bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunoferitin analysis of membrane antigen density: A. young and old human blood cells B. developing erythroid cells and extruded erythroid nuclei
Authors: Skutelsky E. , Marikovsky Yehuda , Danon D.
Published: February 2007

Two immunoferritin techniques, (a) ferritin‐conjugated antibodies and (b) hybrid antibodies, were used to determine the surface antigen density on separated human young and old erythrocytes and on differentiating rabbit erythroid cells. The alterations of surface antigenicity caused by treatment of erythrocytes with neuraminidase were similarly studied.

Old untreated cells have about a 25 % higher labeling density as compared with the young ones. The same age groups when treated with neuraminidase show a 45 % increase in labeling density as compared with untreated cells, but without significant differences between young and old cells. Counts performed on cell membranes labeled with ferritin‐conjugated antibodies or with hybrid antibodies revealed very similar results with both techniques.

A progressive increase in labeling density, reaching a maximum at the orthochromatic erythroblast, follows the erythroid cells' division. A slight decrease in antigen density is observed on the reticulocyte. Some cross‐reaction with leukoid precursors is also observed. A possible correlation between the reduction of negative surface charge and the increase in membrane antigen density is pointed out.

Expelled erythroid nuclei, surrounded by a narrow rim of cytoplasm and membrane, are more heavily labeled than other erythroid cells of the bone marrow. The increase in antigen density on the membrane surrounding the nucleus is already apparent when the nucleus is partially expelled.

The alterations in the surface antigen density on old or neuraminidase‐treated erythrocytes and on expelled erythroid nuclei are attributed to the appearance of antigens previously masked by the neuraminic acid.

The possibility that the increased membrane antigen density on the surface of old erythrocytes and expelled erythroid nuclei, as well as the reduction in negative surface charge, reflects factors determining the recognition of deteriorated membranes by macrophages and leading to their sequestration is discussed.
Immunoglobulin classes in the hen's egg: Their segregation in yolk and white
Authors: Rose M. Elaine , Orlans Eva , Buttress N.
Published: February 2007

Hen's egg yolk contains at least two antigen‐binding subclasses of IgG, derived from the hen serum and transmitted to the chick. IgM and IgA, absent in yolk and in newly hatched chick serum, were detected in the white of unembryonated eggs, in the amniotic fluid of embryonating eggs and in the digestive tract of 19‐day embryos, which also contained IgG. The dual mode of transfer found for maternal Ig of different classes in the fowl is compared with the transfer of maternal immunity in mammals.
Cell‐mediated cytotoxicity to trinitrophenyl‐modified syngeneic lymphocytes
Authors: Shearer G. M.
Published: February 2007

Spleen cells from B10 congenic mouse strains were cultured in vitro by a modification of the Mishell‐Dutton technique with trinitrophenyl (TNP)‐modified syngeneic spleen cells. Five days later, the effector cells generated were incubated with 51 Cr‐labeled unmodified or TNP‐modified spleen or tumor target cells, and the percentage of specific lysis determined. The results obtained using modified syngeneic as well as congenic target cells indicated that although TNP‐modification of the target cells was necessary to obtain lysis, the cytotoxicity was not specific for TNP exclusively, but was primarily directed against modified syngeneic cell surface components which may or may not have included the TNP moiety as an integral part of the recognition unit. A number of criteria were used to demonstrate that the phenomenon was attributed to T cell‐mediated cytotoxicity, and was not due to lymphocyte‐dependent antibody (LDA). These included: (a) failure of TNP‐lysine to block the effector phase; (b) lack of detectable LDA in the culture media; (c) failure of spleen cells from athymic nude donors to generate effector cells; (d) sensitivity of effector cells to rabbit anti‐mouse brain serum; and (e) the generation of effector cells by cortisone‐resistant thymocytes. The specificity observed between the syngeneic TNP‐modified sensitizing and target cells is compatible with the hypothesis that the TNP is altering cell surface proteins which are controlled by genes within distinct regions of the H‐2 major histocompatibility complex, and that these proteins are conformationally changed so as to be immunogenic to syngeneic thymus‐derived lymphocytes.
The nonspecific helper effect of mixed lymphocyte reactions on the induction of T cell‐mediated immunity in vitro
Authors: Altman A. , Cohen I. R.
Published: February 2007

We compared induction of sensitization in the mixed lymphocyte reaction (MLR) and in a mouse anti‐fibroblast reaction. Our study demonstrated that induction processes in these two reactions, both known to be T cell‐mediated reactions, are governed by different factors. Moreover, these two reactions interact with each other and this interaction is manifested by the ability of a MLR occurring during the sensitization phase of the anti‐fibroblast reaction to enhance specific cytolysis measured during the effector phase. This helper effect appears to be immunologically nonspecific, since it can be obtained by the use of third party, antigenically unrelated lymphocytes as stimulator cells in the MLR.
Cellular events in tolerance. IV. The effect of a graft‐versus‐host reaction and endotoxin on hapten‐ and carrier‐specific tolerance
Authors: Ornellas E. P. , Sanfilippo F. , Scott D. W.
Published: February 2007

