Specific Antigen Research Articles

Antigen specificities and proviral integration sites differ in HIV-infected cells by timing of antiretroviral treatment initiation.

Despite effective antiretroviral therapy (ART), persons living with HIV (PWH) harbor reservoirs of persistently infected CD4+ cells, which constitute a barrier to cure. Initiation of ART during acute infection reduces the size of the HIV reservoir, and we hypothesized that in addition, it would favor integration of proviruses in HIV-specific CD4+ T cells, while initiation of ART during chronic HIV infection would favor relatively more proviruses in herpesvirus-specific cells. We further hypothesized that proviruses in acute-ART-initiators would be integrated into antiviral genes, whereas integration sites in chronic-ART-initiators would favor genes associated with cell proliferation and exhaustion. We found the HIV DNA distribution across HIV-specific vs. herpesvirus-specific CD4+ T cells was as hypothesized. HIV integration sites (IS) in acute-ART-initiators were significantly enriched in gene sets controlling lipid metabolism and HIF-1α-mediated hypoxia, both metabolic pathways active in early HIV infection. Persistence of these infected cells during prolonged ART suggests a survival advantage. IS in chronic-ART-initiators were enriched in a gene set controlling EZH2 histone methylation; and methylation has been associated with diminished LTR transcription. These differences we found in antigen specificities and IS distributions within HIV-infected cells might be leveraged in designing cure strategies tailored to the timing of ART initiation.

Antigen specificity shapes antibody functions in tuberculosis.

Tuberculosis (TB) is the number one infectious disease cause of death worldwide in part due to an incomplete understanding of immunity. Emerging data highlight antibody functions as correlates of protection and disease across human TB. However, little is known about how antibody functions impact Mycobacterium tuberculosis (Mtb), the causative agent. Here, we use antigen specificity to understand how antibodies mediate host-Mtb interactions. We focus on Mtb cell wall and ESAT-6 & CFP-10, critical bacterial structural and secreted virulence proteins. In polyclonal IgG from TB patients, we observe that antigen specificity alters IgG subclass and glycosylation that drives Fc receptor binding and effector functions. Through in vitro models of Mtb macrophage infection we find that Mtb cell wall IgG3, sialic acid, and fucose increase opsonophagocytosis of extracellular Mtb and bacterial burden, suggesting that some polyclonal IgG enhance disease. In contrast, ESAT-6 & CFP-10 IgG1 inhibits intracellular Mtb, suggesting that antibodies targeting secreted virulence factors are protective. We test this hypothesis by generating a mAb that reacts to ESAT-6 & CFP-10 and show that it alone inhibits intracellular Mtb. Understanding which antigens elicit antibody mediated disease enhancement and or protection will be critical in appreciating the many roles for antibodies in TB.

Evaluating the Compatibility of New Recombinant Protein Antigens (Trivalent NRRV) with a Mock Pentavalent Combination Vaccine Containing Whole-Cell Pertussis: Analytical and Formulation Challenges.

Introducing new recombinant protein antigens to existing pediatric combination vaccines is important in improving coverage and affordability, especially in low- and middle-income countries (LMICs). This case-study highlights the analytical and formulation challenges encountered with three recombinant non-replicating rotavirus vaccine (NRRV) antigens (t-NRRV formulated with Alhydrogel® adjuvant, AH) combined with a mock multidose formulation of a pediatric pentavalent vaccine used in LMICs. This complex formulation contained (1) vaccine antigens (i.e., whole-cell pertussis (wP), diphtheria (D), tetanus (T), Haemophilus influenza (Hib), and hepatitis B (HepB), (2) a mixture of aluminum-salt adjuvants (AH and Adju-Phos®, AP), and (3) a preservative (thimerosal, TH). Selective, stability-indicating competitive immunoassays were developed to monitor binding of specific mAbs to each antigen, except wP which required the setup of a mouse immunogenicity assay. Simple mixing led to the desorption of t-NRRV antigens from AH and increased degradation during storage. These deleterious effects were caused by specific antigens, AP, and TH. An AH-only pentavalent formulation mitigated t-NRRV antigen desorption; however, the Hib antigen displayed previously reported AH-induced instability. The same rank-ordering of t-NRRV antigen stability (P[8] > P[4] > P[6]) was observed in mock pentavalent formulations and with various preservatives. The lessons learned are discussed to enable future multidose, combination vaccine formulation development with new vaccine candidates.

