Donor lymphocyte infusion after allogeneic haematopoietic cell transplantation for haematological malignancies: basic considerations and best practice recommendations from the EBMT.

Since the early description of three patients with relapsed leukaemia after allogeneic haematopoietic cell transplantation (HCT) who obtained complete remission after donor lymphocyte infusions (DLIs), the added value of this procedure to induce or maintain graft-versus-leukaemia immunity has been undisputed. For more than 30 years, DLIs have become common practice as prophylactic, pre-emptive, or therapeutic immunotherapy. However, as with many aspects of allogeneic HCT, centres have developed their own routines and practices, and many questions related to the optimal applications and toxicity, or to the immunobiology of DLI induced tumour-immunity, remain. As a part of the Practice Harmonization and Guidelines Committee and the Cellular Therapy and Immunobiology Working Party of the European Society for Blood and Marrow Transplantation effort, a panel of experts with clinical and translational knowledge in transplantation immunology and cellular therapy met during a 2-day workshop in September, 2023, in Lille, France, and developed a set of consensus-based recommendations for the application of unmanipulated DLI after allogeneic HCT for haematological malignancies. Given the absence of prospective data in the majority of publications, these recommendations are mostly based on retrospective studies and expert consensus.

Magnesium enhances the graft-versus-tumor effect of donor lymphocytic infusion on hematologic malignancies.

Donor lymphocyte infusion (DLI) cures relapsed hematologic malignancies after allogeneic hematopoietic stem cell transplantation through the graft-versus-tumor (GVT) effect. Although the important role of magnesium in enhancing immunity has been mentioned in studies, limited clinical data have explored how magnesium affects the efficacy of DLI. Besides, although laboratory data demonstrate that magnesium can enhance CD8+ T cells effector function, whether magnesium regulates the tumor killing effect of peripheral blood mononuclear cells (PBMCs) remains to be explored. Here, for the retrospective study, we collected clinical data of relapsed patients receiving DLI and explored the relationship between different serum magnesium levels and patient outcomes. For in vitro studies, we investigated the effect of magnesium on the cytotoxicity of DLI cells which were PBMCs and preliminarily explored the mechanism. Eighty-one patients were enrolled in this study. It was found that the high post-DLI magnesium level was significantly associated with a higher incidence of complete remission (CR) or partial remission (CR/PR) and a higher possibility of survival. The magnesium level after DLI was an independent risk factor of overall survival. In vitro studies proved that increased magnesium enhanced the cytotoxic function of PBMCs on hematologic malignancies. Besides, magnesium modulated LFA-1 headpiece opening. When blocking the integrin-ligand interaction between LFA-1 and ICAM-1, the regulation effect of magnesium on PBMCs was weakened. Therefore, it was possible that magnesium regulated PBMCs effector function by stimulating LFA-1. These results show that serum magnesium levels affect immunological responses mediated by donor lymphocytes in hematologic malignancies.

Rhinovirus/enterovirus identification by electron microscopy in lower respiratory tract infection in a patient with relapsed myelodysplastic syndrome after allogeneic hematopoietic cell transplantation and donor lymphocyte infusion.

Donor lymphocyte infusion (DLI) is a curable treatment option, inducing a graft-versus-tumor effect in patients with relapsed hematological malignancies after allogeneic hematopoietic cell transplantation (allo-HCT). However, not only graft-versus-host disease but also pulmonary complications are problematic adverse events after DLI. Although viral infections can be associated with pulmonary complications after DLI, the mechanism underlying these complications remains unclear. Detecting the causative virus infections after pulmonary complications following DLI is challenging, as invasive examinations, such as bronchoalveolar lavage and lung biopsies, are necessary. Family Picornaviridae, including Human-Rhinovirus (HRV) and Enterovirus (EnV), can induce fatal lower respiratory tract infection (LRTI) in recipients who undergo allo-HCT, which can be underdiagnosed. We encountered a 62-year-old man with relapsed myelodysplastic syndrome 20 days after a second HLA-haplo-identical allo-HCT and 4 DLI procedures who was later found to have HRV and EnV LRTI by postmortem electron microscopy. Despite high-dose immunosuppression, severe hypoxemia did not improve, and he succumbed to respiratory failure. Immunosuppressive therapy for idiopathic pneumonia syndrome after allo-HCT may be effective, but its efficacy for acute respiratory failure after DLI is controversial. Our case indicated that the control of viral replication should be prioritized over that of inflammation in HRV and EnV LRTI after DLI.

