scholarly journals Immune Reconstitution After Gene Therapy Approaches in Patients With X-Linked Severe Combined Immunodeficiency Disease

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Blanco ◽  
Natalia Izotova ◽  
Claire Booth ◽  
Adrian James Thrasher
Keyword(s):  
Gene Therapy ◽  
T Cell ◽  
Nk Cells ◽  
Immune Reconstitution ◽  
Lymphoblastic Leukemia ◽  
Conditioning Regimen ◽  
Cell Recovery ◽  
Hematopoietic Stem ◽  
Conditioning Treatment ◽  
Immunodeficiency Disease

X-linked severe immunodeficiency disease (SCID-X1) is an inherited, rare, and life-threating disease. The genetic origin is a defect in the interleukin 2 receptor γ chain (IL2RG) gene and patients are classically characterized by absence of T and NK cells, as well as presence of partially-functional B cells. Without any treatment the disease is usually lethal during the first year of life. The treatment of choice for these patients is hematopoietic stem cell transplantation, with an excellent survival rate (>90%) if an HLA-matched sibling donor is available. However, when alternative donors are used, the success and survival rates are often lower. Gene therapy has been developed as an alternative treatment initially using γ-retroviral vectors to correct the defective γ chain in the absence of pre-conditioning treatment. The results were highly promising in SCID-X1 infants, showing long-term T-cell recovery and clinical benefit, although NK and B cell recovery was less robust. However, some infants developed T-cell acute lymphoblastic leukemia after the gene therapy, due to vector-mediated insertional mutagenesis. Consequently, considerable efforts have been made to develop safer vectors. The most recent clinical trials using lentiviral vectors together with a low-dose pre-conditioning regimen have demonstrated excellent sustained T cell recovery, but also B and NK cells, in both children and adults. This review provides an overview about the different gene therapy approaches used over the last 20 years to treat SCID-X1 patients, particularly focusing on lymphoid immune reconstitution, as well as the developments that have improved the process and outcomes.

Rapid Immune Reconstitution after a Reduced-Intensity Conditioning Regimen and a CD3-Depleted Haploidentical Stem Cell Graft for Pediatric Refractory Hematologic Malignancies.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5311-5311
Author(s):  
Xiaohua Chen ◽  
Gregory A. Hale ◽  
Raymond C. Barfield ◽  
Ely Benaim ◽  
Wing H. Leung ◽  
...  
Keyword(s):  
Stem Cell ◽  
Nk Cells ◽  
Immune Reconstitution ◽  
Acute Gvhd ◽  
Conditioning Regimen ◽  
Hematologic Malignancies ◽  
Reduced Intensity Conditioning ◽  
Hematopoietic Stem ◽  
Reduced Intensity Conditioning Regimen ◽  
Reduced Intensity

Abstract Haploidentical hematopoietic stem cell transplantation (HaploHSCT) from a mismatched family member (MMFM) donor offers an alternative option for patients who lack an HLA-matched donor. The main obstacles to successful haploidentical hematopoietic stem cell transplantation from a mismatched family member donor are delayed immune reconstitution, vulnerability to infections, and severe graft-versus-host disease (GvHD). Method: We designed a reduced-intensity conditioning regimen that excluded total body irradiation and anti-thymocyte globulin. The graft was immunomagnetically depleted of CD3+ T-cells (CD3 negative selection) and contained a large number of both CD34+ and CD34− stem cells and most other immune cells especailly NK cells. This protocol was used to treat 22 pediatric patients with refractory hematologic malignancies. Results and Discussion: After transplantation, 91% of the patients achieved full donor chimerism. They also showed rapid recovery of CD3+ T-cells, T-cell receptor excision circle counts, TCRβ repertoire diversity and NK-cells during first four months post-transplantation. The incidence and extent of viremia were limited and no lethal infection was seen. Only 9% of patients had grade 3 acute GvHD, while 27% patients had grade 1 and another 27% had grade 2 acute GvHD. This well-tolerated regimen appears to accelerate immune recovery and shorten the duration of early post-transplant immunodeficiency, thereby reducing susceptibility to viral infections. Rapid T-cell reconstitution, retention of NK-cells in the graft, and induction of low grade GvHD may also enhance the potential anti-cancer immune effect.

