bluuebunny/crossref_metadata_2025 huggingface dataset:
aIr-1, a newly found locus on mouse chromosome 16 encoding a trans-acting activator factor for MHC class II gene expression.
Authors: Accolla R S , Jotterand-Bellomo M , Scarpellino L , Maffei A , Carra G , Guardiola J
Published: June 2004

RJ 2.2.5 is a human B cell line that has lost the capacity to express MHC class II genes. The human class II-positive phenotype is restored in somatic cell hybrids between RJ 2.2.5 and mouse spleen cells. By karyotype and molecular studies of an informative family of hybrids we have now shown that the reexpression of human class II gene products, as well as the maintenance of the mouse class II-positive phenotype, correlates with the presence of mouse chromosome 16. Thus, the existence on this mouse chromosome of a newly found locus, designated by us aIr-1, that determines a trans-acting activator function for class II gene expression, is established. Possible implications of this finding are discussed.
Identification of a T3/T cell receptor complex in chickens.
Authors: Chen C L , Ager L L , Gartland G L , Cooper M D
Published: June 2004

A mouse mAb, CT-3, recognizes on chicken T cells a complex of three polypeptides, Mr 20,000, 19,000, and 17,000, two of which are N-glycosylated. The CT-3 antibody is mitogenic for chicken T cells, and it coprecipitates two additional polypeptides of Mr 49,000 and 38,000 in lysates of T cell membranes. Ontogeny studies revealed that 5-6 d after thymic influx of hemopoietic stem cells, their thymocyte progeny begin to express the T3/TCR complex. After hatching 1 wk later, the CT-3+ cells begin splenic migration in large numbers.
Development of multiple organ-localized autoimmune diseases in nude mice after reconstitution of T cell function by rat fetal thymus graft.
Authors: Taguchi O , Takahashi T , Seto M , Namikawa R , Matsuyama M , Nishizuka Y
Published: June 2004

Restoration of T cell function of athymic BALB/c nu/nu mice was investigated after transplantation of xenogeneic thymic rudiments from 15-d-old embryonic rats into kidney subcapsule. The rudiments developed well and formed a proper thymus structure composed of donor epithelia and host lymphocytes. Examination of antibody responses to SRBC revealed that approximately half the normal number of indirect PFCs were observed. Skin grafts from syngeneic BALB/c mice and thymic donor rat strains were accepted, whereas those from allogeneic mice and the rats of other than donor strains were vigorously rejected. Thymus-grafted nude mice under a conventional environment survived without any evident infectious diseases. Histological and immunofluorescence studies, however, showed a high incidence of multiple organ-localized autoimmune diseases in thyroid, salivary gland, stomach, adrenal, prostate, ovary, and testis in mice that produced the corresponding autoantibodies. These results together suggested that rat thymic grafts reconstituted T cell functions of nu/nu mice to a considerable degree, but that organ-localized autoimmune diseases developed, probably because certain auto-antigens of the recipients were recognized by the newly reconstituted host immunity.
Functional study of a monoclonal antibody to IgE Fc receptor (Fc epsilon R2) of eosinophils, platelets, and macrophages.
Authors: Capron M , Jouault T , Prin L , Joseph M , Ameisen J C , Butterworth A E , Papin J P , Kusnierz J P , Capron A
Published: June 2004

An IgM mAb (BB10) was produced by immunization of mice with human eosinophils purified according to their abnormal low density ("hypodense" cells), and previously shown to exhibit increased IgE-dependent antiparasite cytotoxicity. This BB10 antibody, selected for positive fluorescence staining of hypodense blood or lung eosinophils and low or negative staining of normodense eosinophils or neutrophils, could strongly inhibit IgE-dependent cytotoxicity of human eosinophils and platelets. The specificity for the IgE Fc receptor was suggested by the high levels of inhibition of IgE rosettes formed by eosinophils after incubation with the purified IgM fraction of BB10, whereas other receptors (Fc gamma R, CR1) were not affected. On the other hand, BB10, able to inhibit rat eosinophil Fc epsilon R, did not react with the IgE Fc receptor on mast cells or basophils. A technique using radioiodinated BB10 allowed us to quantify the specific binding of BB10 to human eosinophils and platelets. Competition experiments revealed a crossinhibition between the binding of BB10 and IgE, suggesting the specificity of BB10 for the IgE binding site of eosinophil, platelet, and monocyte Fc epsilon R. Three proteins having extrapolated Mr of 32,000, 43,000-45,000, and 97,000 were found in the platelet extract eluted from a BB10 or from an IgE immunosorbent column. These findings confirm the similarities between IgE Fc receptors on human eosinophils, platelets, and macrophages, already observed with polyclonal antibodies directed against the B lymphocyte Fc epsilon receptor. They suggest, moreover, that the mAb BB10 can represent a good reagent for further investigations on the structure and the functions of this IgE Fc receptor (Fc epsilon R2).
Sequences and repertoire of human T cell receptor alpha chain variable region genes in mature T lymphocytes.
Authors: Yoshikai Y , Kimura N , Toyonaga B , Mak T W
Published: June 2004

