bluuebunny/crossref_metadata_2025 huggingface dataset:
Maturation of mitogen‐activated bone marrow‐derived lymphocytes in the absence of proliferation
Authors: Andersson J. , Melchers F.
Published: February 2007

Mouse B lymphocytes respond by increased rates of DNA synthesis 14–24 hours after stimulation with the mitogen lipopolysaccharide. If, at this time, stimulated cells are treated for 12 hours with a “hot pulse” of thymidine, subsequent mitogen‐induced maturation to high rate IgM‐producing plaque‐forming cells is abolished. Thus, B cells stimulated by mitogen to mature also incorporate thymidine into DNA and proliferate.

DNA synthesis is inhibited to 99 % in 48‐hour mitogen‐stimulated B lymphocytes by 10−2 M hydroxyurea or 10−3 M cytosine arabinoside, while protein and IgM synthesis and secretion and the plaque‐forming capacity of those cells are unaffected. When hydroxyurea is added to small, resting B cells at the time of initiation of mitogenic stimulation, these cells mature to 19 S IgM‐ secreting, plaque‐forming cells in the absence of DNA synthesis and proliferation. Maturation in the absence of DNA synthesis is also manifested by an increase in ratios of rates of synthesis and secretion of IgM over those of all proteins in the cell and by the attachment of the “branch” sugars, galactoses and fucoses, to 19 S IgM secreted by the cells. This maturation of B cells in the absence of DNA synthesis occurs within 12 to 30 hours after stimulation and is mitogen dose dependent. The inhibition of B cells to synthesize DNA and to develop into clones of plaque‐forming cells can be reversed by the removal of hydroxyurea for as long as 36 hours after mitogenic stimulation in the presence of the inhibitor.

In the presence of hydroxyurea, B cells are stimulated to immature plasmablast‐like cells containing surface‐bound and little intracytoplasmic Ig within 16 to 24 hours of stimulation. Mature plasma cells containing no detectable surface‐bound Ig, but abundant intracytoplasmic Ig are only developed in the uninhibited, but not in the hydroxyurea‐inhibited mitogen‐stimulated cells later in the response. Thus, two stages of B cell maturation and differentiation can be distinguished: the first stage of an immature plasmablast develops in the absence of DNA synthesis, while the later stage of the development of the mature plasma cell requires DNA synthesis.
Genetic determination of tuberculin hypersensitivity in chicken inbred lines
Authors: Karakoz I. , Krejči J. , Hála K. , Blaszczyk Barbara , Hraba T. , Pekárek J.
Published: February 2007

A dominant inheritance of the ability of CB line chickens to react to tuberculin over the inability of the WB line to develop this type of immune reaction was observed. The tuberculin reactivity in this line seems to be determined by one locus and is associated with the B locus.

The involvement of the B locus in the regulation of tuberculin reactivity in other inbred lines of chickens is supported by the reactivity of the CA. IB (N6F2) birds in which the B allele of the IB line was introduced into the CA genotype. The CA. IB (N6F2) chickens manifest strong tuberculin sensitivity, corresponding to the type of reaction of the IB line, not to the weaker type of response of the CA line. The intensity of the tuberculin reaction of the CA and CC lines resembles that of the CB line, but the proportion of nonreactive birds is higher in these two lines than in CB chickens.
Studies of hyperimmune restricted and partially restricted anti‐pneumococcal polysaccharide antibodies from allotype‐defined pedigreed rabbits. II. Allotypes and idiotypes in sera and electrofocused fractions
Authors: Mage Rose G. , Pincus J. H. , Alexander C. , Freedman M. H.
Published: February 2007

The expression of allelic forms of immunoglobulin during immunization of heterozygotes with pneumococcal vaccines was monitored using anti‐allotype antisera specific for the genetically different forms of rabbit kappa chains (b‐locus allotypes). We also used the a‐locus (VH) allotypic markers of rabbit heavy chains and idiotypic determinants associated with a restricted subpopulation of anti‐polysaccharide antibodies of an individual rabbit. Analysis of fractions obtained by preparative liquid isoelectric focusing (IEF) of antisera from heterozygous rabbits exhibiting restricted antibody responses to type 3 or type 8 pneumococcal polysaccharides, indicated an enrichment for one a or b locus allotype. Enrichment of a specific idiotype from ∼ 11 % in the starting serum up to as high as 65 % in a focused fraction was also obtained. The method of preparative liquid IEF can thus be used to isolate antibodies restricted in allotype and idiotype from antisera. The quantities obtained are sufficient for further chemical and immunological study.
Chemical analysis and electron microscopy studies of human C1q prepared by different methods
Authors: Knobel H. R. , Villiger W. , Isliker H.
Published: February 2007

Five differently isolated and purified human C1q preparation were examined by electron microscopy and analyzed by polyacrylamide gel electrophoresis in 0.1 % sodium dodecyl sulfate and 0.5 M urea. The amino acid and carbohydrate composition of C1q purified by the DNA method are reported and compared with results obtained ion C1q isolated by other procedures.

