Delta-like 1-mediated Notch signaling enhances the in vitro conversion of human memory CD4 T cells into FOXP3-expressing regulatory T cells.

FOXP3-expressing regulatory T cells (Treg) are essential for the prevention of autoimmunity and were shown to be reduced and/or dysfunctional in several autoimmune diseases. Although Treg-based adoptive transfer represents a promising therapy, the large cell number required to achieve clinical efficacy constitutes an important limitation. Therefore, novel strategies to generate bona fide in vitro-induced Treg (iTreg) are critical. In this study, we report that human memory CD4 T cells can be efficiently converted into iTreg, and that Delta-like 1 (DL1)-mediated Notch signaling significantly enhances this process. The iTreg generated in the presence of DL1 featured higher levels of Treg function-associated molecules and were efficient suppressors. Importantly, these iTreg displayed a stable phenotype in long-term cultures, even in the presence of proinflammatory cytokines. Additionally, DL1 potentiated FOXP3 acquisition by memory CD4 cells through the modulation of the TGF-ß signaling pathway and of Foxp3 transcription. Our data demonstrate that iTreg can be efficiently induced from memory CD4 cells, a subset enriched in relevant specificities for targeting in autoimmune diseases, and that DL1 enhances this process. DL1 also enhanced the proliferation and Treg function-associated marker expression of ex vivo-stimulated human circulating FOXP3(+) cells. Manipulation of the Notch signaling pathway constitutes a promising approach to boost the in vitro generation of iTreg and ex vivo Treg expansion, thus facilitating the establishment of effective Treg-based adoptive therapy in autoimmune diseases.

Monocyte and myeloid dendritic cell activation occurs throughout HIV type 2 infection, an attenuated form of HIV disease.

Monocytes and myeloid dendritic cells (mDCs) are important orchestrators of innate and human immunodeficiency virus (HIV)-specific immune responses and of the generalized inflammation that characterizes AIDS progression. To our knowledge, we are the first to investigate monocyte and mDC imbalances in HIV type 2 (HIV-2)-positive patients, who typically feature reduced viremia and slow disease progression despite the recognized ability of HIV-2 to establish viral reservoirs and overcome host restriction factors in myeloid cells. We found a heightened state of monocyte and mDC activation throughout HIV-2 infection (characterized by CD14(bright)CD16(+) expansion, as well as increased levels of soluble CD14, HLA-DR, and CD86), together with progressive mDC depletion. Importantly, HIV-2-positive patients also featured overexpression of the inhibitory molecule PD-L1 on monocytes and mDCs, which may act by limiting the production of proinflammatory molecules. These data, from patients with a naturally occurring form of attenuated HIV disease, challenge current paradigms regarding the role of monocytes in HIV/AIDS and open new perspectives regarding potential strategies to modulate inflammatory states.

Long-term immune reconstitution of naive and memory t cell pools after haploidentical hematopoietic stem cell transplantation.

Haploidentical hematopoietic stem cell transplantation (HSCT) constitutes an important alternative for patients lacking a human leukocyte antigen (HLA)-matched donor. Although the use of haploidentical donors is increasingly common, the long-term impact of generating a donor-derived immune system in the context of an HLA-mismatched thymic environment remains poorly characterized. We performed an in-depth assessment of immune reconstitution in a group of haploidentical HSCT recipients 4 to 6 years posttransplantation, in parallel with the respective parental donors and age-matched healthy control subjects. Our data show that the proportion of naive and memory subsets in the recipients, both within CD8(+) and CD4(+) T cells, more closely resembled that observed in age-matched control subjects than in the donors. HSCT recipients displayed relatively high signal-joint T cell-receptor excision circle levels and a high frequency of the recent thymic emigrant-enriched CD31(+) subset within naive CD4(+) and naive regulatory T cells. Moreover, CD8(+), CD4(+), and regulatory T cells from HSCT recipients displayed a diverse T cell repertoire. These results support a key role for thymic output in T cell reconstitution. Nevertheless, HSCT recipients had significantly shorter telomeres within a naive-enriched CD4(+) T cell population than age-matched control subjects, despite the similar telomere length observed within the most differentiated CD8(+) and CD4(+) T cell subsets. Overall, our data suggest that long-term immune reconstitution was successfully achieved after haploidentical HSCT, a process that appears to have largely relied on de novo T cell production.

First use of thymus transplantation therapy for FOXN1 deficiency (nude/SCID): a report of 2 cases.

