bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross-reactive recognition of mouse cells expressing the bm3 and bm11 mutations within H-2Kb by H-2Kb-restricted herpes simplex virus-specific cytotoxic T lymphocytes.
Authors: Jennings S R
Published: December 2022

Cytotoxic T lymphocytes, generated in C57BL/6 mice in response to herpes simplex virus type 1 (HSV) and known to be restricted in their recognition of HSV-encoded antigen(s) in association with the class I H-2Kb gene product, were consistently found to contain a subpopulation that recognized and lysed uninfected, SV40-transformed cells that expressed the H-2Kbm3 and H-2Kbm11 mutant class I gene products on their cell surface. The mutant cell lines, designated Lgbm3SV and Kbm11SV, share a common amino acid substitution at position 77, with the bm3 mutation having an additional amino acid substitution at position 89. Cross-reactive lysis was observed only after in vivo priming with HSV, suggesting an important role for an antigen-dependent driving step in the expansion of these cross-reactive CTL. The phenotype of the cross-reactive effector population was further confirmed as a T lymphocyte by negative-selection techniques. Limiting dilution analysis of the frequency of cross-reactive CTL precursors suggested that cross-reactivity was mediated by a subpopulation of HSV-specific CTL, and this was confirmed by clonal analysis of the reactivity patterns of short-term, HSV-specific CTL clones. However, analysis of the specificity of the cross-reactive CTL population by cold-target inhibition of bulk culture-derived CTL, or by Spearman ranking analysis of limiting dilution-derived CTL, indicated that the specificity of the cross-reactive population for HSV-infected H-2b target cells and for uninfected bm3 or bm11 target cells was quite distinct. These findings suggested that the cross-reactive CTL population played little, if any, role in the HSV-specific CTL response as measured in vitro. The findings also suggested that the HSV-specific CTL clones able to mediate cross-reactive recognition of the bm3 and bm11 targets had a higher intrinsic avidity for the foreign target than for the inducing antigen.
Anti-T cell immunotoxins containing pokeweed anti-viral protein: potential purging agents for human autologous bone marrow transplantation.
Authors: Ramakrishnan S , Uckun F M , Houston L L
Published: December 2022

The ex vivo anti-leukemic efficacy and stem cell toxicity of two different T cell directed immunotoxins containing pokeweed antiviral protein (PAP) were studied by clonal assays. 5E9-11-PAP, an immunotoxin directed against human transferrin receptors, elicited a maximum leukemic cell kill of 3.9 logs. However, it was also toxic against normal pluripotent stem cells, and therefore is not a clinically useful purgative reagent. PAP conjugated to 3-A1, a monoclonal antibody directed against CD7 (T, p41), was more effective against leukemic T cells than 5E9-11-PAP and eliminated a maximum of 4.8 log of cells. 3A1-PAP was only slightly toxic to pluripotent stem cells: 13% of CFU-GEMM were lost after treatment with 3000 ng of 3A1-PAP/ml, a concentration that eliminated 99.96% of contaminating leukemic T cells from a 200-fold excess of normal bone marrow. Cryopreservation of treated cells by conventional methods did not affect the extreme selectivity and potency of 3A1-PAP. Incubation of 3A1-PAP with peripheral blood mononuclear cells resulted in the complete inhibition of phytohemagglutinin-induced mitogenic response, illustrating the possibility of using this immunotoxin as a potent anti-T cell reagent for prophylaxis against graft vs host disease in allogeneic BMT as well.
The sites of antigen-T cell and antigen-MHC interactions overlap.
Authors: Hansburg D , Appella E
Published: December 2022

The immune responses of B10.A and B10.A(3R) strains of mice to a synthetic variant of moth cytochrome c 86-103 were compared, and an immune response difference between the two strains was found. When T cell hybridomas were made from both strains it was found that the responsive T cells showed degenerate MHC restriction. The hybridomas from B10.A(3R) mice consistently showed a specificity pattern, when tested with allogeneic B10.A APC, different from that seen when syngeneic B10.A(3R) APC were used. The difference in the immune responses of the two strains of mice could be attributed to this APC-expressed specificity. The results were analyzed to determine whether the portion of the antigen that effected T cell memory (the epitope) and the portion that effected APC-expressed specificity (the agretope) were independent. It was found that a) these sites overlap and b) the APC-expressed specificity (i.e., the specificity of agretope recognition) was dependent on the T cell clonotype. This implies that the agretope is not an independent parameter in the process of MHC-restricted antigen recognition. Therefore its employment as an explanation for various phenomena will be limited by the likelihood of circularity.
Effects of diacetyl diamines on in vitro activation and proliferation of human B lymphocytes.
Authors: Lacy J , Summers W C , Canellakis Z N
Published: December 2022

N,N'-Diacetylputrescine (tetramethylenebisacetamide [TMBA]) and its six carbon analog, hexamethylenebisacetamide (HMBA), inhibited the proliferative response of human B lymphocytes to anti-mu and formalinized Cowan I strain Staphylococcal aureus (SAC) stimulation. In contrast, B cell growth factor-stimulated proliferation of human B cells was minimally inhibited by TMBA or HMBA. The antiproliferative effect of these diamine derivatives was specific for anti-mu (or SAC) activation of normal B cells, because the proliferation of PHA-stimulated human T cells and transformed human B cells was not affected by the presence of TMBA or HMBA. The inhibitory effect of diacetyl diamines on anti-mu (or SAC)-induced B cell activation was dose dependent and persisted after removal of the diamine derivatives from the culture media. These studies show that diacetylated derivatives of polyamines modulate human B cell activation in vitro by specific abrogation of anti-mu or SAC activation.
Differential regulation of activation, clonal expansion, and antibody secretion in human B cells.
Authors: Dosch H M , Lam P , Guerin D
Published: December 2022

