bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclosporin A does not prevent expression of Tac antigen, a probable TCGF receptor molecule, on mitogen-stimulated human T cells.
Authors: Miyawaki T , Yachie A , Ohzeki S , Nagaoki T , Taniguchi N
Published: December 2022

Results of recent studies indicated that a monoclonal anti-Tac antibody might recognize the receptor sites or closely related structures for T cell growth factor (TCGF) on activated human T cells. In the present study, we examined the effect of cyclosporin A (CsA) on the expression of Tac antigen by mitogen-stimulated T cells. CsA inhibited the proliferative response of T cells to Con A and PHA in a dose-dependent manner. Both Con A- and PHA-induced cellular proliferation were decreased to about 10% of controls at 5 micrograms/ml of CsA. When T cells were stimulated with these mitogens, many of them expressed Tac antigen on their surfaces, assessed by the immunoperoxidase method. The appearance of Tac-positive cells occurred earlier than a rise of cellular DNA synthesis. Characteristically, CsA showed no inhibitory effect on the expression of Tac antigen by mitogen-stimulated T cells, even at a relatively high concentration of 5 micrograms/ml, whereas the expression of other "activation" antigens reactive with monoclonal anti-Ia, OKT9, or OKT10 antibodies by T cells was blocked completely by CsA. Morphologically, the majority of Tac-positive cells in culture with mitogens alone showed the characteristics of blastoid cells; Tac-positive cells in the culture containing CsA mainly consisted of medium-sized cells, indicating these cells probably accumulated at a stage of partial activation. T cells, once stimulated with Con A or PHA for 3 days whether in the presence or in the absence of CsA, were able to absorb TCGF activity from TCGF-containing media similarly. In addition, T cells, even stimulated in the presence of CsA with these mitogens for 24 hr, were capable of responding to TCGF with the same grade of proliferation as did T cells stimulated with mitogen alone. CsA showed no appreciable inhibition in a TCGF-dependent proliferation of such prestimulated cells. These functional properties of activated T cells might be correlated with their ability to express Tac antigen. These experimental findings present some evidence that CsA might not prevent the expression of probable functional receptor sites for TCGF in mitogen-dependent activation of human T cells.
Regulation of the growth and differentiation of a human monocytic cell line by lymphokines. I. Induction of superoxide anion production and chemiluminescence.
Authors: Clement L T , Lehmeyer J E
Published: December 2022

The U937 human monocytic cell line was studied to determine its ability to generate a respiratory burst after stimulation with phorbol myristate acetate (PMA) or opsonized zymosan. U937 cells cultured in normal medium produced virtually no superoxide anion or chemiluminescence in response to either stimulus. In contrast, U937 cells cultured in medium containing soluble factors from activated lymphocytes produced significant O2- and chemiluminescence when stimulated with PMA or opsonized zymosan. The chemiluminescence in response to PMA was maximal in U937 cells precultured with these soluble factors for 3 days, whereas maximal responsiveness to opsonized zymosan was not observed until 5 to 6 days of lymphokine exposure. Although this ability to generate a respiratory burst persisted for a number of days in U937 cells that were subsequently recultured in normal medium, this responsiveness was gradually lost in the continued absence of these factors. The data indicate that the U937 monocytic cell line can be activated or induced to differentiate by soluble factors released by activated lymphocytes. In the process, these cells acquire the ability to generate a respiratory burst. The U937 cell line may serve as a useful model for the study of the ontogeny and regulation of the respiratory burst during human monocytic differentiation.
Molecular and antigenic nature of isolated Sm.
Authors: Dang H , Fischbach M , Lerner E , Talal N
Published: December 2022

The Sm antigen was isolated and purified from calf thymus nuclear extract by affinity chromatography. The affinity columns were made with serum antibodies from an SLE patient or an anti-Sm monoclonal antibody derived from a hybridoma cell line. Proteins eluted from these two columns had m.w. of 58,000 and 35,000 by SDS polyacrylamide gel electrophoresis. The natural conformation of this antigen appears to be 95,000 in m.w. with the 58,000 particle containing the Sm antigenic determinant. The affinity column-purified antigen detected by the human anti-Sm antibodies is also recognized by anti-Sm antibodies in murine lupus serum, as shown by solid-phase radioimmunoassay. This study 1) demonstrates the molecular and antigenic nature of the Sm antigen and 2) compares the anti-Sm binding capabilities of antibody populations present in sera from SLE patients and from MRL lpr/lpr mice.
Characterization of monoclonal antibodies that define rat T cell alloantigens.
Authors: Ely J M , Greiner D L , Lubaroff D M , Fitch F W
Published: December 2022

