bluuebunny/crossref_metadata_2025 huggingface dataset:
THE SELECTIVE INHIBITION OF MACROPHAGE PHAGOCYTIC RECEPTORS BY ANTI-MEMBRANE ANTIBODIES
Authors: Holland Phillip , Holland Nancy H , Cohn Zanvil A.
Published: June 2004

Rabbit antibodies were prepared against purified mouse macrophages, erythrocytes, and liver lysosomes. In the presence of complement each of these reagents was capable of lysing mouse erythrocytes and macrophages. In the absence of complement, all antisera agglutinated mouse erythrocytes and at high concentration produced a cytotoxic effect on macrophages. At IgG concentrations of 100 µg/ml, no morphological evidence of cytotoxicity was evident. These data suggest the presence of common antigens on the erythrocyte and macrophage plasma membrane.

Anti-macrophage, anti-erythrocyte, and anti-lysosomal γ-globulins and IgG, employed at subtoxic concentrations, all inhibited the attachment and ingestion of opsonized erythrocytes and mycoplasma. This occurred without significant reduction in the phagocytosis of polystyrene particles, formalinized erythrocytes, and yeast cell walls. Each of the anti-membrane IgG antibodies was capable of blocking the Fc receptor on the macrophage plasma membrane. Attachment to the macrophage membrane occurred by means of the Fab region. However, a role for the Fc portion of the molecule was suggested since pepsin-digested IgG was unable to block the receptor.

Each of the IgG antibodies produced a partial blockade of the complement receptor and reduced the ingestion of EAC1,4,2,3 by approximately 50%.
IMMUNE RESPONSES IN VITRO
Authors: Pierce Carl W. , Solliday Susan M. , Asofsky Richard
Published: June 2004

Suppression of Ig class-specific PFC responses by class-specific antibody to mouse immunoglobulin was studied in cultures of spleen cells from immunized mice. In contrast to cultures from normal mice where anti-µ suppressed responses in all Ig classes, anti-µ had progressively less suppressive effect on γ1 and γ2 responses in cultures from immunized mice with time after immunization. This was most pronounced at 10 days after immunization when anti-µ suppressed γM and γA responses, but had no or slight effect on γ1 or γ2 responses which were still suppressed with anti-γ1 and anti-γ2. These changes in precursor cell susceptibility to anti-µ were antigen specific.
THE IMMUNOLOGICALLY SPECIFIC RETENTION OF RECIRCULATING LONG-LIVED LYMPHOCYTES IN LYMPH NODES STIMULATED BY XENOGENEIC ERYTHROCYTES
Authors: Thursh Donald R. , Emeson Eugene E.
Published: June 2004

The lymph nodes of mice actively or adoptively immunized to sheep RBC and/or chicken RBC selectively retain long-lived lymphocytes after challenge with the appropriate antigen. This retention is demonstrable within 8 hr of the time of stimulation, though it probably begins even before this, and it is essentially complete within the first 24 hr. A similar selective retention is seen in nodes regional to the injection of some nonimmunogenic substances such as turpentine, but not others such as colloidal carbon or syngeneic RBC.

In animals adoptively immunized to sheep and chicken RBC simultaneously, there is a preferential accumulation of the labeled long-lived lymphocytes of donors immunized to sheep RBC in lymph nodes challenged with sheep RBC, and a preferential accumulation of lymphocytes (labeled with a different radioisotope) from donors immunized to chicken RBC in lymph nodes challenged with this antigen. This immunologically specific component is demonstrable whether the antigen is given before or after adoptive immunization, suggesting that the only labeled cells capable of specific localization in this system are those cells that normally remain in the recirculating pool. In the present experiments, 31 out of 31 sets of antigenically stimulated lymph nodes have shown radiochemical evidence of immunological specificity in the distribution of donor lymphocytes between them, while corresponding sets of nonstimulated lymph nodes have shown only small random variations in the distribution of donor cells. Two different mechanisms are postulated whereby antigenic stimulation can alter the traffic of recirculating long-lived lymphocytes through stimulated lymph nodes. One affects recirculating cells of a particular immunological specificity, while the other affects recirculating cells without regard to their immunological specificity.
SYNERGY AMONG LYMPHOID CELLS MEDIATING THE GRAFT-VERSUS-HOST RESPONSE
Authors: Cantor Harvey , Asofsky Richard
Published: June 2004

Two types of thymus-derived (T) lymphocytes have been shown to cooperate in the induction of graft-versus-host responses. One cell type is found in highest concentrations in the peripheral blood and lymph node, is extremely sensitive to anti-thymocyte serum (ATS) in vivo, and is probably part of the recirculating lymphoid cell pool (3). The second cell type, found in highest concentrations in the thymus and spleen, is relatively resistant to small doses of ATS in vivo. Both cell types are substantially depleted after neonatal thymectomy.

Moreover, since synergism was also obtained using appropriate mixtures of cells from either parental strain in F1 hosts, it was possible to show that the nonrecirculating cells determined the specificity of the response and were probably the precursors of effector cells in this response. The recirculating T cell appeared to amplify this response. The implications of these data are discussed.
MATERNALLY INDUCED TRANSPLANTATION IMMUNITY, TOLERANCE, AND RUNT DISEASE IN RATS
Authors: Beer Alan E. , Billingham R. E. , Yang S. L.
Published: June 2004

A previous report that the offspring of outbred Sprague-Dawley rats, born of mothers presensitized or tolerant with respect to tissue antigens of the Lewis strain, and reinoculated with Lewis cells during their pregnancy, reject test grafts of Lewis skin in an accelerated manner has been confirmed. This "maternally induced" alteration in reactivity of the progeny has been found to be long lasting, immunologically specific, and probably not due to transfer of humoral antibody. It has been established that the reexposure of the mothers to donor cellular antigen during pregnancy augmented the influence of the prior states of tolerance or sensitivity.

