Percentage Of CD4 Research Articles

Holstein × Montbéliarde-sired F1 generation crossbred female calves have an increased cellular immune response potential compared with purebred Holsteins

It is well known that crossbreds show many advantages over purebreds in improving calf health traits, but the immunological factors responsible for this heterosis remain largely unclear. The objective of this study was to compare the cellular immune responses and antibodies of Holstein (HO) and Montbéliarde-sired × Holstein (MH) F1 generation female calves, and investigate the effects of crossbreeding on the immunity. Fifty three-month-old healthy female calves (25 HO, 25 MH) were selected meticulously in a farm with the same criteria. Subsequently, complete blood count, flow cytometric analysis of T cell subsets and intracellular IFN-γ production, as well as indirect ELISA analysis of antibodies were performed in order to determine the immune profiles of the two groups of calves. We found that MH calves had higher percentage and number of CD4+ and CD8+ T cells than HO calves in the peripheral blood (p < 0.05), with higher MFI of CD44 on CD4+ and CD8+ T cells (p < 0.05). When stimulated by PMA and Ionomycin, the CD4+ and CD8+ T cells from MH calves secreted more IFN-γ than that of HO calves (p < 0.01). These results suggested that some immunological traits have been improved in MH calves, which may be an important cause of heterosis in crossbred animals.

Efficacy and Safety of Switching to Daily Bictegravir Plus Lenacapavir From a Complex Human Immunodeficiency Virus Treatment Regimen: A Randomized, Open-Label, Multicenter Phase 2 Study (ARTISTRY-1).

Complex antiretroviral therapy (ART) regimens, such as those requiring multiple tablets, several doses per day, or both, can negatively affect quality of life and treatment adherence among people with human immunodeficiency virus (HIV). ARTISTRY-1 is a phase 2/3, operationally seamless, randomized, open-label, multicenter, active-controlled study (GS-US-621-6289; NCT05502341). Phase 2 of the study enrolled adults with plasma HIV-1 RNA <50 copies/mL receiving a complex ART regimen for ≥6 months. Efficacy and safety outcomes were evaluated after a switch to bictegravir (BIC) (75-mg) + lenacapavir (LEN) (25- or 50-mg) regimens, compared with continuing on a complex ART regimen through 24 weeks. Overall, 128 participants were assigned randomly to begin BIC 75 mg + LEN 25 mg (n = 51) or BIC 75 mg + LEN 50 mg (n = 52) or continue on their complex ART regimen (n = 25). At week 24, HIV-1 RNA was ≥50 copies/mL in 0 of 51, 1 of 52 (1.9%), and 0 of 25 participants in the 3 groups, respectively. CD4 cell counts and percentages remained stable through week 24; the median change from baseline in CD4 cell count (interquartile range) was 18 (-39 to 70), -16 (-80 to 93), and 42 (-36 to 90) cells/µL, respectively. There were no study discontinuations due to a serious adverse event through week 24. Both BIC + LEN dosing regimens were well tolerated, with similar safety profiles observed between groups. These data support the continued evaluation of the combination of BIC and LEN to optimize treatment in people with HIV and virologic suppression who are receiving complex ART regimens.

Incidence and Risk Factors of Ophthalmic Nerve Palsy in Patients with Tuberculous Meningitis: A Retrospective Study and Literature Review

Abstract Background Tuberculous meningitis (TBM) is a severe form of tuberculosis with significant neurological complications, including ophthalmic nerve palsy (ONP). This study aims to evaluate the incidence and risk factors associated with ONP in TBM patients and systematically review the global situation of optic nerve damage in TBM. Methods This retrospective study included 250 patients diagnosed with TBM at Shanghai Public Health Clinical Center from January 2013 to December 2022. Data on clinical features, imaging results, and treatment outcomes were collected and analyzed, followed by logistic regression analysis to identify key risk factors. Results A total of 250 patients were enrolled in this study. The incidence of ONP was 6.8% (17/250). Patients with ONP had higher intracranial pressure (ICP) (257.69 ± 68.12 mmH2O vs. 191.65 ± 91.58 mmH2O, P = 0.012), higher cerebrospinal fluid (CSF) protein levels (1702.00 [963.70-3074.75] mg/L vs. 967.45 [513.50-1708.73] mg/L, P = 0.016), and more tuberculomas compared to those without ONP (29.4% vs. 10.7%, P = 0.039). Logistic regression analysis identified pre-treatment ICP, CD4 percentage, and presence of tuberculomas as significant risk factors for ONP. Linezolid use was found to be an independent protective factor for the recovery of ONP, with a odds ratio of 16.360 (95% confidence interval: 1.004–266.666, P = 0.050). Conclusion 6.8% (17/250) of patients with TBM developed ONP as a complication. ICP, CD4 counts, and tuberculomas are important predictors of ONP. Linezolid shows potential as a therapeutic agent for improving outcomes in TBM patients with neurological complications, warranting further study.

