bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferon enhances the antibody-dependent cellular cytotoxicity (ADCC) of human polymorphonuclear leukocytes.
Authors: Hokland P , Berg K
Published: December 2022

Polymorphonuclear leukocytes (PMN) from healthy volunteers were tested for ADCC activity against both erythrocyte and tumor targets with and without the addition of human leukocyte interferon (IFN). It was demonstrated that IFN within 30 to 60 min enhanced the reaction in a dose-dependent manner with minimal IFN doses ranging from 1 to 100 units. Formal proof that the augmenting agent was IFN was obtained by using pure IFN proteins in combination with both mock-IFN preparations, which showed no enhancing activity, and anti-IFN antisera, which inhibited the action of the completely purified IFN proteins. In the light of data demonstrating that the IFN effect was most pronounced when the IgG antibodies in the ADCC reaction were present in suboptimal amounts, it is hypothesized that IFN may play a special role in the early nonspecific immune response against non-self antigens.
A microfluorometric assay for the measurement of de novo DNA synthesis in individual cells.
Authors: Gordon L K , Parker C W
Published: December 2022

A microfluorometric assay has been developed for the quantitation of de novo DNA synthesis. The assay reliably detects newly synthesized DNA in individual cells and provides a relative measure of the proportion of new DNA in each cell. When combined with microscopic techniques for cell identification, selected subpopulations can be examined in samples containing a complex mixture of interacting cell types. The assay employs the quenching of Hoechst-33258 fluorescence by bromodeoxyuridine incorporated into newly synthesized DNA. The ability of BUdR to quench H-33258 fluorescence is lost after a brief exposure of ultraviolet fluorescence excitation. Therefore, quenched and unquenched fluorescence intensity measurements from the same cell can be compared. Increases in fluorescence intensity occur only in cells that have synthesized DNA after the addition of BUdR. In addition the change in fluorescence intensity is proportional to the degree of BUdR substitution within the range of the assay and provides a relative measure of DNA synthesis.
Recognition of alternate alleles and mapping of the Qa1 locus.
Authors: Stanton T H , Carbon S , Maynard M
Published: December 2022

Cytotoxicity testing of a new antiserum, B10.A anti-A. TIab, indicates that we have identified products of the Qa1b locus. The strain distribution is antithetical to Qa1a except for strain B10.M, which is reactive with both anti-Qa1a and anti-Qa1b sera, and defines a third allele, Qa1d. Two new recombinants that separate Qa1 and TIa have been established and indicate that Qa1 maps telomeric to TIa. In addition, we have found evidence that other loci, also on chromosome 17, modify the level of detectability of Qa1 antigens by cytotoxic testing.
Activated T cells in human peripheral blood: quantitation with a reverse hemolytic plaque assay.
Authors: Cohen P L , Litvin D A , Winfield J B
Published: December 2022

Rabbit antiserum to culture supernatant of concanavalin A-stimulated peripheral blood mononuclear cells was used in a reverse hemolytic plaque assay to detect activated T lymphocytes in human peripheral blood. The number of plaque-forming cells in fresh, unstimulated lymphocyte preparations was approximately 400/10(6) cells, and increased 7- to 14-fold after stimulation with a variety of mitogens and antigens. The kinetics of the increase paralleled 3H-thymidine incorporation, with a maximum on day 3 of culture. Plaques were eliminated by treatment of cells with anti-Leu-I + complement or by depletion of E-rosettes. The activated T cells were not restricted to a given inducer, suppressor, or Ia+ T cell subset, however. Both mitogen-stimulated culture supernatants and mitogen-activated lymphocytes, but not resting lymphocytes, were effective in absorbing the capacity of the rabbit antiserum to develop plaques. This suggested that the predominant specificity of this antiserum was directed toward surface membrane determinant(s) of T cells actively shed into the medium. This process was shown to require ongoing protein synthesis, and, in mitogen-stimulated lymphocyte preparations, DNA synthesis as well. This approach has enabled detection of a surprisingly large number of endogenously activated T cells in normal human blood, and should be useful for the analysis of immunoregulatory events at the single-cell level.
Interaction of reovirus with cell surface receptors. III. Reovirus type 3 induces capping of viral receptors on murine lymphocytes.
Authors: Epstein R L , Powers M L , Weiner H L
Published: December 2022

We have previously shown that there are receptors for the hemagglutinin of reovirus type 3 on a subset of both murine T and B cells. Using purified reovirus type 3 particles as a ligand, followed by FITC-labeled antiviral antibody we have now been able to demonstrate viral induced capping of the reovirus receptor on both B and T cells. Kinetic studies and inhibition experiments using cytochalasin B and colchicine demonstrate that reovirus-induced capping of the viral receptor on both B and T cells has characteristics identical to the capping of immunoglobulin on B cells by anti-immunoglobulin reagents. Removal of the viral receptor and reexpression after overnight culture was demonstrated after membrane treatment by proteolytic enzymes (trypsin, pronase) or after viral induced modulation of receptor. Protein synthesis was required for reexpression since cyclohexamide prevented the reexpression of receptor in culture. Co-capping studies utilizing 2-color immunofluorescence failed to identify and association between the reovirus receptor and a variety of known surface structures on either B or T cells, but demonstrated independent modulation of the viral receptor from other surface structures. These studies suggest that the lymphocyte surface binding site for reovirus type 3 is a distinct structure that behaves identically in capping studies of both B and T cells, is protein in nature, and is intimately linked to the cell cytoskeleton.
Hemolytic plaque formation by cellular and noncellular elements of human colostrum.
Authors: Laven G T , Crago S S , Kutteh W H , Mestecky J
Published: December 2022

