Breaking Barriers: The Promise and Challenges of Immune Checkpoint Inhibitors in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a highly aggressive malignancy with pronounced immunogenicity, exhibiting rapid proliferation and immune cell infiltration into the tumor microenvironment. TNBC's heterogeneity poses challenges to immunological treatments, inducing resistance mechanisms in the tumor microenvironment. Therapeutic modalities, including immune checkpoint inhibitors (ICIs) targeting PD-1, PD-L1, and CTLA-4, are explored in preclinical and clinical trials. Promising results emerge from combining ICIs with anti-TGF-ß and VISTA, hindering TNBC tumor growth. TNBC cells employ complex evasion strategies involving interactions with stromal and immune cells, suppressing immune recognition through various cytokines, chemokines, and metabolites. The recent focus on unraveling humoral and cellular components aims to disrupt cancer crosstalk within the tumor microenvironment. This review identifies TNBC's latest resistance mechanisms, exploring potential targets for clinical trials to overcome immune checkpoint resistance and enhance patient survival rates.

Cancer Resistance to Immunotherapy: Comprehensive Insights with Future Perspectives.

Cancer immunotherapy is a type of treatment that harnesses the power of the immune systems of patients to target cancer cells with better precision compared to traditional chemotherapy. Several lines of treatment have been approved by the US Food and Drug Administration (FDA) and have led to remarkable success in the treatment of solid tumors, such as melanoma and small-cell lung cancer. These immunotherapies include checkpoint inhibitors, cytokines, and vaccines, while the chimeric antigen receptor (CAR) T-cell treatment has shown better responses in hematological malignancies. Despite these breakthrough achievements, the response to treatment has been variable among patients, and only a small percentage of cancer patients gained from this treatment, depending on the histological type of tumor and other host factors. Cancer cells develop mechanisms to avoid interacting with immune cells in these circumstances, which has an adverse effect on how effectively they react to therapy. These mechanisms arise either due to intrinsic factors within cancer cells or due other cells within the tumor microenvironment (TME). When this scenario is used in a therapeutic setting, the term "resistance to immunotherapy" is applied; "primary resistance" denotes a failure to respond to treatment from the start, and "secondary resistance" denotes a relapse following the initial response to immunotherapy. Here, we provide a thorough summary of the internal and external mechanisms underlying tumor resistance to immunotherapy. Furthermore, a variety of immunotherapies are briefly discussed, along with recent developments that have been employed to prevent relapses following treatment, with a focus on upcoming initiatives to improve the efficacy of immunotherapy for cancer patients.

Clinical Practicum Assessment for Biomedical Science Program from Graduates' Perspective.

The clinical practicum for biomedical science students aims to provide graduates with the knowledge and skills required to work in diagnostic laboratory settings. This study examines graduates' perspectives on content, teachers and clinical training and their satisfaction rates based on the skills gained during training. The study was conducted on females who graduated from Qatar University between 2015 and 2020. We used a previously validated questionnaire called CPAT-QU. Telephonic interviews were conducted and were analyzed using SPSS. The results showed a high satisfaction rate, of 80%, for the content and organization of the clinical training. The participants' main concerns included the evaluation criteria, as 8.7% were not satisfied. The students suggested increasing the length of the training in order to obtain experience that was more practical. The students' satisfaction with the teachers was 70% in terms of their attitude, command of knowledge and ability to convey knowledge. In total, 69.5% of the graduates claimed that their instructors were interested in teaching and 4.4% claimed their instructors conveyed disinterest in teaching. The Qatar University graduates were satisfied with the content of their clinical training. However, they reported some gaps in this training. Identifying these gaps will help in restructuring clinical training to improve student experience.

The crosstalk between H. pylori virulence factors and the PD1:PD-L1 immune checkpoint inhibitors in progression to gastric cancer.

