bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced response to Con A and production of TCGF by lymphocytes of obese strain (OS) chickens with spontaneous autoimmune thyroiditis.
Authors: Schauenstein K , Krömer G , Sundick R S , Wick G
Published: December 2022

The mitogenic response to Con A and the production of T cell growth factor or interleukin 2 (IL 2) by splenic and peripheral blood lymphocytes of obese strain (OS) chickens with spontaneous autoimmune thyroiditis have been investigated. By using an optimized method with Con A-coated chicken erythrocytes (MRC), lymphocytes of OS chickens were found to exhibit significantly elevated mitogenic responses as compared with cells from either Normal White Leghorn chickens (NWL) or animals of the Cornell C-Strain (CS), from which the OS has originally been developed. This difference was observed throughout ontogeny up to 15 mo of age, and was associated with increased levels of IL 2 activity in the culture supernatants. The elevated responsiveness of OS T lymphocytes was also found to be manifested in the expression of receptors for IL 2, because Con A-stimulated lymphocytes of OS birds were significantly more effective than those from normal controls in absorbing IL 2 activity from conditioned media (CM) of stimulated spleen cells. High concentrations of CM were suppressive in IL 2 assays, signaling the presence of an inhibitory factor(s) in addition to IL 2. An additional indication for defective immunoregulation was that CM from OS lymphocyte cultures showed significantly less of this suppressive activity in comparison with CM of normal (NWL and CS) lymphocyte cultures. Finally, the spontaneous uptake of 125IUdR of embryonic and early post hatching OS spleen lymphocytes was consistently and significantly enhanced. This difference, however, in contrast to the one observed in Con A responses, was found to decrease with age. The data are discussed in view of the contradictory results concerning T cell functions reported for several autoimmune states in mammals.
Reconstitution of in vivo cell-mediated lympholysis responses in aged mice with interleukin 2.
Authors: Thoman M L , Weigle W O
Published: December 2022

Advancing age is accompanied by declining immune potential. Both humoral and cellular immune responses are diminished in aged humans and experimental animals. A major lesion preventing effective T cell-mediated responses is the lack of interleukin 2 (IL 2) synthesis in aged mice. Addition of IL 2 can effectively reconstitute in vitro T cell-dependent humoral and cell-mediated immunity. These results have been extended, demonstrating that IL 2-containing lymphokine preparations when administered with antigen can restore the ability of aged mice to generate cytotoxic T lymphocytes in vivo. Furthermore, IL 2 has been identified as the active component of these lymphokine preparations through the use of purified human IL 2 prepared by recombinant DNA and gene cloning technology. The cloned IL 2 is highly effective in enhancing the immune responses of aged animals both in vitro and in vivo.
Comparative effects of various classes of mouse interferons on macrophage activation for tumor cell killing.
Authors: Pace J L , Russell S W , LeBlanc P A , Murasko D M
Published: December 2022

The effects of mouse interferon-alpha (MuIFN-alpha), -beta (MuIFN-beta), and -gamma (MuIFN-gamma) on macrophage activation for tumor cell killing were determined by using proteose peptone-elicited peritoneal macrophages from C3H/HeN and C3H/HeJ mice under conditions that either included or were free of detectable endotoxin. Alone, under the conditions used, none of the interferons was able to activate macrophages directly for tumor cell killing. However, with a second signal provided to responsive macrophages by contaminating endotoxin, added bacterial lipopolysaccharide (LPS), or heat-killed Listeria monocytogenes (HKLM), all three types of interferon induced cytolytic activity, with MuIFN-gamma approximately 500 to 1000-fold more active than either MuIFN-alpha or -beta. Thus, all three interferons were able to prime macrophages for killing but required a second signal before cytolytic activity could be expressed. When MuIFN-gamma was mixed with either MuIFN-alpha or -beta and placed on macrophages, little or no killing developed. Mixtures of MuIFN-gamma with either MuIFN-alpha or -beta did increase the sensitivity of macrophages to triggering by LPS, however, compared with macrophages treated with MuIFN-gamma alone. The results are collectively important because they i) confirm that significant quantitative differences exist between the various interferons with regard to their capacity to prime macrophages for tumor cell killing; ii) indicate that to be an efficient activator each type of interferon must be combined with a second stimulus, such as LPS or HKLM; iii) show that neither MuIFN-alpha nor -beta can provide an efficient second triggering signal for macrophages that are primed by MuIFN-gamma; and iv) document that mixtures of MuIFN-gamma with either MuIFN-alpha or -beta are most efficient at inducing priming, compared with any one of the interferons used alone.
Bone marrow-derived macrophages: development and regulation of differentiation markers by colony-stimulating factor and interferons.
Authors: Warren M K , Vogel S N
Published: December 2022

