bluuebunny/crossref_metadata_2025 huggingface dataset:
“Ia‐like” antigens on human T cells
Authors: Greaves Melvyn F. , Verbi Winston , Festenstein Milliard , Papasteriadis Chrysa , Jaraquemada Dolores , Hayward Anthony
Published: February 2007

Human T lymphocytes have been tested for cell surface p 28,33 “Ia‐like” heteroantigen and DRw alloantigens. Small numbers (1–5%) of sheep (E) rosette or T antigen‐positive, surface immunoglobulin‐negative (E+, T+, smIg−) T cells were Ia+; these cells appeared to be restricted to the TG subset. Following activation by allogeneic lymphocytes or sperm, or by purified protein derivative of tuberculin (PPD), the proportion of positive T cells increased substantially. DRw typing indicated that Ia specificities on activated T cells were not acquired passively from the stimulator cells, suggesting therefore that either “selection” of a small DRw+ cell subset or derepression and/or exposure of DR locus gene products occurs during T cell activation.
Rabbit allotype a locus subspecificities of homogeneous anti‐streptococcal antibodies
Authors: Rodkey L. Scott , Braun Dietmar G.
Published: February 2007

Rabbits were immunized with group A‐variant (Av) streptococcal vaccine to elicit antisera containing antibodies of “restricted heterogeneity” specific for Av polysaccharide. Antibodies that migrated as single bands in polyacrylamide gel isoelectric focusing were isolated on agarose block electrophoresis and preparative isoelectric focusing. These homogeneous antibodies were analyzed for content of the a locus markers by inhibition of allotype‐anti‐allotype radioimmunoassays. Both single‐band preparations and preparations containing 2–5 bands were deficient in content of the a locus markers. These analyses were strongly influenced by the different anti‐allotype antisera used. Single‐band preparations, deficient in a2 or a3 markers, were further used to produce anti‐allotype antisera, and these sera were assayed for reaction with pooled a2 or a3 molecules. The results, in contrast to the a 1 allotype, failed to demonstrate common determinants on either a 2 or a 3 molecules indicating that each a allotype consists of a set of different Ig molecules. The data suggest different evolutionary pathways of the a 1, as opposed to the a 2 and a 3 molecules.
Identification of autoanti‐Thy‐1 antibody in the sera of BALB/c mice immune to P 1798 lymphoma
Authors: Baechtel F. Samuel , Prager Morton D. , Vitetta Ellen S.
Published: February 2007

The specificity was established for the anti‐thymocyte autoantibody which appeared in BALB/c mice (BAA) during immunization to the P 1798 lymphoma. The results indicate that BAA is specific for the Thy‐1 alloantigen of murine T cells. By immunoprecipitation of 125I‐labeled A/J thymocyte surface antigens from freeze‐thaw lysates and electrophoretic resolution of the immunoprecipitates on sodium dodecyl sulfate polyacrylamide gels, the BAA and congenic anti‐Thy‐1.1 or 1.2 were shown to be specific for determinants on the same antigens. Specificity of BAA for Thy‐1.2 was shown also by quantitative absorption studies. Coating P 1798 lymphoma cells with either BAA or anti‐Thy‐1.2 reduced the absorptive capacity of these cells for the same or the reciprocal antiserum. Coating P 1798 with an antiserum to P 1798 which was indifferent to the Thy‐1.2 alloantigen did not diminish the absorptive capacity of these cells for either BAA or anti‐Thy‐1.2. These studies have provided firm evidence that BAA is specific for determinants on the Thy‐1 alloantigen.
A mouse myeloma variant with a defect in light chain synthesis
Authors: Morrison Sherie L. , Scharff Matthew D.
Published: February 2007

A spontaneous assembly variant, B 50, has been isolated from the MPC‐11 mouse myeloma cell line. This variant synthesizes fewer light chains per cell than the parent resulting in the production of a slight molar excess of heavy chains. These changes are associated with a delay and change in the pathway of assembly and a delay in secretion. Spontaneous revertants of B 50 have been obtained, all of which synthesize normal amounts of light chains and assemble and secrete the immunoglobulin molecule through the same pathways and with the same kinetics as the parental cells. A comparison of the tryptic‐chymotryptic peptides of the parental, variant and revertant heavy and light chains did not reveal any differences. These studies indicate that variants in mouse myeloma cells can arise with defects in the quantitative expression of the immunoglobulin gene and suggest that the presence of excess light chains facilitates the assembly and secretion of some immunoglobulin molecules.
T cell tolerance in the chicken. II. Lack of evidence for suppressor cells in tolerant agammaglobulinemic and normal chickens
Authors: Grebenau Mark D. , Chi David S. , Thorbecke G. Jeanette
Published: February 2007

Tolerance to human γ‐globulin (HGG) at the T cell level was readily induced in both normal and bursectomized FP and EL 6 strain chickens by intravenous injection of 5 to 50 mg of soluble HGG. T cells from tolerant chickens, subsequently immunized with HGG in complete Freund's adjuvant (CFA), failed to cooperate in the adoptive immune response to 2, 4, 6‐trinitrophenylated (TNP) HGG with TNP‐immune spleen cells. However, suppressive activity could not be demonstrated when cells from tolerant chickens were combined with cells from HGG and CFA‐sensitized chickens in the recipients, even at a 5 : 1 ratio. HGG‐specific helper activity could be induced, both in bursectomized FP and in intact EL6 spleen cells, but neither tolerant bursectomized nor tolerant intact chicken spleen cells showed suppressor activity in this assay. Such tolerant cells also failed to inhibit formation of helper cell activity upon transfer to intact or bursectomized recipients subsequently exposed to HGG and CFA.