To obviate the complications inherent in working with the outbred Sprague-Dawley rats, the key experiments summarized above were repeated with isogenic Fischer rats as parents and Lewis rats as the tissue donors as before. With this combination it was found that a state of prior sensitization or tolerance in the mothers resulted in the apparent induction of tolerance in some of their progeny. Reinoculation of either the tolerant or sensitized mothers during pregnancy slightly increased the incidence and degree of impairment of their offsprings' capacity to reject Lewis skin grafts. A single intraperitoneal injection of 100 x 106 million Lewis lymphoid cells into normal Fischer rats in the 14th–16th day of pregnancy also weakened the reactivity of their progeny to Lewis test grafts.

Further to test the premise that this weakened reactivity might be due to maternal induction of tolerance, by antenatal transmission of alien cells, the lymphohematopoietic tissue system of adult Fischer females was replaced by that from Lewis donors with the aid of cyclophosphamide. It was anticipated that when these animals were mated with Fischer males, sufficient Lewis leukocytes might cross the placentas to induce high degrees of tolerance. Although normal sized healthy litters were born, about 50% of the infants succumbed to graft-versus-host (GVH) or runt disease within 40 days, many of them giving evidence of being tolerant of Lewis grafts. The mothers, too, developed chronic GVH disease. The offspring of Fischer females made chimeric with cells from (Fischer x Lewis)F1 hybrid donors, as well as their mothers, remained healthy.

Intraperitoneal injection of normal Fischer females, in the 15th–17th day of pregnancy, with 100 million lymphoid cells from specifically sensitized Lewis rats, also caused fatal runt disease to develop in about 50% of their offspring, but left the mothers unscathed.

Taken together, these various findings indicate that in some genetic contexts at least the extent of the natural surreptitious transplacental cellular traffic can be considerably augmented experimentally, though how this comes about and why lymphocytic cells that are foreign to the mother can apparently gain access to fetuses more readily than her own cells remain to be determined.
RAPID BREAKING OF TOLERANCE AGAINST ESCHERICHIA COLI LIPOPOLYSACCHARIDE IN VIVO AND IN VITRO
Authors: Sjöberg Olof
Published: June 2004

The breaking of tolerance against the lipopolysaccharide from E. coli 055:B5 was studied. It was found that immune responsiveness recovered very slowly in vivo, tolerance still existing 3 wk after the last tolerizing injection. However, if spleen cells from tolerant mice were transferred into irradiated syngeneic recipients, the tolerant state was readily broken. Spleen cells transferred 3 days after the last tolerance-maintaining dose did not respond, whereas cells transferred on day 5 or 7 responded equally well as normal spleen cells. It was also possible to break tolerance by incubating tolerant spleen cells, which did not respond after transfer, for 20 hr in vitro before transfer into irradiated recipients. The results suggest that there exist reversibly inactivated cells in tolerant animals and that these cells can be reactivated upon removal of the cells to a neutral environment.
A QUANTITATIVE ASSAY FOR THE PROGENITORS OF BONE MARROW-ASSOCIATED LYMPHOCYTES
Authors: Lafleur Louis , Miller R. G. , Phillips R. A.
Published: June 2004

A cell transfer assay system was developed to study the precursors of bone marrow-associated (B) lymphocytes in the adult mouse. The rationale of the assay is to inject into irradiated mice a cell suspension depleted of B lymphocytes, to wait a period of time to let precursor cells differentiate to B lymphocytes, then to correlate the number of B cells present in the recipient mice with the number of precursor cells injected. The assay as described was shown to be linear in the range of 105–3 x 106 fractionated bone marrow cells. Kinetic studies indicated that precursor cells start producing detectable numbers of B cells within 3 days after transplantation; B cell activity then increases with a doubling time of 24 hr. Physical characterization of that precursor cell has shown that it is lighter and sediments faster than small lymphocytes. Precursor cells were found in bone marrow and spleen but could not be detected in peripheral lymph nodes. Results of physical analysis also indicate that the precursors of B lymphocytes described here may not be pluripotent stem cells for the immune system.
GENETIC FACTORS INFLUENCING C-TYPE RNA VIRUS INDUCTION
Authors: Stephenson John R. , Aaronson Stuart A.
Published: June 2004

Genetic factors were studied which affect the inducibility of C-type RNA viruses from embyro cultures of mouse strains with high and low incidence of spontaneous leukemia. Virus was inducible by chemical treatment from secondary embryo cultures of several inbred strains. Both virus inducibility and the capacity of the virus to persist in cells from which it was activated were found to be inherited as dominant genetic characteristics. The results show that the factors controlling virus activation and persistence in culture also play an important role in spontaneous virus expression in the animal.
DEVELOPMENT OF CHICKEN LYMPHOID SYSTEM
Authors: Choi Yong Sung , Good Robert A.
Published: June 2004

Development of Ig-synthesizing cells in the bursa of chick embryo was studied by immunohistochemical staining method as well as by in vitro incorporation of leucine-3H into Ig. Ig-synthesizing cells are first detected in the bursa of a 14 day old chick embryo and increase with the maturation of the embryo. Acrylamide gel analysis of leucine-3H-labeled Ig shows that synthesis of nonsecretory IgM-H0 precedes that of secretory IgM-H, reflecting an ontogenetic sequence of development of lymphoid cells synthesizing IgM.

