bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does Freund's Adjuvant Denature Protein Antigens? EPR Studies of Emulsified Hemoglobin
Authors: Berzofsky Jay A. , Schechter Alan N. , Kon Hideo 
Published: December 2022

Abstract
Use of complete Freund's adjuvant for production of antibodies to study protein conformation is valid only if emulsification in adjuvant does not denature protein antigens. Using electron paramagnetic resonance to observe directly the protein in situ in the opaque emulsions, we demonstrate that hemoglobin is not denatured by emulsification or storage in adjuvant for 24 hr at 4°C, conditions comparable to the usual handling of antigens before immunization.
Characterization of the Target Cell Receptor for IgE
Authors: Conrad Daniel H. , Froese Arnold 
Published: December 2022

Abstract
Purified rat peritoneal mast cells (RMC) and cultured rat basophilic leukemia (RBL) cells were surface labeled with 125I by using lactoperoxidase, incubated with unlabeled rat monoclonal IgE and subjected to solubilization by treatment with Nonidet P-40 (NP-40). With both cell types significant amounts of radioiodinated material could be specifically precipitated by a “sandwich” system consisting of rabbit anti-rat ε-chain and goat anti-rabbit Ig. The precipitates were dissociated with sodium dodecyl sulfate (SDS) and urea and subsequently analyzed by SDS-polyacrylamide gel electrophoresis. With RMC three radioactive bands were seen. One corresponded to IgE present on the RMC at the time of isolation. A small band migrating in the region of light chain was seen with both specific (anti-IgE) and control precipitates. It showed no demonstrable relationship to IgE. The major radioactive band corresponded to a m.w. of 62,000. This band was dependent upon the presence of IgE and was not found when non-IgE binding control cells were used. With RBL cells, only the IgE-dependent 62,000 dalton peak was present. Saturation of the IgE receptor sites of the RMC or RBL cells before lactoperoxidase labeling almost totally eliminated this radioactive band, indicating that cell-bound IgE rendered this membrane component inaccessible to the radiolabel. These results strongly suggest that this cellular component is identical, at least in part, with the target cell surface receptor for reaginic antibody. The data also further support the hypothesis that the neoplastic RBL cells have a normal surface receptor for IgE.
In Vitro Generation of Secondary Cell-Mediated Cytotoxic Response Against a Syngeneic Gross Virus-Induced Lymphoma in Rats
Authors: Glaser Moshe , Bonnard Guy D. , Herberman Ronald B. 
Published: December 2022

Abstract
Cell-mediated cytotoxic responses against a syngeneic Gross virus-induced lymphoma, (C58NT)D, in W/Fu rats were generated in vitro by using mixed lymphocyte-tumor cell cultures. The source of responding cells was either spleens from normal rats or spleens from rats carrying or having rejected (C58NT)D tumors. Mitomycin C-treated (C58NT)D tumor cells were used as stimulating cells. The secondary anti-tumor cytotoxic response occurred more rapidly and reached higher levels than the primary response, and it was antigen specific. T cells, but not B cells or macrophages, were essential for both the induction and the effector phases of the secondary anti-tumor responses. These data suggest that specific memory T cells persist for long periods of time in the lymphoid organs of (C58NT)D immune rats, which can rapidly become cytotoxic upon re-exposure to antigen.
The Distribution of Terminal Deoxynucleotidyl Transferase (TdT) among Subsets of Thymocytes in the Rat
Authors: Barton Randall , Goldschneider Irving , Bollum F. J. 
Published: December 2022

Abstract
Terminal deoxynucleotidyl transferase (TdT), a unique DNA-polymerizing enzyme, has been shown to be present in a moderately dense subpopulation of rat thymocytes separated on discontinuous Ficoll density gradients. This subpopulation has been characterized by using antigenic and functional markers to identify directly and quantify cortical and medullary thymocytes. The TdT-positive thymocytes are depleted by cortisone administration, lack responsiveness to phytohemagglutinin, concanavalin-A, and histocompatibility alloantigens, bear surface antigens characteristic of cortical thymocytes (bone marrow lymphocyte antigen) and lack surface antigens characteristic of medullary thymocytes (rat-masked thymocyte antigen and histocompatibility antigens). The results indicate that TdT is present exclusively (or in markedly higher concentrations) in a subset of cells which comprises about 65% of cortical thymocytes. Two other major subsets of cortical thymocytes were identified which appeared to be TdT-negative. A minor subset of very low density cortical thymocytes was also defined. These observations have provided insight into the possible pathways of thymocyte ontogeny.
Structure and Function of Immunoglobulin Domains
Authors: Ellerson J. R. , Yasmeen D. , Painter R. H. , Dorrington K. J. 
Published: December 2022