Natural Killer Cell Immune Reconstitution Predicts Outcomes for Patients with Chronic Lymphocytic Leukemia Undergoing Allogeneic Stem Cell Transplantation

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3300-3300
Author(s):  
Don Benson ◽  
Leslie Andritsos ◽  
Mehdi Hamadani ◽  
Thomas Lin ◽  
Joseph Flynn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Immune Reconstitution ◽  
Nk Cell ◽  
Disease Status ◽  
Lymphocytic Leukemia ◽  
T Cell Subsets ◽  
Cell Recovery

Abstract Introduction: Chronic lymphocytic leukemia (CLL), the most common form of leukemia in the Western hemisphere, is associated with severe innate, adaptive and humoral immune dysregulation. CLL remains essentially incurable, with the potential exception of allogeneic stem cell transplantation (ASCT). Natural killer (NK) cells are CD56(+), CD3(−) large granular lymphocytes that comprise a key cellular subset of the innate immune system. Preliminary in vitro data suggest an NK cell versus CLL effect exists, similar to that observed in acute myeloid leukemia (AML) and other blood cancers. Novel immune therapies for CLL (e.g., rituximab, alemtuzumab) likely exert anti-tumor effect, in part, through NK cells, in fact. Although NK cells contribute to the graft-versus-tumor effect following ASCT for other blood cancers, little is known regarding the potential role NK cells may play in the clinical allogeneic transplant setting for CLL. Herein, we provide, to our knowledge, the first report regarding NK cell immune reconstitution following ASCT for CLL. Methods: 27 CLL patients underwent reduced intensity conditioning (RIC) with ASCT. Median age was 52 years (43–69), median number of prior therapies was 3 (2–11). 55% had chemotherapy-refractory disease, and 55% had “high-risk” cytogenetics by FISH (deletion 17p or 11q22-23 abnormality). 14 patients had sibling donors, 15 had volunteerunrelated donors. Conditioning regimens included Fludarabine/TBI/Alemtuzumab (n=8), Fludarabine/Busulfan with (n=9) or without ATG (n=6), and Fludarabine/Cyclophosphamide (n=4). GVHD prophylaxis consisted of tacrolimus/MMF (n=8) or tacrolimus/methotrexate (n=19). Patients underwent bone marrow assessment prior to day +75 following ASCT. Marrow was studied for engraftment, donor chimerism, and disease status as well as lymphoid immune reconstitution by percentage of total lymphocytes and absolute lymphocyte counts by multi-color flow cytometry. Results: NK cell immune reconstitution was predicted by disease status at transplantation. Patients in complete or partial remission at the time of ASCT had more robust NK cell recovery (mean = 45% of total lymphocytes +/− SEM 5%) as compared to patients entering transplant with refractory disease (16% +/− 1, p < 0.01). No differences were observed in CD4(+) or CD8(+) T cells and no lymphocyte subset recovery was associated with CD34(+) or CD3(+) cell dosage. Achieving complete donor chimerism by day +60 was associated with robust NK cell recovery (55% +/− 1 versus 7% +/−1, p = 0.02), recovery of CD4 and CD8 T cells was not associated with chimerism status, however. Patients who went onto exhibit a complete response to ASCT had greater early NK cell reconstitution (31% +/− 3) as compared to those who had no response (8% +/− 1, p = 0.01). No differences in T cell subsets were associated with response. Patients who ultimately achieved complete remission following transplant had a lower CLL:NK cell ratio in marrow (0.35 +/− 0.07) than those who did not (8.1 +/− 1, p = 0.01). However, differences in CLL:CD4(+) and CLL:CD8(+) T cells were not predictive of response. Trends to improvement in progression free survival and overall survival were observed for patients with NK cell reconstitution above the median for the group as compared to those below; no such trends were observed regarding T cell subsets. Greater NK cell reconstitution trended towards ultimate eradication of minimal residual disease following ASCT, but no such trends were observed for T cell subsets. Conclusions: Early NK cell recovery predicts survival following autologous and allogeneic SCT in a number of hematologic malignancies; however, little is known regarding this phenomenon in CLL. To our knowledge, these are the first findings to implicate a potentially important therapeutic role for early NK cell compartment recovery in CLL following ASCT. Further research into restoring and augmenting NK cell function following RIC/ASCT for CLL is warranted.

A Potent Thymic Function Is Associated with a Low Risk of Relapse In Leukemia Patients Treated with Haploidentical Stem Cell Transplantation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1258-1258 ◽  
Author(s):  
Emmanuel Clave ◽  
Daniela Lisini ◽  
Corinne Douay ◽  
Giovanna Giorgiani ◽  
Marc Busson ◽  
...  
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Immune Reconstitution ◽  
Hematological Malignancies ◽  
Conditioning Regimen ◽  
Median Number ◽  
Malignant Diseases ◽  
Hematopoietic Stem ◽  
Thymic Function ◽  
Cd34 Cells

