Autoreactive CD4- CD8- alpha beta T cells to vaccinate adjuvant arthritis.

Studies suggested that experimental autoimmune diseases can effectively be prevented and treated by application of normal autoreactive T cells or autoreactive T cells in an attenuated form. In this study, several autoreactive CD4- CD8- T-cell clones (A2, A6, and A13 cells) were isolated for the first time from the draining lymph nodes of Lewis rats with adjuvant arthritis (AA). Surprisingly, intraperitoneal inoculation with A13 cells, but not A2 or A6 cells protected rats from AA both clinically and histologically. It was demonstrated that A13 cells were CD4- CD8- alpha beta T cells, and showed proliferative responses to irradiated syngeneic spleen cells (antigen-presenting cells; APC). Interestingly, A13 cells proliferated against concanavalin A (Con A) and staphylococcal enterotoxin B (SEB), but did not show any proliferation to Mycobacterium tuberculosis (Mt), or its 65 000 MW heat-shock protein (HSP). Rats protected from AA by inoculation with A13 cells showed a specific anti-idiotypic delayed-type hypersensitivity reaction compared with other autoreactive T cells (A2 or A6 cells). These findings demonstrate that AA can be suppressed by autoreactive CD4- CD8- alpha beta T cells, and these cells may be used as therapeutic agents in experimental autoimmunity.     

Presence of a very small population of Thy-1+, L3T4+ cells producing large amounts of IL-3 in young athymic nude mice.

A mixture of phorbol myristate acetate (PMA) and ionomycin was found to stimulate spleen and lymph node cells (LNC) from 6 to 8 week-old-athymic BALB/c nude mice, as well as from control +/+ mice, to secrete interleukin-3 (IL-3) in vitro. The specificity of the IL-3 bioassay was attested to by the use of rabbit anti-IL-3 antibodies, and by the detection of an accumulation of IL-3 mRNA. Cytotoxic treatment with relevant antibodies showed that the cells responsible for the IL-3 production in athymic nude mice was Thy-1+, L3T4+, Ly2-, while both L3T4+ and Ly 2+ cells produced IL-3 in control +/+ mice. Although the levels of IL-3 secreted by nude LNC varied among experiments, nude LNC were able to produce IL-3 at a level comparable to or higher than +/+ LNC. In addition, nude LNC consistently secreted two to three times more granulocyte-macrophage colony-stimulating factor (GM-CSF) than +/+ LNC, and the majority of GM-CSF secretion was dependent on the presence of L3T4+ cells. In contrast, IL-2 production by nude LNC was markedly limited. Since the flow microfluorometry analysis failed to demonstrate the presence of L3T4+ cells (less than 1%) in nude LNC, compared with 40-50% L3T4+ cells in +/+ LNC, our results suggest that athymic nude mice have a small population of Thy-1+, L3T4+ cells characterized by its ability to secrete IL-3 and GM-CSF at a very high rate.     

Functional regulation of tactile sense by brain-derived neurotrophic factor in adult rats during acute inflammation

Nerve growth factor is present in skin in limiting amounts and is known to regulate the plasticity and the sensitivity of nociceptive neurons. Recently, knock-out mouse studies showed that neurotrophin-3 and brain-derived neurotrophic factor are required for the postnatal survival and functional maturation, respectively, of tactile sensory neurons. However, the roles of neurotrophin-3 and brain-derived neurotrophic factor in adult sensory neurons have not been clarified. Here, we report an unexpected and marked acute loss of tactile sense in the rat hind paw after adjuvant-induced inflammation. This loss was shown to be closely correlated with decreases in the expression of brain-derived neurotrophic factor, and to a lesser extent of neurotrophin-3 in the inflamed skin. Administration of brain-derived neurotrophic factor, but not neurotrophin-3, after inflammation accelerated the recovery of tactile sense.These results suggested a role of brain-derived neurotrophic factor in the physiological regulation of tactile sense in adulthood.     

Characterization of T-cell tolerance to hepatitis B virus (HBV) antigen in transgenic mice.

