Breast cancer poses a global health challenge, yet the influence of ethnicity on the tumor microenvironment (TME) remains understudied. In this investigation, we examined immune cell infiltration in 230 breast cancer samples, emphasizing diverse ethnic populations. Leveraging tissue microarrays (TMAs) and core samples, we applied multiplex immunofluorescence (mIF) to dissect immune cell subtypes across TME regions. Our analysis revealed distinct immune cell distribution patterns, particularly enriched in aggressive molecular subtypes triple-negative and HER2-positive tumors. We observed significant correlations between immune cell abundance and key clinicopathological parameters, including tumor size, lymph node involvement, and patient overall survival. Notably, immune cell location within different TME regions showed varying correlations with clinicopathologic parameters. Additionally, ethnicities exhibited diverse distributions of cells, with certain ethnicities showing higher abundance compared to others. In TMA samples, patients of Chinese and Caribbean origin displayed significantly lower numbers of B cells, TAMs, and FOXP3-positive cells. These findings highlight the intricate interplay between immune cells and breast cancer progression, with implications for personalized treatment strategies. Moving forward, integrating advanced imaging techniques, and exploring immune cell heterogeneity in diverse ethnic cohorts can uncover novel immune signatures and guide tailored immunotherapeutic interventions, ultimately improving breast cancer management.

The theory of immune regulation involves a homeostatic balance between T-helper 1 (Th1) and T-helper 2 (Th2) responses. The Th1 and Th2 theories were introduced in 1986 as a result of studies in mice, whereby T-helper cell subsets were found to direct different immune response pathways. Subsequently, this hypothesis was extended to human immunity, with Th1 cells mediating cellular immunity to fight intracellular pathogens, while Th2 cells mediated humoral immunity to fight extracellular pathogens. Several disease conditions were later found to tilt the balance between Th1 and Th2 immune response pathways, including HIV infection, but the exact mechanism for the shift from Th1 to Th2 cells was poorly understood. This review provides new insights into the molecular biology of HIV, wherein the HIV life cycle is discussed in detail. Insights into the possible mechanism for the Th1 to Th2 shift during HIV infection and the preferential infection of Th2 cells during the late symptomatic stage of HIV disease are also discussed.

Monocytes are key effectors in autoimmunity-related diseases in the central nervous system (CNS) due to the critical roles of these cells in the production of proinflammatory cytokines, differentiation of T-helper (Th) cells, and antigen presentation. The JAK-STAT signaling is crucial for initiating monocytes induced immune responses by relaying cytokines signaling. However, the role of this pathway in modulating the communication between monocytes and Th cells in the pathogenesis of multiple sclerosis (MS) is unclear. Here, we show that the JAK1/2/3 and STAT1/3/5/6 subtypes involved in the demyelination mediated by the differentiation of pathological Th1 and Th17 and the CNS-infiltrating inflammatory monocytes in experimental autoimmune encephalomyelitis (EAE), a model for MS. JAK inhibition prevented the CNS-infiltrating CCR2-dependent Ly6Chi monocytes and monocyte-derived dendritic cells in EAE mice. In parallel, the proportion of GM-CSF+CD4+ T cells and GM-CSF secretion were decreased in pathological Th17 cells by JAK inhibition, which in turns converted CNS-invading monocytes into antigen-presenting cells to mediate tissue damage. Together, our data highlight the therapeutic potential of JAK inhibition in treating EAE by blocking the GM-CSF-driven inflammatory signature of monocytes.

Aim: To explore the clinical implication of serum CDC42 in asthmatic children. Materials & methods: Serum CDC42 from 80 asthmatic children experiencing exacerbation, 80 asthmatic children in remission and 40 healthy controls was detected by ELISA. Results: CDC42 was highest in asthmatic children experiencing exacerbation followed by asthmatic children in remission and healthy controls (p < 0.001). Among asthmatic children experiencing exacerbation, CDC42 positively correlated with exacerbation severity (p = 0.011), Th2 (p = 0.017), TNF-α (p < 0.001), IL-6 (p = 0.009) and IL-8 (p = 0.008) and negatively correlated with Th1/Th2 ratio (p = 0.028). In asthmatic children in remission, CDC42 correlated with lower Th1/Th2 ratio (p = 0.028) and higher TNF-α (p = 0.026). In healthy controls, CDC42 showed no correlation with Th1/2 or inflammatory cytokines. Conclusion: Circulating CDC42 reflects exacerbation risk, Th1/2 imbalance and inflammation in asthmatic children.

