bluuebunny/crossref_metadata_2025 huggingface dataset:
Proliferation and differentiation of hematopoietic stem cells in long-term cultures of adult hamster spleen.
Authors: Arnold E A , Katsnelson I , Hoffman G J
Published: June 2004

We have found that in liquid cultures of spleen cells of adult Syrian hamsters of the F1D strain, the hematopoietic microenvironment is adequate to sustain proliferation of splenic stem cells for periods of greater than 4 mo, and permits granulocytic, monocytic, and megakaryocytic differentiation without secondary repopulation or addition of exogenous growth factors to the basic medium of RPMI 1640 plus 20% horse serum. Intimate topographical relations are established between spleen stromal cells and hematopoietic cell components of the culture is adherent "cell-producing" islets. Some of these islets are associated with multiple hematopoietic cell types such as myeloid, monocytic, and megakaryocytic cells. Other islets are associated with a single cell type such as megakaryocytes, which suggests a limited potential of some adherent stromal cells to direct the differentiation of precursor cells. Cultures of this type provide a simple and convenient model for investigation of the mechanisms controlling differentiation of hematopoietic stem cells, not only for granulocytic and monocytic cells, but for megakaryocytic cells as well.
Characterization of the lymphocyte membrane receptor for factor H (β1H- globulin) with an antibody to anti-factor H idiotype
Authors: Lambris JD , Ross GD
Published: June 2004

Antibody to the binding site (idiotype) of anti-factor H was shown to have specificity for both B lymphocyte membrane H receptors and C3b. Goat F(ab')(2) anti-human H was purified by absorption and elution from H agarose and used for rabbit immunization to produce anti-anti-H (aaH). After absorption with nonimmune goat IgG, (125)I-labeled aaH bound to B lymphocytes and to sheep erythrocytes coated with C3b (EC3b) but did not bind to T lymphocytes or to EC3d. All B cell- and C3b-specific activities of the aaH were removed and subsequently recovered by absorption and elution of the antibody from either C3-agarose or goat-anti-H-agarose. This indicated that the aaH probably recognized a single common antigenic structure that was shared by anti-H, C3b, and the membranes of B cells. Affinity-purified aaH resembled H in that it bound to B cells, blocked the uptake of H onto B cell H receptors, and triggered B cells to release endogenous factor I (C3b inactivator). In addition, aaH functioned with factor I as either a cofactor for cleavage of fluid-phase C3b or a potentiator for cleavage of bound C3b. This same spectrum of C3 binding functions could not be demonstrated with either sheep anti-C3b or rabbit-anti-C3c. Analysis by sodium dodecyl sulfate- polyacrylamide get electrophoresis of the [(3)H]leucine intrinsically labeled B cell proteins reactive with the purified aaH revealed proteins of 100,000 M(r) and 50,000 M(r) without reduction, and after complete reduction of disulfide bonds, a single protein band of 50,000 M(r). This same protein molecular weight profile was also demonstrated with labeled B cell proteins that were absorbed and eluted from H-agarose. Thus, aaH is apparently specific for both B cell H receptors and C3b. However, because parallel analysis of C3b confirmed its known 115,000- and 75,000-M(r) polypeptide chain structure, the H receptor is probably not C3b and shares only the structure of the H binding site with C3b.
HLA-Dw2: a genetic marker for human immune response to short ragweed pollen allergen Ra5. II. Response after ragweed immunotherapy.
Authors: Marsh D G , Meyers D A , Freidhoff L R , Ehrlich-Kautzky E , Roebber M , Norman P S , Hsu S H , Bias W B
Published: June 2004

After artificial immunization (immunotherapy) with ragweed antigens, specific immunoglobulin G (IgG) antibody (Ab) response to Ra5 was significantly associated with HLA-Dw2 (P less than 0.0001). From a total of 61 treated patients, all 22 Dw2+ subjects made good IgG Ab responses to Ra5 by year 2 of therapy (21 by year 1), even though 8 of them had no detectable IgG Ab and 9 had no detectable IgE Ab before therapy. The prevalence of IgG Ab response among 39 Dw2- subjects was markedly lower; only 11 (28%) responded well after 1-9 yr of therapy. Both by univariate and multivariate statistical analysis, Dw2 was also found to be strongly associated with the quantity of IgG Ab produced. In particular, both the strength and significance of the association between Dw2 and log[IgG Ab] response to Ra5 increased over a 3-yr period of ragweed therapy (P = 10(-9) by year 3). Multiple regression analysis also revealed a weak association with HLA-B13, which became apparent only after year 2 of therapy. Genetic hypotheses for these findings are discussed. In particular, the possibility of a second Ir gene, Ir-Ra5', separate from HLA-Dw2 and possibly located elsewhere in the genome, is considered.
Chromosomal location of human kappa and lambda immunoglobulin light chain constant region genes
Authors: McBride OW , Heiter PA , Hollis GF , Swan D , Otey MC , Leder P
Published: June 2004

