bluuebunny/crossref_metadata_2025 huggingface dataset:
RESTRICTION OF THE CAPACITY TO RESPOND TO TWO ANTIGENS BY SINGLE PRECURSORS OF ANTIBODY-PRODUCING CELLS IN CULTURE
Authors: Osoba David
Published: June 2004

Experiments were designed to determine whether or not precursors of antibody-producing cells are restricted in the number of antigens to which they can respond. An in vitro culture system was used, in which the successful production of hemolysin PFC was dependent on the presence of a large number of heavily irradiated spleen cells which did not themselves give rise to PFC, but which supported the production of PFC by a small number of normal spleen cells. All spleen cells were obtained from unimmunized CBA mice. The cells were mixed with either sheep or chicken erythrocytes, or both, cultured for 4 days and analyzed for hemolysin PFC. By reducing the number of unirradiated spleen cells to limiting dilution it was shown that normal spleen cell suspensions contain approximately three times as many precursors capable of responding to chicken erythrocytes as to sheep erythrocytes. In cultures containing both antigens, the number of precursors responding to one antigen was not affected by the presence of the other antigen. In addition, some cultures were positive for PFC-producing hemolysin against chicken erythrocytes, but not against sheep erythrocytes, and vice versa. This pattern of response was independent of the concentration of antigen in the cultures. Thus, the antigen-sensitive precursors for these non-cross-reacting antigens responded independently of each other, indicating that each precursor was restricted in its capacity to respond to more than one antigen prior to stimulation.
CELLULAR DIFFERENTIATION OF THE IMMUNE SYSTEM OF MICE
Authors: Shearer G. M. , Cudkowicz G. , Priore R. L.
Published: June 2004

Spleen cell suspensions of primed donor mice containing precursors of immunocytes have been transplanted into X-irradiated recipient mice 122–138 days after immunization. Following secondary stimulation with antigen (sheep erythrocytes), these precursors, called antigen-sensitive units (ASU), gave rise to progeny cells secreting specific antibody in the spleens of recipients. Single cells releasing IgM hemolysins (direct plaque-forming cells or PFC), IgG hemolysins (indirect PFC), and hemagglutinins (cluster-forming cells or CFC) were enumerated.

By transplanting graded and limiting numbers of primed spleen cells, inocula were found which contained one or a few ASU reaching the recipient spleens. We estimated, thereby, the frequency of ASU detectable by our procedures in donor cell suspensions. The values obtained from direct and in-indirect plaque assays, and from cluster assays were 1 in ∼8.0 x 105, 1 in ∼4.4 x 105, and 1 in ∼5.9 x 105 nucleated spleen cells, respectively. The number of splenic ASU for direct PFC was not greater than that of unimmunized mice; however, immunization greatly increased the number of splenic ASU for indirect PFC and for CFC.

By applying to each recipient spleen direct and indirect plaque tests and cluster tests, we found that positivity for each type of immunocyte was independent from that of the other two types. These results confirm the unipotent nature of splenic ASU in general, and document the commitment of ASU primed with SRBC to generate progeny cells secreting antibody of a single molecular (IgM or IgG) or functional (lysin or agglutinin) class.

We concluded that splenic ASU are composed of relatively differentiated cells of the immune system of mice. With respect to specificity and class differentiation, ASU appear to be as specialized as antibody-producing cells themselves. Our results did not support the view that ASU-derived clonal populations shift from IgM to IgG antibody production.
A QUANTITATIVE STUDY OF THE STIMULATION OF DNA SYNTHESIS IN LYMPH NODE CELL CULTURES BY ANTI-LYMPHOCYTE SERUM, ANTI-GAMMA GLOBULIN SERUM, SPECIFIC ANTIGEN, AND PHYTOHEMAGGLUTININ
Authors: Foerster John , Lamelin Jean-Pierre , Green Ira , Benacerraf Baruj
Published: June 2004

Rabbit anti-guinea pig lymphocyte serum is an efficient stimulus of the synthesis of DNA by guinea pig lymph node cells in vitro. The ability of ALS to stimulate lymphocytes is characterized by its lack of dependence on prior sensitization, the magnitude of the response it elicits, and the stimulation of all sensitive lymph node cells simultaneously within a very narrow range of ALS concentrations. In contrast to this homogeneous response to ALS, the stimulation of lymph node cells by antigen proceeds in graded fashion over a wide range of concentrations, thus reflecting the heterogeneity of the response of sensitized cells to antigen. PHA gives a response which is intermediate between that of ALS and antigen.

ALS appears to have specificity for membrane determinants shared by lymphocytes but not found on other tissues. This specificity does not involve cell-bound gamma globulin. The serum activity mediating lymphocyte stimulation as well as cytotoxicity is readily removed by absorption with lymph node cells.
THE INFLUENCE OF THE CELLULAR INFILTRATE ON THE EVOLUTION AND INTENSITY OF DELAYED HYPERSENSITIVITY REACTIONS
Authors: Hill William C.
Published: June 2004

When a delayed-type hypersensitivity (DTH) reaction is elicted in a sensitive animal at a skin site in which an accumulation of mononuclear cells has been induced by a prior injection of a nonspecific stimulus, those properties characteristic of a DTH reaction, i.e. erythema, edema, and induration, become evident much more rapidly and intensely than a reaction in an unprepared skin site. This rapid, intense reaction has the histology of a classical delayed reaction and persists as long or longer than a classical DTH reaction in the same animal.

