bluuebunny/crossref_metadata_2025 huggingface dataset:
AUTOGENOUS IMMUNITY TO ENDOGENOUS RNA TUMOR VIRUS
Authors: Ihle J. N. , Yurconic M. , Hanna M. G.
Published: June 2004

The radioimmune precipitation assay using 3H-labeled AKR leukemia virus was applied to the detection and quantitation of natural serum antibodies directed against endogenous murine leukemia virus (MuLV) envelope antigens B6C3F1 and BALB/c mice, which have low natural incidences of leukemia and lymphoma, and AKR mice, which have a high incidence, were used in this study. Sera from mice of various age groups were assayed. A marked difference in age-associated levels of the autogenous immune response to endogenous murine leukemia virus was detected, and the quantitative differences among these strains were inversely related to the incidence of lymphoma. The radioimmune precipitation test as applied was 500 times more sensitive than virus neutralization. That the reactions we have observed are specific is suggested by several lines of evidence, including the nonreactivity of normal hamster and absorbed rat serum, the positive reaction of absorbed rat anti-AKR serum, the inhibition of precipitation of labeled virus by purified unlabeled virus, and isopycnic gradient analysis of the reactive products.
COMPARATIVE IMMUNOGENICITY AND ENHANCEABILITY OF INDIVIDUAL H-2K AND H-2D SPECIFICITIES OF THE MURINE HISTOCOMPATIBILITY-2 COMPLEX
Authors: McKenzie Ian F. C. , Snell George D.
Published: June 2004

The immunogenicity of single, private H-2 specificities has been tested. In most cases, the specificity was known to be confined either to H-2K or to H-2D. This was accomplished by the appropriate choice, as donor and recipient, or parent of the F1 hybrid recipient, of congenic strains differing at H-2 only, and of recombinant haplotypes in donor and/or recipient.

By nearly all tests, the H-2K antigen appeared to be a stronger immunogen than the H-2D antigen. Skin grafts with an H-2K difference showed median survival times (MST) of 9.3–14.5 days; for H-2D the values were 13.8–18.6. The difference was also present, though narrowed, for second-set grafts. H-2K grafts regularly engendered a demonstrable cytotoxic antibody response; with H-2D differences the response was absent or very weak. K end cytotoxic titers after multiple immunizations with lymphoid tissues ranged from 1/32 to 1/2,048, D end titers from 0 to 1/128. Hemagglutination titers showed no clear difference.

The results of passive enhancement of skin grafts with H-2 alloantibody produced in donor recipient combinations, identical to those used for the skin grafts showed a different pattern. H-2K, despite its greater immunogenic strength was more easily enhanced than H-2D. Prolongation of MST's for H-2K was 2.4–6.7 days, for H-2D grafts, 0.2–1.5 days.
SKELETAL MUSCLE AS A PRIVILEGED SITE FOR ORTHOTOPIC SKIN ALLOGRAFTS
Authors: Barker Clyde F. , Billingham R. E.
Published: June 2004

A semi-privileged status for rat skin allografts may be achieved by placing them on extensive open beds formed by panniculus carnosus muscle which prevents contact of the transplant with host skin. Such allografts enjoy approximately a twofold increase in their life expectancy, even if transplanted across a strong histocompatibility barrier. Experiments are described which rule out stress or a "central" weakening of response, such as enhancement, as explanations of this phenomenon.

Intact skin "islands" separated from surrounding host skin on all sides by a broad border of bared panniculus were also found to serve as privileged sites. Dye injected into these islands failed to reach the regional nodes until about the 15th day after their preparation. These studies indicate that a lymphatic deficit is responsible for the observed privileged status of the allografts.
RELEASE OF CARTILAGE MUCOPOLYSACCHARIDE-DEGRADING NEUTRAL PROTEASE FROM HUMAN LEUKOCYTES
Authors: Oronsky A. , Ignarro L. , Perper R.
Published: June 2004

The granule fraction of human leukocytes contains neutral protease capable of degrading the noncollagenous protein mucopolysaccharide matrix of cartilage at neutral pH in physiological salt solution. Cartilage degradation was monitored by quantitating the release of 35S from labeled rabbit ear cartilage. Degradation of cartilage matrix occurs when intact viable human leukocytes are incubated with cartilage opsonized with aggregated human gamma globulin (AHGG). During a similar 4 h incubation period cells did not degrade uncoated cartilage or cartilage coated with nonaggregated gamma globulin. Cells remain viable during the enzyme release process as evidenced by the absence of a cytoplasmic enzyme marker (lactic dehydrogenase) in the supernatant and dye exclusion studies. The release of 35S from labeled cartilage by human leukocytes in the presence of cartilage coated with AHGG (nonphagocytic enzyme release) was compared with the cartilage degrading activity of the supernatant from the same number of cells preincubated with a suspension of AHGG (phagocytic enzyme release). Nonphagocytic enzyme release by 5 x 106 cells provoked two to four times more 35S and ß-glucuronidase (ß-G) release from cartilage than phagocytic enzyme release conditions. ß-glucuronidase was used as an indicator of the release of lysosomal granule enzymes.

