bluuebunny/crossref_metadata_2025 huggingface dataset:
The cell surface glycoprotein Mac-1 (CD11b/CD18) mediates neutrophil adhesion and modulates degranulation independently of its quantitative cell surface expression.
Authors: Schleiffenbaum B , Moser R , Patarroyo M , Fehr J
Published: December 2022

It has previously been shown that during degranulation Mac-1 (CD11b/CD18)--a glycoprotein that plays a central role in neutrophil adhesion-is up-regulated on PMN surfaces. It has been assumed that this quantitative change in adhesion Ag expression on the cell surface would in turn lead to increased cellular adhesiveness. In contrast, we found that at an incubation temperature of 16 degrees C, stimulated neutrophil adhesion to plastic tissue culture dishes in the presence of FMLP (2.5 x 10(-6) M), TNF (10 ng/ml), or PAF (1 x 10(-4) M) occurred without cellular degranulation or Mac-1 surface up-regulation as measured cytofluorometrically. As shown by functional inhibition studies employing monoclonal antibodies 60.3 (anti-CD18) and 60.1 (anti-CD11b), adhesion at 16 degrees C, where no CD11b/CD18 up-regulation was seen, is mediated by CD11b/CD18 just as it is at 37 degrees C, where degranulation and CD11b/CD18 up-regulation could be demonstrated. The physiologic importance of these findings was underscored by experiments done on endothelial monolayers, which showed that PMN association with endothelial cells is absolutely independent from the quantitative up-regulation of Mac-1 on PMN surfaces. When neutrophils were stimulated at 37 degrees C by endotoxin, an agent that does not induce aggregation (a form of intercellular adhesion), Mac-1 surface expression increased only after cells had become adherent, whereas cells held in suspension to prevent cell-substrate adhesion neither degranulated nor up-regulated their Mac-1 surface expression. Thus, not only is adherence independent of degranulation and Mac-1 cell surface up-regulation, but both degranulation and Mac-1 surface up-regulation appear to depend on the process of adhesion. Correspondingly, incubation of neutrophils with antibodies 60.1 and 60.3 inhibited not only adhesion of cells stimulated with FMLP at 37 degrees C but degranulation as well. These results indicate that Mac-1 influences degranulation as well as it controls adhesion not by its mere quantity on the cell surface, but rather by an yet undefined molecular modulation.
Regulation of lymphokine response during reinfection by influenza virus. Production of a factor that inhibits lymphokine activity.
Authors: Beck M A , Sheridan J F
Published: December 2022

Mononuclear cells, obtained from the spleens and lungs of influenza virus-seropositive C57BL/6 mice at 2 to 4 days after re-infection with homologous virus (strain A/Bangkok/1/79), produced a low m.w. factor in vitro that prevents the biologic expression, but not production, of the lymphokine, leukocyte migration inhibition factor (LIF). The low m.w. factor inhibited LIF activity without destroying the LIF molecule inasmuch as simple dialysis restored lymphokine activity to culture supernatants. Production of the low m.w. factor was observed from 2 to 4 days after re-infection, at which time the delayed-type hypersensitivity response to viral Ag was suppressed. In contrast, LIF was produced by splenocytes and lung mononuclear cells obtained at all times tested after re-infection (from 2 to 30 days). Production of the low m.w. factor required re-infection of influenza A virus-seropositive mice with type A virus; re-infection with influenza B virus failed to induce production. Ag specificity was also required in vitro for splenocytes to produce the factor; cells from type A virus-re-infected mice required type A Ag stimulation. Cell depletion studies with mAb plus C revealed that macrophages and T cells along with Ag stimulation were required for factor production by spleen cells. However, mononuclear cells obtained within 4 days from the lungs of re-infected mice did not require in vitro Ag stimulation for production of the low m.w. factor, and factor production was dependent upon the presence of CD4+ (L3T4) cells in the culture. Fractionation of culture supernatants over a Sephadex G-50 column indicated that the factor had a molecular mass of 2 to 3 kDa, and by FPLC chromatofocusing over a Mono P column, the factor eluted at a pH of approximately 8.2. Thus, re-exposure of influenza virus-seropositive mice to homologous virus resulted in the production of a low m.w. factor that prevented the biologic expression of LIF, but not its production. Lymphokines are an important component of the delayed-type hypersensitivity response; the presence of mononuclear cells secreting a low m.w. factor and LIF concomitantly at the site of virus replication (lungs) and the capacity of the factor to block the biologic expression of LIF in vitro suggest that the factor may have a role in the regulation of a delayed-type hypersensitivity response in vivo during re-infection.
Tumor necrosis factor inhibits the development of viral meningitis or induces rapid death depending on the severity of inflammation at time of administration.
Authors: Doherty P C , Allan J E , Clark I A
Published: December 2022

Administration of human rTNF to both male and female mice with severe, but clinically inapparent, lymphocytic choriomeningitis caused death within 2 to 3 h. The development of fatal symptoms was accompanied by a two- to threefold reduction in the number of cells present in the cerebrospinal fluid, with this effect being more apparent in female mice. Giving the same dose of rTNF earlier in the course of the disease was not fatal and reduced the level of subsequent meningitis. In addition, prior exposure to rTNF protected against the acute development of lethal disease when a second dose of the cytokine was given later. The extent of this "tolerance" to rTNF was directly related to the degree of reduction of the inflammatory process resulting from the primary exposure to the cytokine.
Immune response gene regulation of immunity to Plasmodium berghei sporozoites and circumsporozoite protein vaccines. Overcoming genetic restriction with whole organism and subunit vaccines.
Authors: Hoffman S L , Berzofsky J A , Isenbarger D , Zeltser E , Majarian W R , Gross M , Ballou W R
Published: December 2022