The chromosomal location of human constant region light chain immunoglobulin (Ig) genes has been determined by analyzing a group of human fibroblast/rodent somatic cell hybrids with nucleic acid probes prepared from cloned human kappa and lambda constant region genes. Human chromosomes in each cell line were identified by isoenzyme analysis. The DNA from hybrid cells was digested with restriction endonucleases, size fractionated by gel electrophoresis, transferred to nitrocellulose or DBM paper, and hybridized with (32)P-labeled nucleic acid probes. The C(κ) gene was assigned to human chromosome 2 and the C(λ) genes to chromosome 22, based upon analysis of these hybrid cell lines, and these assignments were confirmed by analysis of subclones. A group of previously unassigned loci can be mapped to chromosome 2 by virtue of their close linkage to C(κ). The λ and κ light chain and heavy chain Ig genes have now been assigned to all three human chromosomes that are involved in translocations with chromosome 8 in human B cell neoplasms. These techniques and probes provide a means to study the detailed arrangement of human Ig genes and their pseudogenes.
Novel differentiation antigens on late erythrocytic progenitor cells detected by alloantisera made between mouse strains congenic at the Fv-2 locus.
Authors: Vaithilingam D S , Axelrad A A
Published: June 2004

We have investigated the activities of alloantisera produced in B6 (C57BL/6) and B6.S strain mice reciprocally immunized with unwashed bone marrow and spleen cell suspensions from their respective Fv-2 congenic partner strains, B6.S and B6. These antisera inhibited the formation of colonies by the late erythrocytic progenitors (CFU-E) in plasma cultures seeded with unwashed bone marrow or spleen cells; washed cells were unaffected. Erythropoietic burst formation by the early progenitors (BFU-E) was not significantly inhibited by the antisera, whether the cells were washed or unwashed. We conclude (a) that the congenic antisera are capable of recognizing alloantigens controlled by alleles of Fv-2 or of a closely linked gene locus on chromosome 9; (b) that these alloantigens are situated on the surface of erythrocytic progenitor cells and can be removed by washing; and (c) that the expression of the alloantigens on these cells is influenced by their stage of differentiation.
Allosuppressor and allohelper T cells in acute and chronic graft-vs-host disease. I. Alloreactive suppressor cells rather than killer T cells appear to be the decisive effector cells in lethal graft-vs.-host disease.
Authors: Rolink A G , Radaszkiewicz T , Pals S T , van der Meer W G , Gleichmann E
Published: June 2004

Splenic T cells from B10 donors were injected into irradiated (B10 x DBA/2)F1 mice. Either 5 or 6 d later, activated donor T cells were recovered from the spleens of these primary F1 (1 degree F1) recipients and transferred to groups of nonirradiated syngeneic F1 (2 degrees F1) recipients. Whereas day-5-activated parental T cells induced the characteristic symptoms of acute graft-vs.-host disease (GVHD) and eventually lethal GVHD, day-6-activated B10 T cells failed to induce acute GVHD but induced symptoms of chronic GVHD. Interestingly, the inability of day-6-activated T cells to induce lethal GVHD could not be ascribed to a lack in anti-F1 T killer cells. The combined results of functional studies indicated that day-6 cells were enriched for alloreactive helper T cells, whereas day-5 cells were enriched for alloreactive suppressor cells. Hence, our findings indicate that acute GVHD and lethal GVHD are caused by alloreactive donor T suppressor but not T killer cells, and that symptoms of chronic GVHD are caused by alloreactive donor T helper cells.
Helper T cell recognition of the variable domains of a mouse myeloma protein (315). Effect of the major histocompatibility complex and domain conformation.
Authors: Jørgensen T , Hannestad K
Published: June 2004

We have examined the recognition of the variable (V) domain of the heavy (VH) and light (V lambda 2) chains of mouse myeloma protein 315 by helper T cells. Mice were primed with the isolated V domain in complete Freund's adjuvant, and carrier (V domain)-primed spleen cells were transferred together with hapten (NIP)-primed spleen cells to recipient mice that were boosted with NIP3-Fab-315. The helper cell response to both domains was governed by H-2-linked immune response (Ir) genes, and VH-315 and V lambda 2 displayed different Ir phenotypes. H-2k conferred high responsiveness to VH on three different genetic backgrounds, BALB/c, C3H, and B10; mice of the d and b haplotypes were low responders. Conversely, H-2d conferred high responsiveness to V lambda 2 on two backgrounds, BALB/c and C3H, whereas mice of the k haplotype were low responders to this domain. Non-H-2 genes of the B10 background extinguished the helper cell response to V lambda 2 in animals with the high responder d haplotype. The VH Ir gene mapped to the K-A interval of the H-2 complex. Unfolded (completely reduced and alkylated) V domains primed helper cells as efficiently as folded domains for responses to NIP3-Fab-315, indicating that the helper cells recognized an antigenic determinant that was not conformation-dependent. The data indicate that there exists helper T cells which recognize each member of the M315 pair of V domains independent of the other, and that these V domains are recognized like conventional extrinsic protein antigens.
Interferon inhibits the generation of allospecific suppressor T lymphocytes.
Authors: Fradelizi D , Gresser I
Published: June 2004

The effect of human interferon alpha on the differentiation of functional populations of lymphocytes during the human allogeneic response in vitro was studied. Interferon alpha inhibited the generation of allospecific suppressor T lymphocytes that normally develop from lymphocytes primed in vitro against allogeneic cells. This effect was not the result of the destruction by interferon of precursor suppressor cells but rather to inhibition of their differentiation into active suppressor T lymphocytes. This inhibition was reversible and could be overcome by repeated allogeneic stimulation even in the presence of interferon. Inhibition of the generation of allospecific suppressor lymphocytes by interferon might play an important role in the allogeneic response. Interferon inhibited the proliferation of lymphocytes after allogeneic stimulation in a primary mixed lymphocyte reaction but enhanced their cytotoxicity. Despite the inhibitory effect in the primary mixed lymphocyte reaction, the specific secondary proliferative response of lymphocytes primed against a single HLA-DR antigen was only slightly affected by interferon. On the other hand, the nonspecific secondary proliferative response of lymphocytes primed in the presence of interferon was significantly reduced, indicating that interferon might decrease the recruitment of nonspecific "irrelevant" clones of responding cells during the sensitization period.
Uptake and metabolism of monohydroxy-eicosatetraenoic acids by macrophages.
Authors: Pawlowski N A , Scott W A , Andreach M , Cohn Z A
Published: June 2004

