bluuebunny/crossref_metadata_2025 huggingface dataset:
Murine graft vs host disease. A model for study of mechanisms that generate autoantibodies to ribonucleoproteins.
Authors: Gelpi C , Rodriguez-Sanchez J L , Martinez M A , Craft J , Hardin J A
Published: December 2022

We established chronic graft vs host disease in (BALB/c x A/J) F1 mice with the injection of lymphoid cells from the parental A/J strain. These animals developed glomerulonephritis, forefoot edema, alopecia, splenomegaly, and lymphadenopathy to various degrees, and all developed antinuclear antibodies. To determine whether these antibodies were directed against the small nuclear ribonucleoprotein (snRNP) particles that are characteristic targets for autoimmune responses in human rheumatic diseases, sera were studied in the 32P immunoprecipitation and immunoblotting assays. Among 20 mice, antibodies to snRNP developed in 10. These antibodies usually reached maximal levels about 4 wk after induction of graft vs host disease and generally fell thereafter. However, two mice developed antibodies to snRNP between the 10th and 20th wk of follow-up. Sera from six mice strongly recognized the U1 snRNP and an additional serum strongly bound both the U1 and U3 particles. Several sera contained lower levels of antibodies specific for the U3 and possibly pre-U2 snRNP particles. In immunoblots, sera that immunoprecipitated the U1 snRNP bound epitopes located on its 70,000 Da, A, B'/B, and/or C polypeptides. Sera that immunoprecipitated the U3 snRNP recognized a 34,000-Da polypeptide. These polypeptides are known to bear the autoantigenic epitopes that are recognized by human sera containing anti-U1 RNP and anti-U3 RNP autoantibodies. We conclude that chronic graft vs host disease in mice provides a model for the study of the autoimmune responses that characterize human diseases such as mixed connective tissue disease, scleroderma, and SLE.
Tumor necrosis factor-mediated cytotoxicity involves ADP-ribosylation.
Authors: Agarwal S , Drysdale B E , Shin H S
Published: December 2022

The mechanism of TNF-mediated cytotoxicity was studied in several cell lines, including L929 murine fibroblasts. TNF caused a time- and dose-dependent increase of ADP-ribosylation in L929 target cells parallel to cell death. During the course of TNF-mediated cytotoxicity in the presence of actinomycin D, an increase in ADP-ribosylation became apparent between 4 and 6 h after exposure to TNF. Intracellular NAD+ and ATP levels decreased parallel to but not preceding cell death. Two inhibitors of ADP-ribosylation, namely 3-aminobenzamide and nicotinamide, prevented TNF-mediated cytotoxicity. Another target, the human cervical carcinoma cell line ME-180, showed an increase in ADP-ribosylation when treated with TNF, and the cytotoxic action of TNF on this target cell was inhibited by these two inhibitors. In the absence of actinomycin D, treatment of L929 cells with TNF also increased ADP-ribosylation, and the cytotoxic action of TNF was inhibited by nicotinamide. These results indicate that ADP-ribosylation may be involved in the TNF-mediated cytotoxic reaction.
Human granulocyte-macrophage colony-stimulating factor and other cytokines prime human neutrophils for enhanced arachidonic acid release and leukotriene B4 synthesis.
Authors: DiPersio J F , Billing P , Williams R , Gasson J C
Published: December 2022

Human recombinant granulocyte-macrophage CSF (GM-CSF) "primes" neutrophils for enhanced biologic responses to a number of secondary stimuli. Here, we examined the properties of neutrophil priming by GM-CSF and other growth factors such as human rTNF and granulocyte CSF. Although GM-CSF has a negligible direct effect on [3H]arachidonic acid release, it enhances or "primes" neutrophils for three- to fivefold increased release of [3H]arachidonic acid, induced by 1.0 microM A23187 and the chemotactants FMLP, platelet-activating factor, and leukotriene B4 (LTB4) (all 0.1 microM). The priming effects of GM-CSF were concentration- and time-dependent (maximum 100 pM, 1 h at 23 degrees C), and consistent with the determined dissociation constant of the human GM-CSF receptor. Indomethacin (10(-8) M), cycloheximide (100 micrograms/ml), and pertussis toxin (200 ng/ml, 2 h at 37 degrees C) had no effect on GM-CSF-, A23187, or platelet-activating factor-induced [3H]arachidonic acid release. The lipoxygenase inhibitor, nordihydroguaiaretic acid, however, totally abolished A23187-induced [3H]arachidonic acid release from both diluent- and GM-CSF-treated neutrophils. Consistent with this observation, we found that GM-CSF-pretreated neutrophils synthesize increased levels of LTB4 after stimulation with A23187 and chemotactic factors. GM-CSF enhances neutrophil arachidonic acid release and LTB4 synthesis, and thereby may amplify the inflammatory response to chemotactic factors and other physiologically relevant stimuli.
Non-H-2 histocompatibility antigens encoded by Moloney-murine leukemia virus in Mov mouse strains are detectable by skin grafting and cytolytic T lymphocytes.
Authors: Wettstein P J , Colombo M P , Jaenisch R
Published: December 2022