Nanoenzyme Hydrogel Film-Based Portable Point-of-Care Testing Platform for Double-Signal Visual Detection of PSA.

The development of the Point-of-Care Testing (POCT) platform that combines convenience and cost-effectiveness is crucial for enabling the visual detection of disease biomarkers. In this work, a POCT platform for the sensitive in situ detection of prostate specific antigen (PSA) with dual-signal output was constructed by functionalizing the Eppendorf (EP) tube. This was achieved through the modification of aptamer hairpin probes (AHPs) on the lid of the EP tube and the assembly of a nanoenzyme hydrogel film on its inner wall. The target could trigger the release of Ag+ by AHP and subsequently activate Ag+-dependent DNAzyme (Ag-DNAzyme). This would initiate the cleavage of the DNA-Au/Pt NP hydrogel network, leading to the release of Au/Pt NPs. The released Au/Pt NPs exhibit both peroxidase (POD)-like and catalase (CAT)-like activity to produce a colorimetric response and induce liquid flow under pressure. Therefore, the target can be measured visually and quantitatively through colorimetric analysis and the measurement of total dissolved solids (TDS) using a pressure-triggered liquid flow device integrated into the platform. The designed platform is distinguished by its simplicity, specificity, cost-effectiveness, and remarkable sensitivity. It allows for the visual detection of PSA within concentration ranges of 0.5-100 ng/L (colorimetric) and 3-100 ng/L (TDS reading), boasting detection limits as low as 0.15 ng/L (colorimetric) and 0.57 ng/L (TDS reading). The strategy of target-triggered nanoenzyme release significantly enhances sensitivity and provides a guiding approach for visual biomarker detection.

Differences in the characteristics and functions of brain and spinal cord regulatory T cells

T cells play an important role in the acquired immune response, with regulatory T cells (Tregs) serving as key players in immune tolerance. Tregs are found in nonlymphoid and damaged tissues and are referred to as “tissue Tregs”. They have tissue-specific characteristics and contribute to immunomodulation, homeostasis, and tissue repair through interactions with tissue cells. However, important determinants of Treg tissue specificity, such as antigen specificity, tissue environment, and pathology, remain unclear. In this study, we analyzed Tregs in the central nervous system of mice with ischemic stroke and experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. The gene expression pattern of brain Tregs in the EAE model was more similar to that of ischemic stroke Tregs in the brain than to that of spinal cord Tregs. In addition, most T-cell receptors (TCRs) with high clonality were present in both the brain and spinal cord. Furthermore, Gata3+ and Rorc+ Tregs expressed TCRs recognizing MOG in the spinal cord, suggesting a tissue environment conducive to Rorc expression. Tissue-specific chemokine/chemokine receptor interactions in the spinal cord and brain influenced Treg localization. Finally, spinal cord- or brain-derived Tregs had greater anti-inflammatory capacities in EAE mice, respectively. Taken together, these findings suggest that the tissue environment, rather than pathogenesis or antigen specificity, is the primary determinant of the tissue-specific properties of Tregs. These findings may contribute to the development of novel therapies to suppress inflammation through tissue-specific Treg regulation.

The effect of distance reiki on patient reported quality of life, correlated with changes in immune repertoires among patients with multiple myeloma: A pilot study.

