Mucosal immunity to poliovirus in children 0-15 years of age: A community-based study in Karachi, Pakistan in 2019

This study assesses poliovirus type 1 (PV1) immunity in children to inform the contribution of mucosal immunity in and preventing poliovirus circulation. A community-based study was conducted in peri-urban Karachi, Pakistan. Randomly selected children (0-15 years) received oral poliovirus vaccine (OPV) challenge dose. Blood and stool samples were collected at several time points and evaluated for polio-neutralizing antibodies and serotype-specific poliovirus, respectively. 81/589 (14%) children excreted PV1 7 days post-OPV-challenge; 70/81 (86%) were seropositive at baseline. 12/610 (2%) were asymptomatic Wild Poliovirus Type 1 (WPV1) excretors. Most poliovirus excretors had humoral immunity, suggesting mucosal immunity in these children likely waned or never developed. Without mucosal immunity, they are susceptible to poliovirus infection, shedding, and transmission. Asymptomatic WPV1 excretion suggests undetected poliovirus circulation within the community.

Study of some immunological signatures and their association with COVID-19 in a sample of recovered Iraqi patients

Since its emergence about two years ago, the novel coronavirus has continued to be a challenge and threat to public health, struck most parts of the world, leaving more than half a billion cases of infection and more than five million deaths. Immune response abnormalities post-infection with SARS-CoV-2 have been reported, and the mechanisms that lead to them are still ambiguous. This study was conducted to evaluate some immunological markers in the serum samples of COVID-19 convalescent patients and investigate the association of these immunological signatures with their age and sex. The serum levels of immunoglobulin G, interleukin-1 beta, and interferon lambda-1 of 75 patients and 50 healthy control group members were measured, with 55 % males and 45 % females participating and ages ranging from 20 to 80 years. The measurement of the immunological signatures was performed using the enzyme-linked immunosorbent assay (ELISA). The result revealed highly significant elevated levels of the serum immunological signatures of the convalescent group in comparison to the control group, with P-values of 0.00001 for each signature. Moreover, age was observed to have an association with an elevated level of the immunological signatures as it increased in the elderly, whereas no association with sex was detected. The findings strongly suggest that COVID-19 infection results in a persistent inflammatory response, which leads to prolonged post-recovery symptoms. Post-COVID-19 syndrome necessitates additional research to clarify its pathophysiology, pathogenesis, and long-term implications.

Niclosamide Modulates the Cellular and Humoral Immune Response in Balb/c Mice

BACKGROUND

Niclosamide, a STAT3 inhibitor, is widely under investigation due to its anti-cancer properties. STAT3 also exhibits an exciting role in the immune responses.

OBJECTIVE

This study aimed to evaluate the impact of niclosamide on immune response of mice.

METHODS

Niclosamide was administered to balb/c mice. To evaluate cell-mediated immune response, a contact-hypersensitivity (CHS) test, cyclophosphamide-induced neutropenic assay, and carbon clearance test were performed, whereas a humoral immune response was evaluated by hemagglutination assay (HA) and mice lethality test. The concentration of TGF-β1 was determined by enzyme-linked immunosorbent assay (ELISA) on murine peritoneal macrophages.

RESULTS

In the CHS test, niclosamide caused a decrease in skin thickness, significantly exhibiting a decrease in inflammation. A highly significant decrease in overall leukocyte count (lymphocytes and neutrophils) was observed before and after cyclophosphamide injection as compared with the control group. However, only a highly significant decrease in the neutrophil percentage was observed. Niclosamide has decreased the phagocytic process immensely compared with the control. In the HA titer, niclosamide was found to reduce the antibodies' titer compared with the negative control group. In the mice lethality test, the treatment groups have shown an increase in the percentage of mortality. TGF-β1 elevated in peritoneal macrophages when treated with niclosamide, in a dose-dependent manner.