The induction of hapten‐specific and carrier‐specific unresponsiveness has been used as a model of B and T cell unresponsiveness, respectively. Endotoxin (lipopolysaccharide (LPS)) and a graft‐versus‐host (GVH) reaction were then evaluated for their ability to interfere with the induction of B and T cell tolerance in vivo. It was found that LPS, but not a GVH reaction had adjuvant activity in that LPS could convert a B cell tolerogenic signal into an immunogenic one. However, both treatments could partially prevent B cell tolerance induction with trinitrophenyl‐isologous IgG. Under conditions in which the GVH‐induced immunosuppression was minimal, carrier (T cell) tolerance was also reduced by the GVH reaction. LPS did not directly interfere with carrier unresponsiveness. We conclude that LPS can block the induction of unresponsiveness in B cells, whereas a GVH reaction can partially affect both T and B cell tolerance induction.
Direct triggering of B lymphocytes by insolubilized antigen
Authors: Feldmann Marc , Greaves M. F. , Parker D. C. , Rittenberg M. B.
Published: February 2007

The in vitro immune response of mouse spleen cells to trinitrophenylated keyhole limpet hemocyanin (TNP‐KLH) conjugated onto Sepharose beads, TNP‐KLH(B), was investigated. Both primed and unprimed spleen cells responded well to this antigen. TNP‐KLH‐primed spleen gave a greater IgM, but a lesser IgG response to TNP‐KLH(B) than to soluble TNP‐KLH (TNP‐KLH(S)), regardless of its concentration. Spleen cell populations depleted of T cells or macrophages responded well to TNP‐KLH(B), but not to TNP‐KLH(S). Thus, TNP‐KLH(B) directly activates B cells, and the conjugation of a thymus‐dependent antigen, TNP‐KLH, to a particle, Sepharose, rendered it thymus independent. Varying the amount of TNP‐KLH conjugated per bead markedly affected their stimulatory capacity, independently of the total amount of antigen added per culture. No responses occurred with very low or very high substitution levels. In addition, it was found that TNP directly conjugated to aminoethylated polyacrylamide beads at low substitution levels is immunogenic for unprimed spleen cells.

The immunogenicity of TNP‐KLH(B) and trinitrophenylated polyacrylamide beads indicates that binding of antigen at the surface of a cell is sufficient to stimulate it, and that interiorization of intact antigen is not necessary in this process. Furthermore, these results can be interpreted on the basis of a matrix mechanism of B cell triggering, which involves the simultaneous binding of multiple antigenic determinants to B cell receptors.
Induction of B cell tolerance to polysaccharides by exhaustive immunization and during immunosuppression with cyclophosphamide
Authors: Howard J. G. , Courtenay Barbara M.
Published: February 2007

Mice immunized with an optimal (10 μg), but not suboptimal, dose of levan (LE) became specifically unresponsive to a second dose given 2–8 weeks later. No evidence which could implicate an active suppression mechanism was found. In particular (a) spleen cells from unresponsive donors did not inhibit normal cells in a transfer system; (b) equilibration of serum antibody following 2 days celomic parabiosis between LE‐treated and normal mice did not impair responsiveness of the latter. It was concluded that B cells were exhausted in the absence of memory cell accumulation. LE can therefore induce specific B cell deletion, not only directly with 1 mg, but also following immunization with 10 μg. The exhaustive capacity of another polysaccharide, SIII, was found to be much weaker.

Cyclophosphamide (CP) (150 mg/kg) completely suppressed the responses to LE and SIII when injected with them. Recovery following CP alone was nearly complete 2 weeks later, but simultaneous injection of an immunizing amount of LE was succeeded by dose‐related specific tolerance. Total suppression followed only 100 ng LE + CP, a 10 000‐fold reduction in the “high zone” tolerizing dose. The corresponding reduction in SIII experiments was only 5‐fold.

The times for recovery following transfer of spleen cells from donors tolerant of LE in the exhaustion and CP models were 2 and 4 weeks, respectively; periods commensurate with B cell renewal.

The basis for these further differences in the tolerogenic properties of LE and SIII are discussed.
Clones of antibody‐forming cells in pokeweed mitogen‐stimulated microcultures. I. Requirements for the induction of the antibody response of nude spleen cells
Authors: Quintáns J. , Lefkovits I.
Published: February 2007

The effect of pokeweed mitogen (PWM) on the activation of precursor cells specific for sheep red cells (SRC) was studied in the microculture system. It was found that:

(a) PWM does not augment the response of nude spleen cells in the absence of T cells.

(b) When microcultures of nude spleen cells are supplemented with irradiated allogeneic spleen cells, the addition of PWM increases the number of precursor cells engaged in the anti‐SRC response.

(c) Allogeneic supernatant produced in the presence of PWM is more active than that produced in the absence of PWM.
The in vivo effects of concanavalin A on the cellular immune response in BALB/c mice. Inhibition of the delayed hypersensitivity reaction to tuberculin
Authors: Davis S. , Boone C. W.
Published: February 2007

The suppressive effect of concanavalin A (Con A) on the cell‐mediated immune response was demonstrated in BALB/c mice made immune to challenge with tuberculin. 400 μg of Con A administered intraperitoneally simultaneously with injection of antigen into the footpad of primed animals resulted in suppression of the delayed hypersensitivity reaction as detected by a sensitive radioisotopic footpad assay. If Con A was given in a dose of 100 μg three times weekly to normal mice being sensitized to tuberculoprotein, the maximum immune response following complete immunization was significantly suppressed but not abolished.

The suppressive effect of Con A appeared to be due to its binding to cell membranes, since splenic lymphocytes obtained from Con A‐treated immune mice failed to respond in the local adoptive transfer reaction to tuberculin. The lymphocytes regained their immune reactivity to tuberculin if they were first incubated in α‐methyl‐D‐mannoside.