24 human T cell receptor alpha chain messages have been examined by cDNA sequence analysis and Southern blot. The data indicate that there are approximately 40 alpha chain T cell receptor variable gene segments, which can be divided into 12 families. Comparison of the J gene segments from the cDNAs to previously determined germline J alpha sequences places the number of J alpha gene segments over 21, and indicates their number to be approximately 55. Identical nucleotide sequences in independent isolates of V alpha and J alpha gene segments indicate that hypermutation may not be a common mechanism for the expansion of diversity in these genes, and suggest that the major source of diversity within the alpha chain repertoire is a result of recombinational joinings between germline V alpha and J alpha sequences, combined with imprecise junctional joining. Analysis of the V regions of these alpha chain messages reveals the presence of three domains of hypervariability roughly analogous to the CDR1, CDR2, and CDR3 regions of immunoglobulin.
Variable region sequences of murine IgM anti-IgG monoclonal autoantibodies (rheumatoid factors). A structural explanation for the high frequency of IgM anti-IgG B cells.
Authors: Shlomchik M J , Nemazee D A , Sato V L , Van Snick J , Carson D A , Weigert M G
Published: June 2004

The nucleotide sequences of heavy and light chains from 10 monoclonal IgM anti-IgG1 (RF) antibodies were determined and reported here as translated amino acid sequences. Only three families of VK light chains were used in these antibodies: VK1 (two examples), VK8 (three examples), and VK19 (four examples). This represents a significant nonrandom selection of light chains. In contrast, all other variable region gene segments (i.e., VH, DH, JH, and JK) were used in a pattern consistent with random selection from the available pool of germline genes. In two cases, the same anti-IgG1 specificity was generated by a combination of very homologous light chains with unrelated heavy chains. We infer from this that the light chain is the segment used by these antibodies to bind IgG1. The nature of these sequences provides an explanation for the curious observation that as many as 15% of splenic B cells in normal mice may be expressing IgM anti-IgG; if, as our data suggest, certain light chains in combination with many different heavy chains can be used in assembling the anti-IgG specificity, then, because of combinatorial association in which the heavy chain is not relevant for specificity, the fraction of IgM-producing B cells expressing these light chains should approximate the fraction of B cells making IgM anti-IgG. We calculate, based on data presented in several other studies, that 5-17% of B cells express one of the VK types observed in monoclonal RF. This agrees well with estimates for the number of B cells making IgM anti-IgG. In addition, our findings could rule out other explanations of the high percentage of B cells making RF, such as constant stimulation by antigen or presence of numerous antigenic epitopes since it was shown that IgM anti-IgG1 antibodies are not somatically mutated and that they are structurally homogeneous. We aligned the VK sequences of the RF in hopes of finding some primary sequence homology between the represented VK families which might point to residues involved in the binding interaction. Although we found no such homology in the hypervariable regions, we did find significant and unexpected homology in the FR2 and FR3 of these light chains. We noted that these regions are exposed in the Ig structure and postulate that they may be involved in a unique type of binding interaction between two Ig family domains, i.e., VK binding to a constant region domain of IgG.
Isotype-specific immunoregulation. Evidence for a distinct subset of T contrasuppressor cells for IgA responses in murine Peyer's patches.
Authors: Suzuki I , Kitamura K , Kiyono H , Kurita T , Green D R , McGhee J R
Published: June 2004

The ability of murine Peyer's patch (PP) T contrasuppressor cells (Tcs) to reverse oral tolerance to the T cell-dependent (TD) antigen SRBC was studied both in vivo and in vitro. C3H/HeJ mice given SRBC orally for 4 wk are not rendered tolerant to this antigen and were used as a source of PP Tcs cells for adoptive transfer to identically treated, orally tolerized C3H/HeN mice. Transfer of 10(4) or 5 X 10(4) V. villosa-adherent PP T cells resulted in splenic IgM, IgG, and mainly IgA responses in C3H/HeN mice challenged systemically with SRBC. The T cell responsible was Lyt-1+, 2-, L3T4-, I-JK+ and V. villosa lectin-adherent, all characteristics of mature effector Tcs cells. This C3H/HeJ PP Tcs cell subset was also effective when added to in vitro cultures of tolerized spleen cells derived from SRBC-fed, C3H/HeN mice. Interestingly, C3H/HeJ PP Tcs cells restored mainly IgA responses when transferred in vivo or when added to suppressed C3H/HeN splenic cultures. Comparison of the functional activity of Tcs cells derived from spleen or PP of orally immunized C3H/HeJ mice revealed that splenic Tcs cells supported responses of all 3 isotypes; however, PP Tcs cells yielded three-fourfold higher IgA responses, when compared with IgM or IgG anti-SRBC responses. Adherence of C3H/HeJ PP Tcs to an Fc alpha R+ T cell line derived from IgA-specific Th cells resulted in a nonadherent cell fraction that potentiated only IgM and IgG responses, while bound Tcs cells preferentially supported IgA responses. These results suggest that murine PP contain IgA-specific Tcs cells that allow IgA response induction in the presence of Ts cells that mediate oral tolerance.
Double isotype production by a neoplastic B cell line. II. Allelically excluded production of mu and gamma 1 heavy chains without CH gene rearrangement.
Authors: Chen Y W , Word C , Dev V , Uhr J W , Vitetta E S , Tucker P W
Published: June 2004