Since IgM-H0 is not secreted, we further studied biochemical differences between two heavy chains. The difference is attributable to lack of galactose attachment to H0 chains. It is proposed that during differentiation of lymphoid cells synthesizing and secreting Ig, attachment of galactose may play an obligatory role in the development of cellular capacity for Ig secretion.
CELL SURFACE IMMUNOGLOBULIN
Authors: Vitetta Ellen S. , Bianco Celso , Nussenzweig Victor , Uhr Jonathan W.
Published: June 2004

Thymocytes, bone marrow cells, and their derived T and B cell populations were examined for the presence of Ig by the cell surface radioiodination technique. Both IgM and IgG were identified on bone marrow cells. Thymocytes and T cells had no detectable cell surface Ig. Radiolabeling of mixtures of B cells and thymocytes suggest that the method may detect as little as 250 molecules of Ig per cell. Based on these findings, we suggest that the T cell receptor for antigen is not a conventional tetrameric Ig.
IMMUNE AND NATURAL ANTIBODIES TO SYNGENEIC MURINE PLASMA CELL TUMORS
Authors: Herberman Ronald B. , Aoki Tadao
Published: June 2004

Cytotoxic antibody to a plasma cell tumor antigen was produced in syngeneic BALB mice by immunization with viable or inactivated plasma cell tumors. Antibody with the same specificity was found in the sera of normal BALB and other strains of mice. This natural antibody reacted with an antigen with characteristics indistinguishable from the previously described alloantigen, PC.1, and with viral envelope antigen, χVEA. The incidence of cytotoxic reactivity and the antibody titers reached a peak in normal BALB mice at 3–4 months of age, and were lower in 9–12-month old mice. The sera of germfree mice had lower reactivity; but when the mice were transferred to conventional conditions, their sera soon became as active as those of conventional mice.

A virus common to all plasma cell tumors, which is present in latent form in some normal tissues of BALB and other PC.1 positive strains, is suggested as the cause for the PC.1 antigen and for the appearance of natural antibody to it. The considerable evidence for the close association of a virus with plasma cell tumors is presented.
PROTEIN TRANSPORT IN MOUSE KIDNEY UTILIZING TYROSINASE AS AN ULTRASTRUCTURAL TRACER
Authors: Oliver Constance , Essner Edward
Published: June 2004

The morphological basis of glomerular filtration and protein reabsorption in mouse kidney was examined by using mushroom tyrosinase subunits (mol wt 34,500), as an ultrastructural tracer. Almost immediately after injection tyrosinase reaction product was visualized in the glomerulus, and within the capillary lumen extending into the endothelial fenestrae. The entire basement membrane showed accumulations of tyrosinase in the subendothelial and subepithelial layers. The urinary space contained considerable amounts of reaction product, some of which was adsorbed to the cell coat of the podocytes. Reaction product could also be seen in the brush border region of the proximal tubule cells. By 30 min after injection, no tyrosinase reaction product was demonstrable in the glomerulus except for dense vesicles in mesangial cells. Most of the reaction product was localized in absorption droplets in the apical cytoplasm of proximal tubule cells. Occasionally, some tyrosinase reaction product was present within the basal infoldings of these cells. The behavior of tyrosinase in the mouse kidney is in accordance with that of other low molecular weight tracers. The pattern of localization within the basement membrane provides additional support for the presence of two filtration barriers in the glomerulus. The adherence of tyrosinase to the cell coat of the glomerular epithelial cells suggests that this may be an additional mechanism whereby protein is removed from the glomerular filtrate. Tyrosinase subunits may prove to be a useful new tracer for the study of protein transport.
THE EFFECTS OF MERCAPTOETHANOL AND OF PERITONEAL MACROPHAGES ON THE ANTIBODY-FORMING CAPACITY OF NONADHERENT MOUSE SPLEEN CELLS IN VITRO
Authors: Chen Chang , Hirsch James G.
Published: June 2004

Nonadherent mouse spleen cells exhibited poor viability and little or no capacity to form antibodies to sheep red cells in the Mishell-Dutton culture system. Viability and antibody-forming capacity could be restored by addition to these cultures of low concentrations of mercaptoethanol (10–4–10–5 M), or by addition of appropriate numbers of mouse peritoneal macrophages. Macrophage concentrations lower than optimal resulted in lower lymphoid cell viability and correspondingly fewer plaque-forming cells, whereas excess macrophages resulted in marked inhibition of antibody formation despite good viability of the lymphocytes. Restoration of the nonadherent cells with mercaptoethanol was thus much simpler and more reproducible than it was with macrophages; furthermore, the number of plaque-forming cells developed in cultures restored with mercaptoethanol was approximately fourfold higher than it was in cultures restored with optimal numbers of macrophages.

In the presence of mercaptoethanol, the plaque-forming capacity of the nonadherent spleen cells was not increased when small numbers of macrophages were added to the system, nor was it decreased when the few macrophages present in the nonadherent cells were further reduced or eliminated. Excess macrophages inhibited antibody formation in the cultures containing mercaptoethanol as they did in control cultures.

Optimal restoration of plaque-forming capacity to the nonadherent spleen cells with mercaptoethanol required the reducing agent to be present throughout the 4 or 5 day culture period. Addition of mercaptoethanol 1 or more days after initiation of culture, or transfer of the cells to a medium free of mercaptoethanol before completion of the culture resulted in a reduction in the numbers of plaque-forming cells.