The integration and expression of Moloney-murine leukemia virus (M-MuLV) into the germ line of Mov mouse strains on the C57BL/6 background results in the expression of a cell-surface Ag with characteristics expected from non-H-2 histocompatibility Ag: the ability to stimulate graft rejection and generation of CTL. However, both the previously studied Mov-3 and Mov-14 strains differ from the coisogenic C57BL/6 strain by different length segments of chromosome derived from the ICR strain in addition to the integrated M-MuLV genome. To conclusively demonstrate that an Ag encoded by M-MuLV is solely responsible for rejection of Mov skin grafts by coisogenic recipients, we have studied additional Mov strains that differ from coisogenic 129 or BALB/c backgrounds only by integration of an M-MuLV genome. A total of 129 strain recipients reject skin grafts from two viremic Mov strains, Mov-17 and Mov-18. A total of 129 strain hosts primed with either 1) multiple sets of Mov-17 and Mov-18 skin grafts or 2) single injections of Mov-17 and Mov-18 spleen cells produce M-MuLV-specific CTL that could be boosted in primary mixed lymphocyte culture. Generated CTL were reactive with Con A-stimulated lymphoblasts from all tested viremic Mov strains on the B6 and 129 backgrounds as well as B6 lymphomas. Further, we have observed that 129 strain mice reject Mov-9 skin grafts if these skin grafts are transplanted to virgin 129 recipients which have not received prior skin grafts from non-viremic Mov donors. In addition, skin grafts were transplanted from two viremic Mov strains, Mov-15 and Mov-16, to coisogenic BALB/c recipients; rejection of both sets of grafts was observed. However, BALB/c responders did not generate specific CTL after priming in vivo, with either multiple sets of allogeneic grafts or spleen cell injections, and boosting in vitro. These observations confirm the ability of integrated and expressed M-MuLV genomes to encode what is operationally defined as a non-H-2 histocompatibility Ag.
LGL-1: a non-polymorphic antigen expressed on a major population of mouse natural killer cells.
Authors: Mason L , Giardina S L , Hecht T , Ortaldo J , Mathieson B J
Published: December 2022

Rat mAb have been raised to mouse liver-derived large granular lymphocytes (LGL). One of these mAb (4D11) binds specifically to mouse LGL and appears to recognize a non-allelic determinant on NK-active cell populations. The Ag recognized by 4D11 is expressed on LGL of all mouse strains tested, including C57BL/6 (B6), BALB/c, C3H/HeJ, and SJL/J; thus, we have provisionally called this Ag LGL-1. Analysis of various lymphoid and hemopoietic tissues has indicated that only normal tissues known to contain NK activity have 4D11+ cells. With B6 and B6 congenic strains, a positive correlation exists between the number of LGL in a sample and the percentage of 4D11 immunofluorescence-positive cells detected by flow cytometric analysis. Dual color immunofluorescence analyses indicate that some LGL-1+ cells are also stained for Ly-1 and Thy-1. A very small subset exists that is weakly positive for CD3 and LGL-1. However, virtually no cells are seen which co-express LGL-1 and Ly-2. LU activity against YAC-1 targets was increased 7- to 700-fold in LGL-1+ spleen cells obtained by cell sorting from several different strains of mice (B6, BALB/c, C3H/HeJ, SJL/J, and athymic/nude). Sorted, LGL-1- spleen cells contained little or no NK activity. Cells positively selected for LGL-1 also contained between 50 and 60% LGL by morphology. By using facilitated in vitro antibody plus C' treatments, the majority of NK activity can be depleted from both B6 spleen and liver-derived leukocyte populations enriched for NK cells. mAb 4D11 was also shown to precipitate a protein of approximately 87 kDa from the surface of enriched murine NK cells. This mAb should prove valuable for understanding the role of NK cells in the immune response.
A novel in vivo follicular dendritic cell-dependent iccosome-mediated mechanism for delivery of antigen to antigen-processing cells.
Authors: Szakal A K , Kosco M H , Tew J G
Published: December 2022

Recent scanning electron microscopic studies on isolated follicular dendritic cells (FDC) showed that dendrites of certain FDC were "beaded," i.e., consisting of a series of interconnected immune complex coated bodies (termed "iccosomes," measuring 0.3 to 0.7 micron diameter). In vitro these iccosomes detach from one another with ease. The major objectives herein were to establish whether these structures can be detected in sections and whether iccosomes serve to disseminate antigen in vivo. Beginning at day 1, the time point used for isolating beaded FDC, the popliteal lymph nodes of immune C3H mice were studied with light and transmission electron microscopy for 2 wk (i.e., at days 1, 3, 5, 8, and 14) after hind footpad injection of the histochemically detectable antigen, horseradish peroxidase (HRP). Iccosomes (0.25 to 0.38 micron diameter), contoured by a peroxidase (PO)-positive coat of HRP-anti-HRP complexes, were first detected by transmission electron microscopy at day 1 adjacent to cell bodies of certain FDC. Within their limiting membrane they contained flocculent material that was PO positive. At day 3 by light microscopy, germinal centers were seen enlarged and the antigen-retaining reticulum, composed of antigen-bearing FDC, appeared diffuse. This coincided with the transmission electron microscopic visualization of a dispersed state of iccosomes among the follicular lymphocytes. At that time iccosomes were seen attached to the surface of lymphocytes via PO-positive immune complexes and were surrounded by microvillous processes of these cells. Germinal center lymphocytes and tingible body macrophages both responded to contact with iccosomes by endocytosis. Antigen-containing tingible body macrophage were most conspicuous by light microscopy at day 5, when transmission electron microscopy showed that the majority of germinal center lymphocytes contained endocytosed HRP in secondary lysosome-like granules associated with the Golgi apparatus. The number of dispersed iccosomes was markedly reduced by day 5. In controls injected with HSA, a PO-negative antigen, lymphocytes and tingible body macrophages were PO-negative. The presence of antigen in both cell types was confirmed through the use of a gold-conjugated antigen (goat IgG). Simultaneous immunoperoxidase labeling of the same tissues with anti-Ia showed the gold conjugate containing B cells to be Ia+. Antigen-positive B cells and tingible body macrophages were greatly reduced in numbers by day 14, suggesting the intracellular fragmentation of the antigen.(ABSTRACT TRUNCATED AT 400 WORDS)
Receptor-mediated B cell antigen processing. Increased antigenicity of a globular protein covalently coupled to antibodies specific for B cell surface structures.
Authors: Casten L A , Pierce S K
Published: December 2022

