bluuebunny/crossref_metadata_2025 huggingface dataset:
Further evidence against random polyclonal antibody formation in mice with lupus-like graft-vs-host disease.
Authors: van Rappard-Van der Veen F M , Kiesel U , Poels L , Schuler W , Melief C J , Landegent J , Gleichmann E
Published: December 2022

The pathologic symptoms in F1 mice with chronic graft-vs-host disease (GVHD) (GVH F1) strongly resemble those of systemic lupus erythematosus (SLE). Mice with SLE-like GVHD do not produce antibodies to a number of non-self and self antigens. This finding is inconsistent with the widely accepted view that the (auto)-antibody formation in SLE is polyclonal in the sense that B cells are triggered at random, i.e., irrespective of their specificity. In the present study, therefore, we performed a systematic study of the kinetics of total IgM- and IgG-secreting splenic B cells and tested their specificities. The total IgM-secreting B cell population was increased only in the first week after the initiation of SLE-like GVHD; it seemed to reflect a random, but self-limited, polyclonal B cell stimulation. In contrast, the total number of IgG-secreting cells in the GVH F1 mice was increased to a much higher extent than that of the IgM-secreting cells and remained increased. At no time during GVHD was there an increase in the number of plaque-forming cells (PFC) spontaneously secreting IgG antibodies to non-self antigens. The GVH reaction (GVHR) did, however, lead to the appearance of PFC that secreted IgG antibodies to DNA. Similarly, the GVH F1 mice showed high serum titers of antibodies to self antigens characteristic of SLE and to endogenous viruses, but during the entire observation period they failed to develop serum antibodies to non-self antigens and insulin. Hence, the enhanced production of Ig, especially that of IgG, that occurs in SLE-like GVHD is not a random process, because it requires the presence of antigen, or signal 1. The data support our hypothesis that only certain kinds of self antigen, such as DNA and cell membrane epitopes, can cross-link the Ig receptors on the corresponding B cells and thus provide an adequate signal 1. Given the increase in help, or signal 2, in chronic GVHD, only the B cell clones that simultaneously receive an adequate signal 1 seem to be driven into clonal proliferation and IgG secretion.
Changes in Ia expression in mouse kidney during acute graft-vs-host disease.
Authors: Wadgymar A , Urmson J , Baumal R , Halloran P F
Published: December 2022

We induced graft-vs-host disease (GVHD) in mice to determine whether immunologic stimuli could alter renal Ia expression. Two strain combinations were used: B6.C-H-2bm12 into C57BL/6, an I-A mutation difference, and A.SW into A.TL, differing in the I and D regions of H-2. By day 10 after allogeneic reconstitution of lethally irradiated recipients with bone marrow and spleen cells, the recipients had developed acute GVHD, as measured by their spleen to body weight ratio. Histologic examination revealed focal interstitial infiltrates of mononuclear cells in the kidneys. The expression of host Ia in these kidneys was increased up to 10-fold, as measured by absorption, and indirect immunofluorescence indicated that certain renal tubule cells had become strongly positive, suggesting that these were the principal sites of the increase in Ia expression. Similar increases were not observed in donor Ia. Tubule cells may have become Ia positive by passive uptake, or more probably, by the increase of Ia biosynthesis in cells that usually synthesize little or no Ia. Lethal irradiation without reconstitution tended to decrease renal Ia expression, as assessed by absorption and immunofluorescence. The results indicate that renal Ia expression, particularly in renal tubules, can be altered by changes in the immune system, raising the possibility of a role for such altered Ia expression in autoimmune or alloimmune responses involving the kidney.
Human B cell-inducing factor(s) for production of IgM, IgG and IgA: independence from IL 2.
Authors: Ralph P , Welte K , Levi E , Nakoinz I , Litcofsky P B , Mertelsmann R H , Moore M A
Published: December 2022

Human peripheral blood B cells are stimulated into proliferation by killed Staphylococcus aureus bacteria strain Cowan I (Sac). T lymphocytes in the presence of a T cell mitogen induce high numbers of immunoglobulin-secreting cells (ISC) in these Sac-stimulated B cells. The T cells can be largely replaced by a lymphokine factor. We describe here the 11000-fold purification of this B cell-inducing factor (BIF). BIF preparations that are free of IL 2 do not require IL 2 for optimal induction of ISC. This was shown by the lack of effect of IL 2 alone or with suboptimal or optimal concentrations of BIF on the induction of ISC and by the absence of IL 2 production in the purified B cell population which, with other controls, excludes significant T cell contamination. BIF, purified through four fractionation steps and free of IL 2, induces IgM, IgG, and IgA-ISC in approximately the same ratio as unfractionated lymphokine. Because we have not yet attained a pure BIF preparation, the possibility of separate factors for the production of each immunoglobulin isotype cannot be ruled out.
Evidence for specific receptors for interleukin 3 on lymphokine-dependent cell lines established from long-term bone marrow cultures.
Authors: Palaszynski E W , Ihle J N
Published: December 2022

