Chronic active Epstein-Barr virus infection as the initial symptom in a Janus kinase 3 deficiency child: Case report and literature review.

RATIONALE: With the progress of sequencing technology, an increasing number of atypical primary immunodeficiency (PID) patients have been discovered, including Janus kinase 3 (JAK3) gene deficiency. PATIENT CONCERNS: We report a patient who presented with chronic active Epstein-Barr virus (CAEBV) infection but responded poorly to treatment with ganciclovir. DIAGNOSES: Next-generation sequencing (NGS) was performed, including all known PID genes, after which Sanger sequencing was performed to verify the results. Genetic analysis revealed that our patient had 2 novel compound heterozygous mutations of JAK3, a gene previously reported to cause a rare form of autosomal recessive severe combined immunodeficiency with recurrent infections. The p.H27Q mutation came from his father, while p. R222H from his mother. Thus, his diagnosis was corrected for JAK3-deficiency PID and CAEBV. INTERVENTIONS: Maintenance treatment of subcutaneous injection of recombinant human interferon α-2a was given to our patient with 2 MU, 3 times a week. OUTCOMES: Interferon alpha was applied and the EBV infection was gradually controlled and his symptoms ameliorated remarkably. Our patient is in good health now and did not have relapses. LESSONS: The diagnoses of PID should be taken into consideration when CAEBV patients respond poorly to conventional treatments. Good results of our patient indicate that interferon α-2a may be an alternative treatment for those who are unwilling to accept hematopoietic stem cell transplantation (HSCT) like our patient. Literature review identified 59 additional cases of JAK3 deficiency with various infections.

Evidence of innate lymphoid cell redundancy in humans.

Innate lymphoid cells (ILCs) have potent immunological functions in experimental conditions in mice, but their contributions to immunity in natural conditions in humans have remained unclear. We investigated the presence of ILCs in a cohort of patients with severe combined immunodeficiency (SCID). All ILC subsets were absent in patients with SCID who had mutation of the gene encoding the common γ-chain cytokine receptor subunit IL-2Rγ or the gene encoding the tyrosine kinase JAK3. T cell reconstitution was observed in patients with SCID after hematopoietic stem cell transplantation (HSCT), but the patients still had considerably fewer ILCs in the absence of myeloablation than did healthy control subjects, with the exception of rare cases of reconstitution of the ILC1 subset of ILCs. Notably, the ILC deficiencies observed were not associated with any particular susceptibility to disease, with follow-up extending from 7 years to 39 years after HSCT. We thus report here selective ILC deficiency in humans and show that ILCs might be dispensable in natural conditions, if T cells are present and B cell function is preserved.

Cytomegalovirus Meningitis in an Infant with Severe Combined Immunodeficiency.

A 35-day-old female with severe combined immunodeficiency developed cytomegalovirus (CMV) meningitis before undergoing hematopoietic stem cell transplantation. Strategies for timely diagnosis of neonates with congenital or acquired CMV infection and prevention of CMV acquisition in the era of universal newborn severe combined immunodeficiency screening are needed.

Impact of Janus Kinase 3 on Cellular Ca Release, Store Operated Ca(2+) Entry and Na(+)/Ca(2+) Exchanger Activity in Dendritic Cells.