By the use of selected pharmacological agents it was possible to dissociate the enzyme release process from intrinsic enzyme (neutral protease) activity. Neutral protease and ß-G release by human cells in the presence of AHGG-coated cartilage was inhibited by 10–5M colchicine, whereas the protease activity, but not the release process, was inhibited by 10–6M gold thiomalate and 10% human serum. It is suggested that the release of a cartilage degrading neutral protease by viable human cells when exposed to AHGG might be a relevant model for the study of cartilage destruction as it occurs in rheumatoid arthritis.
INDUCTION OF T LYMPHOCYTES FROM PRECURSOR CELLS IN VITRO BY A PRODUCT OF THE THYMUS
Authors: Komuro K. , Boyse E. A.
Published: June 2004

A product of mouse thymus induces cells found in the spleen and bone marrow of nu/nu mice (which lack a thymus), and in 14-day embryonic mouse liver, to differentiate in vitro into T lymphocytes (defined as cells bearing TL and Thy-1 antigens). Thus the in vitro T lymphocyte induction mechanism acts on a cell that is antecedent to any thymus-mediated process.
GENERATION OF CYTOTOXIC LYMPHOCYTES IN MIXED LYMPHOCYTE REACTIONS
Authors: Forman James , Möller Göran
Published: June 2004

Generation of cytotoxic effector cells by a unidirectional mixed lymphocyte reaction (MLR) in the mouse H-2 system was studied using labeled YAC (H-2a) leukemia cells as targets. The responding effector cell displayed a specific cytotoxic effect against target cells of the same H-2 genotype as the stimulating cell population. Killing of syngeneic H-2 cells was not observed, even when the labeled target cells were "innocent bystanders" in cultures where specific target cells were reintroduced. Similar results were found with spleen cells taken from mice sensitized in vivo 7 days earlier. The effector cell was not an adherent cell and was not activated by supernatants from MLR. The supernatants were not cytotoxic by themselves. When concanavalin A or phytohemagglutinin was added to the cytotoxic test system, target and effector cells were agglutinated. Under these conditions, killing of H-2a target cells was observed in mixed cultures where H-2a lymphocytes were also the effector cells. These findings indicate that specifically activated, probably thymus-derived lymphocytes, can kill nonspecifically once they have been activated and providing there is close contact between effector and target cells. Thus, specificity of T cell killing appears to be restricted to recognition and subsequent binding to the targets, the actual effector phase being nonspecific.
THE USE OF BACTERIAL LIPOPOLYSACCHARIDES TO SHOW THAT TWO SIGNALS ARE REQUIRED FOR THE INDUCTION OF ANTIBODY SYNTHESIS
Authors: Watson James , Trenkner Ekkhart , Cohn Melvin
Published: June 2004

Evidence is presented that antigen-sensitive cells require two signals for induction. Normally these two signals are delivered to the cell via the recognition of two determinants on the immunogen: the first the receptor on the antigen-sensitive cell, and the second by the cooperating cell system. The special experimental situation described here depends upon the observation that bacterial lipopolysaccharides (LPS) render immunogenic a variety of haptens. When monovalent haptens (TNP-amino acids) are added to spleen cultures, specific antihapten responses are induced in the presence of LPS. After analyzing competing interpretations of this phenomenon, we propose that the antigenic signal is delivered as the consequence of a conformational change in the receptor upon interacting with antigen, and the second signal is delivered directly via the interaction of LPS with the membrane on the antigen-sensitive cell receiving the antigenic signal, or indirectly via the interaction of LPS with the cooperating cell population. These data imply LPS is not itself a mitogen, but merely completes an inductive stimulus to B cells. The experimental results from these and other studies indicate how these two signals may participate in inductive, suppressive, and paralytic stimuli to antigen-sensitive cells.
TWO DIFFERENT COMPLEMENT RECEPTORS ON HUMAN LYMPHOCYTES
Authors: Ross Gordon D. , Polley Margaret J. , Rabellino Enrique M. , Grey Howard M.
Published: June 2004

In the present study it was shown that normal peripheral lymphocytes have two different complement receptors: one for C3b (the immune adherence receptor) and one for C3b subsequent to its cleavage by C3b inactivator. The two receptors are not cross-reactive and were shown by tests with various antisera to be antigenically distinct. Both the immune adherence receptor and the receptor for C3b inactivator-cleaved C3b were found on normal peripheral lymphocytes and on cultured lymphoblastoid cells. In 15 out of 18 chronic lymphatic leukemia patients, the immune adherence receptor was either partially or completely missing from the peripheral lymphocytes, while the lymphocyte receptor for C3b inactivator-cleaved C3b was retained. Normal erythrocytes, on the other hand, were found to have only the immune adherence receptor. Granulocytes from normal peripheral blood appeared to have only a receptor for C3b and did not have a receptor for C3b inactivator-cleaved C3b.
BENZIMIDAZOLE DERIVATIVES: NEW ENHANCERS OF INFLUENZA VIRUS MULTIPLICATION
Authors: Tamm Igor
Published: June 2004

The enhancing activity of 5-methyl-2-D-ribobenzimidazole on influenza B (Lee) virus yield in chorioallantoic membranes from 10-day old embryonated eggs was compared with that of eight other polyhydroxyalkyl-benzimidazoles. No marked differences in activity were noted with the following six derivatives: 5,6-dimethyl-2-D-ribo; 2-D-gluco; 5-methyl-2-D-gluco; 5,6-dimethyl-2-D-gluco; 5-methyl-2-D-galacto; and 5-methyl-2-L-rhamno. None caused morphological damage to the membranes at a concentration of 3.5 mM. The solubility of the 5-methyl-2-D-arabo and 5-methyl-2-D-manno derivatives was too low to permit quantitative comparisons, but both were active and nontoxic at a concentration of 1.75 mM.

5-Hydroxy-1-methylbenzimidazole and 5-methoxy-1-methylbenzimidazole are more active than 5-methyl-2-D-ribobenzimidazole both with respect to specific activity and maximal enhancement at the highest tolerated dose. The hydroxyl substituent is superior to the methoxyl grouping. Substitution at position 5 is superior to substitution at position 6 with respect to the tolerated dose level and therefore the maximal effect obtainable, but the 6-hydroxy-1-methyl derivative showed the highest specific activity.

