Investigation of the Cellular Immune Response to Recombinant Fragments of Filamentous Hemagglutinin and Pertactin of Bordetella pertussis in BALB/c Mice

High purity and recovery of native filamentous hemagglutinin (FHA) from Bordetella pertussis using affinity chromatography

Filamentous hemagglutinin (FHA) is a critical adhesion molecule produced by Bordetella pertussis (BP), the causative agent of highly contagious respiratory infection known as whooping cough. FHA plays a pivotal role in the pathogenesis of whooping cough and is a key component of acellular pertussis vaccines (aPV). However, conventional purification methods for FHA often involve labor-intensive processes and result in low purity and recovery rates. Therefore, this study explores the use of monoclonal and polyclonal antibodies as specific tools to achieve highly pure and efficient FHA purification. To generate FHA-specific antibodies, polyclonal antibodies were produced by immunizing sheep and monoclonal antibodies (MAbs) were generated by immunizing mice with recombinant and native FHA. The MAbs were selected based on affinity, isotypes, and specificity, which were assessed through ELISA and Western blot assays. Two immunoaffinity columns, one monoclonal and one polyclonal, were prepared for FHA antigen purification. The purity and recovery rates of these purifications were determined using ELISA, SDS-PAGE, and immunoblotting. Furthermore, the MAbs were employed to develop an ELISA assay for FHA antigen concentration determination. The study's findings revealed that immunoaffinity column-based purification of FHA resulted in a highly pure antigen with recovery rates of approximately 57% ± 6.5% and 59% ± 7.9% for monoclonal and polyclonal columns, respectively. Additionally, the developed ELISA exhibited appropriate reactivity for determining FHA antigen concentration. This research demonstrates that affinity chromatography is a viable and advantageous method for purifying FHA, offering superior purity and recovery rates compared to traditional techniques. This approach provides a practical alternative for FHA purification in the context of aPV development.

Chemotherapy reinforces anti-tumor immune response and enhances clinical efficacy of immune checkpoint inhibitors

New evidence suggests that the clinical success of chemotherapy is not merely due to tumor cell toxicity but also arises from the restoration of immunosurveillance, which has been immensely neglected in previous preclinical and clinical researches. There is an urgent need for novel insights into molecular mechanisms and regimens that uplift the efficacy of immunotherapy since only a minority of cancer patients are responsive to immune checkpoint inhibitors (ICIs). Recent findings on combination therapy of chemotherapy and ICIs have shown promising results. This strategy increases tumor recognition and elimination by the host immune system while reducing immunosuppression by the tumor microenvironment. Currently, several preclinical studies are investigating molecular mechanisms that give rise to the immunomodulation by chemotherapeutic agents and exploit them in combination therapy with ICIs in order to achieve a synergistic clinical activity. In this review, we summarize studies that exhibit the capacity of conventional chemotherapeutics to elicit anti-tumor immune responses, thereby facilitating anti-tumor activities of the ICIs. In conclusion, combining chemotherapeutics with ICIs appears to be a promising approach for improving cancer treatment outcomes.

Soluble T Cell Immunoglobulin and Mucin Domain-3 (sTIM-3) Predict Graft-Versus-Host Disease (GVHD) in Iranian Allogeneic Hematopoietic Stem Cell Transplantation

Background: T cell immunoglobulin and mucin domain-3 (TIM-3) is an immune-checkpoint molecule that is upregulated following allogeneic immune responses and could play an important role in the development and pathogenesis of graft-versus-host disease (GVHD). The soluble form of TIM-3 (sTIM-3) is increased following the upregulation of membranous TIM-3. Objectives: The aim of this study was to evaluate the association between plasma level of sTIM-3 and acute GVHD (aGVHD) incidence in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Blood samples were collected from 42 allo-HSCT patients and 20 healthy individuals 2 weeks after allo-HSCT. The plasma level of sTIM-3 was measured using enzyme-linked immunosorbent assay (ELISA). The clinical and demographic data of patients were collected from the clinical documents. Data analysis was evaluated using student t-test and one-way ANOVA tests. P-values less than 0.05 were assumed statistically significant. Results: Among 18 (42.8%) patients with aGVHD symptoms, 10 (23.8%) had severe GVHD and 8 (19%) experienced mild GVHD. Plasma sTIM-3 levels at day +14 were significantly higher in patients who developed aGVHD compared to allo-HSCT patients without GVHD and also the healthy control individuals (P-value = 0.015 and < 0.001). Among the aGVHD patients, the sTIM-3 levels in those with severe GVHD were approximately 2.5 times higher than those with mild GVHD (P-value < 0.001). Conclusions: We have identified a high plasma level of sTIM-3 as a valuable biomarker in predicting the development of acute GVHD, especially severe aGVHD in allo-HSCT patients.