NET-EN treatment leads to delayed HSV-2 infection, enhanced mucin and T cell functions in the female genital tract when compared to DMPA in a preclinical mouse model.

Depot-medroxyprogesterone acetate (DMPA) and Norethisterone Enanthate (NET-EN) are progestin-only injectable contraceptives widely used by women in sub-Sharan Africa, where incidence of HIV-1 and HSV-2 infection remains high. Studies indicate that DMPA usage can increase the risk of HSV-2 infection, but limited data indicate no increased risk with use of NET-EN. We therefore investigated the effects of NET-EN and DMPA on susceptibility to vaginal HSV-2 infection in ovariectomized (OVX) mice and effects on immune responses, particularly in the vaginal tract (VT). OVX mice, when treated with NET-EN and infected intravaginally, had delayed genital pathology, decreased viral shedding, and extended survival compared to DMPA- or untreated OVX mice. CD4+ T cells isolated from VT showed no significant change in frequency with either contraceptive. However, DMPA significantly decreased the total number of VT CD4+ and CD8+ T cells and the number of IFN-γ producing CD4 and CD8 T cells and increased the percentage of CD4 and CD8 T cells producing TNF-α compared to untreated mice. In contrast, NET-EN significantly enhanced percentages of CD8+ T cells compared to DMPA treated mice, and frequencies of IFN-γ+ CD4 and CD8 T cells in the VT compared to untreated mice. Comparative analysis of splenic lymphocytes indicated that DMPA treatment resulted in reduction of CD4+ T cell frequency, but enhanced TNF-α+ CD4 T cells compared to untreated mice. NET-EN enhanced the frequency of CD8 T cells, as well as IFN-γ+ and TNF-α+ CD4, and IFN-γ+ CD8 T cells in the spleen compared to untreated mice. Importantly, we found DMPA treatment that significantly reduced mucin production, whereas NET-EN enhanced expression of cell-associated mucin in VT. High levels of mucin in NET-EN mice were associated with lower levels of HSV-2 virus detected in the vaginal tract. This study provides the first evidence that NET-EN treatment can delay HSV-2 infection compared to DMPA.

Lymphocyte subsets in pediatric acute lymphoblastic leukemia and their prognostic value.

To study the changes of lymphocyte subsets in children with acute lymphoblastic leukemia (ALL) at initial diagnosis and compare them with those of healthy children and patients who have achieved complete remission (CR). Furthermore, we aim to analyze the prognostic significance of lymphocyte subsets in these patients. From May 2011 to December 2015, 405 children with ALL were enrolled in this study. Peripheral blood was collected at the time of diagnosis, and lymphocyte subsets were detected by flow cytometry. Then, the percentages of lymphocyte subsets in each group were compared. In addition, survival and prognostic factor analyses were performed to determine the prognostic value of lymphocyte subsets. Lymphocyte subsets in children with ALL were dramatically different from those in healthy children and patients achieving CR. Additionally, lymphocyte subsets were correlated with different minimal residual disease and risk parameters. Furthermore, percentages of CD3+ T cells and CD4+ T cells and the ratio of CD4/CD8 were associated with different clinical outcomes. Multivariate analysis demonstrated the percentage of CD4+ T cell as an independent predictor for clinical prognosis. Lymphocyte subsets in pediatric ALL undergo dramatic changes and were related to prognosis, especially CD4+ T cells.

Treatment with oclacitinib, a Janus kinase inhibitor, down-regulates and up-regulates CD25 and Foxp3 expression, respectively, in peripheral blood T cells of dogs with atopic dermatitis

