bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis by limiting dilution of interleukin 2‐producing T cells in murine ontogeny
Authors: Ishizaka Sally T. , Stutman Osias
Published: February 2007

The ontogeny of interleukin 2 (IL2) production in young CBA/HT6T6J mice was studied using both bulk culture and limiting dilution methods. The ability of spleen cells in bulk culture to produce IL2 in response to concanavalin A (Con A) was found to rise through the first 2 weeks of life, from no production at day 1, through 20 units/ml at day 6, to 80–100 units/ml in adults. No evidence for suppression of IL2 production by young spleen was found. Limiting dilution analysis of both young spleen and young lymph node (LN) shows that young spleen has a much lower complement of cells producing IL2 in response to Con A or allogeneic stimulation than does adult spleen. The frequency of 6‐day spleen cells producing IL2 in response to Con A is 1/1000, while the adult frequency is approximately 1/50. Young LN, in contrast, has levels of IL2‐producing cells close to those of adult LN, with a frequency of responders to Con A of 1/20. No evidence was found for a deficiency in IL2 production on a per cell basis, in either 6‐day spleen or LN. In examining allogeneic reactivity, a high frequency of cells reacting to strong Mls stimulation was found in both young and adult spleen and LN.
Induction of natural killer‐like cytotoxicity in cultured human thymocytes
Authors: Toribio María Luisa , De Landázuri Manuel O. , López‐Botet Miguel
Published: February 2007

Supernatants containing interleukin 2 (IL2) induce strong proliferation and expression of natural killer (NK)‐like activity in human thymocytes. Different supernatants were compared for: (a) IL2 activity, (b) thymocyte proliferation capacity and (c) induction of NK‐like cytotoxicity. All these activities were present in a partially purified IL2 preparation obtained by gel filtration chromatography (Mr 15000–20000). However, in supernatants from different sources and in the 15000–20000‐Mr semipurified fractions, we observed that the NK‐like cytotoxicity inducer effect did not correlate with either the mitogenicity or the IL2 activity.

The presence in the supernatants of interleukin 1 (IL1), interferon (IFN) or phytohemagglutinin (PHA) does not seem to be a prerequisite for the induction of NK‐like cytotoxicity, since this activity was (a) fully present in supernatants devoid of IL1, IFN and PHA, (b) absent in preparations of IL1 and (c) not augmented after supplementation of the supernatants with IFN‐γ.

We also investigated the cellular characteristics of the precursor thymocytes responsive to IL2 supernatants. Removal of the T3+ cells at the initiation of the culture abrogated the proliferative response and eliminated the generation of NK‐like cytotoxicity. Under the same conditions, removal of the HTA1+ population increased the proliferation and did not affect the NK‐like activity.

Our results suggest that: (a) either IL2 is not responsible for the induction of NK‐like cytotoxicity or its action is modulated by other molecules, and (b) the precursor‐responder population is preferentially included in the mature T3+ subset.
Immune elimination of aging platelets by autologous monocytes: role of membrane‐specific autoantibody
Authors: Khansari Nemat , Fudenberg H. Hugh
Published: February 2007

Membrane‐bound IgG was found only on old populations of platelets from normal individuals. This IgG could be dissociated from senescent cells by repeatedly heating the cells. Heat‐eluted IgG (He‐IgG) prepared from senescent red blood cells was capable of binding to either heat‐treated old platelets or Vibrio choleare neuraminidase (VCN)‐treated young platelets, suggesting expression of a common age‐dependent antigen on the senescent red blood cells and old platelets. We analyzed the role of membrane‐bound IgG in the immune elimination of aging platelets by direct phagocytosis of different platelet subpopulations by autologous monocytes in vitro. While removal of He‐IgG from old platelets inhibited their phagocytosis, preincubation of either heat‐treated old or VCN‐treated young platelets promoted phagocytosis of these cells by autologous monocytes. The phagocytosis of senescent cells required intact IgG on these cells. Either removal of Fc fragments from He‐IgG or treatment of autologous monocytes with Fc fragments prior to the phagocytosis assay resulted in a marked reduction of phagocytosis (> 75%). We conclude that Fc receptors on the monocytes and the presence of membrane‐specific IgG are crucial elements for immune elimination of senescent platelets.
Allotypic restriction of the expression of MOPC460 idiotope after immunization with either anti‐2,4‐dinitrophenyl (DNP) or anti‐idiotypic antibodies
Authors: Sanchez Pierre , Juy Dominique , Cazenave Pierre‐André
Published: February 2007

The MOPC460 idiotype is expressed in mice with the IghCa allotypic haplotype after anti‐2,4‐dinitrophenyl (DNP) immunization. We have previously shown that two monoclonal syngeneic anti‐idiotypic antibodies (IDM 92‐13 and IDM 41‐27) define two distinct idiotopes (the 460.92 and the 460.41) on the M460 idiotype. The current study demonstrates that only one idiotope (460.92) is recurrently expressed after antigen immunization in IghCa positive mice and also that, immunization against the monoclonal anti‐idiotypic molecules induces the synthesis of 460.92 idiotope positive anti‐DNP antibodies. However, the detection of such molecules is only possible when animals with the IghCa allotypic haplotype are immunized with the IDM 92‐13 molecules. Immunization of mice with either of the two monoclonal anti‐idiotypic antibodies never results in the synthesis 460.41 positive molecules. Therefore, whatever protocol of immunization used, the expression of 460.92 was allotypic restricted.
Existence of disulfide‐bonded IgM‐IgA, IgM‐IgG and IgM‐IgG fragment complexes in one patient
Authors: Zhang Hong‐Shan , Gallango Maria L. , Tung Edward , Wang An‐Chuan
Published: February 2007

