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T Mosmann

Publications and source records attributed to T Mosmann.

At least 19 recordsLinked to original sources

In vivo priming of CD4 T cells that produce interleukin (IL)-2 but not IL-4 or interferon (IFN)-gamma, and can subsequently differentiate into IL-4- or IFN-gamma-secreting cells.

The differentiation of antigen-stimulated naive CD4 T cells into T helper (Th)1 or Th2 effector cells can be prevented in vitro by transforming growth factor (TGF)-beta and anti-interferon (IFN)-gamma. These cells proliferate and synthesize interleukin (IL)-2 but not IFN-gamma or IL-4, and can differentiate into either Th1 or Th2 cells. We have now used two-color Elispots to reveal substantial numbers of primed cells producing IL-2 but not IL-4 or IFN-gamma during the Th1- or Th2-biased immune responses induced by soluble proteins or with adjuvants. These cells were CD4(+)CD44(high) and were present during immediate and long-term immune responses of normal mice. Naive T cell receptor for antigen (TCR) transgenic (DO11.10) T cells were primed in vivo after adoptive transfer into normal hosts and FACS((R)) cloned under conditions that did not allow further differentiation. After clonal proliferation, aliquots of each clone were cultured in Th1- or Th2-inducing conditions. Many in vivo-primed cells were uncommitted, secreting IL-2 but not IL-4 or IFN-gamma at the first cloning step, but secreting either IL-4 or IFN-gamma after differentiation in the appropriate conditions. These in vivo-primed, uncommitted, IL-2-producing cells may constitute an expanded pool of antigen-specific cells that provide extra flexibility for immune responses by differentiating into Th1 or Th2 phenotypes later during the same or subsequent immune responses.

Adjuvants, Immunologic↗

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Journal Article↗

Resistance of naive mice to murine hepatitis virus strain 3 requires development of a Th1, but not a Th2, response, whereas pre-existing antibody partially protects against primary infection.

Murine hepatitis virus strain 3 (MHV-3) produces a host-strain-dependent spectrum of disease. The development of liver necrosis has been shown to be related to production of a unique macrophage procoagulant activity (PCA), encoded by the gene fgl-2, in susceptible mice. These studies were designed to examine the influence of Th1/Th2 cells on resistance/susceptibility and production of macrophage procoagulant activity (PCA) in resistant (A/J) and susceptible (Balb/cJ) strains of mice following infection with MHV-3. Immunization of A/J mice with MHV-3 induced a Th1 cellular immune response and one Th1 cell line (3F9.1) protected susceptible mice and inhibited production of PCA by macrophages both in vitro and in vivo. In contrast, immunization of Balb/cJ mice with an attenuated variant of MHV-3 derived from passaging MHV-3 in YAC-1 cells resulted in a Th2 response. Transfer of spleen cells and T cell lines from immunized Balb/cJ mice failed to protect naive susceptible syngeneic mice from infection with MHV-3 and augmented production of IL-1 beta, TNF-alpha and PCA by macrophages to MHV-3 in vitro. Serum from immunized Balb/cJ mice contained high titered neutralizing antibody which protected naive Balb/cJ animals from lethal primary MHV-3 infection. These results demonstrate that susceptible Balb/cJ mice generate a Th2 response following MHV-3 infection and that these Th2 cells neither inhibit MHV-3-induced macrophage PCA production nor protect naive mice from MHV-3 infection. The results suggest that antibody protects against primary infection, but could not eradicate ongoing infection. Ribavirin, a synthetic guanosine analogue prolonged survival to MHV-3 infection, inhibited production and transcription of the macrophage pro-inflammatory cytokines IL-1 beta and TNF-alpha and Th2 cytokines while preserving Th1 cytokine production. Thus, this data defines the differential role of Th1/Th2 lymphocytes in primary and secondary MHV-3 infection and further defines the importance of macrophage inflammatory mediators in the pathogenesis of MHV-3 infection.

Animals↗

Resistance of naive mice to murine hepatitis virus strain 3 requires development of a Th1, but not a Th2, response, whereas pre-existing antibody partially protects against primary infection.

