Activated iNKT cells enhance the anti-tumor effect of antigen specific CD8 T cells on mesothelin-expressing salivary gland cancer.

BACKGROUND: Salivary gland cancers are not sensitive to conventional radiotherapy or chemotherapy regimens. Therefore, the development of a new treatment strategy is of critical importance for improving the prognosis. We examined the expression of mesothelin molecules in salivary gland cancers and the efficacy of adoptive cell therapy based on mesothelin-specific chimeric antigen receptor transduced T cells. METHODS: The expression of mesothelin molecule was studied in salivary gland cancer samples obtained from 16 patients as well as a salivary gland cancer cell line (A-253) and five other cell lines. The activation of mesothelin-specific chimeric antigen receptor-expressing CD8 T cells after stimulation with mesothelin and the effects of invariant natural killer T cells on this activation were evaluated. RESULTS: Mesothelin was detected in the A-253 cells and the surgical specimens except for the case of squamous cell carcinoma to various degrees. Following stimulation with mesothelin expressing cancer cells, chimeric antigen receptor T cells were dose-dependently activated; this activation was enhanced by co-culture with invariant natural killer T cells and subsequently abrogated by treatment with anti-interferon-γ antibodies. Furthermore, the cytotoxicity of chimeric antigen receptor T cells against various cancer cells was further augmented by invariant natural killer T cells. CONCLUSIONS: The use of adoptive transfer with mesothelin-specific chimeric antigen receptor-expressing CD8 T cells against salivary gland cancers is an effective therapy and invariant natural killer T cells are expected to be used in adjuvant treatment for T cell-based immunotherapy.

CD45RA-Foxp3high regulatory T cells have a negative impact on the clinical outcome of head and neck squamous cell carcinoma.

BACKGROUND: Although regulatory T cells (Tregs) are thought to play an important role in immune suppression, their clinical significance in head and neck squamous cell carcinoma (HNSCC) is unclear. A recent study reported Tregs could be divided into functional subsets based on the expression of CD45RA and Foxp3. METHOD: The frequency of circulating Treg subsets was analyzed in patients with HNSCC and compared with the frequency in patients with benign tumors. The association of Treg subsets with the frequency of lymphocyte subsets, status of progression, clinical course, and prognosis were also examined. RESULTS: The frequency of CD4+Foxp3+ Tregs was comparable between HNSCC patients and age-matched benign tumor patients; however, CD45RA-Foxp3high Tregs were significantly increased in HNSCC patients, in particular those with advanced stage tumors. The high frequency of CD45RA-Foxp3high Tregs correlated with a poor prognosis and the low frequency of CD45RA-Foxp3high Tregs before treatment showed a better clinical outcome, even in patients with advanced stage tumors. CD45RA-Foxp3high Treg numbers were decreased after intensive treatments; however, Treg numbers recovered in the early stages of recurrent cases, even before the clinical manifestation. CONCLUSION: CD45RA-Foxp3high Tregs are associated with the clinical course of HNSCC and might be a new target for treatment and an early marker of tumor recurrence in HNSCC patients.

Blockade of programmed death-1/programmed death ligand pathway enhances the antitumor immunity of human invariant natural killer T cells.

The role of invariant natural killer T (iNKT) cells in antitumor immunity has been studied extensively, and clinical trials in patients with advanced cancer have revealed a prolonged survival in some cases. In recent years, humanized blocking antibodies against co-stimulatory molecules such as PD-1 have been developed. The enhancement of T cell function is reported to improve antitumor immunity, leading to positive clinical effects. However, there are limited data on the role of PD-1/programmed death ligand (PDL) molecules in human iNKT cells. In this study, we investigated the interaction between PD-1 on iNKT cells and PDL on antigen-presenting cells (APCs) in the context of iNKT cell stimulation. The blockade of PDL1 at the time of stimulation resulted in increased release of helper T cell (Th) 1 cytokines from iNKT cells, leading to the activation of NK cells. The direct antitumor function of iNKT cells was also enhanced after stimulation with anti-PDL1 antibody-treated APCs. According to these results, we conclude that the co-administration of anti-PDL1 antibody and alpha-galactosylceramide (αGalCer)-pulsed APCs enhances iNKT cell-mediated antitumor immunity.