5-Methoxy-1-methylbenzimidazole increases the yield to a comparable extent as measured by infectivity and hemagglutination titrations. The responses of membranes from individual chicken embryos to the enhancing action of 5-methoxy-1-methylbenzimidazole and 5-methyl-2-D-ribobenzimidazole are similar. 5-Methoxy-1-methylbenzimidazole restores the capacity of membranes from older chicken embryos to produce a large amount of virus after a small inoculum. This derivative increases the yield of virus in membranes treated before infection only. Maximal enhancement is obtained with prolonged treatment, starting before, and continuing after infection. 5-Methoxy-1-methyl-benzimidazole increases the yield of virus from COFAL-negative embryos in which the control yield is very low. Combined treatment with moderate doses of 5-methoxy-1-methylbenzimidazole and 5-methyl-2-D-ribobenzimidazole gives an additive effect.
THE ENHANCEMENT OF MACROPHAGE BACTERIOSTASIS BY PRODUCTS OF ACTIVATED LYMPHOCYTES
Authors: Fowles Robert E. , Fajardo Ileana M. , Leibowitch Jacques L. , David John R.
Published: June 2004

It was reported previously that the incubation of normal guinea pig macrophages with partially purified products of activated lymphocytes resulted in altered macrophage function including increased cell adherence to culture vessels, spreading, phagocytosis, and glucose carbon-1 oxidation. Studies reported here demonstrate that such macrophages also exhibit enhanced bacteriostasis. Lymphocytes were stimulated with concanavalin A, the culture supernatant was chromatographed over Sephadex G-100 and the fraction of mol wt 25,000–55,000, rich in lymphocyte mediators, was cultured with normal guinea pig macrophages for 1–3 days. Macrophages incubated with fractions from unstimulated lymphocyte cultures served as controls. The resulting macrophage monolayers were infected with Listeria monocytogenes. Macrophages incubated with mediator-rich fractions exhibited 2- to 10-fold enhanced bacteriostasis compared to controls. Further studies indicate that this enhancement was attributable to intrinsic changes in the macrophages and not simply a consequence of the number of macrophages on the monolayers. The studies support the concept that macrophage bacteriostasis can be enhanced by lymphocyte mediators. However, macrophages, which have been preincubated directly with sensitive lymphocytes and antigen exhibit even greater bacteriostasis and sometimes bactericidal capacity, suggesting that either a labile lymphocyte factor or direct lymphocyte macrophage interaction may also be involved in bactericidal activity.
MONOCLONAL MACROGLOBULINEMIA IN NZB/NZW F1 MICE
Authors: Sugai Susumu , Pillarisetty Rao , Talal Norman
Published: June 2004

Serum monoclonal macroglobulins were detected in over 30% of NZB/NZW F1 mice greater than 11 mo of age. The monoclonal nature of the IgM was shown by restricted electrophoretic mobility, characteristic appearance on immunoelectrophoresis, restriction to a single light chain type, and ability to induce anti-idiotypic antisera. The monoclonal macroglobulins were separated from antibodies to DNA and RNA that migrated in the 7S region of sucrose gradients. Enlarged lymph nodes were often present in mice with monoclonal IgM, and a transplantable IgM-producing lymphoid tumor was established from the spleen of one animal.
A SEQUENCE OF BIOCHEMICAL EVENTS IN THE ANTIGEN-INDUCED RELEASE OF CHEMICAL MEDIATORS FROM SENSITIZED HUMAN LUNG TISSUE
Authors: Kaliner Michael , Austen K. Frank
Published: June 2004

Five sequential steps interspaced between the antigen activation of human lung fragments sensitized with IgE and the release of the chemical mediators, histamine and slow-reacting substance of anaphylaxis (SRS-A), have been delineated. The experimental design that permits this analysis is based upon the capacity to maintain the serine esterase essential to mediator release in its diisopropylphosphofluoridate (DFP)-resistant precursor state despite antigen challenge and upon the ability to arrest reversibly the reaction sequence by various manipulations. When sensitized lung fragments are challenged with antigen in the presence of DFP, a serine esterase is converted to its active DFP-inhibitable state; this conversion is prevented if antigen challenge in the presence of DFP occurs in calcium-free buffer indicating that immunologic activation of the esterase requires extracellular calcium. The fact that calcium depletion alone does not impair antigen-induced histamine release implies that prevention of esterase activation depends upon both the absence of extracellular calcium and the inactivation of any active esterase by DFP to prevent an autocatalytic feedback activation. Arresting the antigen-induced activation of the serine esterase by the combination of DFP in calcium-free buffer precludes the sequence from reaching the labile, 2-deoxyglucose (2-DG)-inhibitable, energy-requiring step, indicating that proesterase activation precedes this energy-requiring stage. The 2-DG-inhibitable step precedes a second calcium-requiring, EDTA-inhibitable stage, as EDTA prevents glucose reversal of 2-DG inhibition of antigen-challenged tissue, while the presence of 2-DG does not prevent calcium reversal of EDTA inhibition. The finding that isoproterenol prevents calcium reversal of EDTA inhibition of mediator release suggests that the inhibitory site of action of increased concentrations of cyclic AMP is coincident with or subsequent to the second calcium-requiring, EDTA-inhibitable step. Therefore, the sequence of biochemical events initiated by the interaction of antigen with tissue-fixed IgE antibodies appears to proceed from the calcium-requiring activation of a DFP-sensitive serine esterase; the further autocatalytic activation of the esterase; a 2-DG-inhibitable energy requirement; a second calcium-requiring, EDTA-inhibitable stage; and a cyclic AMP-inhibitable step to the release of histamine and SRS-A.
CUTANEOUS BASOPHIL HYPERSENSITIVITY IN CONTACT-SENSITIZED GUINEA PIGS
Authors: Askenase P. W.
Published: June 2004

