Regulatory T (Treg) cells are a special immunosuppressive subset of cluster of differentiation 4-positive (CD4^+‍)‍-T lymphocytes and play a pivotal role in the establishment of immune homeostasis in vivo (Zhang et al., 2021). The transcription factor forkhead box protein P3 (Foxp3) is the master marker of Treg cells, which is highly expressed in Treg cells and is also essential for their suppressive function (Hori et al., 2003). In addition to Foxp3, other regulators of Treg cells have been discovered (Wu et al., 2017, 2022; Wu and Sun, 2023a, 2023b); however, a deeper understanding of the regulation of these cells is required.
T-Lymphocytes, Regulatory ; Gene Expression Regulation ; Forkhead Transcription Factors/metabolism*

Forkhead box (Fox) proteins play critical roles in the regulation of differentiation, proliferation, immunity and aging of cells. Most studies on Fox proteins are limited to cultured cells and rodent. The aim of the current study is to detect by immunohistrochemistry whether FoxO1, FoxO3a and FoxO4 proteins are localized in the stomach and intestine of the pig. The results showed that FoxO4 exists in the mucosa in all parts of the stomach and intestine; FoxO3a exists mainly in the lamina propria and muscularis of some parts. However, FoxO1 is not detectable in all parts of the stomach and intestine. Collectively, the results of the present study indicate that there exists a distinct expression pattern of Fox proteins, and that FoxO4 is a primary forkhead transcriptional factor localized in the gastrointestinal tracts of the pig.
Animals ; Female ; Forkhead Transcription Factors ; metabolism ; Gastrointestinal Tract ; metabolism ; Immunohistochemistry ; Male ; Sus scrofa ; metabolism ; Tissue Distribution

To explore the effectiveness and safety of a Chinese medicinal decoction Wuwei Xiaodu Drink (WWXDD) in inhibiting chronic osteomyelitis via regulatory T cells signaling. The effective constitutes of WWXDD and osteomyelitis related genes were screened. Target proteins were cross-validated using the Venny database. GO function and KEGG pathway analysis were performed for target proteins, while pharmacological network was constructed. The bone properties were analyzed by HE staining and the concentrations of immune factors were measured by ELISA. The expression of CTLA-4 and Foxp3 mRNA and STAT5, p-STAT5, CTLA-4 and Foxp3 protein were detected using Real-time PCR and Western blot, respectively. FACS was used to analyze the percentages of cells. A total of 117 genes overlapped between 785 target genes of the active compounds of WWXDD and 912 osteomyelitis related genes. Inflammation-related genes, including IL-6, TNFα, IL-1β and IL-2 showed high connection degree in the drug-compound-disease-target network. GO function and KEGG pathway analysis revealed that 117 intersection genes mainly enriched in virus infection related pathways, immune related pathways and chemokine signaling pathway. Furthermore, the development of chronic osteomyelitis was suppressed in model rats after treatment with WWXDD. Meanwhile, the concentrations of IL-2 and CD4⁺CD25⁺Foxp3 Treg percentages together with the levels of p-STAT5, CTLA-4 and Foxp3 were also down-regulated. Furthermore, IL-2 and WWXDD drug-containing serum exhibited opposite effects on regulating IL-2, IL-10, TGF-β1, Foxp3, CTLA4 and STAT5. In addition, a STAT5 phosphorylation inhibitor suppressed the expression of Foxp3 and CTLA-4. WWXDD can treat chronic osteomyelitis through suppressing the main regulating factors of Tregs and interfere its immunodepression. Our results bring a new solution for chronic osteomyelitis.
Animals ; Forkhead Transcription Factors/metabolism* ; Interleukin-2/metabolism* ; Osteomyelitis/metabolism* ; Rats ; STAT5 Transcription Factor/metabolism* ; Signal Transduction ; T-Lymphocytes, Regulatory

OBJECTIVETo review the current research into Foxp3(+) regulatory T cells (Treg) cell surface molecules, plasticity of Treg cells and mechanisms of Treg cell suppression and to explore the possibilities to interfere in Treg cell suppression of anti-tumor immunity.

DATA SOURCESA literature search of all English articles was performed on the online electronic PubMed database dated 1995 to 2010. The keywords searched included: CD4(+)CD25(+)Foxp3(+) regulatory T lymphocytes, cancer, and immunotherapy. After finding relevant articles within these search limits, a manual search was conducted through the references from these articles.

STUDY SELECTIONArticles regarding the role of Treg cells in tumor immunity and the utility of Treg cells in tumor immunotherapy.

