bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochemical characterization of Ia alloantigens in guinea pigs. I. Synthesis of Ia antigens by subsets enriched for B cells, T cells, or macrophages.
Authors: Lyons C R , Lipscomb M F , Schlossman S F , Tucker T F , Uhr J W
Published: December 2022

Peritoneal exudate cells from immune guinea pigs consist primarily of T lymphocytes (PEL) and M phi. After selection of PEL from animals immunized with ovalbumin by culture on specific antigen-pulsed syngeneic M phi, recovered T cells (selected PEL) are 75 to 95% Ia+ by both cytotoxicity and immunofluorescent analysis on the FACS using alloantisera to Ia from guinea pigs or mice. The subunit structure of the Ia molecules on T cells is similar to that of Ia molecules obtained from B cells, as determined by radiolabeling, immunoprecipitation, and analysis of gels. Incorporation of labeled amino acids into Ia by selected PEL was shown to be due to T cells because of the lack of effect of depletion of Ig+ cells, the elimination of incorporation with a monoclonal anti-lymphocyte antibody, and the negligible increase in radioactive Ia after addition of large numbers of peritoneal exudate M phi. Furthermore, when F1 (2 x 3) PEL are selected on parental M phi, the selected PEL express both parental (2 and 13) Ia specificities, which suggests that the Ia molecules are not adsorbed by T cells after their release by M phi. Evidence that synthesis by splenocytes is due to B cells was obtained by the results of deletion experiments with alpha Ig and C. Similarly, synthesis of Ia by populations of pulmonary alveolar M phi, which contain greater than 98% M phi as judged by morphology, adherence, and latex ingestion, was demonstrated to be due to M phi because of the lack of effect of removing T and B cells.
Unresponsiveness to experimental allergic encephalomyelitis in mice: replacement of suppressor cells by a soluble factor.
Authors: Lando Z , Dori Y , Teitelbamum D , Arnon R
Published: December 2022

A soluble suppressor factor has been prepared from cells of mice rendered nonsusceptible to experimental allergic encephalomyelitis (EAE) by treatment with mouse spinal cord homogenate in incomplete Freund's adjuvant. The specific activity of this factor can be augmented by using a cell population enriched on plates coated with anti-mouse Fab and the specific antigen, mouse basic encephalitogen (MBE). The resultant suppressor factor had the same biologic activities as the cells from which it originated. Thus, it suppressed specifically the delayed-type hypersensitivity (DTH) response to MBE in vivo, and blocked in vitro the effector lymphocytes that adoptively transfer the DTH response. The suppressor factor reactivity was manifested also by the capacity to suppress the activity of macrophage migration inhibition factor produced by sensitized lymphocytes in the presence of the specific antigen MBE. The suppressor factor is antigen-specific and can bind the MBE in vitro and thus compete with its antibody binding. The most significant activity of the soluble suppressor factor is its ability to interfere with the induction of clinical EAE.
Transfer of lymphocytes of Peyer's patches between immunoglobulin allotype congenic mice: repopulation of the IgA plasma cells in the gut lamina propria.
Authors: Tseng J
Published: December 2022

Repopulation of the IgA plasma cells in the gut lamina propria was studied by lymphocyte transfers between histocompatible, immunoglobulin allotype congenic mice (CB-20 and BALB/cJ). Among the lymphocytes transferred, Peyer's patch lymphocytes showed the highest efficiency in the repopulation. The donor IgA plasma cells appeared suddenly in the gut lamina propria in substantial numbers at day 8, increased exponentially, and repopulated essentially tne entire gut lamina propria at days 12 to 14. By sequential transfer of lymphoid cells, lymphoid cell culture, splenectomy, and jejunum-shielded total body irradiation of the recipient mice, the majority of the patch IgA precursors were found migrating directly to the spleen rather than to the gut lamina propria. The patch IgA precursors resided in the spleen for at least 5 days and then migrated to the gut lamina propria, where they further divided and matured into IgA plasma cells. However, the spleen is not a completely obligatory tissue in the migration route because the repopulation was only partially reduced when patch cells were transferred into splenectomized recipients. In the splenectomized recipients, the patch IgA precursors did not migrate directly to the gut lamina propria either, which suggests that indirect homing to the gut lamina propria is a characteristic of the patch IgA precursor cells.
Influence of age on reactivity of 1-way mixed lymphocyte cultures in young chickens.
Authors: Bacon L D , Lee L
Published: December 2022

A reproducible 1-way mixed lymphocyte culture (MLC) assay was used to study the ontogeny of MLC in N, P, RPRL-72 and RPRL-63 strains of chickens. The chicks were progeny of specific-pathogen-free and lymphoid leukosis virus-free parents and grown in common isolators. When cells were from responder and stimulator chickens of the same age, the RPRL-72 chickens cells responded by 8 wk, whereas cells from chickens of the other 3 strains did not respond significantly until after 14 wk of age. In MLC with 6- and 32-wk-old RPRL-72 and N birds, the age of the responder was not crucial. However, young or old N birds responded extremely well to old 72 stimulator cells, whereas young 72 cells stimulated no, or minimal, response. Thus the age of the stimulator cell is vary important in chicken MLC and appears to depend upon the responder chicken strain.
MHC antigens on mouse trophoblast cells: paucity of Ia antigens despite the presence of H-2K and D.
Authors: Chatterjee-Hasrouni S , Lala P K
Published: December 2022