Cutaneous basophil hypersensitivity, an immune inflammatory reaction characterized by infiltrates of basophils and a delayed time-course, was studied in guinea pigs contact sensitized with oxazolone. Routine histological techniques, employing ordinary paraffin sections, were modified to study this reaction. When biopsies of contact lesions were processed by these methods dense infiltrates of basophils could be demonstrated. Animals sensitized with complete Freund's adjuvant emulsified with oxazolone-keyhole limpet hemocyanin conjugates also developed delayed-in-time responses to contact challenge with oxazolone but not to picryl chloride. These hapten-specific delayed-in-time reactions also contained substantial numbers of basophils. Transfer of serum from actively sensitized guinea pigs resulted in specific accumulation of basophils at challenge sites of recipients. Thus, in this experimental system, cutaneous basophil hypersensitivity was found to be a hapten-specific delayed-in-time reaction that could be transferred with immune serum.
RELEASE OF ENDOTOXIN IN THE FORM OF CELL WALL BLEBS DURING IN VITRO GROWTH OF NEISSERIA MENINGITIDIS
Authors: Devoe I. W. , Gilchrist J. E.
Published: June 2004

Multiple cell wall blebs were observed on the surface of three strains of N. meningitidis taken from log phase cultures. The blebs originated as evaginations of the outer layer of the cell wall. Bleb production was noted on both defined or complex media either as broth or a solid medium. The addition of 10% normal bovine serum to the various media did not affect the production and release of these surface blebs. However, as broth cultures progressed into the stationary phase of growth, the blebs disappeared from the surface of the cells. Blebs were present in substantial quantities in culture supernatant fluids and on cell surfaces and were readily isolated by ultracentrifugation. Analysis for 2-keto-3-deoxyoctonate in cultures revealed that 18% of the total endotoxin of log phase cultures was present in blebs from the cell wall.
FUNCTION OF MACROPHAGES IN ANTIGEN RECOGNITION BY GUINEA PIG T LYMPHOCYTES
Authors: Shevach Ethan M. , Rosenthal Alan S.
Published: June 2004

A number of recent studies have suggested that the main functional role of the product of the immune response (Ir) genes is in the process of antigen recognition by the T lymphocyte. The observation in the accompanying report that the interaction of macrophage-associated antigen with immune T lymphocytes requires that both cells share histocompatibility antigens raised the question as to whether the macrophage played a role in the genetic control of the immune response or even if the macrophage were the primary cell in which the product of the Ir gene is expressed. In the current study, parental macrophages were pulsed with an antigen, the response to which is controlled by an Ir gene lacking in that parent; these macrophages were then mixed with T cells derived from the (nonresponder x responder)F1 and the resultant stimulation was measured. No stimulation was seen when column-purified F1 lymph node lymphocytes were mixed with antigen-pulsed macrophages from the nonresponder parent. However, when the highly reactive peritoneal exudate lymphocyte population was used as the indicator cells, parental macrophages pulsed with an antigen whose Ir gene they lacked were capable of initiating F1 T-cell proliferation. The magnitude of stimulation was approximately 1/10 that seen when macrophages from either the responder parent or the F1 were used. In order to explain this observation, we hypothesize that antigen recognition sites on the T lymphocyte are physically related to a macrophage-binding site and both are linked to the serologically determined histocompatibility antigens. Thus, parental macrophages pulsed with an antigen, whose Ir gene they lack, activate F1 cells poorly because the recognition sites for the antigen are physically related to the macrophage-binding site of the responder parent while the main contacts between the cells are at the nonresponder binding sites. Experiments performed with alloantisera lend support to this hypothesis. Thus, when parental macrophages are pulsed with any antigen and added to F1 T cells, an alloantiserum directed against parental histocompatibility antigens reacts with both the lymphocyte and the macrophage and thereby inhibits macrophage-lymphocyte interaction and abolishes antigen-induced lymphocyte transformation. When the alloantisera are directed at determinants present solely on the T lymphocyte, they only inhibit the recognition of antigens controlled by the Ir gene linked to the histocompatibility antigen against which they are directed. We conclude from these studies that antigen recognition by the T lymphocyte is a complex multicellular event involving more than simple antigen binding to a specific lymphocyte receptor.
PREKALLIKREIN DEFICIENCY IN MAN
Authors: Wuepper Kirk D.
Published: June 2004

Blood plasma obtained from an individual with abnormal thromboplastin formation, due to deficiency of Fletcher factor, was fully corrected by 2% of normal, Hageman factor- or PTA-deficient plasma. It was also reconstituted by addition of highly purified human or rabbit prekallikrein. The plasma failed to generate kinin upon exposure to kaolin, a defect which was also corrected by addition of prekallikrein. Prekallikrein antigen was not detectable in this plasma.

Fletcher factor-deficient plasma did not support the normal generation of PF/dil when dilute plasma was incubated in glass vessels and injected intracutaneously. Small quantities of Fletcher factor-deficient or Hageman factor-deficient plasma corrected the ability of the other to generate PF/dil.

The formation of plasmin in dilute, acidified plasma incubated with kaolin was also abnormal in Fletcher factor-deficient plasma. Plasmin generation was normalized by addition of prekallikrein or small quantities of Hageman factor-deficient plasma.