To investigate the role of specific cytokines in the development of the fully mature macrophage, we have employed murine bone marrow cells that were grown in the presence of CSF-1, a colony-stimulating factor that has been shown to induce the proliferation and differentiation of macrophages from their precursor cells. The CSF-1 employed in these studies was partially purified to ensure removal of contaminating interferon (IFN) from the preparations. After 1 to 2 wk in the presence of the partially purified CSF-1, the adherent macrophages were removed from flasks enzymatically and were recultured at known densities in the absence of CSF-1. Cell surface antigens (Mac-1 and Ia) and Fc receptor capacity (as assessed by Fc-mediated phagocytosis) were examined as markers of macrophage differentiation. Basal levels of Fc receptor capacity and Mac-1 antigen were markedly influenced by exposure to CSF-1, and appear to be modulated by CSF-induced, macrophage-derived IFN. When the bone marrow-derived macrophages were exposed to exogenous IFN in the absence of CSF-1, they proved to be extremely inducible with respect to Fc-mediated phagocytosis (IFN-beta and rIFN-gamma) and Ia antigen expression (rIFN-gamma) when compared with thioglycollate-elicited macrophages. Thus, macrophage growth factors, such as CSF-1, promote macrophage maturation by inducing the production of autostimulatory signals, such as macrophage-derived IFN. In addition, exogenous cytokine stimuli, such as IFN-gamma, further amplify the differentiative potential of these cells. Bone marrow-derived macrophages, propagated under well-defined conditions and never exposed to eliciting agents, provide a powerful model for studying the role of cytokines, such as CSF-1 and IFN, in the differentiative pathway of macrophages.
Activity of rheumatoid factors of different molecular sizes: comparison of autologous monomeric and polymeric monoclonal IgA rheumatoid factors.
Authors: Schrohenloher R E , Koopman W J , Moldoveanu Z , Solomon A
Published: December 2022

Differences in rheumatoid factor (RF) activity among the molecular species of IgA were investigated with the use of monomeric and polymeric monoclonal IgA RF paraprotein from the serum of a patient (PS) with idiopathic hyperviscosity syndrome. After fractionation by gel chromatography in acidic buffer, RF activity as determined by latex fixation and solid-phase radioimmunoassay (RIA) specific for IgA RF was confined to the high m.w. (greater than 7S) fractions. However, after adsorption into polystyrene wells, fractions containing monomeric (7S) IgA, as well as those containing polymeric IgA, bound 125I-labeled heat-aggregated human IgG. These observations were confirmed after further purification of the IgA fractions by passage through a protein A-Sepharose CL-4B column followed by precipitation of the IgA proteins with ammonium sulfate at 50% saturation. After "cross-linkage" by a hybridoma anti-human alpha-chain antibody, the activity of the monomeric IgA preparation in the IgA RF RIA approached that of the polymeric IgA preparation. Gel filtration studies verified that this activity was not due to contamination by polymeric IgA RF. Further, classic RF specificity was confirmed for both the monomeric and polymeric IgA RF by reaction with human Fc-coated but not Fab-coated wells. A control monomeric IgA myeloma protein and normal serum IgA did not react in the RF RIA when analyzed in the presence or absence of the hybridoma anti-alpha-chain antibody. Moreover, the activity of the polymeric IgA RF preparation from patient PS in the RIA was minimally influenced by the hybridoma antibody. These results indicate that IgA RF can coexist in both polymeric and monomeric forms, demonstrate that monomeric IgA RF may escape detection by previously described RIA techniques, and suggest an approach for its detection.
Cellular events during radiation-induced thymic leukemogenesis in mice: abnormal T cell differentiation in the thymus and defect of thymocyte precursors in the bone marrow after split-dose irradiation.
Authors: Muto M , Kubo E , Sado T
Published: December 2022

Cellular events during the development of thymic lymphomas in young B10.BR mice given leukemogenic split-dose irradiation were studied by examining the differentiation of functional T lymphocyte precursors in the regenerating thymus. It was found that leukemogenic radiation treatment resulted in a sustained depression of the level of thymic cytotoxic T lymphocyte precursors (CTLp) and of mixed lymphocyte reactivity of thymus cells when assessed between 1 and 4 mo after irradiation, in spite of the fact that the total number of thymocytes was restored to the normal level within 2 mo and continued to increase thereafter. In vitro mixing studies of normal thymocytes with thymus cells from split-dose irradiated mice provided no evidence for active suppression as a mechanism for this depressed activity. The ability of bone marrow cells from split-dose irradiated mice to regenerate the thymus and to differentiate into functional CTLp was examined by use of supralethally irradiated Thy-1 congenic recipients. Reconstitution of supralethally irradiated B10.BR Thy-1.2 mice with normal bone marrow from B10.BR Thy-1.1 mice resulted in the complete repopulation of host-thymus with donor-derived cells when assessed at 4 wk after reconstitution. Lymphocytes from the regenerating thymus of these animals were shown to contain high levels of CTLp which were donor-derived. On the other hand, when the recipient mice were reconstituted with bone marrow cells from donor mice which had been split-dose irradiated 1 mo earlier, regeneration of the recipient thymus was severely depressed when assessed at 4 wk to 3 mo after reconstitution. Although variable but small numbers of donor-derived Thy-1+ cells were detected, CTL activity for alloantigen could not be induced in these donor-derived cells. The results suggest that T cell precursors derived from split-dose irradiated donor mice were unable to undergo active proliferation and differentiation into functional CTLp. The significance of these findings on radiation-induced thymic leukemogenesis is discussed.
H-2-restricted helper activity mediated by immunoglobulin-bearing lymphocytes.
Authors: Sherr D H , Dorf M E
Published: December 2022