The existence of disulfide‐bonded immunoglobulin (Ig) complexes of IgM‐IgA, IgM‐IgG, and IgM‐IgG, in addition to a monoclonal IgM (x) paraprotein, free kappa chains and fragments of IgG (FIgG), were found in the plasma of a multiple gammopathy patient. This is the first report on the interclass disulfide‐bonded Ig complexes. Upon exposure to a dissociating buffer containing 6 M urea, 0.1 M Tris‐HCl, pH 8.0, a small portion of the IgM‐IgA complexes and most of the IgM‐IgG as well as the IgM‐FIgG complexes dissociated, but the majority of the IgM‐IgA and small amounts of other complexes remained intact. These intact complexes were not the result of antigen‐antibody reactions and were apparently held together by disulfide bonds which could be broken into monomeric Ig basic units (H‐L)2 and smaller components by mild reduction and alkylation.
Public and individual idiotopes in the anti‐poly(Glu60,Ala30,Tyr10) response: analysis by monoclonal antibodies
Authors: Sommé Gerard , Roth Claude , Mazie Jean‐Claude , Salem Patrick , Thèze Jacques
Published: February 2007

From BALB/c mice immunized with anti‐GAT monoclonal antibody (mAb) G5, we have obtained anti‐idiotypic mAb against individual (or private) idiotopes, expressed by G5 as well as anti‐GAT mAb, that are heteroclitic because they recognize poly(Glu50,Tyr50) (GT) better than poly(Glu60,Ala30,Tyr10) (GAT). From BALB/c mice immunized with BALB/c polyclonal anti‐GAT antibodies, anti‐idiotypic mAb directed against public idiotopes expressed following GAT immunization in all individuals of all mouse strains tested have been obtained. Nine anti‐idiotypic mAb were studied in detail. One of these mAb recognizes only polyclonal anti‐GAT antibodies; the other eight recognize polyclonal anti‐GAT antibodies and anti‐GAT mAb. The distribution of the structures recognized by the different anti‐idiotypic mAb on a battery of 20 anti‐GAT mAb allows definition of two families of public idiotopes.
Failure of the human autologous mixed lymphocyte reaction in the absence of foreign antigens
Authors: Kagan Jonathan , Choi Yong Sung
Published: February 2007

The autologous mixed lymphocyte reaction (AMLR) is thought to represent the in vitro proliferation of T cells in response to stimulation by autologous histocompatibility antigens present on non‐T cells. We have investigated the possibility that xenogeneic determinants act as the stimulating antigens in the human AMLR. Exposure of lymphocytes to fetal calf serum and/or sheep red blood cells during fractionation triggers substantial proliferation of T cells, plaque‐forming cell responses, and interleukin 2 production. In contrast, lymphocytes isolated and cultured in the absence of any known foreign substances failed to respond in the AMLR, yet responded significantly when cultured in the presence of fetal calf serum. These results suggest that without exposure to foreign antigens, the human AMLR is difficult to demonstrate in vitro.
The effect of antigen on the development of Peyer's patches in sheep
Authors: Reynolds John D. , Morris Bede
Published: February 2007

The proposition that the development of Peyer's patches (PP) is influenced by anti‐genic stimulation has been examined in sheep. Terminal lengths of ileum containing about half of the ileocecal PP were isolated from the intestinal tracts of fetal lambs during the last month before birth. Antigen was injected into some of these segments and the subsequent development of the PP studied before and after birth.

The injection of either killed B. abortus, ferritin or maternal colostrum into the lumens of the isolated ileal segments did not cause premature growth of the PP follicles, nor did it effect the content of lymphoblasts in them. In contrast, the injection of these antigens into the isolated segments caused the development of germinal centers and plasma cells in the regional mesenteric lymph nodes. Plasma cells also appeared in the lamina propria along the intestinal tract in response to these antigens. These results provided experimental evidence that lymphopoiesis in the follicles of the PP of fetal lambs is not dependent on antigen. The PP in ileal segments that were not injected with antigen and had no contact with antigen subsequently grew at the normal rate before and for the first 2 weeks after birth; after this the growth of the follicles became significantly slower than normal. The follicles in these isolated ileal segments had almost completely disappeared by 3–4 months of age, whereas the follicles in the normal functional ileum did not undergo involution until around 15 months of age. The premature involution in the PP in the isolated segments was prevented by reconnecting the segment to the functional intestinal tract before 3 months of age.
In vitro stimulated lymphocytes as a source of human hybridomas
Authors: Kozbor Danuta , Roder John C.
Published: February 2007

Stimulation of peripheral blood lymphocyte (PBL) cultures from tetanus toxoid (TT)‐immunized donor with Epstein‐Barr virus (EBV) yielded cells with much higher frequencies of hybrid formation (36 × 10−7) compared to unstimulated PBL or cells cultured with pokeweed mitogen or TT antigen. The proportion of hybridomas (approximately 1%) producing anti‐TT antibody was similar in EBV‐ and TT‐stimulated cultures. A marked increase in immunoglobulin secretion was observed after hybridization and preselection of EBV subcultures for high anti‐TT production prior to fusion resulted in a fivefold increase in TT‐specific hybridomas (p<0.001). Most (20/21) specific hybrids produced IgM anti‐TT, whereas one (1/21) produced IgG anti‐TT, possibly due to the immature stage of differentiation in EBV‐stimulated parental cells. The ability to choose an antigen, immunize a human subject and expand the rare antigen‐specific B cells from PBL, in vitro, with EBV, prior to fusion, should yield an increasing spectrum of human monoclonal antibodies for diagnostic, therapeutic or basic studies.
The Ia‐1 gene effects T‐B cell collaboration for the in vitro antibody response
Authors: Sandrin Mauro S. , Craig Jenni S. , McKenzie Ian F. C.
Published: February 2007