The data support the identity of Fletcher factor and prekallikrein.
COMPARISON OF THE YIELD OF INFECTIOUS VIRUS FROM CLONES OF HUMAN AND SIMIAN LYMPHOBLASTOID LINES TRANSFORMED BY EPSTEIN-BARR VIRUS
Authors: Miller George , Lipman Muriel
Published: June 2004

Three lymphoblastoid cell lines, of human, squirrel monkey, and marmoset origin, all transformed by the same strain of Epstein-Barr virus (EBV), differed markedly in their content of infectious virus. Single cell clones were obtained from each line to learn whether these differences were dependent upon factors shared by all cells in each line or upon factors present only in a proportion of the total cell population.

A total of 17 primary clones were examined: 6 human, 6 squirrel monkey, and 5 marmoset. Cloning efficiency on human placental cell feeder layers varied from 16 to 24%. EBV antiserum, present in the cloning suspension, was shown to neutralize all extracellular virus. 15 of the 17 clones released EBV as measured by the transformation assay. Titers of infectious virus released by daughter clones paralleled titers of virus in the parent line. The median virus titers from human, squirrel monkey, and marmoset clones were respectively 101.5, 103.0, and 104.3 50% transforming doses per 0.2 ml. The median yield of virus from clones of the three species was, respectively, 4, 96, and 786 transforming units per 1,000 cells containing viral capsid antigen.

Two nonproducer clones (one human and one squirrel monkey) did not release infectious virus after treatment with 5'-bromodeoxyuridine, or with X ray followed by co-cultivation with marmoset leukocytes. The nonproducer clones could not be superinfected by biologically active EBV.

These results show that differences in production of infectious EBV among the lines tested are reflected in the majority of cells of these lines. The data imply that the mechanism for regulation of the expression of the EBV genome is cellular rather than viral in origin. There are presumably genetic differences among primate species in this regulatory process.
ACTIVATION OF HAGEMAN FACTOR IN SOLID AND FLUID PHASES
Authors: Cochrane C. G. , Revak S. D. , Wuepper K. D.
Published: June 2004

The activation of Hageman factor in solid and fluid phase has been analyzed. Activation of highly purified Hageman factor occurred after it interacted with and became bound to a negatively charged surface. Activation was observed in the absence of enzymes that are inhibitable with diisopropylfluorophosphate, phenyl methyl sulfonyl fluoride and ϵ-amino-n-caproic acid. The binding of [125I]Hageman factor to the negatively charged surface was markedly inhibited by plasma or purified plasma proteins.

Activation of Hageman factor in solution (fluid phase) was obtained with kallikrein, plasmin, and Factor XI (plasma thromboplastin antecedent). Kallikrein was greater than 10 times more active in its ability to activate Hageman factor than plasmin and Factor XI. The data offer a plausible explanation for the finding that highly purified kallikrein promotes clotting of normal plasma. In addition, the combined results of this and previously reported data from this laboratory indicate that the reciprocal activation of Hageman factor by kallikrein in fluid phase is essential for normal rate of activation of the intrinsic-clotting, kinin-forming, and fibrinolytic systems.

Activation of Hageman factor was associated with three different structural changes in the molecule: (a) Purified Hageman factor, activated on negatively charged surfaces retained its native mol wt of 80–90,000. Presumably a conformational change accompanied activation. (b) In fluid phase, activation with kallikrein and plasmin did not result in cleavage of large fragments of rabbit Hageman factor, although the activation required hydrolytic capacity of the enzymes. (c) Activation of human Hageman factor with kallikrein or plasmin was associated with cleavage of the molecule to 52,000, 40,000, and 28,000 mol wt fragments. Activation of rabbit Hageman factor with trypsin resulted in cleavage of the molecule into three fragments, each of 30,000 mol wt as noted previously. This major cleavage occurred simultaneously with activation.
SIMILARITIES IN THE LIGHT CHAINS OF ANTI-γ-GLOBULINS SHOWING CROSS-IDIOTYPIC SPECIFICITIES
Authors: Kunkel H. G. , Winchester R. J. , Joslin F. G. , Capra J. D.
Published: June 2004

A marked homogeneity of the light chains was observed in an analysis of 17 IgM proteins with anti-γ-globulin activity. The V region subgroups of the light chains were determined by both sequence and antigenic analysis. The latter procedure permitted large scale screening for comparisons with control proteins. The two methods showed general agreement in the determination of Kappa III proteins; all proteins positive by antigenic analysis were also positive by sequence but exceptions were noted in the opposite direction. The anti-γ-globulins showed by antigenic analysis a 92% incidence of VK III light chains as compared to an incidence of 27% among 81 control proteins without this activity. A similar selection was observed for an antigen (VK III b) which subdivided the kappa III proteins.

The major Wa group of anti-γ-globulins which had been delineated previously on the basis of cross-idiotypic specificity was primarily responsible for the special light-chain selection. All the proteins of this group contain VK III light chains and all were of the VK III b type. Current evidence indicates that additional light-chain similarities were involved in the cross-idiotypic specificity of the Wa group. It thus appears that for the anti-γ-globulins various levels of selection of light chains are manifest ranging from a preponderance of kappa type, of kappa III subgroup, of kappa III b sub-subgroup and perhaps of still further subdivisions to account for the cross-idiotypic specificity.
HORMONE-LIKE ACTIVITY OF A THYMUS HUMORAL FACTOR ON THE INDUCTION OF IMMUNE COMPETENCE IN LYMPHOID CELLS
Authors: Kook Abraham I. , Trainin Nathan
Published: June 2004

Experiments reported here were performed to understand the mechanism by which THF increases the immunocompetence of spleen cells from NTx mice.

Dibutyryl cAMP or substances which increase intracellular levels of cAMP in lymphocytes such as Poly(A:U), theophylline, or PGE2 were shown to mimic the effect of THF and confer reactivity in an in vitro GvH response to spleen cells from NTx mice. Flufenamic acid, an antagonist to PGE2, was shown to inhibit the induction of competence by this substance. It was found that THF induces competence by activating membranal adenyl cyclase which leads to a rise in intracellular cAMP in thymus-derived cells only. These biochemical changes occur before antigenic stimulation and are unrelated to antigenic challenge.