Invariant NKT cells are resistant to circulating CD15+ myeloid-derived suppressor cells in patients with head and neck cancer.

Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature and progenitor myeloid cells with an immunosuppressive role in various types of cancer, including head and neck squamous cell carcinoma (HNSCC). However, the effect on the host immune system, especially on invariant NKT (iNKT) cells with potent anti-tumor activity, remains unclear. In this study, we investigated the effects of circulating MDSC subsets on the peripheral lymphocytes of patients with head and neck tumors. A significant accumulation of CD15+ granulocytic MDSC (G-MDSC) and CD14+ monocytic MDSC (M-MDSC) was demonstrated in HNSCC patients. The percentage of G-MDSC showed an inverse correlation with the percentage of T cells in the peripheral blood. The increased G-MDSC was significantly associated with advanced clinical stage and poor prognosis of HNSCC patients. The proliferation and viability of T cells were suppressed by CD15+ cells, and the suppression was reversed by adding the hydrogen peroxide scavenger catalase. However, iNKT cell activation upon α-galactosylceramide (αGalCer) stimulation was not affected by the presence or absence of CD15+ G-MDSC. These results indicate that increased G-MDSC negatively affects peripheral T cell immunity, but not iNKT cells, in HNSCC patients, and that T cells are more sensitive to hydrogen peroxide produced by G-MDSC than iNKT cells. Cancer immunotherapy designed to enhance the antitumor activity of iNKT cells by stimulation with αGalCer may remain effective in the presence of G-MDSC.

Effects of perinatal, combined exposure to 1,4-dichlorobenzene and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene on rat female reproductive system.

Prenatal or early postnatal exposure to some synthetic chemicals may affect the later reproductive system of the offspring. 1,4-Dichlorobenzene (DCB) is used as an air freshener and a moth repellent and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) is a persistent metabolite of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane that was used as a pesticide before. DCB concentrations of residential air and oral p,p'-DDE intake through marine products are demonstrated to be rather high in Japan. Such situations lead to high body burden of these pollutants in pregnant women. Consequently, foetuses and neonates will be exposed much more to DCB and p,p'-DDE via the mother. Therefore, the effects of the perinatal, combined exposure to DCB and p,p'-DDE on the female reproductive system have been investigated in mature rat female offspring of dams ingesting 25 p.p.m. DCB (approximately 2 mg/kg) and 125 p.p.m. p,p'-DDE (approximately 10 mg/kg) during the gestational and lactational period. Sexual maturation was fully developed in the rat female offspring perinatally exposed to DCB and/or p,p'-DDE through maternal exposure. The combined effect of DCB and p,p'-DDE was observed, and the ovarian weight was seen to decrease to approximately 80% of the control rat in matured female offspring following perinatal exposure to DCB and p,p'-DDE. This alteration might lead to reproductive dysfunction in matured female offspring. However, biological relevance of the alteration in the ovary remained uncertain in the present study. Further investigations concerning the reproductive function and mechanistic implication are required for elucidating the combined effects of perinatal exposure to DCB and p,p'-DDE on the later female reproductive system entirely.

Effects of perinatal combined exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) and tributyltin (TBT) on rat female reproductive system.