The genetic requirements for helper activity mediated by a unique, Ig-bearing lymphocyte population were studied. This Lyt-1+, I-A+, Thy-1- population, called BH, preferentially helps expression of NPb idiotypic plaque-forming cells when added to T cell-depleted responder cultures. Furthermore, the BH population can directly bind NPb idiotypic determinants. Using H-2 congenic mice, we show that BH helper activity can be expressed only when BH cells share I-A subregion alleles with responder B cell populations. This H-2 restriction is not a result of thymic influences, because the activity of BH cells from athymic mice are also H-2 restricted. Macrophages present in the BH population do not contribute to the H-2 restriction. Results are presented that definitively rule out the possible role for T lymphocytes in BH activity and demonstrate that a single helper population expresses both Lyt-1 and I-A determinants. These results indicate that Ig-bearing cells serve a regulatory as well as an effector role in immune responses and that, like other regulatory lymphoid subsets, their activity is regulated in part by MHC-encoded determinants.
The role of T8 in the cytotoxic activity of cloned cytotoxic T lymphocyte lines specific for class II and class I major histocompatibility complex antigens.
Authors: Spits H , Yssel H , Voordouw A , de Vries J E
Published: December 2022

It is reported here that most cytotoxic T lymphocytes (CTL), which recognize class I major histocompatibility complex (MHC) loci, express the T cell differentiation antigen T8. However, a minority of T8+ CTL clones was found to recognize class II MHC antigens. To test the hypothesis that T8 is involved only in T cell recognition of class I MHC antigens, we studied the role of T8 in the cytotoxic activity of class II MHC-specific CTL. Monoclonal antibodies specific for T8 blocked the activity of most class I MHC-specific CTL clones but did not affect the activity of class II MHC-specific CTL clones. Moreover, a mild trypsin treatment of the clones, which removed and T8 determinant, affected the activity of class I MHC but not that of class II MHC-specific CTL clones. These findings indicate that the class II-specific MHC CTL clones described here did not require T8 for their cytolytic activity. The activity of one T8+ class I MHC-specific (HLA-B27) CTL clone (HG-61) against the B cell line JY, which was used to raise this CTL clone, was not blocked by trypsin treatment of this clone. However, the activity of CTL clone HG-61 against target cells different from JY but carrying the appropriate HLA specificity was blocked by anti-T8 antibodies and trypsin treatment. The implications of these findings for the hypothesis that T8 is involved only in the activity of CTL with a relatively low avidity for class I MHC antigens are discussed.
Functional characterization of human thymocytes: a limiting dilution analysis of precursors with proliferative and cytolytic activities.
Authors: Lopez-Botet M , Moretta L
Published: December 2022

In this report we have analyzed the pool size of human thymocytes capable of proliferating or mediating cytolytic activity. Furthermore, the relationship between these functional capabilities and cell surface antigen expression was studied. Graded numbers of human thymocytes were plated under limiting dilution conditions with irradiated human spleen cells (as a source of feeder cells) and phytohemagglutinin (PHA) in the presence of a saturating concentration of interleukin 2. Cell proliferation, which was evaluated after 20 days of culture, was usually compared with the proliferation of peripheral blood T cell populations cultured under identical conditions. Although essentially all peripheral blood T cells were clonogenic, only 3 to 8% of thymocytes proliferated. Of proliferating microcultures, 48 to 86% showed cytolytic activity in a PHA-dependent assay, whereas 26 to 83% killed the NK-sensitive target cell K-562 in the absence of added lectin. Similar frequency analysis of functional precursors was performed on thymocyte subsets selected according to their expression of T3, T6, T4, and T8 antigens. All precursors of proliferating cells (PTL-P) were found in the T3+ subset. From the comparison of the percentages of total thymocytes capable of proliferation and the proportion of cells brightly stained with anti-T3 antibody, it was evident that only a fraction of T3+ cells was clonogenic. Although the large majority of PTL-P was found in the T6- subpopulation, a small fraction of functional precursors was detected in the T6+ subset. When thymocytes were fractionated according to T4 or T8 antigen expression, it was found that 80 to 90% of the recovered PTL-P were confined to the T4+ fraction, whereas only 20 to 28% of the recovered PTL-P were present in the T8+ subset. Analysis of the precursors of cytolytic T lymphocytes (CTL-P) in thymocyte populations fractionated according to T4 or T8 antigen expression showed that 70 to 90% of the recovered CTL-P were found in the T4+ fraction and 17 to 30% were in the T8+ subset. Because approximately 80% of proliferating T4+ thymocytes had CTL activity (as compared with less than 5% in peripheral blood T4+ lymphocytes), it appears that the subset distribution of thymic CTL-P differs from that of peripheral blood T cells.
Xenogeneic monoclonal antibody to an Ly-6-linked murine cell surface antigen: differential reactivity with T cell subpopulations and bone marrow cells.
Authors: Dumont F J , Coker L Z , Habbersett R C , Treffinger J A
Published: December 2022

