Significant Reduction In CD4 Research Articles

Sirolimus reduces T cell cycling, immune checkpoint marker expression, and HIV-1 DNA in people with HIV

Key HIV cure strategies involve reversing immune dysfunction and limiting the proliferation of infected Tcells. We evaluate the safety of sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, in people with HIV (PWH) and study the impact of sirolimus on HIV-1 reservoir size and HIV-1-specific immunity in a single-arm study of 20weeks of treatment in PWH on antiretroviral therapy (ART). Sirolimus treatment does not impact HIV-1-specific CD8 Tcell responses but leads to a significant decrease in CD4+ Tcell-associated HIV-1 DNA levels at 20weeks of therapy in the primary efficacy population (n= 16; 31% decline, p=0.008). This decline persists for at least 12weeks following cessation of the study drug. Sirolimus treatment also leads to a significant reduction in CD4+ Tcell cycling and PD-1 expression on CD8+ lymphocytes. These data suggest that homeostatic proliferation of infected cells, an important mechanism for HIV persistence, is an intriguing therapeutic target.

Acidity induces durable enhancement of Treg cell suppressive functions for tumor immune evasion

The microenvironment within solid tumors often becomes acidic due to various factors associated with abnormal metabolism and cellular activities, including increased lactate production as a result of dysregulated tumor glycolysis. Recently, we have identified multiple tumor microenvironment (TME) factors that potentiate regulatory T (Treg) cell function in evading anti-tumor immunosurveillance. Despite the strong correlation between lactate and acidity, the potential roles of acidity in intratumoral Treg cell adaptation and underlying molecular mechanisms have gone largely unstudied. In this study, we demonstrate that acidity significantly enhances immunosuppressive functions of nTreg cells, but not iTreg cells, without altering the expression of either FoxP3 or the cell surface receptors CD25, CTLA4, or GITR in these cells. Surprisingly, the addition of lactate, often considered a major contributor to increased acidity of the TME, completely abolished the acidity-induced enhancement of nTreg suppressive functions. Consistently, metabolic flux analyses showed elevated basal mitochondrial respiratory capacity and ATP-coupled respiration in acidity-treated nTreg cells without altering glycolytic capacity. Genome-wide transcriptome and metabolomics analyses revealed alterations in multiple metabolic pathways, particularly the one-carbon folate metabolism pathway, with reduced SAM, folate, and glutathione, in nTreg cells exposed to low pH conditions. Addition of a one-carbon metabolic contributor, formate, diminished the acidity-induced enhancement in nTreg cell suppressive functions, but neither SAM nor glutathione could reverse the phenotype. Remarkably, in vitro transient treatment of nTreg cells resulted in sustained enhancement of their functions, as evidenced by more vigorous tumor growth observed in mice adoptively receiving acidity-treated nTreg cells. Further analysis of intratumoral infiltrated T cells confirmed a significant reduction in CD8+ T cell frequency and their granzyme B production. In summary, our study elucidates how acidity-mediated metabolic reprogramming leads to sustained Treg-mediated tumor immune evasion.

The histone methyltransferase Mixed-lineage-leukemia-1 drives T cell phenotype via Notch signaling in diabetic tissue repair.

Immune cell-mediated inflammation is important in normal tissue regeneration but can be pathologic in diabetic wounds. Limited literature exists on the role of CD4+ T cells in normal or diabetic wound repair; however, the imbalance of CD4+ Th17/Tregs has been found to promote inflammation in other diabetic tissues. Here, using human tissue and murine transgenic models, we identified that the histone methyltransferase Mixed-lineage-leukemia-1 (MLL1) directly regulates the Th17 transcription factor RORγ via an H3K4me3 mechanism and increases expression of Notch receptors and downstream Notch signaling. Furthermore, we found that Notch receptor signaling regulates CD4+ Th cell differentiation and is critical for normal wound repair, and loss of upstream Notch pathway mediators or receptors in CD4+ T cells resulted in the loss of CD4+ Th cell differentiation in wounds. In diabetes, MLL1 and Notch-receptor signaling was upregulated in wound CD4+ Th cells, driving CD4+ T cells toward the Th17 cell phenotype. Treatment of diabetic wound CD4+ T cells with a small molecule inhibitor of MLL1 (MI-2) yielded a significant reduction in CD4+ Th17 cells and IL-17A. This is the first study to our knowledge to identify the MLL1-mediated mechanisms responsible for regulating the Th17/Treg balance in normal and diabetic wounds and to define the complex role of Notch signaling in CD4+ T cells in wounds, where increased or decreased Notch signaling both result in pathologic wound repair. Therapeutic targeting of MLL1 in diabetic CD4+ Th cells may decrease pathologic inflammation through regulation of CD4+ T cell differentiation.