Two facts are evident from these observations. Firstly, early in the development of a delayed reaction, the slow accumulation of mononuclear cells may be completely independent of the presence of specific antigen. Secondly, there is a reaction between specific antigen and an antibody-like substance which may or may not be attached to cells. The reaction develops so rapidly at a prepared site that the pharmacological mediators which are responsible for edema must be presumed to be released abruptly. A classical delayed reaction is attributable to the time needed for the accumulation of cells in sufficient numbers. It follows that the rate-limiting step in a classical delayed reaction is the process of cell accumulation. The present observations indicate that this process is independent of the presence of specific antigen.
GENETIC INFLUENCE ON THE DEVELOPMENT OF RENAL HYPERTENSION IN PARABIOTIC RATS
Authors: Iwai J. , Knudsen K. D. , Dahl L. K. , Heine M. , Leitl G.
Published: June 2004

The effects of several renal manipulations including uninephrectomy, unilateral renal artery constriction, and a combination of these two (Goldblatt procedure) were studied in two strains of rats with opposite constitutional predispositions to experimental hypertension. The protective value of intact renal tissue to protect against hypertension was shown to be genetically determined.

The Goldblatt procedure carried out on only one member of a parabiotic pair induced hypertension in this operated rat but significant hypertension developed in the intact partner only when the operated animal belonged to the strain predisposed to hypertension.

It was speculated that there were qualitative differences in the pressor signals of the two strains of rats. In the strain genetically predisposed to hypertension there are at least two pressor principles: (a) one which is common to both strains, not transmittable via the parabiosis junction and presumably related to the renin-angiotensin system; and (b) a second which is specific for the hypertension-prone strain and can be transmitted through the parabiosis junction. This transmittable agent is probably identical with the factor that produces salt hypertension and is associated with the salt-excreting mechanism.
THE OCCURRENCE AND PROPERTIES OF LEUKOCYTOSIS AND LYMPHOCYTOSIS-STIMULATING MATERIAL IN THE SUPERNATANT FLUIDS OF BORDETELLA PERTUSSIS CULTURES
Authors: Morse Stephen I. , Bray Karen K.
Published: June 2004

1. Leukocytosis- and lymphocytosis-stimulating activity was present in fluid cultures of B. pertussis. The activity was found primarily in the culture supernatant fluid.

2. The sequential changes in the leukocyte response were similar to those previously observed following injection of intact bacteria into mice.

3. Activity was destroyed by heat and was diminished, but not abolished, by prolonged treatment with proteolytic enzymes.

4. A water-insoluble fraction of the culture supernatant fluid was isolated which contained virtually all of the activity. The specific activity was more than 100-fold greater than that of the intact bacteria, and injection of microgram quantities produced a response.

5. The distribution of histamine-sensitizing factor followed that of leukocytosis-stimulating activity. In contrast, mouse protective antigen was localized to the bacterial pellet.
THE ROLE OF THE PLATELET IN THE GENERALIZED SHWARTZMAN REACTION
Authors: Margaretten William , McKay Donald G.
Published: June 2004

Rabbits were injected with an antiplatelet serum to produce selective thrombocytopenia without inducing a significant alteration of their leukocyte counts. Thrombocytopenic levels persisted for 8 hr after the injection of platelet antiserum. During this time, the generalized Shwartzman reaction could not be provoked with the second injection of endotoxin. Since platelet phospholipid is required for the formation of plasma thromboplastin, the results indicate that platelets are essential to the evolution of the generalized Shwartzman reaction and endotoxin triggers the intrinsic rather than the extrinsic clotting system to elicit the lesions.
IMMUNOLOGICAL TOLERANCE IN VITRO: KINETIC STUDIES AT THE CELLULAR LEVEL
Authors: Diener E. , Armstrong W. D.
Published: June 2004

When normal mouse spleen, cells in suspension are cultured in vitro in the presence of polymer from S. adelaide flagellin, an immune response can be obtained as measured at the level of single antibody-forming cells. Cultures were stimulated with different doses of antigen, ranging from 0.2 ng to 3 µg/ml of tissue culture fluid and it was found that the peak number of approximately 500 antibody-forming cells per 106 harvested cells by day 4 was antigen dose dependent, 2–20 ng/ml being the optimal concentration. When more than 1 µg/ml of polymer from S. adelaide together with either 20 ng/ml of polymer from S. waycross or with 4 x 106 sheep erythrocytes were placed in the system, unresponsiveness to S. adelaide, but immunity to the other antigens occurred simultaneously. Cells made immunologically tolerant in vitro to S. adelaide H antigens were transferred into syngeneic lethally irradiated recipients and challenged with the same antigen. The adoptive immune capacity in these mice, as measured at the level of the immunologically competent cell was reduced by 80–90% as compared with relevant controls. Attempts to induce low zone tolerance in vitro were without success. To study the kinetics of tolerance induction in vitro, cells were cultured with tolerogenic doses of antigen for various periods of time, washed, and subsequently cultured with immunogenic doses of antigen for 4 days. It was found, that immunological tolerance may be induced to a significant degree in vitro within a period of 15 min. Similar results were obtained when spleen cells were exposed for various lengths of time to tolerogenic doses of antigen but at a temperature of 4°C instead of 37°C. The results are taken as suggestive evidence that the initial step in tolerance induction is related to the direct interaction between the surface of immune competent cells and antigen molecules.
INHIBITION OF RELEASE OF VACCINIA VIRUS BY N1-ISONICOTINOYL-N2-3-METHYL-4-CHLOROBENZOYLHYDRAZINE
Authors: Kato Nobuo , Eggers Hans J. , Rolly Heinrich
Published: June 2004

N1-isonicotinoyl-N2-3-methyl-4-chlorobenzoylhydrazine (IMCBH) is a selective inhibitor of vaccinia virus multiplication. In concentrations up to 50 µg/ml, IMCBH causes neither toxic morphologic changes, nor does it inhibit the multiplication of cells. Viruses other than vaccinia are not affected by IMCBH. The virus-inhibitory effect of IMCBH is dependent on the type of host cell used, i.e., the compound is effective in chick embryo fibroblasts and monkey kidney cells but not in L cells. IMCBH does not exhibit any protecting effect on vaccinia virus-infected mice or rabbits.