BackgroundOclacitinib (OCL), a Janus kinase inhibitor, is a novel immunomodulatory/immunosuppressive agent which is an approved as the first-line treatment for atopic dermatitis (AD) in dogs. The aim of the study was to investigate the effects of OCL on CD4+ and CD8+ T cells and their selected subsets under clinical conditions, i.e. in dogs suffering from AD, in terms of both safety and immune mechanisms underlying its therapeutic actions. Eight dogs were treated for 28 days with OCL at the recommended dose. Blood samples were taken at day 0, 7, 14 and 28.ResultsThe study showed that the mean percentage and absolute count of CD4+ and CD8+ T cells on the 14th and 28th day of the treatment with OCL did not differ from the corresponding baseline values, i.e. those before the treatment. On the 7th day of the treatment, the mean absolute count of CD4+ T cells and the mean percentage and absolute count of CD8+ T cells were significantly increased. The research found that on the 14th day of the treatment, the mean percentage and absolute count of CD25+CD4+ and CD25+CD8+ T cells were significantly decreased; the reduction in the percentage of CD25+CD4+ T cells persisted on 28th day of the treatment. A two-week treatment with OCL resulted in an increase in the mean percentage of Foxp3+CD4+ T cells, and this effect was sustained at the last time point. The treatment with OCL decreased the eosinophil level but does not affect the absolute counts of basophils, monocytes and neutrophils.ConclusionsThe findings of the study strongly suggest that: (a) in terms of the impact of OCL on the number of PB CD4+ and CD8+ T cells, monthly treatment with the drug should be considered as a relatively safe; (b) the eosinophil-reducing effect and the down-regulation of the AD up-regulated CD25 expression on CD4+ Teff cells may constitute significant elements of the mechanism of action underlying the therapeutic effects of the drug in the treatment of canine AD; (c) the generation of inducible Foxp3-expressing CD4+ regulatory T cells - resulting in the shift of the CD4+ Treg cell (i.e. Foxp3+CD4+)/activated Teff (i.e. CD25+CD4+) cell balance toward an increased proportion of Treg cells - may be considered as additional mechanism involved in producing the immunomodulatory/immunosuppressive properties of OCL.

The kisspeptin effects on the thymic regulatory cell compositions (Th17, Treg, iNKT) &lt;i&gt;in vitro&lt;/i&gt;

The peptide hormone kisspeptin, produced by neurons of the hypothalamus anterior zone, is a key regulator of the gonadostat formation and reproductive function, and has immunoregulatory activity. During pregnancy, kisspeptin is produced by the placenta, presents in the peripheral blood and affects on immune cells that express specific receptors for the hormone, including thymus cells. However, the kisspeptin effects on thymopoiesis during pregnancy have not been studied. The purpose of the work was to study the kisspeptin effect on the thymic regulatory cell composition in vitro. Thymocytes were cultured for 72 hours with kisspeptin at a concentration (9.6 pM) characterizing its maximum level in the peripheral blood during pregnancy, in the presence of CD3/CD28-activating particles and further assessed the regulatory cell composition and Ki-67 and Bcl-2 expression by flow cytometry. The percentage of T regulatory lymphocytes (Treg) was assessed as the percentage of CD4+CD25+FoxP3+ cells; T helper cells producing interleukin17 (Th17), as a percentage of CD4+IL-17A+RORγt+ cells; invariant T lymphocytes with natural killer functions(iNKT), as a percentage of CD3hiVa24Ja18+ cells in thymocyte culture. Dexamethasone (10-6M) was added to induce apoptosis. The effect of kisspeptin-primed thymic plasmacytoid dendritic cells (pDCs) on the regulatory cell composition (Th17, Treg, iNKT) in thymocyte culture was assessed. Thymic pDCs isolated by immunomagnetic separation were cultured for 24 hours with kisspeptin, and then intact autologous thymocytes were added in a ratio of 1:10 and cultured for another 72 hours. The thymocyte incubation of with kisspeptin did not affect the Tregs, iNKT and Th17 percentage in vitro, as well as the expression of Ki-67 and Bcl-2 in these cells. Under dexamethasone influence, the Bcl-2+Th17 percentage in thymocyte cultures with kisspeptin was increased. The Th17 percentage was increased in cultures of kisspeptin-primed pDCs with thymocytes, while the Treg and iNKT number did not change. It can be concluded that kisspeptin has regulatory effects on the Th17 percentage in thymocyte culture in vitro, mediating its effects by influencing thymic pDCs. And kisspeptin acted directly on thymocytes, increases the resistance of thymic Th17 to dexamethasone-induced apoptosis. The obtained results expand our understanding of the hormonal regulation of regulatory cell balance during pregnancy.

Causal association of immune cells and endometritis: a Mendelian randomization study

