Biological effects of probiotics: what impact does Lactobacillus casei shirota have on us?

Probiotics have been defined as live bacteria beneficial to the host when administered in adequate amounts. To evaluate the effect of probiotics on the prevention of carcinogenesis, Lactobacillus casei Shirota (LcS) was given to the patients who had undergone the resection of superficial bladder cancer, and administration of LcS significantly reduced the recurrence rate of bladder cancer. When LcS was given to the patients whose colonic polyps were surgically removed, the recurrence of colorectal cancer with moderate or severe atypia was suppressed. To assess the putative actions of LcS on innate immune responses, we examined the effect of LcS on natural killer (NK) cell activity in humans. Daily ingestion of fermented milk containing LcS restored NK cell activity in healthy subjects with low NK cell activity as well as human T lymphotropic virus (HTLV)-1-associated myelopathy patients. When peripheral blood mononuclear cells from healthy humans were cultured in the presence of heat-killed LcS, NK cell activity was augmented, which were partly mediated by monocyte-derived interleukin (IL)-12. These findings suggest that LcS may help the reinforcement of our defense system against cancer by modulating innate immune functions.

Interleukin-12 is involved in the enhancement of human natural killer cell activity by Lactobacillus casei Shirota

We conducted a placebo-controlled, cross-over trial to examine the effect of Lactobacillus casei Shirota (LcS) on natural killer (NK) cell activity in humans. NK cell activity exhibited a declining trend during the period of placebo ingestion, but NK cell activity increased after intake for 3 weeks of fermented milk containing 4 x 10(10) live LcS. When human peripheral blood mononuclear cells were cultured in the presence of heat-killed LcS, NK cell activity was enhanced. The ability of LcS to enhance NK cell activity and induce interleukin (IL)-12 production was correlated, and the addition of anti-IL-12 monoclonal antibody reduced the enhancement of NK cell activity triggered by LcS. In addition, separation of NK cells from LcS-stimulated monocytes with membrane filter reduced NK cell activity to the intermediate level and almost deprived monocytes of the ability to produce IL-12. These results demonstrate that LcS can enhance NK cell activity in vivo and in vitro in humans, and IL-12 may be responsible for enhancement of NK cell activity triggered by LcS.

Induction of Interleukin-12 by Lactobacillus Strains Having a Rigid Cell Wall Resistant to Intracellular Digestion

Some strains of lactobacilli can stimulate macrophages and dendritic cells to secrete IL-12, which plays a key role in activating innate immunity. We examined the IL-12-inducing ability of 47 Lactobacillus strains belonging to 10 species in mouse peritoneal macrophages, and characterized the properties important for the induction of IL-12. Although considerable differences in IL-12-inducing ability were observed among the strains tested, almost all strains belonging to the Lactobacillus casei group (L. casei, Lactobacillus rhamnosus, and Lactobacillus zeae) or to Lactobacillus fermentum induced high levels of IL-12. Phagocytosis of lactobacilli was necessary for IL-12 induction, and the strains with strong IL-12 induction were relatively resistant to lysis in the macrophages. The sensitivity of Lactobacillus strains to in vitro treatment with M-1 enzyme, a member of the N-acetylmuramidases, was negatively correlated with IL-12-inducing ability. Using a probiotic strain, L. casei strain Shirota (LcS), we showed that the cell wall of LcS could be digested by long-term treatment with a high dose of M-1 enzyme and that the IL-12-inducing ability was diminished according to the duration of the enzyme treatment. The soluble polysaccharide-peptidoglycan complex released from the cell wall of LcS did not induce IL-12, whereas the insoluble intact cell wall of LcS induced IL-12. These results suggest that the intact cell wall structure of lactobacilli is an important element in the ability to induce IL-12 and that Lactobacillus strains having a rigid cell wall resistant to intracellular digestion effectively stimulate macrophages to induce IL-12.

Vascularised bone graft from the base of the second metacarpal for refractory nonunion of the scaphoid

A vascularised bone-graft procedure from the base of the second metacarpal was performed in 14 patients with nonunion of the scaphoid. There were 11 men and three women with a mean age of 22 years. In eight patients, who had dorsiflexed intercalated segment instability (DISI), an open wedge was formed at the site of nonunion, and the vascular pedicle was grafted from the volar side. In the six patients without DISI, transplantation was carried out through the same dorsal skin incision.

Complete bony union was obtained in all patients after a mean post-operative period of 10.2 weeks, and DISI was corrected in all affected patients. According to Cooney’s clinical scoring system, the results were excellent in five, good in six, and fair in three patients. Because of its technical simplicity and the limited dissection needed, the procedure should be considered for the primary surgical treatment of patients with nonunion of the scaphoid.

An accessory role of TCRgammadelta (+) cells in the exacerbation of inflammatory bowel disease in TCRalpha mutant mice

T cell receptor alpha mutant (TCRalpha (-/-)) mice, which spontaneously develop colitis under conventional conditions, did not show any signs of colitis under germ-free conditions, leaving TCRalpha (-)beta (+) cells (beta (dim) cells) and TCRgamma delta (+) cells much reduced. Moreover, TCRalpha (-/-) mice with alymphoplastic mutation (aly/aly TCRalpha (-/-) mice), which lack Peyer's patches and peripheral lymph nodes, did not suffer from colitis. While both beta (dim) cells and TCRgamma delta (+) cells were present in the colons of aly/aly TCRalpha (-/-) mice and aly/+ TCRalpha (-/-) mice, cytotoxicity of colonic TCRgamma delta (+) cells in aly/aly TCRalpha (-/-) mice was almost abolished. Transfer of TCRgamma delta (+) cells from TCRalpha (-/-) mice into scid/scid mice or aly/aly TCRalpha (-/-) mice could not induce colitis, but injection of anti-TCRdelta mAb into TCRalpha (-/-) mice prevented colitis from developing. Finally, TCRalpha (-/-) mice expressing transgenic (Tg) KN6-TCRgamma delta hardly developed colitis, accompanied by colonization of non-cytotoxic Tg TCRgamma delta (+) cells in their colonic mucosa. These results demonstrate that intestinal resident TCRgamma delta (+) cells may be involved in the exacerbation of inflammatory bowel disease in TCRalpha (-/-) mice.

An accessory role of TCRgammadelta (+) cells in the exacerbation of inflammatory bowel disease in TCRalpha mutant mice

T cell receptor alpha mutant (TCRalpha (-/-)) mice, which spontaneously develop colitis under conventional conditions, did not show any signs of colitis under germ-free conditions, leaving TCRalpha (-)beta (+) cells (beta (dim) cells) and TCRgamma delta (+) cells much reduced. Moreover, TCRalpha (-/-) mice with alymphoplastic mutation (aly/aly TCRalpha (-/-) mice), which lack Peyer's patches and peripheral lymph nodes, did not suffer from colitis. While both beta (dim) cells and TCRgamma delta (+) cells were present in the colons of aly/aly TCRalpha (-/-) mice and aly/+ TCRalpha (-/-) mice, cytotoxicity of colonic TCRgamma delta (+) cells in aly/aly TCRalpha (-/-) mice was almost abolished. Transfer of TCRgamma delta (+) cells from TCRalpha (-/-) mice into scid/scid mice or aly/aly TCRalpha (-/-) mice could not induce colitis, but injection of anti-TCRdelta mAb into TCRalpha (-/-) mice prevented colitis from developing. Finally, TCRalpha (-/-) mice expressing transgenic (Tg) KN6-TCRgamma delta hardly developed colitis, accompanied by colonization of non-cytotoxic Tg TCRgamma delta (+) cells in their colonic mucosa. These results demonstrate that intestinal resident TCRgamma delta (+) cells may be involved in the exacerbation of inflammatory bowel disease in TCRalpha (-/-) mice.

Establishment of a mouse thymic epithelial cell line, IT-76MHC and a brief review on cultured thymic epithelial cells

Interactions between thymocytes and thymic stromal cells are essential for thymocyte differentiation, but little evidence has been presented to directly show in vivo functions or interactions of the stromal cells. Among the stromal cells, the thymic epithelial cell has been considered to have profound effect on thymocyte differentiation and maturation. The calcium-depleted medium, originally developed for the culture of mouse epidermal cells, was applied for the culture of the mouse thymic epithelial cells, and successfully, an epithelial cell line, IT-76MHC was obtained from the mouse thymus. IT-76MHC cells were identified as distinct mouse thymic epithelial cells by 1/ mosaic-like arrangement, 2/ presence of well-developed desmosome and 3/ tonofilaments, 4/ positivity for cytokeratin, and 5/ induced expression of MHC class I and II by IFN-gamma treatment. IGF-1, IGF-2, oxytocin and vasopressin were also detected immunohistochemically in IT-76MHC cells. Furthermore, the IT-76MHC thymic epithelial cells, when injected intrathymically in the allogeneic mouse, prolonged the survival of skin graft from the same donor strain that IT-76MHC cells were derived. These results demonstrate that the thymic epithelial cell line IT-76MHC produces modest thymocyte survival factors as well as a growth suppressor, and that IT-76MHC cells have the ability to induce transplantation tolerance probably through their expression of MHC class I and II molecules. Taken altogether, the IT-76MHC thymic epithelial cells have been proved to be useful tools to better understand the in vivo functions of thymic epithelial cells, and to gain a deep insight into their involvement in the critical selection process of thymocytes which still remains obscure. Finally and additionally, literatures so far reported on thymic epithelial cells in culture, especially lines and clones, are reviewed and their identity as well as their functions are discussed.