A panel of monoclonal antibodies with specificity for rat T cell alloantigens was prepared by somatic cell hybridization with the use of spleen cells from either BH (ART-1b, 2b) or NBR (ART-1b, 2a) rats immunized with LEW (ART-1a, 2a) thymus, spleen, or lymph node cells. Comparison of the antibodies resulted in three distinct patterns of complement-mediated cytotoxicity. Further comparison of four representative hybridoma antibodies with antisera having specificity for ART antigens by indirect immunofluorescence demonstrated that two of the three patterns corresponded to anti-ART-1a and anti-ART-2a specificities. The patterns of binding of the anti-ART hybridomas were shown to be different from those produced by mouse monoclonal antibodies having anti-leukocyte-common (L-C) or anti-Thy-1.1 activities as well as antibodies produced by the monoclonal W3/25, which detect a subpopulation of T lymphocytes. Functional studies performed in vitro with cells fractionated by treatment with the monoclonal anti-ART antibodies and complement showed the ART-1 determinant recognized by the hybridoma products BC 84A or BY 12.3 is expressed by mature cytolytic T lymphocytes (CTL) and by cells involved in the generation of CTL during MLR, but not plaque-forming cells. Together, the data suggest the antibodies BC 84A and BY 12.3 can be used to define rat T cell populations. To date, the functional significance of cell populations recognized by monoclonal antibodies having anti-ART-2a or anti-ART-3-like activities has not been determined.
Stimulation of prostaglandin E and thromboxane synthesis in macrophages by purified C3b.
Authors: Hartung H P , Hadding U , Bitter-Suermann D , Gemsa D
Published: December 2022

Complement cleavage product C3b was examined for its effect on macrophages. Albumin-elicited guinea pig peritoneal macrophages kept in short-term culture were challenged with purified homologous C3b, and release of oxygen and arachidonic acid metabolites was studied. C3b at concentrations ranging from 20 to 80 micrograms/ml induced synthesis of large quantities of the arachidonic acid cyclooxygenation products thromboxane B2 (TXB2) and prostaglandin E (PGE) but failed to trigger an oxidative burst. Our findings link together macrophages, complement, and arachidonate metabolites as major participants in inflammatory responses.
Lymphocyte function in experimental African trypanosomiasis. VI. Parasite-specific immunosuppression.
Authors: Dempsey W L , Mansfield J M
Published: December 2022

The ability of mice infected with African trypanosomes to produce antibodies to the surface antigen of the infecting trypanosome variant antigenic type upon primary and secondary exposure was examined. C57BL/10SnJ mice were infected initially with Trypanosoma rhodesiense clone LouTat 1.0. Surface antigen-specific antibody titers (IgM and IgG) to the infecting variant were measured throughout the course of infection; when the titers were sufficiently low, mice were reinfected with LouTat 1.0 trypanosomes and the antibody response was measured. Results demonstrate that mice in the early stage of infection exhibited transient suppression of antibody responses to LouTat 1.0 upon reexposure. In contrast, mice in the terminal phase of the disease were completely suppressed in their ability to mount a humoral response to LouTat 1.0. Trypanocidal chemotherapy of mice restored immunoresponsiveness in that treated mice responded with both IgM and IgG surface antigen-specific antibody to LouTat 1.0. The resulting antibody response, however, was more indicative of a primary humoral response to the parasites rather than a true secondary immune response.
Immunochemical structure of hepatitis B e antigen in the serum.
Authors: Takahashi K , Machida A , Funatsu G , Nomura M , Usuda S , Aoyagi S , Tachibana K , Miyamoto H , Imai M , Nakamura T , Miyakawa Y , Mayumi M
Published: December 2022

Hepatitis B e antigen (HBeAg) constitutes the nucleocapsid of hepatitis B virus (HBV) and occurs in association with plasma proteins, particularly with IgG, in the serum of persons infected with the virus. A polypeptide with an approximate m.w. of 15,500 (P15.5) is obtained either from HBeAg in the serum or from the nucleocapsid of HBV. P15.5 preparations from serum and virus resembled closely each other in the amino acid composition. The C-terminus amino acid sequence of P15.5 from serum was determined to be -Thr-Thr-Val-Val, whereas that from the virus ended with -Thr-Thr. The same sequence of four amino acid residues was found on the gene coding for the nucleopeptide of hepatitis B virus with a molecular size of 19,000 daltons (P19). P15.5 identified on the nucleotide sequence of P19 was composed of 149 amino acid residues with a calculated molecular size of 16,770 daltons. The gene coding for P19 had two -Asp-Pro-connections. By splitting these connections in P19 and P15.5 preparations with formic acid, smaller polypeptides were obtained with sizes predicted from the nucleotide sequence and with the N-terminus amino acid of proline as expected. One of two monoclonal antibodies raised against the core of Dane particles (HBcAg) bound with P15.5 preparations purified from serum and HBV. The IgG fraction from a human serum containing antibodies to HBcAg but not to HBeAg bound with P15.5 also. On the basis of the results obtained, the IgG molecules associated with P15.5 in the serum of persons infected with HBV may well represent the antibodies against HBcAg with limited specificities.
Recovery from a viral respiratory tract infection. IV. Specificity of protection by cytotoxic T lymphocytes.
Authors: Wells M A , Daniel S , Djeu J Y , Kiley S C , Ennis F A
Published: December 2022

Immune spleen cells enhanced for influenza-specific cytotoxic activity after exposure to virus-infected stimulator cells in vitro effect recovery when transferred to nude and immunocompetent mice with influenza pneumonia (5). This protective effect correlated with the virus-specific cytotoxic activity of the transferred lymphocytes and is removed by treatment with anti-0 serum and complement. The experiments presented here indicate that spleen cells taken directly from mice undergoing a primary or secondary infection are less protective than immune spleen cells that are restimulated in vitro before transfer. This decreased ability to clear pulmonary virus and effect survival correlated with their relatively lower levels of influenza-specific cytotoxicity. Protection did not correlate with the level of natural killer cell activity of transferred cells. The results also indicate the immune spleen cells that are protective are influenza A subtype cross-reactive and are H-2-restricted; H-2d immune spleen cells effected recovery of H-2d but not H-2k challenged mice.
Influence of Igh-C- and MHC-linked genes on the activity of immunoglobulin-recognizing T cells.
Authors: Bikoff E , Bona C A
Published: December 2022