Abstract
Exposure of Fc fragments derived from human IgG1 myeloma proteins to acid pH rendered the region between the Cγ2 and Cγ3 domains transiently susceptible to cleavage by trypsin upon return to neutral pH. Trypsin covalently linked to Sepharose was used and two fragments derived from the Cγ2 region and one from the Cγ3 region were purified by column chromatography. On the basis of amino acid analysis, primary sequence data, antigenic properties, and m.w., one of the Cγ2 fragments was shown to consist of two polypeptide chains of unequal mass joined by the inter-heavy chain disulfide bonds. The larger chain corresponded to a stretch of γ-chain between Thr 223 and Lys 338 (Eu numbering) and the shorter chain to the section between Thr 223 and Lys 248. The other Cγ2-fragment was a disulfide-linked dimer of the Thr 223 to Lys 338 sections of the paired γ-chains. When this latter fragment was reduced under mild conditions it dissociated into monomers indicating that there was little or no noncovalent interactions between the Cγ2 domains. The Cγ3-fragment was shown to be a noncovalent dimer composed of the Glu 345 to Lys 349 sections of the two γ-chains although some heterogeneity was apparent at the amino-terminus. Circular dichroism was used to probe the conformational relationships between the isolated domains and the parent Fc. The spectral properties of Fc could not be fully accounted for on the basis of the spectra observed for the isolated domains which suggested that inter-domain interaction might be significant in Fc.
The Chemoattraction of Neutrophils by Heterologous and Homologous Cytotoxic Sera
Authors: Williams Dianne , Esquenazi Violet , Cirocco Robert , Jensen Joerg A. 
Published: December 2022

Abstract
Neutrophils (PMN) migrated in vitro chemotactically along concentration gradients of heterologous and homologous leukocytotoxic, complement-active sera. The heterologous systems consisted of normal, non-immune nurse shark or dog serum and human PMN; the homologous systems consisted of human or dog immune sera and human or dog PMN, respectively. Chemotaxis was induced 1) by fresh cytotoxic sera, 2) by complement alone if the cytotoxic antibodies were with the responding cells or if the cells were passively sensitized with the antibodies, and 3) by individual and combined complement components if the corresponding intermediate PMN-antibody-complement component complexes were the migrating cells. These observations represent a new mechanism of immune chemotaxis: the chemotactic stimulation is a direct consequence of a gradient-controlled immune reaction occurring at and involving the surface of the chemoattracted cell. This mechanism is distinctly different from that which depends on chemotactic factors produced or released independent of and at a distance from the responding cells.
Preferential Expression of Anti-Azobenzenearsonate Antibodies of Heterozygous a1a3 Rabbits in the a1 Allotype
Authors: Foshay Miriam C. , Zimmerman Sarah E. , Spencer Lenore K. , Haurowitz Felix , Knight Katherine L. 
Published: December 2022

Abstract
The preferential expression of anti-As antibodies in the allotype a1 of heterozygous a1a3 rabbits immunized with As-TMA-BSA has been investigated by means of quantitative methods. The average content of the anti-As antibodies in a1 and a3 allotypes was 84 and 11%, respectively; the analogous values for anti-TMA antibodies were 41 and 56%, and for anti-BSA antibodies they were 54 and 41%. The molar anti-As/anti-TMA ratios in the heterozygous animals were approximately the same as in homozygous a1a1 rabbits sensitized with As-TMA-BSA. The very low yields of anti-As-antibodies of allotype a3 cannot be caused by a lack of genes for the production of anti-As antibodies of allotype a3 because a3a3 homozygotes produce considerable amounts of anti-As antibody of allotype a3. Competition between lymphoid cells having anti-As receptors of different allotype and different affinity for the antigenic p-azobenzenearsonate determinant is discussed as a possible cause for the preferential expression in the a1 allotype.
Sensitization of T Lymphocytes in Vitro by Syngeneic Macrophages Fed with Tumor Antigens
Authors: Treves Abraham J. , Schechter Bilha , Cohen Irun R. , Feldman Michael 
Published: December 2022