The polymeric immunoglobulin receptor translocates pneumococci across human nasopharyngeal epithelial cells

The polymeric immunoglobulin receptor (pIgR) plays a crucial role in mucosal immunity against microbial infection by transporting polymeric immunoglobulins (pIg) across the mucosal epithelium. We report here that the human pIgR (hpIgR) can bind to a major pneumococcal adhesin, CbpA. Expression of hpIgR in human nasopharyngeal cells and MDCK cells greatly enhanced pneumococcal adherence and invasion. The hpIgR-mediated bacterial adherence and invasion were abolished by either insertional knockout of cbpA or antibodies against either hpIgR or CbpA. In contrast, rabbit pIgR (rpIgR) did not bind to CbpA and its expression in MDCK cells did not enhance pneumococcal adherence and invasion. These results suggest that pneumococci are a novel example of a pathogen co-opting the pIg transcytosis machinery to promote translocation across a mucosal barrier.

Activation of T-cell receptor-gammadelta+ cells in the intestinal epithelia of KN6 transgenic mice

We analysed the properties of intraepithelial lymphocytes of small intestine (SI-IEL) in KN6-transgenic (Tg) mice expressing cDNA of T-cell receptor (TCR)-gammadelta specific for the T22b molecule. While most splenic Tg TCR-gammadelta+ cells from KN6-Tg mice with H-2d/d background (Tgd/d mice) were Thy-1+ CD8alpha- CD44dull+ CD45RB+ CD69-, Tg TCR-gammadelta+ cells in SI-IEL (Tg gammadelta-IEL) were heterogeneous in the expression of Thy-1, CD8alpha and CD44 molecules and predominantly CD45RB+ CD69+. Tg gammadelta-IEL exhibited a much reduced proliferative response to the antigen (irradiated H-2b splenocytes) than splenic Tg TCR-gammadelta+ cells; the CD44+ subset, but not the CD44- subset, in Tg gammadelta-IEL responded to the antigen. Furthermore, Tg gammadelta-IEL, but not splenic Tg TCR-gammadelta+ cells, displayed cytolytic activity whether they were prepared from conventional or germ-free KN6-Tg mice. Comparative analysis of young and aged KN6-Tg mice revealed that the proportion of CD44+ cells in Tg gammadelta-IEL increased but the proliferative response of Tg gammadelta-IEL to the antigen attenuated in association with ageing. Moreover, although Tg gammadelta-IEL from Tgb/d mice contained a higher proportion of CD44+ cells than Tgd/d mice, they did not respond to the antigen. These results demonstrate that Tg TCR-gammadelta+ cells lose the ability to recognize the antigen following activation in the intestinal epithelia.

Role of gut cryptopatches in early extrathymic maturation of intestinal intraepithelial T cells

Lympho-hemopoietic progenitors residing in murine gut cryptopatches (CP) have been shown to generate intestinal intraepithelial T cells (IEL). To investigate the role of CP in progenitor maturation, we analyzed IEL in male mice with a truncated mutation of common cytokine receptor gamma-chain (CRgamma-/Y) in which CP were undetectable. IEL-expressing TCR-gammadelta (gammadelta-IEL) were absent, and a drastically reduced number of Thy-1highCD4+ and Thy-1highCD8alphabeta+ alphabeta-IEL were present in CRgamma-/Y mice, whereas these alphabeta-IEL disappeared from athymic CRgamma-/Y littermate mice. Athymic CRgamma-/Y mice possessed a small TCR- and alphaEbeta7 integrin-negative IEL population, characterized by the disappearance of the extrathymic CD8alphaalpha+ subset, that expressed pre-Talpha, RAG-2, and TCR-Cbeta but not CD3epsilon transcripts. These TCR- IEL from athymic CRgamma-/Y mice did not undergo Dbeta-Jbeta and Vdelta-Jdelta joinings, despite normal rearrangements at the TCR-beta and -delta loci in thymocytes from euthymic CRgamma-/Y mice. In contrast, athymic severe combined immunodeficient mice in which CP developed normally possessed two major TCR-alphaEbeta7+ CD8alphaalpha+ and CD8- IEL populations that expressed pre-Talpha, RAG-2, TCR-Cbeta, and CD3epsilon transcripts. These findings underscore the role of gut CP in the early extrathymic maturation of CD8alphaalpha+ IEL, including cell-surface expression of alphaEbeta7 integrin, CD3epsilon gene transcription, and TCR gene rearrangements.

Generation of polymeric immunoglobulin receptor-deficient mouse with marked reduction of secretory IgA

We generated mouse lacking exon 2 of polymeric Ig receptor (pIgR) gene by a gene-targeting strategy (pIgR-deficient mouse; pIgR-/- mouse) to define the physiological role of pIgR in the transcytosis of Igs. pIgR-/- mice were born at the expected ratio from a cross between pIgR+/- mice, indicating that disruption of the pIgR gene in mice is not lethal. pIgR and secretory component proteins were not detected in pIgR-/- mice by Western blot analysis. Moreover, immunohistochemical analysis showed that pIgR protein is not expressed in jejunal and colonic epithelial cells of pIgR-/- mice, whereas IgA+ cells are present in the intestinal mucosa of pIgR-/- mice as well as wild-type littermates. Disruption of the pIgR gene caused a remarkable increase in serum IgA concentration and a slight increment of serum IgG and IgE levels, leaving serum IgM level unaltered. In contrast, IgA was much reduced but not negligible in the bile, feces, and intestinal contents of pIgR-/- mice. Additionally, IgA with a molecular mass of 280 kDa preferentially accumulated in the serum of pIgR-/- mice, suggesting that transepithelial transport of dIgA is severely blocked in pIgR-/- mice. These results demonstrate that dIgA is mainly transported by pIgR on the epithelial cells of intestine and hepatocytes, but a small quantity of IgA may be secreted via other pathways.

Prevention of B220+ T cell expansion and prolongation of lifespan induced by Lactobacillus casei in MRL/lpr mice

We examined the therapeutic effect of heat-killed Lactobacillus casei (LC) on MRL/lpr mice. Ingestion of a diet containing 0.05% (w/w) LC from the weaning period prolonged the lifespan and tended to reduce the proportion of B220+ T cells in the spleen and mesenteric lymph nodes (MLN) of MRL/lpr mice. When LC was intraperitoneally injected once a week after the age of 8 weeks, I-A- macrophages accumulated in the spleen as well as the peritoneum and macrophage progenitors increased in the bone marrow. Moreover, the amount of IL-6 mRNA in peritoneal macrophages was reduced by LC injection. Splenocytes from LC-injected MRL/lpr mice exhibited lower proliferative responses to mitogens than those from control MRL/lpr mice and the increase in number of B220+ T cells in the spleen and MLN was prevented by LC injection. However, LC injection affected neither expression of interferon-gamma (IFN-gamma) and IL-4 mRNAs nor proliferative capacities of splenic T cells. Our findings demonstrate that LC injection accelerates macrophage recruitment and prevents the expansion of B220+ T cells without affecting the functions of T cells in MRL/lpr mice. These immunological modulations induced by LC may lead to prolongation of the lifespan of MRL/lpr mice.

Cytolytic and IFN-gamma-producing activities of gamma delta T cells in the mouse intestinal epithelium are T cell receptor-beta-chain dependent

We analyzed the cytolytic activity of intraepithelial T cells (IEL) isolated from the small intestines of 2- to 3-month-old mutant mice rendered deficient in different gene(s) in which the number of IEL expressing either T cell receptor (TCR)-alpha beta (alpha beta-IEL) or TCR-gamma delta (gamma delta-IEL) were absent or markedly diminished. When compared with wild-type littermates, cytolytic activity of gamma delta-IEL was sharply attenuated in TCR-beta mutant mice but remained unaltered in TCR-alpha mutant mice in which a minor population of dull TCR-beta+ (betadim)-IEL was also present. Cytolytic activity of gamma delta-IEL was maintained in mice doubly homozygous for beta2-microglobulin and transporter associated with antigen processing 1 gene mutations in which a conspicuous decrease was noted in absolute numbers of alpha beta-IEL. In contrast, both TCR-delta and IL-7 receptor-alpha gene mutations that lead to lack of gamma delta-IEL generation did not affect the development or cytolytic activity of the remaining alpha beta-IEL. The anti-CD3 and anti-TCR-gamma delta mAb-induced IFN-gamma production of gamma delta-IEL showed the same TCR-alpha and TCR-beta mutation-dependent variability. These results indicate that cytolytic and IFN-gamma-producing activities of gamma delta T cells in mouse intestinal epithelium are TCR-beta-chain-dependent.

Physiological roles of gammadelta T-cell receptor intraepithelial lymphocytes in cytoproliferation and differentiation of mouse intestinal epithelial cells

In this study we aimed to elucidate the physiological role of gammadelta intraepithelial lymphocytes (IEL) in the mouse intestine. For this purpose, we used T-cell receptor (TCR) Vgamma4/Vdelta5 transgenic mice (KN 6 Tg: BALB/c background, H-2d), and compared the immunological and physiological characteristics of the intestinal tracts of KN 6 Tg and non-transgenic (non-Tg) littermates. In KN 6 Tg littermates, 95% of small intestinal (SI) and large intestinal (LI) IEL expressed gammadelta TCR, and their TCR was replaced by Tg gammadelta TCR. In these mice, class II major histocompatibility complex (MHC) expression was up-regulated in the SI epithelium, compared with the non-Tg littermates, under specific pathogen-free (SPF) conditions. Competitive reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the mRNAs of the I-Ealpha chain on the SI epithelial cells was higher in KN 6 Tg than in non-Tg littermates. However, in the LI, class II MHC molecules were not expressed in either KN 6 Tg or non-Tg littermates. The epithelial cell mitotic index in the SI, but not in the LI, was higher in KN 6 Tg than in non-Tg littermates under SPF conditions. However, differentiation markers for SI epithelial cells, such as alkaline phosphatase and disaccharidase (lactase, maltase and sucrase) activities, were similar in KN 6 Tg and non-Tg littermates. MHC class II molecule expression on the SI epithelium was absent in germ-free (GF) Tg mice, but was induced under SPF conditions, coinciding with the increase of interferon-gamma (IFN-gamma) mRNA in gammadelta TCR SI-IEL. These findings suggest that gammadelta TCR IEL regulate epithelial cell regeneration and class II MHC expression, but not cell differentiation in the SI. However, these functions were not observed in the gammadelta TCR IEL in the LI. In addition, the activation step in the gammadelta TCR SI-IEL is dependent on the presence of gut microflora.

