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K Inaba

Publications and source records attributed to K Inaba.

At least 55 records · Page 3Linked to original sources
PubMed1989

Expansion of natural killer cells but not T cells in human interleukin 2/interleukin 2 receptor (Tac) transgenic mice.

Transgenic mice expressing both human IL-2 and the L chain of IL-2-R constitutively had an unusual expansion of Thy-1+/CD3-4-8- large granular lymphocytes, which bore the elevated NK activity. Unexpectedly, the transgenic mice had neither T cell expansion nor autoreactive antibodies. The increase in number and activity of NK cells seems to be responsible for both the severe interstitial pneumonia and lymphocyte depletion in the spleen that we found in these transgenic mice. In addition, we found the selective loss of Purkinje cells in the cerebellum of the mice, which gave rise to their disturbed gait. All the transgenic mice died by 4 wk of age.

Animals↗
PubMed1989

An antigen-independent contact mechanism as an early step in T cell-proliferative responses to dendritic cells.

Dendritic cells bearing antigen efficiently aggregate and stimulate antigen-specific T cells. We describe an experimental model in which an initial, apparently antigen-independent binding step is followed by ligation of the TCR. The model is the polyclonal response to mAb to the CD3 portion of the TCR complex. Epidermal and thymic dendritic cells utilize low levels of Fc receptors to present the anti-CD3 mAb and induce mitogenesis. Within 3 h of coculture, most of the dendritic cells have formed clusters with the resting T lymphocytes, and these clusters are the site for subsequent DNA synthesis and cell growth. However, the binding of dendritic cells to T cells proceeds as efficiently in the absence of anti-CD3 as in its presence, and anti-FcR mAb does not block. CD3 and Fc receptors are essential for the subsequent mitogenesis response in dendritic-T cell clusters. Because an exogenous ligand for the TCR does not seem to be required for the extensive polyclonal clustering of resting lymphocytes to dendritic cells, we suggest that an antigen-independent mechanism mediates the initial interaction. This clustering seems essential for T cell growth since we do not detect, in two-chamber experiments, soluble lymphocyte-activating factors that originate from dendritic-T cell aggregates and that activate anti-CD3-coated T cells.

Animals↗
PubMed1989

[21-hydroxylase deficiency associated with adrenal tumor: case report of two brothers].

Described herein are two brothers with 21-hydroxylase deficiency (21-OHD) associated with adrenal tumors, and these possible mechanisms are discussed. A 34-year-old male was admitted on Jan. 9, 1984 because of an enlarged and tender left breast. Physical examination revealed short stature (152 cm, 76.5 kg), gynecomastia and shortening of metacarpal bone. His testes were small (2.6 X 1.6 X 1.9 cm). Urinary excretion of 17-OHCS was within normal range (5.9 mg/day), but those of 17-KS, 17-KGS and pregnanetriol were markedly increased (44.4, 110 and 22.6 mg/day, respectively). Plasma concentrations of progesterone and ACTH and urinary excretions of estrone, estradiol and estriol were also increased. Urinary excretions of 17-KS were decreased to 11.7 mg/day and 17-KGS to 22.3 mg/day after the ingestion of 2 mg/day dexamethasone for two days. The computed tomography and a scintigraphy with 131I-Adosterol revealed a tumor in the left adrenal gland, and the adrenal arteriography revealed a neovascularity and a tumor stain in the tumor. These data indicated that the patient was suffering from both 21-OHD and the left adrenal tumor. At this point, adenoma or adenocarcinoma of the adrenal gland was suspected. The left adrenal tumor (85 g) was resected on April 10, 1984, and the pathological diagnosis was adrenal adenoma. The patient's endocrinological abnormalities, however, did not improve after the operation. Urinary excretions of 17-KS and KGS were increased to 57.9 and 108.5 mg/day, respectively, in the patient's elder brother, and 63.3 and 127.9 mg/day, respectively, in his younger brother, indicating that they also had 21-OHD. Interestingly, an adrenal tumor was diagnosed by abdominal computed tomography in the elder brother who had the same HLA typing as the present case. The three brothers had 21-OHD, and two of them had both 21-OHD and adrenal tumor. To our knowledge, this is the first report documenting the co-existence of adrenal tumors in brothers with 21-OHD. This suggests that adenoma can be one of the complications of 21-OHD, probably due to the chronic stimulation by ACTH, and that a possible linkage to HLA may exist in such cases.

