The Function of Memory CD8+ T Cells in Immunotherapy for Human Diseases

Memory T (Tm) cells protect against Ags that they have previously contacted with a fast and robust response. Therefore, developing long-lived Tm cells is a prime goal for many vaccines and therapies to treat human diseases. The remarkable characteristics of Tm cells have led scientists and clinicians to devise methods to make Tm cells more useful. Recently, Tm cells have been highlighted for their role in coronavirus disease 2019 vaccines during the ongoing global pandemic. The importance of Tm cells in cancer has been emerging. However, the precise characteristics and functions of Tm cells in these diseases are not completely understood. In this review, we summarize the known characteristics of Tm cells and their implications in the development of vaccines and immunotherapies for human diseases. In addition, we propose to exploit the beneficial characteristics of Tm cells to develop strategies for effective vaccines and overcome the obstacles of immunotherapy.

Effect of Human or Mouse IL-7 on the Homeostasis of Porcine T Lymphocytes

Due to the inconsistent fluctuation of blood supply for transfusion, much attention has been paid to the development of artificial blood using other animals. Although mini-pigs are candidate animals, contamination of mini-pig T cells in artificial blood may cause a major safety concern. Therefore, it is important to analyze the cross-reactivity of IL-7, the major survival factor for T lymphocytes, between human, mouse, and mini-pig. Thus, we compared the protein sequences of IL-7 and found that porcine IL-7 was evolutionarily different from human IL-7. We also observed that when porcine T cells were cultured with either human or mouse IL-7, these cells did not increase the survival or proliferation compared to negative controls. These results suggest that porcine T cells do not recognize human or mouse IL-7 as their survival factor.

Effect of Human or Mouse IL-7 on the Homeostasis of Porcine T Lymphocytes

Due to the inconsistent fluctuation of blood supply for transfusion, much attention has been paid to the development of artificial blood using other animals. Although mini-pigs are candidate animals, contamination of mini-pig T cells in artificial blood may cause a major safety concern. Therefore, it is important to analyze the cross-reactivity of IL-7, the major survival factor for T lymphocytes, between human, mouse, and mini-pig. Thus, we compared the protein sequences of IL-7 and found that porcine IL-7 was evolutionarily different from human IL-7. We also observed that when porcine T cells were cultured with either human or mouse IL-7, these cells did not increase the survival or proliferation compared to negative controls. These results suggest that porcine T cells do not recognize human or mouse IL-7 as their survival factor.

The Roles of CCR7 for the Homing of Memory CD8+ T Cells into Their Survival Niches

Memory CD8+ T cells in the immune system are responsible for the removal of external Ags for a long period of time to protect against re-infection. Naïve to memory CD8+ T cell differentiation and memory CD8+ T cell maintenance require many different factors including local environmental factors. Thus, it has been suggested that the migration of memory CD8+ T cells into specific microenvironments alters their longevity and functions. In this review, we have summarized the subsets of memory CD8+ T cells based on their migratory capacities and described the niche hypothesis for their survival. In addition, the basic roles of CCR7 in conjunction with the migration of memory CD8+ T cells and recent understandings of their survival niches have been introduced. Finally, the applications of altering CCR7 signaling have been discussed.

Decreased Expression of Sphingosine-1-Phosphate Receptor 1 in the Blood Leukocyte of Rheumatoid Arthritis Patients

Sphingosine-1-phosphate (S1P) plays an important role in trafficking leukocytes and developing immune disorders including autoimmunity. In the synovium of rheumatoid arthritis (RA) patients, increased expression of S1P was reported, and the interaction between S1P and S1P receptor 1 (S1P1) has been suggested to regulate the expression of inflammatory genes and the proliferation of synovial cells. In this study, we investigated the level of S1P1 mRNA expression in the blood leukocytes of RA patients. In contrast to the previous reports, the expression level of this gene was not correlated to their clinical scores, disease durations and ages. However, S1P1 was transcribed at a significantly lower level in the circulating leukocytes of RA patients when compared to age-, and sex-matched healthy controls. Since these data may suggest the participation of S1P1, further studies are needed to determine the role of this receptor in the pathogenesis of RA.