Intestinal intraepithelial T lymphocytes. Our T cell horizons are expanding

The alimentary tract is an essential structure for the ingesting of nutrients from the outside, and even most primitive animals have a straight tract that runs from the mouth to the anus. We come into contact with the outside world through our skin and mucous membranes. The surface area of the enteric mucous membrane, which absorbs nutrients, is enlarge through its ciliary structure, and the enteric cavity creates by far the largest external world that we come into contact with. For instance, the enteric mucosal surface of the human gastrointestinal tract covered by a single layer of epithelial cells corresponds to the size of one-and-a-half tennis courts, and the innumerable number of epithelial cells covering this mucous surface are entirely replaced by new epithelial cells in the space of just several days. Simultaneously, the fact that 60-70% of peripheral lymphocytes are congregating in the gastrointestinal tract supports the notion that the enteric mucous membrane represents an extremely dangerous locale, where numerous harmless/precarious external antigens come in through the wide array of food we injest on a daily basis, and the literally infinite amounts of normal intestinal flora intermingled from time to time with life-threatening microbes surge across. Surprisingly, approximately one out of the five cells in the intestinal epithelium are lymphocytes, most of which are ill-defined T cells having unusual, but distinctive characteristics and situated apparently so close to external antigens in the entire body. This article deals with the information that has been accumulated mainly in the past decade concerning the development, phenotypes, and possible function of these yet unacknowledged mucosal T cells that lurk in the anatomical front of the intestine.

A step-wise expansion of intestinal intraepithelial T lymphocytes in association with microbial colonization is defined by sensitivity to cyclosporin A

Murine intestinal intraepithelial lymphocytes (IELs) consist of T cells bearing alpha beta-antigen receptor (alpha beta-IELs) and those bearing gamma delta-IELs). Although gamma delta-IELs outnumber alpha beta-IELs in germ-free (GF) mice, oral inoculation of fecal suspension from conventional (CV) mice into GF mice induced the increase in number of alpha beta-IELs, leaving the number of gamma delta-IELs unchanged, and the number of alpha beta-IELs reached the level of CV mice by 3 weeks after conventionalization. Expansion of alpha beta-IELs and increase in their CD44+ subset in conventionalized mice were not affected until 2 weeks after beginning of daily injection of cyclosporin A (CsA). However, further expansion of alpha beta-IELs during 2-3 weeks after conventionalization was blocked by injection of CsA. Although the relative constitution of CD4- 8-, CD4+ 8-, CD4- 8 alpha alpha+, CD4- 8 alpha beta+ and CD4+ 8+ subsets among alpha beta-IELs was comparable between control and CsA-treated groups, CsA injection resulted in the decrease in ratio of high-density fraction cells to low density fraction cells in IELs. CsA completely abrogated the expansion of T cells in peripheral lymph nodes stimulated by alloantigens in vivo, and proliferation of IELs from GF mice induced by immobilized anti-alpha beta-T-cell receptor (TCR) monoclonal antibodies (mAb) in vitro was also eliminated by CsA. These results indicate that microbial colonization-induced expansion of alpha beta-IELs is subdivided into two steps: the early phase of expansion takes place via TCR-non-mediated pathway and the late phase of expansion requires TCR-mediated signal transduction.

Effects of chitin and chitosan particles on BALB/c mice by oral and parenteral administration

Chitin and chitosan were administered orally and parenterally into mice and their toxicity was investigated. When 5 mg of chitin were injected intraperitoneally every 2 weeks over a 12-week period, the mice were apparently normal, but histologically, many macrophages with hyperplasia were observed in the mesenterium and foreign-body giant-cell-type polykaryocytes were observed in the spleen. The polykaryocytes were also observed in the spleen of the mice injected subcutaneously with 5 mg of chitin, but no other changes were observed. When 5 mg of chitosan were injected intraperitoneally, the body weights of the mice decreased significantly and inactivity was observed in the fifth week. Histologically, many macrophages with hyperplasia were observed in the mesenterium. Subcutaneous injection of 5 mg of chitosan did not evoke the general and cellular abnormalities. Oral administration of 5% chitosan via a casein diet caused mouse body weights to decrease and also decreased the number of Bifidobacterium and Lactobacillus in normal flora of the intestinal tract. These results indicate that special care should be taken in the clinical use of chitin and chitosan over a long time period.

Analysis of cytokine producing activity of intestinal intraepithelial T cells from TCR beta-chain and delta-chain mutant mice

Intestinal intraepithelial T cells (IELs) expressing either gammadelta TCR or alphabeta TCR have been proposed to play an important role in the regulation of intestinal epithelia by producing cytokines that directly influence the adjoining intestinal epithelial cell (IEC) functions. To illuminate this issue, we utilized TCR mutant mice to obtain gammadelta IELs, alphabeta IELs and mixed gammadelta and alphabeta IELs from corresponding alphabeta T-cell-deficient (beta-/-), gammadelta T-cell-deficient (delta-/-) and wild-type (WT) littermate mice. The production of IFN-gamma by these IELs as well as the mRNA for IFN-gamma, TGF-alpha, TGF-beta1, TNF-alpha and TNF-beta in these IELs, in conjunction with the effect of produced cytokines on the expression of class II MHC molecules by the in vitro cell line IEC-6, were investigated. IFN-gamma and TNF-alpha [corrected] specific mRNA were detectable in all freshly isolated gammadelta, alphabeta and WT IELs. In addition to the IFN-gamma and TNF-alpha [corrected] mRNA, alphabeta and WT IELs that had been activated in culture plates coated with anti-CD3 mAb contained mRNA for TGF-beta1 and TNF-beta proteins. In the cultured gammadelta IELs, however, the signals for IFN-gamma and TNF-alpha [corrected] transcripts were weak, and mRNA for the latter two cytokines was almost undetectable. Supernatants from in vitro culturing of alphabeta and WT IELs but not gammadelta IELs induced class II MHC gene expression in IEC-6, whereas, in the presence of anti-IFN-gamma mAb, the same culture supernatants failed to do so. In fact, the concentration of IFN-gamma in supernatants from alphabeta and WT IEL cultures was ten- to twentyfold higher than that in the supernatant from the gammadelta IEL culture. Finally, TGF-alpha specific mRNA was not detectable in the gammadelta and alphabeta IELs even after in vitro activation. These results indicate that alphabeta IELs are superior to gammadelta IELs in the ability to produce IFN-gamma, TGF-beta1, TNF-alpha [corrected] and TNF-beta through TCR crosslinking primary in vitro stimulation.

Identification of novel lymphoid tissues in murine intestinal mucosa where clusters of c-kit+ IL-7R+ Thy1+ lympho-hemopoietic progenitors develop

We have revealed that about one and a half thousand tiny clusters, filled with one thousand closely packed lymphocytes, can be found throughout the murine small and large intestinal mucosa. They are located in crypt lamina propria (cryptopatches; CP) and can be first detected at 14-17 d after birth. A large fraction of lymphocytes in CP expresses c-kit, IL-7R, Thy1 and a lymphocyte function-associated antigen, LFA-1, whereas most of them remain CD3-, TCR alpha beta-, TCR gamma delta-, sIgM-, and B220-. The population size of IL-2R alpha+, HSA+ and Pgp-1+ subsets is variable (20-50%) and the composition of CD8+, Ly-1+, and CD4+ subsets is smaller but also variable (3-20%). In the small intestine, CP do not contain cells undergoing apoptosis nor cells bearing RAG-1 molecules, but do contain dendritic stromal cells bearing CD11c/CD18 molecules. The frequency of DNA replicating cells in CP is higher than that in Peyer's patches (PP), is lower than that in the thymic cortex and is almost comparable with that in the thymic medulla. The numbers of CP remain the same in aged mice (> 114 wk) but double after estrogen treatment even though the thymi are attenuated sharply in both conditions. Thus, with respect to histogenesis, lymphocyte composition and tissue level of cellular behavior, neither PP, isolated lymphoid follicles, peripheral LNs, nor thymus are identical with CP. Finally, CP are virtually absent in lamina propria of IL-7R-deficient mice that display a profound reduction in thymic and peripheral lymphoid cellularity. By contrast, CP are present in germ-free mice and in athymic (nu/nu), SCID, TCR beta x delta-/-, RAG-2-/-, PP-deficient (aly/aly), stem cell factor (Sl/Sld) and c-kit (W/Wv) mutant mice. Taking all of these results together, CP are the first identification of gut-associated murine lymphoid tissues where the generation of IL-7-dependent lympho-hematopoietic progenitors for T and/or B cell descendants may start to take place at the age of commencement of weaning.

