bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody‐Secreting Cell Precursor Frequencies among the Sheep‐Erythrocyte‐Binding Cells after Immunization
Authors: MARTÍNEZ‐MAZA O. , FEHNIGER T.E. , ASHMAN R. F.
Published: June 2006

Controversy concerning the immunologic role of antigen‐binding cells (ABO has prompted us to attempt to quantitate the proportion of stimulable ABC, in immunized animals, which are precursors for cells producing antibody specific for the antigen bound. Using a lipopolysaccharide (LPS)‐driven limiting dilution analysis system, the precursor frequency (PF) of cells secreting IgM and IgG and sheep erythrocyte (SRBQ‐specific IgM and IgG was established for highly purified SRBC antigen‐binding cell (SRBC‐ABC) and unfractionated populations taken from CBA/J mouse spleens on days 5, 12 and 180 of the in vivo primary immune response to SRBC. At all these times, almost all SRBC‐ABC spontaneously secreting immunoglobulin (Ig) secreted SRBC‐specific Ig, and almost all precursors of Ig‐secreting cells in the ABC populations were precursors of cells secreting specific anti‐SRBC antibody. In SRBC‐ABC populations, the PF for total and SRBC‐specific Ig secretion was seen to decrease on days 5 and 12 after immunization and to increase to 3.5 to 7 times nonimmune levels 180 days after immunization. The absolute number of precursors, within the SRBC‐ABC population, for the secretion of SRBC‐specific Ig decreased on day 12 after immunization. In the unfractionated population, the PF for SRBC‐specific Ig secretion temporarily increased after immunization, reaching peak levels 5 days (IgM) and 12 days (IgG) after immunization. These two changes may be related, representing the progress of stimulated cells out of the ABC pool as they lose receptors en roule to full maturation. The small clone sizes on days 5 and 12 indicate that ABC divide less in response to LPS when already engaged in a response to antigen. In contrast, the PF for total IgM and IgG secretion in the unfractionated population was not greatly affected by immunization.
Inhibition of Human NK Cell Cytotoxicity by Induction of Cyclic AMP Depends on Impaired Target Cell Recognition
Authors: ULLBERG M. , JONDAL M. , LANEFELT F. , FREDHOLM B. B.
Published: June 2006

Induction of cyclic AMP (cAMP) depresses natural killer (NK) cell activity. The present results demonstrate that this is dependent on a decreased capacity of the effector cells to conjugate to target cells. This was found either if dibutyryl‐cAMP was used or if cAMP was induced by adenylate cyclase stimulation with prostaglandin E1 (PGE1) or by inhibition of phosphodiesterase activity with the inhibitor ZK 62711. The sites of action for cAMP‐induced NK suppression and Interferon (IFN)‐induced NIC enhancement are demonstrated to be distinct, since IFN acts by increasing the lytic efficiency and the recycling capacity without influencing target binding. Sequential treatment with cAMP/JFN and JFN/cAMP shows that IFN can neither restore target binding when added after cAMP nor protect against the cAMP‐induced target binding inhibition when added before cAMP. The results are discussed in view of earlier data on cAMP in relation to cell membrane functions and cellular recognition, the mechanism underlying the cAMP‐induced target binding inhibition, and the potential of the NK system as an indicator for immunosuppression. The present work also demonstrates the particular subpopulation in peripheral blood which mediates most NK activity, to respond strongly to PGEi stimulation with regard to cAMP induction.
Analysis of the Repertoire of Anti‐Idiotypic B‐Cell Responses to Self‐I‐Ak‐ or ‐I‐Ek‐Reactive Monoclonal Antibodies in A.TL Mice
Authors: DEVAUX C. , PIERRES M.
Published: June 2006

Twenty anti‐idiolypic antisera (anti‐Ids) were produced in A.TL mice to self‐I‐Ak‐ or‐I‐Ek reactive monoclonal antibodies (mAbs), constructed in the A.TH anti‐A.TL combination. The reactivity of these anti‐Ids was examined in a panel of 31 anti‐lak A.TH mAbs, using direct idiotype binding, cross‐competitive inhibition of idiotype binding, and isoelectrofocusing (IEF) assays. Among 13 anti‐Ids produced against anti‐I‐Ak mAbs, one only recognized individual idiotypic specificities (Idls) on its corresponding mAb, while the 12 others identified homologous Idls and recurrent idiotypic specificities also expressed on heterologous anti‐I‐Ak and/or I‐Ek mAbs. Two sets of major cross‐reactive idiotypes (IdXs) were characterized on two groups of mAbs recognizing public Ia.1, I.Ak, r, u and r) or private (la.2, I‐Ak) determinants clustered in two spatially distinct epitope regions of the I‐Ak molecule, respectively. By contrast, most (5/7) of the anti‐Ids raised against mAbs recognizing polymorphic or monomorphic (Ia.7‐like) l‐Ek determinants displayed specificity apparently restricted to their corresponding mAb Idls. This finding contrasted with the previous characterization, using xenogeneic anti‐idiotypic reagents, of an interstrain IdX expressed on all mAbs defining la.7‐like determinants in the IEk epitope group I. These data indicate that A.TL mice can readily develop anti‐idiotypic responses towards self lareactive mAb minor idiotypes (Idls) and that recognition of anti‐lak mAb IdXs in such mice is preferentially observed when anti‐I‐Ak mAbs are used as immunogens.
Chronic Lymphocytic Leukaemia Cells Activated in Vitro Reveal Cellular Changes that Characterize B‐Prolymphocytic Leukaemia and Immunocytoma
Authors: ROBERT K.‐H. , JULIUSSON G. , BIBERFELD P.
Published: June 2006

