BACKGROUND: The costimulatory molecule 4-1BB, a member of nerve growth factor receptor/tumor necrosis factor (NGFR/TNFR) super family, is involved in cell survival and death. METHODS: In this study, female C57BL/6 (H-2(b)) mice were used as a recipient, and DBA/2 (H-2(d)) as a donor to assess a mixed lymphocyte reaction (MLR) and CTL response in vitro, and skin graft survival. IL-2, IFN level was measured by ELISA. RESULTS: Mixed lymphocyte reaction (MLR) analysis showed that 4-1BB- deficient responder cells showed enhanced cellular proliferation over littermate controls. In contrast, IL-2 production was diminished only in 4-1BB knockout cultures. The IFN expression, on the other hand, was comparable between the groups. When female C57BL/6 (H-2(b)) mice were grafted with the trunk skin of DBA/2 (H-2d) mice, the in vivo tissue destruction of 4-1BB-deficient mice was not distinct from the normal littermates. CONCLUSION: These data suggest that 4-1BB is critical for the induction of alloreactive responses in vitro but 4-1BB alone could not change the course of skin rejection in vivo.
Allografts* ; Animals ; Cell Proliferation ; Cell Survival ; Enzyme-Linked Immunosorbent Assay ; Female ; Graft Survival ; Hand ; Humans ; Interleukin-2 ; Lymphocyte Culture Test, Mixed ; Mice* ; Necrosis ; Nerve Growth Factor ; Skin* ; Tissue Donors ; Transplants

BACKGROUND: The costimulatory molecule 4-1BB, a member of nerve growth factor receptor/tumor necrosis factor (NGFR/TNFR) super family, is involved in cell survival and death. METHODS: In this study, female C57BL/6 (H-2(b)) mice were used as a recipient, and DBA/2 (H-2(d)) as a donor to assess a mixed lymphocyte reaction (MLR) and CTL response in vitro, and skin graft survival. IL-2, IFN level was measured by ELISA. RESULTS: Mixed lymphocyte reaction (MLR) analysis showed that 4-1BB- deficient responder cells showed enhanced cellular proliferation over littermate controls. In contrast, IL-2 production was diminished only in 4-1BB knockout cultures. The IFN expression, on the other hand, was comparable between the groups. When female C57BL/6 (H-2(b)) mice were grafted with the trunk skin of DBA/2 (H-2d) mice, the in vivo tissue destruction of 4-1BB-deficient mice was not distinct from the normal littermates. CONCLUSION: These data suggest that 4-1BB is critical for the induction of alloreactive responses in vitro but 4-1BB alone could not change the course of skin rejection in vivo.
Allografts* ; Animals ; Cell Proliferation ; Cell Survival ; Enzyme-Linked Immunosorbent Assay ; Female ; Graft Survival ; Hand ; Humans ; Interleukin-2 ; Lymphocyte Culture Test, Mixed ; Mice* ; Necrosis ; Nerve Growth Factor ; Skin* ; Tissue Donors ; Transplants

Purpose: Recently, there has been an increasing number of kickboard injuries at our orthopedic clinic and emergency room. Therefore, this study is to identify the incidence and characteristics of nonmotorized and electric kickboard injuries with emergency room surveillance. Methods: Between August 2018 and January 2021, patients who visited the emergency room of a tertiary hospital with nonmotorized and electric kickboard injuries were included. The incidence, severity, and characteristics were analyzed. Results: There were a total of 204 patients who visited our emergency room during the study period. There were 139 nonmotorized kickboard injuries with 115 minor, 11 moderate, and 13 severe injuries. Fifty-six electric kickboard injuries were 47 minor, one moderate, and eight severe injuries. The incidence of injury depended on-site and was as follows: face and head (63.7%), upper extremity, lower extremity, abdomen and chest, and spine. Conclusion Face and head injuries were the most common injuries in body part, while minor trauma was the most common diagnosis. With the increasing incidence of kickboard injuries, we should be more mindful that protective equipment and safety rules may be necessary.

4-1BB, a member of the tumor necrosis factor receptor (TNFR) superfamily, is a major costimulatory receptor that is rapidly expressed on the surface of CD4+ and CD8+ T cells after antigen- or mitogen-induced activation. The interaction of 4-1BB with 4-1BBL regulates immunity and promotes the survival and expansion of activated T cells. In this study, the expression of 4-1BB and 4-1BBL was examined during regeneration of the murine thymus following acute cyclophosphamide-induced involution. Four-color flow cytometry showed that 4-1BB and 4-1BBL were present in the normal thymus and were preferentially expressed in the regenerating thymus, mainly in CD4+CD8+ double-positive (DP) thymocytes. Furthermore, the CD4loCD8lo, CD4+CD8lo and CD4loCD8+ thymocyte subsets, representing stages of thymocyte differentiation intermediate between DP and single-positive (SP) thymocytes, also expressed 4-1BB and 4-1BBL during thymus regeneration but to a lesser degree. Interestingly, the 4-1BB and 4-1BBL positive cells among the CD4+CD8+ DP thymocytes present during thymus regeneration were TCR(hi) and CD69+ unlike the corresponding controls. Moreover, the 4-1BB and 4-1BBL positive cells among the intermediate subsets present during thymus regeneration also exhibited TCRhi/int and CD69+/int phenotypes, indicating that 4-1BB and 4-1BBL are predominantly expressed by the positively selected population of the CD4+CD8+ DP and the intermediate thymocytes during thymus regeneration. RT-PCR and Western blot analyses confirmed the presence and elevated levels of 4-1BB and 4-1BBL mRNA and protein in thymocytes during thymus regeneration. We also found that the interaction of 4-1BB with 4-1BBL promoted thymocyte adhesion to thymic epithelial cells. Our results suggest that 4-1BB and 4-1BBL participate in T lymphopoiesis associated with positive selection during recovery from acute thymic involution.
4-1BB Ligand/genetics/*metabolism ; Animals ; Antigens, CD137/genetics/*metabolism ; CD4-Positive T-Lymphocytes/cytology/metabolism ; CD8-Positive T-Lymphocytes/cytology/metabolism ; Cell Adhesion ; Cell Differentiation ; Cell Line ; Cells, Cultured ; Cyclophosphamide/pharmacology ; Epithelial Cells/cytology ; Gene Expression Regulation ; Immunosuppressive Agents/pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; RNA, Messenger/genetics ; *Regeneration ; T-Lymphocytes/*cytology/metabolism ; Thymus Gland/*cytology/drug effects/*physiology