OBJECTIVE: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) modulates antiviral immunity via T cells, but whether these cells are active or abundant in coronavirus disease 2019 (COVID-19) patients is unknown. The present study aimed to investigate the temporal shifting in the T-cell population and their subsets, T-Helper (Th) cell (CD4) and T-Cytotoxic (Tc) cell (CD8) in COVID-19 patients.
METHODS: Thirty confirmed COVID-19 patients (nasal swab reverse transcription-polymerase chain reaction (RT-PCR) confirmed) were enrolled. On the basis of oxygen saturation (SpO2) levels, patients were stratified into two categories: (i) mild (n=11) having fever and SpO2 level >95%, and (ii) severe (n=19) on the ventilator, and in the intensive care unit (ICU) as per the Indian Council of Medical Research (ICMR) guidelines. Thirty age-sex-matched controls without infectious diseases unrelated to COVID-19 were also enrolled in the study. Patients with inflammatory diseases and severe comorbidities that compromise immunity were excluded from the study. Immunophenotyping flow cytometry assay was used to evaluate T-cell viability, Th, and Tc cells population in mild and severe COVID-19 patients on day 1 (at admission) and day 4 (decreasing the infection load) in the second COVID-19 wave (variant: B.1.61).  Categorical variables were expressed as frequency and percentage and p-values were calculated by Chi-square test. All the variables were represented in median and Q1 (25 percentile) and Q3 (75 percentile). The Mann-Whitney test was used to compare the study groups. The Δ mean differences were calculated by using the Paired samples t-test. The statistically significant level was taken as p<0.05.
RESULTS: Hemoglobin, total leukocyte count (TLC), lymphocytes, monocytes, and eosinophils were significantly reduced in patients (p<0.05). A significant decrease of CD4 and CD8 cells in severe COVID-19 patients vs. controls (CD4, median 49; CD8, 40.12; p>0.05) was seen. Th-EM (effector memory)-Tim-3 (T-cell immunoglobulin domain and mucin domain 3)+ was significantly higher (p=0.002) however, Tc-EMRA (effector memory cells re-expressing)-Tim-3+, Tc-Naive-Tim-3+, Tc-EM-PD1+ and Tc-CM (central memory)-Tim-3+ significantly reduced (p<0.05) in mild COVID-19 patients than controls. Similarly, in severe COVID-19 patients, Th-EMRA-Tim-3+, Th-Naive-PD1+, Th-EM-PD1+, Th-EM-Tim 3+ and Th-CM-Tim-3+ showed a significant reduction (p<0.05) and Tc-EMRA-Tim-3+, Tc-Naive-Tim-3+, Tc-EM-PD1+, and Tc-CM-Tim-3+ showed similar results. In mild vs. severe group, decreased T-cells (p=0.001), Th-EMRA-Tim-3+ (p=0.024), and Th-Navie-Tim-3+ (p=0.005), and significantly increased (p<0.05) Tc-Naive-Tim3+ (p=0.001), Tc-EM-Tim-3+ (p=0.031), and Tc-CM-Tim-3+ (p=0.08) were observed. Severe COVID-19 patients showed a significant increase in Th-Naive-Tim3+ (day 4-day 1; δ43, p=0.019), Th-EM-Tim3+ (δ 16.24, p=0.033), and Th-CM-Tim3+ (δ 13.57, p=0.041).
CONCLUSIONS: T-cell populations and CD8 subset help to differentiate the mild and severe COVID-19 patients. Monitoring T cells, especially CD8 subset changes, has important implications for diagnosing and treating mild and severe patients being critically ill.