e23199 Background: Psychological distress and diminished health related quality of life (HRQOL) is associated with multiple myeloma (MM). Complementary and alternative medicine (CAM) is an adjunct to traditional medicine. T-cells are essential to the adaptive immune system. The complementarity determining region (CDR3) of the T cell receptor formed by combination of the V,D,J regions is highly variable and critical for antigen specificity. PCR is used to analyze the TCR-CDR3 to monitor T-cell clonotypes as a measure of antigen specific T cell responses and thereby cancer immunity. Reiki is a Japanese energy healing technique involving noninvasive light touch to modulate energy fields. The primary aim was feasibility and acceptability of Reiki within a structured medical paradigm. Secondary aims were changes in HRQOL and T-cell receptor repertoires with Reiki. Methods: Adult MM patients (pts) on a stable regimen were eligible. Pts randomized in a 1:1:1 to weekly True Reiki (Treiki), Simulated Reiki (Sreiki) or no intervention (NI). The PROMIS-29® assessed HRQOL. A “Was it Worth it” (WIWI) questionnaire was administered post intervention to assess the experience. TCR-CDR3 sequencing was performed on PBMCs at enrollment and end of therapy to determine immune repertoire changes. Samples underwent library preparation and next generation sequencing for TCR repertoire analysis by iRepertoire® Results: Thirty pts were randomized into 3 arms between 12/2020 to 4/2022. Median age 62.5 (range 27-76), 18/30 (60%) female, median time to diagnosis was 48 mo (Range 7-221), 50% had high risk FISH,(90%) had prior ASCT and received median 2 (range 1-13) lines of therapy prior to enrollment. No pts relapsed or progressed during study period. Using WIWI 100% of pts in Treiki and 75% in Sreiki arms found the therapy useful and would do it again; 100% Treiki pts and 87.5% in the Sreiki arm would recommend the study to others. No statistical difference between groups in any HRQOL domains. Among TCR repertoires, no statistically significant difference was observed between groups with respect to Richness, Shannon entropy, Clonality, Diversity 50 (D50) and Inverse Simpson indexes. Each pt showed substantial variability in certain TCR-CDR3 clones and clonal diversity. Conclusions: We successfully demonstrated acceptability and feasibility of Reiki among MM pts, although no impact on HRQOL was shown. Reiki intervention is an easy non-invasive additional option for pts’ to their conventional therapies. The TCR-CDR3 repertoires showed no difference with the reiki intervention but had significant variability. Further research comparing TCR repertoires between MM and age/sex matched healthy controls is ongoing. T-cell directed therapies are evolving in MM, we plan to analyze if changing diversity of TCR-CDR3 repertoires could define how best to sequence these treatments. Clinical trial information: NCT04783038 .

Non-Small Cell Lung Cancer Metastatic Without Oncogenic Alterations.

This overview provides a thorough review of current treatment approaches for first-line management of nononcogenic addicted non-small cell lung cancer. We also address pertinent clinical decision-making queries encountered in everyday practice, such as the optimal treatment strategy for PD-L1-high patients, predictive factors for response to immune checkpoint inhibitors (ICI) both in terms of patient and cancer characteristics, the potential benefits of dual checkpoint blockade, and the unresolved issue of safe discontinuation strategies for long-term responders. Around one in five patients falls into this latter category while the majority develop either primary or acquired resistance to ICI-based first-line therapy, necessitating effective subsequent lines of treatment. Docetaxel, with or without combination of antiangiogenic agents, serves as the backbone of treatment, although evidence in the post-ICI setting is limited. Given that an inflamed tumor microenvironment (TME) is crucial for ICI responses, targeting the TME in cases of acquired resistance alongside continued ICI administration appears rational, although clinical trials so far have failed to confirm this hypothesis. Antibody-drug conjugates have emerged as a promising treatment modality, offering the potential for reduced toxicity and improved efficacy by targeting specific cancer antigens. Moreover, several chemotherapy-free approaches are currently under investigation for treatment-naïve patients, including alternative ICI and drugs targeting epitopes on both cancer and immune cells.

Development of small molecule–drug conjugates based on derivatives of natural proteasome inhibitors that exhibit selectivity for PSMA-expressing cancer cells

In this study, we have developedsmall molecule drug conjugates (SMDCs)consisting ofa prostate specific membrane antigen (PSMA) ligandand syringolin derivatives, which are potent proteasome inhibitors, to selectively deliver syringolin derivatives to prostate cancer cells. Two parent compounds were used for syringolin derivatives with different linkage sites. These SMDCs exhibited PSMA-expressing cell-selective cytotoxicity and they could potentially be used for safer treatment of cancer.