Competitive Repopulation and Allo-Immunologic Pressure Determine Chimerism Kinetics after T Cell-Depleted Allogeneic Stem Cell Transplantation and Donor Lymphocyte Infusion.

After allogeneic stem cell transplantation (alloSCT), patient-derived stem cells that survived the pretransplantation conditioning compete with engrafting donor stem cells for bone marrow (BM) repopulation. In addition, donor-derived alloreactive T cells present in the stem cell product may favor establishment of complete donor-derived hematopoiesis by eliminating patient-derived lymphohematopoietic cells. T cell-depleted alloSCT with sequential transfer of potentially alloreactive T cells by donor lymphocyte infusion (DLI) provides a unique opportunity to selectively study how competitive repopulation and allo-immunologic pressure influence lymphohematopoietic recovery. This study aimed to determine the relative contribution of competitive repopulation and donor-derived anti-recipient alloimmunologic pressure on the establishment of lymphohematopoietic chimerism after alloSCT. In this retrospective cohort study of 281 acute leukemia patients treated according to a protocol combining alemtuzumab-based T cell-depleted alloSCT with prophylactic DLI, we investigated engraftment and quantitative donor chimerism in the BM and immune cell subsets. DLI-induced increase of chimerism and development of graft-versus-host disease (GVHD) were analyzed as complementary indicators for donor-derived anti-recipient alloimmunologic pressure. Profound suppression of patient immune cells by conditioning sufficed for sustained engraftment without necessity for myeloablative conditioning or development of clinically significant GVHD. Although 61% of the patients without any DLI or GVHD showed full donor chimerism (FDC) in the BM at 6 months after alloSCT, only 24% showed FDC in the CD4+ T cell compartment. In contrast, 75% of the patients who had received DLI and 83% of the patients with clinically significant GVHD had FDC in this compartment. In addition, 72% of the patients with mixed hematopoiesis receiving DLI converted to complete donor-derived hematopoiesis, of whom only 34% developed clinically significant GVHD. Our data show that competitive repopulation can be sufficient to reach complete donor-derived hematopoiesis, but that some alloimmunologic pressure is needed for the establishment of a completely donor-derived T cell compartment, either by the development of GVHD or by administration of DLI. We illustrate that it is possible to separate the graft-versus-leukemia effect from GVHD, as conversion to durable complete donor-derived hematopoiesis following DLI did not require induction of clinically significant GVHD.

Spectral flow cytometry cluster analysis of therapeutic donor lymphocyte infusions identifies T cell subsets associated with outcome in patients with AML relapse.