The morphologic, histochemical, and immunohistochemical characteristics of colostral elements that form indirect IgA hemolytic plaques were determined. Microscopic examination of hemolytic plaques revealed noncellular, globular elements at the center of 82% of the plaques formed by colostral cell preparations. Similar globules in colostral cell preparations contained IgA, IgG, IgM, SC, lactoferrin, alpha-lactalbumin, and lipid. Lysates of colostral cell preparations contained large amounts (500 ng/10(6) cells) of polymeric, SC-associated IgA. These findings suggest that plaque formation by colostral cell preparations may be due to the release of passively acquired, preformed S-IgA from colostral elements, rather than active production of IgA by lymphoid cells.
Regulation of human natural killing. I. The role of monocytes, interferon, and prostaglandins.
Authors: Koren H S , Anderson S J , Fischer D G , Copeland C S , Jensen P J
Published: December 2022

We have found that human endogenous natural killer activity as measured in a rapid 51Cr release assay is unaffected by the presence of monocytes. Moreover, stimulation of natural killer cells by poly I:C is independent of monocytes. In contrast, the presence of monocytes in a mixed population of mononuclear cells that have been stimulated by poly I:C suppresses NK activity. The suppression is shown to be partially reversible if indomethacin (10(-6) M) is added to the cultures during stimulation. Culture supernatants of monocytes stimulated with poly I:C are shown to contain PGE1 in a radioimmunoassay, and have NK inhibitory activity comparable to that obtained with exogenous PGE1 added to NK assays at a concentration range of 10(-7) to 10(-9) M. Culture supernatants from poly I:C-stimulated monocytes do not have detectable levels of antiviral activity. In contrast, plastic nonadherent cells stimulated with poly I:C produce significant levels of interferon (100 to 200 U/ml/2 x 10(6) cells) but almost undetectable amounts of PGE. Supernatants of nonadherent cells incubated with indomethacin (10(-6) M) alone augment NK activity. Taken together, the results suggest that stimulation of mononuclear cells with poly I:C is dependent on and regulated by the relative levels of interferon produced by lymphocytes and PGE produced by monocytes.
Myelogenous production and maturation of B lymphocytes in the mouse.
Authors: Landreth K S , Rosse C , Clagett J
Published: December 2022

Cells of the B lymphocyte lineage in young adult murine bone marrow were identified and resolved into compartments based on cell size and the expression of the mu heavy chain of IgM in the cytoplasm (cmu) or on the cell surface (smu). The proliferative status, renewal rate, and intercompartmental transit of cells through the defined compartments were determined using established protocols of in vivo tritiated thymidine (3H-TdR) administration, followed by radioautography of bone marrow smears. In addition, we specifically tested whether any of the defined cell compartments were derived from long-lived lymphocytes that are known to enter the marrow. Only large cells immediately incorporated the DNA precursor and both small cmu+ smu- and cmu+ smu+ cells were postmitotic lymphocytes. Large cmu+ smu- cells were found to be a rapid transit compartment in which the last mitosis of B lymphocyte differentiation takes place. All large cmu+ smu- cells divided only once, and both daughter cells entered the postmitotic small cmu+ smu- population. Large cmu+ smu- cells relied for their maintenance entirely on cell input from an Ig- progenitor compartment. Progenitors of cmu+ smu- large cells were not small lymphocytes, proliferated less rapidly than their descendants, and maintained the input of large cmu+ smu- cells for up to 40 hr. Approximately 70% of small cmu+ smu- cells were the immediate division products of large cmu+ smu- cells, whereas the remainder were derived from a precursor with no detectable mu synthesis. Small cmu+ smu+ cells were the maturation products of small cmu+ smu- cells. This conversion appeared to take place at random rather than as a function of postmitotic age. Renewal times for small cmu+ cells without or with detectable smu were calculated to be 48 and 96 hr, respectively. Only the cmu- smu+ compartment included long-lived cells. All other mu+ populations either proliferated or were replaced by newly produced cells. A conspicuous minor population of large smu+ B cells were detected, and the data relating to these were subjected to several interpretations. These observations provide insight into the origin and fate of B lineage precursors in the marrow and suggest a scheme for the terminal stages of B lymphocytes formation that is similar to the myelogenous production of other hemopoietic cells.
Purification from guinea pig erythrocyte stroma of a decay-accelerating factor for the classical c3 convertase, C4b,2a.
Authors: Nicholson-Weller A , Burge J , Austen K F
Published: December 2022

A protein with decay-accelerating activity for the classical C3 convertase, C4b2a, has been isolated on the basis of this function from guinea pig erythrocyte stroma. The isolation procedure for decay-accelerating factor of stroma (DAF-S) utilizes butanol extraction and chromatography on DEAE-Sephacel, hydroxylapatite, and phenyl Sepharose. Purified DAF-S has a m.w. of 60,000 and 65,000 on reduced and unreduced SDS gels, respectively, and exhibits m.w. of 30,000 and 175,000 on alkaline gradient gels, suggesting multiples of a 60,000-65,000 subunit. Purified DAF-S elicited a monospecific antiserum whose IgG fraction neutralized the decay-accelerating activity for C4b,2a affixed to 10(7) sheep erythrocytes (EAC1,4,2) in a dose-response fashion. The monospecific antiserum diluted up to 1:5120 agglutinated 1 x 10(6) guinea pig erythrocytes, but not sheep or human erythrocytes, suggesting that DAF-S, an integral membrane protein, has species-specific antigens that are expressed on the surface of the guinea pig erythrocyte.
Enumeration of T lymphocyte subsets by monoclonal antibodies in young and aged humans.
Authors: Nagel J E , Chrest F J , Adler W H
Published: December 2022