Research exploring the link between immune cell profiles and the development of endometritis remains scant. This gap necessitates further study to decode the complex interrelations influencing this condition. In this analysis, we leveraged two-sample Mendelian randomization to examine the causal ties between the phenotypes of immune cells and the incidence of endometritis. Our evaluation hinged on data from 3757 participants hailing from Sardinia, focusing on a diverse array of 731 immune phenotypes, and cross-referenced with endometritis data sourced from the UK Biobank. To ensure rigor, we performed sensitivity analyses, utilized MR-Egger and MR-Presso to check for pleiotropy, and applied Cochran’s Q test for assessing the heterogeneity of our findings. Our investigation identified numerous immune characteristics associated with endometritis. For certain immune traits, a lower risk of endometritis was observed, including: Absolute Counts of CD39 + CD4 + T cells, CD25 + CD39 + CD4 regulatory T cells, and CD25 + + CD8 + T cells; Absolute Counts of Switched Memory B cells; CD19 expression on IgD + CD38dim and Switched Memory B cells; CD20 expression on IgD + CD38− Unswitched Memory B cells; percentage of Switched Memory B cells among lymphocytes; CD16-CD56 expression on HLA DR + Natural Killer cells; percentage of CD11c + CD62L− monocytes; CD86 expression on monocytes; CCR2 expression on CD14 + CD16 + monocytes; and CD14 expression on Monocytic Myeloid-Derived Suppressor Cells, with Odds Ratios (ORs) between 0.413 and 0.703. On the contrary, increased risks of endometritis were linked with: the percentage of Effector Memory CD4 + T cells within the CD4 + T cell population; percentages of HLA DR + T cells and HLA DR + CD8 + T cells among T cells; CD4 expression on CD28 + CD4 + T cells; CD20 expression on CD20- CD38- B cells; percentage of IgD + CD24 + B cells within the B cell population; CD62L expression on CD62L + myeloid Dendritic Cells; and Absolute Counts of Plasmacytoid Dendritic Cells, with ORs from 1.473 to 2.677, indicating these traits potentially elevate the risk of developing endometritis. Our research delineates distinct causal links between specific immune cell phenotypes and endometritis, offering new perspectives that could contribute to the pinpointing of new therapeutic avenues for this condition.

Prostate cancer cell-derived exosomes ZNF667-AS1 reduces TGFBR1 mRNA stability to inhibit Treg expansion and DTX resistance by binding to U2AF1

BackgroundDocetaxel (DTX) resistance attenuates anti-tumor effects of DTX on prostate cancer (mCRPC) and drug resistance was related to Treg expansion in tumors. ZNF667-AS1 played a suppressing role in various tumors and tumor-derived exosomes carry lncRNAs to participate in tumor progression. Here, the effects of ZNF667-AS1 on malignant characteristics and DTX resistance in PC and the effect and its underlying molecular mechanism of tumor-derived exosomes carrying ZNF667-AS1 on Treg expansion were investigated.MethodsThe identification of exosomes were determined using TEM, NTA and western blot. The abundance of genes and proteins were evaluated using IHC, RT-qPCR, western blot and FISH. Malignant phenotypes of PC cells were evaluated by means of Edu, scratch test, transwell, CCK-8 and flow cytometry. The percentage of CD4+CD25+Foxp3+ Tregs was detected using flow cytometry. The location of ZNF667-AS1 was detected using nuclear-cytoplasmic fractionation. The co-location of ZNF667-AS1 and U2AF1 protein was detected using IF-FISH assay. The interactions among ZNF667-AS1, TGFBR1 and U2AF1 were verified using RNA pull-down, RIP and dual luciferase activity.ResultsZNF667-AS1 expression in PC samples was lowered, which was negatively relative to poor prognosis and DTX resistance. ZNF667-AS1 overexpression inhibited malignant phenotypes of PC cells, tumor growth and DTX resistance. Besides, DTX resistant cell-derived exosomes expressed lower ZNF667-AS1 expression. Exosomes carrying exogenously high ZNF667-AS1 expression derived PC cells or serum of mice suppressed Treg expansion. On the mechanism, ZNF667-AS1 interacted with U2AF1 to destabilize TGFBR1 mRNA and reduce TGFBR1 expression in CD4+T cells.ConclusionZNF667-AS1 suppressed cell growth of PC cells, tumor growth of mice and DTX resistance to PC cells and exogenously high ZNF667-AS1 expression in tumor-derived exosomes destabilized TGFBR1 mRNA and reduce TGFBR1 expression through interacting with U2AF1, thus resulting in attenuated Treg expansion, which was related to DTX resistance.

Superior retention of aged fat graft by supplementing young adipose-derived stromal cells in a murine model.

In 2021, a meta-analysis showed fat graft retention varied from 26 to 83%. In a retrospective study including patients with Parry-Romberg syndrome, the younger age group had higher satisfaction scores (3.8 vs. 3.0) after fat grafting. Cell-assisted lipotransfer (CAL) could be an alternative to overcome the instability of volume loss; however, no study investigated its effect on old recipients. In an in vitro study, adipose-derived stromal cells (ASCs) from aged and young (52- and 8-weeks old) DsRed B6 mice were characterized by proliferation rates as percentages of Ki-67-positive cells. 68-week-old wild type B6 mice received 150 µL of green fluorescent protein fat (from 69-week-old B6 mice) mixed with saline, 3 x 105 aged or young DsRed ASCs (N, A, and Y groups, respectively) on the scalp (n = 6/group). After 8 weeks, graft volumes were evaluated using micro-computed tomography. Vessel densities were tracked by percentages of CD31 using immunofluorescence staining. Young ASCs showed higher proliferation than the aged (47.1% and 26.2%, respectively, p < 0.05). The Y group showed the highest graft retention (median: N = 41.0%, A = 52.2%, Y = 65.2%, p < 0.05) and percentage of blood vessels (median: N = 27.7%, A = 43.5%, Y = 54.7%, p < 0.05) among the three groups. CAL is effective with old recipients; higher effect was observed by supplementation with younger ASCs due to higher angiogenesis stimulation. However, this is autologous grafting model, further validation of safety, toxicity, and allogenic grafting is required. The results suggest that it is clinically possible to conduct CAL for old adults using autologous ASCs. However, further validation of using allogenic ASCs from young donors to improve graft retention in old adults is required.