YF550-C1, an E3 ligase inhibitor of CBL-B, to demonstrate T cell and NK cell activation and anti-tumor activities in syngeneic and PDX tumor model.

e14570 Background: Casitas B-lineage lymphoma b (CBL-B) is one of ligase in E3 ubiquitin family, which mainly expressed in matured hematopoietic cells, including T and NK cells. Study showed that CBL-B deficiency upregulated interleukin-2 and interferon-gamma secretion during anti-CD3 and anti-CD28 stimulated TCR activation, even without co-stimulator anti-CD28[3]. Except T cells, CBL-B plays important role in NK cells as well. CBL-B was upregulated during NK cell activation. While downregulation of CBL-B enhanced the cytotoxicity of primary human NK cells against hematological cancer cell lines. In vivo studies proved that CBL-B deficiency protected mice from tumor growth by inducing antitumor immunity. Thus, CBL-B shows a promising target for cancer therapy. Methods: We developed a small molecule YF550-C1 that targeted CBL-B, and evaluated the activation on T cell and NK cell function, and the therapeutical effect on syngeneic tumor models. The T cell activation was indicated by levels of IL-2 and IFN-γ from CBL-B knockout or WT CD8+ T cells since stimulated with anti-CD3 or anti-CD3/28 for 48 hours. The resistance of PGE2-induced immunosuppressive was evaluated by measuring IL-2 and IFN-γ since human T cells treated with PGE2 and followed by series diluted YF550-C1 or comparable inhibitor cpd23. OVA specific antigen stimulated CD8+ T activation assay was conducted by coculture OT-1 CD8+ T cells and WT DC cells with 50:1 for 72 hours in the present of 5ug/ml OVA peptide and series diluted YF550-C1. The NK cell cytotoxicity was evaluated by co-culture human NK cells and K562-luc cells with 1.25:1 ratio in the present of 1000nM or 333nM YF550-C1, which indicated by luminance. Syngeneic mouse model that inoculated with different types of murine cancer cell lines was used to evaluate tumor growth. Results: CBL-B deficiency suppressed tumor growth in mouse tumor models and enhanced cytokines release in T cells upon TCR engagement. CBL-B inhibitor, YF550-C1, alleviated PGE2-mediated immunosuppression of human T cell activation. CBL-B inhibitor, YF550-C1, enhanced OVA-specific antigen stimulated CD8+ T cell activation. CBL-B inhibitor, YF550-C1, enhanced cytotoxicity of human NK cell against K562-luc cells. CBL-B inhibitor, YF550-C1, or in combinate with anti-PD-L1 suppressed tumor growth in syngeneic tumor models. Single-agent of CBL-B inhibitor YF550-C1 treatment was sufficient to suppress PD1/PD-L1 resistant NSCLC patient-derived tumor growth. Conclusions: These studies provided insight into the activity of the inhibitor of CBL-B, demonstrating that YF550-C1 displays excellently T cell activation, T cell immunosuppression alleviation, NK cell activation and antitumor activity in multiple preclinical tumor models. Our data showed that YF550-C1 is a promising candidate for cancer treatment as monotherapy or in combination with PD-L1 blockade.

Photoimmunotherapy of Prostate Cancer With Antibody and Fab Fragments Targeting the Prostate Specific Membrane Antigen.

The standard treatment for localized prostate cancer involves surgical removal of the prostate with curative intent. However, when tumor cells persist in the operation site, there is high risk of local recurrence and tumor spread, leading to stressful follow-up treatments, impaired quality of life, and reduced overall survival. This study examined photoimmunotherapy (PIT) as a new treatment option for prostate cancer cells. We generated conjugates consisting of either a humanized antibody or Fab fragments thereof targeting the prostate specific membrane antigen (PSMA), along with our silicon phthalocyanine photosensitizer dye WB692-CB1. PSMA-expressing prostate cancer cells were incubated with the antibody dye or Fab dye conjugates and cell binding was measured using flow cytometry. Cells were irradiated with varying doses of red light for dye activation, and cytotoxicity was determined by erythrosin B staining and subsequent analysis using a Neubauer counting chamber. Specific cytotoxicity was induced with the antibody dye conjugate in the prostate cancer cells in a light dose-dependent manner. Treatment of the cells with the Fab dye conjugate resulted in lower cytotoxicity, which could be attributed to a reduced binding affinity and a reduced dye uptake of the Fab fragment. Our new antibody dye and Fab dye conjugates offer potential for future intraoperative PIT in patients with localized prostate cancer, with the aim to ensure complete removal of tumor cells from the surgical area, to avoid local recurrence, and to improve clinical outcome.