IMCBH interferes with virus release: in single cycle experiments in chick embryo fibroblasts, IMCBH strongly blocks the release of vaccinia virus at concentrations as low as 3 µg/ml, while intracellular virus synthesis is hardly affected. Viral cytopathic changes are completely suppressed by IMCBH within the span of a single cycle infection, although extensive changes eventually occur. By inhibiting virus release from initially infected cells, IMCBH markedly inhibits the multiplication of vaccinia virus in cell cultures infected at low virus/ cell multiplicities.

IMCBH does not inhibit the early toxic cytopathic changes induced by large inocula of vaccinia virus in BHK21 cells.
RABBIT ANTIBODIES TO STREPTOCOCCAL CARBOHYDRATES
Authors: Braun Dietmar G. , Eichmann Klaus , Krause Richard M.
Published: June 2004

In a search for possible genetic factors which may influence the immune response to the streptococcal carbohydrates, over 100 rabbits have been immunized with streptococcal vaccines, and representative examples of high and low response pairs mated. The concentration of precipitins to the group—specific carbohydrates has been measured in the antisera following primary intravenous immunization with heat-killed streptococcal vaccines, Group A, Group A-variant, and Group C. For the majority of rabbits, the concentration of precipitins varied between 1 and 10 mg/ml of antiserum; while in the minority, it was between 11 and 32 mg/ml. The offspring of rabbits with high antibody levels had a significantly higher concentration of antibody than was seen in the offspring of rabbits of low response parents. Such data suggest that the magnitude of the immune response to these carbohydrate antigens is under some form of genetic control.

Not uncommonly in rabbits with hyper-γ-globulinemia following primary immunization, the group-specific precipitins are the predominant component of the γ-globulin. An unusual feature of such components is that they are electrophoretically monodisperse, and possess individual antigenic specificity. In this respect they resemble the myeloma proteins. When a response of this sort is not seen after primary immunization, it may occur after secondary immunization. Therefore, prior exposure to the same or closely related antigen may also have an influence on the occurrence of high concentrations of such uniform antibodies.
GENE CONTROL OF HEMATOPOIESIS
Authors: Mintz Beatrice , Palm Joy
Published: June 2004

Erythropoietic cells of two unrelated strains, C3H (or C3Hf) and C57BL/6, can coexist throughout hematopoiesis in allophenic mice experimentally produced from aggregated, undifferentiated blastomeres of separate genotypes. The presence of two red cell genotypes in these circumstances signifies that the erythroid population must normally be multiclonal, i.e., derived mitotically from at least two genetically determined cells. The two strains were detected by hemagglutination and absorption tests of erythrocytes for the specific histocompatibility antigens dictated by the H-2k and H-2b alleles.

Of 34 C3H(f) ↔ C57BL/6 allophenics tested, 16 had both red cell types; the remaining 18 showed only C3H or C57 red cells and included 12 mice with both cell strains present in some other tissues. All animals with evidence of two H-2 phenotypes among circulating erythrocytes were permanently immunologically tolerant of both antigenic types and remained free of runt disease. They lived a full lifespan, up to 2 yr 7½ months of age.

The data suggest a possible specific selective advantage of C57BL/6 over C3H erythropoietic tissue. There is considerable individual variability, not only in proportions of antigenically distinct erythrocytes, but also in strain composition of other tissues in the same animals. A broad spectrum of distinctive situations is found, in which parameters are varied within or outside of the circulatory system. Allophenic mice can therefore serve as investigative tools for entirely new kinds of experimental studies of gene control mechanisms and blood physiology in normal hematopoiesis and in a number of hereditary blood diseases.
HETEROGENEITY OF ANTIBODY-FORMING CELLS
Authors: Bosman Cesare , Feldman Joseph D. , Pick Edgar
Published: June 2004

Cell suspensions from draining lymph nodes of immune and nonimmune rats were reacted in vitro with 125I-labeled antigens. In light microscopic radioautographs of smears, 17% of the immunized cells were tagged by specific antigen; 2.0% of control cells were positive. In electron microscopic radioautographs, 90% of the labeled elements from immune donors were lymphocytes, blast and plasma cells; 10% were monocytes-macrophages or other elements, including naked nuclei. 15% of the labeled cells from control materials were lymphocytes and plasma cells, while 85% were monocytes-macrophages and naked nuclei.

Within cell suspensions derived from immunized animals there were almost twice as many lymphocytes marked by isotope as plasma cells, and the lymphocytes ranged in morphology from mature monoribosomal elements to immature polyribosomal cells. Antibody-forming cells fixed labeled antigen at their surfaces. The monocyte-macrophage class was distinguished by a high mean grain count and by distribution of grains within cytoplasmic vacuoles and lysosomes.
THE HOST RESPONSE TO CALMETTE-GUÉRIN BACILLUS INFECTION IN MICE
Authors: Blanden R. V. , Lefford M. J. , Mackaness G. B.
Published: June 2004

Heterologous organisms (L. monocytogenes and S. typhimurium) were used to study the rate of development, magnitude, and persistence of the antimicrobial resistance engendered in mice by vaccination with BCG. These same methods were used to investigate the influence of prior vaccination on the host response to reinfection.

