bluuebunny/crossref_metadata_2025 huggingface dataset:
Alloantibodies to PHA-activated lymphocytes detect human Qa-like antigens.
Authors: Gazit E , Gothelf Y , Gil R , Orgad S , Pitman T B , Watson A L , Yang S Y , Yunis E J
Published: December 2022

Platelet-absorbed sera were obtained from placental clots after delivery by multiparous women. These sera contained antibodies that react with PHA-activated lymphocytes after the latter are separated from peripheral blood and expanded with interleukin 2. These alloantibodies did not react with resting T lymphocytes, but reacted with B lymphocytes, PHA-activated lymphocytes, or both types of cells obtained from some but not all of the T lymphocyte donors. Reactions against B lymphocytes were associated with anti-Ia-like antibodies on the basis of blockage by turkey antibodies against human Ia. Reactions against PHA-activated lymphocytes that were blocked by turkey anti-beta 2m were classified as 'HT'. Several antibodies were found to give reactions to HT determinants in separate panels of lymphocytes from Tel Aviv and Boston. The reproducibility of the cytotoxicity reactions was 89%. Altogether, 23 of 1100 sera were found to contain these reactions when screened by a panel of cells obtained from 30 individuals of known HLA phenotypes. Correlation coefficients were determined for all reactions, determining three clusters of significant reactivities: sera 965 and 1032 defined HT-2; sera SF48 and 1642 defined HT-3; and sera 1136, 1605, 1014, and 1227 defined HT-4. HT-2 was found to be inherited with HLA in 11 siblings from four families. Some of these antibodies react with antigens (non-HLA) containing beta 2m that were expressed on activated lymphocytes, but not on resting T lymphocytes, and did not react with thymocytes from the same donors of the peripheral lymphocytes. Our findings suggest that the HT alloantigens expressed on lectin-activated lymphocytes are class I differentiation antigens of a system analogous to the murine Qa system.
Human helper T cell factor(s). III. Characterization of B cell differentiation factor I (BCDF I).
Authors: Hirano T , Teranishi T , Onoue K
Published: December 2022

Staphylococcus aureus Cowan I (SAC) induced proliferation of human B cells but did not lead the cells to differentiate to immunoglobulin (Ig)-producing cells. The differentiation of SAC-stimulated B cells to IgG-producing cells was totally dependent on T cells or T cell factor, designated B cell differentiation factor I (BCDF I). BCDF I exerted its effect on B cells between 48 and 72 hr after the initiation of the culture, at which time the 3H-TdR uptake of SAC-stimulated B cells had already reached a maximal level. Highly purified human IL 2 did not induce the differentiation of SAC-stimulated B cells for IgG-producing cells. Therefore the differentiation-inducing ability of BCDF I was not due to the residual T cells in a purified B cell preparation, which might have been activated by a possible contamination of IL 2 in the BCDF I preparation. The apparent m.w. of BCDF I was estimated to be 20,000 by gel filtration. Isoelectric focusing analysis showed that its activity was distributed in three fractions corresponding to pI 6.5, 7.0, and 8.0. In contrast, BCDF II, which induced IgG production in an Epstein Barr virus-transformed B lymphoblastoid cell line, was focused in the fractions with pI range of 4.8 to 5.5. Thus there are at least two different kinds of BCDF for human B cells, designated here as BCDF I and BCDF II.
Lymphokine regulation of activated (G1) lymphocytes. II. Glucocorticoid and anti-Tac-induced inhibition of human T lymphocyte proliferation.
Authors: Bettens F , Kristensen F , Walker C , Schwuléra U , Bonnard G D , de Weck A L
Published: December 2022

The regulation of the first cell cycle of human, activated (G1) PBL was analyzed by flow cytometry and [3H]thymidine incorporation. Endogenous IL 2 production was blocked in situ by pharmacologic concentration of DEX (100 to 1000 nM), resulting in an 80 to 90% reduction of thymidine uptake. Although T lymphocyte activation (G0-G1a transition) by PHA was unaltered, cells remained in the G1a phase of the cell cycle due to insufficient RNA synthesis for proliferation. The addition of IL 2-containing supernatants reversed this inhibitory effect of DEX by allowing the cells to synthesize more RNA (G1a-G1b transition). Such cells could enter the S phase and proliferate. Similar studies were performed on cells treated with a monoclonal antibody (anti-Tac) against the IL 2 receptor. In these studies, IL 2-induced RNA synthesis, and subsequent proliferation of DEX-treated and PHA-stimulated cells was inhibited by anti-Tac. Anti-Tac did not, however, inhibit the effect of endogenous IL 2 (PHA-stimulated PBL without DEX treatment), although it did bind equally well to such cells. Thus, IL 2 directly or indirectly regulates human T cell proliferation at the level of RNA synthesis. Furthermore, anti-Tac can inhibit the mitogenic signal given by endogenous IL 2, but not by in situ produced IL 2, an observation of importance to further investigations of the mechanisms by which IL 2 interacts with specific receptors to elicit proliferation.
Serologically detectable polymorphism of the HLA-DC alpha-subunit.
Authors: Tosi R , Tanigaki N , Sorrentino R , Centis D , Ferrara G B
Published: December 2022