Identification of immune phenotypes linked to durable graft-versus-leukemia (GVL) response following donor lymphocyte infusions (DLI) is of high clinical relevance. In this prospective observational study of 13 AML relapse patients receiving therapeutic DLI, we longitudinally investigated changes in differentiation stages and exhaustion markers of T cell subsets using cluster analysis of 30-color spectral flow cytometry during 24 months follow-up. DLI cell products and patient samples after DLI were analyzed and correlated to the clinical outcome. Analysis of DLI cell products revealed heterogeneity in the proportions of naïve and antigen experienced T cells. Cell products containing lower levels of effector memory (eff/m) cells and higher amounts of naïve CD4+ and CD8+ T cells were associated with long-term remission. Furthermore, investigation of patient blood samples early after DLI showed that patients relapsing during the study period, had higher levels of CD4+ eff/m T cells and expressed a mosaic of surface molecules implying an exhausted functional state. Of note, this observation preceded the clinical diagnosis of relapse by five months. On the other hand, patients with continuous remission retained lower levels of exhausted CD4+ eff/m T cells more than four months post DLI. Moreover, lower frequencies of exhausted CD8+ eff/m T cells as well as higher amounts of CD4+temra CD45RO+ T cells were present in this group. These results imply the formation of functional long-term memory pool of T cells. Finally, unbiased sample analysis showed that DLI cell products with low levels of eff/m cells both in CD4+ and CD8+ T cell subpopulations associate with a lower relapse incidence. Additionally, competing risk analysis of patient samples taken early after DLI revealed that patients with high amounts of exhausted CD4+ eff/m T cells in their blood exhibited significantly higher rates of relapse. In conclusion, differentially activated T cell clusters, both in the DLI product and in patients post infusion, were associated with AML relapse after DLI. Our study suggests that differences in DLI cell product composition might influence GVL. In-depth monitoring of T cell dynamics post DLI might increase safety and efficacy of this immunotherapy, while further studies are needed to assess the functionality of T cells found in the DLI.

The impact of second-donor lymphocyte infusion on secondary graft failure after allogeneic hematopoietic stem cell transplantation through activation of Foxp3 and regulatory T cells.

Secondary graft failure (SGF) is a fatal complication of allogeneic hematopoietic stem cell transplantation without effective treatment methods, especially after haploidentical transplantation. This study aimed to analyze the efficacy of donor lymphocyte infusion (DLI) from a second donor in treating SGF and the underlying immune mechanisms. A second donor is a candidate donor who did not initially provide stem cells for HLA-matched sibling donor or HLA-haploidentical donor transplantation. We conducted a retrospective study of 237 patients with a median age of 38 years (range 9-56) for whom the degree of mixed chimerism (MC) and complete donor chimerism (CC), mRNA expression levels of Forkhead box P3 (Foxp3), and the proportion of regulatory T cells (Tregs) were regularly assessed. The median time to SGF was 62 days (range 41-117) after transplantation. Twenty-one patients with SGF received DLI, including 12 patients who initially received DLI from a second donor (i.e., a donor other than the transplantation [first] donor) and 9 patients who initially received DLI from the first donor but showed no response. Three of those 9 patients subsequently received DLI from a second donor. The incidence of acute GVHD and chronic GVHD induced by DLI from the second donor was significantly higher than that of DLI from the first donor (P = 0.006). Twenty-one patients with SGF exhibited synchronous MC, and the overall MC rate after transplantation was 65% (range 42%-85%).The proportion of Tregs significantly decreased in SGF patients, from a median of 2.61% ± 0.88% to 0.92% ± 0.23% at the indicated time point after transplantation (P = 0.03). Second-donor DLI resulted in a complete response (CR) in 13 patients, and MC gradually converted into CC; simultaneously, there was a significant increase in the mRNA level of Foxp3 and the proportion of Tregs (baseline, 0.92% ± 0.23% versus CR, 3.61% ± 0.82%; P = 0.01). For the patients who did not respond to DLI from either donor type, there was no significant change in donor chimerism, Foxp3 expression level or Treg proportion. Overall survival and disease-free survival 2 years after DLI were 66.7% ± 3.08% and 59.8% ± 4.11%, respectively. DLI from a second donor may be an effective treatment for SGF, and the mechanism is related to MC-to-CC conversion and activation of Foxp3 and Tregs.

Mapping the evolution of T cell states during response and resistance to adoptive cellular therapy.