The presence of Ia antigens was examined on the surface of trophoblast cells isolated from mouse placentae resulting from mating C57BL/6 female and CBA male mice. A sensitive immunolabeling method was employed in which cells were treated with polyspecific anti-Ia (A.TH anti-A.TL) or monoclonal anti-Ia.17 antibody followed by 125I-labeled protein A and examined with the aid of quantitative radioautography. No appreciable levels of Ia antigens were detectable between days 12 and 17 of pregnancy, although significant amounts of H-2D were always found on the trophoblast cells from the same placentae, and spleen cells as well as thymocytes from control animals always showed the expected degree of labeling for Ia antigens.
The ontogeny and turnover kinetics of paternal H-2K antigenic determinants on the allogeneic murine placenta.
Authors: Raghupathy R , Singh B , Leigh J B , Wegmann T G
Published: December 2022

In previous reports we provided evidence for the expression of paternal H-2Kk antigens on the placenta, accessible to maternal circulation. We have now examined the ontogeny of paternal H-2Kk antigens in the placenta from day 10 to day 17 of gestation and find a steady increase per gram placenta. In order to substantiate the proposal that the placenta functions as an immunoabsorbent barrier preventing the entry of anti-paternal antibodies to the fetus, we monitored the uptake of monoclonal anti-paternal H-2Kk antibody by target (antigen-bearing) and control fetuses and placentas at various intervals after injection. We have previously shown that F(ab')2 anti-H-2Kk behaves like intact immunoglobulin in placental immunoabsorption studies, and demonstrate here that the peak placental uptake of the antibody is not affected by the removal of the Fc portion, whereas its rate of clearance is increased. In contrast to the anti-H-2Kk antibody, monoclonal anti-I-Ak (specificity 17) antibody (IgG2a) shows no placental immunoabsorption.
Inhibitory effect of C-reactive protein on alternative C pathway activation by liposomes and Streptococcus pneumoniae.
Authors: Mold C , Gewurz H
Published: December 2022

C-reactive protein (CRP) is an acute phase serum protein found associated with damaged tissue at sites of inflammation. CRP bound to multivalent phosphocholine-containing or polycationic ligands activates C by the classical pathway. We have previously described liposomes of a particular lipid composition that are able both to activate the alternative pathway of C and to bind CRP. In addition many strains of Streptococcus pneumoniae activate the alternative pathway. We have shown CRP binding to these bacteria as well. Because antibody to an activating surface in many cases enhances alternative pathway activation, we tested CRP for a similar function in these systems. Our results indicate that, in contrast to antibody, CRP inhibits alternative pathway activation. This inhibition by CRP is apparently restricted to surfaces that bind CRP. Thus, CRP binding to membrane or bacterial surfaces can convert them from alternative pathway activation to classical pathway activation.
Induction of parasite-specific helper T lymphocytes during Trypanosoma cruzi infections in mice.
Authors: Burgess D E , Kuhn R E , Carlson K S
Published: December 2022

Development of parasite-specific T helper cells was examined in mice infected with Trypanosoma cruzi. At various times during the course of infection mice were challenged with TNP conjugated to fixed culture forms of T. cruzi (TNP-TC), and the resultant splenic plaque-forming cells (PFC) against TNP were determined. By day 10 post-infection significant responses against TNP-TC were observed but not against TNP-BSA. Infected mice that were not challenged with TNP-TC did not produce anti-TNP PFC, which demonstrated that the TNP-TC response was not the result of nonspecific B cell activation. Treatment of spleen cells from infected mice with anti-theta antiserum plus C ablated the anti-TNP-TC response when these cells were transferred to normal mice that were subsequently challenged with TNP-TC, whereas treatment of the cells with anti-Ig plus C prior to transfer had no effect on the TNP-TC response. These results demonstrate enhancement of parasite-specific Th activity of mice infected with T. cruzi and that cell-cell interaction in development of responses to neoantigens is fully functional when sensitized Th are present, even though the animals are unresponsive to heterologous antigens.
Modulation of Thy-1 alloantibody responses: donor cell-associated H-2 inhibition and augmentation without recipient Ir gene control.
Authors: Clark E A , Lake P , Favila-Castillo L
Published: December 2022

In this study we have found that in vivo PFC responses to Thy-1 are strongly modulated by H-2 gene products in at least 2 ways. First, a profound inhibition of primary PFC responses occurs when foreign H-2 antigens are expressed on Thy-1 incompatible donor cells. This interference effect does not reflect a requirement for H-2-restricted antigen presentation by donor cells, since it is also seen using semi-syngeneic antigenic cells that share a full H-2 haplotype with the recipient. Interference acts more profoundly on slower primary responses than on more rapid secondary responses and requires associative recognition of the H-2 and Thy-1 antigens. By contrast, strong augmentation of the anti-Thy-1 response was obtained when foreign H-2 antigens were expressed in the recipient, as shown by a poor response of an H-2k/k recipient to Thy-1.1 on AKR cells (H-2k) compared with high responses of H-2k/b recipients. A gene controlling this phenotype was mapped to the H-2IA or H-2K regions. However, subsequent experiments revealed that donor recognition of recipient H-2 antigens was required for these high responses; thus, an Ir-gene effect was excluded and an 'intimate form' of an allogeneic effect was postulated. Thus, the immune response to Thy-1 is regulated by at least 3 factors acting at the level of the donor cell, including non-H-2 helper alloantigens, H-2 interference, and H-2-associated allogeneic effects.
Mouse myeloma proteins with lambda 2 and lambda 3 light chains.
Authors: Cotner T , Blaser K , Kriedberg J , Potter M , Eisen H N
Published: December 2022