The patterns of cellular and strain reactivity of a monoclonal antibody (6C3 MAb) derived from the fusion of SP2/0 cells with splenocytes from rats immunized against MRL/MpJ-lpr/lpr T cells were characterized by using flow cytofluorometry (FCF) analysis. This MAb was found to stain 70 to 90% of T cells of mice with the lpr/lpr genotype and 20 to 60% of T cells of congenic +/+ strains. Dual-parameter FCF analysis of Lyt-2 vs 6C3 expression revealed the existence of several Lyt-2- and Lyt-2+ T cell subsets, one of which (Lyt-2- bright 6C3+) was expanded in lpr/lpr-bearing mice. The 6C3 MAb stained only 2 to 5% normal thymocytes but reacted with 40 to 50% bone marrow (BM) cells. A strain survey demonstrated the expression of the 6C3 antigen on peripheral T cells (and BM cells) of all strains examined, with the exception of NOD, NZB/B1NJ, and ST/bJ. Interestingly, in the positive strains, two types of 6C3 staining patterns of T cells were observed: bimodal or trimodal. Study of BXH and CXB recombinant inbred (RI) strains demonstrated that the bimodal and trimodal 6C3 patterns are associated with the Ly-6.1 and Ly-6.2 phenotypes, respectively. Linkage of 6C3 expression with the Ly-6 locus was confirmed by using the congenic C3H.B6-Ly-6b strain. Moreover, the 6C3 staining of T cells in Ly-6.2 strains was reduced by preincubation with the H9/25 and SK-142-446 MAb, which are known to recognize Ly-6.2-associated antigens. Therefore, the 6C3 MAb appears to detect a frame-work determinant on an Ly-6-linked antigen that is absent from T cells of NOD, NZB, and ST/bJ mice. Analysis of (NZB x C58) NX8 RI strains demonstrated a correlation between the lack of 6C3 expression on T cells and unresponsiveness in autologous mixed lymphocyte reaction (a property of NZB/B1NJ mice). The 6C3 MAb should prove useful for further genetic and biochemical analysis of the Ly-6 locus and its product(s), and for the delineation of functional subsets of T cells and BM cells in normal and lpr/lpr-bearing mice.
Production and response to interleukin 2 in vitro and in vivo after bone marrow transplantation in mice.
Authors: Merluzzi V J , Welte K , Last-Barney K , Mertelsmann R , Souza L , Boone T , Savage D M , Quinn D , O'Reilly R J
Published: December 2022

Lymphoid cells from bone marrow radiation chimeras do not produce normal levels of IL 2 but are capable of responding to IL 2 in mitogenic and cytotoxic assays in vitro. The administration of recombinant human IL 2 into host mice that have received allogeneic, H-2-compatible marrow did not enhance mortality.
A new Tla region antigen Qa-11, similar to Qa-2 and associated with B-type beta 2-microglobulin.
Authors: van de Meugheuvel W , van Seventer G , Demant P
Published: December 2022

A new antigen, Qa-11, is detected as a 40,000 dalton band in the SDS-PAGE of immunoprecipitates of radiolabeled lymphocyte membrane preparations. In C57BL H-2 congenic strains, its presence is controlled by a gene in the Tla region. In strains with genetic background other than C57BL it is not expressed. Tests with recombinant inbred strains and with H-3 congenic strains show that, in addition to the Tla region, a gene linked to or identical with the beta 2-microglobulin-b-allele is required for the expression of Qa-11 as well. The mobility of the Qa-11 antigen in SDS-PAGE and in isoelectrofocusing is the same as that of Qa-2 antigen. The Cleveland peptide maps of Qa-2 and Qa-11 are identical as well. This finding, that the Tla region controlled Qa-11 antigen is structurally very similar to the Qa-2 antigen, contrasts with the fact that Tla region products do not react with anti-Qa-2 sera. This paradox could be explained by a separate Qa-11 region between Qa-2 and Tla. Alternatively, it is possible that the Qa-11 antigen is the result of the action of a modifying gene in the Tla region upon a Qa-2 gene product, or that the structural gene for Qa-11 is located in the Qa-2 region and a Tla region gene controls its expression.
An analysis of the structure of the antigen receptor on a pigeon cytochrome c-specific T cell hybrid.
Authors: Samelson L E
Published: December 2022

The monoclonal antibody A2B4-2 has been shown to bind to the antigen receptor on the cloned pigeon cytochrome c-specific T cell hybrid, 2B4. Initial immunoprecipitation and SDS-PAGE analysis with this clonotypic antibody demonstrated that the antigen receptor on this cell had a m.w. of 85,000 to 90,000. Under reducing conditions, the receptor protein appeared as two bands of 45,000 to 50,000 and 40,000 to 44,000 on an SDS-PAGE gel. In this paper the antigen receptor on this T cell hybrid is further characterized. The molecule is shown to be a heterodimer that exists in two different forms on the cell surface. Receptor molecules with an apparent m.w. of 84,000 and 86,000 were isolated by immunoprecipitation and separation on polyacrylamide gradient gels. After reduction, the individual alpha- and beta-chains were separated by isoelectric focusing. In both forms of the receptor, the acidic alpha-chain had an apparent m.w. of 42,000 to 44,000. This alpha-chain associated with one of two forms of beta-chain. One beta-chain had a m.w. of 42,000 to 44,000, with a pI range of 7.5 to 7.9, and the alternate form of the beta-chain, beta', had a m.w. of 46,000 to 48,000 and a more acidic pI range of 6.5 to 7.5. The results of this investigation indicate that under reducing conditions on SDS-PAGE gels, the original upper 45,000 to 50,000 m.w. band represented beta'-chains alone, whereas the lower 40,000 to 44,000 m.w. band represented a mixture of alpha- and beta-chains. Additional data are presented to indicate that this heterodimeric protein has intrachain as well as interchain disulfide bonds. This conclusion was reached from the characteristic pattern of protein migration on SDS-PAGE gels in the presence of a reducing agent concentration gradient. Thus, both chains of the antigen receptor must have intrachain disulfide bonds and may have similar domain structures.
Intracellular retention of the 5-lipoxygenase pathway product, leukotriene B4, by human neutrophils activated with unopsonized zymosan.
Authors: Williams J D , Lee T H , Lewis R A , Austen F
Published: December 2022