The rate of onset and magnitude of the resistance produced by BCG varied with the vaccinating dose. Increased resistance was detected within 48 hr of injecting large numbers of BCG (approximately 108 viable units), but concurrent treatment with isoniazid interrupted its further development. An equal number of heat-killed organisms failed to influence host resistance significantly. The development of tuberculin sensitivity was also dependent upon the continued survival of the immunizing population of BCG.

When vaccinated mice were reinfected with BCG, host resistance in spleen and liver was rapidly augmented to the accompaniment of striking changes in the morphology and microbicidal activity of the peritoneal macrophages. These changes occurred most rapidly in mice with a high level of delayed hypersensitivity at the time of reinfection.
LYMPHOID CELLULAR RESPONSES IN THE BLOOD AFTER IMMUNIZATION IN MAN
Authors: Crowther D. , Fairley G. Hamilton , Sewell R.L.
Published: June 2004

A combined morphological and metabolic study has been made of the lymphoid cells in the blood during the immune response in man. Similar changes were observed in both primary and secondary responses to a number of different microbial antigens. The cellular response involved an increase in numbers of three types of cell; hyperbasophilic medium lymphocytes, plasma cells, and large lymphoid cells. The large lymphoid cells were about 20 µ in diameter with large nuclei, prominent nucleoli, and an intensely basophilic cytoplasm with numerous polyribosomes. About 30% of these cells were in the DNA synthetic phase of cell growth. Electron microscopy has shown that many of the basophilic medium-sized cells have sufficient well-organized endoplasmic reticulum to be included in the plasma cell series. The hyperbasophilic cells labeled more heavily with tritiated uridine and tritiated leucine than the normal small and medium lymphocytes from the peripheral blood of patients not under antigenic stimulation.

The evidence in this paper supports the argument that the atypical mononuclear cells first described by Türk and others in the blood of patients with infections are immunoblasts, plasma cells, and other reactive lymphoid cells representing a circulating population of lymphoid cells derived from lymphoid tissue responding to antigenic stimulation. The presence of such cells may be a valuable indication that an immunological reaction is in progress when direct proof is lacking.
REQUIREMENT FOR CONTINUOUS ANTIGENIC STIMULATION IN THE DEVELOPMENT AND DIFFERENTIATION OF ANTIBODY-FORMING CELLS
Authors: Hanna M. G. , Nettesheim P. , Francis Mary W.
Published: June 2004

The essential role of continuous antigenic stimulation in the development and differentiation of antibody-forming cells as defined in the X-Y-Z immune cell maturation scheme was examined in these studies. Mice were primed with sheep erythrocytes (SRBC) in an attempt to induce maximum immune progenitor cell conversion (X → Y). Subsequently antigen was depleted at 1 or 4 days after priming with isologous specific antibody in order to interrupt further immune cell differentiation (Y → Z). It was reasoned that this condition would result in depression of the functional antibody-producing cell compartment as measured in the intact mice and subsequently in enhancement of the sensitized (Y cell) compartment as measured in the spleen cell transfer system. These data were also correlated with systematic studies of the hyperplasia of the spleen germinal centers.

The effect of passive antibody on the primary response to SRBC was a marked decrease indirect and indirect hemolysin-producing cells (DPFC and IPFC). However, there was a lack of correlation in the degree of antibody-mediated 19S and 7S immune cell suppression during the primary response, the DPFC being much less depressed than the IPFC. As measured in the transfer system there was an enhanced 19S sensitized cell compartment and a depressed 7S sensitized cell compartment in 1 day passively immunized mice. This was true whether or not transfers were performed 1, 2, or 4 wk after priming. Similarly, there was an enhanced 19S-sensitized cell compartment with little or no effect on the 7S-sensitized. cell compartment in 4 day passively immunized mice. These data suggest that progeny of the antigen-stimulated progenitor cells (X cell), as a consequence of lack of further antigenic stimulation, were forced into maturation arrest.

These studies further demonstrate that isologous passive antibody suppresses germinal center growth regardless of whether the antibody is infused 1, 2, or 4 days after priming. In terms of formation of sensitized cells, the marked depression of 7S sensitized cell compartment after passive immunization at 24 hr in contrast to the enhancement of the 19S sensitized cell compartment corresponds to the suppressed growth of germinal centers during the primary response. Thus, if the germinal center is, as suggested, the site of proliferative expansion of immunocompetent cells, these data indicate that the germinal center growth is related to the 7S antibody response and in the formation of "7S memory."
THE EFFECT OF EPITHELIAL REMNANT AND WHOLE ORGAN GRAFTS OF THYMUS ON THE RECOVERY OF THYMECTOMIZED IRRADIATED MICE
Authors: Hays Esther F.
Published: June 2004

Work has been presented which suggests that thymus epithelial reticular cells are not effective in restoring the microscopic morphology of lymphoid tissues and their immunologic capacities. They function in recruiting precursors of thymus lymphocytes from the host animals to produce an organ which, after it becomes architecturally normal, can reconstitute the defective host. Intact thymus grafts in situ from 10–14 days, but not for shorter periods of time, have been shown to result in a return toward normal of these two parameters. Evidence is offered to show that few dividing cellular components in the lymphoid tissue originate from the thymus remnant grafts, and that a minor cellular component is contributed by the intact grafts.