The percentage and absolute number of peripheral blood mononuclear cells reactive with monoclonal antibodies identifying mature thymocytes and T cells (T3+), helper/inducer cells (T4+), and suppressor/cytotoxic cells (T8+) was determined in 19 young (mean age 35 yr) and 31 elderly (mean age 72 yr) individuals. The percent representation but not the absolute number of T cells (T3+) declined significantly (p less than 0.001) in the elderly, and the decline was attributable to both an absolute and relative decrease in the representation of the subpopulation of cytotoxic/suppressor (T8+) cells. The percentage and number of helper/inducer (T4+) T cells was comparable in both age groups.
Lymphokines and aging: interleukin-2 production and activity in aged animals.
Authors: Thoman M L , Weigle W O
Published: December 2022

The capacity of aged animals to produce and respond to the T cell-replacing factor, interleukin-2 (IL-2), has been examined. IL-2 activity in the supernatants of concanavalin A-activated aged spleen cells is 5- to 10-fold lower than comparable supernatants prepared using young spleen cells. This lesion in IL-2 synthesis may limit antibody production to T-dependent antigens, because supplementation with purified IL-2 markedly enhances the number of anti-SRBC plaques generated by aged spleen cells. The response of aged splenocytes can be fully restored to that obtained using young adult cells. However, there appears to be a defect in the ability of aged cells to effectively translate the IL-2 signal into B cell helper activity, in the absence of T lymphocytes. That is, although young adult, nylon wool-purified T cells can interact with aged T-depleted spleen cells, producing a normal high level anti-SRBC response, IL-2 is incapable of reconstituting the response in aged animals to this level. On the other hand, both young adult T cells and IL-2 can interact with young adult T-depleted splenic lymphocytes to produce a normal, high level anti-SRBC response.
Induction of immunoglobulin secreting cells in the human autologous mixed leukocyte reaction: regulation by helper and suppressor lymphocyte subsets defined with monoclonal antibodies.
Authors: Gatenby P A , Kotzin B L , Engleman E G
Published: December 2022

The generation of IgM- and IgG-secreting cells in the human autologous MLR has been confirmed by using a microwell culture system and a reverse hemolytic plaque assay. The regulation of this response by T cell subsets was examined by using monoclonal antibodies that have previously allowed the definition of a Leu-3 helper/inducer subpopulation and a Leu-2 suppressor/cytotoxic subpopulation. These subsets were isolated by "panning" with monoclonal antibodies and were then cultured with autologous non-T cells, which serve as both stimulators of the reaction and a B cell source. The induction of antibody-forming cells was found to be dependent upon the Leu-3 subset whereas the Leu-2 subset not only failed to support C cell maturation, it actively suppressed the Leu-3 induced response. The Leu-3 response was found to be partially sensitive to radiation doses of 1000 rad or greater, whereas Leu-2 mediated suppression, even at high doses of cells, was totally ablated by 1500 rad. Thus, the generation of antibody-forming cells in the human autologous MLR is regulated by a balance of Leu-3 cell help and Leu-2 cell suppression. Such a finding may prove to be of relevance to immunoregulation in both health and disease.
Cutaneous basophil responses and immune resistance of guinea pigs to ticks: passive transfer with peritoneal exudate cells or serum.
Authors: Brown S J , Askenase P W
Published: December 2022

Resistance to infestation by larval Amblyomma americanum or Rhipicephalus sanguineus ticks was transferred to naive guinea pigs with peritoneal exudate cells (PEC) or serum from donors immunized by prior infestation with homologous tick larvae. In the A. americanum system, PEC transfer induced 87% tick rejection, which was similar to the level of resistance in actively sensitized hosts. In the R. sanguineus system, PEC conferred resistance (39% rejection) that was weaker than in actively sensitized hosts (57% rejection). In both systems, immune serum conferred significant but weaker resistance (20 to 29% rejection). In actively sensitized hosts, resistance to each tick species was specific, but there was considerable cross-reactive resistance. Basophils dominated the 24-hr challenge feeding sites of A. americanum ticks in actively sensitized hosts (69% of the infiltrate) and recipients of sensitized PEC (69%). Mononuclear cells were dominant (69% of the infiltrate) in the challenged tissues of immune serum recipients that had a significant but weaker cutaneous basophil response (24%). Mononuclear cells also dominated (58% of the infiltrate) the 24-hr challenge feeding sites of R. sanguineus ticks in actively sensitized hosts, but there were also 24% basophils. These studies demonstrate that immune resistance to tick is dependent on sensitized lymphoid cells or serum components, and that sensitized cells or serum can transfer a cutaneous basophil response that is associated with immune resistance. Rejection of ticks is usually associated with large basophil infiltrates, but sometimes mononuclear cells are dominant. Thus, immune resistance of guinea pigs to ticks is a heterogeneous response in which immune cells and serum probably act to recruit diverse effector leukocytes to mediate rejection that is specific but significantly cross-reactive.
A monoclonal antibody-inhibiting FMLP-induced chemotaxis of human neutrophils.
Authors: Cotter T G , Keeling P J , Henson P M
Published: December 2022