Helper T cell recognition of globular protein antigens requires the intracellular processing of the native molecule by an antigen-presenting cell and subsequent presentation of a peptide fragment, containing the antigenic determinant, on the cell surface where it is recognized by the specific T cell in conjunction with Ia. B lymphocytes can function as antigen-presenting cells and, when antigen is bound by their surface Ig, are greatly enhanced in this capacity. In this report it is demonstrated that pigeon cytochrome c covalently coupled to antibodies directed toward either B cell surface immunoglobulin, class I or class II are effectively processed and presented by B cells to cytochrome c-specific T cells, requiring up to 1000-fold less cytochrome c as compared with cytochrome c alone or cytochrome c coupled to nonspecific immunoglobulin. The potent activity of the cytochrome c-antibody conjugates appears to be due to the ability of B cells to concentrate the antigen when the process becomes receptor mediated rather than to a signal provided to the B cell by the conjugate binding, because cytochrome c was not more effectively presented in the presence of unconjugated antibodies as compared with cytochrome c alone. Furthermore, the binding of the native antigen to B cell surfaces is not alone sufficient for T cell activation, in that the cytochrome c-antibody conjugates require processing and are major histocompatibility complex restricted. The results presented here indicate that surface immunoglobulin is not unique in its ability to facilitate antigen processing and/or presentation and that Ig, class I and class II are capable of transporting the cytochrome c to a cytoplasmic vesicle where proteolysis occurs yielding the required peptide, minimally of 10 amino acids. Cytochrome c coupled to monovalent fragments of anti-Ig-antibodies was nearly as effectively presented as cytochrome c coupled to bivalent antibodies, indicating that phenomena mediated by bivalent binding, such as patching and capping of the surface Ig, were not required for effective antigen presentation. The cytochrome c-antibody conjugates, which allow antigen processing to be initiated by receptor-mediated endocytosis, may provide the necessary tools to unravel the intracellular processes by which protein antigens are processed and presented by B lymphocytes.
Differential effects of interleukin 2 vs B cell growth factor on human B cells.
Authors: Nakagawa T , Nakagawa N , Ambrus J L , Fauci A S
Published: December 2022

The effects of recombinant interleukin 2 (IL-2) and high m.w. (HMW) B cell growth factor (BCGF) were examined on normal human peripheral blood B cells activated with Staphylococcus aureus Cowan I (SAC). When SAC-activated B cells were separated into Tac-antigen (Tac-Ag)+ and Tac-Ag- fractions by a cell sorter, recombinant IL-2 induced only the Tac-Ag+ cells to proliferate, whereas both Tac-Ag+ and Tac-Ag- cells responded to HMW-BCGF (m.w. 60,000). Alternatively, SAC-activated B cells were separated according to density into three fractions: low density (large) cells (82 +/- 15% Tac-Ag+), intermediate density (medium) cells (45 +/- 13% Tac-Ag+), and high density (small) cells (less than 5% Tac-Ag+). Recombinant IL-2 enhanced proliferation of low density cells the most, intermediate density cells less, and high density cells not at all. HMW-BCGF induced all three fractions to proliferate to approximately the same degree. Finally, the effects of IL-2 and BCGF on the DNA and RNA content of the various fractions of B cells was examined. RNA content was greater in IL-2-stimulated B cells than BCGF-stimulated B cells, whereas DNA content was the same in both cell populations. IL-2 and BCGF may preferentially interact with different subpopulations of B cells. The interaction of IL-2 or BCGF with normal activated B cells may induce both similar and different intracellular events.
Interleukin 2 functions through novel interleukin 2 binding molecules in T cells.
Authors: Tanaka T , Saiki O , Doi S , Negoro S , Kishimoto S
Published: December 2022

In this report, we examined whether novel interleukin 2 (IL-2) binding molecules (p70/75) are responsible for signal transduction and internalization of IL-2 in T cells by using a monoclonal antibody H-31 to Tac antigens. We found that H-31 inhibited the binding of IL-2 to Tac antigens but not novel IL-2 binding molecules. Scatchard plot analysis revealed that in the presence of H-31, intermediate affinity sites (Kd = 1 to 1.5 nM) were detectable and the number of them was similar to that of high affinity IL-2 receptor (IL-2R) (Kd = 10 to 15 pM) in the absence of H-31. Furthermore, the kinetics of endocytosis of IL-2 via p70/75 showed the same pattern as via high affinity IL-2R. Finally, high doses of IL-2 (100 to 10,000 U/ml) are required for the proliferation of T cells in the presence of H-31, whereas in the absence of H-31, physiologic doses of IL-2 (1 to 100 U/ml) induced the proliferation. These results taken together suggest that novel IL-2 binding molecules are related to signal transduction of IL-2 and that Tac antigens are essential for constructing of high affinity IL-2R, although Tac antigens may not be responsible for signal transduction.
Endotoxin-induced interferon-gamma production in culture cells derived from BCG-infected C3H/HeJ mice.
Authors: Matsumura H , Nakano M
Published: December 2022