These findings represent the first demonstration of in vivo immunosuppression by Con A of the tuberculin immune response in the mouse. Both the inductive and established responses of the delayed hypersensitivity reaction appear to be affected. The reversible inhibition of the local adoptive transfer of tuberculin immunity suggests the depression of the response is due to binding to or alteration of antigen receptor sites by Con A.
The anti‐virus activity of double‐stranded RNA in the presence of antibody to double‐stranded RNA
Authors: Naysmith J. D. , Sharpe T. J. , Planterose D. N.
Published: February 2007

Mice were given double‐stranded RNA from a fungal source either in saline or emulsified in Freund's complete adjuvant. In each case the animals produced antibodies specific for double‐stranded RNA.

Mice immunized in this way were as well protected against infection with encephalomyocarditis virus following a subsequent injection of double‐stranded RNA as were nonimmunized mice.
Immunogenicity and antigenic specificity of the loop fragment of lysozyme
Authors: Geiger B. , Arnon Ruth
Published: February 2007

The immune response in DBA/1 mice towards the loop fragment of hen egg‐white lysozyme (residues 60–83) was assessed by testing for circulating antibodies on the one hand, and antibody‐forming cells on the other hand. According to the latter criterion, the free loop peptide is immunogenic, eliciting both primary and secondary immune responses. The involvement of T cell population in this response is indicated by the capacity of the loop to exert a “carrier” effect.
Changes in lymphocytes recirculation and liberation of the adoptive memory response from cellular regulation in irradiated recipients
Authors: Cell E. B. , Shand F. L.
Published: February 2007

Thoracic duct lymphocytes from previously immunized (AS2 × As)F1 rats (′TDL), were adoptively transferred to syngenic recipients and triggered by soluble HSA (s‐HSA) the following day. The response of ′TDL in an irradiated recipient was almost two orders of magnitude greater than the response in a nonirradiated adult host. The affinity of the antibody in the adult recipients was significantly reduced, but increased with time. Nonirradiated young recipients (3 weeks old) also supported an adopitve memory response which was comparable in quantity and quality to that found in irradiated host. Theb response of ′TDL declined progressively when transferred into 2‐week‐old or 4‐week‐old radiation chimeras, or was reduced in irradiated hosts when the memory cells were mixed together with nonimmune TDL. The experiements indicate that the differental response between the adult and irradiated recipient is the result of a restrictive control in the former host rather than an enhancing factor in the latter. Lymphocytes in the nonimmune population regulate both the expansion and maturation of the adoptive memory response, the high energy‐binding B cells being at a selective disadvantage. Host irradiation effectively liberates the adoptive response from this cellular control mechanism.

A comparative study of transferred, [14C]leucine‐labeled TDL shows that distribution and homing of lymphocytes to lymph nodes and spleen was not altered by irradiating the recipients. However, adoptively tranferred cells almost completely failed to recirculate in irradiated rats, in contrast to normal recipients. But, the injection of large numbers of unlabeled TDL following irradiation forced more labeled cells into the recirculating pool, suggesting that saturation of depleted lymphoid tissue with lymphocytes is an important factor regulating lymphocytes traffic. The relevance of this „saturation effect”︁ in regulating the adoptive memory response is discussed.
Rabbit alpha‐fetoprotein: normal levels and breakage tolerance with haptenated homologous alpha‐fetoprotein
Authors: Ruoslahti E. , Pihko Helena , Becker M. , Mäkelä O.
Published: February 2007

Nanogram quantities of alpha‐fetoprotein (AFP), a tumor associated fetal protein, were found in the serum of normal adult rabbits by radioimmunoassay. This AFP was isolated and shown to be immunologically identical to fetal AFP by immunodiffusion. Immunizations of rabbits with unmodified or desialylated AFP in complete Freund's adjuvant did not cause antibody formation, indicating the existance of tolerance against homologous AFP. The tolerance could be terminated by immunizing with hapten‐coupled AFP, which resulted in production of rabbit antibodies reacting with unmodified rabbit AFP.
Similar combining sites of IgG1 and IgG2a antibodies in individual mice as judged from affinity and rate constant measurements
Authors: Trissl Dorothea , Kolb H.
Published: February 2007

Within individual sera, mouse IgG1 and IgG2a subclass antibodies against the antigenic detetminant oligio‐D‐Allanine are likely to have similar combining sites. The antibodies are characterized by two methods, by their rate of binding to antigen equipped sheep red blood cells and by the hapten inhibition of antigen binding. The two characteristics are shown to be independent. The subclass antibodies of thirteen different sera differ by a factor of about 10 in their rate constant and by a factor of about 50 in affinity for hapten. In contrast, IgG1 and IgG2a within the same serum have strikingly similar rate constants (factor 1.02–1.33) as well as very similar affinities (factor 1.1–2.7). Since it is higly improbable that correlation in two independent criteria occurs by chance, the IgG1 and IgG2a antibodies are asssumed to have similar combining sites.
Quantitative analysis of an idiotypic determinant of light chains of normal human IgG and IgM
Authors: Ruffilli Ann , Menegozzo M.
Published: February 2007

Normal light chains of human IgG and IgM were analyzed for the presence of the idiotypic determinant of light chains identified by anti‐„a”︁. A quantitative evaluation indicated that this marker of the variable region was present in light chains obtained from IgG nd IgM: however, light chains reacting with anti‐„a”︁ were preferentially associated with IgG molecules.
Influence on allograft rejection of thymectomy at different stages of larval development in urodele amphibian Pleurode waltlii Michah. (Salamandridae)
Authors: Fache B. , Charlemagne J.
Published: February 2007

Thymectomy was performed on the urodele amphibian Pleurodeles waltlii Michah. from the 5th to the 20th week of larvel development. Thymectomized animals were allografted at 7 months of age. The results obtained are as follows (1) Pleurodeles thymectomized before 10 weeks always tolerated allografts; (2) Pleurodeles thymectomized within 11 to 13 weeks generally rejected allografts in a chronic manner, but sometimes tolerated them; (3) normal rejections occurred in Pleurodeles thymectomized at 14 weeks, or later. Stage 52 of the development table (10 weeks of age) is a critical „end stage”︁ for the efficiency of thymectomy.

