bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous production of interleukin 3 by T lymphocytes from autoimmune MRL/MP‐lpr/lpr mice
Authors: Palacios Ronald
Published: February 2007

MRL/MP‐lpr/lpr (MRL/lpr) mice develop a lupus‐like autoimmune disease and a massive generalized lymphadenopathy associated with proliferation of nonmalignant Thy‐1+ Lyt‐1+ cells. The mechanism(s) leading to outgrowth of these cells is unknown.

We report here that Thy‐1+, Lyt‐1+, Lyt‐2− lymphocytes from spleens of MRL/lpr mice, but not from several strains of normal mice, spontaneously secrete IL3. The presence of IL3 is shown by: (a) the ability of the supernatants from unstimulated spleen cells of MRL/lpr (MRL/lpr SUP) to support growth of IL3 but not IL2 addicted cells and (b) the growth‐promoting activity in MRL/lpr SUP was absorbed with IL3‐dependent cells but not with IL2‐dependent cells. Spontaneous release of IL3 was detected in supernatants from spleen cells of 6‐week‐old MRL/lpr mice and the titers of IL3 activity increased with age.

Nylon wool‐enriched cells from spleens of MRL/lpr mice proliferated in response to purified IL3 and IL3 secreted by MRL/lpr T cells, in a manner similar to nylon wool‐passed cells from normal mice. The cells responding to both sources of IL3 were Thy‐1+, Lyt‐1+, Lyt‐2−. Thus, Thy‐1+, Lyt‐1+,2− cells from spleen of MRL/lpr mice spontaneously secrete IL3 and respond normally to this lymphokine.

Four Thy‐1+, Lyt‐1+,2− cell lines derived from unstimulated spleen cells of MRL/lpr mice were established in culture with IL3. These IL3‐sensitive T cell lines help syngeneic and H‐2‐compatible normal small “resting” B cells to mature into plasma cells secreting predominantly IgG1, IgG2 and IgA.

Taken together, these data and previous findings that T cells from MRL/lpr mice have an impaired production of and response to IL2, strongly suggest that abnormal production of IL3 may account for the outgrowth of Thy‐1+, Lyt‐1+,2− cells in the MRL/lpr mouse. Finally, a mechanism linking abnormal production of IL3 and B cell hyperactivity in these animals is proposed.
Immune recognition of insulin by H‐2b mice: the mutation in the I‐A gene of the B6.C‐H‐2bm12 mouse alters the self‐I‐A‐restricted T cell repertoire
Authors: Hochman Paula S. , Huber Brigitte T.
Published: February 2007

The response to heterologous insulin in H‐2b mice is restricted to the A chain loop determinant(s) of beef insulin. The recognition of this specificity requires the expression of the immune response (Ir) gene epitope Ia. W39 which is absent from the I‐Ab mutant B6.C‐H‐2bm12 (bm12) mice. This restriction could reflect the inability of H‐2b antigen‐presenting cells (APC) to present other insulin determinants or may reflect “self‐major histocompatibility complex”‐dependent influences on the generation of the T cell repertoire. To assess these possibilities we analyzed the genetic control and fine specificity of the insulin‐specific T cell repertoire of H‐2b mice by fusing the AKR thymoma BW5147 with T cells of C57BL/6 mice which had been immunized in vivo and challenged in vitro with beef insulin. The cloned hybridomas that we have produced respond to APC either alone or in conjunction with insulin by the production of interleukin 2. The insulin‐specific hybridomas vary in their fine specificity such that some clones recognize a determinant(s) shared by beef, sheep and pork insulin and the isolated B chain, while other clones recognize a determinant(s) shared by beef and sheep insulin only, likely to involve amino acids 8 and/or 10 of the A chain loop. The presentation of insulin to these hybridomas is restricted by I‐Ab, but not by Ia.W39. This analysis revealed that the insulin‐specific immune potential in H‐2b mice is of greater scope than previously defined and led us to consider, whether insulin nonresponder bm12 mice also possess a latent insulin‐specific immune potential. Our study of the insulin‐specific immune recognition by bm12 mice shows that these nonresponders do possess insulin‐specific T cell clones. Despite the fact that the I‐Ab and I‐Abm12 gene products differ only by 3 amino acids, insulin‐specific C57BL/6 and bm12 hybridomas are restricted to recognize exogenous antigen only in the context of C57BL/6 and bm12 APC, respectively. Furthermore, upon direct analysis of autoreactive subclones, a similar although not complete, restriction was observed. The implications of these findings for understanding the mechanism of Ir gene control are discussed.
Dissociation of responses measured by natural cytotoxicity and chemiluminescence
Authors: Ernst Martin , Lange Andrzej , Flad Hans‐Dieter , Havel Albin , Ennen Joachim , Ulmer Artur J.
Published: February 2007

Monocyte/macrophage‐mediated cytotoxicity requires the generation of activated oxygen radicals, which can be measured by chemiluminescence (CL). To investigate whether natural killer (NK) cell activity required activated oxygen species, both cytotoxicity against K562 target cells and CL were measured in cell populations of human peripheral blood. The following results were obtained: (a) Peripheral blood mononuclear cells (MNC) showed NK activity and a response in CL, which could be induced by viable or paraformaldehyde‐fixed K562 target cells as well as by latex particles, (b) Both T cells and non‐T cells exhibited NK activity, but T cells gave no K562‐ or latex‐induced CL responses, (c) Depletion of phagocytic cells from MNC abolished CL, but only marginally affected NK activity, (d) Reconstitution of phagocyte‐depleted MNC with adherent cells revealed a superadditive enhanced CL response, but had no augmenting effect on NK activity, (e) Phagocyte‐depleted cell populations, enriched for NK activity by density gradient centrifugation, did not respond in K562‐ and latex‐induced CL. (f) MNC, highly enriched for NK activity by cell sorting with a cytofluorograf using the fluorescein isothiocyanate‐labeled monoclonal antibody anti‐Leu‐11a, responded only with reduced CL, whereas the NK activity was enriched up to 45‐fold. From these results it is concluded that NK cell‐mediated cytolysis of K562 target cells and K562‐induced CL are not functionally correlated, but represent properties of two distinct cell populations, namely NK cells and monocytes.
Characterization of a (BALB/c × C57BL/6)F1 T cell hybridoma with double specificity: recognition of antigen in context of I‐Ad and autoreactivity to I‐Ab
Authors: Nagase Fumihiko , Waters Stanley J. , Jeanette Thorbecke G. , Bona Constantin A.
Published: February 2007