BACKGROUND: The progression to gastric cancer has been linked to chronic infection with Helicobacter pylori (H. pylori). Immune checkpoint inhibitors (programmed cell death -1, PD-1; programmed cell death -ligand 1, PD-L1) have a role in cancer immune escape. The relationship between H. pylori virulence factors with PD-1, PD-L1 T helper 1 (Th1), T helper 17 (Th17), and regulatory T cell (Treg) response genes, has not been thoroughly investigated in the development of gastric cancer. Therefore, we evaluated how H. pylori virulence factors influence the expression levels of immune-related genes in the development of gastric immunopathology. METHODS: A total of 92 gastric tissues of normal controls and patients with gastritis, gastric ulcer, and gastric cancer were examined for the expression of immune-checkpoint inhibitor genes (PD-1 PD-L1), Th1 (interferon- γ, IFN-γ), Th17 (interleukin- 17, IL-17, Retinoic-acid-receptor- related orphan nuclear receptor gamma t, RORγ-t), and Treg (Forkhead box P3, FOXP3) response genes with quantitative real-time PCR (qRT-PCR). Furthermore, correlation of H. pylori virulence factors' (cytotoxin-associated gene A, cagA; vacuolating cytotoxin gene A, vacA (s1,s2,m1,m2); blood group antigen-binding adhesin gene A, babA, duodenal ulcer promoting gene A, dupA; the putative neuraminyllactose-binding hemagglutinin homolog, hpaA; neutrophil-activating protein A napA; outer inflammatory protein A, oipA; urease A, ureA; and urease B, ureB) genotypes with a degree of inflammation and density of H. pylori were investigated. Next, the relationship between H. pylori virulence factors and immune-checkpoint inhibitor genes, and T-cell response genes was evaluated. Eventually, a decision tree model was developed to determine the clinical outcome of patients using expression data. RESULTS: The intensity of PD-1 and PD-L1 mRNA expression was increased significantly in gastric tissue of patients with gastric ulcer (PD-1: 2.3 fold, p=0.01; PD-L1: 2.1 fold, p=0.004), and gastric cancer (PD-1: 2 fold, p= 0.04; PD-L1: 1.8 fold, p=0.05) compared with control subjects. Also, PD-1: PD-L1 expression was significantly higher in patients with gastritis, who were infected with a marked density of H. pylori compared with its mildly infected counterparts. Furthermore, a novel negative correlation was found between PD-1 (r= -0.43) and PD-L1 (r= -0.42) with FOXP3 in patients with gastritis. CagA-positive H. pylori strain's negative association with PD-L1 expression (r=-0.34) was detected in patients with gastritis. Interestingly, PD-1 mRNA expression correlated positively with vacA s2/m2, in gastritis (r=0.43) and ulcer (r=0.43) patients. Furthermore, PD-1: PDL1 expression negatively correlated with vacA m1/m2 (r=-0.43 for PD-1; r=-0.38 for PD-L1) in gastritis patients. Moreover, an inverse correlation of PDL1 was present with vacA m1 (r=0.52) and vacA s1/m1 (r=0.46) versus vacA m2 (r=-0.44) and vacA m1 (r=0.52) and vacA s1/m2 (r=-0.14) in ulcer patients, respectively. Also, a correlation of vacA m2 (r=-0.47) and vacA s1/s2 (r= 0.45) with PD-1 was detected in ulcer patients. In addition, a novel negative correlation between FOXP3 mRNA levels and napA was shown in patients with gastritis and ulcer (r=-0.59). Finally, a computer-based model that was developed showed that knowing the expression levels of PD-L1, RORγ-t, and vacA s1/m2 would be useful to detect the clinical outcome of a patient. CONCLUSION: Our results suggested that PD-1:PD-L1 immune checkpoint inhibitors were increased in gastric pre-cancerous lesions that progress to gastric cancer. Herein, we report the relationship between H. pylori virulence factors and expression of host immune checkpoint inhibitors for diagnostic prediction of gastric malignancies using computer-based models.

Bacterially activated B-cells drive T cell differentiation towards Tr1 through PD-1/PD-L1 expression.

Regulatory B cells (Bregs) play a crucial role in immunological tolerance primarily through the production of IL-10 in many diseases including autoimmune disorders, allergy, infectious diseases, and cancer. To date, various Breg subsets with overlapping phenotypes have been identified. However, the roles of Bregs in Helicobacter infection are largely unknown. In the present study, we investigate the phenotype and function of Helicobacter -stimulated B cells. Our results demonstrate that Helicobacter felis -stimulated IL-10- producing B cells (Hfstim- IL-10+ B) are composed of B10 and Transitional 2 Marginal Zone Precursor (T2-MZP) cells with expression of CD9, Tim-1, and programmed death 1 (PD-1). On the other hand, Helicobacter felis -stimulated IL-10- nonproducing B (Hfstim- IL-10- B) cells are mainly marginal zone (MZ) B cells that express PD-L1 and secrete TGF-ß, IL-6, and TNF-α, and IgM and IgG2b. Furthermore, we show that both Hfstim- IL-10+ B cells and Hfstim- IL-10- B cells induce CD49b+LAG-3+ Tr1 cells. Here, we describe a novel mechanism for PD-1/PD-L1- driven B cell-dependent Tr1 cell differentiation. Finally, we explore the capability of Hfstim- IL-10- B cells to induce Th17 cell differentiation, which we find to be dependent on TGF-ß. Taken together, the current study demonstrates that Hfstim- B cells induce Tr1 cells through the PD-1/PD-L1 axis and Th17 cells by secreting TGF-ß.

Pulmonary tuberculosis in the West Bank, Palestinian Authority: molecular diagnostic approach.

OBJECTIVE: To compare the effectiveness and feasibility of an insertion sequence (IS6110)-based polymerase chain reaction (PCR) assay with conventional methods of detecting Mycobacterium tuberculosis and to analyse mutations present in the hot spot region of the RNA polymerase B subunit (rpoB) gene associated with rifampin resistance by DNA sequencing. METHODS: Ninety-five sputum samples from 84 clinically suspected cases of tuberculosis were tested for mycobacterial infections by Ziehl Neelsen smear examination, Lowenstein-Jensen culture and IS6110-based PCR assay. RESULTS: Sensitivity and specificity of the PCR were 94%; the sensitivity of culture was 65%, and of smear tests, 59%. Both smear microscopy and culture had 100% specificity. DNA sequencing data of the 305-bp fragment of the rpoB gene for nine clinical isolates revealed one point mutation at position I572F and double mutations at position S531F in two isolates obtained from two patients who did not respond to the anti-tuberculosis therapy. CONCLUSION: IS6110-based PCR can be used routinely in clinical laboratories for rapid detection of Mycobacterium tuberculosis and thus allow early diagnosis and treatment of any contacts by the cheapest method currently available in the Palestinian Authority region. Rapid detection of rifampin resistance isolates will enable efficient treatment of patients and assist in eradication of the disease in the Palestinian territories.