bluuebunny/crossref_metadata_2025_split huggingface dataset:
A colostral protein that induces the growth and differentiation of resting B lymphocytes.
Authors: Julius M H , Janusz M , Lisowski J 
Published: December 2022

Abstract
We describe the first protein of mammalian origin that induces the growth and differentiation of resting B lymphocytes. A proline-rich protein has been isolated from sheep colostrum. A purified proline-rich protein preparation (PRPP) induced resting mouse B cells into and supported their progression through the cell cycle at frequencies comparable with those seen for LPS. Differentiation of resting B cells to plaque formation was also supported as efficiently by PRPP as it was by LPS. However, PRPP was distinct from LPS in that it supported the growth and differentiation of resting B cells derived from either C3H/Tif or C3H/HeJ mice. Splenocytes from neonatal mice responded robustly to PRPP with the growth and differentiation of contained B cells to plaque formation. Unlike LPS, PRPP did not induce detectable Ig isotype switching.
A monoclonal antibody (NKI-L16) directed against a unique epitope on the alpha-chain of human leukocyte function-associated antigen 1 induces homotypic cell-cell interactions.
Authors: Keizer G D , Visser W , Vliem M , Figdor C G 
Published: December 2022

Abstract
In the present study a unique antibody (NKI-L16) reacting with the alpha-chain of the human leukocyte function-associated Ag-1 (LFA-1) is described, which stimulates homotypic cell-cell interactions in a manner very similar to 12-O-tetradecanoyl-phorbol-13-acetate (TPA), in contrast to other anti-LFA-1 mAb which inhibit cell aggregation. The induction of aggregate formation of EBV-transformed B cells (JY) and CTL clones by TPA or NKI-L16 is not accompanied by an increase in the expression of LFA-1. Nevertheless, this cluster formation is LFA-1 dependent, inasmuch as anti-LFA-1 antibodies, other than NKI-L16, completely abrogate aggregation. Simultaneous addition of NKI-L16 and TPA did not result in a further increase of the speed of cluster formation, suggesting that a similar pathway is activated. Immunoprecipitation and enzyme digestion studies revealed that NKI-L16 recognizes a unique epitope on the alpha-chain of LFA-1, most likely situated close to the transmembrane segment of the molecule. It is hypothesized that NKI-L16 or TPA can cause the LFA-1 molecule to convert from an inactive to an active configuration, thereby permitting binding of LFA-1 to its natural ligand.
Cytofluorometric analyses of human T cell CD2/CD4 inter-molecular interactions.
Authors: Bueso-Ramos C E , Donahoe R M , Nicholson J K , Madden J J , Falek A 
Published: December 2022

Abstract
Incubation of human T lymphocytes with saturating concentrations of combinations of certain anti-CD2 and -CD4 mAb results in reciprocal down-regulation of the cell surface density expression of the respective CD molecules. Such reciprocal down-regulation occurs at 0 degrees C in the presence of sodium azide and appears selective for CD2 and CD4 molecules because mAb identifying various other CD T cell surface molecules (anti-Leu2a, -OK-CLL, -W6/32, -beta 2-microglobulin, -4B4) do not modulate CD2 or CD4 R density, and because anti-CD2 mAb (anti-OKT11 and -D66 clone-1) do not alter CD8 R density (anti-OKT8, -Leu2a) and vice versa. Down-regulation of CD2 by mAb specific to CD4 is epitope-specific but does not vary on the basis of the antibody isotype used. The anti-CD4 mAb, Leu3a, was the strongest CD2 down-regulator examined followed by OKT4F. mAb specific to other CD4 epitopes (B, C, D, and E) caused only slight down-regulation of CD2 expression whereas anti-OKT4 and -OKT4A mAb had no significant regulatory effect. Also, mAb specific to the 9.6 (anti-OKT11) and D66 (anti-D66 clone 1) epitopes of the CD2 molecule down-regulated CD4 density detectable with Leu3a, OKT4, and OKT4A anti-CD4 mAb. Down-regulation of CD2 by anti-CD4 mAb also occurred with the transformed T cell line, KE-37, which demonstrates that such effects can occur without mononuclear phagocytic accessory cells. From these data it can be concluded that important T cell immunoregulatory signals may be transmitted intramembranally between CD2 and CD4 glycoproteins.
Intrathymic differentiation and tolerance induction of lymphokine-secreting Lyt-2+ T helper cells.
Authors: Mizuochi T , Singer A 
Published: December 2022