Abstract Abstract 1258 Hematopoietic Stem Cell Transplantation (HSCT) is an effective treatment for many malignant and non malignant diseases in children. Since less than 30% of the patients have an HLA identical related donor, alternative donor/sources of Hematopoietic Stem Cells need to be considered, such as unrelated bone marrow (BM) and Cord Blood (CB) donors or HLA-haploidentical related donors. However, these types of HSCT are associated with a significant delay in immune reconstitution that favors both a high incidence of opportunistic infection and, in the absence of an alloreactive, natural killer cell-mediated effect, disease relapse. Indeed, T-cell depletion of the allograft in the haploidentical setting or T-cell naivety in CB, as well as HLA-disparity and use of serotherapy before HSCT, contribute to this impaired immune reconstitution. In view of the role played by the thymus in immune reconstitution post-allogeneic HSCT, it would be informative to compare thymic-dependent immune reconstitution after these types of HSCT. We have studied immune reconstitution and thymic function through signal joint (sj) and beta T cell Receptor Excision Circles (TREC) quantification in a group of 33 haplo-HSCT pediatric patients and in a group of 24 unrelated CB-HSCT. Patients were transplanted mainly for hematological malignancies (n=46, including 31 Acute Lymphocytic Leukemia and 9 Acute Myeloid Leukemia). All children received a myeloablative conditioning regimen, including the combination of total body irradiation and chemotherapy (n=33) or chemotherapy alone (n=24). In haplo-HSCT, no pharmacological immune-suppression was given after the allograft, while patients given CB-HSCT received cyclosporine-A and steroids as Graft vs. Host Disease (GvHD) prophylaxis. In haplo-HSCT patients the median number of CD34+ cells infused/kg was 20.7 × 106 (range 8.7–41), while in patients given CB-HSCT the median number of nucleated cells infused/kg was 7.1) × 107 (range 1.4–12.5). The only significant difference between the 2 groups was that haplo-HSCT patients were older (p=.0008) than CB-HSCT patients (median age being 7.7 and 3.4 yrs, range 3–17 and 0.75–16 yrs, respectively). Patients treated for an hematological malignancy had a significant lower pre-transplant TREC value (p = .0002 and .004 for sj and beta TREC respectively) than those affected by non-malignant diseases in both groups. Number of sj and betaTREC per 150 000 PBMC or absolute counts per μl of blood, showed a very similar thymic function in both groups despite the older age of haplo-HSCT patients. TREC levels were comparable to those found before transplantation starting from 6 months after HSCT. Cumulative incidence of acute or chronic GvHD was low in both groups, with no significant impact on thymic function. In haplo-HSCT, but not in CB transplantation, patients treated for hematological malignancies (n=27) who relapsed (n=8) had a significantly lower level of thymic function (sjTREC) than those who did not relapse (n=19), before (p=0.03), after 3 (p=0.014) and 6 months (p=0.015) from the allograft. In this group of patients, relapse was not associated with age, conditioning regimen or number of CD34+ cells infused. In conclusion, we demonstrate the crucial importance of thymic function in the Graft-vs. Leukemia effect in the haplo-HSCT setting. Monitoring thymic function could be of predictive value in these patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Comparison of Fixed Vs ALC-Based Doses of Thymoglobulin® (ATG) in Pediatric Patients with Acute Leukemia Given αβhaplo-HSCT: Impact on Immune Reconstitution at Day 90

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 16-16
Author(s):  
Giulia Barbarito ◽  
David C Shyr ◽  
Gopin Saini ◽  
Linda Oppizzi ◽  
Y. Lucy Liu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Reconstitution ◽  
Pediatric Patients ◽  
Conditioning Regimen ◽  
Optimal Dose ◽  
Hematopoietic Stem ◽  
Significant Difference ◽  
Αβ T Cells

