bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF CHRONIC EXCESS SALT INGESTION
Authors: Knudsen Knud D. , Dahl Lewis K. , Thompson Keith , Iwai Junichi , Heine Martha , Leitl George
Published: June 2004

Two strains of rat have been developed by selective breeding: one strain (R rats) is resistant to salt hypertension, the other strain (S rats) is highly susceptible. The inheritance of these traits has been explored in the first (F1) and second (F2) generation of crossbred rats and in backcrosses between parent and first filial (F1 x R, F1 x S) generations. Male F1 rats had an average blood pressure close to the mid-parental (R and S) values, and the average of F2 males was equivalent to that of F1. Male offspring of F1 with R, or F1 with S also showed averages close to the respective mid-parental values. Female offspring showed deviations from this linear relationship, indicating a significant dominance in the female for the genes of normal blood pressure. A model of two autosomal, nonlinked diallelic loci, with a dominance deviation at one locus in the female, gave predictions with a reasonable agreement to the observed values. The same model also appeared compatible with human data if we assume a gene frequency of 0.13 for the hypertensinogenic allele on both loci. Random fluctuations in blood pressure, and incomplete homogeneity of parental strains permit several alternative models. The major conclusions are: that more than one locus is needed to explain the findings though as few as two loci may possibly suffice; the allelic effect seems additive in males, but there is a sex-determined influence on the expression in females; there is no consistent evidence for sex-linked inheritance. Furthermore, this model developed from the study of rats may provide a framework for analysis of human data.
THE METABOLISM OF AMINO ACIDS, PEPTIDES, AND DISULFIDES IN LYSOSOMES OF FIBROBLASTS CULTURED FROM NORMAL INDIVIDUALS AND THOSE WITH CYSTINOSIS
Authors: Schulman Joseph D. , Bradley Kathryn H.
Published: June 2004

The metabolism of amino acids, peptides, and disulfides has been investigates in cultured skin fibroblasts from normal individuals and patients with cystinosis. Human fibroblast lysosomes closely resemble the lysosomes of mouse peritoneal macrophages in having an apparent permeability barrier to amino acids and peptides with molecular weights of greater than 220–230. Cystinotic and normal cells behave similarly in this regard. Normal cells do not undergo lysosomal swelling when exposed to cysteine-penicillamine disulfides, while cystinotic cells are prominently vacuolized under these conditions. Normal lysosomes may have a specific mechanism for the disposal of cystine, and deficient activity of this mechanism in cystinotic lysosomes could result in cystine storage therein. The demonstration that human fibroblasts can be used conveniently to study lysosomal metabolism of small substrates may facilitate investigations of these aspects of lysosomal function in a variety of genetic diseases of man.
SURFACE ANTIGENS OF IMMUNOCOMPETENT CELLS
Authors: Takahashi T. , Carswell E. A. , Thorbecke G. J.
Published: June 2004

Spleen cell transfer studies were done in BALB/c strain mice in an attempt to define the role of θ-antigen-bearing lymphoid cells in immune responses to SE. Incubation with alloantiserum to θ-C3H and rabbit C' virtually completely abolished the ability of the cells to transfer both primary and secondary (IgM and IgG) responses to 650 R irradiated recipients. Normal thymus cells partially reconstituted the ability of such treated cells to transfer the primary but not the secondary response. The results are interpreted as showing immunological memory for SE in the θ-bearing thymus-derived cells.

Incubation of the spleen cells with alloantiserum to the PC.1 antigen present on antibody-forming cells did not significantly affect the ability to transfer either primary or secondary response.
TRANSFORMATION OF FIBROBLASTS BY ALLOGENEIC AND XENOGENEIC TRANSPLANTS OF DEMINERALIZED TOOTH AND BONE
Authors: Huggins Charles , Wiseman Sol , Reddi A. H.
Published: June 2004

Xenogeneic transplants of powdered, dehydrated, demineralized matrix of bone and tooth were well tolerated in three species of rodents. Differences between the species were found in competence of fibroblasts to be transformed into cartilage and bone in vivo by these preparations. Rat fibroblasts were most susceptible to transformation of this sort; they were transformed by demineralized dentin of guinea pig, mouse, and rat, and to a limited extent, by a specimen of decalcified human bone.
WILD-TYPE GROSS LEUKEMIA VIRUS AND THE PATHOGENESIS OF THE GLOMERULONEPHRITIS OF NEW ZEALAND MICE
Authors: Mellors Robert C. , Shirai Toshikazu , Aoki Tadao , Huebner Robert J. , Krawczynski Krzysztof
Published: June 2004

The pathogenesis of the spontaneous glomerulonephritis of NZB and (NZB x NZW) F1 hybrid mice is related at least in part to the formation of natural antibody against antigens of the G (Gross) system, and apparently to the deposition in the glomeruli of immune complexes of G natural antibody with G soluble antigen (GSA), type-specific antigen specified by wild-type Gross leukemia virus. G natural antibody and GSA are detectable in the acid-buffer eluate of the kidneys of NZB mice during the course of the glomerulonephritis. (NZB x NZW) F1 hybrid mice develop glomerulonephritis and produce GSA and free G natural antibody earlier in life than do NZB mice. The proteinuria manifestation of the gomerulonephritis of (NZB x NZW) F1 hybrid mice becomes increasingly prevalent as GSA undergoes immune elimination from the circulation. Gross leukemia virus-specified antigens together with bound immunoglobulins are located in the glomerular lesions of (NZB x NZW) F1 hybrid mice, both in the mesangium as observed in NZB mice and also in the wall of the peripheral capillary loops of the glomeruli.
HETEROGENEITY OF THE CELLULAR IMMUNE RESPONSE
Authors: Bast Robert C. , Manseau Eleanor J. , Dvorak Harold F.
Published: June 2004

Lymph node cells from guinea pigs immunized with HSA in complete Freund's adjuvant were grown in cultures containing different concentrations of specific antigen. Stimulation of thymidine incorporation was induced with progressively lower concentrations of HSA at successive intervals after sensitization. Moreover, the intensity of delayed skin reactions and the magnitude of stimulation in vitro increased over the same interval. These events are considered compatible with an evolution of the cellular immune response resulting from the selection of lymphoid cells by decreasing concentrations of antigen in vivo.

