bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency and cross-reactivity od cytolytic T lymphocyte precursors reacting against male alloantigens.
Authors: Kanagawa O , Louis J , Cerottini J C
Published: December 2022

It is well established that cytotoxic T lymphocytes (CTL) specific for the male minor histocompatibility antigen (H-Y) are generated by restimulation in vitro of in vivo primed spleen cells from C57BL/6 (H-2b) female mice with syngeneic male spleen cells. When tested on target cells from H-2 different strains, the male-specific C57BL/6 CTL populations exhibited significant lysis of DBA/2 (H-2d), A (H-2a), but not C3H (H-2k), male and female target cells. In an attempt to document this cross-reactivity further at the clonal level, a sensitive technique of limiting dilution analysis was used to determine the specificity of C57BL/6 individual CTL precursors (CTL-P) reactive against the male antigen. The mean frequency of anti-H-Y CTL-P in spleens of primed female mice was about 1/3500. Between one-third to one-tenth of these CTL-P produced a progeny that cross-reacted with H-2d (allogeneic) female target cells. These findings were confirmed by the analysis of the reactivity pattern exhibited by male-specific CTL clones derived by limiting dilution. Of 99 clones tested, 13 were found to cross-react with female DBA/2 target cells. These results thus indicate that a relatively large proportion (greater than 10%) of H-2b CTL-P directed against the H-Y antigen cross-react with target cells expressing H-2d alloantigens in the absence of H-Y antigen.
Activation and immunoregulation of antigen-specific human b lymphocyte responses: multifaceted role of the monocyte.
Authors: Gerrard T L , Fauci A S
Published: December 2022

The multifaceted role of the monocyte in the induction and modulation of antigen-specific antibody responses by human B cells was delineated. Monocytes were absolutely required for the induction of specific antibody responses to both TT and KLH in an antigen-induced in vitro assay. Monocytes were also required for the PWM induction of specific antibody in immunized subjects. Pulsing monocytes with specific antigen or with PWM consistently stimulated proliferation of T cells in absence of added antigen and could also stimulate specific antibody synthesis although less consistently. Stimulation of specific antibody responses with antigen required fewer numbers of monocytes than did stimulation of specific antibody responses with PWM. Polyclonal antibody synthesis induced by PWM was also dependent on monocytes. However, polyclonal antibody synthesis induced by supraoptimal concentrations of antigen was usually optimal in the absence of monocytes and was actually suppressed when increased numbers of monocytes were added to monocyte-depleted cultures. Monocyte supernatants could not replace the absolute requirements for monocytes in the induction of specific antibody synthesis. However, monocyte supernatants could profoundly modulate the antigen-specific as well as the polyclonal Ig response of lymphocytes to either antigen or PWM stimulation in a manner closely resembling monocytes themselves. Thus, we demonstrated that monocytes and their products play a critical role in the activation and immunoregulation of antigen-specific antibody responses of human B cells.
Increase of hybridoma formation by human lymphocytes after stimulation in vitro; effect of antigen, endothelial cells, and PWM.
Authors: Astaldi G C , Wright E P , Willems C , Zeijlemaker W P , Janssen M C
Published: December 2022

Peripheral blood lymphocytes from antibody-producing Rh- donors were fused with mouse myeloma cells, and the hybrids were screened for anti-Rh antibody production. Although the resulting hybrids were not stable in long-term culture, they provided a useful test system for an investigation of ways to stimulate human lymphocytes in vitro before fusion in order to maximize the recovery of hybrids producing antibodies with a desired specificity. Although 6-day culture with PWM or with antigen (Rh+ erythrocytes) increased slightly the yield of desired hybrids, exposure of the PBL to antigen in the presence of human endothelial cells was dramatically more effective. This effect was not produced with endothelial cell culture supernatants (HECS) that had been shown previously to enhance hybridoma growth. Culture of PBL before fusion with both PWM and antigen also improved the proportion of active hybridomas, and incubation with antigen plus endothelial cells plus PWM resulted in a very high number of hybridomas, with a very high proportion producing antibody to the immunizing antigen. There are several alternatives to explain the mechanisms involved, but in any case, the technique should be particularly useful when the possibility of fusion of human PBL with a human myeloma line becomes more widely available.
Role of genes in murine major histocompatibility complex (MHC) in the ontogeny of B cells with restricted capacity for cooperation with adherent cells in the production of antibody to thymus-dependent (TD) and thymus-independent type 2 (TI-II) antigens.
Authors: Gorczynski R M , MacRae S
Published: December 2022

We have examined the MHC restriction that exists for cooperation between B lymphocytes and antigen-pulsed accessory cells for antibody responses in tissue culture, using B cells prepared from spleen cell suspensions of progeny born to (B10 x B10.BR)F1 female mice mated with B10 males. At early times post-birth (3 to 6 wk) progeny animals types as H2b contained a population of splenic B cells restricted to MHC antigens expressed on B10.BR macrophages; in contrast, B cells from H2b animals born to the incross (B10 x B10) were as expected, restricted to cooperate only with B10 macrophages. This unusual restriction pattern waned with age such that by 20 wk of age considerably fewer of the B10 progeny born in the backcross mating exhibited this behavior. We interpret these data as evidence that the early B cell repertoire is to some degree 'driven' by exposure to those MHC antigens (in the maternal placental circulation) encountered in utero. Post-birth, continued renewal of the mature B cell pool occurs concomitant with a diversification (and selection) of the B cell repertoire as a result of experience with antigens lacking this maternally imparted genetic information.
Genetic regulation of the antibody response to H-2Db alloantigens in mice. IV. Antigens that activate helper T cells for IgG, coded for by the non-H-2 genome.
Authors: Wernet D , Heinrichs H , Wernet P
Published: December 2022