Serum and ascites fluid from mice bearing 260 different myeloma tumors were screened serologically for myeloma proteins having light chains like that of L315, the lambda 2 chain produced by myeloma MOPC-315. Four proteins, made by myelomas TEPC-952, CBPC-49, ABPC-72, and SAPC-15, were identified. Their light chains were essentially indistinguishable serologically from L315, and each of them also yielded the characteristic C-terminal amino acid (leucine) and C-terminal tryptic peptide of L315. However, amino acid sequences and other findings reported elsewhere have revealed that although the light chain of TEPC-952 is indeed a lambda 2 chain, the light chains of the others (CBPC-49, ABPC-72, and SAPC-15) represent another, slightly different type of light chain, which has been designated lambda 3.
The H-2 phenotype of the thymus dictates the self-specificity expressed by thymic but not splenic cytotoxic T lymphocyte precursors in thymus-engrafted nude mice.
Authors: Kruisbeek A M , Sharrow S O , Mathieson B J , Singer A
Published: December 2022

The present study was performed to examine the specificity of the self-recognition repertoire expressed by TNP-specific CTL precursors present in the thymus and the spleen of congenitally athymic nude mice engrafted with either semiallogeneic or fully allogeneic neonatal thymuses. It was shown that the engrafted thymus lobes were fully repopulated with cells of nude host origin and that the engrafted thymus tissue was capable of reconstituting peripheral CTL function in the nude host. Assessing the specificity of the lymphocytes differentiating within the thymus graft, the present study revealed that CTL precursors of nude host origin in the thymus grafts were nonalloreactive to both nude-host-type and thymus-type MHC determinants but were invariably restricted to the self-recognition of thymus-type, not nude-host-type, MHC determinants. Furthermore, the restricted self-recognition of thymic MHC determinants was not mediated by detectable suppression. In contrast to the restricted self-recognition repertoire of CTL precursors in the thymus of these mice, CTL precursors from the spleens of the same mice were not restricted to the self-recognition of thymus-type MHC determinants but instead recognized TNP in association with both host and thymus-type MHC determinants. These data demonstrate that at least in thymus-engrafted nude mice the self-recognition repertoire of thymocyte CTL, but not spleen CTL, is entirely dictated by the MHC phenotype of the thymus tissue in which they differentiate. It is proposed that the spleen CTL repertoire in these mice reflects the coexistence of at least 2 CTL subpopulations, 1 that differentiated within the engrafted thymus and 1 that differentiated outside the engrafted thymus.
Characterization of the IgE receptor by tryptic mapping.
Authors: Pecoud A R , Conrad D H
Published: December 2022

IgE receptors were labeled by lactoperoxidase-catalyzed surface radioiodination of rat basophilic leukemia (RBL) cells and rat peritoneal mast cells (RMC). After nonionic detergent solubilization and incubation with rat IgE, IgE-receptor complexes were immunoprecipitated using anti-rat IgE. The receptor for IgE was further purified by SDS-PAGE, the receptor peak, in the gel, was submitted to tryptic digestion, and the resulting peptides were analyzed by a 2-dimensional peptide mapping procedure. The peptides were then visualized by autoradiography. IgE receptors from different RBL cell lines exhibit slight differences in m.w., as judged by SDS-PAGE; however, no differences were seen in the tryptic peptide maps of receptors from the different RBL cell lines. In addition, receptors isolated from RMC also mapped identically, indicating that peptides responsible for the m.w. differences may not be labeled. The IgE-binding component of higher m.w., isolated by affinity chromatography on IgE-Sepharose, gave a distinct pattern of tryptic peptides that were different from the receptor. By using IgE-Sepharose and tryptic mapping, this 2nd and IgE-binding component was found on all RBL cell lines and on RMC. The membrane orientation of the receptor was analyzed by tryptic mapping. Tryptic maps obtained from IgE receptors labeled on intact cells (outside labeled only), membrane particles (inside and outside labeled), and in a detergent-solubilized form (all possible sites labeled) were similar, indicating that no other protein site was available to be labeled, in addition to those in the surface exposed binding site. Moreover, saturation of the receptor by IgE prevented its subsequent radioiodination, whether the receptor was labeled on intact cells, on membrane particles, or in a solubilized form, again indicating that no site other than the binding site could be labeled. Cumulatively, these data suggest that the IgE receptor on RBL cells is not a transmembrane protein.
Modulation of Ia-like antigen expression and antigen-presenting activity of human monocytes by endotoxin and zymosan A.
Authors: Yem A W , Parmely M J
Published: December 2022

The environmental agents E. coli endotoxin and zymosan A modulated antigen-specific T cell proliferation in vitro, assessed by 3H-TdR uptake. In the continual presence of these agents, human mononuclear leukocyte responses to the antigens tuberculin PPD, Candida albicans, and mumps were significantly reduced. Treatment of adherent cell-depleted T cells with the agents did not affect their subsequent reactivity to soluble antigens in the presence of normal M phi. However, cultures consisting of pretreated M phi, normal T cells, and soluble antigen gave responses that were only 7 to 38% of control values, indicating that the function of the antigen-presenting cell, not the T cell, was inhibited. This effect was observed only when treatment with endotoxin or zymosan A preceded antigen stimulation by at least 24 hr, suggesting that a gradual inhibition of antigen presentation had occurred. When various ratios of normal antigen-pulsed and agent-treated M phi were cultured with normal T cells, antigen-specific responses were not significantly different from control cultures; this indicated that M phi-mediated suppression was not involved. It did not appear that the inhibition was due to enhanced antigen degradation by the treated M phi because responses were not reconstituted in the presence of excess antigen. After endotoxin or zymosan A treatment of the M phi population the proportion of Ia+ cells was reduced significantly, and surface expression of Ia antigen correlated with the ability of the cell population to present antigens to immune T cells. This suggested that endotoxin and zymosan A induce a loss of surface Ia antigen on antigen-presenting cells that inhibits immune T cell activation.
T cell-mediated cytotoxicity induced by Listeria monocytogenes. II. Specificity of cytolytic effector cells.
Authors: Woan M C , McGregor D D , Forsum U
Published: December 2022