Cells mediating delayed hypersensitivity (TDH cells) were also tolerized by intravenous injection of soluble HGG. Injection of cyclophosphamide (CY), 100 mg/kg intraperitoneally, two days prior to the HGG did not interfere with this tolerance induction. CY also failed to augment the DH reactivity of immunized bursectomized animals, although it did increase the reactivity of intact animals. Thus, a CY‐sensitive suppressor cell did not appear to be responsible for induction of the tolerant state. Moreover, spleen or thymus cells from tolerant bursectomized or intact animals, transferred into normal chickens, were unable to prevent sensitization of the TDH cells in recipients. This was true in both bursectomized and intact recipients and was also not affected by treatment of recipients with CY, used to facilitate entry of tolerant donor cells into recipients' lymphoid tissue. Tolerance was also readily induced in thymectomized chickens.

It was considered unlikely that the generation of suppressor cells was responsible for induction of tolerance to HGG at the T cell level in bursectomized or intact chickens. Since antibody formation could be excluded as a factor in the bursectomized birds, these results were in favor of a T cell deletion model of tolerance. Various ways in which deletion of TDH cells might be achieved are discussed.
Presence of serum IgD and IgD‐containing plasma cells in the mouse
Authors: Bargellesi Antonio , Corte Giorgio , Cosulich Elisabetta , Ferrarini Manlio
Published: February 2007

A new technique which makes use of anti‐δ‐specific allo‐or heteroantisera coupled to Sepharose 4 B has been employed to investigate the presence of IgD molecules in the sera of three mouse strains. The sera were reacted with the insoluble immunosorbents, and the eluted material was labeled with 125I prior to antigenic or sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) analysis. This material reacted with anti‐δ or anti‐L chain reagents, but not with other anti‐class‐specific antisera and, after reduction, was resolved in three discrete bands in SDS‐PAGE. The fastest of these bands comigrated with L chain, whereas the other two moved identically to mouse lymphocyte surface δ chains. Immunofluorescence studies on fixed smears of spleen and Peyer's patches' cells revealed the presence of a small but consistent number of IgD‐containing plasma cells.
Investigation of the human macrophage I. Collection and in vitro cultivation
Authors: Chang Yu‐Hui , Yao Chin‐Sheng
Published: February 2007

By means of blister formation produced by cantharidin, a certain number of human macrophages could be readily obtained from the blister exudate. In the presence of 50% cell‐free exudate, these cells were found to proliferate in vitro. The proliferating cells possessed the morphology and functional characteristics of macrophages.
Characterization of a monoclonal anti‐β2‐microglobulin antibody and its use in the genetic and biochemical analysis of major histocompatibility antigens
Authors: Brodsky Frances M. , Bodmer Walter F. , Parham Peter
Published: February 2007

A monoclonal anti‐β2‐microglobulin (BBM.1 antibody) was produced by cell fusion between the mouse myeloma, P3‐X 63‐Ag8, and spleen cells from a BALB/c mouse immunized with Molt 4, a human T cell line. BBM.1 antibody was fully inhibited by soluble β‐microglobulin and purified HLA‐A, B antigens and reacted with humanmouse somatic cell hybrids only if they had chromosome 15 and expressed human β‐microglobulin. It was cytotoxic in complement‐dependent lysis and of the IgG class. BBM.1 and a monoclonal anti‐HLA‐A, B, C glycoprotein antibody, W6/32 (Barnstable, C. J. et al., Cell 1978. 14: 9.), were used to quantitate relative amounts of β2 ‐microglobulin and HLA‐A, B, C glycoproteins on different human cell types. Thymocytes and the Molt 4 cell line showed a considerable excess of β2‐microglobulin over HLA‐A, B, C glycoproteins, as measured by W6/32 reactivity. B cell lines, peripheral blood lymphocytes, fibroblasts, a HeLa cell derivative, and HSB 2, another T cell line, had equal amounts. Immunological cross‐reactions between HLA‐A, B, C antigens and β‐microgloglobulin and their homologues in other species were detected with the BBM.1 and W6/32 antibodies. The W6/32 antigenic determinant appears to be more highly conserved than that recognized by the BBM.1 antibody.
Idiotypic analysis of antibodies against the terpolymer L‐glutamic acid60‐L‐alanine30‐L‐tyrosine10 (GAT) IV. Induction of CGAT idiotype following immuniza‐ tion with various synthetic polymers containing glutamic acid and tyrosine
Authors: Ju Shyr‐Te , Dorf Martin E.
Published: February 2007

The immune responses of all inbred strains of mice specific to the synthetic terpolymer poly(LGlu60LAla30LTyr10), referred to as GAT10, are characterized by the pres‐ ence of anti‐GAT antibodies which share a common (CGAT) idiotype. In this report, we describe the ability of the synthetic polymers, LGlu33LAla33LTyr33, LGlu51‐ LAla34LTyr15and poly‐L(Tyr, Glu)‐DLAla–LLys [(T,G)‐A–L] to induce antibodies with CGAT idiotypic specificities. All of these polymers contain “GT”‐related deter‐ minants. Following immunization with these polymers, antisera from responder mice bind the corresponding 125I‐labeled antigen and 125I‐labeled poly(LGlu50LTyr50) or GAT10. These antisera shared the CGAT idiotype which is associated with the anti‐ body fraction with binding specificity for GAT10. Collectively, the present results indi‐ cate that GT‐related determinants are required for the induction of the CGAT idio‐ type. Moreover, since the immune responses to these synthetic polymers are under distinct H‐2‐linked immune response (Ir) gene control, a mouse strain can be nonre‐ sponder to one polymer and responder to another; in this case, only the latter polymer induces CGAT idiotype. Thus, although the immune responses of inbred strains of mice to different polymers are under distinct Ir gene control, the antibody responses can be idiotypically related.
Anti‐idiotypic antibodies of IgM‐type produced in carp (Cyprinus carpio L.)
Authors: Richter Roland F. , Ambrosius Herwart
Published: February 2007