Electron microscopy showed that all C1q preparation had six peripheral subunits connected by fibrillar strands to a central subunit. The presence of small amounts of dimers was also observed. The physico‐chemical properties of the molecule are independent of the purification method used. The five C1q preparation labeled with 125I in presence of lactoperoxidase formed two types of noncovalently linked subunits. In each case the smaller (central) subunit contained over thirty times as much radioactivity as the larger (peripheral) subunit supposed to interact with immune complexes. Reduction adn alkylatin confirmed for each preparation the presence of three polypeptide chains, the smaller of which contained essentially all radioactivity.
Five types of lymphocytes (lg− θ−, lg− θ+ weak, lg− θ+strong, lg+ θ− and lg+ θ+) characterized by double immunofluorescence and electrophoretic mobility Organ distribution in normal and nude mice
Authors: Roelants G. E. , Loor F. , von Boehmer H. , Sprent J. , Hägg Lena‐Britt , Mayor Kathleen S. , Rydén Aina
Published: February 2007

The simultaneous detection of Ig and θ on the surface of mouse lymphocytes permits the detection of four cell types (Ig−θ−, Ig−θ+, Ig+θ−, and Ig+θ+) which also have distinct electrophoretic profiles. All types are present in variable proportions in all lymphoid organs studied. Results obtained in congenitally athymic nude mice and in T‐deprived mice define a new type of lymphocyte, the Ig−θ+weak. This cell is non‐recirculating, Ig−, with a low density of θ and a slow electrophoretic mobility. It is a candidate for a T‐committed prethymic cell.
Immunochemical and biochemical study of a human Fcμ fragment (μ‐chain disease)
Authors: Lebreton J. P. , Ropartz C. , Rousseaux J. , Roussel P. , Dautrevaux M. , Biserte G.
Published: February 2007

An abnormal protein, from a patient with μ‐chain disease has been studied: protein BUR. It is devoid of the F(ab″)2μ fragment; molecular weight determinations and immunological data identify the protein as a F(c)5μ fragment. Similarly, carbohydrate determinations and proteolysis experiments relate it to a Fcμ fragment. Nevertheless, the protein, which contains J‐chain, lacks the entire covalently bonded structure of the F(c)5μ fragment. C‐terminal analysis shows a tyrosine residue identical to the C‐termin amino acid of μ‐chains. Sequence of the N‐terminal region determined for 15 residues shows identity with sequence 338–352 and sequence 333–347 of two entire μ‐chains previously studied. The relation of BUR to other heavy chain disease proteins is discussed.
Effect of delayed addition of 2‐mercaptoethanol on the generation of mouse cytotoxic T lymphocytes in mixed leukocyte cultures
Authors: Engers H. D. , Macdonald H. R. , Cerottini J.‐C. , Brunner K. T.
Published: February 2007

The generation of mouse cytolytic T lymphocytes (CTL) in primary or secondary mixed leukocyte cultures (MLC) is greatly enhanced by the addition of 2‐mercaptoethanol (2‐ME) to the culture medium. This enhancement can be equally demonstrated with either reduced or oxidized 2‐ME. Addition of 2‐ME to MLC as late as 3 days after the initiation of the culture results in a peak CTL response which is nearly as high as the one in cultures containing 2‐ME throughout the 4 day‐incubation period. Quantitative analysis of the CTL response in MLC supplemented with 2‐ME on day 3 shows a 50‐fold increase in lytic activity within 24 h, suggesting that cell differentiation, in addition to proliferation, may be affected by this agent.
Mixed lymphocyte reactivity of human lymphocytes primed in vitro. I. Secondary response to allogenic lymphocytes
Authors: Fradelizi D , Dausset J
Published: February 2007

In order to study the mixed lymphocyte culture reactivity of human lymphocytes primed in vitro, a nucleopore culture chamber technique allowing human lymphocytes to be cultured for a period of at least twoweeks has been developed. During the primary culture period in nucleopore chambers, human lymphocytes were sensitized against mitomycin‐treated allogenic stimulating cells. It was shown that the stimulated lymphocytes underwent a blastogenic reaction and the results suggest a reversion to the state of small, resting, primed lymphocytes.

In vitro primed lymphocytes displayed allogenic memory. This was characteristic of a secondary response, which is shown by the following: 1) acceleration, the peak of thymidine incorporation occuring on day 4, 2) specificity, the accelerated response was observed only when theprimed lymphocytes were confronted with the cell used for priming. Contact with a third party cell did not produce this kind of activation. 3) Amplitude; the peak DNA synthesis response was greater than that of unprimed lymphocytes cultivated for the same length of time.
Isolation on discontinuous gradients of bovine albumin of a subpopulation of human lymphocytes exhibiting precursor characteristics
Authors: Gatien J. G. , Schneeberger E. E. , Parkman R , Merler E
Published: February 2007

Purified subpopulations of lymphocytes were obtained from discontinuous bovine serum albumin (BSA) gradients and by rosetting sheeperythrocytes (E) or EAC1‐3. Cells from layers 1 to 3 ofthe BSA gradient which failed to rosette with E were highly reactive with EAC1‐3 and with anti‐human IgM. Demonstrating a high spontaneous rate of DNA synthesis and primitive morphology, these cells responded to pokeweed mitogen, concanavalin A and alloantigens, but not to phytohemagglutinin or soluble antigens. Constituting from 0.5 % to 3.0 % of all lymphocytes from each of the tissues studied, these lymphocytes appear to represent an earlier stage in human lymphocyte development distinct from both T and B cells.
B cell tolerance induced by polymeric antigens. II. Effects of tolerance on hapten‐binding lymphocyte levels in primary and secondaryantibody responses
Authors: Klaus G. G. B.
Published: February 2007

Tolerogenic doses of hapten [2,4‐dinitrophenyl (DNP)]‐coupled type 3 pneumococcal polysaccharide (DNP‐lys2.5−S3) totally abolished the anti‐DNP rosetteforming cell (RFC) response to primary immunization with DNP‐hemocyanin in mice, while lightly substituted antigen (DNP‐lys0.6−S3) had little effect. Both antigens suppressed secondary anti‐DNP RFC responses to DNP‐KLH. Limiting doses of DNP‐lys‐S3 preferentially suppressed antibody‐secreting cell levels, and had less effect on RFC. DNP‐lys2.5−S3 was 500—1000‐fold more potent in “blockading” primary RFC in vitro than DNP‐lys0.6−S3, whereas both antigens were equally effective in blocking secondary RFC.