Within 5 min, resting macrophages metabolize microM quantities of exogenous arachidonic acid (20:4) to cyclooxygenase and lipoxygenase products. Mono-HETEs represent a major class of metabolites recovered from the medium. However, the quantity of mono-Hetes progressively decreases over a 60-min incubation period, with a concomitant increase in more polar lipoxygenase products, suggesting additional metabolic fates for these hydroxy acids. This was directly confirmed by exposing resident macrophage cultures to radiolabeled 15-, 12-, and 5-HETEs (1 microM). 12-30% of the recovered HETEs were cell-associated and predominantly esterified into phospholipid. High pressure liquid chromatography analyses of medium extracts indicated that 50% of each HETE was also converted to 10 or more metabolites over a 60-min time-course, a rate slower than for 20:4. The major metabolite generated from each mono-HETE had the elution characteristics of a di-HETE. The 5-HETE product has a triene spectrum similar to that of 5(S), 12(S)-di-HETE, whereas the 15- and 12-HETE products exhibited single ultraviolet absorption maxima, indicating a metabolic pathway for 5-HETE distinct from the other mono-HETEs. None of the stable cyclooxygenase products of 20:4 (6-keto PGF1 alpha, PGF2 alpha, PGE2, TXB2) nor polar metabolites of mono-HETEs are either incorporated or metabolized. The results indicate that macrophages have the capacity to specifically metabolize 20:4 and mono-HETEs to polar oxygenated products in the absence of a discernible trigger.
Age-dependent deficiency of B lymphocyte lineage precursors in NZB mice.
Authors: Jyonouchi H , Kincade P W , Landreth K S , Lee G , Good R A , Gershwin M E
Published: June 2004

Adult NZB mice (greater than 15 wk old) have very few bone marrow cells that can give rise to sIg+ clonable B cells during liquid culture. This deficiency corresponds to extremely low numbers of cells with cytoplasmic but not surface mu chains of IgM and reduced numbers of cells bearing a high molecular weight B-lineage antigen. Depletion of Thy-1-bearing cells and appropriate mixing experiments did not provide evidence either that suppressor cells are responsible for this phenomenon or that accessory cells are defective in NZB mice. Nor did it seem that B cells were being produced in extramedullary sites. B cell precursors were detectable in very young NZB mice, exceeded control values at 4-5 wk of age, and then declined rapidly. In contrast, these persisted for greater than 1 yr in normal BALB/c, DBA/2, and CBA/H mice. It appears possible that intermediate stages in B-lineage differentiation become prematurely exhausted through an accelerated aging process in NZB mice. These chronological changes have implications for understanding the sequence of events that lead to B lymphocyte formation and the processes that normally regulate it.
Epitope-specific regulation. II. A bistable, Igh-restricted regulatory mechanism central to immunologic memory
Authors: Herzenberg LA , Tokuhisa T , Parks DR , Herzenberg LA
Published: June 2004

Antibody responses to commonly used antigens are regulated by an epitope- specific system composed of Igh-restricted elements responsible for controlling the isotype and allotype responses mounted to each of the epitopes on the antigen. Because these elements can be independently induced to either suppress or support antibody production, this system as a whole provides an effector mechanism capable of selectively controlling the amount, affinity, isotype representation, and epitope-specificity of an antibody response.

Sequential immunizations with a carrier molecule and a hapten conjugated to that carrier (carrier/hapten-carrier immunization) induce suppression for IgG responses to the hapten. IgG(2a), IgG(2b), and IgG(3) responses are easily suppressed, whereas IgG(1) responses tend to be more resistant. Once induced, suppression tends to be maintained; however, repeated stimulation with the hapten (on any carrier) eventually induces antibody production, first for IgG(1) and later for the more suppressible isotypes (IgG(2a), IgG(2b), IgG(3)).

Antibody production, once initiated, also tends to be maintained. Ongoing IgG antihapten responses in animals primed with a hapten-carrier conjugate can be suppressed by subsequent carrier/hapten-carrier immunization (using a different carrier molecule); however, the suppression induced under these circumstances is substantially weaker, i.e., it mainly affects the more suppressible isotypes and is only strong enough to detect clearly in about one-half the immunized animals. Thus, the initiation of antibody production impairs the subsequent induction of suppression, and the initial induction of suppression tends to prevent subsequent initiation of antibody production.