When B10.A(5R) mice are immunized with congenic C57BL/10 cells only 2-ME-sensitive antibodies (IgM type) are found directed against H-2Db. To obtain 2-ME-resistant antibodies (IgG type) 5R mice must be immunized with noncongenic cells (e.g., A.BY); in this case non-H-2 cell surface antigens will activate helper T cells to induce anti-Db IgG antibody production by B cells. An attempt was made to define helper antigens that activate helper T cells. Neither N-2 antigens of seven H-2Db recombinant strains nor a limited set of non-H-2 cell surface antigens were able to serve as helper antigens. By using individual backcross mice as antigen, one helper antigen was found on the background of strain A under the conditions used, whereas other backgrounds may carry more than one antigen. The helper antigen is dominantly expressed in F1 mice and has to be presented on the same cell as H-2Db to induce the switch from IgM to IgG.
Marked in vitro spontaneous secretion of IgA by human rib bone marrow mononuclear cells.
Authors: Alley C D , Nash G S , MacDermott R P
Published: December 2022

Mononuclear cells (MNC) isolated from bone marrow curettaged from human ribs spontaneously produced significant amounts of Iga in 14-day in vitro culture. When culture supernatants were tested for each immunoglobulin isotype by radioimmunoassay at days 7, 14, 21, and 28, the peak of spontaneous IgA production was reached by day 14. Culturing marrow MNC in the presence of the polyclonal activator pokeweed mitogen (PWM) ablated this spontaneous IgA activity, and did not stimulate the production of IgG or IgM. In contrast, peripheral blood MNC produced significant amounts of all three immunoglobulin isotypes studied in the presence of PWM, but minimal immunoglobulin spontaneously. PWM stimulated both marrow and peripheral blood MNC to proliferate as demonstrated by increased DNA synthesis. In view of the opposite effects of PWM on immunoglobulin production by peripheral blood and bone marrow MNC, PWM may be stimulating a different functional or developmental subpopulation of cells in each case. We conclude that the bone marrow is a major site of IgA production in the human, that cells within the bone marrow have a blastogenic response to PWM in vitro, and that spontaneous production of IgA by human marrow MNC is inhibited by PWM.
Induction of B cell differentiation in vitro by bursal epithelium.
Authors: Eerola E , Lassila O , Gilmour D G , Toivanen A
Published: December 2022

The inductive capacity of in vitro cultured epithelium of chicken bursa of Fabricius and of its soluble products on B cells precursors was evaluated. The appearance of surface Ia-like antigens was used as an indicator of the early B cell differentiation in vitro. Cultured bursal epithelium as well as soluble substances produced by it were able to initiate B cell development; Ia alloantigens were induced by both syngeneic and allogeneic epithelia. In both cases the induced Ia antigens represented the genotype of the responding cells.
Complement-induced solubilization of C-reactive protein-pneumococcal C-polysaccharide precipitates: evidence for covalent binding of complement proteins to C-reactive protein and to pneumococcal C-polysaccharide.
Authors: Volanakis J E
Published: December 2022

Insoluble precipitates between C-reactive protein and pneumococcal C-polysaccharide were solubilized by fresh but not heat-inactivated human serum. Solubilization was dependent on the C-reactive protein to C-polysaccharide ratio and the serum concentration and proceeded optimally at 37 degrees C. On 12 to 30% sucrose density gradients solubilized complexes sedimented as a broad peak between the 7S region and the bottom of the tube. In C2-deficient human serum, solubilization was delayed by 30 min and then proceeded at a slow rate. Immunoprecipitation experiments indicated that C3, C4, C5, and to a lesser extent C1q were deposited on solubilized complexes. After dissociating solubilized complexes with EDTA, a considerable percentage of C-polysaccharide coprecipitated with C3, C4, and C5, whereas C-reactive protein coprecipitated with only C3. SDS-PAGE analysis of solubilized precipitates indicated the formation of covalent complexes between fragments of C3 and both C-polysaccharide and C-reactive protein.
The capacity of activated murine macrophages for augmented binding of neoplastic cells: analysis of induction by lymphokine containing MAF and kinetics of the reaction.
Authors: Marino P A , Adams D O
Published: December 2022

The capacity for augmented binding of tumor cells is an initial and necessary part of macrophage-mediated tumor cytotoxicity. To study the induction of binding capacity, we obtained FCS-elicited, inflammatory macrophages from C57BL/6J mice. Exposure of these macrophages to lymphokine(s) containing MAF induced augmented binding capacity in a dose-dependent fashion. Resident peritoneal macrophages did not respond to lymphokine, and endotoxin did not appreciably influence induction of binding. Maximum induction of binding required continuous interaction between macrophages and lymphokine for 6 to 10 hr. The conditions necessary for induction of binding closely paralleled those for induction of priming or cytolysis. Exposure of FCS-elicited macrophages from C3H/HeJ mice, although not of macrophages from A/J mice, induced augmented binding. The data suggest that the augmented capacity for binding tumor cells is induced by lymphokine(s) and that a major part of induction of priming for cytolysis by MAF is induction of such binding.
The regulation of Ig synthesis after marrow transplantation. IV. T4 and T8 subset function in patients with chronic graft-vs-host disease.
Authors: Lum L G , Orcutt-Thordarson N , Seigneuret M C , Storb R
Published: December 2022