We conducted a series of experiments to define Ir gene regulation of the immune response to Plasmodium berghei sporozoites and circumsporozoite (CS) protein-derived subunit vaccines. The studies demonstrated that there is no apparent genetic restriction of the capacity to develop protective immunity against a large sporozoite challenge after immunization with irradiation-attenuated P. berghei sporozoites; that the Th response to (Asp-Pro-Ala-Pro-Pro-Asn-Ala-Asn)n, the predominant protective B epitope on the P. berghei CS protein, is genetically restricted and regulated by Class II genes (I-Ab) and by genes in the Class I region (H-2Dk) or telomeric to this region; and that this restriction can be overcome by immunization with a r protein including the entire P. berghei CS protein. The results support the development of full length human CS protein vaccines to take advantage of all potential T epitopes on this protein.
Phenotypic and functional analysis of the cellular response in regional lymphoid tissue during an acute virus infection.
Authors: Lynch F , Doherty P C , Ceredig R
Published: December 2022

A phenotypic and functional analysis has been made of the cellular response in regional lymphoid tissue of C57BL/6J mice infected with lymphocytic choriomeningitis virus. Massive recruitment of nondividing cells occurred from 3 days after infection, with total numbers of CD8+ T lymphocytes, B220+ B cells, and Thy-1- B220- null cells being high from day 4 to day 6. In contrast, the peak counts for CD4+ T cells were recorded on day 4 and declined dramatically thereafter. Enhanced expression of IL-2R and Ly-24, both of which can be regarded as T cell activation markers, was found for both the CD4+ and the CD8+ subsets, being most prominent for the CD8+ T cells on day 6. Evidence of T cell proliferation was not recognized until days 5 and 6, coincident with enhanced responsiveness of the lymphocytes to rIL-2 and the development of virus-specific cytotoxic activity. Elimination of the CD4+ T cells by treatment of mice with mAb did not modify either the pathogenesis of lymphocytic choriomeningitis, or the expression of activation markers on the CD8+ T cells which are known to be the key effectors in this disease. Thus, the pattern of responsiveness for the CD8+ population is of recruitment to the lymph node, progressive increase in the expression of activation markers and enhanced sensitivity to rIL-2, with late proliferation and generation of cytotoxic activity. This model provides a system for the rigorous in vivo analysis of parameters influencing lymphocyte differentiation and activation in a virus infection.
Molecular study of the T cell repertoire in family contacts and patients with leprosy.
Authors: Mendez-Samperio P , Lamb J , Bothamley G , Stanley P , Ellis C , Ivanyi J
Published: December 2022

The specificity of lymphocyte proliferative responses of 22 family contacts and 7 patients with leprosy were analyzed using Ag fractions from soluble extracts of Mycobacterium leprae and Mycobacterium tuberculosis. Fractions 10-100 kDa m.w. from each extract were separated by SDS-polyacrylamide gel electrophoresis, electroblotted to nitrocellulose membrane and solubilized for use in lymphocyte culture. The main immunogenic fractions for both contacts and patients had m.w. of 12,000 to 22,000, 35,000 to 40,000, and 65,000. Determinants which were either distinct or shared by the two extracts were active in each of the immunogenic fractions. Lymphocyte proliferation following stimulation with separated Ag was found also in five subjects who failed to respond to the whole soluble extracts. Stimulatory synthetic peptides were identified for the 65 kDa protein Ag. This technique has permitted the screening of the T cell immune repertoire for the identification of the immunodominant Ag which merit further purification and molecular characterization.
Reactivity of the human monoclonal antibody 33G2 with repeated sequences of three distinct Plasmodium falciparum antigens.
Authors: Udomsangpetch R , Carlsson J , Wåhlin B , Holmquist G , Ozaki L S , Scherf A , Mattei D , Mercereau-Puijalon O , Uni S , Aikawa M
Published: December 2022

The human mAb 33G2 has high capacity to inhibit in vitro invasion of erythrocytes by Plasmodium falciparum merozoites and, thus, is of special interest with regard to protective immunity against the parasite. In order to obtain more information about asexual blood stage Ag of P. falciparum that are seen by this antibody, material from synchronized P. falciparum cultures was studied by immunofluorescence, immunoelectron microscopy, and immunoblotting. Reactivity was mainly confined to the membrane of infected erythrocytes. Soon after merozoite invasion the antibody stained the erythrocyte membrane. This membrane-associated staining faded during intracellular development of the parasites. Beginning about 18 h after invasion, a dotted pattern appeared which increased in strength with time and persisted to schizont rupture. Pf155/RESA was the major Ag recognized in immunoblots of parasites collected throughout the entire erythrocytic cycle, although other polypeptides also bound the antibody. Among these was a 260-kDa polypeptide found in late trophozoites and schizonts. The specificity of the antibody was analyzed with synthetic peptides corresponding to repeated sequences in the P. falciparum Ag Pf155/RESA, Pf11.1, and Ag332. Synthetic peptides related to Ag332 were the most efficient inhibitors of antibody binding in immunofluorescence studies and cell ELISA. A beta-galactosidase-Ag332 fusion protein was also efficient in reversing reinvasion inhibition caused by 33G2. These results define a family of cross-reactive P. falciparum Ag recognized by mAb 33G2 and suggest that Ag332 was its original target.
Expression of human T cell receptor-gamma delta structural forms.
Authors: Band H , Hochstenbach F , Parker C M , McLean J , Krangel M S , Brenner M B
Published: December 2022