In our accompanying paper, we described a switch variant (BCL1.2.58) that expresses membrane and secreted forms of IgM and IgG1. Both IgM and IgG1 share the same idiotype and use the same VDJ rearrangement. Here, a detailed Southern blot analysis of the entire constant region of the Ig heavy chain (Ig CH) locus of parental (BCL1.B1) and variants (BCL1.B2) DNA showed no detectable rearrangement. Similar analysis of the JH-C mu region led to the conclusion that two heavy chain alleles present in the IgM/IgG1-producing variants carried the same VDJ rearrangement but differed in their 3' flanking regions. One chromosome 12 did not carry any Ig CH genes, whereas, the other chromosome 12 carried one copy of CH genes. In BCL1.B1, however, each of the chromosome 12 alleles carried a full copy of CH genes. Karyotypic analysis confirmed the presence of two translocated t(12;16) chromosomes in both BCL1.2.58 and BCL1.B1 cells, with a break 5' to the VH locus at the distal region (12F2) of chromosome 12, and at the proximal region below the centromere (16B3) of chromosome 16. We conclude that double production of IgM and IgG1 in BCL1.B2 is accomplished by transcription of the corresponding CH genes in germline configuration using a single VDJ on the same chromosome 12.
B cell-stimulatory factor 1 (BSF-1) promotes growth of helper T cell lines.
Authors: Fernandez-Botran R , Krammer P H , Diamantstein T , Uhr J W , Vitetta E S
Published: June 2004

T cell-derived supernatants (SN) that contain B cell-stimulatory factor 1 (BSF-1) and lack IL-2 promote the growth of the IL-2-dependent T cell line, HT-2, as well as three other clones or lines of T cells that can provide help to B cells. The BSF-1 purified from these SNs promotes growth of HT-2 cells approximately 50% as effectively as purified IL-2. A potential involvement for contaminating IL-2 in the BSF-1 preparations was excluded by the demonstration that anti-BSF-1 mAbs blocked the BSF-1-induced growth of HT-2 cells; in contrast, these antibodies did not block the IL-2-induced proliferation of the HT-2 cells. In addition, anti-IL-2 mAbs or anti-IL-2-R antibodies blocked the HT-2 growth-promoting activity of purified IL-2, but not BSF-1. Finally, BSF-1 promoted only a very modest growth of Con A-induced T cell blasts, and failed to induce significant growth in seven other cytotoxic, alloreactive, and long-term T cell lines. Taken together, these results indicate that in addition to its known effects on resting and LPS-stimulated B cells, BSF-1 can promote growth of certain subsets of activated T cells, in particular, those that provide help to B cells.
A human monoclonal macroglobulin with specificity for alpha(2----8)-linked poly-N-acetyl neuraminic acid, the capsular polysaccharide of group B meningococci and Escherichia coli K1, which crossreacts with polynucleotides and with denatured DNA.
Authors: Kabat E A , Nickerson K G , Liao J , Grossbard L , Osserman E F , Glickman E , Chess L , Robbins J B , Schneerson R , Yang Y H
Published: June 2004

We have described an IgM antibody from a patient with macroglobulinemia specifically reacting with poly-alpha(2----8)N-acetyl neuraminic acid (NeuNAc) the capsular polysaccharide of two important human pathogens, group B meningococcus and E. coli K1. This antibody has a narrowly defined specificity in its interactions with polysaccharides, being unable to bind poly-alpha(2----9)NeuNAc or alternating poly-alpha(2----8)alpha(2----9)NeuNAc. However, it shows interesting crossreactivity with seemingly unrelated polynucleotides and denatured DNA, supporting the hypothesis that charged groups with a given spacing may determine the specificity of antigen-antibody interactions on otherwise dissimilar molecular structures. Despite the crossreactivity with denatured DNA and polynucleotides, the antibody does not appear to have adverse effects in the patient. The antibody protects newborn rats against E. coli K1 infection, as well as the standard horse antiserum H46, and one would expect it to prove useful in humans as an adjunct to antibiotic therapy in infections with group B meningococcus and E. coli K1. We have attempted to clone the antibody-producing cells from peripheral blood, and have shown that the relevant cells are present and can be cultured.
Genetic control of the immune response in mice to a Plasmodium falciparum sporozoite vaccine. Widespread nonresponsiveness to single malaria T epitope in highly repetitive vaccine.
Authors: Good M F , Berzofsky J A , Maloy W L , Hayashi Y , Fujii N , Hockmeyer W T , Miller L H
Published: June 2004

Different H-2 congenic strains of mice were immunized with a P. falciparum sporozoite vaccine currently being tested in humans, or with different segments of the vaccine molecule. Specific IgG production or lymph node cell proliferation in response to different antigens was then determined. Only four of seven strains (representing three of eight possible different class II restriction molecules) responded to the vaccine. Of those restriction molecules, only one, I-Ab, was associated with a response to a malaria-encoded T epitope [contained within NP(NANP)3NA], while the other two molecules (E alpha dE beta d and E alpha kE beta s) were associated with a T cell response to a nonmalarial epitope(s) carboxyterminal to the malaria sequence and encoded by a tetracycline resistance gene, read out of frame. If an analogous situation applies in humans, natural boosting by sporozoites will be very restricted. This has serious implications for the effectiveness of the vaccine, since constant high levels of antisporozoite antibodies and possibly antibody-independent T cell effector functions are required for immunity.
Induction of tolerance to one determinant on a synthetic peptide does not affect the response to a second linked determinant. Implications for the mechanism of neonatal tolerance induction.
Authors: Gammon G M , Oki A , Shastri N , Sercarz E E
Published: June 2004

To investigate the mechanism underlying neonatal T cell tolerance, we used synthetic peptides to induce tolerance. We found that induction of tolerance to one determinant on a 23-amino acid peptide did not affect the response to an adjacent determinant on the same peptide. There was no evidence of suppression of the response to the second determinant. Furthermore, even small peptides near the minimal size for a determinant, which would be very unlikely to possess a suppressor T cell-inducing determinant as well as a proliferative T cell-inducing determinant, could induce tolerance. These studies provide in vivo experiments supporting clonal inactivation as the mechanism of neonatal tolerance to immunogenic peptides.
Immunoreactivity of a 70 kD protein purified from Mycobacterium bovis Bacillus Calmette-Guerin by monoclonal antibody affinity chromatography.
Authors: Britton W J , Hellqvist L , Basten A , Inglis A S
Published: June 2004