Cells from animals rendered tolerant to HSA failed to respond to specific antigen in culture. As tolerance waned, stimulation was achieved at high but not low antigen concentrations. Tolerance, measured by cutaneous reactivity or by lymphocyte stimulation, was less readily induced in animals sensitized with adjuvant containing a reduced concentration of mycobacteria. Lymph nodes from these animals contained a large population of cells reactive at high antigen concentration, presumably less susceptible to the toleragenic effect of intravenous antigen.

The dissociation of delayed hypersensitivity and antibody formation observed early in the immune response and upon recovery from tolerance has permitted correlation of lymphocyte stimulation with delayed hypersensitivity and cutaneous basophil hypersensitivity respectively.
ISOLATION OF A TUMOR FACTOR RESPONSIBLE FOR ANGIOGENESIS
Authors: Folkman Judah , Merler Ezio , Abernathy Charles , Williams Gretchen
Published: June 2004

Human and animal solid tumors elaborate a factor which is mitogenic to capillary endothelial cells. This factor has been called tumor-angiogenesis factor. The important components of TAF are RNA and protein. It is suggested that blockade of this factor (inhibition of angiogenesis) might arrest solid tumors at a tiny diameter of a few millimeters.
MACROPHAGE-MELANOCYTE HETEROKARYONS
Authors: Gordon Saimon , Cohn Zanvil
Published: June 2004

Mouse peritoneal macrophages, which do not synthesize DNA in vitro, were fused with melanocytes, a mouse cell strain which proliferates rapidly in vitro. DNA synthesis was induced in macrophage nuclei 2–3 hr after fusion and occurred irrespective of the number of macrophage nuclei present per melanocyte nucleus in each heterokaryon. 50–80% of macrophage nuclei initiated DNA synthesis in the 3–7 hr period after fusion. The activation of most 11–12-day chick red cell nuclei in melanocyte cytoplasm took longer than 10 hr. The lag before DNA synthesis may reflect the heterochromatin content of each nucleus.

Studies with actinomycin showed that heterokaryon RNA synthesis was essential for subsequent macrophage DNA synthesis. This RNA was synthesized 1–4 hr before the DNA and was unlikely to be ribosomal RNA, since it was insensitive to <0.1 µg/ml actinomycin.

Melanocytes and macrophages were treated before fusion with actinomycin and bromotubercidin to bring about a more selective inhibition of RNA synthesis. Macrophages pretreated for 1 hr with 5 µg/ml of actinomycin showed less than 20% of control RNA synthesis in the first 4 hr after fusion, but a normal activation of macrophage DNA synthesis. Pretreatment of melanocytes for 3–7 hr with 5 µg/ml bromotubercidin, a reversible inhibitor of RNA synthesis, prevented macrophage DNA synthesis without affecting macrophage RNA synthesis in the heterokaryons (81% of control). These studies showed that only melanocyte RNA synthesis was essential for the production of macrophage DNA.

The exposure of one cell partner to actinomycin before fusion caused cross-toxicity of the untreated nucleus after fusion. Bromotubercidin, an adenosine analogue which is incorporated into RNA, did not give rise to such cross-toxicity after fusion.

Once the macrophage nucleus becomes activated in the heterokaryon it becomes less sensitive to the action of actinomycin.
TEMPORAL DEVELOPMENT OF RESISTANCE TO PULMONARY TUBERCULOSIS IN SWISS ALBINO MICE
Authors: Izumi Takateru , Costello Richard
Published: June 2004

The course of pulmonary tuberculosis was followed in control and BCG-vaccinated mice. Resistance was evaluated by determining the numbers of virulent mycobacteria recovered from the organs at various intervals after airborn infection.

A limited but significant retardation of growth of challenge bacilli was observed in both pulmonary and splenic tissues of successfully vaccinated animals. This retardation was manifested chiefly during the early stages of the infection. However, the numbers of virulent organisms recovered from the organs of either vaccinated or control animals were much the same at later stages of the infection.

The appearance of pulmonary immunity was related to the stage of development in vivo of the vaccinal population. Only after large numbers of vaccinal bacilli could be recovered from the tissues was heightened resistance observed.
MACROPHAGE-DIGESTED ANTIGEN AS INDUCER OF DELAYED HYPERSENSITIVITY
Authors: Pearson Margot N. , Raffel Sidney
Published: June 2004

Sheep erythrocytes ingested by guinea pig peritoneal macrophages in vitro, and permitted to undergo digestion for various periods, were found after some hours to lose the capacity to induce antibodies while gaining the ability to invoke delayed hypersensitivity. These observations may be related to the known predilection of small molecular immunogens to act as good inducers of delayed reactivity and poor stimulators of antibody. They may be related also to the activity of mycobacterial adjuvant as a vehicle for the induction of delayed hypersensitivity on the basis that this melange activates macrophages to phagocytose and enzymatically degrade macromolecular antigens rapidly. The thesis that small fragments of antigenic molecules may preferentially invoke hypersensitivity can be interpreted on the basis of current concepts of multicellular involvements in immune responses.
THE NATURE OF THE COLICIN K RECEPTOR OF ESCHERICHIA COLI CULLEN
Authors: Weltzien Hans Ulrich , Jesaitis Margeris A.
Published: June 2004

Cell walls of E. coli strains B and Cullen contain specific receptors for colicin K and for the T2, T6, and C16 phages. The receptors for the bacteriocin and the T6 virus are located in the outer layers of the cell wall of these microorganisms and are absent in their cytoplasmic membrane.

