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S T Ju

Publications and source records attributed to S T Ju.

At least 73 records · Page 4Linked to original sources
PubMed1986

Genetic analysis of low lambda 1 chain production in mice.

Several commonly used strains of laboratory mice from Charles River Laboratories were found to produce extremely low or undetectable levels of serum immunoglobulins bearing lambda 1 light chain (lambda 1 Ig). Individual CF-1, CD-1, and CFW random-bred mice were tested for serum lambda 1 levels, lambda 1-specific anti-NP responses, and genomic polymorphisms at the lambda 1 locus. In all cases, a complete correlation among these parameters was observed. The results indicated that nearly all CFW, greater than 70% of CD-1 but none of the CF-1 mice produced low levels of lambda 1 light chain. The low lambda 1 Ig production is due to a genetic defect either similar or identical to that observed in SJL mice. The data suggest that the lambda 1 locus of CD-1, CFW, and SJL mice are derived from a common ancestor. We also surveyed lambda 1 Ig production in a series of wild mice. Mice producing low lambda 1 Ig were frequently observed. The wild mice with low lambda 1 Ig levels were captured in diverse geographic areas, including Europe, Middle East, Asia, and South America. Preliminary study suggests that the defect in the wild mice is different from that of SJL, CD-1, or CFW mice and implies that other mechanisms regulate lambda 1 Ig production in wild mice.

Animal Population Groups↗
PubMed1986

Inducer T-cell-mediated killing of antigen-presenting cells.

L3T4+ inducer/helper T-cell clones, once activated by antigen-presenting cells (APC) expressing the appropriate Ia allele and antigen, autonomously kill their target APC. All 13 L3T4+ inducer T-cell clones tested demonstrated this cytolytic activity. In addition, 11 different target cells representing the three major APC types, namely, macrophages, B cells, and dendritic cells, were all sensitive to this cytolytic activity. Moreover, normal macrophages which were treated with interferon-gamma to increase Ia expression were also killed. These observations convincingly demonstrate that the cytolytic activity of L3T4+ inducer T-cell clones is a general phenomenon. In contrast to other reports, lysis of target APC could not be detected following 4-6 hr of incubation. Marginal lysis was observed after 9 hr and a 20-hr incubation period was required to achieve maximal killing. The kinetics of killing paralleled other parameters of T-cell activation such as IL-2 release and cell proliferation. Activation of T cells for cytolysis of APC requires the interaction of T-cell receptors with Ia and antigen. Monoclonal antibody to Ia, L3T4 and the T-cell receptor inhibited the cytolysis of APC. The ability to mediate nonspecific bystander killing was variable depending on both the T-cell clone and the target. The implications of these findings to immune regulation and autoimmunity are discussed.

Animals↗
PubMed1986

Lack of isotype exclusion and expression of aberrant lambda light chain on secreted MOPC-315 myeloma proteins.

The presence of aberrant lambda 1 light (L) chain fragment (lambda 1 F) on the secreted myeloma protein of MOPC-315 has been demonstrated by serological and immunochemical methods. We developed a highly sensitive radioimmunoassay that utilizes exquisitely specific xenogeneic anti-lambda 1 antibodies to detect the minute amounts of lambda 1 F on lambda 2-bearing MOPC-315 myeloma proteins. In addition, structural evidence that lambda 1 F is present on MOPC-315 myeloma protein was demonstrated by subjecting 125I-labeled MOPC-315 myeloma protein to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions followed by autoradiography. The relative amounts of lambda 1 F and lambda 2-chain on MOPC-315 myeloma were measured by two independent methods. The molar ratio of lambda 1 F to lambda 2 was calculated to be 1:68 by radioimmunoassay and 1:80 by analytical SDS-PAGE. This represents the first demonstration that an aberrant L-chain fragment combines with a heavy chain and is secreted in association with antigen-binding myeloma proteins. The implications of these results on L-chain isotype exclusion are discussed.

Animals↗
PubMed1985

Functional analysis of macrophage hybridomas. II. Antibody-independent tumor cytotoxicity and its dissociation from IL-1 production and Ia expression.