The protein antigens from Mycobacterium bovis (BCG), M. tuberculosis, and M. leprae share a number of common determinants. We have used a murine mAb (L7) recognizing such a determinant on a protein of Mr 70,000 to purify this antigen from M. bovis sonicate by affinity chromatography. Enrichment of the protein in column eluates was confirmed by immunoblotting and in antigen inhibition assays. After radiolabelling with 125I, the protein could be immunoprecipitated with human lepromatous leprosy sera. Stimulation of peripheral blood mononuclear cells from BCG-vaccinated and naturally mantoux-positive individuals induced proliferation and IFN-gamma secretion, while intradermal injection of purified antigen into the same subjects resulted in a delayed-type hypersensitivity reaction. Thus, the 70,000 molecule carried epitopes capable of reacting with B cells, and eliciting a potentially protective T cell response. The first 15 N-terminal residues were sequenced using a gas-phase sequenator.
Role of Ly-6 in lymphocyte activation. II. Induction of T cell activation by monoclonal anti-Ly-6 antibodies.
Authors: Malek T R , Ortega G , Chan C , Kroczek R A , Shevach E M
Published: June 2004

The Ly-6 locus controls the expression and/or encodes for alloantigenic specificities found primarily on subpopulations of murine T and B lymphocytes. We have recently identified and characterized a new rat mAb, D7, that recognizes a nonpolymorphic Ly-6 specificity. After crosslinking by anti-Ig reagents or by Fc receptor-bearing accessory cells, mAb D7 could induce IL-2 production from T cell hybridomas, and in the presence of PMA could trigger a vigorous proliferative response in resting peripheral T cells. The addition of mAb D7 to cultures of antigen- and alloantigen-, but not mitogen-stimulated T cells resulted in a marked augmentation of the proliferative response. A number of other well-characterized mAbs to Ly-6 locus products could also stimulate a T cell proliferative response after crosslinking by anti-Ig and in the presence of PMA. These results strongly suggest that Ly-6 molecules may play a critical role in the T cell activation cascade, either as receptors for an unidentified soluble or cell-associated ligand or as transducing molecules that modulate signals initiated by antigen stimulation of the T3-Ti complex.
Cooperation between cytotoxic and helper T lymphocytes in protection against lethal Sendai virus infection. Protection by T cells is MHC-restricted and MHC-regulated; a model for MHC-disease associations.
Authors: Kast W M , Bronkhorst A M , de Waal L P , Melief C J
Published: June 2004

The in vivo importance of class I MHC regulation of the Tc response to a natural pathogenic agent of high virulence was studied on the basis of our previous demonstration of a major difference in the capacity to generate a Sendai virus-specific Tc response between C57BL/6 (B6, H-2b) mice and H-2Kb mutant B6.C-H-2bm1 (bm 1) mice. These two mouse strains differ from each other only in three amino acids in the crucial H-2Kb restriction element for this response. bm 1 mice, in contrast to B6 mice, are Tc nonresponders against this virus, but show Sendai-specific T cell proliferation, antibody production, and DTH reactions, as well as NK cell activity, equal to those of B6 mice. B6, Sendai Tc-deficient bm 1 and T cell-deficient B6 nu/nu mice differ from each other in susceptibility to lethal pneumonia induced by i.n. inoculation of virulent Sendai virus. The lethal dose (LD50) in B6 mice averaged 152 TCID50, in bm 1 mice, 14 TCID50 and in B6 nu/nu mice 0.5 TCID50. The importance of Tc was also shown by the complete protection of B6 nu/nu mice against infection with a lethal virus dose by i.v. injection of a Sendai virus-specific, IL-2-dependent and H-2Kb-restricted B6 Tc clone. In vivo protection by this Tc clone was H-2Kb-restricted. Apart from Tc, an important role for virus-specific Th cells is evident from the difference in susceptibility between bm 1 and B6 nu/nu mice. This conclusion was supported by the demonstration that the mean survival time of B6 nu/nu and bm 1 nu/nu mice could be significantly prolonged, in an I-Ab-restricted manner, by the injection of in vitro-propagated, Sendai-specific B6 or bm 1 Th clones after a lethal dose of Sendai virus, and by the demonstration that inoculation of these Th clones provided help to virus-specific Tc by means of IL-2 production. Strikingly, Th and Tc cooperate in anti-Sendai virus immunity, since permanent survival of lethally infected nu/nu mice was only achieved by inoculation of a mixture of Tc and Th clones or a mixture of a Tc clone and rIL-2. This study provides a unique model for the study of MHC-disease associations.
Structure and function of three novel MHC class I antigens derived from a C3H ultraviolet-induced fibrosarcoma.
Authors: Linsk R , Vogel J , Stauss H , Forman J , Goodenow R S
Published: June 2004

