bluuebunny/crossref_metadata_2025 huggingface dataset:
T cell-monocyte interactions in the production of humoral factors regulating human granulopoiesis in vitro.
Authors: Herrmann F , Cannistra S A , Griffin J D
Published: December 2022

A variety of monocyte functions are modulated by the T cell lymphokine interferon-gamma (IFN-gamma). We assessed the capacity of IFN-gamma to induce release of granulocyte-monocyte stimulating factors (CSF-GM) from highly purified monocyte preparations. Whereas secretion of CSF-GM by monocytes is negligible in the absence of T cells, CSF-GM secretion is inducible when concentrations of IFN-gamma as low as 10 U/ml are present. This effect could be abrogated by specific neutralizing monoclonal antibody to IFN-gamma and was restricted to monocytes, as resting T cells failed to secrete detectable CSF-GM in response to IFN-gamma. The response of monocyte preparations to IFN-gamma was biphasic in that concentrations greater than 250 U/ml did not induce detectable CSF-GM activity. However, this was shown to be due to the release of a humoral inhibitor of G/M-progenitor cells, and not necessarily due to a lack of CSF-GM secretion.
Isolation and characterization of an antigen-specific suppressor inducer molecule from serum of hyperimmune mice by using a monoclonal antibody.
Authors: Ferguson T A , Iverson G M
Published: December 2022

We have used a rat monoclonal antibody (mAb) (called 14-30) to affinity purify the antigen-binding chain of a suppressor inducer factor (TsiF-AB) from the serum of mice hyperimmune to heterologous erythrocytes. The TsiF-AB requires the addition of a second, antigen-nonspecific component for biologic activity as well as Lyt-2+ T cells in the assay culture. This mAb can be used to affinity purify suppressor inducer factor from a well-characterized TsiF but not suppressor effector factor (TseF) from culture supernatants. Binding of mAb 14-30 to TsiF is independent of the antigen specificity of the suppressor factor and of the strain of origin of the TsiF. The TsiF affinity purified from hyperimmune serum has an apparent m.w. of 68,000 by SDS-PAGE analysis. 2D gel analysis shows that the serum-derived TsiF has charge heterogeneity, all in the acid range.
Fatty acylation of murine Ia alpha, beta, and invariant chains.
Authors: Simonis S , Cullen S E
Published: December 2022

Labeling of murine spleen cells with [3H]palmitate followed by analysis of immunoprecipitated Ia molecules indicated that Ia alpha- and beta-chains and their associated invariant chain contain covalently bound fatty acid. This modification is present in I-A and I-E molecules and has been found in all haplotypes examined. The 3H label was not dissociated from the glycoproteins by detergents or under the denaturing conditions of SDS-polyacrylamide gel electrophoresis. The fatty acid linked to Ii is released by treatment with neutral hydroxylamine, which indicates thioester linkage. The acylation of alpha- and beta-chains appears to involve attachment of palmitoyl groups via an ester linkage sensitive to alkaline hydrolysis. The radioactive species released from the isolated chains by treating with KOH/methanol co-migrated with palmitic acid and palmitic acid methyl ester on thin-layer chromatography.
Interleukin 2 does not induce phosphatidylinositol hydrolysis in activated T cells.
Authors: Mills G B , Stewart D J , Mellors A , Gelfand E W
Published: December 2022

Hydrolysis of phosphatidylinositol-4,5-bisphosphate to diacylglycerol and myoinositol-1,4,5-trisphosphate is thought to be a primary event in the activation of cells by some growth factors, mitogenic lectins, and oncogenes. The mechanism whereby interleukin 2 (IL 2) binding to its receptor on activated T lymphocytes leads to cell proliferation has not been determined. Because the mitogenic has not been determined. Because the mitogenic action of IL 2 resembles that of some growth factors, the possible role of phosphatidylinositol breakdown in the activation of T cells by IL 2 was examined. In human or murine IL 2-sensitive cells, incubation with IL 2 did not alter the rate of turnover of phosphatidylinositol, phosphatidylinositol-5-phosphate, phosphatidylinositol-4,5-bisphosphate, or phosphatidylcholine in 32PO4-loaded cells. IL 2 also did not alter either the isotopic labeling of diacylglycerol or [3H]arachidonic acid release from cells. In addition, IL 2 did not alter the rate of formation of the phosphatidylinositol breakdown products myoinositol-1,4,5-trisphosphate, myoinositol-1,4-bisphosphate, or myoinositol-1-phosphate. In contrast, under similar conditions, IL 2 induced significant increases in [3H]thymidine incorporation and cell proliferation. Mitogenic lectins such as concanavalin A and phytohemagglutinin gave significant changes in isotopic labeling of phosphoinositols, diacylglycerols, and phosphatidylinositols, indicating that phosphatidylinositol hydrolysis induced by mitogenic lectins was detectable in the assay systems. IL 2, in contrast to other growth factors, does not appear to signal cells by increasing phosphatidylinositol breakdown.
Restriction fragment-length polymorphisms of class II gene sequences in mice expressing minor structural variants of I-Ak and I-Ap.
Authors: McConnell T J , Darby B , Wakeland E K
Published: December 2022