Risk Factors of Graft-Versus-Host Disease in the Iranian Allogeneic Hematopoietic Stem Cell Transplantation: A 10-Year Experience

Background: Graft-versus-host disease (GVHD) is a serious complication associated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Thus, it is necessary to evaluate the risk factors of GVHD in allo-HSCT. Herein, we studied the effects of some risk factors on GVHD incidence in patients with allo-HSCT. Methods: We retrospectively evaluated the GVHD incidences and risk factors in 199 patients diagnosed with hematological disorders who underwent allo-HSCT in Taleghani hospital, Tehran, Iran, between 2007 and 2017. The univariable and multivariable analyses of time to event data were performed using the Logistic regression model. Computations were performed using SAS, and the level of statistical significance for univariable and multivariable analyses was set at 20% and 10%, respectively. Results: Acute GVHD (aGVHD) was seen in 59 (29.6%) patients, and 18 (9%) patients developed chronic GVHD (cGVHD). The odds of GVHD incidence in male to female transplants was 3.49 times greater than the male-to-male transplantations (CI, 1.16, 11.5; p<0.001). The patients with body mass index (BMI) below 18.5 had 96% lower odds of GVHD incidence compared with those with BMI above 30 (CI, 0.007-0.27; p=0.013). The odds of GVHD incidence in patients who were negative for cytomegalovirus (CMV) antigen was 76% lower than patients with positive CMV antigen (CI, 0.06-0.93; p=0.081). Conclusion: In a nutshell, our results indicated that the donor-recipient gender disparity, the recipient's BMI, and CMV infection/reactivation status might be pivotal risk factors, which should be taken into account for prevention and management of GVHD.

Personalized Immunotherapy in Colorectal Cancers: Where Do We Stand?

Colorectal cancer (CRC) is the second leading cause of cancer death in the world. Immunotherapy using monoclonal antibodies, immune-checkpoint inhibitors, adoptive cell therapy, and cancer vaccines has raised great hopes for treating poor prognosis metastatic CRCs that are resistant to the conventional therapies. However, high inter-tumor and intra-tumor heterogeneity hinder the success of immunotherapy in CRC. Patients with a similar tumor phenotype respond differently to the same immunotherapy regimen. Mutation-based classification, molecular subtyping, and immunoscoring of CRCs facilitated the multi-aspect grouping of CRC patients and improved immunotherapy. Personalized immunotherapy using tumor-specific neoantigens provides the opportunity to consider each patient as an independent group deserving of individualized immunotherapy. In the recent decade, the development of sequencing and multi-omics techniques has helped us classify patients more precisely. The expansion of such advanced techniques along with the neoantigen-based immunotherapy could herald a new era in treating heterogeneous tumors such as CRC. In this review article, we provided the latest findings in immunotherapy of CRC. We elaborated on the heterogeneity of CRC patients as a bottleneck of CRC immunotherapy and reviewed the latest advances in personalized immunotherapy to overcome CRC heterogeneity.

Plasma exchange followed by convalescent plasma transfusion in COVID-19 patients

Background

Coronavirus disease 2019 (COVID-19) is an emerged pandemic disease with no specific treatment. One of the potential treatments in newly found infectious disease is plasma exchange (PE) with convalescent plasma transfusion (CPT). This case series aimed to evaluate the primary PE and CPT in five Iranian COVID-19 patients.

Methods

Five patients with confirmed COVID-19 who had acute respiratory distress syndrome and were supported by mechanical ventilation were treated with two consecutive PE containing fresh frozen plasma (FFP) of healthy donors and 0.9 % saline solution containing 5 % human albumin. Thereafter, CPT was performed just like PE, except that the FFP in this step was substituted with convalescent ABO-matched plasma. Clinical and laboratory factors were evaluated before and after treatments.

Results

Three to Four patients showed lower body temperature and improved oxygen saturation as well as reduced laboratory factors such as c-reactive protein, lactate dehydrogenase, creatine phosphokinase (total and myocardial isoform), aspartate aminotransferase, blood urea nitrogen, bilirubin (total and direct), D-dimer, interleukin-6, and CD4+/CD8 + T cells ratio initially after PE and continued to improve so that they were discharged. One patient due to secondary hemophagocytic lymphohistiocytosis and extensive lung fungal infection was expired.

Discussion

Overall, the PE followed by CPT was beneficial in reducing acute inflammation led to a considerable improvement in patients’ clinical features. It seems that PE along with CPT could provide clearance of pro-inflammatory mediators as well as the positive effects of CPT. Controlled studies are required to confirm the effect of PE/CPT compared with other therapeutic approaches.