The human TCR-gamma delta occurs in three biochemically distinct forms (forms 1, 2bc, and 2abc). A 40-kDa TCR gamma-chain is disulfide-linked to the TCR delta-chain in form 1, whereas 40-kDa or 55-kDa TCR-gamma polypeptides are noncovalently associated with the TCR delta-chain in forms 2bc and 2abc, respectively. Sequence analysis of TCR-gamma cDNA clones indicates that form 1 utilizes the C gamma 1 gene segment, whereas forms 2bc and 2abc appear to use allelic C gamma 2 gene segments containing either two copies (b and c) or three copies (a, b, and c) of the CII exon, respectively. We transfected TCR-gamma cDNA encoding form 1 or form 2abc into the MOLT-13 cell line that expresses form 2bc. The transfected TCR gamma-chains associate with the resident MOLT-13 TCR-delta, normally part of form 2bc, to yield CD3-associated TCR-gamma delta heterodimers identical to those seen on the donor cell lines (form 1 or 2abc). These transfection experiments show directly that, 1) when a single TCR-delta subunit is available, the presence or absence of disulfide linkage between TCR gamma- and TCR delta-chains is controlled by the TCR gamma-chain, and 2) the difference in the amount of N-linked carbohydrate attached to the transfected TCR-gamma proteins of form 2bc vs form 2abc is influenced by the presence or absence of CII exon copy "a" which appears to alter the secondary and/or tertiary structure of these TCR gamma-chain constant regions, thereby affecting the attachment of N-linked glycans. In contrast to the similar structure and usage of C beta 1 and C beta 2, TCR-gamma delta forms show striking differences in structure and are not equally represented in peripheral blood. Although the role of each form is unknown, it is possible that variable or joining-gene segment selection events or functional differences account for their unequal usage.
Variability of CR2 gene products is due to alternative exon usage and different CR2 alleles.
Authors: Toothaker L E , Henjes A J , Weis J J
Published: December 2022

The gene encoding human complement receptor 2 (CR2) lies within a cluster of genes on human chromosome 1. Polymorphisms have been described for several of these genes or gene products. To examine any possible polymorphisms in the CR2 gene product we have analyzed the CR2 transcriptional products for variations via alternative exon usage and for the presence of different CR2 alleles within the human population. This analysis has suggested that an exon encoding a 60 amino acid short consensus repeat can be alternatively spliced. Evidence for two transcriptional products has been found in a variety of transformed human B cells and two human tonsils. Interestingly the ratio of the two forms of mRNA, that which includes the alternative exon and that which does not, is not constant when examining the RNA from these sources. In addition to the variation introduced by the alternatively spliced product, there appears to exist in the human population at least three different alleles for CR2. These alleles have been defined by multiple nucleotide changes which are not silent but which alter the amino acid encoded at that site. However, we have not identified allelic variants of CR2 which would produce a product varying in the number of long homologous repeats, as has been identified for the various alleles of the closely related protein, human complement receptor 1.
Direct induction of Ia antigen on murine thyroid-derived epithelial cells by reovirus.
Authors: Gaulton G N , Stein M E , Safko B , Stadecker M J
Published: December 2022

The ability of thyroid follicular epithelial cells (TFEC) to act as APC is linked to the expression of class II (Ia) molecules of the MHC. The cloned murine thyroid-derived epithelial cell line M.5 was used to demonstrate the potential effects of virus in the direct induction of Ia molecules on TFEC. Membrane binding and replication of reovirus type 1 in TFEC was demonstrated using fluorescein-labeled antireovirus antibody and fluorescence microscopy. One consequence of the interaction between reovirus and M.5 cells was the induction of Ia Ag and augmented class I molecule expression in M.5 cells. The levels of Ia expression at three days after reovirus binding were amplified 17.3-fold over controls and were 2-fold less than that seen upon treatment of M.5 cells with IFN-gamma. Supernatant transfer experiments showed that the induction of Ia expression was directly linked to the binding of virus to M.5 cells, and was not dependent upon virus replication or the presence of IFN. These results indicate that early events of reovirus binding or receptor internalization on TFEC initiate a signaling process which results in the induction of class II and augmentation of class I MHC protein levels on the cell surface.
Numbers and functions of transplantable primitive immunohematopoietic stem cells. Effects of age.
Authors: Harrison D E , Astle C M , Stone M
Published: December 2022

This report introduces a new method in immunology, a use of the binomial formula with covariance to estimate numbers and proliferative patterns of the most primitive lymphoid precursors. We studied the primitive stem cells (PSC) from which most circulating lymphocytes and erythrocytes were descended during 300 to 400 days in recipients of genetically distinguishable marrow mixtures in competitive repopulation. Equivalent PSC concentrations (Eq. PSC Conc. or Conc.) were estimated, with the notion of common PSCs contributing equally in lymphoid and myeloid compartments. Similar estimation was done for common PSCs from which lymphocytes (and erythrocytes) drawn at successive sampling times about 100 days apart were descended. The percentages of lymphocyte and erythrocyte types, P1 and Pe, measured in each recipient were closely correlated, especially after 6 months and later. Close correlations were also found in cells sampled at successive one hundred day intervals, especially after the first. Apparently a few PSCs or their direct descendents produced most of the blood lymphocytes and E, and this production continued for many months. Concentrations of these PSCs (Equivalent PSC concentrations) were about one per 10(5) marrow cells from young donors. This is much lower than previous estimates, probably because our methods focus only on the most interesting precursors, those from which most of the circulating cells were descended. Equivalent PSC concentrations were about two-fold higher in old donors; old marrow produced correspondingly higher P1 and Pe values, but these declined with time. There were also small increases with time in the P1 and Pe values with young donors. To explain the temporal trends, we suggest that excess concentrations of precursors less primitive than PSC are present in old marrow, and their contribution to the differentiated cell population gradually declines. Possibly such precursors, as well as true PSC, proliferate in old donors to compensate for deficiencies that develop with age.
An alternative pathway of induction of lymphokine production by T lymphocyte clones.
Authors: Dunn D E , Jin J P , Lancki D W , Fitch F W
Published: December 2022

