Iranian journal of immunology
Volume:20 Issue: 1, Winter 2023

The most effective method to minimize the prevalence of infectious diseases is vaccination. Vaccines enhance immunity and provide protection against different kinds of infections. Subunit vaccines are safe and less toxic, but due to their lower immunogenicity, they need adjuvants to boost the immune system. Adjuvants are small particles/molecules integrated into a vaccine to enhance the immunogenic feedback of antigens. They play a significant role to enhance the potency and efficiency of vaccines. There are several types of adjuvants with different mechanisms of action; therefore, improved knowledge of their immunogenicity will help develop a new generation of adjuvants. Many trials have been designed using different kinds of vaccine adjuvants to examine their safety and efficacy, but in practice, only a few have entered in animal and human clinical trials. However, for the development of safe and effective vaccines, it is important to have adequate knowledge of the side effects and toxicity of different adjuvants. The current review discussed the adjuvants which are available for producing modern vaccines as well as some new classes of adjuvants in clinical trials.

Recent research in our laboratory shows that CD4+ T cells express the β2 adrenergic receptor (β2-AR), and the sympathetic neurotransmitter norepinephrine regulates the function of T cells via β2-AR signaling. However, the immunoregulatory effect of β2-AR and its related mechanisms on rheumatoid arthritis is unknown. To explore the effects of β2-AR in collagen-induced arthritis (CIA) on the imbalance of T helper (Th) 17/ regulatory T (Treg) cells. In DBA1/J mice, collagen type II was injected intradermally at the tail base to prepare the CIA model. The specific β2-AR agonist, terbutaline (TBL), was administered intraperitoneally beginning on day 31 and continuing until day 47 after primary vaccination, twice a day. Magnetic beads were used to sort CD3+ T cells subsets from spleen tissues. In vivo, β2-AR agonist TBL alleviated arthritis symptoms in the CIA mice including histopathology of the ankle joints, four limbs’ arthritis score, the thickness of ankle joints, and rear paws. After TBL treatment, in the ankle joints, the levels of proinflammatory factors (IL-17/22) notably decreased and the levels of immunosuppressive factors (IL-10/TGF-β) significantly increased. In vitro, ROR-γt protein expression, Th17 cell number, mRNA expression and the releasing of IL-17/22 from CD3+ T cells reduced following TBL administration. Moreover, TBL enhanced the anti-inflammatory responses of Treg cells. These results suggest that β2-AR activation exerts anti-inflammatory effects through the amelioration of Th17/Treg imbalance in the CIA disease.

Dendritic cells, (DCs) as one of the important immune cell populations, are responsible for the initiation, development, and control of acquired immune responses. Myeloid dendritic cells can be used as a vaccine for several autoimmune diseases and cancers. Tolerogenic probiotics with regulatory properties can affect the maturation and development of immature dendritic cells (IDC) into mature DCs with certain immunomodulatory effects. To assess the immunomodulatory effect of Lactobacillus rhamnosus and Lactobacillus delbrueckii, as two tolerogenic probiotics, in the differentiation and maturation of myeloid dendritic cells. The IDCs were derived from the healthy donors in GM-CSF and IL 4 medium. Mature DCs (MDC) were produced with L. delbrueckii, L. rhamnosus, and LPS from IDCs. Real-Time PCR and flow cytometry were used to confirm the DC maturation and to determine DC markers as well as IDO, IL10, and IL12 expression levels, respectively. Probiotic-derived DCs showed a significant reduction in the level of HLA-DR (P≤0.05), CD86 (P≤0.05), CD80 (P≤0.001), CD83 (P≤0.001), and CD1a. Also, the expression of IDO (P≤0.001) and IL10 increased while IL12 expression decreased (P≤0.001). Our findings revealed that tolerogenic probiotics could induce regulatory DCs by reducing co-stimulatory molecules along with increasing the expression of IDO and IL10 during the differentiation process. Therefore, the induced regulatory DCs probably can be used in the treatment of various inflammatory diseases.