The cultured cells prepared from the spleens and peritoneal exudate cells of the C3H/HeJ strain of mice produce very little or no interferon (IFN) by stimulation of bacterial lipopolysaccharide (LPS). However, the cells taken from LPS-non-responder C3H/HeJ mice which had been infected with Mycobacterium bovis bacillus Calmette-Guérin (BCG) prior to the experiment were capable of producing IFN in culture in the presence of LPS. The peritoneal exudate cells of BCG-primed C3H/HeJ mice were separated into adherent cell and nonadherent cell populations by their adhesiveness to plastic culture dishes. IFN production required the presence of both these cell populations in the same culture, and the IFN activities produced were mainly IFN-gamma. The cultures with nonadherent cells and fixed adherent cells still produced IFN, but the cell cultures reconstituted with the BCG-primed cell population and unprimed cell population produce little if any IFN-gamma. Moreover, when both of the populations were cultured in Marbrook culture vessels separated by a membrane filter, the cultures produced very little or no IFN-gamma. These results indicate that there is a mechanism of IFN-gamma induction by LPS which requires the direct contact between adherent cells and nonadherent cells without the participation of any soluble factor(s) from the adherent cells. The producer cells were mainly in the nonadherent cell population. Previous treatment of nonadherent cells with anti-Thy-1.2 antibody, anti-Lyt-1.1 antibody, anti-L3T4 antibody, or anti-asialo-GM1 antibody and complement diminished the ability of the cells for LPS-induced IFN production with the help of adherent cells. Therefore, it is concluded that both T cells (presumably L3T4+T cells) and asialo-GM1+ natural killer cells in the BCG-primed C3H/HeJ cell cultures produced IFN-gamma in the presence of LPS, and the production was supported by the function of macrophages.
Characterization of macrophage recognition and killing of SV40-transformed tumor cells that are "resistant" or "susceptible" to contact-mediated killing.
Authors: Chapes S K , Duffin D , Paulsen A Q
Published: December 2022

In this report we used the macrophage-"resistant" and -"susceptible" cell lines, F5m and F5b, to determine why AKR or AKR-like virus expression makes the F5m cell line more resistant to in vitro macrophage killing than the F5b cell line. We found that resistance to macrophage killing may be transmitted by an infectious AKR or AKR-like murine leukemia virus and that resistance was concomitant with virus expression as measured by the presence of AKR virus-specific 70 kDa glycoprotein. We report that macrophage cytotoxicity of these cell lines is dependent upon the direct contact between tumor cells and macrophages. In contrast, macrophage-mediated cytostasis occurred via soluble macrophage products and no differential susceptibility of F5b or F5m to macrophage-mediated cytostasis was observed. Macrophage binding of F5b was also significantly better than that of F5m. These data suggest that only the events that depend upon the close contact of macrophages and tumor cells will be affected by the expression of AKR or AKR-like virus. Therefore, the differences in susceptibility of F5m and F5b to direct macrophage-mediated cytotoxicity are apparently because the macrophage binding of F5m is less efficient than the binding of F5b.
Assessment in humans of a synthetic peptide-based vaccine against the sporozoite stage of the human malaria parasite, Plasmodium falciparum.
Authors: Etlinger H M , Felix A M , Gillessen D , Heimer E P , Just M , Pink J R , Sinigaglia F , Stürchler D , Takacs B , Trzeciak A
Published: December 2022

Eleven volunteers were injected with an anti-malaria (Plasmodium falciparum) sporozoite vaccine candidate consisting of a synthetic peptide, Ac-Cys-(NANP)3, coupled to tetanus toxoid (TT) and adsorbed to aluminum hydroxide. Two of the volunteers had no previously known exposure to TT. Eight volunteers made detectable antipeptide, anticircumsporozoite protein or antisporozoite antibodies, whose titers increased after multiple injections in four individuals. The maximum antisporozoite titer obtained in an immunofluorescence assay was 1280. In those individuals who produced antipeptide antibody, the overall correlation between IgG anti-Ac-Cys-(NANP)3 antibody in enzyme-linked immunosorbent assay and IgG antisporozoite reactivity in immunofluorescence was highly significant. However, the fine specificity of antibody varied among volunteers with two individuals producing mostly antipeptide antibody. Anti-TT antibody responses increased in all volunteers with the exception of that person who had the highest pretrial anti-TT titer; this individual was one of the two pre-TT-immunized volunteers who failed to produce anti-Ac-Cys-(NANP)3 or sporozoite antibody. For the two non-TT preimmunized volunteers, one produced an antisporozoite fluorescence titer of 320; the other made no detectable antibody against either Ac-Cys-(NANP)3 or sporozoites during a primary response. For the three volunteers monitored, after the first injection, significant T cell proliferative responses to (NANP)3 were observed, which increased up to 4 wk after immunization, when a second injection was given. Responsiveness then declined to background levels and did not reappear after further immunizations. In contrast, a marked TT-specific proliferation was observed for the duration of the study.
Genetics and primary structure of V kappa gene segments encoding antibody to streptococcal group A carbohydrate. Comparison of V kappa gene structure with idiotope expression.
Authors: Lutz C T , Davie J M
Published: December 2022