BACKGROUND/AIMS: Janus kinase 3 (JAK3), a tyrosine kinase mainly expressed in hematopoietic cells, participates in the signaling stimulating cell proliferation. The kinase is expressed in dendritic cells (DCs), antigen presenting cells involved in the initiation and regulation of antigen-specific T-cell responses. Dendritic cell function is regulated by cytosolic Ca(2+) activity ([Ca(2+)]i). Mediators increasing [Ca(2+)]i in DCs include ATP and the chemokine receptor CXCR4 ligand CXCL12. The present study explored, whether JAK3 participates in the regulation of [Ca(2+)]i in DCs. METHODS: Fura-2 fluorescence was employed to determine [Ca(2+)]i, and whole cell patch clamp to decipher electrogenic transport in immature DCs isolated from bone marrow of JAK3-knockout (jak3(-/-)) or wild-type mice (jak3(+/+)). RESULTS: Without treatment, [Ca(2+)]i was similar in jak3(-/-) and jak3(+/+) DCs. Addition of ATP (100 µM) was followed by transient increase of [Ca(2+)]i reflecting Ca(2+) release from intracellular stores, an effect significantly less pronounced in jak3(-/-) DCs than in jak3(+/+) DCs. CXCL12 administration was followed by a sustained increase of [Ca(2+)]i reflecting receptor operated Ca(2+) entry, an effect significantly less rapid in jak3(-/-) DCs than in jak3(+/+) DCs. In addition, the Ca(2+) release-activated Ca(2+) channel (CRAC) current triggered by IP3-induced Ca(2+) store depletion and CXCL12 was significantly higher in DCs from jak3(+/+) mice than in jak3(-/-) mice. Inhibition of sarcoendoplasmatic reticulum Ca(2+)-ATPase (SERCA) by thapsigargin (1 µM) in the absence of extracellular Ca(2+) was followed by a transient increase of [Ca(2+)]i reflecting Ca(2+) release from intracellular stores, and subsequent readdition of extracellular Ca(2+) in the continued presence of thapsigargin was followed by a sustained increase of [Ca(2+)]i reflecting store operated Ca(2+) entry (SOCE). Both, Ca(2+) release from intracellular stores and SOCE were again significantly lower in jak3(-/-) DCs than in jak3(+/+) DCs. Pretreatment of jak3(+/+) DCs with JAK inhibitor WHI-P154 (22 µM, 10 minutes or 24 hours) significantly blunted both thapsigargin induced Ca(2+) release and subsequent SOCE. Abrupt replacement of Na(+) containing (130 mM) and Ca(2+) free (0 mM) extracellular bath by Na(+) free (0 mM) and Ca(2+) containing (2 mM) extracellular bath increased [Ca(2+)]i reflecting Na(+)/Ca(2+) exchanger activity, an effect again significantly less pronounced in jak3(-/-) DCs than in jak3(+/+) DCs. CONCLUSIONS: JAK3 deficiency is followed by down-regulation of cytosolic Ca(2+) release, receptor and store operated Ca(2+) entry and Na(+)/Ca(2+) exchanger activity in DCs.

Aberrant expression of NF-κB in liver fluke associated cholangiocarcinoma: implications for targeted therapy.

BACKGROUND: Up-regulation and association of nuclear factor kappa B (NF-κB) with carcinogenesis and tumor progression has been reported in several malignancies. In the current study, expression of NF-κB in cholangiocarcinoma (CCA) patient tissues and its clinical significance were determined. The possibility of using NF-κB as the therapeutic target of CCA was demonstrated. METHODOLOGY: Expression of NF-κB in CCA patient tissues was determined using immunohistochemistry. Dehydroxymethylepoxyquinomicin (DHMEQ), a specific NF-κB inhibitor, was used to inhibit NF-κB action. Cell growth was determined using an MTT assay, and cell apoptosis was shown by DNA fragmentation, flow cytometry and immunocytofluorescent staining. Effects of DHMEQ on growth and apoptosis were demonstrated in CCA cell lines and CCA-inoculated mice. DHMEQ-induced apoptosis in patient tissues using a histoculture drug response assay was quantified by TUNEL assay. PRINCIPAL FINDINGS: Normal bile duct epithelia rarely expressed NF-κB (subunits p50, p52 and p65), whereas all CCA patient tissues (n  =  48) over-expressed all NF-κB subunits. Inhibiting NF-κB action by DHMEQ significantly inhibited growth of human CCA cell lines in a dose- and time-dependent manner. DHMEQ increased cell apoptosis by decreasing the anti-apoptotic protein expressions-Bcl-2, XIAP-and activating caspase pathway. DHMEQ effectively reduced tumor size in CCA-inoculated mice and induced cell apoptosis in primary histocultures of CCA patient tissues. CONCLUSIONS: NF-κB was over-expressed in CCA tissues. Inhibition of NF-κB action significantly reduced cell growth and enhanced cell apoptosis. This study highlights NF-κB as a molecular target for CCA therapy.

Efficacy of anti-CD47 antibody-mediated phagocytosis with macrophages against primary effusion lymphoma.