1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) is the most prevalent metabolite of DDT used as a pesticide before and tributyltin (TBT) compounds are used primarily as antifouling agents on vessels, ships, and aqua culture facilities, as they exert biocidal actions. Currently, p,p'-DDE and TBT are ubiquitously distributed in the environment and bio-accumulated in marine products, especially fish or shellfish. Thus, oral p,p'-DDE and TBT intake through marine products is demonstrated to be rather high in Japan. Consequently, the fetus and neonate will be exposed to p,p'-DDE and TBT via mother. Therefore, effects of perinatal combined exposure to p,p'-DDE and TBT on the female reproductive system after maturation have been investigated in rat female offspring of dams ingesting 125ppm p,p'-DDE (approximately 10mg/kg) and 25ppm TBT (approximately 2mg/kg) during the perinatal period from gestation to lactation. In the present study, no deleterious reproductive outcomes were recognized in p,p'-DDE and/or TBT-treated dams. In contrast, growth retardation had developed in rat female offspring following perinatal exposure to TBT and sustained even after cessation of exposures. Further, reduced ovarian weights with elevated serum follicle-stimulating hormone (FSH) concentrations were observed in the reproductive system of matured female offspring following perinatal exposure to TBT. At present, biological relevance of these alterations remains unknown, but there is a possibility that these alterations lead to reproductive malfunctions in matured female offspring.

Effects of perinatal combined exposure to 1,1-dichloro-2,2 bis (p-chlorophenyl) ethylene and tributyltin on male reproductive system.

Prenatal or early postnatal exposure to some synthetic chemicals may affect the later reproductive system of the offspring. There may also be unique responses observed due to exposure to combinations of chemicals that are not observed when the chemicals are present individually. 1,1-Dichloro-2,2 bis (p-chlorophenyl) ethylene (p,p'-DDE) is a persistent metabolite of DDT and tributyltin (TBT) compounds are used primarily as antifouling agents, as they exert biocidal actions. p,p'-DDE and TBT are ubiquitously distributed in the environment. Oral p,p'-DDE and TBT intake through marine products is demonstrated to be high in Japan. Consequently, the foetus and neonate are supposed to be exposed much more to p,p'-DDE and TBT via the maternal body. Therefore, effects of perinatal exposure to p,p'-DDE and/or TBT on the reproductive system after maturation have been investigated in rat male offspring of dams orally administered 125 ppm p,p'-DDE (approximately 10 mg/kg) and 25 ppm TBT (approximately 2 mg/kg) during the gestational and lactational period. In this study, growth retardation attributed to TBT has sustained in rat male offspring after perinatal exposure. However, perinatal exposure to p,p'-DDE and TBT failed to affect the male reproductive organs and sperm parameters in matured male offspring.

Normal Development of Reproductive System in Rat Male Offspring Following Perinatal Combined Exposure to p,p'-DDE and 1,4-Dichlorobenzene.

Prenatal or early postnatal exposure to some synthetic chemicals may affect the later reproductive system of the offspring, and there may also be unique responses observed due to exposure to combinations of chemicals that are not observed when the chemicals are present individually. Organochlorine compounds are ubiquitously distributed in the environment. p,p'-DDE (1,1-dichloro-2,2 bis (p-chlorophenyl) ethylene) is a persistent metabolite of DDT and 1,4-dichlorobenzene (DCB) is used as an air freshener or a moth repellent. Oral p,p'-DDE intake through marine products and DCB concentrations of residential air are demonstrated to be high in Japan. Consequently, the fetus and neonate are supposed to be exposed much more to p,p'-DDE and DCB via the maternal body. Therefore, effects of perinatal combined exposure to p,p'-DDE and DCB on the male reproductive system after maturation have been investigated in rat male offspring of dams ingesting these contaminants during the perinatal period from gestational day 1 to postpartum day 21. In this study, no deteriorated developmental effects have been observed in rat male offspring until maturation following oral administration of 125 ppm p,p'-DDE (approximately 10 mg/kg) and 25 ppm DCB (approximately 2 mg/kg) to dams. Further, no obvious effects of perinatal combined exposure to DCB and p,p'-DDE on the male reproductive organs and sperm parameters were observed in mature male offspring.