We have previously described a variant murine CTL clone that in contrast to all other clones tested, exhibited a novel capacity to produce IFN-gamma in response to IL-2. This alternative pathway of IFN-gamma induction differed from the conventional TCR complex-mediated pathway in that it was independent of elevated intracellular Ca2+ and insensitive to cyclosporine A. We report here the presence of an analogous pathway in the majority of T lymphocyte clones tested, when these clones are stimulated with IL-2 in the presence of syngeneic or third-party splenocytes. The accessory function of splenocytes in this alternative pathway is mediated by the MAC-1+ subpopulation and apparently involves cell-cell contact. However, the structure with which the MAC-1 antibody reacts probably is not involved directly. No involvement of Ag or the TCR for Ag could be demonstrated in this alternative pathway of lymphokine induction. The array of lymphokines induced by this alternative pathway is only a subset of those induced by antigenic stimulation. Finally, as with the previously described variant clone, IL-2-mediated induction of IFN-gamma production by the normal T lymphocyte clones is independent of normal extracellular Ca2+ levels and insensitive to cyclosporine A. Thus, this alternative pathway of lymphokine induction apparently constitutes a distinct signaling pathway in cloned T lymphocytes.
Detection and characterization of a B cell stimulatory factor (BSF-TC) derived from a bone marrow stromal cell line.
Authors: Simpson L , McNiece I , Newberg M , Schetz J , Lynch K R , Quesenberry P , Isakson P C
Published: December 2022

Stromal cell lines derived from murine bone marrow support the growth of immature pre-B cells and produce cytokines that affect the growth and differentiation of other hematopoietic precursors. Conditioned medium (CM) from one such line (TC-1) stimulated marked proliferation of B cells previously activated by anti-Ig (anti-Ig blasts). Proliferation of anti-Ig blasts was not induced by purified cytokines known to be produced by TC-1 (CSF-1, GM-CSF, or G-CSF) or by IL-1, IL-2, IL-3, IL-4, IL-5, or IL-6. Furthermore, IL-2, IL-4, and IL-5, alone or in combination, failed to support proliferation or differentiation of anti-Ig blasts. TC-1 CM enhanced proliferation of B cells that were co-cultured with LPS, anti-Ig, or dextran sulfate; co-stimulation with anti-Ig was unaffected by the presence of monoclonal anti-IL-4. Proliferation of low, but not high, density B cells isolated from spleen was directly stimulated by TC-1 CM. These results suggest that bone marrow stromal cells produce a novel B cell stimulatory factor (BSF-TC) that induces proliferation of activated B cells.
Antisera to the secretory component recognize the murine Fc receptor for IgA.
Authors: Crago S S , Word C J , Tomasi T B
Published: December 2022

Studies were undertaken to determine a possible structural relationship between the secretory component (SC) and the receptor for IgA (Fc alpha R). An IgA-mediated rosetting technique was used to assess the presence of Fc alpha R+ cells in various lymphoid tissues from normal BALB/c mice and mice bearing an IgA plasmacytoma (MOPC 315). Tissues from the MOPC 315-bearing BALB/c mice were found to have a significantly higher percentage of Fc alpha R+ cells; thus, nonadherent spleen cells from MOPC 315-bearing mice were used as a source of Fc alpha R+ cells in these studies. The cells were preincubated with anti-SC and then assayed for the ability of IgA to bind to the Fc alpha R. Antisera to SC from various species inhibited the formation of IgA-mediated rosettes, although preincubation of the Fc alpha R+ cells with antisera directed against other cell surface molecules (e.g., Thy1.2, Lyt1, Lyt2, Fc gamma R, MHC class I and II) or preimmune sera had no significant effect on IgA-mediated rosette formation. Preabsorption of the anti-SC with secretory IgA or with free SC removed the inhibitory effect; preabsorption with myeloma IgA had no effect. These data suggest that SC and Fc alpha R are related serologically and may be structurally related, possible in the IgA-binding region.
Cellular origin of histamine-releasing factor produced by peripheral blood mononuclear cells.
Authors: Alam R , Forsythe P A , Lett-Brown M A , Grant J A
Published: December 2022