Abstract
The present study has assessed thymic influence on the differentiation and recognition specificity of developing Lyt-2+ lymphokine-secreting T cells, and compared it with those of developing Lyt-2+ CTL. It was demonstrated that development of Lyt-2+ lymphokine-secreting Th cells requires an intrathymic differentiation step, and that peripheral Lyt-2+ lymphokine-secreting Th cells, unlike peripheral Lyt-2+ CTL, are profoundly tolerant to intrathymically expressed alloantigens. These data are interpreted as demonstrating that functionally distinct Lyt-2+ T cell populations are heterogeneous in their requirements for differentiation and/or activation.
Expression of IgG Fc receptors in myeloid leukemic cell lines. Effect of colony-stimulating factors and cytokines.
Authors: Liesveld J L , Abboud C N , Looney R J , Ryan D H , Brennan J K 
Published: December 2022

Abstract
Three classes of FcR have been defined on human myeloid cells by their reactivity with mAb; FcRI (mAb 32); FcRII (mAb IV3); and FcRIII (mAb 3G8). We have quantitated the expression of each FcR on human myeloid leukemia cells and cell lines (KG-1, HL-60, U937, and K562). Detailed analysis of FcR surface expression is provided for the U937 cell line after exposure to CSF and cytokines. Increased expression of FcRI and FcRII occurred at 72 h in cells exposed to GCT or Mo cell line-conditioned medium as well as to medium from PHA-treated mononuclear cells. The augmentation of FcRII required protein synthesis and was diminished by a neutralizing antibody to granulocyte-macrophage CSF. We also show that fractions containing natural granulocyte CSF or granulocyte-macrophage CSF as well as r-granulocyte and r-granulocyte-macrophage CSF are capable of inducing FcRII on these cells, whereas other cytokines such as IL-1 and IL-2, TNF-alpha, INF-gamma and macrophages CSF failed to do so.
Separation and comparison of two monokines with lymphocyte-activating factor activity: IL-1 beta and hybridoma growth factor (HGF). Identification of leukocyte-derived HGF as IL-6.
Authors: Van Damme J , Van Beeumen J , Decock B , Van Snick J , De Ley M , Billiau A 
Published: December 2022

Abstract
Supernatants of mitogen-stimulated human leukocytes contain two biologically related cytokines, IL-1 and hybridoma growth factor (HGF). IL-1 beta is a potent inducer of HGF in fibroblasts but has little stimulating effect on monocytes that spontaneously produce HGF. Leukocyte-derived HGF and IL-1 were separated by the use of affinity chromatography on specific antibodies and discriminating assay systems for both cytokines. They had different Mr upon gel filtration and SDS-PAGE. In contrast to IL-1 beta, HGF showed heterogeneity on a cation-exchange column. IL-1 beta and HGF were purified to homogeneity by a sequence of four and five purification steps, respectively. Leukocyte-derived HGF was characterized by analysis of its NH2-terminal amino acid sequence. This revealed complete homology with fibroblast-derived HGF, 26-kDa protein, IFN-beta 2, and B cell stimulatory factor 2, molecules which have collectively been designated as IL-6. IL-1 beta exerted an antiviral and growth-promoting effect of fibroblasts, whereas HGF/IL-6 did not. Both IL-1 and IL-6 possessed lymphocyte-activating factor activity, which could be neutralized only by an anti-serum against the corresponding cytokine.
Certain lymphoid cells contain the membrane-associated component of the phagocyte-specific NADPH oxidase.
Authors: Pick E , Gadba R 
Published: December 2022