The UV-induced, C3H fibrosarcoma, 1591, expresses at least three unique MHC class I antigens not found on normal C3H tissue. Here we report the complete DNA sequence of the three novel class I genes encoding these molecules, and describe in detail the recognition of the individual products by tumor-reactive and allospecific CTL. Remarkably, although C3H does not appear to express H-2L locus information, this C3H tumor expresses two distinct antigens, termed A149 and A166, which are extremely homologous to each other and to the H-2Ld antigen from BALB/c. The gene encoding the third novel class I antigen from 1591, A216, is quite homologous to H-2Kk) throughout its 3' end. Since all three of these genes account for polymorphic restriction fragments not found in C3H, it is likely that they were derived by recombination from the endogenous class I genes of C3H. The DNA sequence homology of A149, A166, and H-2Ld is especially significant given the functional conservation observed between the products of these genes. Limited sequence substitutions appear to correlate with some of the discrete serological differences observed between these molecules. In addition, both A149 and A166 crossreact, but to differing extents, with H-2Ld at the level of T cell recognition. Our results are consistent with the view that CTL recognize complex conformational determinants on class I molecules, but extend previous observations by comparing a set of antigens with discrete and overlapping structural and functional differences.
Cloning of the structural genes of three H8 antigens and of protein III of Neisseria gonorrhoeae.
Authors: Gotschlich E C , Blake M S , Koomey J M , Seiff M , Derman A
Published: June 2004

A bank of gonococcal DNA was constructed in the lambda gt11 expression vector. immunological screening of the bank resulted in the isolation of a clone that contains the structural gene of protein III. In addition, several clones reactive with mAbs specific for the H8 antigen were isolated. DNA hybridization studies revealed that these H8-reactive clones were derived from three different gonococcal genes. When the products produced by these clones were used to absorb antibodies from a rabbit antiserum, and the eluted antibodies were used in immunological studies, it could be shown that the parent gonococcus expressed the product of two of these H8 genes, and in strain R10, these had Mr of approximately 19,700 21,200 respectively. The larger form has not been recognized hitherto because the epitope reactive with the H8 mAb may be masked in this product.
Ia molecule-associated selectivity in T cell recognition of a 23-amino-acid peptide of lysozyme.
Authors: Shastri N , Gammon G , Miller A , Sercarz E E
Published: June 2004

Ak- or Ek-restricted T cells, generated by immunization with a 23-amino-acid peptide of hen egg-white lysozyme (amino acid 74-96), showed a strict correlation between the minimal peptide determinant recognized and the Ia molecule restricting recognition. All Ak-restricted clones obtained from six independently derived lines recognized determinants contained within peptides 74-86, while Ek-restricted clones recognized determinants within 85-96. This correlation was true whether B10.A mice (Ak, Ek) were immunized with peptide 74-96 or with each of the two smaller peptides (74-86 or 85-96). Furthermore, a T cell response could be obtained to peptide 74-86, but not to peptide 85-96 in B10.A (4R) mice, which express only the Ak molecule. Thus, an Ia molecule-associated selectivity exists in the choice of T cell determinants even within this small 23-amino-acid peptide antigen. Significant differences were noted, however, in the boundaries of the minimal peptide determinants recognized within peptide 74-96 by Ak- or Ek-restricted T cells, in comparison to those recognized by Ab-restricted T cells. These results indicate that interaction of the same peptide with distinct Ia molecules results in recognition of unique aspects of the antigenic determinants by the T cell receptor.
Herpesvirus saimiri strain 11 immortalizes a restricted marmoset T8 lymphocyte subpopulation in vitro.
Authors: Kiyotaki M , Desrosiers R C , Letvin N L
Published: June 2004

Herpesvirus saimiri induces a fatal lymphoproliferative syndrome in a variety of New World primate species. We now show that cell lines derived from PBL of the common marmoset by in vitro-immortalization with H. saimiri strain 11 represent a remarkably restricted lymphocyte population. These cell lines have NK cell function, phenotypically express both suppressor/cytotoxic (T8) and NK cell (NKH1)-associated antigens, and express a T cell receptor. This subpopulation of lymphocytes is a very minor population of cells in the peripheral blood of common marmosets (less than or equal to 3%). The specificity in the interaction between H. saimiri strain 11 and a subpopulation of common marmoset lymphocytes represents an example of a restricted viral lymphotropism and may have important implications for the disease induced by this virus in New World monkeys.
Generation of antigen receptor-specific suppressor T cell clones in man.
Authors: Mohagheghpour N , Damle N K , Takada S , Engleman E G
Published: June 2004

We have shown previously that CD8+ T cells proliferate upon exposure to autologous, antigen primed CD4+ T cells, and suppress the response of fresh T cells to the priming antigen but not irrelevant antigens. The stimulus and target of suppression in this system appears to be the antigen receptor on the surface of CD4+ cells, rather than the nominal antigen. In the current study, alloantigen primed CD4+ inducer cells and IL-2-containing medium were used to generate clones of suppressor cells from several individuals. The clones inhibited the response of fresh autologous T cells only to the original allogeneic stimulator cell and to stimulator cells that shared HLA-DR antigens with the priming cell. The clones were also genetically restricted, since they inhibited the response of HLA-A,B-compatible but not HLA-A,B-incompatible individuals. The availability of a method for reproducibly generating antigen receptor-specific suppressor T cell clones in vitro should make it possible to clarify the mechanism, whereby such cells are activated and exert their suppressive effect.
Self-sparing of long-term in vitro-cloned or uncloned cytotoxic T lymphocytes.
Authors: Luciani M F , Brunet J F , Suzan M , Denizot F , Golstein P
Published: June 2004

At least some long-term in vitro-cultured cytotoxic T cell clones and uncloned cell populations are able, in the presence of Con A, to lyse other cells, to be lysed by other cells, but not to lyse themselves. This as-yet-unexplained result may have implications as to the mechanism of T cell-mediated cytotoxicity.
Interaction between anti-DNA and anti-DNA-binding protein autoantibodies in cryoglobulins from sera of patients with systemic lupus erythematosus.
Authors: Reeves W H , Chiorazzi N
Published: June 2004