CONCLUSION

Niclosamide exerts potent immunomodulatory effects by significantly suppressing cell-mediated and humoral immune responses and increasing the levels of TGF-β1 in mice. Niclosamide might be added as an adjuvant to immunosuppressive drugs for the treatment of autoimmune diseases.

Immunogenicity and Reactogenicity of Ad26.COV2.S in Korean Adults: A Prospective Cohort Study

BACKGROUND

As the coronavirus disease 2019 (COVID-19) pandemic continues, there are concerns regarding waning immunity and the emergence of viral variants. The immunogenicity of Ad26.COV2.S against wild-type (WT) and variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated.

METHOD

This prospective cohort study was conducted between June 2021 and January 2022 at two university hospitals in South Korea. Healthy adults who were scheduled to be vaccinated with Ad26.COV2.S were enrolled in this study. The main outcomes included anti-spike (S) IgG antibody and neutralizing antibody responses, S-specific T-cell responses (interferon-γ enzyme-linked immunospot assay), solicited adverse events (AEs), and serious AEs.

RESULTS

Fifty participants aged ≥ 19 years were included in the study. Geometric mean titers (GMTs) of anti-S IgG were 0.4 U/mL at baseline, 5.2 ± 3.0 U/mL at 3-4 weeks, 55.7 ± 2.4 U/mL at 5-8 weeks, and 81.3 ± 2.5 U/mL at 10-12 weeks after vaccination. GMTs of 50% neutralizing dilution (ND50) against WT SARS-CoV-2 were 164.6 ± 4.6 at 3-4 weeks, 313.9 ± 3.6 at 5-8 weeks, and 124.4 ± 2.6 at 10-12 weeks after vaccination. As for the S-specific T-cell responses, the median number of spot-forming units/10⁶ peripheral blood mononuclear cell was 25.0 (5.0-29.2) at baseline, 60.0 (23.3-178.3) at 5-8 weeks, and 35.0 (13.3-71.7) at 10-12 weeks after vaccination. Compared to WT SARS-CoV-2, ND50 against Delta and Omicron variants was attenuated by 3.6-fold and 8.2-fold, respectively. The most frequent AE was injection site pain (82%), followed by myalgia (80%), fatigue (70%), and fever (50%). Most AEs were grade 1-2, and resolved within two days.

CONCLUSION

Single-dose Ad26.COV2.S was safe and immunogenic. NAb titer and S-specific T-cell immunity peak at 5-8 weeks and rather decrease at 10-12 weeks after vaccination. Cross-reactive neutralizing activity against the Omicron variant was negligible.

The role of B lymphocytes in the immuno-biology of non-small-cell lung cancer

Tumour-infiltrating immune cells have been widely implicated to play a significant role in carcinogenesis, through both pro- or anti-tumour effects. The multi-faceted effects of lung cancer associated T lymphocytes have been extensively studied, and yet, the role of B lymphocytes remains an area less studied. In this review, we will describe the current understanding of the role of tumour-infiltrating B lymphocytes in NSCLC, discuss their prognostic significance, their functionality within the tumour microenvironment and ultimately how we might harness B-cell biology to develop B-cell therapeutic strategies in cancer.

Case report of delayed seroprotection rather than non-response after primary three-dose hepatitis B vaccination

We describe a delayed hepatitis B seroprotection 12 weeks after the primary vaccination schedule in a 57-year-old male with smoldering multiple myeloma. Based on undetectable anti-HBs antibodies 6 weeks after the third vaccination, the index person was previously considered to be a hepatitis B vaccine non-responder. Because hepatitis B vaccination started in the 1980s, many hepatitis B vaccine non-responders have received a revaccination regimen. If more cases of genuine delayed hepatitis B seroprotection surface in patients with hematologic malignancies, delayed seroprotection should be considered before the commencement of hepatitis B revaccination.