Serologic and structural analyses of the I-A molecules expressed among a large collection of wild mouse-derived H-2 haplotypes has led to the definition of "families" of I-A alleles which encode antigenically similar molecules that are identical in more than 90% of their tryptic peptides. Two of these families, denoted the I-Ak and I-Ap families, consist of 10 I-A alleles which encode I-A molecules whose structures are closely related to either I-Ap or I-Ak. The evolutionary relationships of the I-A alleles in these families were assessed by a molecular analysis of their genomic structures. The A alpha and A beta alleles within these I-A families were compared by analysis of restriction fragment-length polymorphisms (RFLP) detected at high stringency by Southern blot hybridization with DNA probes specific for either A alpha or A beta. The polymorphic restriction enzyme sites detected in this survey were distributed over more than 7 kb of genomic DNA surrounding each gene. Because both A alpha and A beta are encoded by about 700 bp of exon DNA, the majority of the restriction enzyme sites assayed by this RFLP analysis reflect polymorphisms in noncoding regions. The DNA sequence homologies of these alleles were estimated from the RFLP results with seven restriction endonucleases by calculating the fraction homologous value as defined previously. The results indicate that evolutionarily dissimilar I-A alleles can encode I-A molecules with very similar structures. The five I-A alleles in the I-Ak family could be divided into two discrete groups, denoted K1 and K2, on the basis of their restriction fragment (RF) genotypes. The RF genotypes of alleles within each group shared more than 80% of the restriction fragments for both A and A beta. In contrast, the RF genotypes of alleles in group K1 differed extensively from those in group K2, indicating that alleles in these separate groups may not be evolutionarily closely related. These observations suggest that gene conversion or intragenic recombinational events may have been involved in the evolution of groups K1 and K2 in the I-Ak family. The RF genotypes of alleles in the I-Ap family demonstrated a close evolutionary relationship among all but two of the alleles. These two alleles encoded I-A molecules whose structures were the least related to I-Ap of any of the alleles in the I-Ap family.(ABSTRACT TRUNCATED AT 400 WORDS)
Gene mapping and somatic cell hybrid analysis of the role of human lymphocyte function-associated antigen-3 (LFA-3) in CTL-target cell interactions.
Authors: Barbosa J A , Mentzer S J , Kamarck M E , Hart J , Biro P A , Strominger J L , Burakoff S J
Published: December 2022

LFA-3 is expressed on a wide variety of human cell lines, including those which have been used as recipients for gene transfer of human class I gene products, whereas a murine counterpart is either absent or significantly different such that the anti-LFA-3 monoclonal antibody (MAb) does not bind. By using a somatic cell genetic approach, we demonstrate that LFA-3 is not a major histocompatibility complex-encoded molecule, and that its gene locus maps to human chromosome 1. When LFA-3 and HLA-A2 are coexpressed on the mouse cell surface, anti-LFA-3 MAb interfered with specific recognition and lysis of these target cells by human CTL capable of lysing HLA-A2-expressing mouse transfectants. A significant contribution of the LFA-3 molecule to CTL reactivity was not observed, however, because the presence of LFA-3 did not restore recognition by CTL clones previously found incapable of lysing HLA-A2-expressing mouse transfectants, nor was it required by those human CTL that could lyse mouse cell transfectants. Thus, we have used genetic techniques to demonstrate that LFA-3 may serve a role in CTL-target cell interactions at the target cell level, but is not a molecule absolutely required for human allospecific CTL recognition of HLA antigens expressed on mouse cells. We suggest that LFA-3 may not participate directly in CTL function under normal circumstances, but delivers a more general inhibitory signal only when provoked by bound MAb.
Effect of cyclosporin A and dexamethasone on interleukin 2 receptor gene expression.
Authors: Reed J C , Abidi A H , Alpers J D , Hoover R G , Robb R J , Nowell P C
Published: December 2022

Here we demonstrate that CsA and DEX, at concentrations that markedly inhibited PHA-induced proliferation and IL 2 mRNA accumulation, partially diminished the expression of receptors for IL 2 on PBMC. This inhibition of IL 2 receptor expression occurred at a pretranslational level and involved a reduction in both high affinity and low affinity forms of the receptor. Although both CsA and DEX inhibited IL 2 receptor expression by about 50%, only CsA blocked the PHA-mediated induction of IL 2 responsivity in PBMC cultures. These data provide evidence that 1) CsA and DEX suppress the proliferation of T lymphocytes through distinct (though perhaps overlapping) mechanisms, 2) CsA (but not DEX) blocks the PHA-mediated induction of signals necessary for T cells to become capable of proliferating in response to IL 2, and 3) T cells regulate the expression of their genes for IL 2 and IL 2 receptors, at least in part, through independent mechanisms.
T cell clone producing an IL 1-like activity after stimulation by antigen-presenting B cells.
Authors: Tartakovsky B , Kovacs E J , Takacs L , Durum S K
Published: December 2022

We have analyzed the involvement of IL 1 in a cellular interaction during which murine B cells serve as antigen-presenting cells for a T cell clone (D10.G4.1). This T cell clone was chosen for study because it is highly dependent on exogenous IL 1 for concanavalin A (or anti-receptor antibody)-induced proliferation. We observed that B cells presented either self I-Ak plus nominal antigen or allogeneic I-Ab, and consequently induced proliferation of this T cell clone without any requirement for exogenous IL 1. After an overnight co-culture with allogenic B cells, we detected an IL 1-like activity in lysates of the cell mixture, but were unable to detect a similar activity in the culture medium. This IL 1-like activity was induced in a MHC-restricted manner. We determined that this intracellular IL 1-like activity was derived from the D10.G4.1-responding T cells, rather than from the antigen-presenting B cells. Moreover, we were unable to detect an IL 1-like activity in murine B cells after a variety of stimuli including LPS, anti-Ig, activated T cell supernatants, or combinations of these stimuli. Hybridization of cytoplasmic RNA with an oligonucleotide probe for human IL 1-alpha confirmed the T cell source of the biological activity. The IL 1-like factor derived from the cell culture mixture lysate showed two broad peaks of activity after gel filtration, one in the 10,000 to 20,000 dalton range and the second in the 35,000 to 45,000 dalton range. This first description of IL 1 activity produced by a T cell may introduce a new element to the early events leading to T cell activation and proliferation.
The augmentation of human natural killer cell activity by interferon-gamma is not associated with the induction of the interferon-alpha-inducible proteins.
Authors: Gustafsson A , Sundström S , Lundgren E
Published: December 2022