FOXN1 deficiency is a primary immunodeficiency characterized by athymia, alopecia totalis, and nail dystrophy. Two infants with FOXN1 deficiency were transplanted with cultured postnatal thymus tissue. Subject 1 presented with disseminated Bacillus Calmette-Guérin infection and oligoclonal T cells with no naive markers. Subject 2 had respiratory failure, human herpes virus 6 infection, cytopenias, and no circulating T cells. The subjects were given thymus transplants at 14 and 9 months of life, respectively. Subject 1 received immunosuppression before and for 10 months after transplantation. With follow up of 4.9 and 2.9 years, subjects 1 and 2 are well without infectious complications. The pretransplantation mycobacterial disease in subject 1 and cytopenias in subject 2 resolved. Subject 2 developed autoimmune thyroid disease 1.6 years after transplantation. Both subjects developed functional immunity. Subjects 1 and 2 have 1053/mm(3) and 1232/mm(3) CD3(+) cells, 647/mm(3) and 868/mm(3) CD4(+) T cells, 213/mm(3) and 425/mm(3) naive CD4(+) T cells, and 10 200 and 5700 T-cell receptor rearrangement excision circles per 100 000 CD3(+) cells, respectively. They have normal CD4 T-cell receptor ß variable repertoires. Both subjects developed antigen-specific proliferative responses and have discontinued immunoglobulin replacement. In summary, thymus transplantation led to T-cell reconstitution and function in these FOXN1 deficient infants.

Cell-associated viral burden provides evidence of ongoing viral replication in aviremic HIV-2-infected patients.

Viremia is significantly lower in HIV-2 than in HIV-1 infection, irrespective of disease stage. Nevertheless, the comparable proviral DNA burdens observed for these two infections indicate similar numbers of infected cells. Here we investigated this apparent paradox by assessing cell-associated viral replication. We found that untreated HIV-1-positive (HIV-1(+)) and HIV-2(+) individuals, matched for CD4 T cell depletion, exhibited similar gag mRNA levels, indicating that significant viral transcription is occurring in untreated HIV-2(+) patients, despite the reduced viremia (undetectable to 2.6 × 10(4) RNA copies/ml). However, tat mRNA transcripts were observed at significantly lower levels in HIV-2(+) patients, suggesting that the rate of de novo infection is decreased in these patients. Our data also reveal a direct relationship of gag and tat transcripts with CD4 and CD8 T cell activation, respectively. Antiretroviral therapy (ART)-treated HIV-2(+) patients showed persistent viral replication, irrespective of plasma viremia, possibly contributing to the emergence of drug resistance mutations, persistent hyperimmune activation, and poor CD4 T cell recovery that we observed with these individuals. In conclusion, we provide here evidence of significant ongoing viral replication in HIV-2(+) patients, further emphasizing the dichotomy between amount of plasma virus and cell-associated viral burden and stressing the need for antiretroviral trials and the definition of therapeutic guidelines for HIV-2 infection.

Cardiac noradrenergic denervation in a patient with multiple symmetric lipomatosis.

INTRODUCTION: Multiple symmetric lipomatosis (MSL) is a rare disease of unknown etiology characterized by multiple subcutaneous lipomas with a symmetrical distribution. One interesting aspect about MSL is a high incidence of sudden cardiac death despite a low incidence of metabolic syndrome and coronary arterial disease. Autonomic nervous system dysfunction may probably explain this feature of MSL. CASE REPORT: A 74-year-old man was admitted with acute heart failure and atrial fibrillation. He had a morphotype suggestive of MLS. A (123)I-metaiodobenzylguanidine myocardial scintigraphy was conducted for evaluation of cardiac autonomic nervous integrity, since atrial fibrillation precluded the classical approach. The heart-to-mediastinum ratio was 1.68 (normal >2.2). Ischemia was not detected in myocardial perfusion scintigraphy. CONCLUSION: We present the first reported case of MSL autonomic neuropathy detected by (123)I- metaiodobenzylguanidine scintigraphy and suggest that this approach could play a role in MSL stratification by risk of sudden cardiac death and in exploring MSL disease mechanisms.

Major depletion of plasmacytoid dendritic cells in HIV-2 infection, an attenuated form of HIV disease.