Carp synthesize highly specific anti‐idiotypic antibodies of the IgM class. Anti‐idioty‐ pic antibodies could be elicited in these animals by a human IgM myeloma protein and were detected in a passive hemagglutination assay. The agglutination was com‐ pletely inhibited by approximately 0.15 μg homologous antigen, whereas a 100000‐ fold excess of a heterologous IgM myeloma protein of the same L chain type did not produce any inhibition. A possible subgroup specificity of carp anti‐idiotypic antisera can be excluded.
Monoclonal IgM, IgA and IgG in the serum of a single individual: Immunofluorescence identification of cells producing the immunoglobulins
Authors: Krueger Robert G. , Fair Daryl S. , Kyle Robert A.
Published: February 2007

Monoclonal IgM(ϰ) and IgA(ϰ) in the serum of patient CM were previously shown to share identical, individually specific (Ind) or idiotypic antigenic determinants. A component in the IgG fraction of CM's serum was shown by one of the assay systems to also share Ind determinants with the IgA and IgM. Recent experiments have indicated that the CM IgG monoclonal protein also shares identical Ind determinants with the other two CM immunoglobulins (Ig). These results suggested that the variable regions of the heavy and light chains of the three different classes of Ig were very similar. A direct immunofluorescence assay was used in this study on bone marrow smears of patient CM obtained at two different dates to identify the cells producing these Ig. The reaction of antisera specific for Ind determinants demonstrated that most plasma cells, whether containing IgM, IgA, or IgG, stained with the anti‐Ind antisera; this occurred irrespective of whether the anti‐Ind antisera were generated to the patient's IgM or IgA. The reaction with isotypic antisera revealed cell populations containing either IgM, IgA, or IgG and a significant cell population containing both IgM and IgA. The common occurrence of IgM and IgA‐containing cells which synthesize monoclonal Ig with shared Ind determinants provides evidence consistent with the IgM‐IgA pathway of differentiation of antibody‐producing cells. Further, the tendency toward decreasing numbers of IgM‐staining cells with concomitant increasing numbers of IgA and IgG‐containing cells suggests that the clones of cells producing these Ig were derived from a single precursor cell.
Nature and complexity of the FMR antigenic system
Authors: Bismuth Alain , Kremsdorf Dina , Debré Patrice , Levy Jean Paul
Published: February 2007

The FMR antigen is currently defined as a cell surface antigen shared by Moloney, Rauscher, Friend and Graffi virus‐induced leukemias. Different groups have reported contradictory results showing an association of FMR either with various internal or external virion components or with a nonvirion protein. A study of twelve supposed anti‐FMR antisera using complement‐dependent cytotoxicity assays, and quantitative absorption of their activity on different lymphoma cells show that there exists an “FMR system” rather than an FMR antigen. Several antigenic specificities can be defined which are either common to all the leukemia tested (FMRGi) or limited to the lymphomas induced by certain viruses. In the latter group, at least F, FR, and MRGi antigens can be distinguished. These “FMR antigens” are frequently associated at the lymphoma cell surface with non‐FMR specificities. The so‐called anti‐FMR antisera show a variable specificity pattern generally revealing some but not all of the FMR antigens. Many of them do not contain anti‐FMRGi antibodies. On the contrary, they can react against non‐FMR antigens. Cocapping experiments reveal a comigration of the common FMRGi antigen and the major viral glycoprotein, gp69/71. Absorption of anti‐FMRGi activity by both Rauscher or Moloney virions and by purified Rauscher gp69/71 confirm this result suggesting that FMRGi could be a subgroup specificity of the gp69/71 of exogenous type C viruses. The nature of the other FMR specificity was not studied here. The complexicity of the FMR system probably explains the contradictory results which have been published concerning the nature of FMR antigens. It is probable that several antigens have been studied by different groups under the same name. Very precise technical conditions must be used for the analysis of the FMR system if such confusion is to be avoided in the future.
Sequential study of C 1 q‐binding substances and of anti‐DNA antibodies in (NZB × NZW)F1 mice: Evidence for an acute phase of the lupus disease in 2‐month‐old mice
Authors: Fournié Gilbert J. , Minh Marline Gayral‐Ta , Haas Sylvie , Pourrat Jacques P. , Conte Jean J.
Published: February 2007

Longitudinal studies of C1 q and DNA‐binding substances were performed in sera from 38 (NZB × NZW)F1 female mice between days 39 and 150 of life. Results suggest a two‐phase evolution of circulating immune complexes and anti‐DNA antibodies in young (NZB × NZW)F1 mice and show the existence of an acute phase of the disease during the second month of life of these mice.
Nonprecipitating pig anti‐dinitrophenyl antibody: Factors influencing the conversion into precipitating antibody
Authors: Franě Františ , Olšovská Zdeňa , Š Lubor
Published: February 2007

A high affinity nonprecipitating anti‐2,4‐dinitrophenyl (DNP) IgG antibody constitutes a major fraction of circulating anti‐DNP antibodies at the decline of the anti‐ DNP antibody response in pigs. The purified nonprecipitating antibody forms exclusively soluble complexes with DNP‐PSA (pig serum albumin) or DNP‐PGG (pig IgG). The binding sites are accessible to large ligands; one antibody molecule can combine with two molecules of DNP‐PSA simultaneoulsy.