These data support the concept that the structural and functional development of the lymphatic tissue in thymectomized animals is dependent on thymus lymphoid cells and/or their products, and that the epithelial-reticular cells do not have a direct action in peripheral lymphoid reconstitution.
THE ENHANCEMENT OF BACTERIAL PHAGOCYTOSIS BY SERUM
Authors: Johnston Richard B. , Klemperer Martin R. , Alper Chester A. , Rosen Fred S.
Published: June 2004

The role of serum factors in the phagocytosis of pneumococci was studied employing a spectrophotometric assay which measures reduced nitro blue tetrazolium (NBT) dye. Dye reduction occurs within the phagocyte shortly after bacterial ingestion as measured by the phagocytic index technique and by the uptake of 125I-pneumococci. Bacteria prepared with γG antibody were not phagocytosed unless a small volume of fresh normal serum was added. Using fresh sera deficient in single complement components, it was demonstrated that the first four components are necessary for optimal bacterial phagocytosis. When highly purified complement components were added to the antibody-coated pneumococci, enhancement of phagocytosis was achieved only with the sequential addition of C1, C4, C2, and C3.

Evidence has been presented that human C3 bound to an immune complex exhibits peptidase activity and that this activity is essential for phagocytosis. A heat-labile, dialyzable serum cofactor which enhances C3 peptidase activity enhanced the phagocytosis of pneumococci prepared with purified complement components. A second phagocytosis-promoting cofactor, which is not a complement component, was found to be a heat-labile, 5–6S, beta pseudoglobulin. This protein may stabilize C3 peptidase activity or inhibit enzymatic inactivation of C3.
HUMAN IMMUNITY TO THE MENINGOCOCCUS
Authors: Gotschlich Emil C. , Liu Teh Yung , Artenstein Malcolm S.
Published: June 2004

The group-specific polysaccharides of group A and group C meningococci have been isolated by a new procedure which employs the cationic detergent Cetavlon to precipitate these polysaccharides from the whole culture. The A and C polysaccharide prepared by this method are noteworthy because they are of high molecular weight. The main constituent of the A polysaccharide is N-acetyl, O-acetyl mannosamine phosphate; of the C polysaccharide N-acetyl, O-acetyl neuraminic acid. This purification procedure, when applied to cultures of group B organisms, yields a polysaccharide consisting primarily of N-acetyl neuraminic acid.

A passive hemagglutination test developed to measure antibodies to the polysaccharides demonstrated the specificity of these antigens. Using a hemagglutination inhibition test, these antigens were again found to be group-specific, and this test could be used for serogrouping meningococcal isolates.
PATHOGENESIS OF EXPERIMENTAL CHOLERA
Authors: Finkelstein Richard A. , LoSpalluto Joseph J.
Published: June 2004

Choleragen, a diarrheagenic protein enterotoxin elaborated by Vibrio cholerae, has been isolated from the supernate of fermenter cultures by steps involving ammonium sulfate precipitation, DEAE cellulose, Sephadex G-75, and Agarose A-5m chromatography. The resulting product appears to be pure according to immunoelectrophoretic, disc electrophoretic, ultracentrifugal, and immunologic criteria. Sephadex gel filtration and membrane filtration studies suggest a molecular size of 61,000. The isolated product is highly active in inducing experimental cholera in infant and adult rabbit models. It also elicits, in small dosage, an increased vascular permeability in skin. These observations indicate that choleragenicity and increased vascular permeability are intimately associated phenomena and may be manifestations of the same basic mechanism.

An additional, antigenically identical, protein has also been isolated by the same procedures. The latter substance, termed "choleragenoid", lacks the permeability effect and choleragenicity of the choleragen moiety. Its size (estimated from Sephadex gel filtration at 42,000) is smaller than that of choleragen and it also differs in charge. Choleragenoid may prove useful as a nontoxic immunogen to protect against pathologic effects of V. cholerae infection.
THE PROLIFERATIVE AND ANAMNESTIC ANTIBODY RESPONSE OF RABBIT LYMPHOID CELLS IN VITRO
Authors: Jacobson E. B. , Thorbecke G. J.
Published: June 2004

Popliteal lymph nodes were obtained from rabbits 4 days to 9 months after a primary injection of diphtheria toxoid or bovine γ-globulin into the footpad. The ability of cells from these nodes to proliferate upon reexposure to antigen in vitro was compared to the height of the secondary response produced by tissue fragments. In addition, a comparison was made between the responsiveness of draining and contralateral lymph nodes.

While the secondary antibody response in vitro increased markedly with the time after immunization at which the lymph nodes were taken from the animals, the degree of proliferation induced by antigen was highest with cells from lymph nodes taken early after priming (peak day 7) and was very much lower with lymph node cells taken longer than 3 wk after priming. This striking difference between these two responses has been discussed.

Contralateral lymph nodes were much inferior to draining nodes in their ability to give a secondary antibody response in vitro, and never gave a detectable proliferative response. This difference became less marked with time after priming, but could still be demonstrated after 4 months. These results suggest a concentration of primed cells in the lymphoid tissue draining the site of injection, and a slow release of these cells into the circulation, to be distributed to the remaining lymphoid tissue.
A STUDY OF IMMUNOGLOBULIN STRUCTURE
Authors: Quattrocchi R. , Cioli D. , Baglioni C.
Published: June 2004

102 human Bence Jones proteins have been purified by gel filtration, digested with trypsin, and analyzed by peptide mapping. In several cases Bence Jones "fragments", corresponding to the variable half of the corresponding proteins, were observed. The peptide maps of the proteins were compared to establish whether any identical proteins were present in the sample analyzed. No Bence Jones protein showed a peptide map identical to that of any other protein, although remarkable similarities in the peptide maps were observed for some proteins. Two proteins that gave very similar peptide maps were then examined in detail, by purifying and analyzing the tryptic peptides. It was then found that these two proteins differ in amino acid sequence in at least six positions.