Development and cytolytic function of intestinal intraepithelial T lymphocytes in antigen-minimized mice

Intraepithelial T lymphocytes in the small intestine (IEL) consist of alpha beta T-cell receptor (TCR)-bearing T cells (alpha beta-IEL) and gamma delta TCR-bearing T cells (gamma delta-IEL). Development and cytolytic activation of alpha beta-IEL sharply attenuate in germ-free (GF) mice fed a natural diet (Nat-GF), but the number and cytotoxicity of gamma delta-IEL are comparable between conventional (CV) and Nat-GF mice. In this report, we compared the properties of IEL in Nat-GF mice and GF mice fed antigen-minimized diet (AgM-GF mice) of C57BL/6 strain to evaluate an influence of gut antigenic load on IEL development. Numbers of alpha beta-IEL and gamma delta-IEL in AgM-GF mice were less by 1.9- and 1.4-fold than those in Nat-GF mice, respectively. Significant decreases in the proportions of CD4+8-, CD4-8 alpha beta +, and CD4+8+ subsets and a resultant increase in the ratio of CD4-8 alpha alpha + subset were evident in alpha beta-IEL of Nat-GF mice compared with CV mice, but the subset constitution of alpha beta-IEL was similar between Nat-GF and AgM-GF mice. In contrast, relative composition of gamma delta-IEL was not different between CV, Nat-GF, and AgM-GF mice. alpha beta-IEL displayed low cytolytic activity in Nat-GF mice and were almost deprived of their cytotoxicity under the antigen-minimized condition. While gamma delta-IEL were strongly cytolytic in Nat-GF mice their cytolytic activity was remarkably reduced in AgM-GF mice. These results indicate that gamma delta-IEL are activated independently of microbial colonization in the gastrointestinal tract but their activation occurs in response to the exogenous antigenic substances other than live micro-organisms.

Development of CD8 alpha alpha+ intestinal intraepithelial T cells in beta 2-microglobulin- and/or TAP1-deficient mice

The development of CD8+ intestinal intraepithelial T lymphocytes (IEL) was analyzed in mice that are deficient in the expression of MHC class I molecules, owing to either a mutated beta 2-microglobulin (beta 2m) gene or a mutated transporter associated with Ag processing 1 (TAP1) gene, and in mice doubly homozygous for beta 2m and TAPI mutations. In all mutant mice, the population size of major CD8 alpha alpha+ and CD8 alpha beta+ alpha beta-IEL subsets was reduced drastically, and this resulted in a conspicuous decrease in the total number of alpha beta-IEL. Concomitantly, a compensatory two- to threefold increase in the number of gamma delta-IEL consisting mostly of CD8 alpha alpha+ subset was noted. In radiation bone marrow chimeras, this wild-type/mutant phenotype was determined by the genotype of radioresistant host cells, but was not determined by the genotype of reconstituting bone marrow-derived cells. In beta 2m X TCR-delta double mutant mice, however, the CD8 alpha alpha+ but not CD8 alpha beta+ alpha beta-IEL subset expanded dramatically. Thus, in the absence of gamma delta-IEL, alpha beta-IEL in beta 2m-deficient mice outnumbered those in wild-type littermates. These results indicate that the generation of CD8 alpha alpha+ lymphocyte population of alpha beta- and gamma delta-IEL is not dependent, but that of CD8 alpha beta+ lymphocyte population of alpha beta-IEL is dependent on beta 2m- and/or TAP1-dependent MHC class I molecules, expressed by the controlling cells present in the anatomical site, where the development of IEL takes place.

Development of CD8 alpha alpha+ intestinal intraepithelial T cells in beta 2-microglobulin- and/or TAP1-deficient mice

The development of CD8+ intestinal intraepithelial T lymphocytes (IEL) was analyzed in mice that are deficient in the expression of MHC class I molecules, owing to either a mutated beta 2-microglobulin (beta 2m) gene or a mutated transporter associated with Ag processing 1 (TAP1) gene, and in mice doubly homozygous for beta 2m and TAPI mutations. In all mutant mice, the population size of major CD8 alpha alpha+ and CD8 alpha beta+ alpha beta-IEL subsets was reduced drastically, and this resulted in a conspicuous decrease in the total number of alpha beta-IEL. Concomitantly, a compensatory two- to threefold increase in the number of gamma delta-IEL consisting mostly of CD8 alpha alpha+ subset was noted. In radiation bone marrow chimeras, this wild-type/mutant phenotype was determined by the genotype of radioresistant host cells, but was not determined by the genotype of reconstituting bone marrow-derived cells. In beta 2m X TCR-delta double mutant mice, however, the CD8 alpha alpha+ but not CD8 alpha beta+ alpha beta-IEL subset expanded dramatically. Thus, in the absence of gamma delta-IEL, alpha beta-IEL in beta 2m-deficient mice outnumbered those in wild-type littermates. These results indicate that the generation of CD8 alpha alpha+ lymphocyte population of alpha beta- and gamma delta-IEL is not dependent, but that of CD8 alpha beta+ lymphocyte population of alpha beta-IEL is dependent on beta 2m- and/or TAP1-dependent MHC class I molecules, expressed by the controlling cells present in the anatomical site, where the development of IEL takes place.

Preferential activation of CD4+V beta 5.2/5.3+ intestinal intraepithelial lymphocytes in the inflamed lesions of Crohn's disease

To analyze the nature of intestinal intraepithelial lymphocytes (iIELs) in inflammatory intestinal disease, we established T cell lines of iIELs isolated from endoscopic biopsied ileal and colonic mucosa of Crohn's disease patients. Seven T cell lines from the inflamed terminal ileum of 13 patients, but none of 16 T cell lines from normal terminal ileum, have shown a deviation of T cell receptor variable region gene usage and were enriched in the proportion of CD4+V beta 5.2/5.3+ cells. CD4+V beta 5.2/5.3+ cells in the T cell lines were not increased after stimulation with purified protein derivatives or 65-kDa heat-shock protein but significantly increased after stimulation with staphylococcal enterotoxins C1 and D. Those cells showed increased cytolytic activity against target cells cross-linked by anti-V beta 5.2/5.3 and produced a large amount of interferon-gamma. These results indicated that CD4+V beta 5.2/5.3+ iIELs were preferentially activated in the inflamed lesions of Crohn's disease and may play a possible role in the triggering and progression of human inflammatory intestinal disease.

Induction of TCR-gamma delta+ cells from thymocytes stimulated by a fetal liver-derived hepatocyte clone

We have previously reported that a fetal liver-derived hepatocyte clone, FHC-4D2, can support hematopoiesis in vitro. Here, we show that fetal thymocytes (FT) or adult thymocytes (AT) proliferate on the monolayer of FHC-4D2 cells in the presence of rIL-2. Fresh thymocytes contained few TCR-gamma delta+ cells (< 4% for FT and < 1% for AT); significant numbers of TCR-gamma delta+ cells were detected (2-11% for FT and 15-33% for AT) after the coculture with FHC-4D2 and rIL-2. Although FT-derived TCR-gamma delta+ cells predominantly used the V gamma 5 chain, the major population in AT-derived TCR-gamma delta+ cells used V gamma 1, V gamma 4, or V gamma 7 chains. Both FT- and AT-derived TCR-gamma delta+ cells killed FcR-bearing target cells when incubated with anti-TCR-gamma delta Ab. Half of FT-derived TCR-gamma delta+ cells were CD4-CD8 alpha+8 beta-; the rest were CD4-CD8 alpha-8 beta-. AT-derived TCR-gamma delta+ cells expressed neither CD4 nor CD8 molecules. Separation of thymocytes from FHC-4D2 cells with a membrane filter reduced the proliferative response by two- to threefold. Taken together, these results demonstrate that a fetal hepatocyte clone supports thymocytes to develop preferentially into TCR-gamma delta+ cells in cooperation with rIL-2 through cell-cell contact, that the repertoire and the phenotype of induced TCR-gamma delta+ cells are determined by the age of the mice, and that hepatocytes might thus play an active role in T lymphopoiesis in the fetal liver.

Induction of TCR-gamma delta+ cells from thymocytes stimulated by a fetal liver-derived hepatocyte clone

We have previously reported that a fetal liver-derived hepatocyte clone, FHC-4D2, can support hematopoiesis in vitro. Here, we show that fetal thymocytes (FT) or adult thymocytes (AT) proliferate on the monolayer of FHC-4D2 cells in the presence of rIL-2. Fresh thymocytes contained few TCR-gamma delta+ cells (< 4% for FT and < 1% for AT); significant numbers of TCR-gamma delta+ cells were detected (2-11% for FT and 15-33% for AT) after the coculture with FHC-4D2 and rIL-2. Although FT-derived TCR-gamma delta+ cells predominantly used the V gamma 5 chain, the major population in AT-derived TCR-gamma delta+ cells used V gamma 1, V gamma 4, or V gamma 7 chains. Both FT- and AT-derived TCR-gamma delta+ cells killed FcR-bearing target cells when incubated with anti-TCR-gamma delta Ab. Half of FT-derived TCR-gamma delta+ cells were CD4-CD8 alpha+8 beta-; the rest were CD4-CD8 alpha-8 beta-. AT-derived TCR-gamma delta+ cells expressed neither CD4 nor CD8 molecules. Separation of thymocytes from FHC-4D2 cells with a membrane filter reduced the proliferative response by two- to threefold. Taken together, these results demonstrate that a fetal hepatocyte clone supports thymocytes to develop preferentially into TCR-gamma delta+ cells in cooperation with rIL-2 through cell-cell contact, that the repertoire and the phenotype of induced TCR-gamma delta+ cells are determined by the age of the mice, and that hepatocytes might thus play an active role in T lymphopoiesis in the fetal liver.