Limiting dilution analysis, hemolytic plaque assay, and ELISA procedures were used to study the recruitment, clonal expansion, and antibody secretion in human TNP-specific B cells activated in the presence of TNP-ovalbumin (TNP-OA), pokeweed mitogen (PWM), or regulatory T cells. TNP-OA-responsive, hapten-specific PFC precursor cells occupy approximately 0.5% of all sIgM+/sIgD+ B cells in cord blood, bone marrow, peripheral blood, and tonsil. The PWM-responsive, hapten-specific PFC precursor pool is 70 to 90% smaller and does not express sIgD. Antigen-reactive B cells go through a minimum of three divisions in culture (six to nine PFC per clone), and antibody secretory rates of about 10(4) molecules IgM/cell/hr are achieved. In contrast, PWM-induced clone sizes were at least 60 PFC per clone, with antibody secretory rates of approximately 6 to 7 X 10(4) molecules IgM/cell/hr. Addition of high-dose carrier-primed suppressor T cells to limit dilution cultures reduced PFC precursor cell recruitment by up to 99%. However, in the few clones escaping from suppression, both clonal expansion and antibody secretory rates were much higher than in suppressor cell-free cultures, generating 30 to 60% of the antibody secreted in controls but with consequently much more restricted clonal diversity. When limiting dilution cultures were compared with standard microcultures of 2 X 10(5) cells, both clonal expansion and antibody secretory rates were much lower than expected, with a culture efficiency calculated to be 10 to 20% of that in low-density cultures. Our data suggest that the B cell subsets activated by antigen and by mitogen differ in their abilities for clonal expansion and antibody secretion. The hapten-specific and -responsive B cell family is expressed early in ontogeny, and in adults it is distributed evenly throughout the body. These limiting dilution experiments revealed that the primary effect of regulatory T cells is a drastic reduction in clonal diversity, and much less a mere reduction in overall response magnitude.
Dietary fat and immune function. II. Effects on immune complex nephritis in (NZB x NZW)F1 mice.
Authors: Yumura W , Hattori S , Morrow W J , Mayes D C , Levy J A , Shirai T
Published: December 2022

(NZB x NZW)F1 mice initiated on fat restriction at weanling were significantly protected from the development of immune complex glomerulonephritis. Whereas the mice on high-fat intake demonstrated immune depositions both in capillary walls and mesangial areas in a diffuse granular pattern, those on a low-fat diet with caloric content similar to the high-fat diets exhibited mesangial confinement of the depositions of immunoglobulins, complement, and retroviral gp70. In association with these divergent patterns of immune deposition, the mice on high-fat diets had evidence of extensive diffuse cellular proliferation, wire loop lesion, and sclerosis in the glomeruli. In contrast, most of the mice on the low-fat diet showed only mesangial cell and matrix proliferations. In addition, the group of mice fed high saturated fat showed more severe glomerular pathology as compared to those fed high unsaturated fat. Paradoxically, levels of circulating immune complexes (as measured by the polyethylene glycol precipitation technique) in the high saturated fat group were low and did not correlate with the findings by light and immunofluorescence microscopy. These findings suggest that dietary fat restriction can serve as either a prophylactic or effective therapeutic approach to murine lupus nephritis.
Regulation of the IgM and IgA anti-dextran B1355S response: synergy between IFN-gamma, BCGF II, and IL 2.
Authors: Murray P D , Swain S L , Kagnoff M P
Published: December 2022

T cell help is required for the induction of the humoral antibody response to dextran B1355S, a type II thymus-independent bacterial polysaccharide antigen. In the present study we have identified three B cell growth and differentiation factors that can substitute for T cells in the induction of IgM and IgA antibody responses to alpha(1,3) glucan determinants on dextran B1355S. Dextran B1355S stimulated murine B cell cultures supplemented with a combination of murine recombinant interferon-gamma (IFN-gamma) and a late-acting B cell growth and differentiation factor, BCGF II, produced both IgA and IgM anti-alpha(1,3) dextran plaque-forming cells (PFC). Interleukin 2 (IL 2) was not required for those responses. In contrast, recombinant IFN-gamma and recombinant IL 2 in combination supported the induction of IgA but not IgM anti-alpha(1,3) dextran PFC. In all cases, depletion of surface IgA-bearing B cells significantly decreased IgA but not IgM anti-dextran responses, indicating that the B cells responding to those lymphokines already were committed to IgA expression. These studies indicate that B cell growth and differentiation factors can exhibit differential effects on the induction of IgA compared with IgM responses.
Regulation of T cell proliferation by cloned interferon-alpha mediated by Leu-11b-positive cells.
Authors: Pope R M , McChesney L , Stebbing N , Goldstein L , Talal N
Published: December 2022