Utilizing 125I-labelled IL 3, an assay for specific IL 3 receptors on continuous cell lines was developed. The 32D-cl 23 and FDC-P1 cell lines examined were originally derived from long-term cultures of murine bone marrow supplemented with WEHI-3-conditioned media. Both of these cell lines have been shown to be absolutely dependent on IL 3, a component of WEHI-3-conditioned media, for growth in vitro. The binding of radiolabeled IL 3 to these cells was found to be specific, saturable, reversible, and time and temperature dependent. The specificity of IL 3 binding was demonstrated by the failure of a number of different lymphokines, hormones, and proteins to compete for the binding of radiolabeled IL 3. The IL 3-dependent cell lines uniquely express detectable receptors, whereas other cell lines of various types and origin known to be IL 3 independent had no detectable specific binding of IL 3. A Kd of 5.4 X 10(-11) M and a maximum binding capacity of 6.25 fmol per 1 X 10(6) cells was calculated for 32D-cl 23 from equilibrium binding studies. A similar analysis for FDC-P1 yielded a Kd of 1.7 X 10(-11) and a maximum binding capacity of 1.2 fmol per 1 X 10(6) cells. The data are consistent with the presence of 4000 to 5000 specific high-affinity binding sites/cell on 32D-cl 23, whereas FDC-P1 has 1500 to 2500 specific sites/cell. The Kd calculated for the FDC-P1 cell line from kinetic binding data was 2.5 X 10(-11) M, which agreed well with the Kd of 1.7 X 10(-11) M calculated from equilibrium data.
Chromatographic separation from known cytokines of a helper factor necessary for the generation of murine cytolytic T lymphocytes.
Authors: Garman R D , Taku A , Fan D P
Published: December 2022

A helper factor (CHF) necessary for the generation of primary allospecific CTL using BALB/c (H-2d) responder spleen cell and x-irradiated RDM4 (H-2k) stimulator tumor cells was obtained from cultures of mouse spleen cells stimulated for the production of secondary anti-Sendai virus CTL and fractionated by gel filtration chromatography to obtain a 30,000 m.w. species (CHF30). DEAE-cellulose chromatography separated CHF activity from the majority of interleukin 1 (IL 1), interleukin 2 (IL 2), granulocyte-macrophage colony-stimulating factor (CSF), and interferon (IFN). Interleukin 3 (IL 3) and CHF co-eluted when this procedure was used. Reverse-phase high performance liquid chromatography (HPLC) of CHF30 with a variety of elution conditions allowed the separation of CHF activity from IL 1, IL 2, IL 3, CSF, and IFN. IL 3 and CSF in the CHF30 preparation were stable at 80 degrees C for more than an hour, whereas CHF activity decreased rapidly during the first 10 min of incubation. Trypsin treatment of the same material showed that CHF activity was resistant to digestion for 40 min, whereas IL 3 and CSF lost most of their activities during the first 5 min of incubation. These results indicate that CHF activity is mediated by molecules biologically and biochemically distinct from the well characterized cytokines.
Triggering of affinity-enriched B cells. II. Composition and B cell triggering properties of affinity-purified, antigen-specific, T cell-derived helper factor.
Authors: Shiozawa C , Sawada S , Inazawa M , Diener E
Published: December 2022

Antigen-specific, T cell-derived helper factor (ASHF), recognizing alloantigens on chicken red blood cells (CRBC), had previously been shown to trigger an IgM anti-CRBC response in vitro by 2 X 10(3) affinity-enriched B cells. Triggering signals for B cell proliferation were shown to be substituted by ASHF or lipopolysaccharide, and signals for differentiation to IgM production by Thy-1+ cells. In an effort to demonstrate unequivocally antigen specificity of helper factor, secretory products and cell extracts from helper T cells that had been primed by either the B2 or the B13 chicken alloantigens, were purified by antigen affinity and ion exchange chromatography. With each step of purification, antigen-specific biologic activity of ASHF-containing material increased such that ASHF from B2, but not B13, primed helper T cells would help trigger a B2, but not a B13, -specific response and vice versa. Gel filtration of ASHF suggests it to have a m.w. of at least 50,000. Absorption studies showed that ASHF binds to B cells in the absence of antigen. Delivery of the triggering signal requires ASHF to bind simultaneously to both, the cell surface and the antigen. ASHF consists of at least two subunits that may be separated from each other by chelating agents. This yields two biologically inactive fractions, only one of which binds to the nominal antigen. Upon recombining them in the presence of Ca++, full biologic activity is restored.
A human Ia cytoplasmic determinant located on multiple forms of invariant chain (gamma, gamma 2, gamma 3).
Authors: Quaranta V , Majdic O , Stingl G , Liszka K , Honigsmann H , Knapp W
Published: December 2022

An antigenic determinant present in the cytoplasm, but not on the surface membrane of human Ia+ cells, is defined by a monoclonal antibody (VIC-Y1) and is shown by immunoprecipitation and by NEPHGE to be expressed by Ia oligomers. Immunoprecipitations of cellfree translates and of purified Ia subunits indicate that the VIC-Y1 determinant is located on the Ia gamma-(invariant) chain, as well as on two other related molecules, provisionally termed gamma 2 and gamma 3. Within our experimental conditions, the three forms of gamma-chains co-precipitate exclusively with Ia oligomers. As detected by VIC-Y1 and in the limits of our assays, gamma-chains could not be found at the cell surface; their tissue distribution, determined by cytoplasmic indirect immunofluorescence with VIC-Y1, closely resembles that of Ia antigens, with the possible exception of acute lymphatic leukemia cells (Ia+, gamma-chain-).
Induction of "latent a2" allotype in a1a1 homozygous rabbits as the major part of a bidirectional immune response to immunization with anti-a2 antibody.
Authors: Kazdin D S , Gilman-Sachs A , Dray S , Horng W J
Published: December 2022