The results are confirmed by the fate of second set allografts performed in all these animals.
Synthetic antigens. II. Immunogenic, antigenic and adjuvant properties of a copolymer of styrene and maleic anhydride
Authors: Wieczorek Z. , Starocik Krystyna , Lisowski J. , Zimecki M.
Published: February 2007

Immunogenic, antigenic and adjuvant properties of a polyanionic copolymer of styrene and maleic anhydride (PSM) are are described. The results obtained showed that PSM was immunogenic in BALB/c mice when administered without adjuvant, the optimal dose being 0.01 μg/mouse. Antibodies could be detected only by precipitation in gel but not by agglutination. High molecular weight polymer (290000 daltons) was a stronger immunogen and antigen than copolymers of lower molecular weights (85 000‐210 000 daltons). PSM also showed adjuvant activity and enhanced the humoral response of mice against sheep red blood cells. Adjuvanticity was found only when 1 μg of PSM/mouse was applied. The results obtained suggest that PSM interacts with B rather than T cells.
Antigen‐induced changes in lymphocyte circulatory patterns
Authors: Black S. J.
Published: February 2007

The effect of a splenic or lymph node anti‐sheep red blood cell response on lymphocyte migration patterns in mice was studied. It was found that trapping of lymphocytes in these stimulated organs was indiscriminate and was followed by a period of restricted cell entry or localization; furthermore, reduced cell localization in the spleen, during the splenic response, was accompanied by a reduction in the number of cells localizing in unstimulated brachial and axillary lymph nodes. These results were taken to indicate that major changes occur in lymphocyte circulation during strong splenic immune responses.
Use of formalin‐fixed melanoma cells for the detection of antibodies against surface antigens by a micro‐immune adherence technique
Authors: Müller Christine , Sorg C.
Published: February 2007

Established melanoma cell lines were fixed in suspension with 4 % form lin and tested for antigenic activity against sera from melanoma patient in a micro‐immune adherence test. By incubation of formalin‐fixed cell in serum‐free medium the unspecific background rosette formation was substantially reduced to below 10 %. As could be demonstrated in absorption experiments with viable and formalin‐fixed tumor cells, surface antigens reacting with sera from melanoma patients are largely unaffect by formalin treatment.
The failure to show a necessary role for C3 in the in vitro antibody response
Authors: Waldmann H. , Lachmann P. J.
Published: February 2007

The in vitro antibody response of mouse spleen cells to TNP coupled to both T‐dependent and T‐independent carriers as well as to sheep erythrocytes has been studied to investigate the possible role of complement activation in the induction of antibody formation.

The following has been found.

(1) In vitro responses of both IgM and IgG can be obtained to both T‐dependent and T‐independent antigens in serum‐free media, although they are smaller than those found in serum‐containing media. This shows that no exogenous source of complement is necessary for in vitro antibody formation by spleen cells.

(2) Similarly, normal antibody responses are obtained if the cultures are grown in human serum depleted of C3b‐inactivator, which contains high concentrations of C3b.

(3) In the presence of antibody to mouse C3 the response to the T‐independent antigen is reduced, the IgM responses being more affected than the IgG. However, purified F(ab′)2 anti‐C3 has no inhibitory effect and it therefore seems likely that it is the formation of intact immune complexes containing Fc rather than the interference with C3 function that is responsible for the inhibition seen.

(4) The conventionally purified anti‐complementary factor from cobra venom has no effect on the antibody response in serum‐free culture or when human or fetal calf sera are used. In no experiment was any potentiation of T‐dependent responses observed. However, the presence of quite small concentrations (2 %) of cobra venom factor (CVF)‐treated normal mouse serum produced a profound inhibition of the antibody responses, affecting IgG responses more than IgM, and being T‐dependent more than T‐independent, but no part of the response being unaffected. However, CVF heated to 70 °C which destroys the anticomplementary activity but not the contaminating phospholipase A was equally effective. More highly purified CVF, on the other hand, was not. These findings strongly suggest that the inhibition observed is due to residual phospholipase A reacting with lecithin in the mouse serum rather than to any anticomplementary effect.

(5) Spleen cells taken from mice treated with CVF in vivo were also unable to give a full IgG response to the T‐dependent antigens if challenged 24 h after CVF treatment. However, after 48 h no inhibition was observed.