Abstract
Anionic amphiphiles such as long chain unsaturated fatty acids and SDS were shown to activate the superoxide (O2-) producing NADPH oxidase in a cell-free system derived from sonically disrupted phagocytes (macrophages and granulocytes). O2- production required the cooperation of a membrane associated component sedimenting at 48,000 X g (pi) and a cytosolic factor (sigma). The purpose of the present investigation was to find out whether components pi and sigma were also present in non-phagocytic cells that do not produce O2- when stimulated. It was found that the 48,000 X g pellets of guinea pig lymph node and thymus cell sonicates contained significant amounts of component pi, as shown by their ability to support SDS-elicited NADPH-dependent O2- production when supplemented with macrophage cytosol. Lymph node and thymus pi could be extracted from the membrane by 30 mM octyl glucoside, just as its macrophage-derived equivalent. Combining lymph node and thymus 48,000 X g pellet with autologous cytosol did not yield an active enzyme preparation. Also, cytosol from lymph node and thymus cells could not cooperate with macrophage 48,000 X g pellet, indicating that component sigma was lacking in lymphoid cells. Neither pi nor sigma could be detected in guinea pig kidney, the mouse myeloma cell line MOPC 315 and the canine cell line Cf2Th. The 48,000 X g pellet of all nonphagocytic cells examined contained a b-cytochrome that resembled, by its spectral characteristics, the cytochrome b559 thought to be characteristic of phagocytes. In macrophages, cytochrome b559 represented 80% of b-cytochrome content of the 48,000 X g pellet, whereas in non-phagocytic cells, the equivalent material represented only 50 to 60%. There was no correlation between the presence and quantity of the cytochrome b559-like chromophore in the 48,000 X g pellet of a particular cell type and its ability to cooperate with macrophage cytosol in SDS-elicited O2- production.
T cell receptor beta-chain genes in BW5147 and other AKR tumors. Deletion order of murine V beta gene segments and possible 5' regulatory regions.
Authors: Lee N E , Davis M M 
Published: December 2022

Abstract
The AKR thymoma BW5147 has rearranged both of its TCR beta-chain loci, using the same J beta region (J beta 2.5) in each, but with different V beta gene segments. Although the two rearrangements are expressed approximately equally in cytoplasmic RNA, the principle of allelic exclusion is maintained because only one rearrangement is in-frame and capable of encoding a functional protein. In hybridomas made with BW5147 as the fusion partner, this protein may combine with the alpha-chain protein derived from the normal cell to form new Ag/MHC specificities. An analysis of the sequences upstream from the BW5147 rearrangements and additional V regions suggests that two conserved sequences, 10 and nine nucleotides in length and located adjacent to each other 70 to 100 nucleotides 5' of the initiation codon, may be important in the expression of TCR beta-chain genes. Although B and T cells derive from common stem cells, no sequences are observed in T cells that are homologous to the octamer located 5' of all Ig genes. This implies that at least some of the sequences that regulate transcription are not shared in the two major types of lymphocytes. A survey of BW5147 and six other AKR thymomas using probes for 10 of the 18 known V region families indicates a distribution of V beta rearrangements in the tumors consistent with that found in thymocytes. Four of these tumors have apparent VDJ rearrangements on both chromosomes, with the deletion of other V beta gene segments. These data suggest that the primary mechanism of VDJ beta rearrangement is by looping out and excision of the intervening DNA and that most of the V regions are located 5' to the C region. These data were also used to develop a deletion order of the V beta gene segments in the TCR beta-chain locus.
I.29 lymphoma cells express a nonmutated VH gene before and after H chain switch.
Authors: Klein D , Nietupski J , Sirlin S , Stavnezer J 
Published: December 2022

Abstract
The I.29 B cell lymphoma consists of IgM+ and IgA+ cells which express the same germ-line VH gene. IgA+ cells of the I.29 lymphoma were derived from the IgM+ cells by a typical H chain switch recombination event. The IgM+ cells can be induced with LPS to undergo H chain switching in culture. It has been proposed that the somatic hypermutation process is activated during H chain switch, since V genes expressed in IgG+ and IgA+ cells have more frequently undergone mutation than those expressed in IgM+ cells. We have investigated this question by sequencing VH genes expressed before and after H chain switch in the I.29 lymphoma. We have also sequenced the germ-line VH gene corresponding to the gene expressed by I.29 cells to determine whether the VH gene expressed in the IgM+ cells had already undergone somatic mutation. Our results indicate that somatic mutation was not activated in the precursor cell for the I.29 lymphoma, nor during isotype switch in I.29 cells. It is possible that cells of the I.29 lymphoma, or their precursor, have not received the signal which induces somatic mutation, or that I.29 cells belong to a subset of B cells that cannot be induced to undergo any (or much) somatic mutation.
Idiotype vaccination leads to the emergence of a stable surface Ig-negative variant of the mouse lymphoma BCL1, with different growth characteristics.
Authors: George A J , Spellerberg M B , Stevenson F K 
Published: December 2022