These results suggest that the sensitivity of primed B lymphocytes to inactivation by DNP‐lys‐S3 is related to their high avidity for antigen. Furthermore, this appears to be largely due to a high density of immunoglobulin receptors on primed cells, since the affinitiesof primary and secondary RFC for monovalent hapten were indistinguishable.

Treatment of primarily immunized mice with DNP‐lys2.5−S3 2 h before assay abolished 90 % of RFC. Therefore, the reduction in RFC levels in tolerant mice may be due to cellular blockade by persisting tolerogen. However, it seems unlikely that simple blockade of antigen‐reactive cells is the sole mechanism operative in this system.
Hapten‐induced B cell paralysis. II. Evidence for trivial mechanisms of tolerance
Authors: Gronowicz E , Coutinho A
Published: February 2007

Injection into mice of a free, reactive form of the hapten (4‐hydroxy‐3,5‐dinitrophenyl)acetyl (NNP), induces a state of specific unresponsiveness to the hapten, upon its challenge with thymus‐dependent and independent carriers. This unresponsiveness is maintained in vitro. Both induction and expression of the unresponsive state were found to be independent of T cells.

Analysis of the mechanisms responsible for the B cell “tolerance” demonstrated that the major cause of unresponsiveness in this system is the blockade of specific surface receptors on B cells by the hapten, abolishing the focusing function of these receptors. “Tolerant” B cells, though they were unresponsive to the antigen, could be activated to anti‐hapten antibody secretion by the B cell mitogen lipopolysaccharide (LPS), which does not require Ig‐mediated binding. They also became fully responsive to the antigen NNP‐LPSin specific thymus‐independent responses after 24 hours of in vitro incubation in the absence of tolerogen, conditions which allowdeblocking of Ig surface receptors, and, thus, restorationof the focusing function of these receptors.

These results demonstrate that great care is required for a clearcutdefinition of B cell tolerance. In this example, the tolerant B cells were perfectly responsive to a competent ligand, and no indication of an altered triggering or effector processes was found. It appears that in this, as in many other cases of B cell tolerance, the systems or the animals are tolerant, whereas B cells maintain a resting nonactivated state and are fully responsive to the triggering signal. Thus, the existance oftolerance‐inducing signals resulting in B cell unresponsiveness isquestioned.
Induction of allergic encephalomyelitis using hydrosoluble mycobacterial fractions
Authors: Westall F. C. , Thompson Millie , Migliore‐Samour Daniele , Jollès P.
Published: February 2007

Experimental allergic encephalomyelitis has been induced in guinea pigs employing bovine myelin basic protein as the antigen and a hydrosoluble tetrasaccharide‐heptapeptide from delipidated cells of the human mycobacterial strain H37Ra as adjuvant. The maximum response was observed using 33 μg of antigen and 12.5 μg of adjuvant per animal.
The genetic control of T cell‐mediated immunity against the DBA/2 mastocytoma P‐815. II. Low responsiveness in T cell‐mediated cytotoxicity accompanied by the inability to produce antibodies in a secondary response
Authors: Kölsch E.
Published: February 2007

Low responsiveness of DBA/1 mice in T cell‐mediated cytotoxicity against the DBA/2 mastocytoma P‐815 (H‐2d) is genetically controlled and inherited as a recessive trait. For an analysis of the humoral anti‐H‐2d response of DBA/1 mice after immunization with P‐815 mastocytoma cells both complementdependent lysis (CDL) and the cytotoxicity inhibition assay (CIA) were used to demonstrate antibodies. Both assays show that DBA/1 mice are unable to produce anti‐H‐2d antibodies in a secondary response. Even high doses of immunizing cells give only a weak response. is fully recovered upon allogeneic interaction. A transient primary anti‐H‐2d activity can be found in the CIA but not by CDL.

The data show that the genetically controlled determinant‐specific defect in T cell‐mediated cytotoxicity among DBA/1 mice has its correlate in a blockade of memory formation or expression in the humoral anti‐H‐2d response.
Spontaneous release of T cell receptors for alloantigens. III. The effects of anti‐T cell receptor antiserum, of alloantiserum and of trypsin on T cell receptor release
Authors: Ramseier H.
Published: February 2007

Spleen and lymph node T lymphocytes cultivated in vitro spontaneously released receptors for alloantigens. Among the various specificities, those receptors fitting certain alloantigens could be absorbed by formolized cells or proper genotype without influencing receptors for other alloantigens

Shedding of T cell receptors could be inhibited for 8 h by treating cells with antisera directed against T cell receptors (anti‐RS antisera). Inhibition experiments indicated that resynthesis of T cell receptors appears to be complete by 8 h. Experiments on prevention of receptor shedding revealed highly specific and presumably cytotoxic elimination of T cells with receptors for given alloantigens.

Treatment of cells with alloantiserum obtained by skin graft rejection failed to inhibit spontaneous release of T cell receptors, whereas treatment of lymphocytes with trypsin resulted in an 8‐h delay of receptor shedding similar to that after treatment of cells with anti‐RS antisera. This inhibition was, however, nonspecific.
Derangements of immunoglobulin levels, phytohemagglutinin responsiveness and T and B cell markers in Down's syndrome at different ages
Authors: Burgio G. R. , Ugazio A. G. , Nespoli L. , Marcioni A. F. , Bottelli A. M. , Pasquali F.
Published: February 2007

Immunologic studies were performed in 83 patients with Down's Syndrome (DS) in ages ranging from a few months to 30 years and 76 karyotypically normal age‐matched controls. The results show that both thymus‐dependent and independent functions were impaired in DS with a characteristic age sequence.