An antigen‐specific, IL2‐producing, Lyt‐1+2−, T cell hybridoma has been derived by the fusion of keyhole limpet hemocyanin (KLH)‐primed (BALB/c × C57BL/6)F1 lymph node with BW5147 thymoma cells. The hybridoma FN13‐21 recognizes KLH in association with I‐Ad of BALB/c parental antigen‐presenting cells, and also responds to I‐Ab of the other parent C57BL/6 spleen cells in the absence of antigen. The KLH‐specific response of FN13‐21 is blocked by monoclonal anti‐I‐Ad antibody, while the response to C57BL/6 spleen cells is blocked by anti‐I‐Ab antibody. The specificity of the autoreactivity is to an antigen encoded for in the I‐Ab region, as shown by the pattern of stimulation obtained with spleen cells from H‐2‐recombinant mice.
Characterization of the response of human thymocytes and blood lymphocytes to the synergistic mitogenicity of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) ionomycin
Authors: Delia Domenico , Greaves Melvyn , Villa Silvia , Debraud Filippo
Published: February 2007

The combination of the phorbol ester 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and the calcium ionophore ionomycin is synergistically mitogenic for human fetal and infant thymocytes as well as peripheral blood lymphocytes. Optimal mitogenic stimulation is achieved when TPA and ionomycin are used at doses of 0.5‐1 ng/ml and 0.5‐1 μg/ml, respectively.

Phenotypic analysis and cell sorting show that the thymocytes responsive to the mitogen have a mature or medullary phenotype (T1+, T3+, T11+, T6−, HLA‐A,B++, [TdT]−); similarly in blood the T cell subsets (T11+, T4+ and T11+, T8+) are selectively responsive to TPA‐ionomycin. Both activated lymphocytes and thymocytes express HLA‐DR antigens as well as activation antigens such as T9, T10 and T cell activation antigen. T cells activated by TPA‐ionomycin can be grown for periods of up to 50 days without addition of exogeneous interleukin 2. The observations may have implications for the membrane‐associated signals involved in T cell growth and proliferation.
Polyclonal activation of the murine immune system by an antibody to IgD V. Effect on germinal centers
Authors: Flotte Thomas J. , Finkelman Fred D. , Jeanette Thorbecke G.
Published: February 2007

Heterologous anti‐mouse δ chain has been shown to induce T‐independent polyclonal B cell proliferation by 24 h after injection into mice and a T‐dependent polyclonal increase in the number of IgG‐secreting cells in spleen and lymph nodes 6 days after injection. The effect of anti‐δ on germinal center cells has been difficult to determine, however, since anti‐δ‐induced blast transformation of mantle zone cells makes it difficult to distinguish these cells from germinal center cells. To clarify the effect of anti‐δ on germinal centers, we stained lymph node sections from control and anti‐δ‐injected mice with peanut agglutinin conjugated to horseradish peroxidase which clearly differentiates the germinal center cells from other large and small lymphoid cells.

For the first 5 days after i.v. injection of goat anti‐mouse δ, the germinal center volumes did not differ significantly from those of mice injected with control antibodies. On days 6 and 7 after injection, the lymph node germinal center volumes of anti‐δ‐treated mice increased on average over 10‐fold as compared to those of mice injected with an equal amount of control antibody. Thus, while anti‐δ antibody directly induced blastogenesis of mantle layer B cells, it appears to have little direct effect on germinal center cells. In contrast, rapid germinal center development is seen in anti‐δ‐injected mice during the T‐dependent phase of B cell activation and occurs simultaneously with the appearance of large numbers of IgG‐secreting cells.
T lymphocyte lines induce autoimmune encephalomyelitis, delayed hypersensitivity and bystander encephalitis or arthritis
Authors: Holoshitz Joseph , Naparstek Yacov , Ben‐Nun Avraham , Marquardt Peter , Cohen Irun R.
Published: February 2007

Lines of rat T lymphocytes responsive to the basic protein of myelin (BP) or to the purified protein derivative of Mycobacterium tuberculosis (PPD) were inoculated i.v. into recipient rats. As reported previously, the anti‐BP line cells, but not the anti‐PPD line cells spontaneously accumulated in the central nervous system and caused encephalomyelitis. However, the anti‐PPD line cells could be induced to enter the brain and cause bystander encephalitis by intracerebral inoculation of PPD. Anti‐PPD or anti‐BP line cells could mediate delayed‐type hypersensitivity skin reactions or bystander arthritis elicited by specific antigen. The lines did not cause specific cytolysis in vitro. Susceptibility to delayed‐type hypersensitivity or bystander disease was long lasting in rats inoculated with anti‐PPD line cells, while rats inoculated with anti‐BP line cells were susceptible for only a few days. Thus, lines of T lymphocytes can mediate a variety of pathological reactions directed by the presence of specific antigen, self or foreign.
Identification of a neodeterminant in complexes of human brain Thy‐1
Authors: Almqvist Per , Carlsson Sven
Published: February 2007