Urgent Need to Understand and Prevent Gonococcal Infection: From the Laboratory to Real-World Context.

Neisseria gonorrhoeae is widespread globally. Primary prevention is unsuccessful and antimicrobial resistance threatens optimal management. There is no specific vaccine and natural infection studies show that N. gonorrhoeae can avoid and suppress immune responses. In addition to extensive variation in expression and specificity of many gonococcal surface antigens, it induces a robust inflammatory response through the Th17 pathway with a large influx of neutrophils and inflammatory cytokines but evades macrophages. The Th1- and Th2-mediated response is suppressed, resulting in low, short-lived antibody titers. Real-world evidence suggests that gonorrhea cases are reduced among recipients of N. meningitidis group B vaccines containing outer membrane vesicles (OMV). Although the first randomized trial of an OMV-containing MenB vaccine against N. gonorrhoeae infection did not show statistically significant vaccine efficacy, ongoing trials might shed further light. Several candidate vaccine antigens for a gonococcal-specific vaccine are being evaluated preclinically but only one has reached clinical trials.

Multifunctional bispecific nanovesicles targeting SLAMF7 trigger potent antitumor immunity.

The effectiveness of immune checkpoint inhibitor (ICI) therapy is hindered by the ineffective infiltration and functioning of cytotoxic T cells and the immunosuppressive tumor microenvironment (TME). Signaling lymphocytic activation molecule family member 7 (SLAMF7) is a pivotal co-stimulatory receptor thought to simultaneously trigger natural killer (NK)-cell, T-cell, and macrophage antitumor cytotoxicity. However, the potential of this collaborative immune stimulation in antitumor immunity for solid tumors is under-explored due to the exclusive expression of SLAMF7 by hematopoietic cells. Here, we report the development and characterization of multifunctional bispecific nanovesicles targeting SLAMF7 and Glypican-3-a hepatocellular carcinoma (HCC)-specific tumor antigen. We found that by effectively "decorating" the surface of solid tumors with SLAMF7, these nanovesicles directly induced potent and specific antitumor immunity and remodeled the immunosuppressive TME, sensitizing the tumors to programmed cell death protein 1 (PD-1) blockade. Our findings highlight the potential of SLAMF7-targeted multifunctional bispecific nanovesicles as an anticancer strategy with implications for designing next-generation targeted cancer therapies.

Sub-acute studies on the effects of trona consumption at varied low doses on male fertility and antioxidant properties using Wistar Rats

Geologically known as trona, evaporite, or locally known as greyish potash, akanwu, or kaun, it serves a multitude of purposes in Nigeria. These include, but are not limited to, softening legumes and flesh, augmenting the therapeutic attributes of herbal expectorant remedies, and reducing male libido or fertility. The unrestricted consumption and accessibility of this salt in the local markets of Anambra State, Nigeria, are due to its affordability and accessibility. Currently, there is no investigation into the comprehensive impact of potash's antioxidant properties at various low doses on male fertility. This led to a study that lasted for 28 days and involved rats weighing between 120 g and 140 g. The rats were separated into four groups, with each group consisting of seven rats. Group A was the control group, while groups B, C, and D were the test groups administered doses of 150 mg/kg, 300 mg/kg, and 450 mg/kg of potash, respectively. At the end of the study, the antioxidant properties of potash were tested. Prostate, gland, testis, and blood were collected and analyzed. Data was analyzed with the statistical social science (SPSS) version 27. Results were presented as mean ± standard deviation (SD). A one-way analysis of variance (ANOVA) was used to compare the mean values. Our study found a significant (p<0.05) dose dependent decrease in fertility hormones and semen parameters. Prostate specific antigen (PSA) increased dose-dependently compared to the control. Our findings indicate that trona is rich in antioxidants.