The formation of complexes with DNP‐PSA was studied in various media. No precipitate was formed in saline, in 0.9 M or 0.05 M sodium chloride, in 0.5 M potassium thiocyanate and in several nonionic detergent solutions (0.5% and 1%). Normal pig or guinea pig sera were found to contain a factor, removable by an antigen‐antibody precipitate that caused a partial precipitation of the complexes. A mild alteration of the integrity of the antibody molecule by cleavage of interchain disulfide bonds did not affect the nonprecipitating character of the antibody. In media containing hydrophilic polymers, i.e. various dextrans, polyethylene glycols or a soluble polyamide (poly‐α,β5‐[N(2‐hydroxyethyl)‐DL‐aspartamide]), a functional conversion occurred; the antibody behaved like a precipitin. The precipitate with DNP‐PSA could not be resolubilized upon removal of the polymer by washing. The magnitude of the functional conversion depended on the concentration of the polymer and on its molecular weight, larger molecules being more effective. The effect of the hydrophilic polymers could be potentiated by replacing water in the solvent partly by deuterium oxide.

The findings are compatible with a notion, that in polymer‐containing media the nonprecipitating antibody acquires a conformation functionally equivalent to the conformation of a precipitating antibody and that the altered conformation is stabilized by the lattice of the precipitate with DNP‐PSA.
Mechanisms of clonal abortion tolerogenesis III. Antigen abrogates functional maturation of surfaceimmunoglobulin‐negative adult bone marrowlymphocytes
Authors: Pike Beverley L. , Nossal G. J. V.
Published: February 2007

The fluorescence‐activated cell sorter (FACS) was used to fractionate adult CBAmouse bone marrow cells on the basis of their size and the amount of surfaceimmunoglobulin (sIg) expressed. It was noted that a population of viable, small sIg−cells could generate up to 28% slg+ cells within 24 h in tissue culture. The capacity of various cell fractions to respond to T‐independent stimulation by antibody productionwas studied. Fractionated cells were placed into microculture at limiting dilution inthe presence of thymus “filler” cells, stimulated with E. coli lipopolysaccharide (LPS)and after 3 to 5 days, assayed for the presence of antibody‐forming cell clones to thehapten (4‐hydroxy‐3‐iodo‐5‐nitrophenyl) acetyl (NIP). Through appropriate statistical means, the number of anti‐NIP precursors originally present was calculated. Whilethe sIg+ fraction contained approximately 70 cells in 106 capable of immediate development into anti‐NIP clones, the slg− fraction contained very few reactive cells. However, the cloning capacity of this fraction increased markedly following 24 h of maturation in tissue culture.

When bone marrow cells were exposed to NIP‐coupled human gamma‐globulin (NIP‐HGG) acting as a B cell tolerogen, some tolerance was induced in vitro reflecting therelative immaturity of these cells. When the FACS‐sorted sIg− cells were similarlytreated, there was virtually complete abrogation of their functional maturation intoclonable anti‐NIP precursors. The effect of LPS on cells converting from the sIg− tosIg+ status was investigated. When LPS and NIP‐HGG were concomitantly present, about one‐third of the cells escaped tolerance induction. LPS thus “rescued” somecells from clonal abortion, but certainly did not totally abolish tolerance induction. The significance of these results for the clonal abortion theory of B lymphocytetolerance is briefly discussed. The conclusion is reached that cells converting from thesIg− to sIg+ status in the normal course of differentiation represent a prime target fortolerance induction.
Studies on the generation and expression of H‐2‐controlled T helper function in chimeric mice: Evidence for two levels of H‐2 restriction
Authors: Hiinig Thomas , Schimpl Anneliese
Published: February 2007

F1 → parental, semisyngeneic/semiallogeneic and fully allogeneic bone marrow radiation chimeras were used as a source of helper T cells in the in vitro anamnestic response to dinitrophenylated keyhole limpet hemocyanin. In F1 → parental and in semisyngeneic/semiallogeneic chimeras, a small population of helper T cells restricted to the H‐2 haplotype present in the donor only was shown to co‐exist with T cells restricted to the shared haplotype. Only the population restricted to the donor H‐2 could be demonstrated in allochimeras, presumably due to a lack of antigen‐presenting cells of host origin during priming.

Under assay conditions where, in addition to T cell/macrophage interactions, a direct T‐B cell contact was necessary (“linked” cooperation), the H‐2 restrictions observed were absolute. When direct T‐B cell contact was made unnecessary by a special experimental protocol (“unlinked” cooperation), H‐2 restriction between T and B cells was overcome. Thus, the cellular interactions during the anamnestic immune response to T‐dependent antigens seem to be H‐2‐restricted at two levels: T cell/ macrophage and T‐B cell interactions.
In vitro immunosuppressive effect of serum from orally immunized mice
Authors: Chalon Marie‐Paule , Milne Ross William , Vaerman Jean‐Pierre
Published: February 2007

Mice were orally immunized by 4 daily intragastric (IG) intubations of 4 × 109 sheep red blood cells (SRBC). The serum of such mice (OS), taken two weeks after the first intubation, was compared to normal mouse serum for its suppressive effect on in vitro primary responses of normal spleen cells to SRBC. OS regularly depressed the in vitro response to less than 10% of the normal response. The suppressive effect was dose‐ dependent, antigen‐specific and removable by absorption with SRBC. When cultures were stimulated with SRBC pre‐exposed to OS, the response was also depressed. The suppression was less when the addition of OS was delayed. OS from BALB/c mice efficiently depressed in vitro responses of spleen cells from other strains. Spleen cells, taken 2 weeks after IG immunization, responded normally to in vitro challenge with SRBC. The suppressive factor had the molecular size of an IgG and could be removed by anti‐Ig and anti‐IgG1 but not by anti‐α or anti‐μ immunosorbents. Purified IgG1 was more suppressive than IgG2a and IgG2b despite a similar anti‐SRBC antibody content.
Influenza virus infection of mouse lymphoblasts alters the binding affinity of anti‐H‐2 antibody: Requirement for viral neuraminidase
Authors: Liberti Paul A. , Hackett Charles J. , Askonas Brigitte A.
Published: February 2007