BACKGROUND: Recently, the critical role of CD47 on the surface of resistant cancer cells has been proposed in their evasion of immunosurveillance. Primary effusion lymphoma (PEL) is a subtype of aggressive non-Hodgkin lymphoma that shows serous lymphomatous effusion in body cavities, especially in advanced acquired immunodeficiency syndrome (AIDS). PEL is resistant to conventional chemotherapy and has a poor prognosis. In this study, we evaluated the effect of anti-CD47 antibody (Ab) on PEL in vitro and in vivo. METHODS: Surface CD47 of PEL cell lines was examined by flow cytometry. Efficacy of knocking down CD47 or anti-CD47 Ab-mediated phagocytosis against PEL was evaluated using mouse peritoneal macrophages and human macrophages in vitro. Primary PEL cells were injected intraperitoneally into NOD/Rag-2/Jak3 double-deficient (NRJ) mice to establish a direct xenograft mouse model. RESULTS: Surface CD47 of PEL cell lines was highly expressed. Knocking down CD47 and anti-CD47 Ab promoted phagocytic activities of macrophages in a CD47 expression-dependent manner in vitro. Treatment with anti-CD47 Ab inhibited ascite formation and organ invasion completely in vivo compared with control IgG-treated mice. CONCLUSION: CD47 plays the pivotal role in the immune evasion of PEL cells in body cavities. Therapeutic antibody targeting of CD47 could be an effective therapy for PEL.

Effective elicitation of human effector CD8+ T Cells in HLA-B*51:01 transgenic humanized mice after infection with HIV-1.

Humanized mice are expected to be useful as small animal models for in vivo studies on the pathogenesis of infectious diseases. However, it is well known that human CD8(+) T cells cannot differentiate into effector cells in immunodeficient mice transplanted with only human CD34(+) hematopoietic stem cells (HSCs), because human T cells are not educated by HLA in the mouse thymus. We here established HLA-B*51:01 transgenic humanized mice by transplanting human CD34(+) HSCs into HLA-B*51:01 transgenic NOD/SCID/Jak3(-/-) mice (hNOK/B51Tg mice) and investigated whether human effector CD8(+) T cells would be elicited in the mice or in those infected with HIV-1 NL4-3. There were no differences in the frequency of late effector memory and effector subsets (CD27(low)CD28(-)CD45RA(+/-)CCR7(-) and CD27(-)CD28(-)CD45RA(+/-)CCR7(-), respectively) among human CD8(+) T cells and in that of human CD8(+) T cells expressing CX3CR1 and/or CXCR1 between hNOK/B51Tg and hNOK mice. In contrast, the frequency of late effector memory and effector CD8(+) T cell subsets and of those expressing CX3CR1 and/or CXCR1 was significantly higher in HIV-1-infected hNOK/B51Tg mice than in uninfected ones, whereas there was no difference in that of these subsets between HIV-1-infected and uninfected hNOK mice. These results suggest that hNOK/B51Tg mice had CD8(+) T cells that were capable of differentiating into effector T cells after viral antigen stimulation and had a greater ability to elicit effector CD8(+) T cells than hNOK ones.

Disseminated cryptococcal infection in patient with novel JAK3 mutation severe combined immunodeficiency, with resolution after stem cell transplantation.

Disseminated cryptococcal infection is the second most common cause of death after tuberculosis in acquired immune deficiency syndrome patients. Surprisingly, it has been reported only in few patients with primary immunodeficiency diseases. Herein, we report the clinical presentation and outcome of a 23-month-old boy with novel JAK3 mutation severe combined immunodeficiency disease complicated by severe disseminated cryptococcal infection.

Janus kinase 3 is expressed in erythrocytes, phosphorylated upon energy depletion and involved in the regulation of suicidal erythrocyte death.

Janus kinase 3, a tyrosine kinase expressed in haematopoetic tissues, plays a decisive role in T-lymphocyte survival. JAK3 deficiency leads to (Severe) Combined Immunodeficiency (SCID) resulting from enhanced lymphocyte apoptosis. JAK3 is activated by phosphorylation. Nothing is known about expression of JAK3 in erythrocytes, which may undergo apoptosis-like cell death (eryptosis) characterized by cell membrane scrambling with phosphatidylserine exposure and cell shrinkage. Triggers of eryptosis include energy depletion. The present study utilized immunohistochemistry and confocal microscopy to test for JAK3 expression and phosphorylation, and FACS analysis to determine phosphatidylserine exposure (annexin binding) and cell volume (forward scatter). As a result, JAK3 was expressed in erythrocytes and phosphorylated following 24h and 48h glucose depletion. Forward scatter was slightly but significantly smaller in erythrocytes from JAK3-deficient mice (jak3(-/-)) than in erythrocytes from wild type mice (jak3(+/+)). Annexin V binding was similarly low in both genotypes. The JAK3 inhibitors WHI-P131/JANEX-1 (4-(4'-Hydroxyphenyl)amino-6,7-dimethoxyquinazoline, 156µM) and WHI-P154 (4-[(3'-Bromo-4'-hydroxyphenyl)amino]-6,7-dimethoxyquinazoline, 11.2µM) did not significantly modify annexin V binding or forward scatter. Glucose depletion increased annexin V binding, an effect significantly blunted in jak3(-/-) erythrocytes and in the presence of the JAK3 inhibitors. The observations disclose a completely novel role of Janus kinase 3, i.e. the triggering of cell membrane scrambling in energy depleted erythrocytes.