We made three different lines of hepatitis B virus (HBV) transgenic mice which express different amounts of hepatitis B e antigen (HBeAg) and/or hepatitis B core antigen (HBcAg) to analyse the cellular mechanisms of HBcAg specific T-cell tolerance. BS10 (official designation, 1.2HB-BS10) transgenic mice, which contain the whole HBV genome, express relatively high amounts of HBeAg in the serum and HBcAg in the liver. SPC mice, which contain hepatitis B virus core and precore gene, express small amounts of HBeAg in the serum but not HBcAg in the liver. SC33 mice, which contain only hepatitis B core gene, do not express HBeAg in the serum but express HBcAg in the liver. BS10 mice showed a very low anti-HBc antibody response after primary and secondary immunizations with recombinant HBcAg compared to transgenic host C57BL/6 (B6) mice. SPC mice showed an almost equal level of anti-HBc antibody response compared to B6 mice. SC33 mice contained anti-HBc antibody even before immunization and showed high titres of anti-HBc antibody response after immunization with HBcAg. Analysis of cellular site(s) of low responsiveness of BS10 mice revealed that proliferating and helper T cells are specifically tolerant to HBcAg. B cells and antigen-presenting cells in BS10 mice were not defective. SC33, SPC and BS10 mice differ a little in their developmental expression of HBc/HBeAg. Our results suggest critical roles of the nature (circulating versus non-circulating) as well as the time of expression of self-antigens in T-cell tolerance.     

ASO Visual Abstract: Influence of Damaged Stomach on Anastomotic Leakage After Cervical Esophagogastrostomy for Patients with Esophageal Cancer

Annals of Surgical Oncology -     

Immunohistochemical detection of P-glycoprotein in breast cancer and its significance as a prognostic factor

Overexpression of P-glycoprotein (Pgp) in tumors is one of the major mechanisms which mediates the multidrug resistance (MDR) phenotype. To evaluate the prognostic significance of Pgp in breast cancer, Pgp expression was examined in paraffin-embedded tissue sections of 94 breast cancer specimens by immunohistochemistry. Tissue specimens were obtained by mastectomy without preoperative chemotherapy. UIC2 monoclonal antibody which recognizes an extracellular epitope of human Pgp was employed. Of the 94 breast cancer specimens, 35 (37.2%) were positive for Pgp expression. Pgp expression had no correlation with menopausal or hormone receptor status, axillary lymph node involvement or tumor size. However, a significant correlation was observed between Pgp expression and disease relapse (p = 0.0322). Pgp-positive patients showed a significantly shorter disease-free survival period than Pgp-negative patients by the Kaplan-Meier method (p = 0.0433). These results suggest that immunohistochemical detection of Pgp in breast cancer tissue may have prognostic value after radical operation.     

Renal expression of constitutive NOS and DDAH: separate effects of salt intake and angiotensin

BACKGROUND: Nitric oxide (NO) is generated from NO synthase (NOS) isoforms. These enzymes can be inhibited by asymmetric dimethylarginine, which is inactivated by N(G)-N(G)-dimethylarginine dimethylaminohydrolase (DDAH). The neuroneal (nNOS) type I and endothelial (eNOS) type III constitutive NOS isoforms are expressed predominantly in the macula densa and microvascular endothelium of the renal cortex, respectively. DDAH is expressed at sites of NOS expression. Since NO may coordinate the renal responses to angiotensin II (Ang II) and changes in salt intake, we tested the hypothesis that salt intake regulates the expression of nNOS, eNOS and DDAH by Ang II acting on type 1 (AT(1)) receptors. METHODS: Groups (N = 6) of rats were adapted to low-salt (LS) or high-salt (HS) intakes for 10 days. Other groups of LS and HS rats received the AT(1) receptor antagonist losartan for six days (to test the effects of salt independent of AT(1) receptors). A further group of HS rats received an infusion of Ang II for six days (to test the effect of Ang II independent of salt intake). RESULTS: Compared with HS rats, there was a significant (P < 0.05) increase in LS rats of nNOS protein in kidney and immunohistochemical expression in the macula densa, and of eNOS protein expression and immunohistochemical expression in the microvascular endothelium, and of DDAH protein expression. Losartan prevented these effects of salt on the expression of eNOS or DDAH, both of which were also increased by Ang II infusions in HS rats. In contrast, losartan did not prevent the effects of salt on nNOS expression, which was unresponsive to Ang II infusion. The generation of NO(2)(-) released by slices of renal cortex, in the presence of saturating concentrations of L-arginine, was increased by LS, compared to HS, independent of losartan and by Ang II during HS. CONCLUSION: The expressions of eNOS in cortical microvascular endothelium and DDAH in kidney are enhanced by Ang II acting on AT(1) receptors. The expression of nNOS in the macula densa is enhanced by salt restriction independent of Ang II or AT(1) receptors.