Fam49b dampens TCR signal strength to regulate survival of positively selected thymocytes and peripheral T cells.

The fate of developing T cells is determined by the strength of T cell receptor (TCR) signal they receive in the thymus. This process is finely regulated through the tuning of positive and negative regulators in thymocytes. The Family with sequence similarity 49 member B (Fam49b) protein is a newly discovered negative regulator of TCR signaling that has been shown to suppress Rac-1 activity in vitro in cultured T cell lines. However, the contribution of Fam49b to the thymic development of T cells is unknown. To investigate this important issue, we generated a novel mouse line deficient in Fam49b (Fam49b-KO). We observed that Fam49b-KO double positive (DP) thymocytes underwent excessive negative selection, whereas the positive selection stage was unaffected. Fam49b deficiency impaired the survival of single positive thymocytes and peripheral T cells. This altered development process resulted in significant reductions in CD4 and CD8 single-positive thymocytes as well as peripheral T cells. Interestingly, a large proportion of the TCRγδ+ and CD8αα+TCRαβ+ gut intraepithelial T lymphocytes were absent in Fam49b-KO mice. Our results demonstrate that Fam49b dampens thymocytes TCR signaling in order to escape negative selection during development, uncovering the function of Fam49b as a critical regulator of the selection process to ensure normal thymocyte development and peripheral T cells survival.

Efficacy and safety of neoadjuvant chemoradiotherapy combined with tislelizumab and thymalfasin in the treatment of locally advanced lower rectal cancer.

e15612 Background: Thymalfasin, as an immunomodulator, can enhance the anti-tumor effects of T cells, NK cells, and macrophages. This study explored the efficacy and safety of a new adjuvant treatment regimen for rectal cancer, combining thymalfasin with chemoradiotherapy and the PD-1 inhibitor tislelizumab, and its impact on the immune microenvironment. Methods: This retrospective study enrolled 26 patients with locally advanced rectal cancer from March 2021 to December 2022. Thirteen patients received long-course concurrent chemoradiotherapy combined with concurrent tislelizumab treatment, and thirteen received thymalfasin combined with long-course chemoradiotherapy and concurrent tislelizumab treatment (radiotherapy: 50 Gy/25 f; capecitabine, 1000mg/m2, bid; tislelizumab: 200mg, every 21 days, 3 cycles; Thymalfasin: 1.6mg, biw). The postoperative pathological complete response rate (ypT0N0M0), tumor regression grade (AJCC 8th Version), and adverse event (CTCAE 4.0) incidence were assessed, along with changes in the immune microenvironment before and after treatment using multiplex immunofluorescence staining. Results: The pathological complete response rates observed postoperatively were 61.5% in the treatment group, compared to 38.5% in the control group. The distribution of tumor regression grades 0, 1, 2, and 3 was 69.2%, 15.4%, 15.4%, 0% in the treatment group respectively, and 38.5%, 38.5%, 7.7%, 15.4%, in the control group respectively. The adverse event rates reached 84.6% in the treatment group and 76.9% in the control group, with all events classified as either grade 1 or 2 according to the CTCAE 4.0. Significant reductions in CD4+PD1+ cell density (p < 0.001), CD8+PD1+ cell density (p = 0.024), CD68+ cell density (p = 0.007), the CD4/CD8 ratio (p < 0.001), and the CD68+CD86+/CD68+CD163+ ratio (p = 0.012) were demonstrated through multiplex immunofluorescence following neoadjuvant treatment. The treatment group exhibited significant decreases in CD8+PD1+ cell density (p = 0.025) and CD68+CD163+ cell density (p = 0.021) when compared to the control group. Conclusions: Thymalfasin combined with chemoradiotherapy and tislelizumab as a neoadjuvant treatment regimen for patients with locally advanced lower rectal cancer has shown favorable efficacy and safety. Neoadjuvant chemoradiotherapy combined with immunotherapy restored T cell function and reduced the proportion of tumor-associated macrophages, but macrophages polarized towards an M2-like phenotype. Thymalfasin may play a role by synergizing with the PD-1 inhibitor to restore cytotoxic T cell function and block macrophage polarization towards M2 cells. Clinical trial information: NCT06024356 .