Hemodiafiltration May Be Associated with Senescence-Related Phenotypic Alterations of Lymphocytes, Which May Predict Mortality in Patients Undergoing Dialysis.

Senescence-resembling alterations on the lymphocytes of patients undergoing dialysis have been widely described. However, the pathophysiology behind these phenomena has not been clarified. In this study, we examined the impact of dialysis prescription on T and B lymphocytes, in patients undergoing dialysis.: T and B cell subsets were determined with flow cytometry in 36 patients undergoing hemodialysis and 26 patients undergoing hemodiafiltration, according to the expression of CD45RA, CCR7, CD31, CD28, CD57, and PD1 for T cells, and IgD and CD27 for B cells. The immune phenotype was associated with dialysis modality, hemofiltration volume, and mortality. Compared with hemodialysis, patients undergoing hemodiafiltration had a significantly decreased percentage of CD4+CD28-CD57- T cells [3.8 (2.4-5.3) vs. 2.1 (1.3-3.3)%, respectively, p = 0.002] and exhausted CD4+ T cells [14.1 (8.9-19.4) vs. 8.5 (6.8-11.7)%, respectively, p = 0.005]. Additionally, the hemofiltration volume was negatively correlated with CD8+ EMRA T cells (r = -0.46, p = 0.03). Finally, the increased exhausted CD4+ T cell percentage was associated with increased all-cause mortality in patients undergoing dialysis, independent of age. Hemodiafiltration, especially with high hemofiltration volume, may have beneficial effects on senescence-related immune phenotypes. Immune phenotypes may also be a predicting factor for mortality in patients undergoing dialysis.

Alterations and clinical value of peripheral lymphocyte subsets and inflammatory factors in paragangliomas.

Given the pivotal role of immune and inflammatory responses in tumor patients, the present study aimed to explore alterations and the clinical value of peripheral lymphocyte subsets and inflammatory factors in pheochromocytomas/paragangliomas (PPGLs). The clinical data of 327 patients, including 102 patients with metastatic PPGLs, were retrospectively analysed. Peripheral lymphocyte subsets were determined by flow cytometry. Relationships between immune and inflammatory parameters and clinicopathological characteristics were evaluated by intergroup comparisons and correlation analyses. Univariate and multivariate logistic regression analyses were employed to identify metastatic indicators. The corresponding nomogram was constructed and evaluated for discrimination and calibration. The median age at diagnosis was 45.0 years, and duration of follow-up was 3.0 years. Compared with those in younger patients (<45.0 years), most lymphocyte subsets were significantly reduced in older patients (≥45 years) (P<0.05). The count of lymphocytes, CD3+T cells and CD4+T cells were negatively correlated with 24h-urinary epinephrine and plasma metanephrine levels (R=-0.2∼-0.1, P<0.05). In addition, patients with lymph node (n=37) or bone metastases (n=41) had a lower percentage of CD4+T cells (P<0.05). Multivariate analysis revealed that CD3+T cell≥1446.50/μl, CD4+T cell%<39.95%, CD8+T cell%<24.95%, CD4+/CD8+T cell ratio<2.88, B cell%≥8.65%, TNF-alpha<12.45pg/ml, IL8<30.50pg/ml and PLT≥269.50*109/L were significant indicators of metastatic PPGLs. The area under the curve (AUC) of the nomogram was 0.800 (95% CI: 0.736-0.865). Immunesenescence, characterized by immune dysfunction with aging, was observed in PPGLs. Higher epinephrine and metanephrine levels might impair host's immune response. Monitoring changes in peripheral lymphocyte subsets and serum cytokines could indicate patients' conditions, especially the occurrence of metastasis.