Two 8th Workshop alloantisera, 8W1062 and 8W614, which were classified respectively as anti-DR5 and anti-DR3, were found to react with an Ia preparation from LG38 cells (DR5,5) that was depleted of DR and BR molecules and enriched in DC molecules by pretreatment with a monoclonal antibody and an antiserum against alpha-subunits of DR and BR molecules. The reaction of both alloantisera was inhibited by DR3-positive, DR5-positive, and DRW13-positive individuals. This pattern does not correspond to any of the hitherto reported supertypic specificities. Both antisera were shown to bind to the alpha-subunit isolated from the DC-enriched preparation but not to the beta-subunit. The specificity has been named DC alpha 3. Family studies show the segregation according to the HLA haplotype patterns. This demonstrates by formal genetics criteria the HLA linkage of the locus controlling the DC alpha-subunit.
Glucocorticoid activation of a calcium-dependent endonuclease in thymocyte nuclei leads to cell death.
Authors: Cohen J J , Duke R C
Published: December 2022

Dexamethasone and corticosterone kill mouse thymocytes, as measured by eosin uptake, after several hours of in vitro incubation. This killing requires RNA and protein synthesis, because it is inhibited by cycloheximide, emetine, or actinomycin D. An earlier event than cell death is the extensive fragmentation of nuclear DNA into oligonucleosomal subunits; this fragmentation also requires RNA and protein synthesis. The DNA cleavage results from the action of an endonuclease that preferentially cleaves DNA in the linker regions between nucleosomes. This endonuclease is found constitutively in the nuclei of thymocytes and some other cells, and requires calcium and magnesium ions for its activation; if isolated fresh thymocyte nuclei are incubated with these ions, as much as 77% of their DNA is cleaved within 90 min. Thus, the protein for which synthesis is necessary for glucocorticoid-induced thymocyte death is not the endonuclease itself, but is in some way involved in its activation; we suggest that it may be part of a system for transporting calcium into the nucleus. The endonuclease is inhibited by zinc, which also prevents thymocyte death. It appears that glucocorticoids cause thymocyte death by activating an enzyme that rapidly and extensively degrades DNA. This "death from within" is biochemically and morphologically different from toxic or accidental cell death, such as that induced by azide, heat, or antibody and complement treatment. Although mature T cells also contain the endogenous endonuclease, they lack the glucocorticoid-inducible mechanism for activating it, and are thus glucocorticoid-resistant.
Oxidative killing of the intraerythrocytic malaria parasite Plasmodium yoelii by activated macrophages.
Authors: Ockenhouse C F , Shear H L
Published: December 2022

The capacity of macrophages activated in vivo and in vitro to kill Plasmodium yoelii was investigated. Macrophages activated by BCG-, Con A-, or malaria-induced lymphokines (LK) were cultured with P. yoelii-parasitized erythrocytes (PE). In some experiments, effector and target cells were separated by a 0.45-micron filter. Parasite viability was assessed a) in vivo by injection of mice and quantitative detection of parasites by RIA or b) in vitro by the incorporation of 3H amino acids into parasite proteins. Activated macrophages killed target PE in a dose-dependent manner by elaborating a membrane-permeable soluble factor(s). The addition of small amounts of immune serum augmented the killing of the parasites. LK-activated macrophages underwent an oxidative burst upon the phagocytosis of PE as evidenced by the accumulation of reduced formazan in the NBT assay. The magnitude of the oxidative response corresponded to the number of parasites that were ingested. The phagocytosis-induced oxidative burst was necessary for subsequent killing of Plasmodium. Parasites incubated in microchambers separated from macrophages by a 0.45-micron filter were susceptible to H2O2 released by LK-activated macrophages incubated with PMA, opsonized zymosan, or P. yoelii antigen. Inhibition of protein synthesis by parasites exposed to products of activated macrophages was abrogated by preincubating macrophages with catalase but not with SOD, mannitol, or histidine. These results suggest that phagocytosis-associated oxidative mechanisms mediate the destruction of the malaria parasite. Hence, cell-mediated as well as antibody-dependent mechanisms cooperate in the immune response against malaria.
Monoclonal antibodies to a 140,000-m.w. protein on Plasmodium knowlesi merozoites inhibit their invasion of rhesus erythrocytes.
Authors: Miller L H , David P H , Hudson D E , Hadley T J , Richards R L , Aikawa M
Published: December 2022

Merozoites are the invasive stage of the malaria parasite, which are released from infected erythrocytes to invade other erythrocytes. Antibody to surface antigens on merozoites may prevent invasion by agglutinating merozoites as they are released from infected erythrocytes or by blocking receptors before contact of merozoites with the host erythrocyte. Monoclonal antibodies were produced to a 140,000-m.w. protein on the merozoite surface. The protein was synthesized by the mature intraerythrocytic parasite, the schizont, as a 143,000-m.w. protein and had a m.w. of 140,000 on the surface of free merozoites. The monoclonal antibodies were shown to bind to the surface of merozoites by immune electron microscopy. Ascitic fluid containing four of 11 anti-140,000 monoclonal antibodies partially blocked invasion of erythrocytes by merozoites released from schizont-infected cells. The low invasion rate was always associated with a high frequency of multiply infected erythrocytes (two or more rings per erythrocyte). Monoclonal antibodies purified by (NH4)2SO4 precipitation and diethylaminoethyl column fractionation also blocked invasion and caused multiple invasion of individual erythrocytes. The monoclonal antibodies, incubated with free merozoites, did not block invasion, indicating that the antibodies did not bind to merozoite receptors for erythrocytes. We propose that the reduced rate of invasion and the multiple invasion of erythrocytes, the characteristic of these monoclonal antibodies, was caused by weak agglutination of merozoites as they were released from infected erythrocytes.
The cytolytic T lymphocyte response to the murine cytomegalovirus. I. Distinct maturation stages of cytolytic T lymphocytes constitute the cellular immune response during acute infection of mice with the murine cytomegalovirus.
Authors: Reddehase M J , Keil G M , Koszinowski U H
Published: December 2022