A monoclonal IgG1 antibody, termed NCD3, was raised against human neutrophils and has been shown to inhibit neutrophil chemotaxis. NCD3 displayed a considerable degree of stimulus specificity in that it inhibited N-formyl-methionyl-leucyl-phenylalanine- (FMLP) induced chemotaxis up to 80%, C5a and zymosan-activated plasma induced chemotaxis by only 20% and had no effect on leukotriene B4- (LTB4) or casein-mediated chemotaxis. NCD3 did not inhibit granule enzyme release from neutrophils in response to stimulation by various secretagogues, including FMLP, in the presence or absence of cytochalasin B (CB). Neutrophil phagocytosis of 51Cr-labeled opsonized sheep erythrocytes (51Cr-EAC) and superoxide anion (O2-) production in response to FMLP or phorbol myristate acetate (PMA) stimulation were not affected by pretreating cells with NCD3. Divalency of NCD3 was necessary for inhibition of chemotaxis, suggesting a requirement for cross-linking of the antigenic determinants on the neutrophil membrane surface.
Suppressor cell activity in tumor-bearing mice. III. Co-purification of a factor inhibiting cellular DNA synthesis and DNA polymerase activity.
Authors: Farrar W L , Elgert K D , Foo A S
Published: December 2022

The factor(s) derived from fibrosarcoma-induced suppressor T cells was sensitive to pronase and neuraminidase, but not to trypsin, beta-galactosidase, DNase, or RNase. Protein and RNA, but not DNA, synthesis were required to mediate suppression. Suppressor T cell-derived factor(s) could be precipitated by a 50% saturated ammonium sulfate (SAS) solution. The 50% SAS fraction inhibited both in vitro and in vivo spleen cell blastogenesis, whereas the 80% and unprecipitated fractions had no inhibitory activity. Using Sephadex G-200 chromatography, the 2nd protein fraction (fraction II) contained an inhibitor of both DNA polymerases (IDP) and DNA synthesis (IDS) activity, which possessed no cytotoxic activity. In vitro DNA polymerase alpha activity was suppressed by fraction II, whereas DNA polymerase beta and gamma activities remained unchanged. Molecular weight of IDP/IDS, as determined by Sephadex G-200 gel filtration chromatography, was approximately 14,500. Attempts to separate IDP/IDS activities found in fraction II by anion-exchange chromatography and slab gel electrophoresis were not successful, which suggested that the 2 activities were the same or very similar molecules.
Genetic control of natural resistance to Mycobacterium bovis (BCG) in mice.
Authors: Gros P , Skamene E , Forget A
Published: December 2022

Mice of 12 inbred strains infected i.v. with Mycobacterium bovis (BCG) exhibited 2 distinct patterns of response as determined by the degree of BCG burden in the spleens of animals at 3 wk after infection with 10(4) viable bacilli: susceptible (C57BL/6J and related sublines, BALB/c and DBA/1J) and resistant (A/J, C3H/HeCr, DBA/2J, CBA/J, C57Br, AKR). Mendelian analysis of this trait on segregating backcross and F2 populations derived from the mating of resistant and susceptible progenitors was compatible with the hypothesis that resistance to BCG is controlled by a single, dominant, autosomal gene, which is being given the designation Bcg. The product of the Bcg gene was found to influence the early phase of host response resulting in the genetic advantage of the resistant host being demonstrable as early as 24 hr after infection.
Ir genes of different high responder haplotypes for staphylococcal nuclease are not allelic.
Authors: Berzofsky J A , Pisetsky D S , Killion D J , Hicks G , Sachs D H
Published: December 2022

The Ir gene controlling high responsiveness to staphylococcal nuclease in the H-2d haplotype has been mapped to the I-A subregion, in contrast to that in the H-2k and H-2a haplotypes, which maps in the I-B subregion. The nonallelic high responder genes also confer differences in fine specificity on the antibodies produced. This nonallelism of Ir genes for the same antigen in different haplotypes is consistent with Ir gene mechanisms involving associative recognition of antigen plus Ia by T lymphocytes. It further suggests that products of different subregions can perform the same function.
A shared alloantigenic determinant on Ia antigens encoded by the I-A and I-E subregions: evidence for I region gene duplication.
Authors: Bhattacharya A , Dorf M E , Springer T A
Published: December 2022

Two monoclonal antibodies to mouse Ia antigens were produced by fusion of xenoimmune rat spleen cells with the NSI myeloma. These monoclonal antibodies detect polymorphic determinants present on B cells and activated T lymphocytes from mice carrying the H-2b, H-2d, H-2k, H-2r, and H-2q haplotypes but not from mice carrying the H-2s or H-2r haplotypes. Antigenic site number determinations showed the positive haplotypes can be divided into 2 groups. Mice bearing the H-2b, H-2d, and H-2q haplotypes express a high number--40,000 to 80,000--of antigenic sites per B lymphocyte, and monoclonal antibody plus complement can lyse B cells from these mice. In contrast, mice bearing the H-2k and H-2r haplotypes express a low number of antigenic sites--about 5000 per cell. Spleen cells from mice carrying the latter haplotypes are not lysed with monoclonal antibody and complement. Genetic mapping demonstrated that high and low expression map to the I-A and I-E subregions, respectively. The monoclonal antibodies detect an Ia specificity on I-Ab, I-Ad, I-Ed, and I-Ek molecules. These observations were confirmed using several different experimental approaches, i.e., cytotoxicity, fluorescent staining, competitive inhibition of monoclonal antibody binding, and 2-dimensional gel electrophoresis of immunoprecipitates. The avidity for A alpha b A beta b and E alpha k E beta k is 5 to 7 x 10(-9) M-1. The antigenic determinant is heat labile, which suggests that it is not carbohydrate. The results imply that Ia antigens encoded by distinct subregions share sequence homology, which may be a consequence of ancestral gene duplication.
Genetic control of B cell function. II. Antibody responses of inbred mice to red blood cells are controlled at the B cell level.
Authors: Hetzelberger D , Simon M M , Eichmann K
Published: December 2022