Abstract
We investigated the interaction between T lymphocytes and macrophages in the in vitro sensitization of lymphocytes against tumor cells. Spleen cells were sensitized in vitro by syngeneic peritoneal macrophages that had been fed with cell-free antigen preparation of syngeneic tumor cells. The sensitized T lymphocytes acquired specific cytotoxic activity in vitro and the capacity to inhibit tumor development in vivo. Allogeneic macrophages, syngeneic fibroblasts, or the antigen preparation by itself were not able to sensitize the lymphocytes against the tumor.
Eosinophils and Immune Mechanisms
Authors: Greene Bruce M. , Colley Daniel G. 
Published: December 2022

Abstract
The lymphoid cell population responsible for production of eosinophil stimulation promoter (ESP), a lymphokine which increases migration of eosinophils, was investigated in murine Schistosoma mansoni infection. Con A challenge induced ESP production, whereas LPS did not. Prior treatment with anti-θC3H alloantiserum plus complement in vitro eliminated ESP production; in vivo treatment with rabbit anti-mouse thymocyte serum consistently reduced ESP production by splenic lymphoid cells, but affected lymph node cell ESP production only after exceptionally large doses. Thymocytes did not produce significant amounts of ESP; nor did lymphoid cells from congenitally athymic mice. Depletion of B lymphocytes and macrophages by nylon fiber adherence eliminated antigen-induced ESP production; this was partially restored by addition of non-immune, 72-hr peritoneal exudate cells. Con A-induced ESP production was not affected by nylon fiber treatment. These results demonstrate that ESP is produced by an ATS-sensitive, peripheralized T lymphocyte population, and suggest a macrophage requirement for antigen-induced production of this lymphokine.
The Effect of Serum Inhibitor on the Antigenic and Mitogenic Responses to E. Coli Bacteria
Authors: Poe Wanda J. , Michael J. Gabriel 
Published: December 2022

Abstract
The effect of serum inhibitory factors on the induction of the in vitro immune response and mitogenic response to Escherichia coli antigens in murine spleen cell cultures was investigated. Both normal and congenitally athymic mice served as spleen cell and serum donors. Cultured CBA/J spleen cells produced anti-bacterial antibody in the presence of mouse serum, but the mitogenic response to the bacterial antigen was suppressed by the addition of mouse serum. The addition of mouse serum from either CBA/J or nude mice to nude spleen cell cultures led to suppression of both the antigenic and mitogenic responses to bacterial antigen. The polyclonal antibody response by CBA/J spleen cell cultures to SRBC induced by bacteria was significantly enhanced by the addition of either CBA/J or nude mouse serum. Conversely, the nude spleen cell polyclonal response to SRBC was significantly inhibited by high concentrations of nude or CBA/J mouse serum. These data indicate that inhibition of the specific E. coli and nonspecific polyclonal antibody responses by mouse serum occurs only in cultures of spleen cells taken from mice lacking a population of T lymphocytes.
Mitogen Induction of Murine C-Type Viruses
Authors: Schumann Gebhard , Moroni Christoph 
Published: December 2022

Abstract
We reported previously in vitro induction of endogenous C-type viruses from normal mouse spleen cells by lipopolysaccharide (LPS) as well as by combination treatment with concanavalin A and 5-bromo-2′-deoxyuridine (Con A/BrdU). To identify the cell types sensitive to virus induction and to study the relationship of mitogenicity to virus induction we have compared T cell populations (BALB/c thymus cells and cortisone-resistant thymus cells), B cell populations (nu/nu spleen cells and lymph node cells), adherent BALB/c peritoneal cells and mixed populations (BALB/c spleen cells, macrophage-depleted BALB/c spleen cells, and lymph node cells). LPS-induction occurred only in B cell-containing populations. In contrast, induction by Con A/BrdU depended on the presence of both T and B cells. In both instances, neither macrophages nor hemopoietic cells appeared to be a major source of virus. Treatment with anti-Ig serum and complement reduced virus induction by LPS/BrdU but not by Con A/BrdU suggesting that different cell populations produce virus after stimulation with these two different mitogens.
The Induction by Complement of a Change in KSCN-Dissociable Red Cell Membrane Lipids
Authors: Giavedoni Elda B. , Dalmasso Agustin P. 
Published: December 2022