Plasmacytoid dendritic cells (pDC) provide an important link between innate and acquired immunity, mediating their action mainly through IFN-alpha production. pDC suppress HIV-1 replication, but there is increasing evidence suggesting they may also contribute to the increased levels of cell apoptosis and pan-immune activation associated with disease progression. Although having the same clinical spectrum, HIV-2 infection is characterized by a strikingly lower viremia and a much slower rate of CD4 decline and AIDS progression than HIV-1, irrespective of disease stage. We report here a similar marked reduction in circulating pDC levels in untreated HIV-1 and HIV-2 infections in association with CD4 depletion and T cell activation, in spite of the undetectable viremia found in the majority of HIV-2 patients. Moreover, the same overexpression of CD86 and PD-L1 on circulating pDC was found in both infections irrespective of disease stage or viremia status. Our observation that pDC depletion occurs in HIV-2 infected patients with undetectable viremia indicates that mechanisms other than direct viral infection determine the pDC depletion during persistent infections. However, viremia was associated with an impairment of IFN-alpha production on a per pDC basis upon TLR9 stimulation. These data support the possibility that diminished function in vitro may relate to prior activation by HIV virions in vivo, in agreement with our finding of higher expression levels of the IFN-alpha inducible gene, MxA, in HIV-1 than in HIV-2 individuals. Importantly, serum IFN-alpha levels were not elevated in HIV-2 infected individuals. In conclusion, our data in this unique natural model of "attenuated" HIV immunodeficiency contribute to the understanding of pDC biology in HIV/AIDS pathogenesis, showing that in the absence of detectable viremia a major depletion of circulating pDC in association with a relatively preserved IFN-alpha production does occur.

IL-7 sustains CD31 expression in human naive CD4+ T cells and preferentially expands the CD31+ subset in a PI3K-dependent manner.

The CD31(+) subset of human naive CD4(+) T cells is thought to contain the population of cells that have recently emigrated from the thymus, while their CD31(-) counterparts have been proposed to originate from CD31(+) cells after homeostatic cell division. Naive T-cell maintenance is known to involve homeostatic cytokines such as interleukin-7 (IL-7). It remains to be investigated what role this cytokine has in the homeostasis of naive CD4(+) T-cell subsets defined by CD31 expression. We provide evidence that IL-7 exerts a preferential proliferative effect on CD31(+) naive CD4(+) T cells from adult peripheral blood compared with the CD31(-) subset. IL-7-driven proliferation did not result in loss of CD31 expression, suggesting that CD31(+) naive CD4(+) T cells can undergo cytokine-driven homeostatic proliferation while preserving CD31. Furthermore, IL-7 sustained or increased CD31 expression even in nonproliferating cells. Both proliferation and CD31 maintenance were dependent on the activation of phosphoinositide 3-kinase (PI3K) signaling. Taken together, our data suggest that during adulthood CD31(+) naive CD4(+) T cells are maintained by IL-7 and that IL-7-based therapies may exert a preferential effect on this population.

Malabsorption Syndrome due to Intestinal Amyloidosis as Presentation of Renal Cell Carcinoma.

Renal cell carcinoma accounts for approximately 3% of adult malignancies. Designated in the literature as "the great masquerader," the great diversity of clinical manifestations is associated with the several paraneoplastic syndromes that potentially accompany it. Paraneoplastic amyloidosis is described in about 3-8% of cases, only exceptionally as an initial manifestation, with uncommon gastrointestinal involvement. A rare case of malabsorption by intestinal amyloidosis is presented as initial manifestation of renal cell carcinoma, emphasizing the need for early recognition of these paraneoplastic conditions.

Gag-specific CD4+ T-cell frequency is inversely correlated with proviral load and directly correlated with immune activation in infection with human immunodeficiency virus type 2 (HIV-2) but not HIV-1.

Human immunodeficiency virus type 2 (HIV-2) infection, unlike HIV-1 infection, is normally characterized by low rates of CD4 depletion and low-to-undetectable viremia. We found that the frequency of Gag-specific CD4(+) T cells featured positive correlations with the expression of markers of CD4 activation and a negative correlation with peripheral blood mononuclear cell-associated proviral load in infection with HIV-2, in contrast with HIV-1. Moreover, HIV-2-infected individuals exhibited a greater ability to respond to HIV-1 Gag peptides (heterologous responses). Our data suggest a potential link between HIV-2-specific CD4 responses, immune activation, and viral control, which may in turn relate to the better prognosis associated with HIV-2 infection.

Multiple aseptic liver abscesses as the initial manifestation of Crohn's disease: report of a case.

Aseptic liver abscesses preceding the diagnosis of Crohn's disease are extremely rare. We report a patient with multiple liver abscesses that yielded negative microbiologic investigation and failed to develop full remission under antibiotic therapy. Diagnosis of Crohn's disease of small and large bowel was later established and she was started on sulfasalazine and azathioprine with total regression of the hepatic abscesses. This case illustrates the rare possibility of aseptic liver abscesses as an initial manifestation of Crohn's disease, which could be interpreted in the light of recent data on aberrant homing of gut T memory/effector lymphocytes in the liver.

Facial Paralysis as Initial Manifestation of Light-chain Amyloidosis.