Cloned macrophage hybridoma cells derived from fusions between splenic adherent cells of CKB mice and the drug-marked P388D1 cell line were studied to further understand macrophage-mediated tumoricidal activity at the clonal level. Most of the macrophage hybridomas were specifically activated by a combination of lymphokine and lipopolysaccharide (LPS), but were not activated by either agent alone. There is no apparent correlation between macrophage-mediated tumor cytotoxicity and the ability of LPS to induce interleukin 1 (IL-1) secretion or of concanavalin A (Con A) supernatants containing interferon-gamma to increase H-2 and Ia expression. Thus, one hybridoma clone which was unable to kill tumor cells was still sensitive to LPS and lymphokine activation by the latter criterion.

Animals↗
PubMed1985

Functional analysis of macrophage hybridomas. III. Inhibition of lymphocyte blastogenesis and tumor proliferation.

Four cloned macrophage hybridoma cells prepared by fusion of splenic adherent cells with a P388D1 macrophage tumor markedly inhibited the growth of lymphocytes and tumor cells. Macrophage clones 5, 8, 63, and 64 are strong inhibitors of B-cell blastogenesis, T-cell blastogenesis, and tumor proliferation, while the P388D1, tumor line and clones 13, 59, and 67 demonstrated little inhibitory activity in all three systems. The inhibitory effect of macrophage hybridomas can be detected within 8 hr, although greater inhibition was noted following longer incubation. The correlations among these three assay systems suggest that similar mechanisms may be involved. The data indicate that the inhibition of cell proliferation was not due to cell lysis. Furthermore, the inhibition of lymphocyte proliferation in Con A-stimulated cultures was not accompanied by inhibition of lymphokine production in the same cultures. Neither prostaglandins nor hydrogen peroxide appear to be primarily responsible for growth inhibition. The inhibitory properties of these macrophage hybridoma lines represent a stable phenotype and provide a homogeneous source of cells for further analysis of the phenomenon.

Animals↗
PubMed1985

Variable regions of antibodies to synthetic polypeptides--I. Characterization of an idiotope expressed on antibodies and T-cell factors.

Spleen cells from a Lewis rat immunized with affinity-purified B10 anti-(T,G)-A-L antibody were fused with the non-secreting murine hybridoma SP2/0. Cell lines secreting monoclonal antibodies specific for mu- and kappa-chains, as well as an idiotope on anti-(T,G)-A-L antibodies, were isolated and characterized. The anti-mu and -kappa antibodies, are true anti-isotypes, reacting with sera from all strains of mice tested. The anti-idiotope antibodies recognize a determinant on antibodies binding a GT-containing epitope. The proportion of anti-GAT antibody bearing the idiotope varies markedly in different murine strains. A 1000-fold higher level of antibody from Igha mice than from Ighb and Ighe mice is required to give an equivalent inhibition of the idiotope-anti-idiotope reaction. Analysis of monoclonal antibodies expressing the idiotope indicates that the affinity of binding between idiotope and anti-idiotope can vary by as much as two orders of magnitude. Immunoadsorbants prepared with anti-idiotope antibody bind suppressor factor secreted by a GAT-specific T-cell hybridoma.

Animals↗
PubMed1985

Functional analysis of cloned macrophage hybridomas. IV. Induction and inhibition of mixed lymphocyte responses.