Immune and metabolic checkpoints blockade: Dual wielding against tumors

Recent advances in cancer immunotherapy have raised hopes for treating cancers that are resistant to conventional therapies. Among the various immunotherapy methods, the immune checkpoint (IC) blockers were more promising and have paved their way to the clinic. Tumor cells induce the expression of ICs on the immune cells and derive them to a hyporesponsive exhausted phenotype. IC blockers could hinder immune exhaustion in the tumor microenvironment and reinvigorate immune cells for an efficient antitumor response. Despite the primary success of IC blockers in the clinic, the growing numbers of refractory cases require an in-depth study of the cellular and molecular mechanisms underlying IC expression and function. Immunometabolism is recently found to be a key factor in the regulation of immune responses. Activated or exhausted immune cells exploit different metabolic pathways. Tumor cells can suppress antitumor responses via immunometabolism alteration. Therefore, it is expected that concurrent targeting of ICs and immunometabolism pathways can cause immune cells to restore their antitumor activity. In this review, we dissected the reciprocal interactions of immune cell metabolism with expression and signaling of ICs in the tumor microenvironment. Recent findings on dual targeting of ICs and metabolic checkpoints have also been discussed.

Oncolytic Virotherapy in Solid Tumors: The Challenges and Achievements

Oncolytic virotherapy (OVT) is a promising approach in cancer immunotherapy. Oncolytic viruses (OVs) could be applied in cancer immunotherapy without in-depth knowledge of tumor antigens. The capability of genetic modification makes OVs exciting therapeutic tools with a high potential for manipulation. Improving efficacy, employing immunostimulatory elements, changing the immunosuppressive tumor microenvironment (TME) to inflammatory TME, optimizing their delivery system, and increasing the safety are the main areas of OVs manipulations. Recently, the reciprocal interaction of OVs and TME has become a hot topic for investigators to enhance the efficacy of OVT with less off-target adverse events. Current investigations suggest that the main application of OVT is to provoke the antitumor immune response in the TME, which synergize the effects of other immunotherapies such as immune-checkpoint blockers and adoptive cell therapy. In this review, we focused on the effects of OVs on the TME and antitumor immune responses. Furthermore, OVT challenges, including its moderate efficiency, safety concerns, and delivery strategies, along with recent achievements to overcome challenges, are thoroughly discussed.

Plasma levels of norepinephrine and expression levels of ß2-adrenergic receptor gene correlate with the incidence of acute graft-versus-host disease

Background: Acute graft-versus-host disease is a major complication in allogeneic hematopoietic stem-cell transplantation. Epinephrine and norepinephrine are stress hormones which affect many cells, including immune cells through interaction with adrenergic receptors, mainly β2-adrenergic receptor. The immunomodulatory effects of epinephrine, norepinephrine, and signaling of the adrenergic receptor have been shown to decrease the probability of the acute graft-versus-host disease in animal models. The aim of our study was to investigate the possible correlations between the serum levels of epinephrine and norepinephrine and also leukocytic expression levels of β2-adrenergic receptor with the incidence of acute graft-versus-host disease in patients undergoing allogeneic hematopoietic stem-cell transplantation. Methods: In this study, the plasma levels of epinephrine and norepinephrine and the leukocytic expression of β2-adrenergic receptor gene were measured and compared in allogeneic hematopoietic stem-cell transplantation patients with and without acute graft-versus-host disease. Data were analyzed and illustrated using SPSS 19 and GraphPad Prism 6. The student T-test, Pearson, and Spearman's tests were performed and p<0.05 was considered as significant. Results: We showed that the plasma levels of norepinephrine and the relative amount of the mRNA of β2-adrenergic receptor at 7 and 21 days after allogeneic hematopoietic stem-cell transplantation were significantly lower in patients with acute graft-versus-host disease than recipients without acute graft-versus-host disease. There were also negative correlations between the plasma levels of norepinephrine, leukocytic levels of the mRNA of β2-adrenergic receptor, and the incidence of acute graft-versus-host disease. Conclusion: Our results suggest that stress hormones and their receptor might have a role in preventing acute graft-versus-host disease and could be promising factors in controlling the outcome of allogeneic hematopoietic stem-cell transplantation.