Two gene segments, V kappa-25-39 and V kappa-25-47, that encode antibody to streptococcal group A carbohydrate in A/J mice were found to be more than 95% homologous in nucleotide sequence in both coding and noncoding regions. It was previously shown that V kappa-25-39 encodes immunoglobulins that express the IdX and IdI-1 idiotopes, whereas V kappa-25-47 encodes IdX+, and IdI-1- immunoglobulins. V kappa gene segments that were clearly allelic to V kappa-25-47 are used to encode IdX+, IdI-1- anti-group A carbohydrate antibodies by C.B20 mice and likely by C57BL/6 mice. Murine strains that are deficient in IdI-1 idiotope expression were investigated by Southern blotting with a 5' probe from V kappa-25-39. Two IdI-1-deficient strains, CE/J and C58/J, had a grossly altered V kappa gene segment structure compared with the A/J prototype. In contrast, the IdI-1-deficient strain, C57BL/6, was indistinguishable from A/J with the 5'V kappa-25-39 probe, indicating that more subtle genetic changes account for the loss of IdI-1 expression in C57BL/6 mice. The evolution of V kappa-25-39 and V kappa-25-47 gene segments was deduced by comparison with the homologous V kappa 24B gene segment of Mus pahari. V kappa-25-39 and V kappa-25-47 likely have recently duplicated once in A/J and related strains of laboratory mice and may have duplicated again in CE/J mice. Thus, individual members of the V kappa 24 gene family, to which V kappa-25-39 and V kappa-25-47 belong, are preserved while the number of gene copies expands or contracts. This fact is strong evidence that evolutionary forces have maintained the V kappa 24 gene family, all of which encode antibody specific for carbohydrate found in bacterial pathogens.
Conditioned augmentation of natural killer cell activity. Independence from nociceptive effects and dependence on interferon-beta.
Authors: Solvason H B , Ghanta V K , Hiramoto R N
Published: December 2022

Injection of mice with 20 micrograms polyinosinic: polycytidylic acid (Poly I:C) after exposure to camphor odor results in a conditioned augmentation of natural killer cell (NK) activity. In this study, we show that the conditioned response is not the result of nociceptive stimulation and that interferon-beta (IFN), but not IFN-alpha can replace Poly I:C as the unconditioned stimulus (US). Two conditioned stimuli (CS) were used with equivalent results. A combination CS consisting of a novel taste (saccharin) and a 125 mg/kg injection of LiCl that induces gastric upset was paired with a Poly I:C or IFN-beta (1 X 10(4) IU) injection. This resulted in an augmentation of NK activity when the conditioned animals were reexposed to the saccharin-LiCl CS. In addition, an identical conditioned response was elicited when a camphor odor CS was paired with either of these US. To test whether the conditioned response might be an artifact not detected by our controls, a mock conditioning experiment was performed, which assessed the differential effect of multiple exposures to the saccharin-LiCl CS without a CS/US pairing. The mock conditioned group was significantly suppressed relative to saline treated controls, whereas the mock nonconditioned group and the mock conditioned group that was not reexposed to the CS after conditioning did not show significant suppression. This indicates that the augmentation observed in the conditioned group after CS/US pairing was not the result of exposure to the CS itself. Small doses of Poly I:C (5 micrograms or 2.5 micrograms) given on days 3 and 5 (or on day 5 only) to boost NK activity had the effect of increasing the magnitude of the conditioned response measured on day 6. In addition, an identical conditioned response was observed when the interval between the CS/US pairing and the later CS exposures was changed, which places the test for the conditioned response either on day 6 (CS given on days 3 and 5) or day 10 (CS given on days 7 and 9). These results show that the observed conditioned enhancement of NK activity in conditioned animals is not caused by any nociceptive properties of the CS itself and is dependent on the IFN-beta produced after Poly I:C injection in the conditioned paradigm.
Influence of major histocompatibility complex H-2LD class I molecules on spleen colony-forming units.
Authors: Tange T , Ahmed-Ansari A , Hansen T , Tse H Y
Published: December 2022

To test whether the major histocompatibility complex class I genes are involved in the regulation of hemopoiesis, the stem cell activities of BALB/c-H-2dm2 (Dm2) mice, which are defective in the expression of H-2L antigens, have been compared with those of the wild-type, BALB/c-Kh, in in vivo and in vitro stem cell assays. In spleen colony-forming unit assays, Dm2 as hosts consistently supported a smaller number of colonies than did BALB/c-Kh. However, both Dm2 and BALB/c-Kh supported a comparable number of colonies in in vitro granulocyte-macrophage colony-forming unit and erythroid colony-forming unit assays. These observations together suggest that the mutation in Dm2 has not affected the hemopoietic potential of the stem cells but may probably affect the hemopoietic microenvironment for the development of the stem cells.
T cell-dependent hapten-specific and polyclonal B cell responses require release of interleukin 5.
Authors: Rasmussen R , Takatsu K , Harada N , Takahashi T , Bottomly K
Published: December 2022

CD4+ T cells in the mouse have recently been subdivided into two major subpopulations which differ in their functional activities and in the lymphokines they produce. Although cloned T cells lines representative of both sets will activate B cells in polyclonal responses, only the subset producing interleukin 4 (IL-4) will activate antigen-specific B cells in linked recognition assays. This suggested that IL-4 was essential for such responses. In the present experiments, the requirements were compared for B cell activation in specific as opposed to polyclonal antibody responses by T cell clones of the helper (IL-4 producing) subset. It was found that specific responses involve primarily small B cells, whereas polyclonal responses activate exclusively the large B cells. Second, polyclonal B cell responses can proceed in the absence of T:B contact, whereas specific responses require physical interaction of the two cells. Third, it was found that interleukin 5 (IL-5, formerly known as T cell replacing factor/B cell growth factor II) is essential for these polyclonal responses by inhibition of such responses with monoclonal anti-IL-5 antibody. Anti-IL-5 also inhibits specific antibody responses involving direct T:B interaction. Thus, IL-5 is clearly a critical mediator of differentiation to immunoglobulin secretion of activated B cells, whether such B cells are obtained as large B cells from freshly isolated spleen cells or are initially activated in an IL-4-dependent fashion by cognate interaction by a helper T cell clone.
Induction and characterization of minor histocompatibility antigens. Specific primary cytotoxic T lymphocyte responses in vitro.
Authors: Ando K , Nakashima I , Nagase F , Isobe K , Kawashima K , Hasegawa Y , Yoshida T , Iwamoto T , Hasegawa T , Muro Y
Published: December 2022