Murine hepatitis virus strain 3 (MHV-3) produces a strain-dependent spectrum of disease. The development of liver necrosis has been shown to be related to production of a unique macrophage procoagulant activity (PCA), encoded by the gene fgl-2, in susceptible mice. These studies were designed to examine the influence of Th1/Th2 cells on resistance/susceptibility and production of macrophage PCA in resistant (A/J) and susceptible (BALB/cJ) strains of mice following infection with MHV-3. Immunization of A/J mice with MHV-3 induced a Th1 cellular immune response, and one Th1 cell line (3E9.1) protected susceptible mice and inhibited PCA production by macrophages both in vitro and in vivo. In contrast, immunization of BALB/cJ mice with an attenuated variant of MHV-3 derived from passaging MHV-3 in YAC-1 cells resulted in a Th2 response. Transfer of spleen cells and T cell lines from immunized BALB/cJ mice failed to protect naive susceptible syngeneic mice from infection with MHV-3 and augmented macrophage PCA production to MHV-3 in vitro. However, serum from immunized BALB/cJ mice contained high titrated neutralizing Ab that protected naive BALB/cJ animals from lethal primary MHV-3 infection. These results demonstrate that susceptible BALB/cJ mice generate a Th2 response following MHV-3 infection and that these Th2 cells neither inhibit MHV-3-induced macrophage PCA production nor protect naive mice from MHV-3 infection. The results suggest that Ab protects against primary infection but cannot eradicate ongoing infection. Thus, these data define the differential role of Th1/Th2 lymphocytes in primary and secondary MHV-3 infection and emphasize the importance of PCA in the pathogenesis of MHV-3 infection.

Animals↗

IL-10 prevents naturally occurring fetal loss in the CBA x DBA/2 mating combination, and local defect in IL-10 production in this abortion-prone combination is corrected by in vivo injection of IFN-tau.

CBA x DBA/2 placentae are quantitatively or qualitatively deficient in their production of the anti-inflammatory Th2-type cytokines IL-4 and IL-10 compared with the nonresorption-prone CBA x BALB/c mating combination. Wastage in this mating combination is accompanied by increased levels of local inflammatory cytokines. In addition, alloimmunization enhances the placental production of IL-4 and IL-10 in CBA x DBA/2 matings. Furthermore, rIL-10 by itself completely reverses the high incidence of fetal resorption after i.p. injection. Conversely, anti-IL-10 increases the resorption rate, but only in CBA x DBA/2 matings. On the other hand, injecting either anti-IFN-gamma or pentoxifillin (an anti-TNF agent) partially reduces the resorption. When given together, they produce a synergistic remission of fetal loss. Finally, we report that recombinant ovine trophoblast protein, an IFN-tau which is known to influence reproductive outcome in ruminants, can also counteract increased CBA x DBA/2 fetal resorption. It simultaneously induces increased placental IL-4 and IL-10 production in this mating combination. These results indicate that the placentally produced anti-inflammatory cytokines can play a vital role in the survival to term of the fetal allograft, by counteracting deleterious inflammatory cytokines.

Abortion, Spontaneous↗

In vivo evidence that ultraviolet B-induced suppression of allergic contact sensitivity is associated with functional inactivation of Th1 cells.

Having previously shown in vitro that ultraviolet B (UVB)-treated Langerhans cells (LC) can induce antigen-specific proliferative unresponsiveness and tolerance in Th1 (but not Th2) cells, we wanted to determine whether cutaneous exposure to UVB radiation prior to hapten-painting would produce similar differential effects in hapten-reactive Th1 and Th2 T cells in vivo. C3H/HeN mice were exposed to UVB (200 J/m2/day) through abdominal skin on days -4 through -1, followed by painting dinitrofluorobenzene (DNFB) on the irradiated skin on days -1 and 0. Induction of allergic contact sensitivity (CS) was assayed by ear swelling responses to DNFB and by the proliferative responses of draining lymph node cells (LNC) to DNBS. UVB-irradiated and hapten-painted mice (in comparison to a control panel of unirradiated and DNFB-painted mice) displayed suppressed ear swelling responses to DNFB and suppressed LNC proliferation to DNBS. However, LNC from either panel of mice proliferated well in response to exogenous interleukin 2 (IL-2). To examine effects on Th1 and Th2 cells, lymphokines were assayed from supernatants of DNBS-stimulated LNC. The Th1-associated lymphokines, interferon-gamma and IL-2, were the predominant cytokines detected in samples taken from unirradiated and DNFB-painted mice. Both of these cytokines were reduced markedly in samples from UVB-treated and DNFB-painted mice. Except for miniscule amounts of IL-10, no Th2-associated lymphokines were detected in LNC supernatants from either panel of mice. These results suggest that UVB-induced suppression of CS in vivo is associated with functional inactivation of hapten-reactive Th1 cells.

Animals↗

Production of IL-10 by CD4+ T lymphocytes correlates with down-regulation of Th1 cytokine synthesis in helminth infection.