The autologous T lymphocyte proliferative response (AMLR) induced by a B lymphocyte-enriched non-T, nonadherent cell population (NT, NAC) and by a macrophage-enriched population were both suppressed by the addition of a cloned interferon-alpha (IFN-alpha Con1) directly to the cultures. Preincubation of the stimulating NT, NAC with IFN-alpha Con1 resulted in comparable suppression. In contrast, preincubation of the macrophages with IFN-alpha Con1 resulted in significant augmentation of T cell proliferation. Depletion of Leu-11b-positive cells from the NT, NAC exposed to IFN-alpha Con1 restored the autologous T cell response. Addition of IFN-alpha Con1 activated Leu-11b-positive cells, isolated from the NT, NAC population, was suppressive of the AMLR. Although NK cytotoxicity was irradiation sensitive, suppression of the AMLR by IFN-alpha Con1-activated NT, NAC was resistant, suggesting that different subsets of cells or mechanisms by the same cells may have been responsible. These observations may offer insights into the potential role of cells with the NK phenotype, Leu-11b, and IFN in contributing to immuno-regulatory changes observed in clinical states associated with elevated concentrations of IFN.
Evidence for the involvement of the thromboxane synthase pathway in human natural cytotoxic cell activity.
Authors: Rola-Pleszczynski M , Gagnon L , Bolduc D , LeBreton G
Published: December 2022

We and other investigators have recently shown that inhibitors of lipoxygenase reversibly inhibit natural cytotoxic (NC) or natural killer (NK) cell activity, whereas some inhibitors of cyclooxygenase enhance these functions. In addition, exogenous LTB4 augments NC and NK activity, whereas PGE2 depresses it. In the present studies, we sought to investigate the possible role of the TxA2 synthase pathway in NC function. Inhibition of this pathway by OKY-1581 or dazoxiben significantly inhibited NC activity against HSV-infected cells as well as NK function against K562 target cells. The inhibition was dose dependent, reversible, and not due to direct toxicity. NC activity was also significantly inhibited by the addition of PGE2 or PGI2 to the 4-hr assay, whereas addition of 6-keto-PGF1 alpha had no effect. Addition of PGH2, which could be converted to TxA2 or other PG, had no significant effect, but concomitant use of OKY-1581 produced a greater inhibition of NC function than by using OKY-1581 alone. U44069, a TxA2 analog, was inhibitory by itself and could not alter the inhibition caused by OKY-1581 or dazoxiben. In contrast, the TxA2 receptor blocker 13-APA significantly enhanced NC activity and even reversed the inhibitory effect of U44069 at equimolar (10(-7)M) concentrations. Taken together, these data suggest that most of the inhibitory effect of the TxA2 synthase inhibitors on NC and NK cell function derives from their ability to reorient cyclic endoperoxide metabolism toward more inhibitory compounds. In addition, TxA2 itself could exert a negative feedback on NC function through its receptor, as evidenced by the use of a TxA2 analog and a TxA2 blocker.
Trypanosoma cruzi: expression of antigens on the membrane surface of parasitized cells.
Authors: Araujo F G
Published: December 2022

A direct immunofluorescent antibody test with an anti-Trypanosoma cruzi F(ab')2 conjugate was used to demonstrate antigens of T. cruzi on the membrane surface of intact live or fixed macrophages and L929 mouse fibroblasts infected with the organism. Antigens were demonstrated in 5 to 50% of infected cells, and their presence was not directly related to the number of intracellular organisms. Cells with as few as four intracellular amastigotes had demonstrable surface antigens, whereas some cells with as many as twelve or more organisms did not. Capping of antigen-antibody complexes was noted to begin a few minutes after the addition of the anti-T cruzi F(ab')2 conjugate; by 30 min, most of the parasitized cells had eliminated the complexes, and no surface antigen of parasitic nature could be demonstrated. Although capping may have caused a negative result in a previously positive cell, other mechanisms may be involved, because antigens were not demonstrated in some heavily parasitized cells examined immediately after completion of the test. Treatment of the infected cells with trypsin or chymotrypsin resulted in the absence of demonstrable parasite antigens on the cell membrane surface. However, the antigens were again demonstrated 12 hr after the enzymes were removed. The reappearance of parasite antigens on the surface of infected cells was prevented by treatment of the monolayers with puromycin or tunicamycin. A T cell-enriched population of spleen lymphocytes from mice chronically infected with T. cruzi recognized the membrane-bound antigens and proceeded to destroy the host cell and the intracellular organisms. In this process, noninfected cells were also destroyed, possibly because they were coated with antigens released from intact infected cells or from infected cells that had been lysed by the action of the sensitized lymphocytes or their products.
Immunochemical analysis of the types Ia and Ib group B streptococcal polysaccharides.
Authors: Schifferle R E , Jennings H J , Wessels M R , Katzenellenbogen E , Roy R , Kasper D L
Published: December 2022

The types Ia and Ib group B streptococcal type-specific polysaccharides have remarkable immunologic differences despite a great deal of structural similarity. Although these two complex polysaccharides differ only by a single glycosidic linkage, they are antigenically distinct. Furthermore, terminal sialic acid residues appear to be critical to the immunodeterminant on the type Ia polysaccharide, whereas the antigenicity of the type Ib polysaccharide does not show this dependence on sialic acid. In the current investigation we defined better the immunodeterminant of these polysaccharides. With homologous rabbit antiserum, the type Ia native and core polysaccharides demonstrated partial serologic identity, whereas the type Ib native and core polysaccharides demonstrated complete serologic identity. Surprisingly, the type I degalactosylated polysaccharide, degraded structure, was capable of reacting with a population of antibodies present in type Ia antiserum similar to the complete type Ia native polysaccharide, although demonstrating a reduced level of immunodeterminant expression. Unlike the reactions of the type Ia polysaccharides with homologous rabbit antiserum, the Ib native and core polysaccharides were able to react with identical populations of antibodies in type Ib-specific antiserum. A minor population of antibodies was demonstrated in the type Ib antiserum, which was reactive with the degalactosylated polysaccharide. That a population of antibodies reactive toward the degalactosylated polysaccharide is present in both type Ia and type Ib antisera suggests that the Iabc cross-reacting determinant is due to the presence of serum antibodies reactive with this trisaccharide repeating unit, which is shared by both the type Ia and the type Ib native and core polysaccharides.
Evidence for two trans-acting genes regulating HLA class II antigen expression.
Authors: Salter R D , Alexander J , Levine F , Pious D , Cresswell P
Published: December 2022