To elucidate mechanisms by which T cells eliminate leukemia, we study donor lymphocyte infusion (DLI), an established immunotherapy for relapsed leukemia. We model T cell dynamics by integrating longitudinal, multimodal data from 94,517 bone marrow-derived single T cell transcriptomes in addition to chromatin accessibility and single T cell receptor sequencing from patients undergoing DLI. We find that responsive tumors are defined by enrichment of late-differentiated T cells before DLI and rapid, durable expansion of early differentiated T cells after treatment, highly similar to "terminal" and "precursor" exhausted subsets, respectively. Resistance, in contrast, is defined by heterogeneous T cell dysfunction. Surprisingly, early differentiated T cells in responders mainly originate from pre-existing and novel clonotypes recruited to the leukemic microenvironment, rather than the infusion. Our work provides a paradigm for analyzing longitudinal single-cell profiling of scenarios beyond adoptive cell therapy and introduces Symphony, a Bayesian approach to infer regulatory circuitry underlying T cell subsets, with broad relevance to exhaustion antagonists across cancers.

The Effects of LIT and MLR-Bf on Immune Biomarkers and Pregnancy Outcomes in Women With Previous Early Recurrent Miscarriage: A Retrospective Study.

Background: Immunological failure during pregnancy is considered one of the etiologies of recurrent miscarriage (RM). The decreased production of mixed lymphocyte reaction-blocking factors (MLR-Bf) may play a major role in this condition. Lymphocyte immunotherapy (LIT), which induces the production of MLR-Bf, has been used in treating RM patients since 1984. However, the effectiveness of LIT is currently being heatedly debated. In addition to that, possible changes to the maternal immune system upon induced MLR-Bf production by LIT remains unclear. Objectives: To explore the possible impacts that MLR-Bf may have on the expression of immune biomarkers and pregnancy outcomes, and deduce whether the prevention of miscarriages is possible with LIT or MLR-Bf in RM patients. Materials and Methods: Women with previous early RM (eRM) were enrolled in this retrospective study after they got pregnant again. LIT was implemented before pregnancy and during the first trimester. MLR-Bf and immune biomarkers were checked as the clinical routine. Patients were followed up until 12 gestational weeks. Levels of immune biomarkers and successful pregnancy rates were compared between MLR-Bf- group and MLR-Bf+ group stratified by LIT. Independent associations between LIT, or MLR-Bf, and miscarriage were estimated. All data management and analysis were conducted using SPSS 20.0. Results: A total of 1,038 patients, 497 MLR-Bf- (49 cases accepted LIT), and 541 MLR-Bf+(463 cases induced by LIT) were included in the study. Percentage of lymphocytes, the ratio of CD4+ T cells/lymphocytes, and levels of some rheumatoid biomarkers (anti-U1-nRNP, anti-SAA-52kd, and anti-CENOP B) were statistically higher in MLR-Bf+ group than in MLR-Bf- group among women without LIT. With LIT treatment the successful pregnancy rate was statistically higher in MLR-Bf+ group than in MLR-Bf- group (66.7% vs. 51.0%, P = 0.028) among women with LIT. Meanwhile, LIT was estimated to have an independent negative association with miscarriage. Conclusion: Upon LIT treament levels of immune biomarkers were different in women with and without MLR-Bf when stratified by whether they received LIT. Not MLR-Bf, but LIT, has an independent protective effect on miscarriage.

Haematologic malignancies with unfavourable gene mutations benefit from donor lymphocyte infusion with/without decitabine for prophylaxis of relapse after allogeneic HSCT: A pilot study.

Relapse is the main cause of treatment failure for leukaemia patients with unfavourable gene mutations who receive allogeneic haematopoietic stem cell transplantation (allo-HSCT). There is no consensus on the indication of donor lymphocyte infusion (DLI) for prophylaxis of relapse after allo-HSCT. To evaluate the tolerance and efficacy of prophylactic DLI in patients with unfavourable gene mutations such as FLT3-ITD, TP53, ASXL1, DNMT3A or TET2, we performed a prospective, single-arm study. Prophylactic use of decitabine followed by DLI was planned in patients with TP53 or epigenetic modifier gene mutations. The prophylaxis was planned in 46 recipients: it was administered in 28 patients and it was not administered in 18 patients due to contraindications. No DLI-associated pancytopenia was observed. The cumulative incidences of grade II-IV and III-IV acute graft-versus-host disease (GVHD) at 100 days post-DLI were 25.8% and 11.0%, respectively. The rates of chronic GVHD, non-relapse mortality and relapse at 3 years post-DLI were 21.6%, 25.0% and 26.1%, respectively. The 3-year relapse-free survival and overall survival (OS) rates were 48.9% and 48.2%, respectively. Acute GVHD (HR: 2.30, p = 0.016) and relapse (HR: 2.46, p = 0.003) after DLI were independently associated with inferior OS. Data in the current study showed the feasibility of prophylactic DLI with/without decitabine in the early stage after allo-HSCT in patients with unfavourable gene mutations.