Effects of concurrent exposure to tributyltin and 1,1-dichloro-2,2 bis (p-chlorophenyl) ethylene (p,p'-DDE) on immature male Wistar rats.

Tributyltin and 1, 1-dichloro-2, 2 bis (p-chlorophenyl) ethylene (p,p'-DDE) have been ubiquitously distributed over the world. In Japan, p,p'-DDE and tributyltin are ingested through marine products, in which these substances are accumulated through bio-concentration and the food chain. However, the consequence of potential combined hazards of these substances remains unknown. Therefore, the effects of concurrent exposure to 125 ppm p,p'-DDE and 25 ppm tributyltin were investigated in immature male Wistar rats by oral administration during puberty. In this study, tributyltin promoted the growth of pubertal male rats, while p,p'-DDE itself did not affect the growth but inhibited the growth enhancement by tributyltin. Furthermore, tributyltin reduced thymus weight but p,p'-DDE also prevented this weight reduction. Neither development of male sexual accessory organs nor sexual maturation was affected even by concurrent exposure to p,p'-DDE and tributyltin. No significant changes of serum testosterone, luteinizing hormone, follicle-stimulating hormone concentrations, and epididymal sperm numbers were observed with the administration of p,p'-DDE and/or tributyltin. These results indicate that sexual maturation, male reproductive organ development and sperm production is scarcely affected in immature male Wistar rats even by concurrent exposure to p,p'-DDE and tributyltin at a daily dose of ca. 2 mg/kg tributyltin and 10 mg/kg p,p'-DDE. Moreover, the simultaneous administration of p,p'-DDE with tributyltin counterbalanced the effects that were attributed to tributyltin alone.

Effects of perinatal combined exposure to 1,4-dichlorobenzene and 1,1-dichloro-2, 2-bis (p-chlorophenyl) ethylene on rat male offspring.

1,4-Dichlorobenzene (DCB) is used as an air deodorant or a moth repellent and 1, 1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p,p'-DDE) is a persistent metabolite of 1, 1, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane (DDT) which was used as a pesticide before. DCB concentrations of residential air and oral p,p'-DDE intake through marine products are demonstrated to be very high in Japan and consequently, foetuses and neonates may be exposed much more to DCB and/or p,p'-DDE via the maternal body. It has recently been reported that DCB is oestrogenic and that p,p'-DDE is antiandrogenic. Therefore, the combined effects of perinatal exposure to DCB and p,p'-DDE have been investigated in rat male offspring of dams ingesting these contaminants during the perinatal period from gestational day 1 to postpartum day 21 for 42 days. In this study, no obvious developmental effects on male offspring have been recognized until 6 weeks of age, following oral administration of 25 ppm DCB (approximately 2 mg/kg) and/or 125 ppm p,p'-DDE (approximately 10 mg/kg) to dams. In contrast to female offspring, the thymus weight in male offspring was not affected by DCB at 6 weeks of age, but there might be sexual differences concerning the effects of DCB on the thymus.

Effects of perinatal combined exposure to 1,4-dichlorobenzene and 1,1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p,p'-DDE) on rat female offspring.

1,4-Dichlorobenzene (DCB) is used as an air freshener and a moth repellent and 1, 1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p,p'-DDE) is a persistent metabolite of 1, 1, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane (DDT) previously used as a pesticide. DCB concentrations of residential air and oral p,p'-DDE intake via marine products are demonstrated to be higher in Japan than elsewhere. Consequently, human foetuses and neonates may be exposed to DCB and p,p'-DDE via the mother. Therefore, the combined effects of DCB and p,p'-DDE have been investigated in rat female offspring of dams after ingestion of these contaminants. No deteriorated reproductive outcomes of dams and developmental effects on female offspring were observed following oral administration of 25 ppm DCB (approximately 2 mg/kg) and/or 125 ppm p,p'-DDE (approximately 10 mg/kg) to dams. In this study, the thymus weight of female offspring was preserved by DCB at 6 weeks of age though the biological relevance remains unknown. Simultaneous administration of p,p'-DDE with DCB inhibited this phenomenon, through a mechanism still to be elucidated.