Previous studies have shown that a trans-acting regulatory factor is required for expression of HLA class II molecules in B-LCL, and that a trans-active factor derived from B-LCL induces de novo synthesis of T-LCL-encoded class II antigens in hybrids of T-LCL and B-LCL. To further examine the genetics of class II antigen regulation, we have now fused two different T-LCL with the class II antigen negative B-LCL 6.1.6, a regulatory mutant that does not synthesize a trans-acting factor necessary for transcription of class II genes. Northern blot analysis and cell surface immunofluorescence studies indicate that the hybrids express class II antigens encoded by both 6.1.6 and T-LCL parent cell lines. Thus, expression of class II antigens in these hybrids is controlled by a minimum of two trans-acting regulatory genes. One of these genes is inactivated in the 6.1.6 mutant and is provided by the T-LCL fusion partner. The second regulatory gene may still be active in 6.1.6, but it alone is insufficient for maintenance of class II antigen expression.
Abrogation of species specificity for activation of tumoricidal properties in macrophages by recombinant mouse or human interferon-gamma encapsulated in liposomes.
Authors: Fidler I J , Fogler W E , Kleinerman E S , Saiki I
Published: December 2022

Highly purified human blood monocytes, isolated by continuous Percoll density gradients under endotoxin-free conditions, and mouse peritoneal exudate macrophages (PEM) were activated in vitro by the combination of muramyl dipeptide (MDP) and recombinant interferon-gamma (r-IFN-gamma) to become tumoricidal against their respective tumorigenic target cells. The activation of human monocytes or mouse PEM by free unencapsulated r-IFN-gamma and MDP was species specific: human r-IFN-gamma activated human blood monocytes to lyse allogeneic melanoma cells, but did not activate mouse PEM. Mouse r-IFN-gamma activated mouse PEM to lyse syngeneic melanoma cells, but did not activate cytotoxic properties in human monocytes. The encapsulation of either mouse or human r-IFN-gamma with MDP within the same liposome preparation produced synergistic activation of cytotoxic properties in both PEM and monocytes without apparent species specificity. The activation of tumoricidal properties in macrophages by r-IFN-gamma and MDP occurred as a consequence of intracellular interaction. We base this conclusion on the data showing that whereas free r-IFN-gamma and MDP did not activate macrophages pretreated with pronase, liposome-encapsulated r-IFN-gamma and MDP did. Moreover, the i.v. injection of liposomes containing human or mouse r-IFN-gamma and MDP produced in vivo activation of mouse alveolar macrophages. These data suggest that in contrast to activation with free r-IFN-gamma, which requires binding to macrophage surface receptors, the intracellular interaction of r-IFN-gamma, which produces tumoricidal activity in macrophages, is not species specific.
MHC-restricted cytotoxic response of chicken T cells: expression, augmentation, and clonal characterization.
Authors: Maccubbin D L , Schierman L W
Published: December 2022

Major histocompatibility complex (MHC)-restricted cytotoxicity of chicken lymphocytes was studied by using three reticuloendotheliosis virus (REV)-transformed cell lines as targets in 51Cr-release assays. The cell lines, designated RECC-UG5, RECC-UG6, and RECC-UG8, were developed from bone marrow cells of REV-infected line G-B1, line G-B2, and (G-B1 X G-B2)F1 chickens respectively. Effector cells were obtained from spleens of G-B1, G-B2, F1, and F2 chickens 7 days after inoculation of REV. The inbred G-B1 (MHC genotype B13/B13) and G-B2 (MHC genotype B6/B6) lines originate from a common partially inbred line. Initial studies with effector cells from G-B1 and G-B2 chickens showed that significant cytotoxicity occurred only with syngeneic target cells. The degree of cytotoxicity was markedly enhanced by neonatally treating effector cell donors with cyclophosphamide (CY) and delaying virus challenge until the birds were 4 wk old. Augmentation of cytotoxicity was presumed to be due to elimination of bursal-dependent suppressor T cells by CY. The results with spleen cells from REV-inoculated F2 birds clearly showed that cytotoxicity was MHC restricted; i.e., significant lysis only occurred if effector cells and target cells had a common B system antigen. Lysis of RECC-UG5 targets was three to four times higher than lysis of RECC-UG6 targets when effector cells were from heterozygous (B6/B13)F1 and F2 birds. Because these two target cell lines generally showed a similar degree of lysis by effector cells from syngeneic B homozygous birds, the differences obtained with effector cells from B heterozygous birds was most likely due to differences in the number of effector cells with specificity for each target line. Evidence for an additive cytotoxic effect, considered to be due to the lytic activity of two separate T cell clones, was obtained when F1 effector cells were tested with the F1-derived RECC-UG8 targets. The results of other experiments indicated that the effector cells were of T cell lineage and that their activity was probably directed against virus-induced antigens on the transformed target cells.
Interferon-induced inhibition of receptor-mediated endocytosis of colony-stimulating factor (CSF-1) by murine peritoneal exudate macrophages.
Authors: Chen B D
Published: December 2022