Previously, we induced Ab to a common idiotypic specificity (IdC) of rabbit anti-a2 VH Ab. We observed then that some of the putative anti-IdC Ab molecules induced by immunizing a1a1 rabbits with anti-a2 Ab did not have the expected nominal allotypic markers (a1, x32, or y33) characteristic of the genotype of the immunized rabbits. Thus, immunization of a1 a1 rabbits with a1 anti-a2 Ab induced population of molecules that reacted with anti-a2 Ab but bore an unidentified (unknown) VH region marker. The following observations indicate that these molecules bear a "latent a2" allotypic marker: (a) when the unknown VH molecules were used to immunize a1 a1 and a3 a3 rabbits, anti-a2 Ab was produced; (b) when an a2 a2 rabbit was immunized with the same preparation of unknown VH molecules, an anti-idiotypic Ab was produced; and (c) when the unknown VH molecules were used to inhibit the binding of labeled a2 IgG to anti-a2 Ab, the inhibition curve obtained was essentially the same as that obtained by using normal a2 IgG. Thus, immunization of a1 a1 rabbits with a1 anti-a2 Ab provided a bidirectional stimulus to produce both nominal "a1" anti-IdC Ab and a "latent a2" allotype. The distribution of nominal to latent allotypes induced ranged from 3% nominal/92% latent to 57% nominal/23% latent. In absolute terms, the maximum amount of "latent a2" molecules was 1.18 mg/ml of serum, which far exceeds the amount of latent allotype described by others (0.3 mg/ml of serum). The effective induction of large amounts of "latent a2" allotype may have resulted from a simultaneous stimulation of an idiotope and a paratope on the surface of the "latent a2"-producing cells.
Immunoglobulin light chain classes in a teleost fish.
Authors: Lobb C J , Olson M O , Clem L W
Published: December 2022

Analysis of predominant, approximately 700,000 dalton serum antibody (Ab) of the channel catfish by SDS-PAGE revealed only one molecular mass species of heavy (H) chain (approximately 70,000 daltons), whereas a marked heterogeneity in the relative mobilities of the light (L) chains was evident. Three molecular mass L chain variants of approximately 26,000, approximately 24,000, and approximately 22,000 daltons were observed. The relationships between the L chain variants were not clear until mouse monoclonal Ab (mAb) reactive with catfish immunoglobulin (Ig) were developed. Two of these mAb, designated 3F12 and 1G7, were found to independently recognize different populations of catfish Ig. In addition, when these two mAb were used in combination they immunoprecipitated greater than 95% of specifically purified catfish anti-DNP or anti-fluorescein Ab. The L chains of catfish Ig recovered from immunoabsorbent affinity matrices conjugated with either mAb 3F12 or 1G7 were found to be clearly distinct. Monoclonal Ab 3F12 reacted with a subpopulation of catfish Ig that contained the approximately 24,000 and approximately 22,000 dalton L chain variants, whereas mAb 1G7 reacted with another subpopulation of catfish Ig that contained only the approximately 26,000 dalton L chain variant. Solid phase plate binding assays with the use of mildly reduced catfish Ig H and L chains showed that both of these mAb preferentially reacted with catfish L chains. Subsequent analysis of the two antigenically distinct L chain populations by peptide mapping procedures demonstrated that these L chains were structurally different. Furthermore, analysis of the serum from individual catfish showed the presence of both L chain types in each of 25 catfish examined. These studies strongly suggest that distinct L chain classes have evolved in fish.
The mechanism of intercellular aggregation. I. The kinetics of the Fc gamma receptor-mediated aggregation of P388D1 cells with antibody-coated lymphocytes at 4 degrees C.
Authors: Segal D M , Stephany D A
Published: December 2022

The formation of specific, heterophilic conjugates between cells from the P388D1 mouse macrophage line and antibody-coated mouse spleen cells was followed in cell suspensions at 4 degrees C by dual parameter flow cytometry. Intercellular aggregation in this system is mediated by the binding of the Fc portions of IgG antibodies on the spleen cells with Fc receptors (Fc gamma R) on P388D1. We show that the rate of aggregation reaches a plateau with increasing cell concentrations, suggesting that the initial collision between cells is not the rate limiting step of conjugate formation. The rates of aggregation are strongly dependent upon the cell surface densities of both Fc gamma R and antibody. In conjugates, however, only small fractions of available receptors or antibodies are utilized in bond formation. The rate-limiting step of aggregation, therefore, involves the formation of ligand-receptor bonds, and may be the diffusion of antibodies and receptors toward one another in small areas of intercellular contact. Inhibitor studies implicate microfilaments, but not microtubules, divalent cations, or energy-dependent processes as being important in aggregation. Finally, conjugates are stable when diluted into medium alone, but dissociate in media containing protein A, soluble immune complexes, or anti-Fc gamma R antibodies. This suggests that conjugates are stabilized by multiple intercellular ligand-receptor bonds, which constantly break and reform at the cell:cell interface, and that protein A, immune complexes, and anti-Fc gamma R disaggregate the conjugates by preventing the reformation of broken bonds.
Glycosaminoglycan profiles in cloned granulated lymphocytes with natural killer function and in cultured mast cells: their potential use as biochemical markers.
Authors: Bland C E , Rosenthal K L , Pluznik D H , Dennert G , Hengartner H , Bienenstock J , Metcalfe D D
Published: December 2022