Listeria monocytogenes- (LM) antigen-dependent cytotoxic lymphocytes, identified in a companion manuscript as T cells (CTL), can kill a wide variety of target cells, including syngeneic fibroblasts of both fetal and adult origin, and certain allogeneic and xenogeneic tumor cells. Cold target cell inhibition assays revealed that cells susceptible to lysis can block the cytolytic process in a dose-dependent manner, whereas lysis-resistant cells cannot. Several lines of evidence indicate that to realize their cytolytic potential, LM-dependent CTL must bind to their targets. Aggressor cells that adhere to susceptible target cell monolayers have enhanced cytolytic activity when compared with unfractionated cells or cells that do not adhere. LM-dependent CTL fail to kill when they are separated from susceptible targets by an agar barrier. Arguments against the complicity of a soluble mediator in the killing process derive from the rapid (within 3 hr) expression of cytotoxicity in circumstances where cell contact can occur, and the finding that spent medium in which LM-dependent CTL are either activated or assayed is devoid of cytolytic activity. The specificity of LM-dependent CTL suggests that these effector T cells recognize an as yet unidentified array of antigens that are expressed on a variety of rodent cells. Their cytolytic repertoire cannot be ascribed solely to the polyclonal activation of alloreactive T cells, because responder cells that have been negatively selected for a particular RT-1 haplotype can kill target cells bearing these alloantigens.
Alloreactive cloned T cell lines. V. Differential kinetics of IL 2, CSF, and BCSF release by a cloned T amplifier cell and its variant.
Authors: Ely J M , Prystowsky M B , Eisenberg L , Quintans J , Goldwasser E , Glasebrook A L , Fitch F W
Published: December 2022

A noncytolytic, Thy-1+, MIs-responsive cloned T amplifier cell, designated L2, derived from secondary C57BL/6 anti-DBA/2 mixed leukocyte culture was found to produce IL 2 (Interleukin 2), granulocyte/macrophage colony-stimulating factor (CSF), and a polyclonal B cell-stimulating factor (BCSF) after alloantigenic stimulation. IL 2 activity was present transiently, with maximal levels observed 12 to 24 hr after exposure to alloantigen. Only trace amounts were present 96 hr after initiation of culture. CSF and BCSF activities were present at high levels by 24 hr and remained elevated throughout an 8-day culture period. Further evidence that the lymphokine(s) having IL 2 activity is different from those having CSF and BCSF activities was provided by L2V, a variant of L2 that did not produce IL 2. The time course of CSF and BCSF production by L2V after stimulation with alloantigen was similar to that found with L2, although IL 2 activity was not detected at any time. Since the release of lymphokines from both L2 and L2V cells could be induced by Con A in the absence of stimulating alloantigen, it is likely that the biologically active factors were produced by the cloned T cell.
Intracellular replication and lymphokine-induced destruction of Leishmania tropica in C3H/HeN mouse macrophages.
Authors: Nacy C A , Meltzer M S , Leonard E J , Wyler D J
Published: December 2022

C3H/HeN resident peritoneal macrophages in suspension culture supported continuous replication of L. tropica amastigotes; the total number of intracellular parasites increased 8- to 10-fold over 96 hr in culture. Lymphokine treatment of macrophages markedly affected intracellular replication of the Leishmania. Cultures treated with lymphokines before exposure to L. tropica were more resistant to infection, and 35% fewer cells contained intracellular amastigotes compared to medium-treated controls. Lymphokine-pretreated cells that became infected also inhibited the replication of intracellular amastigotes. Macrophage cultures treated with lymphokines after infection exhibited potent microbicidal activity; 75 to 80% of macrophages were free of intracellular parasites by 72 hr. Fractionation of lymphokine supernatants by Sephadex G-100 demonstrated 3 areas of activity for the induction of macrophage intracellular killing (130,000, 45,000, less than or equal to 10,000 daltons); one of these activity peaks (45,000-m.w. lymphokine(s)) also induced increased resistance to infection with L. tropica.
Characteristics of an antigen-specific helper factor that enhances the in vitro generation of cytotoxic cells directed against a syngeneic tumor.
Authors: Kilburn D G , Talbot F O , Levy J G
Published: December 2022

An antigen-specific helper factor (Hf) that enhances the in vitro generation of tumor-specific cytotoxic T cells (CL) has been isolated from the spleens of DBA/2 mice bearing the syngeneic mastocytoma, P815. This factor enhances the CL response to P815 but not to L1210 (a syngeneic T cell leukemia in DBA/2 mice), B10 minor antigens, or DBA/2 alloantigens. The factor binds specifically to P815 membrane immunoadsorbent columns and can be eluted with 2 M NaCl. P815 Hf did not resemble the lymphokine Il 2 because it did not enhance the proliferative or CL response of thymocytes nor would it support the growth of an IL 2-requiring line of T cells. This factor acted optimally if added late in the culture period in contrast to IL 2, which was more effective if added early. In limiting dilution experiments P815 Hf enhanced the level of CL activity generated but not the number of precursors triggered. IL 2 markedly amplified both of these parameters.
Interleukin 2 deficiency is a common feature of autoimmune mice.
Authors: Dauphinée M J , Kipper S B , Wofsy D , Talal N
Published: December 2022