Apart from its characteristic antiviral activity, interferon (IFN) also exerts a variety of biologic effects on macrophages. We have studied the effect of IFN on the expression of the colony-stimulating factor receptors (CSF-1 receptors) by murine peritoneal exudate macrophages (PEM). At 37 degrees C, murine IFN decreased the expression of the CSF-1 receptor activity in a time- and dose-dependent fashion by PEM from both endotoxin-sensitive (C3H/Sn) and endotoxin-resistant strains (C3H/HeJ) of mice. Scatchard analysis from the binding data suggests that the decreased expression of CSF-1 receptors is a result of decreased number of receptors rather than a decreased binding affinity. When IFN was incubated with anti-IFN before the addition to cultures, the effect was completely abolished indicating that this activity resides in the same molecules as IFN. The suppressed CSF-1 receptor activity on PEM by IFN appeared to be stable. Removal of added IFN never resulted in a full recovery of CSF-1 binding activity by PEM even after prolonged incubation (7 days). IFN also inhibited the receptor-mediated uptake and utilization of CSF-1 molecules by treated cells, which appeared to be a direct effect of the decreased number of CSF-1 receptors. Treatment of PEM with dexamethasone, prostaglandin, transferrin, insulin, or dibutyryl cAMP failed to suppress both the expression of CSF-1 receptors and CSF-1 utilization by PEM. These studies suggest that IFN may play a role in the regulation of both macrophage production and differentiation via the modulation of specific membrane receptors and inhibition of receptor-mediated CSF-1 endocytosis.
Incompatible A antigen expressed in tumors of blood group O individuals: immunochemical, immunohistologic, and enzymatic characterization.
Authors: Clausen H , Hakomori S , Graem N , Dabelsteen E
Published: December 2022

Monofucosyl type 1 chain A (type 1 Aa) and difucosyl type 1 chain A (ALeb), but not other types of A antigens, have been detected by application of carrier type-specific monoclonal anti-A antibodies (AH21 and HH3) in colonic tumors of blood group O individuals. An A-transferase activity (UDP-Gal-NAc:H-alpha-GalNAc transferase) was demonstrated in the extract of one of the O tumors expressing A antigen. The incidence of A antigen expression in O tumors was found to be two out of 15 cases, based on TLC immunostaining of glycolipid extracts, and five out of 50 cases, based on immunofluorescent staining of tumors with AH21 and HH3 antibodies.
Simple sugars with affinity for the macrophage asialoglycoprotein receptor are adjuvants for the humoral immune response to neuraminidase-treated sheep erythrocytes.
Authors: Klerx J P , Molendijk A J , Van Dijk H , Vloet K P , Willers J M
Published: December 2022

The influence of monosaccharides on the humoral immune response of mice to normal and neuraminidase-treated sheep red blood cells (SRBC) was investigated. In these studies, both the sugars and antigen were administered i.p. D-Galactose displayed adjuvant activity for neuraminidase-treated but not for normal SRBC. This activity was optimal at an antigen dose of 3 X 10(6) cells. Other monosaccharides with an axial hydroxyl group at position 4 and D-mannose-6-phosphate behaved like D-galactose, whereas structurally unrelated sugars did not. The adjuvant activity of the saccharides corresponded to the affinity of the substances for the asialo-glycoprotein receptor. The adjuvant effects were also expressed in cobra venom factor-treated and C5-deficient mice. This suggests that blockade of the asialo-receptor rather than complement is involved in this form of immunoadjuvant activity. The findings are also in support of our hypothesis that obstruction of nonimmune antigen elimination, in this case at the level of macrophages, would be one of the mechanisms underlying immunologic adjuvant activity.
A requirement for physical linkage between determinants recognized by helper molecules and cytotoxic T cell precursors in the induction of cytotoxic T cell responses.
Authors: Krowka J F , Singh B , Fotedar A , Mosmann T , Giedlin M A , Pilarski L M
Published: December 2022

It has long been understood that both antibody and delayed-type hypersensitivity responses are induced through collaborative events in which the determinants recognized by the precursor cells must be physically linked to the determinants recognized by the helper. Although it is clear that the generation of memory cytotoxic T lymphocyte precursors (CTLp) involves linked recognition of determinants, the induction of CTL responses has been viewed as being dependent upon interleukin 2 (IL 2), which could be provided by a helper cell, but independent of requirements for antigen bridging. In this work, we have designed a system that lacks exogenous IL 2 by using as our source of help, antigen-specific helper molecules derived from helper T cells. These soluble helper molecules are uncontaminated by IL 2 and unlike a helper cell, are unable to produce IL 2. Helper molecules specific for chicken red blood cells (Crbc) and for a synthetic polypeptide, poly 18, were tested. Thymocyte responders require a source of help to respond to alloantigens intrinsically expressed on the surface of adherent stimulator cells. To analyze the mechanism whereby the helper molecules acted, we used a system involving recognition of haptenic and carrier determinants that were physically linked by virtue of being located on the same cell surface (intra-structural linkage). Adherent stimulator cells were pulsed with Crbc or poly 18 so that the alloantigens recognized by the thymocyte CTLp (intrinsically expressed class I) were either linked or unlinked to the carrier determinants (Crbc or poly 18) presented by the adherent cells and recognized by the helper molecules. Both types of helper molecule were shown to be antigen-specific in crisscross experiments. The helper molecules specific for Crbc were able to induce the thymocyte CTLp only when both hapten and carrier were present on the same stimulator cell surface. Because we were not able to detect a requirement for H-2-restricted recognition of carrier antigen, this inductive event must be viewed as requiring linked associative recognition of determinants, but being noncognate. In contrast, the helper molecules recognizing poly 18 showed a requirement for both physical linkage of determinants and for H-2 restricted recognition, indicating that the mechanism of induction was cognate in nature. Therefore, we have shown that interactions between CTLp and soluble, antigen-specific, helper cell-derived inductive molecules are similar in nature to those of other T cell precursors and of B cells in the stringent requirement for close physical proximity achieved by linked or cognate recognition of determinants across an antigen bridge.
Rapid changes in the regulatory potential of autologous anti-idiotopic T cells during an antigen-driven primary response.
Authors: Cerny J , Cronkhite R , Stout J T
Published: December 2022