Effects of perinatal simultaneous exposure to tributyltin (TBT) and p,p'-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene) on male offspring of Wistar rats.

p,p'-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene; DDE] and tributyltin (TBT) are ubiquitous in the environment and in Japan were shown to bioaccumulate in marine products. Thus these chemicals serve as a source of contaminant in the mammalian food chain. Fetuses and neonates through maternal ingestion may be exposed to DDE and TBT. Therefore, the effects of concurrent exposure to DDE and TBT were investigated in male Wistar rat offspring of dams ingesting these two contaminants. In this study, TBT suppressed the growth and delayed eye opening. However, both growth retardation and delayed eye opening produced by TBT failed to occur in the presence of DDE. Unexpectedly, the prostate weight of male rat offspring was significantly reduced with the administration of TBT but restored in the presence of DDE. These results indicate that TBT and DDE affected the development of male rat offspring following maternal exposure, and simultaneous administration of DDE prevented some of the observed effects of TBT, especially of an antagonistic nature, through a mechanism, still to be determined.

Systemic effects of orally administered p, p'-DDE on immature male Wistar rats during pubertal period.

Systemic effects of p, p'-DDE (1, 1-dichloro-2, 2 bis (p-chlorophenyl) ethylene; DDE) on immature male rats were investigated in pubertal Wistar rats after oral administration of DDE. Special rat chow containing 125 ppm DDE (approximately 10 mg/kg DDE) had been administered daily for 42 d since 6 wk of age and its effects had been observed until 12 wk of age. The administration of DDE did not produce any overt signs of toxicity. Neither physical development nor sexual maturation was affected, and serum biochemistry was not impaired at the dose used in this experiment. Moreover, the male reproductive organs and epididymal sperm count were not affected by the administration of DDE during the pubertal period. Our results showed that even immature male rats were resistant to DDE exposure at the daily dose of ca. 10 mg/kg, but metabolic and immunological changes still remained uncertain. Further investigation should be conducted to reveal all the effects of DDE on immature male rats.

Effects of simultaneous administration of tributyltin (TBT) and p,p(')-DDE on female offspring of Wistar rats.

p,p(')-DDE (DDE) and tributyltin (TBT) occur globally and in Japan were shown to bioaccumulate in marine products, thus serving as a source of contamination in the mammalian food chain. Consequently, fetuses and neonates, through maternal ingestion, may be exposed to DDE and TBT. Therefore, the effects of combined DDE and TBT were investigated in female Wistar rat offspring of dams ingesting these two contaminants. In this study, TBT suppressed the growth of female offspring and delayed eye opening. However, both growth retardation and delayed eye opening produced by TBT failed to occur in the presence of DDE. These results indicated that TBT or DDE affected the development of female rat offspring following maternal exposure and simultaneous administration of DDE prevented some of the observed effects of TBT through a mechanism that remains to be elucidated.

Systemic toxicity of p,p'-DDE in aged male Wistar rats following oral administration.

Systemic toxicity of p,p'-DDE (DDE) in aged male rats was investigated in Wistar rats by oral administration of DDE. About 10 mg/kg DDE had been daily administered for 28 days from 48 weeks to 52 weeks of age and its effects were observed subsequently. The administration of DDE did not give rise to any overt signs of toxicity. Male reproductive organs were not affected and serum biochemistry was not impaired at the dose of this experiment. Organ weights of the liver and spleen slightly increased and the thymus weight reduced with DDE administration. Serum total cholesterol and free T4 levels slightly decreased with DDE administration, albeit statistically insignificant. Our results indicated that even aged male rats were resistant to DDE exposure at the daily dose of ca. 10 mg/kg. However, metabolic and immunological changes still remained uncertain. Further investigation should be performed to reveal the entire effects of DDE on aged male rats.