These findings indicate that THF exerts its effect via cAMP and are in agreement with the concepts which permit to classify THF as a thymus hormone.
PREPARATION AND CHARACTERIZATION OF AN IMMUNOELECTRON MICROSCOPE TRACER CONSISTING OF A HEME-OCTAPEPTIDE COUPLED TO Fab
Authors: Kraehenbuhl J. P. , Galardy R. E. , Jamieson J. D.
Published: June 2004

A heme-octapeptide (mol wt 1,550) has been obtained from cytochrome c by successive pepsin and trypsin hydrolysis and purified by gel filtration and countercurrent distribution. It possesses peroxidatic activity characterized by an apparent Km of 0.2 M, an apparent vmax of 4 mmol/min per mg of peptide, and a pH optimum of 7.0. Using a novel two-step conjugation procedure, the heme-octapeptide was coupled to rabbit Fab antibody fragments by first derivatizing it with the N-hydroxysuccinimide ester of p-formylbenzoic acid and subsequently allowing it to form a Schiff base with the amino groups of Fab. Stable covalent linkages were then obtained by reduction of the Schiff bases with sodium borohydride. The conjugate consists of ∼2 heme-octapeptides attached to each Fab molecule. The molecular weight is 45,000 daltons when coupled to sheep Fab and 50,000 daltons with a Stokes radius of 32 Å, when conjugated to rabbit Fab. Its peroxidatic activity is characterized by an apparent Km of 0.4 M, an apparent vmax of 0.4 mmol/min and per mg of attached heme-octapeptide and a pH optimum of 7.0. The conjugate has been used for the localization at the electron microscope level of secretory immunoglobulins in the mammary gland of lactating rabbits.
ACTIVATION OF T AND B LYMPHOCYTES IN VITRO
Authors: Armerding Dieter , Katz David H.
Published: June 2004

The present studies were undertaken to analyze the nature of the effect of bacterial lipopolysaccharide (LPS) on antibody production in vitro. We have done this by making comparative studies of the effects of LPS on in vitro primary and secondary antibody responses to soluble hapten-protein conjugates and to particulate and soluble sheep erythrocyte antigens. The results obtained demonstrate that the biological action of LPS in vitro may be predominantly manifested on the function of B lymphocytes or T lymphocytes depending on the conditions employed. In the absence of antigen, LPS appears to act primarily on B lymphocytes. In the presence of antigen, however, the data presented here show that LPS significantly influences specific helper T-cell function and it is this latter influence that is predominantly responsible for the adjuvant effects of LPS on antigen-specific antibody responses.
MATURATION OF THE HUMORAL IMMUNE RESPONSE IN MICE
Authors: Spear Patricia G. , Edelman Gerald M.
Published: June 2004

In spite of the prenatal appearance of immunoglobulin-bearing lymphocytes and θ-positive lymphocytes in the spleens of Swiss-L mice, these mice are not able to produce detectable levels of humoral antibodies in response to antigen until after 1 wk of age. Adult levels of response are not achieved until 4–8 wk of age. In the presence of bacterial lipopolysaccharides, which can substitute for or enhance T-cell function, the B cells from young Swiss-L mice were found to be indistinguishable in function from adult B cells, both with respect to the numbers of plaque-forming cells (PFC) produced in vitro in response to antigen and with respect to the kinetics of PFC induction. The spleen cells from young Swiss-L mice are significantly less sensitive than adult spleen cells, however, to stimulation by the T cell mitogens, concanavalin A (Con A) and phytohemagglutinin (PHA). Very few Con A-responsive cells could be detected at birth but the numbers increased sharply with age until 3 wk after birth. On the other hand, PHA-responsive cells could not be detected in the spleen until about 3 wk of age. The latter cells were found to respond also to Con A, but at a lower dose (1 µg/ml) than that required for the bulk of the Con A-responsive cells (3 µg/ml). The cells that respond both to PHA and to Con A appear in the spleen at about the time that Swiss-L mice acquire the ability to produce humoral antibodies, and these cells can be depleted from the spleen by the in vivo administration of antithymocyte serum. The development of humoral immune responses in these mice therefore appears to be correlated with the appearance of recirculating T lymphocytes that are responsive both to PHA and to Con A.
THE CYTOKINETICS OF MONOCYTOSIS IN ACUTE SALMONELLA INFECTION IN THE RAT
Authors: Volkman Alvin , Collins Frank M.
Published: June 2004

The mechanisms responsible for monocytosis occurring in acute Salmonella infection were studied by means of isotopic labeling and autoradiography. Male (Lewis x BN)F1 hybrid rats (160–180 g) were pulse-labeled with [3H]TdR at varying intervals with respect to the time of i.v. injection of about 106 living Salmonella enteritidis. The half time for monocytes in the blood was estimated from the exponential decline in the percentage of labeled monocytes. The average generation time for dividing monocyte precursors in bone marrow was estimated by fitting a regression line to the decline in median grain counts (halving-time = TG). After an initial fall, the absolute number of blood monocytes rose to a plateau about 2.5 x normal on day 5, suggesting the reimposition of steady state conditions. The half time of monocytes in the blood of infected rats was shortened to 25 h throughout the infection, compared with 61 h estimated in uninfected rats. TG was reduced to 15 h (days 1–3) but later reverted to the preinfection level of 34 h (days 4–8). Another early response to infection was the release of immature monocytes into the blood. These cells, however, were too few to offset the initial monocytopenia. Under these conditions, with little or no division of blood monocytes, the sustained monocytosis (days 4–8) must have been due to enlargement of the dividing precursor pool. Excessive loss of monocytes from the blood thus appears to activate a feedback mechanism. However, a more direct stimulating effect on monocyte production by endotoxin could have contributed substantially to the monocytosis.
IDENTIFICATION OF A NOVEL CELL TYPE IN PERIPHERAL LYMPHOID ORGANS OF MICE
Authors: Steinman Ralph M. , Cohn Zanvil A.
Published: June 2004