Induction of alopecia areata in C3H/HeJ mice using cryopreserved lymphocytes.

BACKGROUND: Alopecia areata (AA) is an autoimmune disease resulting in non-scarring hair loss. Animal models are useful means to identify candidates for therapeutic agents. The C3H/HeJ mouse AA model induced via transferring cultured lymphoid cells isolated from AA-affected mice is widely used for AA research. However, this conventional method requires the continuous breeding of AA mice. OBJECTIVE: We aimed to establish a new method to generate AA model using the transfer of cryopreserved cells, which allows the rapid induction of a large number of AA mice when needed. METHODS: We cryopreserved lymph node cells soon after isolation from AA-affected mice and injected thawed-cultured cells into recipient mice. H&E staining, immunohistochemical staining, quantitative real-time PCR and ELISA were conducted to identify pathological characteristics. Flow cytometry was performed to reveal the profile of transferred cells. RESULTS: More than 90 % of recipient mice developed AA-like hair loss and showed inflammatory cell infiltration around anagen hair follicles, markedly increased mRNA expressions of interferon-γ, CXCL11, and granzyme B, and elevated interferon-α protein levels in the skin compared with naïve mice. Higher percentages of effector memory T cells and dendritic cells in transferred cells resulted in a higher incidence of AA. CONCLUSION: This is the first report to establish a method for generating AA mice using cryopreserved lymphocytes. These AA mice have similar pathological characteristics to AA mice generated with the conventional method and AA patients. This convenient and reproducible method is expected to be valuable for AA study.

Passive transfer of allergic encephalomyelitis in rats: a tool for drug mechanism studies and detecting late-acting immunosuppressants.

1. A strategy is described for evaluating drugs against different phases in the development of an auto allergic disease, experimental allergic encephalomyelitis. It is based on a cell transfer technique whereby the disease is passively transferred with lymphoid cells from actively immunized donor rats to normal syngeneic rats = passive recipients. Drugs may be applied in vivo to either the cell donors or the cell recipients or to cells in vitro whilst in transit; their efficiency being determined by the severity of the passive disease (weight loss, paralysis) in the recipients. 2. Examples are given illustrating the application of these techniques to: (a) evaluating the lymphocyte-deactivating activity of various nitrogen mustards in vitro; (b) recognizing drugs, e.g. gold derivatives, clofazimine, etc. that are not conventional immunosuppressant (or cytostatic) agents which, when given to the recipient animals, may prevent the expression of the adopted disease; (c) comparing some known immunosuppressants for potency, duration of action, etc.; (d) demonstrating the versatility of cycloleucine, ICI-47,776, etc. 3. Some merits of the strategy are discussed vis a vis using the local graft-versus-host reaction in rats to search for new drugs.

Combination Therapy With Chemotherapy, Donor Lymphocyte Infusion With Concurrent Blinatumomab in Relapsed/Refractory Acute Precursor B-Lymphoblastic Leukemia.

The therapeutic approach for relapsed/refractory acute lymphoblastic leukemia (ALL) remains to be a challenge. The patient was diagnosed as B-cell ALL at 6 months of age and relapsed for the second time following repeat allogeneic hematopoietic stem cell transplantation (one after first complete remission [CR1] and the other after CR2). During blinatumomab monotherapy, he developed an extramedullary relapse. Finally, the combined therapy with clofarabine, donor lymphocyte infusion, and blinatumomab induced CR of the bone marrow and extramedullary relapse. Unfortunately, the patient developed central nervous system relapse, however, this case showed a promising potential for combination therapy with clofarabine, donor lymphocyte infusion, and blinatumomab in relapsed/refractory B-cell ALL.