Histamine releasing factors (HRF) are a group of cytokines that release histamine and other mediators from mast cells and basophils. It has been speculated that HRF might play a major role in the pathogenesis of allergic diseases. Most investigators have studied PBMC as a source of HRF. This study was undertaken to investigate the cellular origin of HRF. Peripheral blood was processed to isolate and purify monocytes, T cells, CD4- T cells, CD8- T cells and B cells by using plastic adherence, 2-aminoethylisothiomonium-treated SRBC rosetting and negative selection with the use of mAb OKM1, OKT11, OKT8, OKT4, and OKB7 plus C. Highly purified subpopulations of PBMC were cultured alone or in the presence of Con A for 24 h. Supernatants were harvested, dialyzed, and assayed for HRF activity in the basophil histamine release test. We found that all subpopulations of PBMC including T cells, CD4- T cells, CD8- T cells, B cells, and monocytes produce variable quantities of HRF. The spontaneous production is very high in B cells but only barely measurable in T cells and monocytes. The synthesis of HRF by B cells was confirmed by abolishing the release of the activity after treatment of B cells with OKB7 mAb and C. Stimulation of cell populations by Con A significantly enhances HRF production by PBMC and T cells but not by B cells and monocytes. In mixing experiments, unstimulated monocytes + B cells showed synergism, but other combinations demonstrated an additive effect. This is the first demonstration of HRF production by human peripheral blood B cells. The results of this study also suggest that histamine releasing cytokines are of multiple cellular origin. This perhaps contributes to their molecular heterogeneity.
IL-1 and related cytokines enhance thrombin-stimulated PGI2 production in cultured endothelial cells without affecting thrombin-stimulated von Willebrand factor secretion or platelet-activating factor biosynthesis.
Authors: Zavoico G B , Ewenstein B M , Schafer A I , Pober J S
Published: December 2022

We examined the effects of various cytokines on alpha-thrombin-stimulated prostaglandin (PG) I2 production, von Willebrand factor (vWF) secretion, and platelet-activating factor (PAF) synthesis in cultured human umbilical vein endothelial cells (HUVEC). A 24-h pretreatment with IL-1 beta doubled the low level of constitutive PGI2 production. In contrast, alpha-thrombin increased PGI2 production fivefold in untreated HUVEC. The most striking increase in PGI2 production was observed in IL-1 beta-treated HUVEC that were subsequently stimulated with thrombin. PGI2 production was two to three times greater than in untreated, thrombin-stimulated HUVEC and nearly eightfold greater than in IL-1 beta-treated but unstimulated HUVEC. Enhanced thrombin-stimulated PGI2 production was also observed in HUVEC pretreated with the related cytokines IL-1 alpha, TNF, or lymphotoxin. This cytokine effect was selective for PGI2 production because none of these cytokines altered either constitutive or thrombin-stimulated vWF secretion or PAF biosynthesis. IL-1 beta enhancement of thrombin-stimulated PGI2 production was concentration and time dependent and required protein synthesis. IL-1 beta pretreatment also enhanced PGI2 production in response to another agonist, histamine, and to exogenously added substrates, arachidonic acid or PGH2. Our results indicate that activation by IL-1 and related cytokines selectively primes endothelial cells for enhanced PGI2 production, but not vWF secretion or PAF synthesis, in response to thrombin and histamine. The evidence suggests that this effect is mediated through specific induction of biosynthetic enzymes for PGI2.
The recurrent expression of variable region segments in human IgM anti-DNA autoantibodies.
Authors: Dersimonian H , McAdam K P , Mackworth-Young C , Stollar B D
Published: December 2022

RNA sequences for the V regions of human hybridoma-produced autoantibodies were determined by primer extension with reverse transcriptase. The sequencing of IgM autoantibodies from a leprosy patient revealed examples of recurrent use of V region gene segments in different autoantibodies from this patient and a previously studied patient with SLE. Moreover, several gene segments used in these autoantibodies show little alteration from germ-line sequences. mAb TH3, from a patient with leprosy, binds denatured DNA and poly(dT). The center of its H chain CDR35 has a sequence identical to that found previously in two anti-DNA antibodies from a lupus patient; these identities and their overlapping with two other published sequences define a human D-gene segment of approximately 25 nucleotides. Autoantibody TH9, from a leprosy patient, does not bind DNA. Its VH sequence has 87% identity with a VHI anti-DNA antibody, but differs from it markedly in the CDR1 region. TH9 also has a different H chain CDR3. The closely related JH4 or JH5 gene segments are expressed in five lupus or leprosy autoantibodies. In four of the antibodies, examples of V kappa 1, V kappa 3, or V kappa 4 and J kappa 2, or J kappa 5 segments were found. Two distinct leprosy-derived anti-DNA antibodies, 8E10 and TH3, share a completely identical V kappa sequence. This sequence differs in only two positions from that of a germ-line RF L chain gene. Several gene segments that are close to the germ line in sequence encode Ig V regions with autoantibody reactivity. These results provide a base line for determining whether these genes are precursors of more highly diversified antibodies that may be pathogenic in patients with SLE.
The targeting of CD4+ T lymphocytes to a B cell lymphoma. A comparison of anti-CD3-anti-idiotype antibody conjugates and antigen-anti-idiotype antibody conjugates.
Authors: Gravelle M , Ochi A
Published: December 2022

We have targeted CD4+ cytotoxic Th (Th/c) lymphocytes to a B cell lymphoma, through the use of a bispecific antibody containing binding sites for both the CD3 complex on the Th/c and the Id on the surface Ig of the B lymphoma (anti-CD3-anti-Id). Cloned, keyhole limpet hemocyanin (KLH)-specific Th/c cells were nonspecifically activated by the anti-CD3-anti-Id conjugate to lyse the Id+ B lymphoma A20-HL. This cytotoxicity was not inhibited by antibodies to CD4 or LFA-1 alpha molecules. The anti-CD3-anti-Id conjugates also induced non-lytic Th clones to become cytotoxic, a function not elicited when these cells were activated specifically by Ag. We compare this model to our previously described system where we targeted the KLH-specific Th/c cells to the Id+ B lymphoma A20-HL via a conjugate consisting of KLH covalently linked to the anti-Id antibody (KLH-anti-Id). The mechanism involved processing and presentation of KLH by the A20-HL target. This Ag-specific cytotoxicity was MHC class II restricted and was inhibited by antibodies to the CD4 molecule. In both systems, activation of the Th/c cells resulted in bystander killing of tumor but not normal targets. These results may have important implications for the use of Th/c cells in tumor immunotherapy.
Lack of correlation between levels of MHC class I antigen and susceptibility to lysis of small cellular lung carcinoma (SCLC) by natural killer cells.
Authors: Stam N J , Kast W M , Voordouw A C , Pastoors L B , van der Hoeven F A , Melief C J , Ploegh H L
Published: December 2022