The requirement for histocompatibility in the T lymphocyte killing of virus‐infected cells has led us to investigate the effect of influenza virus infection on mouse cell surface histocompatibility (H‐2) antigens. Monoclonal anti‐H‐2 antibody made it possible to develop equilibrium binding conditions for the assay of H‐2 antigen‐antibody interactions on intact cells. Scatchard analysis of anti‐H‐2 binding with normal and virus‐infected cells yielded linear curves indicating homogeneity of the interaction at varied concentrations of antibody through saturating levels. The estimated number of 2 × 105 ‐ 5 × 105 H‐2 antigenic sites per mouse lymphoblast does not appear to change during the course of influenza virus infection.

However, the Ka (binding affinity constant) of anti‐H‐2 binding is rapidly elevated by virus infection (“0” time), continues to increase for 3 h post infection, then decreases. Control cells, treated with normal egg allantoic fluid, show no change in Ka during similar incubation.

This change in Ka requires the presence of active viral neuraminidase. Thermal denaturation of the neuraminidase of the virus particles abolishes their ability to induce Ka alteration, even though hemagglutinin activity is retained. Treatment of cells with neuraminidase of bacterial origin led to an elevation of Ka, but did not mimic the viral effect in time dependence and magnitude of peak responses. The time‐dependent lowering of Ka from peak values appeared to relate to virus replication, since UV light‐inactivated virus‐induced Ka elevation, but did not produce the typical Ka decline at 4‐5 h post infection.

The changes in Ka of anti‐H‐2 binding during influenza infection reflects a virus‐ induced alteration of the H‐2 molecule or its environment in the host cell membrane. The molecular basis of this change and its relation to H‐2‐restricted recognition of influenza virus‐infected cells by cytotoxic T cells requires further study.
Cytotoxicity of human mononuclear cells against chicken and human red blood cells, induced by treatment of the effector cells with phospholipase C
Authors: Northoff Hinnak , Resch Klaus
Published: February 2007

Human mononuclear cells from peripheral blood which were treated with phospholipase C (PLC), became cytotoxic against human or chicken red blood cells. PLC‐ induced cellular cytotoxicity against human red blood cells was further analyzed and compared to anti‐D‐mediated, antibody‐dependent cellular cytotoxicity (ADCC), using the same target cells. ADCC, but not cytotoxicity of PLC‐treated effector cells, was inhibited by free IgG. In addition, iodoacetate strongly enhanced PLC‐induced cytotoxicity, but blocked ADCC completely. Addition of fetal calf serum or human AB serum impaired PLC‐induced cytotoxicity. A similar inhibition was found by adding lecithin liposomes suggesting that the inhibitory effect of sera was also due to their phospholipid content. The data show that cytotoxicity of PLC‐treated effector cells can be clearly distinguished from cellular cytotoxicity, occurring spontaneously or induced by target cell antibodies. We favor the notion that cytotoxicity of PLC‐ treated effector cells against human erythrocytes is due to the action of PLC, adsorbed to the effector cells.
Immunological activity of a T hybrid line I. Production of an H‐2‐related suppressor factor with specificity for sheep red blood cells
Authors: Taussig Michael J. , Corvalán José R. F. , Binns Richard M. , Roser Bruce , Holliman Andrew
Published: February 2007

T lymphocyte hybrid lines have been produced by fusion of the thymoma BW 5147 with spleen cells of C57BL/10 mice primed to sheep red blood cells (SRBC). The supernatant (culture fluid) of a T hybrid designated A1 was able to suppress the primary (IgM) and secondary (IgM and IgG) antibody responses to SRBC in vitro. The suppressive activity of supernatants could be titrated to 50% end points at final dilutions of up to 1:270. The suppression affected only SRBC and haptens coupled to SRBC, except when used at high concentration when some nonspecific suppression was observed. Absorption of the A1 supernatant with SRBC removed all activity, while several other species of red cells failed to do so. The suppressor factor present in A1 supernatant was not removed by anti‐Ig adsorbents, but was removed by anti‐H‐2 antibodies reacting specifically with the haplotype of the spleen cells used in the fusion (H‐2b). The cellular target of action of the factor was apparently a B cell, based on absorption with different cell populations. No genetic restrictions in the activity of the factor were found. Al cells carried H‐2 and Thy‐1 alleles of both parental cells and formed rosettes with SRBC.
Frequencies of mitogen‐reactive B cells in the mouse. Lipopolysaccharide‐, lipoprotein‐ and Nocardia mitogen‐reactive B cells in CBA/N mice
Authors: Huber Brigitte , Melchers Fritz
Published: February 2007

B cell‐defective (CBA/N × BALB/c)F1 male mice have 100 times less lipopolysaccharide‐reactive and 10‐100 times less lipoprotein‐ and Nocardia mitogen‐reactive B cell precursors than F1 female mice with normal B cells.
Allotype suppression in the chicken. I. Generation of chronic suppression in heterozygous but not in homozygous chickens
Authors: Ratcliffe Michael J. H. , Ivanyi Juraj
Published: February 2007