RESULTSThe results show that significant numbers of Treg cells are found in many tumors and it has been shown that the number of tumor infiltrating Treg cells correlates with adverse clinic outcomes. Treg cells are emerging as a key component of acquired tolerance to tumors.

CONCLUSIONSSeveral mechanisms of immunosuppression can be mediated by Treg cell function. Distinct immunosuppressive molecules expressed by Treg cells or diverse molecules related to Treg induction or migration represent potential drug targets for cancer immunotherapy.

Forkhead Transcription Factors ; metabolism ; Humans ; Immunosuppression ; methods ; Immunotherapy ; methods ; Neoplasms ; immunology ; therapy ; T-Lymphocytes, Regulatory ; metabolism

The Forkhead box class O proteins (FOXOs) family consists of highly conserved transcription factors, including FOXO1, FOXO3, FOXO4 and FOXO6. Each member of the FOXOs family is ubiquitously expressed and involved in regulating many biological activities such as tumor cell proliferation, apoptosis, migration and oxidative stress. The activity of FOXOs is mainly regulated by post-translational modification, and its inactivation is mainly mediated by the over-activation of its upstream modifying enzymes, which provides a possibility to use drugs to recover its activity. It is worth noting that FOXOs can not only inhibit, but also promote the occurrence and development of human tumors due to the complex effects of FOXOs. This review will summarize the structure and activity regulation of FOXOs, and discuss their tumor inhibiting effects by limiting cell proliferation and inducing apoptosis, as well as their tumor promoting effects by maintaining cell homeostasis, promoting metastasis and inducing drug resistance, so as to provide new ideas for the pathological research of related diseases and open up new ways to promote broader prevention and treatment strategies.
Humans ; Neoplasms ; Forkhead Transcription Factors/metabolism* ; Protein Processing, Post-Translational ; Oxidative Stress ; Apoptosis

PURPOSE: Recently, Forkhead box M1 (FoxM1) was reported to be correlated with lung maturation and expression of surfactant proteins (SPs) in mice models. However, no study has been conducted in rabbit lungs despite their high homology with human lungs. Thus, we attempted to investigate serial changes in the expressions of FoxM1 and SP-A/B throughout lung maturation in rabbit fetuses. MATERIALS AND METHODS: Pregnant New Zealand White rabbits were grouped according to gestational age from 5 days before to 2 days after the day of expected full term delivery (F5, F4, F3, F2, F1, F0, P1, and P2). A total of 64 fetuses were enrolled after Cesarean sections. The expressions of mRNA and proteins of FoxM1 and SP-A/B in fetal lung tissue were tested by quantitative reverse-transcriptase real-time PCR and Western blot. Furthermore, their correlations were analyzed. RESULTS: The mRNA expression of SP-A/B showed an increasing tendency positively correlated with gestational age, while the expression of FoxM1 mRNA and protein decreased from F5 to F0. A significant negative correlation was found between the expression levels of FoxM1 and SP-A/B (SP-A: R=-0.517, p=0.001; SP-B: R=-0.615, p<0.001). CONCLUSION: Preterm rabbits demonstrated high expression of FoxM1 mRNA and protein in the lungs compared to full term rabbits. Also, the expression of SP-A/B was inversely related with serial changes in FoxM1 expression. This is the first report to suggest an association between FoxM1 and expression of SP-A/B and lung maturation in preterm rabbits.
Animals ; Blotting, Western ; Female ; Fetus/*metabolism ; Forkhead Transcription Factors/*metabolism ; Lung/*metabolism ; Pregnancy ; Pulmonary Surfactant-Associated Protein A/genetics/*metabolism ; Rabbits

Continuous self-renewal and differentiation of spermatogonial stem cells (SSCs) is vital for maintenance of adult spermatogenesis. Although several spermatogonial stem cell regulators have been extensively investigated in rodents, regulatory mechanisms of human SSC self-renewal and differentiation have not been fully established. We analyzed single-cell sequencing data from the human testis and found that forkhead box P4 (FOXP4) expression gradually increased with development of SSCs. Further analysis of its expression patterns in human testicular tissues revealed that FOXP4 specifically marks a subset of spermatogonia with stem cell potential. Conditional inactivation of FOXP4 in human SSC lines suppressed SSC proliferation and significantly activated apoptosis. FOXP4 expressions were markedly suppressed in tissues with dysregulated spermatogenesis. These findings imply that FOXP4 is involved in human SSC proliferation, which will help elucidate on the mechanisms controlling the fate decisions in human SSCs.
Adult ; Humans ; Male ; Cell Differentiation ; Cell Proliferation ; Forkhead Transcription Factors/metabolism* ; Spermatogenesis/genetics* ; Spermatogonia/metabolism* ; Stem Cells/metabolism* ; Testis/metabolism*