Leukaemic blood lymphocytes from a patient in the terminal stage of chronic lymphocytic leukaemia (CLL) according to the Kiel classification were stimulated by lipopolysaccharide from Escherichia coli. During progression to blast transformation, stimulated cells lost receptors for mouse erythrocytes (MRBC), accumulated intracellular Ig (cIg), and expressed more surface membrane immunoglobulin (SmIg). In addition, transforming cells expressed receptors for the monoclonal antibody FMC7, known to distinguish between CLL cells and prolymphocytic leukaemia (B‐PLL) cells. Thus, activation of the patient's CLL cells induced changes in the cellular phenotype so as to resemble B‐PLL. Some clonal cells progressed further to a secretory stage of differentiation. Thus, in vitro stimulation induced cellular changes reminiscent of not only B‐PLL but also immunocytoma. Further studies of this kind may elucidate the relationship between these lymphocytic malignancies.
Cell Surface Structures Required for B‐Cell Activation with Haptenated Syngeneic Cells
Authors: RAMOS T.
Published: June 2006

The requirement for H‐2‐coded antigens on the cell surface of stimulator cells used for induction of B‐cell responsiveness against haptenated (fluorescein isothiocyanate (FITC) syngeneic cells was studied using H‐2‐less F9 teratocarcinoma cell lines. 1 found that FITC‐labelled F9 cells, in contrast to normal spleen cells, could not induce hapten‐specific antibody synthesis. The effect of treatment of stimulator cells with glutaraldehyde or trypsin before or after hapten labelling was also analysed. It was found that regardless of the order of treatment, hapten‐specific antibody synthesis could not be induced by cells treated with glutaraldehyde or trypsin. In addition, hapten‐specific B‐cell unresponsiveness could not be induced by FITC‐labelled glutaraldehyde‐treated syngeneic lymphocytes. However, cold targets treated with trypsin or glutaraldehyde efficiently blocked T‐cell‐mediated cytotoxicity. The requirement for H‐2‐coded antigens for B‐cell activation against haptenated syngeneic lymphocytes is discussed.
Isolation of Human Blood Monocytes with Nycodenz, a New Non‐Ionic lodinated Gradient Medium
Authors: BØYUM A.
Published: June 2006

Monocytes were separated from human blood with Nycodenz, an iodinated gradient medium. Monocytes have a lower average density than lymphocytes, but because of overlapping efficient separation cannot be achieved on the basis of density differences alone. Thus the isolation procedure was based on the assumption that the low‐density fraction of lymphocytes increases its density more than monocytes by expelling water when exposed to an increased osmolarity. Thereby they might pass through a density barrier present initially, whereas the monocytes remain at the top of the gradient layer. Separation fluids with densities ranging from 1.061 to 1.096 g/ml were prepared by mixing Nycodenz with Nad solutions of various concentrations. EDTA‐blood (3 ml) or a leucocyte suspension (2–6 ml) obtained by dextran sedimentation was loaded on 3 ml of separation fluid and centrifuged for 15 min at 1900 rpm. Then the cells in the interface region were collected. At each density level it was possible to obtain an almost pure monocyte suspension (95–98% by increasing the osmolarity. However, the higher the purity, the lower the monocyte yield. Apparently, the viability of monocytes was not affected, even when subjected to an osmo larity of 600 mosmol. For routine use, it appears that separation fluids with densities from 1.061 to 1.078 g/ml and corresponding osmoiarity in the 300 to 410 mosmol range are suitable.
Increase of Peripheral Blood B Cells with Fc Receptor for IgA in Patients with IgA Nephropathy
Authors: ENDOH M. , SAKAI H. , SUGA T. , MIURA M. , TOMINO Y. , NOMOTO Y.
Published: June 2006

A B‐cell subset with Fc receptors for IgA (Bα cells) has been observed in human peripheral blood. To investigate aberrations of B cells in a diseased state, the percentages of Bα cells were enumerated in peripheral blood from patients with IgA nephropathy, which is characterized by preponderant deposition of IgA‐dominant immune complexes in the glomerular mesangial area. The present study showed a significant increase in Bα cells in peripheral blood from patients with IgA nephropathy but not in those with chronic proliferative glomerulo‐nephritis without mesangial IgA deposition. Most FcαR‐bearing cells were observed in surface IgA bearing lymphocytes. No linear correlation was observed between the levels of serum IgA and the percentages of Bα cells. The addition of aggregated IgA to cultures did not induce FcαR‐bearing B cells in vitro. It is postulated that Bα cells might have some pathogenetic role in the development of IgA nephropathy and that some antigenic stimuli might play a role in the increase of peripheral blood Bα cells in patients with IgA nephropathy.
Isolation and Identification of the Naturally Occurring, Newborn Spleen‐Associated Suppressor Cells
Authors: PEELER K. , WIGZELL H. , PECK A. B.
Published: June 2006

Spleens from newborn mice less than 6–7 days of age contain ‘naturally occurring’ suppressor cell populations that are able to inhibit nonspecifically immune responses of third‐party adult spleen cells and alloreactivity in the newborn spleen per se. Isolation of the effectors of this suppressor activity reveals that they are not classical T lymphocytes but, instead, a mixed population of cells of the monocytc series (monoblast/promonocyte/ monocyte) plus mast cells. This mixed population apparently can elicit its suppressor activity in part through secretion of soluble, in vitro culture‐stable material, which in turn initiates activation of the suppressorcell/limb of the immune response. These activities, nevertheless, modulate most strongly the early activation events of T‐cell responses and can result in complete suppression of alloreactive helper and cytotoxic T lymphocytedevelopment. Suppressor activity by mast cells can be demonstrated by degranulation, whereas suppressor activity by monocytes appears inherent in the newborn population. Thus, there are now at least three cell populations in the neonatc spleen—mast cells, monocytes. and T lymphocytes—which caneffect suppressor activity.
Genetic Control of Murine Antibody‐Dependent Cell‐Mediated Cytotoxicity
Authors: ALTMAN J. , BARDOS P. , VAN DER GAAG R. , CARNAUD C.
Published: June 2006