Treatment of partly purified large granular lymphocytes (LGL) with either IFN-alpha or IFN-gamma for 2 hr augmented their NK cell activity. This augmentation was completely inhibited by the addition of 10 micrograms/ml of cycloheximide. In contrast, when the effects of IFN-gamma on the synthesis of specific proteins in these cells was directly studied by use of two-dimensional gel electrophoresis, we found that IFN-gamma was unable to induce any of the earlier detected, IFN-alpha/IFN-beta-inducible proteins within 18 hr of incubation. No additional, IFN-gamma-induced proteins were detected in either the partly purified LGL or purified T cells. In contrast, the effects of the two factors were comparable in the glioma cell line 251 MG. This shows i) that the effects of IFN-alpha and IFN-gamma are dependent on the responder cell type, ii) that there exists at least one mechanism that can augment NK cell activity that is not dependent on the increased synthesis of the IFN-alpha-inducible proteins, and iii) that either the nine IFN-alpha-inducible proteins are not involved in any leukocyte function that is augmentable by both IFN-alpha and IFN-gamma, or that the two factors exert their actions in leukocyte through different mechanisms.
Analysis of anti-streptococcal group A carbohydrate idiotope levels in sera: correlation of magnitude of expression with idiotope position and VK haplotype.
Authors: Greenspan N S , Fulton R J , Davie J M
Published: December 2022

We have employed monoclonal anti-idiotopes to map the corresponding idiotopes on the variable domain of a prototype antibody specific for streptococcal group A carbohydrate (GAC). Idiotope variability, as assessed by direct and competitive binding assays, previously was shown to correlate with idiotope position; determinants farther from the binding site were less variable. We now describe a relationship between idiotope position and idiotope concentration in normal and GAC-immune sera from mice of several inbred and recombinant inbred strains. Employing sera as inhibitors in a competitive radioimmunoassay, we demonstrate that idiotopes farther from the binding site (more proximal) tend to be present at higher levels in GAC-hyperimmune sera. Only the most proximal idiotope was detected in normal serum, and this idiotope was present in normal sera from all 12 strains tested. Finally, significant interstrain differences in patterns of idiotope expression were observed, and some of these differences appear to be correlated with allelic differences at immunoglobulin structural gene loci.
Rheumatoid factor production in 129/Sv mice: involvement of an intestinal infectious agent.
Authors: Coutelier J P , Van der Logt J T , Heessen F W , Warnier G , Van Snick J
Published: December 2022

High titers of IgG2a-specific rheumatoid factors (RF) are frequently observed in colonies of 129/Sv mice. The involvement of a transmissible agent in this phenomenon was shown by the following findings: (i) cesarean-derived and isolator-reared offsprings of RF-positive dams were free of RF, ii) a single intragastric inoculation with intestinal fluid from RF-positive donors elicited chronic RF production in RF-negative recipients, and iii) intestinal fluid collected from these primary recipients induced a comparable RF response in a second set of animals. The nature of this RF-inducing agent, however, remained elusive. Although its ability to pass through filters that efficiently retained bacteria could be unequivocally established, systematic serological analysis failed to detect any significant correlation between RF production and antibody responses to common mouse viruses or Mycoplasma. Moreover, all attempts to identify the RF-inducing agent by electron microscopy or to grow it in nude or newborn mice, as well as in cell cultures, remained unsuccessful.
Murine melanoma-specific tumor rejection activity elicited by a purified, melanoma-associated antigen.
Authors: Hearing V J , Gersten D M , Montague P M , Vieira W D , Galetto G , Law L W
Published: December 2022

B700 is a melanoma-specific glycoprotein antigen, with a m.w. of 65,000 and an isoelectric point of 4.5; this antigen has been shown to bear significant sequence homology to a normally occurring protein, serum albumin. The production of B700 is apparently restricted to all the murine melanomas tested, since a variety of other transformed and untransformed cell lines do not contain detectable levels of this antigen. The capacity of B700 to function as a tumor-specific transplantation antigen (TSTA) is demonstrated in this study. This activity has been titrated, and it is shown that mice immunized with B700 are able to significantly inhibit the growth of B16 F10 melanomas after subcutaneous challenge; immunized mice can also inhibit the establishment and growth of experimental metastases in the lungs after i.v. challenge with B16 melanoma cells. The TSTA was found to cross-protect also against challenge with two other murine melanoma lines, JB/RH and K1735, but was specific in that the growth of two nonmelanoma lines (RBL-5 leukemia and MCA-105 sarcoma) was not affected. B700 is also shown in this study to be unrelated to other known murine tumor antigens, or to murine leukemia virus antigens. It is further shown that mice immunized with B700 produced antibodies specific to B700 that were not cross-reactive with albumins from various mammalian sources.
The extent of oxidative mitogenesis does not correlate with the degree of aldehyde formation of the T lymphocyte membrane.
Authors: Roffman E , Wilchek M
Published: December 2022