Serum immunoglobulin levels were normal in children with DS less then 5 years old; after 6 years of age a definite hyperglobulinemia of the IgG and IgA type was observed. A slight decrease in IgM was observed between 16 and 25 years of age.

In subjects with DS lymphocyte phytohemagglutinin responsiveness was in the normal range during the first decade but it decreased thereafter progressively; the percentage and absolute number of peripheral blood lymphocytes forming “spontaneous rosettes” with sheep erythrocytes were abnormally low at all ages including infancy; the number of circulating lymphocytes with a high density of surface immunoglobulins was always in the normal range.
Formation of plaques by adherent spleen cells from nonimmunized mice, incubated in vitro with the nonadherent fraction of immune allogeneic cells
Authors: Löwy Ilana , Bussard A. E.
Published: February 2007

Twenty‐four‐hour incubation of adherent spleen cells from normal C57BL mice with purified nonadherent spleen cells from CBA mice, in the peak of their primary response against sheep red blood cells, resulted in the appearance of plaque‐forming cells in the adherent cell population. The immunological nature of these plaques was demonstrated by their complement dependency and the inhibitory effect of specific anti‐mouse IgM serum. Direct, but not indirect plaque formation was found to be associated with the adherent cell population for which direct cell to cell contact is necessary. Experiments with cytotoxic specific anti‐strain sera revealed that in this system, the adherent plaque‐forming cells are the nonimmune adherent C57BL cells.
Effect of alloantisera on the immune response of rat spleen cells against sheep red blood cells in vitro
Authors: Bhakdi‐Lehnen Birgit , Günther E.
Published: February 2007

Alloantisera directed against antigens determined by the major histocompatibility system or by the genetic background of the rate are able to completely inhibit the primary IgM immune response of rat spleen cells against sheep red blood cells in vitro. Full inhibition is elicited only when the alloantisera are added during the first 48 hours of cultivation. Alloantisera that inhibit a primary immune response do not inhibit a secondary IgM response to sheep red blood cells in vitro by spleen cells primed 10–28 days before.
A theory of regulation and self‐nonself discrimination in an immune network
Authors: Hoffmann G. W.
Published: February 2007

A mechanism is suggested for the regulation of the immune response that involves antigen‐binding and anti‐idiotypic lymphocytes. The cross‐linking of receptors is postulated to be a general mechanism for triggering T cells, B cells and cytotoxic effector cells (e.g. macrophages). A key role in regulation is ascribed to antigen‐specific T cell‐dependent factors, which are assumed to be able to block the receptors of both T cells and cells of the anti‐idiotypic specificities.

The simple postulates of the model lead to feasible mechanisms for the helper, suppressor and killer roles of T cells, cellular and humoral immune responses, low zone tolerance and the tolerogenic effects of monomers, immune memory, antigenic competition, the abrogation of tolerance with cross‐reacting antigens, the usefulness of the switch from IgM to IgG, and self‐tolerance to both serum antigens and cell surface antigens. Biological roles are suggested for one of the Ia antigens and β2‐microglobulin. The theory leads to a number of predictions, which can be tested experimentally.

A simple mathematical model is included, which provides an indication of how the theory may be further developed on a quantitative basis.
Induction of T and B cell immunity by anti‐idiotypic antibody
Authors: Eichmann K. , Rajewsky K.
Published: February 2007

A small dose of the IgG1 fraction of anti‐idiotypic antibody (āId 1) raised in guinea pigs against a strain A/J antibody specific for streptococcal Group A carbohydrate sensitizes A/J mice against Group A streptococci. This is opposed to the previously established suppressive function of anti‐idiotypic antibody of the IgG2 class (āId 2). Correspondingly, āId 1 but not āId 2 is eliminated from the circulation in the way typical of an immunogenic molecule. However, the stimulatory component in the IgG1 fraction is not necessarily itself IgG1 antibody.

Sensitization occurs in both B and helper T lymphocytes and is specific for Group A streptococci. In the B cell compartment sensitization is restricted to precursor cells expressing the idiotype. The concomitant activation of T helper cells therefore suggests that these cells make use of receptors with a similar or identical idiotype.

Efficient sensitization by āId 1 of both T and B cells is also demonstrated in strain C57L/J mice which upon immunization with Group A streptococci express a partially cross‐reacting idiotype as a minor component. When such animals were primed with āId 1, essentially all of the anti‐carbohydrate antibody carried the partially cross‐reacting idiotype.
Cross‐reactivity patterns of IgM and IgG anti‐lipopolysaccharide antibodies in individual mice
Authors: Di Pauli R.
Published: February 2007

A sensitive method has been developed which permits comparative analysis of IgM and IgG antibody specificity against lipopolysaccharide (LPS) antigen. It is based on hemolysis of LPS‐coated red blood cells and on its inhibition by homologous and heterologous LPS. By appropriate use of anti‐immunoglobulin sera, indirect (facilitated) lysis due to IgG antibodies is obtained, whereas IgM gives direct lysis and is 2‐mercaptoethanol‐sensitive. IgG can be analyzed either by facilitation with a rabbit anti‐mouse Ig or with anti‐allotype sera. By use of anti‐allotype sera in F1 hybrids, both parental antibody types can be studied separately.