The injection of antibody directed against either the IgM‐1 a or IgM‐1 b allotype into heterozygous (M‐la/M‐lb, G‐lg/G‐li) B 14‐line chickens produced suppression of the relevant IgM‐1 and genetically linked IgG‐1 allotypes in their serum, as quantitated by single radial immunodiffusion. Suppression of the IgM‐1 and IgG‐1 allotypes was associated with a compensatory increase in the alternative IgM‐1 and IgG‐1 serum allotype levels. This suppression was induced (a) by passive injection of anti‐allotype antiserum into 13‐day‐old embryonal or neonatal recipients, or (b) by egg yolktransmitted antibody in chickens hatched from homozygous B 14 A (M‐la, G‐lg) hens immunized against the IgM‐l b of the homozygous B14C (M‐lb, G‐li) rooster. Heterozygous chickens injected embryonally with anti‐allotype antiserum were profoundly suppressed for at least 16 weeks after hatching, while neonatally injected chickens showed a gradual recovery of both IgM‐1 and IgG‐1 allotypes over the same period. Suppression of the IgM‐1 b allotype could be induced in heterozygotes which had inherited the M‐lb allele either maternally or paternally. However, no suppression of either IgM‐1 or IgG‐1 levels could be detected in homozygous chickens injected with the relevant anti‐allotype antiserum. Hence, allotype suppression only occurred in M‐1 heterozygous chickens which had an alternative source of B cells available. The involvement of a B cell surveillance mechanism in allotype suppression is postulated and the possible role of suppressor cells is discussed.
Cytotoxic T cell responses to haptenated cells II. On the role of H‐2 genes
Authors: Haas Werner , Pohlit Helmut , von Boehmer Harald
Published: February 2007

Cytotoxic T cell (CTL) responses to cells coupled with high or low doses of the hapten 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl acetic acid (SP) were studied. CTL responses to densely coupled cells were obtained with all mouse strains tested. Only mice carrying the Kk allele responded to sparsely coupled cells. Mice expressing I‐Akbut not Kk were nonresponders. (Responder × nonresponder) F1 hybrids responded in vitro to sparsely coupled cells from responder but not from nonresponder mice. However, responder mice could be cross‐primed in vivo with SP‐coupled cells from nonresponder mice. CTL responding to sparsely coupled cells were restricted to Kk. Cross‐reactive lysis of target cells not carrying the Kk allele was dependent on the hapten density and the H‐2 haplotype carried by the target cells.
Expression of b 4 and b 5 ϰ light chain allotypes by B and pre‐B cells in allotype‐suppressed and neutralized b4b5 rabbits
Authors: Simons Margaret A. , Hayward Anthony R. , Gathings William E. , Lawton Alexander R. , Young‐Cooper Glendowlyn O. , Cooper Max D. , Mage Rose G.
Published: February 2007

In previous studies, we described a primitive lymphoid cell found in fetal liver and in the bone marrow of older rabbits which contained cytoplasmic IgM but lacked surface IgM detectable by immunofluorescence. In heterozygous b4b5 rabbits, the pre‐B cells in which we could detect these kappa chain allotypes appeared to exhibit allelic exclusion. In the present study, we investigated the effects of allotype suppression and its neutralization on the expression of the b4 and b5 allotypes by B and pre‐B cells from the spleens and bone marrow of b4b5 rabbits. We found that in young allotype suppressed rabbits, pre‐B cells of the suppressed allotype persist in bone marrow when B cells of the suppressed allotype are absent or severely depleted. The persistence of pre‐B cells of the suppressed type supports the view that pre‐B cells differ in their responsiveness to external influences such as anti‐Ig compared to B lymphocytes. Injection of serum with b5 immunoglobulin into b4b5 animals suppressed 14‐23 days previously for b5 was followed by the appearance of increased proportions of b 5 B cells in spleen within 24 h. Surviving pre‐B cells are a likely source of these rapidly appearing B cells as well as of the B cells bearing surface immunoglobulin of the suppressed allotype which appear during the recovery phase of allotype suppression.
Specificity of H‐2‐linked Ir gene control in mice: Recognition of the core structure A–L in defined sequence analogues of (T,G)‐A–L
Authors: Stötter Hans , Imm Anita , Meyer‐Delius Margot , Rüde Erwin
Published: February 2007

For further characterization of the processes involved in Ir gene control, the specificity of antibodies and the cross‐reaction on the level of helper T cells was studied for a series of polypeptide antigens related to poly‐L(Tyr,Glu)‐poly‐DL‐Ala–poly‐LLys[(T,G)‐A–L] but carrying more defined side chains. Helper cell specificity was assayed in an in vitro secondary anti‐dinitrophenyl (DNP) response by cross‐stimulation of primed T cells with the various polypeptide carriers. It was established that these polypeptides, although showing the same response pattern, were recognized as distinct entities in the immune response by B and T cells. If this common pattern is due to the effect of the same Ir gene, the latter is unlikely to code directly for the binding site on helper T cells recognizing these antigens. The core structure A–L, although weakly immunogenic itself, is recognized in the response to these antigens concomitantly with the recognition of the tyrosine‐containing peptides. Furthermore, it is shown that the antibody response to DNP‐A–L is under genetic control and that in the antigen Tyr6‐A–L, which has the highest immunogenicity within this group of antigens, the poly‐m‐alanine side chain is important for the genetic control mechanism. Therefore, it is concluded that the effects of Ir genes are related to recognition of the core structure A–L. The relevance of these experimental findings is discussed.
Detection of proteolytic (C 3‐cleaving) activity on mouse mastocytoma (P815) cells and other mouse cell lines by formation of cell contact with C 3‐carrying mouse lymphocytes
Authors: Dierich Manfred P. , Schulz Thomas , Yefenof Eitan , Kiein George
Published: February 2007

Mouse mastocytoma cells (P815) formed rosettes with normal mouse spleen lymphocytes which had been coated with uncleaved human C 3; this interaction was clearly dependent on the amount of C 3. Lymphocytes treated with C 3 b or buffer alone were ineffective. Formation of cell contact could be inhibited by the presence of protease inhibitors such as diisopropyl fluorophosphate, phenyl methyl sulfonyl fluoride and tosyllysyl chloromethyl ketone. Seven out of 13 different cell lines behaved like P 815 cells.

