Dose-volume histograms can be interpreted in different ways.
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Humans↗
Biomedical subjects
S Jayaraman
Publications and source records attributed to S Jayaraman.
Macrophages synthesize and secrete a 25-kilodalton protein that binds insulin-like growth factor-I.
Primary (thymus) and secondary (spleen) murine lymphoid tissues express a 25-kDa protein that binds IGF-I. To determine the cellular source of this insulin-like growth factor binding protein (IGFBP), 11 murine or human cell lines representing T, B, and myeloid cells at various stages of differentiation were characterized by IGF-I affinity cross-linkage and Western ligand blotting. Mature myeloid cells, but not T or B cells, secrete a 25-kDa protein that is capable of binding IGF-I. CSF-1-derived bone marrow macrophages also synthesize this 25-kDa IGFBP. Thymic macrophages, which were estimated to secrete 2 ng of binding protein/10(6) cells-h, were used in conjunction with [125I] IGF-I affinity cross-linking to develop a protein binding immunomobility-shift assay to identify which IGFBP is produced by these cells. An anti-IGFBP-4Ab, but not an anti-IGFBP-2 Ab or normal rabbit serum, shifted the [125I] IGF-IGFBP complex to a higher m.w. position, indicating that the single 25-kDa IGFBP is IGFBP-4. Northern blotting confirmed that transcripts for IGFBP-4 as well as IGF-I are expressed in thymic macrophages. A putative 278-bp IGFBP-4 cDNA fragment (residues 341-618) of rat) that contains two unique cysteine residues found only in IGFBP-4 was cloned and sequenced from thymic macrophages. These clones differed from the rat sequence at only six residues (97% homology), and the deduced amino acid sequence from the murine cDNA was identical with that of the rat sequence. Subsequent studies revealed that IGF-I stimulates DNA synthesis in thymic macrophages. However, two different IGF-I analogues differing in the amino-terminus that bind equally well to the IGF-I receptor but poorly to IGFBPs are as effective as IGF-I at 100-fold lower concentrations. These data demonstrate that murine macrophages are a source of a single 25-kDa secreted protein that binds IGF-, that the molecular identity of this protein is IGFBP-4, and that this binding protein may antagonize the extracellular effects of IGF-I.
Amino Acid Sequence↗
The one-two of T helper cells: does interferon-gamma knock out the Th2 hypothesis for asthma?
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Animals↗
T cell receptor alpha-chain defines the antigen specificity of antigen-specific suppressor factor but does not impart genetic restriction.
Previous studies utilizing NP (4-hydroxy, 3-nitrophenyl acetyl hapten)-specific, T suppressor hybridomas have indicated that expression of TCR-alpha, but not TCR-beta, mRNA is required for expression of Ag-specific suppressor factor bioactivity. Suppressor-effector factor has been shown to be Ag specific and I-J restricted. Although the expression of TCR-alpha mRNA was necessary for suppressor activity, the role of TCR-alpha, as it pertained to the functional properties of T cell suppressor factor (TsF), was not established. To determine which properties of TsF could be accounted for by TCR-alpha expression, TCR-alpha cDNA, derived from NP-specific, suppressor T cell (Ts) hybridomas, was transfected into recipient Ts hybridomas of a second Ag specificity. The resulting heterologous transfectants displayed NP-specific, genetically restricted TsF activity. The Ag specificity corresponded to that of the TCR-alpha donor; however, the genetic restriction was influenced by the recipient cell, implying that TCR-alpha did not control genetic restriction of the TsF. Examination of TCR-beta expression in one of the MHC-restricted transfectants indicated that the genetic restriction of TsF could not be accounted for by TCR-beta gene products. The data support the conclusion that TCR-alpha expression is not only obligate for TsF bioactivity, but that the Ag specificity of the TCR-alpha dictates the Ag specificity of the resulting suppressor factor.
Animals↗
Severe and prolonged inflammatory response to localized cowpox virus infection in footpads of C5-deficient mice: investigation of the role of host complement in poxvirus pathogenesis.