BALB/c Lyt-1+ cells that proliferate in response to NP-modified BALB/c Ig fail to respond to BALB/c Ig modified by a different hapten, TNP. By contrast, when NP-modified BALB/c Ig is used as the immunogen in C.B-20 mice, a strain congenic with BALB/c but expressing the Ighb allotype of C57BL/6 (B6), a partial cross-reaction between NP- and TNP-BALB/c Ig is observed. Similarly, strains expressing different Igh haplotypes also show distinct reactivities toward NP-B6 Ig and NP-modified myeloma proteins. Thus, the proliferative response to NP-modified Ig is regulated by Igh-linked genes. In this paper, we also characterize the T cell proliferative response to IgG2a of the b allotype. We show that allotypic determinants on this molecule are recognized in association with self MHC-encoded gene products and that responsiveness is controlled by MHC-linked Ir genes. Thus, products of MHC-linked genes also influence the activity of Ig-recognizing T cells. Taken together, experiments described in this report suggest that T cells directed against immunogenic determinants on antibody molecules are governed by the same rules as T cells that respond to conventional antigens.
The cell surface phenotype of a naturally occurring human suppressor T-cell of restricted specificity: definition by monoclonal antibodies.
Authors: Brankovan V , Bean M A , Martin P J , Hansen J A , Sadamoto K , Takahashi Y , Akiyama M
Published: December 2022

A series of murine monoclonal antibodies was used to characterize the surface phenotype of a naturally occurring E+ B14-specific suppressor cell present in the blood of a patient with recurrent superficial bladder carcinomas. This suppressor T cell is different from the few naturally occurring suppressors of MLC reported by others in that its function does not require HLA-D compatibility with the cells being suppressed. This patient's T cells had decreased proportions of T3+, 10.2+, 9.3+, and T4+ cells, a normal proportion of T8+ cells, and a markedly increased proportion of Ia-positive cells. The MLC-suppressor assay was used to test the functional activity of cell populations selectively depleted by treatment with monoclonal antibodies and C or enriched by panning. The B14-specific suppressor T cells in this patient expressed T cell markers recognized by monoclonal antibodies 9.6, T3, and the T cell subset marker identified by OKT8 (T8+) but not the subset marker identified by OKT4 (T4-). Ia antigens were present on a substantial portion of these suppressor T cells. Thus, this unique, naturally occurring suppressor T cell has a phenotype similar to that of other T suppressor cells in humans, adding validity to the concept of functionally distinct T cell compartments in human blood.
Induction of phenotypic differentiation, interleukin 2 production, and PHA responsiveness of "immature" human thymocytes by interleukin 1 and phorbol ester.
Authors: de Vries J E , Vyth-Dreese F A , Figdor C G , Spits H , Leemans J M , Bont W S
Published: December 2022

Small human thymocytes (ST) representing 70% of the thymocytes were isolated according to size by centrifugal elutriation. Although these ST contained approximately 30% PNA-cells, they failed to respond to lectins, indicating the existence of a PNA-ST subset that can be considered to belong to the "immature" thymocyte population. The ST were induced to proliferate if, in addition to PHA, IL 1-containing supernatants of highly purified monocyte cultures or 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were present. The incubation of the ST for 90 hr with TPA or IL 1 in the absence of PHA resulted in a strong reduction in the percentage of cells reacting with the immature thymocyte markers TdT and PNA. In addition, the OKT6+ cells were partially reduced after incubation with IL 1. Concomitantly, an increase in the percentage of cells reacting with the mature T cell markers OKT1 and OKT3 was observed, whereas HLA antigens became strongly expressed on all ST. Although IL 1 or TPA were unable to induce proliferation of the ST, these substances induced IL 2 production by these cells. These shifts to cells with more "mature" phenotypes that are able to produce IL 2 were not observed if the ST were incubated with PHA or culture medium only. The responder capacity of the ST to PHA plus TPA was not significantly affected by the depletion of the more "mature" OKT3+ and OKT1+ cells. In addition, in this situation OKT1+, OKT3+, OKT6- cells were found to be generated from OKT1-, OKT3-, OKT6+ cells. Therefore, it could be excluded that the proliferative responses were due to a selective expansion of a preexisting mature T cell population. Our results indicate that TPA mimics IL 1 in the induction of differentiation of the ST to a stage in which subpopulations of these cells are able to produce IL 2 and to respond to PHA. Because only the proliferating ST were found to react with a monoclonal antibody, which is thought to be directed at the IL 2 receptor (anti-Tac), our data suggest that PHA is required for the induction of expression of receptors for IL 2 in those ST subpopulations that are able to proliferate in the presence of IL 2 generated in situ.
Distinction of two subtypes of human leukocyte interferon (IFN-alpha) on B cell activation. B cell proliferation by two subtypes of IFN-alpha.
Authors: Harada H , Shioiri-Nakano K , Mayumi M , Kawai T
Published: December 2022