The receptors for colicin K, phage T2, and the T6 and C16 viruses differ in their stability toward enzymes and chemical reagents. Their specificity must therefore be determined by different chemical groupings.

The colicin K receptor is inactivated by certain proteolytic enzymes and by reagents which combine with tryptophan. It is concluded therefore that proteins or peptides containing this amino acid are essential for biological activity of the receptor.
ACUTE IMMUNE COMPLEX DISEASE IN RABBITS
Authors: Henson P. M. , Cochrane C. G.
Published: June 2004

By depletion of C3 from rabbits undergoing acute experimental immune complex disease with an anticomplementary factor in cobra venom, it has been possible to demonstrate that deposition of the complexes in arteries and glomeruli does not require the complement components reacting after C2.

Immunological reactions, in which platelets release their vasoactive amines, have been examined in rabbits undergoing immune complex disease. A correlation was obtained between the presence of a complement-independent reaction which required blood leukocytes, antigen and platelets, the deposition of immune complexes, and the induction of glomerulonephritis.

C3 depletion did, however, have a marked alleviating effect on the severity of the arterial lesions. Neutrophil accumulation and the subsequent necrotizing arteritis were prevented. In contrast, the character and severity of the glomerulonephritis was not altered by depletion of later-acting complement components.
FACTORS INFLUENCING PULMONARY METHANE EXCRETION IN MAN
Authors: Bond John H. , Engel Rolf R. , Levitt Michael D.
Published: June 2004

Measurements of pulmonary excretion of methane (CH4) were used to obtain information on the CH4-producing bacteria in man. Preliminary studies indicated that (a) all CH4 excreted by man is produced by colonic bacteria, (b) there is no appreciable utilization of CH4 by man, and (c) breath CH4 can serve as a relatively accurate indicator of CH4 production in the intestine.

The rate of pulmonary CH4 excretion varied enormously, ranging from undetectable (<5 x 10–6 ml/min) to 0.66 ml/minute. In general, the CH4 excretion rate for subjects was consistently very low (nonproducers) or relatively large (producers). 33.6% of the adult population were producers of CH4. Whereas diet, age over 10 yr, and sex did not influence the rate of CH4 production, some familial factor appeared to play an important role. 84% of siblings of CH4 producers also were producers, while only 18% of the siblings of nonproducers were found to be CH4 producers. This familial tendency appeared to be determined by early environmental rather than genetic factors.

These studies of CH4 excretion demonstrate that the exposure of individuals to intestinal bacterial metabolites may differ markedly and that these differences may be chronic and determined by familial factors.
A PREALBUMIN ACTIVATOR OF PREKALLIKREIN
Authors: Kaplan Allen P. , Austen K. Frank
Published: June 2004

Activation of a plasma fraction containing unactivated Hageman factor and prekallikrein followed by chromatography of this fraction on DEAE-cellulose revealed four peaks having bradykinin-generating activity. Peak 1 contained kallikrein; peaks 2–3, 4, and 5 each contained prekallikrein-activating activity. Elution of peaks 2–3, 4, and 5 from disc gels after electrophoresis at pH 9.3 revealed peaks of prekallikrein-activating activity located at 5–8, 11–12, 15–16, and 20–26 mm, each of which was associated with a peak of clot-promoting activity which specifically corrected Hageman factor deficiency. Conversion of peak 2 to peaks 3, 4, and 5 was associated with a progressive decrease in size, increase in net negative charge, increased prekallikrein-activating activity, and decreased ability to correct Hageman factor deficiency. Plasminogen and plasmin were found on a DEAE-cellulose chromatogram of serum overlapping peaks 2 and 3. Incubation of active Hageman factor with streptokinase-activated plasminogen resulted in enhanced ability of the mixture to activate prekallikrein. Assessment of the products of this reaction by disc gel electrophoresis demonstrated the formation of the prealbumin prekallikrein activator corresponding to the major prekallikrein activator generated by contact activation of human plasma. The conversion of plasminogen to plasmin and the subsequent cleavage of Hageman factor by plasmin to form activators of prekallikrein represents one pathway in which coagulation, fibrinolysis, and inflammation are linked.
STUDIES ON ANTIGEN-ANTIBODY COMPLEXES
Authors: Mannik Mart , Arend William P. , Hall Anthony P. , Gilliland Bruce C.
Published: June 2004

Solid phase immunoadsorbents were prepared by coupling antigens to agarose. With this technique specific antibodies were easily isolated in large amounts. The γG-globulin class of antibodies isolated in this manner were not denatured as judged by their normal biological half-life in rabbits. Soluble immune complexes at fivefold antigen excess were prepared from isolated specific antibodies and HSA, human λ-chains, human λG-globulins, and a Waldenström's macroglobulin as antigens. In all these preparations a characteristic immune complex was encountered that represented the smallest stable antigen-antibody union. In the HSA-anti-HSA system they were found to be AgAb2 complexes, and Ag2Ab complexes in the γG-anti-γG system. These stable complexes fixed complement ineffectively. Also, a spectrum of larger complexes was present in each system, and these complexes fixed complement effectively.