Enhanced amphiregulin exposure promotes modulation of the high grade serous ovarian cancer tumor immune microenvironment.

High grade serous ovarian cancer (HGSOC) is a lethal gynecologic malignancy in which chemoresistant recurrence rates remain high. Furthermore, HGSOC patients have demonstrated overall low response rates to clinically available immunotherapies. Amphiregulin (AREG), a low affinity epidermal growth factor receptor ligand is known to be significantly upregulated in HGSOC patient tumors following neoadjuvant chemotherapy exposure. While much is known about AREG's role in oncogenesis and classical immunity, it is function in tumor immunology has been comparatively understudied. Therefore, the objective of this present study was to elucidate how increased AREG exposure impacts the ovarian tumor immune microenvironment (OTIME). Using NanoString IO 360 and protein analysis, it was revealed that treatment with recombinant AREG led to prominent upregulation of genes associated with ovarian pathogenesis and immune evasion (CXCL8, CXCL1, CXCL2) along with increased STAT3 activation in HGSOC cells. In vitro co-culture assays consisting of HGSOC cells and peripheral blood mononuclear cells (PBMCs) stimulated with recombinant AREG (rAREG) led to significantly enhanced tumor cell viability. Moreover, PBMCs stimulated with rAREG exhibited significantly lower levels of IFNy and IL-2. In vivo rAREG treatment promoted significant reductions in circulating levels of IL-2 and IL-5. Intratumoral analysis of rAREG treated mice revealed a significant reduction in CD8+ T cells coupled with an upregulation of PD-L1. Finally, combinatorial treatment with an AREG neutralizing antibody and carboplatin led to a synergistic reduction of cell viability in HGSOC cell lines OVCAR8 and PEA2. Overall, this study demonstrates AREG's ability to modulate cytotoxic responses within the OTIME and highlights its role as a novel HGSOC immune target.

Low CD4+ T Cell count among HIV-seronegative Type 2 Diabetes Mellitus patients in Ilorin metropolis

Background and aims: Diabetes Mellitus (DM) is a metabolic disorder that manifests as chronic hyperglycemia accompanied by a dysfunctional metabolism of carbohydrates, lipids, and proteins. Several studies have earlier pointed out several complications associated with the disease and in particular, the sufferer’s susceptibility to various infectious diseases. We therefore sought to investigate the adaptive immune status of the condition, as represented by the assessment of CD4+ T cell count among DM patients. Method: Seventy-six type 2 DM patients were recruited for the study. Thirty (30) age and sex-matched, non-diabetic individuals were enrolled as negative controls. Their fasting blood sugar (FBS), HbA1c, and CD4 count were assayed using standardized procedures. The demographic and clinical data of the studied group and controls were compared with respect to age, sex, BMI, FBS, HbA1c, and CD4+ T cell counts. Result: The mean concentration of glucose (7.82 ± 2.58) and the percentage concentration of HBA1c (8.21 ± 2.31) were significantly higher in DM individuals as against the control (3.67 ± 0.66) (p = 0.0001) and (5.20 ± 0.48) (p = 0.0001) respectively. The CD4+ cell count was also significantly lower in DM subjects (843.58 ± 297.6) when compared with the control (1067.9 ±195.4) (p = 0.035). Conclusion: A significant reduction in CD4+ T cell level was noted among diabetic patients in our study, which could be a contributing factor for aggravating some of the associated complications in DM, especially those that involve susceptibility to infectious diseases. We found out that having Hb-AA is associated with normal or elevated CD4+ T cells in DM patients; whereas having the Hb-AS variant increases the chance of a low CD4+ T cell count. Assessment of CD4+ T cell count should be included as part of periodic investigations in DM patients, especially for those with unresolved complications, in spite of treatment.

Better efficacy, lower recurrence rate and decreased CD8+TRM with guselkumab treatment for generalized pustular psoriasis: A prospective cohort study from China

Generalized pustular psoriasis (GPP) is a severe and uncommon form of psoriasis, for which treatment options are limited. There is an urgent need to expand the treatment options for GPP. Currently, adalimumab, secukinumab, and guselkumab are considered effective for GPP, but there is a lack of prospective direct comparative studies on their efficacy for GPP. We conducted a prospective, single-center, observational study on 50 GPP patients to compare the efficacy, safety, and recurrence rates of these three biologics. Adalimumab, secukinumab, and guselkumab resulted in varying degrees of improvement in patients with GPP, but guselkumab exhibited superior efficacy and a lower recurrence rate than the other two drugs. This enhanced response may be attributed to the significant reduction in CD8+ tissue-resident memory T cells within GPP lesions caused by guselkumab.