We have previously shown that sera from some patients with SLE and related disorders contain autoantibodies to a DNA-binding protein complex designated p70/p80. The present study shows that anti-p70/p80 autoantibodies are frequently accompanied by anti-DNA antibodies and cryoglobulins. When the cryoglobulins were isolated, they were found to be specifically enriched in both anti-p70/p80 and anti-DNA activities. The anti-p70/p80 and anti-DNA antibodies were found to be distinct populations of autoantibodies rather than a single crossreactive species, since they could be separated from one another by chromatography on DNA-cellulose. Certain human anti-DNA mAbs could inhibit the binding of autoimmune polyclonal anti-p70/p80 antibodies to p70/p80, suggesting that anti-DNA antibodies might also associate with the variable regions of some anti-p70/p80 antibodies in the cryoglobulins. Binding of one murine anti-p70/p80 mAb (111-12) also was inhibited by certain human anti-DNA mAbs, but the binding of another murine mAb (162-11) to a different epitope of p70/p80 was not. These studies suggest that certain anti-DNA antibodies may interact with the variable regions of a population of anti-p70/p80 antibodies. The cryoglobulins found in the sera containing both anti-p70/p80 and anti-DNA antibodies may represent immune complexes consisting, in part, of idiotype and antiidiotype.
Prevention of diabetes in BioBreeding/Worcester rats with monoclonal antibodies that recognize T lymphocytes or natural killer cells.
Authors: Like A A , Biron C A , Weringer E J , Byman K , Sroczynski E , Guberski D L
Published: June 2004

Diabetes-prone BioBreeding/Worcester (BB/Wor) rats received thrice weekly injections of mAb against antigens expressed on the surface of all T cells (OX19), cytotoxic/suppressor, and NK cells (OX8), helper/inducer cells (W3/25, OX35, OX38), and Ia+ cells (OX6, 3JP, OX17). Treatment with OX8 or OX19 achieved stable reductions of splenic and peripheral blood NK cells and helper/inducer T lymphocytes, respectively, and protected against diabetes. OX19 injections also prevented lymphocytic insulitis, thyroiditis, and the synthesis of autoantibodies to thyroid colloid and smooth muscle antigens. OX8 injections reduced splenic NK-mediated YAC-1 cell lysis, but did not prevent insulitis, thyroiditis, or autoantibody synthesis. Injections of mAb specific for antigens on the surface of helper/inducer cells, and for cells expressing IaE antigens provided marginal protection against diabetes without reductions of phenotypic subsets. These findings suggest that pancreatic beta cell destruction in the spontaneously diabetic BB/Wor rat is mediated by the combined action of NK and helper/inducer cells.
Tumor necrosis factor and lymphotoxin induce differentiation of human myeloid cell lines in synergy with immune interferon.
Authors: Trinchieri G , Kobayashi M , Rosen M , Loudon R , Murphy M , Perussia B
Published: June 2004

We show that the cytotoxins tumor necrosis factor (TNF) or lymphotoxin (LT), at concentrations of approximately 10(-11) M induce monocytic differentiation of human myeloid cell lines. After 5 d of culture in the presence of rTNF and LT, a significant proportion of the myeloid cell lines express monocyte differentiation antigens and ANAE activity, and become able to reduce nitroblue tetrazolium (NBT) and mediate low levels of ADCC against tumor target cells. These markers of differentiation, however, are maximally induced when rIFN-gamma, at concentrations as low as 4 U/ml, is present simultaneously with the cytotoxins, and the two classes of cytokines act synergistically to induce terminal differentiation. The appearance of monocytic antigens is accompanied by acquisition of morphology and other functional properties of mature monocytic cells, such as chemiluminescence and phagocytosis, and by expression of FcR for monomeric IgG. A decrease in cell proliferation accompanies induced differentiation, and is not due to the cytotoxic properties of TNF or LT, as indicated in simultaneous analysis of surface phenotype and cell cycle. The lack of cytotoxicity of TNF on the HL-60 cell line is also demonstrated by the enhancing effect of TNF on HL-60 cell growth and nucleoside uptake in the first 2 d of culture. These data show that the cytotoxins TNF and LT mediate complex effects on cells of the myelomonocytic lineage and, in synergy with IFN-gamma, can fully induce immature myeloid cells to differentiate into cells with phenotypic, functional, and proliferative characteristics of terminally differentiated myelomonocytic cells.
VH gene expression is restricted in anti-IgG antibodies from MRL autoimmune mice.
Authors: Arant S E , Griffin J A , Koopman W J
Published: June 2004

Antibodies directed against IgG and DNA are found in the sera of autoimmune MRL/Mp lpr/lpr mice. Little is known of the molecular mechanisms underlying expression of such autoantibodies. We have investigated the binding diversity and pattern of VH gene expression in a panel of murine anti-IgG antibodies. We constructed eight hybridoma clones secreting IgM antibodies that bound to mouse IgG by using spleen cells from MRL/Mp lpr/lpr mice varying in age from 4 to 15 wk; one clone was derived from a 32-wk-old MRL +/+ mouse. The monoclonal IgM products exhibited varying binding specificities for intact mouse IgG, fragments of mouse IgG [Fc, Fab, (Fab')2], and heterologous IgG. Two of these antibodies crossreacted with B and/or Z DNA. Probes from seven of eight identified mouse VH gene families (7183, S107, Q52, J558, J606, 36-60, and 3609) were hybridized under high-stringency conditions with cytoplasmic RNA blots from each clone. Six clones hybridized only with the probe from the five-member 36-60 family. The remaining three clones crosshybridized with the 36-60 probe and the probe from the 60 member J558 family, perhaps reflecting somatic mutation from the original germline VH gene resulting in recognition by a probe from another family, in addition to the probe from the original germline family. Our results indicate that spontaneous MRL lpr/lpr anti-IgG antibodies are encoded predominantly by the 36-60 VH gene family and imply a nonrandom selection of this VH gene family in the production of these antibodies.
Peptides as antigens. Importance of orientation.
Authors: Dyrberg T , Oldstone M B
Published: June 2004