A series of macrophage (M phi) hybridomas were generated by fusion of drug-marked P388D1 (H-2d) tumor cells with CKB (H-2k) splenic adherent cells. The ability of this panel of cloned M phi hybridomas expressing various levels of surface Ia antigens to induce allogeneic mixed lymphocytes responses (MLR) was examined. All MLR stimulatory M phi hybridomas expressed surface Ia antigens. However, some Ia+ and all Ia- M phi hybridomas were unable to induce vigorous MLR responses. Furthermore, even after induction of surface Ia antigen expression with Con A supernatants (Con A Sn) or purified interferon-gamma, the nonstimulatory M phi hybridomas remained ineffective at inducing strong MLR proliferative responses. Furthermore, addition of the latter M phi hybridoma clones (both with and without Con A Sn treatment) to conventional MLR cultures resulted in inhibition of MLR responses. The series of inhibitory M phi hybridomas secreted normal levels of IL 1 upon stimulation with lipopolysaccharide. After surface Ia induction with Con A Sn, the inhibitory M phi hybridomas could stimulate secretion of IL 2 and expression of IL 2 receptors. Moreover, although they inhibited conventional MLR responses, IL 2 production and IL 2 receptor expression were not significantly inhibited. Addition of these M phi hybridomas 24 to 48 hr after initiation of MLR response also inhibited MLR proliferation. The results indicated that the group of inhibitory M phi hybridomas can inhibit MLR responses after IL 2 secretion and acquisition of IL 2 receptors. Finally, this inhibitory activity has been maintained during 1 yr of continuous in vitro culture, and the hybridomas represent a stable "homogeneous" subpopulation of inhibitory macrophages. Thus, the inhibitory phenotype appears to reflect arrest at a distinct differentiation stage.

Animals↗
PubMed1984

Effects of V lambda gene diversity on generation of antigen-specific lymphocytes.

Previous studies have shown that dextran B1355 (DEX)- and (4-hydroxy-3-nitrophenyl) acetyl (NP)-coupled antigens triggered, respectively, BALB/c and C57BL/6 (B6) lymphocytes in which the V lambda 1 gene and a specific VH gene (VHDEX and VHNPb) have functionally rearranged. In this paper, we studied whether the closely-related V lambda 2 gene can be utilized in association with these VH genes to generate antigen-specific lymphocytes. We found that the VHDEX gene was restrictedly utilized by the V1 lambda 1 gene to generate anti-DEX lymphocytes, and in contrast, both the V lambda 1 and V lambda 2 genes were utilized together with a VHNPb germline gene to form anti-NP lymphocytes. Southern blot and DNA sequencing of an anti-NP hybridoma confirmed that the germline form of the (186-2) VHNPb gene can be used in association with either the V lambda 1 or V lambda 2 genes.

Animals↗
PubMed1984

The expression of idiotypic determinants on suppressor T cells is independent of T cell Igh genotype.

To investigate the role played by immunoglobulins in the display of idiotope-like determinants by T cells, we investigated whether T cells transferred to congenically athymic mice would display the idiotypes of the nude host or of the T cell donor Igh genotype. 4-Hydroxy-3-nitrophenyl hapten (NP)-specific first-order suppressor T cells (Ts1) from Ighb-bearing mice display the NPb idiotype. Mature peripheral T cells from Igh congenic mice were used for reconstitution of nude mice in acute transfers. Before analyzing the idiotypic properties of the T cells in this system, we verified, using Thy-1 congenic strains, that the suppressor T cells induced were effectively derived from the transferred T cells and not from the host. The following strains of mice were selected for these studies: C57BL/6 (Ighb), B6.Ighn, and C57BL nu/nu. The NP-specific suppressor T cells generated in C57BL nu/nu mice reconstituted with T cells derived from Igh congenic B6.Ighn donors were investigated. Suppressor T cells were induced by i.v. administration of 10(4) NP-coupled B6.Ighn adherent cells. Six days later, the spleen cells from the reconstituted nude mice were treated with anti-NPb antibodies and complement before being transferred to C57BL/6 recipients immediately prior to antigen priming. Treatment with anti-idiotypic reagents depleted suppressor cell activity, which indicates that the suppressor cells obtained from C57BL/6 mice or C57BL nu/nu mice that have been reconstituted with B6.Ighn T cells bear NPb idiotype-related determinants. The data further demonstrate that the idiotype-related determinants expressed on NP-specific Ts1 are controlled not by the Ighn genotype of the T cell donor, but by the genotype of the C57BL nu/nu (Ighb) recipient host. In agreement with these findings, we further verified that the NP-specific suppressor T cells generated in C57BL nu/nu mice reconstituted with B6.Ighn mature T cells display the operational Igh restrictions of C57BL/6 mice and not of B6.Ighn mice. These experiments demonstrate how idiotypic elements expressed on the immunoglobulins of the host influence the specificity of the antigen receptor on T cells. Normally, Ts1 from B6.Ighn mice lack the NPb idiotype-related determinants and their suppressive activity is operationally restricted by the Ighn allotype. However, mature B6.Ighn T cells selected to respond to NP in C57BL nu/nu recipients display idiotype-related determinants and restriction specificities characteristic of the C57BL (Ighb) host. Thus, the environment in which Ts1 are induced and selected affects the Ts1 repertoire. How can we account for this phenomenon?