Involucrin Modulates Vitamin D Receptor Activity in the Epidermis

Terminally differentiated keratinocytes are critical for epidermal function and are surrounded by involucrin (IVL). Increased IVL expression is associated with a near-selective sweep in European populations compared with those in Africa. This positive selection for increased IVL in the epidermis identifies human adaptation outside of Africa. The functional significance is unclear. We hypothesize that IVL modulates the environmentally sensitive vitamin D receptor (VDR) in the epidermis. We investigated VDR activity in Ivl‒/‒ and wild-type mice using vitamin D agonist (MC903) treatment and comprehensively determined the inflammatory response using single-cell RNA sequencing and associated skin microbiome changes using 16S bacterial phylotyping. VDR activity and target gene expression were reduced in Ivl‒/‒ mouse skin, with decreased MC903-mediated skin inflammation and significant reductions in CD4+ T cells, basophils, macrophages, monocytes, and type II basal keratinocytes and an increase in suprabasal keratinocytes. Coinciding with the dampened MC903-mediated inflammation, the skin microbiota of Ivl‒/‒ mice was more stable than that of the wild-type mice, which exhibited an MC903-responsive increase in Bacteroidetes and a decrease in Firmicutes. Together, our studies in Ivl‒/‒ mice identify a functional role for IVL to positively impact VDR activity and suggest an emerging IVL/VDR paradigm for adaptation in the human epidermis.

Primary immunodeficiency in a patient with Kabuki syndrome

Kabuki syndrome is a well-known disease characterized by postnatal growth failure, dysmorphic facial features, skeletal abnormalities, and mental retardation associated with one of the pathogenic mutations in the KMT2D or KDM6A genes. At least 50% of individuals with Kabuki syndrome tend to develop recurrent infections and immune abnormalities, primarily hypogammaglobulinemia. The article describes the clinical course of resistant infectious syndrome in an 18-month-old child without typical dysmorphic and dermatoglyphic manifestations characteristic of Kabuki syndrome. A long history of resistant bacterial infection, enterocolitis, microcephaly, autistic-like behavior, hyperkinetic disorder, CT scan patterns of granulomatous lymphocytic interstitial lung disease (GLILD), suggested the immunodeficiency as part of a hereditary genetically determined syndrome. At the same time, the patient did not experience hypogammaglobulinemia characteristic of Kabuki syndrome. The upper normal response to previously received vaccination and a polyclonal repertoire of B-lymphocytes indicated the absence of disturbances in the humoral immunity. Immunophenotyping revealed the absence of T-regulatory cells (CD4+CD25++CD127–) as well as effector NK cells (CD16+CD56+CD3–) in the peripheral blood. The significant reduction of CD4+CD3+ T-lymphocytes and CD4+/CD8+ index was observed. In addition, no expression of integrin-beta (CD18) on neutrophils revealed.Conclusion. In children under the age of 2, Kabuki syndrome may present difficulties for clinical diagnosis due to the absence of distinctive phenotypic signs. Patients with mental disorders, congenital malformations, recurrent infections suspected of immunodeficiency should be carried out using molecular genetic exploration, including testing for mutations in the KMT2D and KDM6A.

Extract of Laurus nobilis attenuates inflammation and epithelial ulcerations in an experimental model of inflammatory bowel disease

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are classified as chronic inflammatory disorders and typically require anti-inflammatory drug therapies, such as glucocorticoid regimens, non-steroidal anti-inflammatory drugs, and biologics, aimed at reducing inflammation in the bowel wall. However, each of these therapies is accompanied by a list of possible serious side effects. Because of this, there remains an urgent need to identify new pharmacologic options to reduce or prevent the pro-inflammatory events of IBD while minimizing adverse side effects, and to make available more cost-effective treatment modalities. We have previously identified several herbal extracts that demonstrate potent bio-inhibitory activity of the innate immune response. In particular, Laurus nobilis (LN), or more commonly called bay laurel, demonstrated significant anti-inflammatory function by inhibiting nuclear factor-κB activation. Based upon our original in vitro findings, we have now examined the effects of this herbal extract on a murine dextran sodium sulfate (DSS) model of IBD. Hematoxylin and eosin-stained paraffin sections prepared from DSS treated animals show clear epithelial damage, including ulcerations, extensive neutrophil infiltration into the mucosal layer, and granuloma formation. Tissue from DSS treated animals that also received LN extract showed improved tissue morphology more closely resembling that from control animals. In addition, DSS treated mice with co-administration of LN extract showed a significant reduction in CD4+ antibody staining within the mucosal layer in colonic sections indicating reduced lymphocyte infiltration. Based on these findings, we believe that administration of LN extracts may be effective in reducing the intestinal epithelial damage seen in human IBD and warrants further investigation through clinical trials. Lay Summary: Inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis (UC), manifest as chronic inflammation and ulceration of tissues lining the digestive tract. CD involves inflammation of the deeper layers of the digestive tract, including both the small and large intestines, and less commonly, the upper digestive tract. UC involves inflammation along the lining of the colon and rectum. Steroid or biologic treatments for IBD are common, however, are limited due to significant side effects and/or prohibitive cost. In the present study, we provide evidence for use of the natural product, Laurus nobilis (bay leaf), as a safe and effective anti-inflammatory therapy for IBD.