This reciprocal relationship defines a bistable regulatory mechanism, i.e., one that tends to maintain its initially induced state but is capable of shifting to the alternate state when stimulatory conditions so dictate. The operation of such a mechanism permits conditions surrounding the first immunization with an epitope (hapten) to strongly influence but not absolutely determine which and how many of the anti-epitope memory B cells generated by that immunization will subsequently be expressed. Thus, epitope- specific regulation, although subordinate to mechanisms that control memory B cell development (as opposed to expression), plays a key role in determining the magnitude, affinity, and isotype representation of anamnestic (memory) responses produced in response to previously encountered epitopes.
Biological functions of t cell lines with specificity for the intracellular bacterium Listeria monocytogenes in vitro and in vivo.
Authors: Kaufmann S H , Hahn H
Published: June 2004

Peritoneal exudate T lymphocytes from mice immunized with live Listeria monocytogenes were cloned in double-layer soft agar containing heat-killed L. monocytogenes (lower layer) and syngeneic accessory cells (upper layer). Colony-derived T cells were propagated in vitro in the presence of listerial antigen, syngeneic accessory cells, and T cell growth factor. In vitro proliferation, interleukin secretion, and bystander help for B cells of six such T cell lines and several sublines derived from them were found to be antigen dependent and restricted by the H-2IA locus of the major histocompatibility complex. In vivo, these T cell lines conferred delayed-type hypersensitivity to listerial antigen and protection to live L. monocytogenes. It is concluded that different biological functions of acquired antibacterial immunity can be mediated by a single T cell population.
Suppression of T cell-mediated cutaneous basophil hypersensitivity by serum from guinea pigs immunized with mycobacterial adjuvant.
Authors: Mitchell E B , Askenase P W
Published: June 2004

Guinea pigs immunized with protein antigens emulsified with complete Freund's adjuvant (CFA) and skin tested at 3-4 wk have classical tuberculin-type delayed hypersensitivity (DH) reactions with few basophils present. However, recipients of T cells from these animals have delayed responses containing large basophil infiltrates and thus resemble basophil-rich cutaneous basophil hypersensitivity (CBH) responses that are elicited in animals immunized without CFA. This suggests that animals immunized with CFA have T cells with basophil-recruiting capacity but that this activity is suppressed. Using a transfer system, we found that immune serum from donors immunized with CFA had the ability to suppress the basophil-recruiting capacity of immune T cells. When immune serum and peritoneal exudate cells from guinea pigs immunized with CFA were co-transferred intravenously to normal recipients, the cell-mediated transfer of basophil-rich responses was suppressed. The responsible serum factor was antigen nonspecific, had an approximately 70,000 mol wt, and acted preferentially on cells from donors that express basophil-poor DH responses. Thus, tuberculin-type delayed hypersensitivity and CBH might be mediated by a common T cell, but the resulting basophil component of the delayed response depends on the modulation of T cell recruitment of basophils by factors in CFA-immune serum.
Anti-idiotypic antibodies to the Coombs antibody in NZB F1 mice.
Authors: Cohen P L , Eisenberg R A
Published: June 2004

The F1 hybrids of NZB and several normal mouse strains are known to produce less anti-erythrocyte (Coombs) autoantibody and develop a milder hemolytic anemia than their NZB parents. We have found that serum from some (NZB x CBA)F1 mice agglutinated erythrocytes from certain Coombs-positive NZB mice, often in extremely high titer, whereas other (CBA x NZB)F1 sera agglutinated erythrocytes from different individual NZB mice. The agglutination was due to antibody, but was not due to rheumatoid factor activity. Because F(ab')2 fragments of the F1 sera agglutinated erythrocytes coated with F(ab')2 fragments of the appropriate NZB sera, the observed reactivity was probably caused by idiotype-anti-idiotype interactions. In addition, because F1 sera could not agglutinate mouse erythrocytes coated with monovalent NZB Fab' fragments, the recognized idiotype probably involved the antigen-binding site. Anti-idiotypic antibodies against anti-erythrocyte autoantibodies may play an important role in the regulation of autoantibody formation.
Breakdown of C3 after complement activation. Identification of a new fragment C3g, using monoclonal antibodies.
Authors: Lachmann P J , Pangburn M K , Oldroyd R G
Published: June 2004

The physiological breakdown of C3 has been studied using monoclonal anti-C3 antibodies, and it has been found that the later stages of this process--the breakdown of C3bi--is more complex than had previously been recognized. C3bi is the reaction product produced from C3b by the action of factor I which, in the presence of factor H, produces a double cleavage in the alpha chain of C3b. It is here reported that, both on cells and in the fluid phase, the breakdown of C3bi in serum gives rise to two products: C3c and the product previously described as alpha 2D, which we now propose to designate C3d,g. Alpha 2D differs from C3d in that it contains an additional fragment of approximately 8,000 mol wt that carries the antigenic determinant for the clone 9 monoclonal anti-C3 antibody. C3g cannot be precipitated by anti-C3 antisera and therefore behaves as a uni- or bideterminant antigen. The cleavage of C3d,g to C3d and C3g does not occur in sterile serum. It is also still uncertain what enzyme cleaves C3bi to C3c and C3d,g in plasma. Plasmin can do so in vitro, but plasminogen-depleted serum can still produce the cleavage. The antigenic determinant recognized by clone 9 in C3 is not exposed in C3 or C3b, but appears as a neoantigen in C3bi (and in C3d,g). Anti-C3g therefore is a potentially useful ligand for detecting complement-activation products. C3g represents a new, highly anionic C3 fragment and seems not to be identical with the C3e fragment described by others.
Anti-Ia antibody in the sera of normal subjects after in vivo antigenic stimulation.
Authors: Okudaira K , Goodwin J S , Williams R C
Published: June 2004