The cellular and extracellular distribution of leukotriene B4 (LTB4) generated in human neutrophilic polymorphonuclear leukocytes (PMN) stimulated with unopsonized zymosan has been compared with that generated in PMN activated by the calcium ionophore. The amounts of extracellular and intracellular LTB4 were quantitated by radioimmunoassay. The authenticity of the immunoreactive LTB4 was confirmed by the elution of a single immunoreactive peak after reverse phase-high performance liquid chromatography (RP-HPLC) at the retention time of synthetic LTB4, by the identical elution time of a peak of radiolabeled product derived from [3H]arachidonic acid-labeled PMN with the immunoreactive product, and by the comparable chemotactic activity on a weight basis of immunoreactive LTB4 and synthetic LTB4 standard. Under optimal conditions of stimulation by unopsonized zymosan, more than 78% of the generated immunoreactive LTB4 remained intracellular, whereas with optimal activation by the ionophore, less than 8.6% of immunoreactive LTB4 was retained. Resolution by RP-HPLC of the products from the supernatants and cell extracts of [3H]arachidonic acid-labeled PMN stimulated with unopsonized zymosan and those stimulated with calcium ionophore allowed identification and measurement of 5-hydroxyeicosatetraenoic acid (5-HETE), 6-trans-LTB4, LTB4, and omega oxidation products of LTB4 by radioactivity. With zymosan stimulation of PMN, 5-HETE and the 6-trans-LTB4 diastereoisomers were not released, LTB4 was partially released, and the omega oxidation products of LTB4 were preferentially extracellular in distribution. In contrast, with ionophore stimulation, only 5-HETE had any duration of intracellular residence being equally distributed intra- and extracellularly throughout the 30-min period of observation; 6-trans-LTB4, LTB4, and the omega oxidation products of LTB4 were retained at less than 19%. The respective distributions of 5-HETE after zymosan and ionophore stimulation were not altered by the introduction of albumin to the reaction mixtures to prevent reacylation, or by hydrolysis of the cell extract to uncover any product that had been reacylated. The finding that stimulation of PMN with unopsonized zymosan results in the cellular retention of 5-lipoxygenase products suggests that release of these metabolites may be an event that is regulated separately from their generation.
Human natural killer cells limit replication of herpes simplex virus type 1 in vitro.
Authors: Fitzgerald P A , Mendelsohn M , Lopez C
Published: December 2022

Studies were undertaken to determine whether natural killer (NK) cells could inhibit the replication of herpes simplex virus type 1 (HSV-1) in culture. In the absence of effector cells, HSV-1 was found to replicate in fibroblasts with up to a 100-fold increase in virus titer from 4 to 16 hr after incubation at 37 degrees C. Human peripheral blood mononuclear cells were found to limit virus replication in a dose-dependent manner, with the greatest inhibition being observed at the highest concentration evaluated: i.e., an effector:target ratio of 800:1. The antiviral effect was not observed when nonactivated or virus-activated mononuclear cells were added to the virus preparations at the end (instead of the beginning) of the assay period, indicating that the observed effect was not due to a nonspecific toxicity of soluble factors released from freeze-thawed effectors. Neither was inhibition of HSV-1 replication due to the generation of interferon (IFN) during the NK assay, because the addition of anti-IFN did not abrogate the antiviral effect. Thus, the inhibition of viral replication was most likely due to a cytotoxic effector rather than to release of soluble factors. The effector cells responsible for limiting HSV-1 replication were shown to be NK cells by a number of criteria. Mononuclear cells from both HSV-1 seropositive and seronegative donors limited virus replication; their activity could be boosted by pretreatment of effector cells with IFN; the effector cells which limited virus replication were found in Percoll gradient fractions enriched for large granular lymphocytes; and the effector cells shared the cell surface phenotype of NK cells--they were enriched in populations depleted of T cells by panning with Leu-4 and were depleted of activity by treatment with the anti-NK antibody Leu-11b plus complement. We conclude that human NK cells are capable of recognizing and lysing HSV-1-infected target cells before infectious virus progeny are generated. These results suggest that NK cells, acting early in the course of an infection, might serve to limit HSV-1 replication and therefore reduce the virus load in the host before the development of the adaptive immune response and clearance of the infection.
Description of phenotypically distinct T-lymphocyte subsets which mediate helper/DTH and cytotoxic functions in the Syrian hamster.
Authors: Witte P L , Stein-Streilein J , Streilein J W
Published: December 2022

Recent studies describe aberrations in the functions of T lymphocytes from Syrian hamsters. A current proposal links the apparent functional deficiencies of cytotoxic and suppressor T cells with anomalies found in class I molecules of this species (no polymorphism is detected) and speculates that hamsters possess limited heterogeneity of T cell subpopulations, particularly a class I-restricted subset. The present work tests this hypothesis by examining the extent of T cell heterogeneity defined by differential cell surface antigen expression. A panel of mouse monoclonal antibodies against hamster lymphocyte antigens was generated. MAb #20 and #110 bound to most, if not all, peripheral T cells; a third antibody, #38, divided T cells into two subpopulations which were functionally distinct. Cells within the #38-negative subset produced easily detectable IL 2 and mediated delayed-type hypersensitivity to influenza virus. In contrast, isolated 38+ cells produced little IL 2 and required the addition of exogenous T cell growth factor for proliferation to Con A. Treatment of immune cells with mAb #38 and complement abrogated cytolysis to TNP-haptenated or influenza-infected targets. Thus, Syrian hamsters possess at least two T cell subpopulations of discrete functional ability and unique cell surface antigen expression. Although the data suggest that T cells analogous to those of the class I-restricted, Lyt 2+ subset are present in the hamster, it is predicted that the scope of their composite antigen receptor repertoire may be limited by the monomorphism of class I molecules in this species.
Regulation of transplantation immunity in vivo by monoclonal antibodies recognizing host class II restriction elements. I. Genetics and specificity of anti-Ia immunotherapy in murine skin allograft recipients.
Authors: Perry L L , Williams I R
Published: December 2022