After the onset of parasite egg deposition, mice infected with the helminth Schistosoma mansoni mount strong Th2 cytokine responses in the absence of significant Th1 cytokine synthesis. To examine the basis of this immunoregulatory state, spleen or lymph node cells from schistosome-infected mice were stimulated with parasite-specific Ag and the supernatants tested for their capacity to suppress IFN-gamma synthesis by a Th1 cell line. Strong inhibition was observed that was neutralized by a mAb against IL-10, a cytokine previously shown to down-regulate Th1 cytokine synthesis. By means of ELISA measurements the production of IL-10 in schistosome infection was confirmed and shown to depend on CD4+ T cells. IL-10 synthesis stimulated by either mitogen or Ag was observed only at those stages of infection when Th2 response induction and Th1 cytokine down-regulation also occurred and was not detected in mice vaccinated with attenuated parasites. Moreover, the addition of the neutralizing anti-IL-10 mAb to Ag-stimulated spleen cell cultures from infected mice caused a dramatic augmentation in IFN-gamma synthesis. These findings suggest that IL-10 is responsible for the down-regulation of Th1 responses observed in schistosome infections, a phenomenon that may enable the parasite to escape potentially harmful cell-mediated responses.

Animals↗

Evidence for mouse Th1- and Th2-like helper T cells in vivo. Selective reduction of Th1-like cells after total lymphoid irradiation.

Purified CD4+ BALB/c spleen T cells obtained 4-6 wk after total lymphoid irradiation (TLI) helped normal syngeneic B cells to produce a vigorous antibody response to TNP keyhole limpet hemocyanin in adoptive cell transfer experiments. However, the same cells failed to transfer delayed-type hypersensitivity to the adoptive hosts as measured by a foot pad swelling assay. In addition, purified CD4+ cells from TLI-treated mice were unable to induce graft vs. host disease in lethally irradiated allogeneic C57BL/Ka recipient mice. In response to mitogen stimulation, unfractionated spleen cells obtained from TLI mice secreted normal levels of IL-4 and IL-5, but markedly reduced levels of IL-2 and INF-gamma. A total of 229 CD4+ clones from spleen cells of both normal and TLI-treated mice were established, and the cytokine secretion pattern from each clone was analyzed. The results demonstrate that the ratio of Th1- and Th2-like clones in the spleens of normal BALB/c mice is 1:0.6, whereas the ratio in TLI mice is approximately 1:7. These results suggest that Th2-like cells recover rapidly (at approximately 4-6 wk) after TLI treatment and account for the early return of antibody helper activity and secretion of IL-4 and IL-5, but Th1-like cells recover more slowly (in approximately 3 mo) after irradiation, and this accounts for the deficit in cell-mediated immunity and the reduced amount of IL-2 and IFN-gamma secretion.

Animals↗

Interferon-gamma is produced by activated immature mouse thymocytes and inhibits the interleukin 4-induced proliferation of immature thymocytes.

We have recently shown that interleukin 4 (IL-4) (formerly called BSF-1) is a potent stimulator of fetal and adult immature thymocyte proliferation and that adult L3T4-/Lyt-2-thymocytes can be stimulated by calcium ionophore (A23187) and phorbol ester to secrete IL-4 (Zlotnik, A., J. Ransom, G. Frank, M. Fischer, and M. Howard. 1987. Proc. Natl. Acad. Sci. (USA) 84:3856). This report shows that fetal thymocytes (day 15 of gestation) can also be activated to produce IL-4 suggesting that IL-4 may be a mediator of fetal as well as adult immature thymocyte proliferation. Furthermore, we demonstrate that interferon-gamma (IFN-gamma) inhibits the IL-4-mediated proliferation of both fetal and adult L3T4-/Lyt-2-thymocytes. The inhibition of proliferation is blocked by anti-IFN-gamma antibody and is unaffected by indomethacin suggesting that IFN-gamma directly inhibits immature thymocyte proliferation. IFN-gamma does not block the IL-4/phorbol myristate acetate-mediated proliferation of an adult thymocyte population, which is enriched for L3T4-/Lyt-2+ and L3T4+/Lyt-2- cells, suggesting that the inhibitory effect of IFN-gamma is limited to the immature thymocyte population. Both fetal (day 15) and adult L3T4-/Lyt-2--thymocytes can be activated to secrete an IFN-gamma like activity. This activity is neutralized by a monoclonal anti-IFN-gamma antibody indicating that the activity is due to IFN-gamma. mRNA analysis of adult L3T4-/Lyt-2- thymocytes stimulated with A23187 and phorbol myristate acetate confirms that mRNA for both IL-4 and IFN-gamma is induced in adult L3T4-/Lyt-2- thymocytes. These results indicate that IL-4 and IFN-gamma can regulate immature thymocyte proliferation.