We have observed that the intensity of the direct antibody‐dependent cell‐mediated cytotoxicity (ADCC) response after an inoculation of foreign tumour cells varies with the strain of mice studied. The inoculation of a human lymphoblastoid cell‐line into CBA/J, BALB/c, or DBA/2 mice gives rise to a good cytotoxic response by the host K cells armed with specific antibodies. In contrast, A/J, B10.A, C57BL/6 and B10.S mice respond poorly under the same conditions. The high response is dominant in Fi hybrids between high and low responders and is also expressed among F2 backcrosses with the H‐2 phenotype of low responders, suggesting that non‐H‐2 genes are also implicated in the regulation of ADCC. The genetic control is not exerted at the level of antibody secretion but at that of K‐cell activity, since sera from high or low responders are equally effective in arming an ADCC reaction, whereas K cells from low‐responder strains are less efficient than those from high‐responder strains. The natural killer (NK) activity of the same strains has been screened. The results show a good correlation with some high‐ and low‐responder strains, such as CBA and DBA/2 or A/J and SJL, respectively, but not with C57BL/6, B10.S or B10.A strains. Thus, in addition to common genes controlling both lytic functions, there are specific genetic factors influencing the balance between NK and K cells. These findings confirm the general view that NK and K cells represent only partially identical subsets.
IgG Rheumatoid Factor‐Secreting Lymphocytes in Rheumatoid Arthritis: Evaluation of a Haemolytic Plaque‐Forming Cell Technique
Authors: PETERSEN J. , HEILMANN C. , BJERRUM O. J. , INGEMANN‐HANSEN T. , HALKJæR‐KRISTENSEN J.
Published: June 2006

A haemolytic plaque‐forming cell (PFC) assay detecting human B lymphocytes secreting IgG rheumatoid factor (RF) was established using sheep erythrocytes (SRBC) sensitized with rabbit IgG, developing rabbit anti‐human IgG, and complement. IgG–RF PFC were only demonstrated with IgG–depleted guinea‐pig serum as the source of complement. Cells spontaneously secreting IgG‐RF were found among synovial fluid mononuclear cells (mean, 134/106) and synovial tissue mononuclear cells (mean, 1775/106) from patients with rheumatoid arthritis, whereas few were recorded among blood lymphocytes (mean, 3/106). The experiments revealed that the RF–IgG PFC were protein‐synthesizing B lymphocytes. The antibody specificity of the secreted IgF‐RF was verified by the inhibitory effect of exogenous human and rabbit IgG on PFC formation.
Simultaneous Determination of the Concentration and Lytic Activity of Effector Cells that Mediate Natural and Antibody‐Dependent Cytotoxicity
Authors: CALLEWAERT D.M. , GENYEA J. , MAHLE N. H. , DAYNER S. , KORZENIEWSKI C. , SCHULT S.
Published: June 2006

Cellular cytotoxicity reactions can be studied in a manner analogous to that used to measure enzyme activity. This approach yields two parameters; Vmax the maximal rate of target cell lysis that can be achieved by the lymphocyte preparation tested, and KMapp, the apparent Michaelis constant. By analogy to many enzyme‐catalysed reactions, KMapp values for cytotoxicity reactions have generally been interpreted in terms of dissociation constants for the interaction of receptor sites on effector cells with antigens on the target cells, In this paper we demonstrate that experimentally determined KMapp values for natural or antibody‐dependent cytotoxicity reactions are approximately equal to the concentration of NK or K. effector cells in the lymphocyte preparation tested. This result makes possible the simultaneous determination of both effector cell frequency and lytic activity in a given lymphocyte preparation.
Virus Elimination in Acute Lymphocytic Choriomeningitis Virus Infection Correlation with Virus‐Specific Delayed‐Type Hypersensitivity rather than Cytotoxicity
Authors: THOMSEN A. RANDRUP , VOLKERT M. , BRO‐JØRGENSEN K.
Published: June 2006

The immunological effector mechanism responsible for the elimination of virus in murine acute non‐fatal extracranial lymphocytic choriomeningitis virus infection was studied. In this infection virus clearance is generally regarded as the result of a direct action of virus‐specific cytotoxic T cells (Tc cells) on virus‐producing target cells in the infected mouse. However, by manipulating the antiviral immune response by pretreatment with various doses of cyclophosphamide, we found lack of correlation between Te‐cell activity and the clearance of virus. In contrast, we observed a conspicuous correlation between the host's ability to mount a virus‐specific delayed‐type hypersensitivity (DTH) response and its capacity to combat virus. Moreover, pretreatment with silica and carragheenan prolonged viraemia without impairment of the peak Tc‐cell response. These findings indicate that Tc cells have little or no capacity to eliminate virus, at least in the absence of an inflammatory response, and our findings suggest that virus clearance reflects a DTH‐like process.
Comparison of the Cytoplasmic Antigens of Leprosy‐Derived Corynebacteria and Some Mycobacteria
Authors: GUEUR M.C. , HARBOE M. , FONTAINE F. , DELVILLE J. , COCITO C.
Published: June 2006

The immunological relationship between leprosy‐derived corynebacteria (LDC) and reference mycobacteria was analysed by crossed immunoelectrophoresis with intermediate gel. For this purpose, three reference systems (LDC15/anti‐LDC15, LDC18/anti‐LDC8, and LDC8/anti‐LDC8) were developed. They showed 15 to 20 distinct antigenic components in LDC cytoplasm. Extensive cross‐reactivity was observed among different LDC isolates, affecting 3 to 17 components. Moreover, several components were shown to cross‐react with mycobacteria when anti‐bacillus Calmette‐Gudrin (BCG), anti‐Mycobarterium leprae, other antisera and lepromatous leprosy sera were incorporated in the intermediate gel. The major cross‐reactive component, antigen M, was present in all LDC isolates and cross‐reacted with antigen 7 of M. leprae and antigen 60 of M. bovis BCG. The thermostability of these antigens and the specificity of the cross‐reacting antigens were assessed. The data underline the degree of immunochemical homogeneity within the LDC group of microorganisms and relatedness with M. leprae and other mycobacteria.
Relative Immunogenicity in Mice of Different Regions of the Human IgG
Authors: SARNESTO A. , RANTA S. , SEPPÄLÄ I. J. T. , MÄKELÄ O.
Published: June 2006