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (HSCT) remains the treatment of choice for pediatric patients with high risk or refractory leukemia. In the absence of related or unrelated HLA-matched donors, alternative approaches such as HLA-haploidentical HSCT have been implemented. Our group has developed one such approach, αβ T-cell/CD19 B-cell depletion (αβhaplo-HSCT), and demonstrated its clinical efficacy (Bertaina A, Blood 2018). In αβhaplo-HSCT, anti-thymocyte globulin (ATG) is used for preventing graft rejection and graft-versus-host disease (GvHD). However, the optimal dose still needs to be elucidated. Here, we present the first analysis comparing 2 different Thymoglobulin® ATG doses: one fixed at 3.75 mg/Kg, as established in previous European studies with the closely related ATG Grafalon®, and one based on a newly developed algorithm that also integrates absolute lymphocyte count (ALC). METHODS: Between March 2017 and April 2020, 27 pediatric patients (median age 12 years) with hematological malignancies were transplanted at Stanford University's Lucile Packard Children's Hospital. Importantly, 60% of these patients were in CR2 or greater and 2/27 had active disease at the time of HSCT. All children received a fully myeloablative conditioning regimen. On days -9/-8/-7 before αβhaplo-HSCT, patients were given a regimen of Thymoglobulin® ATG. No patient received post-HSCT pharmacological GvHD prophylaxis. The fixed dosage was given to 14 patients in cohort 1 (ATG: 3.75 mg/Kg) and the novel ALC-based dosage to 13 in cohort 2 (ATG ranging between 3-6 mg/Kg). All patients enrolled in this study (BMT Protocol 179 and 351 approved from our IRB) had a minimum follow-up of 100 days, evaluated at Day 30 and 90. Following Admiraal R (Lancet Hematology 2015), we defined CD4 immune reconstitution (IR) as more than 50 CD4 T-cells/ul twice within the first 100 days after HSCT. PBMC were enriched by Ficoll-Hypaque (Sigma Aldrich) density gradient centrifugation. Flow analyses were performed on fresh cells resuspended in PBS 2% FBS on Cytek DxP 10 flow-cytometer. At least 5x104 events of total cells were acquired and analyzed using FloJo software. RESULTS: With a median follow-up of 555 and 124 days for cohort 1 and 2 respectively, 12 patients (85.7%) in cohort 1 and 7 patients (54%) in cohort 2 achieved CD4 immune reconstitution. In cohort 2, CD3 αβ T cells were significantly lower at both Day 30 and Day 90 (P=0.0003, Figure 1A). At Day 90, both the CD4 and CD8 subpopulations were significantly depressed (P=0.01 and P=0.056, respectively, Figure 1C). In both subpopulations, the memory compartment was the most reduced (Figure 1D). The absolute numbers of CD3 γδ T cells did not differ between the cohorts at either Day 30 or 90 (Figure 1B). Viral reactivations were higher in cohort 1 (10/14, 71%) than in cohort 2 (6/13, 46%, P=NS). Half of the reactivations were CMV reactivations, but no patient developed organ disease. There was no statistically significant difference in overall survival and the incidence of relapse in the two cohorts. Three patients developed grade III-IV aGvHD: 2 in cohort 1 (14%) and 1 in cohort 2 (8%, P=NS). Remarkably, the only patient, who developed grade IV aGvHD in cohort 2, did not experience symptoms until Adenovirus reactivation 138 days after HSCT. CONCLUSION: Our analysis confirms that the optimal dose of ATG Thymoglobulin® before αβhaplo-HSCT remains elusive. There were no significant clinical differences between the 2 ATG regimens. However, the ALC-based regimen resulted in the more pronounced reduction of donor-derived memory T cells. Our analysis suggests two intriguing explanations for the observed pattern of results. First, the selective depletion of the memory compartment in both CD4 and CD8 T cells may well be due to a priming effect of ATG Thymoglobulin® on the few αβ T cells left over in the graft. Second, the equivalent reconstitution of naive T cells in the 2 cohorts is likely because the ATG has no impact on the thymus-dependent IR. Remarkably, in our overall cohort, 70% of the patients achieved CD4 IR by 90 days after αβhaplo-HSCT. This result is superior to the best results from other ex vivo T-cell depleted approaches 54%, recently reported by Van Roessel (Cytotherapy 2020). In vivo studies of the pharmacokinetics of ATG in αβhaplo-HSCT recipients and a comparison with the use of Grafalon® are required to shed more light on this crucial topic. Disclosures No relevant conflicts of interest to declare.

scholarly journals Impact of Modifying Conditioning and Immunosuppressive Strategies in Allogeneic Hematopoietic Stem Cell Transplantation in Children with Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5714-5714
Author(s):  
Nawar Dakhallah ◽  
Mylène Beauchemin ◽  
Johanne Richer ◽  
Sonia Cellot ◽  
Pierre Teira ◽  
...  
Keyword(s):  
Stem Cell ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Acute Gvhd ◽  
Lymphoblastic Leukemia ◽  
Chronic Gvhd ◽  
Conditioning Regimen ◽  
Current Approach ◽  
Hematopoietic Stem ◽  
Gvhd Prophylaxis