OBJECTIVE: To investigate the expression of Forkhead Box M1 transcription factor (FoxM1) mRNA and protein in laryngeal squamous cell carcinoma (LSCC) and its clinical significance. METHOD: Immunohistochemistry was used to examine the expression of FoxM1 in 89 LSCC tissues, 89 adjacent normal tissues and 20 laryngeal papilloma (LP) tissues. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to examine the expression of FoxM1 in 20 LSCC tissues, 20 LP tissues and 20 adjacent normal tissues. The relationship between FoxM1 expression and the clinicopathological parameters of LSCC were analyzed. RESULT: FoxM1 mRNA and protein expression were gradually decreased from LSCC to LP and normal tissues. The difference was significant (P<0.05). There was a significantly correlation between FoxM1 and histologic differentiation, T stage, lymph node metastasis and clinical stage. Tumors with poorer differentiation, in higher T stage, with lymph node metastasis or in higher clinical stage presented higher FoxM1 expression than tumors with better differentiation, in lower T stage, without lymph node metastasis or in lower clinical stage (P<0.05). The positive expression of FoxM1 was not related with the age, gender or primary site of LSCC patients (P>0.05). CONCLUSION The up-regulation of FoxM1 may play an important role in the invasion and metastasis of LSCC.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Female ; Forkhead Box Protein M1 ; Forkhead Transcription Factors ; metabolism ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Prognosis

Plateau zokor (Myospalax baileyi) is a subterranean mammal. Plateau zokor has high learning and memory ability, and can determine the location of blocking obstacles in their tunnels. Forkhead box p2 (FOXP2) is a transcription factor implicated in the neural control of orofacial coordination and sensory-motor integration, particularly with respect to learning, memory and vocalization. To explore the association of foxP2 with the high learning and memory ability of plateau zokor, the cDNA of foxP2 of plateau zokor was sequenced; by using plateau pika as control, the expression levels of foxP2 mRNA and FOXP2 protein in brain of plateau zokor were determined by real-time PCR and Western blot, respectively; and the location of FOXP2 protein in the brain of plateau zokor was determined by immunohistochemistry. The result showed that the cDNA sequence of plateau zokor foxP2 was similar to that of other mammals and the amino acid sequences showed a relatively high degree of conservation, with the exception of two particular amino acid substitutions [a Gln (Q)-to-His (H) change at position 231 and a Ser (S)-to-Ile (I) change at position 235]. Higher expression levels of foxP2 mRNA (3-fold higher) and FOXP2 protein (>2-fold higher) were detected in plateau zokor brain relative to plateau pika brain. In plateau zokor brain, FOXP2 protein was highly expressed in the cerebral cortex, thalamus and the striatum (a basal ganglia brain region). The results suggest that the high learning and memory ability of plateau zokor is related to the high expression levels of foxP2 in the brain.
Amino Acid Sequence ; Amino Acid Substitution ; Animals ; Brain ; metabolism ; Forkhead Transcription Factors ; metabolism ; Lagomorpha ; physiology ; Learning ; Memory ; RNA, Messenger

Adaptation of the maternal immune response to accommodate the semi-allogeneic fetus is necessary for pregnancy success, and disturbances in maternal tolerance are implicated in miscarriage. FOXP3, a member of the X chromosome-encoded forkhead transcription factor family, is indispensable for the differentiation of regulatory T cells. Regulatory T cells (CD4+ CD25+ FOXP3+ Treg) are pivotal to the maintenance of self-tolerance and the control of immune homeostasis. Many studies show that CD4+ CD25+ FOXP3+ Treg cells are essential for maternal tolerance of the conceptus. Treg cells accumulate in the decidua and are elevated in maternal blood from early in the first trimester. Inadequate expression of FOXP3 is associated with recurrent spontaneous abortion, unexplained infertility and recurrent implantation failure. CD4+ CD25+ FOXP3+ Treg cells offer an attractive target for treatment of auto-immune disease and allograft tolerance and might become a powerful new tool for the treatment of fertility pathologies stemming from disturbances in immune tolerance. This paper reviews the structure, function, expression regulation of FOXP3 and its relation with reproduction.
Abortion, Habitual ; etiology ; Female ; Forkhead Transcription Factors ; metabolism ; Humans ; Immune Tolerance ; Pregnancy ; immunology ; T-Lymphocytes, Regulatory ; immunology