Inbred strains of mice can be classified into high and low responders with respect to their antibody responses to RBC. In this paper, we investigate the cellular basis of the difference in responsiveness between high- and low-responder strains. In cell-mixing experiments with purified B cells, T cells, and macrophages from 2 different combinations of H-2-identical high- and low-responder strains, we find that the B cells determine high and low responsiveness, whereas T cells and macrophages from low responders function equally as well as those of high responders. We could also exclude that suppressor T cells play an important role in determining high and low responsiveness. It is therefore suggested that low responsiveness is a defect of B cells to become activated in a T helper cell-dependent antibody response. In the previous paper of this series we showed that a limited number of genes (possibly 2), 1 linked to the Igh gene complex and the other(s) of unknown linkage, control the level of responsiveness. Taken together, we think that this represents a novel example of a genetic polymorphism in B cell function that is sufficiently simple, genetically and functionally, to provide a genetic approach to the study of B cell activation.
Binding of C-reactive protein to human lymphocytes. II. Interaction with a subset of cells bearing the Fc receptor.
Authors: James K , Hansen B , Gewurz H
Published: December 2022

In the preceding paper we reported that C-reactive protein (CRP) in the presence of a multimeric binding specificity such as C-polysaccharide (CPS) binds to a small percentage of peripheral blood lymphocytes (PBL). In the present paper additional methods for demonstrating this binding were developed and utilized to help characterize the CRP-binding cell. Heat-modified CRP and E-CPS-CRP each were found to bind to a similar percentage of PBL by microscopic visualization, and an identical degree of binding was observed by cytofluorimetric analysis. Multiple marker studies indicated that CRP-binding cells are found in the T cell, B cell, and null cell categories in a ratio of 2:1:1, respectively. Preferential overlap was seen with IgG FcR-bearing cells, which accounted for 70% of the CRP-binding cells; however, only 12% of the FcR cells bound CRP. These studies indicate that CRP-binding cells predominantly represent a subset of cells bearing FcR, and these cells have the morphologic characteristics of large granular lymphocytes. CRP in the presence of CPS bound to cells of multiple human and murine cultured lines shown to have IgG FcR reactivity, but showed lesser or no binding to cell lines negative for FcR. The precise morphologic and functional characterization of the CRP-binding cells and the nature of the binding site are yet to be established.
Inhibition of C1-mediated immune hemolysis by monomeric and dimeric peptides from the second constant domain of human immunoglobulin G.
Authors: Lukas T J , Muñoz H , Erickson B W
Published: December 2022

Activation of the classical complement cascade by immunoglobulin G involves binding of the first complement component (C1) to a multivalent antigen-IgG complex. Binding occurs by interaction of a site on the surface of the C gamma 2 domain of IgG with a globular head of the C1q subcomponent of C1. Previously we found that the synthetic decapeptide consisting of residues 281-290 from the second constant domain of the gamma-chain of the human IgG1 protein Eu inhibited the binding of human C1 to sensitized erythrocytes. The present study describes inhibition of monomeric and dimeric peptides containing residues 289-292 or 282-292: (formula: see text). On a molar basis, monomeric peptide 282-292 is just as active an inhibitor of C1 binding as peptide 281-290, whereas monomeric peptide 289-292 (tuftsin) is 4 times less active. Peptides 282-292 and 289-292 were each cross-linked at the amino terminus through terephthaloyl-bis(iminodiacetic acid) (Tid). Each dimeric peptide is twice as active on a molar basis as the corresponding monomeric peptide. Dimeric peptide Tid(282-292)2 is just as active on a molar basis as the monomeric 7S form of human IgG1 and 60% as active as the Fc fragment of IgG in inhibiting the binding of human C1 to sensitized erythrocytes. These results suggest that the positively charged residues His-285, Lys-288, Lys-290, and Arg-292, which are located on the outer surface of the C gamma 2 domain, may be involved in the C1q-binding site of human IgG.
T cell recognition of Moloney leukemia virus proteins. III. T cell proliferative responses against gp70 are associated with the production of a lymphokine inducing 20 alpha-hydroxysteroid dehydrogenase in splenic lymphocytes.
Authors: Ihle J N , Lee J C , Rebar L
Published: December 2022