It therefore seems to us that it is unlikely that C3 plays any real part in the in vitro antibody response. Our data – like the occurrence of genetically C3‐deficient humans with apparently normal antibody responses – would seem to preclude any necessary role for C3 in antibody production.
Expression of a mouse Ig V gene in antibodies of three immunoglobulin classes
Authors: Imanishi Thereza , Hurme M. , Sarvas Heikki , Mäkelä O.
Published: February 2007

In an earlier study we found that some mouse strains, including the C57BL/6, produced irregular IgG anti‐(4‐hydroxy‐3‐nitrophenyl)acetyl (NP) antibodies to protein conjugates of this hapten. This antibody had heteroclitic fine specificity and a characteristic isoelectric focusing pattern. Breeding studies suggested that these qualities of the C57BL/6 anti‐NP were controlled by a V gene of the heavy chain. We have now found that this V gene is expressed in anti‐NP antibodies and plaque‐forming cells of all major immunoglobulin classes: IgG, IgA and IgM.
Inactivation of hapten‐modified bacteriophage by antib increased sensitivity of the assay in media containing polyethylene glycol
Authors: Franěk F. , Doskočil J.
Published: February 2007

Inactivation of dinitrophenylated bacteriophage T4 by porcine and rabbit anti‐dinitrophenyl (DNP) antibodies was studied by the complex inactivation method. The inactivation titers increased 20–30 times when polyethylene glycol, mol. wt. 6000, was added to the incubation media. Consequently, the detection of dinitrophenylated serum albumin with the modified bacteriophage could be carried out with higher sensitivity upon addition of polyethylene glycol.
Lack of requirement for thymocytes for efficient antibody formation to trinitrophenylated mouse red cells in mice: Role for thymocytes in suppression of the immune response
Authors: Naor D. , Saltoun Rita , Falkenberg F.
Published: February 2007

The requirement of thymus‐derived cells for the immune response to trinitrophenylated syngeneic mouse red cells (TNP‐MRC) was investigated. In three sets of experiments the following results were obtained: a) irradiated mice which were reconstituted with bone marrow cells alone showed a better anti‐TNP response after injection with TNP‐MRC than those reconstituted with both bone marrow cells and thymocytes. b) Anti‐thymocyte serum augmented the mouse anti‐TNP response to TNP‐MRC. c) Nude thymusless mice showed a better anti‐TNP response to TNP‐MRC than their normal littermate controls. These results indicate that the anti‐TNP response of mice to TNP‐MRC does not require thymus‐derived helper cells. Moreover, thymus‐derived cells have a suppressive effect on the anti‐TNP response.
Histocompatibility antigens acting as helper determinants for tumor‐associated antigens of murine lymphosarcoma
Authors: Colnaghi Maria I.
Published: February 2007

The mechanism of effectiveness of allogeneic versus syngeneic immunization in mounting a humoral specific immune response against tumor‐associated antigens of murine urethan‐induced thymic lymphosarcomas was studied. C57BL mice immunized with untreated or blocked C3Hf lymphoma cells yielded sera with complement‐dependent cytotoxicity for C57BL lymphosarcomas, whereas they did not respond to repeated injections of blocked syngeniec lymphoma cells, indicating a helper activity of alien alloantigens in the reflex of tumor antigens. Thymectomized, lethally‐irradiated and T, but not B‐reconstituted mice produced active sera, suggesting a T‐dependent response. The anti‐tumor activity of the serum ran parallel with the anti‐histocompatibility one. The tumor‐associated and the alien histocompatibility determinants had to be present on the same cell membrane. In addition, active sera were obtained when immunizing syngeneic lymphoma cell inocula were followed by allogeneic normal immunocompetent cells.

It is suggested that either a helper mechanism with B and T cells cooperating in recognizing haptenic tumor‐associated and carrier histocompatibility antigens or a graft‐versus‐host reaction determining an abnormal induction of the immune system is needed in order to detect the weak tumor‐associated antigens of urethan‐induced lymphomas.
Subclasses of T cells with different sensitivities to cytotoxic antibody in the presence of anesthetics
Authors: Lee S.‐K. , Singh J. , Taylor R. B.
Published: February 2007

When cytotoxic titrations were made of rabbit anti‐mouse brain and anti‐Thy‐1.2 sera against mouse lymphoid cells in the presence of sodium barbital or xylocaine, it was observed that a proportion of T cells were much more sensitive (50 x) than the remainder. This effect could be detected with ethidium or fluorescein diacetate as indicators of cell death, but not with trypan blue or 51Cr. The highly sensitive cells were found in all lymphoid tissues, being most numerous in spleen and least in lymph nodes.
p‐Azobenzenearsonate‐L‐tyrosine‐mediated helper function in immune responses of guinea pigs and rats
Authors: Becker M. J. , Ray A. , Andersson L. C. , Mäkelä O.
Published: February 2007

A small bifunctional antigen (4‐hydroxy‐5‐iodo‐3‐nitrophenyl)acetyl‐ϵ‐aminocaproyl‐L‐tyrosine‐azobenzene‐ p‐arsonate [NIP‐cap‐TYR(ABA)] was found to induce fair humoral antibody formation against NIP‐cap but very little anti‐ABA‐TYR. This was observed in rats and guinea pigs. Prior immunization with ABA‐TYR, either as such or coupled to dodecanoylated bovine serum albumin (lipid‐BSA), primed rats for an enhanced anti‐NIP response to NIP‐cap‐TYR(ABA). An attempt to encourage rats to produce anti‐ABA‐TYR in response to the bifunctional antigen by priming them with NIP‐cap‐lipid‐BSA failed.

Priming with ABA‐TYR was dose‐depedent. An injection of 1.5–15 nanomoles per rat primed for an increased production of anti‐NIP while 150 nanomoles did not.