Antibodies reactive with host class II restriction elements exert profound regulatory effects on the immune response to a variety of antigenic stimuli, including tumor, autoantigens, and alloantigens. In the present studies, monoclonal reagents specific for host I-A and I-E glycoproteins were evaluated for their capacity to modulate transplantation immunity in a murine tail skin allograft system. It was found that treatment of A/J mice with 200 micrograms 10-3.6 hybridoma-derived anti-I-Ak antibody daily for 10 days resulted in an average twofold increase in the survival time of B10.A minor antigen-incompatible allografts. Similar results were achieved by using class I, but not H-2-mismatched, donor tissue. Specificity of antibody activity was demonstrated by the failure of isotype-matched reagents recognizing irrelevant class II or relevant class I H-2 antigens to influence rejection under these conditions. Although antibodies reactive with graft as well as host alloantigens provided the greatest degree of prolongation, interaction with host restriction elements alone was sufficient for the in vivo expression of regulatory activity. As in previous studies, anti-I-A treatment was associated with the development of antigen-specific suppressor T cells that serve to dampen allograft immunity without altering secondary responses to unrelated antigens encountered after the initial treatment interval. These data suggest that anti-Ia immunotherapy may provide a clinically relevant approach toward the specific regulation of transplantation immunity in the appropriate donor-recipient combinations.
Induction of IgG secretion in a human B cell clone with recombinant IL 2.
Authors: Kishi H , Inui S , Muraguchi A , Hirano T , Yamamura Y , Kishimoto T
Published: December 2022

A human B cell clone (SGB3) responsive to IL 2 was established. Both recombinant IL 2 and B cell differentiation factor (BCDF) induced IgG secretion in SGB3 cells in a dose-dependent manner, but IL 2 did not affect the proliferation of SGB3 cells. FACS analysis showed that SGB3 cells expressed Tac antigen and anti-Tac antibody inhibited IL 2-induced IgG secretion without any inhibitory effect on BCDF-induced IgG secretion. These results showed that IL 2 could directly act on B cells and provide a differentiation signal through IL 2 receptors distinct from BCDF receptors. Physiologic relevance of IL 2 in the antibody response was discussed.
Lymphokine-like activity of 8-mercaptoguanosine: induction of T and B cell differentiation.
Authors: Feldbush T L , Ballas Z K
Published: December 2022

Lymphocyte proliferation and differentiation result from ordered cellular interactions governed by soluble products (lymphokines). Dissecting the individual steps in these processes has been difficult, due to a paucity of pure lymphokines. Recently, it was reported that the derivatized ribonucleoside 8-mercaptoguanosine (8MGuo) has both mitogenic and differentiative effects on murine B cells. In the present studies, we tested 8MGuo for its ability to stimulate both B and T cell responses. In contrast to the murine studies, 8MGuo does not stimulate rat B cells to proliferate and, when tested for B cell growth factor-like activity, no stimulation was observed. The addition of 8MGuo (0.5 to 1 mM final concentration) to mitogen-stimulated B cells led to a marked increase in IgM and a modest increase in IgG secretion. When mixed with conditioned medium, 8MGuo acted synergistically in stimulating secretion of both isotypes, arguing that 8MGuo has both B cell-differentiating factor-mu (BCDF-mu) and BCDF-gamma activity. 8MGuo had no IL 2-like activity when tested on a mouse IL 2-dependent cell line, and no IL 1-like activity on addition to mouse thymocytes with or without submitogenic doses of lectin. However, when added to cultures of murine allogeneic cells in which the stimulating cell populations had been heat-inactivated, 8MGuo induced the generation of specific allogeneic cytotoxic T lymphocytes. Together, these results suggest that a simple derivatized nucleoside can induce both T and B cell differentiation without concomitant proliferation, and thus represent a unique probe for studying events in lymphocyte differentiation.
Distinction between antigen receptor and IL 2 receptor triggering events in the activation of alloreactive T cell clones with calcium ionophore and phorbol ester.
Authors: Albert F , Hua C , Truneh A , Pierres M , Schmitt-Verhulst A M
Published: December 2022

A previous study indicated that Ca++ ionophores in conjunction with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) could induce normal T lymphocytes to express receptors for the T cell growth factor, interleukin 2 (IL 2), to secrete IL 2, and to proliferate (1). Here we used long-term alloreactive Lyt-2+ cytotoxic or T4+ "helper" T cell clones. In response to their specific alloantigen, all of the clones secreted IFN-gamma but only the T4+ clone secreted IL 2 and proliferated in response to the appropriate alloantigen in the absence of exogenous IL 2. The Ca++ ionophore ionomycin and TPA, used in conjunction, mimicked the effect of specific alloantigen on these T cell clones, i.e., they induced the secretion of IFN-gamma in all clones and the secretion of IL 2 in the T4+ clone. In the absence of exogenous IL 2, a proliferative response was induced only for the IL 2 secreting clone. Increased sensitivity to exogenous IL 2 for some T cell clones was also observed after either alloantigen or ionomycin and TPA treatment; this could be correlated with an increase in the expression of IL 2 receptors 6 hr after a pulse with ionomycin and TPA. These results suggest that, for a given T cell clone, activation of the Ca++ -dependent protein kinase c can replace the antigen-receptor triggering events leading to interleukin secretion and increased expression of IL 2 receptors but cannot substitute for the IL 2 dependent triggering of the IL 2 receptor.
Mouse peritoneal macrophages plated on mannan- and horseradish peroxidase-coated substrates lose the ability to phagocytose by their Fc receptors.
Authors: Sung S S , Nelson R S , Silverstein S C
Published: December 2022