With intact antibodies the disappearance curves of immune complexes from the circulation were composed of three exponential components. The immune complexes larger than AgAb2 were quickly removed from the circulation with half-lives of 0.09–0.37 hr. Their clearance was not dependent on complement components, in that depletion of complement by cobra venom factor and aggregated γG-globulin did not alter the pattern of their removal from the circulation. However, when the interchain disulfide bonds of antibodies were reduced and alkylated, the removal of the λ-anti-λ, HSA-anti-HSA, and γG-anti-γG complexes was altered. In these experiments the disappearance curves were composed of two exponential components and the rapid removal of the greater than AgAb2 complexes did not occur. The immune complexes prepared from reduced and alkylated antibodies fixed complement ineffectively.

The presented data indicate that the rapid removal of circulating immune complexes, containing γG-globulin molecules as antibodies, depends primarily on the number of antibodies involved. Furthermore, complement fixation is not involved in the rapid removal of such complexes. Nevertheless, the rapid removal of immune complexes and their ability to fix complement have similarities for optimal function in that both processes require intact interchain disulfide bonds of antibodies and complexes that exceed the AgAb2 combination.
ON THE NUMBER AND NATURE OF ANTIGEN-SENSITIVE LYMPHOCYTES IN THE BLOOD OF DELAYED-HYPERSENSITIVE HUMAN DONORS
Authors: Jimenez Luis , Bloom Barry R. , Blume Myron R. , Oettgen Herbert F.
Published: June 2004

The virus plaque assay has been successfully employed to enumerate antigen-sensitive cells in the peripheral blood lymphocyte populations of tuberculin-hypersensitive human donors. The method is based on the finding that, while resting lymphocytes are unable to produce a variety of viruses upon infection, lymphocytes activated by specific antigens become capable of virus replication. The average number of antigen-sensitive cells detected in cell populations from donors reacting to first test strength or intermediate test strength tuberculin was approximately 3.6/1000 lymphocytes, and the averages for both groups were similar.

Studies on the kinetics of appearance of these virus plaque-forming cells and on the effects of the mitotic inhibitor, vinblastine, indicate that the activation of these antigen-sensitive cells is a linear process and that the cells must be nondividing cells during this process. These qualities contrast markedly with those described for the mitogenic response and the antibody-producing cells which require cell division and increase exponentially. On the basis of these experiments it is suggested that the antigen-sensitive cell measured in the virus plaque assay is the effector cell in delayed-type hypersensitivity reactions and, in addition, may be one of the cells critically involved in antibody formation.
IMMUNOLOGICAL MEMORY IN VITRO
Authors: Radcliffe Gordon N. , Axelrad Michael A.
Published: June 2004

The immune responses to sheep erythrocytes of mouse spleen cell suspensions from immune and nonimmune donors were compared in vitro. In vivo immunity was only transiently reflected in vitro, and 8 wk after in vivo immunization the responses of cultures from immunized and nonimmunized mice were virtually identical. There appeared to be two mechanisms for an antibody response to sheep erythrocytes. The first was responsible for the early primary response and is unmodified in the immune animal though contributing little to subsequent in vivo responses due to its suppressibility by specific antibody. The second was expressed in the in vivo secondary response but not on in vitro challenge of spleen cells from mice immunized many weeks previously; spleen cell cultures from such immune mice, freed from the antibody of the in vivo environment, once again demonstrate a pure primary-type response.
THE SECONDARY IMMUNE RESPONSE TO A HAPTEN IN VITRO
Authors: Klinman Norman R.
Published: June 2004

The in vitro secondary stimulation of the production of anti-hapten antibody has been analyzed with a view to elucidating the role of the carrier molecule and cell-to-cell interactions in this response. Stimulation was carried out on fragment cultures of the spleens of irradiated BALB/c mice which had been reconstituted with 3–4 x 107 spleen cells from isologous mice previously immunized with DNP-Hy. The results indicated that the response was maximized by stimulation with DNP-Hy, the homologous complex, however anti-DNP antibody production could be obtained by stimulation with DNP on several nonhomologous carriers including poly-D-lysine, a poor immunogen. The results also indicated that while DNP-Hy and DNP-nonhomologous-carrier complexes were stimulatory at equally low DNP concentrations, at DNP concentrations over 10–6 M DNP-Hy was stimulatory, while DNP on nonhomologous carriers was inhibitory. The results are interpreted as indicating that: (a) the affinity of the antigen-cell interaction is more likely determined by multivalent binding than by carrier recognition, (b) that a stimulatory interaction of a polyvalent antigen with a B-lymphocyte cannot be excluded, (c) that if cell-to-cell interaction is necessary for stimulation, then both cells may recognize the same determinant, and (d) that the marked enhancement of antigenic stimulation attributable to carrier recognition may result from stimulatory interactions of cells recognizing different antigenic determinants. A mechanism is postulated whereby stimulation is dependent on the formation of stable complexes resulting from two cells sharing in the binding of numerous antigen molecules. Cells recognizing carrier determinants would increase the probability of such interactions particularly at high antigen concentrations.
THE ENZYMATIC DEGRADATION OF HEMOGLOBIN TO BILE PIGMENTS BY MACROPHAGES
Authors: Pimstone Neville R. , Tenhunen Raimo , Seitz Paul T. , Marver Harvey S. , Schmid Rudi
Published: June 2004

Recent studies have identified and characterized the enzymatic mechanism by which hemoglobin-heme is converted to bilirubin. Under physiologic conditions the enzyme system, microsomal heme-oxygenase, is most active in the spleen followed by the liver and bone marrow, all of which are tissues that normally are involved in the sequestration and metabolism of red cells. Indirect evidence suggested that the reticuloendothelial system is important in this process. To test this hypothesis, conversion of heme to bilirubin was studied in macrophages obtained by chemical or immunological means from the peritoneal cavity or from the lungs of rodents. Homogenates of pure populations of these cells were devoid of heme-oxygenase activity, unless before harvesting the macrophages had been exposed to methemalbumin, microcrystalline hemin, or hemoglobin in vivo. In macrophages exposed to heme pigments, the specific activity of heme-oxygenase was far in excess of that in the spleen or liver. Enzyme activity was also present in the granulomatous tissue surrounding subcutaneous hematomas.