We examined the effect of interferon (IFN), with particular emphasis on the effects of the two subtypes of IFN-alpha (IFN-alpha A and IFN-alpha B) on the B cell proliferation induced by Staphylococcus aureus Cowan I bacterium (SpA Col). An increase of SpA Col-induced proliferation was observed in the presence of 100 to 1000 U/ml of IFN-alpha, but a decrease of SpA Col-induced proliferation was observed in the presence of 1000 to 10,000 U/ml of IFN-beta. The two subtypes of IFN-alpha had different effects on cell proliferation; a significant enhancement was shown in the presence of 1000 to 10,000 U/ml of IFN-alpha A, but inhibition was shown in the presence of 1000 to 10,000 U/ml of IFN-alpha B. In the reconstitution test of the two subtypes of IFN-alpha, the boundary between enhancement and inhibition of SpA Col-induced proliferation was revealed when the proportion of IFN-alpha A and IFN-alpha B (IFN-alpha A:IFN-alpha B) ranged between 8:2 and 9:1. Toward the SpA Col-induced responses, the above IFN were all found to act on B cells directly, independent of the presence of T cells. Proliferative responses by IFN-alpha and IFN-alpha A, however, were shown to be slightly dependent on the presence of monocytes. The lymphocyte proliferation induced by other mitogens (phytohemagglutinin, concanavalin A, pokeweed mitogen, and protein A of S. aureus) were all inhibited by the above IFN.
The interaction of C3b bound to pneumococci with factor H (beta 1H globulin), factor I (C3b/C4b inactivator), and properdin factor B of the human complement system.
Authors: Brown E J , Joiner K A , Gaither T A , Hammer C H , Frank M M
Published: December 2022

Pneumococcal cell walls are potent activators of the alternative complement (C) pathway; pneumococcal capsules are not. C3b that is deposited onto the cell walls of encapsulated organisms, however, functions inefficiently in host defense compared to C3b deposited onto capsular polysaccharides. Results of previous studies with guinea pig erythrocytes suggested that C3b deposited onto surfaces that do not activate the alternative pathway is rapidly inactivated. In the present study, we examined the interactions of C3b bound to pneumococcal capsules, to pneumococcal cell walls, and to the surface of sheep erythrocytes (E) with the serum control proteins, Factor H (beta 1H globulin) (H) and Factor I (C3b/4b inactivator) (I), and with Factor B (B) of the alternative C pathway. Conversion of bound C3b to C3bi was assayed by binding of radiolabeled conglutinin in a quantitative binding assay. Neither pneumococcal cell wall C3b nor capsular C3b was converted efficiently to a conglutinin-binding form by serum incubation. Experiments with purified C components showed that, after incubation with H and I, fewer conglutinin-binding sites were created on pneumococci than on E bearing equal numbers of C3b. Molecular analysis demonstrated that this did not result from cleavage of pneumococcal-bound C3b to an unusual, nonconglutinin-binding form of the molecule. Binding studies in which radiolabeled H was used demonstrated that the majority of C3b that is bound to both pneumococcal capsules and cell walls bound H with a lower affinity than did E-bound C3b. Studies of the binding of radiolabeled B demonstrated that C3b that was bound to pneumococcal cell walls and to E demonstrated equal affinity for B. In contrast, the majority of C3b that was fixed to pneumococcal capsules bound B with only 1/30 as high affinity. We conclude that pneumococcal capsules are not alternative pathway activators because the low affinity of capsular C3b for B leads to inefficient formation of an alternative pathway convertase, C3bBb. With regard to H binding, both cell wall- and capsular-bound C3b act as if they were in a "protected site" and resist degradation by the control proteins.
Induction of granulocyte histaminase release by particle-bound complement C3 cleavage products (C3b, C3bi) and IgG.
Authors: Melamed J , Medicus R G , Arnaout M A , Colten H R
Published: December 2022

The interaction of opsonized particles with human granulocytes promotes a number of important biologic functions, including phagocytosis, superoxide generation, and release of a variety of enzymes, including histaminase. We have previously determined that histaminase release occurs via a C3-dependent process. Although fluid-phase C3b dimers can mediate release, the relative effects of particle-bound C3b and C3bi and of IgG have not been examined. In this report we demonstrate that particle-bound C3 deposited on activators of the alternative C pathway effected histaminase release in the absence of IgG. Particle-bound C3bi and C3b were both effective as mediators of histaminase release. The extent of release varied as a function of the activating surface on which C3 was deposited (zymosan C3b was considerably more potent than C3b bound to rabbit erythrocytes, which was slightly more potent than C3b bound to neuraminidase-treated sheep erythrocytes). In contrast, C3b or C3bi deposited on nonactivating surfaces (such as sheep erythrocytes) at inputs of up to 2,000,000 molecules per granulocyte failed to induce histaminase release unless IgG was also present. The ability of C3b bound to particles that serve as activators of the alternative pathway to induce histaminase release is apparently not the result of decreased susceptibility of C3b to proteolysis or to an increased binding affinity to the C3b receptor, but may relate to the interaction of other surface structures on activating particles with the PMN membrane.
Cellular interactions in the cytotoxic T lymphocyte response to herpes simplex virus antigens: differential antigen activation requirements for the helper T lymphocyte and cytotoxic T lymphocyte precursors.
Authors: Schmid D S , Rouse B T
Published: December 2022