Ligand-conjugated substrates were used to study mouse macrophage receptor-ligand interactions. Both resident and thioglycollate-elicited macrophages plated on substrates conjugated with mannans and horseradish peroxidase (HRP), ligands for the Man/GlcNAc receptor, lost their ability to phagocytose zymosan. In addition, these macrophages also lost their ability to phagocytose IgG-coated erythrocytes (E(IgG] via their Fc receptors (FcR). The abrogation of Fc receptor-mediated phagocytosis occurred as early as 4 hr after macrophage plating on HRP-coated substrates and was dependent on the amount of HRP conjugated to the substrate. Macrophages plated on those substrates showed a 70% reduction in E(IgG) binding and the same decrease (approximately 35%) in binding of 125I-labeled Fab fragment of monoclonal anti-IgG2b FcR antibody as macrophages plated on dinitrophenyl-anti-dinitrophenyl IgG immune complexes. We interpret these results as showing that modulation of macrophage mannose/GlcNAc receptors induces modulation of FcR.
The specificity of the high endothelial venule in bronchus-associated lymphoid tissue (BALT).
Authors: van der Brugge-Gamelkoorn G J , Kraal G
Published: December 2022

By using an in vitro binding assay, the specificity of T and B cell adherence on high endothelial venules (HEV) of bronchus-associated lymphoid tissue (BALT) was studied in the rat and the guinea pig. It was found that the adherence specificity of the BALT HEV is different from that found in Peyer's patches and more closely resembles the specificity of the HEV in mesenteric lymph nodes. The data are discussed in view of a common mucosal immune system.
In vitro regulation of the pathogenic autoantibody response of New Zealand black mice. I. Loss with age of suppressive activity in T cell populations.
Authors: Moore J S , Calkins C E
Published: December 2022

An investigation of the regulation of specific anti-self responses was initiated with the development of an in vitro system in which spleen cells from NZB mice were stimulated by syngeneic mouse erythrocytes (MRBC) to produce MRBC-specific autoantibody-secreting cells. The response was measured by a modification of the focus-forming cell (FFC) assay, which enumerates cells secreting IgG, which specifically bind MRBC. Spleen cells from 9- to 12-mo-old NZB mice developed MRBC-specific FFC after 3 to 5 days in culture with MRBC. Few FFC were detected in the absence of MRBC in culture. Spleen cells from young (1- to 4-mo-old) NZB mice developed few if any FFC. Spleen cell populations containing T cells from young NZB mice suppressed this anti-MRBC response, whereas B cell populations from these young mice did not. In contrast, spleen cells, including T cell-enriched populations from old, Coombs'-positive mice were not capable under the same conditions of producing equivalent suppression of this in vitro autoimmune response. These data suggest that a population of suppressor T cells that may control the autoimmune anti-MRBC response in young NZB mice is lost, or else its activity is masked in old NZB mice that are actively producing anti-MRBC antibody.
Cloned allospecific human helper T cell lines induce an MHC-restricted proliferative response by resting B cells.
Authors: Goldberg D , Green A , Gottlieb A B , Crow M K , Lewison A , Friedman S M
Published: December 2022

To analyze helper T (Th) cell-induced B cell proliferation in man, we have cloned allospecific Th cells, grown them as long-term IL 2-dependent T cell lines (TCL), and analyzed their phenotypic and functional properties. The two TCL described in this report, A-7 and A-57, are both composed exclusively of T3+, T4+, T8- T cells blasts. In proliferative assays, with a panel of x-irradiated allogeneic stimulator cells, A-7 was found to proliferate in response to DR3-bearing cells, whereas A-57 responds to DR2-positive stimulators. Both TCL are capable of providing MHC-restricted polyclonal help for allogeneic B cells, as measured in the reverse hemolytic plaque assay. Of greater interest, x-irradiated A-7 and A-57 cells are capable of inducing a proliferative response by allogeneic B cells that is absolutely MHC restricted at the inductive (Th-APC) level. Thus, x-irradiated A-7 cells only trigger proliferation by DR3+ B cells, whereas A-57 cells selectively activate DR2+ B cells. In contrast, after antigen-specific activation, x-irradiated A-7 and A-57 cells can recruit a significant proliferative response by allogeneic B cells bearing "irrelevant" DR antigens. The possibility that Th-induced B cell proliferation may be restricted at the effector (Th-B cell) level was addressed by fractionating B cell populations into "activated" and "resting" subsets by discontinuous Percoll density gradient centrifugation and further purification by employing a monoclonal antibody directed against an antigen expressed on activated B cells (4F2). These studies demonstrate that activated B cells are readily and nonspecifically recruited to proliferate by activated Th cells, whereas optimal proliferative responses by resting B cells require MHC restricted Th-B cell interaction.
Cellular immunity in Q fever: modulation of responsiveness by a suppressor T cell-monocyte circuit.
Authors: Koster F T , Williams J C , Goodwin J S
Published: December 2022