Background:Hematopoietic stem cell transplants (HSCT) is indicated for some very high-risk childhood acute lymphoblastic leukemia (ALL) patients in complete remission 1 (CR1) and for patients in >CR2. Relapse remains the most frequent complication after transplant. In 2012, in order to decrease the relapse rate, we modified our conditioning and GVHD prophylaxis regimen. Total body irradiation doses were increased, etoposide removed and fludarabine introduced. Anti-thymocyte globulin (ATG) was removed of GVHD prophylaxis regimen and mycophenolate mofetil was added for unrelated marrow grafts. The aim of this study was to compare outcome between previous (PS) and new strategies (NS) prior and after 2012. Methods: This retrospective study included all 47 patients aged 0 to 18 years old who underwent a first HSCT for ALL at Sainte-Justine University Health Center from 2007 to 2017. Our primary endpoint was 2-year event-free survival (EFS) between PS (n=22) and NS (n=25) groups. Secondary endpoints included overall survival (OS), relapse, GVHD, immunological recovery and infection rates. Results: Demographic parameters and leukemia characteristics were not significantly different between groups. In the PS group, median age was 6.1 years [2.7;13.5] and 41% of patients were female. In the NS group, median age was 7.1 years [2.4;11.4] and 44% of patients were female. B-cell and T-cell lineage leukemias were present in respectively 82% and 18% of PS and 76% and 24% in NS. Fourteen percent of patients were transplanted in CR1 in the PS versus 40 % in the NS group. EFS at 2 and 5 years were respectively 46% and 36% with the PS compared to 60% and 53% with the NS (p=0.170). OS at 5 years was significantly higher with the NS (46% vs 75%, p=0.05). Morphologic relapse rates at 5 years of PS and NS were 55% and 30% (p=0.14). Acute GVHD rate at 6 months was superior with the NS (41% vs 80%, p=0.002). Chronic GVHD rate at 5 years was similar between groups. At least one proven infection at 100 days was documented in 96% compared to 88% of patients with the PS and NS respectively (p=0.08). Neutrophil recovery at 60 days and platelets recovery at 180 days were not significantly different. T-cell Immune recovery at 6 months was superior in the NS. Median (min;max) CD3 counts in PS and NS were respectively 339 (132;1152) versus 946 (284;1944) (p=0.009), CD4 counts were 221 (65;612) versus 594 (238;920) (p=0.046) and CD8 counts were 55 (34;414) versus 320 (210;1104) (p<0.001). Conclusion: Compared to the PS, the NS of conditioning regimen and GVHD prophylaxis shows a significant improvement in OS and a tendency towards decreased relapse and increased EFS. However, we found a significant increase in acute GVHD with this regimen, which is explained by the removal of ATG from the regimen. These results highlight the necessity to adjust our strategy with HSCT ALL with the aim of maintaining graft versus leukemia effect without increasing GVHD. Emerging immunotherapy (such as antibody-based and chimeric antigen receptor T cell therapies) might shift the management of refractory and relapsed ALL and our current approach to HSCT. Disclosures Bittencourt: Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy, Other: Travel, accommodations expenses.

Improvement of Canine XSCID by In Vivo Gene Therapy Using RD114/TR-Pseudotyped SIV Lentiviral Vectors.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3275-3275
Author(s):  
Morvarid Moayeri ◽  
Suk See De Ravin ◽  
Douglas R. Kennedy ◽  
Nora Naumann ◽  
Yasuhiro Ikeda ◽  
...  
Keyword(s):  
Gene Therapy ◽  
T Cell ◽  
B Cells ◽  
Immune Reconstitution ◽  
Lentiviral Vectors ◽  
Large Animal ◽  
Hematopoietic Stem ◽  
Dog Model ◽  
Viral Particles

Abstract X-linked severe combined immunodeficiency (XSCID) is characterized by profound immunodeficiency (dysfunctional B cells; absence of T and NK cells) and early mortality, caused by mutations in the IL2RG gene encoding the common gamma chain (γc) of receptors for interleukins (IL)-2,-4,-7,-9,-15 and -21. The standard therapy for XSCID in infants is a T cell depleted bone marrow transplant with either none or very modest conditioning. While 5-yr survival is >95% with HLA-matched sibling donors, most patients receive a haploidentical graft from a parent, resulting in lower survival and less robust immune reconstitution that may be limited to only the T cell lineage. Ex vivo autologous stem cell gene therapy has emerged as an alternate treatment capable of achieving substantial to complete immune reconstitution in infants without a sibling donor. However, some children have developed lymphocytic leukemia, which appears in part to be related to vector insertional mutagenesis. The gammaretroviruses currently in use have potent enhancers in the LTR and have a predilection to insert at the 5′ end of genes. Self-inactivating (SIN) lentivirus vectors may be advantageous because they do not show this property and can be constructed with internal promotors that have less enhancer activity together with insertion of insulators. We have constructed SIN simian immunodeficiency viral vectors (SIVmac) encoding human γc (hγc), with or without a double copy chicken insulator core element in the 3′ LTR. In addition we have pseudotyped the vector with a chimeric RD114 envelope to enhance targeting of hematopoietic stem cells (HSC) and avoid the cytotoxicity of the VSV-G envelope traditionally used with lentivectors. We have previously shown that it is possible to correct a dog model of XSCID using a RD114-pseudotyped gammaretroviral vector encoding the dog γc for in vivo gene therapy. Unlike the mouse model of XSCID which lacks B cells, the dog model more closely resembles the phenotype in humans. We decided to use our in vivo dog model for preclinical testing of safety and efficacy of our SIV hγc vectors. Viral particles were produced by transient transfection of 293T cells with a 4-plasmid system and concentrated by high-speed centrifugation. 30 mls (average 2.4–3×107 viral particles in total) was injected IV into 2–5 day-old pups. Transgene marking in blood lymphocytes was detected as early as 2 wks after treatment, increased within the first 6–8 wks and became relatively stable thereafter. The absolute lymphocyte count was normalized in one dog (injected on the second day after birth) by wk 6 (4000, 76% hγc+), and improved in two other dogs (422, 29% hγc+ at 18 wks; 498, 27% hγc+, at 16 wks) which had received the same amount of virus over 2 days. Furthermore, up to 5% of the myeloid lineage showed gene marking at 10–18 wks after viral delivery, indicating that early committed progenitors or HSCs had been transduced. It is noteworthy that our finding that the hγc can improve the disease phenotype in XSCID dogs makes it an excellent large animal model for preclinical evaluation of vectors. In summary, we have demonstrated that in vivo delivery of SIV lentiviral vectors expressing hγc efficiently reconstitute the T-lymphoid compartment in the XSCID canine model. We plan to monitor these dogs closely for potential adverse events.