The I‐A subregion mutant B6.C‐H‐2bm12 (bm12) and the C57BL/6 parent were used to examine the role of the Ia‐1 gene product as a restriction element in the antibody response to sheep red blood cells (SRBC). Using an in vitro culture system, it was shown that cooperation between histocompatible T cells, B cells and macrophages was required to generate a secondary IgM response to SRBC. The alteration in the Ia‐1 gene in bm12 altered the ability of bm12 T cells to collaborate with C57BL/6 B cells, but not with C57BL/6 macrophages. Similarly, C57BL/6 T cells could not collaborate with bm12 B cells. The mutation in bm12 did not affect the ability of T cells to interact with C57BL/6 macrophages, either in vitro or in vivo, or of bm12 macrophages to interact with C57BL/6 T cells. Thus in this system, the Ia‐1 gene product restricts T‐B cell interaction but not T cell‐macrophage interaction.
Effect of cloned interferon‐γ on expression of H‐2 and Ia antigens on cell lines of hemopoietic, lymphoid, epithelial, fibroblastic and neuronal origin
Authors: Wong Grace H. W. , Clark‐Lewis Ian , Harris Alan W. , Schrader John W.
Published: February 2007

Interferon‐γ (IFN‐γ), tested in the form of the product of a cloned murine IFN‐γ gene, was found to increase the expression of H‐2 antigens on cultured cell lines of a wide variety of cell types including factor‐dependent hemopoietic cells, pre‐B and B cells, macrophages, T cells, mast cells and cell lines of epithelial, fibroblastic and neuronal origin. However, IFN‐γ induced Ia antigens on only B cells, macrophages and T‐dependent mast cells or persisting cells. On the basis of these results, we suggest that a major function of IFN‐γ is to potentiate immune responses by enhancing the expression of H‐2 and Ia antigens on a variety of cell types.
Physiology of IgD III. Effect of treatment with anti‐IgD from birth on the magnitude and isotype distribution of the immune response in the spleen
Authors: Xue Bin , Hirano Takao , Pernis Ben , Ovary Zoltan , Thorbecke G. Jeanette
Published: February 2007

Continued treatment with monoclonal anti‐IgD (Ig‐5a) from birth in BALB/c mice causes a markedly increased responsiveness to i.v. injected dinitrophenylated ovalbumin (DNP‐OVA) with Bordetella pertussis at the age of 8 weeks. The 19 S plaqueforming cell (PFC)/spleen response is particularly enhanced, 6–8‐fold, but all the other isotypes also show increases of 2–6‐fold, including IgA and IgE. Both primary and secondary PFC responses and serum antibody titers are enhanced. After transfer of spleen cells from anti‐Ig‐treated mice to irradiated recipients the IgM/IgG ratio becomes similar to that of controls. In contrast, the response of anti‐IgD‐treated mice to i.p. immunization with either 0.2 or 100 μg DNP‐OVA plus alum is reduced by approximately 80% for each Ig isotype except IgM and remains low upon transfer of spleen cells to recipients. It is concluded that the paucity of B cells in peripheral lymph nodes of the anti‐IgD‐treated mice causes the low responsiveness to i.p. immunization, but that the IgD− B cells in the spleen are quite able to respond and are, in fact, more responsive than IgD+ B cells. This increased responsiveness, together with the higher IgM/IgG ratios for all Ig isotypes and an otherwise similar order of isotype distribution (γ1 > γ2b > γ2a = ϵ ≧ α) as in controls, suggests that a hyperresponsive, but less mature IgD− B cell population is selectively produced in the spleens of mice treated with anti‐IgD from birth.
Rat IgE directed against schistosomula‐released products is cytotoxic for Schistosoma mansoni schistosomula in vitro
Authors: Auriault Claude , Damonneville Martine , Verwaerde Claudie , Pierce Raymond , Joseph Michel , Capron Monique , Capron André
Published: February 2007

The immunogenicity of molecules shed by schistosomula into culture medium (antigens present in schistosomula‐released products, SRP‐A) has been studied. The results obtained show that SRP‐A preferentially induce an IgE response when injected into rats, without the need for adjuvants. Moreover, anti‐SRP‐A IgE is cytotoxic in vitro for the larvae in the presence of macrophages, eosinophils or platelets, which have previously been demonstrated as being the three efficient killer cells for schistosomula in the presence of specific IgE. Immunofluorescence analysis locates the target antigens at the schistosomulum surface. Among the antigens recognized by anti‐SRP‐A IgE, two molecules of 26 and 22 kDa have been identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by western blotting.
Restriction fine specificity of long‐term, hapten‐specific cytotoxic T cell clones: analysis with H‐2Kbm‐mutant mice and H‐2Kb‐specific monoclonal antibodies
Authors: Pircher Hanspeter , Hämmerling Günter , Hengartner Hans
Published: February 2007

The cell‐mediated cytotoxic response against autologous cells modified with the sulfhydryl reagent I‐AED [N‐iodo‐acetyl‐N‐(5‐sulfonic‐1‐naphthyl) ethylene diamine] has been described by Levy, R. B., Shearer, G. M., Richardson, J. C. and Henkart, P. A., [J. Immunol. 1981. 127: 523.]. We have established two H‐2Db‐ and eight H‐2Kb‐restricted, AED ‐specific long‐term cytotoxic T lymphocyte (CTL) clones of C57BL/10 origin. The growth of these clones has been dependent upon presence of both antigen and interleukin 2.