Recent Advances in Nanomaterial-Based Immunotherapy for Prostate Cancer: A Comprehensive Review

Abstract: Prostate Cancer (PCa) remains a global health concern, and recent advancements in nanomaterial- based immunotherapy are reshaping the landscape of its treatment. The advent of Prostate- Specific Antigen (PSA) screening had a significant impact on the PCa burden until the early 21st century, but the ongoing innovations in therapeutic approaches and early detection methods have contributed to a decline in mortality rates. This comprehensive review delves into the evolving role of the immune system in cancer, with a particular emphasis on the latest advances in nanomaterial- based immunotherapy for PCa. The review focuses on the burgeoning field of nanomaterial- based immunotherapy for PCa, particularly in the context of vaccine-based therapies and immune checkpoint inhibitors. Recent developments in clinical trials highlight the effectiveness of immune checkpoint inhibitors, such as CTLA-4 and PD-1 inhibitors, either as standalone treatments or in combination for metastatic Castration-Resistant Prostate Cancer (mCRPC). We highlight ongoing clinical trials that explore PSMA-targeted CAR-T cells for mCRPC patients, offering valuable insights into the promising field of nanomaterial-based immunotherapy. The review also discusses nanomaterial-based vaccine treatments, such as Sipuleucel-T (Provenge®) and G-VAX. These work in different ways to boost the immune system's response to Tumor-Associated Antigens (TAAs). We also explore viral vector-based vaccines and gene therapy approaches, highlighting their potential to enhance the immune system's ability to target prostate cancer cells at the nanoscale. The article concludes with an in-depth discussion of the current and emerging nanomaterial-based biomarkers for PCa diagnosis and prognosis.

Resolution of RHCE Haplotype Ambiguities in Transfusion Settings.

Red blood cell (RBC) transfusion, limited by patient alloimmunization, demands accurate blood group typing. The Rh system requires specific attention due to the limitations of serological phenotyping methods. Although these have been compensated for by molecular biology solutions, some RhCE ambiguities remain unresolved. The RHCE mRNA length is compatible with full-length analysis and haplotype discrimination, but the RHCE mRNA analyses reported so far are based on reticulocyte isolation and molecular biology protocols that are fastidious to implement in a routine context. We aim to present the most efficient reticulocyte isolation method, combined with an RT-PCR sequencing protocol that embraces the phasing of all haplotype configurations and identification of any allele. Two protocols were tested for reticulocyte isolation based either on their size/density properties or on their specific antigenicity. We show that the reticulocyte sorting method by antigen specificity from EDTA blood samples collected up to 48 h before processing is the most efficient and that the combination of an RHCE-specific RT-PCR followed by RHCE allele-specific sequencing enables analysis of cDNA RHCE haplotypes. All samples analyzed show full concordance between RHCE phenotype and haplotype sequencing. Two samples from the immunohematology laboratory with ambiguous results were successfully analyzed and resolved, one of them displaying a novel RHCE allele (RHCE*03 c.340C>T).

Combined cryoablation and PD-1 inhibitor synergistically enhance antitumor immune responses in Lewis lung adenocarcinoma mice via the PI3K/AKT/mTOR pathway

Cryoablation is a therapeutic modality for lung adenocarcinoma that destroys target tumors using lethal levels of cold, resulting in the release of large amounts of specific antigens that activate immune responses. However, tumor immune checkpoint escape mechanisms prevent these released self-antigens from inducing effective anti-tumor immune responses. To overcome this challenge, we propose the use of immune checkpoint inhibitors to relieve T cell inhibition by immune checkpoints and enhance the anti-tumor immune response mediated by cryoablation. We used bilateral tumor-bearing mouse models and a specific cryoablation instrument to study the efficacy of cryoablation combined with PD-1 inhibitors in Lewis lung adenocarcinoma model mice. We found that cryoablation combined with PD-1 inhibitors significantly inhibited the growth of mouse lung adenocarcinoma, prolonged mouse survival, and enhanced the anti-tumor immune response. Moreover, this combined regimen could synergistically promote the activation and proliferation of T cells via the PI3K/AKT/mTOR pathway. The present study provides a strong theoretical basis for the clinical combination of cryoablation and PD-1 inhibitors.