The role and induction requirements of helper T lymphocyte responses to herpes simplex virus type 1 (HSV-1) was examined. Splenocytes from mice that had been primed in vivo with infectious HSV-1 can be restimulated in vitro with live or partially UV-inactivated HSV-1 to generate high levels of herpes virus-specific cytotoxic T lymphocyte (CTL) activity. By comparison, naive splenocytes or splenocytes taken from mice primed with heat-inactivated HSV-1 failed to generate CTL after in vitro viral stimulation. In addition, infectious HSV-primed splenocytes can be rendered unresponsive to secondary in vitro restimulation by pretreatment with anti-Lyt-1 antiserum plus complement. Spleen cells were taken from mice that had been primed and restimulated in vivo with infectious HSV-1. Two days after the second priming, splenocytes were prepared and irradiated. These cells were capable of assisting in the generation of CTL to varying degrees in all of the above unresponsive populations of cells. The irradiated cells did not produce detectable levels of CTL activity when cultured alone with antigen. Also, if the irradiated splenocytes were treated with anti-Lyt-1 plus complement before their addition to cultures, all restorative activity was ablated. In contrast, irradiated splenocytes from mice that had been primed and restimulated in vivo with either heat-inactivated or UV-inactivated HSV-1 were unable to provide help to naive or helper-depleted cultures. The failure to supply helper activity appears not to involve the preferential activation of suppressor cells, as evidenced by cell mixing experiments and the addition of concentrated, antigen-stimulated spleen cell supernatant fluids to secondary anti-HSV-1 splenocyte cultures. Proliferative assays using interleukin 2- (IL 2) dependent cell lines as a measure of relative helper activity indicated that the inactivated forms of HSV-1 were incapable of effectively enlisting helper activity. These experiments therefore suggest that the observed failure of heat-inactivated or UV-inactivated HSV-1 preparations to induce anti-HSV CTL responses reflects the inability of the HSV-1-specific subset of helper T lymphocytes to recognize these forms of the antigen.
Sequential activation of murine mononuclear phagocytes for tumor cytolysis: differential expression of markers by macrophages in the several stages of development.
Authors: Johnson W J , Marino P A , Schreiber R D , Adams D O
Published: December 2022

Murine mononuclear phagocytes in various stages of activation were elicited in vivo or induced in vitro. The cytolytic competence of each type of macrophage, before and after treatment with traces of endotoxin, was quantified. Populations of responsive, primed, and activated macrophages, but not resident macrophages, expressed five markers that have been reported to characterize inflammatory macrophages: increased spreading, increased phagocytosis via Fc and C3 receptors, increased secretion of plasminogen activator, and decreased content of the ectoenzyme 5' nucleotidase. Primed macrophages secreted cytolytic protease (CP) when pulsed with traces of endotoxin; the resident and responsive macrophages did not. The primed macrophages bound tumor cells to a considerable degree; the resident and responsive macrophages did not. The cytolytically activated macrophages bound tumor cells well and secreted lytic protease spontaneously. The capacity for augmented, selective binding of tumor cells is apparently induced in only one step by application of lymphokine(s). The capacity for secreting CP, however, is regulated in two steps; initial priming signals--lymphokine(s)--prepare the macrophages for secretion, and a second signal, such as endotoxin or endotoxin plus tumor cells, triggers the actual release of CP.
Two stages of b cell memory development expressing differential sensitivity to stimulation with thymus-dependent and thymus-independent antigenic forms.
Authors: Rennick D M , Morrow P R , Benjamini E
Published: December 2022

We have shown that spleen cells specifically primed to the decapeptide determinant (a.a. 103-112) of the thymus-dependent (TD) antigen, tobacco mosaic virus protein (TMVP), can be secondarily stimulated to antibody synthesis by either TD or TI forms of the decapeptide. Further, TD- and TI-responsive memory B cells consisted of overlapping populations which were indistinguishable by the specificity and isotype composition of the antibodies which they synthesized. In the present study, two functionally distinct but developmentally related memory B cell subsets were identified by their differential sensitivity to repeated in vivo stimulation with various combinations of TD and TI decapeptide antigens. One subset of memory B cells responded only to TMVP or decapeptide conjugated to succinylated human gamma-globulin (SHGG) with a strict requirement for carrier-primed theta-positive cells. Secondary challenge with these two TD antigens elicited antidecapeptide antibodies and specific memory regeneration. This TD-responsive memory B cell subset contained the precursors of a second memory B cell subset which was activated by decapeptide-Brucella abortus (TI.1 prototype), as well as by TMVP or decapeptide-SHGG. Stimulation of the second memory B cell subpopulation by decapeptide-BA (previously shown not to be dependent on conventional T cell help) was typified by differentiation into antibody-forming cells without significant memory regeneration.
Effects of neonatal anti-delta antibody treatment on the murine immune system. I. Suppression of development of surface IgD+ B cells and expansion of a surface IgM+ IgD- B lymphocyte population.
Authors: Finkelman F D , Mond J J , Metcalf E S
Published: December 2022