Comparative study of human hematopoietic cell engraftment into BALB/c and C57BL/6 strain of rag-2/jak3 double-deficient mice.

Immunodeficient mice are becoming invaluable tools in human stem cell and tumor research. In this study, we generated Rag-2/Jak3 double-deficient (Rag-2⁻/⁻Jak3⁻/⁻) mice with a C57/BL6 and Balb/c genetic background and compared the human lymphohematopoietic cell engraftment rate. Human cord blood-derived CD34+ hematopoietic stem cells were successfully engrafted into Balb/c Rag-2⁻/⁻Jak3⁻/⁻ mice; however, the engraftment rate was far lower in C57/BL6 Rag-2⁻/⁻Jak3⁻/⁻ mice. Transplantation of human peripheral blood mononuclear cells resulted in the same tendency. Thus, a Balb/c background offers superior engraftment capacity than a C57/BL6 background and provides an attractive model for human hematopoietic cell engraftment.

Heterogeneous expression and function of IL-21R and susceptibility to IL-21-mediated apoptosis in follicular lymphoma cells.

OBJECTIVE: Interleukin (IL)-21, a member of the IL-2 family, has antitumor activity and is now being tested in non-Hodgkin's lymphoma in combination with anti-CD20 antibodies. IL-21 may either induce apoptosis or promote growth in different lymphoid malignancies. We therefore investigated the IL-21/IL-21R system in follicular lymphoma (FL) cells. MATERIALS AND METHODS: IL-21R expression was studied by reverse transcription polymerase chain reaction, immunofluorescence, and Western blot analyses. Apoptosis was measured by Annexin-V-propidium iodide staining. Signaling via IL-21R was studied using antibodies specific for phosphorylated Janus-activating kinase and signal transducers and activators of transcription proteins by Western Blot. RESULTS: IL-21R was found on primary FL cells in 15 of 15 cases at diagnosis and IL-21 increased apoptosis in 10 of 10 FL samples. However, cells from areas of diffuse growth in FL and from two diffuse lymphomas evolved from previous FL, showed low IL-21R expression. The latter were also resistant to IL-21-mediated apoptosis. Among lymphoma cell lines bearing the t(14;18) translocation, only 1 of 7 showed increased apoptosis in response to IL-21 stimulation. This cell line was IL-21R-positive, whereas five of six nonresponsive cell lines showed very low IL-21R expression. Intriguingly, one of the IL-21-resistant cell lines (DOHH2) expressed high levels of IL-21R. Treatment with IL-21 or IL-4 upregulated suppressor of cytokine signaling 3 gene expression in the IL-21-responsive cell line, but not in DOHH2 cells, which showed defective Janus-activating kinase/signal transducers and activators of transcription signaling in response to IL-21, in relationship to the lack of Janus-activating kinase 3 gene expression. CONCLUSION: These data indicate that low IL-21R expression or defective signal transduction downstream IL-21R may cause refractoriness to IL-21-mediated effects in some FL cells.

Hybrid liposomes inhibit the growth of primary effusion lymphoma in vitro and in vivo.

Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) infection. It occurs predominantly in human immunodeficiency virus (HIV)-positive patients, is generally resistant to chemotherapy, and has a poor prognosis. Hybrid liposomes (HL), composed of dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene dodecyl ether, inhibited PEL cell proliferation and induced apoptosis in vitro. Intraperitoneal inoculation of the BCBL-1 PEL cell line into NOD/Scid/Jak3 deficient mice induced massive ascites, which were inhibited by HL21 without significant systemic toxicity in the mice. These results suggest that HL21 is an effective and attractive reagent for PEL treatment.

Long-term immune reconstitution after anti-CD52-treated or anti-CD34-treated hematopoietic stem cell transplantation for severe T-lymphocyte immunodeficiency.