Proteoglycans from three cloned, granulated lymphocyte cell lines with natural killer (NK) function (NKB61A2, HY-3, H-1) and one mast cell line (PT-18) were labeled with [35S]sulfate. [35S]proteoglycans were extracted in 1 M NaCl with protease inhibitors to preserve their native structure and were separated from unincorporated [35S]sulfate by Sephadex G-25 chromatography. [35S]proteoglycans from all four cell lines were chromatographed over Sepharose 4B and were found to have a similar range of m.w. The [35S]glycosaminoglycans from each cell line were then separated from parent proteoglycans by treatment with 0.5 M NaOH. The [35S]glycosaminoglycans from the three lymphocyte cell lines exhibited a similar m.w. as assessed by Sepharose 4B gel filtration, whereas the [35S]glycosaminoglycans from the mast cell line chromatographed as a smaller m.w. molecule. [35S )glycosaminoglycan charge characteristics were evaluated with DEAE C1-6B ion exchange chromatography. The consistency of the elution patterns was determined by using [35S]glycosaminoglycans obtained from radiolabelings of each cell line separated by 6 mo in culture. Each NK lymphocyte cell line reproducibly produced two distinct [35S]glycosaminoglycan chains that eluted in two regions well before the commercial heparin marker. The proportions of each chain were dependent upon the specific cell line. The mast cell line produced a single [35S]glycosaminoglycan chain, which eluted overlapping the internal commercial heparin marker, consistent with its higher charge characteristics. [35S]glycosaminoglycans from all cell lines were identified as chondroitin sulfates with the use of specific polysaccharidases. The NK lymphocyte glycosaminoglycans contained chondroitin 4-sulfate disaccharides. The mast cell glycosaminoglycans contained oversulfated disaccharides and chondroitin 4-sulfate disaccharides. Thus, each granulated NK lymphocyte cell line produced chondroitin sulfate glycosaminoglycans that were characteristic of that cell line and of different composition and less charge than those produced by cultured mast cells. These findings demonstrate that glycosaminoglycan profiles are useful biochemical markers in the characterization of diverse granulated cell lines including NK lymphocytes and mast cells.
The antibody specific to type 1 chain blood group A determinant.
Authors: Abe K , Levery S B , Hakomori S
Published: December 2022

Two monoclonal antibodies directed to the blood group A determinant have been established. One hybridoma antibody (AH16), obtained on immunization with human gastric cancer cell MKN45, was directed to the blood group A determinant carried by both type 1 and type 2 chains. The other antibody (AH21) was prepared by immunization with a purified type 1-chain A glycolipid, followed by selection of the hybridoma by positive reaction with the type 1, but negative reaction with the type 2-chain A glycolipid. Thus, the antibody specifically reacts to the A determinant carried by the type 1 chain, but not to the A determinant carried by the type 2 chain; an A determinant carried by type 1 chain differs significantly from that carried by type 2 chain in its conformational structure. The antibody AH16 agglutinates both A1 and A2 human erythrocytes, but AH21 agglutinates neither A1 nor A2 erythrocytes, which supports the results of methylation analysis that blood group A and H determinants in human erythrocytes are exclusively made of the type 2 chain and that A1 and A2 phenotypes are not related to the difference between type 1 and type 2 chains.
Arachidonic acid metabolism in purified human lung mast cells.
Authors: Peters S P , MacGlashan D W , Schulman E S , Schleimer R P , Hayes E C , Rokach J , Adkinson N F , Lichtenstein L M
Published: December 2022

Arachidonic acid metabolism has been explored in preparations of purified human lung mast cells prelabeled with arachidonic acid (AA). Cells were of 83 to greater than 96% purity, and each experiment was performed with four to six different preparations of mast cells. After overnight culture of the purified cells in the presence of 3H-AA, followed by extensive washing in buffer, mast cell uptake of labeled AA was 61.4 +/- 14.8 pmol/10(6) cells with 21 +/- 2.4% of the label in phospholipids, 73 +/- 2.1% in neutral lipids, and 3.6 +/- 0.8% as free AA. Analysis of the distribution of radioactivity in phospholipid classes revealed 51.4 +/- 5.5% of the label in phosphatidylcholine, 14.5 +/- 1.6% in phosphatidylinositol, 12.0 +/- 3.0% in phosphatidylethanolamine, and 9.1 +/- 2.4% in sphingomyelin, with the rest in other phospholipid classes. Challenge of these cells with an optimal concentration of anti-IgE led to the release of 20 +/- 4.0% of cellular histamine and to a reduction in labeled phosphatidylcholine and phosphatidylinositol to 75.5 +/- 8.8% and 84.2 +/- 4.5% of the control levels, respectively, (p less than 0.05); anti-IgE challenge produced no statistically significant change in the quantities of other labeled phospholipids. Activation of human lung mast cells with anti-IgE led to the release of 3.4 +/- 1.3% of the cellular 3H as AA and AA metabolites (1.5 +/- 0.6% as unmetabolized AA) in conjunction with 16 +/- 4.3% of the cellular histamine. Although activation of human lung mast cells with ionophore A23187 caused 70 +/- 1.1% histamine release, a similar quantity of AA and AA metabolites was released (a total of 4.0 +/- 0.8% with 2.3 +/- 1.5% as unmetabolized AA). Analysis of the released metabolites by liquid scintillation spectrometry after high performance liquid chromatography separation showed that approximately equal amounts of metabolites were produced after mast cell activation with anti-IgE and ionophore A23187. In this series of experiments approximately equal amounts of cyclooxygenase and lipoxygenase products were generated.(ABSTRACT TRUNCATED AT 400 WORDS)
Induction of chemiluminescence during interaction of tumoricidal effector cell populations and tumor cells is dependent on the presence of mycoplasma.
Authors: Köppel P , Peterhans E , Bertoni G , Keist R , Groscurth P , Wyler R , Keller R
Published: December 2022