Cytotoxicity and proliferation analysis of AED‐specific Kb‐restricted CTL clones with target and stimulator cells from Kbm‐mutant mice demonstrated two categories of clones (A and B) based on different reactivity patterns against hapten‐modified Kbm‐mutant cells. AED‐modified target cells of bm5, bm6 and bm9 origin were lysed by type A clones but not by type B clones, in contrast to AED‐modified bm3, bm8 and bm11 target cells which were lysed by type B but not by type A clones. None of the clones lysed AED‐modified bm1 target cells, but all of them lysed AED‐modified bm4 and bm10 target cells. The restriction fine specificities for both cytolytic and proliferative activities of the analyzed clones were identical.

A panel of monoclonal antibodies (mAb) directed against the Kb molecule was used to inhibit lysis of AED‐modified target cells by CTL clones. mAb which recognize a cluster of allodeterminants located in the second external domain (C1 domain) of the Kb molecule [Hämmerling, G. J., Rüsch, E., Tada, N., Kimura, S. and Hämmerling, U., Proc. Natl. Acad. Sci. USA 1982. 79: 4737] only inhibited type B clones, whereas inhibition of both type of clones was observed with mAb specific for allodeterminants clustered in the N‐terminal region of Kb.

These findings suggest that different regions on the Kb molecule serve as self determinants for H‐2‐restricted cytotoxicity. We also demonstrate that allodeterminants recognized by mAb and self determinants involved in H‐2 restriction need not be identical. Our data also support the notion that covalent AED modification of H‐2 molecules is not necessary to generate the self plus X antigen for CTL recognition.
Inhibition of T cell proliferation by antibodies to synthetic peptides
Authors: Lamb Jonathan R. , Zanders Edward D. , Lake Phil , Webster Robert G. , Eckels David D. , Woody James N. , Green Nicola , Lerner Richard A. , Feldmann Marc
Published: February 2007

While T cell proliferation to antigen in the presence of antigen‐presenting cells is well known to be readily inhibited by antibodies directed against Class II major histocompatibility complex (MHC) (Ia/HLA‐DR) products, it has not been possible to inhibit proliferation by antibodies directed against the antigen. Because of the implications of these observations for targets of T cell recognition, this phenomenon was reinvestigated using human T cell clones, recognizing a small (24 amino acid) synthetic peptide (termed p20) derived from the influenza hemagglutinin‐1 molecule. It was found that proliferation of clones to p20 was inhibited efficiently (> 90%), using p20 as antigen, and rabbit anti‐p20. Inhibition was possible either by coculturing p20 antigen and antibody to p20 with cloned T cells and antigen‐presenting (E−) cells, or by pulsing antigen‐presenting cells with antigen prior to a brief incubation with antibody before washing the E− cells and using them to stimulate cloned T cells. These results do not indicate why previous attempts had failed, but in view of the different techniques available now (cloned T cells, small synthetic polypeptides, and antibody raised against polypeptide) we investigated the influence of these parameters. It was found that, using cloned T cells, the form of the antigen was of importance, as antibody inhibition of the response to hemagglutinin or whole influenza A was much less apparent. These differences were interpreted as being due to greater access of anti‐p20 to p20 than to hemagglutinin or influenza. If uncloned T cell lines were used, inhibition was also much harder to detect. This was interpreted as masking of inhibition of the response of some clones in the line by interleukin 2‐induced recruitment.
Determinant‐specific regulation of T helper cell responses to murine lambda light chains by both H‐2 and non‐H‐2 genes
Authors: Bogen Bjarne , Hannestad Kristian
Published: February 2007

Previous work has revealed that the T helper cell (Th) responses to an antigenic determinant of Vλ2315 (called λ2.1) is regulated by both H‐2 and non‐H‐2 genes. In the present study this was confirmed and extended to two other determinants, one shared between free λ2315 and λ1J558 (called λ2.2) and one unique for free λ1J558 (called λ1.1). H‐2 genes regulate the responses to the latter determinants, because BALB.B (H‐2b) mice were low responders and BALB/c (H‐2d) mice were high responders. Thus, the H‐2d haplotype on BALB/c background was associated with high responder status. However, when the H‐2d haplotype was examined on other genetic backgrounds than BALB/c, the animals could be classified as either intermediate or low responders, depending upon the non‐H‐2 background. This demonstrated that non‐H‐2 genes also influenced Th responses. Furthermore, C3H‐H‐20, DBA/2 and B10.D2 mice (all H‐2d) responded to only one (λ2.1) but not the other (λ2.2) of two determinants physically linked on the same polypeptide chain (λ2315). This indicated that the non‐H‐2 gene effect is capable of fine discimination, i.e. the non‐H‐2 gene‐mediated low responder phenotype may at least in part be due to failure of recognition of certain antigenic sites, like the H‐2‐linked Ir‐gene defect. F1 hybrids responded to the same determinants as their parental strains; e.g., the BALB/c non‐H‐2 background exerted a dominant influence over the low responder background of C3H, B10 and DBA/2 strains.
The augmentation of tumor‐specific immunity by virus help. I. Demonstration of vaccinia virus‐reactive helper T cell activity involved in enhanced induction of cytotoxic T lymphocyte and antibody responses
Authors: Fujiwara Hiromi , Shimizu Yoshio , Takai Yasuyuki , Wakamiya Nobutaka , Ueda Shigeharu , Kato Shiro , Hamaoka Toshiyuki
Published: February 2007