Cuminum cyminum L. (cumin) seeds are widely used as a spice. Although we previously reported that the aqueous extract of cumin seeds suppresses the degranulation of rat basophilic RBL-2H3 cells, it has not been clarified whether the extract alleviates actual allergy symptoms in vivo. Therefore, in this study, we investigated the effect of oral administration of cumin seed aqueous extract (CAE) in ovalbumin (OVA)-induced allergic rhinitis. BALB/c mice were randomly divided into the following three groups: control group (five mice), OVA group (five mice), and OVA + CAE group (five mice). Allergic rhinitis was induced by sensitization (intraperitoneal, 25 μg OVA and 1.98 mg aluminum hydroxide gel) followed by challenge (intranasal, 400 μg OVA). The oral administration of CAE (25 mg/kg) reduced the sneezing frequency of OVA-induced allergic rhinitis model mice. In addition to reducing the serum immunoglobulin E and IL-4 levels, the oral administration of CAE reduced the production of T-helper type-2 (Th2) cytokines (IL-4, IL-5, IL-10, and IL-13) in the splenocytes of the model mice. Furthermore, a significant increase in the ratio of Th1 to Th2 cells was observed in the CAE-administered group. Our findings suggest that the ingestion of CAE improves T cell balance, the dominant state of Th2, and alleviates allergic rhinitis symptoms.

This work aimed to investigate the role of long non-coding RNA (lncRNA) PCSK6-AS1 in inflammatory bowel disease (IBD). The levels of PCSK6-AS1 in human samples were detected, and its target protein HIPK2 was explored by protein mass spectrometry and ground select test (GST) method. Meanwhile, the HIPK2-STAT1 interaction relation was verified by pull-down assay. In the mouse model, Dextran Sulfate Sodium（DSS） was used to induce mouse colitis, then the effect of PCSK6-AS1 on mouse mucosal barrier was detected by immunohistochemical (IHC) staining, hematoxylin and eosin (H&E) staining, and the proportion of T-helper cells 1（Th1) cells was measured by flow cytometry (FCM). For in-vitro experiments, Th0 cells were used as the objects, and the effect of PCSK6-AS1 on Th1 differentiation was explored by FCM and enzyme-linked immunosorbent assay (ELISA). According to our results, the expression of PCSK6-AS1 in colitis tissues increased. PCSK6-AS1 interacted with HIPK2 to promote the expression of the latter, while HIPK2 promoted STAT1 phosphorylation to regulate Th1 differentiation. Th1 differentiation accelerated the mucosal barrier injury and aggravated the progression of colitis. In the Th0 model, PCSK6-AS1 promoted Th1 differentiation. In the animal model, PCSK6-AS1 enhanced Th1 differentiation in the tissues, decreased the tight junction (TJ) protein levels, and improved the mucosal barrier permeability. Suppressing PCSK6-AS1 and the HIPK2 inhibitor tBID decreased Th1 differentiation and tissue inflammation. According to our results, PCSK6-AS1 promotes Th1 cell differentiation via the HIPK2-STAT1 signaling, thus aggravating the chronic colitis-related mucosal barrier damage and tissue inflammation. PCSK6-AS1 has an important role in the occurrence and development of IBD.

Newborns are highly susceptible to infections; however, the underlying mechanisms that regulate the anti-microbial T-helper cells shortly after birth remain incompletely understood. To address neonatal antigen-specific human T-cell responses against bacteria, Staphylococcus aureus (S. aureus) was used as a model pathogen and comparatively analyzed in terms of the polyclonal staphylococcal enterotoxin B (SEB) superantigen responses. Here, we report that neonatal CD4 T-cells perform activation-induced events upon S. aureus/APC-encounter including the expression of CD40L and PD-1, as well as the production of Th1 cytokines, concomitant to T-cell proliferation. The application of a multiple regression analysis revealed that the proliferation of neonatal T-helper cells was determined by sex, IL-2 receptor expression and the impact of the PD-1/PD-L1 blockade. Indeed, the treatment of S. aureus-activated neonatal T-helper cells with PD-1 and PD-L1 blocking antibodies revealed the specific regulation of the immediate neonatal T-cell responses with respect to the proliferation and frequencies of IFNγ producers, which resembled in part the response of adults\' memory T-cells. Intriguingly, the generation of multifunctional T-helper cells was regulated by the PD-1/PD-L1 axis exclusively in the neonatal CD4 T-cell lineage. Together, albeit missing memory T-cells in neonates, their unexperienced CD4 T-cells are well adapted to mount immediate and strong anti-bacterial responses that are tightly controlled by the PD-1/PD-L1 axis, thereby resembling the regulation of recalled memory T-cells of adults.