The heme-oxygenase system in macrophages resembles that in the spleen and liver in that it is localized in the microsomal fraction, has an absolute requirement for molecular oxygen and NADPH, is inhibited by carbon monoxide, and has a similar Km. These findings indicate that cells of the reticuloendothelial system, presumably including the Kupffer cells of the liver and the macrophages of the spleen, possess the enzymatic machinery for converting hemoglobin-heme to bilirubin. The reaction is a mixed function oxidation, probably involving cytochrome P450 as the terminal oxidase. Enzyme activity in macrophages is capable of regulatory adaptation in response to substrate loads. In the standard assay system for the enzyme, disappearance of heme always was in excess of the amount of bilirubin formed, suggesting the simultaneous presence of alternate routes of heme degradation not involving bilirubin as an end product or intermediate.
ALTERATIONS OF MACROPHAGE FUNCTIONS BY MEDIATORS FROM LYMPHOCYTES
Authors: Nathan Carl F. , Karnovsky Manfred L. , David John R.
Published: June 2004

Sensitized lymphocytes were incubated in vitro with the specific antigen Supernatants from these cultures were chromatographed on Sephadex G-100 columns. Supernatant fractions containing MIF, chemotactic factor, and lymphotoxin, but free of antigen and antibody, were incubated with normal peritoneal exudate macrophages. Macrophage adherence, phagocytosis, spreading, motility, and direct hexose monophosphate oxidation were enhanced, while protein synthesis was unaffected. Thus, antigen-stimulated lymphocytes secrete a factor or factors which enhance certain macrophage functions. Implications for models of cellular immunity and cellular hypersensitivity are discussed.
IN VITRO STUDIES OF COMPLEMENT FUNCTION IN SERA OF C4-DEFICIENT GUINEA PIGS
Authors: Frank Michael M. , May Joseph , Gaither Thelma , Ellman Leonard
Published: June 2004

In vitro studies were performed utilizing sera from a strain of guinea pigs with a total absence of hemolytically active C4. Previous studies in these animals have demonstrated normal complement-dependent inflammatory reactions, suggesting that they are able to bypass their deficiency of C4. In vitro studies with C4-deficient serum also indicate normal activation of late-acting C components. Thus, endotoxin was capable of fixing normal amounts of the late components of complement (C3-9) in these sera, but did not fix C1 and C2. Antigen-antibody complexes fixed both early and late components of complement, although components beyond C4 were fixed less efficiently than in normal sera. Therefore, both in vivo and in vitro evidence indicates that the C4-deficient guinea pigs possess an alternate pathway for activation of late-acting complement components.

Antigenic analysis of C4-deficient serum utilizing both guinea pig anti-C4 antibody and rabbit anti-C4 antibody suggests an absolute deficiency of C4-like molecules. Sera from animals with C4-deficiency were found to have one-half the normal level of C2. Sera from five of eight animals tested had 10–20% normal C1 activity. C3-9 assayed as a complex was normal.
CARRIER FUNCTION IN ANTI-HAPTEN ANTIBODY RESPONSES
Authors: Katz David H. , Davie Joseph M. , Paul William E. , Benacerraf Baruj
Published: June 2004

Administration of nonimmunogenic 2,4-dinitrophenyl (DNP) conjugates of copolymers of D or L-glutamic acid and lysine (GL) induces hapten-specific tolerance in nonimmune and DNP-ovalbumin-primed strain 13 guinea pigs. This tolerant state is evidenced by depressed anti-DNP antibody synthesis in response to challenge with DNP-ovalbumin and by a diminished frequency of DNP-specific antigen-binding cells and of anti-DNP antibody-secreting cells.

Such a nonimmunogenic compound (DNP-D-GL) will nevertheless elicit a DNP-specific anamnestic antibody response when administered at an appropriate time to DNP-ovalbumin-primed guinea pigs undergoing a graft-versus-host reaction. These experiments are discussed in terms of a two-cell theory of stimulation of antibody responses.
IMMUNE RESPONSE TO CHEMICALLY MODIFIED FLAGELLIN
Authors: Parish C. R.
Published: June 2004

Flagellin (mol.wt. 40,000) from S. adelaide organisms and a series of acetoacetyl derivatives of flagellin were tested for their ability to induce humoral and cell-mediated immunity in adult rats. It was found that unmodified flagellin was an excellent inducer of antibody formation but a poor inducer of delayed-type hypersensitivity. In contrast, increasing acetoacetylation steadily destroyed the ability of flagellin to initiate antibody formation but enhanced the capacity of the molecule to induce flagellin-specific cell-mediated immunity and antibody tolerance. In fact, it appeared that in adult rats antibody formation and cell-mediated immunity may well be opposing immunological processes. Furthermore, the affinity of the acetoacetyl flagellins for anti-flagellin antibodies appeared to determine the type of immune response which predominated. High affinity antigen produced antibody formation whereas low affinity antigen induced cell-mediated immunity and antibody tolerance. The importance of affinity was further evidenced by the fact that a CNBr digest of flagellin induced humoral and cellular immune responses identical to an acetoacetylated flagellin of comparable antigenic activity. From these studies it was proposed that both humoral and cell-mediated immunity can be directed against the same antigenic determinants but that the specificity requirements for delayed hypersensitivity (and antibody tolerance) are less than those required for antibody formation.