Lymphocytes that bear surface (s) IgD make up the majority of B cells in mature mice and are the precursors of most antibody secreting cells in primary immune responses made by these mice. In order to study the functional capabilities of the minority sIgD- B lymphocyte population and to gain insight into the possible roles of sIgD, we attempted to abort the development of sigD+ B cells and to expand the sigM+IgD- B cell population by treating mice from birth with affinity-purified rabbit antibodies specific for mouse IgD (RaM delta). RaM delta-suppressed mice had no detectable sIgD+ spleen, lymph node, or bone marrow cells and, on average, only 20% as many sIgM+Ia+ splenic B cells as control mice but had normal numbers of splenic T cells. Lymph nodes from anti-delta suppressed mice were even more depleted of B cells than were spleens from these mice, whereas the percentage of bone marrow B cells in these mice was relatively normal. Germinal centers of anti-delta suppressed mice were fairly normal in appearance, whereas follicular mantle layers, the locus of most sIgD+ B cells in normal mice, were greatly depleted. In addition to their lack of sIgD, splenic B cells of anti-delta suppressed mice differed from those found in control mice in that they bore, on average, twice as much sIgM as control cells, and in that they included an increased percentage of large, DNA synthesizing cells as compared with spleen cells from control mice. However, most sIgM+IgD- splenic B cells from anti-delta suppressed mice were small, nonproliferating cells. B cells from anti-delta suppressed mice insert little or no sIgD into their cell membranes since they continued to bear no detectable sIgD 2 days after in vivo neutralization of RaM delta and since, unlike B cells from control mice, they failed to be activated by a single in vitro injection of a goat anti-mouse delta antibody. Despite their lack of sIgD+ B cells, anti-delta suppressed mice had relatively normal levels of serum IgG as well as normal to increased levels of serum IgM. Thus, sIgM+IgD- B cells appear to have the potential of differentiating into Ig secreting cells in vivo without acquiring sIgD.
Effects of neonatal anti-delta antibody treatment on the murine immune system. II. Functional capacity of a stable sIgM+sIa+sIgD- B cell population.
Authors: Metcalf E S , Mond J J , Finkelman F D
Published: December 2022

Mice were injected from birth with rabbit anti-mouse IgD (RaM delta). Studies in the accompanying paper indicated that the B cells from these mice have a stable sIgM+sIa+sIgD- B cell population. In the studies presented herein the in vivo and in vitro antibody responses of these mice were examined as well as their responsiveness to various B cell mitogens. The results indicate that splenic B cells from RaM delta-suppressed mice differ from normal adult murine splenic B cells by failure to express increased sIa antigen after in vitro stimulation with soluble anti-mu antibodies and failure to proliferate in response to in vitro stimulation with either soluble or Sepharose-bound anti-mu antibody. Nevertheless, these mice generate relatively normal in vivo IgM and IgG antibody responses to TI-2 and to both high and low epitope density forms of TD antigens as well as secondary IgG antibody responses to a TD antigen. In addition, B cells from RaM delta-treated mice generate relatively normal primary in vitro IgM antibody responses to TI-1, TI-2, and TD antigens. These data suggest that sIgD- B cells can produce antibody responses to the majority of antigenic signals even though they appear to lack one or more differentiative pathways.
T cell dependence and factor reconstitution of in vitro antibody responses to TNP-B. Abortus and TNP-Ficoll: restoration of depleted responses with chromatographed fractions of a T cell-derived factor.
Authors: Mond J J , Farrar J , Paul W E , Fuller-Farrar J , Schaefer M , Howard M
Published: December 2022

In vitro anti-trinitrophenyl (TNP) antibody responses to TNP conjugates of killed Brucella abortus organisms (TNP-BA), an antigen previously designated as a type 1 thymus-independent (TI-1) antigen, are markedly diminished after vigorous depletion of T cells, as are the responses to the type 2 TI (TI-2) antigen, TNP-Ficoll. We, therefore, propose that these antigens be redesignated as type 1 and type 2, respectively, to reflect their T cell dependence but to differentiate them from classical T cell-dependent (TD) antigens. T cell-depleted responses to type 1 and type 2 antigens can be restored by the addition of a) EL4 supernatant, b) phenyl-sepharose-purified fractions of EL4 supernatant that are rich in interleukin 2(IL2), and c) pl 4.5-5.5 isoelectric focused (IEF) fractions of EL4 supernatant which are also rich in IL2 activity. Removal of IL2 activity from EL4 supernatant by absorption on IL2-dependent T cells substantially reduced its restorative ability. Whether the active principle in EL4 supernatant activity responsible for restoring responses to type 1 and type 2 antigens is IL2, and whether it acts directly on B cells or by acting on contaminating T cells, is unresolved.
Inhibition of human natural killer (NK) activity and antibody dependent cellular cytotoxicity (ADCC) by lipomodulin, a phospholipase inhibitory protein.
Authors: Hattori T , Hirata F , Hoffman T , Hizuta A , Herberman R B
Published: December 2022

A highly purified preparation of lipomodulin, a phospholipase-inhibitory protein from rabbit neutrophils treated with glucocorticoids, inhibited NK and antibody-dependent cellular cytotoxicity (ADCC) activities of human peripheral blood lymphocytes in a dose-dependent manner. The presence of lipomodulin during the early period of the cytotoxicity assay was necessary to obtain maximal inhibition. The inhibition of NK or ADCC activity by lipomodulin was greater when effector cells were treated with lipomodulin than when target cells were incubated with lipomodulin. As lipomodulin did not block binding of effector cells to target cells, our results suggest that lipomodulin inhibits the cytolytic phase of NK and ADCC activities after binding to target cells, and imply that phospholipase(s) may be involved in NK and ADCC activities.
A defect in the suppressor circuits among OKT4+ cell populations in patients with systemic lupus erythematosus occurs independently of a defect in the OKT8+ suppressor T cell function.
Authors: Sakane T , Kotani H , Takada S , Murakawa Y , Ueda Y
Published: December 2022