Next-Generation Pertussis Vaccines Based on the Induction of Protective T Cells in the Respiratory Tract

Immunization with current acellular pertussis (aP) vaccines protects against severe pertussis, but immunity wanes rapidly after vaccination and these vaccines do not prevent nasal colonization with Bordetella pertussis. Studies in mouse and baboon models have demonstrated that Th1 and Th17 responses are integral to protective immunity induced by previous infection with B. pertussis and immunization with whole cell pertussis (wP) vaccines. Mucosal Th17 cells, IL-17 and secretory IgA (sIgA) are particularly important in generating sustained sterilizing immunity in the nasal cavity. Current aP vaccines induce potent IgG and Th2-skewed T cell responses but are less effective at generating Th1 and Th17 responses and fail to prime respiratory tissue-resident memory T (TRM) cells, that maintain long-term immunity at mucosal sites. In contrast, a live attenuated pertussis vaccine, pertussis outer membrane vesicle (OMV) vaccines or aP vaccines formulated with novel adjuvants do induce cellular immune responses in the respiratory tract, especially when delivered by the intranasal route. An increased understanding of the mechanisms of sustained protective immunity, especially the role of respiratory TRM cells, will facilitate the development of next generation pertussis vaccines that not only protect against pertussis disease, but prevent nasal colonization and transmission of B. pertussis.

Functional significance of lymphocytes in pregnancy and lymphocyte immunotherapy in infertility: A comprehensive review and update

During pregnancy, the fetal-maternal interface underlies several dynamic alterations to permit the fetus to be cultivated and developed in the uterus, in spite of being identifies by the maternal immune system. A large variety of decidual leukocyte populations, including natural killer cells, NKT cells, innate lymphoid cells, dendritic cells, B cells, T cells, subpopulations of helper T cells play a vital role in controlling the trophoblast invasion, angiogenesis as well as vascular remodeling. In contrast, several regulatory immunosuppressive mechanisms, including regulatory T cells, regulatory B cells, several cytokines and mediators are involved in maintain the homeostasis of immune system in the fetal-maternal interface. Nonetheless, aberrant alterations in the balance of immune inflammatory or immunosuppressive arms have been associated with various pregnancy losses and infertilities. As a result, numerous strategies have been developed to revers dysregulated balance of immune players to increase the chance of successful pregnancy. Lymphocyte immunotherapy has been developed through utilization of peripheral white blood cells of the husband or others and administered into the mother to confer an immune tolerance for embryo's antigens. However, the results have not always been promising, implying to further investigations to improve the approach. This review attempts to clarify the involvement of lymphocytes in contributing to the pregnancy outcome and the potential of lymphocyte immunotherapy in treatment of infertilities with dysregulated immune system basis.

The role of serum uric acid in the prediction of graft-versus-host disease in allogeneic hematopoietic stem cell transplantation

Background

Uric acid (UA) level is of the valuable signs of inflammation. However, the role of UA in the outcomes of hematopoietic stem cell transplantation (HSCT) such as GVHD and patients’ overall survival is still a matter of debate. In this study, we aimed to evaluate the relationship between UA levels and GVHD incidence and overall survival in allogeneic HSCT patients.

Methods

A total of 201 patients who were admitted for allogeneic transplantation at Taleghani hospital, Tehran, Iran, were considered for retrospective analysis. Serum UA levels from 1 week before transplantation until 2 weeks after transplantation were used to determine thresholds and find out the association of serum UA levels with GVHD and overall survival.

Results

We showed that the determined thresholds using receiver operating characteristic curves have poor predictive value for GVHD and overall survival. The patients with serum UA higher than 3.4 mg/dL had 37% lower odds of GVHD incidence and 35% lower hazard of death than patients with UA lower than 3.4 mg/dL.

Conclusion

Our results indicated that serum UA levels lower than 3.4 mg/dL could significantly increase the incidence of GVHD and hazard of death. The antioxidant functions of UA could explain the lower incidence of GVHD in hyperuricemic patients. However, the inconsistencies of the previous studies require further investigation to elucidate the role of UA in the prediction of GVHD.

Immunomodulation as a Novel Strategy for Prevention and Treatment of Bordetella spp. Infections

Well-adapted pathogens have evolved to survive the many challenges of a robust immune response. Defending against all host antimicrobials simultaneously would be exceedingly difficult, if not impossible, so many co-evolved organisms utilize immunomodulatory tools to subvert, distract, and/or evade the host immune response. Bordetella spp. present many examples of the diversity of immunomodulators and an exceptional experimental system in which to study them. Recent advances in this experimental system suggest strategies for interventions that tweak immunity to disrupt bacterial immunomodulation, engaging more effective host immunity to better prevent and treat infections. Here we review advances in the understanding of respiratory pathogens, with special focus on Bordetella spp., and prospects for the use of immune-stimulatory interventions in the prevention and treatment of infection.