A variety of host cells, such as activated macrophages, natural killer (NK) cells, and polymorphonuclear leukocytes (PMNL), are cytotoxic for an array of non-antibody-coated tumor cells. Because such effector cells appear to use oxygen-dependent mechanisms to effect tumor cell destruction in certain systems, the possibility of an involvement of toxic oxygen species has been considered. To investigate whether interaction of effector cells with neoplastic cells induces the generation of reactive oxygen species, resting and activated rat macrophages and rat spleen cells (as a source of NK activity) were exposed to viable tumor cells of varied origin, and chemiluminescence was monitored. This sensitive indicator of reactive oxygen generation was stimulated only when tumor cells or culture supernatants were contaminated with mycoplasma. Mycoplasma-free tumor cells and culture supernatants were in no case able to trigger chemiluminescence in any of these effector cell populations. On the other hand, tumor targets were equally susceptible to killing by effector cells irrespective of whether mycoplasma were present. The data suggest that generation of chemiluminescence during interaction of natural cytotoxic cells and neoplastic cells is an artifact and that reactive oxygen species do not function as an effector mechanism in antibody-independent natural killing effected by activated macrophages and NK cells.
Susceptibility of Giardia lamblia trophozoites to the lethal effect of human serum.
Authors: Hill D R , Burge J J , Pearson R D
Published: December 2022

To define the potential role of complement and antibody in host defense against Giardia lamblia, the effect of human serum on axenically cultured G. lamblia trophozoites was studied. Sera from patients without a history of giardiasis and with no detectable antibody by an indirect immunofluorescence antibody (IFA) assay (IFA titers less than 1:2) killed from 8 to 76% of trophozoites (n = 23 sera). Whereas less than 10% of parasites incubated in phosphate-buffered saline alone were killed, 16 sera killed from 10 to 25% and six sera killed from 25 to 75%. One serum with an anti-G lamblia antibody titer of 1:128 killed greater than 98% of the parasites. The complement dependency of killing was demonstrated by abrogation of the lethal effect when serum was chelated with EDTA (7 mM) or was heat-inactivated (56 degrees C, 30 min), and, in an immunofluorescence assay, by detection of C3 on parasites killed by normal serum. When the classical complement pathway was selectively blocked by using serum chelated with Mg+2 (2 mM)-EGTA (8 mM), or serum congenitally deficient for the second component of complement, there was no killing; thus, killing was dependent on the presence of an intact classical pathway. In each of three sera from donors with negative IFA titers, an absorbable factor specific for G. lamblia, possibly antibody not detected by IFA, was required for classical pathway activation. To determine if alteration of the surface of G. lamblia would render it an activator of the alternative pathway of complement, trophozoites were studied after cell death or after treatment with neuraminidase or trypsin. In MgEGTA-chelated serum, dead trophozoites activated the alternative pathway as determined by consumption of Factor B and deposition of C3 on their surface. In contrast, untreated or enzyme-treated living parasites did not activate the alternative pathway.
Topologic mapping of protective and nonprotective epitopes on the variant surface glycoprotein of the WRATat 1 clone of Trypanosoma brucei rhodesiense.
Authors: Hall T , Esser K
Published: December 2022

Monoclonal antibodies were used in competitive antibody binding assays to define and map epitopes on the variant surface glycoprotein of the WRATat 1 clone of T. b. rhodesiense. By using a panel of 30 WRATat 1-specific monoclonal antibodies, 16 epitopes were defined that fall into four clusters, having 1, 1, 3, and 11 distinct epitopes respectively. All epitopes were easily classified as being 1) exposed uniformly on the surface of the trypanosome, 2) exposed only in the region of the flagellar pocket, or 3) "buried", based on the ability or inability of the monoclonal antibodies to bind living trypanosomes in a fluid phase immunofluorescence assay. Monoclonal antibodies that bind exposed surface epitopes are protective, whereas only three of seven that bind exclusively to flagellar pocket epitopes are protective. None of the nine monoclonal antibodies that recognize buried epitopes are protective. Also, antibody-mediated immunity to WRATat 1 trypanosomes is not associated with any particular subclass of antibody. The IgM, IgG1, IgG2a, IgG2b, IgG3, and IgA subclasses each contain examples of protective monoclonal antibodies.
Adoptive immunotherapy of established syngeneic solid tumors: role of T lymphoid subpopulations.
Authors: Rosenstein M , Eberlein T J , Rosenberg S A
Published: December 2022

We have investigated the subpopulations of T cells necessary to mediate the cure of established tumors in two models of successful adoptive immunotherapy. In C57BL/6 mice bearing palpable and disseminated FBL-3 lymphoma, both Lyt-1+ and Lyt-2+ cells played a major role in mediating the regression and permanent cure of mice, whereas in BALB/c mice bearing the Meth A sarcoma the adoptive transfer of Lyt-1+2+ cells played a major role in mediating the regression of tumors and the curing of disease. Identical experiments performed in hybrid (BALB/c X C57BL/6) mice yielded similar results, further supporting our initial observation and indicating that in these two adoptive transfer model systems it is the tumor and not the variable expression of Lyt antigens by the host that determines which T cell subpopulation is required to cure mice of tumors.
Separation and isolation of rat natural killer (NK) cells from T cells with monoclonal antibodies.
Authors: Woda B A , McFadden M L , Welsh R M , Bain K M
Published: December 2022