One of the characteristic cellular immune responses associated with the regression of Moloney leukemia/sarcoma virus-induced tumors is a T cell proliferative response against the major viral envelope glycoprotein, gp70. The results described here demonstrated that associated with this proliferative response is the production of a lymphokine, Interleukin 3 (IL-3). The production of IL-3 was immunologically specific and showed the same specificity as that observed in blastogenic responses. IL-3 production was dependent upon an antigen-specific Thy-1.2+, Lyt-1+, 2- lymphocyte subpopulation but did not require the presence of an Ia+ or an adherent accessory cell. The results also suggested that IL-3 may constitute one of the blastogenic factors previously shown to be involved in the proliferative response to gp70. In particular, purified IL-3 was found to induce proliferation of both normal and immune nylon wool purified splenic lymphocytes. The phenotype of the responding lymphocyte subpopulation was Thy-1.2-, Lyt-1-, 2-, Ig-, and Ia-. Maximal IL-3 production occurred approximately 48 hr after the addition of antigen and its production was significantly blocked by mitomycin C. These characteristics were unlike those for the general production of blastogenic factor activity suggesting that IL-3 is responsible for only a minor component of the proliferative response.
Hypersensitivity pneumonitis in nonhuman primates. I. Studies on the relationship of immunoregulation and disease activity.
Authors: Keller R H , Calvanico N J , Stevens J O
Published: December 2022

We investigated the relationship of immunoregulation to disease activity in a nonhuman primate model of pigeon breeder's disease. Two Macaca arctoides monkeys developed classical symptoms of hypersensitivity pneumonitis after sensitization and prolonged bronchial challenge, whereas 2 other monkeys remained asymptomatic after in vivo challenge. There were no differences in the percentages of T cells, B cells, monocytes, or FC gamma-bearing T cells between symptomatic and asymptomatic animals. Nonetheless, we found a population of concanavalin A-induced, pigeon serum- (PS) induced, and spontaneous T cells that functioned as suppressor cells in autologous in vitro co-cultures in asymptomatic animals that were missing or nonfunctional in symptomatic animals. Monocyte suppressors functioned in both groups. We used low-dose total body irradiation (TBI) to inactivate T suppressor cells. Fifteen radiation units of TBI caused no change in the physical activity, routine chemistries, or blood counts of the 4 animals. After TBI, however, the previously asymptomatic animals developed fever, tachypnea, and signs of pulmonary congestion after in vivo challenge with PS. There was no change in the response to challenge in the symptomatic group. This altered response to in vivo challenge in the previously asymptomatic group persisted for 2 wk after TBI. During this period the difference in vitro immunoregulatory activity between Con A-induced, PS-induced, and spontaneous T cells in symptomatic and asymptomatic animals disappeared. Monocyte suppressors, however, continued to function in both groups after TBI. These data suggest that the monkey is an appropriate model for studies of human HP and that T cell immunoregulation may be an important element in the pathogenesis and disease activity of HP.
Cultured human monocytes require exposure to bacterial products to maintain an optimal oxygen radical response.
Authors: Pabst M J , Hedegaard H B , Johnston R B
Published: December 2022

Freshly isolated human blood monocytes displayed a vigorous oxygen radical response, measured as release of superoxide anion (O2-), after stimulation with phorbol myristate acetate (PMA) or opsonized zymosan. High O2- release was observed with cells isolated by using a variety of procedures. Monocytes cultured in endotoxin-free medium M199 with or without 5% heat-inactivated autologous serum gradually lost this ability to produce O2- in response to PMA over the course of 4 days. The decreased responsiveness to PMA was accompanied by decreased adherence and viability. The loss of function, adherence, and viability was prevented by supplementing the culture medium with either bacterial lipopolysaccharide (LPS) or muramyl dipeptide (MDP). The O2- response of monocytes cultured for several days without bacterial products could be partially restored by the addition of LPS on day 2 or 3 of culture. Partial restoration could be detected in monocytes after only 1 hr of exposure to LPS, although a maximal response required a 2-day exposure. The minimum effective concentration of MDP was 1 ng/ml; stereoisomers of MDP, which are inactive as adjuvants, had no effect at 1 micrograms/ml. The minimum effective concentration of LPS was 1 pg/ml, corresponding to fewer than 10 molecules of LPS per monocyte. These results suggest that exposure to LPS or other bacterial products, represented here by MDP, may be required to preserve the microbicidal potential of human monocyte-macrophages in vivo.
Genetic influences on the adjuvanticity of muramyl dipeptide in vivo.
Authors: Staruch M J , Wood D D
Published: December 2022

The possibility that the adjuvanticity of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) is under genetic control in mice was examined. It was observed that MDP markedly enhances the secondary antibody response of BALB/c mice to bovine albumin but has little enhancing effect on C57BL/10Sn (B10) mice under the same conditions. This strain difference was not abolished by variations in the amount of MDP, the immunization protocol, the assay method, or the antigen used. An analysis of inbred and congenic strains showed that the responsiveness to MDP was influenced by at least two genes, one inside and one outside of the major histocompatibility complex. Mice with the C57BL background and/or the H-2b genome responded weakly to the adjuvant action of MDP, whereas those with the BALB/c or C3H background and/or H-2d or H-2k haplotypes responded more strongly. It is anticipated that the analysis of the mechanism of adjuvanticity of MDP will be facilitated by the use of mice that differ in their response to the adjuvant action of MDP.
Mechanisms controlling TCGF production by cloned sublines of EL-4 azgr in response to stimulation by anti-Thy-1 antibody.
Authors: Shimizu S , Smith R T , Norcross M A , Maino V C
Published: December 2022