Azacitidine and prophylactic donor lymphocyte infusions after hematopoietic stem cell transplantation for pediatric high-risk acute myeloid leukemia.

Post-hematopoietic stem cell transplantation (HSCT) maintenance therapy using azacitidine and prophylactic donor lymphocyte infusions (DLI) was implemented for high-risk acute myeloid leukemia. Azacitidine was started on day +60 as a 5 day course every 28 days for 6 cycles. DLI was given every 6 weeks for 3 doses starting after day +120. Ten patients were treated on this protocol. With a 90% one-year disease free survival, we report this post-HSCT maintenance therapy is feasible, safe, and well tolerated.

Association of CD200 expression in paternal lymphocytes with female Th1/Th2 balance and pregnancy establishment at immunotherapy of recurrent spontaneous abortion.

PROBLEM: We hypothesized that expression of transmembrane glycoprotein CD200 on paternal lymphocytes used for pre-gestational lymphocyte immunotherapy (LIT) of recurrent spontaneous abortion (RSA) can suppress the pro-inflammatory Th1-type immunity required for successful implantation. To reveal the association between CD200 expression, female immune background after LIT, and pregnancy establishment, we have performed this work. METHOD OF STUDY: Pre-gestational alloimmunizations were given to 37 women using paternal peripheral blood leukocytes, combined with additional alloimmunizations in case of pregnancy. Lymphocyte phenotypes were determined by flow cytometry. Cytokines produced by mitogen-stimulated female peripheral blood cells were estimated by FlowCytomix™ technology. RESULTS: We have shown that 78.4% (29/37) of women became pregnant within 12 menstrual cycles after pre-gestational LIT. Pregnancy establishment depends on the intensity of CD200 expression, which is significantly higher on the CD200+ lymphocytes administered to women who later did not achieve pregnancy (P < .05). The expression of CD200 negatively correlates with the ratios of Th1/Th2 cytokines produced by female peripheral blood cells (P < .05) and positively correlates with the frequency of female circulating regulatory T cells after LIT (P < .05). The ROC analysis showed that the intensity of CD200 expression and the Th1/Th2 ratios are the significant predictors of pregnancy establishment after pre-gestational LIT (P < .05 and P < .01, respectively). CONCLUSION: Elevated CD200 expression on allogeneic lymphocytes most likely suppresses the pro-inflammatory Th1-type immunity needed for successful embryo implantation. Therefore, a personalized approach of LIT should be applied to avoid negative effects of such immunomodulation on pregnancy establishment.

Effect of Salvage Chemotherapy Before Donor Lymphocyte Infusion in Patients With Relapse After Allogeneic Hematologic Stem Cell Transplantation.

OBJECTIVES: Allogeneic hematopoietic stem cell transplantation (AHSCT) is an important treatment option in hematologic malignancies. Relapse after AHSCT is an indicator of poor prognosis. These patients may be treated with donor lymphocyte infusion (DLI). The chemotherapy given before DLI increases the success of the treatment by reducing the burden of disease. The aim of this study is to investigate post-DLI graft vs host disease (GvHD) and survival based on the course of chemotherapy given before DLI. METHODS: A total of 23 patients who received DLI because of relapsed disease after AHSCT were enrolled. All of the patients received 1 or more courses of cytoreductive chemotherapy before DLI. RESULTS: Complete remission (CR) after DLI remained in 78.2% of all patients. There is no difference between 1 or multiple courses of chemotherapy in terms of CR (55.6% vs 44.4%; P = .21). During follow-up after DLI, although it did not reach statistical significance (P = .09), the patients receiving single-course chemotherapy tended to have longer survival (36.1 vs 4.3 months, respectively). Four patients who received multiple courses of chemotherapy were lost because of infection-related disease (pneumonia, sepsis) while they were in CR. GvHD development was more frequent in patients receiving multiple courses of chemotherapies (60% of all GvHD patients). CONCLUSION: It has been demonstrated that reducing the tumor burden by multiple-cycle chemotherapy does not have any advantage in terms of CR and does not improve the overall survival.