Generation and evaluation of cancer binding capacity of HLA-A2-WT1 complex-targeting antibody

Wilms’ tumor (WT1), a transcription factor highly expressed in various leukemias and solid tumors, is a highly specific intracellular tumor antigen, requiring presentation through complexation with HLA-restricted peptides.. WT1-derived epitopes are able to assemble with MHC-I and thereby be recognized by T cell receptors (TCR). Identification of new targetable epitopes derived from WT1 on solid tumors is a challenge, but meaningful for the development of therapeutics that could in this way target intracellular oncogenic proteins. In this study, we developed and comprehensively describe methods to validate the formation of the complex of WT1126–134 and HLA-A2. Subsequently, we developed an antibody fragment able to recognize the extracellular complex on the surface of cancer cells. The single chain variable fragment (scFv) of an established TCR-mimic antibody, specifically recognizing the WT1-derived peptide presented by the HLA-A2 complex, was expressed, purified, and functionally validated using a T2 cell antigen presentation model. Furthermore, we evaluated the potential of the WT1-derived peptide as a targetable extracellular antigen in multiple solid tumor cell lines. Our study describes methodology for the evaluation of WT1-derived peptides as tumor-specific antigen on solid tumors, and may facilitate the selection of potential candidates for future immunotherapy targeting WT1 epitopes.

#1305 Analysis of clinicopathological characteristics of membranous nephropathy with concomitant malignancy and literature review

Abstract Background and Aims In recent years, the incidence of membranous nephropathy (MN) with malignancy has gradually increased, but the clinical and pathological characteristics of these patients are still unclear. Method Patients diagnosed with renal biopsy-proven MN and comorbid malignancy detected within 5 years before and after MN diagnosis were included. The control group were diagnosed with renal biopsy-proven IMN with no malignancy and no other clear secondary cause for MN. We present a comprehensive analysis of MN with concomitant malignancy in our cohort and literature review. Results A total of 19 MN patients with concomitant malignancy were evaluated at our center; among them, 13 (68.4%) were male, and the median age was 57.0 (45.0, 69.0) years. Malignancy occurred after the onset of renal disease in 61.1% of patients, with digestive system malignancy (36.8%) ranking as the predominant type. 8 (8/11) patients achieved either PR or CR during the follow-up period. Most patients had pathology typical of IMN. IF showed strong positivity for IgG (100%), whereas only 13 (68.4%) patients were positive for C3. IEM showed electron-dense deposits predominantly located in subepithelial. Specific MN antigen staining of renal tissues from 19 patients showed that the highest percentage was 68.4% (13/19) for PLA2R-only positivity followed by 15.8% (3/19) for THSD7A-only positivity. Specific MN antigen staining of malignant tissue was performed in 5 patients whose tumor samples were available. Only 2 patients expressed the same antigen on kidney and tumor. Screening 17 articles encompassing a total of 21 patients in whom MN-specific antigen staining was performed on both renal and tumor tissues simultaneously. Among these patients, 71.4% (15/21) were male, with a median age of 61.0 years (56.3, 72.8). In this cohort, malignancy was diagnosed before or simultaneously with MN in 15 patients (75.0%), with digestive system malignancy constituting the most prevalent comorbid malignancy, at 33.3%. Notably, THSD7A accounted for the highest proportion of MN antigens, at 66.7% (14/21); among these patients, 78.6% (11/14) also exhibited positive tumor THSD7A staining. Of the 21 patients, 72.2% (13/18) achieved CR or PR. No significant difference between the baseline characteristics was observed between the 19 patients from our center and 21 patients documented in the literature. Therefore, the clinicopathological data of these 40 patients were pooled and compared with 101 IMN patients without malignancy at our center. Compared to patients without malignancy, MN patients with malignancy were older at the time of renal biopsy (P = 0.017), had a lower eGFR (P = 0.035) and demonstrated a lower rate of CR or PR after treatment (P < 0.001). The rate of PLA2R positivity in the glomeruli of MN patients with concomitant malignancy was significantly lower (40.0% vs. 92.1%, P < 0.001), while the rate of THSD7A positivity was significantly higher (42.5% vs. 2.0%, P < 0.001). Renal tissue IgG subclass staining showed that the rate of IgG4 positivity was significantly decreased compared with that in IMN patients (59.3% vs. 90.1%, P < 0.001), and the rate of IgG2 positivity was significantly increased (36.0% vs. 16.5%, P = 0.033). Conclusion To conclude, malignancy screening should be more actively performed for MN patients presenting with the above characteristics.