The results suggest that mouse lymphoid cells do not require macrophages in order to form antibodies to sheep red cells in vitro, provided mercaptoethanol is present in the culture medium. The mechanism of action of mercaptoethanol under these conditions is not completely clear, but one of its effects is to promote the viability of lymphoid cells in the cultures.
A CLASSIFICATION OF THE MURINE LEUKEMIA VIRUSES
Authors: Eckner Robert J. , Steeves Richard A.
Published: June 2004

Coinfection of neonatal BALB/c mice with helper-dependent Friend spleen focus-forming virus (SFFV), as contained in the Friend virus (FV) complex, and antigenically distinct Moloney leukemia virus (MolLV) resulted in the recovery of a MolLV pseudotype of SFFV, abbreviated SFFV(MolLV). The antigenic alteration of SFFV was observed by following its neutralization kinetics in vitro by specific Friend or Moloney typing antiserum.

Effective pseudotype production was accomplished only when N-tropic LLV-F (the natural helper virus in the FV complex) was inhibited in B-type mice coinfected with an NB-tropic MolLV or other murine leukemia virus (MuLV) preparation. SFFV pseudotypes could not be prepared by using murine viruses other than leukemia viruses. SFFV prepared after two serial passages in the presence of MolLV was effectively neutralized by Moloney antiserum, but not by Friend typing antiserum; therefore, the envelope of the pseudotype virus, SFFV(MolLV), is homogeneous. Pseudotype virus was antigenically stable in the absence of continued mixed infection of BALB/c mice with SFFV(MolLV) and MolLV. However, SFFV(MolLV) was easily converted back to the LLV-F type after only one passage in BALB/c mice coinfected with NB-tropic LLV-F. The antigenic interconversion between LLV-F and MolLV types demonstrated that SFFV is defective with respect to the expression of neutralizable envelope antigens.

Analysis of the neutralizable envelope antigens of nine SFFV(MuLV) pseudotypes by a panel of seven typing antisera made possible a "type-specific" SFFV(MuLV) envelope classification. Two major categories have been identified which correspond to the Gross (G) and Friend-Moloney-Rauscher (FMR) subgroups. Further, the FMR subgroup was divided into four types on the basis of distinct neutralization patterns. These results indicated that the specificity observed by cytotoxic G vs. FMR antisera is different from that observed by neutralization kinetics. We therefore suggest that the specific antigens revealed by virus neutralization tests be referred to as type specific.
THYMUS-INDEPENDENT (B) CELL PROLIFERATION IN SPLEEN CELL CULTURES OF MOUSE RADIATION CHIMERAS STIMULATED BY PHYTOHEMAGGLUTININ OR ALLOGENEIC CELLS
Authors: Piguet P.-F. , Vassalli P.
Published: June 2004

Spleen cell cultures of radiation chimeras (thymectomized, lethally irradiated mice repopulated with bone marrow cells and thymocytes bearing different chromosomal markers) were stimulated by phytohemagglutinin (PHA) and F1 allogeneic spleen cells. Karyotypic analyses showed a marked predominance of T mitoses on the 2nd and 3rd days of culture followed by a strong predominance of B mitoses on the 4th and 5th days. Analysis of cells undergoing their first mitoses showed that the majority of T mitoses on day 3 resulted from continuous T cell division, and that most cells entering their first mitoses at that time were of B type. Mixed lymphocyte cultures (MLC) of chimeras immunized against allogeneic spleen cells showed sometimes, but not always, a response different from "primary" MLC, with an earlier and stronger predominance of BM mitoses. The role of stimulated T cells in the induction of B mitoses was shown by (a) the incapacity of T-depleted spleen cells to be stimulated by PHA or in primary or secondary MLC, and (b) the restoration of the mitotic response of B cells to PHA by adding to the T cell-depleted culture either a very small number of T cell (identified by their different karyotype: "in vitro chimeras") or the cell-free supernatant of a 24 hr MLC.
LYSOSOMES OF THE ARTERIAL WALL
Authors: Peters T. J. , Müller M. , de Duve Amo C.
Published: June 2004

Smooth muscle cells were dissociated from normal rabbit aorta by incubating the tissue in Hanks' solution containing elastase, collagenase, and hyaluronidase. The isolated cells contained significant amounts of the following acid hydrolases: N-acetyl-ß-glucosaminidase, N-acetyl-ß-galactosaminidase, ß-galactosidase, ß-glucuronidase, α-mannosidase, ß-glucosidase, acid phosphatase, and cathepsins C and D. The cells were disrupted and fractionated by isopycnic centrifugation on sucrose density gradients in the Beaufay automatic zonal rotor.

Lysosomes with a modal density of 1.16 were identified by the distribution of these acid hydrolases and by the latency of N-acetyl-ß-glucosaminidase and ß-galactosidase. Other particulate enzymes studied in these sucrose gradients included cytochrome oxidase and monoamine oxidase (mitochondria), 5'-nucleotidase and leucyl-ß-naphthylamidase (plasma membrane), and catalase (? peroxisome).

This microanalytical subcellular fractionation technique is applicable to the study of milligram quantities of many other tissues, both normal and pathological.
THE INTERACTION BETWEEN TOXOPLASMA GONDII AND MAMMALIAN CELLS
Authors: Jones Thomas C. , Yeh Shirley , Hirsch James G.
Published: June 2004

Macrophage, fibroblast, and HeLa cell cultures have been infected with Toxoplasma gondii, and observations have been made on parasite entry and fate.

A special procedure was devised for studying the entry of toxoplasmas by electron microscopy. Toxoplasmas were centrifuged onto the cells in the cold; fixation 1–3 min after warming yielded specimens showing numerous examples of parasites in the process of entering cells. The mechanism of entry into macrophages, fibroblasts, and HeLa cells was in all cases by phagocytosis. Micropseudopods were extended by the cells to envelop the attached parasites in a typical phagocytic vacuole. Apparently the toxoplasmas stimulated this response of HeLa cells and fibroblasts, cell types not usually phagocytic. No instance was seen of penetration of toxoplasmas through the cell membrane, or of parasites located free in the cytoplasm.