IL 2 production was studied in autoimmune mice to assess the role of this lymphokine in the pathogenesis of murine lupus. Spleen and lymph node cells from autoimmune-susceptible mice show an age-dependent loss in the ability to produce functional IL 2. This defect correlates with disease expression and is most severe in MLR/Mp-Ipr/Ipr mice. MLR/Mp-Ipr/Ipr thymocytes gradually lose responsiveness to IL 2 with age. These results suggest that the immunoregulatory abnormalities of autoimmune mice may be due in part to IL 2 deficiency.
Assay of membrane complement receptors (CR1 and CR2) with C3b- and C3d-coated fluorescent microspheres.
Authors: Lambris J D , Ross G D
Published: December 2022

A sensitive and specific fluorescence assay for membrane complement (C) receptors (CR1 and CR2) was developed with purified C3b and C3d fragments coupled to fluorescent microspheres (0.9 mu diameter). C3-microspheres (C3-ms) bound to cells with low numbers of receptors that were undetectable by other assay techniques. Inhibition studies with anti-CR1 and anti-CR2 demonstrated that C3b-ms and C3d-ms bound exclusively to CR1 and CR2, respectively. Preparation of the C3-ms required only small amounts of partially purified C3 and no immunoglobulin or other C components. Once formed, the C3-ms were stable for up to 4 mo at 4 degrees C.
Effect of lipid A incorporation on characterization of liposomal model membranes as thymus-independent type 1 or type 2 immunogens.
Authors: Tadakuma T , Yasuda T , Tamauchi H , Saito K , Tsumita T , Kinsky S C
Published: December 2022

We used the following criteria to determine whether liposomal model membranes are thymus-independent type 1 (TI-1) or type 2 (TI-2) immunogens: a) in vivo response of (CBA/N X BALB/c)F1 male and female mice; b) in vitro response of spleen cells from these mice; c) ontogeny of the response in cultures of (C57BL/6 X DBA/2)F1 male cells obtained from mice of different ages; d) ability of a monoclonal anti-delta antibody to block the in vitro response of C57BL/6 spleen cells. The liposomes were sensitized with N(2,4,6-trinitrophenyl-6-N-aminocaproyl)-dipalmitoylphosphatidylethanolamine (TNP-Cap-DPPE) and were prepared without and with incorporation of the B cell mitogen, lipid A. On the basis of the above criteria, liposomes prepared without lipid A can be characterized as a TI-2 immunogen and resemble TNP-Ficoll. In contrast, liposomes prepared with lipid A behave like a TI-1 immunogen such as TNP-BA (trinitrophenylated Brucella abortus). Conversion of liposomes from a TI-2 to a TI-1 immunogen by inclusion of lipid A in the bilayers was achieved under conditions of constant TNP-Cap-DPPE epitope density. Increasing the epitope density in liposomes made without lipid A does not result in transformation of immunogen type. These results, which bear on the features that may distinguish TI-1 from TI-2 immunogens, are discussed with regard to the involvement of macrophages and T cells in the response.
Altered expression of Plasmodium knowlesi variant antigen on the erythrocyte membrane in splenectomized rhesus monkeys.
Authors: Barnwell J W , Howard R J , Miller L H
Published: December 2022

Variant antigens are present on the surface of Plasmodium knowlesi malaria-infected erythrocytes as detected by the schizont-infected cell agglutination (SICA) assay. We found that parasitized erythrocytes passaged in splenectomized monkeys did not agglutinate with immune sera. On the first passage from intact to splenectomized monkeys, the SICA titers decreased 4- to 16-fold; after the second and subsequent passages in splenectomized monkeys, the infected cells became nonagglutinable to all sera tested, including sera from animals infected with the nonagglutinating parasites. This loss of agglutinability could have resulted from selection of a genetically distinct subpopulation of the original parasites or the ability of the original parasites to alter their phenotypic expression. We have designated the new nonagglutinable phenotype, SICA [-], and the agglutinable phenotype, SICA [+]. The loss of agglutinability indicates that the variant antigen normally expressed on the erythrocyte membrane of infected cells is altered or absent. Because SICA [-] parasites developed in the absence of the spleen, the major organ of host defense against malaria, then this organ may in some manner influence or modulate antigenic expression in P. knowlesi and possibly other malaria parasites.
H-2Kb mutations limit the CTL response to SV40 TASA.
Authors: Pan S , Wettstein P J , Knowles B B
Published: December 2022

The cytotoxic T lymphocyte (CTL) responses directed towards SV40 tumor-associated specific antigen (TASA) in nine strains of spontaneously arising Kb mutant mice were analyzed. All nine mutants generated normal levels of H-2Db-restricted response, but the K-end-restricted CTL response varied. B6.C-H-2bm1 (bm1) did not produce K-end-restricted SV40 TASA-specific CTL upon immunization, and SV40-transformed bm1 cells were not lysed by intra-H-2 recombinant Kb [B10.A(5R)] CTL. Nonreciprocal cross-reactive lysis was seen between B6-H-2bm8 (bm8) and B10.A(5R). Strain B6-H-2bm8 mice produce highly specific Kbm8-restricted CTL that lyse SV40-transformed bm8 cells (Kbm8SV) but not B10.A(5R) target cells (K5RSV), although Kbm8SV targets can be partially lysed by B10.A(5R) CTL. The other seven Kb mutants cross-react with B10.A(5R). These experiments definitively show that genes mapping to the K and/or D region directly control the H-2-restricted CTL response to SV40 TASA.
Tumoricidal macrophages isolated from liver granulomas of Schistosoma mansoni-infected mice.
Authors: Loveless S E , Wellhausen S R , Boros D L , Heppner G H
Published: December 2022