This study compares pokeweed mitogen-activated immunoglobulin synthesis functions of T, T4 T8, and B cells from 13 marrow graft recipients with chronic graft-vs-host disease (GVHD), 10 long-term healthy marrow graft recipients, and 20 normal individuals. T cells expressed helper function (greater than 20% of the control) in eight of 10 long-term healthy patients and in only four of 13 patients with chronic GVHD. T4 cells expressed helper activity in all 10 long-term healthy patients, whereas T4 cells in four of 13 chronic GVHD patients did not express helper activity. Chronic GVHD patients had T cells (eight of 13), T4 cells (four of 13), and T8 cells (11 of 13) that suppressed immunoglobulin synthesis by normal T and B cells greater than 50%; radiosensitive and radioresistant suppressors were detected. Three of 10 patients with chronic GVHD and one of the long-term healthy patients had T4 cells that exhibited suppression. T cells from all 20 normal individuals expressed help and none suppressed immunoglobulin production. Altered T, T4, T8, and B cell functions were more frequent in patients with chronic GVHD than in long-term healthy patients or normals. Variable function within a T cell phenotype, variable radiosensitivity of suppressor cells, and higher frequencies of altered function in patients with chronic GVHD suggest there are different maturational stages expressed in each T cell phenotype.
Antigenic structure of sperm whale myoglobin. I. Partition of specificities between antibodies reactive with peptides and native protein.
Authors: Lando G , Berzofsky J A , Reichlin M
Published: December 2022

We have resolved anti-sperm whale Mb antibodies into two distinct populations: One population is reactive only with the native molecule, and the second is reaction with both Mb and peptide fragments. CNBr cleavage of sperm whale Mb yields three peptides: peptide I (1-55), peptide II (56-131), and peptide III (132-153). Immunoadsorbent columns made with these three peptides were used to fractionate antibody to sperm whale Mb. These columns cumulatively bind 60 to 70% of the total antibody present in the four sera studied (the amount of antibody bound by each peptide was proportional to its size). The remaining 30 to 40% of antibody could only bind specifically to an immunoadsorbent column of native Mb. This result indicates that not all antigenic determinants on the native Mb molecule are represented on peptide fragments.
Antigenic structure of sperm whale myoglobin. II. Characterization of antibodies preferentially reactive with peptides arising in response to immunization with the native protein.
Authors: Lando G , Reichlin M
Published: December 2022

The antigenicity of peptide fragments derived from CNBr-cleaved sperm whale Mb has been tested in competitive inhibition assays. These peptides appeared to be very poor inhibitors in a reaction involving radiolabeled sperm whale Mb with antipeptide antibodies, requiring about 10(4)-fold excess of peptides to achieve the same level of inhibition as cold native Mb. However, cold peptides competed much better with radiolabeled peptides for antibody binding than the native protein. These antibodies, preferentially reactive with peptides, originated from sera of animals immunized with the native molecule. This indicates heterogeneity of the antibodies produced against Mb and suggests the presence of diverse antibody subpopulations reactive with different antigenic forms of the protein. Results presented in this paper illustrate that competitive radioimmunoassays preferentially measure antibodies to the radiolabeled species, and this phenomenon can be used to demonstrate distinct populations among antibodies isolated to a single peptide.
Functional analysis of GAT-specific T cell clones: H-2-restricted monoclonal T helper cells do not regulate expression of antibody isotypes.
Authors: Seman M , Zilberfarb V , Gougeon M L , Theze J
Published: December 2022

We obtained T cell clones specific for poly (Glu60, Ala30, Tyr10) (GAT) from GAT-primed lymph node cells of BALB/c mice. The clones consisted of helper cells that were carrier-specific and H-2-restricted and required a hapten-carrier bridge to activate B cells. They may be considered TH1 cells. They could all induce antibody responses of various isotypes in adoptive transfer in vitro. Isotypic patterns of the responses obtained with the clones were identical to those obtained with polyclonal T cells and were not dependent on the number of T helper cells added to the culture. Therefore, our observations demonstrate that classic TH1 cells do not regulate isotype expression on secondary responses. The expression of idiotype-like determinants on the GAT-specific clones was assayed. A syngeneic anti-idiotypic serum (B658), prepared in BALB/c mice against BALB/c anti-GAT antibodies previously characterized, was shown to block specifically the helper activity of GAT-specific T cell lines from BALB/c mice. Under the same experimental conditions the activity of none of the BALB/c clones was affected by serum B658.
Characterization of H-2Db antigens implies haplotype differences in the number of H-2 molecules expressed.
Authors: Melino M R , Nichols E A , Strausser H R , Hansen T H
Published: December 2022