Abstract
During complement lysis of antibody-sensitized sheep erythrocytes (EA) there was a larger loss of membrane phospholipids than during lysis elicited by hypotonic buffer. In addition, membranes prepared from complement-lysed EA had a marked reduction in KSCN (2.4 M)-dissociable membrane cholesterol and phospholipids, as compared to membranes from EA lysed hypotonically. Complement lysis caused a mild reduction in the amount of KSCN-dissociable membrane hexose but no change in the amount of dissociable protein. The impairment in dissociation of membrane lipids was related to the action of C8; it did not occur with membranes from EA that were treated with heat-inactivated (56°C for 30 min) human serum, C4-deficient guinea pig serum, C6-deficient rabbit serum, or the first seven human complement components. EA lysed with limited amounts of complement exhibited a partial impairment in KSCN-dissociable lipids. Membranes from erythrocytes lysed with melittin showed a large increase in dissociation by KSCN of lipids, proteins, and hexoses. Membranes from erythrocytes lysed with lysolecithin or phospholipase C showed, in addition to a reduction in dissociable lipid, a much larger reduction in dissociable hexose than membranes from complement-lysed cells. These profiles of reactivity with 2.4 M KSCN indicate that the membrane pertubations caused by complement may be specific. We conclude that complement lysis is accompanied by a major rearrangement of membrane cholesterol and phospholipid which could be demonstrated in membranes from cells lysed by only one or very few complement lesions. Therefore, it appears that the lesions induce a propagated change in the lipid organization which extends throughout large areas of the membrane. This change might be responsible for the impairment of membrane permeability that follows the action of complement and results in cell destruction.
Secondary IgG Responses to Type III Pueumococcal Polysaccharide
Authors: Braley-Mullen Helen 
Published: December 2022

Abstract
Mice primed with a thymus- (T) dependent form of Type III pneumococcal polysaccharide (S3), i.e., S3 coupled to erythrocytes (S3-RBC) produce S3-specific IgG antibody after secondary challenge with either S3 or S3-RBC. The production of IgG antibody by mice challenged with S3 was shown to be T independent since secondary responses were enhanced when mice were treated with anti-lymphocyte serum (ALS) at the time of secondary challenge with S3 and T-depleted spleen cells responded as well as unfractionated spleen cells to S3 in an adoptive transfer system. Secondary S3-specific IgG responses in mice challenged with S3-RBC were shown to be T dependent by the same criteria. The results obtained by using S3 as the antigen indicate that IgG-producing B cells (B γ cells) can recognize and respond to antigen in the absence of helper T cells. On the other hand, T cells were required for the induction of S3-specific memory B γ cells since mice depleted of T cells by treatment with ALS at the time of priming with S3-RBC failed to produce S3-specific IgG antibody after secondary challenge with either S3 or S3-RBC. Since RBC-specific memory cells were induced in T-deprived mice the results suggest that T cell regulation of IgG antibody production may vary for different antigens.
Inhibition of Stimulation in Murine Mixed Lymphocyte Cultures with an Alloantiserum Directed Against a Shared Ia Determinant
Authors: Schwartz Ronald H. , Fathman C. Garrison , Sachs David H. 
Published: December 2022

Abstract
Pools of high titered alloantisera were raised by immunizing (B10.A/SgSn × A/WySn)F1 mice with C57BL/10Sn(B10) spleen cells. This serum (F1 anti-B10), when added to one-way mixed lymphocyte cultures (MLC), inhibited stimulation of B10.A splenic responders by both B10 and B10.D2/nSn irradiated, splenic stimulators. The B10 stimulation was suppressed approximately 85% whereas the mean suppression of B10.D2 stimulation was approximately 60%. In the former case, the serum contained antibodies reactive with multiple major histocompatibility complex determinants on the stimulator cells. In the latter case, the cytotoxic reactivity of the serum was directed principally against an I region-associated determinant (Ia.8) shared by B10 and B10.D2 and coded for by a gene(s) in the I-A subregion. The magnitude of the suppression of the response to B10.D2 cells (60%) was similar to the reduction in stimulation observed when the Ia.8 difference was eliminated genetically by using (B10 × B10.A)F1 responder cells against irradiated B10.D2 stimulators. Inhibition of MLC by this antiserum was a function of reactivity with stimulator and not responder cells. Although some pools of F1 anti-B10 antiserum produced partial inhibition of the responder cell in a B10.D2 vs B10.Ax MLC combination, the results were inconsistent and not correlated with the anti-Ia.8 cytotoxicity titers. In addition, an F1 anti-B10 antiserum pool, which consistently failed to inhibit the responder cell, nevertheless inhibited both irradiated B10.D2 and (B10.A × B10.D2)F1 cells from stimulating B10.A responder cells. However, this same antiserum did not inhibit stimulation of B10.D2 responder cells by the (B10.A × B10.D2)F1 stimulators. Thus, the binding of antibodies to the non-stimulating antigens on the F1 stimulator cell did not interfere with the capacity of the appropriate stimulating antigens to cause stimulation. All of these results are consistent with the hypothesis that Ia alloantigens are the major stimulating determinants of I region-associated MLC reactions.
Studies on the Terminal Stages of Antibody-Complement-Mediated Killing of a Tumor Cell
Authors: Boyle Michael D. P. , Ohanian Sarkis H. , Borsos Tibor 
Published: December 2022