Essentially all of the toxoplasmas that entered HeLa cells divided with a generation time of 9 hr; the parasites formed large rosettes situated in vacuoles, eventually leading to host cell rupture. Macrophages took in larger numbers of toxoplasmas than did HeLa cells, but approximately half of the parasites inside of macrophages degenerated within a few hours. The surviving toxoplasmas in macrophages divided every 8 hr, forming rosettes and eventually rupturing the cells.
STUDIES OF GENETIC TRANSMISSION OF MURINE LEUKEMIA VIRUS BY AKR MICE
Authors: Rowe Wallace P. , Hartley Janet W.
Published: June 2004

The transmission of murine leukemia virus (MLV) to hybrids between AKR and Fv-1b mice was studied in order to evaluate the effect of the Fv-1 gene on endogenous MLV infection and to attempt to determine if the genetic loci contributed by AKR carry viral genetic determinants. Fv-1 was shown to have a marked suppressive effect on time of appearance of detectable infectious virus and on the titers attained in vivo, but did not affect the ability of the cells to produce virus in vitro after induction with 5-iododeoxyuridine.

The host range type of the virus detected in the hybrid mice was almost always of the type carried by AKR, although the low-virus Fv-1b parents carry the genome of a different host range type. This finding provides strong, but not conclusive, evidence that the virus-inducing loci of AKR contain MLV genetic determinants.
INHIBITORY AND STIMULATORY EFFECTS OF CONCANAVALIN A ON THE RESPONSE OF MOUSE SPLEEN CELL SUSPENSIONS TO ANTIGEN
Authors: Dutton Richard W.
Published: June 2004

The presence of concanavalin A (Con A) inhibits the immune response of mouse spleen cell suspensions to erythrocyte antigens, stimulates the incorporation of tritiated thymidine, and increases cell recovery. Con A also restores the depressed response of cell preparations treated to remove thymus-derived cells. The dose-response curve for all four effects shows peak activity at 2 µg/ml. The depressed in vitro response of spleen cell suspensions from adult thymectomized, irradiated, bone marrow-restored mice is also restored by Con A. Here the dose-response curve is quite different with activity over a much wider range of concentration. The restoration of thymus-derived cell-depleted cultures by Con A is inhibited by the addition of untreated, unirradiated, mouse spleen cell suspensions, but is not inhibited by untreated, irradiated cells.

Small numbers of spleen cells that have been preincubated with Con A and washed will inhibit the response of fresh, untreated cells to antigen. If the mouse spleen cell suspensions are incubated for 24 hr before the addition of Con A, the response to antigen is no longer inhibited but is stimulated instead.

The data are compatible with the hypothesis that there are at least two cell targets for the action of Con A. One cell, that mediates the inhibitor effect, is a short-lived, radiosensitive, thymus-derived cell. The other cell, that mediates the stimulating effect, cannot be identified from the data presented here but may also be of thymus origin on the basis of studies by other investigators.
AN ENZYMATIC FUNCTION ASSOCIATED WITH TRANSFORMATION OF FIBROBLASTS BY ONCOGENIC VIRUSES
Authors: Ossowski L. , Unkeless J. C. , Tobia A. , Quigley J. P. , Rifkin D. B. , Reich E.
Published: June 2004

Chick, hamster, mouse, and rat embryo fibroblast cultures, transformed by either DNA or RNA viruses, show fibrinolytic activity under suitable conditions of growth and in appropriate media; normal counterpart cultures do not. The fibrinolysin is produced by the interaction of two protein factors: one of these, a cell factor, is released by transformed cells and accumulates in the medium when cultures are incubated in the absence of scrum. The second factor, the serum factor, is a specific protein that is present in sera of many avian and mammalian species, including man.

Not all sera yield fibrinolysin on interaction with any given transformed cell factor, and the spectrum of activating sera is distinctive for each cell factor. This pattern appears to be determined by the cell type, rather than by the transforming virus.

An important role for the fibrinolysin in oncogenic transformation is suggested by the following correlations. (a) The initial appearance of fibrinolysin precedes the morphological change after the transfer to permissive temperatures of chick fibroblast cultures infected with a temperature-sensitive mutant of RSV. (b) The initiation of fibrinolysis and of morphological change both require the synthesis of new protein, but not the synthesis of either DNA or rRNA. (c) The activity of the fibrinolysin is correlated with the retention of abnormal morphology in hamster cells transformed by SV-40. (d) The sera of normal chicks effectively activate fibrinolysis with the cell factor from transformed chick cells. In contrast the sera of chicks with RSV tumors do not; these contain an inhibitor of the fibrinolytic activity.
INTERACTION OF HISTOCOMPATIBILITY (HL-A) ANTIBODIES AND COMPLEMENT WITH SYNCHRONIZED HUMAN LYMPHOID CELLS IN CONTINUOUS CULTURE
Authors: Ferrone S. , Cooper N. R. , Pellegrino M. A. , Reisfeld R. A.
Published: June 2004

The interaction of histocompatibility (HL-A) antibodies and complement with synchronized human lymphoid cells in continuous culture has been investigated. The sensitivity of cultured lymphoid cells to HL-A antibody-mediated lysis in the cytotoxic test, the extent of activation of the complement system, the degree to which labeled complement components are bound, and the ability of these cells to absorb HL-A alloantibodies do not vary significantly during the cell growth cycle. The constancy of histocompatibility antigen expression throughout the growth cycle of cultured cells suggests that these cell surface markers are an essential part of membrane cytoarchitecture and could well play a critical role in determining the normal function of the cell membrane.
DELETION OF b5 IMMUNOGLOBULIN-BEARING LYMPHOCYTES IN ALLOTYPE-SUPPRESSED RABBITS
Authors: Harrison Michael R. , Mage Rose G. , Davie Joseph M.
Published: June 2004

The proportion of peripheral blood lymphocytes with cell surface b5 immunoglobulin (Ig) was compared with serum b5 Ig levels in allotype-suppressed and recovering b5 homozygous rabbits in order to establish the cellular defect in suppression and to determine the relation between lymphocyte membrane Ig and secreted Ig of the same allotype.