Extract of Laurus nobilis attenuates inflammation and epithelial ulcerations in an experimental model of inflammatory bowel disease

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are classified as chronic inflammatory disorders and typically require anti-inflammatory drug therapies, such as glucocorticoid regimens, non-steroidal anti-inflammatory drugs, and biologics, aimed at reducing inflammation in the bowel wall. However, each of these therapies is accompanied by a list of possible serious side effects. Because of this, there remains an urgent need to identify new pharmacologic options to reduce or prevent the pro-inflammatory events of IBD while minimizing adverse side effects and making available more cost-effective treatment modalities. We have previously identified several herbal extracts that demonstrate the potent bio-inhibitory activity of the innate immune response. In particular, Laurus nobilis (LN), or more commonly called bay laurel, demonstrated significant anti-inflammatory function by inhibiting nuclear factor-κB activation. Based upon our original in vitro findings, we have now examined the effects of this herbal extract on a murine dextran sodium sulfate (DSS) model of IBD. Hematoxylin and eosin-stained paraffin sections prepared from DSS-treated animals show clear epithelial damage, including ulcerations, extensive neutrophil infiltration into the mucosal layer, and granuloma formation. Tissue from DSS-treated animals that also received LN extract showed improved tissue morphology more closely resembling that from control animals. In addition, DSS-treated mice with co-administration of LN extract showed a significant reduction in CD4+ antibody staining within the mucosal layer in colonic sections indicating reduced lymphocyte infiltration. Based on these findings, we believe that the administration of LN extracts may be effective in reducing the intestinal epithelial damage seen in human IBD and warrants further investigation through clinical trials. Lay Summary: Inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis (UC), manifest as chronic inflammation and ulceration of tissues lining the digestive tract. CD involves inflammation of the deeper layers of the digestive tract, including both the small and large intestines, and less commonly, the upper digestive tract. UC involves inflammation along the lining of the colon and rectum. Steroid or biological treatments for IBD are common, however, they are limited due to significant side effects and/or prohibitive costs. In the present study, we provide evidence for use of the natural product, Laurus nobilis (bay leaf), as a safe and effective anti-inflammatory therapy for IBD.

Free Light Chains, High Mobility Group Box 1, and Mortality in Hemodialysis Patients.

Background: Uremic toxins are associated with immune dysfunction and inflammation. The inadequate removal by hemodialysis (HD) of serum free light chains (FLCs) determines their accumulation. This study evaluated FLCs in HD patients, analyzing their relations with other biomarkers, such as serum high mobility group box 1 (HMGB1). Methods: FLC and HMGB1 were evaluated in a cohort of 119 HD patients. κFLC and λFLC were summated to give a combined (c) FLC concentration. Patients were followed prospectively until the end of the observation period of four years, or until the endpoint: the patient’s death. Results: cFLC values in HD patients were 244.4 (197.9−273.5) mg/L. We detected a significant reduction in CD8+ cells and a decreased CD4+/CD8+ ratio. HMGB1 levels were 94.5 (55−302) pg/mL. After multivariate analysis, cFLCs correlated with β2-microglobulin and the CD4+/CD8+ ratio. Subjects with cFLC values above 263 mg/L and with sHMGB1 values < 80 pg/mL experienced a significantly faster evolution to the endpoint (mean follow-up time to progression of 27.5 and 28.5 months, respectively; p < 0.001). After an adjusted multivariate Cox analysis, cFLCs were associated with 11% increased risk of death, whereas low sHMGB1 increased this risk by 5%. Conclusions: cFLCs and HMGB1 reflect the inflammation and immune dysfunction in HD patients representing two strong and independent risk markers of mortality.