Factors known to be important in producing protein-reactive peptide antibodies include the accessibility of the region from which the peptide sequence is derived, the hydrophilic-phobic character of the sequence, and the length of the peptide. The data presented here indicate that the orientation of the peptide coupled to a carrier protein also influences the binding pattern of peptide antibodies. An octapeptide, representing a sequence from the alpha chain of the human acetylcholine receptor, was coupled either through an N- or C-terminal cysteine-glycine-glycine linker to a carrier protein and used to immunize rabbits. The resulting antisera reacted at comparable titers to the uncoupled immunizing peptides, but did not crossreact with the identical but opposite-linked peptide. Characterization of the binding to other homologous peptides showed that immunization with the N-terminal-linked peptide induced antibodies reactive specifically with the C-terminal amino acid(s). Immunization with the C-linked peptide resulted in antibodies reactive with a site of the peptide near the C-terminus.
Nonhematopoietic cells selected for resistance to tumor necrosis factor produce tumor necrosis factor.
Authors: Rubin B Y , Anderson S L , Sullivan S A , Williamson B D , Carswell E A , Old L J
Published: June 2004

TNF-resistant lines of L cells can be derived from TNF-sensitive populations by repeated exposure to TNF, and these resistant L cells, in contrast to sensitive L cells and other types of cells, lack demonstrable cell surface receptors for TNF. We have now found that TNF-resistant L cells produce a factor that is cytotoxic for L cells and has the following distinguishing characteristics of mouse TNF: it is a protein of 43 kD, composed of 16 kD subunits, that competes with TNF for receptor binding, induces hemorrhagic necrosis of the TNF-sensitive mouse sarcoma Meth A, has synergistic cytotoxic action with interferon, and its activity is neutralized by antibody to TNF. The two conclusions of this study are that cells selected for TNF resistance spontaneously produce a molecule resembling macrophage TNF, and that cells of nonhematopoietic origin are capable of producing TNF.
Expression of a monoclonal antibody-defined, B-lineage transformation antigen specifically identifies Abelson-diseased animals. Genetically determined resistance to Abelson murine leukemia virus acts before induction of gp160(6C3).
Authors: Tidmarsh G F , Dailey M O , Weissman I L
Published: June 2004

Mice genetically susceptible or genetically resistant to the leukemogenic effects of A-MuLV(Mo) were tested for their expression of the B-lineage neoplastic transformation-associated antigen, 6C3Ag. Genetically resistant inbred strains and recombinant inbred lines developed neither cells expressing high levels of 6C3Ag (6C3Aghi) in their hematolymphoid tissues nor Abelson leukemias. Genetically susceptible inbred strains and recombinant inbred lines developed high percentages of 6C3Aghi hematolymphoid cells concomitant with development of Abelson leukemias and lymphomas. Thus the genetically-determined resistance to A-MuLV(Mo) leukemogenesis appears to act at some step(s) after virus infection but before the stage of malignant progression, which is marked by 6C3Ag expression.
Cachectin/tumor necrosis factor mediates changes of skeletal muscle plasma membrane potential.
Authors: Tracey K J , Lowry S F , Beutler B , Cerami A , Albert J D , Shires G T
Published: June 2004

Lethal infections are associated with cellular dysfunction as evidenced by a decrease in the resting transmembrane potential difference (Em) of skeletal muscle fibers. Endotoxin stimulation of macrophages evokes production of cachectin, a protein that has been implicated as a mediator of the lethal effects of endotoxemia. In the present study, rat skeletal muscle fiber Em decreased when incubated with recombinant human cachectin. The reduction of Em induced by cachectin occurred in a dose-related fashion and was inhibited by mAb against the monokine. Infusion of cachectin induced a decline of skeletal muscle Em in vivo, and suggests that cachectin may acutely mediate alterations of skeletal muscle membrane function after infection.
Polyspecificity of antistreptococcal murine monoclonal antibodies and their implications in autoimmunity.
Authors: Cunningham M W , Swerlick R A
Published: June 2004

mAbs produced by immunization of BALB/c mice with Streptococcus pyogenes M type 5 membranes were further characterized for their reaction with S. pyogenes pep M5 protein and with autoantigens associated with human cell lines. mAbs 36.2.2 and 54.2.8 simultaneously reacted with M protein and a membrane protein(s) of S. pyogenes. When cell lines were mixed with 54.2.8, we saw nuclear fluorescence along with staining of the cytoskeleton. Subsequent experiments revealed that 54.2.8 was an anti-DNA antibody that reacted with DNA, poly(I), poly(dT), and weakly with cardiolipin. Its reactivity with the cytoskeleton could be blocked with anti-vimentin. On the other hand, 36.2.2 reacted with the cytoskeleton, sparing the nucleus, and was inhibited by the alpha helical proteins myosin, actin, and keratin. mAb 54.2.8 was inhibited with myosin, but not with actin and keratin. None of the antibodies studied were inhibited by collagen, and none of them were rheumatoid factors. The results imply that Group A streptococci can activate B cell clones against myosin, alpha helical proteins, or DNA, thereby contributing to the enhancement of autoantibody production.
Persistence of chronic myelocytic leukemia despite deletion of rearranged bcr/c-abl sequences in blast crisis.
Authors: Bartram C R , Janssen J W , Becher R , de Klein A , Grosveld G
Published: June 2004