Adenoma↗
PubMed1989

Dynamic conformational changes of 21 S dynein ATPase coupled with ATP hydrolysis revealed by proteolytic digestion.

Conformational changes of 21 S dynein ATPase from sea urchin sperm flagella were examined by tryptic digestion under physiological conditions. In the presence of 2 mM ATP or ADP plus 100 microM inorganic vanadate (Vi), dynein heavy chains were digested by trypsin into quite different polypeptides from those obtained in other cases (no addition, 2 mM ATP, 4 mM adenosine 5'-(beta,gamma-imido)triphosphate, 4 mM adenosine 5'-(beta,gamma-methylene)triphosphate, 2 mM ADP, 100 microM Vi). In the presence of 4 mM adenosine 5'-O-(3-thiotriphosphate), however, the digestion pattern was similar to that in the presence of ATP (ADP) and Vi, to a certain extent. In all conditions other than the presence of ATP (ADP) and Vi, 165- and 135-kDa polypeptides were the main products, whereas in the presence of ATP (ADP) and Vi, 200-, 150/148-, and 105/96-kDa peptides were produced and 320-kDa peptide became rather inaccessible to trypsin. The latter digestion pattern was not observed in the absence of divalent cations. These results suggest that, in the ATP hydrolysis cycle, dynein changes its conformation remarkably in the dynein-ADP-Pi state, which is presumably responsible for force generation.

Adenosine Diphosphate↗
PubMed1989

Macrophage factors which enhance the mixed leukocyte reaction initiated by dendritic cells.

Stimulator cells for the allogeneic MLR are dendritic cells but not macrophages (M phi). M phi, however, enhance the MLR initiated by relatively low doses of dendritic cells. The present report demonstrates that the enhancement of the MLR is mediated by two factors produced by M phi. One is IL-1, inasmuch as it has a Mr approximately 15 kDa, and both partially purified IL-1 and rIL-1 also enhance the MLR. The other has been identified as granulocyte-macrophage (GM)-CSF. It had a Mr approximately 25 kDa, and is reproduced by rGM-CSF. Moreover, the MLR-enhancing activity of both the 25-kDa molecule and rGM-CSF have been neutralized by anti-GM-CSF antiserum. Both IL-1 and GM-CSF have autonomous enhancing activity, but they collaborate with each other in enhancing the MLR. Both factors act on DC to augment their stimulatory activity for allogeneic T lymphocytes.

Adjuvants, Immunologic↗
PubMed1989

A small number of anti-CD3 molecules on dendritic cells stimulate DNA synthesis in mouse T lymphocytes.

Resting T cells enter cell cycle when challenged with anti-CD3 mAb and accessory cells that bear required Fc receptors (FcR). Presentation of anti-CD3 is thought to be a model for antigens presented by accessory cells to the TCR complex. We have obtained evidence that the number of anti-CD3 molecules that are associated with the accessory cell can be very small. We first noticed that thymic dendritic cells and cultured, but not freshly isolated, epidermal Langerhans cells (LC) were active accessory cells for responses to anti-CD3 mAb. DNA synthesis was abrogated by a mAb to the FcR but not by mAb to other molecules used in clonally specific antigen recognition, i.e., class I and II MHC products or CD4 and CD8. The requisite FcR could be identified on the LC but in small numbers. Freshly isolated LC had 20,000 FcR per cell, while the more active cultured LC had only 2,000 sites, using 125I-anti-FcR mAb in quantitative binding studies. Individual LC had similar levels of FcR, as evidenced with a sensitive FACS. FcR could not be detected on T cells or within the dendritic cell cytoplasm, at the start of or during the mitogenesis response. When the response was assessed at 30 h with single cell assays, at least 20 T cells became lymphoblasts per added LC, and at least 8 T cells were synthesizing DNA while in contact with the LC in discrete cell clusters. To the extent that anti-CD3 represents a polyclonal model for antigen presentation to specific T cell clones, these results suggest two conclusions. First, only 200-300 molecules of ligand on dendritic cells may be required to trigger a T cell. Second, the maturation of LC in culture entails "sensitizing" functions other than ligand presentation (anti-CD3 on FcR) to clonotypic T cell receptors.