We showed that sera from normal subjects after antigenic challenge with intradermal PPD or Candida antigens or with subcutaneous tetanus vaccine contain a factor that blocks the binding of mouse monoclonal anti-Ia antibody to Ia-positive T cells or to B35 M cells, an Ia-positive human B cell line. The blocking activity appears 48 to 72 h after antigenic challenge and is gone by day 7. The appearance of the anti-Ia blocking activity coincided with a drop in the percentage of Ia-positive T cells and non-T cells in the peripheral blood of these subjects and also with a decrease in the density of surface Ia on the non-T cell population. The blocking was not genetically restricted; that is, serum from a given subject blocked anti-Ia binding to Ia-positive T cells of subjects with different DR haplotypes. The blocking activity was contained in the IgM fraction of the sera. The blocking activity of the sera was eliminated after absorption of the sera with Ia-positive but not with Ia-negative human cell lines. It would appear, therefore, that the blocking of monoclonal anti-Ia binding is caused by an IgM anti-Ia antibody that appears in normals after in vivo antigenic challenge.
Genetic linkage of the cytolytic T lymphocyte repertoire and immunoglobulin heavy chain genes.
Authors: Sherman L A
Published: June 2004

The specificity repertoire of H-2Kb-specific cytolytic T lymphocytes (CTL) has been examined in B10.D2,BALB/c, and the allotype congenic line CB-20. Comparing their expression of recurrent specificities that serve as markers for the repertoire of each strain indicates that the CTL repertoire of B10.D2 (Ighb) and BALB/c (Igha) differ extensively. In contrast, the repertoires expressed by B10.D2 and CB-20 (Ighb) are essentially identical with respect to their expression of the same recurrent specificities. Taken together with results previously obtained, it is concluded that both major histocompatibility complex and Igh-linked genes affect the CTL specificity repertoire.
Demonstration of a specific receptor for human C5a anaphylatoxin on murine macrophages.
Authors: Chenoweth D E , Goodman M G , Weigle W O
Published: June 2004

Human C5a anaphylatoxin is known to be a potent mediator of the acute inflammatory response. It serves to trigger a wide variety of neutrophil responses after binding to a specific cellular receptor. We have now demonstrated that this bioactive glycopolypeptide is also bound to a specific receptor found on murine resident peritoneal macrophages, thioglycollate-induced exudate macrophages, and the murine cell line P388D1. The apparent Kd of the C5a receptors. Resident macrophages appear to have an average of 2 x 10(5) binding sites per cell, whereas thioglycollate- induced cells have only 4-5 x 10(4) binding sites. The continuous cell line P388D1 is intermediate between these two cell types, exhibiting 8-10 x 10(4) C5a receptors per cell. Neither murine lymphocytes nor the parent cell line P388 displays a measurable number of C5a receptors. Macrophage receptor-C5a binding interactions are followed by cellular uptake and degradation of 125I-C5a, much as is observed with neutrophils. As demonstrated in another paper, binding of C5a to macrophages results in augmentation of the primary humoral immune response as well as enhancement of mixed lymphocyte reactions. These observations suggest that C5a should not only be considered as an acute inflammatory mediator but as an immunopotentiating modulator as well, thus serving as a critical link between complement activation and subsequent immune responses.
Tolerance and autoimmunity to erythroid differentiation (B-G) major histocompatibility complex alloantigens of the chicken.
Authors: Havele C , Wegmann T G , Longenecker B M
Published: June 2004

Hematopoietic chimeras were produced at four different stages of ontogeny between two allogeneic strains of chickens. All chimeras produced by parabiosis at day 12 of embryogenesis and the majority (83%) of the ones produced at day 15 by intravenous injection of allogeneic stem cells remained healthy, chimeric, and specifically tolerant at both the humoral and cell-mediated level throughout a long examination period. Chimeras generated at day 17 of embryogenesis demonstrated specific unresponsiveness at the cell-mediated level but produced specific anti-donor alloantibodies directed against erythrocyte-associated major histocompatibility complex (MHC) (B-G) antigens. These chimeras and a minority (17%) of the chimeras generated at day 15 of embryogenesis developed severe antibody-mediated autoimmune hemolytic anemia after the 5th mo of age and succumbed to massive bursal lymphomas and metastases by the 10th mo of age. The immunological and pathological characteristics of these birds appear to reflect an autoimmune state rather than one of tolerance. Erythroid chimeras generated at day 21 of ontogenic development displayed normal levels of GVH reactivity. These birds were eventually able to eliminate the chimeric state and remained healthy until deliberately killed. These results show that there is a critical period in embryogenesis during which the induction of allogeneic erythrocytic chimerism leads to the development, in adult life, of severe autoimmune anemia, B cell lymphomas, and death. B-G MHC antigens are erythroid differentiation antigens of the chicken. Polymorphic determinants on B-G antigens appear to be important cross-reactive determinants (with environmental bacteria), against which a high background immunity exists. Evidence is presented that the immune response to B-G antigens is responsible for the development of autoimmunity and other pathological events that follow and that tolerance to class I MHC antigens (B-F antigens) shared by lymphocytes erythrocytes is maintained at the same time that B-G tolerance is broken.
Isolation, partial characterization, and localization of a rat renal tubular glycoprotein antigen. Antibody-induced birth defects.
Authors: Leung C C
Published: June 2004