Poxviruses are a large, complex group of highly successful pathogens that cause disease in humans and other animals. They encode several proteins postulated to be involved in the evasion of host immunity and therefore serve as excellent models for understanding virus-host interaction during the early stages of viral infection. Vaccinia virus, the best characterized member of the poxviridae family, encodes a 35-kDa major secretory polypeptide termed vaccinia virus complement control protein (VCP), which is structurally related to the family of human and mouse complement control proteins. Members of the family of complement control proteins have been shown to inhibit complement-mediated opsonization of bacteria and induction of inflammatory and phagocytic responses in vitro. Insertional inactivation of the VCP gene results in attenuation of viral virulence in vivo. The role of host complement in the inflammatory response to poxvirus infection has not been systematically investigated. Prior to determining the role of VCP on inflammatory responses in vivo, we decided to investigate the role of host complement in the progression of viral infection. We have compared the effects of injection of cowpox virus, primarily a rodent virus, into footpads of congenic mice strains B10.D2/nSnJ (C5-sufficient) and B10.D2/oSnJ (C5-deficient). The effects of the injection were monitored macroscopically by measuring the specific swelling response immediately following primary injection and subsequently after reinfection and by histological examination of the stained sections of the footpads. Our results indicate that there is a significant variation in the primary response in the two different mouse strains to cowpox virus infection. The specific swelling response observed in measurements from the footpads of the B10.D2/oSnJ mice was significantly greater, persisted for a longer duration, and was accompanied by severe ulceration, edema, induration, and hemorrhaging. Reinjection of the footpads after a 3-month period, during which time the swelling had subsided and the footpad had fully recovered to its original size and appearance, showed no significant differences between the two strains. This strongly suggests that the host complement plays a significant role during the initial response to poxvirus infection.
Animals↗
[Glycoprotein D (5-23) specific Th2-T-cell line induces HSV-1 keratitis].
BALB/c inbred Igh-1-disparate mice exhibit different susceptibility to the development of HSV-1 stromal keratitis (HSK), which may be due to the differential immune regulation. CD4+ T lymphocytes may be critical for the disease induction. A T-cell line (CD4+, T-cell receptor V beta 8+, interleukin-4+) specific for the N-terminal amino acids 5-23 of glycoprotein D from HSV-1 [gD(5-23)] was established from HSK susceptible C.AL-20 mice. HSK-resistant C.B-17 mice, and HSK-susceptible BALB/c mice were injected intraperitoneally with cells (5 x 10(5)/mouse) alone or combined with HSV-1 corneal inoculation (10(5) PFU, KOS strain). Control groups were injected with HSV-antigen-unrelated cells (PPD specific), or were only HSV-1 infected. Migration of the adoptively transferred gD(5-23) Th2 cells was analyzed by histology, by immunohistochemistry and by cell membrane labelling (PKH26). The transfer of gD(5-23) cells accelerated the disease onset (day 2, compared to day 7 without cells). The transfer of gD(5-23) cells increased the incidence of HSK (BALB/c 100%, C.B-17 20%) compared to mice that were only infected with HSV-1 (BALB/c 75%, C.B-17 0%). Keratitis was more severe in mice injected with gD(5-23) cells. In contrast, the transfer of PPD-specific cells did not influence the disease patterns. Mice injected with gD(5-23) cells and not inoculated with HSV-1 did not develop keratitis. The results suggest that CD4+ MHC class II, V beta 8+, IL-4 expressing T-cells (T helper 2) may be important for the induction of HSK.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Exacerbation of murine herpes simplex virus-mediated stromal keratitis by Th2 type T cells.
Corneal infection of susceptible mice with HSV-1 causes herpetic stromal keratitis (HSK), which serves as a model of human HSK. To study the properties of the T lymphocytes involved in HSK, susceptible mice were immunized with the synthetic peptide corresponding to the amino terminal of HSV-1-associated glycoprotein D (gD 5-23). A CD4+ long-term T cell line and a clone bearing V beta 8.2 TCR were derived from peptide-primed lymph node cells. These T cells recognize gD 5-23 peptide in the context of I-Ed and require CD4 and LFA-1 for Ag-specific proliferation. Significantly, a truncated peptide gD 15-23 induced vigorous proliferation, indicating that these 9 amino acids constitute an epitope recognized by these T cells. The gD-specific T cells produced IL-4 and used it as the autocrine growth factor and hence belong to the Th2 subtype. Adoptive transfer of gD-specific Th2 cells into susceptible mice increased both the onset and severity of HSK after corneal HSV-1 infection. Injection of gD-specific Th2 cells without HSV-1 infection failed to cause eye damage. In addition, an irrelevant Ag-specific Th2 clone failed to induce similar tissue damage when the corresponding Ag was applied to the eye. These data indicate that the T cell-mediated exacerbation of HSK in these studies is dependent on the specific recognition of gD after corneal HSV-1 infection. Finally, gD-specific Th2 cell transfer also rendered HSK-resistant mice susceptible for HSK, suggesting that the freedom from HSK in resistant mice may primarily be due to their inability to produce the pathogenic Th2 cells. The data collectively implicate an important role for Th2 cells in the induction of HSV-mediated keratitis in mice.
