formation and response to concanavalin A associated with HLA system
Authors: Gualde Norbert , Rabinovitch Hélène , Fredon Monique , Rigaud Michel 
Published: February 2007

AbstractThe lipoxygenase product hydroperoxyeicosatetraenoic acid (HPETE) has immunosuppressive properties in vitro and in vivo. It was observed that 15‐HPETE inhibit the sheep red blood cell rosette formation and the concanavalin A‐induced blast transformation of human lymphocytes. This inhibition was HLA‐linked. HLA‐B12 subjects were less sensitive than non‐B12 subjects. It is likely that HPETE acids are macrophage mediators which inhibit some lymphocyte functions.