Antibodies of either class from individual mice may display different cross‐reactivity patterns. Furthermore, for IgM and IgG within a given serum, both similarities and differences have been found. Some of the cross‐reactivity patterns have been followed over one year. With few exceptions, individual patterns remained constant throughout this period.
Immunoglobulin‐bearing lymphocytes of the chicken. I. Heavy chain immunoglobulin commitment and organ distribution
Authors: Hudson L.
Published: February 2007

When purified anti‐immunoglobulin light chain antibodies were used in indirect immunofluorescence or labeled with 125I for autoradiographic staining, a similar percentage of Ig‐bearing lymphocytes were detected by both techniques in lymphoid cell suspensions from the thymus or blood of 8–14‐week‐old chickens. However, a larger proportion of Ig positive lymphocytes were detected in suspensions of bursal cells by the more sensitive autoradiographic method, suggesting a lower surface density of Ig: perhaps on newly differentiated stem cells. In thymus and spleen suspensions, the proportions of Ig positive lymphocytes carrying μ and γ‐chains were roughly equal, whereas in the B cell populations of the bursa and blood, cells carrying surface γ‐chains predominated. IgA‐bearing lymphocytes were only a minor population (<5%) in lymphocyte suspensions prepared from the thymus, bursa, blood and spleen of adult chickens, but formed almost 50% of the Ig‐bearing lymphocytes in the caecal tonsils.
Suppression of immune responses to sheep red cell antigens in rats preimmunized with heterophilic antigen: cellular events
Authors: Hellering I. , Stern K.
Published: February 2007

Depression of humoral immune response to sheep red cells (SRC) has been observed in rats previously immunized with heterophilic (Forssman) antigen. Analogous phenomena were observed by assay of splenic plaque‐forming cells obtained from rats immunized in vivo with heterophilic antigen (HA) and challenged with SRC. Isophilic immune responses were almost completely suppressed. Kinetics of the primary and secondary immune responses were analyzed. Intervals of two to four days between administration of HA and SRC yielded maximal suppression. Primary immune responses to SRC were determined in cultures of splenic cell suspensions derived from rats which had been either injected in vivo with HA or received no treatment. Under these conditions, too, administration of HA interfered with the antibody responses to SRC. Both adherent and nonadherent cells caused inhibition, with this property appearing earlier in adherent than in nonadherent cells. A hypothesis, capable of explaining the observations made in this study and compatible with similar phenomena described in other systems, has been proposed according to which after immunization with HA, SRC are diverted to HA‐stimulated cells which are not equipped to deal with the antigen complex represented by SRC.
Comparison of specificities of humoral and cellular immune responses to haptens
Authors: Alkan Ş. Ş. , El‐Khateeb M.
Published: February 2007

In this study we induced humoral and cellular immunity to three isomers of aminosulfanilic and aminobenzoic acids and compared their respective specificities. These studies were facilitated by using a new method for preferentially inducing a cellular immune response to haptens: the haptens were covalently coupled to mycobacteria and injected into animals in incomplete Freund's adjuvant. Humoral antibody was iduced by coupling the same isomers to bovine serum albumin and injecting them into animals in complete Freund's adjuvant. Both groups of animals were examined for hapten‐specific cellular immunity (migration inhibition factor, delayed skin tests) and for antibody response (passive hemolysin test). The results show that although both cell‐mediated and humoral responses can discriminate the para, meta and ortho isomeric forms of the haptens used, the antibody response demonstrated much less cross‐reactivity. The relevance of this finding to different requirements for B and T cells in antigenic recognition is discussed.
The migration of recirculating autologous and allogeneic lymphocytes through single lymph nodes
Authors: Frost H. , Cahill R. N. P. , Trnka Z.
Published: February 2007

Using cannulated single lymph nodes in sheep the migration of 51 Cr‐labeled autologous and allogeneic recirculating lymphocytes (RL) into efferent lymph was studied after i. v. infusion and infusioninto an afferent lymphatic. The majority of autologous and allogeneic RL appeared in efferent lymph 27–36 h after their infusion i. v. and 6–12 h after intralymphatic infusion. The recovery of i. v. infused allogeneic RL in efferent lymph was only 5–10% that of autologous RL. In contrast, there was no difference in the recovery of autologous and allogeneic RL after infusion into an afferent lymphatic. In primed animals the migration of allogeneic RL through a lymph node was completely inhibited.
Studies on the maturation of thymus stem cells The effects of catecholamines, histamine and peptide hormones on the expression of T cell alloantigens
Authors: Singh Upendra , Owen J. J. T.
Published: February 2007

Studies have been performed in order to investigate the effects of catecholamines, histamine, peptide hormones and various other agents known to increase cellular adenosine 3′:5′‐cyclic monophosphate (cAMP) levels, on the expression of Thy‐1 and TL antigens on 14‐day fetal thymic stem cells. It has been shown that the proportions of Thy‐1 and TL positive cells, as detected by dye exclusion cytotoxicity tests, can be significantly increased by some of these agents and that these effects may be inhibited by β adrenergic and H2 antagonists. The value of these tests as a means for studying normal thymic stem cell maturation and for investigating T cell deficiency is discussed.
Cytophilic activity of enzymatically derived fragments of guinea pig IgG2
Authors: Alexander M. D. , Leslie R. G. Q. , Cohen S.
Published: February 2007