Investigation of the molecular heterogeneity of H-2Db region antigens by using monoclonal antibodies and complex alloantisera has yielded evidence for the existence of only one gene product in this region. Sequential immunoprecipitation and isoelectric focusing analysis suggest that the private H-2.m2 and public H-2.m64 specificities defined by monoclonal or alloantibodies are present on the same molecule. Blocking studies with these reagents indicate these specificities represent two determinants spatially separated on the H-2Db molecule. Functional studies suggest that effector T cells may be generated against both of these determinants or closely associated epitopes, but the majority of the T cells recognize an epitope associated with or identical to the private specificity H-2.m2. Studies of the D region-encoded products of haplotypes besides H-2b have shown two or more distinct molecules can be detected by anti-H-2.m64 in both the H-2d and H-2q haplotypes. The presence of H-2.m64 on a single Db molecule is unique and gives further evidence for the lack of other gene products encoded in this region. Speculations based on the molecular heterogeneity of the D region gene products are made concerning the evolution and genetic organization of H-2 genes.
Role of the major histocompatibility complex in T cell activation of B cell subpopulations: antigen-specific and H-2-restricted monoclonal TH cells activate Lyb-5+ B cells through an antigen-nonspecific and H-2-unrestricted effector pathway.
Authors: Hodes R J , Shigeta M , Hathcock K S , Fathman C G , Singer A
Published: December 2022

Monoclonal T helper (TH) cell populations were employed to study the mechanism of activation of the Lyb-5+ B cell subpopulation in T cell-dependent antibody responses in vitro. It was demonstrated that monoclonal T cell populations were sufficient to help rigorously T-depleted unprimed (B + accessory) cells for direct plaque-forming cell responses to trinitrophenyl- (TNP) conjugated keyhole limpet hemocyanin (KLH). The activation of several lines of cloned (H-2b X H-2k)F1 TH cells was antigen (KLH) specific and H-2 restricted. Individual clones were restricted to H -2b, H-2k, or unique (H-2b X H-2k)F1 encoded determinants. Under the experimental conditions employed, responses mediated by cloned TH cells were found to result in the activation of the Lyb-5+ B cell subpopulation. The activation of Lyb-5+ B cells by cloned TH cells did not require covalent linkage of carrier and hapten, and responses could be stimulated in the presence of free KLH plus TNP conjugated to an irrelevant carrier. The H-2 restriction of TH cell function was shown to reflect a requirement for T cell recognition of determinants expressed by accessory cells, whereas no requirement existed for restricted T cell recognition of B cells. These findings suggest that the help provided by monoclonal TH cells, once activated, was both antigen nonspecific and H-2 unrestricted. Consistent with this interpretation, it was found that the supernatant of antigen-stimulated TH cells provided antigen-nonspecific help to T-depleted spleen cells. Thus, these results demonstrate that the activation of Lyb-5+ B cells by antigen-specific and H-2-restricted monoclonal TH cell populations is itself antigen nonspecific and H-2 unrestricted.
Stimulation of the intracellular killing of Staphylococcus aureus by monocytes: regulation by immunoglobulin G and complement components C3/C3b and B/Bb.
Authors: Leijh P C , van den Barselaar M T , Daha M R , van Furth R
Published: December 2022

The intracellular killing of Staphylococcus aureus by human monocytes requires continuous stimulation by extracellular serum factors interacting with the cells via membrane binding sites. At least 75% of the intracellular killing in the presence of fresh serum was accounted for by the combined stimulatory activities of IgG, C3/C3b, and B/Bb. C3b is a more potent stimulator than C3, and Bb stimulates the killing to the same degree as B. The stimulation of intracellular killing by C3 and C3b occurs by interaction of the stable binding site of this molecule with the C3b receptor in the monocyte membrane. The stimulation of intracellular killing by B and Bb is most probably mediated via a binding site on these proteins interacting with a receptor site in the monocyte membrane. Both complement receptors, i.e., for C3b and B, are pronase sensitive. However, only the C3b receptor can be inhibited by (Fab')2 fragments of anti-C3 receptor antibodies, indicating that the binding sites for C3/C3b and B/bb are different.
The immune response in aged C57BL/6 mice. II. Characterization and reversal of a defect in the ability of aged spleen cells to respond to the adjuvant properties of Fc fragments.
Authors: Morgan E L , Weigle W O
Published: December 2022

Fc fragments derived from papain cleavage of human Ig were found to be unable to enhance the in vitro anti-SRBC response of aged mice. The inability of aged spleen cells to respond to the adjuvant properties of Fc fragments is localized to the aged T cell population. The addition of Fc fragments to cultures of aged B cells and young adult T cells, but not young adult B cells and aged T cells, resulted in an enhanced anti-SRBC response. The Fc fragment adjuvant defect in spleen cells from aged mice can be reversed by the addition of IL 2 to culture. The addition of either Fc fragments alone or IL 2 alone with antigen to intact aged spleen cell populations did not result in an enhanced anti-SRBC response. When aged spleen cell cultures receive both Fc and IL 2, however, a marked enhancement is observed. These data indicate that IL 2 action on aged spleen cells results in the acquisition of reactivity to Fc adjuvant action by aged mice.
Suppression of anti-hapten antibody responses by hapten-specific cytolytic T lymphocytes: role of I-A-associated antigen on target B lymphocytes.
Authors: Moser G , Burakoff S J , Abbas A K
Published: December 2022