Allergic dermatitis (AD) is an inflammatory skin disease that arises from abnormal T lymphocyte activation. A recombinant fusion protein comprising Helicobacter pylori neutrophil-activating protein and maltose binding protein, rMBP-NAP, has been documented as a novel immunomodulatory TLR agonist. To explore the effect of the rMBP-NAP on the OXA-induced AD in a mouse model and clarify the possible action mechanism. The AD animal model was induced by repeated administration of oxazolone (OXA) in BALB/c mice. H&E staining was used to analyze the ear epidermis thickness and the number of infiltrating inflammatory cells. TB staining was used to detect mast cell infiltration in the ear tissue. ELISA was used to analyze the secretion of cytokines IL-4  and IFN-γ in peripheral blood. qRT-PCR was used to determine the expression levels of IL-4, IFN-γ, and IL-13 in ear tissue. OXA induced the establishment of an AD model. After the rMBP-NAP treatment, the thickness of the ear tissue and the number of mast cells infiltrated in AD mice reduced, and the serum and ear tissue levels of IL-4 and IFN-γ increased, but the ratio of IFN-γ (rMBP-NAP group)/IL-4 (rMBP-NAP group) was greater than the ratio of IFN-γ (sensitized group)/IL-4 (sensitized group). The rMBP-NAP improved the disease symptoms including skin lesions in AD, alleviated the inflammation in ear tissue, and restored the Th1/2 balance by inducing a shift from the Th2 to the Th1 response. The results of our work support the use of rMBP-NAP as an immunomodulator for AD treatment in future investigations.

Little is known about MBD2’s epigenetic regulation in the immune pathogenesis of CD4+T cell differentiation. This study attempted to explore the mechanism of methyl-cpg-binding domain protein 2 (MBD2) in CD4+T cell differentiation stimulated by environmental allergen ovalbumin (OVA). Mononuclear cells were separated from the spleen tissues of male C57BL/6 mice. The OVA interfered with the differentiation of splenic mononuclear cells and CD4+T cells. The CD4+T cells were obtained by magnetic beads and identified by CD4 labeled antibody. CD4+T cells were transfected with lentivirus to silence MBD2 gene. A methylation quantification kit was used to detect 5-mC levels. The purity of CD4+T cells reached 95.99% after magnetic beads sorting. Treatment with 200 μg/mL OVA stimulated the CD4+T cells differentiation to Th17 cells and promoted the secretion of IL-17. After being induced, the Th17 cell ratio increased. 5-Aza inhibited the Th17 cell differentiation and the IL-17 level in a dose-dependent manner. Under the intervention of the Th17 induction and 5-Aza, MBD2 silencing inhibited the differentiation of Th17 cell, and decreased the IL-17 and 5-mC levels in the cell supernatants. MBD2 silencing reduced the scale of the Th17 cell and IL-17 levels in the OVA-treated CD4+T cells. MBD2 affected IL-17 and 5-mC levels by mediating the Th17 cell differentiation in splenic CD4+T cells that were interfered with 5-Aza. OVA induced Th17 differentiation and increased IL-17 levels, inhibited by MBD2 silencing.

Staphylococcus aureus is an opportunistic pathogen responsible for various infections with diverse clinical presentation and severity. The α-hemolysin is a major virulence factor in the pathogenesis of S. aureus infections. To produce a chimeric fusion protein for hemolytic detection of the S. aureus isolates and as a component of a multi-antigen vaccine. The fused strategy employed a flexible linker to incorporate the possible B cell and T cell determinants into one chimera (HlaD). The humoral and cellular response to the HlaD in mice was assessed to reveal a non-significant difference compared with the full-length α-hemolysin mutant (Hla H35L). The results of the protective effect, the mimetic lung cell injury, and bacterial clearness demonstrated that the mice vaccinated with the HlaD alleviated the severity of the infection of the S. aureus, and the HlaD could similarly function with Hla H35L. The chimeric fusion (HlaD) provided a diagnostic antigen for hemolysis of the S. aureus strains and a potential vaccine component.