Small cellular lung carcinoma (SCLC) cell lines are susceptible to lysis by NK cells. SCLC, normally negative for MHC class I Ag, were rendered positive for HLA-A and -B Ag by two methods: treatment with IFN-gamma or transfection with HLA class I genes. Exposure to IFN-gamma induced high levels of class I Ag and reduced susceptibility to NK-mediated lysis. However, transfection with either HLA-A2, HLA-B27, or HLA-B27 with beta 2m did not result in reduced susceptibility to NK cells. These transfectants expressed amounts of HLA class I Ag comparable to those in IFN-gamma-treated, untransfected cells. Transfection with the beta 2m gene or plasmid alone neither influenced levels of surface class I Ag nor resulted in reduced susceptibility to lysis by NK cells. Thus, the effects of IFN-gamma on NK susceptibility can be dissociated from the induction of class I Ag.
Growth factor production and requirements during the proliferative response of human T lymphocytes to anti-CD3 monoclonal antibody.
Authors: Granelli-Piperno A , Keane M , Steinman R M
Published: December 2022

Anti-CD3 was administered with three different accessory stimuli to purified populations of human T cells. Sepharose conjugated anti-CD3, monocytes, and PMA each could induce the p55 component of the IL-2R as well as responsiveness to exogenous IL-2. Sepharose anti-CD3 did not induce IL-2, although the levels of IL-2 protein and mRNA were 10 to 30 times higher with PMA than with monocytes. Despite these differences in IL-2 production, the amount of DNA synthesis and the number of lymphoblasts were comparable when monocytes or PMA were used as the accessory stimulus, and the responses were equally sensitive to inhibition by an anti-IL-2R antibody. To pursue the functional relevance of the "supraoptimal" levels of IL-2 that are induced by PMA, anti-CD3-induced lymphoblasts were isolated free of monocytes and challenged with lymphokines. It could be shown that 1) the small amounts of IL-2 in the monocyte-T cell conditioned medium would drive DNA synthesis, but that 2) higher levels of IL-2 (20 to 100 U/ml) were needed to induce IFN-gamma, as well as the mRNA for IL-4 and the p55 IL-2R. We suggest that the capacity to produce high levels of IL-2, as seen with PMA, is required under physiologic conditions for two reasons: to up-regulate the IL-2R when small amounts of Ag rather than large amounts of anti-CD3 are ligands for the T cell, or to induce the release of lymphokines like IL-4 and IFN-gamma from sensitized lymphoblasts.
Modulation of cytokine production by transforming growth factor-beta.
Authors: Chantry D , Turner M , Abney E , Feldmann M
Published: December 2022

Transforming growth factor-beta 1 (TGF-beta 1) is one of a family of polypeptides involved in the regulation of cell growth and differentiation. The effects of human rTGF-beta 1 on the production of IL-1 and TNF by activated PBMC were studied. The addition of TGF-beta 1 alone caused an increase in the levels of mRNA for IL-1 alpha, IL-1 beta, and TGF-alpha. This was due to increased transcription rather than enhanced mRNA stability. The induced mRNA were of the appropriate size as assessed by Northern blotting. However, the mRNA did not appear to be translated into protein, inasmuch as the translation products of IL-1 beta and TNF-alpha were not detected by RIA or ELISA. Furthermore, in experiments utilizing a neutralizing antibody to TGF-beta 1, we were unable to unmask IL-1 biologic activities and unable to detect TNF biologic activity in the WEHI 164 cytotoxicity assay. TGF-beta inhibited in a dose-dependent manner the induction of IL-1 beta by LPS or TNF but not by PHA and PMA. Similarly, LPS induction of TNF-alpha was blocked by TGF-beta, whereas induction of PMA and PHA was completely resistant. TGF-beta 1 did not increase PGE2 secretion or cause elevated intracellular cAMP; thus, the inhibitory effects of TGF-beta 1 seem not to be mediated by PGE2 or cAMP, which have both been implicated in post-transcriptional control of cytokine gene expression. These findings suggest a dual role for TGF-beta 1 in the regulation of cytokine production at both transcriptional and translational levels.
Retention of ligand binding activity by the extracellular domain of the IL-1 receptor.
Authors: Dower S K , Wignall J M , Schooley K , McMahan C J , Jackson J L , Prickett K S , Lupton S , Cosman D , Sims J E
Published: December 2022

The IL-1R on murine T cells is an 80-kDa cell surface glycoprotein which binds both IL-1 alpha and IL-1 beta. We have recently isolated a cDNA clone encoding this molecule. From the primary sequence mature receptor is predicted to be a 557 residue integral membrane protein with a 319 residue carbohydrate-rich extracellular region. We have constructed a cDNA clone encoding this region of the protein (residues 1 to 316). Expression of this cDNA in HeLa cells leads to secretion of a soluble IL-1 alpha binding protein into the culture medium. Quantitative binding experiments with the truncated receptor show that it possesses IL-1 binding properties which are indistinguishable from those of full length IL-1R. Gel filtration chromatography experiments show that a complex can be formed between a single truncated receptor molecule and a single IL-1 alpha molecule.
Regulation of the expression of IL-6 in human monocytes.
Authors: Navarro S , Debili N , Bernaudin J F , Vainchenker W , Doly J
Published: December 2022