Limiting dilution (LD) analysis with two modifications, the expansion and the restimulation LD assay, led to the detection and quantification of two distinct in vivo maturation stages within the lineage of virus-specific self-restricted CTL after infection of mice with the murine cytomegalovirus (MCMV). A low frequency set, representing an average of 15% of the specifically activated CTL-P in a draining lymph node, generated virus-specific lytic activity in the absence of antigen, solely under expansion conditions provided by growth and differentiation interleukins. These cells were considered to be active and were denoted antigen-independent or interleukin-receptive CTL-P (IL-CTL-P). A high frequency set required additional antigen in vitro to generate functionally active clones, and therefore the cells were termed antigen-dependent. Both sets are present in vivo simultaneously at the peak of the acute immune response and represent antigen-activated cells because their existence strictly depends on a preceding priming event. IL-CTL-P disappear quickly after acute infection and are absent during the memory state. It is proposed that the isolation of IL-CTL-P could serve to detect viral antigen expression during persistent and/or recurrent herpes virus infections.
High frequency of splenic anti-class I cytotoxic T lymphocyte precursors correlates with in vivo rejection of K/D region disparate thyroid and islet grafts in mice.
Authors: Isakov N , Bach F H
Published: December 2022

The relationship between the ability of different recombinant mouse strains to reject thyroid and pancreatic islet grafts that differ in class I antigens and the frequencies of the recipients' cytolytic T lymphocyte precursors (CTL-P) directed against donor antigens was examined. We analyzed three different pairs of D region histoincompatible recombinant mouse strains in which unidirectional thyroid graft rejection occurred. Frequency analysis of their splenic CTL-P demonstrated that the mouse strains that rejected the grafts exhibit a relatively high CTL-P frequency against the donor D region-encoded alloantigens at a magnitude similar to that directed against a third party, which differ in the entire H-2 complex. Mouse strains that did not reject thyroid grafts exhibited a relatively low CTL-P frequency against the donor alloantigens, but a normal high frequency against alloantigens encoded by the entire H-2 complex of a third party strain. The effect of different routes of immunization on the two parameters was tested in B10.S(7R) mice, which accept B10.S thyroid grafts permanently. Immunization of B10.S(7R) mice by injection of 50 X 10(6) B10.S spleen cells i.p. did not confer the ability to reject B10.S thyroid grafts and did not affect the low splenic anti-B10.S CTL-P frequency. By contrast, B10.S(7R) mice that were immunized by transplantation of B10.S skin rejected a subsequent B10.S thyroid graft and at the same time demonstrated a fourfold increase in the specific CTL-P frequency. We found that the ability to reject thyroid and pancreatic islet grafts always correlated with high CTL-P frequency against the donor alloantigens; however, acceptance of allografts was not always correlated with low CTL-P frequency. We assume, therefore, that the high frequency of CTL-P against donor alloantigens may be a prerequisite (but is not always sufficient) for rejection of K/D region disparate thyroid and pancreatic islet grafts.
In vitro reeducated T helper cells from sarcoma-bearing mice inhibit sarcoma growth in vivo.
Authors: Forni G , Giovarelli M
Published: December 2022

Spleen cells from BALB/c mice bearing a small, but already clinically evident transplantable methylcholanthrene-induced sarcoma (CE-2) are not able to release interferons, proliferate and perform a cytotoxic response against CE-2 cells, nor able to inhibit their growth in vivo in a Winn-type neutralization assay. They can, however, be reeducated to be efficiently active against the tumor. Spleen cells (25 X 10(6) ) and 10(6) mitomycin C-treated CE-2 cells were cultured in 20 ml of medium for 6 days. The surviving spleen cells were then cultured for another 5 days under the same conditions plus 10% interleukin 2-rich supernatant from a clone of EL-4 thymoma cells stimulated with phorbol-12-myristate-13-acetate. Reeducated spleen cells were then able to inhibit the growth of a 100% lethal dose of CE-2 tumor cells in a Winn-type assay, even when the lymphocyte to tumor cell ratio was 5:1. In vitro, they released interferon-gamma when restimulated by CE-2 cells, and displayed a marked cytotoxicity in an 18-hr assay. Their in vivo tumor-neutralizing activity was not affected by the removal of Lyt-2.2+ lymphocytes, nor by the absorption of cytolytic cells on CE-2 monolayers. The absorbed cell population no longer contained cytotoxic cells nor cytotoxic cell precursors, but still contained CE-2-specific helper cells, which assist the in vitro induction of cytotoxic cells by normal thymocytes. Lyt-2.2-, noncytotoxic, reeducated spleen cells from tumor-bearing mice thus play an important role in tumor neutralization in vivo.
Establishment and functional analysis of a cloned, antigen-specific suppressor effector T cell line.
Authors: Nakauchi H , Ohno I , Kim M , Okumura K , Tada T
Published: December 2022