Human infection with the rickettsia Coxiella burnetii presents as an acute flulike primary Q fever, as a subacute granulomatous hepatitis, or, rarely, as chronic endocarditis. We have previously described lymphocyte unresponsiveness to Coxiella antigen in patients with Q fever endocarditis. This unresponsiveness was antigen specific and was mediated in part by adherent suppressor cells. In this report we show that the adherent suppressor cells work via prostaglandin E2 (PGE2)4 production. Addition of the cyclooxygenase inhibitor indomethacin to cultures of PBMC from patients with endocarditis or chronic laboratory exposure resulted in consistent increases in Coxiella-specific lymphocyte proliferation. The degree of increase in proliferation induced by indomethacin correlated strongly with the amount of PGE2 produced in a 4-hr culture stimulated by Coxiella antigen, but it also correlated with the sensitivity to inhibition of mitogenesis by PGE2. The suppressor mechanism was antigen nonspecific, because induction of suppression in vitro by Coxiella antigen also suppressed Candida-induced proliferation when both antigens were present in the same culture. Addition of indomethacin to these antigen cocultures totally reversed the Coxiella-induced suppression, confirming the evidence above that the nonspecific effector mechanism of suppression was prostaglandin (PG)-mediated. Elicitation of suppression, however, was antigen specific and involved a T cell-monocyte suppressor circuit. Supernatants from Coxiella-stimulated immune T cells and from the suppressor subset (OKT8+-enriched) of those T cells, but not unstimulated immune cells, induced augmented PGE2 production by unrelated nonimmune PBMC. We conclude that the lymphocyte unresponsiveness characterizing patients with Q fever endocarditis is modulated in part by an antigen-specific T suppressor cell which secretes a lymphokine to stimulate PGE2 production by adherent cells.
Calcium requirements for increased complement receptor expression during neutrophil activation.
Authors: Berger M , Birx D L , Wetzler E M , O'Shea J J , Brown E J , Cross A S
Published: December 2022

It has recently been shown that human neutrophils rapidly increase surface expression of membrane receptors for C3b (CR1) and C3bi (CR3) in response to chemoattractants and other stimuli. In the present studies, we used monoclonal antibodies and flow cytometry to assess the role of Ca2+ in this process. Stimulation with ionophore A23187 in the presence of 1.2 mM Ca2+ increased CR1 330% and CR3 650% compared with unstimulated cells at 37 degrees C. Because this indicated that increasing the cytosolic free Ca2+ caused increased receptor expression, we examined the role of Ca2+ in the response to other stimuli as well. Adding 1.2 mM Ca2+ or 5 mM EDTA to the media in which the polymorphonuclear leukocytes were suspended had no effect on the CR1 response to f-MLP or LTB4, whereas Ca2+ slightly enhanced and EDTA markedly inhibited the CR3 response to these stimuli. The effects of Mg2+-EGTA and EDTA were identical. TMB-8 (200 microM), which inhibits the release of Ca2+ from intracellular stores, completely blocked the increased expression of both receptors induced by fMLP or LTB4. Increased expression of both receptors was also prevented by the calmodulin antagonists chlorpromazine (50 microM) and trifluoperazine (10 microM), but not by chlorpromazine sulfoxide. Phorbol myristate acetate (0.1 ng/ml) increased CR1 230% and CR3 265%. Again Ca2+ and EDTA did not alter the CR1 response, whereas Ca2+ increased CR3 to 287% and EDTA reduced CR3 to 187% of control. TMB-8 (250 microM) completely blocked both CR1 and CR3 responses to this stimulus as well. Thus, release of intracellular Ca2+ is necessary and sufficient for increased CR1 expression in response to diverse stimuli, but maximal increases in CR3 expression require an additional influx of extracellular Ca2+. These results indicate that the mechanisms by which the surface expression of the two different complement receptors increase are different in their requirements for extracellular Ca2+. In comparison with the work of others, we suggest that the processes of increased complement receptor expression and secretion of granular enzymes may also differ.
The helper and suppressor functions of primate T cells elicited by a 185K streptococcal antigen, as compared with the helper function elicited by a 4K streptococcal antigen.
Authors: Lehner T , Mehlert A , Avery J , Jones T , Caldwell J
Published: December 2022

Helper and suppressor functions of human T lymphocytes that act on antibody-forming B cells were elicited by a large 185K streptococcal cell wall antigen. However, a small 4K streptococcal peptide elicited helper but no suppressor function. These differences in the functional activities of the large and small m.w. streptococcal antigens (SA) were confirmed by direct immunisation of rhesus monkeys with the 185K-SA and 4K-SA. Sequential studies have shown that whereas the 185K-SA elicits dose-dependent helper and suppressor activities, the 4K-SA elicits only helper function. Cell-depletion studies with human cells suggest that removal of T8+ cells by killing with OK.T8 and complement leads to a loss of suppressor and a broadening in the concentration of 185K-SA, which elicits helper activity. Because the 4K-SA does not elicit suppression, removal of T8+ cells does not affect this function. However, similar depletion of T4+ cells results in loss of the helper activities, both with the 185K-SA and 4K-SA, and again a broadening in the concentration of the 185K-SA, which elicits suppression. Direct comparison by autoradiography between 125I-labeled 185K-SA and 4K-SA suggests that both antigens can bind directly to monocytes or T8+ VV+ cells. Furthermore, both antigens can induce helper function if T4+ cells are reconstituted with either monocytes or T8+ VV+ cells. Attempts will now be made to sequence the amino acid determinants of the 185K-SA, so as to define the epitopes responsible for the two major regulating functions elicited by this antigen.