#710 Rare manifestation of minimal change disease associated with prostate cancer

Abstract Background and Aims Prostate cancer is the most common malignancy in men. Secondary nephrotic syndrome as part of the paraneoplastic syndrome occurs in 11% of cases and is most often associated with membranous glomerulopathy. The association of minimal change disease (MCD) and prostate cancer is extremely rare, where only one case has been described in the available literature. Method We present the case of a 77-year-old patient who was admitted to the Transplantation-Nephrology Department of the University Hospital Martin with 3rd degree acute kidney injury and anasarca with fully developed nephrotic syndrome. Results During hospitalization, there was a gradual elevation of renal parameters and oliguria with the need for hemodialysis treatment. However, as part of the oncological screening, the level of prostate specific antigen was elevated (10.69 ng/l) with subsequent biopsy confirmed adenocarcinoma of the prostate in stage IIB (pT1cN0M0). Renal biopsy was performed with the finding of MCD, in light microscopy without pathological findings, with fully vital, normocellular glomeruli, without interstitial fibrosis and tubular damage, immunofluorescence without significant findings, in the electron microscope, pedicel podocyte fusions were present. Despite the generally valid recommendations for the treatment of prostate cancer of the given stage and age of the patient (follow-up), antiandrogen therapy was started in cooperation with the urologist along with the treatment of MCD with corticosteroids at a dose of 1 mg/kg. The patient experienced a significant improvement in renal parameters with the onset of diuresis without the need for dialysis treatment. Conclusion In the reported case, we describe a rare form of MCD associated with prostate cancer and a rare manifestation in the form of renal failure and the need for dialysis treatment with subsequent complete restitution of renal functions after KS treatment and antiandrogen treatment of the underlying oncological disease.

Homozygosity in any HLA locus is a risk factor for specific antibody production: the taboo concept 2.0.

In a cooperative study of the University Hospital Leipzig, University of Leipzig, and the Charité Berlin on kidney transplant patients, we analysed the occurrence of HLA-specific antibodies with respect to the HLA setup of the patients. We aimed at the definition of specific HLA antigens towards which the patients produced these antibodies. Patients were typed for the relevant HLA determinants using mainly the next-generation technology. Antibody screening was performed by the state-of-the-art multiplex-based technology using microspheres coupled with the respective HLA alleles of HLA class I and II determinants. Patients homozygous for HLA-A*02, HLA-A*03, HLA-A*24, HLA-B*07, HLA-B*18, HLA-B*35, HLA-B*44, HLA-C*03, HLA-C*04, and HLA-C*07 in the class I group and HLA-DRB1*01, HLA-DRB1*03, HLA-DRB1*07, HLA-DRB1*15, HLA-DQA1*01, HLA-DQA1*05, HLA-DQB1*02, HLA-DQB1*03(7), HLA-DQB1*06, HLA-DPA1*01, and HLA-DPB1*04 in the class II group were found to have a significant higher antibody production compared to the heterozygous ones. In general, all HLA determinants are affected. Remarkably, HLA-A*24 homozygous patients can produce antibodies towards all HLA-A determinants, while HLA-B*18 homozygous ones make antibodies towards all HLA-B and selected HLA-A and C antigens, and are associated with an elevation of HLA-DRB1, parts of DQB1 and DPB1 alleles. Homozygosity for the HLA class II HLA-DRB1*01, and HLA-DRB1*15 seems to increase the risk for antibody responses against most of the HLA class I antigens (HLA-A, HLA-B, and HLA-C) in contrast to HLA-DQB1*03(7) where a lower risk towards few HLA-A and HLA-B alleles is found. The widely observed differential antibody response is therefore to be accounted to the patient's HLA type. Homozygous patients are at risk of producing HLA-specific antibodies hampering the outcome of transplantation. Including this information on the allocation procedure might reduce antibody-mediated immune reactivity and prevent graft loss in a patient at risk, increasing the life span of the transplanted organ.