Monoclonal mouse antibodies to human IgG myeloma proteins were produced and characterized by determining their binding to a series of different purified myeloma proteins. Two types of immunization schedules were used. When the same myeloma protein was used for priming and boosting the mouse, all determinants of the molecule were effectively immunogenic. Of the 353 clones originating from these experiments 42% secreted anti‐Fv antibodies, 57% anti‐CH antibodies, and 0.85% anti‐CL, antibodies. In another schedule only the CL and CH regions were the same in priming and boosting; 270 anti‐CH (94%), 18 anti‐CL (16%), and no anti‐Fv hybridomas were found. Our results indicate that a unit mass of the Fv region was 1.3 times more antigenic than a unit mass of the CH region. A unit mass of the CH region was nearly five times more antigenic than a unit mass of the CL domain when the antigenicity of the Fv region had been excluded. When the antigenicity of the Fv region had not been excluded, a unit mass of the CH region was about twenty times more antigenic than a unit mass of the CL domain. The data suggest that an antigenic competition was taking place between different parts of the molecule and that the strongly antigenic region (Fv) was more efficient in competing out the nearest neighbour (CL) than in competing out other parts of the molecule.
Immunoglobulin‐Producing Cells in Blood and Cerebrospinal Fluid during the Course of Aseptic Meningoencephalitis
Authors: FORSBERG P. , KAM‐HANSEN S.
Published: June 2006

The protein A plaque assay was used to quantitate the number of IgG‐, IgA‐, and IgM‐producing cells per 20 × 103 lymphocytes in cerebrospinal fluid (CSF) and peripheral blood (PB) from 23 patients with aseptic meningoencephalitis (AM) in the acute stage 1–10 days after onset (group 1) and during late convalescence after 19–38 days (group II) and in PB from healthy controls. In the acute stage, IgG‐ and IgM‐producing cells were found with significantly higher frequency in both CSF and PB than in the late convalescence. In both patient groups there were more Ig‐producing cells in PB than in CSF. The predominant Ig class in PB of AM patients was IgA, just as in healthy individuals. In CSF, IgA‐ and IgG‐producing cells predominated at similar frequencies. In the group I patients, there were positive correlations between numbers of Ig‐producing cells of each class and the corresponding CSF Ig index, an indicator of intrathecal Ig synthesis. Since high numbers of Ig‐producing cells could be found in CSF that was otherwise normal, enumeration of Ig‐producing cells is considered a more sensitive indicator of the immune response intrathecally than measurement of free Igs
Characteristics of Poxvirus‐Induced Meningitis: Virus‐Specific and Non‐Specific Cytotoxic Effectors in the Inflammatory Exudate
Authors: DOHERTY P. C. , KORNGOLD R.
Published: June 2006

Mice injected intracerebrally with a sublethal dose of vaccinia virus develop severe meningitis. The number of inflammatory cells in cerebrospinal fluid (CSF) increases approximately threefold each day for 3 to 7 days after intracerebral challenge, subsequent to which samples can no longer be obtained because the cisterna magna is obliterated owing to brain swelling. Examination of this inflammatory exudate during the later stages of this pathological process shows evidence of both cytotoxic T lymphocyte (CTL) function and the presence of Lyt1+ and Ly12+ cells on days 6 and 7, In addition, potent non‐T‐cell (Lyt2−) cytotoxic activity is found in CSF taken from younger (12 weeks) mice as early as after day 3 and is still present on day 6. The level of non‐T‐cell‐mediated cytotoxicity in CSF on day 5 or 6 (but not day 3) is considerably decreased in animals that were also given a large dose of virus intravenously to maximize T‐cell stimulation in lymphoid tissue, and the extent of CTL activity is concomitantly increased. The diminution of non‐specific cytotoxic function does not seem to reflect simple dilution in the presence of excess virus‐immune T cells.
In Vitro Immunization for the Production of Antigen‐Specific Lymphocyte Hybridomas
Authors: BORREBAECK C. A. K.
Published: June 2006

Antigen‐specific lymphocyte hybridomas have been produced by a simple in vitro immunization procedure. Non‐immune spleen cells have been activated in vitro, and the B‐cell blasts have subsequently been used for somatic cell hybridization. Hybrids secreting monoclonal antibodies to human myoglobin, pig insulin, and benzo(a)pyrene were obtained with splenocytes that had been immunized 5 days in culture before the hybridization. The frequency of specific hybridomas was the same as or higher than that of hybridomas produced from in vivo‐immunized cells, showing the versatility of the procedure when making monoclonal antibodies to haptens and proteins with a conserved structure or to small amounts of antigen. Monoclonal antibodies of both IgG and IgM isotypes could be isolated.
Cellular Responses to Bacterial Lipopolysaccharide: T Cells Recognize LPS Determinants
Authors: MILNER E. C. B. , RUDBACH J. A. , VONESCHEN K. B.
Published: June 2006

An in vitro proliferative system was used to assess the capacity of lipopolysaccharide (LPS) to induce a specific T‐cell response in mice. Sensitized T cells were generated in vivo by subcutaneous inoculation with LPS. These T cells, which were purified on nylon wool columns, were stimulated to proliferate in vitro by LPS. Results of several lines of experimentation confirmed that the responding cells were T cells. Additional experiments indicated that sensitized T cells could distinguish between LPS and ovalbumin. Finally, it was found that genetic responsiveness to the biological effects of lipid A was required for full clicitation of LPS‐induced T‐cell proliferation. The data were interpreted to indicate that LPS interacted with, and stimulated, antigen‐specific murine T cells.
Mononuclear Cell Factors that Inhibit Fibroblast Collagen Synthesis
Authors: HART P. H. , POWELL L. W. , COOKSLEY W. G. E. , HALLIDAY J. W.
Published: June 2006