Dendritic cells are morphologically distinct cells isolated in vitro from peripheral lymphoid organs of mice. They have a buoyant density of less than 1.082 and can be enriched 7–20-fold by isopycnic centrifugation in albumin columns. Surface adherence of enriched populations may yield cultures containing 50% dendritic cells—preparations which can then be studied in more detail. By functional tests, dendritic cells do not represent morphological variants of either lymphocytes or macrophages. They lack lymphocyte surface differentiation markers and do not exhibit the endocytic capacities of macrophages. In tissue culture, they do not differentiate into macrophages. Dendritic cells have a low labeling index in vitro (1.5–2.5%) following administration of [3H]thymidine, and this property distinguishes them from large lymphocytes and promonocytes. Dendritic cells also do not possess the functional properties of other types of reticular cells proposed to exist in lymphoid organs, i.e., they do not synthesize collagen-like macromolecules, they are not stem cells for erythroid and myeloid colony formation, and they do not retain antigens or immune complexes on their cell surface. Dendritic cells thus represent a novel cell type on both functional and morphological grounds.
CELL-MEDIATED IMMUNITY AGAINST BESNOITIA AND TOXOPLASMA IN SPECIFICALLY AND CROSS-IMMUNIZED HAMSTERS AND IN CULTURES
Authors: Hoff Richard L. , Frenkel J. K.
Published: June 2004

The capacity of hamster peritoneal cell populations to control viability and growth of Besnoitia and Toxoplasma organisms was assessed in vivo and in vitro. Immunized hamsters reduced the homologous organisms 100- to 10,000-fold over a 5-day period, but the heterologous infection increased 100- to 1,000-fold in numbers, similar as in the nonimmune controls. Passively administered antibody was ineffective although lytic cofactors were supplied by hamsters.

In cultures, peritoneal cells from Besnoitia-immune hamsters delayed the growth of homologous parasites to an average of 38.5 h per division; however, in Toxoplasma-immune and nonimmune cells, Besnoitia divided every 12.8 h. Specificity of immunity was pronounced against both infections. With cross-infections, Toxoplasma-immune cultures did not effectively delay Besnoitia growth; however, Besnoitia-immune cultures reduced Toxoplasma growth by one-half. Co-cultivation experiments demonstrated that specifically committed lymphocytes could instruct macrophages to reduce the homologous organism 10-fold, whereas heterologous organisms were reduced only 2-fold.

Lymphocyte supernatants initiated hypersensitivity as indicated by macrophage activation and giant cell formation in culture. However, these supernatants did not transfer infection immunity. Lymphokines could account for the hypersensitivity phenomena, but cell-mediated infection immunity in this model required close lymphocyte-macrophage proximity.

These studies indicate that a number of distinct processes including delayed hypersensitivity, macrophage activation, and specific cellular immunity are acting simultaneously during latent Besnoitia infection of hamsters. All three processes are mediated by lymphoid cells and appear to be specifically induced. Although activated macrophages develop some heightened nonspecific capabilities, these were several orders of magnitude below the specific effects.
FURTHER EVIDENCE OF THE TOXICITY OF NaCl
Authors: Dahl Lewis K. , Tuthill Ralph
Published: June 2004

The spontaneously hypertensive rat (SHR) of Okamoto and Aoki (4) develops significant hypertension without added dietary salt. Many patients with hypertension have little or no alteration in blood pressure from increments or decrements of salt intake. Such observations have led to a widespread belief that dietary NaCl is important in hypertensives only if blood pressure changes are observed after changes in NaCl intake. Such a simplistic view of hypertension fails to take into account the possibility that morbidity and mortality might be lowered by restricting dietary NaCl, without a concomitant lowering of blood pressure.

The effect of a high NaCl intake for periods up to 1 yr has been studied in the SHR with the following conclusions: (a) NaCl accelerated the rate at which hypertension developed in both sexes. (b) The ultimate levels of blood pressure reached by males on either high or low salt diets were similar, however. (c) In females, (1) on high NaCl the average blood pressure ultimately became indistinguishable from males whereas (2) on low NaCl pressure remained significantly lower than that of males. (d) The addition of NaCl to the regimen had a devastating effect on mortality of both sexes and was not directly correlated with the level of blood pressure. Earlier reports were reviewed bearing on the possibility that NaCl is inimical to blood vessels without a necessary relationship to its hypertensinogenic effect. It was concluded that restriction of dietary NaCl would reduce morbidity and mortality in hypertension, whether or not blood pressure was reduced by such measures.
ROLES OF T AND B LYMPHOCYTES IN THE TERMINATION OF UNRESPONSIVENESS TO AUTOLOGOUS THYROGLOBULIN IN MICE
Authors: Clagett James A. , Weigle William O.
Published: June 2004