In rabbits fully suppressed for b5, the absence of circulating b5 Ig is reflected in a complete deletion of b5-bearing lymphocytes. During spontaneous escape from suppression, the appearance of b5-bearing lymphocytes precedes the appearance of detectable serum b5. During recovery from suppression b5-bearing lymphocytes recover rapidly toward normal levels, but circulating b5 levels remain chronically and disproportionately depressed.
IMMUNOLOGIC REACTIONS TO HAPTENS ON AUTOLOGOUS CARRIERS
Authors: Moorhead John W. , Walters Curla S. , Claman Henry N.
Published: June 2004

Both thymus-derived (T) and bone marrow-derived (B) lymphocytes participate in the response to a hapten 4-hydroxy-3-iodo-5-nitrophenylacetic acid (NIP), coupled to a nonimmunogenic isologous carrier, mouse gamma globulin (MGG). Spleen cells from mice immunized with NIP-MGG show increased DNA synthesis in vitro when cultured with NIP-MGG. The participation of and requirement for T cells in the response was demonstrated by treating the spleen cells with anti-θ serum. This treatment resulted in a 77% inhibition of the antigen response. Furthermore, adoptively transferred normal thymus cells could be specifically "activated" by NIP-MGG in vivo and they responded secondarily to the antigen in vitro.

The active participation of B cells in the secondary response was demonstrated by passing the immune spleen cells through a column coated with polyvalent anti-MGG serum. Column filtration reduced the number of NIP-specific plaque-forming cells and NIP-specific rosette-forming cells (both functions of B cells) and produced a 47% inhibition of the NIP-MGG response. The ability of the cells to respond to phytohemagglutinin (PHA) was not affected by column filtration showing that T cells were not being selectively removed. The participation of B cells in the in vitro NIP-MGG response was also shown by treatment of the spleen cells with antiserum specific for MGG and MGG determinants. B cells were removed by treatment with anti-IgM or polyvalent anti-MGG serum plus complement, resulting in a respective 46 and 49% inhibition of the response to NIP-MGG. (Treatment with anti-IgM serum had no effect on T cells.)

The contribution of the hapten NIP to stimulation of T cells was investigated using NIP-MGG-activated thymus cells. These activated T cells responded in vitro very well to the NIP-MGG complex but not to the MGG carrier alone demonstrating the requirement of the hapten for T cell stimulation. The response was also partially inhibited (41%) by incubating the activated cells with NIP coupled to a single amino acid (epsilon-aminocaproic acid) before addition of NIP-MGG. These results demonstrated that T cells recognize the hapten NIP when it is coupled to the isologous carrier MGG.
DIFFERENTIATION OF THYMUS-DERIVED CELLS FROM PRECURSORS IN MOUSE BONE MARROW
Authors: El-Arini M. O. , Osoba D.
Published: June 2004

An experimental model system was developed to study the differentiation of thymus-derived (T) cells from progenitors in bone marrow. In this system transplantation of bone marrow cells depleted of T cells gave rise to T cells in the spleens of irradiated recipients within 15 days of transplantation. Thus, normal bone marrow contains a class of cells that are progeniotrs of T cells (PT cells). PT cells are different from T cells since PT cells are incapable of responding to alloantigen, are θ resistant, and band in a lighter density region than do T cells. The density profile of PT cells is different from that of hematopoietic stem cells (CFU-S); PT cells band in a denser region of the gradient than do CFU-S.
TUMOR INDUCTION BY IMMUNOLOGICALLY ACTIVATED MURINE LEUKEMIA VIRUS
Authors: Armstrong Martine Y. K. , Ruddle Nancy H. , Lipman Muriel B. , Richards Frank F.
Published: June 2004

A graft-vs.-host reaction (GVHR) was induced in young male CAFI and CB6F1 mice by the administration of BALB/cJ spleen cells. A proportion of such mice subsequently developed lymphoreticular rumors. Cell-free extracts (CFEs) prepared from the reticular tissues of CAF1 mice killed at intervals after the induction of the GVHR were tested for their capacity to produce the same tumors in a litter of syngeneic mice inoculated at birth. 12 of 29 (41.4%) such extracts were positive, causing lymphoreticular tumors in one or more littermate recipients. The positive CFEs came from donors killed at all stages of the GVHR, from tumor-bearing mice as well as from non-tumor-bearing mice. However, whereas less than 30% of CFEs from mice killed within 12 mo of GVHR induction were oncogenic, the incidence of oncogenic extracts from mice killed 12–15 mo after GVHR induction rose to 75%. None of the CFEs prepared from nine normal uninjected male CAF1 mice killed between the ages of 8 and 18 mo transmitted tumors to recipients. CFEs prepared from CAF1 mice with the GVHR were tested for infectious murine leukemia virus (MuLV) using the XC assay and also for complement-fixing (CF) group-specific MuLV antigen. Substantial titers of B-tropic MuLV and CF antigen were detected in at least half the extracts from mice killed 11–14 mo after GVHR induction. During the first few months of GVHR induction, MuLV titers were low and CF antigen was absent. Neither infectious MuLV nor CF antigen were detected in CFEs prepared from normal control mice. Serially passed CFEs originating from a CB6F1 GVHR-induced RCN caused similar tumors in successive generations of syngeneic recipient mice. These lymphoreticular tumors were shown to contain infectious MuLV, CF MuLV antigen, and C-type particles. These data together provide evidence that MuLV is activated during the GVHR and that it is responsible for the eventual development of lymphoreticular tumors.
HISTOCOMPATIBILITY-LINKED GENETIC CONTROL OF DISEASE SUSCEPTIBILITY
Authors: Oldstone Michael B. A. , Dixon Frank J. , Mitchell Graham F. , McDevitt Hugh O.
Published: June 2004