Indoleamine 2,3-Dioxygenase 1, Increased in Human Gastric Pre-Neoplasia, Promotes Inflammation and Metaplasia in Mice and Is Associated With Type II Hypersensitivity/Autoimmunity

BACKGROUND & AIMS

Chronic gastrointestinal inflammation increases the risk of cancer by mechanisms that are not well understood. Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-binding enzyme that regulates the immune response via catabolization and regulation of tryptophan availability for immune cell uptake. IDO1 expression is increased during the transition from chronic inflammation to gastric metaplasia. We investigated whether IDO1 contributes to the inflammatory response that mediates loss of parietal cells leading to metaplasia.

METHODS

Chronic gastric inflammation was induced in Ido1^-/- and CB57BL/6 (control) mice by gavage with Helicobacter felis or overexpression of interferon gamma in gastric parietal cells. We also performed studies in Jh^-/- mice, which are devoid of B cells. Gastric tissues were collected and analyzed by flow cytometry, immunostaining, and real-time quantitative polymerase chain reaction. Plasma samples were analyzed by enzyme-linked immunosorbent assay. Gastric tissues were obtained from 20 patients with gastric metaplasia and 20 patients without gastric metaplasia (controls) and analyzed by real-time quantitative polymerase chain reaction; gastric tissue arrays were analyzed by immunohistochemistry. We collected genetic information on gastric cancers from The Cancer Genome Atlas database.

RESULTS

H felis gavage induced significantly lower levels of pseudopyloric metaplasia in Ido1^-/- mice, which had lower frequencies of gastric B cells, than in control mice. Blood plasma from H felis-infected control mice had increased levels of autoantibodies against parietal cells, compared to uninfected control mice, but this increase was lower in Ido1^-/- mice. Chronically inflamed stomachs of Ido1^-/- mice had significantly lower frequencies of natural killer cells in contact with parietal cells, compared with stomachs of control mice. Jh^-/- mice had lower levels of pseudopyloric metaplasia than control mice in response to H felis infection. Human gastric pre-neoplasia and carcinoma specimens had increased levels of IDO1 messenger RNA compared with control gastric tissues, and IDO1 protein colocalized with B cells. Co-clustering of IDO1 messenger RNA with B-cell markers was corroborated by The Cancer Genome Atlas database.

CONCLUSIONS

IDO1 mediates gastric metaplasia by regulating the B-cell compartment. This process appears to be associated with type II hypersensitivity/autoimmunity. The role of autoimmunity in the progression of pseudopyloric metaplasia warrants further investigation.

Hypolipidemic and antioxidative effects of curcumin on blood parameters, humoral immunity, and jejunum histology in Hy-line hens

OBJECTIVE

Turmeric (Curcuma Longa Linn) is a medicinal plant that contains curcumin. There is a growing interest in using curcumin powder (CP) as feed additives for antioxidative and antimicrobial properties to improve human health. This study was conducted to determine the appropriate levels of CP on blood parameters, immunity, and histology of jejunum in hens.

MATERIALS AND METHODS

A total of 200, 58-wk-old Hy-line hens were randomly distributed into 4 treatments (0%, 0.5%, 1.5%, and 2.5% CP or 0, 5, 15, and 25 g/kg feed, respectively) with 5 replicates (10 birds each) for 8 weeks using the completely randomized design. Blood samples were taken from 2 birds per replicate at weeks 61 and 65 to evaluate blood parameters. On weeks 63 and 65, two birds from each replicate received 0.5 ml SRBC (25%) injection in breast muscle and 7 days later, blood samples were collected to evaluate total Ig, IgG, and IgM titers in serum. Two hens were sacrificed at week 65 for the histological study of jejunum.

RESULTS

Curcumin reduced triglycerides at 1.5% and 2.5% and cholesterol and LDL at 2.5% (p<0.05). Improvement of total Ig and IgG titers after the 1(st) and 2(nd) injections were observed. Muscle thickness in jejunum increased (p<0.05) at 1.5% curcumin and the length and surface area of villus were enhanced as well.

CONCLUSION

Our results demonstrate that curcumin can be used as an antioxidant at 1.5% and antilipidemic agent at 2.5% in diet.