Animals↗
PubMed1984

Immunoselection of B cell hybridomas with anti-idiotypic antisera to study the role of heavy and light chains for idiotype expression and antibody activity.

Conventional reconstitution experiments with heavy (H) and light (L) offins of hybridoma anti-poly-(Glu60Ala30Tyr10) (anti-GAT) antibodies demonstrated that H and L chains are required for efficient expression of anti-GAT activity and the previously defined common CGAT idiotype. On the basis of this observation, we treated a CGAT+ hybridoma cell line (F9.195.6), which was produced by fusion with an MOPC 21 (gamma 1, K) secretor line, with anti-CGAT idiotypic antibodies plus complement to select CGAT-variants. Such treatment greatly enhanced the frequency of isolating hybridoma variants. Molecules secreted from these variants bear anti-GAT mu-chain and MOPC 21 L chain (as judged by serology and Southern blot studies), lack GAT binding activity and CGAT idiotype, and exhibit a "new" private idiotype (E8). Anti-private idiotypic sera were successfully used to select a series of CGAT+, E8- clones that secrete molecules bearing only the appropriate anti-GAT mu- and K chains. From E8- hybridoma supernatants, CGAT- molecules bearing MOPC 21 H chain and anti-GAT L chain could be obtained. The data indicate that immunoselection of hybridoma clones with anti-idiotypic antibodies is a convenient means of preparing reconstituted antibody molecules. Furthermore, the data demonstrate that CGAT idiotype determinants are expressed on antibody molecules composed of appropriate H and L chains.

Animals↗
PubMed1984

Preferential induction of specific lambda-isotypic antibodies in mice.

A high proportion (greater than 40%) of lambda-anti-NP antibodies were induced after the administration of hapten conjugates of the relatively T-independent antigen NP-Ficoll. In 11 of 12 strains, lambda 1 anti-NP antibodies were the predominant isotype. In lambda 1-defective SJL mice, lambda 2,3 anti-NP antibodies were the major species after NP-Ficoll immunization. In contrast, the ability to elicit a high proportion of lambda-anti-NP antibodies with the T-dependent conjugate of ovalbumin, NP-OVA, varied among mouse strains. Igh-1b-bearing mice were high producers of lambda 1 anti-NP antibodies (greater than 70% of the response); DBA/2 and BALB/c mice were moderate (40 to 50%) lambda 1 anti-NP producers, and A.TL, AKR, NZB, and C3H mice were low lambda 1 anti-NP producers (less than 10%) after primary NP-OVA immunization. In the latter group, NP-OVA preferentially elicits kappa-bearing anti-NP antibodies. The parameters that influence the distribution of light chain isotypes were investigated. The preferential induction of lambda-anti-NP antibodies with NP-Ficoll was a) partially influenced by Igh-linked genes, b) adjuvant independent, and c) maintained on prolonged immunization. In contrast, induction of a high proportion of kappa-anti-NP antibodies by NP-OVA is (a) strictly regulated by Igh-linked genes and (b) enhanced after hyperimmunization. The immunochemical, genetic, and cellular bases for these observations are discussed.

Adjuvants, Immunologic↗
PubMed1983

Structural bases for public idiotypic specificities of monoclonal antibodies directed against poly(Glu60Ala30Tyr10) and poly(Glu60Ala40) random copolymers.