A long-term cultured suppressor T cell line (3D10) was established from the spleen cells of KLH hyperimmunized C3H mice. The cells of 3D10 suppressed the secondary antibody response against dinitrophenylated KLH both in vitro and in vivo. The 3D10 cells were capable of directly suppressing the antibody response mounted by B cells and Lyt-1+2-helper T cells without participation of Lyt-1+2+ cells, which indicates that 3D10 is an effector rather than an inducer-type suppressor T cell. The cell line was unable to suppress the response against DNP-FGG even in the presence of free KLH. By analysis with a fluorescence-activated cell sorter, 3D10 was found to bear determinants detectable by conventional anti-Ia as well as rabbit anti-VH. The Ia locus was mapped in the I-J subregion and was detected by either conventional or monoclonal anti-I-J antibodies. The I-J determinants detected by monoclonal antibodies were different from those expressed on inducer-type suppressor T cells. The cell line also bears an antigenic determinant detected by a monoclonal SJL anti-SJA/9 antibody (HA16) that recognizes an allotypic determinant on T cells linked to the immunoglobulin heavy chain locus. The results indicate that the cell line 3D10 represents a suppressor effector T cell that acts directly on carrier-specific helper T cells.
Loss of specificity in cytolytic T lymphocyte clones obtained by limit dilution culture of Ly-2+ T cells.
Authors: Shortman K , Wilson A , Scollay R
Published: December 2022

Nonspecific cytotoxicity developed reproducibly and with high frequency in limit dilution cultures consisting of low numbers of murine cells stimulated with concanavalin A in the presence of growth factors and irradiated filler cells. The individual clones in cultures showing nonspecific killing were all derived from single, Thy-1+, Ly-2+ cells. At early times of culture (day 5 or 6), clones appeared to be specific in their lytic activity, as expected of cytolytic T lymphocytes (CTL). On continued culture (day 8 or 9), most of the originally specific CTL clones became nonspecific, killing a range of murine target cells, both syngeneic and allogeneic. The lack of specificity was observed at all effector cell doses. The effector cells responsible for the nonspecific cytolysis were Thy-1+ and Ly-2+, as were most cells in the cultures. The effector cells had the normal DNA content for a dividing T cell population, and most cells in the cultures had a normal chromosome complement. In mixed cultures in which the responder cells and the irradiated filler cells were from different mouse strains, the nonspecific killers displayed the Thy-1 and H-2 allotypes of the responder, and not of the filler cells. The development of a broad cytotoxic potential appears to be a normal and rapid event when Ly-2+ T cell-derived CTL-clones are grown under these conditions; this is a caveat for the use of limit dilution cultures to determine the T cell specificity repertoire. The relationship between these nonspecific CTL, activated lymphocyte killers, and natural killer cells is discussed.
Soluble antigen-primed inducer T cells activate antigen-specific suppressor T cells in the absence of antigen-pulsed accessory cells: phenotypic definition of suppressor-inducer and suppressor-effector cells.
Authors: Damle N K , Mohagheghpour N , Engleman E G
Published: December 2022

This study was undertaken to characterize interactions among human T cell subpopulations involved in the generation of suppressor T cells specific for a soluble antigen. Purified PPD-primed Leu-3+ cells, when co-cultured for 7 days with fresh autologous Leu-2+ cells, induced differentiation of Leu-2+ but not Leu-3+ cells into specific suppressor T cells, which subsequently inhibited the proliferative response of fresh Leu-3+ cells to PPD but not to tetanus toxoid or allogeneic non-T cells. The PPD-specific suppressor effect of activated Leu-2+ cells was not due to altered kinetics of the PPD response and also extended to the secondary response of PPD-primed Leu-3+ cells. Furthermore, only those Leu-2+ cells that lacked the 9.3 marker, an antigen present on the majority of T cells including the precursors of cytotoxic T cells, differentiated into suppressor T cells. To analyze the inducer population, fresh Leu-3+ cells were separated into Leu-3+,8- and Leu-3+,8+ subpopulations with anti-Leu-8 monoclonal antibody, activated with PPD, and then were examined for inducer function. Although both Leu-3+,8- and Leu-3+,8+ cells proliferated in response to PPD and upon activation expressed comparable amounts of HLA-DR (Ia) antigens, the Leu-3+,8+ subpopulation alone induced Leu-2+ cells to become suppressor-effectors in the absence of PPD-pulsed autologous non-T cells. Once activated, however, Leu-2+ suppressor cells inhibited the PPD response of both Leu-3+,8- and Leu-3+,8+ cells. These results indicate that antigen-primed Leu-3+,8+ inducer cells can directly activate Leu-2+, 9.3- precursors of antigen-specific suppressor T cells in the absence of antigen-pulsed autologous non-T cells.
Modulation of mononuclear phagocyte function by intravenous gamma-globulin.
Authors: Kimberly R P , Salmon J E , Bussel J B , Crow M K , Hilgartner M W
Published: December 2022