A definite cytotoxic activity was developed in a BALB/c (H-2d) anti-DBA/2 primary mixed leukocyte culture (MLC), which received interleukin 2 (IL-2) on day 3 of culture. This cytotoxic activity was minor histocompatibility antigens (MIHA)-specific at the stimulator level, and was not developed in a syngeneic (BALB/c anti-BALB/c) MLC. The addition of IL-2 on day 3 of culture was crucial; no or very weak cytotoxic activity was developed in MLC receiving IL-2 on day 0 or on both day 0 and day 3. Only appropriate MIHA-allogeneic tumor cells were lysed as the target of the cytotoxic activity. The cytotoxic activity seemed MIHA-specific also at the target level; it lysed tumor cells of DBA/2 mouse origin but not those of BALB/c (syngeneic) origin. Phenotypes of the cytotoxic effector cell were Thy-1+ Lyt-2+. We concluded from these results that MIHA-specific cytotoxic T lymphocytes (CTL) were generated in the MIHA-allogeneic primary MLC. In this newly developed system, we studied genetic and antigenic requirements for primary anti-MIHA CTL responses in vitro. We demonstrated; among spleen cells (SC) of seven B10 H-2-congenic strains only SC of B10.D2 strain whose major histocompatibility complex (MHC) (H-2d) was compatible with the responder MHC effectively stimulated responder BALB/c (H-2d) SC for an anti-MIHA (DBA-C57BL-common) CTL response. Similarly, only SC of two out of seven C x B recombinant inbred strains (C x B.H and C x B.D), which were compatible at the MHC with responder SC, activated responder BALB/c SC for the response. The possibility that cells responding to H-2 alloantigens suppressed the anti-MIHA response was ruled out. Additional experiments showed that compatibility at the H-2K-end or the H-2D-end of the MHC was sufficient for a definite anti-MIHA response. These provided formal evidence that primary anti-MIHA CTL responses in vitro were MHC-restricted at the stimulator level. We then showed that sonication-disrupted SC or Sephadex G-10 column-passed nonadherent SC failed to stimulate responder SC for a primary anti-MIHA CTL response, whereas G-10-passed nonadherent SC responded well to adherent stimulator cells. Further study demonstrated that Ia+ adherent cells were the most active cell type as stimulator. Finally, we confirmed that the primary anti-MIHA CTL responses to adherent stimulator cells was MHC-restricted.
Mechanism of spontaneous activation of B cells in patients with systemic lupus erythematosus. Analysis with anti-class II antibody.
Authors: Tanaka Y , Shirakawa F , Ota T , Suzuki H , Eto S , Yamashita U
Published: December 2022

The mechanism of spontaneous activation of B cells in patients with systemic lupus erythematosus (SLE) was analyzed by using anti-class II monoclonal antibodies in vitro. B cells from SLE patients showed enhanced proliferation and Ig production by in vitro culture without any stimulation. The number of Ig-producing cells increased during a 5-day culture period, but the addition of anti-class II antibodies such as anti-HLA-DR, DQ, or DP monoclonal antibodies inhibited these B cell responses in a dose-dependent manner. Anti-class I and anti-B1 antibody gave no effect. The inhibitory effect of anti-class II antibodies on B cell responses became more remarkable when B cells were cultured on a longer period. By a Percoll gradient density centrifugation, Ig-producing cells were enriched in the lower density fraction, but became depleted in the higher density fraction. However, B cells of the higher density fraction developed into Ig-producing cells after 5 days of culture and anti-class II antibodies inhibited this development. When mitomycin C- and cycloheximide-treated B cells were added to the in vitro culture of B cells as a stimulator, B cell responses were enhanced in a dose-dependent manner. T cells treated with mitomycin C and cycloheximide had no enhancing effect on B cell responses. Furthermore, the enhancing effect of the stimulator B cells was inhibited by the pretreatment of stimulator B cells with anti-class II antibodies. These results suggest that in patients with SLE the abnormality exists in B precursor cells which are easily activated by interacting with other B cells to differentiate into Ig-producing cells and anti-class II antibodies inhibit the B cell activation by interfering with this cellular interaction.
Positive effects of interferon-alpha on B cell-type chronic lymphocytic leukemia proliferative response.
Authors: Karray S , Delfraissy J F , Merle-Beral H , Wallon C , Debre P , Galanaud P
Published: December 2022

We studied the effect of recombinant interferon-alpha (IFN-alpha) on the proliferative response of normal human B cells and of lymphocytes from 10 patients with B cell-type chronic lymphocytic leukemia. We show that IFN-alpha, which has no effect on B cell proliferation when used alone, can synergize with anti-mu antibody and can support DNA synthesis by anti-mu activated B cells. This was observed with normal B cells and in 4 of 10 patients with B cell-type chronic lymphocytic leukemia. These four patients were all responders to B cell growth factor (BCGF), whereas the responsiveness to IFN-alpha was not correlated with that of IL-2. The positive functional relationship between IFN-alpha and BCGF in these patients is emphasized by the synergistic effect of these two factors in two of these patients, and the lack of inhibition of BCGF response by even supraoptimal concentrations of IFN-alpha. Among the subgroup of patients unable to respond to IFN-alpha, a synergy between IFN-alpha and IL-2 could be observed.
Dietary fish oil modulation of macrophage amyloid P component responses in mice.
Authors: Gonnerman W A , Mortensen R F , Tebo J M , Conte J M , Leslie C A , Cathcart E S
Published: December 2022