A glycoprotein with an apparent 340,000 mol wt (gp 340K) was isolated from rat kidney saline-soluble extract by ammonium sulfate precipitation, DE 52 ion-exchange cellulose chromatography, concanavalin A affinity column, Sephacryl S-300 gel filtration, and discontinuous polyacrylamide gel electrophoresis (PAGE). The relative purity of gp 340K was examined by double immunodiffusion analysis, disc PAGE, and immunoelectrophoresis. Injection of rabbit gp 340K antiserum into pregnant rats during the organogenetic period induced abnormal embryonic development, fetal growth retardation, and embryonic death. Antiserum against the immunocomplexes isolated by immobilized protein A also produced the same embryotoxic effects. The biologic effects of the antisera appeared to be dose dependent. Defects such as anophthalmia, hydrocephaly, exencephaly, cleft palate, cleft lip, and some cardiovascular anomalies were observed. The most frequently observed anomaly was anophthalmia. Immunofluorescent localization studies indicated that gp 340K antibodies localized in vivo in the visceral yolk-sac endodermal cells and the embryonic endoderm. In vitro immunofluorescent localization studies revealed that gp 340K was a component of the renal tubular cells that cross-reacted with antigen in the visceral yolk-sac endodermal cells and embryonic endoderm. The underlying mechanism whereby gp 340K antibodies induce birth defects is not known. Three hypotheses were discussed.
Cell-to-cell interaction controlled by immunoglobulin genes. Role of Thy-1-, Lyt-1+, Ig+ (B') cell in allotype-restricted antibody production.
Authors: Okumura K , Hayakawa K , Tada T
Published: June 2004

A novel lymphocyte subpopulation, designated "B' cell" because of its characteristic dual expression of Ig and Lyt-1 antigen, is described in relation to its ability to augment the in vitro secondary antibody response. The cells are found in the spleens of normal unprimed mice as well as those of athymic nude mice and represent a small of normal unprimed mice as well as those of athymic nude mice and represent a small number (2-3%) of immunoglobulin-positive cells. No other distinguishing surface markers of conventional T and B cells, such as Thy-1, Lyt-2, Ia, and ThB antigens, are detected on the B' cell. In the in vitro anti-hapten secondary antibody response, the addition of a small number of B' cells from unprimed mice to the mixture of T and B cells greatly augmented the anti-hapten antibody formation when the number of carrier-specific helper T cells was limited. This augmentation was observed only when B and B' cells shared the same set of IgVH genes. The identity of the immunoglobulin gene between T cells and B or B' cells was not necessary for optimum antibody production. The results indicate that the presence of B' cells is necessary for the induction of an optimum antibody response when helper T cells are limited. It is suggested that B' cells deliver an additional signal to the B cell network to magnify the antibody response.
Chemiluminescence response of human natural killer cells. I. The relationship between target cell binding, chemiluminescence, and cytolysis.
Authors: Helfand S L , Werkmeister J , Roder J C
Published: June 2004

The binding of tumor cells or fetal fibroblasts to human natural killer (NK) cells led to a rapid chemiluminescence response within seconds of target-effector interaction. The degree of chemiluminescence was dependent on the concentration of NK-enriched lymphocytes or target cells, and plasma membrane vesicles from K562 also induced a chemiluminescence response. Mild glutaraldehyde treatment of effector cells abrogated their ability to generate chemiluminescence, whereas K562 target cells treated in the same way were almost fully able to induce a chemiluminescence response to NK-enriched lymphocytes. These results show a directionality of response with NK as the responders and tumor cells as the stimulators. A survey of eight different tumor cell lines and fetal fibroblast lines revealed a striking correlation (r greater than 0.93, P less than 0.001) between the ability of a given line to bind to NK-enriched lymphocytes, induce chemiluminescence, and to be lysed. Three differentiated sublines of K562 grown in butyrate and cloned induced little chemiluminescence compared with the K562 parent, and they were selectively resistant to NK-mediated binding and cytolysis. In addition, treatment of K562 cells with higher concentrations of glutaraldehyde for longer periods led to varying degrees of target antigen preservation, as measured in cold target competition assays and in conjugate formation. The degree of NK target antigen preservation correlated directly with the ability of the cells to induce chemiluminescence (r greater than 0.95). The degree of NK activation was also important because interferon-pretreated effectors generated more chemiluminescence upon stimulation with K562 or MeWo targets. Monocytes or granulocytes did not contribute to the chemiluminescence induced by NK-sensitive targets. Some NK-resistant tumor cell lines were sensitive to monocyte-mediated cytolysis and also induced chemiluminescence in monocytes but not NK cells. These results show that the target structures recognized by the NK cell may play a role in NK activation because the degree of chemiluminescence was directly proportional to the ability of a given target cell line to bind to the NK cell and to be lysed.
A natural model of immunologic tolerance. Tolerance to murine C5 is mediated by T cells, and antigen is required to maintain unresponsiveness.
Authors: Harris D E , Cairns L , Rosen F S , Borel Y
Published: June 2004

A unique experimental model is described, where natural immunologic tolerance to a well-defined soluble native antigen (murine C5) is examined in congenic strains of mice that differ only by the presence or the absence of C5. A highly sensitive hemolytic assay was developed to detect nanogram amounts of C5 as well as an assay of anti-C5 inhibition of C5 hemolytic activity. The latter was more sensitive than immunodiffusion. Two reciprocal approaches were used to study the cellular basis of tolerance in irradiated hosts of either strain. In the first, lymphoid cells from either strain were transferred to irradiated B10.D2OSN hosts that were lacking C5 and so would not hinder detection of anti-C5 antibody upon challenge with murine C5. Second, lymphoid cells from either strain were transferred to irradiated B10.D2NSN hosts, whose native C5 provided the antigenic stimulus. The immune response of whole nonadherent spleen cell suspension as well as mixtures of T and B cells (separated on the basis of surface immunoglobulin) from either strain were studied. In addition, the duration of tolerance and the antigen requirement to maintain it in irradiated C5-deficient hosts repopulated with C5-sufficient spleen cells was examined. The positive control of irradiated C5-deficient hosts repopulated with syngeneic spleen cells showed a primary and secondary response to immunization. In contrast, C5-sufficient spleen cells failed to respond both in the primary and the secondary response. Because the unresponsiveness was not caused by antigen carryover and was not antigen specific, it represents central tolerance. In C5-sufficient irradiated hosts (where immunization was not required and antigen was present in natural form and physiological concentration), transfer of C5-deficient cells mediated a drop in C5 levels to 10-20% of that noted in unreconstituted controls. T and B cell mixing experiments from the two strains into deficient or sufficient hosts demonstrated that tolerance is T cell dependent and that C5-sufficient or -deficient B cells could cooperate with nontolerant C5-sufficient T cells to produce significant anti-C5 antibody or mediate a significant drop in C5 levels. In addition, the presence of antigen was necessary to maintain tolerance. In conclusion, these results show that (a) natural tolerance to C5 is an active process that is T cell dependent and requires the presence of antigen; (b) in this natural model, clonal abortion does not seem to occur; and (c) both tolerant and nontolerant B cells retain the capacity to produce autoantibody.
Gain/loss of poly(Glu50Tyr50)/poly(Glu60Ala30Tyr10) responsiveness in the bm12 mutant strain.
Authors: Lei H Y , Melvold R W , Miller S D , Waltenbaugh C
Published: June 2004