C3H/He mice were immunized to vaccinia virus by inoculating i.p. viable virus. Their spleen cells (SC) were tested for vaccinia virus‐reactive helper T cell activity capable of augmenting (a) anti‐trinitrophenyl (TNP) cytotoxic T lymphocyte (CTL) response generated from unprimed C3H/He SC (responding cells) or (b) anti‐TNP antibody response generated from TNP‐primed C3H/He SC (responding cells) by the stimulation with syngeneic SC infected with vaccinia virus and subsequently modified with TNP (virus‐self‐TNP). The results demonstrate that cultures of responding cells plus 850 rds X‐irradiated vaccinia virus‐primed SC failed to enhance anti‐TNP CTL or plaque‐forming cell (PFC) responses when in vitro stimulation was provided by either virus‐self or TNP‐self alone. In contrast, these cultures resulted in appreciable augmentation of CTL and PFC responses when stimulated by virus‐self‐TNP. Such a helper activity provided by vaccinia virus‐primed SC was revealed to be T cell mediated and antigen specific. These results are discussed in the context of (a) nature of virus helper antigens, (b) mechanism of help and (c) potential of virus help in augmenting CTL and antibody responses to tumor antigens.
Induction of memory and effector suppressor T cells by perinatal exposure to antigen
Authors: Groth Barbara Fazekas de St. , Basten Antony , Loblay Robert
Published: February 2007

The development of tolerance and suppression after perinatal exposure to antigen was studied to clarify the role of suppressor cells in self tolerance. Deaggregated human gamma globulin (dHGG) was administered transplacentally to fetal mice by injecting their mothers at various stages of pregnancy. Other mice were exposed to dHGG present in the colostrum of foster mothers previously injected with dHGG. Nonspecific suppression was seen on adoptive transfer of spleen cells from all donors less than six weeks of age. After that time, HGG‐specific primary suppression by Ly1−2,3+Ia+ T cells was detected in all animals exposed to dHGG either pre‐ or postnatally and persisted for up to three months. In addition, recall of specific memory suppression by antigen challenge was demonstrable for up to six months. Tolerance, on the other hand, was generated only by higher doses of dHGG in utero and was relatively short‐lived when compared to suppression. The short duration of tolerance could not be attributed to the generation of T helper cells, since no significant HGG‐specific helper activity was detected after perinatal exposure to HGG; rather it was thought to be due to the failure of small doses of dHGG to generate sufficient effector T suppressor (Ts) cells to inactivate the continually increasing number of HGG‐specific B cells being generated during ontogeny. Since perinatal tolerance to HGG is known to be prolonged by repeated exposure to antigen, this model implies that the maintenance of natural self tolerance is Ts cell dependent and requires the continued presence of antigen.
A human T cell tumor which expresses the putative T cell antigen receptor
Authors: Boylston Arthur W. , Goldin Robert D. , Moore Claire S.
Published: February 2007

A monoclonal antibody (mAb) called H1‐2D4 which reacts only with the T cell line HPB‐ALL and not with other T cell lines, normal or activated peripheral blood cells, B lymphoblasts (B‐LCL), or thymocytes has been developed. This mAb cocaps the T3 antigen on HPB‐ALL and anti‐T3 mAb cocaps the antigen which reacts with H1‐2D4. Purified H1‐2D4 precipitates a heterodimer from HPB‐ALL cells which has components with molecular weights of 51000 and 39000. The properties of the molecule recognized by H1‐2D4 suggest that it is the HPB‐ALL equivalent of the putative human T cell antigen receptor.
Direct mitogenic effect of ionophore A23187 on isolated human T helper lymphocytes
Authors: Åkerman Karl E. O. , Andersson Leif C.
Published: February 2007

The Ca2+ ionophore A23187 induces only a weak mitogenic response in cultures of unfractionated mononuclear leukocytes from human blood. When a comitogen, 12‐O‐tetradecanoyl‐phorbol‐13‐acetate, which by itself is nonmitogenic, is added, a greatly increased cell proliferation is obtained. Highly purified T lymphocytes respond by proliferation to A23187 alone. Studies on functional subsets of T cells, fractionated by using the monoclonal antibodies OKT4/OKT8, revealed that A21387 is a strong mitogen for pure T helper cells (T4+). This suggests that increased cytosolic Ca2+ directly triggers a proliferative response in T helper cells with no apparent need for accessory cells.
A mouse monoclonal antibody against rabbit VH allotype shares the predominant idiotype with a rabbit antibody of the same specificity
Authors: Metzger Dennis W.
Published: February 2007

A monoclonal antibody, termed 3‐2F1, is specific for the rabbit VH a1 allotypic marker. This antibody appears to recognize a common a1 determinant since it reacts with all of the a1 immunoglobulin (Ig) that is bound by polyclonal rabbit anti‐a1, and completely inhibits the binding of polyclonal anti‐a1 to a1 Ig. When tested for the predominant IdX‐a1 idiotype previously shown to be expressed on virtually all rabbit anti‐a1 antibody, it was found that 3‐2F1 also bears this idiotype. In fact, sequential absorption and inhibition assays indicate that 3‐2F1 displays the entire set of rabbit IdX‐a1 determinants. The results are consistent with the concept that the anti‐IdX reagent bears a latent internal image of the common VH a1 epitope.
Cloned human T lymphocytes with lymphostimulatory capacity preferentially activate suppressor cells
Authors: Pawelec Graham , Schneider E. Marion , Wernet Peter
Published: February 2007

A proportion of cloned T cells derived from allogeneic mixed leukocyte cultures (MLC) was found to stimulate rapid primary, but not secondary, lymphoproliferative responses of autologous as well as allogeneic peripheral blood mononuclear cells (PBMC). Of eight major histocompatibility complex (MHC) class II‐specific monoclonal antibodies (mAb), the reagent TÜ39 (which preferentially inhibits allostimulation by SB‐ rather than DR‐ or DC‐associated determinants) most strongly inhibited stimulation by these clones. MAb specific for DC or DR molecules inhibited weakly or not at all. Stimulatory, but not nonstimulatory, clones were found to be strongly suppressive when titrated directly into MLC. Suppression was not MHC restricted, was radioresistant (20 Gy) and was not abrogated by the addition of partially purified interleukin 2 to the test cultures. Transfer of PBMC cocultured with stimulatory, but not with nonstimulatory, clones into a second MLC resulted in its strong suppression, suggesting that a suppressor effector population had been “induced” by the clones. These results are consistent with the hypothesis that SB‐like, rather than DR or DC, determinants present on the surface of certain activated T cells are intimately involved in the regulation of cellular immune responses by rapidly inducing suppressor effector cells in normal lymphocyte populations.
Target structure for natural killer cells: evidence against a unique role for transferrin receptor
Authors: Dokhélar Marie‐Christine , Garson Dominique , Testa Ugo , Tursz Thomas
Published: February 2007