Chemical oxidation of T lymphocytes with periodate or the combined action of the enzymes neuraminidase and galactose oxidase (NAGO) results in T cell activation. The latter process includes the production of interleukin 2 (IL 2) and the induction of IL 2 receptors. Because membrane-bound aldehydes act in the transmission of the oxidative mitogenic signal, we designed a comparative study in human thymocytes and peripheral blood leukocytes in order to determine a possible correlation between the degree of the membrane aldehydes generated chemically or enzymatically and the extent of the resulting activation. The differences between periodate- and NAGO-induced aldehydes were demonstrated by flow cytometry of cells stained with a novel fluoresceinated hydrazide and by an electrophoretic procedure performed with biocytin hydrazide and 125I-streptavidin. In both cellular systems, periodate oxidation resulted in stronger formation of aldehydes than NAGO oxidation. However, the IL 2 receptor induced by NAGO formation and the resultant activation were significantly higher than those induced by periodate. The degree of aldehyde formation on peripheral blood leukocytes was also considerably higher than that of thymocytes, yet similar patterns of [3H]thymidine uptake were observed in the mitogenic assays of both cellular systems. The data indicate that no correlation exists between the extent of aldehyde formation and the degree of oxidative mitogenesis. It is thus suggested that relatively few (or maybe only one) membrane-bound aldehyde-containing molecules act in the transmission of the oxidative mitogenic signal.
Development and ontogeny of hamster T cell subpopulations.
Authors: Witte P L , Streilein J W
Published: December 2022

The Syrian hamster is unique among laboratory animals because products of class I MHC genes are monomorphic. Thus, this species may be a model in which to test the relationship between MHC polymorphism and the T cell antigen receptor repertoire. Recently, cytotoxic and helper T cell subpopulations have been distinguished on the basis of cell surface phenotype detected with monoclonal antibodies (mAb). We used these reagents (mAb 110 detects all peripheral T cells and mAb 38 detects cytotoxic T cells) to dissect and categorize thymic populations according to relative maturational status. The two mAb divide thymocytes into four subpopulations in the young adult. Two (110+ 38+, 110+ 38-) were peripheral-like and were housed in the medulla, exclusively; another subset (110- 38+) consisted almost entirely of TdT+ cortical thymocytes. The fourth subset (110- 38-), bearing neither marker, was heterogeneous and consisted mostly of medium-large-size thymocytes, including cells with an early phenotype (nuclear TdT+). Cells with the cortical phenotype proved to be the most sensitive to cortisone treatment, whereas those which expressed the medullary marker, 110, were most resistant. To ascertain the relationship between 110- and 110+ T lineage cells, we followed the appearance of the four thymic subpopulations during ontogeny of the hamster thymus. Adult-like thymic architecture (delineation of cortex and medulla) as well as the two 110- subsets were established before expression of 110 antigen was apparent in the thymus. However, lymphocytes bearing the 110 antigen were found in lymph nodes prior to thymus during ontogeny, concomitant with developing T cell function in peripheral tissue. This finding implies that cells lacking 110 antigen were exported from the thymus and subsequently acquired expression of the molecule in the periphery, and we suggest that acquisition of 110 antigen may be a stage of postthymic maturation. Although 110+ cells appeared to be the most mature subset by several criteria, all functional thymocytes of adults or neonates were not 110+. Thus, we conclude that the 110 marker is acquired after T cells reach functional maturity. Moreover, the response profile of isolated 38+ thymocytes was analogous to peripheral 38+ T cells, suggesting that the dichotomy of function detected with our mAb also occurs before acquisition of 110 antigen. We have modeled what is known about hamster T cell development into a hypothetical scheme.
Accessory cell-T cell interactions involved in anti-CD3-induced T4 and T8 cell proliferation: analysis with monoclonal antibodies.
Authors: Geppert T D , Lipsky P E
Published: December 2022

The effect of monoclonal antibodies (Mab) directed at T cell and accessory cell (AC) surface molecules on OKT3-induced T4 and T8 cell proliferation was examined. Mab directed at nonpolymorphic class I (W6/32, MB40.5) and class II (L243) major histocompatibility complex (MHC)-encoded gene products, an epitope common to LFA-1, CR3, and the p150, 95 molecule (60.3), and a heterodimer present on monocytes (M phi) and activated T cells (4F2) inhibited M phi-supported OKT3-induced proliferation of both T4 and T8 cells. Moreover, an Mab directed at the CD4 molecule (66.1) inhibited OKT3-induced T4 but not T8 cell proliferation, whereas an Mab directed at the CD8 molecule (OKT8) inhibited T8 but not T4 cell responses. With the exception of 66.1, each inhibited OKT3-induced T cell proliferation when added as late as 15 hr after the initiation of culture. Inhibition could not be explained by competition for Fc receptors on the AC. A variety of other Mab including OKT11 and those directed at other HLA-DR and DQ determinants were not inhibitory. The inhibitory Mab were found to diminish T4 cell IL 2 production and IL 2 receptor expression. Consequently, IL 2 reversed some but not all of the Mab-mediated inhibition of T cell proliferation. In contrast to the effects noted with M phi-supported responses, 60.3 and 66.1 but neither L243 nor 4F2 inhibited OKT3-induced T4 cell proliferation supported by Ia- or IFN-gamma-treated Ia+ endothelial cells. None of the Mab tested inhibited T cell proliferation induced by the AC-independent stimuli OKT3 and phorbol myristate acetate (PMA) or calcium ionophore and PMA in the presence or absence of added AC. The data therefore suggest that the Mab inhibit OKT3-induced activation of T4 and T8 cells by preventing necessary interactions between AC and T cell surface proteins. Moreover, the results suggest that different arrays of interaction molecules are involved in OKT3-induced T cell proliferation depending on the nature of the AC and the responding T cell subset.
Abrogation of hybrid resistance to bone marrow engraftment by graft-vs-host-induced immune deficiency.
Authors: Hakim F T , Shearer G M
Published: December 2022