The probability of not finding two identical sequences by examining a sample extracted from populations of light chains of different sizes has been calculated. This has led to an estimate of the minimal size of the population of light chain sequences in humans. The number of light chain sequences appears to be at least a few thousand.

Information on the frequency of Inv and Oz antigenic determinants and on the relative frequency of subtypes of K chains has been obtained. Proteins of KI subtype are found most frequently. The possibility that different subtypes may be predominant in different species is discussed in relation to the evolutionary arguments used in favor of the somatic theories on the origin of variability of immunoglobulin chains.
MOLECULAR MECHANISM OF HEMOLYTIC ANEMIA IN HOMOZYGOUS HEMOGLOBIN C DISEASE
Authors: Lessin Lawrence S. , Jensen Wallace N. , Ponder Eric
Published: June 2004

Erythrocytes from a patient with homozygous hemoglobin C disease were subjected to gradual osmotic dehydration by incubation in hypertonic saline. Serial observations of these cells before and after 4 and 12 hr incubation were carried out by means of interference, Soret absorption, polarization microscopy, and the electron microscope employing the freeze-etching technique. Light microscopic studies showed a progressive contraction of cellular contents into central masses which, after 12 hr dehydration, formed birefringent intracellular hemoglobin crystals in 50–75% of the cells. Electron microscopic study of freeze-etched replicas of these cells at 0, 4, and 12 hr of dehydration reveals progressive aggregation, alignment, and crystallization of hemoglobin molecules. Molecular aggregation found in C-C cells prior to osmotic dehydration was not seen in normal erythrocytes. Aggregation and packing varied from cell to cell. Reticulocytes showed a loosely packed aggregate mesh-work; older cells showed variation of molecular packing, which appeared tightest in cells corresponding to microspherocytes. With further loss of intracellular water, aggregates coalesced into patterns of tighter molecular packing with small regions of alignment, and, finally, crystallization occurred. Hemoglobin molecules measuring 70 A in diameter were readily identified within the period patterns of intracellular crystals. These findings suggest that the hemoglobin C molecules within C-C erythrocytes exist in an aggregated state. As the cell ages, intracellular water is lost and intermolecular distance decreases, hemoglobin C molecules polymerize into intracellular crystals. This pathological behavior of hemoglobin C is associated with a charge alteration conferred by the substitution of beta-6-lysine for glutamic acid on the external surface in the A-helix region of the beta-chain of the molecule, possibly increasing intermolecular attraction. Molecular aggregation accounts for the increased rigidity of C-C cells which leads to accelerated membrane and water loss with resultant microspherocyte formation. The microspherocyte, with highest intracellular hemoglobin concentration, rapidly undergoes intracellular crystallization, and is sequestered and destroyed by reticuloendothelial elements.
CELLULAR DIFFERENTIATION OF THE IMMUNE SYSTEM OF MICE
Authors: Shearer G. M. , Cudkowicz G. , Priore R. L.
Published: June 2004

Thymocytes and marrow cells of unprimed donor mice were mixed in vitro and transplanted into X-irradiated syngeneic mice. 18 hr later, sheep erythrocytes were injected to induce immune responses. Splenic plaque-forming cells (PFC) secreting IgM (direct PFC) or IgG (indirect PFC) hemolytic antibody were enumerated at the time of peak responses.

By transplanting graded and limiting numbers of thymocytes with 4 x 107 marrow cells, inocula were found which contained one or a few thymic antigen-reactive cells (ARC) reaching the recipient spleens, interacting with marrow cells, and inducing PFC formation. The frequency values of ARC inferred from direct and indirect plaque assays were very similar, 1 in ∼107 thymocytes. Furthermore, statistical analysis indicated that the formation of direct PFC was not independent of the formation of indirect PFC. This was interpreted to mean that ARC were not specialized themselves and did not determine the molecular class of antibody to be secreted after interaction with marrow cells.

Spleens of thymus-marrow grafted mice containing one or two ARC and non-limiting numbers of marrow precursors of PFC (P-PFC), had direct and indirect PFC clustered in several focal areas. Assuming that each focal area represented the progeny of one P-PFC that had interacted with ARC, these results confirmed the statistical evidence for lack of class differentiation in thymic ARC, and also indicated that each ARC or its progeny cells interacted with more than one P-PFC of either class.
CELLULAR DIFFERENTIATION OF THE IMMUNE SYSTEM OF MICE
Authors: Cudkowicz G. , Shearer G. M. , Priore R. L.
Published: June 2004

Marrow cells and thymocytes of unprimed donor mice were mixed in vitro and transplanted into X-irradiated syngeneic hosts. 18 hr later sheep erythrocytes were injected to induce immune responses. Splenic plaque-forming cells (PFC) secreting IgM (direct PFC) or IgG (indirect PFC) hemolytic antibody were enumerated at the time of peak responses.