It has been difficult to clearly differentiate rat NK cells from cytotoxic T cells. In this study we have shown that rat NK cells do not express the T cell protein defined by the OX 19 antibody. By using the FACS we have isolated the OX 19- OX 8+ lymphocyte subset that contains virtually all the NK activity. The simultaneous use of the OX 19 and OX 8 antibodies allows the separation of NK cells from T cells.
Interleukin 2 administered in vivo induces the growth of cultured T cells in vivo.
Authors: Cheever M A , Greenberg P D , Irle C , Thompson J A , Urdal D L , Mochizuki D Y , Henney C S , Gillis S
Published: December 2022

The capacity of exogenous IL 2 to induce the growth of antigen-activated T lymphocytes in vivo was evaluated. The in vivo growth of adoptively transferred T lymphocytes that had been previously cultured long-term with IL 2 was initially examined, because in vitro such T cells are exquisitely dependent upon exogenous IL 2 for proliferation and survival. Daily administration of IL 2 in vivo, beginning on the day of cell transfer, induced these IL 2-dependent long-term cultured T lymphocytes to proliferate in vivo, and the magnitude of in vivo growth was proportional to the dose of IL 2 administered. The capacity of IL 2 to induce the in vivo growth of antigen-activated T cells not previously exposed in vitro to exogenous IL 2 was similarly studied. T lymphocytes from the spleens of immune mice, activated by 5-day culture with tumor antigen before transfer, survived poorly in vivo when injected with antigen alone, but demonstrated marked proliferation in vivo in response to antigen and exogenous IL 2. By contrast, immune spleen cells transferred with antigen, but without prior culture, proliferated without supplementary exogenous IL 2. Moreover, the growth of noncultured donor T cells was not augmented by the administration of exogenous IL 2, implying that noncultured spleen cells immune to tumor antigens can produce sufficient amounts of endogenous IL 2 in vivo to sustain maximal T cell growth over the time period examined. Importantly, the ability of exogenous IL 2 to induce donor T cell growth in vivo correlated with its ability to function in vivo to augment the anti-tumor efficacy of specifically immune donor T cells in models for the adoptive therapy of disseminated antigenic murine leukemia. Thus, the current studies highlight the potential of exogenous IL 2 to induce T cell growth in vivo and suggest that the administration of IL 2 in vivo may be useful for augmenting T cell responses that are relatively deficient in the production of endogenous IL 2.
Dual parameter flow cytometric analysis of DNA content, activation antigen expression, and T cell subset proliferation in the human mixed lymphocyte reaction.
Authors: Williams J M , Loertscher R , Cotner T , Reddish M , Shapiro H M , Carpenter C B , Strominger J L , Strom T B
Published: December 2022

This study provides direct correlation via dual parameter flow cytometry (simultaneous assessment of immunofluorescence and DNA content) between mixed lymphocyte reaction (MLR) responder cell entry into the S/G2/M phases of the cell cycle with the kinetics of expression of two activation-associated cell surface proteins, Tac (IL 2 receptor) and 4F2 (unknown metabolic function). A small population of activated cells was identifiable by expression of both Tac and 4F2 antigens before peak DNA synthesis in the MLR. This population of activation antigen-positive cells expanded linearly in size from days 3 to 7 of culture. Treatment of immature MLR cultures with anti-4F2 Mab and complement (C) before DNA synthesis (treatment on day 3, peak DNA synthesis on days 5 to 6) resulted in blunted proliferation and activation antigen expression when the same culture was analyzed after maturation on day 6, indicating that the activated population had been previously detected and removed by anti-4F2 Mab + C. The 4F2 antigen was expressed on a greater percentage of cells in the MLR at all times (days 3 to 9) than was Tac, was present on virtually all S/G2/M phase responder cells, and a large fraction of cells remained intensely 4F2+ subsequent to peak DNA synthesis. In contrast, after initially preceding responder cell entry into the S phase of the cell cycle, the kinetics of Tac antigen expression closely paralleled the kinetics of responder cell proliferation. A subpopulation of cycling responder cells was noted in all MLR cultures studied that expressed Tac antigen weakly or not at all. Cells within both T4 and T8 cell subsets proliferate with similar kinetics in response to alloantigen. The possibility that activation antigens can be utilized to study effector cell generation in the MLR and that this flow cytometric technique may be utilized to analyze the response to various alloantigens is discussed.
A novel human leukocyte differentiation antigen: monoclonal antibody anti-D44 defines a 28 Kd molecule present on immature hematologic cells and a subpopulation of mature T cells.
Authors: Bernard A , Gay-Bellile V , Amiot M , Caillou B , Charbord P , Boumsell L
Published: December 2022