To assess the effects on mononuclear phagocyte function of i.v. gamma-globulin treatment in idiopathic thrombocytopenic purpura, we examined in vivo and in vitro mononuclear phagocyte function in 11 patients before and after therapy. All patients, both splenectomized and non-splenectomized, demonstrated a prolongation of in vivo clearance of autologous IgG-sensitized erythrocytes (p less than 0.01). Concurrent in vitro assessment of blood monocyte function showed decreased IgG-sensitized erythrocyte (EA) rosette formation (mean +/- SD: 31.6% +/- 8.2 vs 24.5% +/- 9.5; p less than 0.03) and decreased affinity of Fc receptor-specific IgG oligomer binding (9.9 +/- 16.3 vs 1.8 +/- 2.1 X 10(8) M-1; p less than 0.008), but no consistent change in the estimate of the maximum number of binding sites. Phagocytosis of two different EA probes was decreased (EhuA:0.49 +/- 0.26 vs 0.25 +/- 0.14 erythrocyte/monocyte/hr; p less than 0.02, EoxA: 1.76 +/- 0.66 vs 1.27 +/- 0.67 erythrocyte/monocyte/hr, p less than 0.05). The change in in vivo mononuclear phagocyte system clearance was significantly correlated with the change in the association constant for oligomer binding (r = 0.98, p less than 0.05). These data demonstrate that i.v. gamma-globulin infusions induce alterations of mononuclear phagocyte function that are not dependent on the presence of autologous serum containing infusate. The change in apparent Fc receptor affinity rather than receptor number may reflect an altered Fc receptor population with different binding properties.
Reactivity of antisera to endogenous primate retrovirus with a human T cell membrane protein: recognition of a nonviral glycoprotein by antibodies directed only against carbohydrate components.
Authors: Markenson J A , Snyder H W
Published: December 2022

A glycosylated protein of approximately 70,000 daltons (gp70) from the surface of human peripheral blood T cells was immunoprecipitated by antisera to the baboon endogenous retrovirus (BEV-M7) and the serologically related feline endogenous retrovirus (RD114) but not by antisera to other retroviruses. Whereas preliminary absorption experiments were consistent with a possible viral specificity for this reaction, detailed biochemical and serologic characterization of the purified cellular protein suggested that it was not related to the gp70 of either M7 or RD114 viruses. The specificity of the reaction was further analyzed by assays of cellular gp70 antigenicity after exposure to exo- and endoglycosidases or trypsin and carbohydrate hapten inhibition studies. The results of these experiments were consistent with the interpretation that the glycoprotein was being recognized by antibody binding to the carbohydrate moiety of the molecule. These results provide an example of an antibody activity that could lead to inappropriate conclusions when sensitive radioimmunoprecipitation techniques are used for the biochemical analysis of antigenic systems. They emphasize the necessity of purifying cellular antigens as a prerequisite to determining the exact basis for a serologic reaction.
Allotypic specificities of murine IgD and IgM recognized by monoclonal antibodies.
Authors: Stall A M , Loken M R
Published: December 2022

Hybridomas generated from mice immunized with allotype and H-2-incompatible spleen cells were screened by flow cytometry. Monoclonal antibodies (MAb) to four of the five known specificities of IgD were identified. The location of these specificities on the IgD molecule was determined by the ability of a given MAb to bind to cells stripped of the Fab fragment by trypsin proteolysis. Igh-5.1 (present on IgDa and IgDe) and Igh-5.5 (unique to IgDe) were both located on the Fab fragment. Results from cross-blocking experiments suggest that, except for Igh-5.3, MAb which recognize the same specificity bind to the same antigenic determinant. Both the trypsin digest and blocking studies indicate that Igh-5.3 is composed of at least two antigenic determinants. AF6-78.25, a MAb specific for IgM of the b, d, and n haplotypes, was also identified; this MAb defines a new specificity, Igh-6.6. On the basis of the reactivities of these MAb, it appears that although the Igh-Ce and Igh-Cd haplotypes are virtually identical at the Igh-3(gamma 2b), Igh-1(gamma 2a), and Igh-2(alpha) loci, they are highly divergent at the Igh-5(delta) and Igh-6(mu) loci. This indicates that the Igh-Cd haplotype may have resulted from a recombination between Igh-Ce and another haplotype.
Chemotactic cytokines: the role of leukocytic pyrogen and epidermal cell thymocyte-activating factor in neutrophil chemotaxis.
Authors: Sauder D N , Mounessa N L , Katz S I , Dinarello C A , Gallin J I
Published: December 2022

Macrophage-derived leukocytic pyrogen (LP) is thought to be similar if not identical to interleukin 1 (IL 1). In addition to macrophages, keratinocytes produce a factor that has similar biologic and biochemical characteristics to IL 1, called epidermal cell thymocyte-activating factor (ETAF). Because many diseases affecting the skin are characterized by infiltration of polymorphonuclear leukocytes (PMN) and some of these disorders are associated with fever, we investigated whether ETAF like LP had pyrogenic activity, and whether ETAF or LP were chemoattractants. ETAF or LP purified by column chromatography and isoelectric focusing were found to have chemotactic activity for PMN. The fractions containing maximal chemotactic activity corresponded to maximal fever-inducing activity and maximum thymocyte-activating activity. Furthermore, the chemotactic activity of ETAF and LP could be blocked by an antibody directed against LP. The results of this study indicate that these mediators, which arise from distinct cell populations, are closely related and may play a vital role in skin as well as distant inflammatory and immunologic events.
Human anti-pneumococci antibody produced by an Epstein Barr virus (EBV)-immortalized cell line.
Authors: Steinitz M , Tamir S , Goldfarb A
Published: December 2022