In murine schistosomiasis, inflammatory macrophages (M phi) are a major cell type of the granulomata that encase eggs of the tropical helminth Schistosoma mansoni as they are deposited in the liver by adult worm pairs. The granulomatous response is vigorous during acute infection (8 wk) and spontaneously undergoes immunomodulation during chronic infection (20 wk). Inflammatory M phi isolated from liver granulomas of 8 and 20-wk schistosome-infected CBA/J mice were assessed for their cytolytic potential. Macrophages from vigorous liver granulomas displayed significant cytolytic activity against 3 mammary tumor lines of strain BALB/cfC3H origin, while leaving untransformed embryo fibroblasts relatively unharmed. The cytolytic activity of inflammatory M phi from immunomodulated lesions was markedly less than that of cells from vigorous lesions at equivalent effector to target (E:T) cell ratios. Granuloma cell preparations depleted of the inflammatory macrophage component were marginally cytolytic at the higher E:T cell ratio; supernatant fluids from cultured inflammatory M phi-enriched cell preparations possessed no tumoricidal activity. The cytolytic potential of the vigorous granuloma M phi was lost subsequent to prolonged in vitro culture. We conclude that inflammatory M phi in S. mansoni egg-elicited granulomas are sufficiently activated to lyse allogeneic tumor cells. The degree of activation appears to correlate directly with the intensity of the granulomatous response.
Leukocyte procoagulant activity in man: an in vitro correlate of delayed-type hypersensitivity.
Authors: Geczy C L , Meyer P A
Published: December 2022

Human mononuclear leukocytes generate cell-bound procoagulant activity (LPCA) after incubation with an antigen (mumps or tuberculin) to which the donor was previously sensitized. An inhibitor of coagulation appears to be liberated into the extracellular culture fluid during incubation of leukocytes with the sensitizing antigen. Removal of this activity before measuring LPCA resulted in a reliable test that correlated directly with delayed skin reactivity. The assay was particularly sensitive in that cells from weakly sensitized donors who reacted only to high doses of tuberculin (100 TU) in the delayed skin tests produced detectable LPCA in vitro. By contrast cells from weakly sensitized donors did not react to PPD in the lymphocyte blast transformation test or the direct macrophage migration inhibition factor test. The LPCA assay correlated closely with the blast transformation and MIF tests in which cells were used from more strongly sensitized donors who reacted in skin tests with lower doses of tuberculin (1 or 10 TU). The assays were antigen-specific in that cells from donors sensitive to mumps antigen but not to tuberculin reacted only to mumps antigen in vitro. The assay was extremely reproducible; cells from individual donors reacted to the same extent over a period of 8 mo). We propose that the assay system reported here represents an improved method for the measurement of cell-mediated immunity in vitro because it requires fewer donor cells, is technically simpler, and is more sensitive than previously described methods.
Concanavalin A triggers T lymphocytes by directly interacting with their receptors for activation.
Authors: Palacios R
Published: December 2022

Anti-HLA-DR antibodies did not inhibit concanavalin A-(Con A) induced T cell proliferation or the generation of suppressor cells capable of inhibiting immunoglobulin synthesis in autologous mononuclear cells after pokeweed mitogen stimulation. Nylon-wool purified T cells (pretreated with anti-HLA-DR antibody and C) exposed to Con A acquired responsiveness to interleukin 2 (IL 2) and were able to absorb this growth factor, whereas nonlectin-treated cells did not respond to IL 2 and could not absorb it. In the presence of interleukin 1 (IL 1), Con A stimulated the synthesis of IL 2 in purified OKT4+ lymphocytes but not OKT8+ cells. However, in the absence of IL 1, neither resting OKT4+ nor Con A-treated OKT4+ cells produced IL 2. Con A by itself did not directly stimulate macrophages to synthesize IL 1, although it could do so in the presence of OKT4+ but not OKT8+ lymphocytes. In addition, Con A induced proliferation of purified T cells provided IL 1 was supplied to the cultures. Cyclosporin A rendered Con A-treated T cells unresponsive to IL 2, made lectin-stimulated OKT4+ lymphocytes unable to respond to IL 1, and inhibited the synthesis of IL 2. Furthermore, this drug abrogated the Con A-stimulated synthesis of IL 1 by acting on OKT4+ lymphocytes and not on macrophages. Finally, cyclosporin-A suppressed the proliferative response and the generation of suppressor T cells induced by Con A. The following are concluded: 1) HLA-DR antigens do not seem to play any role in the triggering of T cells by Con A, and macrophages participate in lectin-induced activation of T cells mainly by providing IL 1. 2) Cyclosporin-A inhibits activation of T cells by interfering with the mechanism by which Con A stimulates T lymphocytes. 3) Con A triggers T lymphocytes by directly interacting with their receptors for activation.
Correction of defective macrophage differentiation in C3H/HeJ mice by an interferon-like molecule.
Authors: Vogel S N , Weedon L L , Moore R N , Rosenstreich D L
Published: December 2022