The autologous mixed lymphocyte reaction (MLR) is thought to be part of a regulatory role of T cells on B cell function. OKT4+, but not OKT8+, cells can proliferate in response to autologous non-T cells. Moreover, the OKT4+ cell population activated early in the course of autologous MLR functioned as inducer cells for the differentiation of B cells, whereas later in the response, the activated OKT4+ cells were particularly enriched in suppressor cells. A part of the autologous MLR appears to be an important pathway for the activation of feedback suppression mechanisms among cells contained within the OKT4+ populations. Patients with systemic lupus erythematosus (SLE) were studied with regard to the following OKT4+ cell functions in vitro after activation in the autologous MLR: a) proliferative response, and b) helper and suppressor activities for differentiation of B cells. A marked reduction in the proliferative response of OKT4+ cells was observed in SLE patients. SLE OKT4+ cells activated in the autologous MLR could function as helper cells but could not exert any suppressor activity. This OKT4+ cell abnormality was present regardless of the disease activity, and occurred in the absence of autoantibodies including anti-T cell antibodies. Instead, SLE anti-T cell antibodies could preferentially eliminate cells bearing the OKT8+ phenotype characteristic of suppressor cells in populations of normal T cells. These results suggest that the defect in the suppressor circuits among OKT4+ cell populations is intrinsic to SLE lymphocytes and that the OKT8+ suppressor T cell defect is caused by antibodies produced by the B cells of SLE patients.
Isolation of immunoglobulin class switch variants from hybridoma lines secreting anti-idiotope antibodies by sequential sublining.
Authors: Müller C E , Rajewsky K
Published: December 2022

The combination of a sensitive radioimmunoassay with a simple limiting dilution approach designated as sequential sublining (ssl) allowed us to isolate spontaneous class switch variants from two hybridoma lines secreting monoclonal anti-idiotope antibodies against a germ-line encoded antibody with defined hapten-binding specificity. We obtained two families of antibodies, one of which consists of IgG1, IgG2b, and IgG2a, the other consisting of IgG1, IgG2b, IgG2a, and IgE antibodies. The members of a family possess identical anti-idiotypic specificity. We describe serologic and biochemical properties of the class switch variants as well as the frequency and order of "forward" and "reverse" switching, and we compare the ssl approach to other related methods. The ssl allows the rapid isolation of somatic mutants, which have acquired a new predefined antigenic determinant, without complicated equipment and even when the frequency of the mutants is as low as 10(-6) or 10(-7).
Leukocyte complement: a possible role for C5 in lymphocyte stimulation.
Authors: Sundsmo J S
Published: December 2022

The results presented here show that Fab' antibody fragments directed to complement proteins C5, C6, and C7 inhibit lymphocyte stimulation in mixed lymphocyte culture (MLC) by up to 65%, as determined by decreased incorporation of 3H-thymidine. Lymphocyte stimulation induced by PHA-mitogen was also inhibited up to 100% by anti-C5 Fab'. Specificity of these reactions was established by the findings that goat anti-C5 or murine hybridoma anti-C5 both inhibited MLC; the inhibitory activity of anti-C5 Fab' was absorbed with highly purified C5 (but not with C3), and antibody directed to C3 did not inhibit lymphocyte stimulation by MLC or PHA. The effects of anti-C5 were exerted in a nontoxic manner. Cleavage of lymphocyte associated C5 with factor B (Bb) or with trypsin resulted in stimulation of lymphocyte thymidine incorporation. Purified C5a was found to induce lymphocyte stimulation in serum-free medium in pulse-chase types of experiments. Anti-C6 and C7 Fab' also inhibited lymphocyte stimulation induced in one-way MLC. These results suggest that C5, C5a, and/or C6 and C7 may play a role in triggering of lymphocyte blastogenesis.
Cell cycle associated changes in histamine release from rat basophilic leukemia cells separated by counterflow centrifugal elutriation.
Authors: Meyer C , Wahl L M , Stadler B M , Siraganian R P
Published: December 2022

This study evaluated histamine release from cells at different stages of the cell cycle. Cells from the cloned rat basophilic leukemia subline (RBL-2H3) were fractionated by counterflow elutriation according to size and density. The smallest cells were predominantly in the G1 phase of the cell cycle. These cells contained the least histamine and after IgE-mediated triggering released the lowest fraction of their total histamine. In contrast cells in the S, G2, and M stages were larger, contained more histamine and released more of their histamine after activation. When G1 stage cells were recultured, there was an increase in cell size, in histamine content and histamine release. Therefore, there is heterogeneity in the capacity of cells for IgE-mediated triggering at different stages in the cell cycle, with optimal release from the more mature cells.
Measurement of leukocyte motility and chemotaxis parameters with a linear under-agarose migration assay.
Authors: Lauffenburger D , Rothman C , Zigmond S H
Published: December 2022