Abstract
Vaccination of mice with tumor-derived idiotypic IgM from the B cell lymphoma, BCL1, induces an anti-idiotypic immune response which suppresses tumor development. One of the mechanisms by which tumor cells can escape attack is by failing to express significant levels of idiotypic immunoglobulin at the cell surface, and a stable variant of this phenotype has been isolated. The variant, termed SNAG 1, continues to synthesize idiotypic IgM, which can be detected in the cytoplasm, but it neither secretes nor expresses IgM on the cell surface (less than 10% of the levels of the original BCL tumor), even though the H and L chains show no gross structural changes. The SNAG 1 cells resemble the parent BCL cells in morphology, in expression of MHC class I and II Ag and in bearing FcR. A significant difference between the BCL lymphoma cells and the variant cells is that the latter fail to respond to LPS by either DNA synthesis or secretion of IgM, suggesting that surface Ig might be required for such a response. The variant has a slower rate of division than the parent tumor both in vitro and in vivo, and a rather different organ distribution. Study of such variants might allow analysis of the mechanisms involved in surface Ig expression and its possible role in tumor cell growth and migration.
T cell recognition of Mlsc,x determinants.
Authors: Abromson-Leeman S R , Laning J C , Dorf M E 
Published: December 2022

Abstract
Among a large number of cow insulin-specific T cell clones derived from both C57BL/10 and B10.A strains, several were found to react to non-MHC-linked gene products of a number of allogeneic strains. The stimulatory moiety for three of these clones correlates, in part, with expression of Mlsc, as defined by mouse strains C3H/HeJ and A/J. In addition, all three of these clones are stimulated by cells from strain PL/J, which has the poorly defined Mlsx allele. The data strongly suggest that Mlsx may, in fact, be Mlsc or is, at least, highly cross-reactive with Mlsc. Segregation analysis by using (B10.D2 X PL/J)F2 mice demonstrates that the Mlsx gene is genetically independent of the Mlsa linked Ly-9 marker on chromosome 1. Further studies with the use of these Mlsc,x-reactive clones reveal that they also recognize a gene product present in many mouse strains including DBA/2 which were previously phenotyped as Mlsa. However, testing of BxD recombinant inbred lines excludes Mlsa as being the stimulatory moiety. We therefore propose reclassification of the Mls phenotypes of several mouse strains based upon a two-locus model for Mls.
Clonal analysis of the BALB/c secondary B cell repertoire specific for a self-antigen, cytochrome c.
Authors: Jemmerson R , Blankenfeld R 
Published: December 2022

Abstract
mAb to rat cytochrome c (cyt c), totaling 556, were produced by individual clones of secondary B lymphocytes from nine groups of five BALB/c mice each in vitro using the splenic focus culture system. Inasmuch as rat and mouse cyt c are identical, these B cells can be considered specific for a self-antigen. The mAb were categorized into specificity groups based on their reactivities with a panel of seven cyts c that differ at two to six amino acid residues. The number of distinct specificities for the native protein was restricted to fewer than 20. Different groups of mice expressed the same specificities at comparable frequencies, including a single dominant one, and the total number of secondary cyt c-specific B cells was constant among groups of mice. This suggests that the acquisition of the secondary B cell specificity repertoire for this self-antigen is regulated. However, it is indeed possible that each specificity group may comprise a number of distinct mAb molecules that have arisen stochastically. Specificities expressed by as few as 1% of the total mAb were observed. Thus, it is likely that the identified specificities reflect the secondary B cell specificity repertoire for rat cyt c. The dominant specificity expressed by 50% of the mAb was characterized by elimination of antigen recognition as a result of replacement of aspartic acid by glutamic acid at position 62. Minor specificities expressed by 19% of the mAb were characterized by more subtle affects of an amino acid change at position 62 and/or an amino acid substitution from rat cyt c at position 60. Antibodies in other specificity groups reacted with epitopes in the region of residues 44 and 47. Whereas substitutions at positions 44, 47, 60, and 62 eliminated recognition by most of the mAb, changes at position 92 and at 103 also appeared to affect the binding of some mAb in the region around residues 60 and 62. The amino acid residues implicated in the recognition by murine mAb of murine cyt c have been shown previously to be involved in the epitopes of foreign mammalian cyt c. Therefore, self-tolerance cannot fully explain the restriction of the epitopes to these regions on foreign mammalian cyt c.
Antigen as a positive and negative regulator of proliferation in cytotoxic lymphocytes. A model for the differential regulation of proliferation and lytic activity.
Authors: Russell J H , Manning D E , McCulley D E , Meleedy-Rey P 
Published: December 2022