Cytolytic T lymphocytes (CTL) specific for 2,4,6-trinitrophenyl (TNP) determinants suppress the effector phase of a secondary anti-TNP antibody responses of murine syngeneic spleen cells in vitro. The cells mediating this suppression are hapten-specific, H-2-restricted, and possess properties typical of CTL. Moreover, the targets of the suppression appear to be antigen-primed B lymphocytes that are recognized by CTL via soluble antigen bound noncovalently to their Ig receptors. The effect of the CTL can be blocked by the addition of monoclonal antibodies directed against I-A molecules but not I-E or H-EK-encoded molecules on the target B cells, even in strain combinations in which the CTL-B cell interaction is restricted only by the H-2K and I regions of the MHC. This result suggests that B lymphocyte-bound antigen tends to associate preferentially with I-A rather than H-2K/D-encoded determinants, and that the suppressive effect of the CTL population is attributable to the minor subset that recognizes hapten-modified Ia antigens. These findings are also discussed in terms of the possible immunoregulatory function of Ia-restricted CTL.
Gamma interferon (IFN gamma) and IFN alpha/beta suppress murine myeloid colony formation (CFU-C)N: magnitude of suppression is dependent upon level of colony-stimulating factor (CSF).
Authors: Klimpel G R , Fleischmann W R , Klimpel K D
Published: December 2022

The effect of different types of interferon (IFN) on macrophage and granulocyte colony formation (CFU-C) in vitro was studied using bone marrow cells from C57BL/6 mice. CFU-C formation was measured at 7 days using a standard methylcellulose culture system with L-cell conditioned medium (LCCM) as a source of colony-stimulating factor activity (CSF), IFN gamma was obtained from staphylococcal enterotoxin A- (SEA) stimulated mouse spleen cells and was partially purified (50-fold) using affinity chromatography. IFN alpha/beta was obtained from Newcastle disease virus-infected mouse L-cells and was partially purified (286-fold) using an AcA 202 column. IFN gamma inhibited CFU-C formation in a dose-dependent manner and was 100 times more inhibitory than IFN alpha/beta. IFN gamma completely suppressed CFU-C formation with as little as 15 units of antiviral activity. In contrast, 1000 to 2000 units of antiviral activity of IFN alpha/beta was required for complete suppression of CFU-C formation. The ability of IFN gamma to inhibit CFU-C formation was completely abolished after pH 2 treatment (24 hr), heat treatment (60 degrees C, 2 hr), or treatment with a specific antiserum against IFN gamma, which indicated that IFN gamma was the mediator of CFU-C inhibition. When IFN gamma and IFN alpha/beta were mixed together and added to bone marrow cells, they had a synergistic effect on the suppression of CFU-C formation. The level of inhibition mediated by both IFN gamma and IFN alpha/beta was totally dependent upon the amount of CSF present in the culture system; increasing the level of CSF could completely overcome the IFN suppressive effect. These results suggest that IFN gamma and IFN alpha/beta may have regulatory roles in hematopoiesis.
Characterization of a suppressive factor produced by a human T hybridoma.
Authors: Grillot-Courvalin C , Dellagi K , Chevalier A , Brouet J C
Published: December 2022

The mode of action and the target cell of a suppressive factor continuously and spontaneously produced by a human hybrid T cell line constructed recently are reported. This factor was shown to suppress pokeweed mitogen-induced B cell differentiation when added within the first 48 hr of culture. It does not suppress B cell differentiation induced by Nocardia extracts, a relatively T-independent mitogen. The target cell for this factor seems to be a T lymphocyte in that it can be absorbed by E-rosetting cells but not by B lymphocytes or monocytes. This factor does not impair mitogen or allogeneic-induced lymphocyte proliferation and has an apparent m.w. of approximately 45,000 as estimated by Sephacryl S200 gel chromatography.
Effect of recent antigen exposure on the functional expression of B cell subpopulations.
Authors: Pillai P S , Scott D W , Piper M , Corley R B
Published: December 2022

We investigated whether the definition of functional B cell subpopulations changes after the exposure of B cells to specific antigen. Recent in vivo priming with fluorescein- (FL) coupled T-independent (TI) antigens leads to an augmentation of the subsequent in vitro responses of B cells to FL-coupled TI antigens, including FL-polymerized flagellin, FL-lipopolysaccharide, and FL-Brucella abortus, as well as a FL-coupled T-dependent (TD) antigen, FL-keyhole limpet hemocyanin (KLH). This effect, which is evident 7 days after priming, is of short duration in that B cells from FL-Ficoll injected mice display normal responsiveness 3 wk after priming. When mice are primed with FL-KLH, the TD antigen, B cells responsive to a subsequent FL-KLH challenge are expanded, but not short-term cross-priming for any of the TI antigen challenges is observed. Limiting dilution precursor analysis shows that B cell populations responding to different FL-coupled TD and TI antigens overlap in unimmunized animals. FL-TI antigen priming induces not only quantitative changes in the responding B cells (increased precursor frequencies) but also results in functional changes in FL-specific B cells. The primed B cells now respond to FL-hapten in a carrier-restricted manner and behave as independent (non-overlapping) subpopulations. We suggest that B cell responses to different forms of the same hapten are influenced in part by their recent "history" of antigenic exposure.
Cellular origin of interleukin 2 (IL 2) in man: evidence for stimulus-restricted IL 2 production by T4+ and T8+ T lymphocytes.
Authors: Meuer S C , Hussey R E , Penta A C , Fitzgerald K A , Stadler B M , Schlossman S F , Reinherz E L
Published: December 2022