Anti-pneumococcal antibody-producing lymphocytes from a patient who was immunized with Pneumovax (a polysaccharide mixture from 14 different pneumococci types) were selected and immortalized with Epstein Barr virus (EBV). The cells of the emerging cloned line were shown on a single cell level assay to secrete an IgM, kappa anti-pneumococci antibody. This human monoclonal antibody bound specifically to polysaccharides of pneumococci type 8, but did not bind to any of the other 13 pneumococci types that were present in the Pneumovax mixture. In competition experiments, inhibition of binding occurred with polysaccharide type 8 and Pneumovax only. This diploid cell line has actively secreted the specific antibody (2.8 micrograms/10(6) cells/ml) now for more than 9 mo. In patients, increased anti-pneumococcal antibody titers generated by active immunization with Pneumovax improves resistance to the corresponding bacterial infection. Production in vitro of human monoclonal antibodies directed toward bacterial and viral antigens enables a new possible approach for passive immune protection.
Revertants from the HLA class II regulatory mutant 6.1.6: implications for the regulation of Ia gene expression.
Authors: Levine F , Pious D
Published: December 2022

Class II (Ia) genes of the human MHC code for developmentally regulated, highly polymorphic cell surface glycoproteins. The control of expression of this highly complex genetic region has not been extensively investigated. We used 6.1.6, a variant of a normal B lymphoblastoid cell that has lost expression of all class II molecules, to study this question. In previous studies, we have shown that the structural genes for class II molecules are intact but are not expressed in 6.1.6 (6), and that the defect is at the transcriptional level (7). In this report, we describe the isolation and characterization of revertants of 6.1.6 that reexpress class II molecules. These revertants have four unusual properties: 1) they are found at a higher frequency (0.7%) than would be expected for a mutational event; 2) they are unstable; 3) they reexpress only a subset of class II molecules; and 4) they have only been found in tetraploid cells. On the basis of previous work with 6.1.6 and the properties of reversion in 6.1.6, we propose a hypothesis for the nature of the defect in 6.1.6 and a model for the regulation of class II molecules.
Modulation of human rheumatoid factor-specific lymphocyte responses with a cross-reactive anti-idiotype bearing the internal image of antigen.
Authors: Fong S , Gilbertson T A , Chen P P , Vaughan J H , Carson D A
Published: December 2022

Rabbit anti-idiotypic antibodies to human rheumatoid factor (RF) autoantibodies were isolated by affinity chromatography on rabbit anti-human IgG Fc Sepharose 4B. The anti-idiotypic antibodies bore the "internal image" of the antigen, human IgG. They reacted specifically with multiple human monoclonal and polyclonal IgM-RF, independent of any particular light or heavy chain amino acid sequence. The anti-idiotypes did not react with IgM or IgG proteins lacking RF activity. The present experiments determined the potential of the "internal image" antibodies to modulate in vitro lymphocyte functions. The addition of anti-idiotypic antibody to peripheral blood mononuclear cell cultures from patients with rheumatoid arthritis elicited lymphocyte proliferation, but not RF synthesis. The antibody did not induce the proliferation of lymphocytes from a normal individual. Moreover, the anti-idiotype specifically suppressed IgM-RF secretory responses when preincubated with B cells before co-culture with autologous pokeweed mitogen-activated T cells. The data show that the anti-idiotypic antibodies with the "internal image" of antigen are capable of interacting with B cell receptors in an antigen-restricted manner, and possess specific immunomodulatory properties.
Hydrocortisone suppresses the generation of nonspecific "anomalous" killers but not specific cytolytic T lymphocytes in human mixed lymphocyte-tumor cultures.
Authors: Muul L M , Gately M K
Published: December 2022

Interpretation of results with the use of effector populations generated in human mixed lymphocyte tumor cultures (MLTC) has in many cases been clouded by the presence of two distinct cytolytic effectors: specific cytolytic T lymphocytes (CTL) and nonspecific anomalous killers (AK). The addition of 5 to 50 X 10(-6) M hydrocortisone sodium succinate (HC) to "three-cell" allogeneic human MLTC containing responder lymphocytes, irradiated allogeneic glioma cells, and irradiated third-party stimulator lymphocytes consistently reduced the generation of AK by greater than 90% while having little or no effect on the generation of CTL specific for antigens present on the glioma cells. HC was similarly effective in blocking the generation of AK when added to cultures of responder cells incubated with lymphokine-containing supernatants from mixed lymphocyte cultures. Kinetic experiments indicated that HC both decreased the initial rate of appearance of AK activity and subsequently caused the AK response to decline more rapidly. HC had only a small inhibitory effect on the lytic action of AK generated in its absence. The ability of HC to suppress strongly the generation of nonspecific but not specific cytolytic effectors suggests that nonspecific AK are not polyclonally activated CTL or CTL at an early stage of differentiation, but rather represent a distinct cytolytic effector system. The inclusion of HC in human MLTC may provide a useful tool for distinguishing between lysis due to the generation of specific CTL and lysis due to the generation of nonspecific AK.
Autologous mixed lymphocyte reaction in patients with myasthenia gravis: correlation with disease activity.
Authors: Greenberg S J , Olanow C W , Dawson D V , Crane B , Roses A D
Published: December 2022