Anti-D44 is a cytotoxic IgG2b monoclonal antibody (MAb), which reacts with two polypeptides of 28 and 30 Kd from human peripheral T cells after western blotting. The antigen is present in low density on bone marrow cells from the myeloid lineage, probably including most CFU-GM; the antigen is present on megakaryocytes but is not detectable on erythroid cells as well as pre-B and B cells. Growth of BFU-E appears to be partially inhibited after treatment with anti-D44 + complement, an effect that should be due to bone marrow T cells rather than to BFU-E destruction. With maturation, the antigen is barely detectable on mature polymorphonuclear neutrophils, and is not detectable on platelets and monocytes. In contrast, cells from the thymic cortex carry a high density of this molecule; medullary thymocytes carry a low density. Large thymocytes ("thymoblasts") distinct from epithelial or interdigitating cells also bear a high density of the antigen. In the periphery, a subpopulation of T cells displays a high density of D44 molecules. D44 antigenic density is not linked to cell growth or to T cell activation. Double labeling and cell sorting experiments have shown that 40% of E rosette-forming cells are D44(+)-CD4+, 10% are CD8(+)-D44+ and 10% are CD4(-)+CD8-, CD2+. In an accompanying report, correlation is shown between expression of the D44 defined molecule on T cell subpopulations and the function they exert. Immunoperoxidase studies of skin, brain, and kidney tissues, facilitated by the fact that the antigen is resistant to inclusion in Epon, which permits staining of semi-thin sections, have not revealed any positive nonhematologic cell.
Monocyte and NK cell cytotoxic activity in human adherent cell preparations: discriminating effects of interferon and lactoferrin.
Authors: Horwitz D A , Bakke A C , Abo W , Nishiya K
Published: December 2022

The comparative cytotoxic specificities of freshly isolated human adherent and nonadherent blood mononuclear cells were examined against seven established target cell lines in 4 and 18 hr chromium release assays. The relative sensitivity of each target cell line to the cytotoxic effects of both adherent and nonadherent effector cells in cultures was identical. Moreover, the relative enhancing effects of interferon on cytotoxicity by both effector cell types were also identical. These adherent cell preparations were contaminated with up to 6% NK cells, as demonstrated by OKM1 staining and flow microfluorometry. These NK cells were loosely adherent and could be removed by vigorous wash procedures. The remaining tightly adherent monocytes also had the capacity to kill K562 cells and Chang cells, but these cytotoxic effects could not be increased by interferon. Enhancement by lactoferrin, however, was consistently observed. Treatment of mononuclear cells with Leu-lla, a monoclonal antibody that reacts with all NK cells, also abolished the enhancing effects of interferon, but not lactoferrin. These studies suggest that caution must be exercised in attributing all cytotoxic activities in adherent cell preparations to monocytes, and that lactoferrin and interferon can be used as functional probes to detect two distinct blood mononuclear cell subsets with natural cytotoxicity.
Phenotypic and functional characterization of T cell clones derived from the cerebrospinal fluid of multiple sclerosis patients.
Authors: Santoli D , Defreitas E C , Sandberg-Wollheim M , Francis M K , Koprowski H
Published: December 2022

We describe here T cell cultures and clones established from the cerebrospinal fluid (CSF) of three patients with multiple sclerosis (MS) and one chronic meningitis patient with pleocytosis. Most of the cultures were activated with phytohemagglutinin (PHA) before growth in mitogen-free interleukin 2 (IL 2), and were never restimulated. Some of the clones obtained have been propagated for over 1 yr and are strictly IL 2-dependent. Immunofluorescence analysis performed with various monoclonal antibodies revealed that the CSF-derived lines had the characteristics of activated T cells with a stable expression of either suppressor/cytotoxic or helper/inducer surface antigens. Most of the clones established had a predominantly suppressor phenotype (OKT8+), except for the clones derived from one MS patient, which expressed only the helper phenotype (anti-Leu-3a+). Consistent with these data, the CSF-derived cultures displayed a variety of immunoregulatory functions, such as the ability to lyse nonspecific and PHA-stimulated target cells, to produce IL 2 upon mitogenic activation, and to modulate polyclonally induced Ig responses. The availability of long-term CSF T cell cultures derived from MS patients at various disease stages might provide a useful tool in investigating the factor(s) involved in the etio-pathogenesis of the disease.
The immunopathology of experimental allergic encephalomyelitis. II. Endothelial cell Ia increases prior to inflammatory cell infiltration.
Authors: Sobel R A , Blanchette B W , Bhan A K , Colvin R B
Published: December 2022

Experimental allergic encephalomyelitis (EAE) is a T cell-mediated neuroimmunologic disease model characterized by meningeal and parenchymal mononuclear cell infiltrates (see preceding companion paper). Here we report enhanced staining for Ia in the central nervous system (CNS) microvasculature endothelium in acute EAE in adult strain 13 guinea pigs (GP) sensitized with GP spinal cord homogenate (SC) or with GP myelin basic protein (MBP) in complete Freund's adjuvant (CFA). Cryostat sections of CNS and other tissues were stained with two monoclonal antibodies, 5S2 and 22C4, to GP Ia determinants, and with polyclonal antibody to factor VIII-related antigen (VIII-RA) as an endothelial cell marker. Morphometric techniques were employed on immunoperoxidase counterstained and coded sections to determine the frequency of Ia+ vessels and cells. Rare (approximately 10% of VIII-RA+) vascular endothelial cells were Ia+ in the CNS of normal and CFA-sensitized controls. SC- or MBP-sensitized strain 13 GP sacrificed on day 7, before the onset of neurologic signs (pre-clinical), had no detectable CNS mononuclear cell infiltrates, but had increased (approximately 30% of VIII-RA+) endothelial cell Ia staining over controls (p less than 0.001). The endothelial Ia staining persisted (approximately 35% of VIII-RA+) in vessels as the animals developed paralysis. There were no differences in endothelial cell Ia between SC- and MBP-induced disease. EAE-resistant strain 2 GP sensitized with SC/CFA had no neurologic signs, and had fewer inflammatory foci than strain 13 GP with EAE, but had similar numbers of Ia+ endothelial cells. No differences in endothelial cell Ia staining were found in non-CNS tissues among any GP groups. In EAE, increased endothelial cell Ia is a pre-inflammatory, target organ-specific alteration that persists during inflammation. The findings suggest that in vivo modulation of endothelial cell Ia may be part of the local immune response. Endothelial cells may play a significant role, in antigen presentation or in promoting T cell migration, in the in situ immune response in the CNS.
Identification and initial characterization of concanavalin A- and interferon-induced human suppressor factors: evidence for a human equivalent of murine soluble immune response suppressor (SIRS).
Authors: Schnaper H W , Pierce C W , Aune T M
Published: December 2022