Human Thy‐1 glyocprotein was purified from brain cortex membranes. Antibodies were produced in rabbits by immunization with purified Thy‐1 and with brain homogenate. Both preparations of antibodies reacted with monomers of 125I‐labeled Thy‐1. In addition, the antibodies against the purified antigen also recognized a determinant which was absent, or present in very low amounts, in homogenates of human brain. Analysis by gel filtration in Nonidet‐P40 or deoxycholate revealed the presence of complexes of purified Thy‐1 that were specifically precipitated by antibodies against this determinant. It was also shown that anti‐monomer antibodies were unable to react with the complex form of Thy‐1. These complexes seemed to be composed of a varying number of Thy‐1 molecules. By treatment with sodium dodecyl sulfate, the multimers were completely dissociated into monomers. The tendency to complex formation seems to be unique for human Thy‐1, since Thy‐1 analogues of other species do not show this property when isolated.
Induction of resting B cells to DNA synthesis by soluble monoclonal anti‐immunoglobulin
Authors: Julius Michael H. , Heusser Christoph H. , Hartmann Klaus‐Ulrich
Published: February 2007

A novel monoclonal anti‐immunoglobulin is described which in soluble form is comparable to lipopolysaccharide in its ability to induce DNA synthesis in populations of resting B cells. It inhibits lipopolysaccharide‐induced B cell maturation to immuno‐globulin secretion while not suppressing mitogen‐induced proliferative responses. B cells from C3H/HeJ mice are stimulated as well as those from C3H/Tif mice demonstrating that the induction capacity of this monoclonal antibody does not involve functional lipopolysaccharide receptor molecules.
The induction of oxazolone‐specific T suppressor afferent cells in mice by hapten‐modified isologous IgG
Authors: Marcinkiewicz Janusz , Bereta Michal , Malinowski Jakub , Ptak Wlodzimierz
Published: February 2007

Injection of isologous 4(ethoxymethylene)‐2‐phenyl‐oxazolin‐5‐one (oxazolone; OX)‐substituted thymocytes or OX‐labeled IgG (OX‐IgG) into mice produces specific unresponsiveness in which immunization with homologous (OX), but not heterologous (picryl chloride), hapten on the skin does not result in significant contact sensitization. However, while injection of OX‐substituted thymocytes triggers suppressor cells which inhibit the effector stage of contact sensitivity reaction, OX‐IgG induces cells which suppress exclusively the afferent stage of reaction. In contrast to OX‐IgG, OX‐substituted F(ab')2 fragments, IgM, and albumin are ineffective. T suppressor afferent cells have Ly‐2 and I‐J surface markers and their precursors are resistant to cyclophosphamide treatment and adult thymectomy. We assume that T suppressor afferent cells recognize antigen in conjunction with intact IgG molecules, although the exact mechanism is unclear.
An attempt to assess the overall diversity of murine T cells using two‐dimensional gel electrophoresis
Authors: Kettman Jack , Lefkovits Ivan
Published: February 2007

The technique of two‐dimensional gel electrophoresis has been applied to study the changes in protein patterns occurring in murine T lymphocytes after activation by a T cell mitogen. The protein maps of individual T cell clones obtained by limiting dilution were also compared. Whole cell lysates from [35S]methionine‐labeled cell clones or cell populations were analyzed and radiofluorographs of gels compared.

We found that, during the events of differentiation and clonal proliferation, a T cell population undergoes dramatic changes resulting in pronounced changes in the protein pattern. In a typical gel with about 1000 detectable spots, there were about 50 changes from one day to the next. Certain regions of gels were compared using highly exposed films; in these, a much higher proportion of spots was found to vary (47/255 spots).

Furthermore, we found that T cell clones obtained by limiting dilution yield a protein pattern that contains both “stable” and “diverse” regions. In the molecular weight region from about 35000–43000, there are 0 to 5 differences when one clone is compared with another. Due to a relatively small number of clones analyzed [16], it is probable that the revealed changes are only a fraction of the diversity which remains to be uncovered.
Changes in the protein pattern of murine B cells after mitogenic stimulation
Authors: Kettman Jack , Lefkovits Ivan
Published: February 2007

The technique of two‐dimensional gel electrophoresis has been applied to study the changes in protein patterns occurring in murine B lymphocytes after activation with the synergistic B cell mitogens lipopolysaccharide and dextran sulfate. Whole cell lysates from [35S]methionine‐labeled mitogen‐activated B cells were analyzed and radiofluorographs of the gels compared. We found that a large number of proteins appear and disappear during the 5‐day activation period (74/206 spots of a nonimmunoglobulin region of the gel). The B cell pattern (in the nonimmunoglobulin region) was also compared with that of mitogen‐activated T cells. We identified 19 T cell‐specific and 29 B cell‐specific proteins, the remaining 1000 or so proteins being common.
Inhibition of IgE binding to mast cells and basophils by monoclonal antibodies to murine IgE
Authors: Baniyash Michal , Eshhar Zelig
Published: February 2007