The extent to which maternal antibodies against the hepatitis B surface antigen (HBsAb) acquired transplacentally affect the immune responses to the hepatitis B vaccine (HBVac) in infants is still uncertain. To explore the impact of the HBsAb on the immune response to the HBVac in a mouse model. According to the doses of the HBVac (2, 5 μg) injected, 267 BALB/c mice were divided into two groups. Each group was subdivided into 3 subgroups based on the doses of the hepatitis B immunoglobulin (HBIG) (0, 25, 50 IU) administered. The HBsAb titers were detected 4 weeks after completing the HepB vaccination. Among all the mice, 40 had an HBsAb titer <100 mIU/mL (non- or low-response to the HBVac). The rates of the HBsAb titer <100 mIU/mL in 0, 25 and 50 IU HBIG groups were 1.1%, 23.1%, and 20.7%, respectively. Multivariate logistic regression analysis showed that the risk factors for low- or non-response to the HBVac were injection with the HBIG, low HBVac dose, and hypodermic injection. The mean HBsAb titers (log10) reduced gradually in the 0, 25 and 50 IU HBIG groups (P<0.001). The HBIG administration has negative impacts on the peak level of the HBsAb and the rate of an effective immune response. This implies that the maternal HBsAb acquired transplacentally might inhibit the immune responses to the HBVac in infants.

Measuring the level of antibodies produced post-vaccination in response to the SARS-CoV-2 spike protein is considered a strategy for estimating the effectiveness of the COVID-19 vaccines. To examine the antibody levels among the healthcare workers in different hospitals in Mashhad, Iran after receiving the second dose of Sputnik V. In this study, we enrolled 230 healthcare workers for evaluating the Gam-COVID-Vac or Sputnik V after the second administration in different hospitals in Mashhad. Antibody levels of spike protein were quantitatively evaluated in a sample of 230 negative RT-PCR tests for the COVID-19 individuals. The analysis has been done based on an immunological assay using enzyme-linked immunosorbent assay (ELISA). The infection history of the subjects and their families was examined through their medical records. Our results demonstrated a significant association between a higher titer of IgG and a previous history of the COVID-19 infection (P<0.001). Moreover, the chance of detecting antibodies titer more than 50 AU/ml was 16.99 in these people which was significantly higher than in people without a history of infection pre-vaccination [%95CI: (7.38,39.12), P<0.001]. This result demonstrates that the efficacy of antibody production is related to the previous history of the SARS-CoV-2 infections. Ongoing monitoring of the level of antibody among vaccinated populations will help evaluating the effect of vaccines on humoral immunity status.

Cancer testis antigens (CTAs) are a class of immune-stimulating antigens often overexpressed in many types of cancers. The usage of the CTAs as immunotherapy targets have been widely investigated in different cancers including melanoma, hematological malignancies, and colorectal cancer. Studies have indicated that the epigenetic regulation of the CTAs such as the methylation status may affect the expression of the CTAs. However, the report on the methylation status of the CTAs is conflicting. The general methylation profile of the CTAs, especially in colorectal cancer, is still elusive.

To determine the methylation profile of the selected CTAs in our colorectal cancer patients.

A total of 54 pairs of colorectal cancer samples were subjected to DNA methylation profiling using the Infinium Human Methylation 450K bead chip.

We found that most of the CTAs were hypomethylated, and CCNA1 and TMEM108 genes were among the few CTAs that were hypermethylated.

Overall, our brief report has managed to show the overall methylation profile in over the 200 CTAs in colorectal cancer and this could be used for further refining any immunotherapy targets.

T-helper 17 (Th17) cell response is engaged in the onset of allergic rhinitis (AR). Moreover, interleukin (IL)-38 is thought to be involved in inhibiting cytokine secretion in the Th17 pathway. To evaluate the regulatory function of IL-38 on abnormal Th17 responses in Chinese patients with AR. Forty-five participants, divided into an AR group (n=25) and a control group (n=20), were recruited for the study. In addition, the expression of IL-38 and Th17-related cytokines was measured as well as the Th17 cell count in participants. By implementing recombinant IL-38 (rIL-38), the intervention of human peripheral blood mononuclear cells (PBMCs) was performed. Then, flow cytometry, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) were used to detect theTh17 milieu. The expression of IL-38 in the AR group notably reduced compared with that in the control, whereas Th17 cell frequency and the expression levels of its transcription factor (RORC) and cytokines (IL-17A and IL-23) increased. The differentiation and immune function of Th17 cells in PBMCs were inhibited by rIL-38. Th17 responses are inhibited by IL-38 in patients with AR. Therefore, the obtained findings indicate that IL-38 is a potential therapeutic target for Chinese patients with AR.