The development of inbred strains of mutant mice has proven useful in ascribing specific gene functions to particular genetic loci within the regions and subregions of the H-2 complex. The B6.C-H-2bm12 (bm12) strain is of particular interest in that, compared to parental C57Bl/6Kh (B6) mice, it bears a presumptive single gene mutation altering the Ab beta chain encoded by the I-A subregion. Our data show that bm12 mice have gained the ability to respond to poly(Glu50Tyr50)(GT) and have lost the ability to make plaque-forming cell or delayed-type hypersensitivity responses to the closely related copolymer, poly(Glu60Ala30Tyr10)(GAT), although retaining the ability to mount a GAT-specific T cell proliferative response. This is in sharp contrast to the parental B6 strain, which is a GT nonresponder and a GAT responder. Thus, this study is the first to report the establishment of responder status as a consequence of mutation. Possible mechanisms accounting for the gain/loss of GT/GAT responsiveness in the context of a two-step helper T cell model are discussed.
Demonstration of a third structurally distinct human Ia beta chain by two-dimensional gel electrophoresis.
Authors: Karr R W , Kannapell C C , Stein J A , Fuller T C , Duquesnoy R J , Rodey G E , Mann D L , Gebel H M , Schwartz B D
Published: June 2004

Previous studies have indicated that HLA-DR homozygous cell lines express two Ia alpha and Ia beta chains that combine to form at least two Ia molecules. This report demonstrates by two-dimensional gel electrophoresis the existence of a third structurally distinct human Ia beta chain on DR2 and DR5 cell lines. This suggests that at least five separate genes control the expression of Ia molecules on HLA-DR homozygous cell lines.
Identification of a T cell hybridoma that produces large quantities of macrophage-activating factor.
Authors: Schreiber R D , Altman A , Katz D H
Published: June 2004

A murine T cell hybridoma, constructed by fusion of alloantigen-activated T cells with the BW5147 T cell lymphoma, which produces a lymphokine capable of inducing tumoricidal activity in macrophages, has been identified. Lymphokine release could be detected only after mitogen stimulation of the T cell hybridoma culture. Upon cloning of the parental hybridoma, 24 out of 27 clones produced tumoricidal-inducing activity. Seven clones produced more cytocidal-inducing activity than did conventional supernatants, generated by concanavalin A stimulation of normal murine spleen cell cultures, which contained macrophage-activating factor (MAF). The supernatant of hybridoma clone 24/G1 was 25 times more active than conventional MAF preparations. Using supernatants from a variety of clones, the levels of macrophage-activating activity and interleukin 2 were found to vary independently of one another. The lymphokine produced by hybridoma clone 24/G1 appeared to be identical to conventional MAF by a variety of criteria including: (a) a requirement for a second signal for induction of tumoricidal activity in macrophages, (b) inactivation after incubation for 1 h at 65 degrees C, and (c) loss of activity after treatment at pH 4.0 but not at pH 5.0. Like conventional MAF, the hybridoma MAF eluted as a single peak after molecular sieve chromatography on Sephadex G100 and exhibited an apparent molecular weight of 55,000. Although somewhat heterogeneous, the majority of hybridoma 24/G1 MAF displayed an isoelectric point of 5.4 as determined using the chromatofocusing technique. These results thus illustrate the usefulness of T cell hybridomas in distinguishing between various lymphokine activities and indicate that the T cell hybridoma clone 24/G1 will be of particular usefulness in achieving the biochemical purification of substantial quantities of murine MAF.
Immunoglobulin idiotopes expressed by T cells. I. Expression of distinct idiotopes detected by monoclonal antibodies on antigen-specific suppressor T cells.
Authors: Cerny J , Heusser C , Wallich R , Hammerling G J , Eardley D D
Published: June 2004