The transferrin receptor (TfR) was recently proposed as putative natural killer (NK) cell target structure. Here data are presented against this hypothesis and it is shown that low TfR expression and high NK sensitivity can occur concommitantly. K562 cells were studied at various stages of cell proliferation. No change in NK sensitivity could be observed between exponential growth and the plateau phase, whereas TfR expression completely disappeared during the latter. Protein synthesis inhibitors such as cycloheximide (1 μg/ml, 48 h) and actinomycin D (50 μg/ml, 48 h), that abolished the TfR expression at the K562 cell surface, had no effect on NK sensitivity. Similarly, hemin induction (0.1 mM, 5 days) did not change NK susceptibility of K562 cells but considerably diminished TfR expression. Moreover, attempts to block NK sensitivity with anti‐TfR monoclonal antibodies were unsuccessful, even when the 42.6 antibody, which is known to bind to the active site of TfR, was used. Finally, no blocking of NK sensitivity could be achieved when K562 cells were preincubated with saturating concentrations of transferrin or when transferrin was added during the NK assay. It therefore seems doubtful that TfR is the unique target structure for NK cells. It remains possible that TfR and NK target structures are often coexpressed on actively dividing cells.
Production of type I (α/β) interferon after virus infection of cloned, alloantigen‐sensitized mouse T lymphocytes
Authors: Cooley Margaret A. , Blackman Michael J. , Morris Alan G.
Published: February 2007

Mouse T lymphocytes sensitized to alloantigens were cloned by limiting dilution in the presence of interleukin 2. Clones were tested for surface markers Thy‐1, Lyt‐1 and Lyt‐2, and for cytotoxic function. Production of interferon (IFN) by clones either (a) stimulated with allogeneic cells; (b) activated with concanavalin A (Con A); or (c) infected with Semliki Forest virus or Newcastle disease virus were assayed. All clones produced IFN upon Con A stimulation and most after virus infection. Analysis of the IFN produced by a single clone, using anti‐IFN antisera, showed that while Con A stimulation induced production of type II IFN (IFN‐γ), the IFN produced after virus infection was type I IFN (IFN‐α/β).
Human lymphoblastoid cell line producing protective monoclonal IgG1, χ anti‐tetanus toxin
Authors: Tiebout Robert F. , Stricker Elisabeth A. M. , Hagenaars Rien , Zeijlemaker Wim P.
Published: February 2007

Peripheral blood lymphocytes from an individual, recently boosted with tetanus toxoid (TT), were transformed with Epstein‐Barr virus. No antigen‐specific selection nor stimulation of B cells was performed prior to transformation. One stable cell line, designated CLB‐Hu‐TT‐1, was established. This cell line has a doubling time of 24 h and yields 10 μg/ml of a monoclonal IgG1,χ anti‐TT antibody in bulk cultures. The antibody is biologically active in that it can protect mice against the effects of tetanus toxin. The cell line has been characterized with regard to some cytoplasmic and membrane markers.
Repopulation of the gut lamina propria with IgA‐containing cells by lymphoid cells isolated from the gut lamina propria
Authors: Tseng Jeenan
Published: February 2007

Migration and lodging properties of IgA cells and their precursors of the gut lamina propria (GLP) were studied by transfer of highly purified GLP lymphoid cells between immunoglobulin allotype‐congenic mice (CB‐20 to BALB/c). The donor IgA‐containing (cIgA) cells appeared in the GLP of the recipients at day 1, peaked at days 12–15 (late repopulation peak) and persisted up to day 20 after cell transfer. An additional peak at day 3 (early repopulation peak) was seen only when large numbers of GLP B cells were transferred. Few cIgA cells appearing in spleen and mesenteric lymph nodes were seen mainly at days 12–15. The early repopulation peak was probably formed by the differentiation and accumulation of IgA blasts, recirculating IgA‐bearing cells and some IgA precursors. The former 2 cell types homed directly back, while the later homed indirectly via spleen to the GLP. The late repopulation peak was possibly formed by the homing and differentiation of Peyer's patch IgA precursors arriving in the GLP with membrane immunoglobulins unchanged. These GLP IgA precursors migrated first to the spleen and later back to the GLP, where they differentiated into IgA plasma cells.
Helper T cell activation for the human B cell response to trinitrophenylated polyacrylamide beads: involvement of the T4 antigen
Authors: Delfraissy Jean‐François , Vazquez Aimé , Wallon Christine , Desmottes Rose‐Marie , Galanaud Pierre
Published: February 2007

The monoclonal antibody (mAb) OKT4A (but not OKT4) inhibits the in vitro antibody response of human peripheral blood mononuclear cells. The target of OKT4A mAb is the helper T cell, as the helper cells for the antibody response to trinitrophenylated polyacrylamide beads (TNP‐PAA) are exclusively in the T4 subset. The OKT4A mAb is still suppressive when the anti‐TNP response of cultures of monocyte‐depleted cells is supported by purified interleukin 1. Both the OKT4A mAb and anti‐DR mAb suppress the non‐specific T cell proliferation in the cultures leading to the in vitro mAb response. A parallel inhibition is observed for the autologous mixed lymphocyte reaction, the nonspecific B cell response, but the T cell response to mitogens is not affected. These results suggest that the recognition of self major histocompatibility complex class II determinants by the T4 molecule plays a major role in the activation of T helper cells for antibody production to this particulate antigen.
On the role of I‐A antigens in lectin‐ and antigen‐induced interleukin 2 production
Authors: Larsson Eva‐Lotta , Coutinho Antonio
Published: February 2007