By transplanting graded and limiting numbers of marrow cells with 5 x 107 thymocytes, inocula were found that contained few precursors of PFC (P-PFC) reaching the recipient spleens, interacting with thymocytes, and generating PFC. However, the frequency of responses in relation to the number of grafted marrow cells did not follow Poisson statistics, presumably because the interaction of marrow cells with thymocytes was more complex than a single or a one-to-one cell event. The frequency of direct PFC responses was greater than that of indirect PFC responses in 13 of 15 groups of mice tested. This was interpreted as evidence for the existence of two classes of P-PFC, each of which was restricted to generate either direct or indirect PFC. The precursors of direct PFC were ∼ 15 times more frequent than those of indirect PFC. Since thymic antigen-reactive cells were not differentiated for antibody class, it follows that antigen-sensitive units reactive to sheep erythrocytes owe their class restriction to specialized marrow cells. Specialization of P-PFC may have arisen within marrow cell lines by differentiation, or may have been conferred upon P-PFC by interaction with other cells, including those of the irradiated host.
CROSSING OVER BETWEEN GENES IN THE IMMUNOGLOBULIN HEAVY CHAIN LINKAGE GROUP OF THE MOUSE
Authors: Lieberman Rose , Potter Michael
Published: June 2004

Immunoglobulin heavy chain genes were found in wild mice (Mus musculus) that could best be explained as recombinants of immunoglobulin genotypes.

In wild mice from Kitty Hawk, N. C., two new heavy chain linkage groups, G3,5,7,8H9,11FfA- and G3,5,8H9,11FfA-, were found, each of which genetically controls both the 3 and 5 distinct immunoglobulin determinants. In inbred strains the 3 and 5 determinants are found independently. The new heavy chain allotype G3,5,7,8H9,11FfA- probably arose from a homologous (intragenic) cross-over between G3,8H9,11FfA- and G5,7,8H9,11FfA14 heavy chain linkage groups. It was suggested that genes controlling G3,8G5,7,8, G3,5,8, and G3,5,7,8 are alleles.

Another homozygous wild mouse (Kyushu, Japan) showed a new heavy chain allotype, 2G1,6,7,8H9,16FsA15. The 2 and G1,6,7,8 determinants are also separated in inbred strains. The 2 determinant in inbred mice is not on the γF, γH, or γA heavy chain and is probably on a γG or γG-like immunoglobulin heavy chain. Papain digestion of serum from the Kyushu mouse showed two electrophoretically different Fc fragments, one carrying the G1,6,7,8 and the other the 2 determinant. The new heavy chain allotype, 2G1,6,7,8H9,16FsA15, of the Kyushu wild mouse probably arose from a nonhomologous (unequal) cross over between 2G-H9,16FsA15 and G1,6,7,8H9,11FfA12,13,14 heavy chain linkage groups. The linkage group of the Kyushu wild mouse has at least five heavy chain genes, while that of the inbred mice has four.
THE CHEMICAL NATURE OF MACROPHAGE RNA-ANTIGEN COMPLEXES AND THEIR RELEVANCE TO IMMUNE INDUCTION
Authors: Roelants Georges E. , Goodman Joel W.
Published: June 2004

10 different compounds, including natural and synthetic polypeptides, proteins, polysaccharides, amino acids, and steroid hormones, were assayed for their capacity to form complexes with peritoneal exudate cell RNA. Only molecules carrying negatively charged groups were able to do so.

The formation of RNA-antigen complexes was unrelated to the immuno-potency of the "antigen," was not an enzyme-dependent reaction, did not require the synthesis of RNA following introduction of the antigen, did not seem to involve antigen-specific RNAs, was not specific for macrophages, since HeLa cells could be used as effectively, and occurred when purified RNA was mixed with antigen only in the presence of divalent cations. The complexes were very stable, once formed, but could be dissociated by exhaustive dialysis against buffers containing a chelating agent.

The macrophage RNA-antigen complex therefore appears to be a chelate between anionic groups on the two components. Based on the total absence of a relationship between immunogenicity and the capacity to form such complexes, as well as the nonspecific nature of complex formation at every level examined, it appears unlikely that RNA-antigen complexes play a physiologically significant role in immune induction.
ULTRASTRUCTURE OF PAPAIN AND PEPSIN DIGESTION FRAGMENTS OF HUMAN IgM GLOBULINS
Authors: Svehag Sven-Eric , Bloth Björn , Seligmann Maxime
Published: June 2004

The ultrastructure of papain and pepsin-digested products of human IgM globulins has been analyzed. Papain digestion was performed both in the presence and absence of cysteine.

The Fcµ fragment was found to represent the central ring structure in the intact IgM molecule, plus a minor part of the appendages extending from the ring. The Fcµ ring structure was occasionally seen to be composed of dimers of short rods, probably identical with the endpieces of two µ-chains. Such dimeric structures, released from the intact Fcµ rings, had a tendency to aggregate sidewise, producing complexes of varying size. The dimensions of the Fcµ fragments were: outer diameter approximately 85 A, inner diameter about 40 A. The length of the protrusions varied from 20–30 A.

The Fabµ preparations contained long strands of sidewise aggregated, short rod-shaped fragments. No aggregates were seen in the F(ab'')2µ preparations. The two Fab''µ units in the dimeric F(ab'')2µ fragments were usually parallel to each other. The dimensions of the Fabµ and F(ab'')2µ fragments were 50–80 A x 30 A and 75–80 A x 55 A, respectively.