NH2-terminal amino acid sequences of heavy and light chains of seven poly(Glu60Ala30Tyr10) (GAT) specific hybridoma products derived from DBA/2 and (DBA/2 X BALB/c)F1 hybrid mice and those of BALB/B polyclonal antibodies have been determined over the first 40 residues. Comparison of these sequences with those of nine other GAT or poly(Glu60Ala40) (GA) specific hybridoma products previously reported allowed the following conclusions. (i) Sequences of hybridoma H and L chains are present in the pool of polyclonal antibodies. (ii) The public CGAT (or pGAT) idiotypic specificities are strictly confined to antibodies exhibiting limited heterogeneity with regard to both the variable heavy (VH) and the variable kappa (V kappa) sequences that may be accounted for by one and two germ-line genes, respectively. (iii) The public idiotypic specificities GA-1, expressed by some anti-GAT and most anti-GA antibodies, make use of the same (or similar) VH germ-line genes as the CGAT or pGAT antibodies but possess a distinctive V kappa sequence. (iv) Antibodies expressing neither of the alternative public specificities mentioned above appear to be more heterogeneous and express VH and V kappa sequences that were found to differ from the basic structures defining the CGAT (pGAT) or GA-1 correlates. It is concluded that CGAT (or pGAT) and GA-1 public idiotypic specificities are germ-line markers of both VH and V kappa regions, an observation in agreement with previously reported serological data.

Animals↗
PubMed1983

Regulation of immune responses by I-J gene products. III. GT-specific suppressor factor is composed of separate I-J and idiotype-bearing chains.

Injection of poly(Glu50Tyr50)(GT) into B10.BR (H-2k) mice induces GT-specific suppressor T cells and a T cell-derived suppressor factor (TsF1), which in turn induces a second-order suppressor T cell (TS2). In the present study, we show that B10.BR GT-TSF1 is composed of separate I-Jk and idiotype-bearing chains linked by disulfide bond(s). Functional suppressive activity requires both chains to be in association. Neither chain alone can induce TS2, indicating that both chains must be seen in association and suggesting a single cellular target for the two chains. Experiments designed to interchange I-J-bearing chains of GT-TSF1 derived from different H-2 haplotypes indicate that only the homologous I-J and idiotype-bearing chains can reassociate into a suppressive moiety. These experiments may imply heterogeneity of I-J region gene products.

Alkylation↗
PubMed1982

Idiotypic analysis of hybridoma antibodies to branched synthetic polymer (Tyr, Glu)-Ala-Lys: idiotypic relationship with antibodies to linear random polymer (Glu60, Ala30, Tyr10).

The expression of three anti-GAT idiotypes, CGAT, Gte, and GA-1, on 17 C57BL/10 and four C3H.SW hybridoma anti-(T,G)-A--L antibodies was analyzed. These hybridoma anti-(T,G)-A--L antibodies exhibited two patterns of fine antigen binding specificity. The majority of the hybridoma antibodies bound the (T,G)-A--L, GT, and GAT polymers but not the GA polymer, and were designated as GT-reactive hybridoma antibodies. A minor population of hybridoma anti(T,G)-A--L antibodies bound to (T,G)-A--L but not to GT, GAT, or GA, i.e., (T,G)-A--L-specific. A complete correlation between fine antigen binding pattern and the expression of CGAT idiotype was demonstrated. None of the 21 hybridoma anti-(T,G)-A--L antibodies expressed the GA-1 idiotype. All of the GT-reactive and none of the GT-nonreactive hybridoma anti-(%,G)-A--L antibodies expressed the CGAT idiotype. Furthermore, the Gte idiotype was found on the majority of CGAT+-bearing C57BL/10 hybridoma anti-(T,G)-A--L antibodies. These results indicate that C57BL/10 anti-(T,G)-A--L antibody repertoire can be grouped into a minimum of three families; i.e., CGAT+ Gte+, CGAT+ Gte-, and CGAT- Gte- families, with the CGAT+ Gte+ family as the major compartment. This is confirmed by the high percentage idiotype binding of serum anti-(T,G)-A--L antibodies with anti-CGAT idiotypic antisera. Finally, anti-idiotypic antisera made against CGAT+ hybridoma anti-GAT or anti-(T,G)-A--L antibodies crossreact extensively with other CGAT+ hybridoma anti-GAT and anti-(T,G)-A--L antibodies. However, additional experiments demonstrated that CGAT+ hybridoma anti-(T,G)-A--L antibodies also possess private idiotypes.