Inducing a stressed phenotype in healthy recipient mice by adoptively transferring CD4+ lymphocytes from mice undergoing chronic psychosocial stress.

Although chronic stress is an acknowledged risk factor for the development of somatic and affective disorders, the cellular and molecular mechanisms underlying stress-induced pathologies are not fully understood. Interestingly, rodent studies involving immune cell transfer suggest that CD4+ T cells might be at least in part involved in reactivation of a chemically-induced colitis by stress. However, until now evidence is lacking that these immune cell types are indeed involved in the development of a "stressed phenotype". The aim of the present study was, therefore, to assess the effects of adoptively transferring total mesenteric lymph node cells (mesLNCs) and CD4+ mesLNCs isolated from chronically-stressed mice into healthy recipient mice on various physiological, immunological and behavioral parameters. To induce chronic psychosocial stress in donor mice we employed the chronic subordinate colony housing (CSC) paradigm. Our data indicate that transfer of total or CD4+ mesLNCs from CSC mice, compared with respective cells from single-housed control (SHC) mice, promoted splenomegaly and interferon (IFN)-γ secretion from in vitro anti-CD3-stimulated mesLNCs in naïve recipient mice. This effect was independent of recipient mice additionally being administered with dextran sulfate sodium (DSS) or not. Transfer of CD4+ mesLNCs additionally increased adrenal weight and secretion of IL-6 from in vitro anti-CD3 stimulated mesLNCs in recipients administered with DSS. Importantly, transfer of neither cell type from CSC vs. SHC donor mice affected anxiety-related behavior of recipient mice in the light-dark box. Taken together, our data demonstrate that typical physiological and immunological, but not behavioral, effects of chronic stress can be induced in naïve recipient mice by adoptively transferring mesLNCs, in particular CD4+ mesLNCs, from chronically stressed donor mice.

How the COVID-19 pandemic changed cellular therapy at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital.

New York is at the epicenter of the coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus. Columbia University Irving Medical Center/NewYork-Presbyterian Hospital (CUIMC/NYPH) had to make changes to its cellular therapy operations to ensure patient, donor, and staff safety and well-being. In this article, we discuss the process changes we instituted for cellular therapy clinical care, collection, processing, and cryopreservation to cope with the rapidly evolving pandemic.

Autologous Splenocyte Reinfusion Improves Antibody-Mediated Immune Response to the 23-Valent Pneumococcal Polysaccharide-Based Vaccine in Splenectomized Mice.

Common clinical options, currently, for necessary splenectomy are vaccinations and antibiotic prophylaxis. However, despite these two adjuncts, there still occur numerous cases of overwhelming post-splenectomy infection. To examine whether reperfusion of critical splenic lymphocytes could boost immune response, we harvested splenic lymphocytes, reperfused the autologous lymphocytes, and then administered a pneumococcal vaccine (PNEUMOVAX®23, i.e., PPSV23) in splenectomized mice. We found that splenectomy impaired the immune response in the splenectomized group compared to the non-splenectomized group; the splenectomized group with lymphocyte reinfusion had a higher response to polysaccharide vaccination based on antibody titer than the splenectomized group without lymphocyte reinfusion. The sham group with the native spleen had the most elevated antibody titer against the PPSV23 polysaccharide antigen. This may be additive, resulting from contributions of the splenic structure, along with the phagocytic function of the spleen and its constituent cells affecting the antibody response. Reinfusion of splenic lymphocytes may enhance immunity without the complications associated with splenic fragment autotransplantation, which never gained acceptance. This technique is safe and simple since the splenic lymphocytes are autologous and, therefore, not self-reactive, and very similar to autologous blood transfusion. This concept may be beneficial in cases of unavoidable splenectomy, especially in pediatric cases.