Adult thymectomized x‐irradiated rats had a poor anti‐NIP response to the bifunctional antigen if they were reconstituted with T‐enriched lymphoid cells from control mice, but a good response if reconstituted with similar cells from ABA‐TYR‐primed syngeneic rats.
Significance of spontaneous autorosettes in rats
Authors: Gluckman J.‐C , Gattegno Liliane , Cornillot P
Published: February 2007

Between 103 and 104 auto‐rosette‐forming cells (RFC) per 106 lymphocytes are observed in lymphoid organs of normal rats in vitro. Counts are significantly higher inthe thymus than in other organs. Contrary to what has been previously described in mice, auto‐RFC are not inhibited by fresh normal rat serum. The data presented are compatible with the hypothesis that auto‐RFC differ from the lymphocytes which recognize only alloerythrocytes according to histocompatibility differences. There is evidence which suggests that autorosette formation is linked to the expression of new determinants on ageing erythrocyte membranes.
Analysis of human thymocyte subpopulations using discontinuous gradients of albumin: precursor lymphocytes in human thymus
Authors: Gatien J. G. , Schneeberger E. E. , Merler E
Published: February 2007

Precursor lymphocytes, obtained from human tissue on bovine serum albumin (BSA) gradients followed by removal of sheep erythrocyte (E)‐reactive thymocytes on Ficoll, are the predominant lymphoid subpopulation found in young fetal thymuses. This subpopulation shows a progressive decline in relative numbers during fetal life, accompanied by a rise in both the relative and absolute numbers of E‐reactive thymocytes. Precursor thymocytes differentiate in vitro to E‐reactive cells resembling T cells in their morphology, sedimentation on BSA gradients, and response to phytohemagglutinin. Agents tending to increase intracellular concentrations of cyclic‐AMP accelerate the rate of differentiation of precursor cells to lymphocytes which closely resembleT cells.
Leukocyte‐dependent antibody in sheep immunized with murine mastocytoma cells
Authors: Grant C. K. , Adams E , Miller H. R. P.
Published: February 2007

Sheep serum removed after hyperimmunization with murine P‐815mastocytoma cells was fractionated and two types of cytotoxic antibody were isolated. Complement‐dependent antibody (CDA) was detected inthe IgM and IgG1 fractions, whereas “leukocyte”‐dependent antibody (LDA) was found in the IgG1 and IgG2 fractions. Effector cells that mediated LDA cytotoxicity were isolated from sheep blood but not from sheep lymph, showing that recirculating lymphocytes do not have LDA effector function. Removal of adherent cells from blood leukocyte suspensions reduced antibody‐mediated cytotoxicity, suggesting that LDA effector leukocytes may be a heterogenous population containing both adherent and nonadherent cells.
Quantitative contributions of IgG, IgM and C3 to erythrophagocytosisand rosette formation by peritoneal macrophages, and anti‐opsoninactivity of dextran sulfate 500
Authors: Wellek Brigitte , Hahn H , Opferkuch W
Published: February 2007

In vitro phagocytosis by guinea pig peritoneal macrophages of immune complexes (EA) was shown to be dependent on IgG antibody in a dosedependent fashion. C3b enhanced phagocytosis of EA at limited IgG antibody concentrations only. When IgM antibody was used for sensitzation ofsheep red blood cells (SRBC), phagocytosis and rosette formation did notoccur in the absence of bound C3. The polyanion, dextran sulfate 500 (DS), was shown to depress both rosette formation and phagocytosis of EAIgG, EAIgGC1423 and EAIgMC1423, as well as immune adherence of human group 0 erythrocytes and hemolytic activity of C3. This effect of DS was seen only when it was actually present in the incubation medium.
Recruitment of effector lymphocytes by initiator lymphocytes. In vivo migration of in vitro sensitized initiator T lymphocytes
Authors: Livant S , Cohen I. R.
Published: February 2007

We previously found that mouse T lymphocytes sensitized in vitro against allo‐ or syngeneic fibroblasts, upon injection into syngeneic recipients, do not themselves differentiate into effector cells, but recruit effector T lymphocytes within the draining lymph nodes. Asaresult of sensitization, these initiator lymphocytes acquire a trypsin‐sensitive membrane property which is necessary for recruitment.

We now report studies on the in vivo migratory behavior of initiator lymphocytes following sensitization. We injected 51Cr‐labeled initiator lymphocytes into recipient footpads and found significantly increased migration of sensitized cells to the draining popliteal lymph node (PLN) during the first day. By amputation ofthe foot at various times, we showed that migration during the first 12—24 hours was critical for subsequent recruitment. Trypsin treatment of initiator lymphocytes abolished this accelerated migration. Lymphocytes triggered nonspecifically by Con A migrated to the PLN like antigen‐sensitized cells. We also compared the migration of injected lymphocytes from the footpad to the PLN in graftversus‐host and host‐versus‐graft reactions, and found these reactions to differ both from each other and from recruitment in terms of lymphocyte migration.

These findings are discussed in terms of the physiology of the cell‐mediated immune response and the notion of peripheral sensitization.
5‐Hydroxytryptophan effect on the development of the immune response: IgM and IgG antibodies and rosette formation in primary and secondary responses
Authors: Devoino Lidia , Eliseeva Ludmila , Eremina Olga , Idova Galina , Cheido Margarita
Published: February 2007

In animals immunized with bovine serum albumin, 5‐hydroxytryptophan prolonged the latent period of the IgM and IgG primary responses, decreased response intensity, delayed the response peak and suppressed IgG immunological memory.