Animals↗
PubMed1981

A common idiotype on SJL and C57BL/6 anti-(4-hydroxy-3-nitrophenyl) acetyl antibodies and its relationship with lambda chain production.

Hybridoma cell lines secreting antibodies specific to (3-nitro-4-hydroxyphenyl) acetyl (NP) were generated by fusion of NP-immunized SJL spleen cells with the SP2/0 cell line. One hybridoma (N-hybridoma) anti-NP antibody (mu, lambda2) was found to partially inhibit (35-40%) the binding of the predominant idiotype in primary C57BL/6 anti-NP antibodies (NPb). Iodinated hybridoma antibody could be completely bound with anti-idiotypic antiserum made against either specifically purified C57BL/6 anti-NP antibodies, SJL anti-NP antibodies, or N-hybridoma antibody. The idiotypic specificities defined with anti-idiotypic antiserum made against N-hybridoma antibody were termed NP-1 idiotype. Strain distribution and genetic mapping studies indicate that the gene(s) controlling the production of NP-1 idiotype is closely associated with Igh-1b and Igh-1e alleles and mapped within the same chromosomal segment that controls the synthesis of NPb idiotype. However, unlike NPb idiotype, the expression of NP-1 idiotype is not influenced by the gene(s) that control lambda1 chain synthesis. Thus, SJL mice that produce low or undetectable levels of NPb idiotype due to a defect in lambda1 chain production express high levels of NP-1 idiotype. Specifically purified C57BL/6 and SJL anti-NP antibodies fully express NP-1 idiotype, the level of which correlates with the level of lambda2 chain-bearing molecules. Nonetheless, further experiments indicate that lambda1-bearing anti-NP antibodies can express extremely weak NP-1 idiotypic cross-reactivity.

Animals↗
PubMed1981

Hapten-specific T cell responses to 4-hydroxy-3-nitrophenyl acetyl. XII. Fine specificity of anti-idiotypic suppressor T cells (Ts2).

The fine specificity of anti-idiotypic, effector-phase suppressor T cells (Ts2) induced by the intravenous injection of syngeneic spleen cells covalently coupled with the 4-hydroxy-3-nitrophenyl acetyl (NP) hapten was studied in an in vitro plaque-forming cell system. By comparing the ability of these suppressor cells to bind monoclonal anti-NP antibodies that express different levels of serologically detected NPb idiotypic determinants, it was shown that anti-idiotypic suppressor T cells do not recognize the predominant NPb idiotypic determinants that are defined by serologic analysis. The implications for the possible expression and/or recognition of different sets of idiotypic determinants on T and B cells are discussed.

Animals↗
PubMed1981

Hapten-specific T cell responses to 4-hydroxy-3-nitrophenyl acetyl. VII. Idiotype-specific suppression of plaque-forming cell responses.

The ability of suppressor cells induced by the intravenous administration of 4-hydro-3-nitrophenyl acetyl (NP)-modified syngeneic cells to reduce an idiotypic B cell response was studied in both an in vivo and an in vitro system. Idiotype-positive B cells were assayed by the ability of guinea pig anti-idiotypic antiserum to specifically inhibit idiotype-positive plaque formation. It was found that up to 57% of the PFC response in vivo and 100% of the PFC response in vitro was inhibitable with antiidiotypic antiserum. The expression of these idiotype-positive B cells could be suppressed by the transfer of spleen cells form mice treated 7 d previously with NP coupled syngeneic cels. T cells are both required and sufficient for the transfer of idiotype specific suppression. The induction of these idiotype-specific T suppressor cells directly with antigen suggests that recognition of unique determinants on cell surfaces is important for regulation of lymphoid cell interactions. The role of idiotype-specific suppressor cells in the network of lymphoid interactions is discussed.

Animals↗