Effects of fecal microorganisms and their chloroform-resistant variants derived from mice, rats, and humans on immunological and physiological characteristics of the intestines of ex-germfree mice

In order to elucidate the nature of intestinal flora affecting the immunological and physiological parameters of the intestine, we produced several kinds of ex-germfree mice associated with fecal organisms and their chloroform-resistant variants derived from mice, rats, and humans. The phenotypes of intraepithelial lymphocytes were changed to those in conventional mice, particularly the increased positive percentage of alpha beta T-cell-receptor and Thy-1-bearing T cells, on association of the microorganisms (MF) and their chloroform resistant variants (MChl) derived from mice, but not rats and humans, with germfree mice. The cytolytic activity of intraepithelial lymphocytes was expressed only in the MF and MChl groups. The induction of the synthesis of fucosyl asialo GM1 glycolipid, the expression of major histocompatibility complex class II molecule, an increase in the mitotic indices of colonic epithelial cells, and a decrease in lactase activity of the small intestinal epithelial cells also occurred only in the two groups. On the other hand, the cecal size (cecal weight/body weight ratio) was reduced in the mice of all groups examined here, there being approximately the same amount and composition of organic acids, such as acetic acid, butyric acid, and propionic acid, in the cecal contents. Taken together, the results suggest that mouse-specific and chloroform-resistant microorganisms, which are difficult to cultivate at present, may contribute to alteration of the immunological and epithelial characteristics of the mouse intestine. Another factor derived from the intestinal flora, for example, bacterial metabolites such as organic acids, may also affect the cecal size.

Development of intestinal intraepithelial T lymphocytes is independent of Peyer's patches and lymph nodes in aly mutant mice

We have previously reported a new spontaneous recessive mutation that induces a generalized lack of lymph nodes (LNs) and Peyer's patches (PPs) accompanied by immunodeficiency in mice (gene symbol, aly). In this study, we have analyzed gut-associated lymphatic tissues of the mutant aly/aly mice and have compared the intestinal intraepithelial T lymphocytes (IEL) in aly/aly and normal aly/+ littermate mice. Immunohistochemical studies revealed that colonization of IEL and lamina propria T cells takes place in the absence of PPs and IgA-producing B cells in the lamina propria. Absolute numbers of Thy-1- IEL-alpha beta and -gamma delta are not altered in aly/aly mutant mice, whereas absolute numbers of Thy-1+ IEL-alpha beta and -gamma delta in aly/aly mice are about half of those in aly/+ mice. In IEL-alpha beta from aly/aly mice, the major CD8 alpha alpha+ and CD8 alpha beta+ subsets are maintained, whereas CD4+ and CD4+, CD8+ subsets are reduced. Although the population size of major CD8 alpha alpha+ and CD4-, CD8- IEL-gamma delta subsets is slightly reduced, the use of TCR-gamma- and -delta-chain variable gene segments by IEL-gamma delta remains almost the same in aly/aly mice. The constitutive cytolytic activity of IEL-alpha beta and -gamma delta is attenuated sharply in the aly/aly condition. This activity is, however, augmented significantly after in vitro stimulation with anti-CD3 mAb. These results indicate that most of the IEL subpopulations develop independently of passage through PPs and mesenteric LNs and that the aly mutation interrupts cytotoxic IEL development during relatively late differentiation steps that convert cytotoxic precursors to the constitutively cytolytic state.

Development of intestinal intraepithelial T lymphocytes is independent of Peyer's patches and lymph nodes in aly mutant mice

We have previously reported a new spontaneous recessive mutation that induces a generalized lack of lymph nodes (LNs) and Peyer's patches (PPs) accompanied by immunodeficiency in mice (gene symbol, aly). In this study, we have analyzed gut-associated lymphatic tissues of the mutant aly/aly mice and have compared the intestinal intraepithelial T lymphocytes (IEL) in aly/aly and normal aly/+ littermate mice. Immunohistochemical studies revealed that colonization of IEL and lamina propria T cells takes place in the absence of PPs and IgA-producing B cells in the lamina propria. Absolute numbers of Thy-1- IEL-alpha beta and -gamma delta are not altered in aly/aly mutant mice, whereas absolute numbers of Thy-1+ IEL-alpha beta and -gamma delta in aly/aly mice are about half of those in aly/+ mice. In IEL-alpha beta from aly/aly mice, the major CD8 alpha alpha+ and CD8 alpha beta+ subsets are maintained, whereas CD4+ and CD4+, CD8+ subsets are reduced. Although the population size of major CD8 alpha alpha+ and CD4-, CD8- IEL-gamma delta subsets is slightly reduced, the use of TCR-gamma- and -delta-chain variable gene segments by IEL-gamma delta remains almost the same in aly/aly mice. The constitutive cytolytic activity of IEL-alpha beta and -gamma delta is attenuated sharply in the aly/aly condition. This activity is, however, augmented significantly after in vitro stimulation with anti-CD3 mAb. These results indicate that most of the IEL subpopulations develop independently of passage through PPs and mesenteric LNs and that the aly mutation interrupts cytotoxic IEL development during relatively late differentiation steps that convert cytotoxic precursors to the constitutively cytolytic state.

Stimulation of in vitro hematopoiesis by a murine fetal hepatocyte clone through cell-cell contact

We have previously shown that a fetal liver-derived epithelial cell clone, FHC-4D2, could support hematopoiesis in vitro through its colony-stimulating factor (CSF) activities in a short-term culture. In this study, since FHC-4D2 cells were found capable of maintaining hematopoietic progenitors in the coculture for a long time, we examined how FHC-4D2 could exert hematopoietic supporting activity in a long-term culture by coculturing adult bone marrow (BM) cells or fetal liver (FL) cells on a monolayer of FHC-4D2 cells. This clone could maintain the colony-forming unit of granulocytes and macrophages (CFU-GM) of BM for > or = 12 weeks under the coculture condition, but the fibroblastic cell clone from the fetal liver, FHC-4A3, could not support the survival of CFU-GM, even for 1 week. In addition to BM CFU-GM, the FHC-4D2 clone also supported the survival of FL CFU-GM, burst-forming unit of erythroid cells (BFUe), and colony-forming unit of mixed progenitors (CFU-Mix) for longer than 4 weeks. When BM cells were separated by a membrane filter from the FHC-4D2 cells in the coculture, the comparable number of CFU-GM was maintained at day 3, but virtually no hematopoietic progenitors were detected at the end of the first week. CFU-GM were present in both nonadherent and adherent cells to the FHC-4D2 cells at day 3 of the coculture, but at day 7, the adherent population contained greater number of CFU-GM. CFU-GM derived from the adherent cells formed larger colonies and contained more bipotential CFU-GM than the nonadherent population. When BM cells from mice given 5-fluorouracil were cocultured with FHC-4D2 cells under the limiting dilution condition, interleukin-3 (IL-3)-responsive CFU-GM were induced from immature hematopoietic progenitor cells that were otherwise unresponsive to IL-3. From these data we conclude that the FHC-4D2 clone could generate and maintain IL-3-responsive hematopoietic progenitors via close contact and that, in the fetal liver, the contact between hepatocytes and hematopoietic cells may be critically important in inducing the differentiation of resting, IL-3-unresponsive immature hematopoietic cells into CFU-GM (progenitors responsive to IL-3) and in triggering the self-renewal of CFU-GM.

[The mechanism of thyroid hormone abnormalities in patients with diabetes mellitus]

In order to clarify the mechanism of impaired thyroid hormone levels in patients with diabetes mellitus, thyroid hormone, thyroid hormone binding inhibitor (THBI), inhibitor of extrathyroidal conversion of T4 to T3 (IEC) and free fatty acid (FFA) were examined. In addition, TRH test was performed on 9 diabetic patients showing poor control of plasma glucose before and after glycemic control. Before glycemic control, fasting plasma glucose and HbA1c were significantly higher than after glycemic control (P < 0.05). T3 and the T3/T4 ratio significantly increased and rT3 significantly decreased after glycemic control (P < 0.05). THBI index and plasma FFA level significantly decreased and %T3 production (IEC) significantly increased after glycemic control (P < 0.05). The response of TSH to TRH significantly increased after glycemic control. In conclusion, (1) the presence of THBI, (2) the presence of IEC, and (3) dysfunction of the hypothalamo-hypophysial-thyroid axis are considered to be involved in abnormal thyroid function in diabetic patients.

[Effects of intermittent cervical traction on muscle pain. Flowmetric and electromyographic studies of the cervical paraspinal muscles]

The effects of cervical intermittent traction on neck and shoulder pain were evaluated in 96 patients. Namely, a 15-second traction of the neck was repeated with a 5-second interval between tractions. In 39 patients, blood flowmetry and electromyography were performed in the cervical paraspinal muscles before and after the traction treatment. The pain was relieved in 76 out of 96 cases (79.2%). The blood flow in the affected muscles was significantly decreased as compared with the controls. However, it showed a significant increase following the treatment in patients whose pain was relieved. The mean frequency of the initial myoelectric signals as observed with the surface electrode on the affected muscles was significantly lower than the controls. It increased however following the traction treatment in the case in which the pain was relieved. In conclusion, it may be stated that the cervical intermittent traction is effective in relieving pain, increasing the frequency of myoelectric signals and improving blood flow in affected muscles.

Cytolytic activity of intestinal intraepithelial lymphocytes in germ-free mice is strain dependent and determined by T cells expressing gamma delta T-cell antigen receptors

We have compared the cytolytic activities and the cellular compositions of the intestinal intraepithelial lymphocyte (i-IEL) populations in three different combinations of conventional (CV) and germ-free (GF) mice. Cytolytic activity of i-IELs expressing gamma delta T-cell antigen receptors (TCRs) is strain dependent in CV mice (high vs. low), and this strain-dependent variability is unaltered in the GF condition. Although absolute numbers of gamma delta i-IELs are slightly decreased, the composition of CD8 alpha alpha+ and CD4-CD8- subsets and the usage of TCR gamma- and delta-chain variable gene segments by gamma delta i-IELs remain the same in GF mice. By contrast, cytolytic activity of alpha beta TCR-expressing i-IELs is uniformly high in CV mice but attenuated sharply in the GF condition. A conspicuous decrease in the total numbers of alpha beta i-IELs is also noted, and CD8 alpha beta+ and CD4+CD8+ subsets are reduced, whereas the CD8 alpha alpha+ subset is expanded in GF mice. These results indicate that microbial deprivation preferentially influences the alpha beta i-IEL population to decrease and become noncytolytic but has little effect on the pool size or characteristics of gamma delta i-IELs. Consequently, cytolytic activity of freshly isolated i-IELs from GF mice is determined by T cells expressing gamma delta TCRs and is found to be strain dependent.