IL-6 is a cellular regulatory molecule with various cell-dependent functions. We have studied the control of IL-6 expression in human monocytes because they play a key role in the production of this molecule. The effects of adherence and different cytokines including CSF-1, IFN-gamma, IL-1 alpha, and granulocyte-macrophage-CSF were tested on IL-6 expression. IL-6 mRNA was usually not detected in the starting population of PBMC. Adherence induced IL-6 gene expression in monocytes in less than 2 h and subsequently IL-6 secretion. Priming of monocytes by adherence was more efficient for IL-6 overinduction by CSF-1. In contrast, high level induction of IL-6 by IFN-gamma in unfractionated PBMC did not require adherence and in situ hybridization revealed that IL-6 mRNA was present in monocytes but not in lymphocytes. A similar phenomenon was observed for IL-1 alpha and granulocyte-macrophage-CSF. Two cell lines, HL-60 and U937, in which monocytic differentiation occurs after induction by PMA, were subsequently investigated. IL-6 was not constitutively detectable in these two cell lines, whereas PMA treatment induced IL-6 expression. This effect was rapid (30 min) and transitory in HL-60, whereas IL-6 mRNA was still detected after 72 h of induction in U937. Addition of human rIL-6 on U937 and HL-60 cells inhibited their proliferation and enhanced expression of HLA class I Ag.
Modulation of tumor necrosis factor-alpha gene expression. Desensitization of prostaglandin E2-induced suppression.
Authors: Spengler R N , Spengler M L , Strieter R M , Remick D G , Larrick J W , Kunkel S L
Published: December 2022

PGE2, an immune mediator, is an inhibitor of LPS-stimulated TNF production and gene transcription. In the present study we determined whether pretreatment with PGE2 could desensitize the suppressive function of PGE2 for the production of macrophage (MO)-derived TNF. CFA-elicited MO were incubated with PGE2 or medium only, washed, and then challenged with graded doses of LPS (0.001 to 1000 ng/ml) in the presence or absence of new PGE2. The concomitant addition of PGE2 with LPS shifted the LPS concentration-effect curve 16-fold to the right with a 52% decrease in the maximum LPS response, while MO pretreated with PGE2, washed, and incubated with LPS plus new PGE2 were desensitized to TNF regulation. These latter conditions resulted in a complete loss of the ability of PGE2 to inhibit MO TNF production as demonstrated by no significant change in the EC50 of LPS. In addition, the PGE2 concentration effect curve was shifted to the right after pretreatment of MO, suggesting a desensitized PGE2 receptor system. At the transcriptional level, pretreatment of MO with PGE2 attenuated the ability of new PGE2 to inhibit LPS-dependent TNF mRNA expression. Further studies demonstrated that, although the concomitant addition of the cyclooxygenase inhibitor indomethacin plus LPS could increase TNF production, MO pretreated with indomethacin, washed, and then challenged with LPS demonstrated an inhibition of TNF expression. MO pretreated with indomethacin also demonstrated an increased sensitivity for exogenous PGE2-induced suppression of TNF mRNA and bioactivity. These investigations further support the role of PGE2 as an immunomodulating compound that may effectively regulate the local concentration of specific monokines needed to maintain an inflammatory lesion.
Regulation of isotype production by IL-4 and IL-5. Effects of lymphokines on Ig production depend on the state of activation of the responding B cells.
Authors: Tonkonogy S L , McKenzie D T , Swain S L
Published: December 2022

The effects of IL-4 and IL-5 on the production of Ig of different isotypes was investigated. We compared B cells from spleen and from Peyer's patches either stimulated with LPS or without added polyclonal stimulation. We also compared high density (small) and low density (large) B cells. The effect of lymphokines depended on the size and source of the B cells as well as on whether LPS was added. As expected, small B cells from either lymphoid compartment responded to LPS alone and IL-4 suppressed IgM and IgG3 production and enhanced IgG1. In contrast, when large B cells were examined, the suppressive effects of IL-4 were much less apparent but the enhancement of IgG1 was still marked. IL-5 alone had only minimal effects in LPS-stimulated cultures but the combination of IL-4 plus IL-5 appeared to overcome much of the IL-4-mediated suppression of IgM, and IgA production was enhanced. In the absence of LPS, a quite different profile is seen. First, small B cells make little if any response. Second, there is dramatic synergy between IL-4 and IL-5 in the response of large B cells, which is independent of isotype. Third, IL-4 does not suppress any isotype in the absence of LPS. Fourth, IL-4 plus IL-5 stimulate large Peyer's patch B cells to produce 10 times more IgA but three times less IgM than large spleen B cells. Fifth, Th2 cells directly stimulate both large and small B cells.
Alterations in megakaryocyte and platelet compartments following in vivo IL-1 beta administration to normal mice.
Authors: Williams D E , Morrissey P J
Published: December 2022