In an attempt to identify the site on IgE which binds with high affinity to the Fcϵ receptor (FcϵR) on mast cells, we established monoclonal anti‐IgE antibodies (mAb) by fusion of myeloma cells with rat splenocytes immunized with purified murine IgE mAb. Six individual mAb were found to react with various IgE mAb of different specificities and not with immunoglobulins of other classes. Three different clusters of epitopes on the Fcϵ portion could be detected by antibody competition studies. These antigenic determinants were expressed on the Fcϵ portion and required the two heavy chains in their native conformation. Two groups of mAb and their Fab′ fragments completely inhibited the binding of 125I‐labeled IgE to rat basophilic leukemia cells (RBL), and one mAb inhibited the specific IgE binding only partially (55–65%). Likewise, the Fab′ fragments of the purified mAb inhibited the antigen‐mediated, IgE‐dependent, serotonin release of RBL cells. These in vitro findings were confirmed by in vivo experiments, which demonstrated that the anti‐IgE mAb could specifically block passive cutaneous anaphylaxis reaction when injected i.d., before challenging with the antigen. The differences in blocking reactivity of the various anti‐IgE mAb are discussed in view of heterogeneity in the IgE‐FcϵR interaction.
Efficiency of antigen presentation to T cell clones by (B cell × B cell lymphoma) hybridomas correlates quantitatively with cell surface Ia antigen expression
Authors: Bekkhoucha Fawzia , Naquet Philippe , Pierres Anne , Marchetto Sylvie , Pierres Michel
Published: February 2007

A series of B cell hybridomas was used as a model system to assess quantitatively the role of Ia molecules in antigen presentation to allo‐ or soluble antigen‐reactive T cell clones. These hybrid cell lines were established by fusion between the HGPRT− BALB/c B cell lymphoma M12.4.1 and LPS‐stimulated spleen blasts from B10.BR (H‐2k) mice. Quantitative cellular absorption of appropriate anti‐Ia monoclonal antibodies and flow cytofluorometric analyses revealed that the B cell hybridomas examined herein expressed constitutively a number of surface I‐Ak or I‐Ek molecules that varied in an order of magnitude of 1 to 5. Such quantitative differences could be correlated precisely with (a) the capacity of B cell hybridomas to activate T cell clones to proliferate and/or to produce interleukin 2 in response to Eβk allodeterminant or to poly(Glu60Ala30Tyr10) presented in the context of I‐Ak restriction element, and (b) the amount of monoclonal anti‐I‐Ak antibody required to inhibit antigen presentation to T cell clones. The possible implications of these data are discussed in the context of current models of regulation of Ia antigen expression by antigen‐presenting cells.
MHC‐ and non‐MHC‐encoded surface antigens of chicken lymphoid cells and erythrocytes recognized by polyclonal xeno‐, allo‐ and monoclonal antibodies
Authors: Wolf Hugo , Hála Karel , Boyd Richard L. , Wick Georg
Published: February 2007

Surface antigens on chicken thymus and bursa cells were analyzed by immunoprecipitation using polyclonal and monoclonal antisera raised against (and specific for) thymus (ATS) or bursa (ABS) cells, respectively. The antigens identified were compared with those governed by the B‐F, B‐L and B‐G regions of the chicken major histocompatibility complex (B complex).

Four proteins were precipitated from thymus cells by 2 polyclonal ATS: both antisera recognized molecules of apparent molecular mass of 172–182, 132–135, 75–76 kDa, and one antiserum in addition recognized a protein of 102 kDa. The 172–182 and 102‐kDa peaks were still demonstrable under reducing conditions indicating that they are composed of a single polypeptide chain, the other 2 were lost under reducing conditions, therefore, must be composed of smaller subunits. Of the 2 monoclonal ATS tested, one identified a single protein of 186 kDa and the other a 135‐kDa protein (in addition to 2 smaller molecules); whether these are the same as those precipitated by the polyclonal antisera remains to be determined as they behaved differently under reducing conditions.

Proteins of 162 and 78–84 kDa were revealed by 2 polyclonal ABS under nonreducing conditions but the former may in one case be a polymer (it disappeared under reducing conditions) and in the other a single molecule. In addition molecules of 182 kDa were identified by one antiserum and of 84 and 60 kDa by the other under nonreducing conditions. Of the 4 monoclonal ABS only one identified a 200‐kDa protein: molecules of 115–125, 90–100, 48–52 and 40–43 kDa were also precipitated, all of which were reduced to smaller molecules. With 2 specific anti‐B‐F alloantisera we were able to precipitate the “conventional” B‐F antigen from red blood cell lysates of CB‐strain chickens resolving into a 40‐kDa peak and a light chain of about 12 kDa corresponding to β2 microglobulin. Precipitates from peripheral blood lymphocytes, bursa and thymus cells revealed an additional protein of 22 kDa. With 2 specific B‐L alloantisera two peaks of 33 kDa and 31 kDa were obtained from peripheral blood lymphocytes. Using anti‐B‐G alloantisera a double band corresponding to 47 and 42 kDa was seen under reducing conditions. There is no evidence from these data to indicate that the polyclonal and monoclonal antibodies are directed towards major histocompatibility complex antigens.
Identification of a 140‐kDa activation antigen as a target structure for a series of human cloned natural killer cell lines
Authors: Hercend Thierry , Schmidt Reinhold , Brennan Agnes , Edson Mary Ann , Reinherz Ellis L. , Schlossman Stuart F. , Ritz Jerome
Published: February 2007

In the present study, we have developed a monoclonal antibody termed anti‐TNKTAR, able to block cytotoxicity mediated by a human natural killer (NK) clone termed JT9. Analysis of the functional effects of anti‐TNKTAR indicated that alteration of the cytotoxic reactions resulted from the binding of the antibody to the membrane of target cells. In addition, it was shown that inhibition of cytotoxicity induced by anti‐TNKTAR could be abolished by lectin approximation.

Immunoprecipitation experiments indicated that TNKTAR antigen is a heterodimeric structure which resolves as a single band at 140 kDa under nonreducing conditions and as two bands at approximately 97 kDa and 40 kDa under reducing conditions in sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. This heterodimer is present on lymphocytes and monocytes in human peripheral blood and perhaps more importantly, the membrane density of TNKTAR antigen increases very early and strongly following lymphocyte activation. In addition, it was shown that TNKTAR is expressed on each single cultured cell line which has been tested, although the density of the antigen varies strongly from one cell line to another.