Enriched subpopulations of peripheral blood mononuclear cells from patients with myasthenia gravis and from normal control individuals were tested for proliferative ability in the autologous mixed lymphocyte reactions. Myasthenia gravis patients were studied at various phases of therapy. Longitudinal patient populations were studied. Purified T cells from untreated patients with active myasthenia gravis demonstrated enhanced proliferative responses when co-cultured with nonmodified autologous non-T cells. Furthermore, treatment by thymectomy with or without prior plasmapheresis was associated with a consequent normalization of the autologous reaction. The enhanced autologous mixed lymphocyte reaction in the pre-treatment group of myasthenia gravis patients was significantly different from the post-treatment and normal control groups (Stimulation Index, p less than 0.01 and p less than 0.02, respectively). This difference in activity was also confirmed in a longitudinal study of 10 patients followed pre- and post-treatment (Stimulation Index, p less than 0.02). There was no difference between the responses of post-treatment patients and normal control individuals. There was no evidence of altered T cell responsiveness or non-T cell stimulation, as measured by the allogeneic mixed lymphocyte reaction or by mitogen-induced lymphocyte proliferation, between pretreatment and post-treatment patients as compared to controls. The responses were not affected by serum substitution experiments whereby myasthenic responder T cells were co-cultured with pooled normal human sera. Other parameters studied included clinical status, anti-acetylcholine receptor antibody levels, and thymic pathology. An intriguing connection between abnormalities in the thymic cell populations and the autoaggressive state in myasthenia may be reflected by the in vitro autologous mixed lymphocyte reaction.
Modulation of the biologic activities of IgE-binding factor. V. The role of glycosylation-enhancing factor and glycosylation-inhibiting factor in determining the nature of IgE-binding factors.
Authors: Iwata M , Huff T F , Ishizaka K
Published: December 2022

Glycosylation-enhancing factor (GEF) and IgE-potentiating factor were detected in culture supernatants of rat mesenteric lymph nodes (MLN) cells obtained 14 days after infection with Nippostrongylus brasiliensis (Nb), but not in supernatants of MLN cells of 8-day Nb-infected rats. Both factors were also released from T cells upon antigenic stimulation of KLH + alum-primed spleen cells. The GEF from the Nb-infected rats and KLH + alum-primed spleen cells had affinity for p-aminobenzamidine agarose and were inactivated by phenylmethylsulfonylfluoride, an inhibitor of serine proteases. These results indicate that the GEF obtained in the two systems is a serine protease and is identical to that obtained by stimulation of normal T cells with lymphocytosis-promoting factor (LPF) from Bordetella pertussis. The concomitant formation of IgE-potentiating factor and GEF by Nb infection, by antigenic simulation of KLH + alum-primed spleen cells, and by treatment of rats with Bordetella pertussis vaccine suggests that the serine protease is involved in a common pathway leading to the selective formation of IgE-potentiating factor. In contrast, glycosylation-inhibiting factor (GIF) is always found during the selective formation of IgE-suppressive factor. IgE-suppressive factor and GIF were formed by MLN cells of 8-day Nb-infected rats and KLH-CFA-primed spleen cells. GIF was detected in culture supernatants of T cell hybridomas 23A4 and 23B6, which form unglycosylated IgE-binding factors upon incubation with IgE. GIF obtained from all of these sources bound to monoclonal anti-lipomodulin. These findings indicate that GIF or lipomodulin is involved in all systems, which leads to the selective formation of IgE-suppressive factor. However, the formation of GIF was not restricted to those conditions in which IgE-suppressive factor was selectively formed. The culture supernatants of MLN cells of 14-day Nb-infected rats and antigen-stimulated KLH + alum-primed spleen cells contained a small amount of GIF, which could be detected after inactivation of GEF. It appears that T cells from these sources formed GEF and GIF, but that GEF overcame the effect of GIF on glycosylation of IgE-binding factors. The results indicate that the nature and biologic activities of IgE-binding factors are decided by the balance between GEF and GIF formed by T cells.
Cytolysis of nucleated cells by complement: inhibition of membrane-transmethylation enhances cell death by C5b-9.
Authors: Hänsch G M , Betz M , Shin M L
Published: December 2022

Inhibition of transmethylation, i.e., enzymatic transfer of methyl groups to phosphatidyl ethanolamine resulting in generation and translocation of phosphatidyl choline, enhances the killing of nucleated cells by complement. Furthermore, under complement attack, transmethylation measured as incorporation of [3H]methyl groups into phosphatidyl choline is enhanced, suggesting that transmethylation functions as a membrane defense mechanism either by increasing the phosphatidyl choline synthesis or by transducing a signal that might trigger another membrane repair process.
Different enzyme classes associated with human natural killer cells may mediate disparate functions.
Authors: Zucker-Franklin D , Yang J , Fuks A
Published: December 2022