Impact of Graft Source on Immune Recovery: Comparions Between Unrelated Umbilical Cord Blood (UCB), HLA Matched Sibling (Sib) Donor and Autologous (Auto) Hematopoietic Stem Cells.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3731-3731
Author(s):  
Sarah Cooley ◽  
John E. Wagner ◽  
Claudio Brunstein ◽  
Mie Hagiwara ◽  
Giordi Orreggio ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Nk Cells ◽  
Clinical Outcomes ◽  
Nk Cell ◽  
Cd4 Count ◽  
Cell Recovery ◽  
Hematopoietic Stem ◽  
The Absolute

Abstract Abstract 3731 Both T cell and natural killer (NK) cell reconstitution have been shown to affect clinical outcomes after hematopoietic stem cell transplantation (HSCT). Killer immunoglobulin-like receptor (KIR) interactions between alloreactive NK cells and their targets can prevent relapse, but may be dysregulated, especially after T cell replete HSCT. T cell recovery is also affected by the stem cell source and T cell content of the graft. To better understand the effects of various NK and T cell subsets we evaluated lymphocyte recovery in 304 adult patients who received either UCB (n=116), Sib (n=84) or Auto (n=94) HSCT for hematologic malignancies between 2003 and 2010 at the University of Minnesota. Peripheral blood mononuclear cells obtained at 3 months after HSCT were stained with CD56, CD3, CD4, CD8, and a cocktail of anti-NK cell KIR antibodies to determine the relative percentage of lymphocyte subsets by flow cytometry. The absolute lymphocyte count (ALC) was measured and used to calculate the absolute (Abs) number of T and NK cells and their subsets. ALC recovery at 3 months was similar among groups (UCB: 901.9 ± 74.5, Sib 890.2 ± 73.0 and Auto 1076.7± 69.4 cells/ul). Abs NK cells were highest in the UCB cohort (375.4 ± 24.9) vs. Sib (183.8 ± 15.4; p<0.0001) or Auto (160.7 ± 11.0; p<0.0001), as were the CD56bright and KIR+ subsets (data not shown). In contrast, Abs T cell recovery was lowest in the UCB group (300.8 ± 39.6) vs. Sib (578.5 ± 57.9; p<0.0001) or Auto (737.3 ± 60.4; p<0.0001). Accordingly, the lowest Abs CD4 count was in the UCB group (158.8 ± 14.7) vs. Sib (272.5 ± 23.5; p<0.0001) or Auto (223.6 ± 20.2; p=0.01), with a similar pattern observed for Abs CD8 counts. We then examined the effect of lymphocyte recovery on clinical outcomes. Multivariate models were constructed for each transplant group with relevant covariates (risk status, conditioning, sex, age, number of UCB units, CMV status, HLA matching (4/6, 5/6, or 6/6), and ABO matching). The most significant effect of lymphocyte recovery on outcomes was observed specifically in the UCB group, where higher ALC was associated with improved OS with a hazard ratio (HR) of 0.86 (95% CI 0.78–0.95) for each unit increase in ALC of 100 cells/ul (p <0.01). A similar trend was observed in Sib recipients but not in the Auto group. Specifically, increases in Abs T cells (HR 0.75 [95% CI 0.58–0.98]; p=0.034), Abs CD4 count (HR 0.63 [95% CI 0.42–0.95]; p=0.03), Abs CD8 count (HR 0.31 [95% CI 0.13–0.73]; p=0.01) and to a lesser extent Abs NK cells (HR 0.85 [95% CI 0.71–1.02]; p=0.085) were associated with improved OS. In the Sib cohort, higher Abs CD4 count was associated with improved OS (HR 0.43 [95% CI 0.20–0.92]; p=0.03) and decreased relapse (HR 0.37 [95% CI 0.37–1.00]; p=0.02), with no other factor having a significant impact. In the Auto group, only Abs NK (HR 0.40 [95% CI 0.16–0.99]; p=0.05) and to a lesser extent Abs KIR+ NK cells (HR 0.17 [95% CI 0.02–1.36]; p=0.09) were associated with improved OS but no other outcomes. The effect of Abs CD4 count on OS in all groups is shown in Figure 1 with survival stratified by quartiles. Figure 1: Figure 1:. In summary, rapid recovery of T cells predicts significantly better survival in patients undergoing UCB and Sib HSCT, while the NK cell effects are less pronounced. In contrast, NK cell effects predominate after Auto HCT. This suggests that more rapid T cell recovery is critical for survival and that defects in NK cell education after allogeneic HSCT may affect their function such that just increasing numbers may not be sufficient for clinical benefit. Appropriate modifications to immune suppression or the use of agents that promote T cell (IL-7) and/or NK cell (IL-15) function and survival may positively influence survival outcomes. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Rapid and Safe T Cell Immune Reconstitution By T Cell Progenitor Injection Following Haploidentical Transplantation for Severe Combined Immunodeficiency (SCID)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1752-1752
Author(s):  
Despina Moshous ◽  
Elisa Magrin ◽  
Sarah Winter ◽  
Benjamin Fournier ◽  
Martin Castelle ◽  
...  
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Immune Reconstitution ◽  
Conditioning Regimen ◽  
Unrelated Donor ◽  
Post Transplantation ◽  
Historical Cohort ◽  
Hematopoietic Stem ◽  
Lymphoid Progenitors