Supernatants harvested from peripheral blood mononuclear cells (PBMC) incubated either with the non‐specific mitogen phytohaemagglutinin‐P (PHA) or with the specific antigen tuberculin purified protein derivative for 72 h decreased collagen synthesis by dermal fibroblasts. PHA‐induced mononuclear cell factors (PHA‐MCF) responsible for decreases in collagen synthesis by dermal fibroblasts were localized by column chromatography on Sephacryl S‐200 to fractions of 30,000‐60,000 daltons. Proteolytic enzymes destroyed the activity of PHA‐MCF, but after incubation with neuraminidase some activity of these factors remained, The activity of PHA‐MCF was not inhibited by incubation with the monosaccharides L‐fucose, L‐rhamnose. N‐acetylglucosamine, and α‐melhyl‐D‐mannoside but was partially destroyed by heating at 80°C for 10 min. The factors were not mitogenic to PBMC. These factors did not appear to resemble any previously characterized factors produced by non‐adherent mononuclear cells. The mechanism by which these factors decreased fibroblast collagen synthesis appeared complex. There was no detectable increase in the release of collagenasc by fibroblasts, nor was a cytotoxic effect apparent. Increased PGE2 production by fibroblasts could not be related to the factor‐induced decrease in fibroblast collagen synthesis.
In Vitro Production of Granular T Cells and Mast Cells by Use of Different Conditioned Media
Authors: COURTOY R. , SCHAAF‐LAFONTAINE N , DEGIOVANNI G. , BONIVER J.
Published: June 2006

Normal mouse spleen cells were cultured in different conditioned media (CM). Mixed lymphocyte culture supernatant (MLC SN) was shown to promote the proliferation of cytotoxic, Thy‐l+, Lyt‐1+, Lyt‐2+, asialo‐GM‐1 +, weakly adherent cells with numerous vacuoles and lysosomc‐like cytoplasmic granules. In contrast, the Con A SN induced the proliferation of non‐cylotoxic, Thy‐1−. Lyt−1−, Lyt‐2−, asialo‐GM‐I, non‐adherent cells with numerous cytoplasmic granules. The ultrastructural morphology of these cells and the cytochemical characteristics of their granules enable us to identify them as mast celts. The different effects of both CM could be related to their T‐cell growth factor (TCGF) content. When the amount of TCGF of these two CM was determined (by assaying growth‐stimulating activity for T‐cell colonies), it appeared that the MLC SN contained larger amounts of TCGF (han the Con A SN used in these experiments.
Analysis of Leptospira Antigens by Crossed Immunoelectrophoresis
Authors: TERPSTRA W. J. , SCHOONE G. J.
Published: June 2006

Serovars icterohaemorrhagiae, canicola, and arboreae of pathogenic Leptospira interrogans and serovar patoc of saprophytic L. biflexa were examined by crossed immunoelectrophoresis. A close antigenic relationship was found between the interrogans serovars. particularly between icterohaemorrhagiae and canicola. To a much lesser extent cross‐reactions were found between interrogans serovars and patoc. Comparison of three different antigenic preparations of icterohaemorrhagiae by tandem crossed immunoelectrophoresis and by absorption experi ments with the patoc reference system showed the presence of several common broadly reactive antigens. Antigen I of the reference system, a genus‐specific heat‐stable protein antigen, was found in all antigenic preparations. It is a diagnostically important antigen.
Dissociation of Soluble Antigen—Antibody Complexes by Rheumatoid Factor IgM
Authors: ALKNER U.
Published: June 2006

Intact rheumatoid factor (RF)‐active IgM dissociated soluble antigen‐antibody complexes formed in the antigen excess zone, whereas trypsin‐digested protein had less effect. The dissociation mechanism involved an interaction between the RF IgM and the Feγ of antibodies in the complexes. RF‐active IgM had no demonstrable effect on antigen—antibody complexes when the antigen or the antibody had been immobilized. This was true irrespective of whether the experiments were performed in the antigen or in the antibody excess zone and despite binding between RF IgM and the immobilized proteins.
Functional Relationship of Human T Lymphocytes, Monocytes and Interleukins
Authors: ULMER A.J. , FLAD H.‐D.
Published: June 2006

The different requirements of human T lymphocytes of different densities for accessory cells and helper factors (Interleukin 1 (Il‐1) and Interleukin 2 (Il‐2)) in the response to phytohacmagglutinin (PHA) were investigated. Humun T lymphocytes were subfractionated by discontinuous density gradient centrifugation. The various T‐cell subsets were stimulated by PHA to form colonies in an agar micro‐culture in the presence or absence of additional adherent cells or crude preparations of Il‐1 or Il‐2. The results show that the higher the density of the fractionated T lymphocytes and the lower the number of cells cultured, the greater is the number of adherent cells or the amount of helper factors required for the stimulation of colony‐forming T lymphocytes. The results are consistent with the assumption that monocytes provide positive modulating activity during mitogenic stimulation of colony‐forming T lymphocytes. The number of monocytes necessary for exerting an optimal modulating activity depends on the number of T cells cultured and the density of the T‐cell fraction. This may reflect a distinct susceptibility of T cells of different densities to monocyte‐mediated helper effects.
Biochemical and Biosynthetic Studies of a Crystallizable Human γ1 Heavy‐Chain Disease Protein
Authors: MIHAESCO E. , GUGLIELMI P. , BROUET J.‐C. , MIHAESCO C.
Published: June 2006

We have studied the structure of a crystallizable γ1 heavy‐chain disease protein that lacks the entire VH and Cγ1 domains. The protein starts within the hinge region at aspartic acid 221 (Eu numbering). The native protein is a disulphide‐linked dimer with an apparent molecular weight of 52,000, consistent with the biochemical data obtained on the whole protein and its cyanogen bromide fragments. The carbohydrate content of this protein was 6.8%. As shown by biosynthesis experiments intracytoplasmic γ chains synthesized by neoplastic cells had an apparent molecular weight similar to that of the serum heavy‐chain disease protein. These data are compared with those obtained for other γ1 heavy‐chain disease proteins beginning in the hinge region, and the mechanisms leading to those abnormal Ig products are discussed.
Complement (C3)‐Receptor‐Mediated Phagocytosis of Agarose Beads by Mouse Macrophages
Authors: JOHNSON E. , ESKELAND T.
Published: June 2006