The role of I‐A molecules in lectin‐ and antigen‐induced interleukin 2 (IL2) production has been analyzed using monoclonal antibodies. Both lectin‐ and antigen [plus major histocompatibility complex (MHC)]‐induced IL2 production were profoundly inhibited by monoclonal anti‐I‐A antibodies, whereas monoclonal anti‐D and anti‐K antibodies had no effect. The anti‐I‐A‐mediated inhibition of lectin‐induced IL2 production was fully overcome by addition of interleukin 1 (IL1), while no recon‐stitution was observed in antigen (plus MHC)‐specific induction. Anti‐I‐A antibodies were also found to inhibit the T cell‐independent induction of IL1 production.

I‐A antigens appear, therefore, to play two distinct roles in the induction of IL2 production: (a) I‐A molecules are directly involved in mediating activation signals to the macrophages at the level of IL1 production; (b) I‐A epitopes act as restricting elements in specific antigen recognition by T helper cells at the level of IL2 production, a requirement which is overcome by lectin.
In vivo and in vitro studies of thymulin in marginally zinc‐deficient mice
Authors: Dardenne Mireille , Savino Wilson , Wade Sali , Kaiserlian Dominique , Lemonnier Daniel , Bach Jean‐François
Published: February 2007

Thymulin (or serum thymic factor, FTS‐Zn), a well‐defined thymic hormone previously shown to be a nonapeptide binding the metal zinc, was studied in mice subjected to a long‐term marginally Zn‐deficient diet. In spite of the absence of thymic atrophy, we observed a significant decrease in the serum levels of thymulin as early as two months after the onset of treatment. However, these levels could be consistently restored after in vitro addition of ZnCl2. The analysis of thymuses from Zn‐deficient mice showed that, despite the apparently normal network of epithelial cells, there was a progressive increase in the number of thymulin‐containing cells (assessed by immunofluorescence with anti‐thymulin monoclonal antibodies) that was already significant after two months of treatment. These results are in keeping with those of previous investigators, showing a specific, altered, thymic endocrine function following Zn deprivation. Nonetheless, our results strongly suggest that the nonactive Zn‐deprived peptide is secreted under these experimental conditions. Furthermore, the fact that the augmented numbers of thymulin‐containing cells were observed in the thymuses following a decrease in the peripheral thymulin (biologically active) brings further evidence for the existence of a feedback mechanism for the secretion of this hormone.
The abnormal function of T cells in chronically anti‐μ‐treated mice with no mature B lymphocytes
Authors: Kim K. Jin , Rollwagen Florence , Asofsky Richard , Lefkovits Ivan
Published: February 2007

T cells from anti‐μ‐treated mice, normal goat serum (NGS)‐treated mice or untreated control mice were compared with respect to their surface antigenic phenotypes, T cell mitogenic responses, helper function and precursor frequency of helper T cells. Anti‐μ treatment arrested the development of B cells at an immature stage, as determined by flow microfluorometry; it resulted in no serum IgM, but detectable levels of IgG by solid‐phase radioimmunoassay. Proliferative responses to phytohemagglutinin and concanavalin A were significantly decreased in T cells obtained from μ‐suppressed C57BL/6 mice, but not from control mice. When T cells from anti‐μ‐treated mice were tested in vitro for their helper activity to collaborate with B cells from nu/nu C57BL/6 mice to give plaque‐forming cells to sheep red blood cells, they provided far less help than did T cells from control mice. The frequency of T helper cells, as measured by limiting dilution analysis, was much lower in the anti‐μ‐than in the NGS‐treated mice. Cell mixing experiments provided evidence for active suppression of T helper function among splenocytes taken from μ‐suppressed mice.
The role of accessory cells in polyclonal T cell activation III. No requirement for recognition of H‐2‐encoded antigens on accessory cells
Authors: Hünig Thomas
Published: February 2007

Highly purified murine lymph node T cells were used to test the hypothesis that polyclonal T cell activation requires the recognition of mitogen‐modified major histocompatibility complex (MHC) antigens on accessory cells (AC) by the T cells. A veriety of tumor cell lines, including macrophage, B and mast cell tumors, as well as thymomas, were shown to function as AC in concanavalin A‐induced T cell activation, even if they expressed only one class of MHC antigens or none at all. In contrast to antigen‐specific responses, where the Lyt‐2+ phenotype is reportedly associated with recognition of class I MHC antigens, T cells enriched for or depleted of Lyt‐2+ cells were not preferentially activated in the presence of class I‐ or class II‐positive AC, respectively.

In addition, as shown by others in the guinea pig and in the rat systems, T cell proliferation induced by oxidation of cell surface sugars is equally effective if T cells or AC are oxidized. T cell mitogens, therefore, do not seem to act by altering MHC antigens on AC, but rather by providing T cell‐AC contact via their agglutinating properties.
The invariant chains of mouse class II antigens: biochemical properties and molecular relationship
Authors: Zecher Reinhard , Ballhausen Wolfgang , Reske Konrad , Linder Dietmar , Schlüter Michael , Stirm Stephan
Published: February 2007