Human suppressor T cells activated by leukocyte interferon have properties similar to murine suppressor cells activated by interferon or by concanavalin A. Murine suppressor cells release a soluble mediator, soluble immune response suppressor (SIRS), which accounts, at least in part, for suppressive activity in murine systems. To compare and contrast murine and human suppressor pathways, we evaluated the suppression of human polyclonal plaque-forming cell responses by concanavalin A, by leukocyte interferon, and by immune interferon, or by suppressor cells activated by these agents. In each instance, suppressive activity was prevented by levamisole, ascorbic acid, catalase, or 2-mercaptoethanol, agents known to interfere with murine SIRS activity. Furthermore, concanavalin A, immune interferon, and leukocyte interferon induced T lymphocytes to release 110,000 to 150,000 m.w. proteins which suppressed responses only when added early in the culture period. As with murine SIRS, suppression by each of these human factors was inhibited by 2-mercaptoethanol, ascorbic acid, catalase, or levamisole. The reaction of human suppressor factors with H2O2 (10(-6) M) activated suppressor factors so that they suppress responses when added late in the culture period. Human suppressor factors were protease- and acid (pH 2)-sensitive. The similarities between these human suppressor factors and murine SIRS show the existence of a human SIRS pathway.
Recombinant interferons increase macrophage Fc receptor capacity.
Authors: Fertsch D , Vogel S N
Published: December 2022

We utilized recombinant interferon preparations to confirm and extend our previous findings that biochemically purified preparations of interferon augment Fc receptor (FcR)-mediated functions. Five different recombinant human alpha-interferons (IFN) were tested and increased Fc-mediated phagocytosis and binding of opsonized erythrocytes with varying efficiencies. We found, however, that when the different alpha-IFN species were ranked with respect to their FcR-enhancing activity, their hierarchy differed from those reported for antiviral, antiproliferative, and NK cell-inducing activities. Recombinant murine gamma-IFN was also found to increase Fc-mediated phagocytosis, but was significantly more potent than either beta-IFN or recombinant alpha-IFN when compared on the basis of antiviral activity. A comparison of the amino acid sequences of the recombinant IFN may help define functional domains of the molecule.
A distinct "slow" cellular pathway involving soluble mediators for the T cell-instructed induction of monocyte tissue factor activity in an allogeneic immune response.
Authors: Helin H , Edgington T S
Published: December 2022

Allogeneic stimulation of human lymphoid cells initiates a collaborative cellular pathway that relatively rapidly induces in monocytes the synthesis and cell surface expression of tissue factor, the initiating cofactor of the extrinsic coagulation pathway. T cells are required for the monocyte procoagulant generation, because the addition of autologous or allogeneic T cells fully reconstitutes the activity in otherwise nonresponding highly purified monocytes. Despite a strict T cell requirement, only low T cell to monocyte ratios are necessary for maximal PCA response. Our results further demonstrate that the collaborative signal from allogeneically stimulated T cells to effector monocytes is transferred by a soluble mediator rather than direct cell to cell contact. Other aspects of the present study include the observation that among normal peripheral blood lymphoid cells, monocytes elicit the strongest allogeneic PCA response. This response is clearly exceeded by that induced upon stimulation with Daudi lymphoblastoid B cells. Our data demonstrate the existence of a second distinct cellular pathway that mediates the lymphoid procoagulant response. This pathway differs from the previously characterized response to bacterial LPS in respect to: a) kinetics of T cell triggering; b) mediation by a soluble product; c) lack of genetic restriction of T cell; monocyte collaboration; and d) deficient capacity for direct T cell induction of the monocyte PCA response.
Preparations of lymphotoxin induce resistance to their own cytotoxic effect.
Authors: Wallach D
Published: December 2022

Preparations of human lymphotoxins (LT) were effectively cytotoxic to HeLa cells when applied in the presence of cycloheximide (CHI). In the absence of CHI, however, they failed to cause any cell death. Moreover, LT applied in the absence of CHI induced resistance that was reflected in decreased vulnerability to subsequent incubation with LT in the presence of CHI. This induction of resistance to LT, in treating cells with preparations of LT, was quite rapid, reaching its maximal extent within 2 hr of LT application. It could also be observed in cells of other cultured human lines besides HeLa (SV80 and WISH), and the range of LT concentrations at which it was observed was similar to that at which death of cells was induced by LT in the presence of CHI. In fractionating LT preparations on DEAE cellulose, the resistance inducing activity appeared to co-purify with the cytotoxic activity, suggesting that both activities reside in the same molecule. We suggest that LT, or some lymphokines that are formed by lymphocytes concomitantly with the formation of LT, can induce cellular mechanisms that interfere with the cytotoxic activity of LT and that CHI makes the cell sensitive to the cytotoxicity of LT by reducing the activity of these protective mechanisms. This kind of negative feedback regulation in the function of LT might contribute to selectivity in their action.