Immunological signature in human cases of monkeypox infection in 2022 outbreak: an observational study

An unprecedented global monkeypox outbreak started in May, 2022. No data are yet available about the dynamics of the immune response against monkeypox virus. The aim of this study was to describe kinetics of T-cell response, inflammatory profile, and pox-specific T-cell induction in patients with laboratory-confirmed monkeypox. 17 patients with laboratory-confirmed monkeypox admitted at the Lazzaro Spallanzani National Institute for Infectious Diseases (Rome, Italy), from May 19, to July 7, 2022, were tested for differentiation and activation profile of CD4 and CD8 T (expression of CD38, PD-1, and CD57 assessed by flow cytometry), frequency of pox-specific T cells (by standard interferon-γ ELISpot), and release of interleukin (IL)-1β, IL-6, IL-8, and tumour necrosis factor (TNF) in plasma (by ELISA). All patients were tested 10-12 days after symptoms onset. In a subgroup of nine patients with a laboratory-confirmed monkeypox, the kinetics of the immune response were analysed longitudinally according to timing from symptoms onset and compared with ten healthy donors (ie, health-care workers recruited from the same institution). Among the 17 patients, ten were HIV negative and seven HIV positive, all with good viro-immunological status. On days 0-3 from symptom onset, patients with laboratory-confirmed monkeypox were characterised by a statistically significant reduction in CD4+ T cells (p=0·0011) and a concurrent increase of CD8+ T cells (p=0·0057) compared with healthy donors. A lower proportion of naive (CD45RA+CD27+) CD4+ T cells was observed in six (67%) of nine patients and a concomitant higher proportion of effector memory (CD45RA-CD27-) CD4+ T cells in all patients; this skewed immune profile tended to normalise over time. A similar differentiated profile was also observed in CD8+ T cells with a consistent expansion of terminally differentiated CD8+ T cells. Patients with monkeypox had a higher proportion of CD4+CD38+ and CD38+CD8+ T-cells than healthy donors, which normalised after 12-20 days from symptom onset. The expression of PD-1 and CD57 on CD4+ and CD8+ T-cells showed kinetics similar to that observed for CD38. Furthermore, the inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF) were higher in patients with monkeypox than in healthy donors and, although they decreased over time, they remained elevated after recovery. Almost all patients (15 [94%] of 16) developed a pox-specific Th1 response. No differences in immune cells profile were observed between patients with and without HIV, whereas paucysimptomatic patients (without systemic symptoms, with less than five skin lesions, and no other mucosal localisation of monkeypox) showed a less perturbed immune profile early after symptom onset. Our data showed the immunological signature of monkeypox virus infection, characterised by an early expansion of activated effector CD4+ and CD8+ T cells that persisted over time. Almost all patients, even regardless of HIV infection, developed a poxvirus-specific Th1 cell response. These results might have implications on the expected immunogenicity of monkeypox vaccination, suggesting that it might not be necessary to vaccinate people who have already been infected. Italian Ministry of Health. For the Italian translation of the abstract see Supplementary Materials section.

Apremilast and narrowband ultraviolet B combination therapy suppresses Th17 axis and promotes melanogenesis in vitiligo skin: a randomized, split-body, pilot study in skin types IV-VI.

Improved repigmentation of generalized vitiligo in skin types IV-VI has been reported in clinical response to combined therapy with apremilast and narrowband (NB)-UVB; however, tissue responses to combined therapy versus NB-UVB monotherapy have not been elucidated. We compared the change from baseline in cellular and molecular markers in vitiligo skin after combined therapy versus NB-UVB monotherapy. We assessed lesional and nonlesional skin samples from enrolled subjects and evaluated for immune infiltrates, inflammatory, and melanogenesis-related markers which were compared across different treatment groups. Combined therapy resulted in significant reduction of CD8+T cells and CD11c+ dendritic cells, downregulation of PDE4B and Th17-related markers, and upregulation of melanogenesis markers. This study was limited to small sample size, skin types IV-VI, and high dropout rate. Our molecular findings support the clinical analysis that apremilast may potentiate NB-UVB in repigmentation of generalized vitiligo in skin types IV-VI.

Effects of 1,25-Dihydroxyvitamin D3 and 25-Hydroxyvitamin D3 on PBMCs From Dairy Cattle Naturally Infected With Mycobacterium avium subsp. paratuberculosis.