Abstract Severe Combined Immunodeficiencies (SCID) are defined by a complete absence of T lymphocytes in the blood and lymphoid organs, with variable defects in other WBC subsets depending on the gene defect. From a clinical perspective SCIDs are characterized by early development of life-threatening infections accounting for early death if untreated. The treatment of choice is allogeneic HSCT with very high success rates if a HLA identical sibling (MRD) or unrelated donor (MUD) is used. However, due to the scarcity of matched-related donors, SCID can benefit from haploidentical HSCT. In contrast to the continuous improvement of HLA compatible donor transplantations, no significant improvements have been obtained over the last twenty years for haploidentical HSCT. The profound immunodeficiency during the first months following haploidentical HSCT exposes patients to opportunistic viral, bacterial and fungal infections, which account for approximately 30-40% of the transplant related mortality (TRM). The rapid restoration of the T-cell compartment is the main aim of stem cell therapy in this setting. To this end we have recently set up a phase I/II clinical trial (ClinicalTrials.gov Identifier: NCT03879876) aiming to accelerate the immune reconstitution by injection of ex vivo generated Human T lymphoid progenitors (ProTcell TM) following haploidentical HSCT. T cell progenitors in this trial are generated in vitro within 7 days from mobilized peripheral blood (mPB) CD34 + hematopoietic stem and precursor cells (HSPCs) using our Notch ligand Delta-like 4 GMP culture platform so called SMART Immune's SMART101 product. This open-label, non-randomized study evaluates safety and efficacy of the SMART101 injection following CD34 + selected, haploidentical HSCT in SCID patients and is designed as a dose-escalation study comprising 6 doses of the SMART101 product obtained from the patient's haploidentical stem cell graft. The aim of this protocol is to define the highest efficacy dose without any toxicity. The conditioning regimen is based on Busulfan and Fludarabine according to IE-WP/EBMT guidelines with upfront administration of ATG to prevent graft rejection. Tight monitoring of ATG serum levels is applied in order to assure injection of SMART101 when ATG is below the lymphotoxicity threshold. Here we report the results of the first two SCID patients. P1 presented a homozygous Artemis deficiency. At diagnosis he had an ALC of 341/µl, with complete absence of T cells (CD3 + &lt; 4/µl, CD4 + &lt; 1/µl, CD8 + &lt; 2/µl) and B cells (CD19 + 0/µl). NK cells were present in the normal range for age (CD16 +CD56 + 331/µl). In the absence of an HLA compatible donor, the patient`s father was chosen as haploidentical stem cell donor. P1 received upfront ATG (5 mg /kg total dose), Busulfan (AUC of 16058 microM.min) and Fludarabine (160 mg/m²). He received Defibrotide prophylaxis from D0 until D+21, as well as Ursodeoxycholic acid until D+80. The CD34 + immunoselected graft contained 1.04 x 10 8 nucleated cells/kg with 24.15 x10 6 CD34 + cells/kg and 4000 CD3 + cells/kg on D0. After ATG monitoring 0.12x10 6 Smart101 cells were administered at D+14 post- HSCT. In the follow-up P1 didn't develop any acute or chronic SAEs, no acute or chronic GVHD, and no infection. He was discharged at D+121 post HSCT. The day +100 post transplantation CD4 + cell count/microliter exceeded 10 times the CD4 + count of our historical cohort of RAG1/2 or Artemis deficient patients transplanted with haploidentical HSCT alone following the same conditioning regimen. At 6 months post HSCT this difference remains important (851 versus 300 CD4 + cells/µl); Ig replacement therapy could be stopped as early as 9 months post transplantation and vaccinations have been started. At last follow up; almost 14 months post HSCT P1 is alive and well. P2 had an undefined molecular SCID diagnosis. She has been treated with the same conditioning regimen and received the second dose of 0.2x10 6 CD7 + cells, but unfortunately died from severe VOD emphasizing the need to replace chemotherapy with less toxic myeloablative agents. The preliminary results obtained after injection of Human T lymphoid progenitors in P1 are encouraging. While deserving confirmation in larger numbers of patients they could represent an important step forward in improving the outcome of haploidentical HSCT for SCID. Disclosures Cavazzana: Smart Immune: Other: co-founder.