Phagocytosis of agarose beads by macrophages. cultured under serum‐free conditions was studied. 48 h was needed before a plateau in the uptake was reached. The ingested agarose beads were coated extracellularly with macrophage‐derived protein before attachment and ingestion of the beads. Intracellularly, the agarose‐linked protein was removed from the agarose. If the ingested agarose beads were extracted from the macrophages within 24 h after the plateau in the uptake was reached, a fraction of the beads could attach to new macrophages, demonstrating modification of the agarose beads by opsonin(s). Because of binding of anti‐human C3c antibodies to beads extracted from the macrophages after 24 h of phagocytosis and the trypsin sensitivity of the protein on the agarose, we conclude that the main opsonin on the agarose beads is C3bi. Requirements for the stimulatory effect of agarose on macrophages are summarized.
Activation of Helper T Cells for B Lymphocytes in Primary Mixed Lymphocyte Cultures
Authors: POBOR G. , PETTERSSON S. , BANDEIRA A. , MARTINEZ‐A. C. , COUTINHO A.
Published: June 2006

Normal BIO.BR (H‐2k, C57B1/6 background) spleen cells, enriched in primary mixed lymphocyte culture (MLC) for antigens of C3H/Tif mice (H‐2k, C3H background), induced normal C3H/Tif but not B10.BR B lymphocytes to proliferate and produce Ig. In contrast, normal B10.BR spleen cells enriched in parallel B10.BR anti‐C57B1/6 (H‐2k) MLC were not able to activate either B10.BR or C57B1/6 B lymphocytes. However, normal B10.BR spleen cells depleted of Lyt 2+ cells before initiation of the MLC, and subsequently enriched either for C3H/Tif or C57B1/6 antigens, activated B lymphocytes of the respective mouse strains specifically and equally well. These experiments show that primary MLC gives rise to effector T helper cells that, on recognition of specific alloantigens. activate normal B lymphocytes of the ‘stimulator’ strain. In response to major histocompatibility complex (MHC) alloantigens, this help is not revealed because of interference by Lyt 2+ lymphocytes. MHC‐reactive T helper cells for B lymphocytes, however, participate in these reactions and constitute the predominant population in long‐term cultures that are maintained by consecutive in vitro restimulations.
Plaque‐Forming Cells in Man
Authors: TAURIS P.
Published: June 2006

This paper describes the results obtained using an indirect protein A plaque‐forming cell (PFC) assay applied to human peripheral blood lymphocytes (PHI) activated with pokeweed mitogen (PWM). A maximal response was obtained after 6 days of culture with regard to the three major classes of immunoglobulin (Ig) investigated. No difference was found between females and males. Tand B lymphocytes mixed in ratios varying from 1:8 to 8:1 and unfraclionalcd cells were investigated. A maximal PFC response of isolated lymphocytes was found in cultures of 1:4 T/B reconstituted suspensions of untreated cells, whereas the maximal response of untreated B and 2000‐rad‐irradiated T lymphocytes was found in cultures with a 4:1 T/B ratio. The number of plaques developed in cultures of unfractionated cells exceeded the response of 4:1 T/B reconstituted untreated lymphocytes but was far below the number of PFC developed in cultures of untreated B and 2000‐rad‐irradiated T lymphocytes. Normal donors developed approximately 70 × 10−3 PFC/IO6 cells. The viability was 85% after the incubation period. No difference was found in the PFC response of cultures of separated, reconstituted T/B lymphocytes set up in autologous and allogeneic combinations.
Plaque‐Forming Cells in Man
Authors: TAURIS P.
Published: June 2006

When the immunoglobulin secretion of 172 normal healthy individuals was investigated with the protein‐A plaque assay, 12 persons (7%) did not develop any plaque‐forming cells (RFC) in cultures of pokeweed mitogen (PWM)‐activated unfractionated peripheral blood lymphocytes (PBL), incubated for 6 days. The effect of irradiation on normal PFC responders and non‐responders was also investigated; 2000‐rad‐irradialed non‐responder T lymphocytes co‐cultured with autologous untreated B lymphocytes restored the PFC response to normal levels. The evidence of a high level of suppressor activity in non‐responder T lymphocytes was further demonstrated by the decreased PFC response of normal B lymphocytes co‐cultured with untreated non‐responder T lymphocytes.
The Role of Calmodulin in Human Natural Killer Cell Activity
Authors: MOON T. D. , MORLEY J. E. , VESSELLA R. L. , LANGE P. H.
Published: June 2006

Calcium is known to play an essential role in the lytic mechanism of natural killer cells (NK), which form a subset of large granular lymphocytes. Many of the intracellular effects of calcium are mediated through the calcium‐binding protein calmodulin. In this study we have demonstrated that the specific calmodulin inhibitors (naphthalene‐sulphonamides) inhibit NK activity in humans at IC50's of 6.9 μM for W7 and 5.2 μM for W13. Comparison of the potency of these compounds with their less active counterparts suggests that NK activity is calmodulin‐dependent.
Genetic Analysis of the Low Responsiveness to Dextran B512 in CB A/N and C57BL/10ScCr Mice
Authors: FERNANDEZ C. , MÖLLER G.
Published: June 2006