The role of vitamin D3 in modulating immune responses has been well-established for over two decades; however, its specific functions have not been extensively detailed in cattle, particularly cattle in different stages of infection with Mycobacterium avium subspecies paratuberculosis (MAP). Consistent with previous work in our lab, the present study showed that infected cattle in the clinical stage of disease have reduced serum 25-hydroxyvitamin D3 [25(OH)D3]. Additionally, effects of vitamin D3 on peripheral blood mononuclear cells (PBMCs) from naturally infected dairy cattle in subclinical (n = 8) or clinical (n = 8) stages of infection were compared to non-infected control cows (n = 8). Briefly, PBMCs were isolated and cultured in vitro with 4 ng/ml 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or 100 ng/ml 25(OH)D3. Treatment with 1,25(OH)2D3 resulted in decreased secretion for some pro-inflammatory cytokines in clinical animals, including IL-1β, IL-6, and IFN-γ. Similar responses for IL-1β and IL-6 were noted with the addition of 25(OH)D3. Additionally, pro-inflammatory cytokine gene expression tended to be upregulated in PBMCs from clinical animals after treatment with 1,25(OH)2D3. In contrast, PBMCs from clinical animals treated with 25(OH)D3 showed downregulation of pro-inflammatory cytokine gene expression, although only significant for IL1B. Following 25(OH)D3 treatment, clinical animals showed significant reduction in CD4+CD25+ T cells. CYP27B1 gene expression was notably decreased in clinical and control animals following 25(OH)D3 treatment but increased in subclinical cows. 1,25(OH)2D3 treatment reduced CYP24A1 gene expression in all groups, while 25(OH)D3 treatment only significantly reduced expression for control cows. Lastly, serum 25(OH)D3 levels were significantly lower in clinical animals. Taken together, these data show vitamin D3 modulates cytokine signaling in cattle at different stages of MAP infection and, therefore, may have implications on disease progression.

Mitochondrial Dysfunction Associates With Acute T Lymphocytopenia and Impaired Functionality in COVID-19 Patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in rapid T lymphocytopenia and functional impairment of T cells. The underlying mechanism, however, remains incompletely understood. In this study, we focused on characterizing the phenotype and kinetics of T-cell subsets with mitochondrial dysfunction (MD) by multicolor flow cytometry and investigating the association between MD and T-cell functionality. While 73.9% of study subjects displayed clinical lymphocytopenia upon hospital admission, a significant reduction of CD4 or CD8 T-cell frequency was found in all asymptomatic, symptomatic, and convalescent cases. CD4 and CD8 T cells with increased MD were found in both asymptomatic and symptomatic patients within the first week of symptom onset. Lower proportion of memory CD8 T cell with MD was found in severe patients than in mild ones at the stage of disease progression. Critically, the frequency of T cells with MD in symptomatic patients was preferentially associated with CD4 T-cell loss and CD8 T-cell hyperactivation, respectively. Patients bearing effector memory CD4 and CD8 T cells with the phenotype of high MD exhibited poorer T-cell responses upon either phorbol 12-myristate-13-acetate (PMA)/ionomycin or SARS-CoV-2 peptide stimulation than those with low MD. Our findings demonstrated an MD-associated mechanism underlying SARS-CoV-2-induced T lymphocytopenia and functional impairment during the acute phase of infection.

MO902SERUM FREE LIGHT CHAINS IN HEMODIALYSIS PATIENTS: A BRIDGE BETWEEN INFLAMMATION, IMMUNE SYSTEM DYSFUNCTION AND MORTALITY RISK