Acute necrotizing inflammatory disease after intracerebral injection of LCM virus is largely dependent on the host immune response to the virus and is controlled, in part, by a dominant gene which is closely linked to the H-2 locus. The F1 hybrid (H-2q/k) from mating a susceptible SWR/J mouse (H-2q/q) to a resistant C3H/HeJ mouse (H-2k/k) is susceptible to LCM virus disease. When such hybrids (H-2q/k) are backcrossed to susceptible parents (H-2q/q), all F2 offspring (H-2q/q, H-2q/k) are highly susceptible. In contrast, hybrid (H-2q/k) backcross to resistant parents (H-2k/k) results in half of the F2 offspring being susceptible (H-2q/k) while the other half are resistant (H-2k/k). Similarly, in congenic H-2q/q and H-2k/k mice, H-2q/q mice are relatively susceptible to acute LCM disease, whereas H-2k/k are resistant.
GRAFT-VERSUS-HOST REACTION ACROSS DIFFERENT REGIONS OF THE H-2 COMPLEX OF THE MOUSE
Authors: Klein Jan , Park Jong M.
Published: June 2004

H-2 crossovers and their parental strains were arranged into 35 combinations in which the adult donor of spleen cells differed from the newborn recipient in the whole H-2 complex, or in three, two, or one region of the complex. A Simonsen splenomegaly assay was then used to test the contribution of the individual H-2 regions to the graft-versus-host reaction (GVHR).

It was shown that the strongest GVHR was associated with the Ir region. Differences in the Ir region caused significant splenomegaly in spite of the fact that no antigens detectable by conventional serological methods have thus far been associated with this region. Differences in the K and D regions showed only a borderline effect on GVHR in spite of the fact that these regions code for most, if not all, of the antigens detectable by conventional serological and transplantation methods. The K region alone caused no stronger GVHR than the D legion alone; however, K + Ir region differences led to much stronger GVHR than D region differences. The Ss-Slp region also showed only a borderline effect on GVHR. Differences in two or more H-2 regions usually caused greater splenomegaly than differences in each of the regions separately.

On the basis of these findings it is concluded that the strongest GVHR is caused by genes distinct from the known histocompatibility genes of the H-2 complex. It is speculated that the GVHR genes are identical with the mixed lymphocyte reaction (MLR) and Ir genes and that the product of these genes are receptors on the surface of the thymus-derived lymphocytes (T cells).
THE INFLUENCE OF THE PARTNER CELL ON THE PRODUCTION OF L VIRUS AND THE EXPRESSION OF VIRAL SURFACE ANTIGEN IN HYBRID CELLS
Authors: Fenyö Eva Maria , Grundner Gertrud , Wiener Francis , Klein Eva , Klein George , Harris Henry
Published: June 2004

The C-type particles produced by the A9 and A9HT sublines of mouse L cells were shown to infect C3H (N type), but not C57BL (B type), mouse embryo fibroblasts. Infection was indicated by distinct single giant cell formation in the XC monolayer used to overlay the mouse embryo fibroblasts. On the basis of these results it was concluded that the L cell virus is N tropic.

A9 and A9HT cells were fused to various mouse cells derived from tumors and normal tissues. The ability to produce the Moloney-type surface antigen and to release infectious virus was introduced by the A9 component into the hybrid cell. Virus production, measured by antigen induction on JLS-V9 cells, was suppressed in those hybrids in which the partner cell had a genotype determining low infectibility with that particular virus (B-type cell). It thus appears that the major genetic locus affecting resistance to infection with leukemia viruses, the Fv-1 locus, regulates infectious virus production in somatic cell hybrids also. The same genetic locus did not seem to govern the expression of all virus-related functions, for the virus-determined membrane antigen was demonstrated in many of the N x B-type hybrids in which production of infectious virus was suppressed.
MECHANISM OF GRAFT-VERSUS-HOST-INDUCED LYMPHADENOPATHY IN MICE
Authors: Emeson Eugene E. , Thursh Donald R.
Published: June 2004

Graft-vs.-host (GVH)-induced lymphadenopathy of the popliteal lymph node has been produced in C57BL/6 x A/J F1 (BAF1) mice by injecting A/J spleen cells into the rear footpads. By giving 51Cr-labeled BAF1 lymphoid cells intravenously to the hosts, 24 h before sacrifice, we have demonstrated that a large portion of the GVH-induced lymphadenopathy is due to the trapping of circuating lymphocytes in the challenged lymph nodes.