Amino Acid Sequence↗
The role of the T cell receptor alpha chain in antigen-specific immune suppression.
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Animals↗
Effects of tamoxifen on the fertility of male rats.
The effects of oral administration of tamoxifen (a synthetic non-steroidal anti-oestrogen) at doses of 40, 200 or 400 micrograms kg-1 day-1 on the circulating concentrations of LH, FSH, prolactin, testosterone and oestradiol, weights of pituitary, testes, secondary sex organs and the fertility of adult male rats were determined. The drug was administered per os daily, for up to 90 days. The fertility of rats treated with tamoxifen for 60, 70, 80 or 90 days was assessed by allowing them to mate with normal female rats of proven fertility. Tamoxifen at 40 micrograms kg-1 day-1 reduced concentrations of testosterone in plasma but had no affect on LH, FSH, prolactin and oestradiol concentrations, and the weights of pituitary, testes, epididymides, ventral prostate and seminal vesicles. Tamoxifen at 40 micrograms kg-1 day-1 reduced potency, fecundity, the number of implantation sites, the fertility index and litter size. Tamoxifen at 200 and 400 micrograms kg-1 day-1 reduced the concentrations of LH and testosterone in plasma and the weights of testes and secondary sex organs compared with controls. Tamoxifen at 400 micrograms kg-1 day-1 was most effective in reducing the number of viable pups, the litter size (< or = 1) and the fecundity (20%). The potency of treated rats (a measure of the presence of an ejaculate) was significantly decreased when compared with controls, but copulation was apparently not affected as mated female rats showed a constant dioestrous phase. Histology of the testes revealed disorganization of the cytoarchitecture of the tubules with obliterated lumen.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Murine herpes simplex virus keratitis is accentuated by CD4+, V beta 8.2+ Th2 T cells.
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Animals↗
Tolerance induction in T helper (Th1) cells by thymic macrophages.
Most macrophages in the peripheral tissues present Ag optimally to a variety of functionally distinct Th cells. Although thymic macrophages have been implicated in deleting autoreactive thymocytes, their role in influencing the functional capacities of mature T cells is not clear. We have established a normal untransformed macrophage cell line, named TMC, from the mouse thymus. The TMC line presents protein Ag to an IL-4-producing Th2 type Th clone after IFN-gamma treatment as evidence by T cell proliferation and the release of IL-3 and IL-4. However, these thymic macrophages are inefficient at stimulating a well characterized cytochrome C-specific IL-2-producing Th1 clone, A.E7. Ag presentation by TMC results in the production of IL-3 but not IL-2 production or proliferation of A.E7 cells. This selective Ag presentation defect to Th1 cells is corrected by the addition of live but not fixed allogeneic irradiated spleen cells, suggesting that the thymic macrophages lack the expression of costimulatory activity required for Th1 activation. This is further demonstrated by the failure of live thymic macrophages to provide costimulatory activity to A.E7 cells stimulated with fixed spleen cells plus the antigenic peptide 81-104. Exposure of A.E7 cells to paraformaldehyde-treated TMC in the presence of 81-104 peptide induces specific hyporesponsiveness, anergy. These data demonstrate that thymic macrophages can have a profound influence on the response of selected T cells to Ag. Furthermore, the nature of the T cell stimulus is also critical because Th1 and Th2 cells responded equally well to the T cell mitogen, Con A, and a bacterial superantigen presented by the thymic macrophages.
Animals↗
Influence of nutritional factors on growth and hydrolytic enzyme production in Nocardia asteroides.
The growth and production of hydrolytic enzymes such as alpha-amylase, esterase and peroxidase as influenced by the type of media, carbon and nitrogen sources and C:N ratio were monitored in Nocardia asteroides at 37 degrees C. Sabouraud dextrose and the synthetic media yielded maximum growth compared with tryptic soy broth. Among the carbon sources (dextrose, fructose, sucrose, maltose, starch and citrate), monosaccharides supported maximum growth and induced higher alpha-amylase activity but repressed the peroxidase activity. On the other hand, the disaccharides and starch produced less growth but induced maximum esterase and peroxidase activities. Glutamate among the nitrogen sources (nitrate, nitrite, ammonium, hydroxylamine, glutamate and casein) supported maximum growth. Glutamate, nitrate and casein induced alpha-amylase and esterase activities but suppressed peroxidase activity. Nitrite, ammonium and hydroxylamine stimulated peroxidase activity to the maximum but repressed alpha-amylase and esterase activities. Low, medium and high C:N ratios induced maximum peroxidase, esterase and alpha-amylase activities, respectively.