The effect of xenogeneic anti-Thy-1 antibody on T cell growth factor (TCGF) production by T lymphoma cell lines has been examined as a model system for T cell activation. EL-4 G12 (a cloned subline of the producer EL-4 azgr cell line) produced TCGF when stimulated by a high concentration of anti-Thy-1, but none was induced by low concentrations of anti-Thy-1. Large amounts of TCGF were produced when these cells were cultured with Fc-receptor positive (FcR+) accessory cells. TCGF production by EL-4 G12 showed dose response kinetics similar to TCGF production by anti-Thy-1-stimulated, purified normal spleen T cells. Goat anti-rabbit IgG (GaRIG) and protein A substituted for this accessory helper effect, but neither FcR+ cells nor Protein A worked when (Fab')2 anti-Thy-1 was used instead of IgG anti-Thy-1. Anti-T-200 monoclonal antibody inhibited anti-Thy-1-induced TCGF production by EL-4 G12 and accessory cells. Phorbol myristic acetate and lymphocyte-activating factor also substituted in part for the accessory cell help. The data suggest there are at least 2 different accessory cell help mechanisms in anti-Thy-1-induced TCGF production, anti-Thy-1-bound membrane aggregation either by GaRIG, Protein A or FcR, and a LAF-dependent mechanism.
Delayed hypersensitivity granuloma formation around Schistosoma mansoni eggs in vitro. I. Definition of the model.
Authors: Doughty B L , Phillips S M
Published: December 2022

An in vitro model of granuloma formation was established in order to study the cellular interactions involved in the formation of delayed hypersensitivity granulomas and the cellular interactions responsible for host modulation of that response in chronic infections of schistosomiasis. This model utilizes Schistosoma mansoni eggs from adult worm pairs that have been cultured in vitro as an antigenic source and spleen cells from either normal or actively infected C57BL/6 mice as the cell donors. The results establish a consistent sequence of events characterized by initial adherence of mononuclear cells to the egg; subsequent blast transformation by these cells; recruitment of additional mononuclear cell populations, including lymphocytes and macrophages; and recruitment of eosinophils and fibroblasts, which are capable of synthesizing collagen. The immunologic nature of this reaction has been established through analyses after presensitization either by natural infection or through the use of soluble egg antigen. These studies have demonstrated the immunologic specificity of the reaction, its dependence on an initial T lymphocyte-mediated event, and recruitment of other cell populations. Preliminary studies show that modulation in vitro reflects the in vivo kinetics of granuloma modulation.
The complete V domain amino acid sequences of two myeloma inulin-binding proteins.
Authors: Johnson N , Slankard J , Paul L , Hood L
Published: December 2022

The myeloma proteins binding inulin afford a unique opportunity to study the V region patterns of variation because of the similarity in the VL as well as the VH regions. The diversity patterns in both the VL and VH regions suggest these proteins are encoded by multiple, very similar V gene segments or that somatic mutation may repeatedly generate identical variants. Because of the close similarity in the V domains of these proteins and the extensive idiotypic analyses that have been carried out previously, several interesting conclusions can be drawn about the nature of idiotypic determinants. First, a single amino acid residue may be involved in determining multiple idiotypic determinants. Second, hapten-inhibitable idiotypes may depend on residues within and outside the hypervariable regions. Third, idiotypic similarity does not always predict a corresponding sequence similarity.
Avidity of antibodies to dsDNA: comparison of IFT on Crithidia luciliae, Farr assay, and PEG assay.
Authors: Smeenk R , van der Lelij G , Aarden L
Published: December 2022

The Farr assay is thought to detect only antibodies to DNA of relative high avidity. This is due to the high salt concentration of the employed ammonium sulfate precipitation, which dissociates DNA-anti-DNA complexes of low avidity. A recently introduced method to detect anti-DNA, the PEG assay, circumvents these dissociating reaction conditions by using polyethylene glycol instead of ammonium sulfate to precipitate the complexes; we therefore thought to measure antibodies to DNA of low avidity as well. We tested this assumption in several ways. It was found that the PEG assay detects a population of antibodies to DNA that are missed by the Farr assay. Complexes made with these antibodies were salt labile and could readily be dissociated by means of excess DNA, whereas Farr-positive antibodies formed stable complexes with DNA. Avidity studies using the method described by Celada et al. indicated that the anti-DNA detected by the PEG assay but missed by the Farr assay was of relatively low avidity. An inverse correlation between avidity and slope of the binding curves in the PEG assay was observed. These results confirm the notion that the PEG assay detects antibodies to DNA of low avidity. The fact that the Farr assay does not measure these antibodies confers possible diagnostic importance upon the PEG assay.
Inability of newborns' or pregnant women's monocytes to suppress pokeweed mitogen-induced responses.
Authors: Durandy A , Fischer A , Griscelli C
Published: December 2022

Although an excess of human adult blood adherent cells inhibits the pokeweed mitogen- (PWM) induced normal adult lymphocyte proliferation and B cell maturation into immunoglobulin-containing cells (ICC), adherent cells collected from newborn infants or pregnant women at time of delivery were unable to exert a similar suppressor activity. After activation by Concanavalin A (Con A), newborns' and pregnant women's adherent cells acquired a suppressor activity comparable to that of control adult adherent cells. The adherent suppressor cell was shown to be radioresistant (3000 rad), indicating its probable monocytic origin. Both monocyte-suppressor activities (MSA) observed in adulthood (spontaneously) and in the neonatal period (after activation) were dependent on prostaglandin E2 (PGE2) secretion, because they were abolished by indomethacin or a specific anti-PGE2 antiserum. Expression of MSA appeared to be under a negative regulation exerted by naturally occurring T suppressor lymphocytes present in the blood of newborns or pregnant women, because incubation of adult monocytes or Con A-activated newborn monocytes with newborns' or pregnant women's T lymphocytes resulted in a dramatic decrease of their MSA. These results strongly suggest that the lack of MSA in the neonatal period and in late pregnancy is a consequence of activation of T suppressor lymphocytes.
T cell subsets required for protection against age-dependent polioencephalomyelitis of C58 mice.
Authors: Bentley D M , Morris R E
Published: December 2022