C3H/HeJ mice possess macrophages that lose the capacity to bind and phagocytose opsonized sheep erythrocytes (EA) when cultured. This defect in Fc receptor capacity is completely overcome by treatment of macrophage monolayers with extremely low concentrations of a lymphokine-rich, Con A-stimulated spleen cells supernatant. In this study we have pursued a biochemical and functional analysis of the lymphokine-rich supernatant to determine the nature of the specific factor responsible for the restoration of Fc receptor function. The chromatographic behavior and physical properties, its co-elution with anti-viral activity through a sequential purification scheme, the parallel activity of purified beta-interferon in enhancing both the binding and phagocytosis of EA, and the abrogation of factor-induced Fc-mediated phagocytosis with anti-Type II interferon antiserum, strongly support the hypothesis that the active factor is gamma- (Type II or immune) interferon (IFN). These studies suggest gamma-IFN may act as a differentiative signal to the macrophage by facilitating enhanced expression of macrophage surface membrane components.
The in vitro and in vivo induction of anti-double-stranded DNA antibodies in normal and autoimmune mice.
Authors: Fish F , Ziff M
Published: December 2022

To determine whether the existence of anti-dsDNA producing lymphocyte clones is limited to autoimmune strains of mice, spleen cells derived from autoimmune mice (NZB, NZB X NZW F1, MRL) and from normal strains (BALB/c, DBA/2, C57BL/6, C3H/eb) were cultured with E. coli lipopolysaccharide (LPS). DNase-treated supernatants from these cultures were assayed for anti-dsDNA antibodies by employing a sensitive solid-phase radioimmunoassay with poly (dA-dT) as the antigen. All tested spleen cells secreted a small yet significant amount of anti-dsDNA upon stimulation with LPS. There was no difference in the amount or in the heavy chain type of anti-dsDNA secreted by cells from normal and autoimmune strain cells. Evidence of clonal expansion in unstimulated cells was observed only in cultures prepared from older autoimmune animals. Removal of T cells from the spleen cell preparations had no marked effect on the spontaneous or stimulated antibody secretion. Anti-dsDNA antibodies could also be induced in vivo by i.p. injection of LPS into young normal animals. Splenocytes from all tested strains spontaneously secreted anti-ssDNA and anti-TNP antibodies in culture, and these were present at relatively high levels in the serum of unstimulated animals. Stimulation with LPS increased secretion of anti-ssDNA and anti-TNP in all strains in vitro and in five of seven strains in vivo as well. It can be concluded that a) the existence of anti-dsDNA-producing clones is not limited to autoimmune strains, and b) these clones are expanded in old but not in young autoimmune mice. They are not expanded in normal mice at any age.
Lymphokine-mediated microbistatic mechanisms restrict Chlamydia psittaci growth in macrophages.
Authors: Byrne G I , Faubion C L
Published: December 2022

The obligate intracellular procaryote Chlamydia psittaci replicated in cultures of macrophages taken from the peritoneal cavities of unstimulated or thioglycollate-elicited A/J mice. When treated with supernatant fluids (lymphokines) from C. psittaci-immune mice spleen cells that were stimulated for 24 hr in vitro by the mitogen concanavalin A, resident macrophages supplemented with heart infusion broth (8 mg/ml) and elicited macrophages markedly suppressed intracellular chlamydial development. Uptake of the parasites was unaffected by LK-activated macrophages. The LK-induced inhibition was a static rather than a cidal effect. Chlamydial replication was detected 24 to 41 hr after removal of LK and infection with C. psittaci. Evidence that intermediates of oxygen metabolism did not contribute to the microbistatic process in either resident or elicited macrophages was provided by the inability of exogenous catalase, deprivation of glucose, or pretreatment with phorbol myristate acetate (PMA) to reverse LK-induced inhibition of parasite replication.
Demonstration of two distinct antigenic determinants on hepatitis B e antigen by monoclonal antibodies.
Authors: Imai M , Nomura M , Gotanda T , Sano T , Tachibana K , Miyamoto H , Takahashi K , Toyama S , Miyakawa Y , Mayumi M
Published: December 2022

Mice were immunized against hepatitis B e antigen (HBeAg) isolated from sera of asymptomatic carriers of hepatitis B virus. Their spleen cells were fused with mouse myeloma (NS-1) cells, and 5 clones of hybridoma cells secreting antibody against HBeAg (anti-HBe) were isolated. For the production of anti-HBe in large scale, cells were cultivated both in vitro and in the peritoneal cavity of ascitic mice. Although monoclonal antibodies produced by these clones showed a strong reactivity of anti-HBe in hemagglutination tests, individual monoclonal anti-HBe did not reveal any precipitin line in immunodiffusion. When 2 of the 5 monoclonal antibodies were mixed together, however, some combinations showed a precipitin line against HBeAg, whereas others did not. Utilizing solid-phase radioimmunoassay involving a number of combinations of monoclonal antibodies used for solid-phase and radiolabeling, the 5 antibodies were classified into 2 groups. Three of the anti-HBe antibodies were found to be directed to 1 determinant of HBeAg (determinant a); the remaining 2 to the other determinant (determinant b). Determinants a and b were detected on HBeAg in the serum, as well as on the polypeptide of 19,000 daltons (P19) derived from the nucleocapsid of hepatitis B virus. Monoclonal anti-HBe antibodies with different specificities may provide useful tools in delineating the antigenic structure of HBeAg and also in evaluating immune responses of the host directed to its subdeterminants.
Dextran-sulfate: a mitogen for human T lymphocytes.
Authors: Palacios R , Sugawara I , Fernandez C
Published: December 2022