Caseins↗
Involvement of protein kinase C in competence induction of macrophages to generate T suppressor cells.
We have previously described an Ia-expressing macrophage hybridoma clone, termed clone 59, which attains the ability to induce Ts cells after activation with murine rIFN-gamma. In this report, we show that a protein kinase C (PKC) activator, PMA (10 ng/ml) can replace IFN-gamma in inducing this form of macrophage competence. IFN-gamma-induced cellular competence was abrogated specifically by a PKC inhibitor but not by inhibitors that have specificity for cyclic nucleotide-dependent protein kinases. Furthermore, PGE2 known to induce protein kinase A in murine macrophages also failed to induce competence. In contrast, the ability to induce Th responses was neither dependent on IFN-gamma nor inhibited by prior treatment with protein kinase inhibitors. Furthermore, PKC depletion of macrophages by treatment with high doses (100 ng/ml) of PMA abrogated their ability to induce Ts cells. In addition, PKC-depleted macrophages failed to regain the ability to stimulate Ts cells after further treatment with IFN-gamma. The ability of IFN-gamma to modulate macrophage-mediated induction of Ts cells does not clearly correlate with an increased Ia expression as inducible expression of Ia was not consistently abrogated by PKC inhibitor treatment. In addition, PKC inhibitors failed to prevent the production of the cytokines IL-1 and IL-6. However, incubation of IFN-gamma or PMA-treated macrophages with antibodies recognizing the putative IJ ligand blocked the ability to induce Ts cells, suggesting the expression of these determinants on accessory cells is responsible for Ts induction.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Prostatic hypoplasia in bonnet monkeys following active immunization with semisynthetic anti-LHRH vaccine.
An active immunization study using semisynthetic anti-luteinizing hormone releasing hormone (LHRH) vaccine was undertaken in adult male bonnet monkeys (Macaca radiata). Four male bonnet monkeys were immunized with LHRH-DT vaccine (100 micrograms/monkey). When the elevation of serum anti-LHRH titers reached an effective concentration, a remarkable decrease in serum testosterone level was observed. The sperm counts at 12 and 20 weeks following immunization in all immunized monkeys were reduced markedly. One representative animal with high antibody titer along with an age-matched control animal was sacrificed 20 weeks following primary immunization. The prostate weight of the immunized monkey was reduced to one-third (0.027) of the control (0.085). A reduction was also observed in other reproductive organs. Remaining animals are being studied for a reversible effect of immunization. Thus the study demonstrates that the size of the prostate can be reduced significantly by inhibition of hypothalamic-pituitary-testicular axis using this anti-LHRH vaccine.
Acid Phosphatase↗
Relationships between antigen-specific helper and inducer suppressor T cell hybridomas.
Ts1, or inducer suppressor T cells, share many phenotypic and functional characteristics with helper/inducer subset of T cells. In order to evaluate the relationship between these cell types, we made a series of new Ts1 hybridomas by the fusion of Ts1 cells with the functionally TCR alpha/beta-negative BW thymoma (BW 1100). Three Ts1 hybridomas (CKB-Ts1-38, CKB-Ts1-53, and CKB-Ts1-81) were established that express TCR and produce Ag-specific suppressor factors constitutively, thus making it possible to study the nature and specificity of Ag receptors, MHC restriction, and lymphokine production by the Ts1 hybridomas. Results presented in this report demonstrate that all the Ts1 hybridomas described here express CD3-associated TCR-alpha beta. These three Ts1 hybridomas recognize Ag (NP-KLH) specifically in a growth inhibition assay and this recognition is restricted by IE molecules. Two of the hybridomas also produce IL-2 or IL-2 and IL-4 upon Ag-specific activation. Thus, by these three criteria the Ts1 hybridomas appear indistinguishable from Th cells. These three Ts1 hybridomas, however, release suppressor factors (TsF1) in the supernatant that suppress both in vivo DTH and in vitro PFC responses in an Ag-specific manner. Like the TsF1 factors characterized previously, the suppression mediated by these factors are Igh restricted and lack H-2 restriction. These factors mediate suppression when given in the induction phase but not during the effector phase of the immune response. The TsF1 factors are absorbed by Ag (NP-BSA), and anti-TCR affinity columns and the suppressor activity can be recovered by elution. The data are consistent with the interpretation that Ts1 inducer-suppressor T cells are related to Th cells; the feature that distinguishes these cells is the ability to produce Ag-binding factors that specifically suppress immune responses.