The hydrolysis products from short term exposure of guinea pig IgG2 to papain and pepsin have been characterized. Papain hydrolysis liberates 4 types of Fc fragment, only one of which retains both an interchain disulfide bond and an intact CH2 domain, cFc, mol. wt. 56 000. The other three fragments noncovalently linked Fc (nFc) (mol. wt. 56 000), incomplete Fc (iFc) (mol. wt. 39 000) and Fc′ (23 000) represent further degradation products of covalently linked complete Fc (cFc). The cytophilic activities of these fragments as well as F(ab′)2 and pFc′ from pepsin hydrolysis, were studied to determine the domain(s) responsible for binding to homologous peritoneal macrophages. Only the native immunoglobulin and the intact cFc manifested cytophilic activity; in particular pepsin‐derived pFc′ and Fc′ were inactive. Following mild reduction and alkylation, performed to affect only the interchain disulfide bonds, the cytophilic activity of cFc was markedly reduced. The low cytophilic activity in the pFc′ fragment suggests that the CH2 domains play a major part in binding to the macrophage Fc receptor through a site(s) stabilized by the interchain disulfide bonds.
The requirement for tetravalency of soybean agglutinin for induction of mitogenic stimulation of lymphocytes
Authors: Schechter B. , Lis H. , Lotan R. , Novogrodsky A. , Sharon N.
Published: February 2007

The mitogenic activity of soybean agglutinin was found to depend on the presence of lectin aggregates formed in lectin preparations stored in the lyophilized state. Such soybean agglutinin preparations gave maximal stimulation of untreated pig lymph node cells and neuraminidase‐treated mouse spleen cells at relatively high concentrations, ranging from 100 to 2000 μg/ml. After separation into unaggregated (divalent) and polymeric (tetra‐and multivalent) fractions, it was found that the unaggregated lectin did not stimulate the cells, while the tetravalent and multivalent fractions were active and gave maximal stimulation at a concentration of 10 μg/ml. These results suggest that soybean agglutinin must have at least four sugar binding sites in order to be able to stimulate lymphocytes.
H‐2 antigen‐specific cytotoxic T cells induced by concanavalin A: estimation of their relative frequency
Authors: Bevan M. J. , Langman R. E. , Cohn M.
Published: February 2007

Specific and nonspecific lysis of DBA/2 (H‐2d) mastocytoma cells, P815, by concanavalin A (Con A)‐induced cytotoxic T cells was studied. In the assay for nonspecific lysis, phytohemagglutinin (PHA) was present to glue the target and killer cells together. We have presented evidence previously to show that PHA reveals only, and all, cytotoxic T cells. In the assay for specific lysis the only glue present was specific receptors on a fraction of the killer cells and surface antigens of P815. We show that when PHA was present, Con A‐induced cells which were syngeneic, semi‐syngeneic, or allogeneic, lysed P8 15 very efficiently in a 4‐h51Cr release assay. However, only Con A‐induced T cells which were allogeneic and did not carry H‐2d lysed P815 when the assay was carried out in the absence of PHA. In an experiment with two target cells, Con A‐induced B10 (H‐2b) T cells lysed B 10.D2 (H‐2d) targets specifically but did not lyse B10 targets, while Con A‐ induced B10.D2 T cells lysed B10 targets specifically but not B10.D2 targets. Furthermore, Con A‐induced B6 (H‐2b) T cells from normal mice lysed P815 specifically but Con A‐induced B6 T cells from irradiated F1(B6 × BALB/c) (H‐2b/d) mice reconstituted with B6 bone marrow did not lyse P815 specifically. A fraction of Con A‐induced T cells therefore appear to bear specific surface receptors for nonself H‐2 coded structures. We describe conditions of assay and a new method of plotting the results such that nonspecific (PHA‐revealed) and specific (PHA‐independent) cytotoxicity can be quantitatively compared. We conclude that 1–4 % of the total Con A‐induced cytotoxic effector T cells are directed against any particular foreign H‐2 haplotype. This is the first estimate of the relative frequency of antigen‐reactive cytotoxic T cells.
Frequency of precursor cells against the enzyme β‐galactosidase An estimate of the BALB/c strain antibody repertoire
Authors: Köhler G.
Published: February 2007

A method has been developed for detecting anti‐β‐galactosidase antibodies after isoelectric focusing in thin layers of polyacrylamide gel. By “staining” with wild‐type enzyme, all antibodies against β‐galactosidase are detected, while a subset of antibodies able to activate a mutant enzyme is detected by staining with that enzyme.

Limiting dilutions of β‐galactosidase‐primed or unprimed spleen cells of BALB/c mice were transferred together with antigen into sublethally irra‐diated syngeneic hosts. The limiting role of the precursor B cells has been judged by the analysis of the clonal distribution of galactosidase‐specific antibodies in recipient sera. The frequency of anti‐wild‐type β‐galactosidase precursor cells was one in 0.42 × 106 in the primed and one in 0.93 × 106 in the unprimed spleen. The frequency of precursor cells for antibodies activating the mutant enzyme was one in 1.5 × 1O6 in the primed and one in 4.6 × 106 in the unprimed spleen. Therefore four and five times less anti‐B (mutant) than anti‐B (wild‐type) precursor cells exist in the spleens of primed and unprimed BALB/c mice, respectively.