The interpretation of quantitative assays for leukocyte chemotactic migration is usually made in terms of measurements such as leading front distance, total migrating cells, and leukotactic index. These quantities allow comparison of cellular migration behavior under specified conditions. They are not useful; however, for comparisons between systems or for correlation with in vivo performance, because they depend upon specific physical aspects of the assay system, such as the geometry, chemoattractant concentration and diffusivity, and observation time. It would be more helpful to measure intrinsic properties of cell movement that could be used for comparison between systems, for correlation with in vivo studies, and to increase our understanding of the cell physiology. In this paper we demonstrate a means of quantitating leukocyte random motility, chemokinesis, and chemotaxis in terms of parameters that do characterize intrinsic cell properties. These parameters are the random motility coefficient and the chemotaxis coefficient, which appear in theoretical models of cell migration. We examine how well such a model describes the leukocyte density profile data observed in a modified under-agarose assay having a linear geometry. Furthermore, we obtain values for the random motility coefficient (and its dependence upon the concentration of the attractant peptide FNLLP) and for the chemotaxis coefficient for leukocytes responding to FNLLP.
Two distinctive patterns of monocyte immunoregulatory and effector functions in heavy human infections with Schistosoma mansoni.
Authors: Olds G R , Kholy A E , Ellner J J
Published: December 2022

We evaluated the relationship between immunoregulatory and effector functions of monocytes in subjects with heavy S. mansoni infection (greater than 400 eggs/g of stool). Two main patterns were found. In seven individuals (mean 601 eggs/g), the depletion of adherent cells from peripheral blood mononuclear cells (PBMC) increased blastogenic responses to soluble worm antigenic preparation (SWAP) from a stimulation index (SI) of 3.2 +/- 1.0 to 11.0 +/- 3.0 (p less than 0.01). The presence of indomethacin (1.0 micrograms/ml) in cultures of PBMC from these subjects increased the SWAP response to 7.1 +/- 2.0 (p less than 0.05). In contrast, neither adherent cell depletion nor indomethacin affected blastogenesis induced by nonschistosome antigens or nonspecific mitogens. In this group of infected individuals, monocyte killing of schistosomula and adherence to plastic were increased 122% (p less than 0.01) and 50% (p less than 0.01) over the respective values obtained in uninfected, age-matched controls. A second pattern was found in 10 individuals with a significantly higher intensity of infection (1339 eggs/g of stool (p less than 0.02)). PBMC from these subjects failed to respond significantly to SWAP (SI = 2.0 +/- 0.5), whereas the levels of responses to other antigens and mitogens were maintained at rates comparable to controls. Adherent cell depletion did not significantly affect the blastogenic response (1.8 +/- 0.2), nor did the presence of indomethacin in cultures (2.0 +/- 0.5). Moreover, monocyte-mediated schistosomula killing was depressed in these individuals (50% of controls, p less than 0.05) as was adherence to plastic (77% of controls, p less than 0.05).
Modulation of granulomatous hypersensitivity. VI. T lymphocyte subsets influence mast cell density in liver granulomas of Schistosoma mansoni-infected mice.
Authors: Weinstock J V , Boros D L
Published: December 2022

In murine schistosomiasis mansoni, a complex series of cell-cell interactions involving T cell subclasses regulates the intensity of the inflammatory granulomatous response. Recent evidence suggests that granuloma mast cells also participate in the regulatory process by the release of histamine. The current study was performed to determine factors that affect the number of granuloma mast cells. More mast cells were detected in liver granulomas from chronically (20-wk) as opposed to acutely (8-wk) infected mice. Adoptive transfer of spleen cells from 20-wk-infected donors into acutely (6-wk) infected recipients increased granuloma mast cell density. Treatment of spleen cells with anti-Thy-1.2 or anti-Lyt-1.1 antiserum and complement, but not anti-Lyt-2.1 or normal mouse serum, abrogated adoptive transfer-induced, augmentation of granuloma mast cell density. Treatment of acutely infected animals with cyclophosphamide or cimetidine (H2 antagonist enhanced granuloma mast cell density. These data suggest that granuloma mast cell density is dependent upon subsets of T lymphocytes.
One (H-2D2b) of the three Db region-controlled molecules (H-2D1b, H-2D2b, H-2Lb) is not detected in bm13 mutant.
Authors: Iványi D , Démant P
Published: December 2022

Analysis of the antigenic heterogeneity of Db region products by the technique of antibody-induced redistribution of cell surface antigens (capping) revealed the existence of two types of H-2 molecules reactive with the monoclonal anti-Db antibody, B22-249R 1 (H-2.m2). The relationship of the two H-2.2-positive molecules described here is similar to that of H-2D and H-2M detected in the products of the Dd region; they differ in the repertoire of the H-2 public specificities, although they share the private specificity. We designate them, in accordance to recently proposed nomenclature, H-2D1b and H-2D2b. Both types of molecule have been detected on T lymphocytes of C57BL/6 (H-2b), C3H.B10(H-2b), and B10.A(2R) (H-2h2, KkDb) strains. In mutant strain B6.C-H-2bm13, however, only one type of H-2.2-positive molecule, H-2D1b, could be detected. This finding resembles the situation in the d haplotype, in which mutant strain B10.D2 (M504) (H-2dm1) had only one molecule (H-2Dd), of the two H-2.4-positive molecules H-2Dd and H-2Md that could be detected. A third Db region molecule, H-2Lb, does not carry the Db private specificity H-2.2, and it is detectable by some of the antibodies against the H-2.28 family of specificities; it is distinct from the Qa-2 molecule. The H-2Lb molecule was detected in all strains tested in this experiment, including the bm13 mutant.