The antibody response of C57BL/6 strain mice to Streptococcus pneumoniae R36a (Pn) is dominated by the T15 idiotype, but the responding cells appear to be idiotypically heterogeneous, in that individual antibody plaque-forming cells (PFC) may express some but not all idiotopes (Id) of the T15 complex. The presence of these distinct Id on the PFC was detected by a plaque-inhibition assay with three different monoclonal anti-Id antibodies, designated AB1-2, MaId5-4, and B36-82. A periodic change in the expression of AB1-2 and MaId5-4 Id was observed during primary (IgM) antibody response to Pn in the spleen. Those two Id were poorly expressed in the log phase of the response between day 2 and day 4 after immunization (few PFC in the spleen bore the Id), but they became detectable on the majority of PFC at the peak of the response, day 5 to day 7. The proportion of the Id-(AB1-2 or MaId5-4) positive PFC declined, again at day 10 after immunization. In contrast, the B36-82 Id was expressed on greater than or equal to 80% PFC throughout the entire primary response. The possibility that the apparent changes in the Pn-reactive cell populations are regulated by autologous anti-Id T cells was tested in vitro. Normal, unimmunized B cells were cultured with Pn, either alone or in the presence of syngeneic T cells isolated from the spleen of mice at the appropriate intervals after immunization: day 2 (T2), day 5 (T5), and days 10 to 14 (T10 to T14); T cells from unimmunized donors (T0) served as a control. The specific response after 4 days in culture was determined in regard to the total PFC as well as the proportion of PFC expressing the Id. Pn-stimulated B cells, alone or with the control T0 cells, produced moderate, variable levels of AB1-2+ and MaId5-4+ PFC. The expression of these two Id in the assay cultures was suppressed by addition of either T2 cells or T10-14 cells, but it was enhanced if T5 cells were added. However, these various T cell populations did not differ in their effect on the total PFC response. Also, the proportion of PFC bearing the third Id, B36-82 was high, and it was not consistently influenced by the added T cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Dual fluorochrome analysis of human B lymphocytes: phenotypic examination of resting, anti-immunoglobulin stimulated, and in vivo activated B cells.
Authors: Anderson K C , Roach J A , Daley J F , Schlossman S F , Nadler L M
Published: December 2022

B cell-enriched preparations were prepared from human peripheral blood and lymphoid tissues by the depletion of T cells and monocytes. Only B cells by virtue of their staining with anti-B1 conjugated to fluorescein were additionally examined. Dual fluorescence staining and flow cytometric analysis demonstrated that the majority of "resting" human peripheral blood and splenic B cells co-express the B cell-restricted B1 and B2 antigens and lack B5, a B cell-restricted activation antigen, and interleukin 2 receptor (IL 2R). In contrast, nearly 2/3 and 1/3 of B1+ cells isolated from lymph node expressed IL 2R and B5 antigens, respectively. When B1+ B cells from peripheral blood and spleen were "activated" by anti-Ig, they lost the B2 antigen and acquired the B5 and/or IL 2R antigens. 2/3 of B1+ cells strongly expressed IL 2R, and up to 1/2 of B1+ cells co-expressed B5. Delineation of increased numbers of B1+ cells that co-express B5 and/or IL 2R within lymphoid tissues obtained from patients with diseases characterized by "activated" B cells provides in vivo confirmation that these phenotypic changes correlate with B cell activation. We believe that the identification and isolation of these and similar subsets of cells defined by differing cell surface phenotypes should further our understanding both of normal B cell activation and the pathophysiology of B cell disease states.
Altered phagocytosis by monocytes from HLA-DR2 and DR3-positive healthy adults is Fc gamma receptor specific.
Authors: Salmon J E , Kimberly R P , Gibofsky A , Fotino M
Published: December 2022