6413 Anti-PD1 induces T1D in an HLA-DQ8, HLA-A2.1 mouse model

Abstract Disclosure: P. Houeiss: None. S. luce: None. C. Boitard: None. Anti-PD1 is an immune checkpoint inhibitor that has revolutionized cancer treatment. It blocks the interaction between PD1, a receptor on the surface of activated or exhausted T cells, and its ligands PDL1 and PDL2, to inhibit the immune response. However, anti-PD1 induces T1D in 0.4-2% of patients raising questions about the risk factors and the mechanisms behind T1D development. Since the pancreas of these patients is inaccessible, we focus on autoimmune diabetes induction in a transgenic mouse model modified to express the T1D susceptibility genes HLA-DQ8, HLA-A2.1 and the human preproinsulin and on identifying new targets to prevent or treat this disease. Thus, 8 to 12 weeks old mice were treated initially with 500 micrograms of anti-PD1 followed by 250 micrograms every other day for 10 days. Control mice received 6 injections of PBS. Mice were followed up for evidence of hyperglycemia for 60 days. Cells and tissues from the pancreas, and the spleens were isolated 15-, 30- or 60-days post-treatment initiation and analyzed by flow cytometry and immunohistochemistry. Although diabetes incidence in treated mice was 14% (n=14), insulitis incidence progressively increased over time reaching 86% on D60 (p=0.005). On Day 15, in the spleen, a significant 10% increase of CD4+Foxp3+CD25- T cells at the expense of the CD4+Foxp3- T cells were seen in the treatment group as compared to the control (37.1±4.25 vs 26±3.5, p&amp;lt;0.01, n=5 per group). In the treatment group, PD1 expression significantly increased on CD4+Foxp3+ T cells whereas PDL1 expression increased on CD4+Foxp3- and CD8+ T cells (p&amp;lt;0.01). On D30, in the pancreas, infiltrates show positive staining for F4/80+, CD4+ and CD8+ T cells with scarce foxp3+ T cells. While the absolute percentage of CD4+Foxp3+ T cells increased in the insulitis and diabetes group, their percentage among CD3+ T cells decreased in the insulitis (10.2%) and diabetes group (3.9%) as compared to the control group (13.5%). Infiltrates were concentrated around the islets and the efferent and afferent vessels, and extended to the exocrine pancreas, leading to secondary acinar destruction. In the pancreatic infiltrates from anti-PD1 treated mice, we noted a significant increase in CD4+ T cells recognizing Ins13-21 monomers as compared to the negative control. PD1 blockade induced an insulitis characterized by a Treg to effector T cells imbalance. Thus, it acted on the early phase of T1D. In conclusion, this model describes a new T1D endotype that shares similarities with ICI induced diabetes in patients. Presentation: 6/2/2024

9300 Anti-PD1 induces T1D in an HLA-DQ8, HLA-A2.1 mouse model

Abstract Disclosure: P. Houeiss: None. S. luce: None. C. Boitard: None. Anti-PD1 is an immune checkpoint inhibitor that has revolutionized cancer treatment. It blocks the interaction between PD1, a receptor on the surface of activated or exhausted T cells, and its ligands PDL1 and PDL2, to inhibit the immune response. However, anti-PD1 induces T1D in 0.4-2% of patients raising questions about the risk factors and the mechanisms behind T1D development. Since the pancreas of these patients is inaccessible, we focus on autoimmune diabetes induction in a transgenic mouse model modified to express the T1D susceptibility genes HLA-DQ8, HLA-A2.1 and the human preproinsulin and on identifying new targets to prevent or treat this disease. Thus, 8 to 12 weeks old mice were treated initially with 500 micrograms of anti-PD1 followed by 250 micrograms every other day for 10 days. Control mice received 6 injections of PBS. Mice were followed up for evidence of hyperglycemia for 60 days. Cells and tissues from the pancreas, and the spleens were isolated 15-, 30- or 60-days post-treatment initiation and analyzed by flow cytometry and immunohistochemistry. Although diabetes incidence in treated mice was 14% (n=14), insulitis incidence progressively increased over time reaching 86% on D60 (p=0.005). On Day 15, in the spleen, a significant 10% increase of CD4+Foxp3+CD25- T cells at the expense of the CD4+Foxp3- T cells were seen in the treatment group as compared to the control (37.1±4.25 vs 26±3.5, p&amp;lt;0.01, n=5 per group). In the treatment group, PD1 expression significantly increased on CD4+Foxp3+ T cells whereas PDL1 expression increased on CD4+Foxp3- and CD8+ T cells (p&amp;lt;0.01). On D30, in the pancreas, infiltrates show positive staining for F4/80+, CD4+ and CD8+ T cells with scarce foxp3+ T cells. While the absolute percentage of CD4+Foxp3+ T cells increased in the insulitis and diabetes group, their percentage among CD3+ T cells decreased in the insulitis (10.2%) and diabetes group (3.9%) as compared to the control group (13.5%). Infiltrates were concentrated around the islets and the efferent and afferent vessels, and extended to the exocrine pancreas, leading to secondary acinar destruction. In the pancreatic infiltrates from anti-PD1 treated mice, we noted a significant increase in CD4+ T cells recognizing Ins13-21 monomers as compared to the negative control. PD1 blockade induced an insulitis characterized by a Treg to effector T cells imbalance. Thus, it acted on the early phase of T1D. In conclusion, this model describes a new T1D endotype that shares similarities with ICI induced diabetes in patients. Presentation: 6/2/2024