Animals↗
PubMed1989

Presentation of exogenous protein antigens by dendritic cells to T cell clones. Intact protein is presented best by immature, epidermal Langerhans cells.

The capacity of dendritic cells to present protein antigens has been studied with two MHC class II-restricted, myoglobin-specific, T cell clones. Spleen dendritic cells and cultured epidermal Langerhans cells (LC) presented native myoglobin weakly and often not at all. These same populations were powerful stimulators of allogeneic T cells in the primary MLR. Freshly isolated LC were in contrast very active in presenting proteins to T cell clones but were weak stimulators of the MLR. Both fresh and cultured LC could present specific peptide fragments of myoglobin to the clones. These results suggest that dendritic cells in nonlymphoid tissues like skin can act as sentinels for presenting antigens in situ, their accessory function developing in two phases. First antigens are captured and appropriately presented. Further handling of antigen then is downregulated while the cells acquire strong sensitizing activity for the growth and function of resting T lymphocytes. The potent MLR stimulating activity of cultured epidermal LC and lymphoid dendritic cells probably reflects prior handling of antigens leading to the formation of allogeneic MHC-peptide complexes.

Animals↗
PubMed1989

Immunogenicity: role of dendritic cells.

In the development of the immune response, the dendritic cell subset of leukocytes plays a key role in enhnacing immunogenicity. Dendritic cells can pick up antigens in the tissues and move to lymphoid organs, through which T cells continually recirculate. It is proposed that dendritic cells at these sites express functions which have been identified in tissue culture models. These involve efficient binding to antigen-specific T lymphocytes, as well as the induction of the lymphokines and growth factor receptors required for immunity. The dendritic cell system, apparently under the control of cytokines, is a sentinel designed to signal T cells that a significant antigen burden is present, and to generate the activated T lymphoblasts that interact with many other cell types to bring about an immune response.

Animals↗
PubMed1989

Anthraniloyl ATP, a fluorescent analog of ATP, as a substrate for dynein ATPase and flagellar motility.

We synthesized an anthraniloyl ATP (ant-ATP), which has a fluorescent anthraniloyl moiety at the OH group of ribose, to elucidate the mechanism of flagellar bend formation and its propagation in relation to the mechanochemical cycle of dynein ATPase. This fluorescent analog of ATP was efficiently hydrolyzed by 21 S dynein from sea urchin sperm flagella with Km = 7.6 microM, whereas the Km was 12 microM when ATP was used as the substrate. Similar Vmax values were obtained with both ATP and ant-ATP. Inhibition of the hydrolysis of ant-ATP by vanadate was a little smaller than that with ATP. Photosensitized cleavage of 21 S dynein heavy chains in the presence of ant-ATP and vanadate was also a little less efficient than that in the presence of ATP and vanadate. Ant-ATP also induced the disintegration of the trypsin-treated axoneme and the motility of demembranated sperm in a manner similar to ATP. When ATP was used as a substrate for the demembranated sperm, the apparent Michaelis constant for beat frequency (Km f) was 0.22 mM and the maximum frequency (fmax) was 36 Hz, whereas Km f) was 0.14 mM and fmax was 20 Hz for ant-ATP. Thus ant-ATP could be an efficient fluorescent analog of ATP for studying dynein ATPase and the mechanisms of flagellar motility.

Adenosine Triphosphatases↗
PubMed1989

The cell surface of mouse dendritic cells: FACS analyses of dendritic cells from different tissues including thymus.