Comparison of Immune Reconstitution after Umbilical Cord Blood (UCB) and Allogenic Peripheral Blood Stem Cell (APBSC) Transplantation in Patients with Advanced Multiple Myeloma (MM) and Acute Myeloid Leukemia (AML).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 5008-5008
Author(s):  
Jean-Come Meniane ◽  
Patrice Ceballos ◽  
Maud Condomines ◽  
Jean-françois Eliaou ◽  
Nathalie Fegueux ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Nk Cells ◽  
Immune Reconstitution ◽  
Tumor Control ◽  
High Dose ◽  
Cell Recovery ◽  
Significant Difference ◽  
Cd8 Cell

Abstract Background. T-cell reconstitution is usually delayed after UCB transplantation, in addition to an impaired thymopoiesis and late memory T cell skewing. NK cells are usually variable, with an initial increase in % and absolute number. The role of these cells is unclear, particularly on tumor control, maybe participating to the T-cell lymphopenia. Patients and methods. F rom 01/03 to 04/07, we retrospectively analysed data concerning lymphocyte recovery for patients having MM and AML, who received allogenic transplantation (AT). We excluded patients with progressive disease before AT, with short follow-up (<120days) and without dominant donor chimerism. 43 patients (MM, n=19; AML, n=24) were included, and they received UCBT (n=13: MM=7 and AML=6; single: n=2 or double: n=11), all with reduced intensity conditioning (RIC) regimen adapted from the Minneapolis protocol, or APBSC (n=30) [RIC (n=23; MM=12 and AML=11), including ATG (n=12/23; AML=10/11) or myelo-ablative conditioning (MAC: n=7, all having AML,]. Immune reconstitution in PB was followed, including CD3+, CD4+, CD8+, CD3−/CD56+, and CD19+ cells, monthly. Prophylaxis of GVHD included cyclosporin A from d-3 to months +3 or +6, according to clinical manifestations of GVHD, and mycophenolate mofetil from d-3 to d+28 after RIC regimen and standard prophylaxis with cyclosporine and short course methotrexate after MAC regimen. Anti-infectious prophylaxis and follow-up were standard. Results. Median age was comparable between groups (MM: DUCB (57y, 42–61), PBSC (55y, 50–68); AML: DUCB (45y, 30–63), PBSC (53y, 21–64). Sex ratio (F/M) was 6/13 for MM, and 11/13 for AML. In the group MM/UCB, NK cells was above 80/mm3 from D-7 to 1 year and peaked at D260 (median=193/mm3), with no statistical difference with the MM/PBSC group (64 at D-7 to 132/mm3). NK cells were significantly higher (p=0.04) for AML/UBC group (from D90: 187/mm3) to D260: 328/mm3), in comparison to AML/PBSC (from 116 to 138/mm3). For CD4 T-lymphocytes, there was a significant difference between MM/UCB and MM/PBSC during the first 3 months [39 to 75/mm3 vs 152 to 175/mm3, p=0.01]. A more rapid recovery of CD4+ was observed in AML/UBC (from 227 to 829/mm3, D90 to 1y), 2-fold higher than in the AML/PBSC at any time. Those differences could be explained by the high-dose therapy given to patients with MM. In addition, patients who received ATG (all AML/PBSC/RIC) had a delayed CD4 recovery. CD8-cell recovery was delayed for UBC groups with a CD8 cell count >200 starting at D230 as compared to the PBSC group (D150 for MM and D90 for AML). B cell recovery was faster in the UCB group [MM/UCB and AML/UCB, >200/mm3 at D230 and D150 as compared to D300 and D230 respectively in MM/PBSC and AML/PBSC (p=NS)]. Conclusion. NK cells increased after UBC more intensively and rapidly than after PBSC AT. T-cell recovery appeared to be associated to pre-treatment intensity and use of ATG. CD4, CD8 counts were highly reduced in UCB compared to PBSC except for CD4+ in AML/UCB. B-cell recovery is not different between both groups (i.e. UCB and PBSC). NK cells from 2 patients are now collected for analysis of their functions particularly their anti-tumoral effect in vitro.

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