The idiotopic repertoire expressed by antigen-specific suppressor T cells (Ts) generated by Streptococcus pneumoniae strain R36a (Pn) in BALB/c strain mice was investigated using a panel of five monoclonal anti-idiotopic antibodies against TEPC-15/HOPC-8 myeloma proteins. Previous studies suggested that the anti-idiotopic antibodies recognize distinct idiotopic determinants within the T15 idiotype, and that Pn-reactive B cells express all of those idiotopes as shown by a specific inhibitory effect of the anti-idiotopic antibodies on induction of anti-Pn response in vitro as well as on the mature antibody plaque-forming cells. In this study we asked the question of whether anti-idiotopic (Id) can block the inductive and/or effector phases of generation of Ts which act on the Pn-reactive B cells. The presence of anti-Id during the activation of T cells with Pn did not prevent the generation of Ts. However, suppression mediated by Ts on responder lymphocytes (cultures of spleen cells or B cels) was inhibited (reversed) by four out of five anti-Id. Some of the antibodies recognize hapten (phosphorylcholine)-inhibitable Id in the paratope of Ig whereas others are directed against nonparatopic Id. These data indicate that the antigen receptor on Ts includes VH sequences both within and without the immunoglobulin in paratope, and that the Id repertoir of Ts overlaps with that of B cells.
Serologic identification of the human secondary B cell antigens. Correlations between function, genetics, and structure.
Authors: Shaw S , DeMars R , Schlossman S F , Smith P L , Lampson L A , Nadler L M
Published: June 2004

The secondary B cell (SB) antigens are polymorphic HLA-linked antigens on human B cells and macrophages that are identified by primed T cell responses but are genetically distinct from the HLA-DR, MB, and MT antigens. Serologic identification of the SB molecule, using the monoclonal antibody ILR1, now makes it possible to correlate the function of these determinants in human T cell recognition with an Ia-like molecular structure and a genetic locus that marks a new HLA subregion. Three lines of evidence indicate that the ILR1 molecule identifies an epitope on some alleles of the SB gene: (a) the polymorphism of ILR1 -reactivity in the population correlates with SB2 SB3; (b) T cell proliferative response to SB2 and SB3 are specifically inhibited by ILR1; and (c) ILR1 reactivity is exactly concordant with the expression of SB2 in a panel of HLA-deletion mutant lymphoblastoid cell line. Together with previous studies, these results indicate that the SB antigens are on Ia-like molecules. Furthermore, the serologic studies of HLA-deletion mutant cell lines demonstrate that there are two HLA regions centromeric to HLA-B controlling expression of Ia-like molecules: a region toward HLA-B that controls expression of HLA-DR, and a region toward GLO that controls expression of SB.
Modulation of human lymphocyte function by C3a and C3a(70-77).
Authors: Payan D G , Trentham D E , Goetzl E J
Published: June 2004

Human C3a and the synthetic octapeptide C3a (70-77), which retains the activities of an anaphylatoxin, inhibit in a concentration-dependent manner the generation of leukocyte inhibitory factor (LIF) activity by human mononuclear leukocytes and T lymphocytes cultured with the mitogens phytohemagglutinin (PHA) or concanavalin A (Con A) or the antigen streptokinase-streptodornase (SK-SD). The generation of LIF activity was inhibited by 50% by 10(-8) M C3a or C3a(70-77) with PHA or Con A as the stimulus, whereas a more than 10-fold higher concentration of C3a(70-77) than C3a was required to achieve the same level of suppression with SK-SD as the stimulus. Similar concentrations of C3a(70-77) inhibited to the same extent the migration of T lymphocytes stimulated by alpha-thioglycerol of Con A. Neither C3a nor C3a(70-77) altered significantly the uptake of [3H]thymidine by human mononuclear cells exposed to PHA, Con A, or SK-SD. The capacity of C3a(70-77)-Sepharose,m but not Sepharose alone, to adsorb or inactivate mononuclear leukocytes required for the generation of LIF activity established a direct interaction. Analysis of the lymphocytes in the effluent from C3a(70-77)-Sepharose columns, using monoclonal antibodies to surface antigens, showed a selective depletion of the helper/inducer population of lymphocytes. C3a might represent an important mediator of the functionally selective regulation of human T lymphocyte activities by the complement system.
H-2L-restricted recognition of viral antigens In the H-2d haplotype, anti-vesicular stomatitis virus cytotoxic T cells are restricted solely by H-2L.
Authors: Ciavarra R , Forman J
Published: June 2004

H-2d-encoded gene products were analyzed as restriction antigens for anti-vesicular stomatitis virus (VSV) cytotoxic T lymphocytes (CTL). Cold target competition experiments revealed that VSV recognition was H-2D region-restricted; H-2K-end-restricted recognition of VSV could not be demonstrated. That VSV is not recognized in the context of K-region-encoded gene products is also supported by the observation that H-2dm1 and H-2dm2 mice, strains that contain H-2Kd but have an alteration in H-2L and/or H-2D/L, are nonresponders in the CTL assay. Two different lines of evidence eliminated H-2Dd, H-2Md, and H-2Rd as the restriction antigens: (a) H-2dm2-VSV inhibitors that express H-2Dd and H-2Md did not block the lysis of P815-VSV targets by Balb/c anti-VSV killer cells, and (b) a hybridoma specific for H-2Dd failed to inhibit killer cell activity in this same effector/target combination. However, two monoclonal antibodies specific for H-2Ld but not H-2Rd completely blocked anti-VSV cytotoxic activity. Taken together, in the H-2d haplotype, anti-VSV CTL recognize VSV solely in the context of the H-2Ld molecule. This is the first demonstration of the exclusive use by a mouse stain of the H-2L molecule only for H-2-restricted recognition, and thus supports the notion that H-2L plays a major role in restricting antigen specific recognition. Finally, the fact that an anti-H-2Ld monoclone completely blocked an H-2dm2 anti-BALB/c CTL response indicates that H-2R, a molecule absent in H-2dm2 anti-BALB/c CTL response indicates that H-2R, a molecule absent in H-2dm2 but not BALB/c, does not sensitize H-2 alloreactive CTL.