Even though the 140‐kDa molecule was found to be widely distributed on activated cells, anti‐TNKTAR had no blocking effects on cytotoxic reactions mediated by a series of either NK or cytotoxic T lymphocyte clones unrelated to JT9. In contrast, anti‐TNKTAR blocked, in an identical fashion, cytotoxicity of JT9 and two additional clones, JT10 and JT11, against a series of 8 sensitive targets. JT9, JT10 and JT11 human cloned NK cell lines have been derived from peripheral blood of one individual donor drawn on month 0 (JT9), 12 (JT10) and 18 (JT11). Most importantly, these three clones initially selected for their capacity to kill K562 cells have been found to express the same 90‐kDa clonotypic antigen receptor structure (termed NKTa) and display identical specificity when tested against a panel of randomly selected target cell lines.

We have previously demonstrated that a unique subset of NK active mature T lymphocytes interact with target cells via 90‐kDa clonotypic determinants in a major histocompatibility complex‐independent fashion. Taken together, the present data strongly supports the view that a surface antigen of 140 kDa, linked to cell activation, serves as a specific recognition structure at the target cell level for these NK‐active T lymphocytes.
The glycosphingolipid globoside as a serological marker on cytolytic T lymphocyte precursors and alloantigen‐responsive proliferating T lymphocytes in murine spleen
Authors: Mühlradt Peter F. , Bethke Ulf , Monner David A. , Petzoldt Klaus
Published: February 2007

Biochemical analyses of murine lymphocytes have shown that the glycosphingolipid globoside (Glo) is present exclusively on alloantigen‐stimulated murine T lymphocytes (Gruner, K. R., Van Eijk, R. V. W. and Mühlradt, P. F., Biochemistry 1981. 20: 4518). An anti‐Glo antibody has now been raised in rabbits immunized with purified antigen. Most activity was recovered in the IgM fraction. The specificity of the antibody was ascertained in an enzyme‐linked immunosorbent assay with purified glycosphingolipids bound to the solid phase. In antibody‐dependent complement lysis experiments the anti‐Glo eliminated about 20% of nylon wool‐nonadherent splenic T cells of CBA/J mice. To determine the functional identity of these Glo+ cells, the effects of Glo+ cell elimination on mitogen stimulation with concanavalin A and lipopolysaccharide, as well as the effects on the mixed lymphocyte culture (MLC) reaction and cell‐mediated lympholysis with mitomycin‐treated DBA/2 splenocytes as stimulator cells were studied. Whereas lipopolysaccharide stimulation was not affected by elimination of Glo+ cells, there was a slight inhibitory effect on the concanavalin A stimulation, and a severe inhibition of the MLC reaction and the generation of H‐2d‐specific cytolytic T lymphocytes. Addition of interleukin 2 increased the MLC reaction, but interleukin 2‐saturated cultures were also severely inhibited by anti‐Glo and complement treatment. Combined treatment with anti‐Glo and anti‐Lyt‐1 or anti‐Lyt‐2 antibodies, and determination of cytolytic T lymphocyte precursor frequencies in limiting dilution cultures after Glo+ cell elimination showed that a large proportion of T cells proliferating in a primary MLC are Lyt‐1+,2+,3+Glo+, whereas in secondary MLC they are Lyt‐1+,2−,3−, Glo+. Fifty % of the cytolytic T lymphocyte precursors in primary as well as secondary MLC are Glo+. The Glo marker is lost upon differentiation to cytolytic T lymphocyte effector cells. It is discussed herein that Glo is a marker for alloantigen‐stimulated precursor T lymphocytes of both helper and cytolytic T cells.
The percentages of six immunoglobulin isotypes in human antibodies to tetanus toxoid: Standardization of isotype‐specific second antibodies in solid‐phase assay
Authors: Seppälä Ilkka J. T. , Routonen Nina , Sarnesto Annikki , Mattila Petri A. , Mäkelä Olli
Published: February 2007

The solid‐phase radioimmunoassay for human antibodies was improved so that it gave the total concentration as well as the concentrations of IgM, IgA, IgG1, IgG2, IgG3 and IgG4 antibodies, all seven in the same “L units”/ml. This was accomplished by standardization of monoclonal antibodies with monoisotypic antibodies rather than myelomas; myelomas were found unsatisfactory for this purpose. For the first time it was possible to determine the isotype composition of an antibody population in percent terms. The weight equivalent of the L‐unit in one hyperimmune tetanus antitoxin preparation was approximately 7.4 ng.

The new solid‐phase radioimmunoassay was applied to tetanus toxoid antibodies of the booster response. Total concentrations varied from 1700–26000 L units/ml (13–200 μg/ml). Concentrations of IgG1 antibodies were 1600–25000 units/ml (average 91% of the total) and concentrations of IgG4 antibodies 12–6900 units/ml (average 6.9% of the total). Antibodies of the other four isotypes were not detected in all sera and together they never exceeded 3% of the total.
Cloned helper T cells can kill B lymphoma cells in the presence of specific antigen: Ia restriction and cognate vs. noncognate interactions in cytolysis
Authors: Tite John P. , Janeway Charles A.
Published: February 2007