Sepsis is a lethal clinical condition with dysregulated cluster of differentiation (CD) 4+ T cells that leads to inflammation and multiorgan injury. Low vitamin D levels are commonly seen in patients with sepsis. Obesity is a state with oxidative stress and chronic inflammation. Both obesity and low vitamin D levels are associated with adverse outcomes in patients with sepsis. This study investigated the effects of calcitriol on CD4+ T-cell polarization and kidney injury during sepsis.
Mice were fed a high-fat diet to induce obesity. One group of obese mice served as the control group and in the other two groups (SS and SD) were performed cecal ligation and puncture (CLP) to induce sepsis. Mice in the SS group were injected with saline and those in the SD group with calcitriol 1 h after CLP via tail vein. Mice with sepsis were euthanized at 12 h and 24 h after CLP, respectively.
Sepsis led to a decrease in circulating CD4+ T-cell percentage, and T helper (Th) 2, Th17, and regulatory T (Treg) cell percentages were upregulated. Compared with the SS group, the SD group maintained blood CD4+ T-cell levels, and were reduced the Th2 and Th17 percentages as well as the Th17:Treg ratio. Also, plasma levels of cathelicidin increased, but inflammatory chemokines and kidney injury markers were reduced. Higher arginase-1 and lower inducible nitric oxide synthase expressions in the SD group indicated M1 macrophage polarized toward the M2 type.
These findings suggest that intravenous calcitriol administration after sepsis modulates the homeostasis of CD4+ T-cell subpopulations associated with alleviating sepsis-induced kidney injury in obese mice.

Immune checkpoint inhibitor (ICI) therapy has revolutionized the breast cancer treatment landscape. However, ICI-induced systemic inflammatory immune-related adverse events (irAE) remain a major clinical challenge. Previous studies in our laboratory and others have demonstrated that a high-salt (HS) diet induces inflammatory activation of CD4+T cells leading to anti-tumor responses. In our current communication, we analyzed the impact of dietary salt modification on therapeutic and systemic outcomes in breast-tumor-bearing mice following anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) monoclonal antibody (mAb) based ICI therapy. As HS diet and anti-CTLA4 mAb both exert pro-inflammatory activation of CD4+T cells, we hypothesized that a combination of these would lead to enhanced irAE response, while low-salt (LS) diet through blunting peripheral inflammatory action of CD4+T cells would reduce irAE response. We utilized an orthotopic murine breast tumor model by injecting Py230 murine breast cancer cells into syngeneic C57Bl/6 mice. In an LS diet cohort, anti-CTLA4 mAb treatment significantly reduced tumor progression (day 35, 339 ± 121 mm3), as compared to isotype mAb (639 ± 163 mm3, p < 0.05). In an HS diet cohort, treatment with anti-CTLA4 reduced the survival rate (day 80, 2/15) compared to respective normal/regular salt (NS) diet cohort (8/15, p < 0.05). Further, HS plus anti-CTLA4 mAb caused an increased expression of inflammatory cytokines (IFNγ and IL-1β) in lung infiltrating and peripheral circulating CD4+T cells. This inflammatory activation of CD4+T cells in the HS plus anti-CTLA4 cohort was associated with the upregulation of inflammasome complex activity. However, an LS diet did not induce any significant irAE response in breast-tumor-bearing mice upon treatment with anti-CTLA4 mAb, thus suggesting the role of high-salt diet in irAE response. Importantly, CD4-specific knock out of osmosensitive transcription factor NFAT5 using CD4cre/creNFAT5flox/flox transgenic mice caused a downregulation of high-salt-mediated inflammatory activation of CD4+T cells and irAE response. Taken together, our data suggest that LS diet inhibits the anti-CTLA4 mAb-induced irAE response while retaining its anti-tumor efficacy.