BACKGROUND: Results of treatment of severe T-lymphocyte immunodeficiencies by means of hematopoietic stem cell (HSC) transplantation have improved. T cell-depleted haploidentical transplantations are successful if there is no HLA-identical donor. Methods to remove T lymphocytes include addition of anti-CD52 antibodies and CD34(+) HSC selection. OBJECTIVE: Assessment of long-term immune function is important after these treatments. We looked at immune reconstitution in 36 survivors for more than 2 years after HSC transplantation for severe T-lymphocyte immunodeficiencies and compared engraftment quality between the 2 T-lymphocyte depletion methods. METHODS: Chimerism, T- and B-lymphocyte subsets, immunoglobulin levels, and specific antibody production at last follow-up were examined. The chi(2) (Fisher exact test) and Wilcoxon rank sum analyses were used to compare the groups. RESULTS: Nineteen patients received anti-CD52-treated and 19 anti-CD34-treated HSCs. More anti-CD52-treated patients had full donor myeloid chimerism (P = .025). All patients had full donor T-lymphocyte chimerism. There was no difference in donor B-lymphocyte chimerism, but significantly more anti-CD52-treated patients had class-switched memory B lymphocytes (P = .024), normal IgG levels, and normal responses to tetanus and Haemophilus influenzae type B vaccination. More anti-CD52-treated patients with common gamma chain or Janus-associated kinase 3 severe combined immunodeficiency had donor B lymphocytes. CONCLUSION: Long-term T-lymphocyte function is good with either treatment method, with a low incidence of graft-versus-host disease. The results imply more incomplete donor chimerism in anti-CD34-treated patients with less B-lymphocyte function.

Kaempferol inhibits IL-4-induced STAT6 activation by specifically targeting JAK3.

IL-4 is involved in several human diseases including allergies, autoimmunity, and cancer. Its effects are mainly mediated through the transcription factor STAT6. Therefore, investigation of compounds that regulate STAT6 activation is of great interest for these diseases. Natural polyphenols are compounds reported to have therapeutic properties in diseases involving IL-4 and STAT6. The aim of this study was to investigate the effect of these compounds in the activation of this transcription factor. We found that in hemopoietic cells from human and mouse origin, some flavonoids were able to inhibit the activation of STAT6 by IL-4. To identify molecular mechanisms, we focused on kaempferol, the compound that showed the greatest inhibitory effect with the lowest cell toxicity. Treatment of cells with kaempferol did not affect activation of Src kinase by IL-4 but did prevent the phosphorylation of JAK1 and JAK3. Further enzymatic analysis demonstrated that kaempferol blocked the in vitro phosphorylation activity of JAK3 without affecting JAK1, suggesting that it specifically targeted JAK3 activity. Accordingly, kaempferol had no effect on STAT6 activation in nonhemopoietic cell lines lacking JAK3, supporting its selective inhibition of IL-4 responses through type I receptors expressing JAK3 but not type II lacking this kinase. The inhibitory effect of kaempferol was also observed in IL-2 but not IL-3-mediated responses and correlated with the inhibition of MLC proliferation. These findings reveal the potential use of kaempferol as a tool for selectively controlling cell responses to IL-4 and, in general, JAK3-dependent responses.

Unusual clinical and immunologic manifestations of transplacentally acquired maternal T cells in severe combined immunodeficiency.

The persistence of transplacentally transferred maternal T cells is common in infants with severe combined immunodeficiency (SCID), occurring in more than half of patients with SCID undergoing transplantation at our institution. These T cells respond poorly to mitogens in vitro but can cause cutaneous graft-versus-host disease; however, other effects of these cells are unknown. We describe 2 infants with SCID who had unusual problems associated with transplacentally transferred maternal T cells. Patient 1 was a 5-month-old girl with Janus kinase 3-deficient SCID who had 4% circulating CD3(+) T cells but no lymphocyte proliferative response to mitogens. Although the number of T cells increased after 2 nonchemoablated, T cell-depleted, haploidentical, paternal bone marrow transplantations, T-cell function failed to develop, and she became pancytopenic. Restriction fragment length polymorphism studies of flow cytometry-sorted blood T cells revealed all to be of maternal origin. A subsequent nonchemoablated, T cell-depleted maternal transplantation resulted in normal T-cell function and marrow recovery. Patient 2 was a 9-month-old girl with IL-7Ralpha-deficient SCID who presented with autoimmune pancytopenia. She had 8% blood T cells (all CD45RO(+)) but no response to mitogens. High-resolution HLA sequence-specific priming typing detected both maternal haplotypes, indicating the presence of maternal cells. Her pancytopenia resolved after treatment with rituximab and was thought to be due to host B-cell activation by transplacentally acquired maternal T cells. Persistent transplacentally acquired maternal T cells in infants with SCID can mediate immunologic functions despite failing to respond to mitogens in vitro. We present evidence that these cells can cause allograft rejection and immune cytopenias.