Most of the remaining enlargement can be attributed to proliferation of host cells within the reacting lymph nodes. Conditions have been defined under which the weights and [14C]thymidine incorporation of the popliteal nodes can be plotted against the dose of injected A/J spleen cells on a double-log scale to give a linear dose-response. The popliteal lymph node GVH assay is a simple and effective means of quantitating immune reactivity to histocompatibility antigens in mice.
PLATELET-DEPENDENT GENERATION OF CHEMOTACTIC ACTIVITY IN SERUM
Authors: Weksler Babette B. , Coupal C. Elaine
Published: June 2004

A protein fraction extracted from the lysosomal granules of human platelets generated chemotactic activity for polymorphonuclear leukocytes when incubated with fresh serum. The platelet factor was also released during platelet aggregation with collagen or epinephrine and appeared to be released during blood clotting. Heated serum did not support the platelet-dependent generation of chemotactic activity. Treatment of fresh serum with antibody to the fifth component of complement also prevented development of activity. Purified human C5 but not C3 yielded chemotactic activity upon incubation with the platelet factor. Thus, human platelets are capable of stimulating chemotaxis via complement activation in a manner similar to leukocytes, and may therefore participate in the early stages of inflammation.
PRODUCTION OF A RABBIT ANTIMOUSE EOSINOPHIL SERUM WITH NO CROSS-REACTIVITY TO NEUTROPHILS
Authors: Mahmoud Adel A. F. , Warren Kenneth S. , Boros Dov L.
Published: June 2004

Antieosinophil serum (AES), obtained by immunizing rabbits with a highly purified suspension of mouse eosinophils, contains high titers of specific agglutinating and cytotoxic antibodies to eosinophils. Absorption with macrophages, lymphocytes, and neutrophils does not affect the antieosinophilic activity while it is markedly lowered by absorption with eosinophils. One dose of AES (0.1 ml) injected into mice with schistosomiasis mansoni caused a mean decrease in circulating eosinophils of 90% within 1 h which was maintained for 5 days, followed by gradual recovery. No other changes in the total or differential white cell counts were noted. In normal mice AES markedly depressed exudation of eosinophils in the peritoneal cavity after repeated saline stimulation. Some of the immunological and clinical implications of a monospecific AES are discussed.
SHEEP RED CELL BINDING TO HUMAN LYMPHOCYTES TREATED WITH NEURAMINIDASE; ENHANCEMENT OF T CELL BINDING AND IDENTIFICATION OF A SUBPOPULATION OF B CELLS
Authors: Bentwich Z. , Douglas S. D. , Skutelsky E. , Kunkel H. G.
Published: June 2004

Neuraminidase treatment of normal human lymphocytes enhances their capacity to form SRBC rosettes; more red cells are bound and the rosettes are more stable. Under these conditions approximately 90% of peripheral blood lymphocytes form rosettes. In addition to the effects on T cells, another population of lymphocytes which possess surface immunoglobulin and have the Fc receptor acquire the rosette-forming property after neuraminidase. This subpopulation of ‘B’ cells represents approximately half of the lymphocytes with surface immunoglobulin but is not found among the leukemic lymphocytes of patients with chronic lymphocytic leukemia. Electron microscope observations indicate close approximation and intimate association of the red cell and lymphocyte membranes after neuraminidase.
EFFECT OF RECENT ANTIGEN PRIMING ON ADOPTIVE IMMUNE RESPONSES
Authors: Sprent J. , Miller J. F. A. P.
Published: June 2004

When spleen, mesenteric lymph node, or Peyer's patch cells from mice primed 24 h before with either sheep erythrocytes (SRC) or horse erythrocytes (HRC) were transferred together with both SRC and HRC to irradiated mice, antibody responses measured 7 days later were very low to the priming antigen but high to the other antigen. This was demonstrated either by measuring numbers of antibody-forming cells in spleen or levels of hemagglutinins in serum. Specific unresponsiveness of the transferred cells was evident in both the 19S and 7S responses. It was observed only when strict experimental conditions were followed: (a) the cell donors had to be primed with not less than 109 erythrocytes given intravenously; (b) the cells had to be transferred between 1 and 2 days after antigen priming; (c) antibody responses in the recipients were measured within 7 days of cell transfer, i.e., partial recovery was evident by 11 days; (d) the transferred cells had to be challenged in the recipients within 1 day after cell transfer: when challenge was delayed for 5 days or longer, responsiveness returned.

The failure of cells from recently primed donors to respond to the priming antigen on adoptive transfer could be overcome by supplementing with normal spleen cells, but not with thymus alone or bone marrow alone. This implied that unresponsiveness occurred at the levels of both T and B lymphocytes, and was not due to a suppressive influence exerted by T cells. Further work is in progress to determine the mechanism of this transient state of specific unresponsiveness.
IMMUNOGLOBULIN MOLECULES ON THE SURFACE OF ACTIVATED T LYMPHOCYTES IN THE RAT
Authors: Goldschneider Irving , Cogen Ronald B.
Published: June 2004

Lewis strain rat lymphocytes were exposed in vitro to a variety of specific and nonspecific blastogenic stimuli. The surfaces of the transformed lymphocytes were examined by indirect immunofluorescence for the presence of T cell antigens and immunoglobulin molecules.

More than 90% of lymphocytes that underwent blast transformation after exposure to foreign histocompatibility antigens (mixed lymphocyte reaction; in vitro allograft reaction), purified tuberculin, phytohemagglutinin (PHA), and concanavalin A (Con-A) had T cell antigenic markers on their surfaces. 70–92% of the antigen-stimulated blast cells also had readily detectable surface immunoglobulin molecules, whereas less than 3% of the PHA- and Con-A-activated cells were Ig+. Pokeweed mitogen (PWM) appeared to activate both B and T cells, but the T cells did not have detectable surface immunoglobulin molecules. Nonactivated control cultures contained T+Ig- lymphocytes almost exclusively.

The results suggest that thymus-dependent rat lymphocytes express increased amounts of detectable immunoglobulin on their surface in response to specific stimulation with antigen. It is postulated that the acquisition of immunological competence by activated T cells may be related to this expression of surface immunoglobulin.