Lethally irradiated F1 mice, heterozygous at the hematopoietic histocompatibility locus Hh-1, which is linked with H-2Db, reject bone marrow grafts from H-2b parents. This hybrid resistance (HR) is reduced by prior injection of H-2b parental spleen cells. Because injection of parental spleen cells produces a profound suppression of F1 immune functions, we investigated whether parental-induced abrogation of HR was due to graft-vs-host-induced immune deficiency (GVHID). HR was assessed by quantifying engraftment of H-2b bone marrow in F1 mice with the use of splenic [125I]IUdR uptake; GVHID, by the ability of F1 spleen cells to generate cytotoxic T lymphocytes (CTL) in vitro. We observed a correlation in the time course and spleen cell dose dependence between loss of HR and GVHID. Both GVHID and loss of HR were dependent on injection of parental T cells; nude or T-depleted spleen cells were ineffective. The injection of B10 recombinant congenic spleens into (B10 X B10.A)F1 mice, before grafting with B10 marrow, demonstrated that only those disparities in major histocompatibility antigens that generated GVH would result in loss of HR. Thus, spleens from (B10 X B10.A(2R]F1 mice (Class I disparity only) did not induce GVHID or affect HR, whereas (B10 X B10.A(5R))F1 spleens (Class I and II disparity) abrogated CTL generation and HR completely. GVHID produced by a class II only disparity, as in (B10 X B10.A(5R))F1 spleens injected into (B6bm12 X B10.A(5R))F1 mice, was also sufficient to markedly reduce HR to B10 bone marrow. This evidence that GVHID can modulate hematopoietic graft rejection may be relevant to the mechanisms of natural resistance to marrow grafts in man.
Binding and mitogenic properties of a galactosyl-specific lectin from the tunicate Didemnum candidum for murine thymocytes and splenocytes.
Authors: Vasta G R , Marchalonis J J , Decker J M
Published: December 2022

The affinity-purified major galactosyl-specific lectin (DCL-I) from the tunicate Didemnum candidum binds and induces blastogenesis in untreated and Vibrio cholerae neuraminidase (VCN)-treated murine splenocytes. However, it only binds and stimulates murine thymocytes when they have been pretreated with VCN. Binding and stimulation of VCN-treated splenocytes and thymocytes is specifically inhibited by D-galactose. Binding of lectin to splenocytes is highly increased by the VCN treatment, but the cells are stimulated to the same extent in both untreated and VCN-treated cells. This suggests that although additional DCL-I carbohydrate acceptors are uncovered by VCN treatment of the splenocytes, the ones responsible for triggering blastogenesis are already exposed on the untreated cells. On the contrary, cleavage of terminal sialic acids from the thymocyte cell surface is required to expose DCL-I carbohydrate acceptors in order to obtain a mitogenic response. Our results suggest that the distribution of cell surface galactosyl carbohydrate moieties to which DCL-I binds is different in thymocytes and splenocytes.
Monocyte procoagulant inducing factor: a lymphokine involved in the T cell-instructed monocyte procoagulant response to antigen.
Authors: Gregory S A , Kornbluth R S , Helin H , Remold H G , Edgington T S
Published: December 2022

A T cell-derived lymphokine couples the recognition of alloantigens by human T inducer cells to monocyte effector procoagulant activity (PCA). This collaborative cellular response results in expression of the functional tissue factor gene product and initiation of the extrinsic coagulation protease cascade as an inflammatory sequelae to the immune response. We now provide initial characterization of this lymphokine, provide evidence that it is a unique lymphokine, and designate it as monocyte procoagulant inducing factor (MPIF). MPIF was produced by alloantigen-stimulated, nylon wool-purified T cells and was not diminished by irradiation. MPIF active supernatants induced PCA in isolated monocytes, and the effect was not modified by the presence of T cells with the responding monocytes, consistent with a direct effect on the monocyte effector cells rather than an indirect effect via an intermediate accessory T cell. Full expression of PCA by monocytes was complete within 4 to 6 hours. MPIF activity in mixed lymphocyte culture (MLC) supernatants (MLC-SN) was stable at pH 2.0 for 24 hr, but was diminished after exposure to pH 10.5 for 30 min. MPIF activity was stable at 56 degrees C but was labile at 63 degrees C or higher. When characterized by chromatography on Sephadex G-100 superfine at either pH 7.2 or 3.6, the activity was recovered in a major discrete peak of about 55,000 daltons, and minor peaks of activity at about 14,000 and greater than 150,000 daltons. There was no correlation between the presence or concentration of INF-gamma, INF-alpha, IL 1, IL 2, GM-CSF, CSF-1, TNF-alpha, TNF-beta (lymphotoxin), or migration inhibitory factor (MIF) with MPIF activity. Each of the previously defined cytokines was analyzed directly for MPIF activity. INF-gamma, INF-alpha, GM-CSF, TNF-alpha, and CSF-1 did not possess MPIF activity over a wide range of concentrations. IL 1 and IL 2 lacked activity at concentrations present in MLC medium positive for MPIF; however, at higher concentrations each demonstrated slight activity. There was a poor correlation between MPIF and MIF activities in MLC-SN, and the content of MIF was insufficient to account for the expressed level of MPIF activity. The lack of identity of these cytokines with MPIF was supported by selected MLC medium that lacked IL 1, IL 2, and MIF and yet contained high MPIF activity. MPIF was additionally distinguished from IL 1, IL 2, and MIF on the basis of separation in Sephadex G-100 superfine.(ABSTRACT TRUNCATED AT 400 WORDS)
In vitro generation of an HTLV-III variant by neutralizing antibody.
Authors: Robert-Guroff M , Reitz M S , Robey W G , Gallo R C
Published: December 2022