Animals↗

Requirement for BSF-1 in the induction of antigen-specific B cell proliferation by a thymus-dependent antigen and carrier-reactive T cell line.

We report here a role of B cell stimulatory factor 1 (BSF-1) in the induction of antigen-specific proliferation of affinity-purified small B lymphocytes by a thymus-dependent antigen and a carrier-reactive T cell line. By using an ovalbumin-reactive T cell line (designated Hen-1), which does not produce BSF-1 following activation, it was possible to demonstrate that the antigen-specific proliferative response of trinitrophenyl (TNP)-binding B cells to TNP-ovalbumin required exogenous BSF-1 in addition to direct interaction with irradiated Hen-1 T cells. The activation obtained under these conditions was highly efficient, being sensitive to antigen doses as low as 0.001 microgram/ml. The addition of saturating amounts of BSF-1 did not alter the antigen-specificity or the requirements for hapten-carrier linkage or major histocompatibility complex-restricted T-B interaction in this system. The involvement of BSF-1 was confirmed by the ability of 11B11 anti-BSF-1 antibody to specifically suppress the response of TNP-binding B cells to TNP-ovalbumin, BSF-1, and irradiated Hen-1 T cells. Finally, this response was augmented by addition of the monokine interleukin 1. These data indicate that the proliferative response of small B cells to the thymus-dependent antigen and carrier-reactive T cell line used in our experiments can be regulated by the same factors that govern B cell proliferation induced by thymus-independent type 2 antigens or anti-IgM antibodies.

Animals↗

B cell stimulatory factor 1 (interleukin 4) is a potent costimulant for normal resting T lymphocytes.

Resting T cells proliferate in response to B cell stimulatory factor 1 (BSF-1; interleukin 4) plus phorbol myristate acetate (PMA). This response is obtained with highly purified T cells and is density independent, suggesting that accessory cells are not required. Both L3T4+ and Lyt-2+ T cells respond to BSF-1 plus PMA. Although BSF-1 alone does not cause T cell proliferation, it maintains the viability of small, dense T cells, indicating that it acts on resting T cells. Furthermore, BSF-1 is required early in the proliferative response of resting T cells to BSF-1 plus PMA, further supporting the concept that it acts on G0 or early G1 cells. However, BSF-1 is also needed late in the first round of division of T cells stimulated with BSF-1 plus PMA. Removing BSF-1 at 24 h of stimulation prevents entry into S phase. These results indicate that BSF-1 is involved in both the induction of competence and in the progression phases of T cell division.

Animals↗

T-cell antigen receptors with identical variable regions but different diversity and joining region gene segments have distinct specificities but cross-reactive idiotypes.

The T-cell antigen receptor alpha-chain genes of an alloreactive, H-2Db-specific cytotoxic T-cell clone (3F9) are described. This study and our work on the 3F9 beta-chain genes reveal that the variable region gene segments for the alpha and beta chains expressed in 3F9 are identical to the ones used by a chicken erythrocyte-specific, I-Ab-restricted helper T-cell clone (LB2). These two clones differ, however, in the diversity and joining portions of the alpha and beta chains of their T-cell receptor molecules. The analysis of 3F9 and LB2 with monoclonal antibodies specific for the 3F9 T-cell receptor shows that these two T-cell clones share the same idiotype; however, 3F9 and LB2 do not exhibit any antigen and/or major histocompatibility complex cross-reactivity. This suggests that the diversity and joining regions of the T-cell receptor may play a key role in antigen and/or major histocompatibility complex recognition.

Animals↗

A requirement for physical linkage between determinants recognized by helper molecules and cytotoxic T cell precursors in the induction of cytotoxic T cell responses.