Abnormal humoral and cellular immune responses have been reported in immune-mediated polyneuropathies. CD137, as a costimulatory molecule and a TNF receptor superfamily member, has been demonstrated to have a key role in the pathogenesis of many autoimmune as well as inflammatory disorders. To evaluate the transcripts levels of CD137, its ligand (CD137L), and the serum levels of soluble CD137 (sCD137) in patients with immune-mediated polyneuropathy. A total of 45 patients and 46 sex and age-matched healthy individuals were enrolled in the study. CD137 and CD137L transcript levels were assessed by the Real-Time PCR, and the serum level of sCD137 was measured using the ELISA technique. The Bayesian regression model was used for statistical analysis at the 0.05 significance level in R 4.1.0 statistical environment. Transcript levels of the CD137 and CD137L were higher in polyneuropathy patients in comparison with the healthy subjects (P=0.006 for both). Conversely, the mean level of sCD137 was significantly lower in the sera of patients compared to the controls (P<0.001). Our findings point to the possible role of CD137 and CD137L in immune-mediated polyneuropathy pathogenesis. More investigations are required to clarify the exact contributions of the mentioned molecules to the pathogenesis of immune-mediated polyneuropathies.

An issue that hinders researchers’ access to Natural Killer (NK) cells is their low proportion in peripheral blood leukocytes. This issue is currently addressed by methods involving a series of differentiation and expansions that are time-consuming and expensive. We have investigated whether the used leukocyte reduction filters, a by-product in the blood transfusion practice that currently is considered waste, can be utilized as a source of the NK cells. Following the blood donation of 46 donors based on the Iranian Blood Transfusion Organization’s protocols, a sample of peripheral blood of each donor and the leukocyte reduction filter used in their donation procedure have been obtained. The entrapped cells were flushed back from the leukocyte reduction filters. Both groups of samples were analyzed using an automatic hematological analyzer. NK cell isolation was done by the MACS negative selection method. The samples have been comparatively analyzed utilizing flow cytometry data of NK cells’ subpopulation compositions, viability, degranulation patterns, and cytotoxic capacity against the K562 cell line. Every major leukocyte population was abundant in the samples extracted from the used leukocyte reduction filters. The NK cells extracted from leukocyte reduction filters did not show any statistically meaningful differences (P<0.5) from peripheral blood samples in terms of subpopulation composition, viability, degranulation potency, and cytotoxic capacity. Used leukocyte reduction filters can be considered an economic, easy to obtain, and robust source of abundant research-grade NK cells.

Several cases of the hemolytic disease of the fetus and newborn (HDFN) caused by immunoglobulin G (IgG) anti-M antibodies have been reported, in which almost all the HDFN-associated anti-M were warmly reacting. Here we report two cases of severe HDFN associated with cold-reacting IgG anti-M. In both cases, pregnancy was terminated, in weeks 33 and 23 respectively, due to a diagnosis of fetal growth retardation (FGR). To our knowledge, these are the most severe HDFN cases caused by cold-reacting IgG anti-M.

Macrophage activation syndrome (MAS), a secondary hemophagocytic lymphohistiocytosis characterized by an excessive systemic inflammatory response, is a life-threatening and rare disease. Cardiovascular damage is a common and severe complication of the disease, however, it is easily ignored and not well studied. Herein, we report two cases of patients with MAS-associated heart damage and review the clinical characteristics, mechanism, and treatment. Case 1 along with systemic lupus erythematosus and Kikuchi necrotizing lymphadenitis occurred in fatal acute heart failure, and case 2 complicated adult-onset Still’s Disease began with atrial fibrillation and had some improvement with the treatment of high dose corticosteroids. MAS-associated heart damage is a critical issue in clinical settings, and the etiology and mechanisms of MAS-associated cardiovascular diseases are likely multifactorial. The manifestations were various and high levels of the cytokines and cardiac damage may contribute to poor prognosis. Therefore, early intensive immunosuppressive therapy probably improves the treatment outcome.