In 5‐hydroxytryptophan‐treated mice, the number of rosette‐forming cells (RFC) in the lymph node and spleen decreased during the primary and secondary responses. This effect was due to the decreased number of IgG RFC and to the later involvement of IgM RFC in theimmune response. The absence of the secondary response was related to unprimed IgG memory cells.

5‐hydroxytryptophan does not inhibit the primary and secondaryresponses after the connections between the hypothalamus and pituitaryhave been disrupted.

The participation of the n.raphe‐hypothalaminc‐pituitary system in immunoregulation and the putative mechanism underlying serotonin effect on the immune response are discussed.
Enzymatic modification of lymphocyte receptors for antigen. III. Resistance of receptors to trypsin at the peak of the immune response
Authors: Ashman R. F.
Published: February 2007

Using sheep erythrocytes (SRBC) as the antigen, two subpopulations of spleen antigen‐binding lymphocytes could be distinguished by a marked difference in the susceptibility of their receptors to trypsin. In unimmunized animals, 30 % of the antigen‐binding cells were trypsin‐resistant, whereas at 5 days after immunization, 80–90% were trypsin‐resistant, indicating an increase of about 50‐fold in trypsin‐resistant antigen‐binding cells per spleen. In contrast, trypsinsensitive cells per spleen were only 4‐fold higher on day 5 than before immunization. Therise in % trypsin sensitivity preceded the increase in rosettes per spleen, implying that immunization produced a preferential increase in trypsinresistant antigen binding cells partly by converting sensitive cells to resistant cells. After the 5th day, the trypsin sensitivity of antigen‐binding cells slowly returned toward the unimmunized level, but a booster injection of SRBC restored trypsin resistance.

Trypsin resistance was not lost in the presence of sodium azide or protein synthesis inhibitors. But a slightly increased trypsin susceptibility was conferred by 2‐deoxyglucose, implying that glycolysis or the glycosylation of protein may be involved in maintaining trypsin resistance.
Micromethods for induction and assay of mouse mixed lymphocyte reactions and cytotoxicity
Authors: Simpson Elizabeth , Gordon R. , Taylor Moya , Mertin J. , Chandler P.
Published: February 2007

A new method in which induction of mixed lymphocyte responses and cytotoxicity can be performed under identical conditions is described. This enables the investigation of the relationship between MLR and cytotoxicity. A micro method for the 51Cr release assay for cytotoxicity is described using both mitogen‐induced blasts and tumors as target cells. Under the conditions used data obtained is suitable for linear regression analysis, enabling quantitative comparisons to be made.
Analysis of the role of different cell types in the genetic regulation of antibody production to the thymus‐independent synthetic polypeptide poly (DTyr, DGlu)‐poly(DPro)‐‐poly (DLys)
Authors: Schmitt‐Verhulst Anne‐Marie , Mozes Edna , Sela M.
Published: February 2007

The immune response potential of mice to the thymus‐independent synthetic polypeptide poly (DTyr, DGlu)‐poly (DPro)‐‐poly(DLys)[D(T, G)‐Pro‐‐L] is genetically regulated. The detect in the ability of low responder mice to mount an immune response to this antigen appears to be expressed in their B cell population since the presence of thymocytes, or addition of “educated T cells” or supernatant of T cells after stimulation with the antigen neither enhanced, nor suppressed the level of antibodies produced in both low and high responder mice. Low responsiveness could not be enhanced either by stimulation of macrophages or by injection of poly(A). poly(U) in contrast to the significant effect of these agents on low responses to the thymus‐dependent poly(LTyr, LGlu)‐poly(LPro)‐‐poly(LLys) [L(T, G)‐Pro‐‐L]. These results suggest that macrophages do not participate in the limiting step, or are not involved at all, in anti‐body production towards the thymus‐independent polypeptide.

The antibodies produced in response to D(T, G)‐Pro‐‐L were found to be mainly of the 7 S class. T cells are not required for the production of mercaptoethanol resistant antibodies to this immunogen since they were found in intact mice as well as in T cell depleted animals.
Precipitin and mitogenic behavior of dimeric and tetrameric concanavalin A
Authors: Sawyer W. H. , Hammarström S. , Möller G. , Goldstein I. J.
Published: February 2007

The results of double diffusion and quantitative precipitin tests show that in contrast to the concanavalin A tetramer, the dimer is incapable of precipitating glycogen. The results support previous work suggesting that dimers composed of two fragmented monomer units possess only one binding site for carbohydrate (McKenzie and Sawyer, J. Biol. Chem. 1973. 248: 549). On the other hand, dimer and tetramer species had similar mitogenic activity as measured by the incorporation of radioactive thymidine by mouse spleen lymphocytes and induced cap formation to similar degrees. Results are discussed in terms of the affinity and valency of the polymeric forms and their stability at the cell surface.
Idiotype suppression. II. Amplification of a suppressor T cell with anti‐idiotypic activity
Authors: Eichmann K.
Published: February 2007

Guinea pig IgG2 anti‐idiotypic antibody (āId2) against the strain A/J antibody A5A has a suppressive effect on the expression of the A5A idiotype in adult A/J mice immunized with Group A streptococci. High doses of āId2 cause an immediate but transient suppression, whereas low doses of āId2 result in a delayed but chronic suppression which lasted for more than 1 year without any indication of recovery.