Polyvinylidene Fluoride Alters Inflammatory Responses by Activation-induced Cell Death in Macrophages

Carbon nanotubes (CNTs) are nanomaterials that have been employed in generating diverse materials. We previously reported that CNTs induce cell death in macrophages, possibly via asbestosis. Therefore, we generated CNT-attached polyvinylidene fluoride (PVDF), which is an established polymer in membrane technology, and then examined whether CNT-attached PVDF is immunologically safe for medical purposes compared to CNT alone. To test this, we treated RAW 264.7 murine macrophages (RAW cells) with CNT-attached PVDF and analyzed the production of nitric oxide (NO), a potent proinflammatory mediator, in these cells. RAW cells treated with CNT-attached PVDF showed reduced NO production in response to lipopolysaccharide. However, the same treatment also decreased the cell number suggesting that this treatment can alter the homeostasis of RAW cells. Although cell cycle of RAW cells was increased by PVDF treatment with or without CNTs, apoptosis was enhanced in these cells. Taken together, these results indicate that PVDF with or without CNTs modulates inflammatory responses possibly due to activation-induced cell death in macrophages.

A Case of Mental Retardation with Paraphilia Treated with Depot Leuprorelin

Paraphilia is a psychiatric disease that has been difficult to cure. However, recently developed therapeutic methods hold promise. The patient was a 20-yr-old male with chief complaints of continuous masturbation, genital exposure, and aggressive behavior that started 2 yr ago. We administered leuprorelin 3.6 mg intramuscular injection per month, a depot gonadotrophin-releasing hormone analogue, to this patient who a severe mentally retardation with paraphilia. The clinical global impression (CGI)-severity, CGI-improvement and aberrant behavior checklist were performed. After one month, we observed significant improvement in symptoms, such as decreases of abnormal sexual behavior and sexual desire. The GnRH analogues are suggested to be used as an alternative or supplementary therapeutic method for sexual offenders after clinical studies.

D8/17 Expression on B Lymphocytes of Children and Adolescents with Tic Disorder

OBJECTIVES: It has been reported that higher percentage of B cells react with monoclonal D8/17 antibody in patients with rheumatic fever, childhood onset obsessive-compulsive disorder, Tourette's disorder, or prepubertal anorexia nervosa. The purpose of this study is to replicate the previous studies in a Korean young population with tic disorder and to identify any relationship between D8/17 and clinical symptoms. METHODS: The binding of D8/17 to B cells was determined in patients with tic disorder (N=21) and healthy controls (N=9) by Fluorescence-Activated Cell Sorter analysis. RESULTS: In the sample examined by this study, the average percentage of B cells expressing D8/17 in tic disorder was 2.05%; healthy controls was 3.15%. No statistically significant differences were found in the mean percentages of D8/17 between the two groups. CONCLUSION: The expression of D8/17 in B cells was very low in this study. No subjects with tic disorder or healthy controls was above 12% in D8/17 positive proportion. Further studies, including higher number of patients and control group members, should be performed.

Environmental Risk Factors in Tic Disorders

Tic disorders, including Tourette syndrome, are known as neurobiologic disorders and as such, much emphasis has been placed on isolating genetic determinants. Although previous reports involving studies of discordance among monozygotic twins have shown the importance of genetic predisposition, they have also supported a role for environmental factors in the development of tic disorders. Therefore, it is important to consider that both genetic and environmental factors contribute to their clinical expression. The goal of this article was to review recent reports regarding the role of environmental factors in development and progression of tics. Specific environmental factors associated either with a more severe course of illness or improved outcomes were discussed. Given that accumulating evidence had suggested the usefulness of behavior therapies in the suppression of tic disorders, particular emphasis was placed on the impact of several contextual factors.