IL-1 has been shown to stimulate the release of granulocyte-macrophage CSF, granulocyte-CSF, and macrophage-CSF from "accessory cell populations" in vitro, and it stimulates the appearance of colony-stimulating activity in the sera of mice in vivo. This cytokine has also been proposed to act on primitive hematopoietic progenitor cells to stimulate expression of receptors for the CSF. We sought to determine whether IL-1 beta could influence platelet and/or megakaryocytes and their progenitor cells following in vivo administration to normal mice. Our results demonstrated that, although administration of IL-1 beta clearly expands the pool of megakaryocyte-CFU and acetylcholinesterase-positive megakaryocytic cells (primarily in the spleen), it causes a transient and dose-dependent reduction of circulating platelets. The associated thrombocytopenia can be abolished by splenectomy before IL-1 beta administration, and is not temporally associated with the development of splenomegaly.
Expression of a binding structure for sialic acid-containing glycoconjugates on rat bone marrow-derived macrophages and its modulation by IFN, TNF-alpha, and dexamethasone.
Authors: Gessl A , Boltz-Nitulescu G , Wiltschke C , Holzinger C , Nemet H , Pernerstorfer T , Förster O
Published: December 2022

Rat macrophages express a binding structure for sialic acid-containing glycoconjugates (sialic acid-binding receptor, SAR) which can be detected by a rosette assay utilizing SRBC coated with bovine brain gangliosides (E-G). Freshly isolated rat bone marrow cells (BMC) contain about 5% SAR-positive cells. Rat BMC cultured for 1 wk with tissue culture media containing CSF-1 differentiate into a virtually pure population of bone marrow-derived macrophages (BMDM phi). All BMDM phi bound E-G coated with an optimal concentration of gangliosides (100 micrograms/ml). When BMC were cultured for 1 wk with murine recombinant granulocyte-macrophage CSF, irrespective of the dose of GM-CSF, approximately 90% of the cells were identified as rat macrophages, and practically all expressed SAR. Only about 50% of BMDM phi bound SRBC coated with a suboptimal concentration of gangliosides (20 micrograms/ml). However, this percentage increased markedly after 8 to 72 h incubation with 1 to 10,000 U/ml purified murine IFN-alpha or IFN-beta, whereas murine or rat rIFN-gamma at doses above 10 U/ml led to a decrease of E-G binding. Human and murine rTNF-alpha enhanced rosette formation in a dose-dependent manner. These effects could be blocked by the respective anti-cytokine antibodies. Treatment of BMDM phi with dexamethasone also augmented E-G rosetting. The enhancement of E-G binding was abolished by pretreatment of BMDM phi with cycloheximide and actinomycin D but not with mitomycin C, suggesting that de novo synthesis of protein and RNA, but not DNA, is required. Our results demonstrate that all rat BMDM phi constitutively bear SAR, and that murine IFN-alpha, IFN-beta, and TNF-alpha, as well as dexamethasone, may augment SAR expression.
Immune response to a molecularly defined internal image idiotope.
Authors: Williams W V , London S D , Weiner D B , Wadsworth S , Berzofsky J A , Robey F , Rubin D H , Greene M I
Published: December 2022

A monoclonal anti-idiotope termed 87.92.6 mimics the neutralization/cell-attachment site of the reovirus type 3 hemagglutinin (HA3). The second complementarity determining regions of the VH and VL of 87.92.6 share sequence similarity with a determinant on the HA3. We have used synthetic peptides (termed VH, VL, and Reo peptides, respectively) to probe the immunologic significance of this sequence similarity. Antibodies specific for Reo peptide or VL peptide neutralized reovirus type 3 infectivity. Although Reo peptide was an effective immunogen by itself, free VL peptide or VH peptide were unable to elicit antibodies unless they were linked to each other (VH-VL peptide). Immunization with reo peptide, 87.92.6, or the HA3 elicited a specific lymphocyte proliferative response to VH peptide, indicating that VH peptide may bear an important TH determinant. As found previously for 87.92.6, VL peptide elicited a delayed-type hypersensitivity response specific for reovirus type 3. Reovirus type 3 specific cytolytic lymphocytes specifically lysed targets coated with VH-VL peptide, but not VH or VL peptide alone. These results suggest that immune cross-reactivity between an external Ag and an internal image antibody can be understood at the primary structural level. These observations may have important implications for understanding the development of autoantibodies, network interactions, and the regulation of immune responses.
Persistent suppression of virus-specific cytotoxic T cell responses after transient depletion of CD4+ T cells in vivo.
Authors: Goronzy J J , Weyand C M
Published: December 2022

Co-administration of soluble Ag and anti-CD4 mAb has been successfully used to induce long term Ag-specific tolerance. The mechanisms underlying persistent immunologic unresponsiveness are unclear. We have now studied whether tolerance toward complex viral Ag expressed on Moloney sarcoma virus (MSV)-transformed tumor cells can be induced when given at the time of severe helper cell depletion. Although mice that had been injected with anti-CD4 mAb at the time of immunization regained the ability to recognize MSV Ag, their humoral and cytotoxic immunity to MSV were severely compromised. Ag-specific low responsiveness was maintained for more than 6 mo. To analyze the T cell repertoire of low responder mice we have estimated precursor frequencies of MSV-specific proliferative and cytotoxic T cells after the CD4+ T cell subset was fully reconstituted. There was no difference in the frequencies of control and low responder mice excluding clonal deletion as the mechanism maintaining low responsiveness. In co-culture experiments the defect in low responder mice could be localized to the regenerated CD4+ T cell subset, suggesting the induction of CD4+ suppressor-inducer cells. Alternatively, regenerated CD4+ cells in anti-CD4 conditioned mice had acquired a defect to provide help for MSV-specific responses. In spite of the potentials to induce low responsiveness to selected Ag by anti-CD4 conditioning, the risk to cause persistent virus-specific immunodeficiency might limit the clinical application of anti-CD4 therapy.