A Sustained-Release Butyrate Tablet Suppresses Ex Vivo T Helper Cell Activation of Osteoarthritis Patients in a Double-Blind Placebo-Controlled Randomized Trial

Degenerative joint disease osteoarthritis (OA) is characterized by the degeneration of cartilage, synovial inflammation and low-grade systemic inflammation in association with microbial dysbiosis and intestinal barrier defects. Butyrate is known for its anti-inflammatory and barrier protective effects and might benefit OA patients. In a double-blind placebo-controlled randomized trial, the effects of four to five weeks of oral treatment with sustained-release (SR) butyrate tablets (600 mg/day) on systemic inflammation and immune function were studied in hand OA patients. Serum markers for systemic inflammation and lipopolysaccharide (LPS) leakage were measured and ex vivo stimulation of whole blood or peripheral blood mononuclear cells (PBMCs) was performed at baseline and after treatment. Butyrate treatment did not affect the serum markers nor the cytokine release of ex vivo LPS-stimulated whole blood or PBMCs nor the phenotype of restimulated monocytes. By contrast, butyrate treatment reduced the percentage of activated T helper (Th) cells and the Th17/Treg ratio in αCD3/CD28-activated PBMCs, though cytokine release upon stimulation remained unaffected. Nevertheless, the percentage of CD4+IL9+ cells was reduced by butyrate as compared to the placebo. In both groups, the frequency of Th1, Treg, Th17, activated Th17, CD4+IFNγ+ and CD4+TNFα+ cells was reduced. This study shows a proof of principle of some immunomodulatory effects using a SR butyrate treatment in hand OA patients. The inflammatory phenotype of Th cells was reduced, as indicated by a reduced percentage of Th9 cells, activated Th cells and improved Th17/Treg balance in ex vivo αCD3/CD28-activated PBMCs. Future studies are warranted to further optimize the butyrate dose regime to ameliorate inflammation in OA patients.

Maternal thirdhand exposure to e-cigarette vapor alters lung and bone marrow immune cell responses in offspring in the absence or presence of influenza infection.

There is increasing evidence that thirdhand exposure to e-cigarette vapor (e-vapor) can have detrimental effects on the lungs. However, whether maternal exposure during pregnancy results in harmful changes to the offspring is unknown. Using two different e-cigarette settings (low vs. high power), BALB/c mice were subjected to thirdhand e-vapor (e-vapor deposited onto towels, towels changed daily) in the absence or presence of nicotine, before, during, and after pregnancy. Male adult offspring were then infected with mouse-adapted influenza A virus (A/PR/8/34 H1N1; Flu) and lung and bone marrow immune cell responses were assessed 7 days postinfection. Maternal thirdhand exposure to low-power (MLP) or high-power (MHP) e-vapor with nicotine (MLP + NIC and MHP + NIC, respectively) increased the percentage of lung immune cells and neutrophils in the bone marrow. Interestingly, Flu-infected offspring from MLP + NIC and MHP + NIC groups had lower percentages of lung alveolar macrophages and more pronounced increases in neutrophils in the bone marrow, when compared with offspring from MSham Flu controls. Flu infection also decreased the percentage of lung CD4+ T cells and increased the percentage of lung CD8+ T cells, irrespective of maternal exposure (MLP -/+ NIC and MHP -/+ NIC). Significantly, both MLP + NIC and MHP + NIC resulted in blunted activation of lung CD4+ T cells, but only MLP + NIC caused blunted activation of lung CD8+ T cells. Together, we show for the first time that maternal thirdhand exposure to e-vapor results in significant, long-lived effects on lung and bone marrow immune cell responses in offspring at baseline and response to Flu infection.NEW & NOTEWORTHY Maternal exposure to environmental residues of e-cigarette use has significant effects on immune cell responses in the lungs and bone marrow of offspring at both baseline and in response to influenza A virus (Flu) infection.

Characterization of Cellular Immune System at Different Ages in Water Buffalo (Bubalus bubalis)