Light-chain (AL) amyloidosis is a systemic disease capable of damaging virtually all body tissues. Neurologic involvement is commonly manifested by dysautonomia and peripheral nervous system affection. However, from 1970 to 2018, only 12 cases of cranial nerve injury associated with AL amyloidosis were identified. Eight months before hospital admission, a previously healthy 61-year-old man complained to his general practitioner of episodes of lipotimia while walking and, three months later, he developed a left facial nerve paralysis assumed, at that time, to be idiopathic. After two months, he started complaining of dyspnea and lower limb edema. Physical examination at admission revealed hypotension, exuberant peripheral edema, jugular venous distention, periorbital purpura and left peripheral facial paralysis. He had elevated troponin and brain natriuretic peptide, mild proteinuria and a monoclonal gammopathy IgG/lambda. Bone marrow biopsy revealed 20% plasmocytes and cardiac ultrasound showed diffuse hypokinesia and restrictive filling pattern. AL amyloidosis with major cardiac involvement was considered and a rectal biopsy revealed amyloid protein. Chemotherapy protocol to AL amyloidosis was initiated but cardiac disease progressed leading to death. Persistent facial nerve paralysis should be considered as a rare initial manifestation of AL amyloidosis allowing an earlier diagnosis.

Monozygotic Twins Concordant for Common Variable Immunodeficiency: Strikingly Similar Clinical and Immune Profile Associated With a Polygenic Burden.

Monozygotic twins provide a unique opportunity to better understand complex genetic diseases and the relative contribution of heritable factors in shaping the immune system throughout life. Common Variable Immunodeficiency Disorders (CVID) are primary antibody defects displaying wide phenotypic and genetic heterogeneity, with monogenic transmission accounting for only a minority of the cases. Here, we report a pair of monozygotic twins concordant for CVID without a family history of primary immunodeficiency. They featured a remarkably similar profile of clinical manifestations and immunological alterations at diagnosis (established at age 37) and along the subsequent 15 years of follow-up. Interestingly, whole-exome sequencing failed to identify a monogenic cause for CVID, but unraveled a combination of heterozygous variants, with a predicted deleterious impact. These variants were found in genes involved in relevant immunological pathways, such as JUN, PTPRC, TLR1, ICAM1, and JAK3. The potential for combinatorial effects translating into the observed disease phenotype is inferred from their roles in immune pathways, namely in T and B cell activation. The combination of these genetic variants is also likely to impose a significant constraint on environmental influences, resulting in a similar immunological phenotype in both twins, despite exposure to different living conditions. Overall, these cases stress the importance of integrating NGS data with clinical and immunological phenotypes at the single-cell level, as provided by multi-dimensional flow-cytometry, in order to understand the complex genetic landscape underlying the vast majority of patients with CVID, as well as those with other immunodeficiencies.

Increased frequency of CD25dimCD4+ T-cells in HIV-2 infection, a naturally occurring attenuated form of HIV-1.

The ability to maintain the CD4-memory pool is currently considered one of the main determinants of AIDS progression. Like HIV-1, HIV-2 infection is characterized by progressive hyper-immune activation, yet it is associated with slower rates of CD4-loss and reduced viremia irrespective of disease stage. In contrast to HIV-1, we observed an increased proportion of CD4(+) T-cells expressing CD25 in HIV-2 infected individuals, independent of the degree of CD4-depletion and levels of immune activation. This was due to CD4(+) T-cells expressing an intermediate intensity of CD25, characterized by an increased ability to produce IL-2 and a lack of other regulatory markers. This expansion, unique to HIV-2 seropositive individuals, may relate to an improved ability to replenish their CD4-memory pool, and thus to the better prognosis that characterizes HIV-2 infection. Identification of the underlying mechanisms regulating this population in HIV-1 and HIV-2 infections may provide a rational for novel therapeutic strategies.

[Pulmonary MALT lymphoma - a rare form of lymphoma]. / Linfoma MALT do pulmão - Uma forma rara de linfoma.

The authors report a case of pulmonary MALT lymphoma in an asymptomatic patient with a chest radiograph showing bilateral infiltrates. The diagnosis was made by surgical lung biopsy performed by video-assisted thoracoscopy. The transbronchial lung and the transthoracic core-needle biopsies were non-diagnostic. The clinical and radiological features of the pulmonary MALT lymphoma are described and relevant diagnostic, prognostic and treatment factors are discussed.

Exuberant liver adenomatosis presenting with iron deficiency anemia.