CBA/N and C57BL/10ScCr mice are low responders to the antigen dextran B512. This is due to the Xid gene in CBA/N mice and to unknown genes in C57BL/10ScCr mice, although this strain is unresponsive to lipopolysaccharide (LPS) due to a defective gene in the fourth chromosome. The female F1 hybrids (C57BL/10ScCrxCBA/N) and (CBA/NxC57BL/10ScCr) were low responders to dextran, although the Xid gene is not expressed in these hybrids, indicating lack of genetic complementation. In contrast, female F1 hybrids between the dextran high‐responder strains CB A or C57BL/10 as one parental strain and the low‐responder strains CBA/N or C57BL/10ScCr as the other parental strain, respectively, were responders to dextran. The C57BL/10ScCr mice did not appear to have an X‐linked gene determining low responsiveness to dextran. The findings suggest that the only defect in CBA/N mice cannot be the Xid gene and the only defect in C57BL/10ScCR mice cannot be the gene determining unresponsiveness to LPS.
An OKT4+ T‐Cell Population with Suppressor Activity in Sézary Syndrome
Authors: FARNARIER‐SEIDEL C. , KAPLANSKI S. , GOLSTEIN M.‐M. , JANCOVICI E. , SAYAG J. , DEPIEDS R.
Published: June 2006

This report describes a case of Sézary syndrome with the surface marker phenotype of a mature distinct T‐cell subset OKT3+. OKT4+. OKT8−. OKT17+. OKIal−(+). Functional studies indicated that the patient's peripheral blood cells showed a very low proliferative response to non‐specific milogens (phytohaemagglutinin. concanavalin A. pokeweed mitogen) and failed to differentiate into plasma cells in a pokeweed mitogen—immunoglobulin‐synthesis‐driven system. In coculture with normal cells the leukuemic cells were able to suppress lectin‐induced T‐cell proliferation and B‐cell differentiation in a dose‐dependent manner. Suppressor function was not radiosensitive and did not require the presence of the OKT8+ subset for expression. These Sézary cells thus represent a suppressive T‐cell subset within the OKT4+ population. This subset may well correspond to the recently described OKT4+. OKT17+ normal suppressor cells. These findings would therefore illustrate a pathological and possibly clonal expansion of a normal OKT4+ suppressor T‐ceil subset.
Identification of an Anti‐Human Osteogenic Sarcoma Monoclonal‐Antibody‐Defined Antigen on Mitogen‐Stimulated Peripheral Blood Mononuclear Cells
Authors: PRICE M. R. , CAMPBELL D. G. , BALDWIN R. W.
Published: June 2006

An anti‐human osteogenic sarcoma monoclonal antibody (mouse IgG2b) termed 79 IT/36 was found to exert complement‐dependent cytotoxicity against phytohaemagglutinin (PHA)‐stimulated peripheral blood mononuclear (PBMN) cells. This reaction was examined by flow cytofluorimetry using indirect membrane immunofluorescence to detect cell‐bound antibody and by measurement of the binding of fluroscreen‐isothiocyanate‐conjugated 791T/36 antibody to cells. The antibody reacted strongly wiih peripheral blood blast cells induced by PHA, and there was negligible reactivity wiih resting lymphocytes. Maximum binding was observed after 3 days' culture with PHA, coinciding with maximum DNA synthesis, and this represented of the order of 2 × 105 antibody molecules bound per cell. After cell surface radioiodination of PHA‐stimulated PBMN cells, detergent lysis and immunoprecipitation of antigen wiih 791T/36 antibody and Sepharose‐protein A, the apparent molecular weight of this antigen was determined to be 72,000 by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. This is identical to that of the 791T/36‐defined antigen expressed on various osteogenic sarcoma cell lines [3, 17], and by this criterion the antigen is distinguishable from other cell surface markers of activated human lymphocytes.
Characterization by Monoclonal Antibodies of the Cytotoxic Effector Cells in Human Peripheral Blood Mononuclear Cells Reactive against Anchorage‐Dependent Tumour Cell Lines
Authors: CHANG Z. L. , HOFFMAN T. , STEVENSON H. C. , TRINCHIERI G. , HERBERMAN R. B.
Published: June 2006

The effector cells for spontaneous cytotoxicity against anchorage‐dependent human or mouse tumour cell lines in a 72‐h iododeoxyuridine‐re lease assay by normal human peripheral blood cells (PBMNC) or monocyle‐enriched fractions were analysed by the use of monoclonal antibodies. PBMNC or adherent or elutriated monocyte‐enriched populations of PBMNC were depleted of monoclonal antibody‐reactive cells by complement‐dependent lysis or separated into monoclonal‐antibody‐positive or ‐negative subsets by an indirect rosetting technique followed by Ficoll‐Hypaque density gradient separation. The experimental data indicated that in both PBMNC and monocyte‐enrichcd populations, an appreciable proportion of the effector cells with cytolytic activity against adherent human or mouse tumour target cells were positive with B73.1.1 (an antibody with a high degree of selectivity for natural killer (NK) cells), B43.4.1 (or OKM1) and with OKT1 la (an antibody recognizing the receptors lor sheep erythrocytes), and had the morphology of large granular cells, which have previously been shown to mediate NK activity. These effector cells were mostly negative for BRL 1, BRL.2. B52.1.1, B44.1.1, B13.4.1 and DR antigens, unlike classical monocytes. Some cells which are cytotoxic for the adherent mouse, SV‐40‐transformed kidney tumour line. TU‐5. may bear BS2.I.1 or other monocyte‐like antigens. Taken together, these results indicate that, in monocyte‐enriched populations, both NK cells and monocytes have cytotoxic effector activity against various human and mouse adherent target cell lines.
Stress Causes Reduced Natural Killer Activity in Mice
Authors: AARSTAD H. J. , GAUDERNACK G. , SELJELID R.
Published: June 2006

The natural killer (NK) activity of spleen cells from C57B1/10 mice subjected to standardized stress conditions was reduced when compared with that of untreated controls. Both the total number of nucleated spleen cells and their cytotoxic activity against an NK‐sensitive target were reduced. The reduction appeared after induction of stress, and the NK activity was reduced throughout an 8‐day stress period.
Fine‐Specificity of the λ and χ L Chains Associated with Antibodies Directed to α(l→3) Glucosyls in Dextran
Authors: BELL C.G.
Published: June 2006