Comparing 51 clones derived from one primed donor mouse, it was possible to demonstrate that at least 43 different mutant‐β‐galactosidase‐activating antibodies can be produced in one mouse. Comparing these 43 clones with 27 clones derived from another donor mouse, only one clone seemed to be common to both mice. From this the repertoire of the BALB/c strain has been estimated to consist of over 1000 different mutant enzyme‐activating antibodies.
Immune complex nephritis in Schistosoma mansoni‐ infected mice
Authors: Natali P. G. , Cioli D.
Published: February 2007

Swiss outbred mice infected with 80–100 cercariae of Schistosoma mansoni developed in 60 % of the cases a wide range of glomemlar lesions involving mainly the mesangium. The lesions were associated with the presence of granular deposits of murine immunoglobulins and C3, suggesting an immune complex mechanism. In addition, nephritic glomeruli in about 20 % of the cases could be stained by a specific rabbit antischistosoma serum after removal of excess host immunoglobulins. The presence of circulating immune complexes in the serum of infected animals was suggested by the increased molecular weight of circulating C3. The onset of the immunopathologic lesions appeared to be related to duration, intensity and type of infection. Single‐sex parasite infection, in fact, led to significant reduction of glomerular lesions.
Mechanisms by which hapten conjugates of pneumococcal polysaccharide interfere with the challenge of anti‐hapten memory cells
Authors: Romano T. J. , Lerman S. P. , Thorbecke G. J.
Published: February 2007

Incubation of trinitrophenylated hemocyanin (TNP‐KLH)‐primed spleen cells with microgram amounts of 2,4‐dinitrophenyl (DNP) or 2,4,6‐trinitrophenyl (TNP) conjugates of pneumococcal polysaccharide type 3 (SIII) for as little as 5 min at 4 °C results in a specific “block” of the 19 S and 7 S adoptive memory response to TNP‐KLH. This hapten‐SIII‐induced block of anti‐hapten memory B cell responsiveness seems to be an example of specific receptor blockade. The block is specific and can be prevented by simultaneous incubation of the primed cells with hapten‐protein conjugates which presumably compete with the hapten‐polysaccharide for attachment to the B cell surface via anti‐hapten Ig receptors. Removal via capping of these Ig receptors by exposure of TNP‐KLH‐primed memory cells to rabbit anti‐mouse Fab serum for 45 min at 37 °C renders these cells refractory to the blocking effect of hapten‐SIII. Once the hapten‐SIII has attached to the memory cells, these blocked cells can be “rescued” (i.e. returned to a state of responsiveness) by incubating these cells with either mouse anti‐SIII at 37 °C or rabbit anti‐DNP serum at 4 °C. Since a papain digest of the IgG fraction of rabbit anti‐DNP did not rescue the cells while the intact IgG did, a capping off of the TNP‐SIII was proposed as the mechanism for this return to responsiveness of the hitherto blocked cells. A rescue was not seen by treatment of recipient mice with such B cell mitogens as dextran sulfate, endotoxin or purified protein derivative of tuberculin.
Migratory patterns of B lymphocytes. V. Surface Ig and migration properties of density gradient‐separated bursa cells
Authors: Dekruyff R. H. , Onikul S. R. , Thorbecke G. J.
Published: February 2007

A study was made of bovine serum albumin density gradient‐separated bursa cells with respect to their distribution on the gradients, % cytotoxicity with anti‐Ig + complement (C) or anti‐μ + C, and localization of fractions in irradiated syngeneic recipients. Layer A showed a higher cytotoxicity with anti‐Ig + C or anti‐μ + C than the others; layer D showed the lowest % cytotoxicity, although a large % of the cells not killed by anti‐Ig were killed by anti‐bursa serum + C. The C + D layers contained a much larger fraction of the Ig+ cells from the bursa in the 1–4‐week‐old than in the 6–12‐week‐old animals, suggesting a relative shift towards lower density of Ig+ bursa cells with age.

When [3H]adenosine‐labeled bursa cells from density gradient fractions were transferred, the % injected radioactivity found in recipient spleens was higher for fractions A and B than for fraction C + D. While 50–60 % of the cells from fractions A and B which localized in spleen were found in germinal centers and follicles, a much lower % of the cells from fraction C + D seen in spleen localized in these areas. The results were in agreement with those of previous studies suggesting that it is primarily the Ig‐bearing population among bursa cells which localizes in follicles.
Induction of immune responsiveness in a genetically low‐responsive tumor‐host combination by chemical modification of the immunogen
Authors: Galili Naomi , Naor D. , Åsjö Birgitta , Klein G.
Published: February 2007

Trinitrophenylated Moloney virus‐induced YAC cells induced a higher cytotoxic antibody response and better protection against small tumor cell doses in syngeneic, low‐responsive strain A mice than nonmodified YAC cells that had been inactivated by irradiation or mitomycin C treatment. The results indicated that genetically determined low responsiveness to a virally induced antigen can be overcome, at least to some extent, by coupling the immunizing cells to a strong immunogenic hapten.
Immunosuppressive activity of Phaseolus coccineus and Phaseolus vulgaris extracts in mice
Authors: Calderón Raquel A. , Córdoba F.
Published: February 2007

Lectin mixtures from 10 samples of Phaseolus coccineus and Phaseolus vulgaris beans were used as immunosuppressive agents in the sheep red blood cell (SRBC) antibody response of the mouse. Some bean samples contain lectins capable of inducing several times better suppression of humoral immunity than concanavalin A and phytohemagglutinin tested before in the same immune system.

High dilutions of the 10 bean extracts were shown to agglutinate mouse, rabbit and sheep erythrocytes in vitro but the titers and “specificities” did not correlate with the immunosuppressive potency and selectivity displayed by the same extracts in mice.