Previous studies have shown that degradation of the acute phase reactant serum amyloid A (SAA) is mediated by enzymes on the plasma membrane of lymphocytes and monocytes. The responsible enzymes had properties of neutral elastases. The present investigations were conducted to explore whether human NK cells enriched by Percoll gradient centrifugation have similar activity and if so, whether the same or different enzyme classes are responsible for proteolysis as well as for tumor cell lysis. Accordingly, human NK cells were enriched on discontinuous Percoll gradients after which the cells were incubated either with SAA or with [3H] proline-labeled melanoma cells at various effector to target cell ratios. When SAA degradation was followed by SDS-polyacrylamide gel electrophoresis, NK fractions proved to be as effective in digesting the protein as unfractionated mononuclear leukocytes. To characterize the enzymes that may be involved in cytotoxicity on the one hand, and SAA degradation on the other, the NK fractions were treated with the following inhibitors: diisopropylfluorophosphate (DFP), soybean trypsin inhibitor, N-p-tosyl-L-lysine chloromethylketone (TLCK), the elastase inhibitors elastatinal, Ac-Ala-Ala-Pro-Val-CH2Cl, Meo-Suc-Ala-Ala-Pro-Val-CH2Cl, and an inhibitor of aryl sulfatase, Na2SO4. Preincubation of the cells with DFP or elastase inhibitors abolished their ability to hydrolyze SAA but did not affect their ability to kill tumor cells. On the other hand TLCK, a potent inhibitor of cytotoxicity, did not bring about any reduction in the proteolysis of SAA. DFP and Na2SO4 diminished cytotoxicity partially. Elimination of NK cells by sorting after incubation of lymphocytes with the monoclonal antisera Leu-7 and Leu-11 abolished cytotoxicity as well as proteolysis. The observations are compatible with the concept that NK cells carry several enzymes with different substrate specificities that may be involved in disparate cellular functions.
Clearance of feline leukemia virus from persistently infected pet cats treated by extracorporeal immunoadsorption is correlated with an enhanced antibody response to FeLV gp 70.
Authors: Snyder H W , Singhal M C , Hardy W D , Jones F R
Published: December 2022

Six persistently feline leukemia virus (FeLV)-infected pet cats were treated by extracorporeal immunoadsorption with Staphylococcus aureus Cowan I (SAC) to remove circulating immune complexes and immunoglobulin G (IgG) from plasma. In three of these cats, the FeLV infection was eliminated, whereas in the other three cats the infection persisted. The amounts of peripheral blood leukocyte (PBL)-associated FeLV, soluble FeLV envelope glycoprotein (gp70) antigens in serum, and FeLV-gp70-specific antibodies were determined in all six cats at different times during treatment. In all of the cats, there were fluctuations in the amounts of FeLV-positive PBL and of serum antigen related to FeLV gp70. The one serologic parameter that always correlated with complete clearance of FeLV in the responder cats was the development of free antibodies to gp70. These results suggest that extracorporeal immunoadsorption treatment stimulates an existing low level antibody response to FeLV in some cats, and that these antibodies mediate the clearance of FeLV. The results also suggest that determination of antibody titer to FeLV is of value in predicting the outcome of extracorporeal immunoadsorption treatments as well as when treatment may be terminated.
sIgD-negative B cells from neonatal mice do not respond to the thymus-independent antigen TNP-BA in limiting dilution cultures.
Authors: McFadden S F , Vitetta E S
Published: December 2022

The majority of B lymphocytes in adult mice express both IgM and IgD on their surface (sIgM and sIgD). A small percentage of sIgM+ splenic B cells lack (or express very low levels of) sIgD. These cells have been termed "mu-predominant" (mu p) B cells. In neonatal mice (5 to 12 days of age), mu p B cells account for more than 50% of the sIg+ cells. There is conflicting evidence concerning the immunocompetency of mup cells in vitro. To study this question further, splenocytes from neonatal BALB/c mice were depleted of sIgD+ B cells by a panning procedure. A portion of the nonadherent (mu p) cell population was analyzed for residual sIgD+ cells by using indirect immunofluorescence in conjunction with the fluorescence-activated cell sorter (FACS). Such cells were then tested for their responsiveness to the thymus-independent (TI) antigen, trinitrophenyl Brucella abortus (TNP-BA), by using a limiting dilution culture system. Results indicate that the depletion of sIgD+ B cells and the decrease in the precursor frequency of splenocytes responding to TNP-BA are very similar, suggesting that virtually all of the responding B cells bear sIgD.
The effect of thymectomy on lupus-prone mice.
Authors: Hang L , Theofilopoulos A N , Balderas R S , Francis S J , Dixon F J
Published: December 2022

The effect of neonatal thymectomy on the induction and/or modification of murine SLE disease was examined in several representative groups of mice with early-life SLE (MRL/Mp-lpr/lpr females, BXSB males, (NZB X W)F1 females, (NZW X BXSB)F1 males and females), late-life SLE (MRL/Mp-+/+ and BXSB females), and normal strains (BALB/c and C57BL/6 females). Our results indicated that thymectomy prevented disease only in the MRL/Mp-lpr/lpr SLE mice, and that this effect diminished as thymectomy was delayed beyond 3 wk post-natally. In the other SLE mice studied, neonatal thymectomy did not modify disease symptoms to any significant degree. Moreover, depletion of mature T cells from donor BXSB male bone marrow did not affect the expression of early-life SLE in thymectomized BXSB female recipients. Neonatal thymectomy did not induce SLE in normal mice. Of note, neonatal thymectomy did not completely deplete the Thy-1.2+ cell population, i.e., 10 to 15% remained in the spleens of the thymectomized mice. This incomplete T cell depletion, together with the previously demonstrated dependence on and hyperresponsiveness of BXSB and (NZB X W)F1 B cells to T helper cell-derived accessory signals, cast doubts on earlier conclusions that B cells from some SLE mice can autonomously proliferate and differentiate to autoantibody-secreting cells. It seems more appropriate to conclude that B cells from the various SLE mice vary in their degree of response to, and production of, T cell-derived helper signals, and thus in their expression of B cell hyperactivity and disease.