Transmission and culture of "parental" virus (HTLV-III) from H9 cells transfected with the cloned isolate (lambda HXB-2D) in human serum possessing HTLV-III neutralizing antibody selected for a "variant" that was not neutralized by the selecting serum but was neutralized by another antibody-positive serum "Control" virus, selected in serum lacking neutralizing antibody, and the variant showed highly similar tryptic peptide maps of the major envelope glycoprotein, and no changes in restriction enzyme patterns of viral DNA. These findings show that HTLV-III type-specific neutralizing antibodies occur, can influence the propagation of variant viruses that may arise, and presumably result from minor changes in the eliciting antigen. The extent to which such type-specific neutralizing antibodies influence immune surveillance against HTLV-III infection in vivo, a question with relevance to future vaccination attempts, remains to be determined. Nucleotide sequencing of the control and variant envelope genes may elucidate a region important for virus neutralization and vaccine development.
Regulation of guinea-pig immune functions by interleukin 2: critical role of natural killer activity in acute HSV-2 genital infection.
Authors: Weinberg A , Basham T Y , Merigan T C
Published: December 2022

We have previously demonstrated that recombinant interleukin 2 (rIL 2) has a protective effect against acute HSV-2 infection in guinea pigs with a biphasic dose response which peaked between 4 and 20 X 10(4) U/kg, whereas 8 X 10(5) U/kg showed no effect on disease. Animals that escaped infection appeared lack immunologic memory to HSV-2, suggesting a nonspecific immune mechanism. In this study we have found that NK activity of fresh splenocytes measured against HSV-2 infected human foreskin fibroblast (HFF) is stimulated in vitro and in vivo by rIL 2 in a biphasic dose range similar to that determined for protection against disease. In contrast, lymphokine-activated killer (LAK)-mediated lysis of P815 showed a linear response to increasing concentrations of rIL 2 both in vitro and in vivo. Transfer of LAK cells did not alter the rate of infection after HSV-2 challenge. Anti-asialo GM-1 eliminated rIL 2 protection against HSV-2 infection. It also blocked HSV-2/HFF lysis and partially decreased P815 lysis in vitro; however, in vivo it inhibited both natural killer (NK) activity and LAK generation, failing to distinguish which of the lytic cells was responsible for the effect against infection. Early IgG production (7 days post-infection) was enhanced by rIL 2 administration before viral inoculation, but it did not influence the rate of infection as compared with controls. Polyclonal IgM secretion was not found to play a role in acute protection. Circulating serum interferon levels were enhanced with increasing concentrations of rIL 2 but did not correlate with the biphasic dose curve for protection. Therefore of these mechanisms the one that is most closely related to the protective effect of rIL 2 against primary HSV-2 infection appears to be NK-mediated lysis, although the other mechanisms may add to this effect.
Assessment of multi-organ system engraftment by genotypic typing using restriction fragment-length polymorphisms and by phenotypic typing using a microcytotoxicity assay.
Authors: Blazar B R , Soderling C C , Vallera D A
Published: December 2022

We report the first application of Southern blotting techniques for the quantitative assessment of the donor or host origin of cell populations present in recipients of allogeneic or sex-mismatched syngeneic murine donor marrow grafts. The sensitivity of this assay system was noted to 1 to 5% for detection of a minor cell population by using cDNA probes that hybridize to single-copy sequences in the murine genome. The use of probes that generate distinguishing autoradiographic patterns due to strain-specific genomic sequence variations obviates the need for retroviral vector transfections (which potentially skew engraftment quantitation). Southern blotting analysis has provided definitive engraftment data in multiple cell populations isolated from both short-term and long-term allogeneic and syngeneic radiation chimeras. In contrast, H-2 typing in a microcytotoxicity assay, a standard typing technique for allogeneic murine donor cell engraftment, was noted to be less sensitive than Southern blotting. This occurred particularly in selected cell populations, in ill-appearing recipients, and in the early post-BMT period. Furthermore, because H-2 typing is a phenotypic assay, the results may be substantially influenced by the passive cell surface acquisition of host H-2 antigens, a process that is not evident with the use of genotyping techniques. Our results establish the superiority of Southern blotting techniques for the quantitation of donor cell engraftment and demonstrate the potential of this methodology when low-level detection of engrafted donor or residual host cells is of critical physiologic importance.
Heteroantibody-mediated cytotoxicity: antibody to the high affinity Fc receptor for IgG mediates cytotoxicity by human monocytes that is enhanced by interferon-gamma and is not blocked by human IgG.
Authors: Shen L , Guyre P M , Anderson C L , Fanger M W
Published: December 2022