The data presented in this paper support the hypothesis that unresponsiveness to autologous thyroglobulin (Tg) exists in the T cells and responsiveness exists in the B cells. Such a conclusion is based on the results of antigen-binding studies where few, if any, thymocytes recognized syngeneic Tg. Comparable numbers of antigen-binding lymphocytes for syngeneic Tg were found in the spleens of normal intact mice and of nude mice. The latter fact suggested that B cells exist which recognize self-constituents. From antigen-suicide experiments, a clearer picture of the susceptibility of B cells to iodinated self-antigen and of the obligatory role of antibody in the induction of lesions was developed. Only bone marrow cells (B cells) were affected by [125I]syngeneic Tg, in which case the incidence of lesions was diminished. From adoptive transfer experiments, the results demonstrate that unresponsiveness may be terminated by immunization with a mixture of heterologous (cross-reacting) Tg's. In this situation T cells are required since a B-cell reconstituted host failed to make antibody (plaque-forming cells) and to develop lesions. T cells in this form of an unresponsive state may recognize determinants on the heterologous Tg unrelated to autologous Tg and as such stimulate the normal complement of B cells to produce antibody that both reacts with autologous and heterologous Tg.
LYMPHOCYTE PROLIFERATION IN VITRO INDUCED BY HAPTEN AUTOLOGOUS PROTEIN CONJUGATES
Authors: Rubin Bent , Wigzell Hans
Published: June 2004

Immune lymph node cells from guinea pigs respond to soluble antigen in vitro by an increase in DNA synthesis. Optimal conditions for this proliferative response were studied in the present article. Under such conditions, immune cells showed increasing responses with increasing antigen concentration in vitro, the threshold dose of activation frequently being as low as 0.02 µg per culture. In contrast, normal lymph node cells (from FCA-stimulated animals) did only respond to antigen at very high doses (20 mg/culture), and immune cell dilution studies could be performed in normal cells without changing the kinetics of the antigen specific response of immune cells.

Fractionation on anti-Ig columns indicated that purified, immune T lymphocytes were quite capable of proliferating in vitro upon antigen stimulation. However, our attempts to adsorb the proliferating cells onto chemically defined immunoadsorbants failed despite the fact that immune B cells (as measured by the rosette assay) were retained almost completely by such a procedure.

Purified, immune T lymphocytes from guinea pigs immunized with different antigen concentrations in vivo and/or obtained at different times after immunization were tested for a differential sensitivity toward antigen-induced DNA synthesis in vitro. However, we were not able to demonstrate any regular increase in sensitivity to antigen in vitro, and if found, it seemed to be more dependent upon the number of antigen reactive cells in the population studied rather than upon differences in the average avidity of the receptors on the cells proliferating in vitro. The results in the present article are discussed in relation to current knowledge and hypotheses on T-lymphocyte receptors.
LACK OF A CORRELATION BETWEEN CELL-MEDIATED IMMUNITY TO THE CARRIER AND THE CARRIER-HAPTEN HELPER EFFECT
Authors: Liew F. Y. , Parish C. R.
Published: June 2004

The relationship between cell-mediated immunity to the carrier and the carrier-hapten helper effect was studied in the rat by using three forms of the carrier which differed in their capacity to induce carrier-specific delayed-type hypersensitivity. The three carriers were polymerized flagellin (POL), flagellin (FIN), and acetoacetylated flagellin (AFIN), which induced FIN-specific delayed-type hypersensitivity in the order AFIN > FIN > POL. Helper cells for the anti-DNP antibody responses to a range of DNP-FIN conjugates appeared to be almost inversely related to cell-mediated immunity to the carrier, being in the order POL > FIN ⪖ AFIN. These differences occurred whether the carriers were injected in saline or FCA, but were less pronounced with the heavily DNP-conjugated flagellins.
BINDING OF AGGREGATED γ-GLOBULIN TO ACTIVATED T LYMPHOCYTES IN THE GUINEA PIG
Authors: van Boxel John A. , Rosenstreich David L.
Published: June 2004

Heat-aggregated guinea pig γ-globulin was shown to bind to the surface membrane of a subclass of guinea pig T lymphocytes. Cells of this subpopulation were identified as T lymphocytes because these cells did not stain for surface Ig (a B-cell marker) but did form spontaneous E-rosettes with rabbit erythrocytes (a T-cell marker). A strikingly high proportion of such aggregate-binding (Agg+), E-rosette-forming (E-rosette+), but surface Ig-negative (Ig-) cells were found in an inflammatory exudate. Thus purified peritoneal exudate lymphocytes (PELs) are known to consist of over 90% T cells, and 59% of these cells bound aggregates. 10% of these Agg+ Ig- E-rosette+ cells were found in draining lymph node cell populations and none in thymus cell populations.

The high frequency amongst PELs suggested that these Aggregate+ Ig- E-rosette+ cells might be activated T cells as these are known to occur in high proportion in PEL populations. Confirmatory evidence for this postulate was provided by the striking increase (from 10% to 46%) of Ig- E-rosette+ cells that bound aggregates when lymph node cells were activated by antigen stimulation in vitro.
RENAL TRANSPLANTATION IN DIABETES MELLITUS IN RATS
Authors: Lee Chue Shue , Mauer S. Michael , Brown David M. , Sutherland David E. R. , Michael Alfred F. , Najarian John S.
Published: June 2004

Immunoglobulins and complement are deposited in the glomerular mesangium of rats with progressive glomerulosclerosis secondary to chemically induced diabetes mellitus. Isotransplantation of a kidney from a rat diabetic for 6 mo into a normal recipient results within 2 mo in the disappearance of IgG, IgM, and ß1C from the mesangium and arrest or reversal of the light microscopic glomerular lesions. Kidneys isotransplanted from normal donors into diabetic rats developed mesangial matrix thickening and deposition of IgG, IgM) and ß1C in the mesangium. No glomerular changes occur upon transplantation of a normal kidney into a normal rat. These findings indicate that diabetic glomerular changes in the rat are reversible and are secondary to the diabetic state rather than to the inducing agent.