C58 mice are rendered susceptible to age-dependent polioencephalomyelitis by the natural aging process or by treatment with immunosuppressive agents. The mechanism of immunologically-mediated resistance was investigated. Susceptibility to the disease results from the loss of protective T cells. Transfer of unfractionated, naive splenic T cells from young donors prevented disease induction in immunosuppressed mice. Spleen cells from aged mice did not render young animals susceptible to disease, nor were they protective. Lyt phenotype analysis of the protective cells showed that the Lyt-1, Lyt-1,2, and Lyt-2 T cell subsets were all required for the generation of a protective response. When young donor animals were presensitized with LDV, transfer of Lyt-2 cells alone was protective.
Preferential response patterns of cytotoxic T lymphocytes specific for fluorescein isothiocyanate-[FITC] modified autologous cells.
Authors: Arora P K , Levy R B , Shearer G M
Published: December 2022

Murine cytotoxic responses to TNP-modified syngeneic cells (TNP-self) have been shown to exhibit preferential recognition of K or D end self products encoded by the H-2 complex. In the present study, a number of B10 congenic and recombinant mouse strains were investigated to determine the H-2K and H-2D-restricted FTC-self CTL response patterns, and these were compared with the CTL response patterns obtained for TNP-self. The results indicate that for strains possessing the H-2k,d,h2,h4 haplotypes, respectively, preferential CTL responses were observed against FTC recognized in association with Kk over Dk, Dd over Kd, and Kk over Db. These patterns of preferential CTL responses were the same as those reported for TNP-self as well as several anti-viral CTL responses. In contrast to the results obtained in the B10.A strain, in which Kk preference was observed over Dd for TNP-self CTL, no preferential CTL response was observed when FTC was recognized in association with Kk and with Dd. In this context, it was observed that the CTL response to FTC recognized in association with Dd was particularly strong. This strong D end-associated response was shown to involve D locus products, and no evidence was obtained indicating that L locus self products were involved. These studies are discussed with respect to the possibility that different haptens can be recognized by CTL in association with different self determinants encoded by the same H-2 gene products.
T cell-mediated immunoregulation of Epstein Barr virus- (EBV) induced B lymphocyte activation in EBV-seropositive and EBV-seronegative individuals.
Authors: Tosato G , Magrath I T , Blaese R M
Published: December 2022

Infection with Epstein Barr virus (EBV) is accompanied by seroconversion and life-long persistence of the virus in B lymphocytes. During acute EBV-induced infectious mononucleosis, suppressor T cells become activated, which may provide an additional mechanism of host defense against the causative agent. When cultures of lymphocytes from normal adults seropositive for EBV were stimulated with the B95-8 strain of EBV, purified B cells produced increasingly higher numbers of immunoglobulin- (Ig) secreting cells, whereas in co-cultures of autologous B and T cells a profound suppressor T cell activity inhibited further B cell activation after 10 to 12 days in culture. No such T cell-mediated inhibitory effect was seen in cultures of lymphocytes obtained from normal adults seronegative for EBV, indicating a correlation between the suppressor effect with evidence of prior immunity to this virus. The T cell-mediated suppression in patients with infectious mononucleosis is characterized by an early-acting inhibitory effect on B cell differentiation that is not specific in that all polyclonal B cell activators are inhibited, whereas in EBV-seropositive normal subjects suppression is delayed in time and affects only EBV-activated cultures. These data indicate that after infection with EBV, immunoregulatory T cells are generated that are capable of inhibiting further EBV-induced activation of autologous B cells and thus may provide an additional unique mechanism of host defense against persisting EBV-infected B cells.
Immune response to phosphorylcholine. IX. Characterization of hybridoma anti-TEPC15 antibodies.
Authors: Wittner M K , Bach M A , Köhler H
Published: December 2022

Hybridoma antibodies against the PC-binding T15 BALB/c myeloma protein were raised by cell fusion with anti-T15 A/He immune cells. The idiotype specificity of these monoclonal anti-T15 antibodies was determined with a panel of different myeloma and hybridoma immunoglobulins. Two types of anti-T15 antibodies are seen. One reacts with a number of different IgA myeloma proteins and with serum IgA of certain strains of mice; this reactivity most likely is due to allotypy. The other group consists of anti-T15 antibodies that are specific for the T15 idiotype and are therefore termed anti-idiotypic. The bindings of the anti-idiotype antibodies to T15 were specifically inhibited by T15 (F(ab')2 but not by other PC-binding myeloma proteins of different idiotypes. The relationship of the idiotype-specific anti-T15 antibodies to the PC-binding site of the T15 idiotype was analyzed by hapten inhibition of anti-idiotypic binding and by inhibition of BALB/c anti-PC splenic hemolytic plaque formation. Anti-T15 antibodies, for which the T15 binding is inhibited by PC or PC-BSA, also specifically inhibit anti-PC plaque formation. These antibodies are labeled site and near-site anti-idiotypic antibodies. Site and near-site-specific anti-idiotypic antibodies recognize different idiotopes on the T15 molecules. The possible differential biologic activities of these anti-idiotopes in idiotype network regulation is considered.