Fc gamma receptor-dependent mononuclear phagocyte system (MPS) clearance of opsonized erythrocytes is prolonged in healthy adults with the class II alloantigens HLA-DR2, DR3, or DQw1, despite normal receptor-specific Fc ligand binding by monocytes in these groups. To investigate the basis for the MPS dysfunction, we determined the phagocytic capacity of blood monocytes from 66 disease-free adults and analyzed the data according to the HLA type of the subjects. The data demonstrate decreased phagocytosis of IgG-sensitized erythrocytes (EA) by monocytes from HLA-DR2, DR3, or DQw1-positive subjects compared with normals without these B cell alloantigens (2.87 +/- 0.83 erythrocytes/monocyte vs 3.87 +/- 1.05, p less than 0.004; 3.01 +/- 0.94 vs 3.87 +/- 1.05, p less than 0.02; 3.18 +/- 0.89 vs 3.87 +/- 1.05, p less than 0.02, respectively). Because HLA-DR2 and DQw1 are in linkage disequilibrium, we compared EA phagocytosis in subjects with DQw1 alone to normals without HLA-DR2, DR3, or DQw1. Among subjects positive only for DQw1, no significant decrease in phagocytosis could be seen (3.46 +/- 0.95 vs 3.87 +/- 1.05, p = NS). To determine whether these differences represented an Fc receptor-specific dysfunction or a more generalized decrease in phagocytic activity, we compared the quantitative phagocytosis of EA with that of neuraminidase-treated erythrocytes (EN), which is Fc receptor independent and beta-glucan receptor mediated. No segregation of phagocytic capacity for EN by HLA class II phenotypes could be demonstrated (DR2, 2.68 +/- 1.30 erythrocytes/monocyte; DR3, 2.95 +/- 1.30; DQw1, 2.84 +/- 1.15; others, 3.06 +/- 1.14). Our data indicate that the decrease in phagocytosis by blood monocytes from normal individuals with HLA-DR2 or DR3, the class II alloantigens associated with systemic lupus erythematosus and other autoimmune diseases, is specific for the Fc receptor-mediated process. This alteration of Fc receptor function among immunogenetically defined individuals may contribute to their predisposition to autoimmune disease. These differences may also apply to other Fc receptor-initiated cellular functions.
Apolipoprotein E is a biologically active constituent of the normal immunoregulatory lipoprotein, LDL-In.
Authors: Pepe M G , Curtiss L K
Published: December 2022

A normal plasma lipoprotein, termed LDL-In, has been shown to be a potent inhibitor of mitogen-driven human lymphocyte proliferation in vitro and of primary antibody responses in the mouse. To determine whether the immunoregulatory activity of LDL-In resided with the protein rather than the lipid constituents of LDL-In, one of the apoproteins of LDL-In, apoprotein E, was isolated from plasma and was analyzed for its inhibitory activity. Apoprotein E, isolated after delipidization of lipoproteins with either methyl ethyl ketone or ethanol and ethyl ether, was immunosuppressive. Furthermore, the characteristics of inhibition of cellular [3H]thymidine uptake by isolated apoprotein E were identical to those characteristics obtained with suppression by LDL-In. Inhibition by apoprotein E and LDL-In required preincubation of the cells with either apoprotein or lipoprotein for 24 hr before exposure of the cells to mitogen for maximal expression of suppressive activity, and this inhibition could not be reversed by removal of non-cell-associated inhibitor before stimulation. Neither apoprotein E or LDL-In was inhibitory when they were added to the cells after mitogen stimulation. The only difference noted between suppression by apoprotein E and LDL-In was that of dose. Compared with quantitative estimates of the apoprotein E content of LDL-In, significantly more isolated apoprotein E was required than lipoprotein-associated E for comparable levels of suppression. The potency of apoprotein E could be increased by adding it to cells in the presence of dimyristoylphosphatidylcholine/cholesterol vesicles. The data suggesting that phospholipid increased the specific activity of apoprotein E by altering its molecular dispersion was obtained from analyses of the interaction of apo E with cells, as well as the plastic culture vessels. The results suggested that the molecular dispersion and perhaps organization of isolated apoprotein E in an aqueous system is critical to its interaction with lymphocytes and subsequently its biological activity.
Partial amino acid sequence and genetic control of latent a2 allotype induced in rabbits by immunization with anti-a2 antibody.
Authors: Davidson M K , Sogn J A , Kazdin D S , Horng W J , Dray S , Gilman-Sachs A
Published: December 2022

We have shown that after immunization of homozygous a1 rabbits of the B immunoglobulin (Ig) heavy chain haplotype with anti-a2 antibody (Ab) a population of molecules appears that has all of the serologic characteristics of the a2 allotype. We have now isolated these putative latent a2 molecules, have separated the heavy chains, and after enzymatic deblocking, have determined the first 19 N-terminal amino acids. For all eight allotype-associated residues, these putative latent a2 molecules have the amino acid residues typical of a2 allotype. As expected, the preimmune IgG from this a1a1 rabbit has the amino acids typical of the a1 allotype. Thus by partial amino acid sequence analysis, we provide additional evidence that the latent a2 allotype can be induced in a1a1 rabbits of the B heavy chain haplotype by immunization with anti-a2 Ab. Rabbits of other heavy chain haplotypes were also immunized with anti-a2 Ab and were tested for their ability to synthesize latent a2 allotype. Thus far, a1a1 rabbits of the A, B, C, and I heavy chain haplotypes all synthesize latent a2 allotype. In contrast, a3a3 rabbits of the G and H heavy chain haplotypes did not synthesize latent a2 allotype.
Plasma membrane and intracellular expression of globotetraosylceramide (globoside) in mouse bone marrow-derived mast cells.
Authors: Katz H R , Austen K F
Published: December 2022