Establishment of a hepatocytic epithelial cell line from the murine fetal liver capable of promoting hemopoietic cell proliferation

Although the fetal liver has been thought to be the main hemopoietic organ in the embryonal period, whether or not hepatocytes play a major role in hemopoiesis remains obscure. We have established an epithelial cell line from the murine fetal liver, which can support hemopoiesis in vitro. The proliferation of the epithelial cells was promoted synergistically by both epidermal growth factor (EGF) and insulin. The cells were identified as epithelial cells by the presence of desmosomes and tight junctions. Cytoplasmic organelles including small mitochondria and dilated Golgi apparati as well as intercellular canalicular structures similar to bile canaliculus also helped in confirming the hepatic origin of the cell line (designated as FHC). The cells in the primary culture were positive for both alpha-fetoprotein and albumin, indicating the hepatocytic nature of the cell line. Cloned FHC cells were demonstrated to have the ability to maintain hemopoietic progenitors in fetal liver and adult bone marrow in the coculture, and among them, FHC-4D2 clone displayed the greatest activity. Hemopoiesis-supporting function could also be seen even when bone marrow cells were separated from FHC-4D2 cells by nitrocellulose membrane. Column chromatography revealed three distinct peaks of hemopoietic activities with different molecular sizes in the supernatant of FHC-4D2. Neutralization test with antibodies and proliferative response to interleukin-3 (IL-3)/granulocyte-macrophage colony stimulating factor (GM-CSF)-responding IC2 cells demonstrated that the hemopoietic activities were attributed to GM-CSF and macrophage colony stimulating factor (M-CSF). Transcripts of GM-CSF and M-CSF were readily detectable in Northern blot analysis, whereas no messages for IL-3, IL-6, CSF for granulocytes (G-CSF) or erythropoietin (EPO) were identified. Therefore, this is the first report on the fetal hepatocyte cell line capable of supporting hemopoiesis.

Plasma free fatty acids, inhibitor of extrathyroidal conversion of T4 to T3 and thyroid hormone binding inhibitor in patients with various nonthyroidal illnesses

In order to clarify the role of free fatty acid (FFA) in thyroid hormone abnormalities in patients with nonthyroidal illness, thyroid function, FFA, inhibitor of extrathyroidal conversion of T4 to T3 (IEC) and thyroid hormone binding inhibitor (THBI) were studied in 99 patients with various nonthyroidal illnesses including diabetes mellitus (DM) (n = 35), liver cirrhosis (LC) (n = 33), chronic obstructive pulmonary disease (COPD) (n = 17) and chronic heart failure (CHF) (n = 14). Patients were divided into three groups based on the level of serum T3: Group I (T3 < 50 ng/dl), Group II (50 < or = T3 < 80) and Group III (80 < or = T3). Serum T4, FT3 and the T3/T4 ratio decreased significantly in the order Group III, Group II and Group I (Group III > II > I). The plasma FFA level was 0.91 +/- 0.12 mmol/l in Group I (P < 0.05, vs. Group III), 0.65 +/- 0.06 in Group II and 0.54 +/- 0.04 in Group III, respectively. The incidence of positive IEC was 80.0% in Group I (P < 0.05, vs. Group III), 53.7% in Group II (P < 0.05, vs. Group III) and 34.2% in Group III. However, IEC was not correlated with the serum T3 concentration. The incidence of positive THBI was 80% in Group I (P < 0.05, vs. Group III), 68.3% in Group II and 47.4% in Group III, but THBI was not correlated with the serum T4 level. Positive correlations were observed among FFA, IEC and THBI (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Disulfide-linked and non-disulfide-linked gamma/delta T-cell antigen receptors: differential expression on T-cell lines and clones derived from normal donors and patients with primary immunodeficiency disorders

We studied the expression of gamma delta T cell receptors (TCR) on T-cell lines and clones derived from peripheral blood lymphocytes (PBL) from certain patients with primary immunodeficiency disorders and normal donors. Immunoprecipitation with the anti-Leu 4, anti-gamma-chain and/or anti-delta-chain monoclonal antibodies followed by SDS-PAGE analysis revealed that 7 of 13 (54%) T-cell lines and clones developed from PBL of patients with primary immunodeficiency disorders expressed non-disulfide-linked gamma delta TCR, utilizing either the C gamma 2abc or the C gamma 2bc gamma-chain constant region gene segment. 5 of 13 (38%) T-cell lines/clones expressed disulfide-linked gamma delta TCR, whereas an additional T-cell line was comprised of T cells expressing either disulfide-linked (C gamma 1) or non-disulfide-linked (C gamma 2bc) gamma delta TCR. T-cell lines and clones developed from four of light patients with primary immunodeficiency disorders exhibited exclusively non-disulfide-linked gamma delta TCR utilizing either the C gamma 2abc or the C gamma 2bc gamma-chain segment. T-cell lines derived from a fifth patient exhibited primarily non-disulfide-linked gamma delta TCR, bringing to five of eight the numbers of patients that expressed exclusively or primarily non-disulfide-linked gamma delta TCR. T-cell lines/clones derived from the remaining three patients exhibited exclusively disulfide-linked gamma delta TCR. The age of these patients varied over a wide range and there was not an association between their age and the type of gamma delta TCR expressed on T-cell lines derived from their PBL. In contrast, to these findings 14 of 16 (87.5%) T-cell clones derived from PBL of normal donors expressed disulfide-linked gamma delta TCR, whereas only 2 of 16 (12.5% expressed non-disulfide linked gamma delta TCR. Among the T-cell clones from normal donors which express disulfide-linked gamma delta TCR two different types were identified. Those exhibiting under reducing conditions on SDS-PAGE two completely resolved polypeptide chains in the range of 37 kD to 44 kD, and those exhibiting under the same conditions indistinguishable overlapping gamma- and delta- chains in the range of 40-42 kD. Several T-cell lines and clones from normal donors or patients with primary immunodeficiency that expressed either disulfide- or non-disulfide-linked gamma delta TCR were delta TCS1+, demonstrating that the delta TCS1 determinant is expressed on both types of gamma delta TCR.(ABSTRACT TRUNCATED AT 400 WORDS)

Gamma/delta T cell antigen receptors expressed on tumor-infiltrating lymphocytes from patients with solid tumors

The expression of gamma/delta T cell antigen receptors (TcR) in T cell lines or clones derived from tumor-infiltrating lymphocytes (TIL) from patients with solid tumors was investigated. gamma/delta TcR T cell lines were derived from TIL from patients with Wilms tumor, sarcoma or metastatic melanoma by stimulation with autologous tumor cells alone and recombinant interleukin 2 and they exhibited nonspecific cytotoxicity against autologous and allogeneic tumor cells, or cells of the K562 or the MEL21 tumor cell lines. Two T cell lines were derived from a patient with Wilms tumor. One of them expressed a non-disulfide-linked gamma/delta TcR using the 60-kDa gamma chain, whereas, the other expressed a disulfide-linked gamma/delta TcR. A T cell line was derived from a patient with sarcoma and expressed a disulfide-linked gamma/delta TcR, whereas, a T cell line derived from a patient with melanoma expressed a non-disulfide-linked gamma chain of 62 kDa. Several T cell clones were developed from patients with metastatic melanoma or Wilms tumor and expressed either disulfide- or non-disulfide-linked gamma/delta TcR. Northern analysis of RNA from certain of these clones revealed a full-length gamma chain transcript, whereas, the alpha or beta chain transcripts were either absent or truncated. These T cell clones exhibited nonspecific cytotoxicity. Both disulfide- and non-disulfide-linked TIL T cell lines and clones expressed the delta TCS1 determinant. gamma/delta TcR+ cells in freshly prepared TIL from these patients were present in low proportions (less than 5%) and their delta TCS1/delta 1 ratios were within the range observed in the peripheral blood of normal donors. These results demonstrate that both disulfide- and non-disulfide-linked gamma/delta TcR are expressed on T cell lines and clones derived from TIL from solid tumors. Non-disulfide-linked gamma/delta TcR using the 56-66-kDa gamma chain are frequently found on TIL-derived T cell lines and clones. These 56-66-kDa gamma chains are rarely expressed on T cell lines or clones derived from peripheral blood lymphocytes of normal donors.

Production of granulocyte-macrophage colony-stimulating factor or GM-CSF-like growth factor by rat thymic epithelial cell line

An epithelial cell line, IT-45R1, has been established from a thymus of normal Wistar rat and was found to produce growth factor which stimulated the proliferation of bone marrow cells. This growth factor induced the formation of colonies composed of macrophages, granulocytes, or both, in semi-solid medium and stimulated the proliferation of an interleukin 3 (IL3)/granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent clone. Neither IL3-dependent clone nor IL6-dependent clone responded to IT-45R1 factor. Additionally, IT-45R1 factor acted on both rat and mouse bone marrow cells but not on human bone marrow cells. Molecular weight of IT-45R1 factor was 30 kD and its isoelectric point was 4.5. To determine whether IT-45R1 factor is GM-CSF or not, Northern blot analysis and neutralization with anti-mouse GM-CSF antibody were carried out. IT-45R1 expressed GM-CSF mRNA, but neither M-CSF nor IL6 transcripts. However, antiserum specific for mouse GM-CSF did not neutralize IT-45R1 factor. Taken together, a rat thymic epithelial cell line, IT-45R1, constitutively produces GM-CSF or GM-CSF-like growth factor.