The surface of dendritic cells from mouse spleen, thymus, and epidermis has been compared with a panel of monoclonal antibodies and the FACS. A method was first developed to isolate populations of large, adherent, thymic dendritic cells that were greater than 90% pure. These were released by collagenase digestion and separated from adherent macrophages after overnight culture. Enrichment was based on the facts that most macrophages remained plastic adherent and rosetted strongly with antibody-coated erythrocytes. As in spleen, thymic dendritic cells were stellate in shape, had abundant class I and II MHC products, lacked many standard macrophage and lymphocyte markers, and actively stimulated the mixed leukocyte reaction. Most spleen and thymic dendritic cells could be lysed by the 7D4 mAb, to the low-affinity IL-2 receptor, and complement but the levels of 7D4 by FACS were low and sometimes not above background. Differences among dendritic cells from different tissues were noted with other mAb. Adherent dendritic cells from thymus all expressed the J11d "B cell" antigen and the NL145 interdigitating cell marker, but lacked the 33D1 spleen dendritic cell antigen. Eighty to ninety percent of spleen dendritic cells were J11d-, NL145-, 33D1+ but the remainder expressed the J11d+, NL145+, 33D1- thymic phenotype. The latter phenotype also was identical to that of epidermal Langerhans' cells. We postulate that the major 33D1+ cell in spleen represents a migratory stage in which dendritic cells are moving from tissues to lymphoid organs.

Animals↗
PubMed1989

Suppression of macrophage Ia antigen expression by endogenous interferon-alpha/beta.

Exogenous interferon-alpha (IFN-alpha) and interferon-beta (IFN-beta) (type I IFNs) are known to suppress the IFN-gamma-dependent expression of class II MHC (Ia) antigens on macrophages (M phi). We report here that the endogenous type I IFNs produced by M phi in response to IFN inducers regulate Ia expression of the M phi themselves. Coculture of M phi with IFN-gamma and polyinosinic-polycytidylic acid [poly(I):poly(C)] resulted in the reduction of Ia expression in comparison with those cultured without poly(I):poly(C). Pretreatment of M phi with poly(I):poly(C) or a bacterial lipopolysaccharide (LPS), which is also a potent IFN inducer, in vitro or in vivo, before being exposed to IFN-gamma was also effective in suppressing the Ia expression. Such suppression was abolished by the addition of anti-IFN-alpha/beta antibodies to the M phi culture along with IFN-gamma. M phi cultured with L-cell conditioned medium (LCM) containing M-CSF were less capable of expressing Ia antigens than those cultured without LCM. The Ia-expressing ability of LCM-treated M phi was also restored by the addition of anti-IFN-alpha/beta antibodies. M phi in the early stage of sterile inflammation were less responsive to IFN-gamma than those in the late stage. These results suggest that endogenous type I IFNs, which are produced in response to natural or synthetic IFN-inducers, regulate M phi Ia expression in an autocrinal manner.

Acute-Phase Reaction↗
PubMed1989

An interleukin-4-dependent precursor clone is an intermediate of the differentiation pathway from an interleukin-3-dependent precursor clone into myeloid cells as well as B lymphocytes.

An interleukin-3-dependent progenitor clone LyD9 and its interleukin-4-dependent derivative clone K-4 were shown to differentiate into myeloid cells as well as B lymphocytes by coculture with bone marrow stroma cells. The K-4 clone is an intermediate between myeloid/lymphoid cells and the LyD9 clone that requires interleukin-4 for differentiation into B lymphocytes and myeloid cells. Granulocyte-macrophage colony stimulating factor-dependent derivatives (LS-1 and K-GM) were also established from induced LyD9 cells. LS-1 and K-GM were myeloid-committed cells.

Animals↗
PubMed1989

Effects of the deregulated expression of human interleukin-2 in transgenic mice.

We constructed transgenic mice that carry the cDNA of human interleukin-2 (IL-2) under the control of the H-2Kd promoter. The IL-2 transgenic mice expressed human IL-2 mRNA in the thymus, spleen, bone marrow, lung, muscle and skin. Human IL-2 protein was also detected in their sera. The IL-2 transgenic mice suffered from alopecia and pneumonia, but no typical autoimmune reactions seemed to be involved in these lesions. In the epidermis of the IL-2 transgenic mice there was an increase in Thy-1+ dendritic epidermal cells (DEC), which might be involved in the skin lesion. Immune responses of their spleen cells against antigens were significantly impaired whereas their spleen cells responded well to polyclonal lymphocyte activators.