Some remarkable immunological features of the flagellin system were revealed. Flagellin induced comparable delayed-type hypersensitivity when injected in either saline or FCA. Furthermore, FCA only slightly enhanced the delayed responses induced by the acetoacetyl flagellins and in fact these preparations produced antibody tolerance whether injected in saline or adjuvant.

Finally, in contrast to the adult tolerance induced by the acetoacetylated flagellins, which existed only at the antibody level, tolerance in neonatal rats existed at the level of both humoral and cell-mediated immunity. This finding is the first indication of a fundamental difference between neonatal and adult tolerance.

The significance of these findings is discussed in the light of current immunological concepts and a hypothesis proposed to explain these phenomena.
THE DISTRIBUTION OF 51CR-LABELED LYMPHOCYTES INTO ANTIGEN-STIMULATED MICE
Authors: Zatz Marion M. , Lance Eugene M.
Published: June 2004

The localization of syngeneic 51Cr-labeled lymph node cells was investigated in CBA/J mice previously challenged with sheep erythrocytes, Salmonella H antigen, keyhole limpet hemocyanin, C57BL/6J skin, or rat skin. The effect of time, dose, and route of antigen administration on lymphocyte migration was studied in both primary and secondary responses.

When the distribution pattern of lymphocytes was examined after 20–24 hr, it was found that increased localization of labeled cells occurred in spleen after intravenous or intraperitoneal antigen injection, and in draining lymph nodes after subcutaneous antigen injection or skin grafting. Increased localization (trapping) of lymphocytes was antigen dose dependent and could be demonstrated when 1–6 hr had elapsed between intravenous antigen administration, or when 24 hr had elapsed between subcutaneous antigen administration and intravenous cell infusion. Trapping was transient, lasting approximately 24 hr. Maximal trapping of lymphocytes in the draining nodes occurred 9 days after skin grafting in the first-set allograft response, and 3 days after grafting in the second-set allograft and first-set xenograft responses.

The cell type trapped, the specificity and mechanism of action of the trap, and the role of lymphocyte trapping in the initiation of immune responses are discussed.
CELL SURFACE IMMUNOGLOBULIN
Authors: Vitetta Ellen S. , Baur Sonia , Uhr Jonathan W.
Published: June 2004

The proteins on surfaces of living splenic lymphocytes from normal BALB/c mice were iodinated enzymatically. Such cells were fractionated into two sub-populations: one composed almost exclusively of small lymphocytes and the other mainly of large lymphocytes and plasma cells. Specific immunoprecipitation of radiolabeled surface Ig obtained from lysates of these cell populations indicated that approximately 2–3% of the acid-precipitable radioactivity from the cell surface is Ig. Moreover, 95% of the H chain radioactivity from the Ig of the small lymphocyte fraction and 90% from the large lymphocyte-plasma cell fraction was characterized as µ by precipitation with anti-µ sera as well as by molecular weight determination on polyacrylamide gels in sodium dodecyl sulfate. The Ig was recovered from the cell surface in the form of an IgM monomer. Control experiments suggested that the monomer did not result from depolymerization of 19S IgM by the methods used to radiolabel and isolate the molecule. 3H-tyrosine labeling of IgM produced by meyloma cells and radio-iodination of IgM in solution gave the same ratios of µL radioactivity as radiolabeling of IgM on cells, indicating that the tyrosine residues of L and µ-chains of cell surface IgM are available to the lactoperoxidase during the iodination. This is consistent with the hypothesis that cell surface IgM is entirely on the outside of the plasma membrane presumably attached to it by its Fc fragment. These results, together with previous reports by others, suggest that IgM, in its monomeric form, is the main antigen-specific receptor on lymphocytes of normal mice.
DEFECTS IN HEMATOPOIETIC DIFFERENTIATION IN NZB AND NZC MICE
Authors: Warner Noel L. , Moore Malcolm A. S.
Published: June 2004

Hematopoietic stem cell activity in inbred NZB and NZC mice has been determined by transplantation and endogenous spleen colony assays. Whereas NZB mice show normal colony-forming unit (CFU) activity in the transplantation assay, they show markedly elevated endogenous CFU. NZC mice also show this markedly elevated endogenous CFU activity, but in the transplantation assay show only about 5–10% of normal CFU counts. When NZC stem cells are tested for CFU activity in irradiated recipients of the H-2d type, almost normal colony numbers occur. NZB stem cells however also cannot form colonies in NZC mice. These results suggest that NZC mice have a defect in the micro-environment of the spleen which renders them incapable of allowing transplanted CFU to form colonies.

Genetic analysis of both the NZC defect as a CFU recipient, and the elevated endogenous count in NZB and NZC, shows that both are controlled by single recessive genes which are not linked to either coat color, agouti, H-2 or Ig loci. Of even more relevance is the finding that these hematopoietic abnormalities are not linked to the genes involved in controlling autoantibody formation to red cells in the NZB mice. These mice therefore appear to show two distinct hematopoietic abnormalities, the analysis of which may be of considerable value in understanding the detailed events of hematopoietic stem cell differentiation.
IMMUNE RESPONSES IN VITRO
Authors: Pierce Carl W. , Johnson Barbara M. , Gershon Harriet E. , Asofsky Richard
Published: June 2004