IL-2-dependent murine T-cell lines and clones expressing gamma/delta T-cell antigen receptors. I. Functional and biochemical characterization

We have developed two stable IL-2-dependent T-cell lines designated AKV-I and AKV-N from the enlarged spleens, respectively, of an AKV1 and an NFS mouse. Immunofluorescence staining with the appropriate monoclonal antibodies revealed that cells of the AKV-I cell line were alpha beta TCR-CD3+CD4-CD5-CD8+CD25+, whereas cells of the AKV-N cell line were alpha beta TCR-CD3+CD4-CD5+CD8-CD25+. A number of T-cell clones were developed from the AKV-I or AKV-N T-cell lines by limiting dilution and analysed by immunofluorescence. All clones tested were alpha beta TCR-CD3+CD4-CD25+. Certain T-cell clones expressed the CD5 antigen, whereas others expressed the CD8 antigen. The AKV-I cell line responded by proliferation to rIL2, rIL4, phorbol myristate acetate (PMA), PMA plus IL-4 and PMA plus PHA or Con A. In contrast, the AKV-N cell line did not respond to rIL-4 or rIL-4 plus PMA and exhibited only a modest proliferative response to PMA alone. Both AKV-I and AKV-N T-cell lines as well as a large number of T-cell clones examined were able to lyse cells of the PU5-IR murine cell line in the presence of the anti-CD3 (clone 145-2C11) MoAb, demonstrating their ability to mediate cytotoxicity in this system. Biochemical analysis of both AKV lines and a number of clones by immunoprecipitation with the anti-CD3 MoAb, followed by one-dimensional (either non-reducing or reducing) or two-dimensional (non-reducing/reducing) SDS-PAGE, revealed that the AKV lines and clones expressed a disulphide-linked dimer. Under non-reducing conditions, a band in the range of 75-85 kDa was observed and upon reduction it was resolved into two discrete polypeptide chains of 43-44 kDa and 48 kDa in certain AKV-I cells or 38 kDa and 42 kDa in certain AKV-N cells. In other T-cell clones or lines a broad band of 42-47 kDa was observed in AKV-I cells or 38-45 kDa in AKV-N cells. These results suggest the presence of different forms of disulphide-linked dimers on these cells. Northern blotting analysis using probes specific for the constant regions of the alpha-, beta-, gamma- and delta-chains of the T-cell antigen receptor revealed that all the AKV cell lines or clones tested expressed full-length alpha-, gamma- and delta-chain mRNA, whereas beta-chain mRNA was absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Murine thymic nurse cell clone supports the growth of fetal thymocytes in the presence of interleukin 2

To investigate the role of thymic nurse cells (TNC) in activation and differentiation of fetal CD4-CD8- (double-negative) thymocytes, we have co-cultured murine fetal thymocytes (14-15 days of gestation) with an established murine TNC clone. We show here that TNC induced the growth of the fetal double-negative thymocytes in the presence of recombinant interleukin 2 (rIL2). Activated fetal thymocytes markedly formed lymphocyte-TNC complexes and proliferated extensively after 5 days in the co-culture. The activated fetal thymocytes in this co-culture condition remained double negative after 10 days in culture. None of them gave rise to phenotypically and functionally competent lymphocytes during this period. TNC alone and the supernatant of TNC had no effect on activation. The presence of both TNC and rIL2 was necessary for the growth of fetal thymocytes in our system. The proliferation of fetal thymocytes was inhibited by a monoclonal antibody against mouse IL2 receptors (IL2R). The fetal thymocytes could be maintained further in this co-culture condition. The prolonged cultivation of fetal thymocytes resulted in the establishment of the fetal thymocyte line and its several clones. CD4 single-positive cells of activated fetal thymocytes first appeared 14 days after the onset of culture and their number increased, whereas CD8+ cells or CD4CD8 double-positive cells were not observed. These results indicate that fetal CD4-CD8- thymocytes underwent phenotypic change after long periods of culture. All established clones of fetal thymocytes are CD4 single positive showing lymphocyte-TNC interactions but do not express CD3 complex. Northern blot analysis detected mRNA for the gamma T cell receptor, but no messages for the delta, alpha or beta T cell receptor. Chemical cross-linking of 125I-labelled IL2 revealed that the 90-kDa band (presumably considered to be the IL2R beta chain) was clearly present in IL2-responsive fetal clones, whereas freshly isolated day 14-15 fetal thymocytes lacked the band. Taken together, TNC might be involved in the differentiation and/or expansion of murine fetal thymocytes by inducing IL2R beta chain, which forms the functional IL2R together with IL2R alpha chain and CD4, one of the T cell accessory molecules, on the cell surface through direct cell-cell interaction.

[Radioimmunoassay for dexamethasone and its plasma levels after oral administration in patients with liver disease]

Dexamethasone (DXM), one of the strong synthetic glucocorticoids, has been used widely for therapeutic purposes and for evaluation of the hypothalamic-pituitary-adrenal axis. However, information concerning the plasma concentrations of DXM and its metabolism in various liver diseases is limited. In this study, plasma DXM levels were examined in patients with chronic inactive hepatitis (CH), patients with liver cirrhosis (LC) and normal subjects (NR) after oral administration of one milligram DXM. Plasma DXM levels were measured directly in plasma extract, using reliable and sensitive radioimmunoassay (RIA). The antiserum was obtained by immunizing rabbits with DXM-3-oxime-bovine serum albumin conjugate. Standard curves for DXM were obtained over the range 10-5000 pg. The cross reactivity of endogenous steroids with DXM antiserum was less than 0.1%. In the group of NR, the peak of plasma DXM was 20.9 +/- 2.9 ng/ml within 1.3 +/- 0.4 hours after administration. Half time of its disappearance was 3.3 +/- 1.1 hours, and plasma DXM disappeared in 24 hours, remaining less than 1 ng/ml. In patients with CH and those with LC, the peak levels of DXM were 10.8 +/- 1.0 ng/ml and 10.5 +/- 0.5 ng/ml, respectively, and those values were significantly lower than those of NR. Half time of DXM disappearance in patients with CH and in those with LC were 6.2 +/- 0.6 and 6.3 +/- 0.6 hours, respectively, significantly prolonged compared with that of NR. Although DXM metabolism was impaired in CH as well as in LC, the retention rate of indocyanine green (ICG) at 15 minutes in CH was found within the normal range, 10.0 +/- 1.1%, respectively. These results might suggest that the impaired DXM metabolism in patients with chronic liver disease may be affected not only by the decreased hepatic blood flow but also by some other factors.

Effect of sodium valproate on the secretion of proopiomelanocortin derived peptides from cultured rat anterior pituitary cells

We examined effects of sodium valproate, a gamma amino butyric acid (GABA)-transaminase inhibitor, on the secretion of immunoreactive (IR)-ACTH and IR-beta-endorphin/LPH from cultured rat anterior pituitary cells to determine whether sodium valproate has a direct action on the secretion of ACTH and its related peptides from the cultured rat anterior pituitary gland. During the 3 h incubation, the basal secretion of IR-ACTH and IR-beta-endorphin/LPH decreased to 50.8% and 58.3%, respectively, of the control concentration after adding 10(-7) M sodium valproate into the incubation media and to 67.7% and 69.3%, respectively, of the control levels with 10(-8) M sodium valproate. However, sodium valproate at a concentration of 10(-6) M or 10(-9) M did not affect the basal concentration of IR-ACTH and IR-beta-endorphin/LPH. Sodium valproate at a concentration of 10(-7) M significantly attenuated the stimulated release of IR-ACTH and IR-beta-endorphin/LPH by 10(-9) or 10(-10) M of ovine corticotrophin releasing factor. These results indicate that sodium valproate could directly effect rat anterior pituitary cells to suppress both basal and stimulated release of proopiomelanocortin derived peptides and this supports the hypothesis that sodium valproate has a direct effect at the pituitary corticotroph in reducing plasma ACTH.

Disulfide-linked gamma delta T cell antigen receptors expressed on T cells derived from patients with primary immunodeficiency disorders

T cell lines or clones from two patients, one with a partial DiGeorge syndrome and one with severe common variable immunodeficiency expressed disulfide-linked gamma delta T cell antigen receptor (TCR) comprised of a gamma-chain polypeptide of 40-43 kD, and a delta-chain polypeptide of 37-40 kD. This gamma delta TCR appears to be similar to that found on T cell clones, and lines derived from peripheral blood lymphocytes from normal donors. Previous studies have shown that T cell lines derived from the peripheral blood of patients with immunodeficiency disorders express non-disulfide-linked gamma delta TCR. In contrast to the latter and coincident with findings in the present study, the vast majority of T cell lines and clones derived from the peripheral blood of normal donors express disulfide-linked gamma delta TCR.