Two immunosuppressive bean extracts, assayed in lymphocyte cultures, were found to stimulate DNA synthesis of murine spleen T cells. This interaction appears to be a necessary step for the reduction of antibody synthesis to SRBC in the whole animal.
A study of the immunoglobulin classes present on the membrane and in the cytoplasm of human tonsil plasma cells
Authors: Ferrarini M. , Viale Giovanna , Risso Angela , Pernis B.
Published: February 2007

The problem of whether immunoglobulin (Ig)‐containing plasma cells expressed membrane Ig has been investigated using cells from human tonsils. In tonsils, IgG‐containing cells are predominant, but a certain number of IgM, IgA and IgD‐containing cells are also present. By using a double staining immunofluorescent technique for the simultaneous detection of membrane and intracytoplasmic Ig, it has been possible to ascertain that the large majority of IgA, IgM and IgD‐containing cells had membrane immunoglobulin (mIg) of a class coincident with that of intracytoplasmic Ig. In addition a noticeable proportion of IgM‐containing cells expressed membrane IgD, thus indicating that a certain number of these cells bore both membrane IgM and IgD. About 60 % of IgG‐containing cells had membrane IgG, while the remaining cells did not express mIg. Furthermore the surface staining of these cells was generally fainter than that of the cells containing other Ig classes.

Experiments on the surface light chain type expressed by the single Ig‐containing cells (IgCC) as compared to that found in the cytoplasm have shown that in the large majority of IgCC the light chain type of mIg coincided with that of intracytoplasmic Ig. Discordant light chain types of membrane and cytoplasmic Ig were found on about 12% of IgCC only. These values can be taken as a measure of how many IgCC had passively acquired mIg.
Expression of la determinants on immunocompetent cells
Authors: Hämmerling G. J. , Eichmann K.
Published: February 2007

The expression of Ia (immune response region‐associated) antigens on the surface of lymphocyte subpopulations with defined immunological functions has been investigated by negative selection of subpopulations with anti‐Ia sera and complement. la determinants were found on both unprimed (IgM) and on primed (IgG) antibody‐forming precursor cells. No Ia antigens were detected on the surface of helper T cells. In contrast, suppressor T cells were sensitive to treatment with anti‐Ia sera and complement demonstrating the presence of Ia determinants on this T cell subpopulation.
Antigenic determinants of heavy chain variable regions: immunological typing of the human immunoglobulin VHIII subgroup
Authors: Rivat Liliane , Rivat C. , Lebreton J.‐P. , Ropartz C.
Published: February 2007

An antigenic determinant of the VHIII variable region subgroup was defined by means of a heterologous specific antiserum using a hemagglutination inhibition procedure. The specificity of this antiserum was established in inhibition experiments with proteins either of known primary structure or belonging to a definite VH subgroup.

A series of IgG, IgA, IgM and IgD monoclonal proteins was examined for the presence of this VHIII subgroup antigenic determinant. The data showed that 50% of the IgG, 62% of the IgA, 55 % of the IgM and 41% of the IgD were VHIII‐positive, and that certain “blocked” monoclonal immunoglobulins belonged to this subgroup. A preferential association of the VHIII antigenic determinant with the IgG1 and IgG3 subclasses was observed among IgG myeloma proteins while the preferential association was only observed with the JgG1 subclass when anti‐Rh antibodies were studied. The VHIII subgroup exhibited nonallelic behavior.
Role of epitope density in the induction of tolerance and immunity with thymus‐independent antigens. III. Interaction of epitope density and receptor avidity
Authors: Desaymard Catherine , Pearce Barbara , Feldmann Marc
Published: February 2007

The induction of B cell tolerance to 2,4‐dinitrophenyl conjugates of polysaccharide antigens (levan or dextran) was studied in mice primed with keyhole limpet hemocyanin (KLH) or 2,4,6‐trinitrophenylated KLH. The relationship of the epitope density of the tolerogen with avidity of B cell receptors (as judged indirectly by a plaque inhibition assay) was investigated. It was found that high avidity precursors (IgG) were tolerized by antigen of much lower epitope density, and at lower concentration, than were low avidity precursors (especially IgM cells). IgA cells were intermediate in behavior. These results suggest that the epitope density effect acts by ensuring a necessary degree and/or energy of antigen binding.
T cell necessity in the pathogenesis of experimental autoimmune encephalomyelitis in mice
Authors: Bernard C. C. A. , Leydon Jennifer , Mackay I. R.
Published: February 2007

Cellular transfer of experimental autoimmune encephalomyelitis (EAE) was effected in mice with lymph node and spleen cells from appropriately immunized donors. In contrast to lymphoid cells, immune serum did not transfer this autoimmune disease nor did serum have any facilitating or inhibitory effect on the capacity of lymphoid cells to transfer EAE. Transfer of EAE was effected in normal mice, lightly irradiated (350 rad) and lethally irradiated (850 rad) and bone marrow‐protected mice, but not in mice which had been given 850 rad total‐body irradiation. There was a striking augmentation of severity of transferred EAE in the lightly irradiated recipients, possibly attributable to selective radiosensitivity of suppressor T cells. Cell‐mediated immunity but not circulating antibody to basic protein of myelin was demonstrated in recipients with transferred EAE.

The immune lymphoid cells responsible for transfer of EAE were T lymphocytes. Thus transfer was successful after passage of sensitized cells through anti‐immunoglobulin columns and was abrogated following treatment with anti‐Thy‐1 serum and complement.

Neonatally thymectomized mice failed to develop either EAE, cell‐mediated immunity or humoral antibody against myelin basic protein (BPM). Inhibition of EAE and immune responsiveness was solely due to the removal of the source of thymus lymphocytes, because reconstitution of neonatally thymectomized mice with T lymphocytes completely restored these functions. It is concluded that T lymphocytes are required for the production and adoptive transfer of EAE, for the development of cell‐mediated immunity to BPM and for the production of antibody to BPM.