The human T cell subset(s) responsible for production of interleukin 2 (IL 2) was investigated in the present study. For this purpose, highly purified T4+ and T8+ T lymphocytes were stimulated with mitogens and alloantigens. Subsequently, culture supernatants were analyzed for IL 2 activity in each of two assay systems: 1) proliferation of long-term T cell lines and 2) induction of cytotoxic effector cells from a resting T8+ population incubated in MLC. Mitogen stimulation led to secretion of equivalent amounts of IL 2 from both the major T cell subsets; in contrast, after allogeneic activation, IL 2 was produced predominantly from the T4+ subset. The stimulus dependency of IL 2 production suggests that the individual functional repertoires of T4+ and T8+ T cell subsets may be linked to unique surface receptors and/or interaction molecules involved in cell triggering rather than a restricted capacity to produce lymphokine.
Antigen-specific human T lymphocyte clones: mechanisms of inhibition of proliferative responses by xenoantiserum to human nonpolymorphic HLA-DR antigens.
Authors: Lamb J R , Eckels D D , Ketterer E A , Sell T W , Woody J N
Published: December 2022

We studied the effects of xenoantiserum to human nonpolymorphic Ia-like antigens upon in vitro antigen-specific T cell proliferative responses in unfractionated PBL populations and at the monoclonal level. Our findings suggest that the xenoantiserum, although it inhibits the antigen-specific response of unfractionated PBL and allospecific T cell clones, does not inhibit the proliferative response to cloned influenza virus immune human T lymphocytes, and therefore may be mediating inhibition by dual mechanisms: direct inhibition of alloantigen recognition and induction of nonspecific suppression. Kinetic differences may explain these phenomena. In cocultivation experiments with a virus-specific clone, the RaIa antiserum appears to induce an OKT3+,8+,4-, radiosensitive regulatory subset of lymphocytes. When adoptively transferred, these induced cells inhibit the TLC response in an antigen-nonspecific and genetically nonrestricted manner. We discuss the various modes and levels of inhibition of antigen-specific proliferation by anti-Ia antisera and their multiple activities.
Interferon-mediated inhibition of human polyclonal immunoglobulin synthesis.
Authors: Fleisher T A , Attallah A M , Tosato G , Blaese R M , Greene W C
Published: December 2022

Human lymphoblastoid IFN suppressed human polyclonal Ig synthesis in a dose-related manner, with 71% mean inhibition of antibody production found when 1000 units of IFN were added to the cultures. This suppression was demonstrated to be mediated by an electrophoretically pure preparation of IFN. Furthermore, IFN inhibition of both the T-dependent and the T-independent polyclonal activators was not the result of direct cellular cytotoxicity. IFN-mediated suppression of human polyclonal Ig production does not result from induction of T suppressor cells, and in a T helper cell-independent system this inhibition appears to result from either a direct action on the B cells or an indirect effect via monocytes.
Monoclonal antibodies coupled to LPS specifically induce synthesis of immunoglobulins with complementary variable region determinants.
Authors: Primi D , Cazenave P A
Published: December 2022

The aim of this work was to investigate whether LPS coupled to monoclonal immunoglobulins would, at certain critical doses, specifically trigger B cells carrying immunoglobulins with V region complementary to that of the immunogen. Thus sera of BALB/c mice injected with 5 micrograms of LPS-M-460 contained immunoglobulins that specifically reacted with the M-460 protein. Similarly, injection of LPS coupled to a monoclonal anti-M-460 immunoglobulin F6(51) resulted in the selective production of antibodies specific for F6(51). In addition, radioimmunoassay studies clearly showed that the induced immunoglobulins reacted with F6(51) through idiotypic interactions. This immune response is independent from T cells because nu/nu responded as well as their heterologous littermates. Kinetic studies showed that the titer of F6(51) complementary antibodies in mice injected with F6(51)-LPS remained elevated for more than 1 mo, and that the majority of these immunoglobulins belong to the IgM class. Surprisingly, F6(51)-LPS induced F6(51)-specific antibodies only in mice with the Igh-a allotypic haplotype, indicating that although thymus-independent, the response is under regulation. Finally, addition of small amounts of F6(51)-LPS to cultures of B cells from BALB/c mice resulted in the secretion of antibodies capable of reacting with F6(51). These low concentrations failed to activate nonspecific cells. Consequently our data offer the possibility of selectively inducing in vivo or in vitro idiotype-positive immune responses in the complete absence of the antigen recognized by the induced immunoglobulins.
The quantitative relationship between clearance rate constants and number of C1-fixing sites.
Authors: Meryhew N L , Marsden K , Runquist O A
Published: December 2022

The rate equation correlating kinetic data for immune-mediated clearance of RBC in guinea pigs was extended to human studies. Rate constants were evaluated for clearance of IgG, IgM, and cold agglutinin-sensitized RBC in normal human volunteers as well as for clearance of IgM-sensitized cells from a small group of patients with primary biliary cirrhosis. All rate constants evaluated in the clearance of sensitized RBC were found to correlate with the number of C1-fixing sites. These correlations not only provide additional support for the mechanism from which the rate of equation was derived, but also allow a quantitative prediction of rate constants and clearance patterns based on the level of sensitization. In addition, the analysis of data from abnormal clearance studies produced rate constants that provided both identification and quantification of the specific defective reaction(s).
Arachidonic acid metabolism of the murine eosinophil. II. Involvement of the lipoxygenase pathway in the response to the lymphokine eosinophil stimulation promoter.
Authors: Rand T H , Turk J , Maas R L , Colley D G
Published: December 2022