Animals↗
Characterization of T cell clones from an athymic mouse.
Although Thy-1+ lymphocytes have been observed in lymphoid tissues of athymic mice, attempts to analyze these cells on the clonal level have previously yielded only populations of CD4-CD8+ cytolytic T cells. Furthermore, studies of responses of these cells to various mitogenic stimuli have demonstrated significant defects in the ability of these cells to proliferate in culture. We report here on the cloning and maintenance in long term culture of T cells from an athymic mouse stimulated in vitro with allogeneic spleen cells. Of 10 Thy-1+ clones, 7 CD4+CD8- and 3 CD4-CD8+ Ag-specific cells were obtained. Among the CD4+ T cells, we observed a variety of specificities, including an autoreactive I-Aq specific clone, a minor lymphocyte stimulating determinant (Mls)-reactive clone, and five allo-I-Ad-specific CD4+ clones; a class II-specific CD4-CD8+ clone was also obtained. In addition, we observed two Thy-1-CD3+ clones (one of which is also CD4+ and expresses V beta 8) which are constitutively responsive to the lymphokines IL-2 and IL-4. Of 11 clones tested, 7 produce IL-2 and/or IL-4 lymphokines after stimulation through the TCR, whereas 4 do not, requiring exogenous lymphokines for optimal responses to Ag. Of 10 clones tested for IL-2R expression, 3 had notably low levels, correlating with low proliferative responses to IL-2. The results reveal the spectrum of T cells available to a mouse which is congenitally athymic and describe the heterogeneity of immune defects expressed in such cells at the clonal level.
Animals↗
Enhancement of in vivo cell-mediated immune responses by three distinct cytokines.
The ability of recombinant/purified cytokines to augment delayed-type hypersensitivity (DTH) responses was investigated. Suboptimal doses of haptenized SC were treated in vitro with purified or recombinant derived cytokines and tested for their ability to enhance DTH in vivo. With the use of this protocol, it was shown that both human and mouse rIL-6, as well as mouse rTNF-alpha, potentiated DTH in a dose-dependent manner. In accordance with these data, IL-6/TNF-alpha-containing supernatant from long term nonlymphoid cell lines also possessed the ability to augment DTH. By using the same protocol, we have also identified T cell hybridomas that produce DTH-augmenting activity constitutively. The hybridoma-derived factor, termed the T cell enhancing factor (TCEF), was functionally distinguishable from the defined cytokines IL-1 through IL-6, IFN-gamma, and TNF by bioassay. Furthermore, RNA derived from the hybridoma failed to hybridize with cDNA probes specific for IL-1 to IL-6, IFN-gamma, TNF-alpha, and granulocyte-macrophage CSF. Further characterization of the serum-free conditioned media derived from the hybridoma indicated that the TCEF was a soluble acid labile glycoprotein (Mr greater than 30,000). Finally, we investigated the cellular requirements for DTH augmentation by IL-6, TNF-alpha, and TCEF; all are dependent upon the presence of T cells in the immunizing inoculum. We propose that these cytokines play a critical role in the development of DTH responses in vivo.
Animals↗
Histopathological changes in reproductive organs of male Wistar rats following active immunization against LHRH.
Histopathological changes induced by immune responses generated against luteinizing hormone releasing hormone (LHRH) were studied in adult male Wistar rats. Active immunization with a semisynthetic anti-LHRH vaccine, LHRH D-Lys6, (10, 40, and 80 micrograms/animal) conjugated with diphtheria toxoid, produced bioeffective antibodies as indicated by significant reduction in circulating testosterone levels. At the 14th week after immunization the animals were sacrificed and reproductive organs were evaluated. These organs were studied for histopathological changes and compared with those of nonimmunized control rats. Marked hypoplastic changes were observed in the genital organs. Testicular changes such as arrest of spermatogenesis at the spermatocyte level and atrophic changes in the interstitial Leydig cells were noticed in treated animals. Similarly attenuation of secretory epithelial cells with substantial increase in the stromal tissues was observed in the prostate and seminal vesicles. The current observation suggests the possible usefulness of this anti-LHRH vaccine under clinical conditions where reduction in androgenic response is desired as in the case of hormone-dependent prostatic carcinoma.
Animals↗