Dextran-sulfate (DxS) induced proliferation of human peripheral blood T lymphocytes but not of adult or neonatal B lymphocytes. The mitogenic activity on T cells by DxS required the presence of accessory cells because DxS was unable to trigger T cells to DNA synthesis in the absence of accessory cells. In addition, DxS stimulated OKT4+8- T cells to produce interleukin 2, a process that also occurred only in the presence of accessory cells. Cyclosporin-A strongly suppressed T cell proliferation induced by DxS by rendering T cells unresponsive to interleukin 2 and by inhibiting the synthesis of this T cell growth factor by OKT4+ T cells. These results indicate that DxS is a mitogen for human T lymphocytes but not for adult or neonatal B lymphocytes. The mechanism by which DxS triggers T cells is discussed.
Concanavalin A supernatant recruits antigen-insensitive IgG memory B lymphocyte precursors into an antigen-sensitive precursor pool.
Authors: Kaattari S L , Rittenberg M B
Published: December 2022

Spleen cells from mice primed to trinitrophenyl-keyhole limpet hemocyanin (TNP-KLH) generate IgG anti-TNP memory responses when stimulated in vitro with either thymus-dependent (TD) or thymus-independent (TI) forms of the hapten. When supernatants from Con A-stimulated spleen cells (Con A Sup) were added to such secondary cultures the TI responses to DNP-dextran or TNP-T4 were augmented; the TD response to TNP-KLH was suppressed. Passage over Sephadex and addition of alpha-methyl-D-mannoside did not inhibit augmentation by Con A Sup, indicating that augmentation did not result from direct action of the lectin on the responding cells. Augmentation occurred equally well in cultures that had been depleted of T cells by treatment with anti-Thy-1.2 and complement. Limiting dilution analyses revealed that Con A Sup increased the frequency of TI-responding precursors approximately threefold while causing a concomitant decrease in TD-responding precursors. To determine the relationship of the additional TI precursors and those normally detected in the absence of Con A Sup, the TI-responding IgG precursors were first eliminated through selective suicide by using DNP-dextran plus BUdR and light treatment; subsequently no TI-responding IgG PFC could be detected to DNP-dextran unless Con A Sup was also added. The data suggest Con A Sup may augment the TI responses to DNP-dextran and TNP-T4 by recruiting additional precursors from a memory cell pool formerly insensitive to these forms of antigen.
Expression of the major cross-reactive idiotype in a primary anti-azobenzenearsonate response.
Authors: Lucas A , Henry C
Published: December 2022

We have studied the occurrence of IgM plaque-forming cells secreting the cross-reactive idiotype (CRI) characteristic of the anti-azobenzenearsonate antibody responses in individual mice of different strains after one injection of the T-independent antigen, p-azobenzenearsonate-Brucella. Under these conditions of stimulation we find that idiotype is not unique to the Igh-1e and Igh-1d allotypes, but is expressed prominently in Igh-1a and Igh-1j strains and to a lesser but significant extent in Igh-1c and Igh-1b strains. We confirmed previous work that idiotype expression in mice hyperimmunized with protein conjugates of azobenzenearsonate is mainly restricted to mice of the Igh-1e allotype, but we find the display to be less marked than in mice given a single injection of the Brucella conjugate. We conclude that the B cell repertoire is inadequately revealed by analysis of serum antibodies of hyperimmune mice. We suggest the apparent correlation of the anti-azobenzenearsonate idiotype to allotype may be influenced by the activity of heavy chain regulatory genes, rather than the presence or absence of structural genes coding for the major CRI. We cannot exclude the possibility that the previously designated CRI-negative strains may express a cross-reactive determinant that is not necessarily a product of the CRI gene family.
Binding properties of IgE receptors on normal mouse mast cells.
Authors: Sterk A R , Ishizaka T
Published: December 2022

Normal rat mast cells and mouse mast cells were purified, and the binding of rat IgE and mouse IgE to IgE receptors was measured. When normal rat mast cells were saturated with either rat IgE or mouse IgE, comparable numbers of IgE molecules bound to the cells. The number of the receptors on rat mast cells was approximately 3 X 10(5)/cell. The forward rate constant, K1, dissociation constant K-1, and equilibrium constant, KA, for rat IgE and mouse IgE were almost similar; KA for rat IgE and mouse IgE were 8 X 10(9) M-1 and 2.5 X 10(9) M-1, respectively. The results indicated that rat IgE and mouse IgE bind to the same IgE receptors on rat mast cells with comparable affinity. It was also found that IgE from the two species bound to mouse mast cells with high affinity. Forward rate constant, K1, for the binding of mouse IgE and rat IgE to IgE receptors on mast cells from BALB/c mice were 1.9 X 10(5) M-1 sec-1 and 1.5 X 10(5) M-1 sec-1, respectively. Mouse IgE and rat IgE dissociate from the receptors with comparable rate (approximately 10(-4) sec-1). However, mouse mast cells appear to have two distinct types of IgE receptors. One type binds both rat IgE and mouse IgE with comparable affinity, whereas the second type binds only mouse IgE. This type of receptor comprises about one-third to one-half of IgE receptors on mast cells of CBA/J mice, and about one-half to two-thirds of IgE receptors in BALB/c mice. Although the binding of rat IgE to these receptors was not detected, the presence of rat IgE along with 125I-mouse IgE interferred with the binding of the latter protein to the receptors. It was suggested that rat IgE might associate with the second type receptors with a forward rate constant comparable to those of mouse IgE, but dissociate rapidly from the receptors.