Abstract Background and Aims Uremic toxins, poor removed by conventional hemodialysis (HD), represent independent risk factors for mortality in end-stage renal disease (ESRD). Middle uremic toxin molecules were associated to pathological features of uremia, such as immune dysfunction and inflammation. These two entities are not mutually exclusive, but they could represent two sides of the same coin. ESRD-associated inflammation is closely related to the activation of innate immune system. Free light chain (FLC) may be a specific assessment of inflammation, representing a direct function of adaptive immunity through B-cell lineage production rather than a general marker of inflammation. While several studies have assessed the relation between FLCs and mortality risk in chronic kidney disease (CKD), FLCs, as uremic toxins in non-multiple myeloma dialyzed patients, were marginally analyzed. The aim of this prospective study was to evaluate the clinical impact of FLCs levels in HD patients, during a 2-years follow-up analysing the relations with biomarkers of inflammation, such as C-reactive protein (CRP) and procalcitonin (PCT), main lymphocytes subsets, such as CD4+ and CD8+ T cell count and high mobility group box (HMGB) -1 levels, as expression of the innate immune system. The potential link between FLCs levels and mortality risk was assessed. Method 190 patients on chronic hemodialysis at the Nephrology and Dialysis Unit of Papardo Hospital in Messina, Italy, were enrolled and followed for 2 years. Inclusion criteria were: age &amp;gt;18 years, absence or &amp;lt;200 ml/die residual diuresis, κ/λ ratio within the renal reference range (0.37–3.1). Receiver operating characteristics (ROC) analysis was performed to estimate the cut-off points of HMGB-1 and cFLC. Kaplan-Meier survival analysis and Cox proportional multivariate hazards model were used for clinical outcome. Results HD patients were characterized by high FLC levels. κFLC values were 182.3 (IQR: 140.2 – 216.1) mg/L, whereas λFLC levels were 108.2 (IQR: 72.7 – 143.2) mg/L. The median combined (c) FLC concentration was 182.9 mg/L (IQR = 207.8 – 330.2), which was extremely greater than the median reported in the general population (normal range = 9.3 – 43.3 mg/L) and in CKD patients [68.9 mg/L (IQR = 49.4 – 100.9)]. No differences in cFLC levels were revealed according to dialysis techniques. HD patients showed significant reduction of CD4+ and CD4+/CD8+ ratio. High HMGB1 levels were detected in HD patients (161.3 ± 39.7 ng/ml) and positively related to PCT and cFLC (r = - 0.38; p &amp;lt; 0.001), with an inverse relation to CD4+/CD8+ ratio. cFLC positively correlated with β2 microglobulin, hemoglobin, and HMGB1. Conversely, an inverse correlation was revealed with surrogate markers of inflammation, such as CRP, procalcitonin, neutrophil counts. There were 49 deaths during the follow-up. The majority (23/49) of deaths were attributed to cardiovascular disease, the remainder to infection and malignancy. cFLCs and sHMGB-1 levels in this group were significantly elevated. By ROC analysis, HMGB-1 levels &amp;gt; 100.9 ng/mL and cFLC &amp;gt; 223.4 mg/l were associated with a significantly lower survival rate (p &amp;lt; 0.02 by log-rank test) than for patients with lower levels when using Kaplan-Meier analysis. After adjusting for confounding factors, by Cox proportional hazards method, the difference remained statistically significant (p = 0.02) Conclusion Our study demonstrated an independent relation between high cFLC levels and mortality in HD patients. cFLCs represent a potential biomarker of “inflammunity”, a physiopathological process playing a pivotal role in ESRD, based on a vicious circle between inflammation and immune dysfunction. Further in-depth examinations should be verify our findings, determining whether therapeutic measures targeting cFLC balance, such as hemodiafiltration and expanded dialysis, would be helpful to reduce the “inflammunity” process, characterizing dialyzed patients.

EBV DNA increase in COVID-19 patients with impaired lymphocyte subpopulation count

ObjectivesThe immunologic profile and opportunistic viral DNA increase were monitored in Italian patients with COVID-19 in order to identify markers of disease severity. MethodsA total of 104 patients infected with SARS-CoV-2 were evaluated in the study. Of them, 42/104 (40.4%) were hospitalized in an intensive care unit (ICU) and 62/104(59.6%) in a sub-intensive care unit (SICU). Human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV), Parvovirus B19 and Human Herpesvirus 6 virus reactivations were determined by real-time PCR, and lymphocyte subpopulation counts were determined by flow cytometry. ResultsAmong opportunistic viruses, only EBV was consistently detected. EBV DNA was observed in 40/42 (95.2%) of the ICU patients and in 51/61 (83.6%) of the SICU patients. Comparing the two groups of patients, the EBV DNA median level among ICU patients was significantly higher than that observed in SICU patients. In parallel, a significant reduction of CD8 T cell and NK count in ICU patients as compared with SICU patients was observed (p<0.05). In contrast, B cell count was significantly increased in ICU patients (p=0.0172). ConclusionsA correlation between reduced CD8+ T cells and NK counts, EBV DNA levels and COVID-19 severity was observed. Other opportunistic viral infections were not observed. The relationship between EBV load and COVID-19 severity should be further evaluated in longitudinal studies.

SnapshotDx Quiz: December 2020

SnapshotDx Quiz: December 2020