The results strongly suggested that a proteolytic activity on mouse tumor cells led to a cooperation with uncleaved C3 on a carrier cell to connect these two cells. We interpreted these data in analogy to the complement‐dependent bridge formation mechanism (M. P. Dierich and B. Landen, J. Exp. Med. 1977. 146: 1484): uncleaved C3, attached to mouse spleen lymphocytes as carriers, becomes cleaved by enzymes associated with the tumor cells tested; by this cleavage, the labile binding site is released on C3 (nascent C3b) and anchors the C3‐carrying cell to the protease‐ carrying cell; since this labile binding site is short‐lived, this process can be induced by membrane‐associated proteases only. The nature of the proteases and the biological implications of this process are as yet uncertain.
Surface markers on natural killer cells of the mouse
Authors: Habu Sonoko , Hayakawa Kyoko , Okumura Ko , Tada Tomio
Published: February 2007

Rabbit antiserum against mouse brain tissue (anti‐brain‐associated T cell antigen, anti‐BAT) was capable of killing splenic natural killer (NK) cells of CBA/J, BALB/c, C 57 BL/6 J, C 3 H/He and nude mice, which were detected with Molony virus‐induced lymphoma (YAC‐1) and radiation‐induced leukemia (RL ♂ 1) cells as targets. The same antiserum abolished T cell functions, e.g. carrier‐specific helper function and the responsiveness to concanavalin A, but not B cell functions, e.g. immunological memory for the secondary antibody response and the responsiveness to lipopolysac‐ charide. After absorption of the anti‐BAT with thymocytes, the ability to kill T cells was completely abrogated, leaving the activity to kill NK cells intact. No other heterologous and isologous antisera, i.e. rabbit anti‐mouse thymocyte antiserum, goat antiserum against antigens shared by thymus and B cells, anti‐Thy‐1.2 and anti‐la antisera, could eliminate NK function regardless of their definite reactivity against T or B cells. The results indicate that the absorbed anti‐BAT can distinguish NK cells from other known subsets of T and B cells.
Markers of macrophage heterogeneity. I. Studies of macrophages from various organs of normal mice
Authors: Roubin Regine , Zolla‐Pazner Susan
Published: February 2007

A unique subpopulation of macrophages (MΦ) was identified among the spleen and bone marrow MΦ of normal mice. After 24 h of culture, approximately 2.5% of the adherent cells cluster into “foci” of 10–30 cells. On the basis of their phagocytic and morphologic characteristics, these focus‐forming MΦ (FF‐MΦ) appeared to be highly activated. Uncoated sheep erythrocytes (E) were ingested by FF‐MΦ indicating that opsonization was not a prerequisite for phagocytosis. However, IgM‐coated E (EIgM) were more readily phagocytosed by FF‐MΦ than were E suggesting that IgM is recognized as an effective opsonin by these cells. EIgM and E coated with IgM and complement(C) (ElgMC) were ingested by approximately the same percentage of FF‐ MΦ; thus, if these cells possess complement receptors in addition to structures which bind EIgM, the C receptors do not enhance the ability of FF‐MΦ to ingest opsonized particles.

The non‐focus‐forming MΦ, e.g. individual MΦ (I‐MΦ), in the spleen and bone marrow can, themselves, be divided into various subpopulations distinguished by their ability to bind and ingest E, EIgM and ElgMC. These may represent various subpopulations of MΦ or MΦ at various stages of activation or differentiation.

While spleen and bone marrow MΦ contained FF‐MΦ and I‐MΦ which vary in their ability to ingest E, EIgM and ElgMC, the MΦ of the peritoneum and blood of normal mice were far more homogeneous. Peritoneal and blood MΦ did not form foci, and did not ingest E or EIgM in significant amounts although a small percentage were able to ingest ElgMC. These data suggest that the population of MΦ in the spleen and bone marrow are far more heterogeneous than those found in the peritoneum or blood and that binding and phagocytosis of various coated and uncoated erythrocytes can be studied to elucidate this heterogeneity.
Identification of TL+ thymocytes with different Lyt phenotypes
Authors: Kisielow Paweł , Dráber Petr , Wysocka Maria
Published: February 2007

The surface antigenic phenotype of BALB/c thymocytes has been analyzed by sequential cytotoxic treatment with Lyt‐1.2, Lyt‐2.2 and TL.2 antisera plus complement. Two new minor subpopulations with TL+Lyt‐l+2− and TL+Lyt‐l−2+ phenotypes have been identified providing direct evidence for the heterogeneity of the Lyt phenotype among the TL‐positive supopulation of thymocytes. This finding suggests that differentiation pathways of Lyt subsets of T cells are more complex than originally proposed and that commitment to separate lines of differentiation may occur already at the level of immature, cortical thymocytes.
Chemiluminescence and immune cell activation II. Enhancement of concanavalin A‐induced chemiluminescence following in vitro preincubation of rat thymocytes; dependency on macrophage‐ lymphocyte interaction
Authors: Wrogemann Klaus , Weidemann Maurice J. , Ketelsen Uwe‐Peter , Wekerle Hartmut , Fischer Herbert
Published: February 2007

The immediate chemiluminescence (CL) response to concanavalin A (Con A) of rat thymocytes is enhanced 10 to 20‐fold when the cells are preincubated in serum‐free medium for 5–20 h. During this period, multiple encounters between lymphocytes and macrophages occur which morphologically appear as rosettes or grape‐like cell aggregates. Addition of bone marrow‐derived macrophages increases the number of cell aggregates and also the CTL response to Con A. Paradoxically, removal of macrophage‐containing cell aggregates after cocultivation leaves a pure thymocyte population which strongly responds to Con A with CL.