Alopecia↗
PubMed1989

Two states of the conformation of 21S outer arm dynein coupled with ATP hydrolysis.

Tryptic digestion of 21S outer arm dynein from sea urchin sperm flagella in the presence of ATP (or ADP) and vanadate produced quite different polypeptides from those obtained in the absence of ATP (ADP) and/or vanadate (Inaba and Mohri (1989) J. Biol. Chem. 264, 8384-8388). The 21S dynein heavy chains were consistently digested into 165- and 135-kDa polypeptides in the absence of both ATP (ADP) and vanadate. In the presence of 2 mM ADP and 100 microM vanadate, 300-kDa polypeptide, which appeared to be a precursor of 165- and 135-kDa polypeptides, became less accessible to trypsin, and 165- and 135-kDa polypeptides were digested into 150-/148-kDa and 96-kDa polypeptides, respectively. Quantitative analysis of the degradation of 165- and 135-kDa polypeptides showed that the conformations of these polypeptides change remarkably in the presence of ATP (ADP) and vanadate, and slightly in the presence of ATP gamma S. Photoaffinity labeling with 8-azidoadenosine 5'-triphosphate and vanadate-mediated photocleavage of dynein heavy chains revealed that both adenine- and gamma-Pi-binding sites were located on 165- and 150-/148-kDa polypeptides, but not on 135-kDa polypeptide. These results suggest that the conformational change occurring in the 165-kDa region on binding ATP spreads to the 135-kDa region and causes the conformational change of the 135-kDa region.

Adenine↗
PubMed1989

Tumor-specific T cells which form clusters with dendritic cells and tumor cells and deliver macrophage-activating factors.

T cells prepared from tumor (Meth A)-bearing mice were cocultured with homologous tumor cells and splenic dendritic cells to enrich tumor-specific T cells by the separation of clusters. T blasts generated from clusters were capable of inhibiting the in vivo tumor cell growth. The culture supernatant of clustering cells (CLSN) was effective in activating macrophages (M phi) to be cytostatic and cytocidal against tumor cells. Moreover, it was found that CLSN contains at least 3 distinct factors; one was identified as interferon-gamma (IFN-gamma), and the others are so far unidentified, but one acts synergistically with IFN-gamma, possibly as the second signal, and the other cooperates with lipopolysaccharide but not with IFN-gamma. We propose that the tumor-specific T cells secrete soluble mediators which cooperate with each other in M phi activation against tumor cells.

Animals↗
PubMed1989

Transport of phagosomes in mouse peritoneal macrophages.

Mouse macrophages were elicited by the peritoneal injection of chondroitin sulfate solution, harvested and purified, and used as experimental materials. Small and large (diameter: 0.9 microns and 3.0 microns, respectively) polystyrene beads (PB) were used as ingested particles. When the macrophages were incubated with Hank's solution containing small or large PB for 30 min, the phagosomes containing small or large PB were usually randomly distributed. When the macrophages were further incubated for 45 min in PB-free medium, both small and large phagosomes containing PB accumulated at the perinuclear region. The transport of large phagosomes containing 3.0 microns PB was inhibited by cytochalasin B, but not by vinblastine or podophyllotoxin. Conversely, the transport of small phagosomes containing 0.9 microns PB was not inhibited by cytochalasin B but was inhibited by vinblastine or podophyllotoxin. Immunofluorescence microscopy showed that the small phagosomes appeared to accumulate at the central region of the microtubule network. The large phagosomes, on the other hand, appeared to be surrounded by actin-rich cytoplasm, and in some cells actin filament-like structures could be seen around large phagosomes. These results suggest that there are two different transport systems of phagosomes in macrophages. Phagosomes smaller than 0.9 microns in diameter are, probably, mainly transported to the perinuclear region by a microtubule-based motility system and those larger than 3.0 microns in diameter by an actin-based mechanism. It was observed electron-microscopically that accumulated phagosomes containing PB could fuse with each other and form larger phagosomes.

Animals↗