The function of BALB/c primary B precursors, responding to dextran (dex) B‐1355. and the fine‐specificity of the B‐1355‐binding. λ and χ, monufocal antibody (Ab) generated by the precursors have been examined. In splenic fragments from Lymulus polyphemus haemocyanin (LPH)‐primed, lethally irradiated, euthymic or nu/nu BALB/c mice cultured with thymus‐independent (TI)dex B‐1355, B‐1355‐lipopulysaccharide (LPS). B‐1355‐LPS‐LPH. or thymus‐dependent (TD) dex B‐1355‐LPH, the λ1 precursors responded with B‐1355‐binding Ab substantially equally with respect to precursor frequency, rate of Ah production, and range of fine‐specificity, hut not with respect to frequency of the IdX and IdI isotypes related to the VH and DH associated with the λ1. The λ2 contributed minimally to the repertoire. The χ precursors responded with B‐1355‐binding Ab at a rate nearly equal to the λ1 only under TD stimulus in cuthymic fragments. A comparison of the λ1 and χ Ah fine‐specificity, by inhibition of binding with dex differing in epitope contents and configurations, showed marked restriction in the χ relative to the λ1. Only approximately 10% of the relatively more abundant χ TD response showed fine α(1→3) specificity similar to that of the λ1. The λ1 fine‐specificity diversity resided mainly in the IdI fraction.
Leu 7+(HNK‐l+) Cells
Authors: PORWIT‐KSIAZEK A. , KSIAZEK T. , BIBERFELD P.
Published: June 2006

In the present immunohistoehemical studies. Leu 7+ (HNK‐l+. human natural killer and killer) cells were found to occupy preferentially germinal centres of follicles in lymph nodes and tonsils. Leu 7+ cells were also present in germinal‐like zones of spleen follicles and in mantle zones of hyperplastie thymus follicles and varied in localization in lymph nodes involved in different types of follicukir centre cell‐derived malignant lymphomas. Most of the Leu 7+ cells in the follicles expressed the Leu 3 (helper inducer) marker. Double staining studies of tonsil sheep erythrocyte‐rosetting and peripheral Mood mononuclear cell suspensions showed that two main, mutually complementary, suhpopulalions of Leu 7+ cells could he distinguished in hot h cases, namely Leu 7+/Leu 4+ (subdivided into Leu 2+ (suppressor/cytotoxic) and Leu 3+) and Leu 7 +/ Leu 4−. including mostly cells with OKM 1 (myelomonocytic) characteristics. Thus, in the tonsil cell suspension the cells with Leu 7+ Leu 3+/OKM 1− imrmmophenotype strongly predominated, whereas among peripheral blood mononuclear cells Leu 7+ Leu 2+/OKM 1− and Leu 7+/OKM 1− iimmunophenotypes were mostly observed.
Leu 7+(HNK‐l+) Cells
Authors: PORWIT‐KSIAZEK A. , AMAN P. , KSIAZEK T. , BIBERFELD P.
Published: June 2006

In the present study, combined methods (indirect immunofluorescence with monoclonal antibodies. Percoll density fractionation, FACS analysis, and the cytotoxicity test) were used for further characterization of peripheralblood Leu 7+ cells (human NK and K cells). The Leu 7+ cell content was found to be relatively higher in the low‐density cell fraction in which cells of large granular lymphocyte morphology predominated. However, Leu 7+ cells were also present in intermediate and high‐density fractions. Low‐density Leu 7+ cells were characterized by bothLeu 2 (T suppressor/cytotoxic) and OKM1 (myelomonocytic) markers, whereas among high‐density Leu 7+ cells the Leu 2 phenotype strictly predominated. Depletion of OKT 3+ cells from the non‐adherent cell population caused a decrease of cells with T helper and T suppressor phenotypes but did not have this effect on Leu 7+ and OKM1+ cells. After depletion of Leu 7+ cells from the OKT3 population the content of both T suppressor and OKM1+ cells decreased. Both the present results and previous reports enable us to conclude that two main Leu 7+ cell subpopulations are present in blood, namely Leu 7+ Leu 2+/Leu 4+ and Leu 7+/OKM 1+ cells. The presence of small and large Leu 7+ cells was also shown by FACSanalysis.
Effect of Irradiation on Rat Renal Transplant Rejection
Authors: NEMLANDER A.
Published: June 2006

Leucocytes were selectively eliminated either from a DA renal allograftor from a WF host by irradiation of either the host or the graft on different days after the transplantation. The recovery of inflammatory leucocytes and the generation of lymphoid killer cells—that is, the natural killer (NK) cells and the cytotoxic T lymphocytes (CTL)—were analysed separately in the two compartments. Early irradiation of the graft did not affect the recovery of leucocytes in either compartment. The NK activity was only slightly reduced in the graft but was distinctly reduced in the spleen. A delay in the generation of the CTL activity was observed in the spleen. Late irradiation of the graft reduced the recovery of leucocytes in both compartments. The disappearance of the NK activity increased in the graft but not in the spleen. The CTL activity in the spleen developed normally up to day 6, whereafter it declined. After selective irradiation of the host a fair number of leucocytes remained in the graft, compared with a nearly complete disappearance of leucocytes from the graft and blood. The NK and CTL activity declined rapidly in both compartments. The data demonstrate a bidirectional interdependence between the graft and the host during the rejection.
Anti‐IgA in Selective IgA Deficiency
Authors: HAMMARSTROM L. , PERSSON M. A. A. , SMITH C. I. E.
Published: June 2006

Anti‐IgA antibodies were found in 14 of 33 (42%) IgA‐deficient donors. In healthy IgA‐deficient blood donors anti‐IgA appeared associated with the presence of HLA DR3. The antibodies were mainly of the IgG1 and, in high‐titred sera, IgG4 subclasses. Sera containing high‐titred anti‐IgA selectively impaired IgA synthesis in vitro as induced by direct and indirect polyclonal B‐cell activators. These antibodies may play a role in the pathogenesis and/or the maintenance of IgA deficiency.