Increased production of cytotoxic macrophage progenitors by Lactobacillus casei in mice

Heat-killed Lactobacillus casei YIT9018 (LC9018), when administered intravenously to normal mice, induced increase in Mac-1+ cells and Mac-2+ cells but not in Mac-3+ cells in spleen. The number of both populations changed in the same time course and was maximal 14 d after the administration. To know the effect of LC9018 on hematopoietic progenitor level, we examined the number of macrophage colony-forming cells (M-CFC), granulocyte-macrophage CFC (GM-CFC), and colony-forming units in spleen (CFU-S) in bone marrow 3 d after the administration. LC9018 stimulated the proliferation of M-CFC but not that of GM-CFC and CFU-S. LC9018-induced M-CFC were similar to normal M-CFC in dependence on macrophage colony-stimulating factor (M-CSF) and buoyant density. M-CFC-derived macrophages cultured in the presence of M-CSF expressed Mac-1 and Mac-2 but not Mac-3. They showed cytotoxic activity against syngenic tumor cells, Meth A, via direct contact, when assayed by using an in vitro colony inhibition assay or an in vivo Winn test. These results indicate that LC9018 stimulates the proliferation of cytotoxic macrophage progenitors in bone marrow and induces their differentiation in spleen. These effects may be one of the ways in which LC9018 suppresses tumor growth.

Regulation of natural killer cytotoxicity by recombinant alpha interferons. Augmentation by IFN-alpha 7, an interferon similar to IFN-alpha J

The structure-function relationship of several recombinant human alpha interferons (IFN-alpha) (IFN-alpha 1, IFN-alpha 2, IFN-alpha 4, IFN-alpha 7, IFN-alpha 2/alpha 1 and IFN-delta 4 alpha 1) was investigated with respect to their ability to augment natural killer (NK) cytotoxicity of human peripheral blood mononuclear cells (PBMC) against hemopoietic tumor cell lines. Although all these IFNs significantly augmented NK cytotoxicity against the K562, Daudi and U937 targets, significant quantitave differences were observed in their ability to augment NK. INF-alpha 4, IFN-alpha 2 and IFN-alpha 2/alpha 1 were able to augment NK at low concentrations (less than 0.1 ng/ml), whereas IFN-alpha 7, IFN-alpha 1 and IFN-delta 4 alpha 1 required significantly higher concentrations (3 ng/ml or higher). The cumulative rank order of INFs on the basis of NK augmenting ability was found to be: IFN-alpha 4 approximately IFN-alpha 2 approximately IFN-alpha 2/alpha 1 greater than IFN-alpha 7 greater than IFN-alpha 1 approximately IFN-delta 4 alpha 1. To determine synergism or potentiation in the ability of IFNs to augment NK cytotoxicity, we investigated the effect of simultaneous, sequential and reversed order of treatment of human PBMC by these IFNs. Such potentiation or synergism was not observed. In addition, all these IFNs were able to augment NK cytotoxicity against targets from malignant melanoma cell lines. IFN-alpha 7 augmented regularly and reproducibly NK cytotoxicity in 15 of 19 normal donors examined (79%). This augmentation was blocked by an anti-IFN-alpha antibody. Concentrations of IFN-alpha 7 as low as 0.06 ng/ml were able significantly to augment NK cytotoxicity of PBMC after incubation for one hour at 37 degrees C. In contrast to these findings, IFN-alpha J, an interferon similar to IFN-alpha 7, has been report to be incapable of augmenting NK cytotoxicity and also of interfering with augmentation of NK by other IFNs. Sequential treatment of PBMC first with IFN-alpha 7 and then with other interferons did not prevent the augmentation of NK. Similarly, simultaneous treatment with IFN-alpha 7 and other interferons did not prevent augmentation of NK. In both treatments IFN-alpha J has been reported to prevent augmentation of NK. IFN alpha J and IFN-alpha 7 differ only by one amino acid, at position 107, where a lysine in IFN-alpha J has been replaced by a glutamic acid in the IFN-alpha 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a monoclonal antibody specific for the gamma chain of the T-cell antigen receptor using an open reading frame expression vector

To develop an anti-framework monoclonal antibody (mab) specific for the gamma (gamma)-chain of the T-cell antigen receptor (TCR), we expressed a part of the constant region of the gamma-chain (C gamma 2 gene segment) in E. coli using the pWR590 vector. This plasmid contains the E. coli lac promoter, operator, a truncated beta-galactosidase (beta-gal) gene (coding for the first 590 of the 1,007 amino acids of the beta-gal) and a polylinker region (at the 3' end of the beta-gal) containing nine restriction sites. These can be cleaved by any one of eight common restriction enzymes, permitting the introduction of the DNA fragment of interest. We employed the pT gamma 1 gamma-chain cDNA probe, which like the vast majority of the gamma-chain specific probes is aberrant and contains an in-frame stop codon at the junction of V and J regions. Computer analysis of the pT gamma 1 sequence revealed several MaeIII restriction sites that could result in a number of fragments. One of these fragments consisted of 245 base pairs (nucleotides 404-648) and contained most of the CI exon of the C gamma 2. Successful insertion of this fragment to the pWR590 vector was confirmed using restriction enzyme analysis. The C gamma insert was 12% of the construct. Expression of the pWR590-HpT gamma 1 recombinant plasmid in E. coli followed by SDS-PAGE analysis revealed a hybrid protein with a molecular weight of 85 kd which constituted at least 25% of the total E. coli insoluble protein. In contrast, cells transformed with the control pWR590 vector without insert expressed a 78 kd polypeptide chain. We developed several mabs against the pWR590-HpT gamma 1 hybrid protein by fusing spleen lymphocytes from BALB/c mice immunized with the pWR590-HpT gamma 1 protein, with cells of the NS1 mouse myeloma cell line. Screening of the mabs was carried out by ELISA against the pWR590-HpT gamma 1 hybrid protein and the control pWR590 beta-gal protein (beta-gal 590), derived by expressing in E. coli the pWR590 vector without gamma-chain insert. Two groups of mabs were obtained, those reacting with the pWR590-HpT gamma 1 hybrid protein only and those reacting with both the hybrid and the control beta-gal 590 proteins. The specificity of these mabs was further studied by Western blotting with similar results.(ABSTRACT TRUNCATED AT 400 WORDS)

Molecular heterogeneity of gamma delta T-cell antigen receptors expressed by CD4- CD8- T-cell clones from normal donors: both disulfide- and non-disulfide-linked receptors are delta TCS1+

We investigated the molecular heterogeneity of gamma delta T-cell antigen receptors (TCR) expressed on T-cell clones generated from peripheral blood lymphocytes of normal donors. Extensive molecular heterogeneity was seen at the gamma-chain level and, to a lesser extent, at the delta-chain level. Both disulfide and non-disulfide gamma delta TCR were found and use different gamma chains with similar molecular masses (range, 41-43 kDa). In contrast, gamma chains of 55-60 kDa, which are expressed on T-cell lines derived from the peripheral blood of patients with immunodeficiency disorders, were not found on T-cell clones derived from the peripheral blood of normal donors. delta chains expressed on these T-cell clones had a molecular mass of 37 kDa and were either disulfide or nondisulfide linked. Significant delta-chain heterogeneity was identified in these clones using the anti-delta TCS1 and the anti-TCR delta 1 monoclonal antibodies. All clones tested were TCR delta 1+, whereas only 25% of the clones were delta TCS1+. The anti-delta TCS1 monoclonal antibody stained and immunoprecipitated both disulfide- and non-disulfide-linked gamma delta TCRs from different T-cell clones from normal donors.

[An inhibitor of extrathyroidal conversion of thyroxine to 3,5,3'-triiodothyronine (IEC) in plasma of patients with various nonthyroidal illnesses]

To evaluate the role of a circulating inhibitor of extrathyroidal conversion of T4 to T3 (IEC) in the causation of low T3 states in patients with various nonthyroidal illnesses (NTI), we measured the in vitro T3 production in the presence of ether extract of plasma. Blood samples were obtained from 22 normal subjects and 140 patients with various NTI; liver cirrhosis (LC) 37, diabetes mellitus (DM) 48, respiratory failure (RF) 15, chronic renal failure (CRF) 10 and others 30. The assay procedure of in vitro T3 production was as follows. Rat liver homogenate was incubated with 2.5 microM T4 in the presence of evaporated ether extract of plasma and the amount of T3 produced was quantified by RIA. In each assay, control plasma extracts taken from the two normal subjects were used. The results were expressed as a percentage of the control value (%T3 production), and estimated as positive IEC when %T3 production was under 72.7%, that was 2SD below the mean value of normal controls. Patients were divided into three groups; Group I (T3 greater than or equal to 80 ng/dl), Group II (80 greater than T3 greater than or equal to 50) and Group III (50 greater than T3). The %T3 productions were 88.5 +/- 22.0 in Group I, 84.9 +/- 31.5 in Group II and 78.9 +/- 34.0 in Group III respectively. The %T3 productions of each group were significantly lower than that of normal control, 101.9 +/- 14.6. IEC was positive 23.4% in Group I, 41.9% in Group II and 43.8% in Group III. There were eight nonsurvivors, and they all belonged to Group III, in which both serum T3 and T4 were subnormal. In nonsurvivors, serum concentrations of T3 (20 +/- 11 ng/dl) and TSH (1.2 +/- 1.1 microU/ml) were significantly lower than that of survivors in Group III (T3; 38 +/- 10 ng/dl p less than 0.005, TSH; 2.8 +/- 1.4 microU/ml p less than 0.05). The %T3 productions were 83.8 +/- 32.1 in survivors and 64.8 +/- 37.9 in nonsurvivors, and the incidences of positive IEC were 37.5% in survivors and 62.5% in nonsurvivors. From the standpoint of the underlying illnesses, serum concentrations of T3 (mean +/- SD ng/dl) were 49 +/- 21 in LC, 64 +/- 11 in DM, 40 +/- 22 in RF and 63 +/- 15 in CRF, and %T3 productions were 60.6 +/- 26.5 in LC, 82.5 +/- 25.8 in DM, 109.6 +/- 32.1 in RF and 97.6 +/- 24.3 in CRF.(ABSTRACT TRUNCATED AT 400 WORDS)