Abstract
Transformation of T* to dead cells was prevented by 3′5′ cAMP. The effect of 3′5′ cAMP was dose, time, and temperature dependent. T* washed free of 3′5′ cAMP after short-term incubation proceeded to die to the same extent as control cells. After 3 hr of incubation of T* with 3′5′ cAMP the level of killing was significantly reduced. The 3′5′ cyclic nucleotides of uridine, guanine, cytosine, and thymidine and the 2′3′ cyclic adenosine nucleotide were not effective. It was concluded that prolonged treatment of T* with 3′5′ cAMP either irreversibly blocked the damage-producing process or facilitated the repair of damaged sites.
An in Vitro Assay for T Cell Immunity to Malaria in Mice
Authors: Weinbaum Fredric I. , Evans Charles B. , Tigelaar Robert E. 
Published: December 2022

Abstract
After infection with a nonlethal strain of murine malaria (17XNL Plasmodium berghei yoelli), BALB/c mice are then resistant to a lethal strain (17XL P. b. yoelli). BALB/c mice were infected with 17XNL, and challenged 3 weeks later, after clearing their parasitemias, with 17XL. Three weeks thereafter, spleen cells from such immune animals were used to define an early peaking T-dependent (anti-ϑ sensitive) antigen-specific proliferative response when incubated in vitro with 17XL infected RBC, or a saline soluble 17XL antigen preparation. T dependent responsiveness of spleen cells from uninoculated control animals to the 17XL antigen preparation was also observed, but demonstrated a much different (delayed) kinetics from that observed with immune cells.
Naturally Soluble Tumor Antigens from Guinea Pig Hepatomas: Isolation and Partial Characterization
Authors: Detrick-Hooks Barbara , Smith Howard G. , Bast Robert C. , Dunkel Virginia C. , Borsos Tibor 
Published: December 2022

Abstract
Naturally soluble tumor antigens were detected in the ascites fluid of guinea pigs bearing an ascites tumor and from exhausted tissue culture media of cultured tumor cells. Two antigenically distinct cell lines of diethylnitrosamine-induced strain-2 guinea pig hepatomas (line-10 and line-1) served as the source of tumor antigens. Tumor antigen activity was detected by four different techniques: immunodiffusion, inhibition of complement-mediated cytotoxicity, inhibition of membrane immunofluorescence, and delayed cutaneous hypersensitivity. With syngeneic tumorspecific antiserum, line-10 guinea pig tumor antigens were detected by immunofluorescence in the concentrated ascites and tissue culture fluids. With a xenogeneic antiserum, demonstrated to be tumor specific, line-10 tumor antigens were detected not only in the concentrated ascites and tissue culture fluids but also in two of the partially purified fractions of these fluids. When the line-10 concentrated ascites and its fraction I were subjected to ultracentrifugation at 300,000 × G for 1 hr, the antigen activity was retained in the supernatant and thus by this criterion the tumor antigens detected in these samples are soluble.
Immunodiffusion data indicate that more than one antigen is present in the line-10 system since three lines of precipitation were detected when line-10 concentrated ascites was reacted with the line-10 tumor-specific antiserum. In contrast to this, the line-10-concentrated tissue culture fluid displayed only one line of precipitation.
Although tumor antigens could not be demonstrated in the other antigenically distinct tumor cell line, line-1, by immunodiffusion or inhibition of membrane immunofluorescence, inhibition of complement-mediated cytotoxicity was able to detect tumor antigens in the line-1 concentrated ascites and tissue culture fluids.