Arthritis-susceptible B10.RIII mice, maintained on either fish oil (FO) or corn oil (CO) diets (5% by weight), and amyloid-susceptible CBA/J mice fed chow diets were given 20 micrograms purified LPS by i.p. injection. Both strains of mice responded to LPS with a 20- to 30-fold increase in plasma amyloid P component (AP) levels. There were no differences in the response between males and females or between FO and CO treatment groups. The data demonstrated that cultured peritoneal macrophages (M phi) respond to LPS stimulation with increased secretion of AP. In contrast to plasma AP levels, the MO response to LPS stimulation, as measured by production of AP, was influenced by both gender and diet. Although M phi from both male and female mice on the CO diet and male mice on the FO diet responded similarly, those from female mice on the FO diet secreted only 25 to 35% as much AP as did the other three groups. There were no dietary effects on the LPS-induced serum amyloid A protein response nor was there detectable serum amyloid A protein produced by the M phi. These results demonstrate that unstimulated, resident peritoneal M phi secrete AP as a normal constituent and in increasing amounts in response to LPS stimulation.
Monoclonal antibodies to the major feline allergen Fel d I. II. Single step affinity purification of Fel d I, N-terminal sequence analysis, and development of a sensitive two-site immunoassay to assess Fel d I exposure.
Authors: Chapman M D , Aalberse R C , Brown M J , Platts-Mills T A
Published: December 2022

Two mAb were used to develop new techniques for the purification and quantitation of the major feline salivary allergen, Felis domesticus allergen I (Fel d I). The allergen was purified from aqueous house dust extract with a high Fel d I content by affinity chromatography over a monoclonal immunosorbent and elution with 4 mM HCl, pH 2.5. This single step procedure gave 40 to 50% recovery of 90% pure allergen which, following final purification by size exclusion HPLC, showed a single line on immunodiffusion and crossed immunoelectrophoresis against monospecific anti-Fel d I and polyclonal anti-cat dander antibodies. The m.w. of native Fel d I was 39,000 on size exclusion HPLC, and 17,000 under nonreducing conditions on gel electrophoresis. The N-terminal amino acid sequence (33 residues) showed no homology with other known protein sequences. The combination of the SDS-PAGE and N-terminal sequence data suggests that Fel d I is a non-covalently linked homodimer. A two-site RIA was developed using mAb directed against different epitopes on Fel d I. This assay was species-specific, highly sensitive (0.0004 U/ml), and showed an excellent correlation with a polyclonal inhibition RIA (n = 27, r = 0.93, p less than 0.001). Cat allergen extracts used for immediate skin tests showed marked differences in Fel d I content (from 0.1 to 30 U/ml). Consistently high Fel d I levels were found at monthly intervals in six dust samples from four houses with cats (10 to 100 U/g of dust). Comparisons of Fel d I and mite and pollen allergen levels showed that house dust can contain greater than 100 micrograms/g of either of these allergens and is a potent source of foreign environmental antigens. Monoclonal affinity chromatography provides a major breakthrough in the purification of Fel d I, from a source material that would otherwise have been considered impossible (house dust). The mAb assay for Fel d I is both more sensitive and more easily standardized than existing techniques. These techniques will allow full structural and antigenic analysis of Fel d I and more detailed studies on the relationship between cat antigen exposure and the development of asthma.
Heart-reactive antibodies in rabbit anti-Streptococcus mutans sera fail to cross-react with Streptococcus mutans.
Authors: Swartzwelder F J , Barua P K , Albini B , Stinson M W
Published: December 2022

Immunization of rabbits with Streptococcus mutans antigens results in the production of serum antibodies that bind in vitro to human, rabbit, and monkey cardiac muscle. Antibodies to heart, however, have also been reported to occur at lower titers in the sera of unimmunized rabbits. In this study, the specificities of heart-reactive antibodies (HRA) in sera of unimmunized and S. mutans-immunized rabbits were compared using indirect immunofluorescence, Western blot, and Bio-Dot immunoassays. Both groups of sera gave striational indirect immunofluorescence-staining patterns on thin sections of native human and monkey cardiac muscle. Western blot analyses revealed that antibodies in normal sera bound 9 to 20 components of human, rabbit, and monkey heart. The major bands had Mr of 205,000, 160,000, 135,000, and 70,000. Several of the normal sera did not have antibody activity to S. mutans antigens, indicating that these HRA do not cross-react with these bacteria. Although immunization of rabbits with S. mutans caused increased titers of HRA (two to three doubling dilutions), Western blot assays using anti-S. mutans sera showed banding patterns qualitatively similar to those of normal sera on heart extracts. Antibodies to skeletal muscle myosin were detected in both serum groups. Of eighteen normal rabbit sera sixteen had antimyosin titers of 10 to 40, whereas all eighteen anti-S. mutans sera had titers of 10 to 160. Affinity-purified antimyosin antibodies isolated from anti-S. mutans serum did not bind to S. mutans components. Conversely, affinity-purified antibodies to S. mutans antigens did not bind to myosin or to other cardiac muscle components. Among these were antibodies to the 185-kDa cell wall protein (also known as B, I/II, IF, Spa A, and P1) previously believed to possess antigenic mimicry. HRA were removed from anti-S. mutans sera by absorption with S. mutans but this effect was not specific, because a non-cross-reactive internal standard antibody was also absorbed to the same extent. Because previous evidence for antigenic mimicry between S. mutans and cardiac muscle was based on serum cross-absorption experiments, this immunologic relationship is not substantiated. These results indicated that naturally occurring antibodies to cardiac muscle components are present in the sera of unimmunized rabbits and that immunization with S. mutans does not stimulate production of new heart-reactive antibody, but rather serves to boost antibody production by preexisting clones of self-reactive B-lymphocytes.
Suppressive substance produced by T cells from mice chronically infected with Trypanosoma cruzi. II. Partial biochemical characterization.
Authors: Liew F Y , Schmidt J A , Liu D S , Millott S M , Scott M T , Dhaliwal J S , Croft S L
Published: December 2022