Eosinophil stimulation promoter (ESP) is a murine lymphokine that enhances the migration of eosinophils. Exogenous arachidonic acid between 0.5 and 2 micrograms/ml potentiated the activity of ESP on murine eosinophil migration, whereas such concentrations did not affect migration in the absence of ESP. Among the lipoxygenase products identified from an enriched population of murine eosinophils, leukotriene B4 (optimal activity at 100 ng/ml) and 12-HETE (optimal activity at 2 micrograms/ml) stimulated migration of these cells. Another lipoxygenase product from these cells 15-HETE inhibited ESP-induced migration; between 5 and 10 micrograms/ml 15-HETE decreased by one-half both stimulated migration and 12-HETE biosynthesis. Structurally diverse drugs at concentrations that inhibited HETE biosynthesis inhibited ESP-induced migration. The concentrations that decreased migration activity by one-half were 5 microM NDGA, 10 microM ETYA, and 150 microM BW755C. Aspirin and indomethacin at concentrations reported to inhibit prostaglandin biosynthesis did not substantially inhibit ESP activity, but concentrations of indomethacin above 20 microM caused concentration-dependent inhibition of migration. The selective lipoxygenases inhibitor 134,7,10,13-eicosatetraynoic acid was more potent than ETYA in inhibition of ESP-induced migration, and the selective cyclooxygenase inhibitor 6,9,12-octadecatriynoic acid did not effect inhibition. These results are consistent with the hypothesis that stimulation of eosinophils by the lymphokine ESP involves the generation of lipoxygenase products from arachidonic acid, which positively and negatively regulate the migratory activities of these cells.
Functional activity in vivo of effector T cell populations. I. Antitumor activity exhibited by allogeneic mixed leukocyte culture cells.
Authors: Engers H D , Sorenson G D , Terres G , Horvath C , Brunner K T
Published: December 2022

The in vivo activity of murine cytolytic T lymphocyte-containing effector cell populations generated in vitro was studied in a tumor allograft model system by monitoring the elimination of 131I-IUdR-labeled tumor cells with whole-body counting techniques. Mice were irradiated sublethally and 16 hr later 131I-labeled tumor cells were injected either subcutaneously or i.p. Simultaneously, graded doses of various effector cell populations were injected i.v. and the mice were counted daily to assess the potential elimination of the radiolabeled tumor cells. Thus, allogeneic 2 degrees mixed leukocyte culture cells were observed to eliminate allogeneic but not syngeneic tumor cells in a dose-dependent manner, with as few as 0.2 x 10(6) effector cells causing significant destruction of 2 x 10(6) allogeneic tumor cells. The protective effect of the mixed leukocyte culture cells was considerably reduced when Lyt-2+-bearing lymphocytes were eliminated by treatment with monoclonal antibody plus complement. In additional experiments, Lyt-2+ lymphocytes positively selected by enrichment on antibody-coated petri dishes gave efficient protection, in the absence of Lyt-2- cells. Surprisingly, when several different cloned, specific, long-term allogeneic cytolytic T cells lines were injected either i.p. of i.v., tumor cell destruction was observed only after i.p. injection.
Generation of a cloned NK cell line derived from the "null cell" fraction of human peripheral blood.
Authors: Hercend T , Meuer S , Reinherz E L , Schlossman S F , Ritz J
Published: December 2022

The present studies were designed to determine the conditions for generation of human NK clones. First the "null cell" (NC) fraction of human peripheral blood mononuclear cells, which contains the NK effectors, was purified using negative selection with anti-T3, anti-T8, anti-B1, and anti-Mo2 monoclonal antibodies. Subsequently, NC were cloned by limiting dilution using a combination of phytohemagglutinin (PHA) and lymphocyte-conditioned medium (LCM) as an initial stimulus. Colonies could be easily obtained with this procedure, but the maintenance of long-term growth of the cultures represented a major problem. A cloned cell line termed JT1 was generated and has been proliferating continuously in culture for more than 6 mo. The phenotype of JT1 cells was analyzed several times with a series of monoclonal antibodies. These cells did not express surface markers related to thymic (T3-, T4-, T8-, T11-), B cells (B1-, J5-), or myelomonocytic (Mo1-, Mo2-, MY7-) differentiation. In contrast, 95% of JT1 cells reacted with the anti-T10 monoclonal antibody. T9, Ia, and J2 antigens were also present on JT1 cells, but their expression appeared variable from one determination to another. This cloned cell line maintains a strong cytotoxicity against common NK targets, such as K562 and Molt 4 cell lines, and a moderate ADCC activity. In addition, after several months in culture, JT1 cells are still capable of being regulated by interferon, because this lymphokine rapidly enhances cytotoxicity against K562 cells.
Serologically detectable MHC and tumor-associated antigens on B16 melanoma variants and humoral immunity in mice bearing these tumors.
Authors: Baniyash M , Smorodinsky N I , Yaakubovicz M , Witz I P
Published: December 2022