Cloned, Lyt‐1,2−, antigen‐specific, Ia‐restricted T cell lines can inhibit the growth of Ia‐bearing B lymphoma cells in the presence of specific antigen. This effect is due to cytolysis of the B lymphoma cells in an antigen‐specific, Ia‐restricted manner by the cloned T cell lines. These cloned T cell lines can also kill lipopolysaccharide‐activated normal B cells, while they activate resting B cells to divide and secrete immunoglobulin and are thus helper T cells as well as cytolytic T cells. The mechanism of cytolysis was examined in detail. Killing was mediated by a nonspecific mechanism after specific stimulation of the T cells with antigen presented in the context of the appropriate la glycoprotein complex, possibly implying a role for a soluble mediator. This simple system involving two clonal populations allows a detailed analysis of T‐B interactions. Our studies are consistent with the view that both cognate and noncognate interactions of Ia‐restricted T cells with B cells are mediated by nonspecific factors. Thus, the difference between interactions that appear to be cognate and those that appear to be noncognate may be quantitative rather than qualitative. That two cloned populations of cells can show either pattern of interaction depending on T‐B ratio provides strong support for this view. Finally, that cloned helper T cells can kill activated B cells in an antigen‐specific fashion may provide a new mechanism of immune regulation that would be especially important in responses to self antigens in vivo.
T cell competence to heterologous and homologous thyroglobulins during the induction of experimental autoimmune thyroiditis
Authors: Romball Carole G. , Weigle William O.
Published: February 2007

The ability of T cells to respond to homologous vs. heterologous thyroglobulins (Tg) has been evaluated using different models for the induction of experimental autoimmune thyroiditis. Substantial levels of T cell activation could be demonstrated to heterologous Tg following immunization with heterologous Tg in complete Freund's adjuvant, whereas only minimal levels of T cell activation to homologous Tg could be obtained following immunization with homologous Tg in complete Freund's adjuvant. Using this immunization protocol, heterologous and homologous Tg induced equivalent levels of serum antibody to the immunizing Tg. However, when injected in incomplete Freund's adjuvant, homologous Tg induced less antibody than heterologous Tg. Even greater differences in serum antibody levels to heterologous and homologous Tg were apparent following immunization with soluble Tg. These differences are attributed to the presence of only a minimal level of T cell competence for homologous Tg, which is capable of inducing experimental autoimmune thyroiditis with stringent immunization protocols, but not with weaker immunization regimens.
Suppression of IgE responses in inbred rats by repeated respiratory tract exposure to antigen: Responder phenotype influences isotype specificity of induced tolerance
Authors: Sedgwick Jon D. , Holt Patrick G.
Published: February 2007

Repeated exposure of rats to an aerosol of ovalbumin (OVA) induced tolerance to subsequent parenteral challenge with the same antigen. In the low‐IgE responder WAG strain, responses in both the IgE and IgG classes were affected, whereas rats of the moderate (Lou/M) and high‐IgE responder BN strain developed high titers of anti‐OVA IgG in serum during exposure with concomitant tolerance in the IgE class. Repeated parenteral challenge, however, failed to elicit significant secondary anti‐OVA IgG responses in the Lou/M and BN strains, suggesting that the isotype specificity of induced tolerance in these strains was not absolute. Spleen and respiratory tract lymph node cells, but not serum from aerosol‐exposed BN rats, were capable of transferring IgE isotype‐ and antigen‐specific tolerance. Dose response experiments demonstrated that the low‐IgE responder WAG strain was exquisitely sensitive to tolerance induction in response to antigen inhalation, being susceptible to dosages in the nanogram range; at least 1000 times more antigen was required in the high‐IgE responder BN to induce comparable tolerance in the IgE class. It was also apparent that the IgE isotype was more readily suppressed than the IgG isotype in both high‐and low‐IgE responder strains.
Induction of human interleukin 1 mRNA measured by collagenase‐ and prostaglandin E2‐stimulating activity in rheumatoid synovial cells
Authors: Dayer Jean‐Michel , Zavadil‐Grob Carolyn , Ucla Catherine , Mach Bernard
Published: February 2007

Human blood peripheral monocyte/macrophages release in culture a mononuclear cell factor (MCF) which stimulates the production of collagenase and prostaglandin E2 by human rheumatoid synovial cells and dermal fibroblasts. These two products play a role in connective tissue destruction. MCF has an apparent molecular weight of ∼15000 and is biologically and biochemically indistinguishable from interleukin 1. MCF therefore belongs to the well‐documented nonimmune biological activities attributed to interleukin 1. Studies on the mechanisms of production and action of such monokine(s) have been difficult in view of the minute quantities produced by freshly isolated cells or from human monocytic lines. Starting from lectin‐stimulated human blood mononuclear cells, we have isolated poly(A) RNA and studied its translation following microinjection into Xenopus laevis oocytes. The mRNA translation products stimulated collagenase and prostaglandin E2 production in human rheumatoid synovial cells and dermal fibroblasts. The size of MCF‐mRNA was estimated to be 10 S. The mRNA of a member of the interleukin 1 family can now be studied in a system based on a specific and direct relevant biological assay and eventually compared with those of other monokines.
Functional characteristics of murine macrophages responding to migration inhibitory factors
Authors: Michels Elmar , Stenzinger Werner , Sorg Clemens
Published: February 2007

Mouse bone marrow cells differentiate in culture in the presence of L cell‐conditioned medium to macrophages (MΦ). Proliferation, release of plasminogen activator, expression of transglutaminase, random motility and response to a standard preparation of purified MΦ migration inhibitory factor (MIF) was recorded daily up to 14 days. After an initial phase of proliferation, precursor cells differentiated into MΦ. In the course of maturation, plasminogen activator production was transiently expressed between day 4 and 12; beginning on day 5 the cells expressed intracellular transglutaminase. Random motility of cells was high at the beginning of culture but steadily declined thereafter. The response to MIF was only expressed between day 5 and 8. However, it was possible to induce MIF responsiveness in mature, unresponsive MΦ by the addition of L cell‐conditioned medium. To characterize the MIF‐responsive MΦ type further, bone marrow‐derived MΦ at day 6 of culture were separated on a hypotonic Percoll gradient into three distinct cell bands. While all densities of MΦ displayed random migration, only cells with a density between 1.060 and 1.065 were responsive to MIF. We conclude that the response of MΦ to MIF is a phenotypic trait transiently expressed in the course of maturation.
Induced latent allotypes within rabbit anti‐crossreactive idiotype reagents. Direct immunoelectron microscopic evidence
Authors: Roux Kenneth H. , Metzger Dennis W. , Kazdin Dori S. , Horng Wayne J.
Published: February 2007