The proteins p40 (Mr = 40000), p32 (Mr = 32000), p28 (Mr = 28000), p20 (Mr = 20000) and p10 (Mr = 10000) are described which occur in noncovalent association with the polymorphic α,β heterodimer of class II antigens. They were investigated with respect to their molecular characteristics and their mutual structural relationship. p32, the predominant species of this group corresponds to the invariant chain γ (Ii). In contrast to the polymorphic subunits α and β, proteins p40, p28, p20 and p10 migrated like γ in electrophoretically constant positions, when class II molecules of different subregions and different alleles were assessed by two‐dimensional gel electrophoresis [1st dimension, isoelectric focusing; 2nd dimension, sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis]. Analogous to γ, they are therefore designated invariant chains. The low Mr species of this group do not arise from higher Mr forms as preparation artefacts. Short‐term pulse‐chase analysis and cell‐free translation of sucrose gradient‐fractionated mRNA in conjunction with specific immunoprecipitation rendered the possibility unlikely that individual components of this set of proteins existed in a precursor‐product relationship within the cell. Comparative enzymatic fragmentation on SDS polyacrylamide gels as well as tryptic peptide map comparisons by high performance liquid chromatography revealed a high structural relatedness among all members of this group of invariant proteins.
Both Fc receptors and lymphocyte‐function‐associated antigen 1 on human Tγ lymphocytes are required for antibody‐dependent cellular cytotoxicity (killer cell activity)
Authors: Miedema Frank , Tetteroo Pedro A. T. , Hesselink Wim G. , Werner Guy , Spits Hergen , Melief Cornelis J. M.
Published: February 2007

A monoclonal antibody, designated CLB‐LFA‐1/1, directed to the human lymphocyte‐function‐associated antigen 1 (LFA‐1) was raised by immunization of mice with the peripheral blood lymphocytes of a Tγ lymphocytosis patient. The monoclonal antibody was selected by inhibition of the natural killer cell and the antibody‐dependent killer cell activity of the patient's Tγ lymphocytes. In addition, the monoclonal antibody was shown to inhibit the cytotoxic activity of T cell clones specific for either class I or class II HLA molecules. The antigen recognized by CLB‐LFA‐1/1 consisted of three polypeptide chains with molecular weights of 180000 (α), 155000 and 94000 (β). The antibody reacted with T cells, B cells, monocytes and granulocytes, and stained normal Tγ cells and Tγ cells of patients with Tγ lymphocytosis two‐ to threefold stronger than normal T cells. It was shown that LFA‐1 and the Fc receptor on Tγ cells did not comodulate and it is therefore concluded that Fc receptors and LFA‐1 are independent membrane structures, both required for the killer cell activity of Tγ cells.
Monoclonal antibodies specific for murine IgM I. Characterization of antigenic determinants on the four constant domains of the μ heavy chain
Authors: Leptin Maria , Potash Mary Jane , Grützmann Rudolf , Heusser Christoph , Shulman Marc , Köhler Georges , Melchers Fritz
Published: February 2007

Seventeen monoclonal rat antibodies with specificities for mouse μ heavy chain recognize seven distinguishable determinants that are located on the four constant region domains. All determinants are present on secreted, intracellular and membrane bound IgM, and all but two are expressed on isolated μ heavy chain. One antibody, specific for a site in the first constant region domain, recognizes a determinant that is present on IgM of AKR, C3H/HeJ, C57BL/6J, SJL, DBA/2, BALB/c, NZB and CBA/J mouse strains, but not on IgM of A.TH, A/J and A.CA strains of mice.
Pneumococcal cell wall phosphorylcholine elicits polyclonal antibody secretion in mice
Authors: Bach Mark A. , Beckmann Enrique , Levitt Daniel
Published: February 2007

Immunization of mice with phosphorylcholine (PC)‐bearing Staphylococcus pneumoniae Type 2, strain 36a (R36a) results in both a PC‐specific and a polyclonal increase in splenic plaque‐forming cells. The polyclonal increase was observed in all strains tested, including those bearing an X‐linked immune defect resulting in an undetectable anti‐PC immune response. The magnitude of the polyclonal response is directly related to the amount of bacterial surface PC as detected by enzyme‐linked immunosorbent assay. Congenially athymic (nude) mice mount an anti‐PC plaque‐forming cell response after R36a immunization but fail to produce a significant polyclonal response. From our results it appears that PC on the cell wall of a bacterium acts both as a polyclonal activator and a specific antigen, stimulating each by different mechanisms.
Phosphorylcholine on isologous red blood cells induces polyclonal but not anti‐phosphorylcholine plaque‐forming cells in mice
Authors: Beckmann Enrique , Bach Mark A. , Levitt Daniel
Published: February 2007

It has been demonstrated in the preceeding report (Bach, M. A., Beckmann, E. and Levitt, D., Eur. J. Immunol. 1984. 14: 589) that phosphorylcholine (PC) on the bacterium Streptococcus pneumoniae R36a stimulated polyclonal as well as anti‐PC plaque‐forming cells (PFC) in mouse spleen in vivo. In this study, red blood cells from BALB/c mice (MRBC) were either conjugated with PC, 2,4,6‐trinitrophenyl (TNP) or treated with phospholipase A2 (PLA2) to expose PC on the cell membrane (determined by hemagglutination with the anti‐PC myeloma HOPC8). When BALB/c mice were immunized i.v. with the conjugated or enzyme‐treated MRBC, a significant polyclonal antibody response ocurred (p < 0.05) using PC‐MRBC or PLA2‐treated MRBC, but not with TNP‐MRBC or sham‐treated MRBC. No anti‐PC or anti‐MRBC immunoglobulin‐secreting cells developed after immunization. Repeated immunization with PC‐MRBC resulted in similar levels of protein A PFC after each immunization but no anti‐PC, anti‐MRBC or anti‐PC‐MRBC PFC.

Thus, PC on R36a or isologous RBC stimulated increased numbers of splenic plaqueforming cells. In the case of R36a, 10‐25% of these PFC produced antibodies directed towards PC. In contrast, PC‐MRBC or PLA2‐treated MRBC, failed to evoke any anti‐PC antibody responses.