We report on a Ph+ chronic myelocytic leukemia (CML) case, cytogenetically characterized by the occurrence of a second Philadelphia (Ph) chromosome in lymphoid blast crisis of T cell lineage. In situ hybridization analyses showed a deletion of translocated c-abl sequences, present on the Ph during chronic state, from both Ph in acute state. Moreover, Southern blot analyses of blastic cells exhibited a rearrangement within bcr, but a deletion of 5' bcr sequences, and Northern blots failed to detect the hybrid 8.5 kb bcr/c-abl transcript usually observed in Ph+ CML.
Subcellular location and properties of bactericidal factors from human neutrophils.
Authors: Gabay J E , Heiple J M , Cohn Z A , Nathan C F
Published: June 2004

We examined the subcellular location of bactericidal factors (BF) in human neutrophils, using an efficient fractionation scheme. Nitrogen bomb cavitates of DIFP-treated PMN were centrifuged through discontinuous Percoll gradients, each fraction extracted with 0.05 M glycine, pH 2.0, and tested for the killing of Escherichia coli. greater than 90% of BF coisolated with the azurophil granules. After lysis of azurophils, 98% of azurophil-derived BF (ADBF) sedimented with the membrane. ADBF activity was solubilized from azurophil membrane with either acid or nonionic detergent (Triton X-100, Triton X-114). Bactericidal activity was linear with respect to protein concentration over the range 0.3-30 micrograms/ml. 0.1-0.3 microgram/ml ADBF killed 10(5) E. coli within 30 min at 37 degrees C. At 1.4 micrograms/ml, 50% of 2 X 10(5) bacteria were killed within 5 min. ADBF was effective between pH 5-8, with peak activity at pH 5.5. Glucose (20 mM), EDTA (1-25 mM), and physiologic concentrations of NaCl or KCl had little or no inhibitory effect on ADBF. ADBF killed both Gram-positive and Gram-negative virulent clinical isolates, including listeria, staphylococci, beta-hemolytic streptococci, and Pseudomonas aeruginosa. Thus, under these conditions of cell disruption, fractionation, extraction, and assay, almost all BF in human PMN appeared to be localized to the membrane of azurophilic granules as a highly potent, broad-spectrum, rapidly acting protein(s) effective in physiologic medium. Some of these properties appear to distinguish ADBF from previously described PMN bactericidal proteins.
Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain.
Authors: Miller J , Germain R N
Published: June 2004

The intracytoplasmic forms of class II (or Ia) major histocompatibility complex heterodimers are associated with a third glycoprotein, termed the invariant chain (Ii). This specific interaction has led to the view that Ii plays a necessary role in the assembly, intracellular transport, and/or membrane insertion of Ia molecules. To test this hypothesis directly, we have transfected complementary DNA clones that encode murine class II alpha and beta chains into cells that do not express any endogenous Ii messenger RNA (mRNA) (COS-7 and BALB/c 3T3 cells). After DNA-mediated gene transfer, significant cell surface expression of Ia was observed in transient expression assays using COS-7 cells and a stable expression system using BALB/c 3T3 cells. Furthermore, the total levels of class II alpha and beta mRNA were similar in Ii- cells (transfected BALB/c 3T3) and in Ii+ cells (B cell hybridoma) that expressed nearly identical amounts of surface Ia, suggesting that the efficiency of Ia expression was equivalent in the two cell types and, therefore, independent of Ii. These results indicate that the physiologic role for Ii is not simply to mediate membrane expression of Ia molecules, and that alternative hypotheses concerning the true function of this molecule need to be considered.
Extracellular matrix-modulated expression of human cell surface glycoproteins A42 and J143. Intrinsic and extrinsic signals determine antigenic phenotype.
Authors: Rettig W J , Murty V V , Mattes M J , Chaganti R S , Old L J
Published: June 2004

We have used serologic, biochemical, and genetic methods to characterize two stage-specific human differentiation antigens of neural and melanocytic cells: A42 (57,000 Mr glycoprotein) and J143 (140,000/30,000 Mr glycoprotein). The genes determining A42 and J143 cell surface expression in rodent-human hybrids were chromosomally mapped, and the respective human chromosomes were introduced into rodent cells derived from distinct differentiation lineages. Serologic analysis of the resulting hybrid clones has permitted the identification of two types of regulatory signals determining A42 and J143 expression. First, both antigens are expressed in hybrids constructed with antigen-positive human cells and also in certain hybrids constructed with antigen-negative human cells, indicating that intrinsic signals provided by the differentiation program of the rodent fusion partner induce antigen expression. Second, a series of human-mouse neuroblastoma hybrids, which are A42- or J143- when cultured on plastic surfaces, can be induced to express the antigens when cultured on substrates coated with extracellular matrix (ECM) produced by bovine corneal endothelial cells or fibronectin. This induction of antigen expression by extrinsic, ECM-derived signals is accompanied in the neuroblastoma hybrids by increased substrate adhesiveness and cell spreading and by characteristic changes in cell morphology. A similar program of phenotypic changes is also seen in spontaneous variants of human neuroblastoma and Ewing's sarcoma cells and in ECM-induced Ewing's sarcoma cells. These findings suggest that ECM-derived signals have a role analogous to mitogens and soluble differentiation factors in modulating differentiation phenotypes and tissue-specific patterns of cell surface antigen expression.