Chronic suppression is transferred by as few as 105 spleen cells, but an interval of 6 weeks after transfer is required for completion of suppression. The suppressive capacity of āId2‐induced suppressor cells was virtually inexhaustable in 4 consecutive transfers spaced at 3 month intervals. The suppressor cell is a T cell which adheres to histamine‐rabbit serum albumin‐Sepharose 2B columns.
Separation of complement‐dependent and lymphocytedependent cytotoxic activity in human sera
Authors: Miller June L. , Mann D. L. , Yust I.
Published: February 2007

Two human sera having both complement‐dependent and lymphocyte‐dependent antibody activities (CDA, LDA) were applied to isoelectrofocusing columns. Maximum LDA activity for both sera was found focused at a higher pH than maximum CDA activity. The studies suggest that LDA molecules may exist without having complement‐dependent activity.
Sharing of idiotypic specificities between different antibody populations from an individual rabbit
Authors: Urbain J. , Tasiaux N. , Leuwenkroon R. , Van Acker A. , Mariame B.
Published: February 2007

Rabbits hyperimmunized with tobacco mosaic virus synthesize very heterogeneous antibodies. Despite this, specific anti‐idiotypic sera recognizing a large part (70%) of these antibodies can be raised in rabbits matched for allotypic specificities a1, a2, a3, b4, b5, b6, c7, and b9. Different rabbits synthesize antibodies with different idiotypic specificities. However, in the serum of a single rabbit antibody fractions of different isoelectric pH share some idiotypic specificities. The results show that, at least in certain cases, antibodies against one antigen are not simply a random collection of immunoglobulin which happen to fit with this antigen, but that some definite relationship exists between the products of different clones which have been activated by antigen. These findings are discussed in the light of network concepts of the immune system.
In vitro studies on the selective binding of IgG from different species to tissue sections of the bovine mammary gland
Authors: Kemler R. , Mossmann H. , Strohmaier Ulrike , Kickhöfen B. , Hammer D. K.
Published: February 2007

Tissue sections of the mammary gland of cattle provide a sensitive and reproducible model for studying the initial events of the selective transport of bovine IgGs by the acinar epithelium (AE). Mammary tissue was reacted with purified antibody to horseradish peroxidase (HRP) and exposed to HRP. The sites of peroxidase activity were revealed cytochemically.

The highly selective binding of IgGs by AE of the colostrum‐forming gland but never of the lactating gland was most notable, whereas IgG1 and IgG2 subclasses and IgM and IgA lacked any binding capacity. An inhibition assay showed that the inhibitory capacity of IgGs was abolished by either alanylation or acetylation, whereas binding of IgGs was blocked by both Fab/c and isolated H‐chains, but not by F(ab′)2, Fab and Fc. The inhibitory pattern suggests that the region on the IgGs molecule involved in binding to the AE receptor may be located within the CH2 domian.

In addition, IgG preparations of human, sheep and rabbit origin were found to be equally efficient in inhibiting the binding of IgGs to AE, whereas no inhibition was obtained with nonmammalian (turtle and chicken) IgG. Similarly, human myeloma proteins of the subclasses IgG1 and IgG3 caused complete inhibition, while IgG2 and IgG4 were inefficient. It is suggested that molecular evolution of IgG within mammalian species is accompanied by the conservation of structures fitting to receptors on the cells surface of different species.
Specific unresponsiveness in nude mice given antigen before T cells
Authors: Kindred Berenice
Published: February 2007

Nude mice given antigen before being given congenic T cells are specifically tolerant to that antigen and recovery of the ability to respond takes at least 2 weeks. If, after giving antigen, spleen cells are transferred to irradiated congenic recipients together with normal congenic thymocytes, the recipients usually remain unresponsive. Treatment of the spleen cells with supernatant from lysed cells renders them responsive in transfer. Spleen cells from unresponsive mice do not suppress normal spleen cells in transfer and the unresponsiveness is not broken by allogeneic cells. It is therefore probable that this is a case of reversible blocking of the B cell receptors and that T cells are not involved.
Differences in the immunological activities of antibody‐secreting cell precursors in mouse spleen selected on the basis of antigen‐binding capacity
Authors: Lafleur L. , Mitchell G. F.
Published: February 2007

Mouse spleen cells transfer a retarded and lower than normal IgG antibody response after removal of cells with a high antigen‐binding capacity. The population enriched in these latter cells transfers a response equal to or, more often, higher than the response of the unfractionated controls and does not appear to have originated from previous priming of the mice. These cells are present in athymic nude mice and appear to be more susceptible to inactivation by an anti‐Ig antiserum and complement than precursors of IgM antibody‐secreting cells.
The clonal origin of cells contributing to successive phases of a cyclical immune response
Authors: Phillips J. M. , Dresser D. W.
Published: February 2007

A single injection of mice with a low dose of sheep red blood cells results in a cyclic appearance of antibody‐forming cells of the IgG classes. The peaks of the responses occur at the same time in the spleen and the thoracic lymph nodes. We have investigated the phenomenon with respect to IgG2a response by using the isoelectric focusing overlay assay and have assumed that in the great majority of cases, after immunization with limiting amounts of antigen, an individual spectrotype represents a “clonal” product.

Enumeration of spectrotypes which arise only in the first peak and those which arise only in the second, suggests that the second peak of plaque‐forming cells can be accounted for on the basis of the stimulation of a second population of precursor cells. Several possible mechanisms whereby new antigen‐sensitive precursor cells can be turned on late in a primary response are discussed.