We have demonstrated for the first time that mouse spleen cells stimulated in vitro with heterologous erythrocytes developed immunoglobulin class-specific γM, γ1, γ2a+2b, and γA plaque-forming cell (PFC) responses. A modification of the hemolytic plaque technique, the addition of goat anti-mouse µ-chain antibody to the assay preparation, specifically prevented development of all γM PFC and enabled accurate and reproducible enumeration of immunoglobulin class-specific PFC after treatment with appropriate monospecific anti-globulins and complement. Culture conditions, with regard to medium, atmosphere, agitation, and spleen cell densities, were similar to those previously shown to support only γM PFC responses. Evaluation of the kinetics of appearance of PFC showed that γM PFC reached maximum numbers on days 4–5; the magnitude of this response was 3–10 times greater than γ1 γ2a+2b, or γA PFC which reached maximum numbers on days 5–6. Optimal erythrocyte antigen dose for γM PFC responses was 107/culture, whereas a dose of 106 erythrocytes/culture consistently stimulated optimal γ1 γ2a+2b, or γA PFC responses. Investigations of the effects of anti-erythrocyte antibody on γM and γG PFC responses indicated that antibody suppressed these responses by neutralizing the effective antigenic stimulus at the macrophage-dependent phase of the response. At the same antibody concentration, γG PFC responses were more effectively suppressed than γM PFC responses. Further, γG responses could be almost completely suppressed by antibody as long as 48 hr after initiation of cultures, whereas γM PFC responses could only be completely suppressed during the first 24 hr. These results were discusssed in terms of the role of antigen in the stimulation γM and γG antibody.
SPECIFIC IMMUNE RESPONSE GENES OF THE GUINEA PIG
Authors: Bluestein Harry G. , Green Ira , Benacerraf Baruj
Published: June 2004

The ability of guinea pigs to make immune responses to GA, a linear random copolymer of L-glutamic acid and L-alanine, GT, a random linear copolymer of L-glutamic acid and L-tyrosine, and PLL, a linear homopolymer of L-lysine, is controlled by different autosomal dominant genes specific for each of those polymers. We have investigated the relationship between the PLL gene and the GA and GT immune response genes by simultaneously immunizing random-bred Hartley strain guinea pigs with GA and PLL, GT and PLL, or GA and GT.

In most Hartley guinea pigs the ability to respond immunologically to GA and to PLL is inherited together; that is, most animals responding to GA respond to PLL and vice versa. However, a few animals respond to either GA or to PLL but not both, demonstrating that the GA and PLL immune response genes are not identical but linked in most Hartley animals. Conversely, when simultaneously immunized with GT and PLL, most Hartley guinea pigs respond to either PLL or GT but not both, indicating that GT and PLL responsiveness tends to segregate away from each other. Thus, the GT and PLL immune response genes also are not inherited independently but, rather, behave as alleles or pseudoalleles. Similar results are observed when Hartley guinea pigs are simultaneously immunized with GA and GT. The ability to respond to GA segregates away from the ability to respond to GT.

Our studies demonstrated that the specific immune response genes thus far identified in guinea pigs controlling the ability to respond to GA, GT, and PLL, respectively, are found on the same chromosome. In most Hartley animals, the GA and PLL immune response genes are often linked, i.e. occur on the same chromosome strand, and tend to behave as alleles or pseudoalleles to the GT immune response gene.
RECEPTORS ON IMMUNOCOMPETENT CELLS
Authors: Davie Joseph M. , Rosenthal Alan S. , Paul William E.
Published: June 2004

Guinea pigs immunized with 2,4-dinitrophenyl-guinea pig albumin (DNP-GPA) possess lymphocytes which specifically bind sufficient DNP-GPA-125I to their surface to be detected by radioautography. These lymphocytes are present in the draining lymph nodes in a frequency of ∼50/1000 lymphocytes in animals immunized 2–4 wk earlier with DNP-GPA in complete Freund's adjuvant. Nonimmunized animals have ∼0.4 DNP-GPA antigen-binding cells (ABC) per 1000 lymphocytes. An increase in the frequency of DNP-GPA ABC in peripheral blood is detectable by 5 days after immunization, which is before the time that serum anti-DNP antibody is measurable.

The receptors of these ABC are hapten specific in that free ϵ-DNP-L-lysine, at low concentration, inhibits the binding of DNP-GPA-125I; DNP bovine serum alumbin (DNP-BSA) is equivalent to DNP-GPA in the inhibition of binding of DNP-GPA-125I to ABC; and both DNP-GPA agarose beads and DNP-BSA agarose beads specifically adsorb DNP-GPA-125I ABC. Anti-immunoglobulin antisera, particularly anti-γ2 sera, inhibit the binding of DNP-GPA-125I to these cells implying that the receptors are immunoglobulin, primarily of the γ2 heavy chain class.

DNP-GPA-125I ABC appear to represent precursors of antibody-secreting cells and have specificity characteristics which are very different from cells, of similarly immunized guinea pigs, which mediate a cellular immune response to DNP-GPA.
IMMUNOCHEMISTRY OF THE COMMON ANTIGEN OF ENTEROBACTERIACEAE (KUNIN)
Authors: Hammarström Sten , Carlsson Hans Erik , Perlmann Peter , Svensson Sigfrid
Published: June 2004

Preparations of E. coli 014 lipopolysaccharide (LPS) contain a common enterobacterial antigen (CA) in large amounts or in an immunogenic form. Chemical analysis revealed, in addition to o-acetyl groups, only those sugars which are present in the basal core structure of the E. coli or Salmonella LPS (e.g., galactose, glucose, glucosamine, heptose, and ketodeoxyoctonate). On treatment with acetic acid (pH 3.2) at 100°C for 1.5 hr, a fragment was liberated which after gel filtration on Sephadex G-50 appeared in the molecular weight range of 2–3 x 103. The fragment inhibited precipitation of alkali-treated E. coli 014 LPS by antibodies to CA from anti-E. coli 014 serum. It also inhibited hemagglutination between anti-CA antibodies and red cells coated with E. coli 08 LPS. Chemical analysis of the fragment indicated that it corresponded to the core region of E. coli 014 LPS. It contained a heptose and ketodeoxyoctonate in addition to glucose and galactose. However the fraction lacked glucosamine.