Abstract
The goal of these experiments has been to capitalize on the functionally distinct responses of heteroclitic CTL to cross-reactive Ag to explore the role of Ag in regulating CTL proliferation and lytic function. The experiments here have examined one of these clones in detail but several such clones appear similar. The principal findings were: 1) proliferation and lysis may be optimally stimulated by quantitatively different interactions, 2) Ag can have negative as well as positive effects on the proliferative potential of the responding cell, and 3) both positive and negative effects on lysis can be mimicked by agents which are similar to the second messengers produced by stimulating the TCR.
A T cell surface molecule different from CD2 is involved in spontaneous rosette formation with erythrocytes.
Authors: Bernard A , Aubrit F , Raynal B , Pham D , Boumsell L 
Published: December 2022

Abstract
Increasing evidence indicates that rosettes which spontaneously from between human T cells and E might be of physiologic relevance. We show here that another T cell-surface molecule than CD2 is involved in rosette formation. Four mAb have been obtained reacting with human T cells that block rosettes with E from many species, including autologous cells. They react with a molecule, we termed E2, which is actively synthetized by T and monocytic cells. Immunoprecipitation revealed a major 32-kDa band. Immunoblots revealed a major 32-kDa band and a minor 20-kDa band. This molecule was detected on all T cells tested--and present at high densities on corticothymocytes, but at low densities on medullary thymocytes. It was also found on monocytes but not on B cells. However B-CLL cells did carry this molecule. E2 molecules were also detected on nonhematologic cells. Together with the recent evidence that 3 molecules from the erythrocyte surface are also involved for rosettes, intricate molecular interactions would account for adhesion of T cells to autologous E and possibly autologous nucleated cells.
Clearance and organ localization of small DNA anti-DNA immune complexes in mice.
Authors: Emlen W , Burdick G 
Published: December 2022

Abstract
DNA anti-DNA immune complexes (IC) play a major role in the pathogenesis of SLE. We studied the clearance and organ localization of small DNA anti-DNA IC formed at different Ag/antibody ratios in normal mice. IC formed at Ag excess, containing areas of "exposed" DNA not covered by IgG, showed rapid Ag-mediated clearance from the circulation by the liver. DNAse digestion of these IC in vitro yielded small IC devoid of exposed DNA that were cleared more slowly from the circulation. IC formed at antibody excess were cleared by an Ag-independent mechanism at rates proportional to the number of IgG in the IC. None of the IC studied bound significantly to complement receptors on circulating cells in vivo or in vitro. For all IC, after initial rapid clearance, 10 to 20% of the injected material persisted in the circulation. Analysis of these IC showed that they were processed in vivo to yield complexes similar to those generated by in vitro DNAse digestion. We conclude that IC containing exposed DNA are removed rapidly from the circulation by Ag-mediated clearance. However, in vivo processing of IC occurs to yield smaller IC that are cleared slowly. We propose that these IC containing small DNA may persist in the circulation and accumulate in tissues, thereby playing an important role in the pathogenesis of tissue injury in SLE.
HLA-DR4 restricted lymphocyte proliferation to a Mycobacterium tuberculosis extract in rheumatoid arthritis and healthy subjects.
Authors: Palacios-Boix A A , Estrada-G I , Colston M J , Panayi G S 
Published: December 2022

Abstract
The ability of an antigenic extract of Mycobacterium tuberculosis to induce proliferation of PMBC from rheumatoid arthritis (RA) patients and normal controls was examined. The subjects were further classified as bearing or not bearing the HLA-DR4 phenotype, since this specificity is regarded as a genetic determinant commonly associated with RA. The mycobacterial extract induced significantly higher proliferative responses in lymphocytes from all HLA-DR4 positive as compared to HLA-DR4 negative subjects regardless of whether they had RA or not. This response was maximal at day 6 of incubation and could be abrogated by anti-DR/DQ mAb added to the culture. SDS-PAGE of this extract revealed three major protein bands located at Mr 14, 47, and 65 kDa. After fractionation, Western blotting, and resuspension of protein-laden nitrocellulose particles, only the 14- and 47-kDa proteins retained the original proliferative capacity of the mycobacterial extract. The band separating with a Mr of 47 kDa was found to be the most strongly associated with the HLA-DR4 restricted lymphocyte proliferation, and represents a newly identified M. tuberculosis Ag of relevance in T cell responses. These data provide insight into the pathogenic potential of certain bacterial Ag which could trigger or perpetuate inflammatory disorders when presented in the appropriate genetical background.