Culture supernatants of splenic T cells from susceptible CBA mice chronically infected with Trypanosoma cruzi contain a suppressive substance which can inhibit the induction of delayed-type hypersensitivity (DTH) to a wide range of antigens. The suppressive substance is distinct from T. cruzi antigen inasmuch as the supernatant depleted of any residual T. cruzi antigen by an affinity column still retains the suppressive activity, whereas addition of T. cruzi antigens to control supernatant did not confer suppressive function. The suppressive supernatant does not contain detectable levels of IL-1, IL-2, IL-3, or IFN-gamma but a modest level of IL-1 and IL-2 inhibitory activities. However, both these inhibitory activities elute at a different position from the DTH suppressive activity on gel filtration. The DTH suppressive activity is heat labile (1 h, 56 degrees C), cryostable, but destroyed by trypsin treatment. It binds to ricin but not to lentil lectin. Sepharose 4B gel filtration and HPLC analysis in mild chaotropic agents (urea, ethylene glycol) demonstrate that the suppressive substance has an apparent Mr of 30 to 60 kDa, but full DTH-suppressive activity is retained only in an aggregated form.
Characterization of an anti-Ly-6 monoclonal antibody which defines and activates cytolytic T lymphocytes.
Authors: Havran W L , Lancki D W , Moldwin R L , Dialynas D P , Fitch F W
Published: December 2022

HK1.4 mAb was identified based on its ability to stimulate proliferation of cloned murine CTL. Within the lymphoid lineage, mAb HK1.4 bound exclusively to CTL, regardless of the expression of Lyt-2 or MHC restriction. HK1.4 mAb also bound to 40% of bone marrow cells and less than 5% of thymocytes from all mouse strains tested. Based on the tissue distribution of the determinant with which it reacted and the ability to cross-block binding of the anti-Ly-6 mAb H9/25, mAb HK1.4 appeared to react with a product of the Ly-6 locus. However, significant differences were observed between the properties of mAb HK1.4 and other, previously described anti-Ly-6 mAb. Cell proliferation and lymphokine release by cloned CTL were stimulated by culture with mAb HK1.4 alone or in the presence of non-stimulatory levels of IL-2. This proliferation and lymphokine release were not blocked by the addition of soluble anti-Lyt-2 or anti-IL-2R mAb. Activation induced by HK1.4 mAb proceeds in the absence of accessory cells, of cross-linking of the TCR, or the addition of mitogens or PMA. Stimulation of cells by anti-TCR mAb was not blocked by the addition of soluble HK1.4 mAb, and the stimulatory effects of HK1.4 and anti-TCR mAb were not additive. However, IL-2-driven proliferation of CTL clones was dramatically inhibited by the addition of HK1.4 mAb.HK1.4 mAb had no effect on Ag-specific or lectin-facilitated cytolysis. Taken together, these data indicate that mAb HK1.4 operates via an IL-2-independent pathway of activation that is also independent of the TCR.
Regulation of the CD2 alternate pathway of T cell activation by CD3. Evidence for heterologous desensitization.
Authors: Holter W , Majdic O , Stockinger H , Howard B H , Knapp W
Published: December 2022

Normal resting T cells were stimulated through the alternate CD2 pathway. A CD3 mAb VIT3 completely blocked their proliferative response. The time interval for 50% inhibition lasted for 24 h after the onset of CD2 stimulation. Mitogen-activated cloned long term cultured T cells could also be stimulated via CD2. This proliferative response was again inhibitable by VIT3, indicating that CD3 regulates the CD2 pathway not only in resting cells, but also in lymphocytes actively involved in an Ir. T cells were further loaded with Quin2 and their free cytoplasmic Ca2+ levels were monitored in response to CD3 and CD2 stimulation. Antibodies directed against both surface R triggered a rapid elevation of Ca2+ levels. Both responses were abrogated when the cells had been treated overnight with VIT3. The free cytoplasmic Ca2+ levels of VIT3-pretreated cells, however, were not higher than those of control cells. These results point to a functional interaction between CD3 and CD2 possibly at the level of signal transducing proteins. Finally, cholera toxin was found to inhibit the Ca2+ response in Jurkat T cells. Both the CD3 and CD2 stimulation were sensitive to cholera toxin, indicating that a GTP-binding protein may be involved in signal transduction for both surface structures.
IL-2-dependent proliferation of thymic accessory cells.
Authors: Rocha B , Lehuen A , Papiernik M
Published: December 2022

Phagocytic cells of the thymic reticulum are Ia-positive accessory cells continuously produced in long term thymic stroma cultures. We show in the present paper that phagocytic cells of the thymic reticulum have R for IL-2. They share this property with splenic accessory cells produced in vitro by the same technique but have the unique property of proliferating in the presence of rIL-2. This proliferation is not enhanced by Con-A, is not linked to a lymphoid contaminant, and is specifically inhibited by an anti-IL-2R mAb.