We compared the expression of serologically detectable MHC and tumor-associated antigens on low and high metastasis variants of B16 melanoma tumor. Complement-dependent cytotoxicity, radioimmunobinding, and quantitative absorption assays showed that with respect to both types of antigens the low metastasis variant B16-F1 expressed a higher serologically detectable antigenicity than B16-F10, its high metastasis counterpart. A reverse situation existed in terms of in vivo immunogenicity of these metastasis variants. Sera from C57BL/6 mice bearing locally growing B16-F10 tumors had a higher binding activity to B16 cells than sera from B16-F1 bearers. Accordingly, in vivo propagating B16-F10 tumors had a higher content of tumor-associated Ig than B16-F1 tumors.
LPS-induced differentiation of a murine B cell leukemia (BCL1): changes in surface and secreted IgM.
Authors: Lafrenz D , Koretz S , Stratte P T , Ward R B , Strober S
Published: December 2022

We examined the effect of LPS-induced differentiation on surface and secreted IgM in a cloned BCL1 in vitro cell line. Incubation of this cell line with LPS resulted in a decrease in the amount of membrane IgM, measured by both immunofluorescence and immunoprecipitation, and an increase in IgM secretion, measured by plaque-forming cells (PFC). Activation to high rate secretion was independent of cell cycle in synchronized cells and was independent of DNA synthesis because PFC formation was not inhibited by hydroxyurea. Almost all cells in the in vitro line were shown to contain large quantities of intracytoplasmic IgM before LPS activation. Thus, it would appear that the in vitro cell line represents a partially activated stage of differentiation compared to normal resting B cells or to the in vivo line of BCL1. Analysis of the two forms of mRNA coding for membrane and secreted IgM showed that, at least for cells at the level of differentiation examined here, the control of membrane IgM expression is post-transcriptional. The differentiation of resting B cells to the plasma cell level appears to consist of multiple stages of differentiation. The present data suggest that LPS provides at least two signals of activation. One induces the resting cell to synthesize cytoplasmic IgM, increase surface IgM, and to begin cell division. The second induces the secretion of intracytoplasmic IgM associated with a decrease in surface IgM.
Local adoptive transfer of skin delayed-type hypersensitivity initiated by a single T lymphocyte.
Authors: Marchal G , Seman M , Milon G , Truffa-Bachi P , Zilberfarb V
Published: December 2022

In vivo primed T cells injected in the footpad of naive recipients elicit a typical delayed-type hypersensitivity (DTH) reaction in the presence of their specific antigen. The values of the footpad swelling obtained after these transfers show a clear distinction between negative and positive responses. Serial dilutions of primed T cell populations allow the establishment of titration curves by limiting dilution analysis according to Poisson distribution. The single hit titration curve indicates that a unique cell type underlies the DTH reaction. Furthermore, by using cloned T cells it can be demonstrated that the transfer of a single cell is able to initiate a DTH reaction. The revelation of T cell activity at unit level needs an optimal dose of antigen mixed with the sampled cells.
Neonatal suppression with anti-Ia antibody. I. Suppression of murine B lymphocyte development.
Authors: Fultz M J , Scher I , Finkelman F D , Kincade P , Mond J J
Published: December 2022

To investigate the role of sIa in B lymphocyte development, mice were injected from birth with hybridoma anti-Ia antibody. There was on the average a 95% reduction in the number of sIgD+ cells, and 85% diminution in the number of sIgM+ cells, a small but significant increase in the number of sIgM+ sIgD- sla- B cells, as well as a dramatic increase in the number of sIgM- cells bearing a B lineage antigen. Exposure of cells to high doses of anti-Ia antibody in vitro or in vivo for 24 hr did not affect the number of sIg+ lymphocytes. Thus, it appears that chronic anti-Ia administration critically alters normal B lymphocyte development.
Regulation of rat B cell responses by T cell subsets and interleukin 2.
Authors: Rosenberg J S , Gilman S C , Feldman J D
Published: December 2022

T cell and interleukin 2 (IL 2) regulation of two phases of B cell activation, 3H-TdR uptake and differentiation to antibody-forming cells, were examined. Monoclonal antibody specific for rat kappa light chains (Mab alpha K) stimulated 3H-TdR uptake in vitro in B cell fractions of Lewis spleen cell populations in the presence of T cells and macrophages (M phi); IL 2 reconstituted the response in enriched B cell cultures depleted of T cells and M phi. When IL 2 was added to primary in vitro cultures, spleen cells yielded 100 to 400 anti-SRBC PFC/culture; no PFC were recorded in the absence of IL 2. These results suggested that IL 2 served as a " second signal" for activation in responsive B cell populations. When monoclonal antibody specific for the W3/25+ T cell subset (Mab W3/25) was incorporated into the assay system, both 3H-TdR uptake and PFC responses were inhibited. IL 2 enhancement of B cell responses or responses of reconstituted B cell and T cell fractions was eliminated in the presence of Mab W3/25, indicating that IL 2 mediation of B cell responses was due in part to participation of W3/25+ T cell helper function. In contrast, monoclonal antibody directed to the OX8-bearing T cells (Mab OX8) had no effect on B cell responses. W3/25+ T cells provided helper activity in the generation of a PFC response, whereas OX8+ cells suppressed the antibody response. W3/25+ T cells responded to antigenic stimuli in the presence of IL 2 by undergoing increased blast transformation. OX8+ cells did not exhibit any response. These data define a regulatory network by which T cells, IL 2, and B cells interact to produce in vitro DNA synthesis and antibody formation in activated rat B cells.