Intratumoral or intraperitoneal hemorrhage is a recognized complication of liver adenomatosis. We report a case of multifocal massive liver adenomatosis presenting as chronic iron deficiency anemia. Clinicians' awareness about this atypical presentation not highlighted in the literature is important to allow timely diagnosis and surgical intervention to prevent fatal complications.

Disseminated Necrotizing Leukoencephalopathy Complicating Septic Shock in an Immunocompetent Patient.

Disseminated necrotizing leukoencephalopathy (DNL) is characterized by multiple microscopic foci of white matter necrosis. DNL was initially thought to be exclusively associated with immunosuppression conditions but it has been recently described in immunocompetent patients in septic shock. A 90-year-old immunocompetent woman with no previous neurological impairment presented with septic shock and drowsiness that responded well to therapy with clinical improvement and a full neurological recovery. Unexpectedly deterioration with progression to coma occurred. Investigation excluded other causes and Magnetic Resonance Imaging (MRI) was consistent with the diagnosis of DNL showing bilateral multifocal white matter lesions with a nonvascular pattern with restricted diffusion. Neurological impairment persisted with progression to death. DNL is an unexpected diagnosis in an immunocompetent patient. We compared the present case to those found in the literature of DNL complicating septic shock and discuss the antemortem diagnosis based on MRI findings.

Multisystemic Sarcoidosis with Early Gastrointestinal Symptoms.

Sarcoidosis involving the digestive tract is very rare and requires a strict differential diagnosis with other systemic granulomatous diseases. We present a case of multisystemic granulomatosis involving the stomach and colon, causing initial digestive symptoms. Pulmonary nodules, pleural effusion, ascites, hepatomegaly, splenomegaly, and mesenteric as well as retroperitoneal and axillary lymphadenopathy were subsequently identified. The reticulo-endothelial expression, the hypercalcemia and, above all, a rapid and complete resolution after corticosteroids supported the hypothesis of sarcoidosis involving the digestive tract. A brief review of digestive tract involvement in sarcoidosis and of the distinctive features of sarcoidosis with gastrointestinal involvement and Crohn's disease with a rare form of pleuro-pulmonary involvement is presented.

Methimazole associated eosinophilic pleural effusion: a case report.

BACKGROUND: Adverse reactions associated to anti-thyroid drugs include fever, rash, arthralgia, agranulocytosis and hepatitis that are thought to be hypersensitivity reactions. Five cases of pleural effusion associated to thionamides have also been reported, two with propylthiouracil and three with carbimazole. CASE PRESENTATION: We report here a case of a 75-year-old man admitted because of unilateral pleural effusion. The patient had a recent diagnosis of hyperthyroidism and 6 days after starting methimazole complained of pleuritic chest pain. He had elevated C-reactive protein and erythrocyte sedimentation rate and normal white blood cell count and liver enzymes. Chest radiography showed a moderate right pleural effusion and the ultrasound revealed a loculated effusion that was shown to be an eosinophilic exudate. CONCLUSIONS: The temporal relationship between methimazole intake and the development of pleural effusion combined with the extensive exclusion of alternative causes, namely infectious, neoplastic and primary auto-immune diseases, led to the diagnosis of hypersensitivity reaction to methimazole. The thionamide was stopped and corticosteroid was started with complete resolution of the pleural effusion in 3 months. Awareness of this rare adverse reaction of anti-thyroid drugs is important and methimazole can be added to the list of possible etiologies of drug-induced eosinophilic pleural effusion.

Iron Refractory Iron Deficiency Anemia in Dizygotic Twins Due to a Novel TMPRSS6 Gene Mutation in Addition to Polymorphisms Associated With High Susceptibility to Develop Ferropenic Anemia.

Iron refractory iron deficiency anemia (IRIDA) is an autosomal recessive ferropenic anemia. Its hypochromic microcytic pattern is associated with low transferrin saturation, normal-high ferritin, and inappropriately high hepcidin level. This entity is caused by mutants of the TMPRSS6 gene that encodes the protein matriptase II, which influences hepcidin expression, an iron metabolism counterregulatory protein. We report two 29-year-old dizygotic female twins with ferropenic, hypochromic microcytic anemia with 20 years of evolution, refractory to oral iron therapy. After exclusion of gastrointestinal etiologies, IRIDA diagnosis was suspected and a novel mutation in the TMPRSS6 gene was identified. It was found in intron 11 (c.1396+4 A>T) and seems to affect the gene expression. In addition, 3 polymorphisms already associated with a higher risk of developing iron deficiency anemia were also found (D521D, V736A, and Y739Y). Our case reports an undescribed mutation causing IRIDA and supports the hypothesis that this clinical syndrome may be more common than previously thought and its genetics more heterogeneous than initially described.