Enterobacterial CA has previously been found to cross-react with colon antigen of ulcerative colitis. These results should provide a chemical basis for further studies of this cross-reactivity.
IMMUNOGLOBULINS ON THE SURFACE OF THYMUS-DERIVED CELLS ENGAGED IN THE INITIATION OF A HUMORAL IMMUNE RESPONSE
Authors: Lesley J. F. , Kettman J. R. , Dutton R. W.
Published: June 2004

Preculture treatment of normal spleen cells with antiserum against mouse kappa light chains and complement was found to inhibit in vitro responses of these cells to TNP and erythrocyte (carrier) antigens, primarily by elimination of a thymus-derived helper component required for the response. Spleen populations inactivated in this way could be reconstituted with irradiated, carrier-immune spleen cells or with carrier-educated thymus-derived spleen cells. The ability of helper populations (i.e. irradiated, carrier-immune spleen cells or carrier-educated thymus-derived spleen cells) to enhance the response of normal spleen cells to hapten was eliminated by pretreatment of the helper cells with anti-kappa serum and complement. No significant effect of anti-kappa and complement treatment on precursor cell populations in normal spleen or bone-marrow-derived spleen could be demonstrated. The data are interpreted as evidence for the presence of immunoglobulin components. The function of these molecules is not established but it would be reasonable to assume that they are involved in antigen recognition, on the surface of thymus-derived cells.
THE COMPARTMENTALIZATION OF ANTIGEN-REACTIVE LYMPHOCYTES IN DESENSITIZED GUINEA PIGS
Authors: Schlossman Stuart F. , Levin Howard A. , Rocklin Ross E. , David John R.
Published: June 2004

A single injection of ϵ,DNP-Lys7–10 can render previously sensitized guinea pigs specifically unreactive to subsequent intradermal challenge with that antigen. Antigen-reactive lymphocytes, as assayed by macrophage-migration in-inhibition or thymidine incorporation, were depleted from the peritoneal exudates of those animals. In contrast, it was intriguing to find that lymph node lymphocytes from such animals responded normally in the antigen-induced thymidine incorporation assay. These studies demonstrate a compartmentalization of antigen-reactive lymphocytes in desensitized animals which may account for the short-lived nature of this phenomenon.
SURFACE IMMUNOGLOBULINS ON THYMUS AND THYMUS-DERIVED LYMPHOID CELLS
Authors: Bankhurst Arthur D. , Warner Noel L. , Sprent John
Published: June 2004

Lymphoid cells from thymus, thoracic duct lymph (TDL), and thoracic duct lymph in irradiated animals reconstituted with allogeneic thymus cells (TTDL) were labeled with radioiodinated anti-immunoglobulins using radioautographic techniques. Thymus and TTDL were labeled (14.4 and 37.0%, respectively) with anti-light chain protein after prolonged exposures (30–60 days). No labeling was observed on thymus and TTDL with anti-polyheavy chain globulin. In contrast 18.5–19.0% of TDL labeled on short exposure (6 days) with anti-polyheavy chain and anti-light chain materials. It is proposed that the difference between the labeling observed on short exposures versus long exposures can be related to the difference in surface density of immunoglobulins between nonthymus-derived (B) and thymus-derived (T) cells.

The distribution of labeled cells in the thymus was preferentially among the larger cells (greater than 10 µ diameter). The TTDL population was mostly composed of a larger, blast-like population and the distribution of label was independent of size.

As the thymus and TTDL preparations contain almost exclusively T cells, this represents a direct demonstration of surface immunoglobulin light chains on T lymphoid cells.
THE DEVELOPMENT OF HYPERSENSITIVE LYMPHOCYTES IN CELL CULTURE
Authors: Ginsburg Haim , Hollander Nurit , Feldman Michael
Published: June 2004

An in vitro cell-mediated immune response to pokeweed mitogen (PWM) is described. Rat lymphocytes were stimulated by PWM, by phytohemagglutinin (PHA), and by concanavalin A (ConA). In the presence of PWM only a fraction of the lymphocytes underwent blastogenesis. This was in contrast to the apparent total blastogenesis obtained in response to PHA or ConA. When blast cells derived from each of the mitogens were plated on rat fibroblast monolayer in the absence of mitogen they differentiated into a distinct type of lymphocyte termed "secondary lymphocyte." Addition of mitogens to cultures of these lymphocytes resulted in a retransformation to blast cells.

The secondary lymphocytes were tested for their ability to effect lysis in the presence of each of the three mitogens. In. the presence of PWM, lysis of fibroblasts produced by PWM-lymphocytes was considerably more efficient than lysis obtained by ConA- or PHA-lymphocytes. No difference in effect on target fibroblasts was obtained when the three types of secondary lymphocytes were tested in the presence of either PHA or ConA. The stimulating action of PWM on lymphocytes was shown to be immunologically specific. No such specificity was found in the case of PHA or ConA.

The results are interpreted to indicate that PWM combines with cell membranes and acts on the lymphocytes as a "transplantation antigen." Lymphocytes capable of responding to "PWM-transplantation antigen" transform to blast cells capable of specifically lysing PWM-conjugated fibroblasts. In the absence of the mitogen, PWM-induced blast cells differentiate to lymphocytes hypersensitive to PWM.