Immunization of rabbits with anti‐VHa allotype antibody leads to the production of an “anti‐cross‐reactive idiotype (IdX)” reagent which appears to recognize a highly conserved IdX on anti‐allotype antibodies. In many rabbits, a large percentage of this “anti‐IdX” reagent does not express the nominal VHa framework allotype of the rabbit from which it was derived and is otherwise serologically indistinguishable from the original antigen, i.e. al or a2 allotype. To determine whether these anti‐IdX molecules were in fact anti‐IdX (or internal images) or were induced immunoglobulins bearing latent VHa allotypes, immunoelectron microscopic analysis of the molecules in complex with Fab anti‐allotype antibody was conducted. The results show that the complexes do not resemble idiotype‐anti‐idiotype interactions but are essentially indistinguishable from allotype‐anti‐allotype complexes. We conclude that a major component of the “anti‐idiotype” response of these anti‐VHa‐immunized rabbits is the production of Ig molecules bearing latent VHa allotypes.
Immune response to the p‐azobenzenearsonate‐L‐glutamic acid60‐L‐alanine30‐L‐tyrosine10 (GAT) conjugate. III. Mechanisms of Ir gene‐controlled phenotype conversion
Authors: de Castaneda Maria Flores , Regnier Daniel , Hermier Brigitte , Dubert Jean‐Marie , Seman Michel
Published: February 2007

Immunization of GT (random copolymer of L‐glutamic acid51‐L‐tyrosine49) nonresponder animals with p‐azobenzenearsonate (ABA) GT conjugates elicits an antibody response to both ABA and GT epitopes which is induced by ABA‐specific T helper cells. Expression of these hapten‐specific helpers is under the control of an I region gene which also regulates the proliferative T cell response to ABA. Conversion of the unresponsive phenotype to GT is, therefore, dependent on the ABA Ir gene and escapes the influence of the GT‐specific I region‐controlled suppressive pathway. Studies on the influence of ABA/polymer coupling ratio on T and B cell responses suggest that ABA‐specific T cells, like conventional carrier‐specific helpers, require linked interactions with B lymphocytes to provide helper signals. GAT (terpolymer of L‐glutamic acid60‐L‐alanine30‐L‐tyrosine10) nonresponder animals immunized with ABA‐GAT conjugates also develop an antibody response to ABA which is induced by ABA‐specific T helper cells. Comparison of antibody affinity, specificity, isotypes and idiotypes in different mouse strains demonstrates that hapten‐specific helper cells stimulate antibody responses to ABA which are qualitatively similar to those induced by GAT‐specific helpers. However, ABA‐specific helper cells do not permit the conversion of the I region gene‐controlled nonresponder phenotype to GAT. The data suggests that high ABA density, which is required for optimal ABA help expression, extinguishes the immunogenicity of GAT determinants at both T and B cell levels.
Differentiation of murine B cell precursors in agar culture. Frequency, surface marker analysis and requirements for growth of clonable pre‐B cells
Authors: Paige Christopher J. , Gisler Roland H. , McKearn John P. , Iscove Norman N.
Published: February 2007

A semi‐solid agar assay is described in which B cell progenitors, already present in day 12 fetal liver, generate colonies which contain antibody‐secreting cells. Panning experiments, in which cells which initiate colony formation are depleted on plates coated with monoclonal antibodies, suggest that by the 13th day of gestation they express the antigen recognized by the monoclonal antibody AA4.1 and by day 14 they also express the B220 form of Ly‐5 recognized by the monoclonal antibody 14.8. By similar criteria the precursor cells do not express μ, I‐A, I‐E or Lyb‐2. Growth of cells in this assay is dependent upon soluble products provided by either fetal liver adherent cells, bone marrow adherent cells or colony‐stimulating factor‐containing conditioned media derived from placenta cells, L929 cells, WEHI‐3 B(D−) cells, T helper cells or mouse lung cells. These experiments define two sets of growth conditions. In the first, when support is provided by fetal liver adherent cells, the limiting component appears to be the B cell precursor, allowing us to estimate the frequency of these cells during ontogeny. We find approximately 1 clonable pre‐B cell in 300000 fetal liver cells on day 12 of gestation and 1 in 6000 by day 16. Under the second set of growth conditions, when support is provided by bone marrow adherent cells or colony‐stimulating factor‐containing conditioned media, more than one cell, colony or cell product is limiting. Highly purified samples of granulocyte/macrophage colony‐stimulating factor, colony‐stimulating factor 1 and multilineage‐hematopoietic growth factor are effective in this assay suggesting that the colony‐stimulating factors are the active components under these conditions.
Thymic hormone‐containing cells. VI. Immunohistologic evidence for the simultaneous presence of thymulin, thymopoietin and thymosin α1 in normal and pathological human thymuses
Authors: Savino Wilson , Dardenne Mireille
Published: February 2007