An IgG1 monoclonal antibody, 32.2, raised against the 72,000 dalton monocyte high affinity Fc receptor, was used to examine the role of this receptor in ADCC. This antibody did not inhibit the binding of human IgG1 to monocytes or to the U937 cell line, nor did it block or stimulate their killing of IgG-coated chicken erythrocytes (CE). Whole 32.2 or its Fab fragments were cross-linked to Fab fragments of rabbit anti-CE by using the agent SPDP. The resulting heteroantibodies (32.2 X Fab anti-CE) mediated monocyte and U937 cytotoxicity against CE, whereas an anti-HLA X anti-CE reagent did not. Both FcR expression and heteroantibody-mediated cytotoxicity were increased by culturing monocytes or U937 with IFN-gamma. Although IgG-mediated ADCC was significantly inhibited by 40 micrograms/ml human IgG1, cytotoxicity mediated by 32.2 X Fab anti-CE was not blocked by 2 mg/ml human IgG1, suggesting that such cytotoxicity might not be blocked by IgG in vivo. These data indicate the potential of 32.2 heteroantibodies in analysis of FcR function and in therapy.
Immunochemical characterization and purification of Sm-97, a Schistosoma mansoni antigen monospecifically recognized by antibodies from mice protectively immunized with a nonliving vaccine.
Authors: Pearce E J , James S L , Dalton J , Barrall A , Ramos C , Strand M , Sher A
Published: December 2022

Mice protected against Schistosoma mansoni infection by intradermal (i.d.) vaccination with nonliving schistosomula or soluble extracts of larval or adult schistosomes (SCHLAP and SWAP, respectively) produce antibodies that react by Western blot analysis with one antigen of Mr (X 10(-3)) 97 in SWAP prepared in the presence of protease inhibitors and two antigens of Mr (X 10(-3)) 95 and 78 in SWAP prepared in their absence. Vaccine antibodies also immunoprecipitated a single 97k molecule, with a pI of 5.5, from detergent extracts of [35S] methionine-labeled schistosomes. Three hybridomas, produced from spleen cells of i.d. immunized mice, all recognized both the 95k/78k doublet and the 97k antigen, indicating that the two lower Mr components are degradation products of the same 97k molecule. The 97k/95k/78k complex (Sm-97) was purified by affinity chromatography and found to constitute 0.5% of the total protein in SWAP. 125I-concanavalin A bound weakly to purified Sm-97, indicating that this antigen is minimally glycosylated. By indirect immunofluorescence, Sm-97 was localized to regions just below the tegumental and gut syncitia of adult worms. Mice protected by i.d. vaccination produced high titers (1:10,240) of anti-Sm-97 antibodies, whereas chronically infected mice responded at a much lower level (titer 1:640). In contrast, mice protectively immunized with irradiated cercariae and mice nonprophylactically inoculated by the i.v. route failed to produce detectable anti-Sm-97 antibodies. Competitive radioimmunoassays performed with 125I-labeled monoclonal antibodies and purified antigen defined at least two distinct epitopes on Sm-97. Antibodies from i.d. vaccinated mice recognized both monoclonal antibody-defined epitopes, whereas anti-Sm-97 antibodies in chronic infection sera recognized neither. Finally, purified Sm-97 was shown to elicit delayed-type hypersensitivity in i.d. vaccinated mice, suggesting that this molecule is also capable of evoking cell-mediated responses, a finding consistent with its proposed function as a vaccine immunogen.
Specific lymphocyte-target cell conjugate formation between tumor-specific helper T-cell hybridomas and IA-bearing RCS tumors and IE-bearing allogeneic cells. I. Role of Ia and both L3T4 and LFA-1 antigens in recognition/binding.
Authors: Ohnishi K , Bonavida B
Published: December 2022

The studies reported here describe the feasibility of using single cell techniques with nonadherent target cells for the formation of T helper lymphocyte-target cell conjugates in an Ia recognition system. We have taken advantage of four tumor-specific T cell hybridomas lines, two of which respond only to IA-bearing RCS tumor cells of SJL/J (H-2s) origin, and the other two that respond to both RCS and IA- or IE-bearing allogeneic cells of H-2k,d haplotypes. The conjugate frequency between the T cell hybridomas and target cells was scored microscopically and was facilitated by labeling the lymphocyte with fluorescein. The frequency of conjugate formation ranged from 20 to 40% above background. Conjugate formation was antigen specific and correlated well with the hybridoma specificity determined by IL 2 responses after antigenic stimulation. The cross-reactive hybridomas formed conjugates with RCS and LPS blasts derived from CBA or DBA/2 origin, but not with cells of syngeneic or other allogeneic strains. Conjugate formation with RCS was inhibited greater than 50% with mAb directed against IAs determinants on the RCS tumor cells, and conjugate formation with allogeneic cells was blocked only with mAb directed to either IA/IEk or IA/IEd specificities directed against the alpha or beta polypeptide chain. Blocking of conjugate formation was also achieved by various mAb directed against surface membrane molecules associated with the T cell hybridomas. LFA-1 mAb inhibited significantly the formation of conjugates. However, L3T4 mAb blocked only partially the conjugates. Other antibodies directed against Lyt-1 or Thy-1.2 antigens were without blocking effect. The poor blocking observed with L3T4 mAb did not correlate with the almost complete blocking observed in the IL 2 response by the same hybridomas. These studies of the syngeneic anti-RCS tumor response directed against IA-bearing RCS showed that the conjugate assay permits mapping of tumor-associated Ia epitopes. In addition, the results of these studies demonstrate the feasibility of conjugate formation in determining the antigenic specificity of the T helper system. This assay system can be used to establish the minimal frequency of antigen-reactive cells and can divide the T helper response into multiple steps (i.e., recognition/binding, activation, proliferation, and lymphokine release) and determine the surface membrane molecules involved in recognition.
Antibody-induced antigenic modulation is antigen dependent: characterization of 22 proteins on a malignant human B cell line.
Authors: Pesando J M , Hoffman P , Abed M
Published: December 2022