These findings provide morphological evidence that the C-terminal ends of the µ-chains (the Fcµ fragment) make up the central ring structure in the IgM molecule. They further indicate that the F(ab'')2µ fragments constitute about ¾ of the appendages extending from this ring structure.
EFFECTS OF SHORT-TERM EPITHELIAL RETICULAR CELL AND WHOLE ORGAN THYMUS GRAFTS IN NEONATALLY THYMECTOMIZED MICE
Authors: Hays Esther F. , Alpert Paul F.
Published: June 2004

Neonatally thymectomized mice were implanted with thymus grafts composed of epithelial reticular cells for periods of 7 and 14 days. Regardless of whether the grafts were placed immediately after thymectomy, or at 3 wk of age, there was little recovery of the lymphocyte depletion and impaired immunologic responsiveness, characteristically found in a neonatally thymectomized host. The findings were similar in animals studied at 2 months or 2 wk after graft removal. Many of the short-term remnant grafts were populated with lymphocytes and had attained the morphologic appearance of thymus by 14 days.

A lesser degree of lymphocyte depletion and impaired responsiveness to SRBC occurred if thymectomy was delayed until 7 days of age, if remnant grafts were removed after 2 months, and if intact neonatal thymus was used for the short-term grafts. Complete normality was found in some of the animals in all of these groups.

These observations suggest a direct role for mature thymus lymphocytes in reconstituting the neonatally thymectomized host and indicate that epithelial cell function is to direct the maturation of cells that ultimately behave as thymus lymphocytes.
HEAVY AND LIGHT CHAIN ALLOTYPIC MARKERS ON RABBIT HOMOCYTOTROPIC ANTIBODY
Authors: Kindt T. J. , Todd C. W.
Published: June 2004

Evidence has been presented that rabbit homocytotropic antibody prepared against ovalbumin bears allotypic markers of both group a (heavy chain) and group b (light chain). This was shown by specific removal of activity in passive cutaneous anaphylaxis assays by anti-allotype immunoadsorbents.

The homocytotropic antibody has properties which indicate that it belongs to a new class of rabbit immunoglobulin. These results demonstrate that this newly described class possesses the allotypes of both groups a and b, as has been previously shown for other rabbit immunoglobulin classes.
ELECTRON MICROSCOPIC STUDIES ON STREPTOCOCCI
Authors: Swanson John , Hsu Konrad C. , Gotschlich Emil C.
Published: June 2004

The presence of M antigens on group A streptococci is associated with hairlike fimbriae that cover the surface of the streptococcal cell wall and are demonstrable by electron microscopy. These fimbriae also may be associated with R antigen. Like M protein, the surface fimbriae are destroyed by trypsin treatment and reappear when "trypsinized" streptococci are reincubated in fresh, trypsin-free broth.

Ferritin-conjugated, type-specific antibodies localize on homologous M+ cells in a pattern suggestive of several M antigenic sites along the length of individual surface fimbria. The M-associated fimbriae remain on the residual cell wall after removal of the bulk of group-specific polysaccharide through nitrous acid extraction. This suggests attachment of the fimbriae to the mucopeptide and minor polysaccharide components remaining in the nitrous acid-extracted wall.

The pattern of localization of ferritin-conjugated antibodies on homologous streptococci before and after trypsin exposure and upon reincubation of the trypsinized cells in fresh medium suggests the following hypothesis: M antigen is secreted by the cell, is partially excreted through the otherwise intact cell wall, and is bound by the wall so that M protein occupies a peripheral, exposed position on the surfaces of the streptococcal cell wall.
THE IMMUNOGENICITY OF DINITROPHENYL AMINO ACIDS
Authors: Frey J. R. , de Weck A. L. , Geleick H. , Lergier W.
Published: June 2004

Numerous dinitrophenyl amino acid preparations injected intradermally induced contact hypersensitivity to dinitrochlorobenzene, delayed type skin reactions to DNP-amino acids, and anti-DNP antibodies in guinea pigs. Some DNP-amino adds induced precipitating anti-DNP antibodies in rabbits as well.

Some of the DNP-ammo acids studied were regularly immunogenic, possible immunogenic impurities having been excluded by extensive purification procedures. Others were either constantly nonimmunogenic or irregularly immunogenic, e.g., their immunogenicity varying from one preparation lot to another.

By means of extensive chemical analyses and the establishment of dose-response curves, we were able to demonstrate in most cases that the immunogenicity was not due to contamination with unreacted dinitrofluorobenzene or other DNP derivatives, to photodecomposition or other degradation products, or to DNP-protein contaminants. Nevertheless, the irregular immunogenicity of several DNP-amino acid preparations can only be explained by a highly immunogenic impurity (or impurities) which we were unable to detect analytically.

The regular immunogenicity of some other DNP-amino acids (e.g. di-DNP-L-histidine) appears to be based on a "transconjugation" phenomenon, the DNP group being able to split off from its amino acid carrier and to conjugate secondarily with proteins in vivo and in vitro. Accordingly, the interpretation of some recent data concerning the immunogenicity of low molecular weight hapten-amino acids may have to be reevaluated.
THE EIGHTH COMPONENT OF HUMAN COMPLEMENT (C8): ISOLATION, CHARACTERIZATION, AND HEMOLYTIC EFFICIENCY
Authors: Manni Jorge A. , Müller-Eberhard Hans J.
Published: June 2004

A method was described allowing the isolation of the eighth component of complement, C8, from human serum. C8 is an immunochemically definable, heretofore unrecognized serum protein with a molecular weight of approximately 150,000 and an electrophoretic mobility of a γ1-globulin. It may be obtained with 5% yield as a 5000-fold purified, physicochemically and immunochemically homogeneous protein. Under optimal experimental conditions, a few molecules of C8 were found sufficient for lysis of a cell.