Our results confirm that macrophage‐depleted “competent” lymphocytes are capable of CL and, furthermore, that “competence” is gained during cocultivation with macrophages. We are therefore convinced that measurements of macrophage and lymphocyte CL are a powerful tool for further elucidation of lymphocyte differentiation and of interactions between macrophages and lymphocytes.
Generation of cytolytic T lymphocytes in vitro. O XI. Accessory cell requirement in secondary responses to particulate alloantigen
Authors: Degiovanni Gérard , Cerottini Jean‐Charles , Brunner K. Theodor
Published: February 2007

The non‐T accessory cell requirement for cytolytic T lymphocyte (CTL) generation in vitro was studied in a system which makes use of particulate membrane preparations as a source of alloantigen, and spleen cells from alloimmune mice as a source of responding cells. It is shown that removal of nylon‐adherent cells from the responding cell population strongly reduced CTL generation, whereas direct removal of Ig+, phagocytic or plastic‐adherent cells had no effect. The CTL response of the nylon‐ nonadherent cell population could be reconstituted by the addition of normal spleen cells, which by themselves do not generate CTL in response to particulate alloantigen. The accessory cell function of normal spleen cells was not affected by depletion of T cells or of phagocytic cells, but was sensitive to γ‐irradiation (1000 rd). The system thus demonstrates the requirement for a nylon‐adherent accessory cell population in the secondary CTL response to particulate alloantigens which does not exhibit the typical characteristics of T cells, B cells or macrophages.
Evidence of the presence in normal serum of a carrier of the serum thymic factor (FTS)
Authors: Dardenne Mireille , Pléau Jean‐Marie , Bach Jean‐François
Published: February 2007

Chromatography of normal human or mouse serum on Sephadex G‐150 revealed the presence of two peaks of activity in the rosette assay used for the characterization of the serum thymic factor (FTS). one peak corresponded to the elution volume of FTS (mol. wt. 867), the other to molecules with mol. wts. of 40000–60000. Both peaks were absent in serum of thymectomized (Tx) mice but could be induced in such Tx mice by injection of synthetic FTS. Study of the biological half‐life of both peaks (assessed by the rosette assay) and demonstration of their specific retention on anti‐ FTS immunosorbent indicate, altogether with direct binding experiments, that FTS is transported in serum by a molecule with a mol. wt. of the order of that of albumin or prealbumin. It is apparent that FTS bound to this molecule is responsible for the biological FTS‐like activity associated with large mol. wt. fractions of normal serum.
Mechanism of T cell activation I. A screening of “step one” ligands
Authors: Larsson Eva‐Lotta , Coutinho Antonio
Published: February 2007

A number of ligands which bind to T cell surfaces were screened on murine spleen cells for their functional ability to induce either of the two necessary steps in the process of T cell triggering: (a) expression of growth receptors by T lymphocytes and (b) production of T cell growth factors in cultures containing both T cells and accessory cells. Among four lectins tested, concanavalin A was found to induce both responses but is primarily a “step 2” ligand, in particular at low concentrations; leucoagglutinin was the most potent “step 1” ligand with very limited “step 2” activity; wheat germ agglutinin and soybean lectin were inactive. Direct mitogenicity of the lectin to normal spleen cell cultures was limited by the poorest of these two functional properties. A number of rabbit anti‐lymphocyte antisera, anti‐Thy‐1 alloantisera, anti‐H‐2 and anti‐Ia monoclonal antibodies, as well as complexes of rabbit IgG, were all found to be devoid of “step 1” activity, and consequently, non‐ mitogenic for spleen cells. In contrast, a rabbit anti‐mouse brain antiserum, although also devoid of mitogenicity, was found to be capable of “step 1” induction.

These results suggest that not all rearrangements of T cell surface membrane components upon binding of a ligand result in the functional expression of growth receptors. This appears to be the result of selective interactions with specific sites which include structures binding to concanavalin A, leucoagglutinin and rabbit anti‐mouse brain antibodies.
Biochemical characterization of an Fc receptor of rabbit lymphocytes
Authors: Sire Joséphine , Kahn‐Perles Brigitte , Collé Allain , Bourgois Alain
Published: February 2007

Isolation of Fc‐binding molecules was performed by complexing IgG antibodies and the corresponding antigens in lysates of radiolabeled rabbit lymphoid cells. A single‐ chain molecule of 110000 apparent mol. wt. (unreduced) or 120000 (reduced) was observed in sodium dodecyl sulfate polyacrylamide gel electrophoresis when the antibodies were in the IgG form but not as F (ab′),. This molecule was very susceptible to proteolysis, but the fragments thus produced remained associated by disulfide bridges, and the binding properties of the molecule were conserved. The molecule and its proteolytic fragments (mol. wts. 75 000, 45 000 and 20 000) were very similar to those obtained for the mouse Fc receptor under similar conditions, and therefore the molecule was designated as rabbit Fc receptor. Among several precipitating systems used, some Ig‐anti‐Ig complexes appeared to be the most efficient in co precipitating the rabbit Fc receptor. Remarkably high titers of Fc receptor were found on lymphocyte membrane of infected rabbits, in agreement with a possible role of this molecule in immune regulation.