The cellular localization of globotetraosylceramide (globoside), one of the predominant neutral glycosphingolipids of mouse interleukin 3-dependent, bone marrow culture-derived mast cells (BMMC), has been determined by immunologic and chemical methods. Although less than 10% of BMMC expressed globoside on their surface, as assessed by cytofluorographic analysis of the binding of a mouse monoclonal IgM anti-globoside antibody, treatment of BMMC with nonactivating doses of pronase, trypsin, or neuraminidase increased the percentage of BMMC binding anti-globoside antibody by an average of six, three, or sixfold respectively. That most BMMC had globoside on their plasma membrane was confirmed by the surface radiolabeling of globoside with galactose oxidase and sodium borotritide, as detected by autoradiography of thin layer chromatograms of the extracted neutral glycosphingolipids. Thus, BMMC expressed globoside on their plasma membrane, but accessibility of a large probe such as IgM antibody to the glycosphingolipid was impeded by surrounding surface molecules. All BMMC bound anti-globoside antibody intracellularly, as assessed by indirect immunofluorescence staining and fluorescence microscopy on acetone-permeabilized cells, and the pattern of staining suggested that globoside was associated with the secretory granules of BMMC. Immunologic activation of BMMC resulted in a fivefold increase in the surface expression of globoside, as detected by cytofluorographic analysis of the binding of monoclonal anti-globoside antibody. The findings suggest that activation of BMMC causes a reorganization of the plasma membrane such that globoside is more exposed or that activation is accompanied by movement of globoside from internal membranes to the plasma membrane. The increased expression of globoside is a novel marker of the activated mouse BMMC.
Induction of protective immunity against Schistosoma mansoni by a nonliving vaccine. III. Correlation of resistance with induction of activated larvacidal macrophages.
Authors: James S L
Published: December 2022

Mice protected against Schistosoma mansoni infection by intradermal (i.d.) immunization with nonliving larval or adult worm antigens plus bacterial adjuvant developed 24-hr skin test responsiveness to schistosome antigens with the histologic features of delayed hypersensitivity. Intraperitoneal antigen injection elicited a mononuclear cell-enriched exudative population containing macrophages activated for direct cytotoxicity against schistosomula and tumor cell targets. This was likely to be due to in vivo exposure to macrophage-activating lymphokines, since these cells were unresponsive to further lymphokine stimulation in vitro and splenocytes from immunized mice reacted to specific in vitro antigen challenge by production of lymphokines capable of conferring larvacidal activity upon control macrophages. In contrast, mice treated with schistosome antigens by i.v. injection, which were not protected against challenge infection, failed to develop delayed hypersensitivity or activated macrophages in response to specific antigen challenge in vivo, and the titers of macrophage-activating lymphokine produced by in vitro antigen-stimulated splenocytes from these mice were threefold to fourfold lower than those produced by cells from animals immunized by the i.d. route. Thus, sensitization for cell-mediated immune responses including lymphokine production and macrophage activation correlated with induction of resistance to S. mansoni in this model of vaccination.
Induction of protective immunity against Schistosoma mansoni by a nonliving vaccine. IV. Fractionation and antigenic properties of a soluble adult worm immunoprophylactic activity.
Authors: Sher A , Pearce E , Hieny S , James S
Published: December 2022

An aqueous buffer-soluble, nonparticulate fraction of adult Schistosoma mansoni worms (SWAP) was separated by gel filtration on Ultragel AcA-34, and portions of the eluate were tested for their capacity to induce protective immunity against cercarial challenge when administered intradermally to mice in combination with the adjuvant BCG. All of the immunogenic activity was found in a single peak of protein excluded in the void volume of the column. This same fraction was determined by SDS-PAGE and Western immunoblotting to be unique in that it contained a component of Mr (X 10(-3) 97 (97,000) recognized monospecifically by antibodies from mice vaccinated with unseparated SWAP plus BCG. Similarly, the protective fraction was unique in possessing the capacity to elicit 24 hr delayed footpad swelling responses, as well as lymphokine production, in SWAP-BCG-immunized mice. These results suggest that the immunogenic activity of SWAP resides in a restricted population of molecules, and possibly in the 97,000 antigen detected with antibodies from vaccinated animals. Because both the protective capacity of unfractionated SWAP and the serologic reactivity of the 97,000 antigen are sensitive to digestion with protease, it is likely that the immunologic activity of these molecules is dependent on peptide-bonded structural elements.
Induction of bone marrow allograft rejection and hybrid resistance in nonresponder recipients by antibody: is there evidence for a dual receptor interaction in acute marrow graft rejection?
Authors: Dennert G , Anderson C G , Warner J
Published: December 2022

Acute marrow graft rejection in allogeneic or semiallogeneic donor-recipient mouse combinations has been suggested to be caused by natural killer (NK) cells. The unique in vitro specificity of NK cells for tumor cells, however, does not explain the specific rejection of bone marrow grafts by NK cells. Recent experiments have implicated antibody in marrow graft recipients as the specificity-inducing component that guides NK cells in an antibody-dependent cytotoxic (ADCC) reaction to attack the marrow graft. On the basis of this hypothesis, one would postulate that nonresponder marrow graft recipients can be converted into responders by injection with antibody of appropriate specificity. Results presented in this report show that this is indeed possible. Specific monoclonal or polyclonal antibody of IgG isotype induces marrow graft rejection in nonresponder recipients. This can be demonstrated in allogeneic as well as in semi-allogeneic (hybrid resistance) donor-recipient strain combinations. Antibody-induced marrow graft rejection is independent of complement and dependent on the presence of NK cells. Surprisingly, graft rejection induced by antibody is quite efficient in allogeneic and semiallogeneic marrow donor-recipient combinations, whereas it is generally poor in syngeneic combinations. This result is not understood if NK cells lyse bone marrow cells solely in an ADCC-type reaction. Because NK cells can lyse targets in an antibody-dependent as well as independent reaction, it is proposed that the binding of NK cells to targets via their receptors plays an additional role in the rejection of bone marrow in vivo. Preliminary evidence for this possibility is that NK cells in the apparent absence of antibody may have a detectable suppressive effect on the growth of marrow grafts in F1 hybrid mice transplanted with parental marrow grafts.