The localization of the three best‐defined thymic hormones, namely, thymulin, thymopoietin and thymosin α1 was studied by immunofluorescence using antibodies directed against these three molecules. With both human thymus frozen sections and cultured cells, thymic hormones were found exclusively in the epithelial component (recognized by its keratin content), in normal as well as pathological thymuses. The double‐labeling experiments using the different anti‐thymic hormone antibodies showed that the same epithelial cells contained the three hormones. These results suggest that the production of different hormones in the thymus is accomplished by the same epithelial cells.
Serological and partial molecular characterization of a Thy‐1 homolog in tunicates
Authors: Mansour Mohamed H. , Cooper Edwin L.
Published: February 2007

The occurrence of a Thy‐1 homolog in the tissues of the advanced invertebrate group of tunicates has been investigated by using two monoclonal antibodies specific to rodent Thy‐1.1 determinants and a heterologous anti‐rat Thy‐1 antiserum. In cellular and soluble‐phase radioimmunoassays for Thy‐1 using intact hemocytes, tissue extracts and hemolymph, membrane‐bound and soluble Thy‐1.1 cross‐reacting determinants have been detected. Immunoprecipitation experiments with hemocyte deoxycholate extracts and hemolymph, labeled with 125I by lactoperoxidase/chloramine T and with NaB3H4 by galactose oxidase, established the association of the Thy‐1.1 cross‐reacting determinants with a single glycoprotein of apparent m.w. estimated at 27000 in hemocytes and 22 500 in hemolymph by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The significance of this finding is discussed in relation to the phylogenetic emergence of the Thy‐1 molecule during evolution.
Induction of cytolytic cells by pure recombinant human interleukin 2
Authors: Devos Rene , Plaetinck Geert , Fiers Walter
Published: February 2007

Purified recombinant human interleukin 2, produced in Escherichia coli, was sufficient to generate cytolytic cells in concanavalin A‐stimulated, T helper cell‐depleted (Lyt‐1.1−) or accessory cell‐depleted (Ia−) murine spleen cell cultures. Moreover, recombinant interleukin 2 (rIL 2) was able (even at 0.5 ng/ml) to induce cytolytic cells in undepleted murine spleen cell cultures and undepleted human peripheral blood lymphocyte cultures in the absence of a mitogen. Purified recombinant human interferon‐γ, produced in Chinese hamster ovary cells, did not induce either cytolytic activity or IL2 responsiveness in human peripheral blood lymphocyte cultures. Possibly, the rIL2‐induced cytolytic cells are formed as a result of nonspecific secondary cytotoxic T lymphocyte activation.
Long‐term suppressor cell lines. I. Demonstration of suppressive function
Authors: Levich Judith D. , Weigle William O. , Parks D. Elliot
Published: February 2007

Suppressor T cell (Ts) lines have been generated and maintained in culture for over one year. Cells from these lines suppress proliferation by primed lymph node cells and antibody production by primed spleen cells. Ts were originally obtained from either spleens of mice rendered tolerant to human gamma globulin (HGG) or short‐term cultures of normal spleen cells. Ts from these two sources have previously been shown to exhibit antigen specificity in that only HGG‐specific immune responses were suppressed. Prolonged culture of Ts, however, leads to 2 events: (a) an enrichment for suppressive activity in the cultures; and (b) a polyclonal activation of Ts which is demonstrated by the acquired ability of Ts cell lines to regulate responses to antigens other than HGG. Ts cell lines still contain HGG‐specific Ts which can be isolated by their capacity to bind to HGG‐coated plates. Only HGG‐specific immune responses are suppressed by the HGG‐binding Ts.
Long‐term suppressor cell lines. II. Suppressor‐target interactions
Authors: Levich Judith D. , Weigle William O. , Parks D. Elliot
Published: February 2007

Long‐term nonhybridized murine suppressor T cell (Ts) lines, some of which have been in culture for over one year, are genetically restricted in their ability to suppress proliferation of primed lymph node cells (LNC). The genetic restriction maps to the I region of the major histocompatibility complex and resides in either the I‐A, I‐E or I‐J locus. Suppressive activity is only slightly decreased following irradiation of the Ts with 2000 rds. The target for suppressive activity expressed by Ts cell lines is the helper T cell as suggested by experiments in which LNC proliferation was maximally suppressed when Ts were present early in the assay culture. The identity of the target cell was confirmed by experiments in which Ts were shown to suppress the anti‐human gamma globulin plaque‐forming cell response resulting from co‐culture of primed B cells with cloned human gamma globulin‐specific helper T cells.
Anti‐DNA autoantibody activity and idiotypic relationships of human monoclonal proteins
Authors: Zouali Moncef , Fine Jean‐Marius , Eyquem André
Published: February 2007

Previous studies showed that polyclonal anti‐DNA antibodies from patients with systemic lupus erythematosus (SLE) share cross‐reactive idiotypes (CRI). In this report, we used human myeloma proteins (HMP), isolated from the serum of patients with multiple myeloma or Waldenström macroglobulinemia, as probes to further explore this idiotypic cross‐reactivity. Fourty‐four HMP were tested for DNA‐binding capacity and for expression of CRI associated with lupus anti‐DNA antibodies. Anti‐DNA IgG were immunoaffinity purified from the serum of patient TOF with severe SLE. A xenogeneic anti‐idiotype antibody to this IgG was raised in rabbit. This anti‐idiotype recognized CRI associated with the combining site of anti‐DNA IgG from unrelated SLE patients. Using inhibition competitive‐immunoassays, we found that these CRI were present on all but one of the DNA‐binding HMP. Furthermore, we observed that these CRI were detectable on an IgG2λ, a HMP devoid of anti‐DNA activity. These findings are in agreement with those previously obtained in similar studies using murine monoclonal anti‐DNA antibodies. These converging results suggest that antibodies expressing anti‐DNA‐related CRI and antibodies exhibiting anti‐DNA‐binding affinity constitute overlapping molecular subpopulations.