The Effects of Stimulation with PMA/Ionomycin on CD4+ T Cell Proliferation and Surface CD4 Molecule Modulation of Patients with LRBA Deficiency and CVID with the Unsolved Genetic Defect.

BACKGROUND: Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiencies. LPS-responsive beige-like anchor protein (LRBA) deficiency is a combined immunodeficiency characterized by a CVID-like phenotype. Affected patients by LRBA and CVID present a wide range of clinical manifestations, including hypogammaglobulinemia, recurrent infections, autoimmunity, as well as T cell abnormality. METHODS: The study population comprised of patients with CVID (n=10), LRBA deficiency (n=11), and healthy controls (n=12). CD4+ T cell frequency and CD4 MFI (mean fluorescence intensity) were evaluated using flow cytometry before and after stimulation with PMA/ION. RESULTS: The frequencies of CD4+ T cells were significantly lower in patients with LRBA deficiency than in HCs before and after treatment. In the unstimulated state, the CD4+ T cells frequency in CVID patients was significantly lower than in HCs. There were no statistically significant differences between patients and healthy individuals in CD4+ T cell proliferation. Compared to HCs, LRBA and CVID patients showed a lower CD4 MFI in unstimulated conditions. Furthermore, CD4 MFI decreased in both patients and the control group following activation. CONCLUSION: Despite the reported decrease in CD4+ T cell frequency in patients with CVID and LRBA deficiency, our findings demonstrated that their CD4+ T cells have a normal proliferative response to stimuli similar to healthy individuals.

Evaluation of Expression of LRBA and CTLA-4 Proteins in Common Variable Immunodeficiency Patients.

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease with a heterogeneous genetic background. Lipopolysaccharide-responsive beige-like anchor (LRBA), as well as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), have important regulatory roles in the immune responses. Here, we have investigated the expression of LRBA and CTLA-4 proteins in CVID patients with at least one presentation of early-onset occurrence, autoimmunity, or enteropathy. In this study, 20 newly diagnosed CVID patients without infection only phenotype, and ten healthy individuals were enrolled. The expressions of LRBA and CTLA-4 proteins were assessed by western blotting and flow cytometry, respectively. The patients were divided into two groups of autoimmunity-positive (11 cases) and autoimmunity-negative (9 patients). LRBA and CTLA-4 expressions were significantly lower in autoimmune-positive patients than in healthy individuals (P = .03 and P = .03, respectively). Autoimmune-negative patients had lower expression of LRBA and CTLA-4 than the control group, although it was not significant. There was a positive correlation between the expressions of LRBA and CTLA-4 in both groups of patients (P < .05). Furthermore, the highest frequency of LRBA (85.7%) and CTLA-4 (71.4%) defects was detected in those with concomitant presence of autoimmunity, enteropathy, and early-onset occurrence. Concurrent presence of autoimmunity, enteropathy, and early-onset occurrence in CVID patients could be indicative of a lack of expression in LRBA and CTLA-4 proteins. This could be helpful in early diagnosis and initiation of appropriate treatment in these patients prior to genetic confirmation.

Significance of TIM-3 expression by CD4+ and CD8+ T lymphocytes in tumor-draining lymph nodes from patients with breast cancer.

T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), which is expressed by immune and nonimmune cells, has been shown to play immunoregulatory roles in the tumor microenvironment. In this study we assessed the expression of TIM-3 by T cells from tumor draining lymph nodes (TDLNs) of patients with breast cancer and its association with disease progression. Lymphocytes were isolated from 41 TDLNs, and flow cytometry was used to determine the expression of TIM-3 on CD4+ and CD8+ T cells, along with the simultaneous expression of CD25, Foxp3 and TIM-3 in CD4+ T cells. The results showed that the frequency of TIM-3+CD8+ T cells was associated with higher tumor grade, and the geometric mean fluorescence intensity (gMFI) of TIM-3 in CD4+ and CD8+ T cells was significantly higher in patients with more than 9 involved lymph nodes than those with fewer involved nodes. The gMFI of TIM3 in CD4+ T cells also showed a direct correlation with the number of metastatic lymph nodes. Phenotypic characterization of TIM-3+CD4+ T cells showed that the majority of CD4+TIM3+ lymphocytes were Foxp3 ̶ CD25 ̶, and the majority of Foxp3+CD25+ regulatory T cells were TIM-3-. Our findings showed that TIM-3 was expressed by CD4+, CD8+ and regulatory T cells in breast TDLNs, and that expression on CD4+ and CD8+ T cells was mostly associated with poor prognosticators such as a higher number of involved lymph nodes or higher tumor grade. More studies are required to confirm TIM-3 as a prognostic marker and a target for immunotherapy in breast cancer.

The balance of regulatory and stimulatory B cell subsets in breast cancer draining lymph nodes correlates with tumor prognostic factors.

AIMS: B cells can promote or inhibit immune responses against breast cancer. We investigated changes in the frequency of B cells with stimulatory or regulatory capacity in breast tumor draining lymph nodes during cancer progression. MAIN METHODS: We isolated mononuclear cells from fresh axillary lymph nodes (LNs) of 44 patients with breast cancer and stained lymphocytes with antibodies against CD19, CD80, CD86, CD39 and CD73. To assess programmed death-1 (PD-1) and PD-ligand 1 (PD-L1) expression, lymphocytes were briefly stimulated, stained for CD19, PD-1 and PD-L1, and examined with flow cytometry. KEY FINDINGS: The frequency of CD80+ B cells was higher in nonmetastatic lymph nodes, while the percentage of CD86+ B cells showed a positive relationship with higher tumor grade and higher numbers of involved LNs. A small proportion of unstimulated B cells expressed PD-1 or PD-L1 but these molecules were rapidly upregulated on B cells following activation. The frequency of stimulated PD-L1+ B cells showed an inverse association with estrogen and progesterone receptor expression and a nonsignificant positive association with tumor grade. In addition, the percentage of unstimulated PD-1+ B cells was higher in patients with higher-grade tumors. CD73 expression on B cells was associated with lower numbers of involved LNs, and the frequency of CD39+ B cells was higher in patients with larger tumors. SIGNIFICANCE: CD86+, CD39+, PD-1+ and PD-L1+ B cells showed associations with poor prognostic factors, therefore their potential role in the suppression of the immune responses against breast cancer should be evaluated in greater detail.