Expression of several of the surface antigens on normal and malignant hematopoietic cells is reduced or is modulated by incubation with specific antibodies. Although antigenic modulation provides a means by which cells can escape antibody-mediated immune destruction, the physiologic significance and frequency of this phenomenon are both poorly understood. To begin to address these issues, we identified and characterized surface antigens on the malignant B cell line Laz 221 established from a patient with acute lymphoblastic leukemia (ALL). Indirect immunofluorescence analysis with the use of 26 hematopoietic cell populations and immune precipitation studies with the use of iodinated ALL cells indicate that 163 monoclonal antibodies (MoAb) identify 22 different proteins on this cell line, including at least six previously described surface molecules. Seven of these antigens are expressed by all nucleated cells examined, whereas only the mu chain of immunoglobulin is B cell specific. Incubation of specific MoAb with cultures of Laz 221 cells at 37 degrees C reduces or modulates surface expression of five of these 22 antigens (p45, immunoglobulin mu chain, transferrin receptor, common ALL antigen (CD10), and p105). Studies that made use of multiple MoAb specific for the same antigen suggest that the capacity for antigenic modulation is an intrinsic property of individual antigens. These studies also suggest that the murine immune response to shared human antigens varies from one immunizing cell population to another. For example, three of the antigens present on Laz 221 cells were only identified by MoAb raised to the Burkitt's cell line Ramos and vice-versa. Only one of these six shared antigens is present in greater amounts on the immunogenic cell population. Immunogenicity of individual human antigens in the mouse may be a function of their cell surface environment.
IgG antinuclear antibodies with cross-reactive rheumatoid factor activity.
Authors: Darwin B S , Grudier J P , Klatt C L , Pisetsky D S
Published: December 2022

To investigate whether IgG antinuclear antibodies have cross-reactive rheumatoid factor activity, monoclonal IgG antibodies to DNA and Sm from autoimmune MRL-lpr/lpr mice were assayed by ELISA for binding to IgG antigens. Of the nine anti-DNA and anti-Sm monoclonals tested, six showed significant binding to affinity-purified rabbit IgG (RIgG) and human IgG (HIgG). To confirm that cross-reactivities were due to a single antibody, immunoabsorption of a representative polyspecific monoclonal termed C11 (anti-DNA, anti-Sm) on either Sepharose-DNA or Sepharose-RIgG resulted in marked loss of activity to the three antigens DNA, Sm and RIgG compared with immunoabsorption on Sepharose-bovine serum albumin. The monomolecular nature of the cross-reacting antibody was also suggested by inhibition analysis of C11; DNA inhibited C11 binding to RIgG 64%, whereas Sm inhibited binding to RIgG 33%. Aggregated RIgG and HIgG, however, did not inhibit binding of C11 to DNA, Sm, or solid-phase RIgG, probably reflecting the low affinity of this antibody for fluid phase Ig. Together, these findings suggest that antinuclear autoantibodies of the IgG, as well as the IgM, class have polyspecific IgG binding activity and suggest that IgG antinuclear antibodies may emerge from rheumatoid factor responses.
Immunolocalization and partial characterization of a nucleolar autoantigen (PM-Scl) associated with polymyositis/scleroderma overlap syndromes.
Authors: Reimer G , Scheer U , Peters J M , Tan E M
Published: December 2022

Precipitating anti-PM-Scl antibodies are present in sera from patients with polymyositis, scleroderma, and polymyositis/scleroderma overlap syndromes. By indirect immunofluorescence microscopy, anti-PM-Scl antibodies stained the nucleolus in cells of different tissues and species, suggesting that the antigen is highly conserved. By electron microscopy, anti-PM-Scl antibodies reacted primarily with the granular component of the nucleolus. Drugs that inhibit rRNA synthesis had a marked effect on the expression of PM-Scl antigen. In actinomycin D-treated cells, immunofluorescence staining by anti-PM-Scl was significantly reduced with residual staining restricted to the granular regions of nucleoli. Treatment with 5,6-dichloro-beta-D-ribofuranosylbenzimidazole (DRB) also selectively reduced nucleolar staining. On a molecular level, anti-PM-Scl antibodies precipitated 11 polypeptides with molecular weights (Mr) ranging from 110,000 to 20,000. The Mr 80,000 and 20,000 polypeptides were phosphorylated. Evidence suggests that the PM-Scl antigen complex may be related to a preribosomal particle.
Identification of monoclonal antibodies specific for the T cell receptor complex by Fc receptor-mediated CTL lysis.
Authors: Leo O , Sachs D H , Samelson L E , Foo M , Quinones R , Gress R , Bluestone J A
Published: December 2022

Monoclonal antibodies (mAb) directed at the T cell receptor complex (TcR) on cloned T cells have generally been identified by their ability to inhibit the clone's antigen-specific function. Because such inhibition is highly dependent on antibody concentration and affinity, detection of anti-clonotypic antibodies to murine alloreactive T cells has been very difficult. In this report, an alternative method is described on the basis of the ability of antibodies specific for the TcR complex to activate T cells in an antigen-independent manner. The assay is based upon the observation that soluble antibodies to human T3 promote lysis of irrelevant, Fc receptor-positive targets by a human CTL line. By using this approach, an anti-TcR mAb has been identified among a panel of murine mAb generated against an alloreactive CTL clone. Induction of lysis by soluble anti-TcR mAb has been shown to require both the expression of Fc receptors on the target cell and conjugate formation between the effector and the target cell. This assay provides a screening procedure that is much more sensitive than inhibition of function, and it preferentially detects antibodies specific for cell surface molecules involved in T cell activation.