It has long been understood that both antibody and delayed-type hypersensitivity responses are induced through collaborative events in which the determinants recognized by the precursor cells must be physically linked to the determinants recognized by the helper. Although it is clear that the generation of memory cytotoxic T lymphocyte precursors (CTLp) involves linked recognition of determinants, the induction of CTL responses has been viewed as being dependent upon interleukin 2 (IL 2), which could be provided by a helper cell, but independent of requirements for antigen bridging. In this work, we have designed a system that lacks exogenous IL 2 by using as our source of help, antigen-specific helper molecules derived from helper T cells. These soluble helper molecules are uncontaminated by IL 2 and unlike a helper cell, are unable to produce IL 2. Helper molecules specific for chicken red blood cells (Crbc) and for a synthetic polypeptide, poly 18, were tested. Thymocyte responders require a source of help to respond to alloantigens intrinsically expressed on the surface of adherent stimulator cells. To analyze the mechanism whereby the helper molecules acted, we used a system involving recognition of haptenic and carrier determinants that were physically linked by virtue of being located on the same cell surface (intra-structural linkage). Adherent stimulator cells were pulsed with Crbc or poly 18 so that the alloantigens recognized by the thymocyte CTLp (intrinsically expressed class I) were either linked or unlinked to the carrier determinants (Crbc or poly 18) presented by the adherent cells and recognized by the helper molecules. Both types of helper molecule were shown to be antigen-specific in crisscross experiments. The helper molecules specific for Crbc were able to induce the thymocyte CTLp only when both hapten and carrier were present on the same stimulator cell surface. Because we were not able to detect a requirement for H-2-restricted recognition of carrier antigen, this inductive event must be viewed as requiring linked associative recognition of determinants, but being noncognate. In contrast, the helper molecules recognizing poly 18 showed a requirement for both physical linkage of determinants and for H-2 restricted recognition, indicating that the mechanism of induction was cognate in nature. Therefore, we have shown that interactions between CTLp and soluble, antigen-specific, helper cell-derived inductive molecules are similar in nature to those of other T cell precursors and of B cells in the stringent requirement for close physical proximity achieved by linked or cognate recognition of determinants across an antigen bridge.

Animals↗

Isolation and characterization of a human interleukin cDNA clone, homologous to mouse B-cell stimulatory factor 1, that expresses B-cell- and T-cell-stimulating activities.

A cDNA sequence coding for a human interleukin has been isolated from a concanavalin A-activated human T-cell cDNA library based on homology with a mouse interleukin cDNA that expresses B-cell stimulatory factor 1 (BSF-1) activity and T-cell- and mast-cell-stimulating activities. The human cDNA contains a single open reading frame encoding a protein of 153 amino acid residues including a putative signal peptide. Amino acid sequences of the mouse and human polypeptides, deduced from their cDNAs, share extensive homology with the exception of about 40 amino acid residues near the middle portion, which share little homology. Supernatant of COS-7 monkey cells transfected with the human cDNA clone stimulated proliferation of human helper T-cell clones and of anti-IgM-activated human B cells, two properties of mouse BSF-1 on mouse cells. These results indicate that this human cDNA clone encodes a protein structurally and functionally homologous to mouse BSF-1.

Amino Acid Sequence↗

Isolation and characterization of a mouse interleukin cDNA clone that expresses B-cell stimulatory factor 1 activities and T-cell- and mast-cell-stimulating activities.

A cDNA sequence coding for a unique mouse interleukin that expresses B-cell-, T-cell, and mast-cell-stimulating activities has been isolated from a mouse helper T-cell cDNA library. The library, constructed in the pcD expression vector, was screened by transfecting COS monkey cells with DNA pools to express the products encoded by full-length cDNA inserts. By assaying the transfected cell supernatants, we identified clones encoding a factor that stimulates T-cell and mast cell lines. This factor also induces Ia expression on resting B cells and enhances IgG1 and IgE production by B cells, two properties of B-cell-stimulatory factor 1. The DNA sequence codes for a polypeptide of 140 amino acid residues including a putative signal peptide. These results demonstrate that a single cDNA clone distinct from interleukin 2 and interleukin 3 encodes a polypeptide with multiple biological activities.

Amino Acid Sequence↗

Use of a cDNA expression vector for isolation of mouse interleukin 2 cDNA clones: expression of T-cell growth-factor activity after transfection of monkey cells.

A cDNA sequence coding for mouse interleukin 2 (IL-2) has been cloned from a cDNA library prepared from mRNA derived from a concanavalin A-activated mouse T-cell clone. The library was constructed by using the pcD vector system, which permits the expression of cDNA inserts in mammalian cells. Screening of the library was performed by transfecting COS-7 monkey cells with pools of cDNA clones in order to express the products encoded by full-length cDNA inserts. By assaying the supernatant fluid, IL-2 cDNA clones that express T-cell growth-factor (TCGF) activity were identified. The DNA sequence codes for a polypeptide of 169 amino acid residues including a putative signal peptide. The mouse IL-2 amino acid sequence deduced from the nucleotide sequence of its cDNA shares extensive homology with the human IL-2 amino acid sequence reported previously. These results demonstrate that identification of full-length cDNA clones for many lymphokines may be achieved entirely on the basis of detection of the functional polypeptides in mammalian cells.

Amino Acid Sequence↗