In recent years, there has been an increased interest in understanding the immune system of the water buffalo due to the increased economic impact of this species. The study aimed to perform an in-depth evaluation of lymphoid and myeloid cells in water buffalo of different ages. We assess three multicolor panels of antibodies to evaluate by flow cytometry the percentage of the CD3+ CD4+, CD8+, and γδ T lymphocytes; CD79+ and CD21+ B lymphocytes; monocytes and cM, intM, and ncMsubsets; NK cells, granulocytes, and peripheral blood mononuclear cell (PBMC). Seventy-eight animals from three different farms were divided into three groups by age (26 in each group): 80-100 days old calves, 16-18 months old heifers, and 4-6 years old cows. Significant differences by Kruskal-Wallis test were found between age groups in the percentage of CD4+, CD8+, γδ T lymphocytes, NK cells (P=0.0001), total monocytes (P=0.0008), granulocytes (P=0.0358) and PBMC (P=0.0056). Between the farms, the adult animals showed differences in the percentage ofCD3+ (P=0.0152), CD4+ (P=0.0047), CD8+ (P=0.0019), CD4:CD8 ratio (P=0.0033) and γδ (P=0.0013) T lymphocytes; CD21+ B lymphocytes (P=0.0007);total monocytes (P=0.0100), cM and ncM subsets (P=0.0320;P=0.0252), granulocytes (P=0.0030) and PBMC (P=0.0120). The calves showed significant differences in CD79+ and CD21+ B lymphocytes (P=0.0141; P=0.0049), total monocytes (P=0.0010), cM, intM and ncM subsets (P=0.0335; P=0.0499; P=0.0065). The heifers group in CD21+ B subset (P=0.0439).In summary, this study provides the composition of lymphoid and myeloid cells in this species for the first time, highlighting large differences between age groups and between different herds.

Identifying immune checkpoints on dysregulated T-cells as prognostic biomarkers for multiple myeloma patients with COVID-19.

Broad T cell phenotypic alterations and potential dysfunctions were prominent in COVID-19. There are few and inconclusive data about the role of immune checkpoints for T cell exhaustion/activation during SARS-CoV-2 infection in multiple myeloma (MM) patients. We tested T cell subsets and immune checkpoints in 177 MM patients with COVID-19, as well as in 32 healthy infected controls and 42 uninfected MM patients. The percentage of CD4+ and CD8+ subpopulation and immune checkpoints (PD-1, TIGIT, TIM-3, LAG-3, CTLA-4, OX40, and 4-1BB) were evaluated by flow cytometry. We have found that pronounced lymphopenia and inverted CD4/CD8 ratio in severe COVID-19 patients were especially developed within the first month after infection. And T cell subset dysregulation was persistent in severe patients recovering from SARS-CoV-2 infection. Immune checkpoints on CD4+ T cells were variable and uncorrelated with the level of adaptive immunity, while the proportion of CD4+ T cells was positively correlated with humoral immune response. PD-1 and TIGIT on CD8+ T cells were significantly elevated in severe patients and sustained for more than 2 months, which was associated with impaired cellular immune function. Moreover, exhausted molecules PD-1 and TIGIT on T cells were reduced in immunotherapy patients. The prolonged T cell dysregulation after severe SARS-CoV-2 infection highlights the close surveillance from reinfection in MM patients even during convalescence. PD-1 and TIGIT on CD8+ T cells could be important prognostic factors to stratify prognosis in MM patients with COVID-19. Moreover, immunotherapy may downregulate the expression of exhausted checkpoints PD-1 and TIGIT, leading to T cell overactivation and severe COVID-19.

Oral magnesium reduces levels of pathogenic autoantibodies and skin disease in murine lupus

BackgroundSystemic Lupus Erythematosus (SLE) has a strong genetic susceptibility, but little is known about the impact of diet on disease severity. The Western diet is typically deficient in magnesium (Mg), and given the immunomodulatory effects of Mg, we hypothesized that the low Mg intake increases disease risk and that increasing Mg intake would reduce severity of murine lupus. Here, we placed 12-week old MRL/lpr female lupus mice on a normal (Mg500) or a high (Mg2800) Mg diet for 9 weeks. Urine and blood were collected during the study for quantification of urinary albumin, BUN, anti-dsDNA antibodies, and immune phenotyping.ResultsMRL/lpr lupus mice on high Mg2800 diet had significantly fewer skin lesions and less severe skin histology score, and reduced levels of pathogenic anti-dsDNA antibodies, compared with the Mg500 group (143.8±75.0 vs. 47.4±36.2 × 106U/ml; P < 0.05). The high Mg2800 group had a nearly two-fold increase in the percentage of CD4+FOXP3+ Treg cells compared to controls (19.9±5.4 vs. 11.4±5.5%; P < 0.05). Treg percentages inversely correlated with the concentration of anti-dsDNA. None of the mice developed arthritis during the observation period and there were no significant differences in weight, proteinuria, BUN or kidney histology.ConclusionIn conclusion, oral supplementation of Mg has a protective effect in a murine lupus model and may represent an inexpensive and safe adjuvant in the treatment of SLE.

Recurrent ocular toxoplasmosis is associated with interferon-gamma deficiency possibly due to genetic origin

ObjectiveOcular toxoplasmosis (OT) can cause posterior uveitis; causes of recurrent OT are not well understood. We explored clinical, immunological and genetic properties associated with recurrent OT.Methods and analysisA recurrent OT...